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Sample records for free-living atlantic walruses

  1. Population structure and gene flow of the Atlantic walrus (Odobenus rosmarus rosmarus) in the eastern Atlantic Arctic based on mitochondrial DNA and microsatellite variation.

    PubMed

    Andersen, L W; Born, E W; Gjertz, I; Wiig, O; Holm, L E; Bendixen, C

    1998-10-01

    The population structure of the Atlantic walrus, Odobenus rosmarus rosmarus, was studied using 11 polymorphic microsatellites and restriction fragment length polymorphism detected in the NADH-dehydrogenase ND1, ND2 and ND3/4 segments in mtDNA. A total of 105 walrus samples were analysed from northwest (NW) Greenland, east (E) Greenland, Svalbard and Franz Joseph Land. Two of the 10 haplotypes detected in the four samples were diagnostic for the NW Greenland sample, which implied that the group of walruses in this area is evolutionary distinct from walruses in the other three areas. One individual sampled in E Greenland exhibited a Pacific haplotype, which proved a connection between the Pacific walrus and walruses in eastern Greenland. The Franz Joseph Land, Svalbard and E Greenland samples shared the most common haplotype, indicating very little differentiation at the mtDNA level. Gene flow (Nm) estimates among the four areas indicated a very restricted exchange of female genes between NW Greenland and the more eastern Atlantic Arctic samples, and a closer relationship between the three samples composing the eastern Atlantic Arctic. The genetic variation at 11 polymorphic microsatellite loci grouped individuals into three populations, NW Greenland, E Greenland and a common Franz Joseph Land-Svalbard population, which were connected by moderate gene flow. PMID:9787444

  2. Occurrence of Prosthenorchis elegans in Free-living Primates from the Atlantic Forest of Southern Bahia, Brazil.

    PubMed

    Catenacci, Lilian S; Colosio, Adriana C; Oliveira, Leonardo C; De Vleeschouwer, Kristel M; Munhoz, Alexandre D; Deem, Sharon L; Pinto, Jaqueline M S

    2016-04-28

    Parasite prevalence and abundance are important factors affecting species' conservation. During necropsies on a free-living golden-headed lion tamarin ( Leontopithecus chrysomelas ) and two Wied's marmosets ( Callithrix kuhlii ) in the Atlantic Forest of southern Bahia, Brazil, we collected a large number of adult intestinal parasites that we identified as Prosthenorchis elegans. This parasite is pathogenic for neotropical primates. Prosthenorchis spp. infestation is influenced by diet with increased risk of exposure from ingesting invertebrate intermediate hosts. The biological similarities and sympatric nature of these two nonhuman primates support that they may harbor similar infectious and parasitic agents. PMID:26981688

  3. Co-occurrence Analysis of Microbial Taxa in the Atlantic Ocean Reveals High Connectivity in the Free-Living Bacterioplankton.

    PubMed

    Milici, Mathias; Deng, Zhi-Luo; Tomasch, Jürgen; Decelle, Johan; Wos-Oxley, Melissa L; Wang, Hui; Jáuregui, Ruy; Plumeier, Iris; Giebel, Helge-Ansgar; Badewien, Thomas H; Wurst, Mascha; Pieper, Dietmar H; Simon, Meinhard; Wagner-Döbler, Irene

    2016-01-01

    We determined the taxonomic composition of the bacterioplankton of the epipelagic zone of the Atlantic Ocean along a latitudinal transect (51°S-47°N) using Illumina sequencing of the V5-V6 region of the 16S rRNA gene and inferred co-occurrence networks. Bacterioplankon community composition was distinct for Longhurstian provinces and water depth. Free-living microbial communities (between 0.22 and 3 μm) were dominated by highly abundant and ubiquitous taxa with streamlined genomes (e.g., SAR11, SAR86, OM1, Prochlorococcus) and could clearly be separated from particle-associated communities which were dominated by Bacteroidetes, Planktomycetes, Verrucomicrobia, and Roseobacters. From a total of 369 different communities we then inferred co-occurrence networks for each size fraction and depth layer of the plankton between bacteria and between bacteria and phototrophic micro-eukaryotes. The inferred networks showed a reduction of edges in the deepest layer of the photic zone. Networks comprised of free-living bacteria had a larger amount of connections per OTU when compared to the particle associated communities throughout the water column. Negative correlations accounted for roughly one third of the total edges in the free-living communities at all depths, while they decreased with depth in the particle associated communities where they amounted for roughly 10% of the total in the last part of the epipelagic zone. Co-occurrence networks of bacteria with phototrophic micro-eukaryotes were not taxon-specific, and dominated by mutual exclusion (~60%). The data show a high degree of specialization to micro-environments in the water column and highlight the importance of interdependencies particularly between free-living bacteria in the upper layers of the epipelagic zone. PMID:27199970

  4. Co-occurrence Analysis of Microbial Taxa in the Atlantic Ocean Reveals High Connectivity in the Free-Living Bacterioplankton

    PubMed Central

    Milici, Mathias; Deng, Zhi-Luo; Tomasch, Jürgen; Decelle, Johan; Wos-Oxley, Melissa L.; Wang, Hui; Jáuregui, Ruy; Plumeier, Iris; Giebel, Helge-Ansgar; Badewien, Thomas H.; Wurst, Mascha; Pieper, Dietmar H.; Simon, Meinhard; Wagner-Döbler, Irene

    2016-01-01

    We determined the taxonomic composition of the bacterioplankton of the epipelagic zone of the Atlantic Ocean along a latitudinal transect (51°S–47°N) using Illumina sequencing of the V5-V6 region of the 16S rRNA gene and inferred co-occurrence networks. Bacterioplankon community composition was distinct for Longhurstian provinces and water depth. Free-living microbial communities (between 0.22 and 3 μm) were dominated by highly abundant and ubiquitous taxa with streamlined genomes (e.g., SAR11, SAR86, OM1, Prochlorococcus) and could clearly be separated from particle-associated communities which were dominated by Bacteroidetes, Planktomycetes, Verrucomicrobia, and Roseobacters. From a total of 369 different communities we then inferred co-occurrence networks for each size fraction and depth layer of the plankton between bacteria and between bacteria and phototrophic micro-eukaryotes. The inferred networks showed a reduction of edges in the deepest layer of the photic zone. Networks comprised of free-living bacteria had a larger amount of connections per OTU when compared to the particle associated communities throughout the water column. Negative correlations accounted for roughly one third of the total edges in the free-living communities at all depths, while they decreased with depth in the particle associated communities where they amounted for roughly 10% of the total in the last part of the epipelagic zone. Co-occurrence networks of bacteria with phototrophic micro-eukaryotes were not taxon-specific, and dominated by mutual exclusion (~60%). The data show a high degree of specialization to micro-environments in the water column and highlight the importance of interdependencies particularly between free-living bacteria in the upper layers of the epipelagic zone. PMID:27199970

  5. Levels of cadmium and mercury in the hair of Atlantic walruses (Odobenus rosmarus rosmarus) from Svalbard, Norway

    SciTech Connect

    Wiig, O.; Renzoni, A.; Gjertz, I.

    1999-08-01

    Hair samples of 15 adult male Atlantic walruses (Odobenus rosmarus rosmarus) collected from anesthetized individuals at Svalbard, Norway, were analyzed for cadmium and total mercury. The mean level of cadmium was 0.860 {+-} 0.321 {micro}g/g dry weight and the mean level of mercury was 0.235 {+-} 0.100 {micro}g/g dry weight. Levels of cadmium and mercury in hair of walruses from other areas are not known. Both cadmium and mercury levels in hair of walruses from Svalbard are relatively low compared to the levels found in the hair of other marine mammal species. It has been documented from a number of marine species, including marine mammals such as ringed seals and polar bears, that both cadmium and mercury levels of Svalbard are lower than in other areas. It is uncertain as to what degree levels in hair reflect levels in internal organs in walruses. In rare and highly endangered species or populations tissue samples can be difficult to collect. In walruses, it is possible to collect hair from anesthetized individuals or at the haul-out sites during molt, to monitor heavy metal levels of the population.

  6. Mother-calf vocal communication in Atlantic walrus: a first field experimental study.

    PubMed

    Charrier, Isabelle; Aubin, Thierry; Mathevon, Nicolas

    2010-05-01

    In all colonial pinnipeds studied, mother-young vocal recognition exists and allows rapid and reliable meetings in spite of the confusing environment of the breeding colony. The efficiency of this recognition process guarantees pup survival, especially in species where females alternate foraging sea trips and lactation periods on land. The Atlantic Walrus (Odobenus rosmarus rosmarus) is a highly gregarious pinniped with females attending their calves for an extended period of time (2-3 years). Although we expect mother-calf vocal recognition to occur in this species due to the high density of individuals packed in herds, it has never been experimentally demonstrated. Here, we assessed the individual stereotypy of both mother and calf barks recorded in the wild by measuring frequency and temporal acoustic parameters. Both discriminant function and artificial neural network analyses resulted in high correct classification rates, underlying a well-defined individual stereotypy in parameters related to frequency modulation and frequency values. Playback experiments showed that mothers were more responsive to the barks of their own calf than to those of unrelated young. Finally, propagation experiments revealed that barks propagate at greater distances over water surface than over ice, acoustic features such as frequency modulation and frequency spectrum being highly resistant to degradation during propagation. Thus, acoustic analysis and propagation experiments suggest that these frequency parameters might be the key acoustic features involved in the individual identification process. This experimental study clearly demonstrates that Atlantic walrus has developed a highly reliable mother-calf vocal communication allowing such strong social bond. PMID:19960216

  7. Towards a Better Understanding of the Effects of UV on Atlantic Walruses, Odobenus rosmarus rosmarus: A Study Combining Histological Data with Local Ecological Knowledge.

    PubMed

    Martinez-Levasseur, Laura M; Furgal, Chris M; Hammill, Mike O; Burness, Gary

    2016-01-01

    Walruses, Odobenus rosmarus, play a key role in the Arctic ecosystem, including northern Indigenous communities, which are reliant upon walruses for aspects of their diet and culture. However, walruses face varied environmental threats including rising sea-water temperatures and decreasing ice cover. An underappreciated threat may be the large amount of solar ultraviolet radiation (UV) that continues to reach the Arctic as a result of ozone loss. UV has been shown to negatively affect whales. Like whales, walrus skin is unprotected by fur, but in contrast, walruses spend long periods of time hauled-out on land. In this study, we combined the results of histological analyses of skin sections from five Atlantic walruses, Odobenus rosmarus rosmarus, collected in Nunavik (Northern Quebec, Canada) with qualitative data obtained through the interviews of 33 local walrus hunters and Inuit Elders. Histological analyses allowed us to explore UV-induced cellular lesions and interviews with experienced walrus hunters and Elders helped us to study the incidences and temporal changes of UV-induced gross lesions in walruses. At the microscopic scale, we detected a range of skin abnormalities consistent with UV damage. However, currently such UV effects do not seem to be widely observed at the whole-animal level (i.e., absence of skin blistering, erythema, eye cataract) by individuals interviewed. Although walruses may experience skin damage under normal everyday UV exposure, the long-term data from local walrus hunters and Inuit Elders did not report a relation between the increased sun radiation secondary to ozone loss and walrus health. PMID:27049757

  8. Towards a Better Understanding of the Effects of UV on Atlantic Walruses, Odobenus rosmarus rosmarus: A Study Combining Histological Data with Local Ecological Knowledge

    PubMed Central

    Martinez-Levasseur, Laura M.; Furgal, Chris M.; Hammill, Mike O.; Burness, Gary

    2016-01-01

    Walruses, Odobenus rosmarus, play a key role in the Arctic ecosystem, including northern Indigenous communities, which are reliant upon walruses for aspects of their diet and culture. However, walruses face varied environmental threats including rising sea-water temperatures and decreasing ice cover. An underappreciated threat may be the large amount of solar ultraviolet radiation (UV) that continues to reach the Arctic as a result of ozone loss. UV has been shown to negatively affect whales. Like whales, walrus skin is unprotected by fur, but in contrast, walruses spend long periods of time hauled-out on land. In this study, we combined the results of histological analyses of skin sections from five Atlantic walruses, Odobenus rosmarus rosmarus, collected in Nunavik (Northern Quebec, Canada) with qualitative data obtained through the interviews of 33 local walrus hunters and Inuit Elders. Histological analyses allowed us to explore UV-induced cellular lesions and interviews with experienced walrus hunters and Elders helped us to study the incidences and temporal changes of UV-induced gross lesions in walruses. At the microscopic scale, we detected a range of skin abnormalities consistent with UV damage. However, currently such UV effects do not seem to be widely observed at the whole-animal level (i.e., absence of skin blistering, erythema, eye cataract) by individuals interviewed. Although walruses may experience skin damage under normal everyday UV exposure, the long-term data from local walrus hunters and Inuit Elders did not report a relation between the increased sun radiation secondary to ozone loss and walrus health. PMID:27049757

  9. Free-living nematode species (Nematoda) dwelling in hydrothermal sites of the North Mid-Atlantic Ridge

    NASA Astrophysics Data System (ADS)

    Tchesunov, Alexei V.

    2015-12-01

    Morphological descriptions of seven free-living nematode species from hydrothermal sites of the Mid-Atlantic Ridge are presented. Four of them are new for science: Paracanthonchus olgae sp. n. (Chromadorida, Cyatholaimidae), Prochromadora helenae sp. n. (Chromadorida, Chromadoridae), Prochaetosoma ventriverruca sp. n. (Desmodorida, Draconematidae) and Leptolaimus hydrothermalis sp. n. (Plectida, Leptolaimidae). Two species have been previously recorded in hydrothermal habitats, and one species is recorded for the first time in such an environment. Oncholaimus scanicus (Enoplida, Oncholaimidae) was formerly known from only the type locality in non-hydrothermal shallow milieu of the Norway Sea. O. scanicus is a very abundant species in Menez Gwen, Lucky Strike and Lost City hydrothermal sites, and population of the last locality differs from other two in some morphometric characteristics. Desmodora marci (Desmodorida, Desmodoridae) was previously known from other remote deep-sea hydrothermal localities in south-western and north-eastern Pacific. Halomonhystera vandoverae (Monhysterida, Monhysteridae) was described and repeatedly found in mass in Snake Pit hydrothermal site. The whole hydrothermal nematode assemblages are featured by low diversity in comparison with either shelf or deep-sea non-hydrothermal communities. The nematode species list of the Atlantic hydrothermal vents consists of representatives of common shallow-water genera; the new species are also related to some shelf species. On the average, the hydrothermal species differ from those of slope and abyssal plains of comparable depths by larger sizes, diversity of buccal structures, presence of food content in the gut and ripe eggs in uteri.

  10. Feeding behaviour of free-ranging walruses with notes on apparent dextrality of flipper use

    PubMed Central

    Levermann, Nette; Galatius, Anders; Ehlme, Göran; Rysgaard, Søren; Born, Erik W

    2003-01-01

    Background Direct observations of underwater behaviour of free-living marine mammals are rare. This is particularly true for large and potentially dangerous species such as the walrus (Odobenus rosmarus). Walruses are highly specialised predators on benthic invertebrates – especially bivalves. The unique feeding niche of walruses has led to speculations as to their underwater foraging behaviour. Based on observations of walruses in captivity and signs of predation left on the sea floor by free-living walruses, various types of feeding behaviour have been suggested in the literature. In this study, however, the underwater feeding behaviour of wild adult male Atlantic walruses (O. r. rosmarus) is documented for the first time in their natural habitat by scuba-divers. The video recordings indicated a predisposition for use of the right front flipper during feeding. This tendency towards dextrality was explored further by examining a museum collection of extremities of walrus skeletons. Results During July and August 2001, twelve video-recordings of foraging adult male walruses were made in Young Sound (74°18 N; 20°15 V), Northeast Greenland. The recordings did not allow for differentiation among animals, however based on notes by the photographer at least five different individuals were involved. The walruses showed four different foraging behaviours; removing sediment by beating the right flipper, removing sediment by beating the left flipper, removing sediment by use of a water-jet from the mouth and rooting through sediment with the muzzle. There was a significant preference for using right flipper over left flipper during foraging. Measurements of the dimensions of forelimbs from 23 walrus skeletons revealed that the length of the right scapula, humerus, and ulna was significantly greater than that of the left, supporting our field observations of walruses showing a tendency of dextrality in flipper use. Conclusion We suggest that the four feeding behaviours

  11. The late Wisconsinan and Holocene record of Walrus (Odobenus rosmarus) from North America: A review with new data from Arctic and Atlantic Canada

    USGS Publications Warehouse

    Dyke, A.S.; Hooper, J.; Harington, C.R.; Savelle, J.M.

    1999-01-01

    The Late Wisconsinan and Holocene record of the Atlantic walrus is known from numerous collections of bones and tusks from Arctic Canada and south to North Carolina, as well as from many archaeological sites in the Arctic and Subarctic. In contrast, the Pacific walrus has no dated Late Wisconsinan or early Holocene record in North America, and it may have been displaced into the northwest Pacific at Last Glacial Maximum (LGM). The Atlantic walrus rapidly exploited newly deglaciated territory, moving northward from its LGM refugium and reaching the Bay of Fundy by 12800 B.P., the Grand Banks by 12500 B.P., southern Labrador by 11500 B.P., and the central Canadian Arctic Archipelago (CAA) by 9700 B.P. Its southern range limit may have retracted to the Bay of Fundy by ca. 7500 B.P. Within the CAA, walrus remains cluster in two main age groups: 9700 to 8500 B.P. and 5000 to 4/3000 B.P. This pattern strongly resembles the distribution of bowhead whale radiocarbon ages from the same area, which suggests a common control by sea-ice conditions. Walrus remains occur in Indian culture archaeological sites as old as 7500 B.P. and, in some cases (Namu, British Columbia, and Mackinac Island, Michigan), they evidently represent long-distance human transport. They are much more common in Paleoeskimo and Neoeskimo culture sites. However, they occur in very low abundances, and generally as debitage, in sites older than Dorset (2500 B.P.). The walrus, therefore, may not have been hunted by early Paleoeskimos. Beginning with Early Dorset, walrus remains occur in definite diet-related contexts. Middle Dorset (2300 to 1500 B.P.) and late Thule (<400 B.P.) sites are missing from the High Arctic, and there may be a similar gap in the middle Pre-Dorset (3400 to 2600 B.P.). Sea-ice conditions at these times may have adversely affected availability of walrus and other marine mammal resources. Walrus is a prominent faunal element in Middle Dorset sites on the Labrador coast; this is

  12. Demographic inferences using short-read genomic data in an approximate Bayesian computation framework: in silico evaluation of power, biases and proof of concept in Atlantic walrus.

    PubMed

    Shafer, Aaron B A; Gattepaille, Lucie M; Stewart, Robert E A; Wolf, Jochen B W

    2015-01-01

    Approximate Bayesian computation (ABC) is a powerful tool for model-based inference of demographic histories from large genetic data sets. For most organisms, its implementation has been hampered by the lack of sufficient genetic data. Genotyping-by-sequencing (GBS) provides cheap genome-scale data to fill this gap, but its potential has not fully been exploited. Here, we explored power, precision and biases of a coalescent-based ABC approach where GBS data were modelled with either a population mutation parameter (θ) or a fixed site (FS) approach, allowing single or several segregating sites per locus. With simulated data ranging from 500 to 50 000 loci, a variety of demographic models could be reliably inferred across a range of timescales and migration scenarios. Posterior estimates were informative with 1000 loci for migration and split time in simple population divergence models. In more complex models, posterior distributions were wide and almost reverted to the uninformative prior even with 50 000 loci. ABC parameter estimates, however, were generally more accurate than an alternative composite-likelihood method. Bottleneck scenarios proved particularly difficult, and only recent bottlenecks without recovery could be reliably detected and dated. Notably, minor-allele-frequency filters - usual practice for GBS data - negatively affected nearly all estimates. With this in mind, we used a combination of FS and θ approaches on empirical GBS data generated from the Atlantic walrus (Odobenus rosmarus rosmarus), collectively providing support for a population split before the last glacial maximum followed by asymmetrical migration and a high Arctic bottleneck. Overall, this study evaluates the potential and limitations of GBS data in an ABC-coalescence framework and proposes a best-practice approach. PMID:25482153

  13. Molecular method for determining sex of walruses

    USGS Publications Warehouse

    Fischbach, A.S.; Jay, C.V.; Jackson, J.V.; Andersen, L.W.; Sage, G.K.; Talbot, S.L.

    2008-01-01

    We evaluated the ability of a set of published trans-species molecular sexing primers and a set of walrus-specific primers, which we developed, to accurately identify sex of 235 Pacific walruses (Odobenus rosmarus divergens). The trans-species primers were developed for mammals and targeted the X- and Y-gametologs of the zinc finger protein genes (ZFX, ZFY). We extended this method by using these primers to obtain sequence from Pacific and Atlantic walrus (0. r. rosmarus) ZFX and ZFY genes to develop new walrus-specific primers, which yield polymerase chain reaction products of distinct lengths (327 and 288 base pairs from the X- and Y-chromosome, respectively), allowing them to be used for sex determination. Both methods yielded a determination of sex in all but 1-2% of samples with an accuracy of 99.6-100%. Our walrus-specific primers offer the advantage of small fragment size and facile application to automated electrophoresis and visualization.

  14. Spatial variation and low diversity in the major histocompatibility complex in walrus (Odobenus rosmarus)

    USGS Publications Warehouse

    Sonsthagen, Sarah A.; Fales, Krystal; Jay, Chadwick V.; Sage, George K.; Talbot, Sandra L.

    2014-01-01

    Increased global temperature and associated changes to Arctic habitats will likely result in the northward advance of species, including an influx of pathogens novel to the Arctic. How species respond to these immunological challenges will depend in part on the adaptive potential of their immune response system. We compared levels of genetic diversity at a gene associated with adaptive immune response [Class II major histocompatibility complex (MHC), DQB exon 2] between populations of walrus (Odobenus rosmarus), a sea ice-dependent Arctic species. Walrus was represented by only five MHC DQB alleles, with frequency differences observed between Pacific and Atlantic populations. MHC DQB alleles appear to be under balancing selection, and most (80 %; n = 4/5) of the alleles were observed in walruses from both oceans, suggesting broad scale differences in the frequency of exposure and diversity of pathogens may be influencing levels of heterozygosity at DQB in walruses. Limited genetic diversity at MHC, however, suggests that walrus may have a reduced capacity to respond to novel immunological challenges associated with shifts in ecological communities and environmental stressors predicted for changing climates. This is particularly pertinent for walrus, since reductions in summer sea ice may facilitate both northward expansion of marine species and associated pathogens from more temperate regions, and exchange of marine mammals and associated pathogens through the recently opened Northwest Passage between the Atlantic and Pacific Oceans in the Canadian high Arctic.

  15. Microorganisms Resistant to Free-Living Amoebae

    PubMed Central

    Greub, Gilbert; Raoult, Didier

    2004-01-01

    Free-living amoebae feed on bacteria, fungi, and algae. However, some microorganisms have evolved to become resistant to these protists. These amoeba-resistant microorganisms include established pathogens, such as Cryptococcus neoformans, Legionella spp., Chlamydophila pneumoniae, Mycobacterium avium, Listeria monocytogenes, Pseudomonas aeruginosa, and Francisella tularensis, and emerging pathogens, such as Bosea spp., Simkania negevensis, Parachlamydia acanthamoebae, and Legionella-like amoebal pathogens. Some of these amoeba-resistant bacteria (ARB) are lytic for their amoebal host, while others are considered endosymbionts, since a stable host-parasite ratio is maintained. Free-living amoebae represent an important reservoir of ARB and may, while encysted, protect the internalized bacteria from chlorine and other biocides. Free-living amoebae may act as a Trojan horse, bringing hidden ARB within the human “Troy,” and may produce vesicles filled with ARB, increasing their transmission potential. Free-living amoebae may also play a role in the selection of virulence traits and in adaptation to survival in macrophages. Thus, intra-amoebal growth was found to enhance virulence, and similar mechanisms seem to be implicated in the survival of ARB in response to both amoebae and macrophages. Moreover, free-living amoebae represent a useful tool for the culture of some intracellular bacteria and new bacterial species that might be potential emerging pathogens. PMID:15084508

  16. Behavioral sleep in the walrus.

    PubMed

    Pryaslova, Julia P; Lyamin, Oleg I; Siegel, Jerome M; Mukhametov, Lev M

    2009-07-19

    In this study we examined behavioral sleep in the walrus, the only living species of the family Odobenidae. The behavior of four 1.5-2-year-old captive walruses was videotaped continuously for 7-17 days and scored in 1-min epochs. When walruses had access to water and land, behavioral sleep, the combined amount of quiet and rapid eye movement (REM) sleep, occupied on average 17+/-4% of 24 h (n=4) with the majority of sleep occurring on land. All walruses alternated periods of almost continuous swimming lasting for 40-84 h with periods of rest on land lasting for 2-19 h. When in water they were predominantly awake (88-99% of the time). On land walruses were asleep on average 40-74% of the time. The total sleep time varied between 0 and 60% of 24h with the daily amount of REM sleep ranging from 0 to 5% of 24 h. In water, walruses slept while floating at the surface, lying on the bottom or standing and leaning against the pool wall. REM sleep in water occurred in all positions. On land the breathing pattern was regular during quiet sleep (most pauses were <30s) and arrhythmic in REM sleep (apneas lasted up to 160 s). While in water the irregularity of breathing further increased (apneas were >4 min) and all REM sleep episodes occurred during a single apnea. Data indicate that the pattern of sleep and breathing in walruses is similar to the Otariidae seals while on land and the Phocidae seals while in water. PMID:19428620

  17. Chlamydial infections in free-living birds

    USGS Publications Warehouse

    Brand, C.J.

    1989-01-01

    Most studies of chlamydial infections in free-living wild birds have been limited to surveys for the presence of Chlamydia psittaci or antibody to C psittaci and have largely been done in association with the identification of chlamydiosis in human beings, commercial fowl, or pet birds. The emphasis of these studies has been to determine the prevalence of infection and the potential role of wild birds in the spread of chlamydiae to domestic birds and human beings. Little is known about the epizootiology of chlamydiosis in free-living birds or its affect on their population dynamics. The following article is a summary of reported studies of chlamydiosis in free-living wild birds in relation to host range, ecologic aspects of transmission and maintenance, and the prevalence of disease.

  18. Developmental diversity in free-living flatworms

    PubMed Central

    2012-01-01

    Flatworm embryology has attracted attention since the early beginnings of comparative evolutionary biology. Considered for a long time the most basal bilaterians, the Platyhelminthes (excluding Acoelomorpha) are now robustly placed within the Spiralia. Despite having lost their relevance to explain the transition from radially to bilaterally symmetrical animals, the study of flatworm embryology is still of great importance to understand the diversification of bilaterians and of developmental mechanisms. Flatworms are acoelomate organisms generally with a simple centralized nervous system, a blind gut, and lacking a circulatory organ, a skeleton and a respiratory system other than the epidermis. Regeneration and asexual reproduction, based on a totipotent neoblast stem cell system, are broadly present among different groups of flatworms. While some more basally branching groups - such as polyclad flatworms - retain the ancestral quartet spiral cleavage pattern, most flatworms have significantly diverged from this pattern and exhibit unique strategies to specify the common adult body plan. Most free-living flatworms (i.e. Platyhelminthes excluding the parasitic Neodermata) are directly developing, whereas in polyclads, also indirect developers with an intermediate free-living larval stage and subsequent metamorphosis are found. A comparative study of developmental diversity may help understanding major questions in evolutionary biology, such as the evolution of cleavage patterns, gastrulation and axial specification, the evolution of larval types, and the diversification and specialization of organ systems. In this review, we present a thorough overview of the embryonic development of the different groups of free-living (turbellarian) platyhelminths, including the Catenulida, Macrostomorpha, Polycladida, Lecithoepitheliata, Proseriata, Bothrioplanida, Rhabdocoela, Fecampiida, Prolecithophora and Tricladida, and discuss their main features under a consensus phylogeny

  19. Infections with free-living amebae.

    PubMed

    Visvesvara, Govinda S

    2013-01-01

    Acanthamoeba spp., Balamuthia mandrillaris, and Naegleria fowleri are mitochondria-bearing, free-living eukaryotic amebae that have been known to cause infections of the central nervous system (CNS) of humans and other animals. Several species of Acanthamoeba belonging to several different genotypes cause an insidious and chronic disease, granulomatous amebic encephalitis (GAE), principally in immunocompromised hosts including persons infected with HIV/AIDS. Acanthamoeba spp., belonging to mostly group 2, also cause infection of the human cornea, Acanthamoeba keratitis. Balamuthia mandrillaris causes GAE in both immunocompromised and immunocompetent hosts mostly in the very young or very old individuals. Both Acanthamoeba spp. and B. mandrillaris also cause a disseminated disease including the lungs, skin, kidneys, and uterus. Naegleria fowleri, on the other hand, causes an acute and fulminating, necrotizing infection of the CNS called primary amebic meningoencephalitis (PAM) in children and young adults with a history of recent exposure to warm fresh water. Additionally, another free-living ameba Sappinia pedata, previously described as S. diploidea, also has caused a single case of amebic meningoencephalitis. In this review the biology of these amebae, clinical manifestations, molecular and immunological diagnosis, and epidemiological features associated with GAE and PAM are discussed. PMID:23829906

  20. Free-living amebic meningoencephalitides: comparative study.

    PubMed

    Martínez, A J

    1977-01-01

    Primary amebic meningoencephalitis (PAM) is an infectious disease essentially confined to the central nervous system (CNS) and caused by free-living ameboflagellates of the genus Naegleria (N) and Acanthamoeba (A). N produces an acute fulminant, usually fatal hemorrhagic-necrotizing meningoencephalitis, associated with an inflammatory reaction composed of neutrophils, eosinophils, macrophages and a few lymphocytes. The incubation period is between 3-7 days. Typically, PAM occurs in healthy, young individuals, who frequently have a history of swimming or washing their face in infested waters. The portal of entry into the CNS is through the olfactory neuroepithelium, at the level of the cribriform plate and invasion of the amyelinic submucosal nervous plexus. Trophozoites are the only amebic forms found in the lesions. By contrast, A produces a sub-acute or chronic granulamotous meningoencephalitis (AM) with multinucleated foreign body giant cells, lymphocytes and monocytes. Cysts and trophozoites may be present in the lesions. AM have been reported in chronically ill debilitated individuals, some of them under immunosuppressive therapy, without history of recent swimming. The portal of entry into the CNS appears to be by hematogenous route. The incubation period is unknown, but perhaps more than 10 days. This comparison indicates that infection due to Naegleria produces a clearly defined clinco-pathological entity, which differs significantly from that due to Acanthamoeba, and both species of amebus should be considered in the differential diagnosis of amebic meningoencephalitis. PMID:616542

  1. Free-living amoebae: Health concerns in the indoor environment

    SciTech Connect

    Tyndall, R.L.; Ironside, K.S.

    1990-01-01

    Free-living amoebae are the most likely protozoa implicated in health concerns of the indoor environment. These amoebae can be the source of allergic reactions, eye infections or, on rare occasions, encephalitis. While too large to be effectively aerosolized, free- living amoebae can support the multiplication of pathogens such as Legionella which are easily aerosolized and infectious via the pulmonary route. Traditional detection methods for free-living amoebae are laborious and time consuming. Newer techniques for rapidly detecting and quantitating free-living amoebae such as monoclonal antibodies, flow cytometry, gene probes, and laser optics have or could be employed. 25 refs.

  2. Assessment of the Extirpated Maritimes Walrus Using Morphological and Ancient DNA Analysis

    PubMed Central

    McLeod, Brenna A.; Frasier, Timothy R.; Lucas, Zoe

    2014-01-01

    Species biogeography is a result of complex events and factors associated with climate change, ecological interactions, anthropogenic impacts, physical geography, and evolution. To understand the contemporary biogeography of a species, it is necessary to understand its history. Specimens from areas of localized extinction are important, as extirpation of species from these areas may represent the loss of unique adaptations and a distinctive evolutionary trajectory. The walrus (Odobenus rosmarus) has a discontinuous circumpolar distribution in the arctic and subarctic that once included the southeastern Canadian Maritimes region. However, exploitation of the Maritimes population during the 16th-18th centuries led to extirpation, and the species has not inhabited areas south of 55°N for ∼250 years. We examined genetic and morphological characteristics of specimens from the Maritimes, Atlantic (O. r. rosmarus) and Pacific (O. r. divergens) populations to test the hypothesis that the first group was distinctive. Analysis of Atlantic and Maritimes specimens indicated that most skull and mandibular measurements were significantly different between the Maritimes and Atlantic groups and discriminant analysis of principal components confirmed them as distinctive groups, with complete isolation of skull features. The Maritimes walrus appear to have been larger animals, with larger and more robust tusks, skulls and mandibles. The mtDNA control region haplotypes identified in Maritimes specimens were unique to the region and a greater average number of nucleotide differences were found between the regions (Atlantic and Maritimes) than within either group. Levels of diversity (h and π) were lower in the Maritimes, consistent with other studies of species at range margins. Our data suggest that the Maritimes walrus was a morphologically and genetically distinctive group that was on a different evolutionary path from other walrus found in the north Atlantic. PMID:24924490

  3. Assessment of the extirpated Maritimes walrus using morphological and ancient DNA analysis.

    PubMed

    McLeod, Brenna A; Frasier, Timothy R; Lucas, Zoe

    2014-01-01

    Species biogeography is a result of complex events and factors associated with climate change, ecological interactions, anthropogenic impacts, physical geography, and evolution. To understand the contemporary biogeography of a species, it is necessary to understand its history. Specimens from areas of localized extinction are important, as extirpation of species from these areas may represent the loss of unique adaptations and a distinctive evolutionary trajectory. The walrus (Odobenus rosmarus) has a discontinuous circumpolar distribution in the arctic and subarctic that once included the southeastern Canadian Maritimes region. However, exploitation of the Maritimes population during the 16th-18th centuries led to extirpation, and the species has not inhabited areas south of 55°N for ∼250 years. We examined genetic and morphological characteristics of specimens from the Maritimes, Atlantic (O. r. rosmarus) and Pacific (O. r. divergens) populations to test the hypothesis that the first group was distinctive. Analysis of Atlantic and Maritimes specimens indicated that most skull and mandibular measurements were significantly different between the Maritimes and Atlantic groups and discriminant analysis of principal components confirmed them as distinctive groups, with complete isolation of skull features. The Maritimes walrus appear to have been larger animals, with larger and more robust tusks, skulls and mandibles. The mtDNA control region haplotypes identified in Maritimes specimens were unique to the region and a greater average number of nucleotide differences were found between the regions (Atlantic and Maritimes) than within either group. Levels of diversity (h and π) were lower in the Maritimes, consistent with other studies of species at range margins. Our data suggest that the Maritimes walrus was a morphologically and genetically distinctive group that was on a different evolutionary path from other walrus found in the north Atlantic. PMID:24924490

  4. Hemosporidian parasites of free-living birds in the São Paulo Zoo, Brazil.

    PubMed

    Chagas, Carolina Romeiro Fernandes; Guimarães, Lilian de Oliveira; Monteiro, Eliana Ferreira; Valkiūnas, Gediminas; Katayama, Michele Viana; Santos, Stéfanie Vanessa; Guida, Fernanda Junqueira Vaz; Simões, Roseli França; Kirchgatter, Karin

    2016-04-01

    Numerous studies addressed the diversity of bird Plasmodium and Haemoproteus parasites. However, a few have been carried out in continental avian hotspot regions such as Brazil, a country with markedly different biomes, including Amazon, Brazilian Savanna, Atlantic Forest, Caatinga, Pantanal, and Pampas. We present the first study on hemosporidian (Haemosporida) parasites in free-living birds from an Atlantic Forest fragment where more than 80 avian species have been reported. Within this area, the São Paulo Zoo locates, and it is the fourth largest zoo in the world and the largest in Latin America. A total of 133 free-living bird samples representing 12 species were collected in the zoo, with the overall hemosporidian prevalence of 18 % by PCR-based diagnostics. Twenty-four positive PCR signals were reported from four different bird species, including migratory ones. Columba livia, an urban species, considered nowadays a pest in big cities, showed 100 % prevalence of Haemoproteus spp., mainly Haemoproteus columbae. We discuss the epidemiological importance of new parasites introduced by migratory birds in the São Paulo Zoo area and the risk it poses to the captive species, which are natives or exotics. We also warn about the influence these parasites can have on the biodiversity and the structure of host populations by altering the competitive interaction between the free-living and the captive birds. PMID:26677094

  5. Blood protozoa of free-living birds

    USGS Publications Warehouse

    Herman, C.M.

    1969-01-01

    Blood protozoa were first reported from wild birds in 1884. Since then numerous surveys throughout the world have demonstrated their presence in a wide variety of hosts and localities with continuing designations of new species. Taxonomic determinations include parasites in the genera Plasmodium, Haemoproteus, Leucocytozoon, Babesia, Lankesterella and Trypanosoma. Transmission of Plasmodium by mosquitoes was demonstrated with a bird parasite before these insects were proven as vectors of human malaria. All the genera under consideration require an insect vector to complete their life-cycles and susceptible vectors have been demonstrated. Most experimental work on the blood protozoa of birds has been carried on with captive birds. An extensive volume of research has been conducted on Plasmodium because of its close similarity to malaria in man. Field studies that would provide information on the epizootiology of occurrence of these parasites in wild populations have been very limited, mainly confined to single blood film surveys. Such data are inadequate to provide an understanding of true prevalence or incidence or of factual knowledge of their impact on the wild population. Mechanisms for procuring such information are available in some cases and can be developed to fit other situations. Isodiagnosis, inoculation of blood from wild birds into susceptible captive hosts, has revealed a prevalence of over 60 % for Plasmodium in situations where microscope examination of single peripheral blood preparations yielded less than 1 %. Culture of bone marrow collected by biopsy demonstrates high prevalence of trypanosomes even when none are evident from microscopic examination of blood. Often preparations of tissues collected at necropsy reveal Leucocytozoon and Lankesterella when examination of peripheral blood gave no indication of infection. Methods developed by bird ringers provide techniques for obtaining repeat examinations of free-living birds that can yield further

  6. The use of singleplex and nested PCR to detect Batrachochytrium dendrobatidis in free-living frogs

    PubMed Central

    Coutinho, Selene Dall'Acqua; Burke, Julieta Catarina; de Paula, Catia Dejuste; Rodrigues, Miguel Trefaut; Catão-Dias, José Luiz

    2015-01-01

    Many microorganisms are able to cause diseases in amphibians, and in the past few years one of the most reported has been Batrachochytrium dendrobatidis. This fungus was first reported in Brazil in 2005; following this, other reports were made in specimens deposited in museum collections, captive and free-living frogs. The aim of this study was to compare singleplex and nested-PCR techniques to detect B. dendrobatidis in free-living and apparently healthy adult frogs from the Brazilian Atlantic Forest. The sample collection area was a protected government park, with no general entrance permitted and no management of the animals there. Swabs were taken from the skin of 107 animals without macroscopic lesions and they were maintained in ethanol p.a. Fungal DNA was extracted and identification of B. dendrobatidis was performed using singleplex and nested-PCR techniques, employing specific primers sequences. B. dendrobatidis was detected in 61/107 (57%) and 18/107 (17%) animals, respectively by nested and singleplex-PCR. Nested-PCR was statistically more sensible than the conventional for the detection of B. dendrobatidis (Chi-square = 37.1; α = 1%) and the agreement between both techniques was considered just fair (Kappa = 0.27). The high prevalence obtained confirms that these fungi occur in free-living frogs from the Brazilian Atlantic Forest with no macroscopic lesions, characterizing the state of asymptomatic carrier. We concluded that the nested-PCR technique, due to its ease of execution and reproducibility, can be recommended as one of the alternatives in epidemiological surveys to detect B. dendrobatidis in healthy free-living frog populations. PMID:26273273

  7. The use of singleplex and nested PCR to detect Batrachochytrium dendrobatidis in free-living frogs.

    PubMed

    Coutinho, Selene Dall'Acqua; Burke, Julieta Catarina; de Paula, Catia Dejuste; Rodrigues, Miguel Trefaut; Catão-Dias, José Luiz

    2015-06-01

    Many microorganisms are able to cause diseases in amphibians, and in the past few years one of the most reported has been Batrachochytrium dendrobatidis. This fungus was first reported in Brazil in 2005; following this, other reports were made in specimens deposited in museum collections, captive and free-living frogs. The aim of this study was to compare singleplex and nested-PCR techniques to detect B. dendrobatidis in free-living and apparently healthy adult frogs from the Brazilian Atlantic Forest. The sample collection area was a protected government park, with no general entrance permitted and no management of the animals there. Swabs were taken from the skin of 107 animals without macroscopic lesions and they were maintained in ethanol p.a. Fungal DNA was extracted and identification of B. dendrobatidis was performed using singleplex and nested-PCR techniques, employing specific primers sequences. B. dendrobatidis was detected in 61/107 (57%) and 18/107 (17%) animals, respectively by nested and singleplex-PCR. Nested-PCR was statistically more sensible than the conventional for the detection of B. dendrobatidis (Chi-square = 37.1; α = 1%) and the agreement between both techniques was considered just fair (Kappa = 0.27). The high prevalence obtained confirms that these fungi occur in free-living frogs from the Brazilian Atlantic Forest with no macroscopic lesions, characterizing the state of asymptomatic carrier. We concluded that the nested-PCR technique, due to its ease of execution and reproducibility, can be recommended as one of the alternatives in epidemiological surveys to detect B. dendrobatidis in healthy free-living frog populations. PMID:26273273

  8. Pacific Walrus Response to Arctic Sea Ice Losses

    USGS Publications Warehouse

    Jay, Chadwick V.; Fischbach, Anthony S.

    2008-01-01

    Sea ice plays an important role in the life of the Pacific walrus (Odobenus rosmarus divergens). U.S. Geological Survey (USGS) scientists are seeking to understand how losses of sea ice during summer over important foraging grounds in the Chukchi Sea will affect walruses. USGS scientists recently modified a remotely deployed satellite radio-tag that will aid in studying walrus foraging habitats and behaviors. Information from the tags will help USGS understand how walruses are responding to their changing environment.

  9. 50 CFR 216.85 - Walrus and Otter Islands.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 10 2012-10-01 2012-10-01 false Walrus and Otter Islands. 216.85 Section... MAMMALS Pribilof Islands Administration § 216.85 Walrus and Otter Islands. By Executive Order 1044, dated February 27, 1909, Walrus and Otter Islands were set aside as bird reservations. All persons are...

  10. 50 CFR 18.94 - Pacific walrus (Alaska).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Pacific walrus (Alaska). 18.94 Section 18... Marine Mammal Species § 18.94 Pacific walrus (Alaska). (a) Pursuant to sections 101(a)(3)(A) 103, and 109... walrus (Odobenus rosmarus) in waters or on lands subject to the jurisdiction of the State of Alaska,...

  11. 50 CFR 216.85 - Walrus and Otter Islands.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Walrus and Otter Islands. 216.85 Section... MAMMALS Pribilof Islands Administration § 216.85 Walrus and Otter Islands. By Executive Order 1044, dated February 27, 1909, Walrus and Otter Islands were set aside as bird reservations. All persons are...

  12. 50 CFR 216.85 - Walrus and Otter Islands.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 9 2011-10-01 2011-10-01 false Walrus and Otter Islands. 216.85 Section... MAMMALS Pribilof Islands Administration § 216.85 Walrus and Otter Islands. By Executive Order 1044, dated February 27, 1909, Walrus and Otter Islands were set aside as bird reservations. All persons are...

  13. 50 CFR 216.85 - Walrus and Otter Islands.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 10 2014-10-01 2014-10-01 false Walrus and Otter Islands. 216.85 Section... MAMMALS Pribilof Islands Administration § 216.85 Walrus and Otter Islands. By Executive Order 1044, dated February 27, 1909, Walrus and Otter Islands were set aside as bird reservations. All persons are...

  14. 50 CFR 18.94 - Pacific walrus (Alaska).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 9 2013-10-01 2013-10-01 false Pacific walrus (Alaska). 18.94 Section 18... Marine Mammal Species § 18.94 Pacific walrus (Alaska). (a) Pursuant to sections 101(a)(3)(A) 103, and 109... walrus (Odobenus rosmarus) in waters or on lands subject to the jurisdiction of the State of Alaska,...

  15. 50 CFR 216.85 - Walrus and Otter Islands.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 10 2013-10-01 2013-10-01 false Walrus and Otter Islands. 216.85 Section... MAMMALS Pribilof Islands Administration § 216.85 Walrus and Otter Islands. By Executive Order 1044, dated February 27, 1909, Walrus and Otter Islands were set aside as bird reservations. All persons are...

  16. First Gammaherpesvirus detection in a free-living Mediterranean bottlenose dolphin.

    PubMed

    Lecis, Roberta; Tocchetti, Marco; Rotta, Andrea; Naitana, Salvatore; Ganges, Llilianne; Pittau, Marco; Alberti, Alberto

    2014-12-01

    Recently, herpes viruses have been detected in different cetacean species from the Atlantic and in Mediterranean striped dolphins (Stenella coeruleoalba). While pathogens such as cetacean morbillivirus have been widely studied following recent epizootics, herpesvirus (HV) distribution and pathogenic effects in cetaceans are still understudied. This study reports the first molecular identification of a Gammaherpesvirus in the genital mucosa of a free-living Mediterranean bottlenose dolphin (Tursiops truncatus) stranded off the coast of central Italy. Sequenced herpesviral PCR product was closely related to other HVs recently isolated in the genital mucosa of various cetacean species. PMID:25632684

  17. Free-living flatworms under the knife: past and present

    PubMed Central

    Gschwentner, Robert; Rieger, Reinhard

    2006-01-01

    Traditionally, regeneration research has been closely tied to flatworm research, as flatworms (Plathelminthes) were among the first animals where the phenomenon of regeneration was discovered. Since then, the main focus of flatworm regeneration research was on triclads, for which various phenomena were observed and a number of theories developed. However, free-living flatworms encompass a number of other taxa where regeneration was found to be possible. This review aims to display and to compare regeneration in all major free-living flatworm taxa, with special focus on a new player in the field of regeneration, Macrostomum lignano (Macrostomorpha). Findings on the regeneration capacity of this organism provide clues for links between regeneration and (post-)embryonic development, starvation, and asexual reproduction. The role of the nervous system and especially the brain for regeneration is discussed, and similarities as well as particularities in regeneration among free-living flatworms are pointed out. PMID:17146688

  18. Study of sleep in a walrus.

    PubMed

    Lyamin, O I; Kosenko, P O; Vyssotski, A L; Lapierre, J L; Siegel, J M; Mukhametov, L M

    2012-01-01

    Several behavioral and physiological adaptations have been developed in evolution of Pinnipeds allowing them to sleep both on land and in water. To date sleep has been examined in detail in eared and true seals (the families of Otariidae and Phocidae). The aim of this study was to examine sleep in another semiaquatic mammal - the walrus, which is the only extant representative of the family Odobenidae. Slow wave and paradoxical sleep (SWS and PS) in the examined walrus (2 year old female, weight 130 kg) averaged 19.4 ± 2.0 and 6.9 ± 1.1% of 24-h when on land, and 20.5 ± 0.8% of 24-h and 1.1 ± 0.6% when in water, respectively. The average duration of PS episode was 6.4 ± 0.6 min (maximum 23 min) when on land and 1.8 ± 0.1 min (maximum 3.3 min) when in water. In water, sleep occurred predominantly while the walrus submerged and lay on the bottom of the pool (89% of total sleep time). The walrus usually woke up while emerging to the surface for breathing. Most often EEG slow waves developed synchronously in both cortical hemispheres (90% of SWS time when on land and 97% when in water). Short episodes of interhemispheric EEG asymmetry usually coincided with brief opening of one eye. The pattern of sleep in the walrus was similar to the pattern of sleep in the Otariidae seals while on land (predominantly bilateral SWS, accompanied by regular breathing) and to the pattern of sleep in the Phocidae while in water (sleep during apneas both in depth and at the surface, interrupted by brief arousal when emerging for breathing). PMID:22760621

  19. Ocean environmental effects on walrus communication

    NASA Astrophysics Data System (ADS)

    Denes, Samuel L.

    This work aimed to develop source characteristics and transmission effects for the acoustic breeding displays of male Pacific walrus (Odobenus rosmarus divergens). Pacific walrus breeding activities occur in late winter in the Bering Sea, an area renowned for extreme weather conditions and high biological productivity. During the breeding season, males perform acoustic displays while swimming in the vicinity of females hauled out on ice. Underwater vocalizations heard by individuals hauled out on ice may be important in the mate selection process. The extreme environment in which walrus breeding activities occur precludes direct observation of these animals during this important period and has resulted in a lack of data. A combination of remote-sensing data, captive animal research, controlled environment experiment, and computational modeling was used to increase our understanding of the acoustic displays of Pacific walrus. Analysis of recordings of captive and wild male Pacific walrus vocalizations during breeding season provided quantification of source characteristics. Working with a captive animal provided the ability to make direct observations of a male producing breeding vocalizations and the direct calculation of source level. The mean peak to peak source level of the impulsive knocks produced by the captive male was 183 dB (re: 1 microPa) with the middle 95% of the knocks between 168 dB and 195 dB. The broadband knock signals contained significant acoustic energy up to 13 kHz. To estimate source level from wild vocalizations, the location of the source walrus first needed to be determined. Using a method of relative multipath arrival time, more than 37,000 knocks were localized from six years of data from autonomous recorders deployed in the Bering Sea. The mean peak-peak source level from the wild recordings was 177 dB (re: 1 microPa) with 95% of the knocks between 163 dB and 189 dB. For both wild and captive vocalizations, a significant relationship

  20. Accuracy of Step Recording in Free-Living Adults

    ERIC Educational Resources Information Center

    Behrens, Timothy K.; Dinger, Mary K.; Vesely, Sara K.; Fields, David A.

    2007-01-01

    The purpose of this study was to investigate how accurately free-living adults record their pedometer steps on step logs. Researchers used three different methods to examine the accuracy of participant-recorded steps: tests of equivalence, correlation coefficients, and Bland-Altman plots. Findings indicate that participant-recorded steps…

  1. Application of airborne thermal imagery to surveys of Pacific walrus

    USGS Publications Warehouse

    Burn, D.M.; Webber, M.A.; Udevitz, M.S.

    2006-01-01

    We conducted tests of airborne thermal imagery of Pacific walrus to determine if this technology can be used to detect walrus groups on sea ice and estimate the number of walruses present in each group. In April 2002 we collected thermal imagery of 37 walrus groups in the Bering Sea at spatial resolutions ranging from 1-4 m. We also collected high-resolution digital aerial photographs of the same groups. Walruses were considerably warmer than the background environment of ice, snow, and seawater and were easily detected in thermal imagery. We found a significant linear relation between walrus group size and the amount of heat measured by the thermal sensor at all 4 spatial resolutions tested. This relation can be used in a double-sampling framework to estimate total walrus numbers from a thermal survey of a sample of units within an area and photographs from a subsample of the thermally detected groups. Previous methods used in visual aerial surveys of Pacific walrus have sampled only a small percentage of available habitat, resulting in population estimates with low precision. Results of this study indicate that an aerial survey using a thermal sensor can cover as much as 4 times the area per hour of flight time with greater reliability than visual observation.

  2. 50 CFR 18.94 - Pacific walrus (Alaska).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 9 2014-10-01 2014-10-01 false Pacific walrus (Alaska). 18.94 Section 18... Marine Mammal Species § 18.94 Pacific walrus (Alaska). (a) Pursuant to sections 101(a)(3)(A) 103, and 109 of the Marine Mammal Protection Act of 1972, the moratorium on the hunting and killing of...

  3. 50 CFR 18.94 - Pacific walrus (Alaska).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Pacific walrus (Alaska). 18.94 Section 18... Marine Mammal Species § 18.94 Pacific walrus (Alaska). (a) Pursuant to sections 101(a)(3)(A) 103, and 109 of the Marine Mammal Protection Act of 1972, the moratorium on the hunting and killing of...

  4. 50 CFR 18.94 - Pacific walrus (Alaska).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 9 2012-10-01 2012-10-01 false Pacific walrus (Alaska). 18.94 Section 18... Marine Mammal Species § 18.94 Pacific walrus (Alaska). (a) Pursuant to sections 101(a)(3)(A) 103, and 109 of the Marine Mammal Protection Act of 1972, the moratorium on the hunting and killing of...

  5. Toxoplasma gondii antibodies in free-living African mammals.

    PubMed

    Riemann, G P; Burridge, M J; Behymer, D E; Franti, C E

    1975-10-01

    Twelve species of free-living African mammals from Kenya, Tanzania, Uganda and Zambia were tested for antibodies to Toxoplasma gondii using the indirect hemagglutination test. Of 157 animals sampled, 20 (13%) were seropositive. T. gondii antibodies were detected in Burchell's zebra, (Equus burchelli), hippopotamus (Hippopotamus amphibius), African elephant (Loxodonta africana), defassa waterbuck (Kobus defassa), lion (Panthera leo), and rock hyrax (Procavia capensis), The highest titers were found in elephants, two having titers of 1:4096 and one of 1:8192. These results are discussed in relation to the maintenance of T. gondii among African wildlife. PMID:1195497

  6. Natural infection by endoparasites among free-living wild animals.

    PubMed

    Holsback, Luciane; Cardoso, Mauro José Lahm; Fagnani, Rafael; Patelli, Thaís Helena Constantino

    2013-01-01

    The objective of this study was to investigate the frequency of occurrence and variety of intestinal parasites among free-living wild animals. Fecal samples from wild mammals and birds at rehabilitation centers in the states of Mato Grosso do Sul and São Paulo were analyzed by sedimentation and flotation-centrifugation methods. Parasite eggs, oocysts, cysts and/or trophozoites were found in 71% of the samples. Cryptosporidium sp. oocysts were detected in fecal samples from oncillas (Leopardus tigrinus) and scaly-headed parrots (Pionus maximiliani). Giardia cysts were identified in the feces of a gray brocket (Mazama gouazoubira). Among the most common parasites found, there were eggs from Toxocara cati, Toxascaris leonina and Ancylostoma tubaeforme, and from Cestoda. Several Enterobius sp. eggs were found in the feces of red howler monkeys (Alouatta seniculus). It can be concluded from this study that despite the small number of samples, the diversity of parasites found was noteworthy. Additional information about parasite endofauna in wild animals is needed, since their presence might suggest that there could be proximity to and interactions with domestic animals and/or humans. In addition, further studies on parasites from free-living wild animals are of prime importance for understanding the intensity of anthropic changes in wild environments. PMID:23778826

  7. Cocultivation of Legionella pneumophila and free-living amoebae

    SciTech Connect

    Tyndall, R.L.; Domingue, E.L.

    1982-10-01

    Studies of the interaction of Legionella pneumophila with free-living amoebae showed that Naegleria lovaniensis and Acanthamoeba royreba could use L. pneumophia as a sole food source. However, growth of the amoebae on nonnutrient agar plates seeded with L. pneumophila was slower than growth on nonnutrient agar plates seeded with Escherichia coli. On inoculation of L. pneumophila into axenic cultures of N. lovaniensis and A. roryba, 99.9% of the L. pneumophila was destroyed within 24 h. After several weeks, however, some amoeba cultures became chronically infected and supported the growth of L. pneumophila. Amoebae exposed to L. pneumophila and containing adhered L. pneumophila, L. pneumophila antigens, or both, showed no increased pathogenic potential on intranasal inoculation of weanling mice. Similarly, L. pneumophila propagated in chronically infected amoeba cultures showed no increase in virulence on intraperitoneal inoculation of guinea pigs relative to L. pneumophila grown in yeast extract broth. 20 references, 1 figure, 4 tables.

  8. Intestinal proteases of free-living and parasitic astigmatid mites.

    PubMed

    Holt, Deborah C; Burgess, Stewart T G; Reynolds, Simone L; Mahmood, Wajahat; Fischer, Katja

    2013-02-01

    Among arthropod pests, mites are responsible for considerable damage to crops, humans and other animals. However, detailed physiological data on these organisms remain sparse, mainly because of their small size but possibly also because of their extreme diversity. Focusing on intestinal proteases, we draw together information from three distinct mite species that all feed on skin but have separately adapted to a free-living, a strictly ecto-parasitic and a parasitic lifestyle. A wide range of studies involving immunohistology, molecular biology, X-ray crystallography and enzyme biochemistry of mite gut proteases suggests that these creatures have diverged considerably as house dust mites, sheep scab mites and scabies mites. Each species has evolved a particular variation of a presumably ancestral repertoire of digestive enzymes that have become specifically adapted to their individual environmental requirements. PMID:22427061

  9. Genetic Variation in the Free-Living Amoeba Naegleria fowleri

    PubMed Central

    Pélandakis, Michel; De Jonckheere, Johan F.; Pernin, Pierre

    1998-01-01

    In this study, 30 strains of the pathogenic free-living amoeba Naegleria fowleri were investigated by using the randomly amplified polymorphic DNA (RAPD) method. The present study confirmed our previous finding that RAPD variation is not correlated with geographical origin. In particular, Mexican strains belong to the variant previously detected in Asia, Europe, and the United States. In France, surprisingly, strains from Cattenom gave RAPD patterns identical to those of the Japanese strains. In addition, all of these strains, together with an additional French strain from Chooz, exhibited similarities to South Pacific strains. The results also confirmed the presence of numerous variants in Europe, whereas only two variants were detected in the United States. The two variants found in the United States were different from the South Pacific variants. These findings do not support the previous hypothesis concerning the origin and modes of dispersal of N. fowleri. PMID:9687460

  10. Viruses in close associations with free-living amoebae.

    PubMed

    Scheid, Patrick

    2015-11-01

    As both groups of organisms, free-living amoebae (FLA) and viruses, can be found in aquatic environments side by side, it appears obvious that there are multiple interactions with respect to host-endocytobiont relationships. Several relationships between viruses and protozoan hosts are described and it was the discovery of the so called "giant viruses," associated with amoebae, which gave another dimension to these interactions. Mimiviruses, Pandoraviruses and Pithoviruses are examples for interesting viral endocytobionts within FLA. In the Mimivirus viral factories, viral DNA undergoes replication and transcription, and the DNA is prepared to be packed in procapsids. Theses Mimivirus factories can be considered as efficient "production lines" where, at any given moment, all stages of viral generation including membrane biogenesis, capsid assembly and genome encapsidation, are occurring concomitantly. There are some hints that similar replication factories are involved as well during the Pandoravirus development. Some scientists favour the assumption that the giant viruses have received many of their genes from their hosts or from sympatric occurring endocytobionts via lateral gene transfer. This hypothesis would mean that this type of transfer has been an important process in the evolution of genomes in the context of the intracellular parasitic or endocytobiotic lifestyle. In turn, that would migitate against hypothesizing development of a new branch in the tree of life. Based on the described scenarios to explain the presence of genes related to translation, it is also possible that earlier ancestors of today's DNA viruses were involved in the origin of eukaryotes. That possibly could in turn support the idea that cellular organisms could have evolved from viruses with growing autarkic properties. In future we expect the discovery of further (giant) viruses within free-living amoebae and other protozoa through genomic, transcriptomic and proteomic analyses. PMID

  11. Divergent movements of walrus and sea ice in the Nothern Bering Sea

    USGS Publications Warehouse

    Jay, Chadwick V.; Udevitz, Mark S.; Kwok, Ron; Fischbach, Anthony S.; Douglas, David C.

    2010-01-01

    The Pacific walrus Odobenus rosmarus divergens is a large Arctic pinniped of the Chukchi and Bering Seas. Reductions of sea ice projected to occur in the Arctic by mid-century raise concerns for conservation of the Pacific walrus. To understand the significance of sea ice loss to the viability of walruses, it would be useful to better understand the spatial associations between the movements of sea ice and walruses. We investigated whether local-scale (~1 to 100 km) walrus movements correspond to movements of sea ice in the Bering Sea in early spring, using locations from radio-tracked walruses and measures of ice floe movements from processed synthetic aperture radar satellite imagery. We used generalized linear mixed-effects models to analyze the angle between walrus and ice floe movement vectors and the distance between the final geographic position of walruses and their associated ice floes (displacement), as functions of observation duration, proportion of time the walrus was in water, and geographic region. Analyses were based on 121 walrus-ice vector pairs and observations lasting 12 to 36 h. Angles and displacements increased with observation duration, proportion of time the walrus spent in the water, and varied among regions (regional mean angles ranged from 40° to 81° and mean displacements ranged from 15 to 35 km). Our results indicated a lack of correspondence between walruses and their initially associated ice floes, suggesting that local areas of walrus activities were independent of the movement of ice floes.

  12. Light pollution disrupts sleep in free-living animals.

    PubMed

    Raap, Thomas; Pinxten, Rianne; Eens, Marcel

    2015-01-01

    Artificial lighting can alter individual behaviour, with often drastic and potentially negative effects on biological rhythms, daily activity and reproduction. Whether this is caused by a disruption of sleep, an important widespread behaviour enabling animals to recover from daily stress, is unclear. We tested the hypothesis that light pollution disrupts sleep by recording individual sleep behaviour of great tits, Parus major, that were roosting in dark nest-boxes and were exposed to light-emitting diode light the following night. Their behaviour was compared to that of control birds sleeping in dark nest-boxes on both nights. Artificial lighting caused experimental birds to wake up earlier, sleep less (-5%) and spent less time in the nest-box as they left their nest-box earlier in the morning. Experimental birds did not enter the nest-box or fall asleep later than controls. Although individuals in lit nest-boxes did not wake up more often nor decreased the length of their sleep bouts, females spent a greater proportion of the night awake. Our study provides the first direct proof that light pollution has a significant impact on sleep in free-living animals, in particular in the morning, and highlights a mechanism for potential effects of light pollution on fitness. PMID:26337732

  13. Dispersal and gene flow in free-living marine nematodes.

    PubMed

    Derycke, Sofie; Backeljau, Thierry; Moens, Tom

    2013-01-01

    Dispersal and gene flow determine connectivity among populations, and can be studied through population genetics and phylogeography. We here review the results of such a framework for free-living marine nematodes. Although field experiments have illustrated substantial dispersal in nematodes at ecological time scales, analysis of the genetic diversity illustrated the importance of priority effects, founder effects and genetic bottlenecks for population structuring between patches <1 km apart. In contrast, only little genetic structuring was observed within an estuary (<50 km), indicating that these small scale fluctuations in genetic differentiation are stabilized over deeper time scales through extensive gene flow. Interestingly, nematode species with contrasting life histories (extreme colonizers vs persisters) or with different habitat preferences (algae vs sediment) show similar, low genetic structuring. Finally, historical events have shaped the genetic pattern of marine nematodes and show that gene flow is restricted at large geographical scales. We also discuss the presence of substantial cryptic diversity in marine nematodes, and end with highlighting future important steps to further unravel nematode evolution and diversity. PMID:23356547

  14. Dispersal and gene flow in free-living marine nematodes

    PubMed Central

    2013-01-01

    Dispersal and gene flow determine connectivity among populations, and can be studied through population genetics and phylogeography. We here review the results of such a framework for free-living marine nematodes. Although field experiments have illustrated substantial dispersal in nematodes at ecological time scales, analysis of the genetic diversity illustrated the importance of priority effects, founder effects and genetic bottlenecks for population structuring between patches <1 km apart. In contrast, only little genetic structuring was observed within an estuary (<50 km), indicating that these small scale fluctuations in genetic differentiation are stabilized over deeper time scales through extensive gene flow. Interestingly, nematode species with contrasting life histories (extreme colonizers vs persisters) or with different habitat preferences (algae vs sediment) show similar, low genetic structuring. Finally, historical events have shaped the genetic pattern of marine nematodes and show that gene flow is restricted at large geographical scales. We also discuss the presence of substantial cryptic diversity in marine nematodes, and end with highlighting future important steps to further unravel nematode evolution and diversity. PMID:23356547

  15. Nutrient compensatory foraging in a free-living social insect

    NASA Astrophysics Data System (ADS)

    Christensen, Keri L.; Gallacher, Anthony P.; Martin, Lizzie; Tong, Desmond; Elgar, Mark A.

    2010-10-01

    The geometric framework model predicts that animal foraging decisions are influenced by their dietary history, with animals targeting a combination of essential nutrients through compensatory foraging. We provide experimental confirmation of nutrient-specific compensatory foraging in a natural, free-living population of social insects by supplementing their diet with sources of protein- or carbohydrate-rich food. Colonies of the ant Iridomyrmex suchieri were provided with feeders containing food rich in either carbohydrate or protein for 6 days, and were then provided with a feeder containing the same or different diet. The patterns of recruitment were consistent with the geometric framework: while feeders with a carbohydrate diet typically attracted more workers than did feeders with protein diet, the difference in recruitment between the two nutrients was smaller if the colonies had had prior access to carbohydrate than protein. Further, fewer ants visited feeders if the colony had had prior access to protein than to carbohydrates, suggesting that the larvae play a role in worker foraging behaviour.

  16. Light pollution disrupts sleep in free-living animals

    PubMed Central

    Raap, Thomas; Pinxten, Rianne; Eens, Marcel

    2015-01-01

    Artificial lighting can alter individual behaviour, with often drastic and potentially negative effects on biological rhythms, daily activity and reproduction. Whether this is caused by a disruption of sleep, an important widespread behaviour enabling animals to recover from daily stress, is unclear. We tested the hypothesis that light pollution disrupts sleep by recording individual sleep behaviour of great tits, Parus major, that were roosting in dark nest-boxes and were exposed to light-emitting diode light the following night. Their behaviour was compared to that of control birds sleeping in dark nest-boxes on both nights. Artificial lighting caused experimental birds to wake up earlier, sleep less (–5%) and spent less time in the nest-box as they left their nest-box earlier in the morning. Experimental birds did not enter the nest-box or fall asleep later than controls. Although individuals in lit nest-boxes did not wake up more often nor decreased the length of their sleep bouts, females spent a greater proportion of the night awake. Our study provides the first direct proof that light pollution has a significant impact on sleep in free-living animals, in particular in the morning, and highlights a mechanism for potential effects of light pollution on fitness. PMID:26337732

  17. In silico ionomics segregates parasitic from free-living eukaryotes.

    PubMed

    Greganova, Eva; Steinmann, Michael; Mäser, Pascal; Fankhauser, Niklaus

    2013-01-01

    Ion transporters are fundamental to life. Due to their ancient origin and conservation in sequence, ion transporters are also particularly well suited for comparative genomics of distantly related species. Here, we perform genome-wide ion transporter profiling as a basis for comparative genomics of eukaryotes. From a given predicted proteome, we identify all bona fide ion channels, ion porters, and ion pumps. Concentrating on unicellular eukaryotes (n = 37), we demonstrate that clustering of species according to their repertoire of ion transporters segregates obligate endoparasites (n = 23) on the one hand, from free-living species and facultative parasites (n = 14) on the other hand. This surprising finding indicates strong convergent evolution of the parasites regarding the acquisition and homeostasis of inorganic ions. Random forest classification identifies transporters of ammonia, plus transporters of iron and other transition metals, as the most informative for distinguishing the obligate parasites. Thus, in silico ionomics further underscores the importance of iron in infection biology and suggests access to host sources of nitrogen and transition metals to be selective forces in the evolution of parasitism. This finding is in agreement with the phenomenon of iron withholding as a primordial antimicrobial strategy of infected mammals. PMID:24048281

  18. In Silico Ionomics Segregates Parasitic from Free-Living Eukaryotes

    PubMed Central

    Greganova, Eva; Steinmann, Michael; Mäser, Pascal; Fankhauser, Niklaus

    2013-01-01

    Ion transporters are fundamental to life. Due to their ancient origin and conservation in sequence, ion transporters are also particularly well suited for comparative genomics of distantly related species. Here, we perform genome-wide ion transporter profiling as a basis for comparative genomics of eukaryotes. From a given predicted proteome, we identify all bona fide ion channels, ion porters, and ion pumps. Concentrating on unicellular eukaryotes (n = 37), we demonstrate that clustering of species according to their repertoire of ion transporters segregates obligate endoparasites (n = 23) on the one hand, from free-living species and facultative parasites (n = 14) on the other hand. This surprising finding indicates strong convergent evolution of the parasites regarding the acquisition and homeostasis of inorganic ions. Random forest classification identifies transporters of ammonia, plus transporters of iron and other transition metals, as the most informative for distinguishing the obligate parasites. Thus, in silico ionomics further underscores the importance of iron in infection biology and suggests access to host sources of nitrogen and transition metals to be selective forces in the evolution of parasitism. This finding is in agreement with the phenomenon of iron withholding as a primordial antimicrobial strategy of infected mammals. PMID:24048281

  19. Microsporidian infection in a free-living marine nematode.

    PubMed

    Ardila-Garcia, A M; Fast, N M

    2012-12-01

    Microsporidia are unicellular fungi that are obligate endoparasites. Although nematodes are one of the most abundant and diverse animal groups, the only confirmed report of microsporidian infection was that of the "nematode killer" (Nematocida parisii). N. parisii was isolated from a wild Caenorhabditis sp. and causes an acute and lethal intestinal infection in a lab strain of Caenorhabditis elegans. We set out to characterize a microsporidian infection in a wild nematode to determine whether the infection pattern of N. parisii in the lab is typical of microsporidian infections in nematodes. We describe a novel microsporidian species named Sporanauta perivermis (marine spore of roundworms) and characterize its infection in its natural host, the free-living marine nematode Odontophora rectangula. S. perivermis is not closely related to N. parisii and differs strikingly in all aspects of infection. Examination by transmission electron microscopy (TEM) revealed that the infection was localized in the hypodermal and muscle tissues only and did not involve the intestines. Fluorescent in situ hybridization (FISH) confirmed infection in the muscle and hypodermis, and surprisingly, it also revealed that the parasite infects O. rectangula eggs, suggesting a vertical mode of transmission. Our observations highlight the importance of studying parasites in their natural hosts and indicate that not all nematode-infecting microsporidia are "nematode killers"; instead, microsporidiosis can be more versatile and chronic in the wild. PMID:23087371

  20. Microsporidian Infection in a Free-Living Marine Nematode

    PubMed Central

    Ardila-Garcia, A. M.

    2012-01-01

    Microsporidia are unicellular fungi that are obligate endoparasites. Although nematodes are one of the most abundant and diverse animal groups, the only confirmed report of microsporidian infection was that of the “nematode killer” (Nematocida parisii). N. parisii was isolated from a wild Caenorhabditis sp. and causes an acute and lethal intestinal infection in a lab strain of Caenorhabditis elegans. We set out to characterize a microsporidian infection in a wild nematode to determine whether the infection pattern of N. parisii in the lab is typical of microsporidian infections in nematodes. We describe a novel microsporidian species named Sporanauta perivermis (marine spore of roundworms) and characterize its infection in its natural host, the free-living marine nematode Odontophora rectangula. S. perivermis is not closely related to N. parisii and differs strikingly in all aspects of infection. Examination by transmission electron microscopy (TEM) revealed that the infection was localized in the hypodermal and muscle tissues only and did not involve the intestines. Fluorescent in situ hybridization (FISH) confirmed infection in the muscle and hypodermis, and surprisingly, it also revealed that the parasite infects O. rectangula eggs, suggesting a vertical mode of transmission. Our observations highlight the importance of studying parasites in their natural hosts and indicate that not all nematode-infecting microsporidia are “nematode killers”; instead, microsporidiosis can be more versatile and chronic in the wild. PMID:23087371

  1. Cosmopolitan metapopulations of free-living microbial eukaryotes.

    PubMed

    Finlay, Bland J; Fenchel, Tom

    2004-06-01

    Metapopulations of macroscopic organisms tend to be geographically restricted, but free-living protists and other microbial eukaryotes present a different picture. Here we show that most organisms smaller than 1 mm occur worldwide wherever their required habitats are realised. This is a consequence of ubiquitous dispersal driven by huge population sizes, and the consequently low probability of local extinction. Organisms larger than 10 mm are much less abundant, and rarely cosmopolitan. The supporting data, together with the discovery that the 1-10 mm size range accommodates a transition from cosmopolitan to regionally-restricted distribution, were derived from extensive inventories of eukaryotic species in a freshwater pond (1278 species), and a shallow marine bay (785 species). All accessible records were examined to establish the extent of global coverage by these species. Some groups of microbial eukaryotes are severely undersampled (e.g. naked amoebae; marine meiofauna in the southern hemisphere) but this fails to weaken evidence that metapopulations of microbial eukaryotes are cosmopolitan. PMID:15305798

  2. Eating frequency and energy regulation in free-living adults consuming self-selected diets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The relative importance of eating frequency to weight control is poorly understood. This review examines the evidence to date on the role of eating frequency in weight control in free-living adults. The majority of cross-sectional studies in free-living adults show an inverse relationship between ea...

  3. Diversity of free-living amoebae in a dual distribution (potable and recycled) water system

    EPA Science Inventory

    Free-living amoebae are known to facilitate the growth of water associated pathogens. This study, for the first time, explored the diversity of free-living amoebae in a dual distribution (potable and recycled) water system in Rouse Hill NSW, Australia. Water and biofilm samples w...

  4. Pacific Walrus and climate change: observations and predictions.

    PubMed

    Maccracken, James G

    2012-08-01

    The extent and duration of sea-ice habitats used by Pacific walrus (Odobenus rosmarus divergens) are diminishing resulting in altered walrus behavior, mortality, and distribution. I document changes that have occurred over the past several decades and make predictions to the end of the 21st century. Climate models project that sea ice will monotonically decline resulting in more ice-free summers of longer duration. Several stressors that may impact walruses are directly influenced by sea ice. How these stressors materialize were modeled as most likely-case, worst-case, and best-case scenarios for the mid- and late-21st century, resulting in four comprehensive working hypotheses that can help identify and prioritize management and research projects, identify comprehensive mitigation actions, and guide monitoring programs to track future developments and adjust programs as needed. In the short term, the most plausible hypotheses predict a continuing northward shift in walrus distribution, increasing use of coastal haulouts in summer and fall, and a population reduction set by the carrying capacity of the near shore environment and subsistence hunting. Alternatively, under worst-case conditions, the population will decline to a level where the probability of extinction is high. In the long term, walrus may seasonally abandon the Bering and Chukchi Seas for sea-ice refugia to the northwest and northeast, ocean warming and pH decline alter walrus food resources, and subsistence hunting exacerbates a large population decline. However, conditions that reverse current trends in sea ice loss cannot be ruled out. Which hypothesis comes to fruition depends on how the stressors develop and the success of mitigation measures. Best-case scenarios indicate that successful mitigation of unsustainable harvests and terrestrial haulout-related mortalities can be effective. Management and research should focus on monitoring, elucidating effects, and mitigation, while ultimately

  5. Pacific Walrus and climate change: observations and predictions

    PubMed Central

    MacCracken, James G

    2012-01-01

    The extent and duration of sea-ice habitats used by Pacific walrus (Odobenus rosmarus divergens) are diminishing resulting in altered walrus behavior, mortality, and distribution. I document changes that have occurred over the past several decades and make predictions to the end of the 21st century. Climate models project that sea ice will monotonically decline resulting in more ice-free summers of longer duration. Several stressors that may impact walruses are directly influenced by sea ice. How these stressors materialize were modeled as most likely-case, worst-case, and best-case scenarios for the mid- and late-21st century, resulting in four comprehensive working hypotheses that can help identify and prioritize management and research projects, identify comprehensive mitigation actions, and guide monitoring programs to track future developments and adjust programs as needed. In the short term, the most plausible hypotheses predict a continuing northward shift in walrus distribution, increasing use of coastal haulouts in summer and fall, and a population reduction set by the carrying capacity of the near shore environment and subsistence hunting. Alternatively, under worst-case conditions, the population will decline to a level where the probability of extinction is high. In the long term, walrus may seasonally abandon the Bering and Chukchi Seas for sea-ice refugia to the northwest and northeast, ocean warming and pH decline alter walrus food resources, and subsistence hunting exacerbates a large population decline. However, conditions that reverse current trends in sea ice loss cannot be ruled out. Which hypothesis comes to fruition depends on how the stressors develop and the success of mitigation measures. Best-case scenarios indicate that successful mitigation of unsustainable harvests and terrestrial haulout-related mortalities can be effective. Management and research should focus on monitoring, elucidating effects, and mitigation, while ultimately

  6. Free-living fungal symbionts (Lepiotaceae) of fungus-growing ants (Attini: Formicidae).

    PubMed

    Vo, Tanya L; Mueller, Ulrich G; Mikheyev, Alexander S

    2009-01-01

    Surveys of leucocoprinaceous fungi (Lepiotaceae, Agaricales, Basidiomycota) in the rainforests of Panama and Brazil revealed several free-living counterparts of fungi cultivated by primitive attine ants (the lower Attini, Formicidae, Hymenoptera), adding to two such collections identified in a survey by Mueller et al (1998). The accumulated evidence supports the hypothesis that perhaps all fungi of lower attine ants have close free-living relatives. Free-living counterparts of ant-cultivated fungi are collected most readily during the early rainy season; in particular these are free-living mushrooms of fungal counterparts that are cultivated as yeasts in gardens of ants in the Cyphomyrmex rimosus group. Free-living and symbiotic fungi of these yeast-cultivating ant species might represent a promising study system to compare the biology of sympatric, conspecific fungi existing outside versus inside the attine symbiosis. PMID:19397193

  7. Results and evaluation of a survey to estimate Pacific walrus population size, 2006

    USGS Publications Warehouse

    Speckman, S.G.; Chernook, V.I.; Burn, D.M.; Udevitz, M.S.; Kochnev, A.A.; Vasilev, A.; Jay, C.V.; Lisovsky, A.; Fischbach, A.S.; Benter, R.B.

    2011-01-01

    In spring 2006, we conducted a collaborative U.S.-Russia survey to estimate abundance of the Pacific walrus (Odobenus rosmarus divergens). The Bering Sea was partitioned into survey blocks, and a systematic random sample of transects within a subset of the blocks was surveyed with airborne thermal scanners using standard strip-transect methodology. Counts of walruses in photographed groups were used to model the relation between thermal signatures and the number of walruses in groups, which was used to estimate the number of walruses in groups that were detected by the scanner but not photographed. We also modeled the probability of thermally detecting various-sized walrus groups to estimate the number of walruses in groups undetected by the scanner. We used data from radio-tagged walruses to adjust on-ice estimates to account for walruses in the water during the survey. The estimated area of available habitat averaged 668,000 km2 and the area of surveyed blocks was 318,204 km2. The number of Pacific walruses within the surveyed area was estimated at 129,000 with 95% confidence limits of 55,000-507,000 individuals. Poor weather conditions precluded surveying in other areas; therefore, this value represents the number of Pacific walruses within about half of potential walrus habitat. ?? 2010 by the Society for Marine Mammalogy.

  8. Walrus distributional and foraging response to changing ice and benthic conditions in the Chukchi Sea

    USGS Publications Warehouse

    Jay, Chadwick V.; Grebmeier, Jacqueline M.; Fischbach, Anthony S.

    2012-01-01

    Arctic species such as the Pacific walrus (Odobenus rosmarus divergens) are facing a rapidly changing environment. Walruses are benthic foragers and may shift their spatial patterns of foraging in response to changes in prey distribution. We used data from satellite radio-tags attached to walruses in 2009-2010 to map walrus foraging locations with concurrent sampling of benthic infauna to examine relationships between distributions of dominant walrus prey and spatial patterns of walrus foraging. Walrus foraging was concentrated offshore in the NE Chukchi Sea, and coastal areas of northwestern Alaska when sea ice was sparse. Walrus foraging areas in August-September were coincident with the biomass of two dominant bivalve taxa (Tellinidae and Nuculidae) and sipunculid worms. Walrusforaging costs associated with increased travel time to higher biomass food patches from land may be significantly higher than the costs from sea ice haul-outs and result in reduced energy storesin walruses. Identifying what resources are selected by walruses and how those resources are distributed in space and time will improve our ability to forecast how walruses might respond to a changing climate.

  9. Indication of two Pacific walrus stocks from whole tooth elemental analysis

    USGS Publications Warehouse

    Jay, C.V.; Outridge, P.M.; Garlich-Miller, J. L.

    2008-01-01

    The Pacific walrus (Odobenus rosmarus divergens) is considered to be a single panmictic population for management purposes. However, studies on population structuring in this species are limited; in part, because portions of the population's range are often inaccessible. Therefore, alternative and complementary methods for investigating stock structure in the Pacific walrus are of particular interest. We used measures of elemental concentrations in whole tooth sections from ICP-MS in a discriminant analysis to investigate evidence of stock separation between walruses from two of three known breeding areas (S.E. Bering, St Lawrence, and Anadyr Gulf). Elemental compositions of teeth from female and male walruses from the S.E. Bering and St Lawrence breeding areas were significantly different, providing evidence of separate stocks. We also obtained insights into the potential relation of walruses from non-breeding areas to walruses from these breeding groups based on similarities in their dental elemental profiles. ?? 2008 Springer-Verlag.

  10. Results and evaluation of a survey to estimate Pacific walrus population size, 2006

    USGS Publications Warehouse

    Speckman, Suzann G.; Chernook, Vladimir I.; Burn, Douglas M.; Udevitz, Mark S.; Kochnev, Anatoly A.; Vasilev, Alexander; Jay, Chadwick V.; Lisovsky, Alexander; Fischbach, Anthony S.; Benter, R. Bradley

    2011-01-01

    In spring 2006, we conducted a collaborative U.S.-Russia survey to estimate abundance of the Pacific walrus (Odobenus rosmarus divergens). The Bering Sea was partitioned into survey blocks, and a systematic random sample of transects within a subset of the blocks was surveyed with airborne thermal scanners using standard strip-transect methodology. Counts of walruses in photographed groups were used to model the relation between thermal signatures and the number of walruses in groups, which was used to estimate the number of walruses in groups that were detected by the scanner but not photographed. We also modeled the probability of thermally detecting various-sized walrus groups to estimate the number of walruses in groups undetected by the scanner. We used data from radio-tagged walruses to adjust on-ice estimates to account for walruses in the water during the survey. The estimated area of available habitat averaged 668,000 km2 and the area of surveyed blocks was 318,204 km2. The number of Pacific walruses within the surveyed area was estimated at 129,000 with 95% confidence limits of 55,000 to 507,000 individuals. This value can be used by managers as a minimum estimate of the total population size.

  11. Genetic diversity of free-living Symbiodinium in the Caribbean: the importance of habitats and seasons

    NASA Astrophysics Data System (ADS)

    Granados-Cifuentes, Camila; Neigel, Joseph; Leberg, Paul; Rodriguez-Lanetty, Mauricio

    2015-09-01

    Although reef corals are dependent of the dinoflagellate Symbiodinium, the large majority of corals spawn gametes that do not contain their vital symbiont. This suggests the existence of a pool of Symbiodinium in the environment, of which surprisingly little is known. Reefs around Curaçao (Caribbean) were sampled for free-living Symbiodinium at three time periods (summer 2009, summer 2010, and winter 2010) to characterize different habitats (water column, coral rubble, sediment, the macroalgae Halimeda spp., Dictyota spp., and Lobophora variegata, and the seagrass Thalassia testudinum) that could serve as environmental sources of symbionts for corals. We detected the common clades of Symbiodinium that engage in symbiosis with Caribbean coral hosts A, B, and C using Symbiodinium-specific primers of the hypervariable region of the chloroplast 23S ribosomal DNA gene. We also discovered clade G and, for the first time in the Caribbean, the presence of free-living Symbiodinium clades F and H. Additionally, this study expands the habitat range of free-living Symbiodinium as environmental Symbiodinium was detected in T. testudinum seagrass beds. The patterns of association between free-living Symbiodinium types and habitats were shown to be complex. An interesting, strong association was seen between some clade A sequence types and sediment, suggesting that sediment could be a niche where clade A radiated from a free-living ancestor. Other interesting relationships were seen between sequence types of Symbiodinium clade C with Halimeda spp. and clades B and F with T. testudinium. These relationships highlight the importance of some macroalgae and seagrasses in hosting free-living Symbiodinium. Finally, studies spanning beyond a 1-yr cycle are needed to further expand on our results in order to better understand the variation of Symbiodinium in the environment through time. All together, results presented here showed that the great diversity of free-living Symbiodinium has

  12. Vocal learning in seals, sea lions, and walruses.

    PubMed

    Reichmuth, Colleen; Casey, Caroline

    2014-10-01

    The pinnipeds provide a variety of clues to those interested in the vocal learning capabilities of non-human animals. Observational and experimental studies of seals, sea lions, and walruses reveal elements of vocal development, contextual control, plasticity in expression and learning, and even imitation of complex sounds. Consideration of the factors that influence the expression of these capabilities informs understanding of the behavioral and structural mechanisms that support vocal learning in mammals and the evolutionary forces shaping these capabilities. PMID:25042930

  13. Summer diving behavior of male walruses in Bristol Bay, Alaska

    USGS Publications Warehouse

    Jay, C.V.; Farley, Sean D.; Garner, G.W.

    2001-01-01

    Pacific walruses (Odobenus rosmarus divergens) make trips from ice or land haul-out sites to forage for benthic prey. We describe dive and trip characteristics from time-depth-recorder data collected over a one-month period during summer from four male Pacific walruses in Bristol Bay, Alaska. Dives were classified into four types. Shallow (4 m), short (2.7 min), square-shaped dives accounted for 11% of trip time, and many were probably associated with traveling. Shallow (2 m) and very short (0.5 min) dives composed only 1% of trip time. Deep (41 m), long (7.2 min), square-shaped dives accounted for 46% of trip time and were undoubtedly associated with benthic foraging. V-shaped dives ranged widely in depth, were of moderate duration (4.7 min), and composed 3% of trip time. These dives may have been associated with navigation or exploration of the seafloor for potential prey habitat. Surface intervals between dives were similar among dive types, and generally lasted 1-2 min. Total foraging time was strongly correlated with trip duration and there was no apparent diel pattern of diving in any dive type among animals. We found no correlation between dive duration and postdive surface interval within dive types, suggesting that diving occurred within aerobic dive limits. Trip duration varied considerably within and among walruses (0.3-9.4 d), and there was evidence that some of the very short trips were unrelated to foraging. Overall, walruses were in the water for 76.6% of the time, of which 60.3% was spent diving.

  14. Photoadaptation of photosynthetic carbon uptake by solitary Radiolaria: comparisons with free-living phytoplankton

    NASA Astrophysics Data System (ADS)

    Rivkin, Richard B.; Lessard, Evelyn J.

    1986-08-01

    Carbon uptake, the activity of carboxylating enzymes, and chlorophyll a concentrations of symbiont-containing radiolarians and free-living phytoplankton were examined in the Sargasso Sea. Unlike free-living phytoplankton, Radiolaria collected from the surface waters and at the base of the euphotic zone had identical photosynthetic characteristics: the assimilation ratio, photosynthetic capacity, RuBPCase activity and saturation light intensity were independent of the depth within the euphotic zone from which Radiolaria were collected. The radiolarian's intracellular environment is enriched with N and P relative to the nutrient dilute water column. Since RuBPCase can comprise a significant proportion of the symbiont's cellular nitrogen, the constant and high RuBPCase activity and photosynthetic capacity may result from the symbiotic algae devoting a larger proportion of their cellular nitrogen quota carboxylating enzymes than free-living algae.

  15. A Common Scaling Rule for Abundance, Energetics, and Production of Parasitic and Free-Living Species

    PubMed Central

    Hechinger, Ryan F.; Lafferty, Kevin D.; Dobson, Andy P.; Brown, James H.; Kuris, Armand M.

    2011-01-01

    The metabolic theory of ecology uses the scaling of metabolism with body size and temperature to explain the causes and consequences of species abundance. However, the theory and its empirical tests have never simultaneously examined parasites alongside free-living species. This is unfortunate because parasites represent at least half of species diversity. We show that metabolic scaling theory could not account for the abundance of parasitic or free-living species in three estuarine food webs until accounting for trophic dynamics. Analyses then revealed that the abundance of all species uniformly scaled with body mass to the −¾ power. This result indicates “production equivalence,” where biomass production within trophic levels is invariant of body size across all species and functional groups: invertebrate or vertebrate, ectothermic or endothermic, and free-living or parasitic. PMID:21778398

  16. A common scaling rule for abundance, energetics, and production of parasitic and free-living species

    USGS Publications Warehouse

    Hechinger, Ryan F.; Lafferty, Kevin D.; Dobson, Andy P.; Brown, James H.; Kuris, Armand M.

    2011-01-01

    The metabolic theory of ecology uses the scaling of metabolism with body size and temperature to explain the causes and consequences of species abundance. However, the theory and its empirical tests have never simultaneously examined parasites alongside free-living species. This is unfortunate because parasites represent at least half of species diversity. We show that metabolic scaling theory could not account for the abundance of parasitic or free-living species in three estuarine food webs until accounting for trophic dynamics. Analyses then revealed that the abundance of all species uniformly scaled with body mass to the - 3/4 power. This result indicates "production equivalence," where biomass production within trophic levels is invariant of body size across all species and functional groups: invertebrate or vertebrate, ectothermic or endothermic, and free-living or parasitic.

  17. Functional ecology of free-living nitrogen fixation: A contemporary perspective

    USGS Publications Warehouse

    Reed, Sasha C.; Cleveland, Cory C.; Townsend, Alan R.

    2011-01-01

    Nitrogen (N) availability is thought to frequently limit terrestrial ecosystem processes, and explicit consideration of N biogeochemistry, including biological N2 fixation, is central to understanding ecosystem responses to environmental change. Yet, the importance of free-living N2 fixation—a process that occurs on a wide variety of substrates, is nearly ubiquitous in terrestrial ecosystems, and may often represent the dominant pathway for acquiring newly available N—is often underappreciated. Here, we draw from studies that investigate free-living N2 fixation from functional, physiological, genetic, and ecological perspectives. We show that recent research and analytical advances have generated a wealth of new information that provides novel insight into the ecology of N2 fixation as well as raises new questions and priorities for future work. These priorities include a need to better integrate free-living N2 fixation into conceptual and analytical evaluations of the N cycle's role in a variety of global change scenarios.

  18. Phenotypic and Genotypic Comparison of Symbiotic and Free-Living Cyanobacteria from a Single Field Site

    PubMed Central

    West, N. J.; Adams, D. G.

    1997-01-01

    PCR amplification techniques were used to compare cyanobacterial symbionts from a cyanobacterium-bryophyte symbiosis and free-living cyanobacteria from the same field site. Thirty-one symbiotic cyanobacteria were isolated from the hornwort Phaeoceros sp. at several closely spaced locations, and 40 free-living cyanobacteria were isolated from the immediate vicinity of the same plants. One of the symbiotic isolates was a species of Calothrix, a genus not previously known to form bryophyte symbioses, and the remainder were Nostoc spp. Of the free-living strains, two were Calothrix spp., three were Chlorogloeopsis spp. and the rest were Nostoc spp. All of the symbiotic and all but one of the free-living strains were able to reconstitute the symbiosis with axenic cultures of both Phaeoceros and the liverwort Blasia sp. Axenic cyanobacterial strains were compared by DNA amplification using PCR with either short arbitrary primers or primers specific for the regions flanking the 16S-23S rRNA internal transcribed spacer. With one exception, the two techniques produced complementary results and confirmed for the first time that a diversity of symbiotic cyanobacteria infect Phaeoceros in the field. Symbionts from adjacent colonies were different as often as they were the same, showing that the same thallus could be infected with many different cyanobacterial strains. Strains found to be identical by the techniques employed here were often found as symbionts in different thalli at the same locale but were never found free-living. Only one of the free-living strains, and none of the symbiotic strains, was found at more than one sample site, implying a highly localized distribution of strains. PMID:16535734

  19. Effects of Holothuroid Ichtyotoxic Saponins on the Gills of Free-Living Fishes and Symbiotic Pearlfishes.

    PubMed

    Eeckhaut, Igor; Caulier, Guillaume; Brasseur, Lola; Flammang, Patrick; Gerbaux, Pascal; Parmentier, Eric

    2015-06-01

    Several carapid fishes, known as pearlfishes, are endosymbiotic in holothuroids and asteroids. These echinoderms contain a strong concentration of saponins that are efficient membranolytic repellents to predators. We compared the effects of exposure to saponins from the sea cucumber body wall and from the Cuvierian tubules on the behavior and gill ultrastructure of pearlfishes and free-living fishes. Saponins were extracted from the body wall of two holothuroids, the Mediterranean Holothuria forskali and the tropical Bohadschia atra, and from the water surrounding the Cuvierian tubules of B. atra. Five species of carapids that live in symbiosis with holothuroids and seven species of free-living fishes were exposed to these extracts. The free-living fishes exhibited a stress response and died about 45 times faster than pearlfishes when exposed to the same quantity of saponins. Cuvierian tubules and saponins extracted from the body wall were lethal to the free-living fishes, whereas the carapids were much less sensitive. The carapids did not exhibit a stress response. The high toxicity shown by Cuvierian tubules was not explained by the nature of the saponins that were identified by mass spectrometry, but it is likely due to the higher concentration of saponins in the tubules. Histology and scanning and transmission electron microscopy of the gills of the free-living fishes and pearlfishes showed that saponins act at the level of the secondary lamellae where they induce the detachment of the epithelia, create edema at the level of the epithelia, and induce pores in the epithelial cells that lead to their destruction and the invasion of inner cells (pillar cells and red blood cells). This sequence of events happens 5 min after saponin exposure in free-living fishes and after 1 h in carapids. PMID:26124451

  20. Free-living marine nematodes from San Antonio Bay (Río Negro, Argentina).

    PubMed

    Villares, Gabriela; Lo Russo, Virginia; Pastor de Ward, Catalina; Milano, Viviana; Miyashiro, Lidia; Mazzanti, Renato

    2016-01-01

    The dataset of free-living marine nematodes of San Antonio Bay is based on sediment samples collected in February 2009 during doctoral theses funded by CONICET grants. A total of 36 samples has been taken at three locations in the San Antonio Bay, Santa Cruz Province, Argentina on the coastal littoral at three tidal levels. This presents a unique and important collection for benthic biodiversity assessment of Patagonian nematodes as this area remains one of the least known regions. In total 7,743 specimens of free-living marine nematodes belonging to two classes, eight orders, 37 families, 94 genera and 104 species were collected. PMID:27110176

  1. Free-living marine nematodes from San Antonio Bay (Río Negro, Argentina)

    PubMed Central

    Villares, Gabriela; Lo Russo, Virginia; Pastor de Ward, Catalina; Milano, Viviana; Miyashiro, Lidia; Mazzanti, Renato

    2016-01-01

    Abstract The dataset of free-living marine nematodes of San Antonio Bay is based on sediment samples collected in February 2009 during doctoral theses funded by CONICET grants. A total of 36 samples has been taken at three locations in the San Antonio Bay, Santa Cruz Province, Argentina on the coastal littoral at three tidal levels. This presents a unique and important collection for benthic biodiversity assessment of Patagonian nematodes as this area remains one of the least known regions. In total 7,743 specimens of free-living marine nematodes belonging to two classes, eight orders, 37 families, 94 genera and 104 species were collected. PMID:27110176

  2. Sub-Regional Sea Ice Preferences of Pacific Walrus in the Bering Sea Using SAR Data

    NASA Astrophysics Data System (ADS)

    Sacco, A.; Mahoney, A. R.; Eicken, H.; Johnson, M. A.; Ray, C.

    2014-12-01

    The Pacific walrus (O. r. divergens) uses winter sea ice in the Bering Sea for numerous parts of its natural history including courtship, foraging, and migration. Recent and predicted loss of sea ice has caused the Pacific walrus to be considered for an elevated status under the Endangered Species Act. Study of the ice conditions during this period is required to investigate changes in the Bering Sea ice pack and its effects on walrus sustainability. Using Radarsat-1 data and second-order texture statistics, a classification system was devised to separate sea ice into three distinguishable classes based on walrus needs of open water availability in the pack ice: discontinuous pack ice, continuous pack ice, and open water. Classifications are performed on sub-regional image areas to facilitate classification of heterogeneous seascapes which are thought to be distinguishable by walrus. Spatial, as well as temporal, changes in the seascape cover, based on the classification, are achieved. These results are then combined with ship-based observations of walrus to quantify walrus habitat preference. The three-class algorithm has a success rate of 94% for the discontinuous ice and continuous pack ice. Radarsat-1 images from 2004 - 2008 were analyzed for changes in seasonal and annual discontinuous ice extent. After classification, the spatial extent of discontinuous ice was found to vary throughout 2004 - 2008 in the Bering Sea shelf. Walrus are also shown to prefer discontinuous pack far from the southernmost ice edge. Maps of walrus habitat preference and persistent areas of sea ice seascapes are created and then can be used for the walrus' status consideration under the Endangered Species Act in addition to general species management issues.

  3. Investigational drug available directly from CDC for the treatment of infections with free-living amebae.

    PubMed

    2013-08-23

    Infections caused by free-living amebae (FLA) are severe and life-threatening. These infections include primary amebic meningoencephalitis (PAM) caused by Naegleria fowleri and granulomatous amebic encephalitis caused by Balamuthia mandrillaris and Acanthamoeba species. Although several drugs have in vitro activity against FLA, mortality from these infections remains>90% despite treatment with combinations of drugs. PMID:23965830

  4. Quantifying the effect of fire disturbance on free-living nitrogen fixation in tropical ecosystems

    NASA Astrophysics Data System (ADS)

    De Oliveira Bomfim, B.; Silva, L. C. R.; Marimon-Junior, B. H.; Marimon, B.; Horwath, W. R.; Neves, L.

    2015-12-01

    Tropical forests and savannas are among the most important biomes on Earth, supporting more than half of all plant and animal species on the planet. Despite growing interest in biogeochemical processes that affect tropical forest dynamics, many, including biological nitrogen fixation (BNF), are still poorly understood. Free-living N-fixers are thought to play a key role in tropical ecosystems, alleviating N and P limitation, supporting above and below ground biomass production, as well as carbon storage in plants and soil, but this influence has yet to be quantified. Of particular interest, the spatial distribution and identity of free-living BNF under disturbance regimes that commonly lead to the conversion of forests to savannas is currently unknown. To address this critical gap in knowledge, we measured free-living BNF quantifying rates of N fixation under contrasting fire regimes in the Amazon-Cerrado transition of central Brazil. Samples were collected in 4 ha of floodable forests affected by fire and 1 ha of unburned (seasonally flooded) forest located at the Araguaia State Park, Mato Grosso State, Brazil. Free-living N-fixation rates were measured by both 15N2 (98 atom% 15N) and acethylene reduction assay (ARA). Samples were incubated in the field and left in the dark at room temperature for 12 hours. In the next few weeks we will quantify N fixation rates that will be presented in the upcoming AGU meeting.

  5. Dietary Adherence Monitoring Tool for Free-living, Controlled Feeding Studies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Objective: To devise a dietary adherence monitoring tool for use in controlled human feeding trials involving free-living study participants. Methods: A scoring tool was devised to measure and track dietary adherence for an 8-wk randomized trial evaluating the effects of two different dietary patter...

  6. Use of cell cultures as an indicator of pathogenicity of free-living amoebae.

    PubMed Central

    Cursons, R T; Brown, T J

    1978-01-01

    Results comparing the time needed for the development of cytopathic effects in cell cultures with that needed to cause death in mice using inocula of Naegleria and Acanthamoeba are presented. The significance of the source and concentration of the inocula is demonstrated. The use of cell cultures as an indicator of the pathogenicity of free-living amoebae is discussed. Images PMID:342543

  7. Comparison of Yamax pedometer and GT3X accelerometer steps in a free-living sample

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our objective was to compare steps detected by the Yamax pedometer (PEDO) versus the GT3X accelerometer (ACCEL) in free-living adults. Daily PEDO and ACCEL steps were collected from a sample of 23 overweight and obese participants (18 females; mean +/- sd: age = 52.6 +/- 8.4 yr.; body mass index = 3...

  8. On the run: free-living mushroom corals avoiding interaction with sponges

    NASA Astrophysics Data System (ADS)

    Hoeksema, B. W.; de Voogd, N. J.

    2012-06-01

    Individuals of the free-living mushroom coral Heliofungia fralinae moved away when placed in contact with fragments of the toxic haplosclerid sponge Callyspongia (Euplacella) biru. This reaction was not evoked by three other sponge species. The experiment demonstrated that mobility of mushroom corals helps them to flee from organisms that secrete secondary metabolites in competition for space.

  9. TOXOPLASMA GONDII : UPTAKE AND SURVIVAL OF OOCYSTS IN FREE-LIVING AMOEBAE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Waterborne transmission of the oocyst stage of Toxoplasma gondii can cause outbreaks of clinical toxoplasmosis in humans and infection of marine mammals. In water-related environments and soil, free-living amoebae are considered potential carriers of various pathogens, but knowledge on interactions ...

  10. STUDY OF PATHOGENIC FREE-LIVING AMEBAS IN FRESH-WATER LAKES IN VIRGINIA

    EPA Science Inventory

    Pathogenic free-living amebas may produce fatal infection of the central nervous system known as Primary Amebic Meningoencephalitis (PAM). In Richmond, Virginia, 17 cases have occurred, more than in any other location in the world. The objectives were to examine freshwater lakes ...

  11. Sensitivity of free-living amoeba trophozoites and cysts to water disinfectants.

    PubMed

    Dupuy, Mathieu; Berne, Florence; Herbelin, Pascaline; Binet, Marie; Berthelot, Nelsie; Rodier, Marie-Hélène; Soreau, Sylvie; Héchard, Yann

    2014-03-01

    Free-living amoebae are naturally present in water. These protozoa could be pathogenic and could also shelter pathogenic bacteria. Thus, they are described as a potential hazard for health. Also, free-living amoebae have been described to be resistant to biocides, especially under their cyst resistant form. There are several studies on amoeba treatments but none of them compare sensitivity of trophozoites and cysts from different genus to various water disinfectants. In our study, we tested chlorine, monochloramine and chlorine dioxide on both cysts and trophozoites from three strains, belonging to the three main genera of free-living amoebae. The results show that, comparing cysts to trophozoites inactivation, only the Acanthamoeba cysts were highly more resistant to treatment than trophozoites. Comparison of the disinfectant efficiency led to conclude that chlorine dioxide was the most efficient treatment in our conditions and was particularly efficient against cysts. In conclusion, our results would help to adapt water treatments in order to target free-living amoebae in water networks. PMID:23932411

  12. Influence of Activity Monitor Location and Bout Duration on Free-Living Physical Activity

    ERIC Educational Resources Information Center

    Heil, Daniel P.; Bennett, Gary G.; Bond, Kathleen S.; Webster, Michael D.; Wolin, Kathleen Y.

    2009-01-01

    The purpose of this study was to evaluate the influence of the location (ankle, hip, wrist) where an activity monitor (AM) is worn and of the minimum bout duration (BD) on physical activity (PA) variables during free-living monitoring. Study 1 participants wore AMs at three locations for 1 day while wearing the Intelligent Device for Energy…

  13. Species distribution within the free-living marine nematode genus Dichromadora in the Weddell Sea and adjacent areas

    NASA Astrophysics Data System (ADS)

    Vermeeren, Hannelore; Vanreusel, Ann; Vanhove, Sandra

    2004-07-01

    Studies of Antarctic, free-living, marine nematodes are mostly restricted to genus level. In the current study, the genus Dichromadora (Kreis, H.A., 1929. Capita Zoologica 2(7), 1-98) is analysed to species level. Dichromadora is one of the genera that are frequently present along the continental margin of the eastern Weddell Sea. Samples were retrieved from the 1000-2000 m depth line in the eastern Weddell Sea (Halley Bay, Vestkapp and Kapp Norvegia), South Sandwich Trench and the Drake Passage. Eight species are distinguished within the genus Dichromadora of which seven are new to science. Out of these seven species, five are described taxonomically: Dichromadora weddellensis sp. n. , Dichromadora southernis sp. n. , Dichromadora polarsternis sp. n., Dichromadora parva sp. n., and Dichromadora polaris sp. n. The two other species ( D. spec A, D. spec B) receive, as to the scarcety of available specimens, no scientific name. The distribution of the Dichromadora species from Antarctica are discussed in the context of deep-sea (1000-2000 m) observations in Arctic, Atlantic, Pacific and Indian oceans.

  14. Focal palatine erosion in captive and free-living cheetahs (Acinonyx jubatus) and other felid species.

    PubMed

    Zordan, Martýn; Deem, Sharon L; Sanchez, Carlos R

    2012-01-01

    We examined 1,092 skulls of captive and free-living individuals, representing 33 felid species, to determine the prevalence of focal palatine erosion (FPE). FPE was detected in 3.2% of cats evaluated, including cheetah (Acinonyx jubatus) and 14 other felid species. The prevalence of FPE between cheetah (9.4%; n = 64) and non-cheetah species (2.8%; n = 1,028) (χ(2) test; P = 0.004) and between captive (5.7%; n = 246) and free-living (2.4%; n = 824) individuals (χ(2) test; P = 0.010) were significantly different, with prevalence between captive (19%; n = 21) and free-living (2.9%; n = 34) cheetahs approaching significance (Fisher's exact test; P = 0.064). FPE was diagnosed with equal prevalence in skulls from individuals in which the lower molars did not meet the palatine bone (60.6%) and individuals in which it did (39.4%; n = 33) (χ(2) test; P = 0.139). In cheetahs with FPE, one was a captive animal in Germany, one a free-living cheetah from Mali, one captive cheetah from Kenya, and three captive cheetahs of unknown origin. Additionally, we evaluated the medical records of 49 captive cheetahs in Namibia. Of these cheetahs, 48 (98.0%) had clinical signs consistent with FPE, although only 16 of these 48 (39.6%) had perforation of the palatine bone. Based on physical examinations, FPE was diagnosed in two caracals (Caracal caracal) and one fishing cat (Prionailurus viverrinus) from a North American Zoo. Results from this study confirm FPE in cheetahs outside of Namibia, in a minimum of 15 felid species, and a higher FPE prevalence in captive individuals than free-living ones. Clinical implications of these findings and recommendations for future studies are provided. PMID:21541986

  15. Pacific Walrus (Odobenus rosmarus divergens) Resource Selection in the Northern Bering Sea

    PubMed Central

    Jay, Chadwick V.; Grebmeier, Jacqueline M.; Fischbach, Anthony S.; McDonald, Trent L.; Cooper, Lee W.; Hornsby, Fawn

    2014-01-01

    The Pacific walrus is a large benthivore with an annual range extending across the continental shelves of the Bering and Chukchi Seas. We used a discrete choice model to estimate site selection by adult radio-tagged walruses relative to the availability of the caloric biomass of benthic infauna and sea ice concentration in a prominent walrus wintering area in the northern Bering Sea (St. Lawrence Island polynya) in 2006, 2008, and 2009. At least 60% of the total caloric biomass of dominant macroinfauna in the study area was composed of members of the bivalve families Nuculidae, Tellinidae, and Nuculanidae. Model estimates indicated walrus site selection was related most strongly to tellinid bivalve caloric biomass distribution and that walruses selected lower ice concentrations from the mostly high ice concentrations that were available to them (quartiles: 76%, 93%, and 99%). Areas with high average predicted walrus site selection generally coincided with areas of high organic carbon input identified in other studies. Projected decreases in sea ice in the St. Lawrence Island polynya and the potential for a concomitant decline of bivalves in the region could result in a northward shift in the wintering grounds of walruses in the northern Bering Sea. PMID:24717979

  16. Pacific walrus (Odobenus rosmarus divergens) resource selection in the Northern Bering Sea.

    PubMed

    Jay, Chadwick V; Grebmeier, Jacqueline M; Fischbach, Anthony S; McDonald, Trent L; Cooper, Lee W; Hornsby, Fawn

    2014-01-01

    The Pacific walrus is a large benthivore with an annual range extending across the continental shelves of the Bering and Chukchi Seas. We used a discrete choice model to estimate site selection by adult radio-tagged walruses relative to the availability of the caloric biomass of benthic infauna and sea ice concentration in a prominent walrus wintering area in the northern Bering Sea (St. Lawrence Island polynya) in 2006, 2008, and 2009. At least 60% of the total caloric biomass of dominant macroinfauna in the study area was composed of members of the bivalve families Nuculidae, Tellinidae, and Nuculanidae. Model estimates indicated walrus site selection was related most strongly to tellinid bivalve caloric biomass distribution and that walruses selected lower ice concentrations from the mostly high ice concentrations that were available to them (quartiles: 76%, 93%, and 99%). Areas with high average predicted walrus site selection generally coincided with areas of high organic carbon input identified in other studies. Projected decreases in sea ice in the St. Lawrence Island polynya and the potential for a concomitant decline of bivalves in the region could result in a northward shift in the wintering grounds of walruses in the northern Bering Sea. PMID:24717979

  17. Pacific walrus (Odobenus rosmarus divergens) resource selection in the northern Bering Sea

    USGS Publications Warehouse

    Jay, Chadwick V.; Grebmeier, Jacqueline M.; Fischbach, Anthony S.; McDonald, Trent L.; Cooper, Lee W.; Hornsby, Fawn

    2014-01-01

    The Pacific walrus is a large benthivore with an annual range extending across the continental shelves of the Bering and Chukchi Seas. We used a discrete choice model to estimate site selection by adult radio-tagged walruses relative to the availability of the caloric biomass of benthic infauna and sea ice concentration in a prominent walrus wintering area in the northern Bering Sea (St. Lawrence Island polynya) in 2006, 2008, and 2009. At least 60% of the total caloric biomass of dominant macroinfauna in the study area was composed of members of the bivalve families Nuculidae, Tellinidae, and Nuculanidae. Model estimates indicated walrus site selection was related most strongly to tellinid bivalve caloric biomass distribution and that walruses selected lower ice concentrations from the mostly high ice concentrations that were available to them (quartiles: 76%, 93%, and 99%). Areas with high average predicted walrus site selection generally coincided with areas of high organic carbon input identified in other studies. Projected decreases in sea ice in the St. Lawrence Island polynya and the potential for a concomitant decline of bivalves in the region could result in a northward shift in the wintering grounds of walruses in the northern Bering Sea.

  18. An improved procedure for detection and enumeration of walrus signatures in airborne thermal imagery

    USGS Publications Warehouse

    Burn, Douglas M.; Udevitz, Mark S.; Speckman, Suzann G.; Benter, R. Bradley

    2009-01-01

    In recent years, application of remote sensing to marine mammal surveys has been a promising area of investigation for wildlife managers and researchers. In April 2006, the United States and Russia conducted an aerial survey of Pacific walrus (Odobenus rosmarus divergens) using thermal infrared sensors to detect groups of animals resting on pack ice in the Bering Sea. The goal of this survey was to estimate the size of the Pacific walrus population. An initial analysis of the U.S. data using previously-established methods resulted in lower detectability of walrus groups in the imagery and higher variability in calibration models than was expected based on pilot studies. This paper describes an improved procedure for detection and enumeration of walrus groups in airborne thermal imagery. Thermal images were first subdivided into smaller 200 x 200 pixel "tiles." We calculated three statistics to represent characteristics of walrus signatures from the temperature histogram for each the. Tiles that exhibited one or more of these characteristics were examined further to determine if walrus signatures were present. We used cluster analysis on tiles that contained walrus signatures to determine which pixels belonged to each group. We then calculated a thermal index value for each walrus group in the imagery and used generalized linear models to estimate detection functions (the probability of a group having a positive index value) and calibration functions (the size of a group as a function of its index value) based on counts from matched digital aerial photographs. The new method described here improved our ability to detect walrus groups at both 2 m and 4 m spatial resolution. In addition, the resulting calibration models have lower variance than the original method. We anticipate that the use of this new procedure will greatly improve the quality of the population estimate derived from these data. This procedure may also have broader applicability to thermal infrared

  19. Walrus areas of use in the Chukchi Sea during sparse sea ice cover

    USGS Publications Warehouse

    Jay, Chadwick V.; Fischbach, Anthony S.; Kochnev, Anatoly A.

    2012-01-01

    The Pacific walrus Odobenus rosmarus divergens feeds on benthic invertebrates on the continental shelf of the Chukchi and Bering Seas and rests on sea ice between foraging trips. With climate warming, ice-free periods in the Chukchi Sea have increased and are projected to increase further in frequency and duration. We radio-tracked walruses to estimate areas of walrus foraging and occupancy in the Chukchi Sea from June to November of 2008 to 2011, years when sea ice was sparse over the continental shelf in comparison to historical records. The earlier and more extensive sea ice retreat in June to September, and delayed freeze-up of sea ice in October to November, created conditions for walruses to arrive earlier and stay later in the Chukchi Sea than in the past. The lack of sea ice over the continental shelf from September to October caused walruses to forage in nearshore areas instead of offshore areas as in the past. Walruses did not frequent the deep waters of the Arctic Basin when sea ice retreated off the shelf. Walruses foraged in most areas they occupied, and areas of concentrated foraging generally corresponded to regions of high benthic biomass, such as in the northeastern (Hanna Shoal) and southwestern Chukchi Sea. A notable exception was the occurrence of concentrated foraging in a nearshore area of northwestern Alaska that is apparently depauperate in walrus prey. With increasing sea ice loss, it is likely that walruses will increase their use of coastal haul-outs and nearshore foraging areas, with consequences to the population that are yet to be understood.

  20. An improved procedure for detection and enumeration of walrus signatures in airborne thermal imagery

    NASA Astrophysics Data System (ADS)

    Burn, Douglas M.; Udevitz, Mark S.; Speckman, Suzann G.; Benter, R. Bradley

    2009-10-01

    In recent years, application of remote sensing to marine mammal surveys has been a promising area of investigation for wildlife managers and researchers. In April 2006, the United States and Russia conducted an aerial survey of Pacific walrus ( Odobenus rosmarus divergens) using thermal infrared sensors to detect groups of animals resting on pack ice in the Bering Sea. The goal of this survey was to estimate the size of the Pacific walrus population. An initial analysis of the U.S. data using previously-established methods resulted in lower detectability of walrus groups in the imagery and higher variability in calibration models than was expected based on pilot studies. This paper describes an improved procedure for detection and enumeration of walrus groups in airborne thermal imagery. Thermal images were first subdivided into smaller 200 × 200 pixel "tiles." We calculated three statistics to represent characteristics of walrus signatures from the temperature histogram for each tile. Tiles that exhibited one or more of these characteristics were examined further to determine if walrus signatures were present. We used cluster analysis on tiles that contained walrus signatures to determine which pixels belonged to each group. We then calculated a thermal index value for each walrus group in the imagery and used generalized linear models to estimate detection functions (the probability of a group having a positive index value) and calibration functions (the size of a group as a function of its index value) based on counts from matched digital aerial photographs. The new method described here improved our ability to detect walrus groups at both 2 m and 4 m spatial resolution. In addition, the resulting calibration models have lower variance than the original method. We anticipate that the use of this new procedure will greatly improve the quality of the population estimate derived from these data. This procedure may also have broader applicability to thermal

  1. Detection and identification of free-living amoeba from aquatic environment in different seasons in Taiwan

    NASA Astrophysics Data System (ADS)

    Tzeng, K.; Hsu, B.; Tsai, H.; Huang, P.; Tsai, J.; Kao, P.; Huang, K.; Chen, J.

    2013-12-01

    Free-living amoeba includes Acanthamoeba and Naegleria, which are widely distributed in water and soil. Human infection with free-living amoeba leads to serious illness, even lethal. For example, central nervous system infection will cause amoebic meningoencephalitis, and infections will cause amoebic keratitis. The presence of free-living amoeba in environment water can be used as a water quality indicator in ecosystem assessment. In Taiwan, reservoirs are indispensable because of the water source are limited by the steep terrain and the short river flow. Therefore, we need to pay more attention in the quality control of reservoirs water. The aims of this study are to investigate the presence of free-living amoeba in Taiwan reservoirs, and to compare the differences among seasons. At last, the identification and genotyping of Acanthamoeba and Naegleria are investigated. In this study, we use polymerase chain reaction with specific primers to analyze the presence of free-living amoeba in aquatic environment. We collected total 60 samples from reservoirs in Taiwan. The water samples are divided into two parts for both direct concentration method and culture method. The results show the different detection rates among seasons. For Acanthamoeba, the detection rates were 28.3% (17 of 60 water samples), 21.7% (13 of 60 water samples) and 8.3% (5 of 60 water samples) in autumn, winter and spring, respectively. For Naegleria, the detection rates were 6.7% (4 of 60 water samples), 0% (0 of 60 water samples) and 0% (0 of 60 water samples) were detected positive in autumn, winter and spring, respectively. Sequence analysis showed that the major genotypes in Acanthamoeba were T3, T4, T10 and T11 in autumn, T2, T4 and T10 in winter, T4 in spring. Due to the presences of Acanthamoeba and Naegleria in reservoirs, we should pay more attention in water quality monitoring to prevent the potential risks of diseases. Keywords: free-living amoeba, Acanthamoeba, Naegleria, polymerase

  2. Coccidioidomycosis in a Pacific walrus (Odobenus rosmarus divergens).

    PubMed

    Schmitt, Todd L; Procter, Diana G

    2014-03-01

    An 11 yr-old female Pacific walrus (Odobenus rosmarus divergens) demonstrated decreased appetite and weight loss approximately 4 wk after truck transport from a northern California facility to a southern California facility. An initial blood analysis revealed a leukocytosis of 22,800 white blood cells (WBC)/microl, with a left shift, low iron (58 microg/dl), and mild hyperglobulinemia (4.3 g/dl). Empiric antibiotic therapy was started with amoxicillin and clavulanic acid (14 mg/kg p.o. b.i.d.). Clinical improvement was observed initially; however, follow-up blood analysis demonstrated a persistent leukocytosis (24,000 WBC/microl), with left shift and progressive hyperglobulinemia (6.7 mg/dl). As a result of the relapse of clinical signs on antibiotic therapy, aggressive antifungal therapy was initiated with voriconazole (1.8 mg/kg p.o. s.i.d.). Concurrent fungal immunodiffusion antibody assays and complement fixation were repetitively positive for coccidioidomycosis. The walrus improved clinically over the next 3 mo and is currently stable on antifungal therapy at its originating facility in northern California. PMID:24712180

  3. Toxoplasmosis in captive dolphins (Tursiops truncatus) and walrus (Odobenus rosmarus).

    PubMed

    Dubey, J P; Mergl, J; Gehring, E; Sundar, N; Velmurugan, G V; Kwok, O C H; Grigg, M E; Su, C; Martineau, D

    2009-02-01

    Toxoplasma gondii infection in marine mammals is intriguing and indicative of contamination of the ocean environment and coastal waters with oocysts. Toxoplasma gondii infection was detected in captive marine mammals at a sea aquarium in Canada. Antibodies to T. gondii were found in all 7 bottlenose dolphins (Tursiops truncatus) tested. Two of these dolphins, as well as a walrus (Odobenus rosmarus) at the facility, died. Encephalitis and T. gondii tissue cysts were identified in histological sections of the brain of 1 dolphin (dolphin no. 1). Another dolphin (dolphin no. 2) had mild focal encephalitis without visible organisms, but viable T. gondii was isolated by bioassay in mice and cats from its brain and skeletal muscle; this strain was designated TgDoCA1. The PCR-RFLP typing using 11 markers (B1, SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico) identified a Type II strain. The DNA sequencing of B1 and SAG1 alleles amplified from TgDoCA1 and directly from the brains of dolphin no. 1 and the walrus showed archetypal alleles consistent with infection by a Type II strain. No unique polymorphisms were detected. This is apparently the first report of isolation of T. gondii from a marine mammal in Canada. PMID:19245284

  4. Free-living marine nematodes from San Julián Bay (Santa Cruz, Argentina).

    PubMed

    Pastor de Ward, Catalina; Lo Russo, Virginia; Villares, Gabriela; Milano, Viviana; Miyashiro, Lidia; Mazzanti, Renato

    2015-01-01

    The free-living marine nematodes of San Julián Bay dataset is based on sediment samples collected in January 2009 during the project PICT AGENCIA-FONCYT 2/33345-2005. A total of 36 samples have been taken at three locations in the San Julián Bay, Santa Cruz Province, Argentina on the coastal littoral at three tidal levels. This presents a unique and important collection for the nematode benthic biodiversity assessment as this area remains one of the least known regions in Patagonia. In total 10,030 specimens of free-living marine nematodes belonging to 2 classes, 9 orders, 35 families, 78 genera and 125 species were collected. The San Julián city site presented a very high species richness. PMID:25878534

  5. Streptococcus pyogenes Infection in a Free-Living European Hedgehog (Erinaceus europaeus).

    PubMed

    Franklinos, Lydia H V; Efstratiou, Androulla; Macgregor, Shaheed K; John, Shinto K; Hopkins, Timothy; Cunningham, Andrew A; Lawson, Becki

    2015-12-01

    Streptococcus pyogenes, a common pathogen of humans, was isolated from the carcass of a free-living European hedgehog (Erinaceus europaeus) found in northern England in June 2014. The animal had abscessation of the deep right cervical lymph node, mesenteric lymph nodes and liver. The S. pyogenes strain isolated from the lesions, peritoneal and pleural cavities was characterised as emm 28, which can be associated with invasive disease in humans. This is the first known report of S. pyogenes in a hedgehog and in any free-living wild animal that has been confirmed by gene sequencing. As close associations between wild hedgehogs and people in England are common, we hypothesise that this case might have resulted from anthroponotic infection. PMID:26242215

  6. Free-living marine nematodes from San Julián Bay (Santa Cruz, Argentina)

    PubMed Central

    Pastor de Ward, Catalina; Lo Russo, Virginia; Villares, Gabriela; Milano, Viviana; Miyashiro, Lidia; Mazzanti, Renato

    2015-01-01

    Abstract The free-living marine nematodes of San Julián Bay dataset is based on sediment samples collected in January 2009 during the project PICT AGENCIA-FONCYT 2/33345-2005. A total of 36 samples have been taken at three locations in the San Julián Bay, Santa Cruz Province, Argentina on the coastal littoral at three tidal levels. This presents a unique and important collection for the nematode benthic biodiversity assessment as this area remains one of the least known regions in Patagonia. In total 10,030 specimens of free-living marine nematodes belonging to 2 classes, 9 orders, 35 families, 78 genera and 125 species were collected. The San Julián city site presented a very high species richness. PMID:25878534

  7. The effect of triflumuron (SIR8514) on the free-living stages of sheep nematodes.

    PubMed

    Waller, P J; Lacey, E

    1986-06-01

    Studies both in vitro and in vivo showed that the insect growth regulator, triflumuron, exhibited potent larvacidal effects against the free-living stages of Trichostrongylus colubriformis. Effects were not as marked on the closely related nematodes, Haemonchus contortus and Ostertagia circumcincta. Nevertheless, these findings suggest that growth regulators may be used to develop novel methods of nematode control, and thus offer alternatives or adjuncts to conventional anthelmintic therapy and at the same time reduce the selection for anthelmintic resistance. PMID:3739204

  8. Cadmium, lead, and mercury exposure assessment among croatian consumers of free-living game.

    PubMed

    Lazarus, Maja; Prevendar Crnić, Andreja; Bilandžić, Nina; Kusak, Josip; Reljić, Slaven

    2014-09-01

    Free-living game can be an important source of dietary cadmium and lead; the question is whether exposure to these two elements is such that it might cause adverse health effects in the consumers. The aim of this study was to estimate dietary exposure to cadmium, lead, and mercury from free-living big game (fallow deer, roe deer, red deer, wild boar, and brown bear), and to mercury from small game (pheasant and hare), hunted in Croatia from 1990 to 2012. The exposure assessment was based on available literature data and our own measurements of metal levels in the tissues of the game, by taking into account different consumption frequencies (four times a year, once a month and once a week). Exposure was expressed as percentage of (provisional) tolerable weekly intake [(P)TWI] values set by the European Food Safety Authority (EFSA). Consumption of game meat (0.002-0.5 % PTWI) and liver (0.005-6 % PTWI) assumed for the general population (four times a year) does not pose a health risk to consumers from the general population, nor does monthly (0.02-6 % PTWI) and weekly (0.1-24 % PTWI) consumption of game meat. However, because of the high percentage of free-living game liver and kidney samples exceeding the legislative limits for cadmium (2-99 %) and lead (1-82 %), people should keep the consumption of certain game species' offal as low as possible. Children and pregnant and lactating women should avoid eating game offal altogether. Free-living game liver could be an important source of cadmium if consumed on a monthly basis (3-74 % TWI), and if consumed weekly (11-297 % TWI), it could even give rise to toxicological concern. PMID:25205692

  9. Distribution of free-living amoebae in a treatment system of textile industrial wastewater.

    PubMed

    Ramirez, Elizabeth; Robles, Esperanza; Martinez, Blanca; Ayala, Reynaldo; Sainz, Guadalupe; Martinez, Maria Elena; Gonzalez, Maria Elena

    2014-11-01

    Free-living amoebae have been found in soil, air and a variety of aquatic environments, but few studies have been conducted on industrial wastewater and none on wastewater from the textile industry. The aim of this study was to determine the presence and distribution of free-living amoebae in a biological treatment system that treats textile industrial wastewater. Samples were taken from input, aeration tank, sedimentation tank and output. Samples were centrifuged at 1200g for 15min, the sediment was seeded on non-nutritive agar with Enterobacter aerogenes (NNE) and the plates were incubated at 30 and 37°C. Free-living amoebae were present in all stages of the treatment system. The highest number of amoebic isolates was found in the aeration tank and no seasonal distribution was observed during the year. A total of 14 amoeba genera were isolated: Acanthamoeba, Echinamoeba, Korotnevella, Mayorella, Naegleria, Platyamoeba, Saccamoeba, Stachyamoeba, Thecamoeba, Vahlkampfia, Vannella, Vermamoeba, Vexillifera and Willaertia. The most frequently found amoebae were Acanthamoeba and Vermamoeba which were found in all treatment system stages. The constant presence and diversity of free-living amoebae in the treatment system were important findings due to the characteristics of the wastewater from the textile plant in terms of the residue content from colorants, fixers, carriers, surfactants, etc., used in fabric dyeing and finishing processes. The factors that determined the presence and distribution of amoebae in the activated sludge system were their capacity to form cysts, which allowed them to resist adverse conditions; food availability; an average temperature of 27-33°C; dissolved oxygen in average concentrations above 2mg/L, and pH in a range of 5.9-7.1. PMID:25072828

  10. Reliability of Pedometer-Determined Free-Living Physical Activity Data in College Women

    ERIC Educational Resources Information Center

    Felton, Gwen M.; Tudor-Locke, Catrine; Burkett, Lee

    2006-01-01

    This study examined stability and reliability of free-living physical activity assessed by pedometer in 69 young female college students (M age = 18.7 years, SD = 1.2, range: 18-25 years; body mass index = 23.2 kg/m[superscript 2], SD = 0.6) for two complete weeks (Week 1 and Week 2) separated by 12 weeks. During Week 1, participants took an…

  11. Noninvasive Tuberculosis Screening in Free-Living Primate Populations in Gombe National Park, Tanzania.

    PubMed

    Wolf, Tiffany M; Sreevatsan, Srinand; Singer, Randall S; Lipende, Iddi; Collins, Anthony; Gillespie, Thomas R; Lonsdorf, Elizabeth V; Travis, Dominic A

    2016-03-01

    Recent advances in noninvasive detection methods for mycobacterial infection in primates create new opportunities for exploring the epidemiology of tuberculosis in free-living species. Chimpanzees (Pan troglodytes schweinfurthii) and baboons (Papio anubis) in Gombe National Park, Tanzania, were screened for infection with pathogens of the Mycobacterium tuberculosis Complex using Fecal IS6110 PCR; none was positive. This study demonstrates the feasibility of large-scale mycobacterial screening in wild primates. PMID:26419483

  12. Free-living monitoring of Parkinson's disease: Lessons from the field.

    PubMed

    Del Din, Silvia; Godfrey, Alan; Mazzà, Claudia; Lord, Sue; Rochester, Lynn

    2016-09-01

    Wearable technology comprises miniaturized sensors (eg, accelerometers) worn on the body and/or paired with mobile devices (eg, smart phones) allowing continuous patient monitoring in unsupervised, habitual environments (termed free-living). Wearable technologies are revolutionizing approaches to health care as a result of their utility, accessibility, and affordability. They are positioned to transform Parkinson's disease (PD) management through the provision of individualized, comprehensive, and representative data. This is particularly relevant in PD where symptoms are often triggered by task and free-living environmental challenges that cannot be replicated with sufficient veracity elsewhere. This review concerns use of wearable technology in free-living environments for people with PD. It outlines the potential advantages of wearable technologies and evidence for these to accurately detect and measure clinically relevant features including motor symptoms, falls risk, freezing of gait, gait, functional mobility, and physical activity. Technological limitations and challenges are highlighted, and advances concerning broader aspects are discussed. Recommendations to overcome key challenges are made. To date there is no fully validated system to monitor clinical features or activities in free-living environments. Robust accuracy and validity metrics for some features have been reported, and wearable technology may be used in these cases with a degree of confidence. Utility and acceptability appears reasonable, although testing has largely been informal. Key recommendations include adopting a multidisciplinary approach for standardizing definitions, protocols, and outcomes. Robust validation of developed algorithms and sensor-based metrics is required along with testing of utility. These advances are required before widespread clinical adoption of wearable technology can be realized. © 2016 International Parkinson and Movement Disorder Society. PMID:27452964

  13. Diverse modes of reproduction in the marine free-living ciliate Glauconema trihymene

    PubMed Central

    2010-01-01

    Background Most free-living ciliates reproduce by equal fission or budding during vegetative growth. In certain ciliates, reproduction occurs inside the cyst wall, viz. reproductive cysts, but more complex reproductive strategies have generally been thought to be confined to parasitic or symbiotic species, e.g. Radiophrya spp. Results In addition to equal fission, asymmetric binary division and reproductive cysts were discovered in the free-living bacterivorous scuticociliate Glauconema trihymene Thompson, 1966. Asymmetric division is an innate physiological state that can be induced by sufficient food, and the higher the food concentration, the longer the asymmetric division persists. During asymmetric division, nuclear and somatic structures divide with transiently arrested cytokinesis and variable positioning of macronuclei. Phylogenetic analysis, based on the small subunit of ribosomal DNA (SSU rDNA) sequences, showed that the G. trihymene isolate studied here nests with typical scuticociliates and is paraphyletic to both the symbiotic apostome and astome ciliates, some of which also produce progeny by asymmetric division. Conclusions The asymmetric division in G. trihymene has no precedent among undisturbed free-living ciliates. The coexistence of multiple modes of reproduction may represent a previously undescribed reproductive strategy for ciliates living on food patches in coastal waters. This may also be indicative of similar reproductive strategies among other polyphenic ciliates, which have not been intensively studied. Asymmetric division provides a special opportunity for studying ciliates' phenotypic plasticity and may also illuminate the origins of multicellularity. PMID:20388205

  14. Free-Living Physical Activity in COPD: Assessment with Accelerometer and Activity Checklist

    PubMed Central

    MATTHESS, KIRBY; STOLZMANN, KELLY; REILLY, JOHN; GARSHICK, ERIC

    2009-01-01

    Rationale In order to assess participation in physical activities (PA) and disability in chronic obstructive pulmonary disease (COPD), we evaluated the use of an accelerometer and checklist to measure free-living PA. Methods 17 males with stable COPD completed a daily activity checklist for 14 days. 10 subjects concurrently wore an accelerometer (FitSense, Southborough, MA) that records steps per day. Regression models assessed relationships between steps per day, number of daily checklist activities performed, and clinical measures of COPD status. Results The average steps per day ranged from 406 to 4,856. The median intra-subject coefficient of variation for steps per day was 0.52 (interquartile range [IQR] 0.41-0.58) and for number of daily checklist activities performed was 0.28 (IQR 0.22-0.32). A higher number of steps per day were associated with a greater distance walked on the 6-minute walk test and better health-related quality of life. A higher number of daily checklist activities performed was associated with a higher FEV1 % predicted and lower BODE index. Conclusions It is feasible to prospectively measure free-living PA in COPD using an unobtrusive accelerometer and simple activity checklist. There is low intra-subject variation in free-living PA, which is significantly associated with clinical measures of COPD status. PMID:19533541

  15. Validation of a portable EMG device to assess muscle activity during free-living situations.

    PubMed

    Walters, T J; Kaschinske, K A; Strath, S J; Swartz, A M; Keenan, K G

    2013-10-01

    Portable amplifiers that record electromyograms (EMGs) for longer than four hours are commonly priced over $20,000 USD. This cost, and the technical challenges associated with recording EMGs during free-living situations, typically restrict EMG use to laboratory settings. A low-cost system (μEMG; OT Bioelecttronica, 100€), using specialized concentric bipolar electrodes, has been developed specifically for free-living situations. The purpose of this study was to validate the μEMG system by comparing EMGs from μEMG with a laboratory-based alternative (Telemyo 900; Noraxon USA, Inc.). Surface EMGs from biceps brachii (BB) and tibialis anterior (TA) of ten subjects were recorded simultaneously with both systems as subjects performed maximal voluntary contractions (MVCs), submaximal contractions at 25%, 50%, and 75% MVC, seven simulated activities of daily living (ADLs), and >60min of simulated free-living inside the laboratory. In general, EMG parameters (e.g., average full-wave rectified EMG amplitude) derived from both systems were not significantly different for all outcome variables, except there were small differences across systems in baseline noise and absolute EMG amplitudes during MVCs. These results suggest that μEMG is a valid approach to the long-term recording of EMG. PMID:23830889

  16. GASTROINTESTINAL PARASITES OF CAPTIVE AND FREE-LIVING LEMURS AND DOMESTIC CARNIVORES IN EASTERN MADAGASCAR.

    PubMed

    Alexander, Amy B; Poirotte, Clémence; Porton, Ingrid J; Freeman, Karen L M; Rasambainarivo, Fidisoa; Olson, Kimberly G; Iambana, Bernard; Deem, Sharon L

    2016-03-01

    Fecal samples from captive and free-living lemurs at Ivoloina Zoological Park (IZP) and domestic carnivores from six villages surrounding IZP were evaluated between July and August 2012. Free-living lemurs from Betampona Natural Reserve (BNR), a relatively pristine rainforest fragment 40 km away, were also evaluated in November 2013. All 33 dogs sampled (100%) and 16 of 22 cats sampled (72.7%) were parasitized, predominantly with nematodes (strongyles, ascarids, and spirurids) as well as cestodes and protozoans. Similar types of parasites were identified in the lemur populations. Identification of spirurid nematodes and protozoans in the lemur fecal samples were of concern due to previously documented morbidity and mortality in lemurs from these parasitic agents. Twelve of 13 free-living (93%) and 31 of 49 captive (63%) lemurs sampled at IZP had a higher parasite prevalence than lemurs at BNR, with 13 of 24 (54%) being parasitized. The lemurs in BNR are likely at risk of increased exposure to these parasites and, therefore, increased morbidity and mortality, as humans and their domestic animals are encroaching on this natural area. PMID:27010275

  17. Cooling and freezing of sperm from captive, free-living and endangered squirrel monkey species.

    PubMed

    Oliveira, Karol G; Santos, Regiane R; Leão, Danuza L; Brito, Adriel B; Lima, Julianne S; Sampaio, Wlaísa V; Domingues, Sheyla F S

    2016-06-01

    Germoplasm banking is an important tool for the preservation of genetic material from Neotropical primates in captivity, and from free living species, especially the endangered ones like Saimiri vanzolinii (Black-headed squirrel monkey), a primate with a low incidence area (870 km(2) of floodplains) in the southern part of the Mamirauá Sustainable Development Reserve, Brazil. Therefore, in the present study we aimed to develop a sperm cryopreservation protocol comparing sperm cooling in presence (T1) and absence (T2) of egg yolk, and to test freezing protocols to preserve semen from captive (Saimiri collinsi), and free-living (Saimiri vanzolinii, Saimiri cassiquiarensis and Saimiri macrodon) New World primates. Cooling preserved sperm of S. collinsi in all evaluated microscopic parameters, except for sperm motility. No differences were observed among the treatments, indicating that semen of this species can be cooled without egg yolk. Freezing did not affect sperm quality of S. collinsi, except plasma membrane integrity that was negatively affected. Generally, a good maintenance rate was observed between cooling and thawing of semen for the four species, showing the positive translational application of protocols from S. collinsi to the free-living species. Developed freezing protocol proved to be useful for sperm cryopreservation of S. collinsi and in field conditions. PMID:26994833

  18. Toward Objective Monitoring of Ingestive Behavior in Free-living Population

    PubMed Central

    Sazonov, Edward S.; Schuckers, Stephanie A.C.; Lopez-Meyer, Paulo; Makeyev, Oleksandr; Melanson, Edward L.; Neuman, Michael R.; Hill, James O.

    2010-01-01

    Understanding of eating behaviors associated with obesity requires objective and accurate monitoring of food intake patterns. Accurate methods are available for measuring total energy expenditure and its components in free-living populations, but methods for measuring food intake in free-living people are far less accurate and involve self-reporting or subjective monitoring. We suggest that chews and swallows can be used for objective monitoring of ingestive behavior. This hypothesis was verified in a human study involving 20 subjects. Chews and swallows were captured during periods of quiet resting, talking, and meals of varying size. The counts of chews and swallows along with other derived metrics were used to build prediction models for detection of food intake, differentiation between liquids and solids, and for estimation of the mass of ingested food. The proposed prediction models were able to detect periods of food intake with >95% accuracy and a fine time resolution of 30 s, differentiate solid foods from liquids with >91% accuracy, and predict mass of ingested food with >91% accuracy for solids and >83% accuracy for liquids. In earlier publications, we have shown that chews and swallows can be captured by noninvasive sensors that could be developed into a wearable device. Thus, the proposed methodology could lead to the development of an innovative new way of assessing human eating behavior in free-living conditions. PMID:19444225

  19. Optimizing culture conditions for free-living stages of the nematode parasite Strongyloides ratti.

    PubMed

    Dulovic, Alex; Puller, Vadim; Streit, Adrian

    2016-09-01

    The rat parasitic nematode Strongyloides ratti (S. ratti) has recently emerged as a model system for various aspects of parasite biology and evolution. In addition to parasitic parthenogenetic females, this species can also form facultative free-living generations of sexually reproducing adults. These free-living worms are bacteriovorous and grow very well when cultured in the feces of their host. However, in fecal cultures the worms are rather difficult to find for observation and experimental manipulation. Therefore, it has also been attempted to raise S. ratti on Nematode Growth Media (NGM) plates with Escherichia coli OP50 as food, exactly as described for the model nematode Caenorhabditis elegans. Whilst worms did grow on these plates, their longevity and reproductive output compared to fecal cultures were dramatically reduced. In order to improve the culture success we tested other plates occasionally used for C. elegans and, starting from the best performing one, systematically varied the plate composition, the temperature and the food in order to further optimize the conditions. Here we present a plate culturing protocol for free-living stages of S. ratti with strongly improved reproductive success and longevity. PMID:27334397

  20. Bovine virus diarrhea virus in free-living deer from Denmark.

    PubMed

    Nielsen, S S; Roensholt, L; Bitsch, V

    2000-07-01

    Free-living deer are suggested as a possible source of infection of cattle with bovine virus diarrhea (BVD) virus. To examine this hypothesis blood samples from 476 free-living deer were collected during two different periods and tested for BVD virus and antibody in Denmark. In 1995-96, 207 animals were tested. These included 149 roe deer (Capreolus capreolus), 29 fallow deer (Dama dama), 20 red deer (Cervus elaphus) and one sika deer (Cervus sika). For the remaining eight animals no species information was available. In 1998-99, 269 animals were tested including 212 roe deer and 57 red deer. The animals were selected from areas with a relatively high prevalence of cattle herds with a BVD persistent infection status in 1997 and 1998. All 207 samples from 1995-96 were found antibody-negative except two samples from red deer. Only 158 of the 207 samples were tested for virus and were all found negative. Of the 269 samples from 1998-99 all but one were antibody negative. The positive sample was from a red deer. All samples were virus-negative. It appears that BVD infection does not occur in roe deer in Denmark. The presence of antibody in a few red deer from various districts in Jutland probably results from cattle to deer transmission, rather than spread among deer. Hence, the possibility of free-living deer as a source of infection for cattle in Denmark seems to be remote. PMID:10941751

  1. Evolutionary Analysis of Mitogenomes from Parasitic and Free-Living Flatworms

    PubMed Central

    Frías-López, Cristina; Littlewood, D. Timothy J.; Rozas, Julio; Riutort, Marta

    2015-01-01

    Mitochondrial genomes (mitogenomes) are useful and relatively accessible sources of molecular data to explore and understand the evolutionary history and relationships of eukaryotic organisms across diverse taxonomic levels. The availability of complete mitogenomes from Platyhelminthes is limited; of the 40 or so published most are from parasitic flatworms (Neodermata). Here, we present the mitogenomes of two free-living flatworms (Tricladida): the complete genome of the freshwater species Crenobia alpina (Planariidae) and a nearly complete genome of the land planarian Obama sp. (Geoplanidae). Moreover, we have reanotated the published mitogenome of the species Dugesia japonica (Dugesiidae). This contribution almost doubles the total number of mtDNAs published for Tricladida, a species-rich group including model organisms and economically important invasive species. We took the opportunity to conduct comparative mitogenomic analyses between available free-living and selected parasitic flatworms in order to gain insights into the putative effect of life cycle on nucleotide composition through mutation and natural selection. Unexpectedly, we did not find any molecular hallmark of a selective relaxation in mitogenomes of parasitic flatworms; on the contrary, three out of the four studied free-living triclad mitogenomes exhibit higher A+T content and selective relaxation levels. Additionally, we provide new and valuable molecular data to develop markers for future phylogenetic studies on planariids and geoplanids. PMID:25793530

  2. The effect of elevated temperature and substrate on free-living Symbiodinium cultures

    NASA Astrophysics Data System (ADS)

    Nitschke, M. R.; Davy, S. K.; Cribb, T. H.; Ward, S.

    2015-03-01

    Elevated temperatures can produce a range of serious, deleterious effects on marine invertebrate— Symbiodinium symbioses. The responses of free-living Symbiodinium to elevated temperature, however, have been little studied, especially in the context of their natural habitat. In this study, we investigated physiological responses of two Symbiodinium cultures to elevated temperature, an exclusively free-living ITS2 clade A (strain HI-0509) and the symbiosis-forming ITS2 type A1 (strain CCMP2467). Free-living Symbiodinium strains have recently been isolated from benthic sediments, and both cultures were therefore grown with or without a microhabitat of carbonate sediment at 25, 28 or 31 °C. Maximum quantum yield of photosystem II ( F v/ F m) and specific growth rate were measured as response variables. In culture, Symbiodinium cells exhibit motility in a helical swimming pattern, and therefore, revolutions per minute (RPM) were also measured with video microscopy. The exclusively free-living clade A was physiologically superior to Symbiodinium A1 across all measured variables and treatment combinations. F v/ F m remained relatively stable through time (at approximately 0.55) and was not substantially affected by temperature or the presence or the absence of sediment. Populations of the exclusively free-living Symbiodinium A reproduced faster with sediment than without and exhibited high levels of motility across all treatments (surpassing 300 RPM). In contrast, the F v/ F m of A1 dropped to 0.42 in sediment (relative to cultures without sediment) and exhibited dramatic declines in cell concentration, most severely at 31 °C. A > 50 % reduction in motility was also observed at 31 °C. Even in the absence of sediment, elevated temperature was observed to reduce population growth and cell motility of type A1. We suggest that vital behaviours linked to motility (such as vertical migration and the locating of potential hosts) may become impaired during future thermal

  3. Ecology of the free-living stages of major trichostrongylid parasites of sheep.

    PubMed

    O'Connor, Lauren J; Walkden-Brown, Stephen W; Kahn, Lewis P

    2006-11-30

    Significant developments over recent decades make it timely to review the ecology of the major gastrointestinal nematode (GIN) species of sheep. These include the relentless development and spread of anthelmintic resistance in all of the major sheep production regions of the world, and the consequent drive towards integrated parasite management (IPM) systems incorporating non-chemotherapeutic strategies such as grazing management. The success of such programs is dependent on a detailed understanding of the environmental influences on the free-living stages of the nematode lifecycle. Major reviews of the subject were conducted prior to 1980, however considerable work has been completed since, including the development of mathematical models describing the epidemiology of GIN infection. Knowledge of the temperature thresholds for free-living development has also improved, while investigations of moisture influences and interactions with temperature have allowed more effective exploitation of environmental effects for IPM. This review re-evaluates our understanding of the factors that determine the success or failure of the free-living phases of the lifecycle in light of these developments. Temperature and moisture are the dominant influences on the free-living stages of Haemonchus contortus, Teladorsagia circumcincta and Trichostrongylus colubriformis, with the effects of pasture conditions playing a significant modulating role. Early in the free-living phase, the developmental success of the three GIN species is limited by susceptibility to cold temperatures. In general, H. contortus is most susceptible, followed by T. colubriformis and then T. circumcincta. The length of the development cycle is dependent largely on temperature, with development rate increasing at warmer temperatures. However, in order for development to proceed to the infective larval stage, addition of moisture is generally required. There has been considerably less work quantifying the effects

  4. Pacific walrus coastal haulout database, 1852-2016— Background report

    USGS Publications Warehouse

    Fischbach, Anthony S.; Kochnev, Anatoly A.; Garlich-Miller, Joel L.; Jay, Chadwick V.

    2016-01-01

    Walruses are large benthic predators that rest out of water between foraging bouts. Coastal “haulouts” (places where walruses rest) are formed by adult males in summer and sometimes by females and young when sea ice is absent, and are often used repeatedly across seasons and years. Understanding the geography and historical use of haulouts provides a context for conservation efforts. We summarize information on Pacific walrus haulouts from available reports (n =151), interviews with coastal residents and aviators, and personal observations of the authors. We provide this in the form of a georeferenced database that can be queried and displayed with standard geographic information system and database management software. The database contains 150 records of Pacific walrus haulouts, with a summary of basic characteristics on maximum haulout aggregation size, age-sex composition, season of use, and decade of most recent use. Citations to reports are provided in the appendix and as a bibliographic database. Haulouts were distributed across the coasts of the Pacific walrus range; however, the largest (maximum >10,000 walruses) of the haulouts reported in the recent 4 decades (n=19) were concentrated on the Russian shores in regions near the Bering Strait and northward into the western Chukchi Sea (n=17). Haulouts of adult female and young walruses primarily occurred in the Bering Strait region and areas northward, with others occurring in the central Bering Sea, Gulf of Anadyr, and Saint Lawrence Island regions. The Gulf of Anadyr was the only region to contain female and young walrus haulouts, which formed after the northward spring migration and prior to autumn ice formation.

  5. Object-Oriented Analysis of Sea Ice Fragmentation Using SAR Imagery to Determine Pacific Walrus Habitat

    NASA Astrophysics Data System (ADS)

    Brigham, C.; Kolkowitz, I.; Dolson, M.; Rudy, J.; Brooks, A.; Hiatt, C.; Schmidt, C. L.; Skiles, J.

    2006-12-01

    Changes in climate are causing alterations in sea ice formation resulting in a changing habitat for Pacific walrus (Odobenus rosmarus divergens). Students from NASA Ames Research Center's DEVELOP Internship Program worked with the US Fish and Wildlife Service (USFWS) in Alaska to assess the use of satellite imagery for studying walrus habitat on sea ice. Few studies use satellite imagery to observe marine mammal habitats in polar regions because of the difficulty in obtaining imagery and georeferenced data points of species location for the same time period. This study used a method for sea ice image analysis that incorporated remote sensing segmentation and classification techniques with RADARSAT1 SAR (Synthetic Aperture Radar) imagery. Results were correlated with ground point data to determine the relationships of sea ice features to walrus' preferred habitat. MODIS data were utilized, where possible, to verify the classifications of sea ice surfaces obtained by RADARSAT1. The goal of the study was to define geophysical information from radar images that correlate with georeferenced species data points for the same time period. The students determined that walrus prefer thin to medium ice thicknesses. This finding means that aircraft census of walrus populations will not need to be done over areas of thick ice, saving flight time and allowing USFWS personnel to concentrate on locations where walrus populations can be expected to be found.

  6. BESMEX: Bering Sea marine mammal experiment. [with the primary target species being the walrus and bowhead whale

    NASA Technical Reports Server (NTRS)

    Ray, G. C.; Wartzok, D.

    1974-01-01

    Predictive ecological models are being studied for the management and conservation of the walrus, and the bowhead whale in the Bering Sea. The influence of sea ice on the distribution, and carrying capacity of the area for these two mammals is to be investigated with the primary target species being the walrus. Remote sensing and radio tracking is considered a requirement for assessing the walrus ecosystem.

  7. Estimation of free-living energy expenditure using a novel activity monitor designed to minimize obtrusiveness.

    PubMed

    Bonomi, Alberto G; Plasqui, Guy; Goris, Annelies H C; Westerterp, Klass R

    2010-09-01

    The aim of this study was to investigate the ability of a novel activity monitor designed to be minimally obtrusive in predicting free-living energy expenditure. Subjects were 18 men and 12 women (age: 41 +/- 11 years, BMI: 24.4 +/- 3 kg/m(2)). The habitual physical activity was monitored for 14 days using a DirectLife triaxial accelerometer for movement registration (Tracmor(D)) (Philips New Wellness Solutions, Lifestyle Incubator, the Netherlands). Tracmor(D) output was expressed as activity counts per day (Cnts/d). Simultaneously, total energy expenditure (TEE) was measured in free living conditions using doubly labeled water (DLW). Activity energy expenditure (AEE) and the physical activity level (PAL) were determined from TEE and sleeping metabolic rate (SMR). A multiple-linear regression model predicted 76% of the variance in TEE, using as independent variables SMR (partial-r(2) = 0.55, P < 0.001), and Cnts/d (partial r(2) = 0.21, P < 0.001). The s.e. of TEE estimates was 0.9 MJ/day or 7.4% of the average TEE. A model based on body mass (partial-r(2) = 0.31, P < 0.001) and Cnts/d (partial-r(2) = 0.23, P < 0.001) predicted 54% of the variance in TEE. Cnts/d were significantly and positively associated with AEE (r = 0.54, P < 0.01), PAL (r = 0.68, P < 0.001), and AEE corrected by body mass (r = 0.71, P < 0.001). This study showed that the Tracmor(D) is a highly accurate instrument for predicting free-living energy expenditure. The miniaturized design did not harm the ability of the instrument in measuring physical activity and in determining outcome parameters of physical activity such as TEE, AEE, and PAL. PMID:20186133

  8. Free-living bodonids and derived parasitic trypanosomatids: but what lies in between?

    PubMed

    Stevens, Jamie R

    2014-03-01

    Inclusion of suitable out-group taxa has been of particular importance in accurate reconstruction of evolutionary relationships among trypanosomatids. However, the persistence of researchers focusing on insect trypansomatids appears to have paid off, and a novel, apparently-monoxenous parasite isolated from mosquitoes has recently been characterised. Critically, phylogenetic and phylogenomic analyses robustly position this new species, Paratrypanosoma confusum, between free-living bodonid out-group taxa and other trypanosomatids, thereby overcoming some of the issues associated with previously utilised out-groups. PMID:24468209

  9. Monitoring of Yersinia enterocolitica strains from free-living animals using different methods.

    PubMed

    Syczyło, K; Platt-Samoraj, A; Bancerz-Kisiel, A; Szczerba-Turek, A; Lipczyńska, K; Jabłoński, A; Procajło, Z; Szweda, W

    2016-01-01

    The aim of the study was to monitor Y. enterocolitica strains from free-living animals captured during 2011-2014 hunting seasons in Poland using warm (ITC) and cold (PSB) enrichment and molecular examination. Over 1600 samples have been cultured. After ITC/PSB enrichment 237 strains presenting features characteristic for Y. enterocolitica were isolated. Molecular examination using multiplex PCR revealed 140 isolates from PSB and 78 from ITC. The concentration of pathogenic Yersinia in asymptomatic carriers is low and the PCR detection should be preceded by bacteriological examination. PMID:27096808

  10. Epidemiologic determinants of aural abscessation in free-living eastern box turtles (Terrapene carolina) in Virginia.

    PubMed

    Brown, Justin D; Sleeman, Jonathan M; Elvinger, François

    2003-10-01

    Epidemiologic determinants of 46 cases of aural abscessation in free-living eastern box turtles (Terrapene carolina) admitted to the Wildlife Center of Virginia (Virginia, USA) from 1991 to 2000 were evaluated. County human population density, year and season of admission, weight, and sex did not affect the risk for box turtles to develop aural abscessation. Counties with cases of aural abscessation were not randomly distributed, but rather were clustered into two multi-county regions. Geographic location was the only risk factor associated with aural abscessation in box turtles found in this study. Possible etiologies could include chronic infectious disease, malnutrition, or chronic exposure to environmental contamination with organochlorine compounds. PMID:14733291

  11. Extrapolating laboratory avian toxicity data to free-living birds: Comparison of the toxicity of parathion to captive and free-living European starlings

    USGS Publications Warehouse

    Grue, C.E.; Rattner, B.A.; Bunck, C.M.

    1993-01-01

    In 1985 and 1986, we captured nesting wild female European starlings with young 8-10 days of age. Birds were weighted, banded, and given one of four dosages of the OP insecticide parathion (50, 72, 104 or 150 mg/kg dissolved in corn oil) or pure corn-oil (control). and their young weighed. Nest boxes (7- 12/treatment) were observed and young re-weighed 2-3 days postdose to determine presence/absence of the females. If necessary, males were captured and fate of young used to confirm female response. Brain ChE inhibition in dosed birds (based on a pilot study) was 55-74%. EC50's (failure to return to nest box) for the females was 74 mg/kg in 1985 and 92 mg/kg in 1986. Confidence limit (95%) for these estimates overlapped LD50's for captive female starlings dosed with the OP in spring and early summer 1987 (136, 128 mg/kg, respectively). Results suggest that responses of captive and free-living birds to potentially lethal concentrations of OP's are similar, despite the additional stresses in the wild.

  12. Energy demands for maintenance, growth, pregnancy, and lactation of female Pacific walruses (Odobenus rosmarus divergens)

    USGS Publications Warehouse

    Noren, Shawn R.; Udevitz, Mark S.; Jay, Chadwick V.

    2014-01-01

    Decreases in sea ice have altered habitat use and activity patterns of female Pacific walruses Odobenus rosmarus divergens and could affect their energetic demands, reproductive success, and population status. However, a lack of physiological data from walruses has hampered efforts to develop the bioenergetics models required for fully understanding potential population-level impacts. We analyzed long-term longitudinal data sets of caloric consumption and body mass from nine female Pacific walruses housed at six aquaria using a hierarchical Bayesian approach to quantify relative energetic demands for maintenance, growth, pregnancy, and lactation. By examining body mass fluctuations in response to food consumption, the model explicitly uncoupled caloric demand from caloric intake. This is important for pinnipeds because they sequester and deplete large quantities of lipids throughout their lifetimes. Model outputs were scaled to account for activity levels typical of free-ranging Pacific walruses, averaging 83% of the time active in water and 17% of the time hauled-out resting. Estimated caloric requirements ranged from 26,900 kcal d−1 for 2-yr-olds to 93,370 kcal d−1 for simultaneously lactating and pregnant walruses. Daily consumption requirements were higher for pregnancy than lactation, reflecting energetic demands of increasing body size and lipid deposition during pregnancy. Although walruses forage during lactation, fat sequestered during pregnancy sustained 27% of caloric requirements during the first month of lactation, suggesting that walruses use a mixed strategy of capital and income breeding. Ultimately, this model will aid in our understanding of the energetic and population consequences of sea ice loss.

  13. A Reevaluation of the Morphology, Paleoecology, and Phylogenetic Relationships of the Enigmatic Walrus Pelagiarctos

    PubMed Central

    Boessenecker, Robert W.; Churchill, Morgan

    2013-01-01

    Background A number of aberrant walruses (Odobenidae) have been described from the Neogene of the North Pacific, including specialized suction-feeding and generalist fish-eating taxa. At least one of these fossil walruses has been hypothesized to have been a specialized predator of other marine mammals, the middle Miocene walrus Pelagiarctos thomasi from the Sharktooth Hill Bonebed of California (16.1–14.5 Ma). Methodology/Principal Findings A new specimen of Pelagiarctos from the middle Miocene “Topanga” Formation of southern California (17.5–15 Ma) allows a reassessment of the morphology and feeding ecology of this extinct walrus. The mandibles of this new specimen are robust with large canines, bulbous premolars with prominent paraconid, metaconid, hypoconid cusps, crenulated lingual cingula with small talonid basins, M2 present, double-rooted P3–M1, single-rooted P1 and M2, and a P2 with a bilobate root. Because this specimen lacks a fused mandibular symphysis like Pelagiarctos thomasi, it is instead referred to Pelagiarctos sp. This specimen is more informative than the fragmentary holotype of Pelagiarctos thomasi, permitting Pelagiarctos to be included within a phylogenetic analysis for the first time. Analysis of a matrix composed of 90 cranial, dental, mandibular and postcranial characters indicates that Pelagiarctos is an early diverging walrus and sister to the late Miocene walrus Imagotaria downsi. We reevaluate the evidence for a macropredatory lifestyle for Pelagiarctos, and we find no evidence of specialization towards a macrophagous diet, suggesting that Pelagiarctos was a generalist feeder with the ability to feed on large prey. Conclusions/Significance This new specimen of Pelagiarctos adds to the knowledge of this problematic taxon. The phylogenetic analysis conclusively demonstrates that Pelagiarctos is an early diverging walrus. Pelagiarctos does not show morphological specializations associated with macrophagy, and was likely a

  14. Energy demands for maintenance, growth, pregnancy, and lactation of female Pacific walruses (Odobenus rosmarus divergens).

    PubMed

    Noren, Shawn R; Udevitz, Mark S; Jay, Chadwick V

    2014-01-01

    Decreases in sea ice have altered habitat use and activity patterns of female Pacific walruses Odobenus rosmarus divergens and could affect their energetic demands, reproductive success, and population status. However, a lack of physiological data from walruses has hampered efforts to develop the bioenergetics models required for fully understanding potential population-level impacts. We analyzed long-term longitudinal data sets of caloric consumption and body mass from nine female Pacific walruses housed at six aquaria using a hierarchical Bayesian approach to quantify relative energetic demands for maintenance, growth, pregnancy, and lactation. By examining body mass fluctuations in response to food consumption, the model explicitly uncoupled caloric demand from caloric intake. This is important for pinnipeds because they sequester and deplete large quantities of lipids throughout their lifetimes. Model outputs were scaled to account for activity levels typical of free-ranging Pacific walruses, averaging 83% of the time active in water and 17% of the time hauled-out resting. Estimated caloric requirements ranged from 26,900 kcal d(-1) for 2-yr-olds to 93,370 kcal d(-1) for simultaneously lactating and pregnant walruses. Daily consumption requirements were higher for pregnancy than lactation, reflecting energetic demands of increasing body size and lipid deposition during pregnancy. Although walruses forage during lactation, fat sequestered during pregnancy sustained 27% of caloric requirements during the first month of lactation, suggesting that walruses use a mixed strategy of capital and income breeding. Ultimately, this model will aid in our understanding of the energetic and population consequences of sea ice loss. PMID:25461648

  15. Projected status of the Pacific walrus (Odobenus rosmarus divergens) in the twenty-first century

    USGS Publications Warehouse

    Jay, Chadwick V.; Marcot, Bruce G.; Douglas, David C.

    2011-01-01

    Extensive and rapid losses of sea ice in the Arctic have raised conservation concerns for the Pacific walrus (Odobenus rosmarus divergens), a large pinniped inhabiting arctic and subarctic continental shelf waters of the Chukchi and Bering seas. We developed a Bayesian network model to integrate potential effects of changing environmental conditions and anthropogenic stressors on the future status of the Pacific walrus population at four periods through the twenty-first century. The model framework allowed for inclusion of various sources and levels of knowledge, and representation of structural and parameter uncertainties. Walrus outcome probabilities through the century reflected a clear trend of worsening conditions for the subspecies. From the current observation period to the end of century, the greatest change in walrus outcome probabilities was a progressive decrease in the outcome state of robust and a concomitant increase in the outcome state of vulnerable. The probabilities of rare and extirpated states each progressively increased but remained <10% through the end of the century. The summed probabilities of vulnerable, rare, and extirpated (P(v,r,e)) increased from a current level of 10% in 2004 to 22% by 2050 and 40% by 2095. The degree of uncertainty in walrus outcomes increased monotonically over future periods. In the model, sea ice habitat (particularly for summer/fall) and harvest levels had the greatest influence on future population outcomes. Other potential stressors had much smaller influences on walrus outcomes, mostly because of uncertainty in their future states and our current poor understanding of their mechanistic influence on walrus abundance.

  16. Projected status of the Pacific walrus (Odobenus rosmarus divergens) in the twenty-first century

    USGS Publications Warehouse

    Jay, C.V.; Marcot, B.G.; Douglas, D.C.

    2011-01-01

    Extensive and rapid losses of sea ice in the Arctic have raised conservation concerns for the Pacific walrus (Odobenus rosmarus divergens), a large pinniped inhabiting arctic and subarctic continental shelf waters of the Chukchi and Bering seas. We developed a Bayesian network model to integrate potential effects of changing environmental conditions and anthropogenic stressors on the future status of the Pacific walrus population at four periods through the twenty-first century. The model framework allowed for inclusion of various sources and levels of knowledge, and representation of structural and parameter uncertainties. Walrus outcome probabilities through the century reflected a clear trend of worsening conditions for the subspecies. From the current observation period to the end of century, the greatest change in walrus outcome probabilities was a progressive decrease in the outcome state of robust and a concomitant increase in the outcome state of vulnerable. The probabilities of rare and extirpated states each progressively increased but remained >10% through the end of the century. The summed probabilities of vulnerable, rare, and extirpated (P(v,r,e)) increased from a current level of 10% in 2004 to 22% by 2050 and 40% by 2095. The degree of uncertainty in walrus outcomes increased monotonically over future periods. In the model, sea ice habitat (particularly for summer/fall) and harvest levels had the greatest influence on future population outcomes. Other potential stressors had much smaller influences on walrus outcomes, mostly because of uncertainty in their future states and our current poor understanding of their mechanistic influence on walrus abundance. ?? 2011 US Government.

  17. Emerging trends in free-living amebic infections of the brain: implications for organ transplantation.

    PubMed

    Diaz, James H; Boudreaux, J Philip

    2013-01-01

    This epidemiological review analyzed cases of Naegleria fowleri primary amebic meningoencephalitis (PAM) and Balamuthia mandrillaris granulomatous amebic encephalitis (GAE) for behavioral and demographic risk factors for pathogen exposures and potential transmission by organ transplantation. The Centers for Disease Control and Prevention (CDC) Naegleria Workgroup Registry provided 121 cases of laboratory-confirmed PAM over the period, 1937-2007. The CDC and the California Encephalitis Project provided 28 cases of GAE over the period, 1994-2010. There was a statistically significant increase in clusters of PAM cases between the periods, 1937-1996 and 1997-2007. Risk factors for PAM included male gender, freshwater exposures, summer exposures, and exposures in southern-tier US (United States) states. Risk factors for GAE included male gender, exposures in southern-tier US states, Hispanic ethnicity in California, occupational or recreational contacts with soil, and recent organ transplantation. Fatal free-living amebic infections of the brain are increasing today due to more frequent environmental, recreational, and occupational exposures; organ transplantation; and unanticipated clusters of PAM due to N. fowleri inoculations following nasal sinus irrigation using neti pots filled with municipal tap water. Potential organ donors dying from meningoencephalitis of unexplained causes should be screened for free-living amebic infections of the brain capable of hematogenous dissemination in organ recipients. PMID:25073256

  18. Isolation and Molecular Characterization of Free-Living Amoebae from Different Water Sources in Italy

    PubMed Central

    Montalbano Di Filippo, Margherita; Santoro, Maristella; Lovreglio, Piero; Monno, Rosa; Capolongo, Carmen; Calia, Carla; Fumarola, Luciana; D’Alfonso, Rossella; Berrilli, Federica; Di Cave, David

    2015-01-01

    Free-living amoebae (FLA) are protozoa ubiquitous in Nature, isolated from a variety of environments worldwide. In addition to their natural distribution, some species have been found to be pathogenic to humans. In the present study a survey was conducted in order to evaluate the presence and to characterize at molecular level the isolates of amoebic organisms collected from different water sources in Italy. A total of 160 water samples were analyzed by culture and microscopic examination. FLA were found in 46 (28.7%) of the investigated water samples. Groundwater, well waters, and ornamental fountain waters were the sources with higher prevalence rates (85.7%, 50.0%, and 45.9%, respectively). Identification of FLA species/genotypes, based on the 18S rDNA regions, allowed to identify 18 (39.1%) Acanthamoeba isolates (genotypes T4 and T15) and 21 (45.6%) Vermamoeba vermiformis isolates. Other FLA species, including Vahlkampfia sp. and Naegleria spp., previously reported in Italy, were not recovered. The occurrence of potentially pathogenic free-living amoebae in habitats related to human population, as reported in the present study, supports the relevance of FLA as a potential health threat to humans. PMID:25811766

  19. Selective disappearance of individuals with high levels of glycated haemoglobin in a free-living bird.

    PubMed

    Récapet, Charlotte; Sibeaux, Adélaïde; Cauchard, Laure; Doligez, Blandine; Bize, Pierre

    2016-08-01

    Although disruption of glucose homeostasis is a hallmark of ageing in humans and laboratory model organisms, we have little information on the importance of this process in free-living animals. Poor control of blood glucose levels leads to irreversible protein glycation. Hence, levels of protein glycation are hypothesized to increase with age and to be associated with a decline in survival. We tested these predictions by measuring blood glycated haemoglobin in 274 adult collared flycatchers of known age and estimating individual probability of recapture in the following 2 years. Results show a strong decrease in glycated haemoglobin from age 1 to 5 years and an increase thereafter. Individuals with high levels of glycated haemoglobin had a lower probability of recapture, even after controlling for effects of age and dispersal. Altogether, our findings suggest that poor control of glucose homoeostasis is associated with lower survival in this free-living bird population, and that the selective disappearance of individuals with the highest glycation levels could account for the counterintuitive age-related decline in glycated haemoglobin in the early age categories. PMID:27555645

  20. Nematofauna in the Adriatic Sea: review and check-list of free-living nematode species

    NASA Astrophysics Data System (ADS)

    Travizi, Ana; Vidaković, Jasna

    1998-02-01

    The present paper presents a collection and synthesis of data found in numerous publications on Adriatic Sea nematofauna, as well as unpublished, data mentioned in annotations. For this purpose, a chronological order of investigations and a general survey of the species that occurred in the Adriatic Sea are given. In all, 281 free-living nematode species comprised in 133 genera and 34 families were discerned and listed in a taxonomic review, according to their spatial distribution. In special cases, descriptions of habitat features were noted. The position of species characterized by high population densities, their importance, and contribution to the faunistic composition of certain parts of the Adriatic were also discussed. The summary of the results, of prevailing research on free-living marine nematodes serves as a tool for making distinctions concerning the research level and state of nematofauna knowledge in different parts of the Adriatic Sea. Northern Adriatic nematofauna has been considerably more intensively investigated than that of the Central and South Adriatic.

  1. Free-living nematodes in the freshwater food web: a review.

    PubMed

    Majdi, Nabil; Traunspurger, Walter

    2015-03-01

    Free-living nematodes are well-recognized as an abundant and ubiquitous component of benthic communities in inland waters. Compelling evidence from soil and marine ecosystems has highlighted the importance of nematodes as trophic intermediaries between microbial production and higher trophic levels. However, the paucity of empirical evidence of their role in freshwater ecosystems has hampered their inclusion in our understanding of freshwater food web functioning. This literature survey provides an overview of research efforts in the field of freshwater nematode ecology and of the complex trophic interactions between free-living nematodes and microbes, other meiofauna, macro-invertebrates, and fishes. Based on an analysis of the relevant literature and an appreciation of the potential of emerging approaches for the evaluation of nematode trophic ecology, we point out research gaps and recommend relevant directions for further research. The latter include (i) interactions of nematodes with protozoans and fungi; (ii) nonconsumptive effects of nematodes on microbial activity and the effects of nematodes on associated key ecosystem processes (decomposition, primary production); and (iii) the feeding selectivity and intraspecific feeding variability of nematodes and their potential impacts on the structure of benthic communities. PMID:25861114

  2. Presence of free-living amoebae in portable and stationary eye wash stations

    SciTech Connect

    Tyndall, R.L.; Lyle, M.M.; Ironside, K.S.

    1987-11-01

    Portable and stationary eye wash stations were tested for the presence of free-living amoebae. Such amoebae may be found in potable waters, and at least one genera, the Acanthamoebae, can cause severe infections when introduced into traumatized eyes. Concentrates or filtrates of water from eye wash stations were placed on nonnutrient agar plates seeded with Escherichia coli. Resultant outgrowths of free-living amoebae, which were morphologically identified as mixtures of Hartmannella and Acanthamoebae, were inoculated intranasally into weanling mice. Subsequently, brain and lung tissues from inject mice were tested for amoebae as an indication of persistent infection. Acanthamoebae and Hartmannella were detected in some eye wash stations at each of four test sites. Both portable and stationary stations harbored Acanthamoebae. Some of the isolates caused persistent pulmonary infection but were not isolated from brain tissue. Flushing stationary eye wash stations temporarily reduced the number of stations positive for amoebae. Treatment of portable stations with 25 ppm of free chlorine also reduced the number of stations harboring amoebae but caused corrosion in some of the stations.

  3. [Comparative characteristics of free-living ultramicroscopical bacteria obtained from extremal biotopes].

    PubMed

    Suzina, N E; Esikova, T Z; Oleinikov, R R; Gafarov, B; Shorokhov, A P; Polivtseva, V N; Ross, D V; Abashina, T N; Duda, V I; Boronin, A M

    2015-01-01

    We isolated 50 strains of free-living ultrasmall bacteria with a cell volume that varies from 0.02 to 1.3 microm3 from a range of extremal natural biotopes, namely permafrost soils, oil slime, soils, lake silt, thermal swamp moss, and the skin integuments of the clawed frog, Xenopus laevis. Of them, 15 isolates, characterized by a cell size of less than 0.1 microm3 and a genome size from 1.5 to 2.4 Mb, were subsumed to ultramicrobacteria belonging to different philogenetic groups (Alphaproteobacteria, Bacteroidetes, Actinobacteria) and genera (Kaistia, Chryseobacterium, Microbacterium, Leucobacter, Leifsonia, and Agrococcus) of the Bacteria domain. They are free-living mesophilic heterotrophic aerobic bacteria. The representatives of Kaistia and Chryseobacterium genera were capable of facultative parasitism on other species of chemo-organotrophic bacteria and cyanobacteria. The ultramicrobacteria differed in their morpholgy, cell ultrastructural organization, and physiological and biochemical features. According to the fine structure of their cell walls, the isolates were subdivided into two groups, namely Gram-positive and Gram-negative forms. PMID:26027350

  4. Inertial measurements of free-living activities: assessing mobility to predict falls.

    PubMed

    Wang, Kejia; Lovell, Nigel H; Del Rosario, Michael B; Liu, Ying; Wang, Jingjing; Narayanan, Michael R; Brodie, Matthew A D; Delbaere, Kim; Menant, Jasmine; Lord, Stephen R; Redmond, Stephen J

    2014-01-01

    An exploratory analysis was conducted into how simple features, from acceleration at the lower back and ankle during simulated free-living walking, stair ascent and descent, correlate with age, the overall fall risk from a clinically validated Physiological Profile Assessment (PPA), and its sub-components. Inertial data were captured from 92 older adults aged 78-95 (42 female, mean age 84.1, standard deviation 3.9 years). The dominant frequency, peak width from Welch's power spectral density estimate, and signal variance along each axis, from each sensor location and for each activity were calculated. Several correlations were found between these features and the physiological risk factors. The strongest correlations were from the dominant frequency at the ankle along the mediolateral direction during stair ascent (Spearman's correlation coefficient p = - 0.45) with anterioposterior sway, and signal variance of the anterioposterior acceleration at the lower back during stair descent (p = - 0.45) with age. These findings should aid future attempts to classify activities and predict falls in older adults, based on true free-living data from a range of activities. PMID:25571580

  5. Inbreeding effects on immune response in free-living song sparrows (Melospiza melodia)

    PubMed Central

    Reid, Jane M; Arcese, Peter; Keller, Lukas F; Elliott, Kyle H; Sampson, Laura; Hasselquist, Dennis

    2006-01-01

    The consequences of inbreeding for host immunity to parasitic infection have broad implications for the evolutionary and dynamical impacts of parasites on populations where inbreeding occurs. To rigorously assess the magnitude and the prevalence of inbreeding effects on immunity, multiple components of host immune response should be related to inbreeding coefficient (f) in free-living individuals. We used a pedigreed, free-living population of song sparrows (Melospiza melodia) to test whether individual responses to widely used experimental immune challenges varied consistently with f. The patagial swelling response to phytohaemagglutinin declined markedly with f in both females and males in both 2002 and 2003, although overall inbreeding depression was greater in males. The primary antibody response to tetanus toxoid declined with f in females but not in males in both 2004 and 2005. Primary antibody responses to diphtheria toxoid were low but tended to decline with f in 2004. Overall inbreeding depression did not solely reflect particularly strong immune responses in outbred offspring of immigrant–native pairings or weak responses in highly inbred individuals. These data indicate substantial and apparently sex-specific inbreeding effects on immune response, implying that inbred hosts may be relatively susceptible to parasitic infection to differing degrees in males and females. PMID:17254994

  6. A validation of extraction methods for noninvasive sampling of glucocorticoids in free-living ground squirrels.

    PubMed

    Mateo, Jill M; Cavigelli, Sonia A

    2005-01-01

    Fecal hormone assays provide a powerful tool for noninvasive monitoring of endocrine status in wild animals. In this study we validated a protocol for extracting and measuring glucocorticoids in free-living and captive Belding's ground squirrels (Spermophilus beldingi). We first compared two commonly used extraction protocols to determine which performed better with commercially available antibodies. We next verified the preferred extraction method by correlating circulating and fecal glucocorticoid measures from a group of individuals over time. For this comparison, we used both a cortisol and a corticosterone antibody to determine which had greater affinity to the fecal metabolites. Cortisol was the primary circulating glucocorticoid, but both hormones were present in well above detectable concentrations in the blood, which does not occur in other sciurids. In addition, the cortisol antibody showed greater binding with the fecal extracts than did the corticosterone antibody. Finally, we used adrenocorticotropic hormone and dexamethasone challenges to demonstrate that changes in adrenal functioning are reflected in changing fecal corticoid levels. These results suggest that our extraction protocol provides a fast, reliable assay of stress hormones in free-living ground squirrels without the confounding influence of short-term rises in glucocorticoid concentrations caused by handling and restraint stress and that it can facilitate ecological and evolutionary studies of stress in wild species. PMID:16228945

  7. Seasonal glucocorticoid responses to capture in wild free-living mammals.

    PubMed

    Romero, L Michael; Meister, Cecile J; Cyr, Nicole E; Kenagy, G J; Wingfield, John C

    2008-02-01

    We determined baseline and capture-induced glucocorticoid concentrations during two different seasons in three species of wild free-living rodents: brown lemmings (Lemmus trimucronatus), golden-mantled ground squirrels (Spermophilus saturatus), and yellow-pine chipmunks (Tamias amoenus). Initial blood samples were obtained within 3 min of capture, so that initial glucocorticoid levels reflect baseline titers of undisturbed animals. Animals were held for an additional 30 min, when a second blood sample was taken to measure stress-induced glucocorticoid titers. The primary glucocorticoid differed in each species. Lemmings secreted extremely large amounts of corticosterone (as high as 8,000 ng/ml). These high concentrations were accompanied by high corticosterone-binding globulin capacity and resistance to negative feedback. Squirrels and chipmunks secreted a mixture of cortisol and corticosterone (10-400 ng/ml). In males of all three species and female squirrels and chipmunks, glucocorticoid levels were significantly elevated 30 min after capture. Baseline and 30-min glucocorticoid levels differed seasonally in each species. Levels were higher during summer (with no snow cover) than in spring (with approximately 60% snow cover) in female lemmings, higher during breeding than before hibernation in squirrels, and higher postreproductively than during breeding in chipmunks. Together, these data indicate that glucocorticoid responses to stress in these free-living species are similar to those in laboratory species, but the magnitude of the response appears to depend on life-history features specific to each species. PMID:18094060

  8. Application of flow cytometry to studies of pathogenic free-living amoebae.

    PubMed Central

    Muldrow, L L; Tyndall, R L; Fliermans, C B

    1982-01-01

    Species of small, free-living amoebae of the genera Naegleria and Acanthamoeba can cause fatal amoebic meningoencephalitis. Previous investigations have shown that pathogenic amoebae are associated with thermally altered water. Flow cytometric techniques for identifying species of pathogenic and nonpathogenic amoebae from such water have been developed, using immunofluorescence and fluorescein-bound concanavalin A. Flow cytometry is accomplished with a cytofluorograph, in which cells are dispersed in a suspended carrier liquid and passed in front of a focused argon ion laser beam. Cells are then distinguished by the degree of scattered light (size) or fluorescence. Flow cytometry techniques have proven efficient for environmental samples, as indicated by the identification of pathogenic Naegleria fowleri and nonpathogenic Naegleri gruberi and Acanthamoeba castellanii isolated from the Savannah River Plant in South Carolina. Cytofluorographic analysis of environmental samples has several advantages over the current methods of isolation and classification of free-living amoebae. With this system, it is possible to rapidly identify species and quantitate mixtures of pathogenic amoebae in environmental samples. Cytofluorographic analysis of amoebic isolates reduces the time presently required to screen environmental sites for pathogenic amoebae. The cytofluorograph permits detection and species identification of nonthermophilic Naegleria spp. and Acanthamoeba spp. that could not easily be isolated for species identification by conventional methods. Other advantages of flow cytometry over fluorescent microscopy include a high degree of statistical precision due to the large numbers measured, high immunofluorescent titers, and elimination of subjectivity and fluorescence fading. PMID:6186196

  9. Increased Mycoplasma hyopneumoniae Disease Prevalence in Domestic Hybrids Among Free-Living Wild Boar.

    PubMed

    Goedbloed, Daniel J; van Hooft, Pim; Lutz, Walburga; Megens, Hendrik-Jan; van Wieren, Sip E; Ydenberg, Ron C; Prins, Herbert H T

    2015-12-01

    Wildlife immune genes are subject to natural selection exerted by pathogens. In contrast, domestic immune genes are largely protected from pathogen selection by veterinary care. Introgression of domestic alleles into the wild could lead to increased disease susceptibility, but observations are scarce due to low introgression rates, low disease prevalence and reduced survival of domestic hybrids. Here we report the first observation of a deleterious effect of domestic introgression on disease prevalence in a free-living large mammal. A fraction of 462 randomly sampled free-living European wild boar (Sus scrofa) was genetically identified as recent wild boar-domestic pig hybrids based on 351 SNP data. Analysis of antibody prevalence against the bacterial pathogen Mycoplasma hyopneumoniae (Mhyo) showed an increased Mhyo prevalence in wild-domestic hybrids. We argue that the most likely mechanism explaining the observed association between domestic hybrid status and Mhyo antibody prevalence would be introgression of deleterious domestic alleles. We hypothesise that large-scale use of antibiotics in the swine breeding sector may have played a role in shaping the relatively deleterious properties of domestic swine immune genes and that domestic introgression may also lead to increased wildlife disease susceptibility in the case of other species. PMID:26391376

  10. Response of Plant Parasitic and Free Living Soil Nematodes to Composted Animal Manure Soil Amendments

    PubMed Central

    Renčo, M.; Kováčik, P.

    2012-01-01

    In an outside pot experiment, dry pig manure processed on pine sawdust litter and fermented for seven days by house fly larvae (fermented manure), and pine sawdust applied alone, and in combination with a spring application of inorganic nitrogen fertilizer were used to determine their effects on plant parasitic and free-living soil nematodes on sugar beets (cv. Antek). Non amended soil was used as a control. All treatments with fermented pig manure and sawdust with nitrogen fertilizer decreased number of plant parasitic nematodes and also root-fungal feeding nematodes compared to the untreated control. Sawdust applied alone had no effect on plant parasitic and root-fungal feeding nematode suppression. Free-living nematodes which were mainly bacteriovores and fungivores were significantly more abundant in soil amended with fermented pig manure, while the sawdust had no effect on these nematodes. The effect of all tested treatments on omnivores-predators was rather random, and in general, the number of these nematodes decreased after soil amendment applications compared to the untreated control. PMID:23482503

  11. Interaction of free-living marine nematodes in the artificial mangrove environment (Southeast Coast of India).

    PubMed

    Ansari, K G Mohamed Thameemul; Manokaran, S; Raja, S; Lyla, P S; Khan, S Ajmal

    2014-01-01

    Free-living marine nematode diversity was analyzed between Avicennia marina and Rhizophora mucronata mangrove covers of the Vellar Estuary (southeast coast of India). A total of 4,976 specimens of free-living marine nematodes were collected in 56 species. Comparatively, a higher species richness was obtained for A. marina (52 species) than for R. mucronata (44 species), whereas 40 species commonly existed in both mangrove covers. A higher density of nematodes was found in sediments of sandy nature, whereas there was lower total organic carbon compared to silt/clay composition; epigrowth feeders were dominant over the other feeding groups based on organic enrichment in surface sediments. Principal component analysis clearly explained the relationship between the environmental parameters of various months. Higher R values of analysis of similarities revealed significant differences in nematode assemblages between months, and it was quite evident by non-metric multidimensional scaling. Diversity indices showed higher values in the dry months. RELATE analysis explained serial changes in nematode species composition between months, and a relationship between biotic and abiotic variables was clarified using the BIO-ENV procedure. Viscosia spp., Metachromadora spp., Theristus spp., and Sphaerolaimus spp. were candidate species of A. marina leaf interaction by observation. PMID:23928719

  12. Free-Living Nematodes in the Freshwater Food Web: A Review

    PubMed Central

    Majdi, Nabil; Traunspurger, Walter

    2015-01-01

    Free-living nematodes are well-recognized as an abundant and ubiquitous component of benthic communities in inland waters. Compelling evidence from soil and marine ecosystems has highlighted the importance of nematodes as trophic intermediaries between microbial production and higher trophic levels. However, the paucity of empirical evidence of their role in freshwater ecosystems has hampered their inclusion in our understanding of freshwater food web functioning. This literature survey provides an overview of research efforts in the field of freshwater nematode ecology and of the complex trophic interactions between free-living nematodes and microbes, other meiofauna, macro-invertebrates, and fishes. Based on an analysis of the relevant literature and an appreciation of the potential of emerging approaches for the evaluation of nematode trophic ecology, we point out research gaps and recommend relevant directions for further research. The latter include (i) interactions of nematodes with protozoans and fungi; (ii) nonconsumptive effects of nematodes on microbial activity and the effects of nematodes on associated key ecosystem processes (decomposition, primary production); and (iii) the feeding selectivity and intraspecific feeding variability of nematodes and their potential impacts on the structure of benthic communities. PMID:25861114

  13. Free-living amoebae used to isolate consortia capable of degrading trichloroethylene

    SciTech Connect

    Tyndall, R.L.; Katz, D.S.; Little, C.D.; Kennedy, J.R.

    1991-12-31

    The interaction of protozoa with prokaryotes is well documented. These interactions can be either ecto- or endosymbiotic. An example of photosynthetic symbiosis is the well-defined interaction between paramecium and entrapped Chlorella. Paramecium can also form symbiotic relationships with gram-negative heterotrophic bacteria. Jeon has described an interaction between amoebae and engulfed bacteria, that eventuated into a dependency of the amoebae on the presence of the engulfed bacterium. Free-living amoebae and tetrahymena can engulf and subsequently provide the necessary niche for the replication of Legionella. Acanthamoebae trophozoites and cysts can harbor and support the replication of unidentified gram-negative bacteria. King has recently shown that bacteria associated with free-living amoebae are more resistant to toxic environments. Assuming that methylotrophic bacteria in situ are a part of a mixed community, and based on our observations that bacteria associated with protozoa may not be easily isolated by standard techniques, we attempted to use protozoa as a tool to isolate TCE-degrading bacteria.

  14. Tyrosinase expression during black truffle development: from free living mycelium to ripe fruit body.

    PubMed

    Zarivi, Osvaldo; Bonfigli, Antonella; Colafarina, Sabrina; Aimola, Pierpaolo; Ragnelli, Anna Maria; Pacioni, Giovanni; Miranda, Michele

    2011-12-01

    The present work studies the expression of tyrosinase (monophenol:diphenol oxygen oxidoreductase, EC 1.14.18.1) during the development of the black truffle Tuber melanosporum Vittad., an ectomycorrhizal fungus of great biological and economic interest. As widely reported in the literature, melanins and the enzymes that synthesize them, are of paramount importance in fungal development and sexual differentiation. Tyrosinase and laccase are the enzymes that produce melanins from monophenols and diphenols. We have detected tyrosinase expression from the stage of free living mycelium, through the mychorrizal stage and the six fruit body developmental stages by measuring the levels of tyrosinase mRNA by quantitative PCR (q-PCR), spectrophotometry, histochemistry, immunohistochemistry and electrophoresis. Tyrosinase is always expressed, from the free living mycelium to the ripe fruit body developmental stages, when it is very low. The switching off of the tyrosinase gene during T. melanosporum development when the fruit body is ripe and no more cell walls are to be built is discussed in relation of thioflavour production. Specific primers, prepared from the cloned T. melanosporum tyrosinase cDNA were used for the q-PCR and the deduced aminoacid sequences of the CuA and CuB binding sites were compared to those of various ascomycetes and basidiomycetes. PMID:21945278

  15. Genetic Correlates of Individual Differences in Sleep Behavior of Free-Living Great Tits (Parus major)

    PubMed Central

    Stuber, Erica F.; Baumgartner, Christine; Dingemanse, Niels J.; Kempenaers, Bart; Mueller, Jakob C.

    2016-01-01

    Within populations, free-living birds display considerable variation in observable sleep behaviors, reflecting dynamic interactions between individuals and their environment. Genes are expected to contribute to repeatable between-individual differences in sleep behaviors, which may be associated with individual fitness. We identified and genotyped polymorphisms in nine candidate genes for sleep, and measured five repeatable sleep behaviors in free-living great tits (Parus major), partly replicating a previous study in blue tits (Cyanistes caeruleus). Microsatellites in the CLOCK and NPAS2 clock genes exhibited an association with sleep duration relative to night length, and morning latency to exit the nest box, respectively. Furthermore, microsatellites in the NPSR1 and PCSK2 genes associated with relative sleep duration and proportion of time spent awake at night, respectively. Given the detection rate of associations in the same models run with random markers instead of candidate genes, we expected two associations to arise by chance. The detection of four associations between candidate genes and sleep, however, suggests that clock genes, a clock-related gene, or a gene involved in the melanocortin system, could play key roles in maintaining phenotypic variation in sleep behavior in avian populations. Knowledge of the genetic architecture underlying sleep behavior in the wild is important because it will enable ecologists to assess the evolution of sleep in response to selection. PMID:26739645

  16. Changes in free-living bacterial community diversity reflect the magnitude of environmental variability.

    PubMed

    Ortmann, Alice C; Ortell, Natalie

    2014-01-01

    A 2-year study was undertaken to compare patterns in the diversity of free-living bacteria in a river-dominated estuary and offshore, on the shelf, to determine whether changes in the free-living bacterial community could be related to differences in environmental seasonality and variability. Although the environmental conditions inshore were significantly more variable than those on the shelf and demonstrated clear seasonal patterns, there were no significant differences in the alpha diversity of the communities based on richness, evenness, or phylogenetic diversity. Comparison of communities using Bray-Curtis similarity indicated no significant differences in the magnitude of change between sequential samples from inshore and on the shelf. Seasonal differences were detected both inshore and on the shelf. However, analysis using the weighted UniFrac distance indicated significantly lower overall change between shelf samples with no significant seasonal differences. These findings suggest different patterns of change between the two sites. Inshore, changes in the relative abundance of distantly related bacterial species reflect the larger environmental variability, while on the shelf, changes in the relative abundance of closely related bacterial species or strains may result in a more functionally stable community. Thus, the magnitude of environmental change can alter patterns of bacterial diversity in marine systems. PMID:24117806

  17. Apoptosis as a mechanism of cytolysis of tumor cells by a pathogenic free-living amoeba.

    PubMed Central

    Alizadeh, H; Pidherney, M S; McCulley, J P; Niederkorn, J Y

    1994-01-01

    Previous studies have shown that trophozoites of the pathogenic free-living amoeba Acanthamoeba castellanii rapidly lysed a variety of tumor cells in vitro. Tumor cells undergoing parasite-mediated lysis displayed characteristic cell membrane blebbing reminiscent of apoptosis. The present investigation examined the role of apoptosis (programmed cell death) in Acanthamoeba-mediated tumor cell lysis. The results showed that more than 70% of tumor cell DNA was fragmented following exposure to Acanthamoeba cell extracts. By contrast, only 7% of untreated control cells underwent DNA fragmentation. DNA fragmentation increased significantly in a dose-dependent fashion following concentration of the parasite extract. Apoptosis was also confirmed by DNA ladder formation. Characteristic DNA ladders, consisting of multimers of approximately 180 to 200 bp, were produced by tumor cells exposed to Acanthamoeba cell extracts. The morphology of tumor cell lysis was examined by light and scanning electron microscopy. Tumor cells exposed to parasite extract displayed morphological features characteristic of apoptosis including cell shrinkage, cell membrane blebbing, formation of apoptotic bodies, and nuclear condensation. By contrast, similar effects were not found in tumor cells exposed to extract similarly prepared from normal mammalian cells (i.e., human keratocytes). The results suggest that at least one species of pathogenic free-living amoeba is able to lyse tumor cells by a process that culminates in apoptosis. Images PMID:8132336

  18. Isolation, identification and antibiotic resistance of Campylobacter strains isolated from domestic and free-living pigeons.

    PubMed

    Dudzic, A; Urban-Chmiel, R; Stępień-Pyśniak, D; Dec, M; Puchalski, A; Wernicki, A

    2016-04-01

    1. The aim of this study was to evaluate the occurrence of Campylobacter spp. in domestic and free-living pigeons and to evaluate the antibiotic resistance profiles. 2. The material consisted of cloacal swabs obtained from 108 homing pigeons and fresh faeces from 72 wild birds from Lublin and its vicinity. The identification of strains isolated on differential/selective media for Campylobacter spp. was carried out by MALDI-TOF and PCR. The susceptibility to antibiotics was evaluated by minimum inhibitory concentration (MIC) in Mueller-Hinton broth. 3. A total of 35 strains of Campylobacter spp. were isolated; 27 were identified as Campylobacter jejuni and 8 as Campylobacter coli. Over half of the isolates were resistant to erythromycin and streptomycin, 40% of strains were resistant to tetracycline and ampicillin and 37% isolates were resistant to amoxicillin. Resistance to two or more antibiotics was observed in all strains tested. 4. The results indicate that both domestic and free-living pigeons are reservoirs for bacteria of the genus Campylobacter, which are characterised by varied and growing resistance to commonly used antibiotics. PMID:26841300

  19. Pathology of aural abscesses in free-living Eastern box turtles (Terrapene carolina carolina).

    PubMed

    Brown, Justin D; Richards, Jean M; Robertson, John; Holladay, Steven; Sleeman, Jonathan M

    2004-10-01

    Aural abscess or abscess of the middle ear is common in free-living Eastern box turtles (Terrapene carolina carolina) of Virginia (USA) and elsewhere. Although its etiology remains unknown, hypovitaminosis A has been suggested on the basis of similar lesions occurring in captive chelonians fed diets that are deficient in vitamin A. This hypothesis was supported by significantly greater body burdens of organochlorine compounds (reported disruptors of vitamin A metabolism) and a nonsignificant trend toward lower serum and hepatic vitamin A levels in free-living box turtles with this lesion. The tympanic epithelium was evaluated in 27 box turtles (10 with aural abscesses and 17 without). Lesions of the tympanic epithelium of box turtles with aural abscesses included hyperplasia, squamous metaplasia, hyperemia, cellular sloughing, granulomatous inflammation, and bacterial infection. These changes were more severe in turtles with aural abscesses than in those without and were more severe in tympanic cavities that had an abscess compared to those without when the lesion was unilateral. Organs from 21 box turtles (10 with aural abscesses and 11 without) from the study population were examined for microscopic lesions, and minimal histopathologic changes were found, none of which were similar to those found in the tympanic epithelium. Histopathologic changes in box turtles with aural abscesses were consistent with a syndrome that may involve hypovitaminosis A. PMID:15650088

  20. Specific Hopanoid Classes Differentially Affect Free-Living and Symbiotic States of Bradyrhizobium diazoefficiens

    PubMed Central

    Kulkarni, Gargi; Busset, Nicolas; Molinaro, Antonio; Gargani, Daniel; Chaintreuil, Clemence; Silipo, Alba

    2015-01-01

    ABSTRACT A better understanding of how bacteria resist stresses encountered during the progression of plant-microbe symbioses will advance our ability to stimulate plant growth. Here, we show that the symbiotic system comprising the nitrogen-fixing bacterium Bradyrhizobium diazoefficiens and the legume Aeschynomene afraspera requires hopanoid production for optimal fitness. While methylated (2Me) hopanoids contribute to growth under plant-cell-like microaerobic and acidic conditions in the free-living state, they are dispensable during symbiosis. In contrast, synthesis of extended (C35) hopanoids is required for growth microaerobically and under various stress conditions (high temperature, low pH, high osmolarity, bile salts, oxidative stress, and antimicrobial peptides) in the free-living state and also during symbiosis. These defects might be due to a less rigid membrane resulting from the absence of free or lipidA-bound C35 hopanoids or the accumulation of the C30 hopanoid diploptene. Our results also show that C35 hopanoids are necessary for symbiosis only with the host Aeschynomene afraspera but not with soybean. This difference is likely related to the presence of cysteine-rich antimicrobial peptides in Aeschynomene nodules that induce drastic modification in bacterial morphology and physiology. The study of hopanoid mutants in plant symbionts thus provides an opportunity to gain insight into host-microbe interactions during later stages of symbiotic progression, as well as the microenvironmental conditions for which hopanoids provide a fitness advantage. PMID:26489859

  1. A Model of Extracellular Enzymes in Free-Living Microbes: Which Strategy Pays Off?

    PubMed Central

    Thygesen, Uffe H.; Riemann, Lasse; Stedmon, Colin A.

    2015-01-01

    An initial modeling approach was applied to analyze how a single, nonmotile, free-living, heterotrophic bacterial cell may optimize the deployment of its extracellular enzymes. Free-living cells live in a dilute and complex substrate field, and to gain enough substrate, their extracellular enzymes must be utilized efficiently. The model revealed that surface-attached and free enzymes generate unique enzyme and substrate fields, and each deployment strategy has distinctive advantages. For a solitary cell, surface-attached enzymes are suggested to be the most cost-efficient strategy. This strategy entails potential substrates being reduced to very low concentrations. Free enzymes, on the other hand, generate a radically different substrate field, which suggests significant benefits for the strategy if free cells engage in social foraging or experience high substrate concentrations. Swimming has a slight positive effect for the attached-enzyme strategy, while the effect is negative for the free-enzyme strategy. The results of this study suggest that specific dissolved organic compounds in the ocean likely persist below a threshold concentration impervious to biological utilization. This could help explain the persistence and apparent refractory state of oceanic dissolved organic matter (DOM). Microbial extracellular enzyme strategies, therefore, have important implications for larger-scale processes, such as shaping the role of DOM in ocean carbon sequestration. PMID:26253668

  2. Estimating Age Ratios and Size of Pacific Walrus Herds on Coastal Haulouts using Video Imaging

    PubMed Central

    Monson, Daniel H.; Udevitz, Mark S.; Jay, Chadwick V.

    2013-01-01

    During Arctic summers, sea ice provides resting habitat for Pacific walruses as it drifts over foraging areas in the eastern Chukchi Sea. Climate-driven reductions in sea ice have recently created ice-free conditions in the Chukchi Sea by late summer causing walruses to rest at coastal haulouts along the Chukotka and Alaska coasts, which provides an opportunity to study walruses at relatively accessible locations. Walrus age can be determined from the ratio of tusk length to snout dimensions. We evaluated use of images obtained from a gyro-stabilized video system mounted on a helicopter flying at high altitudes (to avoid disturbance) to classify the sex and age of walruses hauled out on Alaska beaches in 2010–2011. We were able to classify 95% of randomly selected individuals to either an 8- or 3-category age class, and we found measurement-based age classifications were more repeatable than visual classifications when using images presenting the correct head profile. Herd density at coastal haulouts averaged 0.88 walruses/m2 (std. err. = 0.02), herd size ranged from 8,300 to 19,400 (CV 0.03–0.06) and we documented ∼30,000 animals along ∼1 km of beach in 2011. Within the herds, dependent walruses (0–2 yr-olds) tended to be located closer to water, and this tendency became more pronounced as the herd spent more time on the beach. Therefore, unbiased estimation of herd age-ratios will require a sampling design that allows for spatial and temporal structuring. In addition, randomly sampling walruses available at the edge of the herd for other purposes (e.g., tagging, biopsying) will not sample walruses with an age structure representative of the herd. Sea ice losses are projected to continue, and population age structure data collected with aerial videography at coastal haulouts may provide demographic information vital to ongoing efforts to understand effects of climate change on this species. PMID:23936106

  3. Estimating age ratios and size of Pacific walrus herds on coastal haulouts using video imaging

    USGS Publications Warehouse

    Monson, Daniel H.; Udevitz, Mark S.; Jay, Chadwick V.

    2013-01-01

    During Arctic summers, sea ice provides resting habitat for Pacific walruses as it drifts over foraging areas in the eastern Chukchi Sea. Climate-driven reductions in sea ice have recently created ice-free conditions in the Chukchi Sea by late summer causing walruses to rest at coastal haulouts along the Chukotka and Alaska coasts, which provides an opportunity to study walruses at relatively accessible locations. Walrus age can be determined from the ratio of tusk length to snout dimensions. We evaluated use of images obtained from a gyro-stabilized video system mounted on a helicopter flying at high altitudes (to avoid disturbance) to classify the sex and age of walruses hauled out on Alaska beaches in 2010–2011. We were able to classify 95% of randomly selected individuals to either an 8- or 3-category age class, and we found measurement-based age classifications were more repeatable than visual classifications when using images presenting the correct head profile. Herd density at coastal haulouts averaged 0.88 walruses/m2 (std. err. = 0.02), herd size ranged from 8,300 to 19,400 (CV 0.03–0.06) and we documented ~30,000 animals along ~1 km of beach in 2011. Within the herds, dependent walruses (0–2 yr-olds) tended to be located closer to water, and this tendency became more pronounced as the herd spent more time on the beach. Therefore, unbiased estimation of herd age-ratios will require a sampling design that allows for spatial and temporal structuring. In addition, randomly sampling walruses available at the edge of the herd for other purposes (e.g., tagging, biopsying) will not sample walruses with an age structure representative of the herd. Sea ice losses are projected to continue, and population age structure data collected with aerial videography at coastal haulouts may provide demographic information vital to ongoing efforts to understand effects of climate change on this species.

  4. Estimating age ratios and size of pacific walrus herds on coastal haulouts using video imaging.

    PubMed

    Monson, Daniel H; Udevitz, Mark S; Jay, Chadwick V

    2013-01-01

    During Arctic summers, sea ice provides resting habitat for Pacific walruses as it drifts over foraging areas in the eastern Chukchi Sea. Climate-driven reductions in sea ice have recently created ice-free conditions in the Chukchi Sea by late summer causing walruses to rest at coastal haulouts along the Chukotka and Alaska coasts, which provides an opportunity to study walruses at relatively accessible locations. Walrus age can be determined from the ratio of tusk length to snout dimensions. We evaluated use of images obtained from a gyro-stabilized video system mounted on a helicopter flying at high altitudes (to avoid disturbance) to classify the sex and age of walruses hauled out on Alaska beaches in 2010-2011. We were able to classify 95% of randomly selected individuals to either an 8- or 3-category age class, and we found measurement-based age classifications were more repeatable than visual classifications when using images presenting the correct head profile. Herd density at coastal haulouts averaged 0.88 walruses/m(2) (std. err. = 0.02), herd size ranged from 8,300 to 19,400 (CV 0.03-0.06) and we documented ∼30,000 animals along ∼1 km of beach in 2011. Within the herds, dependent walruses (0-2 yr-olds) tended to be located closer to water, and this tendency became more pronounced as the herd spent more time on the beach. Therefore, unbiased estimation of herd age-ratios will require a sampling design that allows for spatial and temporal structuring. In addition, randomly sampling walruses available at the edge of the herd for other purposes (e.g., tagging, biopsying) will not sample walruses with an age structure representative of the herd. Sea ice losses are projected to continue, and population age structure data collected with aerial videography at coastal haulouts may provide demographic information vital to ongoing efforts to understand effects of climate change on this species. PMID:23936106

  5. Estimation of walrus populations on sea ice with infrared imagery and aerial photography

    USGS Publications Warehouse

    Udevitz, M.S.; Burn, D.M.; Webber, M.A.

    2008-01-01

    Population sizes of ice-associated pinnipeds have often been estimated with visual or photographic aerial surveys, but these methods require relatively slow speeds and low altitudes, limiting the area they can cover. Recent developments in infrared imagery and its integration with digital photography could allow substantially larger areas to be surveyed and more accurate enumeration of individuals, thereby solving major problems with previous survey methods. We conducted a trial survey in April 2003 to estimate the number of Pacific walruses (Odobenus rosmarus divergens) hauled out on sea ice around St. Lawrence Island, Alaska. The survey used high altitude infrared imagery to detect groups of walruses on strip transects. Low altitude digital photography was used to determine the number of walruses in a sample of detected groups and calibrate the infrared imagery for estimating the total number of walruses. We propose a survey design incorporating this approach with satellite radio telemetry to estimate the proportion of the population in the water and additional low-level flights to estimate the proportion of the hauled-out population in groups too small to be detected in the infrared imagery. We believe that this approach offers the potential for obtaining reliable population estimates for walruses and other ice-associated pinnipeds. ?? 2007 by the Society for Marine Mammalogy.

  6. Novel sound production through contingency learning in the Pacific walrus (Odobenus rosmarus divergens).

    PubMed

    Schusterman, Ronald J; Reichmuth, Colleen

    2008-04-01

    Walruses (Odobenus rosmarus) are highly vocal amphibious mammals with a range of anatomical specializations that can provide plasticity to their sound emissions. The objective of this descriptive study was to determine whether contingency learning could be used to increase variability and induce novelty in the acoustic behavior of walruses. The subjects were two twelve-year-old captive walruses, a male and a female that had previously been conditioned using food reinforcement to produce several specific sounds in response to different discriminative cues. In the current task, these individuals were encouraged to produce novel sounds and novel sound combinations in air by withholding reinforcement for sounds previously emitted in a given session and providing reinforcement only for qualitative differences in emitted sounds. Following training in air, the walruses were tested under water with the same reinforcement contingency. The subjects responded as they had done in air, by varying their underwater sound emissions until reinforcement was provided. Many of the sounds and sound combinations produced by the subjects during underwater testing were quite different from those produced during training in air and those produced under water during baseline observations. Both the male and female spontaneously emitted knocks and soft bells which are components of the songs known to be emitted by mature male walruses during the breeding season. The finding that reinforced variability can induce creativity in sound production is consistent with recent experiments on budgerigar birds showing that vocal topographies, like motor responses, may be influenced by contingency learning. PMID:18038276

  7. Modeling haul-out behavior of walruses in Bering Sea ice

    USGS Publications Warehouse

    Udevitz, M.S.; Jay, C.V.; Fischbach, A.S.; Garlich-Miller, J. L.

    2009-01-01

    Understanding haul-out behavior of ice-associated pinnipeds is essential for designing and interpreting popula-tion surveys and for assessing effects of potential changes in their ice environments. We used satellite-linked transmitters to obtain sequential information about location and haul-out state for Pacific walruses, Odobenus rosmarus divergens (Il-liger, 1815), in the Bering Sea during April of 2004, 2005, and 2006. We used these data in a generalized mixed model of haul-out bout durations and a hierarchical Bayesian model of haul-out probabilities to assess factors related to walrus haul-out behavior, and provide the first predictive model of walrus haul-out behavior in sea ice habitat. Average haul-out bout duration was 9 h, but durations of haul-out bouts tended to increase with durations of preceding in-water bouts. On aver-age, tagged walruses spent only about 17% of their time hauled out on sea ice. Probability of being hauled out decreased with wind speed, increased with temperature, and followed a diurnal cycle with the highest values in the evening. Our haul-out probability model can be used to estimate the proportion of the population that is unavailable for detection in spring surveys of Pacific walruses on sea ice.

  8. Decadal Bering Sea seascape change: consequences for Pacific walruses and indigenous hunters.

    PubMed

    Ray, G Carleton; Hufford, Gary L; Overland, James E; Krupnik, Igor; McCormick-Ray, Jerry; Frey, Karen; Labunski, Elizabeth

    2016-01-01

    The most significant factors currently affecting the Pacific walrus (Odobenus rosmarus divergens) population are climate change and consequent changes in sea-ice morphology and dynamics. This paper integrates recent physical sea-ice change in the Bering Sea with biological and ecological conditions of walruses in their winter-spring reproductive habitat. Historically, walrus in winter-spring depended on a critical mass of sea-ice habitat to optimize social networking, reproductive fitness, feeding behavior, migration, and energetic efficiency. During 2003-2013, our cross-disciplinary, multiscale analysis from shipboard observations, satellite imagery, and ice-floe tracking, reinforced by information from indigenous subsistence hunters, documented change of sea-ice structure from a plastic continuum to a "mixing bowl" of ice floes moving more independently. This fragmentation of winter habitat preconditions the walrus population toward dispersal mortality and will also negatively affect the availability of resources for indigenous communities. We urge an expanded research and management agenda that integrates walrus natural history and habitat more completely with changing sea-ice morphology and dynamics at multiple scales, while also meeting the needs of local communities. PMID:27039507

  9. The prospects for biological control of the free-living stages of nematode parasites of livestock.

    PubMed

    Waller, P J; Faedo, M

    1996-01-01

    Control of nematode parasites of livestock is focused almost entirely on the parasitic stages within the host. Current methods rely on anthelmintic drugs, but these are under increasing threat with the development of resistance covering the whole spectrum of anthelmintics amongst the important nematode species of a range of livestock. However, invariably the greatest proportion of the parasite biomass resides not within the animal hosts, but in the external environment-commonly on pasture. It is in this environment that the free-living stages are vulnerable to a range of abiotic factors (extremes in temperature and desiccation) and biotic factors (macro- and micro-organisms) that may decimate their numbers. Of the latter, there are organisms, which exert their effects either indirectly by rendering faecal deposits inimical for the development of nematode eggs through to infective larvae, or directly by acting as pathogens or by exploiting the free-living stages as a food source. Within this vast assemblage of organisms, which include microarthropods, protozoa, viruses, bacteria and fungi, could well emerge a variety of biological control agents of nematode parasites. At present, greatest interest lies with the nematode-destroying fungi. Work has progressed from Petri dishes, to plots, to paddocks with several species of the genus Arthrobotrys and Duddingtonia flagrans. These studies indicate that the voracious nematophagous capabilities of these fungi, clearly demonstrated in vitro, translate to reductions in the number of infective larvae on pasture and indicate that levels of control, comparable to conventional schemes using anthelmintics, can be achieved. The challenge now lies in developing methods of administration of fungi to animals which can be applied under practical farm conditions. However, the pursuit of candidates for biological control of nematode parasites of livestock should not involve just a few species of nematophagous fungi. More than 100

  10. Movements of walruses radio-tagged in Bristol Bay, Alaska

    USGS Publications Warehouse

    Jay, C.V.; Hills, S.

    2005-01-01

    Satellite radio-location data from 57 adult male Pacific walruses (Odobenus rosmarus divergens) were used to estimate haul-out fidelity, broadly describe seasonal foraging distributions, and determine the approximate timing of autumn migration from Bristol Bay, Alaska. Data were collected intermittently during 1987-91 and 1995-2000, primarily during the period from May to October. Transmitter longevity ranged from less than 1 day to 560 days (median 75 d). The four tagging sites were the only haul-outs that were commonly used in the bay from spring through autumn. Mean fidelity, defined as the chance that an animal will return to an area where it previously hauled out, was 0.56 (SE = 0.09). However, small sample sizes precluded comparisons of fidelity among years and among haul-outs by season. No tagged animals migrated out of the bay between spring and early autumn. Combined monthly locations suggest that foraging occurred primarily in the southern and eastern areas of the bay in spring and gradually shifted towards northwestern areas in late autumn and winter. Ninety-eight percent of the in-water locations were in waters under 60 m deep, which account for 76% of the study area. Some animals migrated out of the bay in late autumn and winter; others remained within the bay throughout the year. Those making long-range migrations departed the bay during November and December. ?? The Arctic Institute of North America.

  11. Response of free-living marine nematodes to the southern Yellow Sea Cold Water Mass.

    PubMed

    Xu, Man; Liu, Qinghe; Zhang, Zhinan; Liu, Xiaoshou

    2016-04-15

    The Yellow Sea Cold Water Mass is a remarkable seasonal hydrographic event in the bottom water of the Yellow Sea. In order to reveal the response of free-living marine nematodes to this event, community structure and biodiversity indices of nematodes were studied in June and November 2013. The dominant species were Dorylaimopsis rabalaisi, Spilophorella sp., Daptonema sp., Sabatieria sp. and Parasphaerolaimus sp. In terms of trophic structure, epigrowth feeders were the most dominant group. Correlation analysis showed that Shannon-Wiener diversity index had significantly negative correlation with sediment silt-clay percentage, organic matter content and water content. Results of BIOENV indicated that sediment phaeophorbide content, water content, bottom water salinity and temperature were the most important factors related to nematode community. In conclusion, community structure and biodiversity indices of nematodes were consistent in the two sampling seasons. PMID:26965091

  12. Effect of flagellates on free-living bacterial abundance in an organically contaminated aquifer

    USGS Publications Warehouse

    Kinner, N.E.; Harvey, R.W.; Kazmierkiewicz-Tabaka, M.

    1997-01-01

    Little is known about the role of protists in the saturated subsurface. Porous media microcosms containing bacteria and protists, were used to determine whether flagellates from an organically contaminated aquifer could substantively affect the number of free- living bacteria (FLB). When flagellates were present, the 3-40% maximum breakthrough of fluorescent y labelled FLB injected into the microcosms was much lower than the 60-130% observed for killed controls Grazing and clearance rates (3-27 FLB flag-1 h-1 and 12-23 nI flag-1 h-1, respectively) calculated from the data were in the range reported for flagellates in other aqueous environments. The data provide evidence that flagellate bacterivory is an important control on groundwater FLB populations.

  13. Genotyping of Cryptosporidium spp. from free-living wild birds from Brazil.

    PubMed

    Sevá, Anaiá da Paixão; Funada, Mikaela Renata; Richtzenhain, Leonardo; Guimarães, Marta Brito; Souza, Sheila de Oliveira; Allegretti, Luciana; Sinhorini, Juliana Anaya; Duarte, Vanessa Vertematti; Soares, Rodrigo Martins

    2011-01-10

    In wild and domestic birds, cryptosporidiosis is often associated with infections by Cryptosporidium galli, Cryptosporidium baileyi and Cryptosporidium meleagridis. In addition to these species, a number of avian Cryptosporidium species yet to be fully characterized are commonly found among exotic and wild avian isolates. The present study aimed to detect and identify samples of Cryptosporidium spp. from free-living wild birds, in order to contribute to the knowledge of the variability of this parasite in the free-living population of Brazil. Stool samples were collected from 242 birds, with the following proportions of individuals: 50 Emberizidae (20.7%), 112 Psittacidae (46.3%), 44 Cardinalidae (18.2%), 12 Turdidae (5.0%), eight Ramphastidae (3.3%), seven Icteridae (2.9%), three Estrilididae (1.2%), two Contigidae (0.8%), two Thraupidae (0.8%) and two Fringilidae (0.8%). Among the 242 fecal samples from wild birds, 16 (6.6%) were positive for the presence of oocysts of Cryptosporidium. Molecular characterization of the 16 samples of Cryptosporidium, were performed with phylogenetic reconstructions employing 292 positions of 18S rDNA. None of the samples of birds was characterized as C. meleagridis. C. galli was identified in one rufous-bellied thrush (Turdus rufiventris), five green-winged saltators (Saltator similis), one slate-coloured seedeater (Sporophila schistacea), one goldfinch (Carduelis carduelis) and three saffron finches (Sicalis flaveola). One goldfinch isolate, one buffy-fronted seedeater (Sporophila frontalis), one red-cowled cardinal (Paroaria dominicana) and one other saffron finch (S. flaveola) were identified as C. baileyi. Avian genotype II was found in an isolate from a white-eyed parakeet (Aratinga leucophthalma). Clinical symptoms of cryptosporidiosis in birds have already been described and the number of wild birds which were shedding parasites was high. Therefore, further epidemiological research and disease surveillance of birds in the

  14. Nervous system immunohistochemistry of the parasitic cnidarian Polypodium hydriforme at its free-living stage.

    PubMed

    Raikova, Ekaterina V; Raikova, Olga I

    2016-04-01

    Polypodium hydriforme, the only species in Polypodiozoa, which is currently considered a class of Cnidaria, and likely a sister group to Medusozoa (together with Myxozoa), is a cnidarian adapted to intracellular parasitism inside sturgeon oocytes. Free-living P. hydriforme lives on river bottoms; it walks on supporting tentacles and uses sensory tentacles to capture food and bring it to the mouth. The nervous system of free-living P. hydriforme was studied by confocal microscopy and immunohistochemistry using antibodies to FMRF-amide and α-tubulin combined with phalloidin-staining of F-actin fibres. A sensory FMRF-amide immunoreactive (IR) nerve net and an α-tubulin IR nerve net have been identified. The FMRF-amide IR nerve net underlies the epidermis along the tentacles and around the mouth; it consists of neurites emanating from epidermal sensory cells and basiepidermal ganglion cells, and it connects with cnidocytes. A deeper-lying α-tubulin IR nerve net occurs only in tentacles and looks like chains of different-sized beads crossing the mesoglea and entwining muscles. Anti-α-tubulin staining also reveals microtubules in muscle cells following the longitudinal muscle fibres or the thin circular F-actin fibres of the tentacles. Cnidocytes in the tentacles are embedded in a regular hexagonal non-neural network formed by the tubulin IR cytoskeleton of epidermal cells. Cnidocils of the cnidocytes around the mouth and in walking tentacles are identical, but those in sensory tentacles differ in length and width. The possible homology of the tubulin IR nerve net with motor nerve nets of cnidarians is discussed. The absence of a classic nerve ring around the mouth and the lack of specialised sense organs are considered to be plesiomorphic characters for Cnidaria. PMID:26897553

  15. Prevalence of influenza A viruses in livestock and free-living waterfowl in Uganda

    PubMed Central

    2014-01-01

    Background Avian influenza viruses may cause severe disease in a variety of domestic animal species worldwide, with high mortality in chickens and turkeys. To reduce the information gap about prevalence of these viruses in animals in Uganda, this study was undertaken. Results Influenza A virus prevalence by RT-PCR was 1.1% (45/4,052) while seroprevalence by ELISA was 0.8% (24/2,970). Virus prevalence was highest in domestic ducks (2.7%, 17/629) and turkeys (2.6%, 2/76), followed by free-living waterfowl (1.3%, 12/929) and swine (1.4%, 7/511). A lower proportion of chicken samples (0.4%, 7/1,865) tested positive. No influenza A virus was isolated. A seasonal prevalence of these viruses in waterfowl was 0.7% (4/561) for the dry and 2.2% (8/368) for the wet season. In poultry, prevalence was 0.2% (2/863) for the dry and 1.4% (24/1,713) for the wet season, while that of swine was 0.0% (0/159) and 2.0% (7/352) in the two seasons, respectively. Of the 45 RT-PCR positive samples, 13 (28.9%) of them were H5 but none was H7. The 19 swine sera positive for influenza antibodies by ELISA were positive for H1 antibodies by HAI assay, but the subtype(s) of ELISA positive poultry sera could not be determined. Antibodies in the poultry sera could have been those against subtypes not included in the HAI test panel. Conclusions The study has demonstrated occurrence of influenza A viruses in animals in Uganda. The results suggest that increase in volumes of migratory waterfowl in the country could be associated with increased prevalence of these viruses in free-living waterfowl and poultry. PMID:24576325

  16. Energetic Assessment of the Nonexercise Activities under Free-Living Conditions

    PubMed Central

    2016-01-01

    Nonexercise activities (NAs) are common types of physical activity in daily life and critical component in energy expenditure. However, energetic assessment of NA, particularly in free-living subjects, is a technical challenge. In this study, mechanical modeling and portable device were used to evaluate five common types of NA in daily life: sit to stand, lie to sit, bowing while standing, squat, and right leg over left. A human indirect calorimeter was used to measure the activity energy expenditure of NA. Mechanical work and mechanical efficiency of NA were calculated for mechanical modeling. Thirty-two male subjects were recruited for the study (20 subjects for the development of models and 12 subjects for evaluation of models). The average (mean ± SD) mechanical work of 5 NAs was 2.31 ± 0.50, 2.88 ± 0.57, 1.75 ± 0.55, 3.96 ± 1.25, and 1.25 ± 0.51 J/kg·m, respectively. The mean mechanical efficiencies of those activities were 22.0 ± 3.3%, 26.5 ± 5.1%, 19.8 ± 3.7%, 24.0 ± 5.5%, and 26.3 ± 5.5%. The activity energy expenditure estimated by the models was not significantly different from the measurements by the calorimeter (p > 0.05) with accuracies of 102.2 ± 20.7%, 103.7 ± 25.8%, 105.6 ± 14.6%, 101.1 ± 28.0%, and 95.8 ± 20.7%, respectively, for those activities. These findings suggest that the mechanical models combined with a portable device can provide an alternative method for the energetic analysis of nonexercise activities under free-living condition. PMID:27493966

  17. Polar bear and walrus response to the rapid decline in Arctic sea ice

    USGS Publications Warehouse

    Oakley, K.; Whalen, M.; Douglas, D.; Udevitz, M.; Atwood, T.; Jay, C.

    2012-01-01

    The Arctic is warming faster than other regions of the world due to positive climate feedbacks associated with loss of snow and ice. One highly visible consequence has been a rapid decline in Arctic sea ice over the past 3 decades - a decline projected to continue and result in ice-free summers likely as soon as 2030. The polar bear (Ursus maritimus) and the Pacific walrus (Odobenus rosmarus divergens) are dependent on sea ice over the continental shelves of the Arctic Ocean's marginal seas. The continental shelves are shallow regions with high biological productivity, supporting abundant marine life within the water column and on the sea floor. Polar bears use sea ice as a platform for hunting ice seals; walruses use sea ice as a resting platform between dives to forage for clams and other bottom-dwelling invertebrates. How have sea ice changes affected polar bears and walruses? How will anticipated changes affect them in the future?

  18. Grapevine red blotch-associated virus is Present in Free-Living Vitis spp. Proximal to Cultivated Grapevines.

    PubMed

    Perry, Keith L; McLane, Heather; Hyder, Muhammad Z; Dangl, Gerald S; Thompson, Jeremy R; Fuchs, Marc F

    2016-06-01

    Red blotch is an emerging disease of grapevine associated with grapevine red blotch-associated virus (GRBaV). The virus spreads with infected planting stocks but no vector of epidemiological significance has been conclusively identified. A vineyard block of red-blotch-affected Vitis vinifera 'Cabernet franc' clone 214 was observed in California, with a clustering of infected, symptomatic vines focused along one edge of the field proximal to a riparian habitat with free-living Vitis spp. No genetic heterogeneity was observed in a 587-nucleotide region of the GRBaV genome in a population of 44 Cabernet franc clone 214 isolates. By contrast, genetic differences were observed in isolates from other cultivars and clones growing in adjacent blocks. GRBaV was confirmed infecting four free-living vines, two of which were shown to be V. californica × V. vinifera hybrids. The genomes of three free-living GRBaV vine isolates and seven from V. vinifera cultivars were compared; free-living vine isolates were shown to be more similar to each other and a 'Merlot' isolate than to the other cultivated vine isolates. The finding that GRBaV is present in free-living Vitis spp. indicates the virus can be spread by natural (nonhuman-mediated) means, and we hypothesize that in-field spread of GRBaV is occurring. PMID:26960112

  19. Predicting free-living energy expenditure using a miniaturized ear-worn sensor: an evaluation against doubly labeled water.

    PubMed

    Bouarfa, Loubna; Atallah, Louis; Kwasnicki, Richard Mark; Pettitt, Claire; Frost, Gary; Yang, Guang-Zhong

    2014-02-01

    Accurate estimation of daily total energy expenditure (EE)is a prerequisite for assisted weight management and assessing certain health conditions. The use of wearable sensors for predicting free-living EE is challenged by consistent sensor placement, user compliance, and estimation methods used. This paper examines whether a single ear-worn accelerometer can be used for EE estimation under free-living conditions.An EE prediction model as first derived and validated in a controlled setting using healthy subjects involving different physical activities. Ten different activities were assessed showing a tenfold cross validation error of 0.24. Furthermore, the EE prediction model shows a mean absolute deviation(MAD) below 1.2 metabolic equivalent of tasks. The same model was applied to a free-living setting with a different population for further validation. The results were compared against those derived from doubly labeled water. In free-living settings, the predicted daily EE has a correlation of 0.74, p 0.008, and a MAD of 272 kcal day. These results demonstrate that laboratory-derived prediction models can be used to predict EE under free-living conditions [corrected]. PMID:24108707

  20. Gray whale and walrus feeding excavation on the Bering Shelf, Alaska.

    USGS Publications Warehouse

    Nelson, C.H.; Johnson, K.R.; Barber, J.H., Jr.

    1987-01-01

    The gray whales (average mouth length, 2.0 m), when suction feeding on infaunal amphipods, create shallow pits in the sea floor, typically 2.5m x 1.5m x 10cm deep, which are distinct and mappable on sidescan sonographs. Similarly, walrus, when foraging for shallow clams, create long, linear feeding furrows that average 47 x 0.4 x 0.1m (length-width-depth). The whale feeding pits are commonly enlarged and oriented by seasonal storm-related scour. Walrus-feeding features are smaller, formed in higher-energy environments, and modified more rapidly than whale-feeding pits. -from Authors

  1. Status of free-living amoebae (Acanthamoeba spp., Naegleria fowleri, Balamuthia mandrillaris) in drinking water supplies in Karachi, Pakistan.

    PubMed

    Yousuf, Farzana Abubakar; Siddiqui, Ruqaiyyah; Subhani, Faysal; Khan, Naveed Ahmed

    2013-06-01

    The ability of pathogenic free-living amoebae to produce infections is a growing concern. In this study, we investigated the presence of free-living amoebae (Acanthamoeba spp., Naegleria fowleri, Balamuthia mandrillaris) in drinking water supplies in Karachi, Pakistan. Fifty-two domestic tap water samples were examined. Amoebae were identified by morphological characteristics and polymerase chain reaction. Thirty percent of the examined samples were positive for Acanthamoeba spp., 8% for N. fowleri while B. mandrillaris were not recovered. Additionally we examined secretory IgA antibody to Acanthamoeba and B. mandrillaris. Acanthamoeba antibody prevalence rate was 100% in both males and females, while B. mandrillaris antibody prevalence rate was 5.5% in males only (females were negative). Our findings suggest that free-living amoebae are a potential health hazard in domestic water supplies in Karachi, Pakistan. PMID:23708583

  2. Cardiorespiratory fitness estimation using wearable sensors: Laboratory and free-living analysis of context-specific submaximal heart rates.

    PubMed

    Altini, Marco; Casale, Pierluigi; Penders, Julien; Ten Velde, Gabrielle; Plasqui, Guy; Amft, Oliver

    2016-05-01

    In this work, we propose to use pattern recognition methods to determine submaximal heart rate (HR) during specific contexts, such as walking at a certain speed, using wearable sensors in free living, and using context-specific HR to estimate cardiorespiratory fitness (CRF). CRF of 51 participants was assessed by a maximal exertion test (V̇o2 max). Participants wore a combined accelerometer and HR monitor during a laboratory-based simulation of activities of daily living and for 2 wk in free living. Anthropometrics, HR while lying down, and walking at predefined speeds in laboratory settings were used to estimate CRF. Explained variance (R(2)) was 0.64 for anthropometrics, and increased up to 0.74 for context-specific HR (0.73-0.78 when including fat-free mass). Next, we developed activity recognition and walking speed estimation algorithms to determine the same contexts (i.e., lying down and walking) in free living. Context-specific HR in free living was highly correlated with laboratory measurements (Pearson's r = 0.71-0.75). R(2) for CRF estimation was 0.65 when anthropometrics were used as predictors, and increased up to 0.77 when including free-living context-specific HR (i.e., HR while walking at 5.5 km/h). R(2) varied between 0.73 and 0.80 when including fat-free mass among the predictors. Root mean-square error was reduced from 354.7 to 281.0 ml/min by the inclusion of context-specific HR parameters (21% error reduction). We conclude that pattern recognition techniques can be used to contextualize HR in free living and estimated CRF with accuracy comparable to what can be obtained with laboratory measurements of HR response to walking. PMID:26940653

  3. Diversity and activity of free-living nitrogen-fixing bacteria and total bacteria in organic and conventionally managed soils.

    PubMed

    Orr, Caroline H; James, Angela; Leifert, Carlo; Cooper, Julia M; Cummings, Stephen P

    2011-02-01

    Agricultural soils are heterogeneous environments in which conditions affecting microbial growth and diversity fluctuate widely in space and time. In this study, the molecular ecology of the total bacterial and free-living nitrogen-fixing communities in soils from the Nafferton Factorial Systems Comparison (NFSC) study in northeast England were examined. The field experiment was factorial in design, with organic versus conventional crop rotation, crop protection, and fertility management factors. Soils were sampled on three dates (March, June, and September) in 2007. Total RNA was extracted from all soil samples and reverse transcribed. Denaturing gradient gel electrophoresis (DGGE) and quantitative PCR (qPCR) were used to analyze nifH and 16S rRNA genes in order to study free-living diazotrophs and the total bacterial community, respectively. Crop rotation was shown to have a significant effect on total bacterial diversity (and that of free-living N fixers) (P ≤ 0.001). On all three dates, nifH activity was higher in the conventional crop rotation. In contrast, qPCR analysis of free-living N fixers indicated significantly higher levels of activity in conventionally fertilized plots in June (P = 0.0324) and in plots with organic crop protection in September (P = 0.0143). To our knowledge, the effects of organic and conventional farming systems on free-living diazotrophs have never been studied. An increased understanding of the impacts of management practices on free-living N fixers could allow modifications in soil management practices to optimize the activity of these organisms. PMID:21131514

  4. Comparison of nucleic acid content in populations of free-living and symbiotic Rhizobium meliloti by flow microfluorometry.

    PubMed Central

    Paau, A S; Lee, D; Cowles, J R

    1977-01-01

    Populations of symbiotic Rhizobium meliloti extracted from alfalfa nodules were shown by flow microfluorometry to contain a significant number of bacteroids with higher nucleic acid content than the free-living rhizobia. Bacteroids with lower nucleic acid content than the free-living bacteria were not detected in significant quantities in these populations. These results indicate that the incapability of bacteroids to reestablish growth in nutrient media may not be caused by a decrease in nucleic acid content of the symbiotic rhizobia. PMID:838682

  5. Response of Pacific walruses to disturbances from capture and handling activities at a haul-out in Bristol Bay, Alaska

    USGS Publications Warehouse

    Jay, C.V.; Olson, T.L.; Garner, G.W.; Ballachey, B.E.

    1998-01-01

    Observations were made on hems of the Pacific walrus (Odobenus rosmarus divergens) to study their response during the capturing and handling of adult males in summer 1995 at a haul-out at Cape Peirce in southwestern Alaska. Three behaviors (alertness, displacement, and dispersal) were quantified from 16 capture sessions. Herd sizes ranged from 622 to 5,289 walruses. Handling of an immobilized walrus consisted of attempts to attach telemetry devices to the tusks and collect various biological samples. Handling activities resulted in an average of about 10-fold or greater levels of behavior in alertness, displacement, and dispersal than during precapture and darting periods. High levels of behavior usually occurred within the first 45 min of handling. In 8 of 10 capture sessions, walruses returned to predisturbance levels of behavior within 40 min of cessation of the handling disturbance. Alertness and displacement were moderately and negatively correlated with herd size during the handling period, which may reflect an effect of a threshold distance from the point of disturbance to responding individuals. Observations of walruses tagged with VHF radio transmitters indicated that the activities from a given capture session did not preclude tagged walruses from using the haul-out over a subsequent 11-wk monitoring period. Moreover, non-tagged walruses continued to extensively use the haul-out during and after the period in which capture sessions were conducted.

  6. A year long study of the presence of free living amoeba in Spain.

    PubMed

    Magnet, A; Fenoy, S; Galván, A L; Izquierdo, F; Rueda, C; Fernandez Vadillo, C; Del Aguila, C

    2013-12-01

    Free-living amoeba such as Acanthamoeba and Balamuthia mandrillaris can act as opportunistic parasites on a wide range of vertebrates and they are becoming a serious threat to human health due to the resistance of their cysts to harsh environmental conditions, disinfectants, some water treatment practices and their ubiquitous distribution. This work was carried out in order to study the presence of these free-living amoebae (FLA) and their possible seasonality in a continental-Mediterranean climate in different types of water. For this purpose, a total of 223 water samples were collected during one year from four drinking water treatment plants (DWTP), seven wastewater treatment plants (WWTP) and six locations of influence (LI) on four river basins from Spain. Water samples were concentrated using the IDEXX Filta-Max(®) system and analyzed by a triplex real time PCR that detects Acanthamoeba, B. mandrillaris and Naegleria fowleri. Agar plates were also seeded for Acanthamoeba culture. From the three FLA studied, N. fowleri was not detected in any sample while B. mandrillaris was found at the entrance of a DWTP; this being, to our knowledge, the first report of these protozoa in water worldwide. On the other hand, the presence of Acanthamoeba observed was higher, 94.6% of the studied points were positive by real time PCR and 85.2% by culture, resulting in 99.1% positive for Acanthamoeba with both methods. All genetically analyzed Acanthamoeba were genotype T4 but nine different T4/DF3 sequences were observed, three of them being described for the first time, assigning new codes. No seasonal distribution of Acanthamoeba was found. These facts should serve as a warning to contact lens wearers of the risk of a poor hygiene when handling their contact lenses. It should also serve as a signal to physicians to consider FLA as a possible causative agent of nervous system infections as well as Acanthamoeba keratitis due to their high environmental presence shown in this

  7. Free-Living Turtles Are a Reservoir for Salmonella but Not for Campylobacter

    PubMed Central

    Marin, Clara; Ingresa-Capaccioni, Sofia; González-Bodi, Sara; Marco-Jiménez, Francisco; Vega, Santiago

    2013-01-01

    Different studies have reported the prevalence of Salmonella in turtles and its role in reptile-associated salmonellosis in humans, but there is a lack of scientific literature related with the epidemiology of Campylobacter in turtles. The aim of this study was to evaluate the prevalence of Campylobacter and Salmonella in free-living native (Emys orbicularis, n=83) and exotic (Trachemysscriptaelegans, n=117) turtles from 11 natural ponds in Eastern Spain. In addition, different types of samples (cloacal swabs, intestinal content and water from Turtle containers) were compared. Regardless of the turtle species, natural ponds where individuals were captured and the type of sample taken, Campylobacter was not detected. Salmonella was isolated in similar proportions in native (8.0±3.1%) and exotic (15.0±3.3%) turtles (p=0.189). The prevalence of Salmonella positive turtles was associated with the natural ponds where animals were captured. Captured turtles from 8 of the 11 natural ponds were positive, ranged between 3.0±3.1% and 60.0±11.0%. Serotyping revealed 8 different serovars among four Salmonella enterica subspecies: S. enterica subsp. enterica (n = 21), S. enterica subsp. salamae (n = 2), S. enterica subsp. diarizonae (n = 3), and S. enterica subsp. houtenae (n = 1). Two serovars were predominant: S. Thompson (n=16) and S. typhimurium (n=3). In addition, there was an effect of sample type on Salmonella detection. The highest isolation of Salmonella was obtained from intestinal content samples (12.0±3.0%), while lower percentages were found for water from the containers and cloacal swabs (8.0±2.5% and 3.0±1.5%, respectively). Our results imply that free-living turtles are a risk factor for Salmonella transmission, but do not seem to be a reservoir for Campylobacter. We therefore rule out turtles as a risk factor for human campylobacteriosis. Nevertheless, further studies should be undertaken in other countries to confirm these results. PMID:23951312

  8. A model for the dynamics of the free-living stages of equine cyathostomins.

    PubMed

    Leathwick, Dave M; Donecker, John M; Nielsen, Martin K

    2015-04-30

    Anthelmintic resistance in strongyle nematode parasites of horses is an expanding global problem and steps need to be taken to slow its development before control becomes more problematic. A move away from traditional deworming programmes, involving frequent whole-herd treatments with broad spectrum anthelmintics, to a more strategic or targeted use of chemicals is required. However, anthelmintic resistance management strategies which also maintain effective control are invariably more complicated and often require a greater understanding of both nematode epidemiology and grazing management, than does the simple routine use of chemicals. Here, as a first step in applying a modelling approach to resistance management in horses, a model is proposed to describe the dynamics on pasture of the free-living stages of equine cyathostomins. Firstly, the development and survival of the pre-infective stages is considered as a single process driven by temperature, and secondly, two populations of infective stage larvae (L3) are considered; those within the faecal pat and those on the herbage. Both are modelled using the box-car train approach which allows for variable development rates within a cohort of individuals and full overlap of generations. Uniquely, L3 survival is modelled as an ageing process where larvae progress through physiological age classes at a rate determined by temperature and rainfall. Model output reflects the dynamics of free-living stages under a range of environments. Under extreme cold, there is no development to L3 but eggs can survive for long periods to develop if conditions become favourable, while L3 survival is reduced under repeated freeze-thaw cycles. Under tropical conditions, development is rapid and a large number of L3 can be produced but survival of L3 is short. In temperate climates development tends to be slower, with large numbers of L3 produced over the warmer months but fewer over winter, and L3 survival tends to be higher all year

  9. Are baseline and short-term corticosterone stress responses in free-living amphibians repeatable?

    PubMed

    Narayan, Edward J; Cockrem, John F; Hero, Jean-Marc

    2013-01-01

    Amphibians respond to environmental stressors by secreting corticosterone, a stress hormone which promotes physiological and behavioral responses. Capture handling can be used to stimulate physiological stress response in amphibians. The use of single blood sampling and presentation of mean data often limits the quantification of within and between individual variation in baseline and short-term corticosterone stress responses in amphibians. It is important for studies of amphibian physiological ecology to determine whether baseline and short-term corticosterone stress responses are consistent or not. We quantified repeatability (r), a statistical measure of consistency, in baseline and short-term corticosterone stress responses to a standard capture and handling stress protocol in free-living adult male cane toads (Rhinella marina). Corticosterone metabolite concentrations were measured entirely non-invasively in male toad urine samples via an enzyme-immunoassay. During the first sampling occasion, urine samples were collected manually from individual male toads (n=20) immediately upon field capture. Toads were handled for 5min then transferred to plastic bags (constituting a mild stressor), and urine samples were collected hourly over 8h in the field. The toads were resampled for baseline (0h) urine corticosterone with hourly urine sampling over 8h (for quantification of the stress induced corticosterone) at 14 day intervals on three consecutive occasions. Within and between sample variations in urinary corticosterone metabolite concentrations were also quantified. All toads expressed a corticosterone stress response over 8h to our standard capture and handling stress protocol. Variations both within and between toads was higher for corrected integrated corticosterone concentrations than corticosterone concentrations at baseline, 3 or 6h. Baseline urinary corticosterone metabolite concentration of the male toads was highly repeatable (r=0.877) together with high

  10. Persistent organic pollutants in Alaskan ringed seal (Phoca hispida) and walrus (Odobenus rosmarus) blubber

    USGS Publications Warehouse

    Kucklick, J.R.; Krahn, M.M.; Becker, P.R.; Porter, B.J.; Schantz, M.M.; York, G.S.; O'Hara, T. M.; Wise, S.A.

    2006-01-01

    Since 1987, the Alaska Marine Mammal Tissue Archival Project (AMMTAP) has collected tissues from 18 marine mammal species. Specimens are archived in the National Institute of Standards and Technology's National Biomonitoring Specimen Bank (NIST-NBSB). AMMTAP has collected blubber, liver and/or kidney specimens from a number of ringed seals (Phoca hispida) from the areas near Nome and Barrow, Alaska and walruses (Odobenus rosmarus) from several locations in the Bering Sea. Thirty-three ringed seal and 15 walrus blubber samples from the NIST-NBSB were analyzed for persistent organic pollutants (POPs). The compounds determined included PCBs (28 congeners or congener groups), DDT and related compounds, hexachlorobenzene (HCB), hexachlorocyclohexane isomers (HCHs), chlordanes, dieldrin, and mirex. POP concentrations in ringed seal blubber were significantly higher in Barrow than in Nome when statistically accounting for the interaction of age and gender; HCB, however, was not statistically different between the two locations. Unlike males, POP concentrations and age were not significantly correlated in females probably as a result of lactational loss. POP concentrations in walrus blubber were lower than in ringed seal blubber for ??PCBs, chlordanes, and HCHs, but higher for dieldrin and mirex. POP concentrations in ringed seals and walrus from Alaska provide further evidence that the western Arctic tends to have lower or similar POP concentrations compared to the eastern Canadian Arctic. ?? The Royal Society of Chemistry 2006.

  11. Persistent organic pollutants in Alaskan ringed seal (Phoca hispida) and walrus (Odobenus rosmarus) blubber

    USGS Publications Warehouse

    Kucklick, John R.; Krahn, Margaret M.; Becker, Paul R.; Porter, Barbara J.; Schantz, Michele M.; York, Geoffrey S.; O'Hara, Todd M.; Wise, Stephen A.

    2006-01-01

    Since 1987, the Alaska Marine Mammal Tissue Archival Project (AMMTAP) has collected tissues from 18 marine mammal species. Specimens are archived in the National Institute of Standards and Technology's National Biomonitoring Specimen Bank (NIST-NBSB). AMMTAP has collected blubber, liver and/or kidney specimens from a number of ringed seals (Phoca hispida) from the areas near Nome and Barrow, Alaska and walruses (Odobenus rosmarus) from several locations in the Bering Sea. Thirty-three ringed seal and 15 walrus blubber samples from the NIST-NBSB were analyzed for persistent organic pollutants (POPs). The compounds determined included PCBs (28 congeners or congener groups), DDT and related compounds, hexachlorobenzene (HCB), hexachlorocyclohexane isomers (HCHs), chlordanes, dieldrin, and mirex. POP concentrations in ringed seal blubber were significantly higher in Barrow than in Nome when statistically accounting for the interaction of age and gender; HCB, however, was not statistically different between the two locations. Unlike males, POP concentrations and age were not significantly correlated in females probably as a result of lactational loss. POP concentrations in walrus blubber were lower than in ringed seal blubber for ΣPCBs, chlordanes, and HCHs, but higher for dieldrin and mirex. POP concentrations in ringed seals and walrus from Alaska provide further evidence that the western Arctic tends to have lower or similar POP concentrations compared to the eastern Canadian Arctic.

  12. Demography of the Pacific walrus (Odobenus rosmarus divergens): 1974-2006

    USGS Publications Warehouse

    Taylor, Rebecca L.; Udevitz, Mark S.

    2015-01-01

    Global climate change may fundamentally alter population dynamics of many species for which baseline population parameter estimates are imprecise or lacking. Historically, the Pacific walrus is thought to have been limited by harvest, but it may become limited by global warming-induced reductions in sea ice. Loss of sea ice, on which walruses rest between foraging bouts, may reduce access to food, thus lowering vital rates. Rigorous walrus survival rate estimates do not exist, and other population parameter estimates are out of date or have well-documented bias and imprecision. To provide useful population parameter estimates we developed a Bayesian, hidden process demographic model of walrus population dynamics from 1974 through 2006 that combined annual age-specific harvest estimates with five population size estimates, six standing age structure estimates, and two reproductive rate estimates. Median density independent natural survival was high for juveniles (0.97) and adults (0.99), and annual density dependent vital rates rose from 0.06 to 0.11 for reproduction, 0.31 to 0.59 for survival of neonatal calves, and 0.39 to 0.85 for survival of older calves, concomitant with a population decline. This integrated population model provides a baseline for estimating changing population dynamics resulting from changing harvests or sea ice.

  13. Isolation and identification of free-living amoebae from tap water in Sivas, Turkey.

    PubMed

    Coşkun, Kübra Açıkalın; Ozçelik, Semra; Tutar, Lütfi; Elaldı, Nazif; Tutar, Yusuf

    2013-01-01

    The present work focuses on a local survey of free-living amoebae (FLA) that cause opportunistic and nonopportunistic infections in humans. Determining the prevalence of FLA in water sources can shine a light on the need to prevent FLA related illnesses. A total of 150 samples of tap water were collected from six districts of Sivas province. The samples were filtered and seeded on nonnutrient agar containing Escherichia coli spread. Thirty-three (22%) out of 150 samples were found to be positive for FLA. The FLA were identified by morphology and by PCR using 18S rDNA gene. The morphological analysis and partial sequencing of the 18S rDNA gene revealed the presence of three different species, Acanthamoeba castellanii, Acanthamoeba polyphaga, and Hartmannella vermiformis. Naegleria fowleri, Balamuthia mandrillaris, or Sappinia sp. was not isolated during the study. All A. castellanii and A. polyphaga sequence types were found to be genotype T4 that contains most of the pathogenic Acanthamoeba strains. The results indicated the occurrence and distribution of FLA species in tap water in these localities of Sivas, Turkey. Furthermore, the presence of temperature tolerant Acanthamoeba genotype T4 in tap water in the region must be taken into account for health risks. PMID:23971043

  14. Daily foraging patterns in free-living birds: exploring the predation–starvation trade-off

    PubMed Central

    Bonter, David N.; Zuckerberg, Benjamin; Sedgwick, Carolyn W.; Hochachka, Wesley M.

    2013-01-01

    Daily patterns in the foraging behaviour of birds are assumed to balance the counteracting risks of predation and starvation. Predation risks are a function of the influence of weight on flight performance and foraging behaviours that may expose individuals to predators. Although recent research sheds light on daily patterns in weight gain, little data exist on daily foraging routines in free-living birds. In order to test the predictions of various hypotheses about daily patterns of foraging, we quantified the activity of four species of passerines in winter using radio-frequency identification receivers built into supplemental feeding stations. From records of 472 368 feeder visits by tagged birds, we found that birds generally started to feed before sunrise and continued to forage at a steady to increasing rate throughout the day. Foraging in most species terminated well before sunset, suggesting their required level of energy reserves was being reached before the end of the day. These results support the risk-spreading theorem over a long-standing hypothesis predicting bimodality in foraging behaviour purportedly driven by a trade-off between the risks of starvation and predation. Given the increased energetic demands experienced by birds during colder weather, our results suggest that birds' perceptions of risk are biased towards starvation avoidance in winter. PMID:23595267

  15. Biodiversity of free-living marine nematodes in the southern Yellow Sea, China

    NASA Astrophysics Data System (ADS)

    Liu, Xiaoshou; Xu, Man; Hua, Er; Zhang, Zhinan

    2016-02-01

    Biodiversity patterns of free-living marine nematodes were studied using specific, taxonomic and phylogenetic diversity measures in the southern Yellow Sea, China. The results showed that the average of Shannon-Wiener diversity index ( H') in the study area was 3.17. The higher values were distributed in the east part of Shandong coastal waters and north part of Jiangsu coastal waters, while the lower values were distributed in the southern Yellow Sea Cold Water Mass (YSCWM). The average of taxonomic diversity ( Δ) was 62.09 in the study region. The higher values were distributed in the transitional areas between the coastal areas and the southern YSCWM, while the lower values were distributed near the north part of Jiangsu coastal waters and the YSCWM. Results of correlation analysis of species diversity and taxonomic diversity showed that some of the two kinds of diversity index were independent, which suggested that combining the two kinds of diversity indices can reflect the ecological characteristics better. A test for 95% probability funnels of average taxonomic distinctness and variation in taxonomic distinctness suggested that Station 8794 (in the YSCWM) was outside of the 95% probability funnels, which may be due to the environmental stress. Results of correlation analysis between marine nematodes biodiversity and environmental variables showed that the sediment characteristics (Mdø and Silt-clay fraction) and phaeophorbide a (Pha- a) were the most important factors to determine the biodiversity patterns of marine nematodes.

  16. Occurrence and diversity of free-living protozoa on butterhead lettuce.

    PubMed

    Vaerewijck, Mario J M; Sabbe, Koen; Baré, Julie; Houf, Kurt

    2011-05-27

    The occurrence and diversity of free-living protozoa (FLP) on butterhead lettuce (Lactuca sativa L.) was investigated using four different sampling techniques (washing, swabbing, homogenization, and excising). FLP were recovered from all leaf samples (n=64), and cultures were FLP-positive after 1 week. Identification of FLP was performed by light microscopy and sequencing of denaturing gradient gel electrophoresis (DGGE)-separated 18S rRNA gene fragments. Bodo saltans, Spumella (-like) spp. and Cercozoa were the most common heterotrophic nanoflagellates. Amoebae belonged mainly to the Vannellida and Tubulinida. Colpoda steinii and Cyclidium glaucoma were the most common ciliates. The total number of FLP on middle leaves estimated by the Most Probable Number method ranged from 9.3 × 10(2)MPN/g to 2.4 × 10(5)MPN/g leaf, with flagellates (92 MPN/g to 2.4 ×10(5)MPN/g) being more abundant than amoebae (<3 MPN/g to 9.3 × 10(3)MPN/g) and ciliates (<3 MPN/g to 9.3 × 10(2)MPN/g). Washing or rinsing leaves followed by spin-drying in a household salad spinner reduced the protozoan number with maximum one log unit. Our survey shows that FLP on lettuce leaves are a common and diverse but largely unexplored group of microorganisms. PMID:21513995

  17. Epidemiology of viral haemorrhagic disease and myxomatosis in a free-living population of wild rabbits.

    PubMed

    Calvete, C; Estrada, R; Villafuerte, R; Osácar, J J; Lucientes, J

    2002-06-22

    From January 1993 to June 1996, the epidemiology of myxomatosis and viral haemorrhagic disease (VHD) was studied in a free-living population of wild rabbits (Oryctolagus cuniculus) in Spain by means of serological surveys and radiotracking. Myxomatosis was endemic and associated with the breeding period. Its serological pattern was characterised by a 100 per cent prevalence of antibodies in adult rabbits and a rapid increase in antibodies in young rabbits in their first year. No mortality from myxomatosis was detected in adults, and mortality in young rabbits could not be estimated because of interference by predators and scavengers and the deaths of many radiotagged rabbits inside their burrows. VHD was also an endemic disease associated with the breeding period. Adults had a higher prevalence of antibodies against VHD than young rabbits, reaching values of 80 to 90 per cent. During the study, there was an increase in rabbit numbers as a result of a decrease in mortality from predation which was associated with an increase in mortality due to VHD and in the prevalence of antibodies to VHD. Mortality from VHD was lower in rabbits with VHD antibodies than in seronegative rabbits, but some mortality from the disease was also detected in seropositive rabbits. The annual mean mortality rate due to VHD in adult rabbits was estimated to be 21.8 per cent. PMID:12135072

  18. Clinical pathology and parasitologic evaluation of free-living nestlings of the Hyacinth Macaw (Anodorhynchus hyacinthinus).

    PubMed

    Allgayer, M C; Guedes, N M R; Chiminazzo, C; Cziulik, M; Weimer, T A

    2009-10-01

    This study evaluated the health status and established hematologic and serum biochemistry parameters for free-living nestlings of the Hyacinth Macaw (Anodorhynchus hyacinthinus) from the Brazilian Pantanal (19 degrees 51'-19 degrees 58'S; 56 degrees 17'-56 degrees 24'W), for four consecutive years (from December 2003 through December 2006). Physical examinations indicated that all the birds were in good health. Endoparasites and blood parasites were not detected in any of the nestlings, and ectoparasites seemed to be limited to Philornis sp. (Diptera: Muscidae). Significantly higher levels of total white blood cells and heterophils, glucose, total protein, triglycerides, and phosphorus were observed in females. In females, higher cholesterol levels and packed cell volumes were observed in older birds, and total white blood cell and heterophil counts were higher in young animals. In males, uric acid levels were higher in older individuals. Wild Pantanal Hyacinth Macaws feed on only two species of palm nuts (Acrocomia totai and Scheelea phalerta). This limited food habit has a strong impact on population size and may alter the clinical pathology parameters of these birds. Therefore, knowledge of blood levels in normal individuals is essential to assess the physiologic and pathologic condition of wild macaws, to assess the effects of environmental changes on their health, and to contribute to conservation strategies of this endangered species. PMID:19901373

  19. Proteases from Entamoeba spp. and Pathogenic Free-Living Amoebae as Virulence Factors

    PubMed Central

    Serrano-Luna, Jesús; Piña-Vázquez, Carolina; Reyes-López, Magda; Ortiz-Estrada, Guillermo

    2013-01-01

    The standard reference for pathogenic and nonpathogenic amoebae is the human parasite Entamoeba histolytica; a direct correlation between virulence and protease expression has been demonstrated for this amoeba. Traditionally, proteases are considered virulence factors, including those that produce cytopathic effects in the host or that have been implicated in manipulating the immune response. Here, we expand the scope to other amoebae, including less-pathogenic Entamoeba species and highly pathogenic free-living amoebae. In this paper, proteases that affect mucin, extracellular matrix, immune system components, and diverse tissues and cells are included, based on studies in amoebic cultures and animal models. We also include proteases used by amoebae to degrade iron-containing proteins because iron scavenger capacity is currently considered a virulence factor for pathogens. In addition, proteases that have a role in adhesion and encystation, which are essential for establishing and transmitting infection, are discussed. The study of proteases and their specific inhibitors is relevant to the search for new therapeutic targets and to increase the power of drugs used to treat the diseases caused by these complex microorganisms. PMID:23476670

  20. Associations of free-living bacteria and dissolved organic compounds in a plume of contaminated groundwater

    USGS Publications Warehouse

    Harvey, R.W.; Barber, L.B., II

    1992-01-01

    Associations of free-living bacteria (FLB) and dissolved organic contaminants in a 4-km-long plume of sewage-contaminated groundwater were investigated. Abundance of FLB in the core of the plume (as delineated by maximum specific conductance) steadily decreased in the direction of flow from a point 0.25 km downgradient from the source to the toe of the plume. At 0.25 km downgradient, FLB comprised up to 31% of the total bacterial population, but constituted < 7% of the population at 2 km downgradient. Abundance of FLB correlated strongly (r = 0.80 n = 23) with total dissolved organic carbon (DOC) in contaminated groundwater between 0.64 and 2.1 km downgradient, although distributions of individual contaminants such as di-, tri- and tetrachloroethene were highly variable, and their association with FLB less clear. Numbers of FLB in the downgradient portion of the plume which is contaminated with branched-chain alkylbenzenesulfonate (ABS) surfactants were low (< 5??108/L) in spite of relatively high levels of DOC (up to 4 mg/L). However, abundance of FLB correlated strongly with non-surfactant DOC along vertical transects through the plume. The ratio of FLB to DOC and the ratio of FLB to attached bacteria generally decreased in the direction of flow and, consequently, with the age of the organic contaminants.

  1. Persistent diel melatonin rhythmicity during the Arctic summer in free-living willow warblers.

    PubMed

    Silverin, Bengt; Gwinner, Eberhard; Van't Hof, Thomas J; Schwabl, Ingrid; Fusani, Leonida; Hau, Michaela; Helm, Barbara

    2009-06-01

    Arctic environments are challenging for circadian systems. Around the solstices, the most important zeitgeber, the change between night and day, is reduced to minor fluctuations in light intensities. However, many species including songbirds nonetheless show clear diel activity patterns. Here we examine the possible physiological basis underlying diel rhythmicity under continuous Arctic summer light. Rhythmic secretion of the hormone melatonin constitutes an important part of the songbird circadian system and its experimental suppression, e.g., by constant light, usually leads to behavioral arrhythmia. We therefore studied melatonin patterns in a free-living migratory songbird, the willow warbler (Phylloscopus trochilus), that maintains diel activity during the Arctic summer. We compared melatonin profiles during late spring and summer solstice in two Swedish populations from the south (58 degrees N) and near the Arctic circle (66 degrees N). We found the northern Swedish population maintained clear diel changes in melatonin secretion during the summer solstice, although peak concentrations were lower than in southern Sweden. Melatonin levels were highest before midnight and in good accordance with periods of reduced activity. The maintenance of diel melatonin rhythmicity under conditions of continuous light may be one of the physiological mechanisms that enables continued functioning of the circadian system. PMID:19374903

  2. Behavioral correlates of heart rates of free-living Greater White-fronted Geese

    USGS Publications Warehouse

    Ely, C.R.; Ward, D.H.; Bollinger, K.S.

    1999-01-01

    We simultaneously monitored the heart rate and behavior of nine free-living Greater White-fronted Geese (Anser albifrons) on their wintering grounds in northern California. Heart rates of wild geese were monitored via abdominally-implanted radio transmitters with electrodes that received electrical impulses of the heart and emitted a radio signal with each ventricular contraction. Post-operative birds appeared to behave normally, readily rejoining flocks and flying up to 15 km daily from night-time roost sites to feed in surrounding agricultural fields. Heart rates varied significantly among individuals and among behaviors, and ranged from less than 100 beats per minute (BPM) during resting, to over 400 BPM during flight. Heart rates varied from 80 to 140 BPM during non-strenuous activities such as walking, feeding, and maintenance activities, to about 180 BPM when birds became alert, and over 400 BPM when birds were startled, even if they did not take flight. Postflight heart rate recovery time averaged < 10 sec. During agonistic encounters, heart rate exceeded 400 BPM; heart rates during social interactions were not predictable solely from postures, as heart rates were context-dependent, and were highest in initial encounters among individuals. Instantaneous measures of physiological parameters, such as heart rate, are often better indicators of the degree of response to external stimuli than visual observations and can be used to improve estimates of energy expenditure based solely on activity data.

  3. A smartphone-driven methodology for estimating physical activities and energy expenditure in free living conditions.

    PubMed

    Guidoux, Romain; Duclos, Martine; Fleury, Gérard; Lacomme, Philippe; Lamaudière, Nicolas; Manenq, Pierre-Henri; Paris, Ludivine; Ren, Libo; Rousset, Sylvie

    2014-12-01

    This paper introduces a function dedicated to the estimation of total energy expenditure (TEE) of daily activities based on data from accelerometers integrated into smartphones. The use of mass-market sensors such as accelerometers offers a promising solution for the general public due to the growing smartphone market over the last decade. The TEE estimation function quality was evaluated using data from intensive numerical experiments based, first, on 12 volunteers equipped with a smartphone and two research sensors (Armband and Actiheart) in controlled conditions (CC) and, then, on 30 other volunteers in free-living conditions (FLC). The TEE given by these two sensors in both conditions and estimated from the metabolic equivalent tasks (MET) in CC served as references during the creation and evaluation of the function. The TEE mean gap in absolute value between the function and the three references was 7.0%, 16.4% and 2.7% in CC, and 17.0% and 23.7% according to Armband and Actiheart, respectively, in FLC. This is the first step in the definition of a new feedback mechanism that promotes self-management and daily-efficiency evaluation of physical activity as part of an information system dedicated to the prevention of chronic diseases. PMID:25048352

  4. Free-living amoebae (FLA) co-occurring with legionellae in industrial waters.

    PubMed

    Scheikl, Ute; Sommer, Regina; Kirschner, Alexander; Rameder, Alexandra; Schrammel, Barbara; Zweimüller, Irene; Wesner, Wolfgang; Hinker, Manfred; Walochnik, Julia

    2014-08-01

    Legionella pneumophila is known as the causative agent of Legionnaires' disease and free-living amoebae (FLA) can serve as vehicles for legionellae. The aim of this study was to screen industrial waters for the occurrence of FLA and their co-occurrence with legionellae. A total of 201 water samples, including 129 cooling waters and 72 process waters, and 30 cooling lubricants were included in the study. Treated waters were screened periodically, pre and post treatment. Altogether, 72.6% of the water samples were positive for FLA, acanthamoebae being most prevalent (in 23.9% of the samples) followed by Vermamoeba vermiformis (19.4%). Only one cooling lubricant was positive (Acanthamoeba genotype T4). Legionella spp. were detected in 34.8% of the water samples and in 15% in high concentrations (>1000 CFU/100 ml). Altogether, 81.4% of the Legionella-positive samples were positive for FLA by standard methods. By applying a highly sensitive nested PCR to a representative set of random samples it was revealed that Legionella spp. always co-occurred with Acanthamoeba spp. Although the addition of disinfectants did influence amoebal density and diversity, treated waters showed no difference concerning FLA in the interphases of disinfection. It appears that FLA can re-colonize treated waters within a short period of time. PMID:25062389

  5. Complementary data on four methods for sampling free-living ticks in the Brazilian Pantanal.

    PubMed

    Ramos, Vanessa do Nascimento; Osava, Carolina Fonseca; Piovezan, Ubiratan; Szabó, Matias Pablo Juan

    2014-01-01

    In this study, four methods for sampling free-living ticks that are used in ecological and human tick-bite risk studies were evaluated. Cloth dragging, carbon dioxide traps and visual searches and inspection of plant litter on the ground were used in field and forest areas within the Brazilian Pantanal. Among the three tick species collected, Amblyomma sculptum predominated, followed by Amblyomma parvum and Amblyomma ovale. Dragging, a cheap and simple technique, yielded the highest numbers of ticks, particularly nymphs. The visual search detected a high number of adult ticks and provided information on tick questing height. Even though laborious, plant litter examination showed that large numbers of ticks may use this stratum. Carbon dioxide (CO2) traps are expensive and difficult to handle, but they are highly efficient for adult ticks, especially A. parvum. These data indicate that one method alone is incapable of providing a representative sample of the tick fauna in a particular area and that multiple techniques should be used for tick population studies. PMID:25517531

  6. Abundance, diversity and community composition of free-living protozoa on vegetable sprouts.

    PubMed

    Chavatte, N; Lambrecht, E; Van Damme, I; Sabbe, K; Houf, K

    2016-05-01

    Interactions with free-living protozoa (FLP) have been implicated in the persistence of pathogenic bacteria on food products. In order to assess the potential involvement of FLP in this contamination, detailed knowledge on their occurrence, abundance and diversity on food products is required. In the present study, enrichment and cultivation methods were used to inventory and quantify FLP on eight types of commercial vegetable sprouts (alfalfa, beetroot, cress, green pea, leek, mung bean, red cabbage and rosabi). In parallel, total aerobic bacteria and Escherichia coli counts were performed. The vegetable sprouts harbored diverse communities of FLP, with Tetrahymena (ciliate), Bodo saltans and cercomonads (flagellates), and Acanthamoeba and Vannella (amoebae) as the dominant taxa. Protozoan community composition and abundance significantly differed between the sprout types. Beetroot harbored the most abundant and diverse FLP communities, with many unique species such as Korotnevella sp., Vannella sp., Chilodonella sp., Podophrya sp. and Sphaerophrya sp. In contrast, mung bean sprouts were species-poor and had low FLP numbers. Sampling month and company had no significant influence, suggesting that seasonal and local factors are of minor importance. Likewise, no significant relationship between protozoan community composition and bacterial load was observed. PMID:26742616

  7. Particle-Associated Differ from Free-Living Bacteria in Surface Waters of the Baltic Sea

    PubMed Central

    Rieck, Angelika; Herlemann, Daniel P. R.; Jürgens, Klaus; Grossart, Hans-Peter

    2015-01-01

    Many studies on bacterial community composition (BCC) do not distinguish between particle-associated (PA) and free-living (FL) bacteria or neglect the PA fraction by pre-filtration removing most particles. Although temporal and spatial gradients in environmental variables are known to shape BCC, it remains unclear how and to what extent PA and FL bacterial diversity responds to such environmental changes. To elucidate the BCC of both bacterial fractions related to different environmental settings, we studied surface samples of three Baltic Sea stations (marine, mesohaline, and oligohaline) in two different seasons (summer and fall/winter). Amplicon sequencing of the 16 S rRNA gene revealed significant differences in BCC of both bacterial fractions among stations and seasons, with a particularly high number of PA operational taxonomic units (OTUs at genus-level) at the marine station in both seasons. “Shannon and Simpson indices” showed a higher diversity of PA than FL bacteria at the marine station in both seasons and at the oligohaline station in fall/winter. In general, a high fraction of bacterial OTUs was found exclusively in the PA fraction (52% of total OTUs). These findings indicate that PA bacteria significantly contribute to overall bacterial richness and that they differ from FL bacteria. Therefore, to gain a deeper understanding on diversity and dynamics of aquatic bacteria, PA and FL bacteria should be generally studied independently. PMID:26648911

  8. The control of food intake of free-living humans: putting the pieces back together.

    PubMed

    de Castro, John M

    2010-07-14

    The control of food intake has been studied using reductionism; by separately investigating environmental, physiological, and genetic variables. The general model of intake regulation attempts to reassemble the pieces into an organized whole. It postulates that intake is influenced by sets of both physiological factors which have negative feedback loops to intake and environmental factors which do not. Data and behavioral genetic analysis on a number of environmental, psychological, dietary, and social variables demonstrate that they have large impacts on the intake of free-living humans in their everyday environments and their magnitude and impact on intake are influenced by heredity. Recent evidence of built environment influences on activity and intake further indicate the profound influence of environmental circumstances on both intake and expenditure. A computer simulation of the general model of intake regulation demonstrates that the model predicts different maintained levels of intake and body weight depending upon the external environment and that change in the environment can produce new sustained levels. It is suggested that eating is influenced by a myriad of physiological and non-physiological factors and that total intake results from the integral of their influences. It is concluded that recombining the components broken down in the reductionistic process results in a functional whole that can well describe human behavior in natural environments. The paper represents an invited review by a symposium, award winner or keynote speaker at the Society for the Study of Ingestive Behavior [SSIB] Annual Meeting in Portland, July 2009. PMID:20450867

  9. Functional thioredoxin reductase from pathogenic and free-living Leptospira spp.

    PubMed

    Sasoni, Natalia; Iglesias, Alberto A; Guerrero, Sergio A; Arias, Diego G

    2016-08-01

    Low molecular mass thiols and antioxidant enzymes have essential functions to detoxify reactive oxygen and nitrogen species maintaining cellular redox balance. The metabolic pathways for redox homeostasis in pathogenic (Leptospira interrogans) and free-living (Leptospira biflexa) leptospires species were not functionally characterized. We performed biochemical studies on recombinantly produced proteins to in depth analyze kinetic and structural properties of thioredoxin reductase (LinTrxR) and thioredoxin (LinTrx) from L. interrogans, and two TrxRs (LbiTrxR1 and LbiTrxR2) from L. biflexa. All the TrxRs were characterized as homodimeric flavoproteins, with LinTrxR and LbiTrxR1 catalyzing the NADPH dependent reduction of LinTrx and DTNB. The thioredoxin system from L. interrogans was able to use glutathione disulfide, lipoamide disulfide, cystine and bis-γ-glutamyl cysteine and homologous peroxiredoxin as substrates. Classic TrxR activity of LinTrxR2 had not been evidenced in vitro, but recombinant Escherichia coli cells overexpressing LbiTrxR2 showed high tolerance to oxidative stress. The enzymatic systems herein characterized could play a key role for the maintenance of redox homeostasis and the function of defense mechanisms against reactive oxidant species in Leptospira spp. Our results contribute to the general knowledge about redox biochemistry in these bacteria, positioning TrxR as a critical molecular target for the development of new anti-leptospiral drugs. PMID:27178006

  10. Long-term viral serology of semi-free-living and captive ungulates.

    PubMed

    Frölich, K; Flach, E J

    1998-06-01

    Between 1973 and 1994, blood samples were collected at Whipsnade Wild Animal Park (UK) from three ungulate species kept in enclosures, including 28 European bison (Bison bonasus), 37 scimitar-horned oryx (Oryx dammah), and 49 Père David's deer (Elaphurus davidianus), and also from 144 semi-free-living Chinese water deer (Hydropotes inermis). These samples were tested for the presence of antibodies against three bovine viral diarrhea virus (BVDV)-like strains, three alpha-herpesvirus strains, enzootic hemorrhagic disease virus (EHDV) of deer, bovine respiratory syncytial virus (BRSV), bovine adenovirus 3 (BAV-3), and enzootic bovine leucosis virus (EBLV). Thirty-three individuals (13.1%) had antibodies to one or more of the three BVDV-like viruses, with titers ranging from 1:5 to 1:16, and 17 individuals (6.6%) were positive for antibodies to one or more of the three alpha-herpesviruses, with titers between 1:4 and 1:80. The highest titers and greatest proportion of seropositivity were against SH9/11, a recently isolated cytopathogenic pestivirus from wild roe deer (Capreolus capreolus). There were no positive reactors to BRSV and EHDV, and there was only one BAV-3 positive reactor, a scimitar-horned oryx, and one EBLV reactor, a European bison. There is no serologic evidence that semi-free-ranging Chinese water deer are important reservoirs or transmitters of the viral diseases investigated. PMID:9732031

  11. Acanthamoeba and other free-living amoebae in bat guano, an extreme habitat.

    PubMed

    Mulec, Janez; Dietersdorfer, Elisabeth; Üstüntürk-Onan, Miray; Walochnik, Julia

    2016-04-01

    Several representatives of the so-called free-living amoebae (FLA) are of medical relevance, not only as facultative pathogens but also as vehicles for pathogenic bacteria. Some FLA can survive and even grow under extreme environmental conditions. Bat guano is an exceptional habitat, the conditions becoming gradually more extreme with aging. In the current study, samples of bat guano of different ages from five caves in Slovenia were screened for the presence of FLA. FLA were isolated from almost all guano samples, including guano with a pH of 3.5. Only the two samples that had been drawn from >20-year-old guano were negative for FLA. Generally, FLA diversity correlated to high concentrations of cultivable bacteria (∼10(8) CFU/g) and fungi (∼10(5) CFU/g). Interestingly, the absence of FLA in seasoned guanos was mirrored by the presence of dictyostelid slime moulds. The isolated amoebae were identified as belonging to the genera Acanthamoeba, Copromyxa, Naegleria, Sappinia, Tetramitus, Thecamoeba, Vahlkampfia, Vannella and Vermamoeba. To the best of our knowledge, this is the first study on the diversity of FLA in guano. PMID:26678653

  12. Free-living spirochetes from Cape Cod microbial mats detected by electron microscopy

    NASA Technical Reports Server (NTRS)

    Teal, T. H.; Chapman, M.; Guillemette, T.; Margulis, L.

    1996-01-01

    Spirochetes from microbial mats and anaerobic mud samples collected in salt marshes were studied by light microscopy, whole mount and thin section transmission electron microscopy. Enriched in cellobiose-rifampin medium, selective for Spirochaeta bajacaliforniensis, seven distinguishable spirochete morphotypes were observed. Their diameters ranged from 0.17 micron to > 0.45 micron. Six of these morphotypes came from southwest Cape Cod, Massachusetts: five from Microcoleus-dominated mat samples collected at Sippewissett salt marsh and one from anoxic mud collected at School Street salt marsh (on the east side of Eel Pond). The seventh morphotype was enriched from anoxic mud sampled from the north central Cape Cod, at the Sandy Neck salt marsh. Five of these morphotypes are similar or identical to previously described spirochetes (Leptospira, Spirochaeta halophila, Spirochaeta bajacaliforniensis, Spirosymplokos deltaeiberi and Treponema), whereas the other two have unique features that suggest they have not been previously described. One of the morphotypes resembles Spirosymplokos deltaeiberi (the largest free-living spirochete described), in its large variable diameter (0.4-3.0 microns), cytoplasmic granules, and spherical (round) bodies with composite structure. This resemblance permits its tentative identification as a Sippewissett strain of Spirosymplokos deltaeiberi. Microbial mats samples collected in sterile Petri dishes and stored dry for more than four years yielded many organisms upon rewetting, including small unidentified spirochetes in at least 4 out of 100 enrichments.

  13. Comparison of total energy expenditure assessed by two devices in controlled and free-living conditions.

    PubMed

    Rousset, Sylvie; Fardet, Anthony; Lacomme, Philippe; Normand, Sylvie; Montaurier, Christophe; Boirie, Yves; Morio, Béatrice

    2015-01-01

    The objective of this study was to evaluate the validity of total energy expenditure (TEE) provided by Actiheart and Armband. Normal-weight adult volunteers wore both devices either for 17 hours in a calorimetric chamber (CC, n = 49) or for 10 days in free-living conditions (FLC) outside the laboratory (n = 41). The two devices and indirect calorimetry or doubly labelled water, respectively, were used to estimate TEE in the CC group and FLC group. In the CC, the relative value of TEE error was not significant (p > 0.05) for Actiheart but significantly different from zero for Armband, showing TEE underestimation (-4.9%, p < 0.0001). However, the mean absolute values of errors were significantly different between Actiheart and Armband: 8.6% and 6.7%, respectively (p = 0.05). Armband was more accurate for estimating TEE during sleeping, rest, recovery periods and sitting-standing. Actiheart provided better estimation during step and walking. In FLC, no significant error in relative value was detected. Nevertheless, Armband produced smaller errors in absolute value than Actiheart (8.6% vs. 12.8%). The distributions of differences were more scattered around the means, suggesting a higher inter-individual variability in TEE estimated by Actiheart than by Armband. Our results show that both monitors are appropriate for estimating TEE. Armband is more effective than Actiheart at the individual level for daily light-intensity activities. PMID:25141769

  14. Portion size effects on weight gain in a free living setting

    PubMed Central

    French, Simone A; Mitchell, Nathan R; Wolfson, Julian; Harnack, Lisa J; Jeffery, Robert W; Gerlach, Anne F; Blundell, John E; Pentel, Paul R

    2014-01-01

    Objective Examine the effect of weekday exposure over six months to different lunch sizes on energy intake and body weight in a free-living sample of working adults. Design and Methods Adults (n=233) were randomly assigned to one of three lunch size groups (400 kcal; 800 kcal; 1600 kcal) or to a no-free lunch control group for six months. Weight and energy intake were measured at baseline, and months 1, 3, and 6. Results Lunch energy was significantly higher in the 800 and 1600 kcal groups compared to the 400 kcal group (p < 0.0001). Total energy was significantly higher for the 1600 kcal group compared to the 400 and 800 kcal groups (p = 0.02). Body weight change at six months did not significantly differ at the 5% level by experimental group (1600 kcal group: +1.1 kg (sd=0.44); 800 kcal group: −0.1 kg (sd=0.42); 400 kcal group: −0.1 kg (sd=0.43); control group: 1.1 (sd=0.42); p=.07). Weight gain over time was significant in the 1600 kcal box lunch group (p < 0.05). Conclusions Weekday exposure for six months to a 1600 kcal lunch caused significant increases in total energy intake and weight gain. PMID:24510841

  15. Occurrence of free-living amoebae in streams of the Mexico Basin.

    PubMed

    Bonilla-Lemus, Patricia; Caballero Villegas, Adán S; Carmona Jiménez, Javier; Lugo Vázquez, Alfonso

    2014-11-01

    Free-living amoebae (FLA) are protozoa that are widely distributed in nature. They are important in the cycling of nutrients in aquatic food chains, but their distribution in natural aquatic environments is not well known. We conducted a survey to determine the presence and distribution of FLA and their relation to some physicochemical parameters in streams of the Mexico Basin in Central Mexico. Thirty-two sites from 18 streams were sampled. Samples were centrifuged and cultured onto NNA-media to isolate amoebae. Identifications were based on morphology. The pathogenicity of Acanthamoeba isolates was tested. Oxygen saturation, temperature, pH, specific conductance, water flow, dissolved reactive phosphorus, nitrites, nitrates, ammonia, dissolved inorganic nitrogen and coliforms were determined. One hundred-and-twenty FLA representing 18 genera were identified. The most frequent genera were Vannella, Rosculus and Acanthamoeba. The frequency of potentially pathogenic FLA was low and only 3 Acanthamoeba isolates were invasive in mice. The highest species richness of FLA was found in streams located into agriculture activity areas and those close to small villages that discharge wastewater into them. Water temperatures were always below 17°C. Oxygen saturation and pH were within the limits for the growth of most FLA. The presence of Acanthamoeba and Naegleria was low; nevertheless, they include potentially pathogenic species and can act as vectors and reservoirs for microbial pathogens and can produce human infections. PMID:25014111

  16. Effect of cytokinins and auxins on the growth of free-living conchocelis of Porphyra yezoensis

    NASA Astrophysics Data System (ADS)

    de-Lin, Duan; Xiu-Geng, Fei; Hong-Xu, Ren; Xiong, Chen; Ying, Zhu

    1995-09-01

    IAA 3-Indolylacetic acid, NAA a-Naphthylacetic acid and cytokinins in PESI culture medium were used in a study on the effects of plant hormones on the growth of free-living conchocelis of Porphyra yezoensis which showed that its growth in medium with cytokinins, IAA and NAA was more rapid than that in medium with non—phytohormones; that the optimal concentrations for promoting growth were 10 μg/L for IAA and ZA (Zeatin), and 0.1 μg/L for BA 6-Benzyl amino purine and KIN 6-Furfurylamino- purine. Mix use of NAA, IAA and cytokinins, NAA/ZA 1-1000/1 μg/L, NAA/BA 10/1-1000 μg/L, NAA/KIN 1/1-1000 μg/L promoted growth. IAA/ZA 0.1-1/0.1-1 μg/L; IAA/BA 0.1-1/0.1-10 μg/L IAA/KIN 1/0.1-1000 μg/L also promoted growth.

  17. Particle-Associated Differ from Free-Living Bacteria in Surface Waters of the Baltic Sea.

    PubMed

    Rieck, Angelika; Herlemann, Daniel P R; Jürgens, Klaus; Grossart, Hans-Peter

    2015-01-01

    Many studies on bacterial community composition (BCC) do not distinguish between particle-associated (PA) and free-living (FL) bacteria or neglect the PA fraction by pre-filtration removing most particles. Although temporal and spatial gradients in environmental variables are known to shape BCC, it remains unclear how and to what extent PA and FL bacterial diversity responds to such environmental changes. To elucidate the BCC of both bacterial fractions related to different environmental settings, we studied surface samples of three Baltic Sea stations (marine, mesohaline, and oligohaline) in two different seasons (summer and fall/winter). Amplicon sequencing of the 16 S rRNA gene revealed significant differences in BCC of both bacterial fractions among stations and seasons, with a particularly high number of PA operational taxonomic units (OTUs at genus-level) at the marine station in both seasons. "Shannon and Simpson indices" showed a higher diversity of PA than FL bacteria at the marine station in both seasons and at the oligohaline station in fall/winter. In general, a high fraction of bacterial OTUs was found exclusively in the PA fraction (52% of total OTUs). These findings indicate that PA bacteria significantly contribute to overall bacterial richness and that they differ from FL bacteria. Therefore, to gain a deeper understanding on diversity and dynamics of aquatic bacteria, PA and FL bacteria should be generally studied independently. PMID:26648911

  18. Longitudinal gonadal steroid excretion in free-living male and female meerkats (Suricata suricatta).

    PubMed

    Moss, A M; Clutton-Brock, T H; Monfort, S L

    2001-05-01

    Slender-tailed meerkats (Suricata suricatta) are small, diurnal, cooperatively breeding mongooses of the family Herpestidae. A prerequisite to fully understanding the mating system of meerkats is the development of a normative reproductive-endocrine database. This study examined longitudinal gonadal steroid excretion in all adult and juvenile individuals of both sexes within a social group of free-living meerkats sampled across an entire breeding season. The specific objectives of this study were to (1) validate noninvasive (fecal and urinary) gonadal steroid hormone monitoring techniques in male (testosterone) and female (estrogens, progestagens) meerkats; (2) test the feasibility of using these noninvasive methods under field conditions; (3) characterize the endocrine correlates associated with the female reproductive cycle, including estrus, gestation, and postpartum estrus; (4) examine longitudinal androgen excretion in males; and (5) determine whether social status (i.e., dominant versus subordinate) affected gonadal steroid excretion. In females, the results demonstrated the physiological validity of noninvasive monitoring in meerkats by corresponding excretory hormone concentrations to major reproductive events (i.e., estrous, pregnancy, parturition). Hormone excretory patterns during estrous intervals suggested possible mechanisms whereby reproductive suppression may operate in female meerkats. In males, androgen excretion did not correspond to changes in reproductive and aggressive behaviors, suggesting that dominance, and hence breeding access to females, was not regulated strictly by gonadal steroid production. The consistency in androgen excretion among male meerkats indicated that reproductive suppression may be mediated by behavioral (i.e., intermale aggression) rather than physiological (i.e., depressed spermatogenesis) mechanisms. PMID:11316421

  19. Phaeohyphomycosis in a free-living eastern box turtle (Terrapene carolina carolina).

    PubMed

    Joyner, Priscilla H; Shreve, Allison A; Spahr, John; Fountain, Andrea L; Sleeman, Jonathan M

    2006-10-01

    A free-ranging eastern box turtle (Terrapene carolina carolina) was referred to the Wildlife Center of Virginia with a three-month history of marked swelling of the right hind limb initially diagnosed as chromomycosis by histopathology. Hematology revealed severe anemia (9%), leukocytosis (12.8 cells x 10(3)/microl), heterophilia (6.14 cells x 10(3)/microl), and monocytosis (0.51 cells x 10(3)/microl). Gross necropsy revealed a firm, encapsulated 3 x 1 cm subcutaneous mass filled with dark brown-black, friable necrotic material of the distal right hind limb. Microscopically, the mass was characterized by a granulomatous inflammatory process with numerous multinucleated histiocytic giant cells. Fungal elements were present within necrotic centers and associated with multinucleated cells. Special stains revealed numerous phaeoid hyphae and yeast; Exophiala jeanselmei was isolated by routine mycologic culture. Phaeohyphomycosis was diagnosed based on the histologic appearance of the fungal elements within the mass and culture results. There was no histopathological evidence of systemic infection. This is the first report of phaeohyphomycosis caused by fungi of the genus Exophiala in free-living reptiles. PMID:17255461

  20. Free-living freshwater amoebae differ in their susceptibility to the pathogenic bacterium Legionella pneumophila.

    PubMed

    Dey, Rafik; Bodennec, Jacques; Mameri, Mouh Oulhadj; Pernin, Pierre

    2009-01-01

    Legionella pneumophila is known as a facultative intracellular parasite of free-living soil and freshwater amoebae, of which several species have been shown to support the growth of the pathogenic bacteria. We report for the first time the behaviour of two strains (c2c and Z503) of the amoeba Willaertia magna towards different strains of L. pneumophila serogroup 1 and compared it with Acanthamoeba castellanii and Hartmannella vermiformis, known to be L. pneumophila permissive. In contrast to the results seen with other amoebae, W. magna c2c inhibited the growth of one strain of Legionella (L. pneumophila, Paris), but not of others belonging to the same serogroup (L. pneumophila, Philadelphia and L. pneumophila, Lens). Also, the different L. pneumophila inhibited cell growth and induced cell death in A. castellanii, H. vermiformis and W. magna Z503 within 3-4 days while W. magna c2c strain remained unaffected even up to 7 days. Electron microscopy demonstrated that the formation of numerous replicative phagosomes observed within Acanthamoeba and Hartmannella is rarely seen in W. magna c2c cocultured with L. pneumophila. Moreover, the morphological differences were observed between L. pneumophila cultured either with Willaertia or other amoebae. These observations show that amoebae are not all equally permissive to L. pneumophila and highlight W. magna c2c as particularly resistant towards some strains of this bacterium. PMID:19016880

  1. Aspects of nitrogen-fixing Actinobacteria, in particular free-living and symbiotic Frankia.

    PubMed

    Sellstedt, Anita; Richau, Kerstin H

    2013-05-01

    Studies of nitrogen-fixing properties among the Gram-positive Actinobacteria revealed that some species of Arthrobacter, Agromyces, Corynebacterium, Mycobacterium, Micromonospora, Propionibacteria and Streptomyces have nitrogen-fixing capacity. This is also valid for Frankia that fix nitrogen both in free-living and in symbiotic conditions. Frankia symbiosis results from interaction between the Frankia bacteria and dicotyledonous plants, that is, actinorhiza. These plants, which are important in forestry and agroforestry, form, together with the legumes (Fabales), a single nitrogen-fixing clade. It has been shown that a receptor-like kinase gene, SymRK, is necessary for nodulation in actinorhizal plants as well as in legumes and arbuscular mycorrhizal fungi. Recently, the involvement of isoflavonoids as signal molecules during nodulation of an actinorhizal plant was shown. The genome sizes of three Frankia species, Frankia EANpec, ACN14a and CcI3, are different, revealing a relationship between genome size and geographical distribution. Recent genomic sequencing data of Frankia represent genomes from cluster I to IV, indicating that the genome of DgI is one of the smallest genomes in Frankia. In addition, nonsymbiotic Frankiales such as Acidothermus cellulolyticus, Blastococcus saxoobsidens, Geodermatophilus obscurus and Modestobacter marinus have a variety of genome sizes ranging from 2.4 to 5.57 Mb. PMID:23461635

  2. [Establishment of two cell lines secreting monoclonal antibodies against pathogenic free-living amoeba in Shanghai].

    PubMed

    Li, L; Li, H L; Shen, Q W; Lang, S

    1993-01-01

    Taking Naegleria australiensis, a species of pathogenic free-living amoeba (isolated in Shanghai in 1986), as antigen, two cell lines which provided potentially permanent source of monoclonal antibodies were established by lymphocytic hybridoma technique. The results of identification showed that: (1) the two cell lines could secret two different kinds of McAbs; (2) both of the McAbs were IgG (by gel diffusion); (3) McAbs produced in BALB/c mice were at high concentrations. One of them had a titer of > or = 1:8,192 and the other > or = 1:1,024 (by enzyme linked immunosorbent assay). A decline of the titers after purification by salting-out method was shown. One of the purified McAbs had a titer of > or = 1:2,024 and the other > or = 1:128. We have adopted two ways of recovering cryopreserved cells: ordinary recovering and "direct" recovering. The latter way was more practical because it could reduce the cycle of antibody production, and avoid contamination and chromosome variation. Experiments with different doses of cells revealed that, if the latter way was used, the optimal dose was 3 to 5 x 10(6) cells per mouse. PMID:8168238

  3. Do free-living amoebae in treated drinking water systems present an emerging health risk?

    PubMed

    Thomas, Jacqueline M; Ashbolt, Nicholas J

    2011-02-01

    There is an expanding body of evidence that free-living amoebae (FLA) increase both the numbers and virulence of water-based, human-pathogenic, amoeba-resisting microorganisms (ARM). Legionella spp., Mycobacterium spp., and other opportunistic human pathogens are known to be both ARM and also the etiologic agents of potentially fatal human lung infections. However, comparatively little is known about the FLA that may facilitate ARM growth in drinking water. This review examines the available literature on FLA in treated drinking water systems; in total 26 studies from 18 different countries. FLA were reported to breakthrough the water treatment barrier and enter distribution systems, in addition to the expected post-treatment system ingress. Once in the distribution system there is evidence of FLA colonization and regrowth especially in reservoirs and in-premise plumbing storage tanks. At the point of use the average FLA detection rate was 45% but highly variable (n = 16, σ = 31) due to both differences in both assay methods and the type of water systems examined. This review reveals that FLA are consistently detected in treated drinking water systems around the world and present a yet unquantified emerging health risk. However, more research is urgently required before accurate risks assessments can be undertaken to assess the impacts on human health, in households and institutions, due to exposure to FLA facilitated pathogenic ARM. PMID:21194220

  4. Functional genomics of hsp-90 in parasitic and free-living nematodes

    PubMed Central

    Gillan, Victoria; Maitland, Kirsty; McCormack, Gillian; Nik Him, Nik A.I.I.; Devaney, Eileen

    2009-01-01

    Heat shock protein 90 (Hsp-90) is a highly conserved essential protein in eukaryotes. Here we describe the molecular characterisation of hsp-90 from three nematodes, the free-living Caenorhabditis elegans (Ce) and the parasitic worms Brugia pahangi (Bp) and Haemonchus contortus (Hc). These molecules were functionally characterised by rescue of a Ce-daf-21 (hsp-90) null mutant. Our results show a gradient of rescue: the C. elegans endogenous gene provided full rescue of the daf-21 mutant, while Hc-hsp-90 provided partial rescue. In contrast, no rescue could be obtained using a variety of Bp-hsp-90 constructs, despite the fact that Bp-hsp-90 was transcribed and translated in the mutant worms. daf-21 RNA interference (RNAi) experiments were carried out to determine whether knock-down of the endogenous daf-21 mRNA in N2 worms could be complemented by expression of either parasite gene. However neither parasite gene could rescue the daf-21 (RNAi) phenotypes. These results indicate that factors other than the level of sequence identity are important for determining whether parasite genes can functionally complement in C. elegans. PMID:19401205

  5. Seroprevalence of Toxoplasma gondii in free-living Amazon river dolphins (Inia geoffrensis) from central Amazon, Brazil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii is an important pathogen in aquatic mammals and its presence in these animals may indicate water contamination of aquatic environment by oocysts. Serum samples from 95 dolphins from free-living Amazon River dolphins (Inia geoffrensis) from Sustainable Development Reserve Mamirauá (...

  6. Seroprevalence of Toxoplasma gondii in free-living amazon river dolphins (Inia geoffrensis) from central Amazon, Brazil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii is an important pathogen in aquatic mammals and its presence in these animals may indicate water contamination of aquatic environment by oocysts. Serum samples from 95 dolphins from free-living Amazon River dolphins (Inia geoffrensis) from Sustainable Development Reserve Mamirauá (...

  7. Monoaminergic signaling as a target for anthelmintic drug discovery: receptor conservation among the free-living and parasitic nematodes.

    PubMed

    Komuniecki, Richard; Law, Wen Jing; Jex, Aaron; Geldhof, Peter; Gray, John; Bamber, Bruce; Gasser, Robin B

    2012-05-01

    This review is designed to summarize the information on monoamine-dependent paralysis as a target for anthelmintic development, examine the conservation of monoamine receptors in the genomes of both free-living and parasitic nematodes, and highlight the utility of the Caenorhabditis elegans model system for dissecting the monoaminergic modulation of locomotory decision-making. PMID:22343182

  8. Description of free-living marine nematodes found in the intestine of fishes from the Brazilian coast.

    PubMed

    Abolafia, Joaquín; Ruiz-Cuenca, Alba N; Fernandes, Berenice M M; Cohen, Simone C; Cárdenas, Melissa Q

    2015-01-01

    The marine nematodes usually comprise free-living species, although a few are parasitic. However, several cases of free-living nematodes found accidentally in the digestive tract of certain vertebrates, especially fishes, have sometimes been recorded and categorized as pseudoparasites. In the present work, two species of marine fishes, the rhomboid crappie, Diapterus rhombeus, and the silvered crappie, Eucinostomus argenteus (Perciformes: Gerreidae), from Angra dos Reis on the coast of Rio de Janeiro (Brazil) were examined. Seven species of free-living marine nematodes were found in the digestive tract of these fish. Several of these species remain unknown as free-living forms in Brazil. The combination of the fish feeding strategies and the poor preservation of the body of the nematode specimens found could indicate that these nematodes are pseudoparasites, appearing in the fishes' digestive tracts through accidental ingestion and thereafter surviving for brief periods of time. Descriptions, illustrations and tables of measurements are provided for all species. Six of these species (Croconema torquens, Dorylaimopsis pellucida, Oncholaimellus labiatus, Parodontophora breviamphida, Prooncholaimus ornatus, Trissonchulus latus) have been reported for the first time from the Brazilian coast. PMID:25947787

  9. CHARACTERIZATION OF AMINOPEPTIDASE IN THE FREE-LIVING NEMATODE PANAGRELLUS REDIVIVUS: SUBCELLULAR DISTRIBUTION AND POSSIBLE ROLE IN NEUROPEPTIDE METABOLISM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aminopeptidase was detected in homogenates of the free-living nematode Panagrellus redivivus with the aminoacyl substrate L-alanine-4-nitroanilide (Ala-4-NA). Subcellular distribution of the enzyme was unequal, with approximately 80 percent of total aminopeptidase in the soluble fraction and the rem...

  10. Hematologic and Total Plasma Protein Values in Free-Living Red-tailed Amazon Parrot Nestlings (Amazona brasiliensis) in Paraná State, Brazil.

    PubMed

    Vaz, Frederico F; Locatelli-Dittrich, Rosangela; Sipinski, Elenise A B; Abbud, Maria C; Sezerban, Rafael M; Schmidt, Elizabeth M S; Dittrich, Jaqueline; Cavalheiro, Maria L

    2015-09-01

    The red-tailed Amazon parrot (Amazona brasiliensis) is an endangered psittacid species that is endemic in the south and southeast Brazilian Atlantic coastal region. Hematologic evaluation is important to monitor the health of these birds, and information about laboratory values for this species is scarce. Hematologic and total plasma protein profiles were determined for 33 free-living nestling parrots in Paraná state, Brazil. Parrots were temporarily removed from the nest and manually restrained to record body weight and collect blood samples. Mean body weight was <400 g in 13 birds (group 1) and >400 g in 20 birds (group 2). Significantly higher levels of mean corpuscular hemoglobin concentrations, white blood cell counts, monocytes, and basophils were observed in younger birds (group 1). A stress leukogram (high white blood cell and heterophil count) was found in all nestlings, suggesting stress induced by capture and restraint. Parameters obtained in this study will be essential to assess the physiologic and pathologic condition of wild parrots, to evaluate the effects of environmental changes on their health, and to contribute to conservation efforts of this endangered species. PMID:26378664

  11. Bioenergetics model for estimating food requirements of female Pacific walruses (Odobenus rosmarus divergens)

    USGS Publications Warehouse

    Noren, S.R.; Udevitz, M.S.; Jay, C.V.

    2012-01-01

    Pacific walruses Odobenus rosmarus divergens use sea ice as a platform for resting, nursing, and accessing extensive benthic foraging grounds. The extent of summer sea ice in the Chukchi Sea has decreased substantially in recent decades, causing walruses to alter habitat use and activity patterns which could affect their energy requirements. We developed a bioenergetics model to estimate caloric demand of female walruses, accounting for maintenance, growth, activity (active in-water and hauled-out resting), molt, and reproductive costs. Estimates for non-reproductive females 0–12 yr old (65−810 kg) ranged from 16359 to 68960 kcal d−1 (74−257 kcal d−1 kg−1) for years with readily available sea ice for which we assumed animals spent 83% of their time in water. This translated into the energy content of 3200–5960 clams per day, equivalent to 7–8% and 14–9% of body mass per day for 5–12 and 2–4 yr olds, respectively. Estimated consumption rates of 12 yr old females were minimally affected by pregnancy, but lactation had a large impact, increasing consumption rates to 15% of body mass per day. Increasing the proportion of time in water to 93%, as might happen if walruses were required to spend more time foraging during ice-free periods, increased daily caloric demand by 6–7% for non-lactating females. We provide the first bioenergetics-based estimates of energy requirements for walruses and a first step towards establishing bioenergetic linkages between demography and prey requirements that can ultimately be used in predicting this population’s response to environmental change.

  12. Data logging of body temperatures provides precise information on phenology of reproductive events in a free-living arctic hibernator

    USGS Publications Warehouse

    Williams, C.T.; Sheriff, M.J.; Schmutz, J.A.; Kohl, F.; Toien, O.; Buck, C.L.; Barnes, B.M.

    2011-01-01

    Precise measures of phenology are critical to understanding how animals organize their annual cycles and how individuals and populations respond to climate-induced changes in physical and ecological stressors. We show that patterns of core body temperature (T b) can be used to precisely determine the timing of key seasonal events including hibernation, mating and parturition, and immergence and emergence from the hibernacula in free-living arctic ground squirrels (Urocitellus parryii). Using temperature loggers that recorded T b every 20 min for up to 18 months, we monitored core T b from three females that subsequently gave birth in captivity and from 66 female and 57 male ground squirrels free-living in the northern foothills of the Brooks Range Alaska. In addition, dates of emergence from hibernation were visually confirmed for four free-living male squirrels. Average T b in captive females decreased by 0.5–1.0°C during gestation and abruptly increased by 1–1.5°C on the day of parturition. In free-living females, similar shifts in T b were observed in 78% (n = 9) of yearlings and 94% (n = 31) of adults; females without the shift are assumed not to have given birth. Three of four ground squirrels for which dates of emergence from hibernation were visually confirmed did not exhibit obvious diurnal rhythms in T b until they first emerged onto the surface when T b patterns became diurnal. In free-living males undergoing reproductive maturation, this pre-emergence euthermic interval averaged 20.4 days (n = 56). T b-loggers represent a cost-effective and logistically feasible method to precisely investigate the phenology of reproduction and hibernation in ground squirrels.

  13. Sea-ice habitat preference of the Pacific walrus (Odobenus rosmarus divergens) in the Bering Sea: A multiscaled approach

    NASA Astrophysics Data System (ADS)

    Sacco, Alexander Edward

    The goal of this thesis is to define specific parameters of mesoscale sea-ice seascapes for which walruses show preference during important periods of their natural history. This research thesis incorporates sea-ice geophysics, marine-mammal ecology, remote sensing, computer vision techniques, and traditional ecological knowledge of indigenous subsistence hunters in order to quantitatively study walrus preference of sea ice during the spring migration in the Bering Sea. Using an approach that applies seascape ecology, or landscape ecology to the marine environment, our goal is to define specific parameters of ice patch descriptors, or mesoscale seascapes in order to evaluate and describe potential walrus preference for such ice and the ecological services it provides during an important period of their life-cycle. The importance of specific sea-ice properties to walrus occupation motivates an investigation into how walruses use sea ice at multiple spatial scales when previous research suggests that walruses do not show preference for particular floes. Analysis of aerial imagery, using image processing techniques and digital geomorphometric measurements (floe size, shape, and arrangement), demonstrated that while a particular floe may not be preferred, at larger scales a collection of floes, specifically an ice patch (< 4 km2), was preferred. This shows that walruses occupy ice patches with distinct ice features such as floe convexity, spatial density, and young ice and open water concentration. Ice patches that are occupied by adult and juvenile walruses show a small number of characteristics that vary from those ice patches that were visually unoccupied. Using synthetic aperture radar imagery, we analyzed co-located walrus observations and statistical texture analysis of radar imagery to quantify seascape preferences of walruses during the spring migration. At a coarse resolution of 100 -- 9,000 km2, seascape analysis shows that, for the years 2006 -- 2008

  14. The Wageningen Lowland Runoff Simulator (WALRUS): a lumped rainfall-runoff model for catchments with shallow groundwater

    NASA Astrophysics Data System (ADS)

    Brauer, C. C.; Teuling, A. J.; Torfs, P. J. J. F.; Uijlenhoet, R.

    2014-10-01

    We present the Wageningen Lowland Runoff Simulator (WALRUS), a novel rainfall-runoff model to fill the gap between complex, spatially distributed models which are often used in lowland catchments and simple, parametric (conceptual) models which have mostly been developed for sloping catchments. WALRUS explicitly accounts for processes that are important in lowland areas, notably (1) groundwater-unsaturated zone coupling, (2) wetness-dependent flow routes, (3) groundwater-surface water feedbacks and (4) seepage and surface water supply. WALRUS consists of a coupled groundwater-vadose zone reservoir, a quickflow reservoir and a surface water reservoir. WALRUS is suitable for operational use because it is computationally efficient and numerically stable (achieved with a flexible time step approach). In the open source model code default relations have been implemented, leaving only four parameters which require calibration. For research purposes, these defaults can easily be changed. Numerical experiments show that the implemented feedbacks have the desired effect on the system variables.

  15. The Wageningen Lowland Runoff Simulator (WALRUS): a lumped rainfall-runoff model for catchments with shallow groundwater

    NASA Astrophysics Data System (ADS)

    Brauer, C. C.; Teuling, A. J.; Torfs, P. J. J. F.; Uijlenhoet, R.

    2014-02-01

    We present the Wageningen Lowland Runoff Simulator (WALRUS), a novel rainfall-runoff model to fill the gap between complex, spatially distributed models which are often used in lowland catchments and simple, parametric (conceptual) models which have mostly been developed for mountainous catchments. WALRUS explicitly accounts for processes that are important in lowland areas, notably (1) groundwater-unsaturated zone coupling, (2) wetness-dependent flow routes, (3) groundwater-surface water feedbacks and (4) seepage and surface water supply. WALRUS consists of a coupled groundwater-vadose zone reservoir, a quickflow reservoir and a surface water reservoir. WALRUS is suitable for operational use because it is computationally efficient and numerically stable (achieved with a flexible time step approach). In the open source model code default relations have been implemented, leaving only four parameters which require calibration. For research purposes, these defaults can easily be changed. Numerical experiments show that the implemented feedbacks have the desired effect on the system variables.

  16. Detection of free-living amoebae by using multiplex quantitative PCR.

    PubMed

    Le Calvez, Thomas; Trouilhé, Marie-Cécile; Humeau, Philippe; Moletta-Denat, Marina; Frère, Jacques; Héchard, Yann

    2012-06-01

    Free-living amoebae (FLA) are protozoa found worldwide in soil and aquatic environments, which are able to colonize man-made water networks. Some FLA have the potential to be pathogenic and others might harbour pathogenic bacteria. Indeed, FLA feed on bacteria, but some bacteria could resist phagocytosis and either survive in FLA or even multiply within FLA. These bacteria are collectively named amoeba resistant bacteria (ARB). The best characterized example is Legionella pneumophila, for which FLA is the main reservoir in the environment. Not only could FLA be a reservoir that protects ARB, some bacteria might become more resistant to treatment and be more virulent. Thus, it is of medical significance to quantify FLA populations in soil, water or the environment. The main limitation for the quantification of FLA is that classical culture is not efficient and reliable for many genera and 'strains'. Thus, several PCR-based quantification methods have been published for various FLA. However, thus far, no method has been published to simultaneously quantify the main FLA genera in the same PCR reaction. In this study, we developed a multiplex qPCR method to detect both Amoebozoan (i.e. Acanthamoeba, Hartmannella and Echinamoeba) and Vahlkampfiidae (i.e. Vahlkampfia and Naegleria) using 18S ribosomal RNA as the target gene. This method was shown to be specific, reliable and sensitive, could be used for the quantification of FLA and is likely to be useful to anticipate risks due to FLA or pathogenic bacteria, such as L. pneumophila. PMID:22449586

  17. Presence of Legionella and Free-Living Amoebae in Composts and Bioaerosols from Composting Facilities

    PubMed Central

    Conza, Lisa; Pagani, Simona Casati; Gaia, Valeria

    2013-01-01

    Several species of Legionella cause Legionnaires’ disease (LD). Infection may occur through inhalation of Legionella or amoebal vesicles. The reservoirs of Legionella are water, soil, potting soil and compost. Some species of free-living amoebae (FLA) that are naturally present in water and soil were described as hosts for Legionella. This study aimed to understand whether or not the composting facilities could be sources of community-acquired Legionella infections after development of bioaerosols containing Legionella or FLA. We looked for the presence of Legionella (by co-culture) and FLA (by culture) in composts and bioaerosols collected at four composting facilities located in southern Switzerland. We investigated the association between the presence of Legionella and compost and air parameters and presence of FLA. Legionella spp. (including L. pneumophila) were detected in 69.3% (61/88) of the composts and FLA (mainly Acanthamoeba, Vermamoeba, Naegleria and Stenamoeba) in 92.0% (81/88). L. pneumophila and L. bozemanii were most frequently isolated. FLA as potential host for Legionella spp. were isolated from 40.9% (36/88) of the composts in all facilities. In Legionella-positive samples the temperature of compost was significantly lower (P = 0.012) than in Legionella-negative samples. Of 47 bioaerosol samples, 19.1% (9/47) were positive for FLA and 10.6% (5/47) for L. pneumophila. Composts (62.8%) were positive for Legionella and FLA contemporaneously, but both microorganisms were never detected simultaneously in bioaerosols. Compost can release bioaerosol containing FLA or Legionella and could represent a source of infection of community-acquired Legionella infections for workers and nearby residents. PMID:23844174

  18. Genome sequence of the Fleming strain of Micrococcus luteus, a simple free- living actinobacterium

    SciTech Connect

    Young, Michael; Artsatbanov, Vladislav; Beller, Harry R.; Chandra, Govind; Chater, Keith F.; Dover, Lynn G.; Goh, Ee-Been; Kahan, Tamar; Kaprelyants, Arseny S.; Kyrpides, Nikos; Lapidus, Alla; Lowry, Stephen R.; Lykidis, Athanasios; Mahillon, Jacques; Markowitz, Viktor; Mavrommatis, Konstantinos; Mukamolova, Galina V.; Oren, Aharon; Rokem, J. Stefan; Smith, Margaret C. M.; Young, Danielle I.; Greenblatt, Charles L.

    2009-11-01

    Micrococcus luteus (NCTC2665, Fleming strain) has one of the smallest genomes of free living actinobacteria sequenced to date, comprising a single circular chromosome of 2,501,097 bp (G+C content 73%) predicted to encode 2403 proteins. The genome shows extensive synteny with that of the closely related organism, Kocuria rhizophila, from which it was taxonomically separated relatively recently. Despite its small size, the genome harbors 73 IS elements, almost all of which are closely related to elements found in other actinobacteria. An IS element is inserted into the rrs gene of one of only two rrn operons found in M. luteus. The genome encodes only four sigma factors and fourteen response regulators, indicative of adaptation to a rather strict ecological niche (mammalian skin). The high sensitivity of M. luteus to {Beta}-lactam antibiotics may result from the presence of a reduced set of penicillin binding proteins and the absence of a wblC gene, which plays an important role in antibiotic resistance in other actinobacteria. Consistent with the restricted range of compounds it can use as a sole source of carbon for energy and growth, M. luteus has a minimal complement of genes concerned with carbohydrate transport and metabolism and its inability to utilize glucose as a sole carbon source may be due to the apparent absence of a gene encoding glucokinase. Uniquely among characterized bacteria, M. luteus appears to be able to metabolize glycogen only via trehalose, and to make trehalose only via glycogen. It has very few genes associated with secondary metabolism. In contrast to other actinobacteria, M. luteus encodes only one resuscitation-promoting factor (Rpf) required for emergence from dormancy and its complement of other dormancy-related proteins is also much reduced. M. luteus is capable of long-chain alkene biosynthesis, which is of interest for advanced biofuel production; a three gene cluster essential for this metabolism has been identified in the genome.

  19. Shoot Feeding as a Nutrient Acquisition Strategy in Free-Living Psylloids

    PubMed Central

    Steinbauer, Martin J.

    2013-01-01

    Shoot feeding by sucking insects is accepted as an adaptation to feeding where plant nutrients are most concentrated and/or of higher quality. Psylloids are an important hemipteran taxon, most of which are free-living and comprise many shoot feeding species, whose nutritional ecology has been largely ignored. I conducted a longitudinal study of Ctenarytaina eucalypti (Maskell) and C. bipartita Burckhardt et al. (Aphalaridae) feeding on eucalypts to document how within-plant (ontogenic) variation in nutritional quality, in particular of free amino acids, determines host suitability and hence the distribution and abundance of nymphs. Nymphs were most abundant within developing apical buds but were not more abundant on branchlets of greater vigour (indicated by rate of extension). Nymphs could be found up to two (C. bipartita) to three (C. eucalypti) alternate leaf pairs distant from apical buds but infrequently and in low numbers; they were never found on older, fully expanded leaves. The position of a leaf on a branchlet (indicative of age) determined its nutritional quality. Younger leaves had higher water contents, lower chlorophyll contents and differed in amino acid (essential and non-essential) composition compared to older leaves. The abundance of C. eucalypti nymphs on expanding leaves and in buds was positively correlated with the concentrations of methionine, valine and threonine in E. globulus leaves at the same or comparable position on a branchlet. The abundance of C. bipartita nymphs was positively correlated with foliar leucine concentrations. Shoot feeding by these two psyllids facilitates access to more concentrated, better quality plant nutrients but may not entirely explain the adaptive significance of their behaviour. The humid microclimate created by the architecture of the hosts’ apical buds protects eggs and nymphs from desiccation and is suggested to have had a significant influence on the evolution of host utilisation strategies of psyllids

  20. Osteoarthritis of the temporo-mandibular joint in free-living Soay sheep on St Kilda.

    PubMed

    Arthur, Colin; Watt, Kathryn; Nussey, Daniel H; Pemberton, Josephine M; Pilkington, Jill G; Herman, Jeremy S; Timmons, Zena L; Clements, Dylan N; Scott, Philip R

    2015-01-01

    Osteoarthritis (OA) is a common degenerative disease of synovial joints with the potential to cause pathology and welfare issues in both domestic and wild ruminants. Previous work has identified OA of the elbow joint in domestic sheep, but the prevalence of OA of the jaw and in particular the temporomandibular joint (TMJ) has not been previously reported. Following up a previous report of a single case of TMJ OA in a free-living population of Soay sheep on St Kilda in the Outer Hebrides, an archive of 2736 jaw bones collected from this population between 1985 and 2010 was surveyed. Evidence of TMJ OA was found in 35 sheep. Of these, 15 cases were unilateral (11 right side, 4 left side) and the remaining 20 were bilateral. TMJ pathology was much more common in females than males: only 3/35 cases were in males, with overall prevalence at 2.3% for females and 0.2% in males. Radiographic examination of TMJ with OA revealed extensive bone re-modelling with osteophytosis, particularly of the condyle of the mandible. There was a highly significant age-dependence in TMJ OA incidence among age classes: 30/35 cases occurred in geriatric sheep (aged 7 years or more; 11.1% prevalence within this age class), four in adults (2-6 years old; 0.9% prevalence), one in yearlings (0.3% prevalence) and none in lambs. The low incidence in males was confounded by sex differences in longevity: while 18% of females sampled died in the geriatric age class, only 2% of males did so. Although the low prevalence of the pathology limited the ability to test its association with other traits, it was possible to examine relationships with reproductive performance measures amongst geriatric females with and without TMJ OA. Although there were trends towards lower fecundity and lower lamb birth weight in the breeding season prior to death, these were not statistically significant. PMID:25458883

  1. Carriage of Staphylococcus aureus by Free-Living Wild Animals in Spain

    PubMed Central

    Mentaberre, Gregorio; Sánchez, Sergio; Fernández-Llario, Pedro; Casas-Díaz, Encarna; Mateos, Ana; Vidal, Dolors; Lavín, Santiago; Fernández-Garayzábal, José-Francisco; Domínguez, Lucas

    2014-01-01

    The presence of methicillin-susceptible Staphylococcus aureus (MSSA) was analyzed in different free-living wild animals to assess the genetic diversity and predominant genotypes on each animal species. Samples were taken from the skin and/or nares, and isolates were characterized by spa typing, multilocus sequence typing (MLST) and antimicrobial susceptibility testing. The proportion of MSSA carriers were 5.00, 22.93, 19.78, and 17.67% in Eurasian griffon vulture, Iberian ibex, red deer, and wild boar, respectively (P = 0.057). A higher proportion of isolates (P = 0.000) were recovered from nasal samples (78.51%) than skin samples (21.49%), but the 9.26% of red deer and 18.25% of wild boar would have been undetected if only nasal samples had been tested. Sixty-three different spa types were identified, including 25 new spa types. The most common were t528 (43.59%) in Iberian ibex, t548 and t11212 (15.79% and 14.04%) in red deer, and t3750 (36.11%) in wild boar. By MLST, 27 STs were detected, of which 12 had not been described previously. The most frequent were ST581 for Iberian ibex (48.72%), ST425 for red deer (29.82%), and ST2328 for wild boar (42.36%). Isolates from Eurasian griffon vulture belong to ST133. Host specificity has been observed for the most frequent spa types and STs (P = 0.000). The highest resistance percentage was found against benzylpenicillin (average, 22.2%), although most of the S. aureus isolates were susceptible to all antimicrobial tested. Basically, MSSA isolates were different from those MRSA isolates previously detected in the same animal species. PMID:24907325

  2. Morphological and molecular identification of free living amoeba isolated from hospital water in Tunisia.

    PubMed

    Trabelsi, Houaida; Dendana, F; Neji, S; Sellami, H; Cheikhrouhou, F; Makni, F; Ayadi, A

    2016-01-01

    Free-living amoebae (FLA) are opportunistic and ubiquitous protozoa that are widely found in various environmental sources. They are known to cause serious human infections. The aim of our study was to detect FLA and Acanthamoeba spp. in hospital water circuits. Eighty-four water samples were collected over a period of 4 months (September-December 2011) from different wards of the Sfax University Hospital (surgical services, intensive care unit, operating theater, and water storage tanks). FLA were detected in 53.5 % of samples as follows: surgical services (80 %), operating theater and surgical intensive care unit (13.3 %), medical intensive care unit (0 %), water storage tanks (6.6 %). The predominant morphotype was the acanthopodial (89 %). The others morphotypes were as follows: monopodial (40 %), dactylopodial (22 %), rugosa (62 %), eruptive (24 %), fan shaped (18 %), and polypodial (18 %). Acanthamoeba was found in 40 samples (47.6 %). 64.2 % of isolates were identified as Acanthamoeba spp. by PCR, using primers to amplify a region of 18S rDNA which showed variation in the product length. Sequence analysis of five PCR products identified Acanthamoeba sp. These isolates belong to T4, T10, and T11 genotypes, and to our knowledge this is the first report of the T10 and T11 genotype in Tunisia.The occurrence of potentially pathogenic FLA in the hospital environment may represent a health risk for patients, since these organisms can cause severe opportunistic illness and also can harbor pathogenic agents. Thus, increased awareness regarding these parasites and recognition of their importance, particularly in immunocompromised patients is crucial. PMID:26468150

  3. Presence of Legionella and free-living Amoebae in composts and bioaerosols from composting facilities.

    PubMed

    Conza, Lisa; Pagani, Simona Casati; Gaia, Valeria

    2013-01-01

    Several species of Legionella cause Legionnaires' disease (LD). Infection may occur through inhalation of Legionella or amoebal vesicles. The reservoirs of Legionella are water, soil, potting soil and compost. Some species of free-living amoebae (FLA) that are naturally present in water and soil were described as hosts for Legionella. This study aimed to understand whether or not the composting facilities could be sources of community-acquired Legionella infections after development of bioaerosols containing Legionella or FLA. We looked for the presence of Legionella (by co-culture) and FLA (by culture) in composts and bioaerosols collected at four composting facilities located in southern Switzerland. We investigated the association between the presence of Legionella and compost and air parameters and presence of FLA. Legionella spp. (including L. pneumophila) were detected in 69.3% (61/88) of the composts and FLA (mainly Acanthamoeba, Vermamoeba, Naegleria and Stenamoeba) in 92.0% (81/88). L. pneumophila and L. bozemanii were most frequently isolated. FLA as potential host for Legionella spp. were isolated from 40.9% (36/88) of the composts in all facilities. In Legionella-positive samples the temperature of compost was significantly lower (P = 0.012) than in Legionella-negative samples. Of 47 bioaerosol samples, 19.1% (9/47) were positive for FLA and 10.6% (5/47) for L. pneumophila. Composts (62.8%) were positive for Legionella and FLA contemporaneously, but both microorganisms were never detected simultaneously in bioaerosols. Compost can release bioaerosol containing FLA or Legionella and could represent a source of infection of community-acquired Legionella infections for workers and nearby residents. PMID:23844174

  4. Interrelated effects of mycorrhiza and free-living nitrogen fixers cascade up to aboveground herbivores

    PubMed Central

    Khaitov, Botir; Patiño-Ruiz, José David; Pina, Tatiana; Schausberger, Peter

    2015-01-01

    Aboveground plant performance is strongly influenced by belowground microorganisms, some of which are pathogenic and have negative effects, while others, such as nitrogen-fixing bacteria and arbuscular mycorrhizal fungi, usually have positive effects. Recent research revealed that belowground interactions between plants and functionally distinct groups of microorganisms cascade up to aboveground plant associates such as herbivores and their natural enemies. However, while functionally distinct belowground microorganisms commonly co-occur in the rhizosphere, their combined effects, and relative contributions, respectively, on performance of aboveground plant-associated organisms are virtually unexplored. Here, we scrutinized and disentangled the effects of free-living nitrogen-fixing (diazotrophic) bacteria Azotobacter chroococcum (DB) and arbuscular mycorrhizal fungi Glomus mosseae (AMF) on host plant choice and reproduction of the herbivorous two-spotted spider mite Tetranychus urticae on common bean plants Phaseolus vulgaris. Additionally, we assessed plant growth, and AMF and DB occurrence and density as affected by each other. Both AMF alone and DB alone increased spider mite reproduction to similar levels, as compared to the control, and exerted additive effects under co-occurrence. These effects were similarly apparent in host plant choice, that is, the mites preferred leaves from plants with both AMF and DB to plants with AMF or DB to plants grown without AMF and DB. DB, which also act as AMF helper bacteria, enhanced root colonization by AMF, whereas AMF did not affect DB abundance. AMF but not DB increased growth of reproductive plant tissue and seed production, respectively. Both AMF and DB increased the biomass of vegetative aboveground plant tissue. Our study breaks new ground in multitrophic belowground–aboveground research by providing first insights into the fitness implications of plant-mediated interactions between interrelated belowground fungi

  5. Feeding by heterotrophic dinoflagellates and ciliates on the free-living dinoflagellate Symbiodinium sp. (Clade E).

    PubMed

    Jeong, Hae Jin; Lim, An Suk; Yoo, Yeong Du; Lee, Moo Joon; Lee, Kyung Ha; Jang, Tae Young; Lee, Kitack

    2014-01-01

    To investigate heterotrophic protists grazing on Symbiodinium sp., we tested whether the common heterotrophic dinoflagellates Gyrodinium dominans, Gyrodinium moestrupii, Gyrodinium spirale, Oblea rotundata, Oxyrrhis marina, and Polykrikos kofoidii and the ciliates Balanion sp. and Parastrombidinopsis sp. preyed on the free-living dinoflagellate Symbiodinium sp. (clade E). We measured the growth and ingestion rates of O. marina and G. dominans on Symbiodinium sp. as a function of prey concentration. Furthermore, we compared the results to those obtained for other algal prey species. In addition, we measured the growth and ingestion rates of other predators at single prey concentrations at which these rates of O. marina and G. dominans were saturated. All predators tested in the present study, except Balanion sp., preyed on Symbiodinium sp. The specific growth rates of O. marina and G. dominans on Symbiodinium sp. increased rapidly with increasing mean prey concentration < ca. 740-815 ng C/ml (7,400-8,150 cells/ml), but became saturated at higher concentrations. The maximum growth rates of O. marina and G. dominans on Symbiodinium sp. (0.87 and 0.61/d) were much higher than those of G. moestrupii and P. kofoidii (0.11 and 0.04/d). Symbiodinium sp. did not support positive growth of G. spirale, O. rotundata, and Parastrombidinopsis sp. However, the maximum ingestion rates of P. kofoidii and Parastrombidinopsis sp. (6.7-10.0 ng C/predator/d) were much higher than those of O. marina and G. dominans on Symbiodinium sp. (1.9-2.1 ng C/predator/d). The results of the present study suggest that Symbiodinium sp. may increase or maintain the populations of some predators. PMID:24102740

  6. Diversity of free-living marine nematodes (Enoplida) from Baja California assessed by integrative taxonomy.

    PubMed

    Pereira, Tiago José; Fonseca, Gustavo; Mundo-Ocampo, Manuel; Guilherme, Betânia Cristina; Rocha-Olivares, Axayácatl

    2010-01-01

    We used morphological and molecular approaches to evaluate the diversity of free-living marine nematodes (order Enoplida) at four coastal sites in the Gulf of California and three on the Pacific coast of Baja California, Mexico. We identified 22 morphological species belonging to six families, of which Thoracostomopsidae and Oncholaimidae were the most diverse. The genus Mesacanthion (Thoracostomopsidae) was the most widespread and diverse. Five allopatric species, genetically and morphologically differentiated, were found in two localities in the Gulf of California (M. sp1 and M. sp2) and three in the Pacific coast (M. sp3, M. sp4 and M. sp5). Overall, we produced 19 and 20 sequences for the 18S and 28S genes, respectively. Neither gene displayed intraspecific polymorphisms, which allowed us to establish that some morphological variation was likely either ontogenetic or due to phenotypic plasticity. Although 18S and 28S phylogenies were topologically congruent (incongruence length difference test, P > 0.05), divergences between species were much higher in the 28S gene. Moreover, this gene possessed a stronger phylogenetic signal to resolve relationships involving Rhabdodemania and Bathylaimus. On the other hand, the close relationship of Pareurystomina (Enchilidiidae) with oncholaimids warrants further study. The 28S sequences (D2D3 domain) may be better suited for DNA barcoding of marine nematodes than those from the 18S rDNA, particularly for differentiating closely related or cryptic species. Finally, our results underline the relevance of adopting an integrative approach encompassing morphological and molecular analyses to improve the assessment of marine nematode diversity and advance their taxonomy. PMID:24391248

  7. Identifying and Characterizing Alternative Molecular Markers for the Symbiotic and Free-Living Dinoflagellate Genus Symbiodinium

    PubMed Central

    Pochon, Xavier; Putnam, Hollie M.; Burki, Fabien; Gates, Ruth D.

    2012-01-01

    Dinoflagellates in the genus Symbiodinium are best known as endosymbionts of corals and other invertebrate as well as protist hosts, but also exist free-living in coastal environments. Despite their importance in marine ecosystems, less than 10 loci have been used to explore phylogenetic relationships in this group, and only the multi-copy nuclear ribosomal Internal Transcribed Spacer (ITS) regions 1 and 2 have been used to characterize fine-scale genetic diversity within the nine clades (A–I) that comprise the genus. Here, we describe a three-step molecular approach focused on 1) identifying new candidate genes for phylogenetic analysis of Symbiodinium spp., 2) characterizing the phylogenetic relationship of these candidate genes from DNA samples spanning eight Symbiodinium clades (A–H), and 3) conducting in-depth phylogenetic analyses of candidate genes displaying genetic divergences equal or higher than those within the ITS-2 of Symbiodinium clade C. To this end, we used bioinformatics tools and reciprocal comparisons to identify homologous genes from 55,551 cDNA sequences representing two Symbiodinium and six additional dinoflagellate EST libraries. Of the 84 candidate genes identified, 7 Symbiodinium genes (elf2, coI, coIII, cob, calmodulin, rad24, and actin) were characterized by sequencing 23 DNA samples spanning eight Symbiodinium clades (A–H). Four genes displaying higher rates of genetic divergences than ITS-2 within clade C were selected for in-depth phylogenetic analyses, which revealed that calmodulin has limited taxonomic utility but that coI, rad24, and actin behave predictably with respect to Symbiodinium lineage C and are potential candidates as new markers for this group. The approach for targeting candidate genes described here can serve as a model for future studies aimed at identifying and testing new phylogenetically informative genes for taxa where transcriptomic and genomics data are available. PMID:22238660

  8. Pilot project to investigate over-wintering of free-living gastrointestinal nematode larvae of sheep in Ontario, Canada.

    PubMed

    Falzon, Laura C; Menzies, Paula I; VanLeeuwen, John; Shakya, Krishna P; Jones-Bitton, Andria; Avula, Jacob; Jansen, Jocelyn T; Peregrine, Andrew S

    2014-08-01

    This study investigated the overwintering survival and infectivity of free-living gastrointestinal nematode (GIN) stages on pasture. The presence of GIN larvae was assessed on 3 sheep farms in Ontario with a reported history of clinical haemonchosis, by collecting monthly pasture samples over the winter months of 2009/2010. The infectivity of GIN larvae on spring pastures was evaluated using 16 tracer lambs. Air and soil temperature and moisture were recorded hourly. Free-living stages of Trichostrongylus spp. and Nematodirus spp. were isolated from herbage samples. Gastrointestinal nematodes were recovered from all tracer lambs on all farms; Teladorsagia sp. was the predominant species. Very low levels of Haemonchus contortus were recovered from 1 animal on 1 farm. The results suggest that Haemonchus larvae do not survive well on pasture, while Teladorsagia sp., Trichostrongylus spp. and Nematodirus spp. are able to overwinter on pasture in Ontario and are still infective for sheep in the spring. PMID:25082990

  9. Pilot project to investigate over-wintering of free-living gastrointestinal nematode larvae of sheep in Ontario, Canada

    PubMed Central

    Falzon, Laura C.; Menzies, Paula I.; VanLeeuwen, John; Shakya, Krishna P.; Jones-Bitton, Andria; Avula, Jacob; Jansen, Jocelyn T.; Peregrine, Andrew S.

    2014-01-01

    This study investigated the overwintering survival and infectivity of free-living gastrointestinal nematode (GIN) stages on pasture. The presence of GIN larvae was assessed on 3 sheep farms in Ontario with a reported history of clinical haemonchosis, by collecting monthly pasture samples over the winter months of 2009/2010. The infectivity of GIN larvae on spring pastures was evaluated using 16 tracer lambs. Air and soil temperature and moisture were recorded hourly. Free-living stages of Trichostrongylus spp. and Nematodirus spp. were isolated from herbage samples. Gastrointestinal nematodes were recovered from all tracer lambs on all farms; Teladorsagia sp. was the predominant species. Very low levels of Haemonchus contortus were recovered from 1 animal on 1 farm. The results suggest that Haemonchus larvae do not survive well on pasture, while Teladorsagia sp., Trichostrongylus spp. and Nematodirus spp. are able to overwinter on pasture in Ontario and are still infective for sheep in the spring. PMID:25082990

  10. Exposure of free-living jaguars to Toxoplasma gondii, Neospora caninum and Sarcocystis neurona in the Brazilian Pantanal.

    PubMed

    Onuma, Selma Samiko Miyazaki; Melo, Andréia Lima Tomé; Kantek, Daniel Luis Zanella; Crawshaw-Junior, Peter Gransden; Morato, Ronaldo Gonçalves; May-Júnior, Joares Adenílson; Pacheco, Thábata dos Anjos; Aguiar, Daniel Moura de

    2014-01-01

    Toxoplasma gondii, Neospora caninum and Sarcocystis neurona are related apicomplexan parasites that cause reproductive and neurological disorders in a wide range of domestic and wild animals. In the present study, the immunofluorescence antibody test (IFAT) was used to investigate the presence of antibodies against T. gondii, N. caninum and S. neurona in the sera of 11 free-living jaguars (Panthera onca) in two protected areas in the Pantanal region of Mato Grosso state, Brazil. Ten jaguars (90.9%) showed seropositivity for T. gondii, eight (72.7%) for S. neurona, and seven (63.6%) for N. caninum antigens. Our findings reveal exposure of jaguars to these related coccidian parasites and circulation of these pathogens in this wild ecosystem. To the best of our knowledge, this is the first serological detection of N. caninum and S. neurona in free-living jaguars. PMID:25517539

  11. Transmission electron microscopy sample preparation protocols for the ultrastructural study of cysts of free-living protozoa.

    PubMed

    Lambrecht, Ellen; Baré, Julie; Claeys, Myriam; Chavatte, Natascha; Bert, Wim; Sabbe, Koen; Houf, Kurt

    2015-04-01

    Cysts of free-living protozoa have an impact on the ecology and epidemiology of bacteria because they may act as a transmission vector or shelter the bacteria against hash environmental conditions. Detection and localization of intracystic bacteria and examination of the en- and excystment dynamics is a major challenge because no detailed protocols for ultrastructural analysis of cysts are currently available. Transmission electron microscopy (TEM) is ideally suited for those analyses; however, conventional TEM protocols are not satisfactory for cysts of free-living protozoa. Here we report on the design and testing of four protocols for TEM sample preparation of cysts. Two protocols, one based on chemical fixation in coated well plates and one on high-pressure freezing, were selected as the most effective for TEM-based ultrastructural studies of cysts. Our protocols will enable improved analysis of cyst structure and a better understanding of bacterial survival mechanisms in cysts. PMID:25861930

  12. Clinical Mycoplasma sp. Infections in Free-living Three-toed Box Turtles ( Terrapene carolina triunguis) in Missouri, USA.

    PubMed

    Palmer, Jamie L; Blake, Stephen; Wellehan, James F X; Childress, April L; Deem, Sharon L

    2016-04-28

    Mycoplasma species, which can cause upper respiratory tract disease (URTD), are significant pathogens of birds, mammals, fish, and reptiles. Mycoplasmosis is of high concern for chelonian conservation, with the most well-documented cases in gopher and desert tortoises. Mycoplasma sp. infections have been reported in captive and free-living box turtles ( Terrapene spp.). We documented URTD associated with Mycoplasma sp. in two free-living, three-toed box turtles ( Terrapene carolina triunguis) in Missouri, US. Both turtles were Mycoplasma sp. positive by PCR and had URTD-like clinical signs, including nasal and ocular discharge, palpebral edema, lethargy, and weight loss, during a 6-8-wk period between June and September 2014. PMID:27124328

  13. Competition Between Entomopathogenic and Free-Living Bactivorous Nematodes in Larvae of the Weevil Diaprepes abbreviatus

    PubMed Central

    Duncan, L. W.; Dunn, D. C.; Bague, G.; Nguyen, K.

    2003-01-01

    Field and laboratory experiments were conducted to determine the degree to which free-living, bactivorous nematodes (FLBN) are able to competitively displace entomopathogenic nematodes (EPN) from insect cadavers. Two hundred larvae of the insect Diaprepes abbreviatus were buried at regular intervals during 2 years in experimental plots that were untreated or treated twice annually with Steinernema riobrave. Larvae were recovered after 7 days, and nematodes emerging from cadavers during the next 30 days were identified. The monthly prevalence of FLBN was directly related to that of S. riobrave (r = 0.38; P = 0.001) but was not related to the prevalence of the endemic EPN, S. diaprepesi, Heterorhabditis zealandica, H. indica, or H. bacteriophora (r = 0.02; P = 0.80). In a second experiment, treatment of small field plots with S. riobrave increased the prevalence of insect cadavers in which only FLBN were detected compared to untreated controls (30% vs. 14%; P = 0.052), and increased numbers of FLBN per buried insect by more than 10-fold. In the laboratory, sand microcosms containing one D. abbreviatus larva were treated with (i) the FLBN, Pellioditis sp.; (ii) S. riobrave; (iii) S. riobrave + Pellioditis; or (iv) neither nematode. Insect mortality was higher in the presence of both nematodes (57%) than when S. riobrave was alone (42%) (P = 0.01). An average of 59.2 Pellioditis sp. g-1 insect body weight emerged in the presence of S. riobrave, whereas 6.2 nematodes g-1 insect were recovered in the absence of the EPN (P = 0.01). Pellioditis sp. reduced the number of S. riobrave per cadaver by 84%; (P = 0.03), and per available insect by 82% (P = 0.001), compared to S. riobrave alone. Population size of S. diaprepesi was not affected by Pellioditis sp. in experiments of the same design. Faster development (P = 0.05) and nutrient appropriation within the insect cadaver by S. diaprepesi compared to S. riobrave may increase the fitness of the former species to compete with

  14. Diversity of the free-living marine and freshwater Copepoda (Crustacea) in Costa Rica: a review

    PubMed Central

    Morales-Ramírez, Álvaro; Suárez-Morales, Eduardo; Corrales-Ugalde, Marco; Garrote, Octavio Esquivel

    2014-01-01

    Abstract The studies on marine copepods of Costa Rica started in the 1990’s and focused on the largest coastal-estuarine systems in the country, particularly along the Pacific coast. Diversity is widely variable among these systems: 40 species have been recorded in the Culebra Bay influenced by upwelling, northern Pacific coast, only 12 in the Gulf of Nicoya estuarine system, and 38 in Golfo Dulce, an anoxic basin in the southern Pacific coast of the country. Freshwater environments of Costa Rica are known to harbor a moderate diversity of continental copepods (25 species), which includes 6 calanoids, 17 cyclopoids and only two harpacticoids. Of the +100 freshwater species recorded in Central America, six are known only from Costa Rica, and one appears to be endemic to this country. The freshwater copepod fauna of Costa Rica is clearly the best known in Central America. Overall, six of the 10 orders of Copepoda are reported from Costa Rica. A previous summary by 2001 of the free-living copepod diversity in the country included 80 marine species (67 pelagic, 13 benthic). By 2009, the number of marine species increased to 209: 164 from the Pacific (49% of the copepod fauna from the Eastern Tropical Pacific) and 45 from the Caribbean coast (8% of species known from the Caribbean Basin). Both the Caribbean and Pacific species lists are growing. Additional collections of copepods at Cocos Island, an oceanic island 530 km away of the Pacific coast, have revealed many new records, including five new marine species from Costa Rica. Currently, the known diversity of marine copepods of Costa Rica is still in development and represents up to 52.6% of the total marine microcrustaceans recorded in the country. Future sampling and taxonomic efforts in the marine habitats should emphasize oceanic environments including deep waters but also littoral communities. Several Costa Rican records of freshwater copepods are likely to represent undescribed species. Also, the

  15. Differentiation of free-living Anabaena and Nostoc cyanobacteria on the basis of fatty acid composition.

    PubMed

    Caudales, R; Wells, J M

    1992-04-01

    The cellular fatty acids of free-living, nitrogen-fixing cyanobacteria belonging to the genera Anabaena and Nostoc were analyzed to differentiate the genera. The fatty acid compositions of 10 Anabaena strains and 10 Nostoc strains that were grown for 12 days on BG-11o medium were determined by gas-liquid chromatography-mass spectroscopy. Of the 53 fatty acids detected, 17 were major components; the average level for each of these 17 fatty acids was at least 0.9% of the total fatty acids (in at least one of the genera). These fatty acids included (with mean percentages in the Anabaena and Nostoc strains, respectively) the saturated fatty acids 16:0 (30.55 and 23.23%) and 18:0 (0.77 and 1.27%); several unsaturated fatty acids, including 14:1 cis-7 (2.50 and 0.11%), 14:1 cis-9 (3.10 and 3.41%), a polyunsaturated 16-carbon (sites undetermined) fatty acid with an equivalent chain length of 15.30 (1.20 and 1.03%), 16:4 cis-4 (0.95 and 0.87%), 16:3 cis-6 (2.16 and 1.51%), 16:1 cis-7 (1.44 and 0.36%), 16:1 cis-9 (6.53 and 18.76%), 16:1 trans-9 (4.02 and 1.35%), 16:1 cis-11 (1.62 and 0.42%), 18:2 cis-9 (10.16 and 12.44%), 18:3 cis-9 (18.19 and 17.25%), 18:1 cis-9 (4.01 and 5.10%), and 18:1 trans-9 (0.92 and 1.94%); and the branched-chain fatty acids iso-16:0 (2.50 and 1.14%) and iso-15:1 (0.34 and 2.05%).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1581185

  16. Effects of thermal additions on the presence of pathogenic and nonpathogenic free-living amoebae at the Savannah River Laboratory

    SciTech Connect

    Tyndall, R.L.

    1980-01-01

    A study of the effect of thermal additions on the presence of free-living thermophilic amoeba at the Savannah River site was undertaken. Seasonality effects and the influence of varied degrees of thermal enrichment on the numbers and types of thermophilic pathogenic and nonpathogenic amoeba were determined. In addition, the ability of thermophilic nonpathogenic Naegleria to competitively inhibit the growth of the pathogenic Naegleria was defined and related to water quality differences.

  17. Free-Living and Particle-Associated Bacterioplankton in Large Rivers of the Mississippi River Basin Demonstrate Biogeographic Patterns

    PubMed Central

    Millar, Justin J.; Payne, Jason T.; Ochs, Clifford A.

    2014-01-01

    The different drainage basins of large rivers such as the Mississippi River represent interesting systems in which to study patterns in freshwater microbial biogeography. Spatial variability in bacterioplankton communities in six major rivers (the Upper Mississippi, Missouri, Illinois, Ohio, Tennessee, and Arkansas) of the Mississippi River Basin was characterized using Ion Torrent 16S rRNA amplicon sequencing. When all systems were combined, particle-associated (>3 μm) bacterial assemblages were found to be different from free-living bacterioplankton in terms of overall community structure, partly because of differences in the proportional abundance of sequences affiliated with major bacterial lineages (Alphaproteobacteria, Cyanobacteria, and Planctomycetes). Both particle-associated and free-living communities ordinated by river system, a pattern that was apparent even after rare sequences or those affiliated with Cyanobacteria were removed from the analyses. Ordination of samples by river system correlated with environmental characteristics of each river, such as nutrient status and turbidity. Communities in the Upper Mississippi and the Missouri and in the Ohio and the Tennessee, pairs of rivers that join each other, contained similar taxa in terms of presence-absence data but differed in the proportional abundance of major lineages. The most common sequence types detected in particle-associated communities were picocyanobacteria in the Synechococcus/Prochlorococcus/Cyanobium (Syn/Pro) clade, while free-living communities also contained a high proportion of LD12 (SAR11/Pelagibacter)-like Alphaproteobacteria. This research shows that while different tributaries of large river systems such as the Mississippi River harbor distinct bacterioplankton communities, there is also microhabitat variation such as that between free-living and particle-associated assemblages. PMID:25217018

  18. Bacterial communities associated with Microcystis colonies differ from free-living communities living in the same ecosystem.

    PubMed

    Parveen, Bushra; Ravet, Viviane; Djediat, Chakib; Mary, Isabelle; Quiblier, Catherine; Debroas, Didier; Humbert, Jean-François

    2013-10-01

    The search for a better understanding of why cyanobacteria often dominate phytoplankton communities in eutrophic freshwater ecosystems has led to a growing interest in the interactions between cyanobacteria and bacteria. Against this background, we studied the location of bacteria within Microcystis colonies, and compared the structural and phylogenetic diversity of Microcystis-attached and free-living bacterial communities living in the same French lake, the Villerest reservoir. Using transmission electron microscopy, we show that most of the bacteria inside the colonies were located close to detrital materials that probably resulted from lysis of Microcystis cells. The 16S rRNA sequencing approach revealed a clear distinction between the attached and free-living communities at the levels of both their general structure and their operational taxonomic unit (OTU) composition. In particular, Microcystis colonies appeared to be depleted of Actinobacteria, but conversely enriched in Gammaproteobacteria, in particular when the bloom was declining. At the OTU level, a clear distinction was also found between attached and free-living bacteria, and new clades were identified among our sequences. All these findings suggest that Microcystis colonies constitute a distinct habitat for bacteria living in freshwater ecosystems, and that direct and indirect interactions (cell lysis, nutrient recycling, etc.) may occur between them inside these colonies. PMID:24115622

  19. Effects of the Integration of Sunn Hemp and Soil Solarization on Plant-Parasitic and Free-Living Nematodes

    PubMed Central

    Marahatta, Sharadchandra P.; Wang, Koon-Hui; Sipes, Brent S.; Hooks, Cerruti R. R.

    2012-01-01

    Sunn hemp (SH), Crotolaria juncea, is known to suppress Rotylenchulus reniformis and weeds while enhancing free-living nematodes involved in nutrient cycling. Field trials were conducted in 2009 (Trial I) and 2010 (Trial II) to examine if SH cover cropping could suppress R. reniformis and weeds while enhancing free-living nematodes if integrated with soil solarization (SOL). Cover cropping of SH, soil solarization, and SH followed by SOL (SHSOL) were compared to weedy fallow control (C). Rotylenchulus reniformis population was suppressed by SHSOL at the end of cover cropping or solarization period (Pi) in Trial I, but not in Trial II. However, SOL and SHSOL did not suppress R. reniformis compared to SH in either trial. SH enhanced abundance of bacterivores and suppressed the % herbivores only at Pi in Trial II. At termination of the experiment, SH resulted in a higher enrichment index indicating greater soil nutrient availability, and a higher structure index indicating a less disturbed nematode community compared to C. SOL suppressed bacterivores and fungivores only in Trial II but not in Trial I. On the other hand, SHSOL enhanced bacterivores and fungivores only at Pi in Trial I. Weeds were suppressed by SH, SOL and SHSOL throughout the experiment. SHSOL suppressed R. reniformis and enhanced free-living nematodes better than SOL, and suppressed weeds better than SH. PMID:23482700

  20. Effects of the integration of sunn hemp and soil solarization on plant-parasitic and free-living nematodes.

    PubMed

    Marahatta, Sharadchandra P; Wang, Koon-Hui; Sipes, Brent S; Hooks, Cerruti R R

    2012-03-01

    Sunn hemp (SH), Crotolaria juncea, is known to suppress Rotylenchulus reniformis and weeds while enhancing free-living nematodes involved in nutrient cycling. Field trials were conducted in 2009 (Trial I) and 2010 (Trial II) to examine if SH cover cropping could suppress R. reniformis and weeds while enhancing free-living nematodes if integrated with soil solarization (SOL). Cover cropping of SH, soil solarization, and SH followed by SOL (SHSOL) were compared to weedy fallow control (C). Rotylenchulus reniformis population was suppressed by SHSOL at the end of cover cropping or solarization period (Pi) in Trial I, but not in Trial II. However, SOL and SHSOL did not suppress R. reniformis compared to SH in either trial. SH enhanced abundance of bacterivores and suppressed the % herbivores only at Pi in Trial II. At termination of the experiment, SH resulted in a higher enrichment index indicating greater soil nutrient availability, and a higher structure index indicating a less disturbed nematode community compared to C. SOL suppressed bacterivores and fungivores only in Trial II but not in Trial I. On the other hand, SHSOL enhanced bacterivores and fungivores only at Pi in Trial I. Weeds were suppressed by SH, SOL and SHSOL throughout the experiment. SHSOL suppressed R. reniformis and enhanced free-living nematodes better than SOL, and suppressed weeds better than SH. PMID:23482700

  1. Composition and enzymatic function of particle-associated and free-living bacteria: a coastal/offshore comparison

    PubMed Central

    D'Ambrosio, Lindsay; Ziervogel, Kai; MacGregor, Barbara; Teske, Andreas; Arnosti, Carol

    2014-01-01

    We compared the function and composition of free-living and particle-associated microbial communities at an inshore site in coastal North Carolina and across a depth profile on the Blake Ridge (offshore). Hydrolysis rates of six different polysaccharide substrates were compared for particle-associated (>3 μm) and free-living (<3 to 0.2 μm) microbial communities. The 16S rRNA- and rDNA-based clone libraries were produced from the same filters used to measure hydrolysis rates. Particle-associated and free-living communities resembled one another; they also showed similar enzymatic hydrolysis rates and substrate preferences. All six polysaccharides were hydrolyzed inshore. Offshore, only a subset was hydrolyzed in surface water and at depths of 146 and 505 m; just three polysaccharides were hydrolyzed at 505 m. The spectrum of bacterial taxa changed more subtly between inshore and offshore surface waters, but changed greatly with depth offshore. None of the OTUs occurred at all sites: 27 out of the 28 major OTUs defined in this study were found either exclusively in a surface or in a mid-depth/bottom water sample. This distinction was evident with both 16S rRNA and rDNA analyses. At the offshore site, despite the low community overlap, bacterial communities maintained a degree of functional redundancy on the whole bacterial community level with respect to hydrolysis of high-molecular-weight substrates. PMID:24763371

  2. Walrus foraging marks on the seafloor in Bristol Bay, Alaska: a reconnaissance survey

    NASA Astrophysics Data System (ADS)

    Bornhold, Brian D.; Jay, Chadwick V.; McConnaughey, Robert; Rathwell, Glenda; Rhynas, Karl; Collins, William

    2005-11-01

    A reconnaissance sidescan sonar survey in Bristol Bay, Alaska revealed extensive areas of seafloor with features related to walrus foraging. They are similar to those seen in areas such as the outer Bering Sea and Chukchi Sea. Two types of feature were observed: (a) small (≪1 m diameter) shallow pits, often in clusters ranging in density from 5 pits per hectare to 35 pits per hectare; and, (b) more abundant, narrow, sinuous furrows, typically 5 to 10 m long with some reaching 20 m or more. Most foraging marks were in less than 60 m water depth in areas of sandy seafloor that were smooth, hummocky or characterized by degraded bedforms; the absence of foraging marks in other areas may be related, in part, to their more dynamic nature. The distribution of foraging marks was consistent in a general way with walrus locations from satellite telemetry studies.

  3. Walrus foraging marks on the seafloor in Bristol Bay, Alaska: A reconnaissance survey

    USGS Publications Warehouse

    Bornhold, B.D.; Jay, C.V.; McConnaughey, R.; Rathwell, G.; Rhynas, K.; Collins, W.

    2005-01-01

    A reconnaissance sidescan sonar survey in Bristol Bay, Alaska revealed extensive areas of seafloor with features related to walrus foraging. They are similar to those seen in areas such as the outer Bering Sea and Chukchi Sea. Two types of feature were observed: (a) small (??? 1 m diameter) shallow pits, often in clusters ranging in density from 5 pits per hectare to 35 pits per hectare; and, (b) more abundant, narrow, sinuous furrows, typically 5 to 10 m long with some reaching 20 m or more. Most foraging marks were in less than 60 m water depth in areas of sandy seafloor that were smooth, hummocky or characterized by degraded bedforms; the absence of foraging marks in other areas may be related, in part, to their more dynamic nature. The distribution of foraging marks was consistent in a general way with walrus locations from satellite telemetry studies. ?? Springer-Verlag 2005.

  4. Temporal association of serum progesterone concentrations and vaginal cytology in walruses (Odobenus rosmarus).

    PubMed

    Kinoshita, K; Kiwata, M; Kuwano, R; Sato, N; Tanaka, T; Nagata, M; Taira, H; Kusunoki, H

    2012-03-15

    Concentrations of serum estradiol-17β and progesterone were monitored in six female walruses using an enzyme immunoassay. Progesterone concentrations increased from March to May in females aged 6 y or older, and subsequently declined (October). No significant elevation of estradiol-17β concentration was detected before an elevation of progesterone concentration. Vaginal smears from four females were examined with Papanicolaou staining. In all females, most epithelial cells were basophilic intermediate-superficial cells; no color change from basophilic to eosinophilic of the cells was detected. Meanwhile, the percentage of anucleate cells in vaginal smears reached its highest value before the elevation of progesterone concentration, followed by an increase in the percentage of leukocytes. We inferred that the change in populations of anucleate cells and leukocytes in vaginal smears reflected ovarian status and CL formation in female walruses. PMID:22153266

  5. Walrus foraging marks on the seafloor in Bristol Bay, Alaska: a reconnaissance survey

    USGS Publications Warehouse

    Bornhold, B.D.; Jay, C.V.; McConnaughey, R.; Rathwell, G.; Rhynas, K.; Collins, W.

    2005-01-01

    A reconnaissance sidescan sonar survey in Bristol Bay, Alaska revealed extensive areas of seafloor with features related to walrus foraging. They are similar to those seen in areas such as the outer Bering Sea and Chukchi Sea. Two types of feature were observed: (a) small (<<1 m diameter) shallow pits, often in clusters ranging in density from 5 to 35 pits per hectare; and, (b) more abundant, narrow, sinuous furrows, typically 5 to 10 m long with some reaching 20 m or more. Most foraging marks were in less than 60 m water depth in areas of sandy seafloor that were smooth, hummocky or characterized by degraded bedforms; the absence of foraging marks in other areas may be related, in part, to their more dynamic nature. The distribution of foraging marks was consistent in a general way with walrus locations from satellite telemetry studies.

  6. 137Cs and 210Po in Pacific walrus and bearded seal from St. Lawrence Island, Alaska.

    PubMed

    Hamilton, Terry; Seagars, Dana; Jokela, Terry; Layton, David

    2008-06-01

    The activity concentration of Cesium-137 ((137)Cs) and naturally-occurring Polonium-210 ((210)Po) were measured in the muscle tissue, kidney and liver of Pacific walrus (Odobenus rosmarus divergens) and bearded seal (Erignathus barbatus) collected by native hunters from the Bering Sea during May 1996. The mean (137)Cs concentrations in muscle, liver and kidney of Pacific walrus were 0.07, 0.09 and 0.07 Bq kg(-1) (n=5, wet weight), respectively, and 0.17, 0.10, and 0.17 Bq kg(-1) (n=2, wet weight), respectively, in bearded seal. In general, (137)Cs tissue concentrations are significantly lower than those previously reported for mammals from other regions. By comparison, (210)Po activity concentrations are more variable and appear to be higher level compared with mammal data from other regions. The mean (210)Po concentration in the muscle tissue, liver and kidney of Pacific walrus (n=5, wet weight) were 28.7, 189, and 174 Bq kg(-1), respectively. This compares with (210)Po concentration values (n=2, wet weight) of 27, 207 and 68 Bq kg(-1) measured in the muscle tissue, liver and kidney, of bearded seal, respectively. Estimated concentration factors--as defined by the radionuclide concentration ratio between the target tissue to that in sea water--were two to three orders of magnitude higher for (210)Po that those of (137)Cs. We conclude from radiological dose estimates that ingestion of (137)Cs in foods derived from walrus and seal will pose no threat to human health. This work has important implications for assessment of risks of Alaskan coastal communities concerned about the dumping of nuclear waste in the Russia Arctic. PMID:18371988

  7. Sex-specific energetics of Pacific walruses (Odobenus rosmarus divergens) during the nursing interval

    USGS Publications Warehouse

    Noren, Shawn R.; Udevitz, Mark S.; Jay, Chadwick V.

    2016-01-01

    Habitat use and activity patterns of Pacific walruses (Odobenus rosmarus divergens) have changed with climate-induced reductions in sea ice. Increases in the time active in water could result in negative energy balance, precluding females from sustaining lactation, which could impact population demographics. Little is known about lactation costs in walruses. We examined the energetics of 0–2-yr-old walrus calves by using Bayesian hierarchical models based on longitudinal husbandry records of growth (n = 6 females and 7 males) and caloric intake (n = 5 females and 6 males) as a proxy for maternal lactation costs. Males and females had similar growth patterns; mean mass increased from 68 kg at birth to 301 kg by 2 yr. Females had a 2,000 kcal kg−1 higher mass storage (growth) cost than males; females typically synthesize and deposit greater amounts of adipose, which is more energy dense than lean tissue. In contrast, males had higher metabolic (basal and activity) costs, ranging from 600 to 1,800 kcal d−1 greater than similarly sized females; males are typically leaner, and muscle is more metabolically active than adipose. Yet total daily energy requirements (storage plus metabolic components) were similar across sexes, summing to approximately 190,000 kcal over the first month postpartum. Based on these estimates and assuming that 8,103 kcal is recovered from 1 kg of mass loss in adult female walruses, suckling calves could deplete 23 kg of their mother’s body mass over the first month after parturition if none of the lactation costs is met through ingested prey.

  8. Rapid maturation of the muscle biochemistry that supports diving in Pacific walruses (Odobenus rosmarus divergens).

    PubMed

    Noren, Shawn R; Jay, Chadwick V; Burns, Jennifer M; Fischbach, Anthony S

    2015-10-01

    Physiological constraints dictate animals' ability to exploit habitats. For marine mammals, it is important to quantify physiological limits that influence diving and their ability to alter foraging behaviors. We characterized age-specific dive limits of walruses by measuring anaerobic (acid-buffering capacity) and aerobic (myoglobin content) capacities of the muscles that power hind (longissimus dorsi) and fore (supraspinatus) flipper propulsion. Mean buffering capacities were similar across muscles and age classes (a fetus, five neonatal calves, a 3 month old and 20 adults), ranging from 41.31 to 54.14 slykes and 42.00 to 46.93 slykes in the longissimus and supraspinatus, respectively. Mean myoglobin in the fetus and neonatal calves fell within a narrow range (longissimus: 0.92-1.68 g 100 g(-1) wet muscle mass; supraspinatus: 0.88-1.64 g 100 g(-1) wet muscle mass). By 3 months post-partum, myoglobin in the longissimus increased by 79%, but levels in the supraspinatus remained unaltered. From 3 months post-partum to adulthood, myoglobin increased by an additional 26% in the longissimus and increased by 126% in the supraspinatus; myoglobin remained greater in the longissimus compared with the supraspinatus. Walruses are unique among marine mammals because they are born with a mature muscle acid-buffering capacity and attain mature myoglobin content early in life. Despite rapid physiological development, small body size limits the diving capacity of immature walruses and extreme sexual dimorphism reduces the diving capacity of adult females compared with adult males. Thus, free-ranging immature walruses likely exhibit the shortest foraging dives while adult males are capable of the longest foraging dives. PMID:26347559

  9. The Wageningen Lowland Runoff Simulator (WALRUS): application to the Hupsel Brook catchment and the Cabauw polder

    NASA Astrophysics Data System (ADS)

    Brauer, C. C.; Torfs, P. J. J. F.; Teuling, A. J.; Uijlenhoet, R.

    2014-10-01

    The Wageningen Lowland Runoff Simulator (WALRUS) is a new parametric (conceptual) rainfall-runoff model which accounts explicitly for processes that are important in lowland areas, such as groundwater-unsaturated zone coupling, wetness-dependent flowroutes, groundwater-surface water feedbacks, and seepage and surface water supply (see companion paper by Brauer et al., 2014). Lowland catchments can be divided into slightly sloping, freely draining catchments and flat polders with controlled water levels. Here, we apply WALRUS to two contrasting Dutch catchments: the Hupsel Brook catchment and the Cabauw polder. In both catchments, WALRUS performs well: Nash-Sutcliffe efficiencies obtained after calibration on 1 year of discharge observations are 0.87 for the Hupsel Brook catchment and 0.83 for the Cabauw polder, with values of 0.74 and 0.76 for validation. The model also performs well during floods and droughts and can forecast the effect of control operations. Through the dynamic division between quick and slow flowroutes controlled by a wetness index, temporal and spatial variability in groundwater depths can be accounted for, which results in adequate simulation of discharge peaks as well as low flows. The performance of WALRUS is most sensitive to the parameter controlling the wetness index and the groundwater reservoir constant, and to a lesser extent to the quickflow reservoir constant. The effects of these three parameters can be identified in the discharge time series, which indicates that the model is not overparameterised (parsimonious). Forcing uncertainty was found to have a larger effect on modelled discharge than parameter uncertainty and uncertainty in initial conditions.

  10. The Wageningen Lowland Runoff Simulator (WALRUS): application to the Hupsel Brook catchment and Cabauw polder

    NASA Astrophysics Data System (ADS)

    Brauer, C. C.; Torfs, P. J. J. F.; Teuling, A. J.; Uijlenhoet, R.

    2014-02-01

    The Wageningen Lowland Runoff Simulator (WALRUS) is a new parametric (conceptual) rainfall-runoff model which accounts explicitly for processes that are important in lowland areas, such as groundwater-unsaturated zone coupling, wetness-dependent flowroutes, groundwater-surface water feedbacks, and seepage and surface water supply (see companion paper by Brauer et al., 2014). Lowland catchments can be divided into slightly sloping, freely draining catchments and flat polders with controlled water levels. Here, we apply WALRUS to two contrasting Dutch catchments: the Hupsel Brook catchment and Cabauw polder. In both catchments, WALRUS performs well: Nash-Sutcliffe efficiencies obtained after calibration on one year of discharge observations are 0.87 for the Hupsel Brook catchment and 0.83 for the Cabauw polder, with values of 0.74 and 0.76 for validation. The model also performs well during floods and droughts and can forecast the effect of control operations. Through the dynamic division between quick and slow flowroutes controlled by a wetness index, temporal and spatial variability in groundwater depths can be accounted for, which results in adequate simulation of discharge peaks as well as low flows. The performance of WALRUS is most sensitive to the parameter controlling the wetness index and the groundwater reservoir constant, and to a lesser extent to the quickflow reservoir constant. The effects of these three parameters can be identified in the discharge time series, which indicates that the model is not overparameterised (parsimonious). Forcing uncertainty was found to have a larger effect on modelled discharge than parameter uncertainty and uncertainty in initial conditions.

  11. Sex-Specific Energetics of Pacific Walruses (Odobenus rosmarus divergens) during the Nursing Interval.

    PubMed

    Noren, Shawn R; Udevitz, Mark S; Jay, Chadwick V

    2016-01-01

    Habitat use and activity patterns of Pacific walruses (Odobenus rosmarus divergens) have changed with climate-induced reductions in sea ice. Increases in the time active in water could result in negative energy balance, precluding females from sustaining lactation, which could impact population demographics. Little is known about lactation costs in walruses. We examined the energetics of 0-2-yr-old walrus calves by using Bayesian hierarchical models based on longitudinal husbandry records of growth (n = 6 females and 7 males) and caloric intake (n = 5 females and 6 males) as a proxy for maternal lactation costs. Males and females had similar growth patterns; mean mass increased from 68 kg at birth to 301 kg by 2 yr. Females had a 2,000 kcal kg(-1) higher mass storage (growth) cost than males; females typically synthesize and deposit greater amounts of adipose, which is more energy dense than lean tissue. In contrast, males had higher metabolic (basal and activity) costs, ranging from 600 to 1,800 kcal d(-1) greater than similarly sized females; males are typically leaner, and muscle is more metabolically active than adipose. Yet total daily energy requirements (storage plus metabolic components) were similar across sexes, summing to approximately 190,000 kcal over the first month postpartum. Based on these estimates and assuming that 8,103 kcal is recovered from 1 kg of mass loss in adult female walruses, suckling calves could deplete 23 kg of their mother's body mass over the first month after parturition if none of the lactation costs is met through ingested prey. PMID:27082720

  12. 137Cs and 210Po in Pacific Walrus and Bearded Seal from St. Lawrence Island, Alaska

    SciTech Connect

    Hamilton, T F; Seagars, D J; Jokela, T; Layton, D

    2005-02-02

    The activity concentration of Cesium-137 ({sup 137}Cs) and naturally-occurring Polonium-210 ({sup 210}Po) were measured in the muscle tissue, kidney and liver of Pacific walrus (Odobenus rosmarus divergens) and bearded seal (Erignathus barbatus) collected by native hunters from the Bering Sea. The mean {sup 137}Cs concentrations in muscle, liver and kidney of Pacific walrus were 0.07, 0.09 and 0.07 Bq kg{sup -1} (N= 5, wet weight), respectively, and 0.17, 0.10, and 0.17 Bq kg{sup -1} (N=2, wet weight), respectively, in bearded seal. In general, {sup 137}Cs tissue concentrations are significantly lower than those previously reported for mammals from other regions. By comparison, {sup 210}Po activity concentrations appear to be higher than those reported elsewhere but a larger variation. The mean {sup 210}Po concentration in the muscle tissue, liver and kidney of Pacific walrus (N=5, wet weight) were 28.7, 189, and 174 Bq kg{sup -1}, respectively. This compares with {sup 210}Po concentration values (N=2, wet weight) of 27, 207, and 68 Bq kg{sup -1} measured in the muscle tissue, liver and kidney, of bearded seal, respectively. Estimated bioaccumulation factors--as defined by the radionuclide concentration ratio between the target tissue to that in sea water--were two to three orders of magnitude higher for {sup 210}Po that those of {sup 137}Cs. We conclude from radiological dose estimates that ingestion of {sup 137}Cs in foods derived from walrus and seal will pose no threat to human health. This work has important implications for assessing health risks to Alaskan coastal communities concerned about the dumping of nuclear waste in the Russia Arctic.

  13. Rapid maturation of the muscle biochemistry that supports diving in Pacific walruses (Odobenus rosmarus divergens)

    USGS Publications Warehouse

    Norem, Shawn R.; Jay, Chadwick V.; Burns, Jennifer M.; Fischbach, Anthony S.

    2015-01-01

    Physiological constraints dictate animals’ ability to exploit habitats. For marine mammals, it is important to quantify physiological limits that influence diving and their ability to alter foraging behaviors. We characterized age-specific dive limits of walruses by measuring anaerobic (acid-buffering capacity) and aerobic (myoglobin content) capacities of the muscles that power hind (longissimus dorsi) and fore (supraspinatus) flipper propulsion. Mean buffering capacities were similar across muscles and age classes (a fetus, five neonatal calves, a 3 month old and 20 adults), ranging from 41.31 to 54.14 slykes and 42.00 to 46.93 slykes in the longissimus and supraspinatus, respectively. Mean myoglobin in the fetus and neonatal calves fell within a narrow range (longissimus: 0.92–1.68 g 100 g−1 wet muscle mass; supraspinatus: 0.88–1.64 g 100 g−1 wet muscle mass). By 3 months post-partum, myoglobin in the longissimus increased by 79%, but levels in the supraspinatus remained unaltered. From 3 months post-partum to adulthood, myoglobin increased by an additional 26% in the longissimus and increased by 126% in the supraspinatus; myoglobin remained greater in the longissimus compared with the supraspinatus. Walruses are unique among marine mammals because they are born with a mature muscle acid-buffering capacity and attain mature myoglobin content early in life. Despite rapid physiological development, small body size limits the diving capacity of immature walruses and extreme sexual dimorphism reduces the diving capacity of adult females compared with adult males. Thus, free-ranging immature walruses likely exhibit the shortest foraging dives while adult males are capable of the longest foraging dives.

  14. Tracking of Pacific walruses in the Chukchi Sea using a single hydrophone.

    PubMed

    Mouy, Xavier; Hannay, David; Zykov, Mikhail; Martin, Bruce

    2012-02-01

    The vocal repertoire of Pacific walruses includes underwater sound pulses referred to as knocks and bell-like calls. An extended acoustic monitoring program was performed in summer 2007 over a large region of the eastern Chukchi Sea using autonomous seabed-mounted acoustic recorders. Walrus knocks were identified in many of the recordings and most of these sounds included multiple bottom and surface reflected signals. This paper investigates the use of a localization technique based on relative multipath arrival times (RMATs) for potential behavior studies. First, knocks are detected using a semi-automated kurtosis-based algorithm. Then RMATs are matched to values predicted by a ray-tracing model. Walrus tracks with vertical and horizontal movements were obtained. The tracks included repeated dives between 4.0 m and 15.5 m depth and a deep dive to the sea bottom (53 m). Depths at which bell-like sounds are produced, average knock production rate and source levels estimates of the knocks were determined. Bell sounds were produced at all depths throughout the dives. Average knock production rates varied from 59 to 75 knocks/min. Average source level of the knocks was estimated to 177.6 ± 7.5 dB re 1 μPa peak @ 1 m. PMID:22352508

  15. Sea Ice for Walrus Outlook — A Collaboration to Benefit Both Stakeholders and Science

    NASA Astrophysics Data System (ADS)

    Creek, K. R.

    2015-12-01

    Started in 2010, the Sea Ice for Walrus Outlook (SIWO, http://www.arcus.org/search-program/siwo) is a collaborative effort between stakeholders, forecasters, and researchers. An annual project that runs roughly from April to June, dependent on ice conditions, SIWO serves as a resource for Alaska Native subsistence hunters and coastal communities. It provides weekly reports with information on sea ice conditions relevant to walrus in the Northern Bering Sea and southern Chukchi Sea regions of Alaska. Weather and ice forecasters at the National Weather Service provide ten-day outlooks on upcoming conditions, climate scientists and sea-ice researchers at NOAA and the University of Alaska contribute their perspectives and in-situ observations, the Eskimo Walrus Commission provides connections with local communities, and Alaska Native sea-ice experts submit on-the-ground observations. The project is managed by the Arctic Research Consortium of the U.S. (ARCUS, with funding from the National Science Foundation's Division of Arctic Sciences). The goal of the SIWO project is to assist village communities while simultaneously evaluating the accuracy of scientific forecasts. Originally conceptualized by stakeholders themselves, various organizations and researchers became involved to fulfill and support its different roles. Stakeholders have used data from the project both to help plan hunting trips and also to assist in obtaining a declaration of emergency status after a particularly poor hunting season.

  16. Occurrence of Ehrlichia canis in free-living primates of the genus Callithrix.

    PubMed

    Mafra, Claudio; Barcelos, Rafael Mazioli; Mantovani, Cynthia; Carrizo, Juliana; Soares, Adriano Carlos; Moreira, Higo Nasser Sant'Anna; Maia, Natasha Lagos; da Silva, Fernanda de Fátima Rodrigues; e Silva, Vinícius Herold Dornelas; Boere, Vanner; e Silva, Ita de Oliveira

    2015-01-01

    Bacteria of the genus Ehrlichia are Gram-negative and coccoid-shaped microorganisms that cause ehrlichiosis - a serious infectious disease that often leads to death. These bacteria present a strong zoonotic potential and primates may act as reservoir hosts. This study involved a molecular analysis to detect these microorganisms in blood samples collected from nineteen primates of the genus Callithrix living free in an Atlantic Forest fragment in the municipality of Viçosa, state of Minas Gerais, Brazil. One of the 19 primates was found to be infected with Ehrlichia canis. This finding points to a new wild host of E. canis with a strong potential for transmission to humans because of its increasing contact with people. This is the first report of Ehrlichia spp. in primate of the genus Callithrix. PMID:25909257

  17. Cryptic diversity of free-living parabasalids, Pseudotrichomonas keilini and Lacusteria cypriaca n. g., n. sp., as inferred from small subunit rDNA sequences.

    PubMed

    Yubuki, Naoji; Céza, Vít; Cepicka, Ivan; Yabuki, Akinori; Inagaki, Yuji; Nakayama, Takeshi; Inouye, Isao; Leander, Brian S

    2010-01-01

    Ultrastructural and molecular phylogenetic evidence indicate that the Parabasalia consists of seven main subgroups: the Trichomonadida, Honigbergiellida, Hypotrichomonadida, Tritrichomonadida, Cristamonadida, Spirotrichonymphida, and Trichonymphida. Only five species of free-living parabasalids are known: Monotrichomonas carabina, Ditrichomonas honigbergii, Honigbergiella sp., Tetratrichomonas undula, and Pseudotrichomonas keilini. Phylogenetic analyses show that free-living species do not form a clade and instead branch in several different positions within the context of their parasitic relatives. Because the diversity of free-living parabasalids is poorly understood, the systematics of these lineages is in a significant state of disarray. In order to better understand the phylogenetic distribution of free-living parabasalids, we sequenced the small subunit rDNA from three different strains reminiscent of P. keilini; the strains were isolated from different geographical locations: (1) mangrove sediments in Japan and (2) sediments in Cyprus. These data demonstrated that the free-living parabasalids P. keilini and Lacusteria cypriaca n. g., n. sp., form a paraphyletic assemblage near the origin of a clade consisting mostly of parasitic trichomonadids (e.g. Trichomonas vaginalis). This paraphyletic distribution of similar morphotypes indicates that free-living trichomonadids represent a compelling example of morphostasis that provides insight into the suite of features present in the most recent free-living ancestor of their parasitic relatives. PMID:20880033

  18. New deep-sea large free-living nematodes from macrobenthos in the Kuril-Kamchatka Trench (the North-Western Pacific)

    NASA Astrophysics Data System (ADS)

    Fadeeva, Natalia; Mordukhovich, Vladimir; Zograf, Julia

    2015-01-01

    The composition of deep-sea nematode assemblages of the North-Western (NW) Pacific is poorly-studied. According to the available literature data more than 700 valid species of nematodes were reported from the depth of 400 m and deeper, out of that only 6 species were registered in the NW Pacific: 2 species from the coast of the Japanese Islands and 4 from the Sea of Japan. Ecological studies of the deep-sea nematode communities of this region are scanty and represent very scarce and fragmentary information. The first recent study of free-living nematodes collected from the abyssal plain adjacent to the Kuril-Kamchatka Trench has revealed more than 50 species of nematodes in macrobenthic samples. Families Anticomidae, Comesomatidae, Desmodoridae, Leptosomatidae, Oncholaimidae, Oxystominidae, Phanodermatidae, Siphonolaimidae and Thoracostomopsidae were the most abundant and diverse. Such taxonomic composition differs greatly from previously described meiobenthical nematode communities of NW Pacific and even World Ocean and similar to macrofaunal nematode assemblages of the Atlantic and Arctic regions. Several genera of nematodes can be considered as new records for the NW Pacific region. Micoletzkyia kamchatika sp. nov., Metaphanoderma improvisa sp. nov., and Phylloncholaimus palmaris sp. nov. are described from the Kuril-Kamchatka Trench. Micoletzkyia kamchatika sp. nov. is particularly characterized by a developed cuticular cephalic capsule underlying amphids, relatively small amphids, and the shape of the gubernaculum. Metaphanoderma improvisa sp. nov. is particularly characterized by a developed cuticular cephalic capsule, relatively large amphids, and the absence of pigmented eye spots. Phylloncholaimus palmaris sp. nov. is similar to the type species in many measurements but may be differentiated from that by the smaller amphid, shape of spicules and gubernaculums and by large precloacal papillae with four setae.

  19. Underwater Acoustic Localization and Tracking of Pacific Walruses in the Northeastern Chukchi Sea

    NASA Astrophysics Data System (ADS)

    Rideout, Brendan Pearce

    This thesis develops and demonstrates an approach for estimating the three-dimensional (3D) location of a vocalizing underwater marine mammal using acoustic arrival time measurements at three spatially separated receivers while providing rigorous location uncertainties. To properly account for uncertainty in the measurements of receiver parameters (e.g., 3D receiver locations and synchronization times) and environmental parameters (water depth and sound speed correction), these quantities are treated as unknowns constrained with prior estimates and prior uncertainties. While previous localization algorithms have solved for an unknown scaling factor on the prior uncertainties as part of the inversion, in this work unknown scaling factors on both the prior and arrival time uncertainties are estimated. Maximum a posteriori estimates for sound source locations and times, receiver parameters, and environmental parameters are calculated simultaneously. Posterior uncertainties for all unknowns are calculated and incorporate both arrival time and prior uncertainties. Simulation results demonstrated that, for the case considered here, linearization errors are generally small and that the lack of an accurate sound speed profile does not necessarily cause large uncertainties or biases in the estimated positions. The primary motivation for this work was to develop an algorithm for locating underwater Pacific walruses in the coastal waters around Alaska. In 2009, an array of approximately 40 underwater acoustic receivers was deployed in the northeastern Chukchi Sea (northwest of Alaska) from August to October to record the vocalizations of marine mammals including Pacific walruses and bowhead whales. Three of these receivers were placed in a triangular arrangement approximately 400 m apart near the Hanna Shoal (northwest of Wainwright, Alaska). A sequence of walrus knock vocalizations from this data set was processed using the localization algorithm developed in this thesis

  20. Glycaemic Profiles of Children With Overweight and Obesity in Free-living Conditions in Association With Cardiometabolic Risk.

    PubMed

    Rijks, Jesse; Karnebeek, Kylie; van Dijk, Jan-Willem; Dorenbos, Elke; Gerver, Willem-Jan; Stouthart, Pauline; Plat, Jogchum; Vreugdenhil, Anita

    2016-01-01

    Insulin resistance is common among children with overweight and obesity. However, knowledge about glucose fluctuations in these children is scarce. This study aims to evaluate glycaemic profiles in children with overweight and obesity in free-living conditions, and to examine the association between glycaemic profiles with insulin resistance and cardiovascular risk parameters. One hundred eleven children with overweight and obesity were included. 48-hour sensor glucose concentrations in free-living conditions, fasting plasma and post-glucose load concentrations, serum lipid and lipoprotein concentrations, homeostatic model assessment of insulin resistance (HOMA-IR), and blood pressure were evaluated. Hyperglycaemic glucose excursions (≥7.8 mmol/L) were observed in 25% (n = 28) of the children. The median sensor glucose concentration was 5.0 (2.7-7.3) mmol/L, and correlated with fasting plasma glucose concentrations (rs = 0.190, p = 0.046), serum insulin concentrations (rs = 0.218, p = 0.021), and HOMA-IR (rs = 0.230, p = 0.015). The hyperglycaemic area under the curve (AUC) correlated with waist circumference z-score (rs = 0.455, p = 0.025), triacylglycerol concentrations (rs = 0.425, p = 0.024), and HOMA-IR (rs = 0.616, p < 0.001). In conclusion, hyperglycaemic glucose excursions are frequently observed in children with overweight and obesity in free-living conditions. Children with insulin resistance had higher median sensor glucose concentrations and a larger hyperglycaemic sensor glucose AUC, which are both associated with specific parameters predicting cardiovascular disease risk. PMID:27534260

  1. Glycaemic Profiles of Children With Overweight and Obesity in Free-living Conditions in Association With Cardiometabolic Risk

    PubMed Central

    Rijks, Jesse; Karnebeek, Kylie; van Dijk, Jan-Willem; Dorenbos, Elke; Gerver, Willem-Jan; Stouthart, Pauline; Plat, Jogchum; Vreugdenhil, Anita

    2016-01-01

    Insulin resistance is common among children with overweight and obesity. However, knowledge about glucose fluctuations in these children is scarce. This study aims to evaluate glycaemic profiles in children with overweight and obesity in free-living conditions, and to examine the association between glycaemic profiles with insulin resistance and cardiovascular risk parameters. One hundred eleven children with overweight and obesity were included. 48-hour sensor glucose concentrations in free-living conditions, fasting plasma and post-glucose load concentrations, serum lipid and lipoprotein concentrations, homeostatic model assessment of insulin resistance (HOMA-IR), and blood pressure were evaluated. Hyperglycaemic glucose excursions (≥7.8 mmol/L) were observed in 25% (n = 28) of the children. The median sensor glucose concentration was 5.0 (2.7–7.3) mmol/L, and correlated with fasting plasma glucose concentrations (rs = 0.190, p = 0.046), serum insulin concentrations (rs = 0.218, p = 0.021), and HOMA-IR (rs = 0.230, p = 0.015). The hyperglycaemic area under the curve (AUC) correlated with waist circumference z-score (rs = 0.455, p = 0.025), triacylglycerol concentrations (rs = 0.425, p = 0.024), and HOMA-IR (rs = 0.616, p < 0.001). In conclusion, hyperglycaemic glucose excursions are frequently observed in children with overweight and obesity in free-living conditions. Children with insulin resistance had higher median sensor glucose concentrations and a larger hyperglycaemic sensor glucose AUC, which are both associated with specific parameters predicting cardiovascular disease risk. PMID:27534260

  2. Geochemistry and Mixing Drive the Spatial Distribution of Free-Living Archaea and Bacteria in Yellowstone Lake

    PubMed Central

    Kan, Jinjun; Clingenpeel, Scott; Dow, Charles L.; McDermott, Timothy R.; Macur, Richard E.; Inskeep, William P.; Nealson, Kenneth H.

    2016-01-01

    Yellowstone Lake, the largest subalpine lake in the United States, harbors great novelty and diversity of Bacteria and Archaea. Size-fractionated water samples (0.1–0.8, 0.8–3.0, and 3.0–20 μm) were collected from surface photic zone, deep mixing zone, and vent fluids at different locations in the lake by using a remotely operated vehicle (ROV). Quantification with real-time PCR indicated that Bacteria dominated free-living microorganisms with Bacteria/Archaea ratios ranging from 4037:1 (surface water) to 25:1 (vent water). Microbial population structures (both Bacteria and Archaea) were assessed using 454-FLX sequencing with a total of 662,302 pyrosequencing reads for V1 and V2 regions of 16S rRNA genes. Non-metric multidimensional scaling (NMDS) analyses indicated that strong spatial distribution patterns existed from surface to deep vents for free-living Archaea and Bacteria in the lake. Along with pH, major vent-associated geochemical constituents including CH4, CO2, H2, DIC (dissolved inorganic carbon), DOC (dissolved organic carbon), SO42-, O2 and metals were likely the major drivers for microbial population structures, however, mixing events occurring in the lake also impacted the distribution patterns. Distinct Bacteria and Archaea were present among size fractions, and bigger size fractions included particle-associated microbes (> 3 μm) and contained higher predicted operational taxonomic unit richness and microbial diversities (genus level) than free-living ones (<0.8 μm). Our study represents the first attempt at addressing the spatial distribution of Bacteria and Archaea in Yellowstone Lake, and our results highlight the variable contribution of Archaea and Bacteria to the hydrogeochemical-relevant metabolism of hydrogen, carbon, nitrogen, and sulfur. PMID:26973602

  3. Geochemistry and Mixing Drive the Spatial Distribution of Free-Living Archaea and Bacteria in Yellowstone Lake.

    PubMed

    Kan, Jinjun; Clingenpeel, Scott; Dow, Charles L; McDermott, Timothy R; Macur, Richard E; Inskeep, William P; Nealson, Kenneth H

    2016-01-01

    Yellowstone Lake, the largest subalpine lake in the United States, harbors great novelty and diversity of Bacteria and Archaea. Size-fractionated water samples (0.1-0.8, 0.8-3.0, and 3.0-20 μm) were collected from surface photic zone, deep mixing zone, and vent fluids at different locations in the lake by using a remotely operated vehicle (ROV). Quantification with real-time PCR indicated that Bacteria dominated free-living microorganisms with Bacteria/Archaea ratios ranging from 4037:1 (surface water) to 25:1 (vent water). Microbial population structures (both Bacteria and Archaea) were assessed using 454-FLX sequencing with a total of 662,302 pyrosequencing reads for V1 and V2 regions of 16S rRNA genes. Non-metric multidimensional scaling (NMDS) analyses indicated that strong spatial distribution patterns existed from surface to deep vents for free-living Archaea and Bacteria in the lake. Along with pH, major vent-associated geochemical constituents including CH4, CO2, H2, DIC (dissolved inorganic carbon), DOC (dissolved organic carbon), SO4 (2-), O2 and metals were likely the major drivers for microbial population structures, however, mixing events occurring in the lake also impacted the distribution patterns. Distinct Bacteria and Archaea were present among size fractions, and bigger size fractions included particle-associated microbes (> 3 μm) and contained higher predicted operational taxonomic unit richness and microbial diversities (genus level) than free-living ones (<0.8 μm). Our study represents the first attempt at addressing the spatial distribution of Bacteria and Archaea in Yellowstone Lake, and our results highlight the variable contribution of Archaea and Bacteria to the hydrogeochemical-relevant metabolism of hydrogen, carbon, nitrogen, and sulfur. PMID:26973602

  4. Stress Management in Cyst-Forming Free-Living Protists: Programmed Cell Death and/or Encystment

    PubMed Central

    Khan, Naveed Ahmed; Iqbal, Junaid

    2015-01-01

    In the face of harsh conditions and given a choice, a cell may (i) undergo programmed cell death, (ii) transform into a cancer cell, or (iii) enclose itself into a cyst form. In metazoans, the available evidence suggests that cellular machinery exists only to execute or avoid programmed cell death, while the ability to form a cyst was either lost or never developed. For cyst-forming free-living protists, here we pose the question whether the ability to encyst was gained at the expense of the programmed cell death or both functions coexist to counter unfavorable environmental conditions with mutually exclusive phenotypes. PMID:25648302

  5. Free-living Acanthamoeba and Naegleria spp. amebae in water sources of León, Nicaragua.

    PubMed

    Leiva, Byron; Clasdotter, Emma; Linder, Ewert; Winiecka-Krusnell, Jadwiga

    2008-06-01

    Free-living amebae (FLA) are known to occur worldwide in water-related biotopes, but only limited information is available on these organisms in developing countries and so far no information on their presence is available from Nicaragua. The aims of this study were to evaluate the prevalence of potentially pathogenic Acanthamoeba spp. and Naegleria spp. in different water sources to which the population of Le6n municipality is exposed. Since pathogenic amebae are thermotolerant, we were especially interested in the occurrence of FLA in geothermal areas. Water samples were collected from Le6n area in Nicaragua: 88 samples were from rivers and springs, 111 from wells, 74 from water taps and 21 from water tanks in urban and suburban Le6n and from three nearby geothermal areas of San Jacinto, Posoltega and Tipitapa. Amebae were identified using morphological and physiological criteria, immunohistochemical staining procedures and molecular methods. Indirect immunofluorescent test was performed on cysts and trophozoites fixed on microscopical slides and incubated for 30 min at room temperature in separate experiments with the following antibodies: rabbit-anti N fowleri/N lovanensis (Nf-Pab), mouse monoclonal antibody anti N. fowleri (Nf-5D12u), rabbit antibodies against Acanthamoeba spp. And fluorescent in situ hybridization (FISH) was performed using 18S rRNA-targeted fluorescent oligonucleotide probes. Probes: GSP for the detection of Acanthamoeba and NAEG1088 for the detection of Naegleria. Free-living amebae were recovered from approximately 43 % of the samples. Acanthamoeba spp was found in 21% of samples from León municipality and in 2% of samples from geothermal areas. Amoeboflagellates were found in 10 % of samples from Le6n and in 19% in geothermal areas. Fifty three percent of tested wells in the geothermal area contained thermotolerant amoeboflagellates. Naegleria spp. was identified in 24 out of 39 (61.5 %) of isolated amoeboflagellates. Twelve of them were

  6. Free-living protozoa in the gastrointestinal tract and feces of pigs: Exploration of an unknown world and towards a protocol for the recovery of free-living protozoa.

    PubMed

    Chavatte, N; Lambrecht, E; Van Damme, I; Sabbe, K; Houf, K

    2016-07-30

    Associations with free-living protozoa (FLP) have been implicated in the persistence of foodborne pathogenic bacteria in food-related environments. To date however no information is available on the presence of FLP in the gastrointestinal tract (GIT) of pigs, which represents an important reservoir for zoonotic foodborne bacteria and hence a potential location for associations with FLP. This is at least partly due to the lack of adequate protocols to recover FLP from intestinal content and feces. In the present study different protocols to recover FLP from the porcine GIT and feces were tested. The most effective protocols were then applied to explore the presence of live FLP in the pig GIT and feces. A filtration based protocol was identified as the most suitable method to recover viable FLP from the porcine GIT and feces. Cultivable FLP were recovered from different parts of the GIT, suggesting at least a transient presence of FLP in this habitat. Free-living amoebae species (Acanthamoeba spp., Hyperamoeba sp., Vannella sp., Vermamoeba vermiformis, hartmannellids and vahlkampfiids) but also ciliates (Colpoda sp. and Tetrahymena/Glaucoma lookalike) and flagellates (cercomonads, bodonids and glissomonads) were recovered and cultured from pig intestinal content. Acanthamoeba hatchetti and Filamoeba sinensis were isolated for the first time from pig intestinal content. Despite high gastric acidity, non-cyst forming amoeba species were also detected which suggests survival of their trophozoites in the animal GIT. PMID:27369581

  7. Detection of Free-Living Amoebae Using Amoebal Enrichment in a Wastewater Treatment Plant of Gauteng Province, South Africa

    PubMed Central

    Muchesa, P.; Mwamba, O.; Barnard, T. G.; Bartie, C.

    2014-01-01

    Free-living amoebae pose a potential health risk in water systems as they may be pathogenic and harbor potential pathogenic bacteria known as amoebae resistant bacteria. Free-living amoebae were observed in 150 (87.2%) of the environmental water samples. In particular, Acanthamoeba sp. was identified in 22 (12.8%) using amoebal enrichment and confirmed by molecular analysis. FLA were isolated in all 8 stages of the wastewater treatment plant using the amoebal enrichment technique. A total of 16 (9.3%) samples were positive for FLA from influent, 20 (11.6%) from bioreactor feed, 16 (9.3%) from anaerobic zone, 16 (9.3%) from anoxic zone, 32 (18.6%) from aerators, 16 (9.3%) from bioreactor effluent, 11 (6.4%) from bioreactor final effluent, and 45 (26.2%) from maturation pond. This study provides baseline information on the occurrence of amoebae in wastewater treatment plant. This has health implications on receiving water bodies as some FLA are pathogenic and are also involved in the transmission and dissemination of pathogenic bacteria. PMID:25530964

  8. Detection and Molecular Characterization of Potentially Pathogenic Free-living Amoebae from Water Sources in Kish Island, Southern Iran

    PubMed Central

    Niyyati, Maryam; Lasgerdi, Zohreh; Lorenzo-Morales, Jacob

    2015-01-01

    Amoebic keratitis, a sight-threatening corneal infection, mainly occurs in contact lens wearers who wash their eyes with tap water. The present research was conducted to identify the occurrence of potentially pathogenic free-living amoebae (FLA) in tap water sources on Kish Island, a tourist region in Iran. Amoebae were detected using a culture-enriched method and by polymerase chain reaction (PCR)/sequencing of the diagnostic fragment 3 region of the 18S rRNA gene of Acanthamoeba. In the case of other free-living amoebae species, PCR/sequencing analysis of the 18S rDNA was conducted. Results of this study showed the presence of Acanthamoeba belonging to T3, T4, T5, and T11 genotypes in tap water sources. Additionally, Vermamoebae vermiformis was detected in three water samples. This is the first report of the Acanthamoeba genotypes T3, T4, T5, and T11 and V. vermiformis species in tap water sources in a tourist region in Iran. PMID:25922581

  9. Endosymbiosis In Statu Nascendi: Close Phylogenetic RelationshipBetween Obligately Endosymbiotic and Obligately Free-LivingPolynucleobacter Strains (Betaproteobacteria)

    SciTech Connect

    Vannini, Claudia; Pockl, Matthias; Petroni, Giulio; Wu, Qinglong; Lang, Elke; Stackebrandt, Erko; Schrallhammer, Martina; Richardson, PaulM.; Hahn, Martin W.

    2006-07-21

    Bacterial strains affiliated to the phylogenetically shallowsubcluster C (PnecC) of the 28 Polynucleobacter cluster, which ischaracterized by a minimal 16S rRNA gene sequence similarity of approx.98.5 percent, have been reported to occur as obligate endosymbionts of 30ciliates (Euplotes spp.), as well as to occur as free-living cells in thepelagic zone of freshwater habitats. We investigated if these two groupsof closely related bacteria represent 32 strains fundamentally differingin lifestyle, or if they simply represent different stages of afacultative endosymbiotic lifestyle. The phylogenetic analysis of 16SrRNA gene and 16S34 23S ITS sequences of five endosymbiont strains fromtwo different Euplotes species and 40 pure culture strains demonstratedhost-species-specific clustering of the endosymbiont 36 sequences withinthe PnecC subcluster. The sequences of the endosymbionts showedcharacteristics indicating an obligate endosymbiotic lifestyle.Cultivation experiments 38 revealed fundamental differences inphysiological adaptations, and determination of the genome sizesindicated a slight size reduction in endosymbiotic strains. We concludethat the 40 two groups of PnecC bacteria represent obligately free-livingand obligately endosymbiotic strains, respectively, and do not representdifferent stages of the same complex lifecycle. 42 These closely relatedstrains occupy completely separated ecological niches. To our bestknowledge, this is the closest phylogenetic relationship between obligateendosymbionts and 44 obligately free-living bacteria everrevealed.

  10. Curtisia dentata (Cornaceae) leaf extracts and isolated compounds inhibit motility of parasitic and free-living nematodes.

    PubMed

    Shai, L J; Bizimenyera, E S; Bagla, V; McGaw, L J; Eloff, J N

    2009-06-01

    Haemonchus contortus and Trichostrongylus colubriformis are among the most important parasitic nematodes of small ruminants. Caenorhabditis elegans, a free-living nematode, is used as a model for evaluating anthelmintic activity of a variety of test substances. Extracts of several medicinal plants are useful in vitro and in vivo against nematode development. Extracts of Curtisia dentata, a South African medicinal plant, and compounds isolated from leaves of this plant were investigated for anthelmintic activity against T. colubriformis, H. contortus and C. elegans. The acetone and dichloromethane extracts were active against all nematodes at concentrations as low as 160 microg/ml. Betulinic acid and lupeol were active against the parasitic nematodes only at the high concentrations of 1000 and 200 microg/ml, respectively. All compounds were effective against C. elegans with active concentrations as low as 8 microg/ml. Betulinic acid was less active than lupeol and ursolic acid against C. elegans. The acetone and dichloromethane extracts were also active against C. elegans with a concentration of 0.31 mg/ml resulting in almost 80% inhibition of larval motility. The use of free-living nematodes may provide information on the activity of potential anthelmintics against parasitic nematodes. Extracts of various medicinal plant species may provide solutions to ill-health of small ruminants caused by parasitic nematodes in poor communities of southern Africa. PMID:20698444

  11. Evaluation of antibiotics as a methodological procedure to inhibit free-living and biofilm bacteria in marine zooplankton culture.

    PubMed

    Agostini, Vanessa O; Macedo, Alexandre J; Muxagata, Erik

    2016-01-01

    There is a problem with keeping culture medium completely or partially free from bacteria. The use of prokaryotic metabolic inhibitors, such as antibiotics, is suggested as an alternative solution, although such substances should not harm non-target organisms. Thus, the aim of this study was to assess the effectiveness of antibiotic treatments in inhibiting free-living and biofilm bacteria and their half-life in artificial marine environment using the copepod Acartia tonsa as bioindicador of non-harmful antibiotic combinations. Regarding to results, the application of 0.025 g L-1 penicillin G potassium + 0.08 g L-1 streptomycin sulphate + 0.04 g L-1 neomycin sulphate showed great potential for use in marine cultures and scientific experiments without lethal effects to non-target organisms. The effect of this combination starts within the first six hours of exposure and reduces up to 93 % the bacterial density, but the half-life is short, requiring replacement. No adverse changes in water quality were observed within 168 hours of exposure. As a conclusion, we can infer that this treatment was an effective procedure for zooplankton cultures and scientific experiments with the aim of measuring the role of free-living and biofilm in the marine community. PMID:27168369

  12. Heligmosomoides polygyrus reduces infestation of Ixodes ricinus in free-living yellow-necked mice, Apodemus flavicollis.

    PubMed

    Ferrari, N; Cattadori, I M; Rizzoli, A; Hudson, P J

    2009-03-01

    Free-living animals are usually inhabited by a community of parasitic species that can interact with each other and alter both host susceptibility and parasite transmission. In this study we tested the prediction that an increase in the gastrointestinal nematode Heligmosomoides polygyrus would increase the infestation of the tick Ixodes ricinus, in free-living yellow-necked mice, Apodemus flavicollis. An extensive cross-sectional trapping survey identified a negative relationship between H. polygyrus and I. ricinus counter to the prediction. An experimental reduction of the nematode infection through anthelmintic treatment resulted in an increase in tick infestation, suggesting that this negative association was one of cause and effect. Host characteristics (breeding condition and age) and habitat variables also contributed to affect tick infestation. While these results were counter to the prediction, they still support the hypothesis that interactions between parasite species can shape parasite community dynamics in natural systems. Laboratory models may act differently from natural populations and the mechanism generating the negative association is discussed. PMID:19154651

  13. Preliminary study on applicability of microsatellite DNA primers from parasite protozoa Trypanosoma cruzi in free-living protozoa

    NASA Astrophysics Data System (ADS)

    Zhang, Wenjing; Yu, Yuhe; Shen, Yunfen; Miao, Wei; Feng, Weisong

    2004-04-01

    In this paper, we took the lead in studying on specificity of the microsatellite DNA loci and applicability of microsatellite DNA primers in protozoa. In order to study characters of microsatellites in free-living protozoa, eight microsatellite loci primers developed from Trypanosoma cruzi (MCLE01, SCLE10, MCLE08, SCLE11, MCLF10, MCLG10, MCL03, MCL05) were employed to amplify microsatellite in four free-living protozoa, including Bodo designis, Euglena gracilis FACHB848, Paramecium bruzise and Tetrahymena thermophila BF1. In the amplification systems of P. bruzise, four loci (SCLE10, SCLE11, MCLF10, MCL03) were amplified successfully, and four amplification fragments were in proper size. In genome of E. gracilis FACHB848, five of eight primers brought five clear amplification bands. In B. designis, three (No.4, 5 and 7) of eight loci produced clear and sharp products without stutter bands, whereas no bands appeared in T. thermophila BF1. Further, eight 300 500 bp amplification fragments were cloned and sequenced. Nevertheless, all sequenced products did not contain corresponding microsatellite sequence, although Bodo is in the same order and has the nearest phylogenetic relation with Trypanosoma among these four species. Thus, the microsatellite DNA primers can not be applied among order or more far taxa, and the specificity of microsatellite DNA is very high in protozoa. The results of this study will contribute to our understanding of microsatellite DNA in protozoa.

  14. Overproduction of Indole-3-Acetic Acid in Free-Living Rhizobia Induces Transcriptional Changes Resembling Those Occurring in Nodule Bacteroids.

    PubMed

    Defez, Roberto; Esposito, Roberta; Angelini, Claudia; Bianco, Carmen

    2016-06-01

    Free-living bacteria grown under aerobic conditions were used to investigate, by next-generation RNA sequencing analysis, the transcriptional profiles of Sinorhizobium meliloti wild-type 1021 and its derivative, RD64, overproducing the main auxin indole-3-acetic acid (IAA). Among the upregulated genes in RD64 cells, we detected the main nitrogen-fixation regulator fixJ, the two intermediate regulators fixK and nifA, and several other genes known to be FixJ targets. The gene coding for the sigma factor RpoH1 and other genes involved in stress response, regulated in a RpoH1-dependent manner in S. meliloti, were also induced in RD64 cells. Under microaerobic condition, quantitative real-time polymerase chain reaction analysis revealed that the genes fixJL and nifA were up-regulated in RD64 cells as compared with 1021 cells. This work provided evidence that the overexpression of IAA in S. meliloti free-living cells induced many of the transcriptional changes that normally occur in nitrogen-fixing root nodule. PMID:27003799

  15. Free-Living and Plankton-Associated Vibrios: Assessment in Ballast Water, Harbor Areas, and Coastal Ecosystems in Brazil

    PubMed Central

    Rivera, Irma N. G.; Souza, Keili M. C.; Souza, Claudiana P.; Lopes, Rubens M.

    2013-01-01

    Ballast water (BW) is a major transport vector of exotic aquatic species and pathogenic microorganisms. The wide-ranging spread of toxigenic Vibrio cholerae O1 from harbor areas has been frequently ascribed to discharge of contaminated BW into eutrophic coastal environments, such as during the onset of the seventh cholera pandemic in South America in the early 1990s. To determine the microbiological hazards of BWs transported to Brazilian ports, we evaluated water and plankton samples taken from (i) BW tanks of recently arrived ships, (ii) port areas along the Brazilian coastline from ∼1 to 32°S and (iii) three coastal areas in São Paulo State. Vibrio concentration and toxigenic V. cholerae O1 occurrence were analyzed. Plankton-associated vibrios were more abundant than free-living vibrios in all studied environments. V. cholerae was found in 9.5% of ballast tanks and 24.2% of port samples, both as free-living and attached forms and, apart from the Santos harbor, was absent off São Paulo State. Toxigenic V. cholerae O1 isolates (ctxA+, tcpA+), involved in cholera disease, were found in BW (2%) and harbor (2%) samples. These results confirm that BW is an important carrier of pathogenic organisms, and that monitoring of vibrios and other plankton-attached bacteria is of paramount importance in BW management programs. PMID:23335920

  16. Variation in abundance and community structure of particle-attached and free-living bacteria in the South China Sea

    NASA Astrophysics Data System (ADS)

    Li, Jiangtao; Wei, Bingbing; Wang, Jiani; Liu, Ying; Dasgupta, Shamik; Zhang, Li; Fang, Jiasong

    2015-12-01

    Bacteria play a crucial role in the biological transfer of carbon in the ocean, especially in the transformation of particulate organic carbon (POC) to dissolved organic carbon (DOC), yet little information is available for their abundance and community structures in mesopelagic and bathypelagic waters. Here we present results of our investigation on the spatial variations of abundance and community composition of the particle-attached (PA) and free-living (FL) bacterial assemblages at different depths (500 m, 800 m, and 1500 m) in the South China Sea (SCS). Our results showed that the abundance of FL bacteria was an order of magnitude higher than that of PA bacteria. The relative abundance of FL bacteria increased from 82% at 500 m to 93% at 1500 m. In all cases, the FL bacteria assemblages were more diverse than the PA fraction. The PA bacterial assemblage was dominated by members of the Rhodobacterales of the α-Proteobacteria and the Alteromonadales of the γ-Proteobacteria. In contrast, the FL bacteria assemblages displayed distinctive spatial heterogeneity and were dominant by different phylotypes at different depths. However, certain bacterial taxa of the α- and γ-Proteobacteria co-occurred in both the FL and PA fractions, with proportions being varied with depth. These results highlight the coexistence of particle-attached and free-living bacteria specialists and generalists, and provide valuable information in understanding the role of different bacterial assemblages in the deep-ocean carbon cycle.

  17. Metabolic effects of dark chocolate consumption on energy, gut microbiota, and stress-related metabolism in free-living subjects.

    PubMed

    Martin, Francois-Pierre J; Rezzi, Serge; Peré-Trepat, Emma; Kamlage, Beate; Collino, Sebastiano; Leibold, Edgar; Kastler, Jürgen; Rein, Dietrich; Fay, Laurent B; Kochhar, Sunil

    2009-12-01

    Dietary preferences influence basal human metabolism and gut microbiome activity that in turn may have long-term health consequences. The present study reports the metabolic responses of free living subjects to a daily consumption of 40 g of dark chocolate for up to 14 days. A clinical trial was performed on a population of 30 human subjects, who were classified in low and high anxiety traits using validated psychological questionnaires. Biological fluids (urine and blood plasma) were collected during 3 test days at the beginning, midtime and at the end of a 2 week study. NMR and MS-based metabonomics were employed to study global changes in metabolism due to the chocolate consumption. Human subjects with higher anxiety trait showed a distinct metabolic profile indicative of a different energy homeostasis (lactate, citrate, succinate, trans-aconitate, urea, proline), hormonal metabolism (adrenaline, DOPA, 3-methoxy-tyrosine) and gut microbial activity (methylamines, p-cresol sulfate, hippurate). Dark chocolate reduced the urinary excretion of the stress hormone cortisol and catecholamines and partially normalized stress-related differences in energy metabolism (glycine, citrate, trans-aconitate, proline, beta-alanine) and gut microbial activities (hippurate and p-cresol sulfate). The study provides strong evidence that a daily consumption of 40 g of dark chocolate during a period of 2 weeks is sufficient to modify the metabolism of free living and healthy human subjects, as per variation of both host and gut microbial metabolism. PMID:19810704

  18. Testosterone treatment is immunosuppressive in superb fairy-wrens, yet free-living males with high testosterone are more immunocompetent.

    PubMed

    Peters, A

    2000-05-01

    The immunocompetence handicap hypothesis proposes that the immunosuppressive effect of testosterone enforces honesty of sexual signalling via a physiological trade-off between signal intensity and immunocompetence. However, evidence that testosterone is immunosuppressive is scant, particularly in birds. I studied the correlation between immunocompetence and testosterone in superb fairy-wrens (Malurus cyaneus), a species with intense intersexual selection. Males are seasonally dichromatic and testosterone increases during the moult from dull brown eclipse plumage into bright nuptial plumage. I determined the primary antibody response to immunization with sheep red blood cells (SRBCs) in (i) control and testosterone-implanted males in captivity, and (ii) a cross-section of free-living males with basal and elevated testosterone (in eclipse plumage, moulting and in nuptial plumage). Experimental treatment with testosterone decreased the likelihood of an antibody response to SRBCs in captive birds. In contrast, free-living males which had acquired the nuptial plumage and had naturally elevated testosterone were more likely to respond to SRBCs than males in eclipse plumage with basal testosterone levels. The association between higher immunocompetence and higher immunosuppressive testosterone could arise if both are positively correlated with male phenotypic quality In addition, the association could result if males compensate for potential immunosuppression by enhancing their humoral immune responses, particularly since high testosterone is linked to other demanding activities such as moulting and courtship displays. PMID:10853730

  19. Seroprevalence of Toxoplasma gondii in free-living Amazon River dolphins (Inia geoffrensis) from central Amazon, Brazil.

    PubMed

    Santos, P S; Albuquerque, G R; da Silva, V M F; Martin, A R; Marvulo, M F V; Souza, S L P; Ragozo, A M A; Nascimento, C C; Gennari, S M; Dubey, J P; Silva, J C R

    2011-12-29

    Toxoplasma gondii is an important pathogen in aquatic mammals and its presence in these animals may indicate the water contamination of aquatic environment by oocysts. Serum samples from 95 free-living Amazon River dolphins (Inia geoffrensis) from the Mamirauá Sustainable Development Reserve (RDSM), Tefé, Amazonas, Central Amazon, Brazil were tested for T. gondii antibodies using the modified agglutination test (MAT). Antibodies (MAT ≥ 25) to T. gondii were found in 82 (86.3%) dolphins with titers of 1:25 in 24, 1:50 in 56, and 1:500 in 2. Results suggest a high level contamination of the aquatic environment of the home range of these animals. PMID:21764516

  20. Techniques to measure free-living energy expenditure during pregnancy – A guide for clinicians and researchers

    PubMed Central

    Abeysekera, Minoli V; Morris, Jack A

    2014-01-01

    As maternal overweight and obesity increase in prevalence, the need to optimise gestational weight gain has entered the forefront due to the well-documented poor fetal and maternal outcomes associated with excess adipose tissue. Measurements of changes in energy expenditure form crucial components of effective weight management programmes, and they are also important for clarifying the energy requirements of pregnancy. This review evaluates the primary techniques for measuring free-living energy expenditure for use in pregnancy, with special consideration of the dynamic physiological changes that occur in this state. The methods that will be discussed include the doubly labelled water method, activity recall and activity logs, heart rate monitors and motion sensors. This article may be useful for clinicians seeking to implement active gestational weight management by enabling advice on increases in caloric intake linked to measured changes in energy expenditure, and for researchers studying energy metabolism in pregnancy.

  1. A new gall crab species (Brachyura, Cryptochiridae) associated with the free-living coral Trachyphyllia geoffroyi (Scleractinia, Merulinidae)

    PubMed Central

    van der Meij, Sancia E.T.

    2015-01-01

    Abstract A new species of gall crab is described from the free-living stony coral Trachyphyllia geoffroyi. Specimens were collected during field work in Lembeh Strait (Indonesia) and off Kudat (Malaysian Borneo). This new species, here named Lithoscaptus semperi sp. n., is the ninth species assigned to the genus. It can be separated from its congeners by not having the internal orbital angle extending beyond the external orbital angle, and by the stout female P2 merus with prominent distomesial projection. In addition, the carapace surface appears smooth, despite having small tubercles on the anterior half, and is without noticeable spines, other than those on the frontal margin. The distinctive carapace pattern in life is a diagnostic character in male specimens. PMID:25987871

  2. Capture and penetration processes of the free-living juveniles of Trichostrongylus colubriformis (Nematoda) by the nematophagous fungus, Arthrobotrys oligospora.

    PubMed

    Murray, D S; Wharton, D A

    1990-08-01

    The nematode-trapping fungus Arthrobotrys oligospora traps and invades all the free-living juvenile stages of the trichostrongyle nematode Trichostrongylus colubriformis. The processes of capture and invasion of the 1st-stage juveniles are described using differential interference contrast optics and 3-D reconstruction techniques. The adhesive responsible for capture is well preserved using a freeze-substitution technique for scanning electron microscopy. The invasion process of the ensheathed 3rd-stage juvenile of T. colubriformis takes much longer than in the 1st- or 2nd-stage juvenile and involves the formation of secondary infection pegs between the sheath and the cuticle which appear to penetrate the cuticle by physical pressure. PMID:2235080

  3. Effect of nestling status and brood size on concentration of corticosterone of free-living kittiwake chicks.

    PubMed

    Brewer, John H; O'Reilly, Kathleen M; Buck, C Loren

    2010-03-01

    Vertebrates respond to perceived stressors through increased plasma concentrations of glucocorticoids. However, there is considerable variation within and across species in the circumstances and degree to which glucocorticoid levels are elevated. We measured baseline and acute stress-induced levels of corticosterone of free-living, black-legged kittiwake chicks (Rissa tridactyla) across four consecutive breeding seasons in the northern Gulf of Alaska to determine the effect of hatching order and brood size on corticosterone levels of chicks. We sampled 12- to 15-day-old chicks from intact broods (i.e., no brood reduction) at three colonies from 2002-2005 (n=164). Baseline and stress-induced levels of corticosterone did not vary by hatching order or brood size. These results suggest that the adrenocortical function of kittiwake chicks from broods that survive intact through 12-15 days is not affected by either hatching order or brood size. PMID:19699742

  4. Estimating free-living human energy expenditure: Practical aspects of the doubly labeled water method and its applications

    PubMed Central

    Kazuko, Ishikawa-Takata; Kim, Eunkyung; Kim, Jeonghyun; Yoon, Jinsook

    2014-01-01

    The accuracy and noninvasive nature of the doubly labeled water (DLW) method makes it ideal for the study of human energy metabolism in free-living conditions. However, the DLW method is not always practical in many developing and Asian countries because of the high costs of isotopes and equipment for isotope analysis as well as the expertise required for analysis. This review provides information about the theoretical background and practical aspects of the DLW method, including optimal dose, basic protocols of two- and multiple-point approaches, experimental procedures, and isotopic analysis. We also introduce applications of DLW data, such as determining the equations of estimated energy requirement and validation studies of energy intake. PMID:24944767

  5. Bio-recovery of non-essential heavy metals by intra- and extracellular mechanisms in free-living microorganisms.

    PubMed

    García-García, Jorge D; Sánchez-Thomas, Rosina; Moreno-Sánchez, Rafael

    2016-01-01

    Free-living microorganisms may become suitable models for recovery of non-essential and essential heavy metals from wastewater bodies and soils by using and enhancing their accumulating and/or leaching abilities. This review analyzes the variety of different mechanisms developed mainly in bacteria, protists and microalgae to accumulate heavy metals, being the most relevant those involving phytochelatin and metallothionein biosyntheses; phosphate/polyphosphate metabolism; compartmentalization of heavy metal-complexes into vacuoles, chloroplasts and mitochondria; and secretion of malate and other organic acids. Cyanide biosynthesis for extra-cellular heavy metal bioleaching is also examined. These metabolic/cellular processes are herein analyzed at the transcriptional, kinetic and metabolic levels to provide mechanistic basis for developing genetically engineered microorganisms with greater capacities and efficiencies for heavy metal recovery, recycling of heavy metals, biosensing of metal ions, and engineering of metalloenzymes. PMID:27184302

  6. Identification of Free-Living and Particle-Associated Microbial Communities Present in Hadal Regions of the Mariana Trench

    PubMed Central

    Tarn, Jonathan; Peoples, Logan M.; Hardy, Kevin; Cameron, James; Bartlett, Douglas H.

    2016-01-01

    Relatively few studies have described the microbial populations present in ultra-deep hadal environments, largely as a result of difficulties associated with sampling. Here we report Illumina-tag V6 16S rRNA sequence-based analyses of the free-living and particle-associated microbial communities recovered from locations within two of the deepest hadal sites on Earth, the Challenger Deep (10,918 meters below surface-mbs) and the Sirena Deep (10,667 mbs) within the Mariana Trench, as well as one control site (Ulithi Atoll, 761 mbs). Seawater samples were collected using an autonomous lander positioned ~1 m above the seafloor. The bacterial populations within the Mariana Trench bottom water samples were dissimilar to other deep-sea microbial communities, though with overlap with those of diffuse flow hydrothermal vents and deep-subsurface locations. Distinct particle-associated and free-living bacterial communities were found to exist. The hadal bacterial populations were also markedly different from one another, indicating the likelihood of different chemical conditions at the two sites. In contrast to the bacteria, the hadal archaeal communities were more similar to other less deep datasets and to each other due to an abundance of cosmopolitan deep-sea taxa. The hadal communities were enriched in 34 bacterial and 4 archaeal operational taxonomic units (OTUs) including members of the Gammaproteobacteria, Epsilonproteobacteria, Marinimicrobia, Cyanobacteria, Deltaproteobacteria, Gemmatimonadetes, Atribacteria, Spirochaetes, and Euryarchaeota. Sequences matching cultivated piezophiles were notably enriched in the Challenger Deep, especially within the particle-associated fraction, and were found in higher abundances than in other hadal studies, where they were either far less prevalent or missing. Our results indicate the importance of heterotrophy, sulfur-cycling, and methane and hydrogen utilization within the bottom waters of the deeper regions of the Mariana Trench

  7. Quantifying the Contribution of Entire Free-Living Nematode Communities to Carbon Mineralization under Contrasting C and N Availability

    PubMed Central

    Gebremikael, Mesfin Tsegaye; Steel, Hanne; Bert, Wim; Maenhout, Peter; Sleutel, Steven; De Neve, Stefaan

    2015-01-01

    To understand the roles of nematodes in organic matter (OM) decomposition, experimental setups should include the entire nematode community, the native soil microflora, and their food sources. Yet, published studies are often based on either simplified experimental setups, using only a few selected species of nematode and their respective prey, despite the multitude of species present in natural soil, or on indirect estimation of the mineralization process using O2 consumption and the fresh weight of nematodes. We set up a six-month incubation experiment to quantify the contribution of the entire free living nematode community to carbon (C) mineralization under realistic conditions. The following treatments were compared with and without grass-clover amendment: defaunated soil reinoculated with the entire free living nematode communities (+Nem) and defaunated soil that was not reinoculated (-Nem). We also included untreated fresh soil as a control (CTR). Nematode abundances and diversity in +Nem was comparable to the CTR showing the success of the reinoculation. No significant differences in C mineralization were found between +Nem and -Nem treatments of the amended and unamended samples at the end of incubation. Other related parameters such as microbial biomass C and enzymatic activities did not show significant differences between +Nem and -Nem treatments in both amended and unamended samples. These findings show that the collective contribution of the entire nematode community to C mineralization is small. Previous reports in literature based on simplified experimental setups and indirect estimations are contrasting with the findings of the current study and further investigations are needed to elucidate the extent and the mechanisms of nematode involvement in C mineralization. PMID:26393517

  8. Identifying Drug (Cocaine) Intake Events from Acute Physiological Response in the Presence of Free-living Physical Activity

    PubMed Central

    Hossain, Syed Monowar; Ali, Amin Ahsan; Rahman, Mahbubur; Ertin, Emre; Epstein, David; Kennedy, Ashley; Preston, Kenzie; Umbricht, Annie; Chen, Yixin; Kumar, Santosh

    2014-01-01

    A variety of health and behavioral states can potentially be inferred from physiological measurements that can now be collected in the natural free-living environment. The major challenge, however, is to develop computational models for automated detection of health events that can work reliably in the natural field environment. In this paper, we develop a physiologically-informed model to automatically detect drug (cocaine) use events in the free-living environment of participants from their electrocardiogram (ECG) measurements. The key to reliably detecting drug use events in the field is to incorporate the knowledge of autonomic nervous system (ANS) behavior in the model development so as to decompose the activation effect of cocaine from the natural recovery behavior of the parasympathetic nervous system (after an episode of physical activity). We collect 89 days of data from 9 active drug users in two residential lab environments and 922 days of data from 42 active drug users in the field environment, for a total of 11,283 hours. We develop a model that tracks the natural recovery by the parasympathetic nervous system and then estimates the dampening caused to the recovery by the activation of the sympathetic nervous system due to cocaine. We develop efficient methods to screen and clean the ECG time series data and extract candidate windows to assess for potential drug use. We then apply our model on the recovery segments from these windows. Our model achieves 100% true positive rate while keeping the false positive rate to 0.87/day over (9+ hours/day of) lab data and to 1.13/day over (11+ hours/day of) field data. PMID:25531010

  9. Metabolism of free-living and particle-associated prokaryotes: Consequences for carbon flux around a Southern Ocean archipelago

    NASA Astrophysics Data System (ADS)

    Schapira, Mathilde; McQuaid, Christopher D.; Froneman, Pierre W.

    2012-02-01

    The sub-Antarctic Prince Edward archipelago lies in the path of the Antarctic Circumpolar Current, giving the islands a distinct upstream/downstream axis. Here we examined the possibility of an Island Mass Effect on the prokaryotic community, comparing prokaryotic metabolism in the upstream, inter-island and downstream regions of the islands. Abundance and flow cytometric community structure, heterotrophic production (PHP) and respiration rates (R-ETS) were investigated separately for the particle-associated (PA) and free-living (FL) prokaryote communities. Temperature, salinity structure and low chlorophyll a concentrations (< 0.4 μg l- 1) suggested a flow-through hydrological regime prevailed during the study. FL and PA abundances and PHP did not vary significantly over the study area. In contrast, FL and PA R-ETS decreased significantly along the upstream to downstream axis. This decrease in R-ETS resulted in high prokaryotic growth efficiencies (PGE) downstream of the islands. This suggests higher carbon sequestration efficiency downstream than upstream of the islands. No significant differences were observed between FL and PA-PGE downstream. In contrast, PA-PGE was significantly higher than FL-PGE at most upstream stations, suggesting quite different carbon utilisation by free-living and particle-associated prokaryotes with potentially important implications for overall carbon flux around the Archipelago. These findings provide new insights into the metabolic and functional roles of the two prokaryotic fractions within pelagic ecosystems. In particular, the observation that carbon consumption on particles is higher than would be expected from estimates of bulk PGE has important implications for our understanding of carbon cycling in the ocean.

  10. Identification of Free-Living and Particle-Associated Microbial Communities Present in Hadal Regions of the Mariana Trench.

    PubMed

    Tarn, Jonathan; Peoples, Logan M; Hardy, Kevin; Cameron, James; Bartlett, Douglas H

    2016-01-01

    Relatively few studies have described the microbial populations present in ultra-deep hadal environments, largely as a result of difficulties associated with sampling. Here we report Illumina-tag V6 16S rRNA sequence-based analyses of the free-living and particle-associated microbial communities recovered from locations within two of the deepest hadal sites on Earth, the Challenger Deep (10,918 meters below surface-mbs) and the Sirena Deep (10,667 mbs) within the Mariana Trench, as well as one control site (Ulithi Atoll, 761 mbs). Seawater samples were collected using an autonomous lander positioned ~1 m above the seafloor. The bacterial populations within the Mariana Trench bottom water samples were dissimilar to other deep-sea microbial communities, though with overlap with those of diffuse flow hydrothermal vents and deep-subsurface locations. Distinct particle-associated and free-living bacterial communities were found to exist. The hadal bacterial populations were also markedly different from one another, indicating the likelihood of different chemical conditions at the two sites. In contrast to the bacteria, the hadal archaeal communities were more similar to other less deep datasets and to each other due to an abundance of cosmopolitan deep-sea taxa. The hadal communities were enriched in 34 bacterial and 4 archaeal operational taxonomic units (OTUs) including members of the Gammaproteobacteria, Epsilonproteobacteria, Marinimicrobia, Cyanobacteria, Deltaproteobacteria, Gemmatimonadetes, Atribacteria, Spirochaetes, and Euryarchaeota. Sequences matching cultivated piezophiles were notably enriched in the Challenger Deep, especially within the particle-associated fraction, and were found in higher abundances than in other hadal studies, where they were either far less prevalent or missing. Our results indicate the importance of heterotrophy, sulfur-cycling, and methane and hydrogen utilization within the bottom waters of the deeper regions of the Mariana Trench

  11. Immune function in a free-living bird varies over the annual cycle, but seasonal patterns differ between years.

    PubMed

    Hegemann, Arne; Matson, Kevin D; Both, Christiaan; Tieleman, B Irene

    2012-11-01

    A central hypothesis of eco-immunology proposes trade-offs between immune defences and competing physiological and behavioural processes, leading to immunological variation within and among annual-cycle stages, as has been revealed for some species. However, few studies have simultaneously investigated patterns of multiple immune indices over the entire annual cycle in free-living birds, and none has investigated the consistency of seasonal patterns across multiple years. We quantified lysis, agglutination, haptoglobin, leukocyte profiles, and body mass in free-living skylarks (Alauda arvensis) through two complete annual cycles and within and between four breeding seasons. The skylarks' annual cycle is characterised by annually repeated changes in energy and time budgets, social structure and diet. If trade-offs relating to these cyclic changes shape evolution, predictable intra-annual immune patterns may result. Alternatively, intra-annual immune patterns may vary among years if fluctuating environmental changes affect the cost-benefit balances of immune function. We found significant variation in immune indices and body mass across the annual cycle, and these patterns differed between years. Immune parameters differed between four breeding seasons, and in all years, lysis and agglutination increased as the season progressed independent of average levels. Population-level patterns (intra-annual, inter-annual, within breeding season) were consistent with within-individual patterns based on repeated measurements. We found little evidence for sex differences, and only haptoglobin was correlated (negatively) with body mass. We conclude that immune modulation is not simply a pre-programmed phenomenon that reflects predictable ecological changes. Instead, fluctuating environmental conditions that vary among years likely contribute to the immunological variation that we observed. PMID:22562421

  12. Resveratrol metabolites in urine as a biomarker of wine intake in free-living subjects: The PREDIMED Study.

    PubMed

    Zamora-Ros, Raul; Urpí-Sardà, Mireia; Lamuela-Raventós, Rosa M; Estruch, Ramon; Martínez-González, Miguel Angel; Bulló, Mònica; Arós, Fernando; Cherubini, Antonio; Andres-Lacueva, Cristina

    2009-06-15

    Several clinical and epidemiological studies have shown that moderate wine consumption may exert a protective effect against oxidative stress involved in several diseases, such as cardiovascular and neurodegenerative disorders. However, the epidemiological assessment of wine consumption has usually been obtained using self-reported questionnaires containing less reliable information for assessing total intake than nutritional biomarkers. A reliable biomarker for wine consumption is, therefore, needed. To validate urinary resveratrol metabolites (RMs) as a biomarker of wine consumption in a large cohort of free-living subjects, 1000 consecutive subjects entering a substudy of the PREDIMED trial (Prevención con Dieta Mediterránea) were evaluated. Data were collected in a validated semiquantitative food frequency questionnaire. RMs were measured in morning urine by LC-MS/MS. Urinary RM values correlated directly with reported daily amounts of wine consumed (r=0.895; p<0.001). One drink of wine per week can be detected. Using a cut-off of 411.4 nmol/g creatinine, the measurement of urinary RMs could discriminate wine consumers from non-wine consumers with a sensitivity of 93.3% (95% confidence interval (CI) 91.5-94.7%) and a specificity of 92.1% (CI 90.2-93.7%). Urinary RMs fulfill the criteria to be considered as a nutritional biomarker of wine consumption in a large sample of free-living subjects. This biomarker would provide an additional tool for investigating more precisely the relationship between wine consumption and health benefits. PMID:19167481

  13. Underwater passive acoustic localization of Pacific walruses in the northeastern Chukchi Sea.

    PubMed

    Rideout, Brendan P; Dosso, Stan E; Hannay, David E

    2013-09-01

    This paper develops and applies a linearized Bayesian localization algorithm based on acoustic arrival times of marine mammal vocalizations at spatially-separated receivers which provides three-dimensional (3D) location estimates with rigorous uncertainty analysis. To properly account for uncertainty in receiver parameters (3D hydrophone locations and synchronization times) and environmental parameters (water depth and sound-speed correction), these quantities are treated as unknowns constrained by prior estimates and prior uncertainties. Unknown scaling factors on both the prior and arrival-time uncertainties are estimated by minimizing Akaike's Bayesian information criterion (a maximum entropy condition). Maximum a posteriori estimates for sound source locations and times, receiver parameters, and environmental parameters are calculated simultaneously using measurements of arrival times for direct and interface-reflected acoustic paths. Posterior uncertainties for all unknowns incorporate both arrival time and prior uncertainties. Monte Carlo simulation results demonstrate that, for the cases considered here, linearization errors are small and the lack of an accurate sound-speed profile does not cause significant biases in the estimated locations. A sequence of Pacific walrus vocalizations, recorded in the Chukchi Sea northwest of Alaska, is localized using this technique, yielding a track estimate and uncertainties with an estimated speed comparable to normal walrus swim speeds. PMID:23968051

  14. Performance of a satellite-linked GPS on Pacific walruses (Odobenus rosmarus divergens)

    USGS Publications Warehouse

    Jay, C.V.; Garner, G.W.

    2002-01-01

    We evaluated the utility of a satellite-linked GPS in obtaining location data from Pacific walruses (Odobenus rosmarus divergens). A unit was attached to one of the tusks of each of three adult male walruses in Bristol Bay, Alaska. The units were designed to relay GPS positions through the Argos Data Collection and Location System. The GPS was only minimally effective in obtaining location data. An average of only 5% of the attempts yielded a position, and only a small number of these were locations at sea. The paucity of successful attempts was probably due to infrequent and brief surfacings of the GPS, the proximity of cliffs to predominant haul-out sites in the study region, and the packing of animals when they were hauled out in herds. Argos was effective in relaying GPS positions in this study, but as GPS technology advances, and its application to marine mammal studies becomes more prevalent, it seems that the greatest challenge to the study of many species will be in data retrieval.

  15. Pulmonary Mast Cell Tumor and Possible Paraganglioma in a Free-ranging Pacific Walrus ( Odobenus rosmarus divergens), Barrow, Alaska, USA.

    PubMed

    Seguel, Mauricio; Stimmelmayr, Raphaela; Howerth, Elizabeth; Gottdenker, Nicole

    2016-04-28

    We describe a pulmonary mast cell tumor in a subsistence-harvested free-ranging Pacific walrus (Odobenus rosmarus divergens). Neoplastic cells effacing a focal area of pulmonary parenchyma were characterized by rare metachromatic granules and positive staining for C-kit. We also report co-occurrence of a peribronchial mass with a morphologic and immunohistochemical profile compatible with paraganglioma. PMID:27054472

  16. Limitations of an optimum sustainable population or potential biological removal approach for conserving marine mammals: Pacific walrus case study.

    PubMed

    Robards, Martin D; Burns, John J; Meek, Chanda L; Watson, Annette

    2009-10-01

    Decision rules are the agreed-upon points at which specific management interventions are initiated. For marine mammal management under the U.S. Marine Mammal Protection Act (MMPA), decision rules are usually based on either a numeric population or biological-removal approach. However, for walrus and other ice-associated pinnipeds, the inability to reliably assess population numbers or biological removals highlights a significant gap in the MMPA, particularly when the Arctic environment is rapidly changing. We describe the MMPA's ecosystem-based management goals, and why managers have bypassed these goals in favor of an approach that depends upon numerical population assessment. We then revisit the statute's primary goals in light of current knowledge about the Pacific walrus ecosystem and new developments in environmental governance. We argue that to monitor and respond to changes in the walrus ecosystem, decision rules should be based on scientific criteria that depend less on the currently-impractical goal of accurately enumerating population size and trends, or removals from that population. Rather, managers should base decisions on ecological needs and observed ecological changes. To implement this approach would require an amendment to the MMPA that supports filling the gap in management with achievable decision rules. Alternatively, walrus and other ice-associated pinnipeds will remain largely unmanaged during a period of profound environmental change. PMID:19783356

  17. Use of stable isotopes of N and C to explain unexpectedly high levels of PCBs and other organochlorines in walrus

    SciTech Connect

    Muir, D.; Segstro, M.; Stewart, R.; Hobson, K.; Olpinski, S.

    1994-12-31

    Walrus (Odobenus rosmarus) blubber from Inukjuak and Akulivik (E. Hudson Bay), Foxe Basin and E. Baffin Is. was analyzed for PCB congeners and other persistent organochlorines (DDT, toxaphene, chlordanes) as part of studies documenting spatial trends in contaminants in Canadian arctic marine biota. Samples from 18 of 53 individuals had wet weight concentrations of {Sigma}PCBs ranging from 1 to 20 {mu}g//g; the remaining individuals had much lower concentrations. Highest concentrations were found in samples from Inukjuak where 11 of 13 animals (males and females) had high levels. {Sigma}PCB concentrations greater than 0.5 {mu}g/g were unexpected based on previous studies in Greenland and Alaska. Local contamination was ruled out because DDT, chlordanes and toxaphene were all elevated, and high levels were found in both males and females from 2 of 4 other locations. {sup 13}C and {sup 15}N isotope measurements using muscle samples from the jaws of walrus and seals, showed that walrus with high EPCB had higher {delta}{sup 15}N values than those with low PCBs. The results suggest that the walrus with elevated organochlorines are feeding at a higher trophic level than those with low levels and are probably utilizing ringed seals (Phoca hispida) for a significant proportion of their diet.

  18. 78 FR 23284 - Marine Mammal Protection Act; Draft Revised Stock Assessment Reports for the Pacific Walrus and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-18

    ...- Stock Nmin Rmax Fr PBR year average) Stock status Fishery/other Subsistence Pacific Walrus 129,000 0.08... productivity of the population or the species, keeping in mind the carrying capacity of the habitat and the... its geographic range; 2. A minimum population estimate, maximum net productivity rate, and...

  19. Diversity and Activity of Free-Living Nitrogen-Fixing Bacteria and Total Bacteria in Organic and Conventionally Managed Soils ▿ †

    PubMed Central

    Orr, Caroline H.; James, Angela; Leifert, Carlo; Cooper, Julia M.; Cummings, Stephen P.

    2011-01-01

    Agricultural soils are heterogeneous environments in which conditions affecting microbial growth and diversity fluctuate widely in space and time. In this study, the molecular ecology of the total bacterial and free-living nitrogen-fixing communities in soils from the Nafferton Factorial Systems Comparison (NFSC) study in northeast England were examined. The field experiment was factorial in design, with organic versus conventional crop rotation, crop protection, and fertility management factors. Soils were sampled on three dates (March, June, and September) in 2007. Total RNA was extracted from all soil samples and reverse transcribed. Denaturing gradient gel electrophoresis (DGGE) and quantitative PCR (qPCR) were used to analyze nifH and 16S rRNA genes in order to study free-living diazotrophs and the total bacterial community, respectively. Crop rotation was shown to have a significant effect on total bacterial diversity (and that of free-living N fixers) (P ≤ 0.001). On all three dates, nifH activity was higher in the conventional crop rotation. In contrast, qPCR analysis of free-living N fixers indicated significantly higher levels of activity in conventionally fertilized plots in June (P = 0.0324) and in plots with organic crop protection in September (P = 0.0143). To our knowledge, the effects of organic and conventional farming systems on free-living diazotrophs have never been studied. An increased understanding of the impacts of management practices on free-living N fixers could allow modifications in soil management practices to optimize the activity of these organisms. PMID:21131514

  20. Identification of differentially expressed proteins between free-living and activated third-stage larvae of Haemonchus contortus.

    PubMed

    Wang, Fang; Xu, Lixin; Song, Xiaokai; Li, Xiangrui; Yan, Ruofeng

    2016-01-15

    The disease caused by Haemonchus contortus, a blood-feeding nematode of small ruminants, is of major economic importance worldwide. The infective third-stage larva (L3) of this nematode is enclosed in a second cuticle. Once the L3 is ingested by the host, the outer cuticle undergoes an exsheathment process that marks the transition from the free-living stage to the parasitic stage. This study explored the changes in protein expression relative to this transition. Proteins extracted from free living L3 and exsheathed L3 (xL3) were analyzed by two dimensional differential gel electrophoresis (2D-DIGE). More than 2200 protein spots were recognized, and 124 of them was found to be differentially expressed (average ratio of xL3/L3>1.5 or xL3/L3<-1.5, p<0.05). Of these, 83 spots were up-regulated and 41 spots were down-regulated in xL3 when compared with L3. These differentially expressed spots were analyzed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) or MALDI-TOF-MS/MS and 40 proteins were identified. To predict the functions of these identified proteins, they were assigned for gene ontology (GO) annotation. Results showed that the proteins may be involved in biological processes of reproduction, cellular organization or biogenesis, multi-cellular organismal processes, single-organism processes, metabolic processes, signaling, biological regulation, response to stimulus, cellular processes, biological adhesion, growth, locomotion, localization, developmental processes and multi-organism processes. Kyoto Encyclopedia of Genes and Genomes (KEGG) annotations were also performed, which was useful for exploring the process of metabolism and signal transduction pathways. This study indicated that some key alterations taking place, during the transition from L3 to xL3 may be interesting antiparasite targets, and some of the proteins involved in this process might be candidate antigens for vaccine development. PMID:26790740

  1. Pacific walruses, indigenous hunters, and climate change: Bridging scientific and indigenous knowledge

    NASA Astrophysics Data System (ADS)

    Krupnik, Igor; Ray, G. Carleton

    2007-11-01

    This paper presents and evaluates two perspectives on changing climate-walrus-human relationships in the Beringian region, from the viewpoints of marine biology and ecology, and from that of indigenous hunters. Bridging these types of knowledge is vital in order to grasp the complexity of the processes involved and for advancing understanding of subarctic marine ecosystems that are currently experiencing rapid ecological and social change. We argue that despite substantial gaps and distinctions, information generated by scientists and indigenous hunters have many similarities. Differences in interpretation are primarily due to scaling and temporal rates of change of knowledge, which could be rectified through more active sharing of expertise and records, enhanced documentation of indigenous observations, more collaborative research, and increased insight from the social sciences.

  2. Presence of potentially pathogenic free-living amoebae strains from well water samples in Guinea-Bissau.

    PubMed

    Baquero, Rocío A; Reyes-Batlle, María; Nicola, Graciela G; Martín-Navarro, Carmen M; López-Arencibia, Atteneri; Guillermo Esteban, J; Valladares, Basilio; Martínez-Carretero, Enrique; Piñero, José E; Lorenzo-Morales, Jacob

    2014-06-01

    Free-living amoebae (FLA) include opportunistic pathogens such as Naegleria fowleri, Balamuthia mandrillaris, and the genera Sappinia and Acanthamoeba. In this study, a survey was conducted in order to evaluate the presence of potentially pathogenic amoebic strains in water samples collected from wells located in the western part of Guinea-Bissau. The samples were left to precipitate for 48 hours and then the sediments were seeded on non-nutrient agar plates containing Escherichia coli spread and cultures were checked daily for the presence of FLA. Identification of FLA strains was based on the morphological and polymerase chain reaction (PCR) using the 18S rDNA or 16S mitochondrial rDNA genes in the case of Naegleria and Balamuthia genera, respectively. In the case of positive samples of Acanthamoeba, strains were further classified at the genotype level by sequencing the diagnostic fragment 3 (DF3) region located in the 18S rDNA gene as previously described. Sappinia sp. was not isolated during the study and thus, no molecular analysis was performed for this genus. The obtained results revealed the presence of Acanthamoeba (genotypes T3 and T4), Naegleria fowleri, and Balamuthia mandrillaris. To the best of our knowledge, this is the first report demonstrating the presence of FLA in water bodies from Guinea-Bissau and the first report on the isolation of Balamuthia mandrillaris from environmental sources in Africa. PMID:24934796

  3. Seasonal and spatial variability of free-living bacterial community composition along an estuarine gradient (Ria de Aveiro, Portugal)

    NASA Astrophysics Data System (ADS)

    Henriques, Isabel S.; Alves, Artur; Tacão, Marta; Almeida, Adelaide; Cunha, Ângela; Correia, António

    2006-06-01

    We examined the dynamics of the free-living bacterial community in the Ria de Aveiro estuary (Portugal) using 16S rDNA PCR-denaturing gradient gel electrophoresis (DGGE). Samples were collected along the salinity gradient in April, July and October 2003 and January 2004. Analysis of DGGE profiles indicated that the compositional shifts within this community occurred between the brackish and freshwater sections. Those shifts were particularly evident in samples collected in April, October and January. Less pronounced changes were also detected along the salinity gradient in the marine and brackish sections. Seasonally driven changes in microbial community in this estuary also occur. Canonical correspondence analysis (CCA) revealed that salinity and temperature accounted for a significant amount of the variability in the bacterioplankton community composition (26%). Dominant phylotypes were identified either by direct sequencing or by cloning and sequencing DGGE bands. Analysis of DNA sequences revealed that the dominant bacterial groups changed from Bacteroidetes, Alpha-proteobacteria and Gamma-proteobacteria in the marine-brackish section to Bacteroidetes, Beta-proteobacteria, Delta-proteobacteria and Epsilon-proteobacteria in the freshwater section of the estuary.

  4. Simultaneous measurement of free-living energy expenditure by the doubly labeled water method and heart-rate monitoring

    SciTech Connect

    Livingstone, M.B.; Prentice, A.M.; Coward, W.A.; Ceesay, S.M.; Strain, J.J.; McKenna, P.G.; Nevin, G.B.; Barker, M.E.; Hickey, R.J. )

    1990-07-01

    Total energy expenditure (TEE) was measured simultaneously in 14 free-living adults over 15 d by the doubly labeled water (DLW) method and for 2-4 separate days by heart-rate (HR) monitoring. Individual curves for HR vs oxygen consumption (VO2) were obtained and an HR (FLEX HR: 97 +/- 8 beats/min, range 84-113 beats/min) that discriminated between rest and activity was identified. Calibration curves were used to assign an energy value to daytime HR above FLEX HR. Below FLEX HR energy expenditure was taken as resting metabolism. Sleeping energy expenditure was assumed to be equal to basal metabolic rate. Average HR TEE (12.99 +/- 3.83 MJ/d) and average DLW TEE (12.89 +/- 3.80 MJ/d) were similar. HR TEE discrepancies ranged from -22.2% to +52.1%, with nine values lying within +/- 10% of DLW TEE estimates. The FLEX HR method provides a close estimation of the TEE of population groups. However, an increased number of sampling days may improve the precision of individual estimates of TEE.

  5. From the Cover: Genome analysis of the smallest free-living eukaryote Ostreococcus tauri unveils many unique features

    NASA Astrophysics Data System (ADS)

    Derelle, Evelyne; Ferraz, Conchita; Rombauts, Stephane; Rouzé, Pierre; Worden, Alexandra Z.; Robbens, Steven; Partensky, Frédéric; Degroeve, Sven; Echeynié, Sophie; Cooke, Richard; Saeys, Yvan; Wuyts, Jan; Jabbari, Kamel; Bowler, Chris; Panaud, Olivier; Piégu, Benoît; Ball, Steven G.; Ral, Jean-Philippe; Bouget, François-Yves; Piganeau, Gwenael; de Baets, Bernard; Picard, André; Delseny, Michel; Demaille, Jacques; van de Peer, Yves; Moreau, Hervé

    2006-08-01

    The green lineage is reportedly 1,500 million years old, evolving shortly after the endosymbiosis event that gave rise to early photosynthetic eukaryotes. In this study, we unveil the complete genome sequence of an ancient member of this lineage, the unicellular green alga Ostreococcus tauri (Prasinophyceae). This cosmopolitan marine primary producer is the world's smallest free-living eukaryote known to date. Features likely reflecting optimization of environmentally relevant pathways, including resource acquisition, unusual photosynthesis apparatus, and genes potentially involved in C4 photosynthesis, were observed, as was downsizing of many gene families. Overall, the 12.56-Mb nuclear genome has an extremely high gene density, in part because of extensive reduction of intergenic regions and other forms of compaction such as gene fusion. However, the genome is structurally complex. It exhibits previously unobserved levels of heterogeneity for a eukaryote. Two chromosomes differ structurally from the other eighteen. Both have a significantly biased G+C content, and, remarkably, they contain the majority of transposable elements. Many chromosome 2 genes also have unique codon usage and splicing, but phylogenetic analysis and composition do not support alien gene origin. In contrast, most chromosome 19 genes show no similarity to green lineage genes and a large number of them are specialized in cell surface processes. Taken together, the complete genome sequence, unusual features, and downsized gene families, make O. tauri an ideal model system for research on eukaryotic genome evolution, including chromosome specialization and green lineage ancestry. genome heterogeneity | genome sequence | green alga | Prasinophyceae | gene prediction

  6. Hind limb malformations in free-living northern leopard frogs (Rana pipiens) from Maine, Minnesota, and Vermont suggest multiple etiologies

    USGS Publications Warehouse

    Meteyer, C.U.; Loeffler, I.K.; Fallon, J.F.; Converse, K.A.; Green, E.; Helgen, J.C.; Kersten, S.; Levey, R.; Eaton-Poole, L.; Burkhart, J.G.

    2000-01-01

    Background Reports of malformed frogs have increased throughout the North American continent in recent years. Most of the observed malformations have involved the hind limbs. The goal of this study was to accurately characterize the hind limb malformations in wild frogs as an important step toward understanding the possible etiologies. Methods During 1997 and 1998, 182 recently metamorphosed northern leopard frogs (Rana pipiens) were collected from Minnesota, Vermont, and Maine. Malformed hind limbs were present in 157 (86%) of these frogs, which underwent necropsy and radiographic evaluation at the National Wildlife Health Center. These malformations are described in detail and classified into four major categories: (1) no limb (amelia); (2) multiple limbs or limb elements (polymelia, polydactyly, polyphalangy); (3) reduced limb segments or elements (phocomelia, ectromelia, ectrodactyly, and brachydactyly; and (4) distally complete but malformed limb (bone rotations, bridging, skin webbing, and micromelia). Results Amelia and reduced segments and/or elements were the most common finding. Frogs with bilateral hind limb malformations were not common, and in only eight of these 22 frogs were the malformations symmetrical. Malformations of a given type tended to occur in frogs collected from the same site, but the types of malformations varied widely among all three states, and between study sites within Minnesota. Conclusions Clustering of malformation type suggests that developmental events may produce a variety of phenotypes depending on the timing, sequence, and severity of the environmental insult. Hind limb malformations in free-living frogs transcend current mechanistic explanations of tetrapod limb development.

  7. Comparison of RP-HPLC modes to analyse the N-glycome of the free-living nematode Pristionchus pacificus

    PubMed Central

    Yan, Shi; Wilson, Iain B. H.; Paschinger, Katharina

    2015-01-01

    Pristionchus pacificus is a free-living nematode increasingly used as an organism for comparison to the more familiar model Caenorhabditis elegans. In this study, we examined the N-glycans of this organism isolated after serial release with peptide:N-glycosidases F and A; after fluorescent labelling with 2-aminopyridine, chromatographic fractionation by three types of reversed-phase HPLC (with either classical C18, fused core C18 or alkylamide bonded phases) followed by mass spectrometric analyses revealed key features of its N-glycome. In addition to paucimannosidic and oligomannosidic glycans typical of invertebrates, N-glycans with two core fucose residues were detected. Furthermore, a range of glycans carrying up to three phosphorylcholine residues was observed whereas, unlike C. elegans, no tetrafucosylated N-glycans were detected. Structures with three fucose residues, unusual methylation of core α1,3-fucose or with galactosylated fucose motifs were found in low amounts; these features may correlate with a different ensemble or expression of glycosyltransferase genes as compared to C. elegans. From an analytical perspective, both the alkylamide RP-amide and fused core C18 columns, as compared to a classical C18 material, offer advantages in terms of resolution and of elution properties, as some minor pyridylamino-labelled glycans (e.g., those carrying phosphorylcholine) appear in earlier fractions and so potential losses of such structures due to insufficient gradient length can be avoided. PMID:25639343

  8. Comparison of RP-HPLC modes to analyse the N-glycome of the free-living nematode Pristionchus pacificus.

    PubMed

    Yan, Shi; Wilson, Iain B H; Paschinger, Katharina

    2015-06-01

    Pristionchus pacificus is a free-living nematode increasingly used as an organism for comparison to the more familiar model Caenorhabditis elegans. In this study, we examined the N-glycans of this organism isolated after serial release with peptide:N-glycosidases F and A; after fluorescent labelling with 2-aminopyridine, chromatographic fractionation by three types of RP-HPLC (with either classical C18, fused core C18 or alkylamide-bonded phases) followed by mass spectrometric analyses revealed key features of its N-glycome. In addition to paucimannosidic and oligomannosidic glycans typical of invertebrates, N-glycans with two core fucose residues were detected. Furthermore, a range of glycans carrying up to three phosphorylcholine residues was observed whereas, unlike C. elegans, no tetrafucosylated N-glycans were detected. Structures with three fucose residues, unusual methylation of core α1,3-fucose or with galactosylated fucose motifs were found in low amounts; these features may correlate with a different ensemble or expression of glycosyltransferase genes as compared to C. elegans. From an analytical perspective, both the alkylamide RP-amide and fused core C18 columns, as compared to a classical C18 material, offer advantages in terms of resolution and of elution properties, as some minor pyridylamino-labelled glycans (e.g. those carrying phosphorylcholine) appear in earlier fractions and so potential losses of such structures due to insufficient gradient length can be avoided. PMID:25639343

  9. Dynamic nano-imaging of label-free living cells using electron beam excitation-assisted optical microscope

    NASA Astrophysics Data System (ADS)

    Fukuta, Masahiro; Kanamori, Satoshi; Furukawa, Taichi; Nawa, Yasunori; Inami, Wataru; Lin, Sheng; Kawata, Yoshimasa; Terakawa, Susumu

    2015-11-01

    Optical microscopes are effective tools for cellular function analysis because biological cells can be observed non-destructively and non-invasively in the living state in either water or atmosphere condition. Label-free optical imaging technique such as phase-contrast microscopy has been analysed many cellular functions, and it is essential technology for bioscience field. However, the diffraction limit of light makes it is difficult to image nano-structures in a label-free living cell, for example the endoplasmic reticulum, the Golgi body and the localization of proteins. Here we demonstrate the dynamic imaging of a label-free cell with high spatial resolution by using an electron beam excitation-assisted optical (EXA) microscope. We observed the dynamic movement of the nucleus and nano-scale granules in living cells with better than 100 nm spatial resolution and a signal-to-noise ratio (SNR) around 10. Our results contribute to the development of cellular function analysis and open up new bioscience applications.

  10. Plant growth promoting potential of free-living diazotrophs and other rhizobacteria isolated from Northern Indian soil.

    PubMed

    Ahmad, Farah; Ahmad, Iqbal; Aqil, Farrukh; Ahmed Wani, Aijaz; Sousche, Yogesh S

    2006-10-01

    The viable count of free-living diazotrophic bacteria in different crop rhizospheres varied from 1.11 x 10(4) to 8.5 x 10(5) CFU/g of soil. The majority of the diazotrophs phenotypically belong to either Azotobacter chroococcum, non-A. chroococcum type and to a heterogenous group tentatively named putative nitrogen-fixing (PNF) bacteria. In this study, 25 isolates of the PNF group were screened for their multiple plant growth-promoting (PGP) traits and grouped into 5 PGP types. An isolate, PNF(11) showed promising PGP potential in vitro and was characterized as a species of Achromobacter by 16S rRNA analysis. The isolate PNF(11) along with three other previously isolated PGP bacteria, Azotobacter sp. (AZS(3)), fluorescent pseudomonas (Ps(5)), Bacillus sp. (Bc(1)) were selected for crop inoculation response in green house experiment on Vigna radiata var.T44. Plants from inoculated and control pots were sampled and analyzed at 30, 45 and 60 days after sowing for various vegetative, nodule-related data and yield parameters. The findings indicated that selected isolate of PNF bacteria, and other PGP isolates with multiple activities significantly improve the plant growth parameters, yield parameters of Vigna radiata T44 over control and also show good compatibility with Bradyrhizobium inoculation. PMID:17004301

  11. Effects of increasing levels of pharmaceutical penicillin G contamination on structure of free living nematode communities in experimental microcosms.

    PubMed

    Nasri, Ahmed; Jouili, Soufiane; Boufahja, Fehmi; Hedfi, Amor; Mahmoudi, Ezzeddine; Aïssa, Patricia; Essid, Naceur; Beyrem, Hamouda

    2015-07-01

    A microcosm experiment was conducted to examine the effects of the pharmaceutical (penicillin G) on free living nematode communities of a Tunisian coastal zone (South-Western Mediterranean Sea). Sediments were contaminated with five penicillin G dose [D1 (3 mgL(-1)), D2 (30 mgL(-1)), D3 (300 mgL(-1)), D4 (600 mgL(-1)), D5 (700 mgL(-1))], and effects were examined after 30 days. Results showed significant differences between nematode assemblages from undisturbed controls and those from penicillin G treatments. Most univariate measures, including diversity (H'), species richness (d), equitability (J) and number of species (S) decreased significantly with increasing level of the antibiotic contamination. Results from multivariate analyses of the species abundance data demonstrated that responses of nematode species to the penicillin treatments were varied: Kraspedonema octogoniata and Paracomesoma dubium were eliminated at all the antibiotic doses tested and seemed to be intolerant species to penicillin G contamination; Oncholaimus campylocercoides although survived even the highest dose D5, showed definite reduction in its abundance and may be classified as "opportunistic" species at this dose, whereas, Nannolaimoides decoratus which showed a positive response with an increase in density even at highest concentration of contaminant, seems to be "penicillin G resistant" species. PMID:26148743

  12. Environmental factors shaping cultured free-living amoebae and their associated bacterial community within drinking water network.

    PubMed

    Delafont, Vincent; Bouchon, Didier; Héchard, Yann; Moulin, Laurent

    2016-09-01

    Free-living amoebae (FLA) constitute an important part of eukaryotic populations colonising drinking water networks. However, little is known about the factors influencing their ecology in such environments. Because of their status as reservoir of potentially pathogenic bacteria, understanding environmental factors impacting FLA populations and their associated bacterial community is crucial. Through sampling of a large drinking water network, the diversity of cultivable FLA and their bacterial community were investigated by an amplicon sequencing approach, and their correlation with physicochemical parameters was studied. While FLA ubiquitously colonised the water network all year long, significant changes in population composition were observed. These changes were partially explained by several environmental parameters, namely water origin, temperature, pH and chlorine concentration. The characterisation of FLA associated bacterial community reflected a diverse but rather stable consortium composed of nearly 1400 OTUs. The definition of a core community highlighted the predominance of only few genera, majorly dominated by Pseudomonas and Stenotrophomonas. Co-occurrence analysis also showed significant patterns of FLA-bacteria association, and allowed uncovering potentially new FLA - bacteria interactions. From our knowledge, this study is the first that combines a large sampling scheme with high-throughput identification of FLA together with associated bacteria, along with their influencing environmental parameters. Our results demonstrate the importance of physicochemical parameters in the ecology of FLA and their bacterial community in water networks. PMID:27219048

  13. Effect of water and nitrogen additions on free-living nitrogen fixer populations in desert grass root zones.

    PubMed Central

    Herman, R P; Provencio, K R; Torrez, R J; Seager, G M

    1993-01-01

    In this study we measured changes in population levels of free-living N2-fixing bacteria in the root zones of potted Bouteloua eriopoda and Sporobolus flexuosus plants as well as the photosynthetic indices of the plants in response to added nitrogen, added water, and added water plus nitrogen treatments. In addition, N2 fixer population changes in response to added carbon source and nitrogen were measured in plant-free soil columns. There were significant increases in the numbers of N2 fixers associated with both plant species in the water and the water plus nitrogen treatments. Both treatments increased the photosynthetic index, suggesting that plant exudates were driving N2 fixer population changes. Population increases were greatest in the water plus nitrogen treatments, indicating that added nitrogen was synergistic with added water and suggesting that nitrogen addition spared bacteria the metabolic cost of N2 fixation, allowing greater reproduction. Plant-free column studies demonstrated a synergistic carbon-nitrogen effect when carbon levels were limiting (low malate addition) but not when carbon was abundant (high malate), further supporting this hypothesis. The results of this study indicate the presence of N2 fixer populations which interact with plants and which may play a role in the nitrogen balance of desert grasslands. PMID:8215373

  14. Molecular and biochemical characterization of S-adenosylmethionine decarboxylase from the free-living nematode Caenorhabditis elegans.

    PubMed Central

    Da'dara, A A; Walter, R D

    1998-01-01

    S-Adenosylmethionine decarboxylase (SAMDC) is a major regulatory enzyme in the polyamine biosynthesis and is considered a potentially important drug target for the chemotherapy of proliferative and parasitic diseases. To study regulatory mechanisms which are involved in the expression of SAMDC of the free-living nematode Caenorhabditis elegans, we have isolated the SAMDC gene and cDNA. Genomic Southern-blot analysis suggests that the C. elegans SAMDC is encoded by a single-copy gene which spans 3.9 kb and consists of six exons and five introns. The first two introns are located in the 5'-untranslated region (UTR). Analyses of the 5'-flanking region of the gene revealed several consensus sequences for the binding of different transcription factors such as CBP, AP2, cMyb, VPE2 and others. The C. elegans SAMDC mRNA possesses an open reading frame (ORF) which encodes a polypeptide of 368 amino acids, corresponding to a SAMDC proenzyme with a calculated molecular mass of 42141 Da. The active form of the C. elegans SAMDC is a heterotetramer, consisting of two subunits of 32 and 10 kDa derived from cleavage of the pro-enzyme. The SAMDC mRNA has an unusually long 5'-UTR of 477 nucleotides. This region has a small ORF which could encode a putative peptide of 17 residues. Moreover, the C. elegans SAMDC mRNA is trans-spliced with the 22 nucleotides spliced leader sequence at the 5'-end. PMID:9841864

  15. Response of free-living nitrogen-fixing microorganisms to land use change in the Amazon rainforest.

    PubMed

    Mirza, Babur S; Potisap, Chotima; Nüsslein, Klaus; Bohannan, Brendan J M; Rodrigues, Jorge L M

    2014-01-01

    The Amazon rainforest, the largest equatorial forest in the world, is being cleared for pasture and agricultural use at alarming rates. Tropical deforestation is known to cause alterations in microbial communities at taxonomic and phylogenetic levels, but it is unclear whether microbial functional groups are altered. We asked whether free-living nitrogen-fixing microorganisms (diazotrophs) respond to deforestation in the Amazon rainforest, using analysis of the marker gene nifH. Clone libraries were generated from soil samples collected from a primary forest, a 5-year-old pasture originally converted from primary forest, and a secondary forest established after pasture abandonment. Although diazotroph richness did not significantly change among the three plots, diazotroph community composition was altered with forest-to-pasture conversion, and phylogenetic similarity was higher among pasture communities than among those in forests. There was also 10-fold increase in nifH gene abundance following conversion from primary forest to pasture. Three environmental factors were associated with the observed changes: soil acidity, total N concentration, and C/N ratio. Our results suggest a partial restoration to initial levels of abundance and community structure of diazotrophs following pasture abandonment, with primary and secondary forests sharing similar communities. We postulate that the response of diazotrophs to land use change is a direct consequence of changes in plant communities, particularly the higher N demand of pasture plant communities for supporting aboveground plant growth. PMID:24162570

  16. Glycosylinositol-phosphoceramide in the free-living protozoan Paramecium primaurelia: modification of core glycans by mannosyl phosphate.

    PubMed Central

    Azzouz, N; Striepen, B; Gerold, P; Capdeville, Y; Schwarz, R T

    1995-01-01

    Glycolipids synthesized in a cell-free system prepared from the free-living protozoan Paramecium primaurelia and labelled with [3H]mannose and [3H]glucosamine using GDP-[3H]mannose and UDP-[3H]N-acetyl glucosamine, respectively, were identified and structurally characterized as glycosylinositol-phosphoceramides (GIP-ceramides). The ceramide-based lipid was also found in the GIP membrane anchor of the G surface antigen of P.primaurelia, strain 156. Using a combination of in vitro labelling with GDP-[3H]mannose and in vivo labelling with 33P, we found that the core glycans of the P.primaurelia GIP-ceramides were substituted with an acid-labile modification identified as mannosyl phosphate. The modification of the glycosylinositol-phospholipid core glycan by mannosyl phosphate has not been described to date in other organisms. The biosynthesis of GIP-ceramide intermediates in P.primaurelia was studied by a pulse-chase analysis. Their structural characterization is reported. We propose the following structure for the putative GIP-ceramide membrane anchor precursor of P.primaurelia surface proteins: ethanolamine phosphate-6Man-alpha 1-2Man-alpha 1-6Man-(mannosyl phosphate)-alpha 1-4glucosamine-inositol-phosphoceramide. PMID:7556085

  17. Do Hormones, Telomere Lengths, and Oxidative Stress form an Integrated Phenotype? A Case Study in Free-Living Tree Swallows.

    PubMed

    Ouyang, J Q; Lendvai, Á Z; Moore, I T; Bonier, F; Haussmann, M F

    2016-08-01

    Synopsis All organisms must anticipate and balance energetic demands and available resources in order to maximize fitness. As hormones coordinate many interactions between an organism's internal condition and the external environment, they may be key in mediating the allocation of resources to meet these demands. However, given that individuals differ considerably in how they react to changes in energetic demand, we asked whether variations in endocrine traits also correspond with life history variation. We tested whether natural variation in glucocorticoid hormone levels, oxidative stress measurements, and condition related to reproductive effort in a free-living songbird, the tree swallow, Tachycineta bicolor We then tested whether any of these traits predicted the probability of a particular individual's return to the local population in the following two years, an indicator of survival in this philopatric species. We found that males and females with longer telomeres had lighter nestlings. Moreover, individuals with lower plasma antioxidant capacity and higher reactive oxygen metabolites (i.e., greater oxidative stress) were less likely to return to the population. However, none of these traits were related to glucocorticoid levels. Our findings suggest a trade-off between reproduction and survival, with individuals with shorter telomeres having heavier nestlings but potentially paying a cost in terms of higher oxidative stress and lower survival. Interestingly, the evidence of this trade-off was unrelated to natural variation in glucocorticoids. PMID:27252220

  18. Complete Mitochondrial Genome of the Free-Living Earwig, Challia fletcheri (Dermaptera: Pygidicranidae) and Phylogeny of Polyneoptera

    PubMed Central

    Wan, Xinlong; Kim, Man Il; Kim, Min Jee; Kim, Iksoo

    2012-01-01

    The insect order Dermaptera, belonging to Polyneoptera, includes ∼2,000 extant species, but no dermapteran mitochondrial genome has been sequenced. We sequenced the complete mitochondrial genome of the free-living earwig, Challia fletcheri, compared its genomic features to other available mitochondrial sequences from polyneopterous insects. In addition, the Dermaptera, together with the other known polyneopteran mitochondrial genome sequences (protein coding, ribosomal RNA, and transfer RNA genes), were employed to understand the phylogeny of Polyneoptera, one of the least resolved insect phylogenies, with emphasis on the placement of Dermaptera. The complete mitochondrial genome of C. fletcheri presents the following several unusual features: the longest size in insects is 20,456 bp; it harbors the largest tandem repeat units (TRU) among insects; it displays T- and G-skewness on the major strand and A- and C-skewness on the minor strand, which is a reversal of the general pattern found in most insect mitochondrial genomes, and it possesses a unique gene arrangement characterized by a series of gene translocations and/or inversions. The reversal pattern of skewness is explained in terms of inversion of replication origin. All phylogenetic analyses consistently placed Dermaptera as the sister to Plecoptera, leaving them as the most basal lineage of Polyneoptera or sister to Ephemeroptera, and placed Odonata consistently as the most basal lineage of the Pterygota. PMID:22879905

  19. Free-living amoebae and their associated bacteria in Austrian cooling towers: a 1-year routine screening.

    PubMed

    Scheikl, Ute; Tsao, Han-Fei; Horn, Matthias; Indra, Alexander; Walochnik, Julia

    2016-09-01

    Free-living amoebae (FLA) are widely spread in the environment and known to cause rare but often serious infections. Besides this, FLA may serve as vehicles for bacterial pathogens. In particular, Legionella pneumophila is known to replicate within FLA thereby also gaining enhanced infectivity. Cooling towers have been the source of outbreaks of Legionnaires' disease in the past and are thus usually screened for legionellae on a routine basis, not considering, however, FLA and their vehicle function. The aim of this study was to incorporate a screening system for host amoebae into a Legionella routine screening. A new real-time PCR-based screening system for various groups of FLA was established. Three cooling towers were screened every 2 weeks over the period of 1 year for FLA and Legionella spp., by culture and molecular methods in parallel. Altogether, 83.3 % of the cooling tower samples were positive for FLA, Acanthamoeba being the dominating genus. Interestingly, 69.7 % of the cooling tower samples were not suitable for the standard Legionella screening due to their high organic burden. In the remaining samples, positivity for Legionella spp. was 25 % by culture, but overall positivity was 50 % by molecular methods. Several amoebal isolates revealed intracellular bacteria. PMID:27177720

  20. Serosurvey for antibodies to malignant catarrhal fever-associated viruses in free-living and captive cervids in Germany.

    PubMed

    Frölich, K; Li, H; Müller-Doblies, U

    1998-10-01

    A total of 486 serum samples collected from several species of both free-living and captive cervids in Germany was examined for antibodies against malignant catarrhal fever (MCF)-associated viruses (MCFV) by a competitive-inhibition enzyme-linked immunosorbent assay (CI-ELISA). Eleven (2%) of these samples were positive for antibodies against MCFV. Among 157 serum samples collected from 16 different species of captive deer including four (7%) of 54 fallow deer and one (7%) of 14 sika deer (Cervus nippon) were seropositive. Among 329 samples from three species of free-ranging deer, including 253 roe deer (Capreolus capreolus), 22 red deer (Cervus elaphus) and 54 fallow deer (Cervus dama), only fallow deer were antibody-positive. Of the 25 fallow deer samples collected between 1990 and 1993, four (16%) were seropositive. Among 29 free-ranging fallow deer samples collected in the hunting period 1996-1997, antibodies to MCFV were detected in two (7%) of these sera. All of these fallow deer samples were collected from a circumscribed area in northern Germany. In the same area a high seroprevalence (72%) to MCFV was observed in domestic sheep (n = 50). Among 20 sheep samples (buffy coat) and 15 fallow deer samples (spleen or lymph nodes) examined for ovine herpesvirus 2 (OvHV-2) by PCR, all 20 sheep samples examined were OvHV-2 positive, but all of the 15 fallow deer samples, including seven seropositive deer, were OvHV-2 negative. PMID:9813848

  1. Corticosterone stress response shows long-term repeatability and links to personality in free-living Nazca boobies.

    PubMed

    Grace, Jacquelyn K; Anderson, David J

    2014-11-01

    The concept of "coping styles", or consistently different responses to stressors, is of broad interest in behavioral ecology and biomedicine. Two critical predictions of this concept are individual consistency of neurophysiological and behavioral responses (relative to population variability) and a negative relationship between aggression/proactivity and hypothalamic-pituitary-adrenal axis reactivity. Recent studies failed to provide strong support for these predictions, especially outside of strictly controlled conditions, and long-term measures to test the first prediction are rare. Here, we demonstrate individual repeatability across 2-3years of maximum circulating corticosterone concentration [CORT] and area under the [CORT] response curve (AUCI) during a standard capture-restraint test in wild, free-living adult Nazca boobies (Sula granti). We also show that the stress response predicts the personality traits aggression and anxiety in these birds (measured in the wild); however, the strength of these results was weak. Maximum [CORT] and AUCI showed higher repeatability between years than baseline [CORT]. After controlling breeding status, sex, mass, date sampled, and their interactions, baseline [CORT] was most closely related to personality traits, followed by AUCI, and then maximum [CORT]. The direction of these relationships depended on whether the testing context was social or non-social. [CORT] parameters had little to no relationship with cross-context plasticity in personality traits. Our results generally affirm two critical predictions of coping styles, but match the emerging trend that these relationships are weak in the wild, and may depend on testing context. PMID:25220912

  2. Food Intake and Dietary Glycaemic Index in Free-Living Adults with and without Type 2 Diabetes Mellitus

    PubMed Central

    McGeoch, Susan C.; Holtrop, Grietje; Fyfe, Claire; Lobley, Gerald E.; Pearson, Donald W. M.; Abraham, Prakash; Megson, Ian L.; MacRury, Sandra M.; Johnstone, Alexandra M.

    2011-01-01

    A recent Cochrane review concluded that low glycaemic index (GI) diets are beneficial in glycaemic control for patients with type 2 diabetes mellitus (T2DM). There are limited UK data regarding the dietary GI in free-living adults with and without T2DM. We measured the energy and macronutrient intake and the dietary GI in a group (n = 19) of individuals with diet controlled T2DM and a group (n = 19) without diabetes, matched for age, BMI and gender. Subjects completed a three-day weighed dietary record. Patients with T2DM consumed more daily portions of wholegrains (2.3 vs. 1.1, P = 0.003), more dietary fibre (32.1 vs. 20.9 g, P < 0.001) and had a lower diet GI (53.5 vs. 57.7, P = 0.009) than subjects without T2DM. Both groups had elevated fat and salt intake and low fruit and vegetable intake, relative to current UK recommendations. Conclusions: Patients with T2DM may already consume a lower GI diet than the general population but further efforts are needed to reduce dietary GI and achieve other nutrient targets. PMID:22254116

  3. Distinct compositions of free-living, particle-associated and benthic communities of the Roseobacter group in the North Sea.

    PubMed

    Kanukollu, Saranya; Wemheuer, Bernd; Herber, Janina; Billerbeck, Sara; Lucas, Judith; Daniel, Rolf; Simon, Meinhard; Cypionka, Heribert; Engelen, Bert

    2016-01-01

    The Roseobacter group is one of the predominant lineages in the marine environment. While most investigations focus on pelagic roseobacters, the distribution and metabolic potential of benthic representatives is less understood. In this study, the diversity of the Roseobacter group was characterized in sediment and water samples along the German/Scandinavian North Sea coast by 16S rRNA gene analysis and cultivation-based methods. Molecular analysis indicated an increasing diversity between communities of the Roseobacter group from the sea surface to the seafloor and revealed distinct compositions of free-living and attached fractions. Culture media containing dimethyl sulfide (DMS), dimethyl sulfonium propionate (DMSP) or dimethyl sulfoxide (DMSO) stimulated growth of roseobacters showing highest most probable numbers (MPN) in DMSO-containing dilutions of surface sediments (2.1 × 10(7) roseobacters cm(-3)). Twenty roseobacters (12 from sediments) were isolated from DMSP- and DMS-containing cultures. Sequences of the isolates represented 0.04% of all Bacteria and 4.7% of all roseobacters in the pyrosequencing dataset from sediments. Growth experiments with the isolate Shimia sp. SK013 indicated that benthic roseobacters are able to switch between aerobic and anaerobic utilization of organic sulfur compounds. This response to changing redox conditions might be an adaptation to specific environmental conditions on particles and in sediments. PMID:26607167

  4. The effect of an indirect anthelmintic treatment on parasites and breeding success of free-living pheasants Phasianus colchicus.

    PubMed

    Draycott, R A H; Woodburn, M I A; Ling, D E; Sage, R B

    2006-12-01

    In Great Britain free-living common pheasants Phasianus colchicus are often managed at high densities owing to their popularity as a quarry species. They are prone to infection by a range of parasite species including Heterakis gallinarum, Capillaria spp. and Syngamus trachea. In 1995 the efficacy of an indirect anthelmintic technique for controlling parasitic worm burdens of pheasants was determined in a pilot study on a shooting estate in the south of England. Between 2000 and 2003 a large-scale field experiment was conducted on nine estates in eastern England to determine the effect of the technique on parasite burden and pheasant breeding success. In the absence of anthelmintic treatment worm burdens increased rapidly through March and April, whereas birds given anthelmintic-treated grain had lower worm burdens during the same period. The breeding success of pheasants was significantly higher on plots provided with anthelmintic treatment, although no long-term increases in population densities were observed. The burdens of the most common parasite H. gallinarum were significantly lower in pheasants from treatment plots six weeks after the anthelmintic treatment had ceased, but spring treatment did not influence parasite burden in the following winter. PMID:17125551

  5. Absence of detectable Salmonella cloacal shedding in free-living reptiles on admission to the wildlife center of Virginia.

    PubMed

    Richards, Jean M; Brown, Justin D; Kelly, Terra R; Fountain, Andrea L; Sleeman, Jonathan M

    2004-12-01

    Salmonellosis is an important reptile-associated zoonotic infection in the United States. Cloacal swabs were collected from reptiles admitted to the Wildlife Center of Virginia, Waynesboro, Virginia, cultured for Salmonella using Hektoen and xylose lysine deoxycholate agars, and inoculated in selenite broth. All three were incubated at 37 degrees C for 18-24 hr. Seventy-five animals were included in the study, representing eight species, 34 eastern box turtles (Terrapene carolina carolina), 14 eastern painted turtles (Chrysemys picta picta), 14 snapping turtles (Chelydra serpentina), 6 black rat snakes (Elaphe obsoleta obsoleta), 2 redbelly turtles (Pseudemys rubriventris), 2 yellowbelly sliders (Trachemys scripta scripta), 2 eastern garter snakes (Thamnophis sirtalis sirtalis), and 1 eastern river cooter (Pseudemys concinna concinna). All cultures were negative for Salmonella spp., which is in contrast to the high prevalence of Salmonella cloacal shedding reported in captive reptiles but similar to previous reports in free-living North American reptiles. We recommend, nonetheless, practicing proper hygiene methods when handling and housing all reptiles. PMID:15732603

  6. Three new and two known free-living marine nematode species of the family Ironidae from the East China Sea.

    PubMed

    Chen, Yu Zhen; Guo, Yu Qing

    2015-01-01

    Three new and two known species of free-living marine nematodes of the family Ironidae from the East China Sea are described and illustrated. Conilia sinensis sp. nov. is identified by the relatively large body size (1883-2399 µm); the well developed lips; the number, shape and length of spicule (single and striated, length 87-100 µm as arc); the shape of telamon; the number of supplements (1). Pheronous donghaiensis sp. nov. is characterized by its sharp tail point; caudal gland absent; buccal cavity armed with four big solid teeth and rows of minute denticles; spicules stout, with central septum at proximal end, male caudal region with two rows of small conical subventral papillae. Trissonchulus latispiculum sp. nov. can be distinguished by its head not set off from remaining body, tail short and blunt, buccal cavity with minute denticles, spinneret opening slightly ventrally, spicule broad and alate with central septum and head on proximal end. Trissonchulus benepapillosus (Schulz, 1935) and Trissonchulus oceanus Cobb 1920 which are first reported from China, are redescribed in detail with emphasis on new or hitherto poorly described morphological features. Types are deposited in the Institute of Oceanology, Chinese Academy of Sciences. PMID:26624035

  7. Complete mitochondrial genome of the free-living earwig, Challia fletcheri (Dermaptera: Pygidicranidae) and phylogeny of Polyneoptera.

    PubMed

    Wan, Xinlong; Kim, Man Il; Kim, Min Jee; Kim, Iksoo

    2012-01-01

    The insect order Dermaptera, belonging to Polyneoptera, includes ∼2,000 extant species, but no dermapteran mitochondrial genome has been sequenced. We sequenced the complete mitochondrial genome of the free-living earwig, Challia fletcheri, compared its genomic features to other available mitochondrial sequences from polyneopterous insects. In addition, the Dermaptera, together with the other known polyneopteran mitochondrial genome sequences (protein coding, ribosomal RNA, and transfer RNA genes), were employed to understand the phylogeny of Polyneoptera, one of the least resolved insect phylogenies, with emphasis on the placement of Dermaptera. The complete mitochondrial genome of C. fletcheri presents the following several unusual features: the longest size in insects is 20,456 bp; it harbors the largest tandem repeat units (TRU) among insects; it displays T- and G-skewness on the major strand and A- and C-skewness on the minor strand, which is a reversal of the general pattern found in most insect mitochondrial genomes, and it possesses a unique gene arrangement characterized by a series of gene translocations and/or inversions. The reversal pattern of skewness is explained in terms of inversion of replication origin. All phylogenetic analyses consistently placed Dermaptera as the sister to Plecoptera, leaving them as the most basal lineage of Polyneoptera or sister to Ephemeroptera, and placed Odonata consistently as the most basal lineage of the Pterygota. PMID:22879905

  8. A Hydroalcoholic Extract from Paullinia pinnata L. Roots Exerts Anthelmintic Activity against Free-Living and Parasitic Nematodes.

    PubMed

    Spiegler, Verena; Liebau, Eva; Peppler, Carolin; Raue, Katharina; Werne, Steffen; Strube, Christina; Heckendorn, Felix; Agyare, Christian; Stark, Timo; Hofmann, Thomas; Hensel, Andreas

    2016-08-01

    Paullinia pinnata is a medicinal plant traditionally used in West Africa against a wide range of diseases including soil-transmitted helminthiases. In this study, a hydroethanolic root extract was investigated for its phytochemical composition and in vitro activity against the free-living nematode Caenorhabditis elegans as well as the larval stages of the parasitic helminths Ancylostoma caninum, Haemonchus contortus, Toxocara cati, and Trichuris vulpis.LC-MS analysis of the ethanol-water (1 : 1) extract revealed epicatechin and different A-type linked oligomeric and polymeric procyanidins as the predominant compounds.Within an in vitro mortality assay, the extract showed a lethal activity against T. cati (LC50 of 112 µg/mL), T. vulpis (LC50 of 17 µg/mL), and C. elegans (LC50 2.5 of mg/mL), but not against A. caninum. Additionally, effects on egg hatching and larval migration of H. contortus were investigated, but no inhibitory activity was observed.Overall, these findings rationalize the traditional use of the root extract from P. pinnata as an anthelmintic remedy and provide insight into the phytochemical composition of the extract. PMID:27286336

  9. Presence of potentially pathogenic free-living amoebae strains from well water samples in Guinea-Bissau

    PubMed Central

    Baquero, Rocío A; Reyes-Batlle, María; Nicola, Graciela G; Martín-Navarro, Carmen M; López-Arencibia, Atteneri; Guillermo Esteban, J; Valladares, Basilio; Martínez-Carretero, Enrique; Piñero, José E; Lorenzo-Morales, Jacob

    2014-01-01

    Free-living amoebae (FLA) include opportunistic pathogens such as Naegleria fowleri, Balamuthia mandrillaris, and the genera Sappinia and Acanthamoeba. In this study, a survey was conducted in order to evaluate the presence of potentially pathogenic amoebic strains in water samples collected from wells located in the western part of Guinea-Bissau. The samples were left to precipitate for 48 hours and then the sediments were seeded on non-nutrient agar plates containing Escherichia coli spread and cultures were checked daily for the presence of FLA. Identification of FLA strains was based on the morphological and polymerase chain reaction (PCR) using the 18S rDNA or 16S mitochondrial rDNA genes in the case of Naegleria and Balamuthia genera, respectively. In the case of positive samples of Acanthamoeba, strains were further classified at the genotype level by sequencing the diagnostic fragment 3 (DF3) region located in the 18S rDNA gene as previously described. Sappinia sp. was not isolated during the study and thus, no molecular analysis was performed for this genus. The obtained results revealed the presence of Acanthamoeba (genotypes T3 and T4), Naegleria fowleri, and Balamuthia mandrillaris. To the best of our knowledge, this is the first report demonstrating the presence of FLA in water bodies from Guinea-Bissau and the first report on the isolation of Balamuthia mandrillaris from environmental sources in Africa. PMID:24934796

  10. The influence of wind and ice on spring walrus hunting success on St. Lawrence Island, Alaska

    NASA Astrophysics Data System (ADS)

    Huntington, Henry P.; Noongwook, George; Bond, Nicholas A.; Benter, Bradley; Snyder, Jonathan A.; Zhang, Jinlun

    2013-10-01

    St. Lawrence Island Yupik hunters on St. Lawrence Island, Alaska, take hundreds of Pacific walrus (Odobenus rosmarus divergens) each year. The harvest and associated effort (hunting trips taken), however, are variable from year to year and also from day to day, influenced by physical environmental factors among other variables. We used data from 1996 to 2010 to construct generalized additive models (GAMs) to examine several relationships among the variables. Physical factors explained 18% of the variability in harvest in Savoonga and 25% of the variability in effort; the corresponding figures for Gambell were 24% and 32%. Effort alone explained 63% of the harvest in Savoonga and 59% in Gambell. Physical factors played a relatively smaller role in determining hunting efficiency (walrus taken per hunting trip), explaining 15% of the variability in efficiency in Savoonga and 22% in Gambell, suggesting that physical factors play a larger role in determining whether to hunt than in the outcome of the hunt once undertaken. Combining physical factors with effort explained 70% of the harvest variability in Savoonga and 66% in Gambell. Although these results indicate that other factors (e.g. fuel prices, socioeconomic conditions) collectively cause a greater share of variability in harvest and effort than ice and wind, at least as indicated by the measures used as predictors in the GAMs, they also suggest that environmental change is also likely to influence future harvest levels, and that climate models that yield appropriately scaled data on ice and wind around St. Lawrence Island may be of use in determining the magnitude and direction of those influences.

  11. Spatial genetic structure and asymmetrical gene flow within the Pacific walrus

    USGS Publications Warehouse

    Sonsthagen, Sarah A.; Jay, Chadwick V.; Fischbach, Anthony S.; Sage, George K.; Talbot, Sandra L.

    2012-01-01

    Pacific walruses (Odobenus rosmarus divergens) occupying shelf waters of Pacific Arctic seas migrate during spring and summer from 3 breeding areas in the Bering Sea to form sexually segregated nonbreeding aggregations. We assessed genetic relationships among 2 putative breeding populations and 6 nonbreeding aggregations. Analyses of mitochondrial DNA (mtDNA) control region sequence data suggest that males are distinct among breeding populations (ΦST=0.051), and between the eastern Chukchi and other nonbreeding aggregations (ΦST=0.336–0.449). Nonbreeding female aggregations were genetically distinct across marker types (microsatellite FST=0.019; mtDNA ΦST=0.313), as was eastern Chukchi and all other nonbreeding aggregations (microsatellite FST=0.019–0.035; mtDNA ΦST=0.386–0.389). Gene flow estimates are asymmetrical from St. Lawrence Island into the southeastern Bering breeding population for both sexes. Partitioning of haplotype frequencies among breeding populations suggests that individuals exhibit some degree of philopatry, although weak. High levels of genetic differentiation among eastern Chukchi and all other nonbreeding aggregations, but considerably lower genetic differentiation between breeding populations, suggest that at least 1 genetically distinct breeding population remained unsampled. Limited genetic structure at microsatellite loci between assayed breeding areas can emerge from several processes, including male-mediated gene flow, or population admixture following a decrease in census size (i.e., due to commercial harvest during 1880–1950s) and subsequent recovery. Nevertheless, high levels of genetic diversity in the Pacific walrus, which withstood prolonged decreases in census numbers with little impact on neutral genetic diversity, may reflect resiliency in the face of past environmental challenges.

  12. Efficacy of amitraz-impregnated collars on white-tailed deer in reducing free-living populations of lone star ticks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over a seven year period, we monitored the effect of a commercially available, amitraz impregnated anti-tick collar in controlling free-living populations of lone star ticks, Amblyomma americanum (L.) when manually fitted around the neck of white-tailed deer, Odocoileus virginianus (Zimmermann). St...

  13. Complete Genome Sequence of Endomicrobium proavitum, a Free-Living Relative of the Intracellular Symbionts of Termite Gut Flagellates (Phylum Elusimicrobia)

    PubMed Central

    Zheng, Hao

    2015-01-01

    We sequenced the complete genome of Endomicrobium proavitum strain Rsa215, the first isolate of the class Endomicrobia (phylum Elusimicrobia). It is the closest free-living relative of the endosymbionts of termite gut flagellates and thereby provides an excellent model for studying the evolutionary processes during the establishment of an intracellular symbiosis. PMID:26184928

  14. Changes during late-stage embryonic development from egg-juvenile to free-living hatchling in Chinese freshwater crab Sinopotamon yangtsekiense (Decapoda, Brachyura, Potamidae)

    NASA Astrophysics Data System (ADS)

    Xue, Junzeng; Liu, Yan; Cumberlidge, Neil; Wu, Huixian

    2013-05-01

    This study expands on recent reports that direct development in the Chinese potamid freshwater crab Sinopotamon yangtsekiense involves the completion of all brachyuran larval stages (nauplius, zoea, and megalopa) inside the egg case during embryonic development. Detailed studies of embryonic development in this species revealed the presence of an additional larval stage (the egg-juvenile) between the megalopa and the free-living hatchling crab. We described and compared the appendages of the head, thorax, and abdomen of the egg-juvenile with those of the hatchling crab in S. yangtsekiense. Significant differences were found between most of the appendages of these two stages with a soft exoskeleton in the egg-juvenile, no joint articulation, a slimmer appearance, and a lack of setae when compared with the newly emerged free-living hatchling crab. These modifications of the appendages are related to the confinement within the egg case of the egg-megalopa and egg-juvenile during direct development, and the need for the free-living hatchling freshwater crab to move, feed, and respire. In marine crabs, the megalopa gives rise to the first crab stage whereas in freshwater crabs the egg-juvenile follows the megalopa and immediately precedes the free-living first crab stage.

  15. Comparison of GT3X accelerometer and Yamax pedometer steps/day in a free-living sample of overweight and obese adults

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The purpose of this study was to compare steps/day detected by the YAMAX SW-200 pedometer versus the Actigraph GT3X accelerometer in free-living adults. Daily YAMAX and GT3X steps were collected from a sample of 23 overweight and obese participants (78% female; age = 52.6 +/- 8.4 yr.; BMI = 31.0 +/-...

  16. Efficacy of amitraz-impregnated collars on white-tailed deer (Artiodactyla: Cervidae) in reducing free-living populations of lone star ticks (Acari: Ixodidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over a seven year period, we monitored the effect of a commercially available, amitraz impregnated anti-tick collar in controlling free-living populations of lone star ticks, Amblyomma americanum (L.) when manually fitted around necks of white-tailed deer, Odocoileus virginianus (Zimmermann). Study...

  17. In vitro proteolysis of nematode FLPs by preparations from the free-living nematode Panagrellus redivivus and two plant-parasitic nematodes (Heterodera glycines and Meloidogyne incognita)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proteolytic activities in extracts from three nematodes, the plant parasites Heterodera glycines and Meloidogyne incognita, and the free-living Panagrellus redivivus, were surveyed for substrate preferences using a battery of seven FRET-modified peptide substrates, all derived from members of the la...

  18. Efficacy of amitraz collars on white-tailed deer, Odocoileus virginianus (Zimmerman) (Artiodactyla: Cervidae) against free-living populations of Lone Star Ticks, Amblyomma americanum (L.) (Acari: Ixodidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Collars containing the acaricide amitraz were fitted around necks of white-tailed deer, Odocoileus virginianus (Zimmermann) confined in a 38.8 ha deer-fenced, densely vegetated plot in south Texas to determine efficacy in controlling free-living populations of lone star ticks, Amblyomma americanum (...

  19. Effects of supplementing n-3 fatty acid enriched eggs and walnuts on cardiovascular disease risk markers in healthy free-living lacto-ovo-vegetarians: a randomized, crossover, free-living intervention study

    PubMed Central

    2014-01-01

    Background Plant and marine n-3 fatty acids (FA) may favorably modify select markers of cardiovascular disease risk. Whether supplementing the habitual diet of lacto-ovo-vegetarians (LOV) with walnuts (containing α-linolenic acid, ALA) and n-3 FA enriched eggs (containing primarily docosahexaenoic acid, DHA and ALA) would have equivalent effects on CVD risk factors is explored in this study. Methods In this study, 20 healthy free-living LOVs following their habitual diet were randomly assigned in a crossover design to receive one of three supplements: n-3 FA enriched egg (6/week), walnuts (28.4 g, 6/week) or a standard egg, 6/week (control) for 8 weeks each with 4-wk washout between treatments. Erythrocyte membrane fatty acids, serum lipids and inflammatory markers were measured at the end of each treatment. Results Dietary compliance was observed by an expected increase in erythrocyte membrane ALA following the walnut treatment and in DHA following the n-3 FA enriched egg treatment. Walnut treatment lowered serum triacylglycerol, total cholesterol and Apo B (p < 0.05) compared to the standard egg but not the n-3 FA enriched egg treatment. However, walnut treatment significantly reduced total: HDL cholesterol ratio compared to both egg treatments. There were no differences between treatments for any of the inflammatory markers. Conclusions For LOV, a direct source of DHA such as n-3 FA enriched eggs seems necessary to increase membrane levels of DHA. However for producing an overall favorable blood lipid profile, daily consumption of a handful of walnuts rich in ALA may be a preferred option for lacto-ovo vegetarian. PMID:24673793

  20. Enumeration of Pacific Walrus Carcasses on Beaches of the Chukchi Sea in Alaska Following a Mortality Event, September 2009

    USGS Publications Warehouse

    Fischbach, A.S.; Monson, D.H.; Jay, C.V.

    2009-01-01

    On September 14, 2009, we encountered substantial numbers of fresh walrus carcasses on the Alaskan shores of the Chukchi Sea near Icy Cape. We enumerated 131 carcasses using geo-referenced strip transect photography and visual counts of solitary carcasses. All appeared to be young animals based on review of aerial photographs and reference to 12 carcasses that we examined on the ground. The events that led to the death of these animals are unknown, but appear to be related to the loss of sea ice over the Chukchi Sea continental shelf. In years prior to this event, other investigators have linked walrus deaths at other Chukchi Sea coastal haulouts to trampling, exhaustion from prolonged exposure to open sea conditions, and separation of calves from their mothers.

  1. Bioaccumulation of persistent organochlorine pesticides (OCPs) by gray whale and Pacific walrus from the western part of the Bering Sea.

    PubMed

    Tsygankov, Vasiliy Yu; Boyarova, Margarita D; Lukyanova, Olga N

    2015-10-15

    The feeding habits of a gray whale (Eschrichtius robustus) and a Pacific walrus (Odobenus rosmarus divergens), caught from the western Bering Sea in the summers of 2010 and 2011, have been studied, and concentration of persistent organochlorine pesticides (OCPs) in their organs determined. The total OCP concentration (∑HCH+∑DDT) in muscles and liver of the gray whales varies from 297 to 3581 and from 769 to 13,808 ng/g lipids, respectively. The total OCP concentration (∑HCH+∑DDT) in muscles and liver of the Pacific walruses varies from 197 to 5659 and from 4856 to 90,263 ng/g lipids, respectively. The specifics of diet as a source of pesticide accumulation in these two marine mammal species are discussed. PMID:26169228

  2. [Investigation of potentially pathogenic free-living amoebae and their in vivo pathogenicity in water supplies of Turkey].

    PubMed

    Yazar, Süleyman; Gürbüz, Esra; Sönmez, Mehmet Fatih; Çetinkaya, Ülfet; Kuk, Salih

    2016-07-01

    Free-living amoebae (FLA) are found widely in soil and water in the nature. Among them in which potentially pathogenic for humans and animals are known as "potential pathogenic free-living amoebae (PPFLA)". PPFLA are characterized as the causes of clinical manifestations leading to death especially in immunosuppressed people. Four genus of PPFLA (Acanthamoeba, Naegleria, Balamuthia and Sappinia) are known to be pathogenic to humans. The aims of this study were to investigate the presence of PPFLA in the water supplies in Turkey and to determine their in vivo pathogenicity. A total of 664 water samples were collected from the ponds, rivers, streams and wells found in provinces located at different regions (central, western, eastern and southeastern regions) of Turkey. These samples were initially inoculated in the monoxenic culture media and evaluated by both microscopy and polymerase chain reaction (PCR) in terms of the presence of FLA. The samples identified as positive were then cultured in axenic media, the growth of amoebae that were confirmed microscopically, were than studied with PCR for molecular characterization. The isolates that were found positive by PCR from axenic cultures were inoculated intranasally to immunocompetent and immunodeficient (athymic) [BALB/c Rag2(-/-) gamma(c)(-/-)] BALB/c mice followed by the evaluation on the 21st day by histopathological and molecular methods to investigate their in vivo pathogenicity. In our study, 143 water samples were detected as positive in monoxenic cultures and 41 of them were detected as positive in axenic cultures. Twenty of 41 samples detected as positive in axenic culture could be continued in culture for three months. As a result of PCR using primers common to SYA, only nine have been identified from 20 samples as positive. According to the result of the PCR with specific primers, all (n= 9) were positive for Acanthamoeba sp., eight for Sappini sp. and five for Balamuthia mandrillaris, while none was

  3. The Wageningen Lowland Runoff Simulator (WALRUS): implementation and application to the freely draining Hupsel Brook catchment and controlled Cabauw polder

    NASA Astrophysics Data System (ADS)

    Brauer, Claudia; Torfs, Paul; Teuling, Ryan; Uijlenhoet, Remko

    2014-05-01

    Recently, we developed the Wageningen Lowland Runoff Simulator (WALRUS) to fill the gap between complex, spatially distributed models which are often used in lowland catchments and simple, parametric models which have mostly been developed for mountainous catchments. This parametric rainfall-runoff model can be used all over the world in both freely draining lowland catchments and polders with controlled water levels. Here, we present the model implementation, opportunities for practical application and experience from validation studies with data from two field sites. The open source model code is implemented in R and is set-up such that it can be used by both practitioners and researchers. For direct use by practitioners, defaults are implemented for relations between model variables and to compute initial conditions, leaving only four parameters which require calibration. For research purposes, the defaults can easily be changed. WALRUS is computationally efficient, which allows operational forecasting and uncertainty estimation by creating ensembles. An approach for flexible time steps increases numerical stability and makes model parameter values independent of time step size, which facilitates use of the model with the same parameter set for multi-year water balance studies as well as detailed analyses of individual flood peaks. We applied WALRUS to two contrasting Dutch catchments: the slightly sloping, freely draining Hupsel Brook catchment and the flat Cabauw polder with controlled water levels. In both catchments, WALRUS performs well during the years used for calibration and validation. The model also performs well during extremely wet periods (flash flood in the Hupsel Brook catchment in August 2010) and extremely dry periods (summer 1976) and can forecast the effect of control operations (changing weir elevations and surface water supply).

  4. Behavior and body mass changes of a mother and calf Pacific walrus (Odobenus rosmarus divergens) during the suckling period.

    PubMed

    Kastelein, Ronald A; van den Belt, Ivanka; Jennings, Nancy; de Kruijf, Richard

    2015-01-01

    The behavior of a 13-year-old female Pacific walrus and her first calf is described during the first 7 months of the 19-month suckling period. The calf vocalized before 62% of suckling sessions. The mother immediately responded after 84% of vocalizations; after 44% she allowed a suckling session. The number of suckling sessions per 24-h period decreased from on average nine in the second week after birth to two by the thirteenth week. Thereafter, the number of suckling sessions fluctuated between 3 and 5/day. The average suckling session duration increased from 4 min/day to around 17 min/day. The average effective suckling time per session increased from on average 2 to 10 min. The number of breaks decreased during the study period from around 40 to 20 per session. The mother spent on average 47% of her time resting, the calf 44%. The remaining time was spent in locomotion, and suckling, playing, investigating, and looking. Mother and calf spent on average 51% of time indoors. The mother spent 43% of her time in the water, the calf 39%. The calf's body mass at birth was 55 kg; it increased to 178 kg at 27 weeks. The mother did not eat for the first 5 days after delivery, and she ate less than usual during the next 6 days. The mother's mass eventually stabilized at 1024 kg (>before gestation). The calf was not given formula and was weaned onto fish. This is the first detailed description of a captive Pacific walrus's suckling period. It could benefit the husbandry of future captive-born walruses, and may elucidate the behavior of wild walruses during suckling. PMID:25511011

  5. Ecology and Biogeography of Free-Living Nematodes Associated with Chemosynthetic Environments in the Deep Sea: A Review

    PubMed Central

    Vanreusel, Ann; De Groote, Annelies; Gollner, Sabine; Bright, Monika

    2010-01-01

    Background Here, insight is provided into the present knowledge on free-living nematodes associated with chemosynthetic environments in the deep sea. It was investigated if the same trends of high standing stock, low diversity, and the dominance of a specialized fauna, as observed for macro-invertebrates, are also present in the nematodes in both vents and seeps. Methodology This review is based on existing literature, in combination with integrated analysis of datasets, obtained through the Census of Marine Life program on Biogeography of Deep-Water Chemosynthetic Ecosystems (ChEss). Findings Nematodes are often thriving in the sulphidic sediments of deep cold seeps, with standing stock values ocassionaly exceeding largely the numbers at background sites. Vents seem not characterized by elevated densities. Both chemosynthetic driven ecosystems are showing low nematode diversity, and high dominance of single species. Genera richness seems inversely correlated to vent and seep fluid emissions, associated with distinct habitat types. Deep-sea cold seeps and hydrothermal vents are, however, highly dissimilar in terms of community composition and dominant taxa. There is no unique affinity of particular nematode taxa with seeps or vents. Conclusions It seems that shallow water relatives, rather than typical deep-sea taxa, have successfully colonized the reduced sediments of seeps at large water depth. For vents, the taxonomic similarity with adjacent regular sediments is much higher, supporting rather the importance of local adaptation, than that of long distance distribution. Likely the ephemeral nature of vents, its long distance offshore and the absence of pelagic transport mechanisms, have prevented so far the establishment of a successful and typical vent nematode fauna. Some future perspectives in meiofauna research are provided in order to get a more integrated picture of vent and seep biological processes, including all components of the marine ecosystem. PMID

  6. Free-living ciliates as potential reservoirs for eukaryotic parasites: occurrence of a trypanosomatid in the macronucleus of Euplotes encysticus

    PubMed Central

    2014-01-01

    Background Flagellates of the family Trypanosomatidae are obligate endoparasites, which can be found in various hosts. Several genera infect insects and occur as monoxenous parasites especially in representatives of Diptera and Hemiptera. These trypanosomatid flagellates probably share the worldwide distribution of their hosts, which are often infested by large numbers of endoparasites. Traditionally, their taxonomy was based on morphology, host origin, and life cycle. Here we report the characterization of a trypanosomatid infection detected in a protozoan, a ciliate collected from a polluted freshwater pond in a suburb of New Delhi (India). Methods Live observations and morphological studies applying light, fluorescence and transmission electron microscopy were conducted. Molecular analyses of host and parasite were performed and used for phylogenetic reconstructions and species (host) or genus level (parasite) identification. Results Although the morphological characteristics were not revealing, a high similarity of the trypanosomatids 18S rRNA gene sequence to Herpetomonas ztiplika and Herpetomonas trimorpha (Kinetoplastida, Trypanosomatidae), both parasites of biting midges (Culicoides kibunensis and Culicoides truncorum, respectively) allowed the assignment to this genus. The majority of the host population displayed a heavy infection that significantly affected the shape of the host macronucleus, which was the main site of parasite localization. In addition, the growth rate of host cultures, identified as Euplotes encysticus according to cell morphology and 18S rRNA gene sequence, was severely impacted by the infection. Conclusions The host-parasite system described here represents a recent example of free-living protists acting as environmental reservoirs for parasitic eukaryotic microorganisms. PMID:24774858

  7. Vitamin D status and its associated factors of free living Malay adults in a tropical country, Malaysia.

    PubMed

    Moy, Foong Ming

    2011-09-01

    Vitamin D status is influenced by sun exposure, geographic latitude, daily outdoor activities, body surface exposed to sunlight and dietary intakes. Malaysia, is sunny all year round. However, the vitamin D status of this population especially among the healthy and free living adults is not known. Therefore a study of vitamin D status and associated factors was initiated among an existing Malay cohort in Kuala Lumpur. A total of 380 subjects were sampled to have their vitamin D status assessed using 25-hydroxyvitamin D (25(OH)D). A short questionnaire enquiring socio-demographic characteristics, exposure to sunlight and clothing style was administered. Their mean age was 48.5±5.2years and the mean 25(OH)D for males and females were 56.2±18.9nmol/L and 36.2±13.4nmol/L respectively. There were significant positive correlation for sun exposure score (r=0.27, p<0.001) and negative correlation for sun protection score (r=-0.41, p<0.001) with 25(OH)D levels. In the logistic regression model, females (OR=2.93; 95% CI: 1.17, 7.31), BMI (1.1; 1.03, 1.20) and sun exposure score (0.998; 0.996, 0.999) were significantly associated with vitamin D status as represented by 25(OH)D levels. Our findings show that obesity, lifestyle behaviours and clothing style are directly associated with our participants especially females' low vitamin D status. PMID:21636288

  8. Overnight Closed-Loop Insulin Delivery in Young People With Type 1 Diabetes: A Free-Living, Randomized Clinical Trial

    PubMed Central

    Hovorka, Roman; Elleri, Daniela; Thabit, Hood; Allen, Janet M.; Leelarathna, Lalantha; El-Khairi, Ranna; Kumareswaran, Kavita; Caldwell, Karen; Calhoun, Peter; Kollman, Craig; Murphy, Helen R.; Acerini, Carlo L.; Wilinska, Malgorzata E.; Nodale, Marianna; Dunger, David B.

    2014-01-01

    OBJECTIVE To evaluate feasibility, safety, and efficacy of overnight closed-loop insulin delivery in free-living youth with type 1 diabetes. RESEARCH DESIGN AND METHODS Overnight closed loop was evaluated at home by 16 pump-treated adolescents with type 1 diabetes aged 12–18 years. Over a 3-week period, overnight insulin delivery was directed by a closed-loop system, and on another 3-week period sensor-augmented therapy was applied. The order of interventions was random. The primary end point was time when adjusted sensor glucose was between 3.9 and 8.0 mmol/L from 2300 to 0700 h. RESULTS Closed loop was constantly applied over at least 4 h on 269 nights (80%); sensor data were collected over at least 4 h on 282 control nights (84%). Closed loop increased time spent with glucose in target by a median 15% (interquartile range −9 to 43; P < 0.001). Mean overnight glucose was reduced by a mean 14 (SD 58) mg/dL (P < 0.001). Time when glucose was <70 mg/dL was low in both groups, but nights with glucose <63 mg/dL for at least 20 min were less frequent during closed loop (10 vs. 17%; P = 0.01). Despite lower total daily insulin doses by a median 2.3 (interquartile range −4.7 to 9.3) units (P = 0.009), overall 24-h glucose was reduced by a mean 9 (SD 41) mg/dL (P = 0.006) during closed loop. CONCLUSIONS Unsupervised home use of overnight closed loop in adolescents with type 1 diabetes is safe and feasible. Glucose control was improved during the day and night with fewer episodes of nocturnal hypoglycemia. PMID:24757227

  9. Seasonal changes in morphology and function of the gastrointestinal tract of free-living alpine marmots ( Marmota marmota).

    PubMed

    Hume, D; Beiglböck, C; Ruf, T; Frey-Roos, F; Bruns, U; Arnold, W

    2002-04-01

    The gastrointestinal tracts of 76 free-living alpine marmots ( Marmota marmota) shot during a population control program in Switzerland were collected and analysed for patterns of change in morphology and function over the period from emergence from hibernation in April to just before re-entry into hibernation in September. Between first emergence and mid-summer (July) the fresh tissue mass of the stomach increased by 105%, the small intestine by 259% (among the largest recorded for a mammal), caecum by 185%, proximal colon by 138%, and distal colon by 144%. Mitotic activity was greatest in the small intestine; the mitotic index was high (40%) compared with indexes in the stomach and hindgut (approximately 4%) even at emergence, and increased to approximately 60% by mid-summer. Microbial activity in the caecum was also significant at emergence. The stomach (length) and caecum (length and fresh mass) increased in response to ingested food earlier than did the small intestine. Between mid-summer and September there were decreases in small intestinal tissue mass and mitotic activity. It is concluded that the gastrointestinal tract of alpine marmots probably continues to function throughout hibernation at a low level, with a mid-winter trough as part of an endogenous circannual rhythm. However, after emergence in spring, increases in size and activity of the tract appear to be a response to ingested food rather than to an endogenous signal. The early signs of down-regulation of the small intestine before re-entry into hibernation, together with its delayed up-regulation in response to food in spring, are consistent with the high costs of maintaining this section of the digestive system. PMID:11919701

  10. Microscopic and molecular studies of the diversity of free-living protozoa in meat-cutting plants.

    PubMed

    Vaerewijck, Mario J M; Sabbe, Koen; Baré, Julie; Houf, Kurt

    2008-09-01

    The diversity of free-living protozoa in five meat-cutting plants was determined. Light microscopy after enrichment culturing was combined with sequencing of PCR-amplified, denaturing gradient gel electrophoresis (DGGE)-separated 18S rRNA gene fragments, which was used as a fast screening method. The general results of the survey showed that a protozoan community of amoebae, ciliates, and flagellates was present in all of the plants. Protozoa were detected mainly in floor drains, in standing water on the floor, on soiled bars of cutting tables, on plastic pallets, and in out-of-use hot water knife sanitizers, but they were also detected on surfaces which come into direct contact with meat, such as conveyer belts, working surfaces of cutting tables, and needles of a meat tenderizer. After 7 days of incubation at refrigerator temperature, protozoa were detected in about one-half of the enrichment cultures. Based on microscopic observations, 61 morphospecies were found, and Bodo saltans, Bodo spp., Epistylis spp., Glaucoma scintillans, Petalomonas spp., Prodiscophrya collini, and Vannella sp. were the most frequently encountered identified organisms. Sequencing of DGGE bands resulted in identification of a total of 49 phylotypes, including representatives of the Amoebozoa, Chromalveolata, Excavata, Opisthokonta, and Rhizaria. Sequences of small heterotrophic flagellates were affiliated mainly with the Alveolata (Apicomplexa), Stramenopiles (Chrysophyceae), and Rhizaria (Cercozoa). This survey showed that there is high protozoan species richness in meat-cutting plants and that the species included species related to known hosts of food-borne pathogens. PMID:18641165

  11. Validity of activity monitors worn at multiple nontraditional locations under controlled and free-living conditions in young adult women.

    PubMed

    Kumahara, Hideaki; Ayabe, Makoto; Ichibakase, Misato; Tashima, Akari; Chiwata, Maiko; Takashi, Tomomi

    2015-05-01

    The purpose of this study was to examine the validity of counting steps and computing indices of moderate-to-vigorous physical activity (MVPA) using miniature activity monitors with 3-D technology worn at various locations under controlled (CON) and free-living conditions (FL). Kenz e-style2, Tanita Calorism Smart, and Omron Calori Scan HJA-306 activity monitors were assessed. Nine and 31 young adult women were assigned to the CON and FL studies, respectively. While walking or jogging on a treadmill at 5 different speeds, the subjects simultaneously carried the 3 different monitors in a pants pocket (PP), a chest shirt pocket, and a shoulder bag (B). Under the FL condition, the 3 monitors were placed only at the PP and B locations for practical reasons. Significant effects of monitor location and walking/jogging speed on the step count measured by the 3 monitors were evaluated under the CON condition. Monitors placed at both PP and B tended to underestimate the number of steps; however, there were no significant differences between the values obtained with the Kenz monitor and those obtained with a criterion accelerometer under the FL condition. Moreover, strong correlations were observed between steps measured by monitors placed at PP and steps measured by the criterion accelerometer. The amount of MVPA for the PP location and the non-carrying duration of the bag for the B location were considered to be important determinants of the accuracy of step counting under the FL condition. In conclusion, monitors placed at the PP location, especially the Kenz monitor, showed acceptable accuracy for young adult women in real-life settings. In contrast, MVPA indices assessed using these monitors showed limited validity. PMID:25832964

  12. Chemical immobilization and anesthesia of free-living aardvarks (Orycteropus afer) with ketamine-medetomidine-midazolam and isoflurane.

    PubMed

    Rey, Benjamin; Costello, Mary-Ann; Fuller, Andrea; Haw, Anna; Hetem, Robyn S; Mitchell, Duncan; Meyer, Leith C R

    2014-10-01

    Abstract We evaluated the effectiveness of a ketamine-medetomidine-midazolam drug combination administered intramuscularly by remote injection followed by isoflurane anesthesia in free-living aardvarks (Orycteropus afer). Seven aardvarks weighing 33-45 kg were immobilized to perform surgical implantation of temperature loggers using 3.8 mg/kg ketamine, 0.1 mg/kg medetomidine, and 0.25 mg/kg midazolam. Immobilized aardvarks were transported to a surgical theater and received 0.5-1% isoflurane in oxygen after tracheal intubation. After surgery, medetomidine was antagonized with 0.5 mg/kg atipamezole, and aardvarks were released at the site of capture. We recorded induction and recovery times, clinical and physiologic parameters, and conducted blood gas analyses before and during isoflurane administration. Aardvarks showed initial effects within 3 min and reached lateral recumbency within 7 min after drug administration. Heart rate (50-67 beats/min), respiratory rate (10-15 breaths/min), oxygen hemoglobin saturation (SaO2; 90-97%), and rectal temperature (34.0-37.5 C) were within acceptable physiologic ranges. Mean arterial blood pressure was initially high (146 ± 12 mmHg), but the hypertension resolved over time. Rectal temperature dropped significantly during anesthesia. Four animals had to be treated to relieve apnea. Blood gas analyses revealed mild to moderate hypercapnia but no hypoxaemia. The ketamine-medetomidine-midazolam combination provided effective immobilization. Combined with a low concentration of isoflurane, it can be used for prolonged surgical procedures in wild aardvarks. However, caution is needed, and monitoring of clinical parameters is required. PMID:25014906

  13. Telomere dynamics in free-living edible dormice (Glis glis): the impact of hibernation and food supply

    PubMed Central

    Cornils, Jessica S.; Smith, Steve; Moodley, Yoshan; Ruf, Thomas

    2016-01-01

    ABSTRACT We studied the impact of hibernation and food supply on relative telomere length (RTL), an indicator for aging and somatic maintenance, in free-living edible dormice. Small hibernators such as dormice have ∼50% higher maximum longevity than non-hibernators. Increased longevity could theoretically be due to prolonged torpor directly slowing cellular damage and RTL shortening. However, although mitosis is arrested in mammals at low body temperatures, recent evidence points to accelerated RTL shortening during periodic re-warming (arousal) from torpor. Therefore, we hypothesized that these arousals during hibernation should have a negative effect on RTL. Here, we show that RTL was shortened in all animals over the course of ∼1 year, during which dormice hibernated for 7.5–11.4 months. The rate of periodic arousals, rather than the time spent euthermic during the hibernation season, was the best predictor of RTL shortening. This finding points to negative effects on RTL of the transition from low torpor to high euthermic body temperature and metabolic rate during arousals, possibly because of increased oxidative stress. The animals were, however, able to elongate their telomeres during the active season, when food availability was increased by supplemental feeding in a year of low natural food abundance. We conclude that in addition to their energetic costs, periodic arousals also lead to accelerated cellular damage in terms of RTL shortening. Although dormice are able to counteract and even over-compensate for the negative effects of hibernation, restoration of RTL appears to be energetically costly. PMID:27535986

  14. Genetic variation and phylogeography of free-living mouse species (genus Mus) in the Balkans and the Middle East.

    PubMed

    Macholán, M; Vyskocilová, M; Bonhomme, F; Krystufek, B; Orth, A; Vohralík, V

    2007-11-01

    This work presents a study of the distribution and pattern of variation throughout the ranges of three free-living mouse species of the genus Mus-M. macedonicus, M. spicilegus, and a M. cypriacus - based on sequencing of two segments of the mitochondrial DNA (mtDNA) control region. The study shows a similar level of variability in the three species and suggests their recent population expansion. The highest proportion of variation is found within populations indicating low genetic structuring. Phylogenetic analysis confirms the significant divergence of a mitochondrial lineage of M. macedonicus from Israel, recently described as a new subspecies, M. macedonicus spretoides. Conversely, no genetic hiatus is revealed between European and Asian populations of M. macedonicus macedonicus. Although phylogenetic relationships among M. spicilegus populations could not be unravelled precisely, the results suggest a recent westward expansion of the species. The mtDNA divergence between M. macedonicus and M. spicilegus is 7.3%, suggesting their split between c. 700,000 and 1 million years ago. These dates correspond with a coalescent estimate about 720,000 years ago. On the other hand, M. cypriacus appeared almost twice as divergent from the former species (4.5%) as from the latter (8.8%) suggesting a divergence of c. 430,000-610,000 years ago (coalescent approximately 490,000 years ago) and 830,000-1.2 million years ago (coalescent approximately 780,000 years ago), respectively. Approximate times of population expansion have also been estimated for all taxa and groups of populations. Existence of several glacial refuges and various colonization scenarios are discussed; since all estimated divergence times fall within interglacial periods it seems that climatic oscillations did not play a crucial role in the evolution of the three species. PMID:17908218

  15. Survival of free-living Acholeplasma in aerated pig manure slurry revealed by 13C-labeled bacterial biomass probing

    PubMed Central

    Hanajima, Dai; Aoyagi, Tomo; Hori, Tomoyuki

    2015-01-01

    Many studies have been performed on microbial community succession and/or predominant taxa during the composting process; however, the ecophysiological roles of microorganisms are not well understood because microbial community structures are highly diverse and dynamic. Bacteria are the most important contributors to the organic-waste decomposition process, while decayed bacterial cells can serve as readily digested substrates for other microbial populations. In this study, we investigated the active bacterial species responsible for the assimilation of dead bacterial cells and their components in aerated pig manure slurry by using 13C-labeled bacterial biomass probing. After 3 days of forced aeration, 13C-labeled and unlabeled dead Escherichia coli cell suspensions were added to the slurry. The suspensions contained 13C-labeled and unlabeled bacterial cell components, possibly including the cell wall and membrane, as well as intracellular materials. RNA extracted from each slurry sample 2 h after addition of E. coli suspension was density-resolved by isopycnic centrifugation and analyzed by terminal restriction fragment length polymorphism, followed by cloning and sequencing of bacterial 16S rRNA genes. In the heavy isotopically labeled RNA fraction, the predominant 13C-assimilating population was identified as belonging to the genus Acholeplasma, which was not detected in control heavy RNA. Acholeplasma spp. have limited biosynthetic capabilities and possess a wide variety of transporters, resulting in their metabolic dependence on external carbon and energy sources. The prevalence of Acholeplasma spp. was further confirmed in aerated pig manure slurry from four different pig farms by pyrosequencing of 16S rRNA genes; their relative abundance was ∼4.4%. Free-living Acholeplasma spp. had a competitive advantage for utilizing dead bacterial cells and their components more rapidly relative to other microbial populations, thus allowing the survival and prevalence

  16. Telomere dynamics in free-living edible dormice (Glis glis): the impact of hibernation and food supply.

    PubMed

    Hoelzl, Franz; Cornils, Jessica S; Smith, Steve; Moodley, Yoshan; Ruf, Thomas

    2016-08-15

    We studied the impact of hibernation and food supply on relative telomere length (RTL), an indicator for aging and somatic maintenance, in free-living edible dormice. Small hibernators such as dormice have ∼50% higher maximum longevity than non-hibernators. Increased longevity could theoretically be due to prolonged torpor directly slowing cellular damage and RTL shortening. However, although mitosis is arrested in mammals at low body temperatures, recent evidence points to accelerated RTL shortening during periodic re-warming (arousal) from torpor. Therefore, we hypothesized that these arousals during hibernation should have a negative effect on RTL. Here, we show that RTL was shortened in all animals over the course of ∼1 year, during which dormice hibernated for 7.5-11.4 months. The rate of periodic arousals, rather than the time spent euthermic during the hibernation season, was the best predictor of RTL shortening. This finding points to negative effects on RTL of the transition from low torpor to high euthermic body temperature and metabolic rate during arousals, possibly because of increased oxidative stress. The animals were, however, able to elongate their telomeres during the active season, when food availability was increased by supplemental feeding in a year of low natural food abundance. We conclude that in addition to their energetic costs, periodic arousals also lead to accelerated cellular damage in terms of RTL shortening. Although dormice are able to counteract and even over-compensate for the negative effects of hibernation, restoration of RTL appears to be energetically costly. PMID:27535986

  17. Novel expression of Haemonchus contortus vaccine candidate aminopeptidase H11 using the free-living nematode Caenorhabditis elegans

    PubMed Central

    2013-01-01

    With the problem of parasitic nematode drug resistance increasing, vaccine development offers an alternative sustainable control approach. For some parasitic nematodes, native extracts enriched for specific proteins are highly protective. However, recombinant forms of these proteins have failed to replicate this protection. This is thought to be due to differences in glycosylation and/or conformation between native and recombinant proteins. We have exploited the free-living nematode Caenorhabditis elegans to examine its suitability as an alternative system for recombinant expression of parasitic nematode vaccine candidates. We focussed on Haemonchus contortus aminopeptidase H11 glycoprotein, which is enriched in a gut membrane fraction capable of inducing significant protection against this important ovine gastrointestinal nematode. We show that H. contortus H11 expressed in C. elegans is enzymatically active and MALDI mass spectrometry identifies similar di- and tri-fucosylated structures to those on native H11, with fucose at the 3- and/or 6-positions of the proximal GlcNAc. Some glycan structural differences were observed, such as lack of LDNF. Serum antibody to native H11 binds to C. elegans recombinant H11 and most of the antibody to rH11 or native H11 is directed to glycan moieties. Despite these similarities, no reduction in worm burden or faecal egg count was observed following immunisation of sheep with C. elegans-expressed recombinant H11 protein. The findings suggest that the di- and tri-fucosylated N-glycans expressed on rH11 do not contribute to the protective effect of H11 and that additional components present in native H11-enriched extract are likely required for enhancing the antibody response necessary for protection. PMID:24289031

  18. Epidemic Clones, Oceanic Gene Pools, and Eco-LD in the Free Living Marine Pathogen Vibrio parahaemolyticus.

    PubMed

    Cui, Yujun; Yang, Xianwei; Didelot, Xavier; Guo, Chenyi; Li, Dongfang; Yan, Yanfeng; Zhang, Yiquan; Yuan, Yanting; Yang, Huanming; Wang, Jian; Wang, Jun; Song, Yajun; Zhou, Dongsheng; Falush, Daniel; Yang, Ruifu

    2015-06-01

    We investigated global patterns of variation in 157 whole-genome sequences of Vibrio parahaemolyticus, a free-living and seafood associated marine bacterium. Pandemic clones, responsible for recent outbreaks of gastroenteritis in humans, have spread globally. However, there are oceanic gene pools, one located in the oceans surrounding Asia and another in the Mexican Gulf. Frequent recombination means that most isolates have acquired the genetic profile of their current location. We investigated the genetic structure in the Asian gene pool by calculating the effective population size in two different ways. Under standard neutral models, the two estimates should give similar answers but we found a 27-fold difference. We propose that this discrepancy is caused by the subdivision of the species into a hundred or more ecotypes which are maintained stably in the population. To investigate the genetic factors involved, we used 51 unrelated isolates to conduct a genome-wide scan for epistatically interacting loci. We found a single example of strong epistasis between distant genome regions. A majority of strains had a type VI secretion system associated with bacterial killing. The remaining strains had genes associated with biofilm formation and regulated by cyclic dimeric GMP signaling. All strains had one or other of the two systems and none of isolate had complete complements of both systems, although several strains had remnants. Further "top down" analysis of patterns of linkage disequilibrium within frequently recombining species will allow a detailed understanding of how selection acts to structure the pattern of variation within natural bacterial populations. PMID:25605790

  19. Use of human chorionic gonadotropin in a male Pacific walrus (Odobenus rosmarus divergens) to induce rut and achieve a pregnancy in a nulliparous female.

    PubMed

    Muraco, Holley S; Coombs, Leah D; Procter, Dianna G; Turek, Paul J; Muraco, Michael J

    2012-01-01

    Walrus in US zoos have a very low reproductive rate of 11 births in 80 years, and little is known about Pacific walrus (Odobenus rosmarus divergens) reproductive biology. To address this, we initiated a program in which detailed biological data were recorded on captive walrus. As part of a 7-year study, 1 male and 1 female 16-year-old captive Pacific walrus were carefully monitored with weekly serum hormone analysis, daily glans penis smears for spermatozoa, and abdominal ultrasound for pregnancy. The female ovulated once annually from late December through mid-January and then exhibited 9 months of sustained elevated progesterone. This nonconceptive estrous cycle profile is consistent with reports from wild walrus females. In contrast, the male's seasonal rut routinely occurred in late February through May with a serum testosterone peak in March. This profile differed from the reported adult male cycle in wild walrus of November through March. During the period of the female's ovulation, the male had nadir testosterone levels and was consistently azoospermic. Likewise, during the male's spermatogenic rut in the spring, the female was anovulatory with elevated progesterone. On this basis, the male was treated for 14 weeks with human chorionic gonadotropin (hCG) in an attempt to increase testosterone levels in synchrony with the female's annual ovulation. The treatment successfully induced rut characterized by sustained elevated serum testosterone levels and production of spermatozoa. The male and female successfully bred, and the female became pregnant. Upon discontinuation of hCG treatment, the male resumed baseline testosterone levels. We theorize that the lack of synchronization of rut and ovulatory cycles is a primary reason for reproductive failure in these captive walrus. PMID:22207706

  20. The Wageningen Lowland Runoff Simulator (WALRUS): a Novel Open Source Rainfall-Runoff Model for Areas with Shallow Groundwater

    NASA Astrophysics Data System (ADS)

    Brauer, C.; Teuling, R.; Torfs, P.; Uijlenhoet, R.

    2014-12-01

    Recently, we developed the Wageningen Lowland Runoff Simulator (WALRUS) to fill the gap between complex, spatially distributed models which are often used in lowland regions and simple, parametric models which have mostly been developed for mountainous catchments. This parametric rainfall-runoff model can be used all over the world, both in freely draining lowland catchments and polders with controlled water levels. Here, we present the model implementation and our recent experience in training students and practitioners to use the model. WALRUS has several advantages that facilitate practical application. Firstly, WALRUS is computationally efficient, which allows for operational forecasting and uncertainty estimation by running ensembles. Secondly, the code is set-up such that it can be used by both practitioners and researchers. For direct use by practitioners, defaults are implemented for relations between model variables and for the computation of initial conditions based on discharge only, leaving only four parameters which require calibration. For research purposes, the defaults can easily be changed. Finally, an approach for flexible time steps increases numerical stability and makes model parameter values independent of time step size, which facilitates use of the model with the same parameter set for multi-year water balance studies as well as detailed analyses of individual flood peaks. The open source model code is currently implemented in R and compiled into a package. This package will be made available through the R CRAN server. A small massive open online course (MOOC) is being developed to give students, researchers and practitioners a step-by-step WALRUS-training. This course contains explanations about model elements and its advantages and limitations, as well as hands-on exercises to learn how to use WALRUS. All code, course, literature and examples will be collected on a dedicated website, which can be found via www

  1. Presentation and prognostic indicators for free-living black cockatoos (Calyptorhynchus spp.) admitted to an Australian zoo veterinary hospital over 10 years.

    PubMed

    Le Souëf, Anna; Holyoake, Carly; Vitali, Simone; Warren, Kristin

    2015-04-01

    The veterinary records of three species of free-living, endangered black cockatoos (Calyptorhynchus spp.; n = 565) admitted to the Perth Zoo Veterinary Hospital in Western Australia during a 10-yr period (2000-09) were analyzed to determine the effect of clinical presentation and treatment on survival to release. The most-common reason for admission was trauma (at least 76.7% of cases), and trauma was also the most-frequent finding on necropsy examination (80.1% of cases). Anemia and paralysis-paresis were significant factors determining the decreased likelihood of survival of cockatoos undergoing rehabilitation. Human activities, in particular vehicle strike, were significant causes of morbidity and mortality in free-living black cockatoo populations. PMID:25647589

  2. Dermatophytosis caused by Microsporum canis and Microsporum gypseum in free-living Bradypus variegatus (Schiz, 1825) in the state of Pernambuco, Brazil.

    PubMed

    Xavier, Gileno Antônio Araújo; da Silva, Leonildo Bento Galiza; da Silva, Davi Rubem; de Moraes Peixoto, Rodolfo; Lino, Gileno Câmara; Mota, Rinaldo Aparecido

    2008-07-01

    Three cases of dermatophytosis in free living brown-throated three-toed sloths (Bradypus variegatus) in the Zona da Mata, North of Pernambuco State, Brazil, were studied. Two animals presented areas of alopecia on the pelvic member and thorax and one animal on the pelvic member only. The three animals presented scabs. Hair and scabs samples were submitted to microscopical examination after treatment with a 30 % KOH and cultivated in Mycosel Agar. The direct examination indicated the presence of arthrospores in the hair. Colonies grown after seven days of culture were confirmed as Microsporum based on examination of the structure of the macroconidia. This is the first observation of dermatophytosis caused by Microsporum canis and Microsporum gypseum in free living sloths in the State of Pernambuco. PMID:24031255

  3. Measuring free-living physical activity in COPD patients: Deriving methodology standards for clinical trials through a review of research studies.

    PubMed

    Byrom, Bill; Rowe, David A

    2016-03-01

    This article presents a review of the research literature to identify the methodology used and outcome measures derived in the use of accelerometers to measure free-living activity in patients with COPD. Using this and existing empirical validity evidence we further identify standards for use, and recommended clinical outcome measures from continuous accelerometer data to describe pertinent measures of sedentary behaviour and physical activity in this and similar patient populations. We provide measures of the strength of evidence to support our recommendations and identify areas requiring continued research. Our findings support the use of accelerometry in clinical trials to understand and measure treatment-related changes in free-living physical activity and sedentary behaviour in patient populations with limited activity. PMID:26806669

  4. Contrasting genomic properties of free-living and particle-attached microbial assemblages within a coastal ecosystem

    PubMed Central

    Smith, Maria W.; Zeigler Allen, Lisa; Allen, Andrew E.; Herfort, Lydie; Simon, Holly M.

    2013-01-01

    The Columbia River (CR) is a powerful economic and environmental driver in the US Pacific Northwest. Microbial communities in the water column were analyzed from four diverse habitats: (1) an estuarine turbidity maximum (ETM), (2) a chlorophyll maximum of the river plume, (3) an upwelling-associated hypoxic zone, and (4) the deep ocean bottom. Three size fractions, 0.1–0.8, 0.8–3, and 3–200 μm were collected for each habitat in August 2007, and used for DNA isolation and 454 sequencing, resulting in 12 metagenomes of >5 million reads (>1.6 Gbp). To characterize the dominant microorganisms and metabolisms contributing to coastal biogeochemistry, we used predicted peptide and rRNA data. The 3- and 0.8-μm metagenomes, representing particulate fractions, were taxonomically diverse across habitats. The 3-μm size fractions contained a high abundance of eukaryota with diatoms dominating the hypoxic water and plume, while cryptophytes were more abundant in the ETM. The 0.1-μm metagenomes represented mainly free-living bacteria and archaea. The most abundant archaeal hits were observed in the deep ocean and hypoxic water (19% of prokaryotic peptides in the 0.1-μm metagenomes), and were homologous to Nitrosopumilus maritimus (ammonia-oxidizing Thaumarchaeota). Bacteria dominated metagenomes of all samples. In the euphotic zone (estuary, plume and hypoxic ocean), the most abundant bacterial taxa (≥40% of prokaryotic peptides) represented aerobic photoheterotrophs. In contrast, the low-oxygen, deep water metagenome was enriched with sequences for strict and facultative anaerobes. Interestingly, many of the same anaerobic bacterial families were enriched in the 3-μm size fraction of the ETM (2–10X more abundant relative to the 0.1-μm metagenome), indicating possible formation of anoxic microniches within particles. Results from this study provide a metagenome perspective on ecosystem-scale metabolism in an upwelling-influenced river-dominated coastal margin

  5. Gastrointestinal parasites of free-living Indo-Pacific bottlenose dolphins (Tursiops aduncus) in the Northern Red Sea, Egypt.

    PubMed

    Kleinertz, S; Hermosilla, C; Ziltener, A; Kreicker, S; Hirzmann, J; Abdel-Ghaffar, F; Taubert, A

    2014-04-01

    The present study represents the first report on the gastrointestinal parasite fauna infecting the free-living and alive Indo-Pacific bottlenose dolphins (Tursiops aduncus) inhabiting waters of the Red Sea at Hurghada, Egypt. A total of 94 individual faecal samples of the examined bottlenose dolphins were collected during several diving expeditions within their natural habitats. Using classical parasitological techniques, such as sodium acetate acetic acid formalin method, carbol fuchsin-stained faecal smears, coproantigen ELISA, PCR and macroscopical analyses, the study revealed infections with 21 different parasite species belonging to protozoans and metazoans with some of them bearing zoonotic and/or pathogenic potential. Four identified parasite species are potential zoonotic species (Giardia spp., Cryptosporidium spp., Diphyllobothrium spp., Ascaridida indet.); three of them are known to have high pathogenic potential for the examined dolphin species (Nasitrema attenuata, Zalophotrema spp. and Pholeter gastrophilus) and some appear to be directly associated with stranding events. In detail, the study indicates stages of ten protozoan species (Giardia spp., Sarcocystis spp., Isospora (like) spp., Cystoisospora (like) spp., Ciliata indet. I and II, Holotricha indet., Dinoflagellata indet., Hexamita (like) spp., Cryptosporidium spp.), seven trematode species (N. attenuata, Nasitrema spp. I and II, Zalophotrema curilensis, Zalophotrema spp., Pholeter gastrophilus, Trematoda indet.), one cestode species (Diphyllobothrium spp.), two nematode species (Ascaridida indet, Capillaria spp.) and one crustacean parasite (Cymothoidae indet.). Additionally, we molecularly identified adult worms of Anisakis typica in individual dolphin vomitus samples by molecular analyses. A. typica is a common parasite of various dolphin species of warmer temperate and tropical waters and has not been attributed as food-borne parasitic zoonoses so far. Overall, these parasitological findings

  6. Effect of elevated CO2 on the dynamics of particle attached and free living bacterioplankton communities in an Arctic fjord

    NASA Astrophysics Data System (ADS)

    Sperling, M.; Piontek, J.; Gerdts, G.; Wichels, A.; Schunck, H.; Roy, A.-S.; La Roche, J.; Gilbert, J.; Bittner, L.; Romac, S.; Riebesell, U.; Engel, A.

    2012-08-01

    The increase in atmospheric carbon dioxide (CO2) results in acidification of the oceans, expected to lead to the fastest drop in ocean pH in the last 300 million years, if anthropogenic emissions are continued at present rate. Due to higher solubility of gases in cold waters and increased exposure to the atmosphere by decreasing ice cover, the Arctic Ocean will be among the areas most strongly affected by ocean acidification. Yet, the response of the plankton community of high latitudes to ocean acidification has not been studied so far. This work is part of the Arctic campaign of the European Project on Ocean Acidification (EPOCA) in 2010, employing 9 in situ mesocosms of about 45 000 l each to simulate ocean acidification in Kongsfjorden, Svalbard (78°56.2' N 11°53.6' E). In the present study, we investigated effects of elevated CO2 on the composition and richness of particle attached (PA; >3 μm) and free living (FL; <3 μm >0.2 μm) bacterial communities by Automated Ribosomal Intergenic Spacer Analysis (ARISA) in 6 of the mesocosms and the surrounding fjord, ranging from 185 to 1050 initial μatm pCO2. ARISA was able to resolve about 20-30 bacterial band-classes per sample and allowed for a detailed investigation of the explicit richness. Both, the PA and the FL bacterioplankton community exhibited a strong temporal development, which was driven mainly by temperature and phytoplankton development. In response to the breakdown of a picophytoplankton bloom (phase 3 of the experiment), number of ARISA-band classes in the PA-community were reduced at low and medium CO2 (∼180-600 μatm) by about 25%, while it was more or less stable at high CO2 (∼ 650-800 μatm). We hypothesise that enhanced viral lysis and enhanced availability of organic substrates at high CO2 resulted in a more diverse PA-bacterial community in the post-bloom phase. Despite lower cell numbers and extracellular enzyme activities in the post-bloom phase, bacterial protein production was

  7. Metagenomic profiles of free-living archaea, bacteria and small eukaryotes in coastal areas of Sichang island, Thailand

    PubMed Central

    2012-01-01

    useful biotechnology gas and enzymes that could also function in high-saline and high-temperature conditions. Tham Phang contained less abundant archaea, bacteria and fungi, and the majority of the extracted metagenomes belonged to animal kingdom. Many microorganisms in Tham Phang were essential for nutrient-recycling and pharmaceuticals, for instances, Streptomyces, Pennicilium and Saccharomyces. Together, the study provided metagenomic profiles of free-living prokaryotes and eukaryotes in coastal areas of Sichang island. PMID:23282134

  8. Contrasting genomic properties of free-living and particle-attached microbial assemblages within a coastal ecosystem.

    PubMed

    Smith, Maria W; Zeigler Allen, Lisa; Allen, Andrew E; Herfort, Lydie; Simon, Holly M

    2013-01-01

    The Columbia River (CR) is a powerful economic and environmental driver in the US Pacific Northwest. Microbial communities in the water column were analyzed from four diverse habitats: (1) an estuarine turbidity maximum (ETM), (2) a chlorophyll maximum of the river plume, (3) an upwelling-associated hypoxic zone, and (4) the deep ocean bottom. Three size fractions, 0.1-0.8, 0.8-3, and 3-200 μm were collected for each habitat in August 2007, and used for DNA isolation and 454 sequencing, resulting in 12 metagenomes of >5 million reads (>1.6 Gbp). To characterize the dominant microorganisms and metabolisms contributing to coastal biogeochemistry, we used predicted peptide and rRNA data. The 3- and 0.8-μm metagenomes, representing particulate fractions, were taxonomically diverse across habitats. The 3-μm size fractions contained a high abundance of eukaryota with diatoms dominating the hypoxic water and plume, while cryptophytes were more abundant in the ETM. The 0.1-μm metagenomes represented mainly free-living bacteria and archaea. The most abundant archaeal hits were observed in the deep ocean and hypoxic water (19% of prokaryotic peptides in the 0.1-μm metagenomes), and were homologous to Nitrosopumilus maritimus (ammonia-oxidizing Thaumarchaeota). Bacteria dominated metagenomes of all samples. In the euphotic zone (estuary, plume and hypoxic ocean), the most abundant bacterial taxa (≥40% of prokaryotic peptides) represented aerobic photoheterotrophs. In contrast, the low-oxygen, deep water metagenome was enriched with sequences for strict and facultative anaerobes. Interestingly, many of the same anaerobic bacterial families were enriched in the 3-μm size fraction of the ETM (2-10X more abundant relative to the 0.1-μm metagenome), indicating possible formation of anoxic microniches within particles. Results from this study provide a metagenome perspective on ecosystem-scale metabolism in an upwelling-influenced river-dominated coastal margin. PMID

  9. Genome Sequence of the Fleming Strain of Micrococcus luteus, a Simple Free-Living Actinobacterium▿ †‡

    PubMed Central

    Young, Michael; Artsatbanov, Vladislav; Beller, Harry R.; Chandra, Govind; Chater, Keith F.; Dover, Lynn G.; Goh, Ee-Been; Kahan, Tamar; Kaprelyants, Arseny S.; Kyrpides, Nikos; Lapidus, Alla; Lowry, Stephen R.; Lykidis, Athanasios; Mahillon, Jacques; Markowitz, Victor; Mavromatis, Konstantinos; Mukamolova, Galina V.; Oren, Aharon; Rokem, J. Stefan; Smith, Margaret C. M.; Young, Danielle I.; Greenblatt, Charles L.

    2010-01-01

    Micrococcus luteus (NCTC2665, “Fleming strain”) has one of the smallest genomes of free-living actinobacteria sequenced to date, comprising a single circular chromosome of 2,501,097 bp (G+C content, 73%) predicted to encode 2,403 proteins. The genome shows extensive synteny with that of the closely related organism, Kocuria rhizophila, from which it was taxonomically separated relatively recently. Despite its small size, the genome harbors 73 insertion sequence (IS) elements, almost all of which are closely related to elements found in other actinobacteria. An IS element is inserted into the rrs gene of one of only two rrn operons found in M. luteus. The genome encodes only four sigma factors and 14 response regulators, a finding indicative of adaptation to a rather strict ecological niche (mammalian skin). The high sensitivity of M. luteus to β-lactam antibiotics may result from the presence of a reduced set of penicillin-binding proteins and the absence of a wblC gene, which plays an important role in the antibiotic resistance in other actinobacteria. Consistent with the restricted range of compounds it can use as a sole source of carbon for energy and growth, M. luteus has a minimal complement of genes concerned with carbohydrate transport and metabolism and its inability to utilize glucose as a sole carbon source may be due to the apparent absence of a gene encoding glucokinase. Uniquely among characterized bacteria, M. luteus appears to be able to metabolize glycogen only via trehalose and to make trehalose only via glycogen. It has very few genes associated with secondary metabolism. In contrast to most other actinobacteria, M. luteus encodes only one resuscitation-promoting factor (Rpf) required for emergence from dormancy, and its complement of other dormancy-related proteins is also much reduced. M. luteus is capable of long-chain alkene biosynthesis, which is of interest for advanced biofuel production; a three-gene cluster essential for this

  10. Kinetics of capture and infection of infective larvae of trichostrongylides and free-living nematodes Panagrellus sp. by Duddingtonia flagrans.

    PubMed

    da Cruz, Daniela Guedes; Araújo, Flávia Biasoli; Molento, Marcelo Beltrão; Damatta, Renato Augusto; de Paula Santos, Clóvis

    2011-10-01

    Duddingtonia flagrans, a nematode-trapping fungus, has been investigated as an agent for biological control against infective larvae of gastrointestinal nematode parasites of production animals. The initial process of nematode-trapping fungi infection is based on an interaction between the trap structure of the fungus and the surface of the nematode cuticle. This report investigates by light and scanning electron microscopy the kinetics of capture and infection during the interaction of D. flagrans with the infective larvae (L(3)) of trichostrongylides and the free-living nematode Panagrellus sp. D. flagrans was cultivated for 7 days in a Petri dish containing agar-water. L(3) and Panagrellus sp. were inoculated in the Petri dishes and the samples consisting of agar-L(3)-fungi and agar-Panagrellus sp.-fungi were collected after 10, 20, 30, 40, 50, 60, and 70 min and 3, 4, 5, 10, 15, 20, and 25 h of interaction. All samples were observed by light microscopy. The samples with 1, 5, 15, and 25 h of interaction were also analyzed by scanning electron microscopy. The interaction was monitored up to 25 h. An initial differentiation of predation structures was observed after 30 min of interaction. The presence of traps and of captured L(3) or Panagrellus sp. occurred after 70 min. The live captured nematodes were observed up to 3 h of interaction. However, after 4 h, all Panagrellus sp. were dead. It took 15 h of interaction for the fungus to invade the L(3), and the presence of hyphae inside the nematode near the region of penetration was evident. At this time, the hyphae had filled the whole body of Panagrellus sp. The complete occupation of the body of L(3) occurred at 20 h of interaction and with 25 h the nematode was completely damaged except for the cuticle. Although the double cuticle of L(3) slows the penetration of D. flagrans, it was possible to verify that the process of trap formation and capture occurs quickly when both nematodes were tested, suggesting that

  11. Occurrence and molecular characterization of free-living amoeba species (Acanthamoeba, Hartmannella, and Saccamoeba limax) in various surface water resources of Iran.

    PubMed

    Mahmoudi, Mohammad Reza; Rahmati, Behnaz; Seyedpour, Seyed Hosssen; Karanis, Panagiotis

    2015-12-01

    This study was conducted to determine the presence and molecular identity of Acanthamoeba species in the surface water resources of four provinces in Iran, namely Guilan, Mazandaran (North of Iran), Alborz, and Tehran (capital city), using culture- and molecular-based methods. During March to November 2014, 49 surface water samples were collected from environmental water sources-the distinct surface waters of Guilan, Mazandaran, Alborz, and Tehran provinces, in Iran. For the isolation of Acanthamoeba species, approximately 500 ml of the water samples were filtered through a cellulose nitrate membrane with a pore size of 0.45 μ. The filter was transferred onto non-nutrient agar plates seeded with Gram-negative bacteria (Escherichia coli) as a food source. The presence of Acanthamoeba was confirmed by the genus-specific primer pair JDP1 and 2, and/or NA primers were used to identify Acanthamoeba and certain other free-living amoebae. In total, 38 out of 49 samples were positive by culture and/or PCR for Acanthamoeba and other free-living amoebae from all three provinces. By sequencing the positive isolates, the strains were shown to belong to Acanthamoeba (16 isolates belonged to T4 and 2 isolates belonged to T5), Hartmannella vermiformis (3/24), and Saccamoeba limax (2/24). The T4 and T5 genotypes were detected in Guilan and Mazandaran provinces. Two isolates from Guilan and Tehran provinces belonged to S. limax, and H. vermiformis was detected in Guilan province. The results of this study highlight the need to pay more attention to free-living amoebae, as human activity was observed in all of the localities from which these samples were taken. These surface waters can be potential sources for the distribution and transmission of pathogenic Acanthamoeba in the study areas, and free-living amoebas (FLA) (particularly the Acanthamoeba species) can serve as hosts for and vehicles of various microorganisms. PMID:26346454

  12. Effect of abandonment on diversity and abundance of free-living nitrogen-fixing bacteria and total bacteria in the cropland soils of Hulun Buir, Inner Mongolia.

    PubMed

    Huhe; Borjigin, Shinchilelt; Cheng, Yunxiang; Nomura, Nobukiko; Nakajima, Toshiaki; Nakamura, Toru; Uchiyama, Hiroo

    2014-01-01

    In Inner Mongolia, steppe grasslands face desertification or degradation because of human over activity. One of the reasons for this condition is that croplands have been abandoned after inappropriate agricultural management. The soils in these croplands present heterogeneous environments in which conditions affecting microbial growth and diversity fluctuate widely in space and time. In this study, we assessed the molecular ecology of total and free-living nitrogen-fixing bacterial communities in soils from steppe grasslands and croplands that were abandoned for different periods (1, 5, and 25 years) and compared the degree of recovery. The abandoned croplands included in the study were natural restoration areas without human activity. Denaturing gradient gel electrophoresis and quantitative PCR (qPCR) were used to analyze the nifH and 16S rRNA genes to study free-living diazotrophs and the total bacterial community, respectively. The diversities of free-living nitrogen fixers and total bacteria were significantly different between each site (P<0.001). Neither the total bacteria nor nifH gene community structure of a cropland abandoned for 25 years was significantly different from those of steppe grasslands. In contrast, results of qPCR analysis of free-living nitrogen fixers and total bacteria showed significantly high abundance levels in steppe grassland (P<0.01 and P<0.03, respectively). In this study, the microbial communities and their gene abundances were assessed in croplands that had been abandoned for different periods. An understanding of how environmental factors and changes in microbial communities affect abandoned croplands could aid in appropriate soil management to optimize the structures of soil microorganisms. PMID:25268844

  13. The Majority of Free-Living Autotrophic Bacteria use the Reductive TCA Cycle for Carbon Fixation at Deep-Sea Hydrothermal Vents

    NASA Astrophysics Data System (ADS)

    Campbell, B. J.; Cary, C.

    2003-12-01

    Deep-sea hydrothermal vents support large micro and macroscopic communities, without the input of photosynthesis. Autotrophic production at these vents is based on hydrothermal vent fluid chemistry. Primary production has been thought to occur mainly via hydrogen sulfide oxidation through the Calvin-Benson pathway, as measured by the presence of Rubisco in endosymbionts of several invertebrate hosts. Recently, we characterized two fosmids from a large insert library of the epsilon Proteobacterial episymbionts of Alvinella pompejana. Both contained sequences encoding ATP citrate lyase, a key enzyme in the reverse TCA cycle, an alternate carbon dioxide fixation pathway. Previous investigators have demonstrated the dominance of the epsilon subdivision in the free-living bacterial communities at hydrothermal vents. Based on these results, our working hypothesis is: The rTCA cycle is the dominant pathway for carbon fixation in the free-living bacterial communities at hydrothermal vents. A selection of free-living bacterial communities from various geographic locations (9N, East Pacific Rise and Guaymas Basin) were screened for the presence, diversity and expression (via RT-PCR) of Rubisco (forms I and II) and ATP citrate lyase. Our results indicate that the ATP citrate lyase gene is diverse and is consistently expressed in several types of vent communities. The two forms of Rubisco are not consistently present or expressed in the same environments. These results indicate that chemoautotrophic production in the free-living bacterial communities at deep-sea hydrothermal vents is dominated by bacteria that utilize the rTCA cycle, and parallels the phylogenetic dominance of members of the epsilon subdivision of Proteobacteria.

  14. Shelters of leaf-tying herbivores decompose faster than leaves damaged by free-living insects: Implications for nutrient turnover in polluted habitats.

    PubMed

    Kozlov, Mikhail V; Zverev, Vitali; Zvereva, Elena L

    2016-10-15

    Leaf-eating insects can influence decomposition processes by modifying quality of leaf litter, and this impact can be especially pronounced in habitats where leaf-eating insects reach high densities, for example in heavily polluted areas. We hypothesized that the decomposition rate is faster for shelters of leaf-tying larvae than for leaves damaged by free-living insects, in particular due to the accumulation of larval frass within shelters. We exposed litter bags containing samples of three different compositions (shelters built by moth larvae, leaves damaged by free-living insects and intact leaves of mountain birch, Betula pubescens ssp. czerepanovii) for one year at two heavily polluted sites near the nickel-copper smelter at Monchegorsk in north-western Russia and at two unpolluted sites. The decomposition rate of leaves damaged by free-living insects was 91% of that of undamaged leaves, whereas the mass loss of leaves composing shelters did not differ of that of undamaged leaves. These differences between leaves damaged by different guilds of herbivorous insects were uniform across the study sites, although the decomposition rate in polluted sites was reduced to 77% of that in unpolluted sites. Addition of larval frass to undamaged leaves had no effect on the subsequent decomposition rate. Therefore we suggest that damaged leaves tied by shelter-building larvae decompose faster than untied damaged leaves due to a looser physical structure of the litter, which creates favourable conditions for detritivores and soil decomposers. Thus, while leaf damage by insects per se reduces litter quality and its decomposition rate, structuring of litter by leaf-tying insects counterbalances these negative effects. We conclude that leaf-tying larvae, in contrast to free-living defoliators, do not impose negative effects on nutrient turnover rate even at their high densities, which are frequently observed in heavily polluted sites. PMID:27288287

  15. Effect of Abandonment on Diversity and Abundance of Free-Living Nitrogen-Fixing Bacteria and Total Bacteria in the Cropland Soils of Hulun Buir, Inner Mongolia

    PubMed Central

    Huhe; Borjigin, Shinchilelt; Cheng, Yunxiang; Nomura, Nobukiko; Nakajima, Toshiaki; Nakamura, Toru; Uchiyama, Hiroo

    2014-01-01

    In Inner Mongolia, steppe grasslands face desertification or degradation because of human over activity. One of the reasons for this condition is that croplands have been abandoned after inappropriate agricultural management. The soils in these croplands present heterogeneous environments in which conditions affecting microbial growth and diversity fluctuate widely in space and time. In this study, we assessed the molecular ecology of total and free-living nitrogen-fixing bacterial communities in soils from steppe grasslands and croplands that were abandoned for different periods (1, 5, and 25 years) and compared the degree of recovery. The abandoned croplands included in the study were natural restoration areas without human activity. Denaturing gradient gel electrophoresis and quantitative PCR (qPCR) were used to analyze the nifH and 16S rRNA genes to study free-living diazotrophs and the total bacterial community, respectively. The diversities of free-living nitrogen fixers and total bacteria were significantly different between each site (P<0.001). Neither the total bacteria nor nifH gene community structure of a cropland abandoned for 25 years was significantly different from those of steppe grasslands. In contrast, results of qPCR analysis of free-living nitrogen fixers and total bacteria showed significantly high abundance levels in steppe grassland (P<0.01 and P<0.03, respectively). In this study, the microbial communities and their gene abundances were assessed in croplands that had been abandoned for different periods. An understanding of how environmental factors and changes in microbial communities affect abandoned croplands could aid in appropriate soil management to optimize the structures of soil microorganisms. PMID:25268844

  16. Examination of food reward and energy intake under laboratory and free-living conditions in a trait binge eating subtype of obesity

    PubMed Central

    Dalton, Michelle; Blundell, John; Finlayson, Graham S.

    2013-01-01

    Background/Aims: Trait binge eating has been proposed as a “hedonic subtype” of obesity characterized by enhanced food liking and wanting, and a preference for high-fat sweet foods in the laboratory. The current study examined the influence of trait binge eating in overweight or obese women on eating behavior under laboratory and free-living conditions over a 48-h period. Methods: In a matched pairs design, 24 overweight or obese females (BMI: 30.30 ± 2.60 kg/m2; Age: 25.42 ± 3.65 years) with high or low scores on the Binge Eating Scale (BSE) were divided into one of two groups; Obese Binge (O-B) and Obese Non-binge (O-NB). Energy intake was assessed using combined laboratory energy intake measures and 24-h dietary recall procedures. Liking and wanting were assessed using the Leeds Food Preference Questionnaire (LFPQ). Results: There was a significant association between overall energy consumed, and energy consumed from snack foods under laboratory and free-living conditions. O-B exhibited a greater preference for sweet snack foods in their laboratory and free-living eating behavior. These findings were supported by greater laboratory-based measures of wanting and craving for this food type in O-B. In addition, O-B consumed significantly more energy than their estimated daily energy requirements in the laboratory suggesting that they over-consumed compared to O-NB. Conclusions: The measurement concordance between laboratory and free-living based energy intake supports the validity of laboratory-based test meal methodologies Variation in trait binge eating was associated with increased craving and wanting for high-fat sweet foods and overconsumption in the laboratory. These findings support the use of trait binge eating as a common hedonic subtype of obesity and extend the relevance of this subtype to habitual patterns of energy intake. PMID:24155732

  17. PCR detection and analysis of the free-living amoeba Naegleria in hot springs in Yellowstone and Grand Teton National Parks.

    PubMed

    Sheehan, Kathy B; Fagg, Jennifer A; Ferris, Michael J; Henson, Joan M

    2003-10-01

    Free-living thermotolerant amoebae pose a significant health risk to people who soak and swim in habitats suitable for their growth, such as hot springs. In this survey of 23 different hot springs in Yellowstone and Grand Teton National Parks, we used PCR with primer sets specific for Naegleria to detect three sequence types that represent species not previously described, as well as a fourth sequence type identified as the pathogen Naegleria fowleri. PMID:14532044

  18. Comparative analysis of macrophage migration inhibitory factors (MIFs) from the parasitic nematode Onchocerca volvulus and the free-living nematode Caenorhabditis elegans.

    PubMed

    Ajonina-Ekoti, Irene; Kurosinski, Marc Andre; Younis, Abuelhassan Elshazly; Ndjonka, Dieudonne; Tanyi, Manchang Kingsley; Achukwi, Mbunkah; Eisenbarth, Albert; Ajonina, Caroline; Lüersen, Kai; Breloer, Minka; Brattig, Norbert W; Liebau, Eva

    2013-09-01

    The macrophage migration inhibitory factors (MIFs) from the filarial parasite Onchocerca volvulus (OvMIF) were compared to the MIFs from the free-living nematode Caenorhabditis elegans (CeMIF) with respect to molecular, biochemical and immunological properties. Except for CeMIF-4, all other MIFs demonstrated tautomerase activity. Surprisingly, OvMIF-1 displayed oxidoreductase activity. The strongest immunostaining for OvMIF-1 was observed in the outer cellular covering of the adult worm body, the syncytial hypodermis; moderate immunostaining was observed in the uterine wall. The generation of a strong humoral immune response towards OvMIF-1 and reduced reactivity to OvMIF-2 was indicated by high IgG levels in patients infected with O. volvulus and cows infected with the closely related Onchocerca ochengi, both MIFs revealing identical amino acid sequences. Using Litomosoides sigmodontis-infected mice, a laboratory model for filarial infection, MIFs derived from the tissue-dwelling O. volvulus, the rodent gut-dwelling Strongyloides ratti and from free-living C. elegans were recognized, suggesting that L. sigmodontis MIF-specific IgM and IgG1 were produced during L. sigmodontis infection of mice and cross-reacted with all MIF proteins tested. Thus, MIF apparently functions as a target of B cell response during nematode infection, but in the natural Onchocerca-specific human and bovine infection, the induced antibodies can discriminate between MIFs derived from parasitic or free-living nematodes. PMID:23820606

  19. Illumina sequencing-based analysis of free-living bacterial community dynamics during an Akashiwo sanguine bloom in Xiamen sea, China

    PubMed Central

    Yang, Caiyun; Li, Yi; Zhou, Benjamin; Zhou, Yanyan; Zheng, Wei; Tian, Yun; Van Nostrand, Joy D.; Wu, Liyou; He, Zhili; Zhou, Jizhong; Zheng, Tianling

    2015-01-01

    Although phytoplankton are the major source of marine dissolved organic matter (DOM), their blooms are a global problem that can greatly affect marine ecological systems, especially free-living bacteria, which are the primary DOM degraders. In this study, we analyzed free-living bacterial communities from Xiamen sea during an Akashiwo sanguine bloom using Illumina MiSeq sequencing of 16S rRNA gene amplicons. The bloom was probably stimulated by low salinity and ended after abatement of eutrophication pollution. A total of 658,446 sequence reads and 11,807 OTUs were obtained in both bloom and control samples with Alpha-proteobacteria and Gamma-proteobacteria being the predominant classes detected. The bloom decreased bacterial diversity, increased species evenness, and significantly changed the bacterial community structure. Bacterial communities within the bloom were more homogeneous than those within the control area. The bacteria stimulated by this bloom included the SAR86 and SAR116 clades and the AEGEAN-169 marine group, but a few were suppressed. In addition, many bacteria known to be associated with phytoplankton were detected only in the bloom samples. This study revealed the great influence of an A. sanguinea bloom on free-living bacterial communities, and provided new insights into the relationship between bacteria and A. sanguinea in marine ecosystems. PMID:25684124

  20. Cloacal aerobic bacterial flora and absence of viruses in free-living slow worms (Anguis fragilis), grass snakes (Natrix natrix) and European Adders (Vipera berus) from Germany.

    PubMed

    Schmidt, Volker; Mock, Ronja; Burgkhardt, Eileen; Junghanns, Anja; Ortlieb, Falk; Szabo, Istvan; Marschang, Rachel; Blindow, Irmgard; Krautwald-Junghanns, Maria-Elisabeth

    2014-12-01

    Disease problems caused by viral or bacterial pathogens are common in reptiles kept in captivity. There is no information available on the incidence of viral pathogens or the physiological cloacal bacterial flora of common free-living reptiles in Germany. Therefore, 56 free-living reptiles including 23 European adders (Vipera berus), 12 grass snakes (Natrix natrix) and 21 slow worms (Anguis fragilis) were investigated on the island Hiddensee in northeastern Germany. Pharyngeal and cloacal swabs were taken immediately after capture. Bacteriological examination was performed from the cloacal swabs to study the aerobic cloacal flora. Molecular biological examination included amplification of DNA or RNA from adeno-, rana- and ferlaviruses as well as culturing on Russell's viper heart cells for virus isolation. Salmonella spp. were isolated from European adders but not from the other reptiles examined. The minimal inhibitory concentration was determined from the isolated Salmonella spp. However, some potentially human pathogenic bacteria, such as Proteus vulgaris, Aeromonas hydrophila, Klebsiella pneumoniae and Escherichia coli were isolated. Viruses were not detected in any of the examined reptiles. To the authors' best knowledge, the present study is the first survey of viral pathogens in free-living snakes and slow worms in Germany and the first survey of cloacal aerobic bacterial flora of slow worms. PMID:24866333

  1. Potential population-level effects of increased haulout-related mortality of Pacific walrus calves

    USGS Publications Warehouse

    Udevitz, Mark S.; Taylor, Rebecca L.; Garlich-Miller, Joel L.; Quakenbush, Lori T.; Snyder, Jonathan A.

    2013-01-01

    Availability of summer sea ice has been decreasing in the Chukchi Sea during recent decades, and increasing numbers of Pacific walruses have begun using coastal haulouts in late summer during years when sea ice retreats beyond the continental shelf. Calves and yearlings are particularly susceptible to being crushed during disturbance events that cause the herd to panic and stampede at these large haulouts, but the potential population-level effects of this mortality are unknown. We used recent harvest data, along with previous assumptions about demographic parameters for this population, to estimate female population size and structure in 2009 and project these numbers forward using a range of assumptions about future harvests and haulout-related mortality that might result from increased use of coastal haulouts during late summer. We found that if demographic parameters were held constant, the levels of harvest that occurred during 1990–2008 would have allowed the population to grow during that period. Our projections indicate, however, that an increase in haulout-related mortality affecting only calves has a greater effect on the population than an equivalent increase in harvest-related mortality distributed among all age classes. Therefore, disturbance-related mortality of calves at coastal haulouts may have relatively important population consequences.

  2. Observer variability in pinniped counts: Ground-based enumeration of walruses at haul-out sites

    USGS Publications Warehouse

    Udevitz, M.S.; Jay, C.V.; Cody, M.B.

    2005-01-01

    Pinnipeds are often monitored by counting individuals at haul-out sites, but the often large numbers of densely packed individuals at these sites are difficult to enumerate accurately. Errors in enumeration can induce bias and reduce precision in estimates of population size and trend. We used data from paired observers monitoring walrus haul-outs in Bristol Bay, Alaska, to quantify observer variability and assess its relative importance. The probability of a pair of observers making identical counts was 50 individuals. Mean count differences ranged up to 25% for the largest counts, depending on beach and observers. In at least some cases, there was a clear tendency for counts of one observer to be consistently greater than counts of the other observer in a pair, indicating that counts of at least one of the observers were biased. These results suggest that efforts to improve accuracy of counts will be worthwhile. However, we also found that variation among observers was relatively small compared to variation among visits to a beach so that efforts to account for other sources of variation will be more important.

  3. Azospirillum, a free-living nitrogen-fixing bacterium closely associated with grasses: genetic, biochemical and ecological aspects.

    PubMed

    Steenhoudt, O; Vanderleyden, J

    2000-10-01

    Azospirillum represents the best characterized genus of plant growth-promoting rhizobacteria. Other free-living diazotrophs repeatedly detected in association with plant roots, include Acetobacter diazotrophicus, Herbaspirillum seropedicae, Azoarcus spp. and Azotobacter. Four aspects of the Azospirillum-plant root interaction are highlighted: natural habitat, plant root interaction, nitrogen fixation and biosynthesis of plant growth hormones. Each of these aspects is dealt with in a comparative way. Azospirilla are predominantly surface-colonizing bacteria, whereas A. diazotrophicus, H. seropedicae and Azoarcus sp. are endophytic diazotrophs. The attachment of Azospirillum cells to plant roots occurs in two steps. The polar flagellum, of which the flagellin was shown to be a glycoprotein, mediates the adsorption step. An as yet unidentified surface polysaccharide is believed to be essential in the subsequent anchoring phase. In Azoarcus sp. the attachment process is mediated by type IV pili. Nitrogen fixation structural genes (nif) are highly conserved among all nitrogen-fixing bacteria, and in all diazotrophic species of the class of proteobacteria examined, the transcriptional activator NifA is required for expression of other nif genes in response to two major environmental signals (oxygen and fixed N). However, the mechanisms involved in this control can vary in different organisms. In Azospirillum brasilense and H. seropedicae (alpha- and beta-subgroup, respectively), NifA is inactive in conditions of excess nitrogen. Activation of NifA upon removal of fixed N seems to involve, either directly or indirectly, the signal transduction protein P(II). The presence of four conserved cysteine residues in the NifA protein might be an indication that NifA is directly sensitive to oxygen. In Azotobacter vinelandii (gamma-subgroup) nifA is cotranscribed with a second gene nifL. The nifL gene product inactivates NifA in response to high oxygen tension and cellular

  4. Isolation and identification of pathogenic free-living amoeba from surface and tap water of Shiraz City using morphological and molecular methods.

    PubMed

    Armand, B; Motazedian, M H; Asgari, Q

    2016-01-01

    Free-living amoebae (FLA) are the most abundant and widely distributed protozoa in the environment. An investigation was conducted to determine the presence of free-living amoebae (FLA), Acanthamoeba and Vermamoeba in waterfronts of parks and squares and tap water of Shiraz City, Iran. FLA are considered pathogenic for human. These ubiquitous organisms have been isolated from different environments such as water, soil, and air. Eighty-two water samples were collected from different places of Shiraz City during the summer of 2013. All samples were processed in Dept. of Parasitology and Mycology, Shiraz University of Medical Sciences, Fars, Iran. Samples were screened for FLA and identified by morphological characters in the cultures, PCR amplification targeting specific genes for each genus and sequencing determined frequent species and genotypes base on NCBI database. Overall, 48 samples were positive for Acanthamoeba and Vermamoeba in non-nutrient agar culture based on morphological characteristics. The PCR examination was done successfully. Sequencing results were revealed T4 (62.96 %) genotypes as the most common genotype of Acanthamoeba in the Shiraz water sources. In addition, T5 (33.33 %) and T15 (3.71 %) were isolated from water supplies. Vermamoeba vermiformis was known the dominant species from this genus. The high frequency of Acanthamoeba spp. and Vermamoeba in different environmental water sources of Shiraz is an alert for the public health related to water sources. The result highlights a need for taking more attention to water supplies in order to prevent illnesses related to free-living amoebae. PMID:26412057

  5. The adaptive evolution divergence of triosephosphate isomerases between parasitic and free-living flatworms and the discovery of a potential universal target against flatworm parasites.

    PubMed

    Chen, Bing; Wen, Jian-Fan

    2011-08-01

    Triosephosphate isomerase (TIM) is an important drug target or vaccine candidate for pathogenetic organisms such as schistosomes. Parasitic and free-living flatworms shared their last common ancestor but diverged from each other for adapting to parasitic and free-living lives afterwards, respectively. Therefore, adaptive evolution divergence must have occurred between them. Here, for the first time, TIMs were identified from three free-living planarian flatworms, namely Dugesia japonica, Dugesia ryukyuensis, and Schmidtea mediterranea. When these were compared with parasitic flatworms and other organisms, the following results were obtained: (1) planarian TIM genes each contain only one intron, while parasitic flatworm genes each contain other four introns, which are usually present in common metazoans, suggesting planarian-specific intron loss must have occurred; (2) planarian TIM protein sequences are more similar to those of vertebrates rather than to their parasitic relatives or other invertebrates. This implies that relatively rapid evolution occurred in parasitic flatworm TIMs; (3) All the investigated parasitic flatworm TIMs contain a unique tripeptide insert (SXD/E), which may imply its insertion importance to the adaptation of parasitic life. Moreover, our homology modeling results showed the insert region was largely surface-exposed and predicted to be of a B cell epitope location. Finally, the insert is located within one of the three regions previously suggested to be promising immunogenic epitopes in Schistosoma mansoni TIM. Therefore, this unique insert might be significant to developing new effective vaccines or specific drugs against all parasitic flatworm diseases such as schistosomiasis and taeniosis/cysticercosis. PMID:21246382

  6. Free-Living Protozoa in Two Unchlorinated Drinking Water Supplies, Identified by Phylogenic Analysis of 18S rRNA Gene Sequences▿ †

    PubMed Central

    Valster, Rinske M.; Wullings, Bart A.; Bakker, Geo; Smidt, Hauke; van der Kooij, Dick

    2009-01-01

    Free-living protozoan communities in water supplies may include hosts for Legionella pneumophila and other undesired bacteria, as well as pathogens. This study aimed at identifying free-living protozoa in two unchlorinated groundwater supplies, using cultivation-independent molecular approaches. For this purpose, samples (<20°C) of treated water, distributed water, and distribution system biofilms were collected from supply A, with a low concentration of natural organic matter (NOM) (<0.5 ppm of C), and from supply B, with a high NOM concentration (7.9 ppm of C). Eukaryotic communities were studied using terminal restriction fragment length polymorphism and clone library analyses of partial 18S rRNA gene fragments and a Hartmannella vermiformis-specific quantitative PCR (qPCR). In both supplies, highly diverse eukaryotic communities were observed, including free-living protozoa, fungi, and metazoa. Sequences of protozoa clustered with Amoebozoa (10 operational taxonomic units [OTUs]), Cercozoa (39 OTUs), Choanozoa (26 OTUs), Ciliophora (29 OTUs), Euglenozoa (13 OTUs), Myzozoa (5 OTUs), and Stramenopiles (5 OTUs). A large variety of protozoa were present in both supplies, but the estimated values for protozoan richness did not differ significantly. H. vermiformis was observed in both supplies but was not a predominant protozoan. One OTU with the highest similarity to Acanthamoeba polyphaga, an opportunistic human pathogen and a host for undesired bacteria, was observed in supply A. The high level of NOM in supply B corresponded with an elevated level of active biomass and with elevated concentrations of H. vermiformis in distributed water. Hence, the application of qPCR may be promising in elucidating the relationship between drinking water quality and the presence of specific protozoa. PMID:19465529

  7. Validation of Physical Activity Tracking via Android Smartphones Compared to ActiGraph Accelerometer: Laboratory-Based and Free-Living Validation Studies

    PubMed Central

    Buman, Matthew P; Grieco, Lauren; Rosenberger, Mary; Winter, Sandra J; Haskell, William; King, Abby C

    2015-01-01

    Background There is increasing interest in using smartphones as stand-alone physical activity monitors via their built-in accelerometers, but there is presently limited data on the validity of this approach. Objective The purpose of this work was to determine the validity and reliability of 3 Android smartphones for measuring physical activity among midlife and older adults. Methods A laboratory (study 1) and a free-living (study 2) protocol were conducted. In study 1, individuals engaged in prescribed activities including sedentary (eg, sitting), light (sweeping), moderate (eg, walking 3 mph on a treadmill), and vigorous (eg, jogging 5 mph on a treadmill) activity over a 2-hour period wearing both an ActiGraph and 3 Android smartphones (ie, HTC MyTouch, Google Nexus One, and Motorola Cliq). In the free-living study, individuals engaged in usual daily activities over 7 days while wearing an Android smartphone (Google Nexus One) and an ActiGraph. Results Study 1 included 15 participants (age: mean 55.5, SD 6.6 years; women: 56%, 8/15). Correlations between the ActiGraph and the 3 phones were strong to very strong (ρ=.77-.82). Further, after excluding bicycling and standing, cut-point derived classifications of activities yielded a high percentage of activities classified correctly according to intensity level (eg, 78%-91% by phone) that were similar to the ActiGraph’s percent correctly classified (ie, 91%). Study 2 included 23 participants (age: mean 57.0, SD 6.4 years; women: 74%, 17/23). Within the free-living context, results suggested a moderate correlation (ie, ρ=.59, P<.001) between the raw ActiGraph counts/minute and the phone’s raw counts/minute and a strong correlation on minutes of moderate-to-vigorous physical activity (MVPA; ie, ρ=.67, P<.001). Results from Bland-Altman plots suggested close mean absolute estimates of sedentary (mean difference=–26 min/day of sedentary behavior) and MVPA (mean difference=–1.3 min/day of MVPA) although there

  8. Enamel ultrastructure of fossil and modern pinnipeds: evaluating hypotheses of feeding adaptations in the extinct walrus Pelagiarctos

    NASA Astrophysics Data System (ADS)

    Loch, Carolina; Boessenecker, Robert W.; Churchill, Morgan; Kieser, Jules

    2016-06-01

    This study aimed to assess the enamel ultrastructure in modern otariid pinnipeds and in the extinct walrus Pelagiarctos. Teeth of the New Zealand fur seal ( Arctocephalus forsteri), sea lion ( Phocarctos hookeri), and fossil walrus Pelagiarctos thomasi were embedded, sectioned, etched, and analyzed via scanning electron microscopy. The enamel of NZ otariids and Pelagiarctos was prismatic and moderately thick, measuring 150-450 μm on average. It consisted of transversely oriented Hunter-Schreger bands (HSBs) from the enamel-dentine junction (EDJ) to near the outer surface, where it faded into prismless enamel less than 10 μm thick. The width of HSB was variable and averaged between 6 and 10 prisms, and they presented an undulating course both in longitudinal and cross sections. The overall organization of the enamel was similar in all teeth sampled; however, the enamel was thicker in canines and postcanines than in incisors. The crowns of all teeth sampled were uniformly covered by enamel; however, the grooved incisors lacked an enamel cover on the posterior side of the buccal face. Large tubules and tuft-like structures were seen at the EDJ. HSB enamel as well as tubules and tufts at the EDJ suggest increased occlusal loads during feeding, a biomechanical adaptation to avoid enamel cracking and failure. Despite overall simplification in tooth morphology and reduced mastication, the fossil and modern pinnipeds analyzed here retained the complex undulating HSB structure of other fossils and living Carnivora, while other marine mammals such as cetaceans developed simplified radial enamel.

  9. The influence of feeding, enrichment, and seasonal context on the behavior of Pacific Walruses (Odobenus rosmarus divergens).

    PubMed

    Franks, Becca; Lyn, Heidi; Klein, Lauren; Reiss, Diana

    2010-01-01

    Though some research exists concerning general behavior and activity patterns of Walruses in zoos or aquariums, less is known about how these patterns change in response to various environmental and temporal contexts. This study presents two studies assessing behavioral changes in relation to feeding period, object enrichment (OE), and season in a social group of four Pacific Walruses at the New York Aquarium. Study 1 examined behavior in relation to feeding context (nonfeed, prefeed, postfeed); data were collected over a three-week period, resulting in 47 observation sessions for each feeding context. Study 2 examined behavior in relation to OE and season; data were collected in two phases resulting in 12 enrichment and 9 no-enrichment (NE) observation sessions (Phase 1), and 21 enrichment and 18 NE observation sessions (Phase 2). Study 1 showed that after feeding, oral behavior increased while social behavior and total swim frequency decreased. In Study 2, both swim frequency and social behavior were found to interact with OE and phase, while oral behavior remained constant across all conditions. As in the wild, both studies found all animals to be swimming the majority of the time. Though every animal spent much of its swim time engaged in an Individual Swimming Pattern (ISP), both studies showed that the proportion of ISP (in relation to total time swimming) remained stable across all contexts, suggesting a potential functional role of the ISPs. These results are discussed in light of the ongoing debate over the role of stereotypies in welfare assessment. PMID:19722224

  10. Climatic influences on development and survival of free-living stages of equine strongyles: implications for worm control strategies and managing anthelmintic resistance.

    PubMed

    Nielsen, Martin K; Kaplan, Ray M; Thamsborg, Stig M; Monrad, Jesper; Olsen, Susanne N

    2007-07-01

    Development of resistance to anthelmintic drugs by horse strongyles constitutes a growing threat to equine health because it is unknown when new drug classes can be expected on the market. Consequently, parasite control strategies should attempt to maintain drug efficacy for as long as possible. The proportion of a parasite population that is not exposed to anthelmintic treatment is described as being "in refugia" and although many factors affect the rate at which resistance develops, levels of refugia are considered the most important as these parasites are not selected by treatment and so provide a pool of sensitive genes in the population. Accordingly, treatment should be avoided when pasture refugia are small because such treatments will place significant selection pressure for resistance on worm populations. Given this new paradigm for parasite control, it has become important to identify seasons and circumstances wherein refugia are diminished. Free-living stages of equine strongyles are highly dependent on climatic influences, and this review summarises studies of strongyle development and survival under laboratory and field conditions in Northern (cool) temperate, Southern (warm) temperate and subtropical/tropical climates. In Northern temperate climates, refugia are smallest during the winter. In contrast, refugia are lowest during the summer in warm temperate and subtropical/tropical climates. Although adverse seasonal changes clearly have significant effects on the ability of free living stages of strongyle nematode parasites to survive and develop, available data suggest that climatic influences cannot effectively "clean" pastures from one grazing season to the next. PMID:16815051

  11. How to spend the summer? Free-living dormice (Glis glis) can hibernate for 11 months in non-reproductive years.

    PubMed

    Hoelzl, Franz; Bieber, Claudia; Cornils, Jessica S; Gerritsmann, Hanno; Stalder, Gabrielle L; Walzer, Chris; Ruf, Thomas

    2015-12-01

    Edible dormice are arboreal rodents adapted to yearly fluctuations in seed production of European beech, a major food source for this species. In years of low beech seed abundance, dormice skip reproduction and non-reproductive dormice fed ad libitum in captivity can display summer dormancy in addition to winter hibernation. To test whether summer dormancy, that is, a very early onset of hibernation, actually occurs in free-living dormice, we monitored core body temperature (Tb) over ~12 months in 17 animals during a year of beech seeding failure in the Vienna Woods. We found that 8 out of 17 dormice indeed re-entered hibernation as early as in June/July, with five of them having extreme hibernation durations of 11 months or more (total range: 7.8-11.4 months). Thus, we show for the first time that a free-living mammal relying on natural food resources can continuously hibernate for >11 months. Early onset of hibernation was associated with high body mass in the spring, but the distribution of hibernation onset was bimodal with prolonged hibernation starting either early (prior to July 28) or late (after August 30). This could not be explained by differences in body mass alone. Animals with a late hibernation onset continued to maintain high nocturnal Tb's throughout summer but used short, shallow torpor bouts (mean duration 7.44 ± 0.9 h), as well as occasional multiday torpor for up to 161 h. PMID:26293446

  12. Determination of perfluorinated sulfonate and perfluorinated acids in tissues of free-living European beaver (castor fiber L.) by d-SPE/ micro-UHPLC-MS/MS.

    PubMed

    Surma, Magdalena; Giżejewski, Zygmunt; Zieliński, Henryk

    2015-10-01

    Perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA) are the main representatives of an rising class of persistent organic pollutants (POPs), perfluorochemicals (PFCs). In this study, determination of selected PFCs concentration in liver, brain, tail, adipose and peritoneum tissues of free-living European beaver (Castor fiber L.) was addressed. Tissue samples, collected from beavers living in Masurian Lakeland (NE Poland), were analyzed by dispersive Solid Phase Extraction (d-SPE) with micro-UHPLC-MS/MS system. In a group of ten selected pefrluorinated compounds only two perfluorinated acids (PFOA and PFNA) and one perfluorinated sulfonate (PFOS) were quantified. PFOA was detected in all analysed tissue samples in both female and male beavers in a range from 0.55 to 0.98ngg(-1) ww whereas PFOS was identified in all analyzed female beaver tissues and only in liver, subcutaneous adipose and peritoneum tissues of male beavers at the concentration level from 0.86 to 5.08ngg(-1) ww. PFNA was only identified in female beaver tissues (liver, subcutaneous adipose and peritoneum) in a range from 1.50 to 6.61ngg(-1) ww. This study demonstrated the bioaccumulation of PFCs in tissue samples collected from beavers living in area known as green lungs of Poland. The results provided in this study indicate for the increasing risk of PFCs occurrence in the environment and the level of PFCs in tissue of free-living European beavers may serve as bioindicator of environmental pollution by these compounds. PMID:26143169

  13. Novel European free-living, non-diazotrophic Bradyrhizobium isolates from contrasting soils that lack nodulation and nitrogen fixation genes - a genome comparison.

    PubMed

    Jones, Frances Patricia; Clark, Ian M; King, Robert; Shaw, Liz J; Woodward, Martin J; Hirsch, Penny R

    2016-01-01

    The slow-growing genus Bradyrhizobium is biologically important in soils, with different representatives found to perform a range of biochemical functions including photosynthesis, induction of root nodules and symbiotic nitrogen fixation and denitrification. Consequently, the role of the genus in soil ecology and biogeochemical transformations is of agricultural and environmental significance. Some isolates of Bradyrhizobium have been shown to be non-symbiotic and do not possess the ability to form nodules. Here we present the genome and gene annotations of two such free-living Bradyrhizobium isolates, named G22 and BF49, from soils with differing long-term management regimes (grassland and bare fallow respectively) in addition to carbon metabolism analysis. These Bradyrhizobium isolates are the first to be isolated and sequenced from European soil and are the first free-living Bradyrhizobium isolates, lacking both nodulation and nitrogen fixation genes, to have their genomes sequenced and assembled from cultured samples. The G22 and BF49 genomes are distinctly different with respect to size and number of genes; the grassland isolate also contains a plasmid. There are also a number of functional differences between these isolates and other published genomes, suggesting that this ubiquitous genus is extremely heterogeneous and has roles within the community not including symbiotic nitrogen fixation. PMID:27162150

  14. RNA-Seq and Microarrays Analyses Reveal Global Differential Transcriptomes of Mesorhizobium huakuii 7653R between Bacteroids and Free-Living Cells

    PubMed Central

    Peng, Jieli; Hao, Baohai; Liu, Liu; Wang, Shanming; Ma, Binguang; Yang, Yi; Xie, Fuli; Li, Youguo

    2014-01-01

    Mesorhizobium huakuii 7653R occurs either in nitrogen-fixing symbiosis with its host plant, Astragalus sinicus, or free-living in the soil. The M. huakuii 7653R genome has recently been sequenced. To better understand the complex biochemical and developmental changes that occur in 7653R during bacteroid development, RNA-Seq and Microarrays were used to investigate the differential transcriptomes of 7653R bacteroids and free-living cells. The two approaches identified several thousand differentially expressed genes. The most prominent up-regulation occurred in the symbiosis plasmids, meanwhile gene expression is concentrated to a set of genes (clusters) in bacteroids to fulfill corresponding functional requirements. The results suggested that the main energy metabolism is active while fatty acid metabolism is inactive in bacteroid and that most of genes relevant to cell cycle are down-regulated accordingly. For a global analysis, we reconstructed a protein-protein interaction (PPI) network for 7653R and integrated gene expression data into the network using Cytoscape. A highly inter-connected subnetwork, with function enrichment for nitrogen fixation, was found, and a set of hubs and previously uncharacterized genes participating in nitrogen fixation were identified. The results described here provide a broader biological landscape and novel insights that elucidate rhizobial bacteroid differentiation, nitrogen fixation and related novel gene functions. PMID:24695521

  15. Exploring the potential synergistic effects of chemical disinfectants and UV on the inactivation of free-living bacteria and treatment of biofilms in a pilot-scale system.

    PubMed

    Vankerckhoven, E; Verbessem, B; Crauwels, S; Declerck, P; Muylaert, K; Willems, K A; Rediers, H

    2011-01-01

    The main objective of this study is to explore possible synergistic or additive effects of combinations of chemical disinfectants (sodium hypochlorite, peracetic acid, hydrogen peroxide, chlorine dioxide) and UV in their efficacy in inactivating free-living bacteria and removing biofilms. In contrast to most studies, this study examines disinfection of municipal water in a pilot-scale system using a mixed bacterial suspension, which enables a better simulation of the conditions encountered in actual industrial environments. It was shown that the combination of either hypochlorite, hydrogen peroxide, peracetic acid, or chlorine dioxide with UV yielded additive effects on the inactivation of free-living bacteria. Actual synergy was observed for the combination of UV and 5 ppm hydrogen peroxide. Regarding biofilm treatment, additive effects were observed using the combination of hydrogen peroxide and UV. The promising results obtained in this study indicate that the combination of UV and chemical disinfectants can considerably reduce the amount of chemicals required for the effective disinfection and treatment of biofilms. PMID:22214077

  16. Novel European free-living, non-diazotrophic Bradyrhizobium isolates from contrasting soils that lack nodulation and nitrogen fixation genes – a genome comparison

    NASA Astrophysics Data System (ADS)

    Jones, Frances Patricia; Clark, Ian M.; King, Robert; Shaw, Liz J.; Woodward, Martin J.; Hirsch, Penny R.

    2016-05-01

    The slow-growing genus Bradyrhizobium is biologically important in soils, with different representatives found to perform a range of biochemical functions including photosynthesis, induction of root nodules and symbiotic nitrogen fixation and denitrification. Consequently, the role of the genus in soil ecology and biogeochemical transformations is of agricultural and environmental significance. Some isolates of Bradyrhizobium have been shown to be non-symbiotic and do not possess the ability to form nodules. Here we present the genome and gene annotations of two such free-living Bradyrhizobium isolates, named G22 and BF49, from soils with differing long-term management regimes (grassland and bare fallow respectively) in addition to carbon metabolism analysis. These Bradyrhizobium isolates are the first to be isolated and sequenced from European soil and are the first free-living Bradyrhizobium isolates, lacking both nodulation and nitrogen fixation genes, to have their genomes sequenced and assembled from cultured samples. The G22 and BF49 genomes are distinctly different with respect to size and number of genes; the grassland isolate also contains a plasmid. There are also a number of functional differences between these isolates and other published genomes, suggesting that this ubiquitous genus is extremely heterogeneous and has roles within the community not including symbiotic nitrogen fixation.

  17. Chlamydophila psittaci in free-living Blue-fronted Amazon parrots (Amazona aestiva) and Hyacinth macaws (Anodorhynchus hyacinthinus) in the Pantanal of Mato Grosso do Sul, Brazil.

    PubMed

    de Freitas Raso, Tânia; Seixas, Gláucia Helena Fernandes; Guedes, Neiva Maria Robaldo; Pinto, Aramis Augusto

    2006-10-31

    Chlamydophila psittaci (C. psittaci) infection was evaluated in 77 free-living nestlings of Blue-fronted Amazon parrots (Amazona aestiva) and Hyacinth macaws (Anodorhynchus hyacinthinus) in the Pantanal of Mato Grosso do Sul, Brazil. Tracheal and cloacal swab samples from 32 wild parrot and 45 macaw nestlings were submitted to semi-nested PCR, while serum samples were submitted to complement fixation test (CFT). Although all 32 Amazon parrot serum samples were negative by CFT, cloacal swabs from two birds were positive for Chlamydophila DNA by semi-nested PCR (6.3%); these positive birds were 32 and 45 days old. In macaws, tracheal and cloacal swabs were positive in 8.9% and 26.7% of the samples, respectively. Complement-fixing antibodies were detected in 4.8% of the macaw nestlings; macaw nestlings with positive findings were between 33 and 88 days old. These results indicate widespread dissemination of this pathogen in the two evaluated psittacine populations. No birds had clinical signs suggestive of chlamydiosis. To the best of our knowledge, this is the first report on C. psittaci in free-living Blue-fronted Amazon parrots and Hyacinth macaws in Brazil. PMID:16893616

  18. Phylogeny and classification of the Litostomatea (Protista, Ciliophora), with emphasis on free-living taxa and the 18S rRNA gene.

    PubMed

    Vd'ačný, Peter; Bourland, William A; Orsi, William; Epstein, Slava S; Foissner, Wilhelm

    2011-05-01

    The class Litostomatea is a highly diverse ciliate taxon comprising hundreds of species ranging from aerobic, free-living predators to anaerobic endocommensals. This is traditionally reflected by classifying the Litostomatea into the subclasses Haptoria and Trichostomatia. The morphological classifications of the Haptoria conflict with the molecular phylogenies, which indicate polyphyly and numerous homoplasies. Thus, we analyzed the genealogy of 53 in-group species with morphological and molecular methods, including 12 new sequences from free-living taxa. The phylogenetic analyses and some strong morphological traits show: (i) body polarization and simplification of the oral apparatus as main evolutionary trends in the Litostomatea and (ii) three distinct lineages (subclasses): the Rhynchostomatia comprising Tracheliida and Dileptida; the Haptoria comprising Lacrymariida, Haptorida, Didiniida, Pleurostomatida and Spathidiida; and the Trichostomatia. The curious Homalozoon cannot be assigned to any of the haptorian orders, but is basal to a clade containing the Didiniida and Pleurostomatida. The internal relationships of the Spathidiida remain obscure because many of them and some "traditional" haptorids form separate branches within the basal polytomy of the order, indicating one or several radiations and convergent evolution. Due to the high divergence in the 18S rRNA gene, the chaeneids and cyclotrichiids are classified incertae sedis. PMID:21333743

  19. Novel European free-living, non-diazotrophic Bradyrhizobium isolates from contrasting soils that lack nodulation and nitrogen fixation genes – a genome comparison

    PubMed Central

    Jones, Frances Patricia; Clark, Ian M.; King, Robert; Shaw, Liz J.; Woodward, Martin J.; Hirsch, Penny R.

    2016-01-01

    The slow-growing genus Bradyrhizobium is biologically important in soils, with different representatives found to perform a range of biochemical functions including photosynthesis, induction of root nodules and symbiotic nitrogen fixation and denitrification. Consequently, the role of the genus in soil ecology and biogeochemical transformations is of agricultural and environmental significance. Some isolates of Bradyrhizobium have been shown to be non-symbiotic and do not possess the ability to form nodules. Here we present the genome and gene annotations of two such free-living Bradyrhizobium isolates, named G22 and BF49, from soils with differing long-term management regimes (grassland and bare fallow respectively) in addition to carbon metabolism analysis. These Bradyrhizobium isolates are the first to be isolated and sequenced from European soil and are the first free-living Bradyrhizobium isolates, lacking both nodulation and nitrogen fixation genes, to have their genomes sequenced and assembled from cultured samples. The G22 and BF49 genomes are distinctly different with respect to size and number of genes; the grassland isolate also contains a plasmid. There are also a number of functional differences between these isolates and other published genomes, suggesting that this ubiquitous genus is extremely heterogeneous and has roles within the community not including symbiotic nitrogen fixation. PMID:27162150

  20. Energy expenditure in underweight free-living adults: impact of energy supplementation as determined by doubly labeled water and indirect calorimetry

    SciTech Connect

    Riumallo, J.A.; Schoeller, D.; Barrera, G.; Gattas, V.; Uauy, R.

    1989-02-01

    The effect of energy supplementation was evaluated in six underweight adults under free-living conditions. Customary energy intake (EI) over 4 wk and estimated body composition were defined. Then for 12 wk subjects were fed their customary EI under controlled conditions to assure stable energy reserve. Finally, intake was increased by a mean of 720 kcal/d for 8 wk adjusted to increase body fat from 9 to 18%. Body weight (means +/- SD) increased from 55.2 +/- 3.4 to 57.0 +/- 4.2 kg. Body fat gain was highly variable ranging from 0.6 to 3.8 kg. Energy expenditure (EE) by the factorial and doubly labeled water methods did not change. Fat storage accounted for 66% of the supplemental energy; 237 kcal/d remained unaccounted for. EE by the factorial method, which uses indirect calorimetry or isotopic measurements, were highly correlated (r = 0.8; p less than 0.01). Under the conditions of this study EI does not affect EE. The labeled water method permits the evaluation of energy expenditure in free-living conditions.

  1. Pesticides in Ichkeul Lake-Bizerta Lagoon Watershed in Tunisia: use, occurrence, and effects on bacteria and free-living marine nematodes.

    PubMed

    Salem, Fida Ben; Said, Olfa Ben; Aissa, Patricia; Mahmoudi, Ezzeddine; Monperrus, Mathilde; Grunberger, Olivier; Duran, Robert

    2016-01-01

    This study aimed to identify the most commonly used agricultural pesticides around Ichkeul Lake-Bizerta Lagoon watershed. First survey of pesticide use on agricultural watershed was performed with farmers, Regional Commissioner for Agricultural Development, and pesticide dealers. Then, sediment contamination by pesticides and response of benthic communities (bacteria and free-living marine nematode) were investigated. The analysis of 22 active organochlorine pesticides in sediments was performed according to quick, easy, cheap, effective, rugged, and safe (QuEChERS) method, biodiversity of indigenous bacterial community sediment was determined by terminal restriction fragment length polymorphism (T-RFLP), and free-living marine nematodes were counted. The results of the field survey showed that iodosulfuron, mesosulfuron, 2,4-dichlorophenoxyacetic acid (2,4 D), glyphosate, and fenoxaprops were the most used herbicides, tebuconazole and epoxiconazole the most used fungicides, and deltamethrin the most used insecticide. Sixteen organochlorine pesticide compounds among the 22 examined were detected in sediments up to 2 ppm in Ichkeul Lake, endrin, dieldrin, and hexachlorocyclohexane being the most detected molecules. The most pesticide-contaminated site in the lake presented the higher density of nematode, but when considering all sites, no clear correlation with organochlorine pesticide (OCP) content could be established. The bacterial community structure in the most contaminated site in the lake was characterized by the terminal restriction fragments (T-RFs) 97, 146, 258, 285, and 335 while the most contaminated site in the lagoon was characterized by the T-RFs 54, 263, 315, 403, and 428. Interestingly, T-RFs 38 and 143 were found in the most contaminated sites of both lake and lagoon ecosystems, indicating that they were resistant to OCPs and able to cope with environmental fluctuation of salinity. In contrast, the T-RFs 63, 100, 118, and 381 in the lake and the T

  2. Phylogenetic Differences in Attached and Free-Living Bacterial Communities in a Temperate Coastal Lagoon during Summer, Revealed via High-Throughput 16S rRNA Gene Sequencing

    PubMed Central

    Mohit, Vani; Archambault, Philippe; Toupoint, Nicolas

    2014-01-01

    Most of what is known about coastal free-living and attached bacterial diversity is based on open coasts, with high particulate and nutrient riverine supply, terrestrial runoffs, and anthropogenic activities. The Magdalen Islands in the Gulf of St. Lawrence (Canada) are dominated by shallow lagoons with small, relatively pristine catchments and no freshwater input apart from rain. Such conditions provided an opportunity to investigate coastal free-living and attached marine bacterial diversity in the absence of confounding effects of steep freshwater gradients. We found significant differences between the two communities and marked temporal patterns in both. Taxonomic richness and diversity were greater in the attached than in the free-living community, increasing over summer, especially within the least abundant bacterial phyla. The highest number of reads fell within the SAR 11 clade (Pelagibacter, Alphaproteobacteria), which dominated free-living communities. The attached communities had deeper phylum-level diversity than the free-living fraction. Distance-based redundancy analysis indicated that the particulate organic matter (POM) concentration was the main variable separating early and late summer samples with salinity and temperature changes also significantly correlated to bacterial community structure. Our approach using high-throughput sequencing detected differences in free-living versus attached bacteria in the absence of riverine input, in keeping with the concept that marine attached communities are distinct from cooccurring free-living taxa. This diversity likely reflects the diverse microhabitats of available particles, implying that the total bacterial diversity in coastal systems is linked to particle supply and variability, with implications for understanding microbial biodiversity in marine systems. PMID:24463966

  3. The Wageningen Lowland Runoff Simulator (WALRUS): development of a novel parametric rainfall-runoff model using field experience

    NASA Astrophysics Data System (ADS)

    Brauer, Claudia; Torfs, Paul; Teuling, Ryan; Uijlenhoet, Remko

    2014-05-01

    We present the Wageningen Lowland Runoff Simulator (WALRUS), a novel rainfall-runoff model to fill the gap between complex, spatially distributed models for lowland catchments and simple, parametric models for mountainous catchments. From observations and experience from two Dutch field sites (the Hupsel Brook catchment and the Cabauw polder), we identified key processes for runoff generation in lowland catchments and important feedbacks between components in the hydrological system. We used this knowledge to design a parametric model which can be used all over the world in both freely draining lowland catchments and polders with controlled water levels. While using only four parameters which require calibration, WALRUS explicitly accounts for processes that are important in lowland areas: (1) Groundwater-unsaturated zone coupling: WALRUS contains one soil reservoir, which is divided effectively by the (dynamic) groundwater table into a groundwater zone and a vadose zone. The condition of this soil reservoir is described by two strongly dependent variables: the groundwater depth and the storage deficit (the effective thickness of empty pores). This implementation enables capillary rise when the top soil has dried through evapotranspiration. (2) Wetness-dependent flowroutes: The storage deficit determines the division of rain water between the soil reservoir (slow routes: infiltration, percolation and groundwater flow) and a quickflow reservoir (quick routes: drainpipe, macropore and overland flow). (3) Groundwater-surface water feedbacks: Surface water forms an explicit part of the model structure. Drainage depends on the difference between surface water level and groundwater level (rather than groundwater level alone), allowing for feedbacks and infiltration of surface water into the soil. (4) Seepage and surface water supply: Groundwater seepage and surface water supply or extraction (pumping) are added to or subtracted from the soil or surface water reservoir

  4. Coexistence of Legionella pneumophila Bacteria and Free-Living Amoebae in Lakes Serving as a Cooling System of a Power Plant.

    PubMed

    Zbikowska, Elżbieta; Kletkiewicz, Hanna; Walczak, Maciej; Burkowska, Aleksandra

    2014-01-01

    The study was aimed at determining whether potentially pathogenic free-living amoebae (FLA) and Legionella pneumophila can be found in lakes serving as a natural cooling system of a power plant. Water samples were collected from five lakes forming the cooling system of the power plants Pątnów and Konin (Poland). The numbers of investigated organisms were determined with the use of a very sensitive molecular method-fluorescence in situ hybridization (FISH). The result of the present study shows that thermally altered aquatic environments provide perfect conditions for the growth of L. pneumophila and amoebae. The bacteria were identified in the biofilm throughout the entire research period and in the subsurface water layer in July and August. Hartmanella sp. and/or Naegleria fowleri were identified in the biofilm throughout the entire research period. PMID:25132694

  5. DETECTION OF Leptospira spp. AND Brucella abortus ANTIBODIES IN FREE-LIVING JAGUARS (Panthera onca) IN TWO PROTECTED AREAS OF NORTHERN PANTANAL, BRAZIL

    PubMed Central

    ONUMA, Selma Samiko Miyazaki; KANTEK, Daniel Luis Zanella; CRAWSHAW, Peter Gransden; MORATO, Ronaldo Gonçalves; MAY-JÚNIOR, Joares Adenilson; de MORAIS, Zenaide Maria; FERREIRA, José Soares; de AGUIAR, Daniel Moura

    2015-01-01

     This study aimed to assess the exposure of free-living jaguars (Panthera onca) to Leptospira spp. and Brucella abortus in two conservation units in the Pantanal of Mato Grosso, Brazil. The presence of antibodies in blood samples of eleven jaguars was investigated using autochthonous antigens isolated in Brazil added to reference antigen collection applied to diagnosis of leptospirosis by Microscopic Agglutination Test (MAT). The Rose Bengal test was applied for B. abortus antibodies. Two (18.2%) jaguars were seroreactive for the Leptospira spp. antigen and the serovar considered as most infective in both animals was a Brazilian isolate of serovar Canicola (L01). All jaguars were seronegative for B. abortus. These data indicate that the inclusion of autochthonous antigens in serological studies can significantly increase the number of reactive animals, as well as modify the epidemiological profile of Leptospira spp. infection. PMID:25923900

  6. A new solitary free-living species of the genus Sphenopus (Cnidaria, Anthozoa, Zoantharia, Sphenopidae) from Okinawa-jima Island, Japan.

    PubMed

    Fujii, Takuma; Reimer, James Davis

    2016-01-01

    A new species of free-living solitary zoantharian is described from Okinawa, Japan. Sphenopus exilis sp. n. occurs on silty seafloors in Kin Bay and Oura Bay on the east coast of Okinawa-jima Island. Sphenopus exilis sp. n. is easily distinguished from other Sphenopus species by its small polyp size and slender shape, although there were relatively few differences between Sphenopus exilis sp. n. and Sphenopus marsupialis in the molecular phylogenetic analyses. Currently, very little is known about the ecology and diversity of Sphenopus species. Thus, reviewing each species carefully via combined morphological and molecular analyses by using newly obtained specimens from type localities is required to clearly understand and distinguish the species within the genus Sphenopus. PMID:27551219

  7. A new solitary free-living species of the genus Sphenopus (Cnidaria, Anthozoa, Zoantharia, Sphenopidae) from Okinawa-jima Island, Japan

    PubMed Central

    Fujii, Takuma; Reimer, James Davis

    2016-01-01

    Abstract A new species of free-living solitary zoantharian is described from Okinawa, Japan. Sphenopus exilis sp. n. occurs on silty seafloors in Kin Bay and Oura Bay on the east coast of Okinawa-jima Island. Sphenopus exilis sp. n. is easily distinguished from other Sphenopus species by its small polyp size and slender shape, although there were relatively few differences between Sphenopus exilis sp. n. and Sphenopus marsupialis in the molecular phylogenetic analyses. Currently, very little is known about the ecology and diversity of Sphenopus species. Thus, reviewing each species carefully via combined morphological and molecular analyses by using newly obtained specimens from type localities is required to clearly understand and distinguish the species within the genus Sphenopus. PMID:27551219

  8. Article for the "Free-living amoebae special issue": Isolation and characterisation of various amoebophagous fungi and evaluation of their prey spectrum.

    PubMed

    Michel, Rolf; Walochnik, Julia; Scheid, Patrick

    2014-11-01

    This article gives an overview on the isolation and characterisation of endoparasitic fungi invading free-living amoebae (FLA), including the ones forming thalli inside their hosts such as Cochlonema euryblastum and also the predatory fungi which capture amoebae by adhesive hyphae. Acaulopage spp. and Stylopage spp. trap, intrude, and exploit amoebal trophozoites. Previous phylogenetic studies proved Cochlonema to be a member of the Zoopagales. The genetic investigation of Acaulopage tetraceros demonstrated its close relationship to Cochlonema. Co-cultivation of A. tetraceros with a number of FLA revealed a great prey spectrum of this amoebophageous fungus. In addition it was shown that solitary amoebal stages of slime moulds such as Dictyostelium sp. and Physarum sp. are also suited as welcome prey amoebae. PMID:25311445

  9. Genome sequence of the free-living aerobic spirochete Turneriella parva type strain (HT), and emendation of the species Turneriella parva

    SciTech Connect

    Stackebrandt, Erko; Chertkov, Olga; Lapidus, Alla L.; Nolan, Matt; Lucas, Susan; Hammon, Nancy; Deshpande, Shweta; Cheng, Jan-Fang; Tapia, Roxanne; Goodwin, Lynne A.; Pitluck, Sam; Liolios, Konstantinos; Pagani, Ioanna; Ivanova, N; Mavromatis, K; Mikhailova, Natalia; Huntemann, Marcel; Pati, Amrita; Chen, Amy; Palaniappan, Krishna; Land, Miriam L; Pan, Chongle; Rohde, Manfred; Gronow, Sabine; Goker, Markus; Detter, J. Chris; Bristow, James; Eisen, Jonathan; Markowitz, Victor; Hugenholtz, Philip; Woyke, Tanja; Kyrpides, Nikos C; Klenk, Hans-Peter

    2013-01-01

    Turneriella parva Levett et al. 2005 is the only species of the genus Turneriella which was es- tablished as a result of the reclassification of Leptospira parva Hovind-Hougen et al. 1982. Together with Leptonema and Leptospira, Turneriella constitutes the family Leptospiraceae, within the order Spirochaetales. Here we describe the features of this free-living aerobic spi- rochete together with the complete genome sequence and annotation. This is the first com- plete genome sequence of a member of the genus Turneriella and the 13th member of the family Leptospiraceae for which a complete or draft genome sequence is now available. The 4,409,302 bp long genome with its 4,169 protein-coding and 45 RNA genes is part of the Genomic Encyclopedia of Bacteria and Archaea project.

  10. Discovery of a free-living chlorophyll d-producing cyanobacterium with a hybrid proteobacterial/cyanobacterial small-subunit rRNA gene

    PubMed Central

    Miller, Scott R.; Augustine, Sunny; Olson, Tien Le; Blankenship, Robert E.; Selker, Jeanne; Wood, A. Michelle

    2005-01-01

    Chlorophyll d-producing cyanobacteria are a recently described group of phototrophic bacteria that is a major focus of photosynthesis research, previously known only from marine environments in symbiosis with eukaryotes. We have discovered a free-living member of this group from a eutrophic hypersaline lake. Phylogenetic analyses indicated these strains are closely related to each other but not to prochlorophyte cyanobacteria that also use an alternative form of chlorophyll as the major light-harvesting pigment. We have also demonstrated that these bacteria acquired a fragment of the small-subunit rRNA gene encoding a conserved hairpin in the bacterial ribosome from a proteobacterial donor at least 10 million years before the present. Thus, our most widely used phylogenetic marker can be a mosaic of sequence fragments with widely divergent evolutionary histories. PMID:15637160

  11. ASSOCIATIONS OF SOLUBLE FIBER, WHOLE FRUITS/VEGETABLES, AND JUICE WITH PLASMA BETA-CAROTENE CONCENTRATIONS IN A FREE-LIVING POPULATION OF BREAST CANCER SURVIVORS

    PubMed Central

    Kolodziejczyk, Julia K.; Flatt, Shirley W.; Natarajan, Loki; Patterson, Ruth; Pierce, John P.; Norman, Gregory J.

    2012-01-01

    Objective Soluble fiber and the physical state of fruits/vegetables affect plasma ß-carotene concentrations; however, most of this research was conducted in laboratory-based settings. These analyses investigated the relationship between soluble fiber and juiced vs. whole fruits/vegetables to plasma ß-carotene concentrations in a free-living population. Method This cross-sectional analysis used 12-month follow-up data from the Women’s Healthy Eating & Living Study (WHEL) (1995-2006), a study to improve diet in breast cancer survivors in the Western United States. The dietary nutrients considered in this analysis included intake of soluble fiber (g), ß-carotene from fruit/vegetable juice (mg), and ß-carotene from whole fruits/vegetables (mg). A linear regression model was used to assess the relationship of the variables to plasma ß-carotene concentrations. Results Out of 3,088 women enrolled in WHEL 2,397 women had complete data (mean age=54). The final model accounted for approximately 49% of the explained variance in plasma ß-carotene concentrations. Fruit/vegetable juice had the largest, positive relation to plasma ß-carotene concentrations (standardized parameter estimate=0.23, p < 0.01) followed by whole fruits/vegetables (standardized parameter estimate=0.09, p < 0.01). Conclusion: Soluble fiber may inhibit ß-carotene absorption; therefore, consumption of juice may increase plasma ß-carotene concentrations more than whole fruits/vegetables in free-living populations. PMID:23127215

  12. Variation in the daily rhythm of body temperature of free-living Arabian oryx (Oryx leucoryx): does water limitation drive heterothermy?

    PubMed

    Hetem, Robyn Sheila; Strauss, Willem Maartin; Fick, Linda Gayle; Maloney, Shane Kevin; Meyer, Leith Carl Rodney; Shobrak, Mohammed; Fuller, Andrea; Mitchell, Duncan

    2010-10-01

    Heterothermy, a variability in body temperature beyond the limits of homeothermy, has been advanced as a key adaptation of Arabian oryx (Oryx leucoryx) to their arid-zone life. We measured body temperature using implanted data loggers, for a 1-year period, in five oryx free-living in the deserts of Saudi Arabia. As predicted for adaptive heterothermy, during hot months compared to cooler months, not only were maximum daily body temperatures higher (41.1 ± 0.3 vs. 39.7 ± 0.1°C, P = 0.0002) but minimum daily body temperatures also were lower (36.1 ± 0.3 vs. 36.8 ± 0.2°C, P = 0.04), resulting in a larger daily amplitude of the body temperature rhythm (5.0 ± 0.5 vs. 2.9 ± 0.2°C, P = 0.0007), while mean daily body temperature rose by only 0.4°C. The maximum daily amplitude of the body temperature rhythm reached 7.7°C for two of our oryx during the hot-dry period, the largest amplitude ever recorded for a large mammal. Body temperature variability was influenced not only by ambient temperature but also water availability, with oryx displaying larger daily amplitudes of the body temperature rhythm during warm-dry months compared to warm-wet months (3.6 ± 0.6 vs. 2.3 ± 0.3°C, P = 0.005), even though ambient temperatures were the same. Free-living Arabian oryx therefore employ heterothermy greater than that recorded in any other large mammal, but water limitation, rather than high ambient temperature, seems to be the primary driver of this heterothermy. PMID:20502901

  13. Efficacy of amitraz applied to white-tailed deer by the '4-poster' topical treatment device in controlling free-living lone star ticks (Acari: Ixodidae).

    PubMed

    Pound, J M; Miller, J A; George, J E

    2000-11-01

    White-tailed deer treated themselves with a commercial pour-on acaricide formulation containing 2% amitraz as they fed from an ARS-patented '4-poster' topical treatment device. Whole kernel corn attracted deer to a single device placed in each of two deer-fenced pastures. In the treatment pasture, the rollers of the treatment device were charged with the acaricide, whereas the rollers of the device in the other pasture remained untreated. Deer were allowed to use the '4-posters' during periods of tick activity beginning in early to midspring and lasting through late summer to early fall for three consecutive years. Pretreatment sampling of adults and nymphs with dry-ice traps and larval masses with flip cloths showed no significant differences in population indices between the two pastures; however, after the third year of treatment, control of nymphal and adult ticks in the treated pasture was 91.9 and 93.7%, respectively, when compared with the untreated pasture. Control of larval masses increased from 68.4% in year 1 to 96.4% in year 2, but declined to 88.0% in year 3, probably because of the presence of feral hogs. This study demonstrated that application of amitraz to white-tailed deer through free-choice interaction with a '4-poster' device significantly reduced the abundance of free-living lone star ticks in a deer-fenced experimental pasture. Moreover, the yearly pattern of incremental increases in control and the final percentage control values for all three parasitic life stages in this topical application study were similar in magnitude to that observed in a previously conducted study in which the systemic acaricide ivermectin was used to reduce populations of free-living ticks by controlling ticks on deer. PMID:11126544

  14. Low validity of the Sensewear Pro3 activity monitor compared to indirect calorimetry during simulated free living in patients with osteoarthritis of the hip

    PubMed Central

    2014-01-01

    Background To validate physical activity estimates by the Sensewear Pro3 activity monitor compared with indirect calorimetry during simulated free living in patients diagnosed with osteoarthritis of the hip pre or post total hip arthroplasty. Methods Twenty patients diagnosed with hip osteoarthritis (10 pre- and 10 post total hip arthroplasty; 40% female; age: 63.3 ± 9.0; BMI: 23.7 ± 3.7). All patients completed a 2 hour protocol of simulated free living with 8 different typical physical activity types. Energy consumption (kcal/min) was estimated by the Sense Wear pro3 Armband activity monitor and validated against indirect calorimetry (criterion method) by means of a portable unit (Cosmed K4b2). Bias and variance was analyzed using functional ANOVA. Results Mean bias during all activities was 1.5 Kcal/min 95%CI [1.3; 1.8] corresponding to 72% (overestimation). Normal gait speed showed an overestimation of 2.8 Kcal/min, 95%CI [2.3; 3.3] (93%) while an underestimation of -1.1 Kcal/min, 95%CI [-1.8; -0.3] (-25%) was recorded during stair climb. Activities dominated by upper body movements showed large overestimation with 4.37 Kcal/min, 95%CI [3.8; 5.1] (170%) being recorded during gardening. Both bias and variance appeared to be dependent on activity type. Conclusion The activity monitor generally overestimated the energy consumption during common activities of low to medium intensity in the patient group. The size and direction of the bias was highly dependent on the activity type which indicates the activity monitor is of limited value in patients with hip osteoarthritis and that the results do not express the real energy expenditure. PMID:24552503

  15. Effect of beetroot juice on lowering blood pressure in free-living, disease-free adults: a randomized, placebo-controlled trial

    PubMed Central

    2012-01-01

    Background The consumption of beetroot juice on a low nitrate diet may lower blood pressure (BP) and therefore reduce the risk of cardiovascular events. However, it is unknown if its inclusion as part of a normal diet has a similar effect on BP. The aim of the study was to conduct a randomized controlled trial with free-living adults to investigate if consuming beetroot juice in addition to a normal diet produces a measureable reduction in BP. Method Fifteen women and fifteen men participated in a double-blind, randomized, placebo-controlled, crossover study. Volunteers were randomized to receive 500 g of beetroot and apple juice (BJ) or a placebo juice (PL). Volunteers had BP measured at baseline and at least hourly for 24-h following juice consumption using an ambulatory blood pressure monitor (ABPM). Volunteers remained at the clinic for 1-h before resuming normal non-strenuous daily activities. The identical procedure was repeated 2-wk later with the drink (BJ or PL) not consumed on the first visit. Results Overall, there was a trend (P=0.064) to lower systolic blood pressure (SBP) at 6-h after drinking BJ relative to PL. Analysis in men only (n=13) after adjustment for baseline differences demonstrated a significant (P<0.05) reduction in SBP of 4 – 5 mmHg at 6-h after drinking BJ. Conclusions Beetroot juice will lower BP in men when consumed as part of a normal diet in free-living healthy adults. Trial registration anzctr.org.au ACTRN12612000445875 PMID:23231777

  16. Autocalibration of accelerometer data for free-living physical activity assessment using local gravity and temperature: an evaluation on four continents

    PubMed Central

    van Hees, Vincent T.; Fang, Zhou; Langford, Joss; Assah, Felix; Mohammad, Anwar; da Silva, Inacio C. M.; Trenell, Michael I.; White, Tom; Wareham, Nicholas J.

    2014-01-01

    Wearable acceleration sensors are increasingly used for the assessment of free-living physical activity. Acceleration sensor calibration is a potential source of error. This study aims to describe and evaluate an autocalibration method to minimize calibration error using segments within the free-living records (no extra experiments needed). The autocalibration method entailed the extraction of nonmovement periods in the data, for which the measured vector magnitude should ideally be the gravitational acceleration (1 g); this property was used to derive calibration correction factors using an iterative closest-point fitting process. The reduction in calibration error was evaluated in data from four cohorts: UK (n = 921), Kuwait (n = 120), Cameroon (n = 311), and Brazil (n = 200). Our method significantly reduced calibration error in all cohorts (P < 0.01), ranging from 16.6 to 3.0 mg in the Kuwaiti cohort to 76.7 to 8.0 mg error in the Brazil cohort. Utilizing temperature sensor data resulted in a small nonsignificant additional improvement (P > 0.05). Temperature correction coefficients were highest for the z-axis, e.g., 19.6-mg offset per 5°C. Further, application of the autocalibration method had a significant impact on typical metrics used for describing human physical activity, e.g., in Brazil average wrist acceleration was 0.2 to 51% lower than uncalibrated values depending on metric selection (P < 0.01). The autocalibration method as presented helps reduce the calibration error in wearable acceleration sensor data and improves comparability of physical activity measures across study locations. Temperature ultization seems essential when temperature deviates substantially from the average temperature in the record but not for multiday summary measures. PMID:25103964

  17. Reversible oxygen-tolerant hydrogenase carried by free-living N2-fixing bacteria isolated from the rhizospheres of rice, maize, and wheat

    PubMed Central

    Roumagnac, Philippe; Richaud, Pierre; Barakat, Mohamed; Ortet, Philippe; Roncato, Marie-Anne; Heulin, Thierry; Peltier, Gilles; Achouak, Wafa; Cournac, Laurent

    2012-01-01

    Hydrogen production by microorganisms is often described as a promising sustainable and clean energy source, but still faces several obstacles, which prevent practical application. Among them, oxygen sensitivity of hydrogenases represents one of the major limitations hampering the biotechnological implementation of photobiological production processes. Here, we describe a hierarchical biodiversity-based approach, including a chemochromic screening of hydrogenase activity of hundreds of bacterial strains collected from several ecosystems, followed by mass spectrometry measurements of hydrogenase activity of a selection of the H2-oxidizing bacterial strains identified during the screen. In all, 131 of 1266 strains, isolated from cereal rhizospheres and basins containing irradiating waste, were scored as H2-oxidizing bacteria, including Pseudomonas sp., Serratia sp., Stenotrophomonas sp., Enterobacter sp., Rahnella sp., Burkholderia sp., and Ralstonia sp. isolates. Four free-living N2-fixing bacteria harbored a high and oxygen-tolerant hydrogenase activity, which was not fully inhibited within entire cells up to 150–250 μmol/L O2 concentration or within soluble protein extracts up to 25–30 μmol/L. The only hydrogenase-related genes that we could reveal in these strains were of the hyc type (subunits of formate hydrogenlyase complex). The four free-living N2-fixing bacteria were closely related to Enterobacter radicincitans based on the sequences of four genes (16S rRNA, rpoB, hsp60, and hycE genes). These results should bring interesting prospects for microbial biohydrogen production and might have ecophysiological significance for bacterial adaptation to the oxic–anoxic interfaces in the rhizosphere. PMID:23233392

  18. Effect of chlorine and temperature on free-living protozoa in operational man-made water systems (cooling towers and hot sanitary water systems) in Catalonia.

    PubMed

    Canals, Oriol; Serrano-Suárez, Alejandra; Salvadó, Humbert; Méndez, Javier; Cervero-Aragó, Sílvia; Ruiz de Porras, Vicenç; Dellundé, Jordi; Araujo, Rosa

    2015-05-01

    In recent decades, free-living protozoa (FLP) have gained prominence as the focus of research studies due to their pathogenicity to humans and their close relationship with the survival and growth of pathogenic amoeba-resisting bacteria. In the present work, we studied the presence of FLP in operational man-made water systems, i.e. cooling towers (CT) and hot sanitary water systems (HSWS), related to a high risk of Legionella spp. outbreaks, as well as the effect of the biocides used, i.e. chlorine in CT and high temperature in HSWS, on FLP. In CT samples, high-chlorine concentrations (7.5 ± 1.5 mg chlorine L(-1)) reduced the presence of FLP by 63.8 % compared to samples with low-chlorine concentrations (0.04 ± 0.08 mg chlorine L(-1)). Flagellates and amoebae were observed in samples collected with a level of 8 mg chlorine L(-1), which would indicate that some FLP, including the free-living amoeba (FLA) Acanthamoeba spp., are resistant to the discontinuous chlorine disinfection method used in the CT studied. Regarding HSWS samples, the amount of FLP detected in high-temperatures samples (53.1 ± 5.7 °C) was 38 % lower than in low-temperature samples (27.8 ± 5.8 °C). The effect of high temperature on FLP was chiefly observed in the results obtained by the culture method, in which there was a clear reduction in the presence of FLP at temperatures higher than 50 °C, but not in those obtained by PCR. The findings presented here show that the presence of FLP in operational man-made water systems should be taken into account in future regulations. PMID:25410311

  19. Spatial variability of particle-attached and free-living bacterial diversity in surface waters from the Mackenzie River to the Beaufort Sea (Canadian Arctic)

    NASA Astrophysics Data System (ADS)

    Ortega-Retuerta, E.; Joux, F.; Jeffrey, W. H.; Ghiglione, J.-F.

    2012-12-01

    We explored the patterns of total and active bacterial community structure in a gradient covering surface waters from the Mackenzie River to the coastal Beaufort Sea, Canadian Arctic Ocean, with a particular focus on free-living vs. particle-attached communities. Capillary electrophoresis-single strand conformation polymorphism (CE-SSCP) showed significant differences when comparing river, coast and open sea bacterial community structures. In contrast to the river and coastal waters, total (16S rDNA-based) and active (16S rRNA-based) communities in the open sea samples were not significantly different, suggesting that most present bacterial groups were equally active in this area. Additionally, we observed significant differences between particle-attached (PA) and free-living (FL) bacterial communities in the open sea, but similar structure in the two fractions for coastal and river samples. Direct multivariate statistical analyses showed that total community structure was mainly driven by salinity (proxy of DOC and CDOM), suspended particles, amino acids and chlorophyll a. 16S rRNA genes pyrosequencing of selected samples confirmed these significant differences from river to sea and also between PA and FL fractions only in open sea samples, and PA samples generally showed higher diversity (Shannon, Simpson and Chao indices) than FL samples. At the class level, Opitutae was most abundant in the PA fraction of the sea sample, followed by Flavobacteria and Gammaproteobacteria, while the FL sea sample was dominated by Alphaproteobacteria. Finally, the coast and river samples, both PA and FL fractions, were dominated by Betaproteobacteria, Alphaproteobacteria and Actinobacteria. These results highlight the coexistence of particle specialists and generalists and the role of particle quality in structuring bacterial communities in the area. These results may also serve as a~basis to predict further changes in bacterial communities should climate change lead to further

  20. Autocalibration of accelerometer data for free-living physical activity assessment using local gravity and temperature: an evaluation on four continents.

    PubMed

    van Hees, Vincent T; Fang, Zhou; Langford, Joss; Assah, Felix; Mohammad, Anwar; da Silva, Inacio C M; Trenell, Michael I; White, Tom; Wareham, Nicholas J; Brage, Søren

    2014-10-01

    Wearable acceleration sensors are increasingly used for the assessment of free-living physical activity. Acceleration sensor calibration is a potential source of error. This study aims to describe and evaluate an autocalibration method to minimize calibration error using segments within the free-living records (no extra experiments needed). The autocalibration method entailed the extraction of nonmovement periods in the data, for which the measured vector magnitude should ideally be the gravitational acceleration (1 g); this property was used to derive calibration correction factors using an iterative closest-point fitting process. The reduction in calibration error was evaluated in data from four cohorts: UK (n = 921), Kuwait (n = 120), Cameroon (n = 311), and Brazil (n = 200). Our method significantly reduced calibration error in all cohorts (P < 0.01), ranging from 16.6 to 3.0 mg in the Kuwaiti cohort to 76.7 to 8.0 mg error in the Brazil cohort. Utilizing temperature sensor data resulted in a small nonsignificant additional improvement (P > 0.05). Temperature correction coefficients were highest for the z-axis, e.g., 19.6-mg offset per 5°C. Further, application of the autocalibration method had a significant impact on typical metrics used for describing human physical activity, e.g., in Brazil average wrist acceleration was 0.2 to 51% lower than uncalibrated values depending on metric selection (P < 0.01). The autocalibration method as presented helps reduce the calibration error in wearable acceleration sensor data and improves comparability of physical activity measures across study locations. Temperature ultization seems essential when temperature deviates substantially from the average temperature in the record but not for multiday summary measures. PMID:25103964

  1. Achieving the salt intake target of 6 g/day in the current food supply in free-living adults using two dietary education strategies.

    PubMed

    Ireland, Dani-Maree; Clifton, Peter M; Keogh, Jennifer B

    2010-05-01

    There are national targets for salt intake of 6 g salt/day in Australia and the United States. Despite this, there is limited knowledge about the effectiveness of dietary education in reducing salt intake to this level. The objective of this study was to investigate whether dietary education enabled a reduction in salt consumption. In an 8-week parallel study, 49 healthy free-living adults were recruited from the Adelaide community by newspaper advertisement. In a randomized parallel design, participants received dietary education to choose foods identified by either Australia's National Heart Foundation Tick symbol or by the Food Standards Australia and New Zealand's low-salt guideline of 120 mg sodium/100 g food. Sodium excretion was assessed by 24-hour urinary sodium collections at baseline and weeks 4 and 8. Participants' experiences of following the education strategies were recorded by self-administered questionnaire. These data were collected between August and October 2008. Forty-three participants completed the study. After 8 weeks, urinary sodium excretion decreased from 121+/-50 to 106+/-47 mmol/24 hours (7.3+/-3.0 to 6.4+/-2.8 g salt/24 hours) in the Tick group and from 132+/-44 to 98+/-50 mmol/24 hours (7.9+/-2.6 to 6.0+/-3.0 g salt/24 hours) in the Food Standards Australia New Zealand group (P<0.05, with no between-group difference). Barriers to salt reduction were limited variety and food choice, difficulty when eating out, and increased time associated with identifying foods. In conclusion, dietary sodium reduction is possible among free-living individuals who received dietary advice. PMID:20430138

  2. Dimorphic tusks and adaptive strategies in a new species of walrus-like dolphin (Odobenocetopsidae) from the Pliocene of Peru

    NASA Astrophysics Data System (ADS)

    de Muizon, Christian; Domning, Daryl P.; Parrish, Mary

    1999-09-01

    Three new specimens of the walrus-like dolphin Odobenocetops from the Pliocene of Peru, shed new light on the anatomy and adaptive strategies of this unique Cetacean. Odobenocetops leptodon nov. sp. is represented by a skull, which bears a 1 35-cm-long needle-like right tusk and a small 25-cm-long left tusk the apex of which was erupted. The long tusk was probably held almost parallel to the axis of the body when swimming. In contrast to O. peruvianus, O. leptodon probably had a small melon and, therefore, echolocation ability, but had reduced (or no) binocular vision. A skull of O. peruvianus with two small tusks similar in size is referred to a female.

  3. Enamel ultrastructure of fossil and modern pinnipeds: evaluating hypotheses of feeding adaptations in the extinct walrus Pelagiarctos.

    PubMed

    Loch, Carolina; Boessenecker, Robert W; Churchill, Morgan; Kieser, Jules

    2016-06-01

    This study aimed to assess the enamel ultrastructure in modern otariid pinnipeds and in the extinct walrus Pelagiarctos. Teeth of the New Zealand fur seal (Arctocephalus forsteri), sea lion (Phocarctos hookeri), and fossil walrus Pelagiarctos thomasi were embedded, sectioned, etched, and analyzed via scanning electron microscopy. The enamel of NZ otariids and Pelagiarctos was prismatic and moderately thick, measuring 150-450 μm on average. It consisted of transversely oriented Hunter-Schreger bands (HSBs) from the enamel-dentine junction (EDJ) to near the outer surface, where it faded into prismless enamel less than 10 μm thick. The width of HSB was variable and averaged between 6 and 10 prisms, and they presented an undulating course both in longitudinal and cross sections. The overall organization of the enamel was similar in all teeth sampled; however, the enamel was thicker in canines and postcanines than in incisors. The crowns of all teeth sampled were uniformly covered by enamel; however, the grooved incisors lacked an enamel cover on the posterior side of the buccal face. Large tubules and tuft-like structures were seen at the EDJ. HSB enamel as well as tubules and tufts at the EDJ suggest increased occlusal loads during feeding, a biomechanical adaptation to avoid enamel cracking and failure. Despite overall simplification in tooth morphology and reduced mastication, the fossil and modern pinnipeds analyzed here retained the complex undulating HSB structure of other fossils and living Carnivora, while other marine mammals such as cetaceans developed simplified radial enamel. PMID:27142598

  4. Identifying a reliable blubber measurement site to assess body condition in a marine mammal with topographically variable blubber, the Pacific walrus

    USGS Publications Warehouse

    Noren, Shawn R.; Udevitz, Mark S.; Triggs, Lisa; Paschke, Jessa; Oland, Lisa; Jay, Chadwick V.

    2015-01-01

    Pacific walruses may be unable to meet caloric requirements in the changing Arctic ecosystem, which could affect body condition and have population-level consequences. Body condition has historically been monitored by measuring blubber thickness over the xiphoid process (sternum). This may be an unreliable condition index because blubber at other sites along the body may be preferentially targeted to balance energetic demands. Animals in aquaria provided an opportunity for controlled study of how blubber topography is altered by caloric intake. Morphology, body mass, blubber thickness (21 sites), and caloric intake of five mature, nonpregnant, nonlactating female walruses were measured monthly (12 month minimum). Body condition (mass × standard length−1) was described by a model that included caloric intake and a seasonal effect, and scaled positively with estimates of total blubber mass. Blubber thicknesses (1.91–10.69 cm) varied topographically and were similar to values reported for free-ranging female walruses. Body condition was most closely related to blubber thickness measured dorsomedially in the region of the anterior insertion of the pectoral flippers (shoulders); sternum blubber thickness was a relatively poor indicator of condition. This study demonstrates the importance of validating condition metrics before using them to monitor free-ranging populations.

  5. Using Personal Mobile Phones to Assess Dietary Intake in Free-Living Adolescents: Comparison of Face-to-Face Versus Telephone Training

    PubMed Central

    Sabaté, Joan

    2016-01-01

    Background Traditional paper-based methods to assess food intake can be cumbersome for adolescents; use of mobile phones to track and photograph what they eat may be a more convenient, reliable, and compelling way to collect data. Objective Our aims were to determine (1) the feasibility of using personal mobile phones to send food records with digital images (FRDIs) among free-living adolescents and (2) whether the quality of food records differed between a high-level intervention group (ie, face-to-face training plus real-time support) and a low-level intervention group (ie, telephone training plus next-day follow-up). Methods Adolescents (N=42, 11 males and 31 females) aged 12-18 years who had a mobile phone with camera enrolled in the study via consecutive sampling. The first group (n=21) received face-to-face training while the second group (n=21) was trained via telephone. Participants received a fiducial marker (FM) and completed a 1-day FRDI using their mobile phones. At every eating occasion, participants were to (1) take clear images of their meals/food with a correctly placed fiducial marker before eating, (2) send the image immediately to a designated email address, (3) right after completing a meal, send a text message listing the time and name of the meal, foods eaten, and amounts eaten, and (4) before sleep, send an “end” text message to indicate completion of food recording. Those who received face-to-face training received real-time support during reporting; those trained by telephone received next-day follow-up. Descriptive statistics and comparison tests were used to determine performance of the groups. Results All participants (N=42) who underwent training completed their 1-day FRDI. A significantly greater proportion of the low-level intervention group compared to the high-level intervention group placed their FM correctly in the image (95% vs 43%, P<.001), had complete information for each meal in their food record (95% vs 71%, P=.04), and

  6. Molecular detection of nematicidal crystalliferous Bacillus thuringiensis strains of Iran and evaluation of their toxicity on free-living and plant-parasitic nematodes.

    PubMed

    Salehi Jouzani, Gholamreza; Seifinejad, Ali; Saeedizadeh, Abbas; Nazarian, Amin; Yousefloo, Majid; Soheilivand, Saeed; Mousivand, Maryam; Jahangiri, Rosa; Yazdani, Mehdi; Amiri, Reza Maali; Akbari, Sepideh

    2008-10-01

    The characterization of nematode-effective strains and cry genes in the Iranian Bacillus thuringiensis (Bt) collection (70 isolates) is presented. Characterization was based on PCR analysis using 12 specific primers for cry5, cry6, cry12, cry13, cry14, and cry21 genes encoding proteins active against nematodes, crystal morphology, and protein band patterns as well as their nematicidal activity on root-knot nematode (Meloidogyne incognita) and two free-living nematodes (Chiloplacus tenuis and Acrobeloides enoplus). PCR results with primers for these genes showed that 22 isolates (31.5%) contain a minimum of one nematode-active cry gene. Strains containing the cry6 gene were the most abundant and represent 22.8% of the isolates. Bt strains harboring cry14 genes were also abundant (14.2%). cry21 and cry5 genes were less abundant, found in 4.2% and 2.8% of the strains, respectively. In total, six different nematode-active cry gene profiles were detected in this collection. Four isolates did not show the expected PCR product size for cry5, cry6, and cry21 genes; they might contain potentially novel insecticidal crystal protein genes. Twenty-two Bt isolates containing nematode-active cry genes were selected for preliminary bioassays on M. incognita. Based on these bioassays, four isolates were selected for detailed bioassays. Isolates YD5 and KON4 at 2 x 10(8) CFU/mL concentrations showed 77% and 81% toxicity on M. incognita, respectively. The free-living nematodes C. tenuis and A. enoplus were more susceptible and the highest mortality was observed within 48 h of incubation at all of the concentrations tested. Maximum mortality was recorded for isolates SN1 and KON4 at 2 x 10(8) CFU/mL concentrations and resulted in 68% and 77% adults deaths of C. tenuis and 68% and 72% for A. enoplus, respectively. Our results showed that PCR is a useful technique for toxicity prediction of nematicidal Bt isolates. PMID:18923549

  7. A Mobile Phone Food Record App to Digitally Capture Dietary Intake for Adolescents in a Free-Living Environment: Usability Study

    PubMed Central

    Sieling, Jared; Moon, Jon; Johnson, LuAnn; Roemmich, James N; Whigham, Leah

    2015-01-01

    Background Mobile technologies are emerging as valuable tools to collect and assess dietary intake. Adolescents readily accept and adopt new technologies; thus, a food record app (FRapp) may be a useful tool to better understand adolescents’ dietary intake and eating patterns. Objective We sought to determine the amenability of adolescents, in a free-living environment with minimal parental input, to use the FRapp to record their dietary intake. Methods Eighteen community-dwelling adolescents (11-14 years) received detailed instructions to record their dietary intake for 3-7 days using the FRapp. Participants were instructed to capture before and after images of all foods and beverages consumed and to include a fiducial marker in the image. Participants were also asked to provide text descriptors including amount and type of all foods and beverages consumed. Results Eight of 18 participants were able to follow all instructions: included pre- and post-meal images, a fiducial marker, and a text descriptor and collected diet records on 2 weekdays and 1 weekend day. Dietary intake was recorded on average for 3.2 (SD 1.3 days; 68% weekdays and 32% weekend days) with an average of 2.2 (SD 1.1) eating events per day per participant. A total of 143 eating events were recorded, of which 109 had at least one associated image and 34 were recorded with text only. Of the 109 eating events with images, 66 included all foods, beverages and a fiducial marker and 44 included both a pre- and post-meal image. Text was included with 78 of the captured images. Of the meals recorded, 36, 33, 35, and 39 were breakfasts, lunches, dinners, and snacks, respectively. Conclusions These data suggest that mobile devices equipped with an app to record dietary intake will be used by adolescents in a free-living environment; however, a minority of participants followed all directions. User-friendly mobile food record apps may increase participant amenability, increasing our understanding of

  8. Free-living nematode peptides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    All nematodes employ a wide array of peptide messengers to control nearly all aspects of the life cycle, including hatching, locomotion, feeding, defense, mating, reproduction, and other behavioral and metabolic events. There are molecular and biological similarities, as well as significant differen...

  9. Free-living bacterial communities associated with tubeworm (Ridgeia piscesae) aggregations in contrasting diffuse flow hydrothermal vent habitats at the Main Endeavour Field, Juan de Fuca Ridge

    PubMed Central

    Forget, Nathalie L; Kim Juniper, S

    2013-01-01

    We systematically studied free-living bacterial diversity within aggregations of the vestimentiferan tubeworm Ridgeia piscesae sampled from two contrasting flow regimes (High Flow and Low Flow) in the Endeavour Hydrothermal Vents Marine Protected Area (MPA) on the Juan de Fuca Ridge (Northeast Pacific). Eight samples of particulate detritus were recovered from paired tubeworm grabs from four vent sites. Most sequences (454 tag and Sanger methods) were affiliated to the Epsilonproteobacteria, and the sulfur-oxidizing genus Sulfurovum was dominant in all samples. Gammaproteobacteria were also detected, mainly in Low Flow sequence libraries, and were affiliated with known methanotrophs and decomposers. The cooccurrence of sulfur reducers from the Deltaproteobacteria and the Epsilonproteobacteria suggests internal sulfur cycling within these habitats. Other phyla detected included Bacteroidetes, Actinobacteria, Chloroflexi, Firmicutes, Planctomycetes, Verrucomicrobia, and Deinococcus–Thermus. Statistically significant relationships between sequence library composition and habitat type suggest a predictable pattern for High Flow and Low Flow environments. Most sequences significantly more represented in High Flow libraries were related to sulfur and hydrogen oxidizers, while mainly heterotrophic groups were more represented in Low Flow libraries. Differences in temperature, available energy for metabolism, and stability between High Flow and Low Flow habitats potentially explain their distinct bacterial communities. PMID:23401293

  10. Pyrosequencing analysis of free-living and attached bacterial communities in Meiliang Bay, Lake Taihu, a large eutrophic shallow lake in China.

    PubMed

    Tang, Xiangming; Li, Linlin; Shao, Keqiang; Wang, Boweng; Cai, Xianlei; Zhang, Lei; Chao, Jianying; Gao, Guang

    2015-01-01

    To elucidate the relationship between particle-attached (PA, ≥ 5.0 μm) and free-living (FL, 0.2-5.0 μm) bacterial communities, samplings were collected seasonally from November 2011 to August 2012 in Meiliang Bay, Lake Taihu, China. We used 454 pyrosequencing of 16S rRNA genes to study bacterial diversity and structure of PA and FL communities. The analysis rendered 37,985 highly qualified reads, subsequently assigned to 1755 operational taxonomic units (97% similarity) for the 8 samples. Although 27 high-level taxonomic groups were obtained, the 3 dominant phyla (Proteobacteria, Actinobacteria, and Bacteroidetes) comprised about 75.9% and 82.4% of the PA and FL fractions, respectively. Overall, we found no significant differences between community types, as indicated by ANOSIM R statistics (R = 0.063, P > 0.05) and the Parsimony test (P = 0.222). Dynamics of bacterial communities were correlated with changes in concentrations of total suspended solids (TSS) and total phosphorus (TP). In summer, a significant taxonomic overlap in the 2 size fractions was observed when Cyanobacteria, a major contributor of TSS and TP, dominated in the water, highlighting the potential rapid exchange between PA and FL bacterial populations in large shallow eutrophic lakes. PMID:25496473

  11. Changes in the community structure of free-living heterotrophic bacteria in the open tropical Pacific Ocean in response to microalgal lysate-derived dissolved organic matter.

    PubMed

    Tada, Yuya; Suzuki, Koji

    2016-07-01

    Dissolved organic matter derived from phytoplankton (DOMP) can affect the bacterial biomass and community structure in aquatic ecosystems. Here, we examined the community response of free-living heterotrophic bacteria, with respect to cellular nucleic acid levels, to the DOMP lysates derived from three phytoplankton strains in the open tropical Pacific. The free amino acid (FAA) composition of each DOMP lysate differed among the microalgal strains. Terminal restriction fragment-length polymorphism analyses with 16S rRNA genes revealed that the community shifts of high nucleic acid (HNA) and low nucleic acid (LNA) bacteria varied significantly with the different DOMP lysate treatments. Furthermore, the FAA composition in DOMP lysates significantly affected the bacterial community shifts in HNA and LNA. Similarity percentage analysis using 16S rRNA gene deep-sequencing revealed that the DOMP lysates from the pelagophyte Pelagomonas calceolata caused relatively large community shifts with Alcaligenes predominating in the HNA fraction. In contrast, the DOMP lysate from the diatom Thalassiosira oceanica induced a community shift in the LNA fraction with a predominance of uncultured Actinobacteria Thus, the data indicate that the DOMP lysates from different microalgae constitute a primary factor altering the dominant bacterial groups in the open ocean. PMID:27162185

  12. Two new free-living marine nematode species of the genus Anoplostoma (Anoplostomatidae) from the mangrove habitats of Xiamen Bay, East China Sea

    NASA Astrophysics Data System (ADS)

    Li, Yongxiang; Guo, Yuqing

    2016-02-01

    Two new species of free-living marine nematode from mangrove habitats in Xiamen Bay are identified. Anoplostoma tumidum sp. nov. is characterized by relatively short outer labial setae (0.86-1.00 h. d.), long tail (c 7.2-8.9, c' 8.3-10.5), an instinct swollen distal portion of slender spicule (Sc 94-101 µm), and well developed copulatory bursae without bursal papillae. A. tumidum sp. nov. differs from all valid species of genus Anoplostoma in copulatory apparatus of males with a distinct swollen distal portion of spicule, and a relatively obvious constriction of head. A. paraviviparum sp. nov. is characterized by relatively long outer labial setae (1.11-1.22 h. d.), and tail (c 6.6-8.5, c' 8.6-10.2); elongated spicules with distinct knob-like proximal and pointed distal ends (Sc 46-69 µm); distinct strip-like gubernaculum (length with 11-15µm); well developed copulatory bursae with precloacal papillae and post-cloacal papillae; and a distinct constriction of head. A. paraviviparum sp. nov. is similar to A. viviparum Bastian, 1865, but differs in the reproductive mode of female and the constriction of head.

  13. The soil flagellate Proleptomonas faecicola: cell organisation and phylogeny suggest that the only described free-living trypanosomatid is not a kinetoplastid but has cercomonad affinities.

    PubMed

    Vickerman, Keith; Le Ray, Dominique; Hoef-Emden, Kerstin; De Jonckheere, Johan

    2002-03-01

    The only putative free-living trypanosomatid is Proleptomonas faecicola described first by Woodcock in 1916 as a coprophilic flagellate with striking Leptomonas-like flagellar movement but lacking a kinetoplast. P faecicola was later identified by Sandon in 1927 as a widespread non-phagotrophic inhabitant of soils. No division stages were seen by either observer. An organism conforming to Woodcock's light microscope description has been isolated from tapwater and cultivated axenically in various serum-containing media. Division has been shown to occur in an aflagellate stage enclosed in a thin cyst wall. Electron microscopy of the flagellate stage reveals that, in addition to the long locomotory flagellum, a second non-motile flagellum is present attached to the body along its entire length. The flagellate's ultrastructure lacks all the major features of the Trypanosomatidae. The several mitochondria of Proleptomonas have tubular cristae and lie between intracytoplasmic microtubules originating as a loose cone associated with the flagellar basal bodies. This cytoskeleton is much reduced in the division cyst. A comparable Proleptomonas-like flagellate with similar division cysts has been observed in soil samples from farmland. Phylogenetic analysis based on SSU rRNA gene sequences suggests that the cultured organism identified here as Proleptomonas is unrelated to the Kinetoplastida and has affinities with the Phylum Cercozoa Cavalier-Smith, even though in morphology, life cycle and mode of feeding it bears little resemblance to any member of that diverse grouping. PMID:12022280

  14. Microbiological quality in Finnish public swimming pools and whirlpools with special reference to free living amoebae: a risk factor for contact lens wearers?

    PubMed Central

    Vesaluoma, M; Kalso, S; Jokipii, L; Warhurst, D; Pönkä, A; Tervo, T

    1995-01-01

    To assess the possible risk of microbial keratitis associated with swimming or bathing in public pools, the microbiological quality as well as the presence of free living amoebae in 16 halogenated swimming pools and whirlpools, located in Helsinki, Finland, was determined. Five additional whirlpools situated in the ferries cruising from Finland to Sweden were included in the study. Other parameters investigated were the total bacterial count, identification of Pseudomonas aeruginosa and Staphylococcus aureus, measurement of free residual and combined chlorine, potassium permanganate index, urine, pH, and turbidity. Amoebae were detected in 41% of the pool water samples studied. Seven of 11 whirlpools and four of 10 swimming pools were shown to contain amoebae. An Acanthamoeba species was isolated from only one outdoor swimming pool; the other amoebae belonged to the genera Vexillifera, Flabellula, Hartmannella, and Rugipes. Although not a single verified case of Acanthamoeba keratitis has been found in Finland, the findings show that there is a theoretical risk of amoebic and bacterial keratitis associated with swimming or bathing in properly cleaned public pools. Consequently, we do not recommend swimming or bathing with contact lenses. PMID:7696241

  15. Resting and daily energy expenditures of free-living field voles are positively correlated but reflect extrinsic rather than intrinsic effects

    PubMed Central

    Speakman, J. R.; Ergon, T.; Cavanagh, R.; Reid, K.; Scantlebury, D. M.; Lambin, X.

    2003-01-01

    Resting metabolic rates at thermoneutral (RMRts) are unexpectedly variable. One explanation is that high RMRts intrinsically potentiate a greater total daily energy expenditure (DEE), but recent work has suggested that DEE is extrinsically defined by the environment, which independently affects RMRt. This extrinsic effect could occur because expenditure is forced upwards in poor habitats or enabled to rise in good habitats. We provide here an intraspecific test for an association between RMRt and DEE that separates intrinsic from extrinsic effects and forcing from enabling effects. We measured the DEE and RMRt of 75 free-living short-tailed field voles at two time points in late winter. Across all sites, there was a positive link between individual variation in RMRt and DEE. This correlation, however, emerged only because of an effect across sites, rather than because of an intrinsic association within sites. We defined site quality from the survivorship of voles at the sites and the time at which they commenced breeding in spring. The associations between DEE/RMRt and site quality suggested that in February voles in poorer sites had higher energy demands, indicating that DEE was forced upwards, but in March the opposite was true, with higher demands in good sites, indicating that high expenditure was enabled. These data show that daily energy demands are extrinsically defined, with a link to RMRt that is secondary or independent. Both forcing and enabling effects of the environment may pertain at different times of year. PMID:14615588

  16. Can parasites be indicators of free-living diversity? Relationships between species richness and the abundance of larval trematodes and of local benthos and fishes

    USGS Publications Warehouse

    Hechinger, R.F.; Lafferty, K.D.; Huspeni, T.C.; Brooks, A.J.; Kuris, A.M.

    2007-01-01

    Measuring biodiversity is difficult. This has led to efforts to seek taxa whose species richness correlates with the species richness of other taxa. Such indicator taxa could then reduce the time and cost of assessing the biodiversity of the more extensive community. The search for species richness correlations has yielded mixed results, however. This may be primarily because of the lack of functional relationships between the taxa studied. Trematode parasites are highly promising bioindicators. Diverse assemblages of larval trematode parasites are easily sampled in intermediate host snails. Through their life cycles these parasites are functionally coupled with the surrounding free-living diversity of vertebrate and invertebrate animals. It has been shown that larval trematodes in snails correlate positively with bird diversity and abundance. Here, we explore whether trematodes also correlate with standard measures of fishes, and large and small benthos, for 32 sites in three wetlands. We found associations between trematodes and benthic communities that were not consistent across wetlands. The associations were, however, consistently positive for large benthic species richness and density. Some of the contrasting associations between trematode and benthos may be explained by negative associations between large and small benthos. We found no associations with fish communities (probably because of the inadequacy of standard "snapshot" sampling methods for highly mobile fishes). The results support further exploration of trematodes as bioindicators of diversity and abundance of animal communities. ?? 2006 Springer-Verlag.

  17. Free-living bacterial communities associated with tubeworm (Ridgeia piscesae) aggregations in contrasting diffuse flow hydrothermal vent habitats at the Main Endeavour Field, Juan de Fuca Ridge.

    PubMed

    Forget, Nathalie L; Kim Juniper, S

    2013-04-01

    We systematically studied free-living bacterial diversity within aggregations of the vestimentiferan tubeworm Ridgeia piscesae sampled from two contrasting flow regimes (High Flow and Low Flow) in the Endeavour Hydrothermal Vents Marine Protected Area (MPA) on the Juan de Fuca Ridge (Northeast Pacific). Eight samples of particulate detritus were recovered from paired tubeworm grabs from four vent sites. Most sequences (454 tag and Sanger methods) were affiliated to the Epsilonproteobacteria, and the sulfur-oxidizing genus Sulfurovum was dominant in all samples. Gammaproteobacteria were also detected, mainly in Low Flow sequence libraries, and were affiliated with known methanotrophs and decomposers. The cooccurrence of sulfur reducers from the Deltaproteobacteria and the Epsilonproteobacteria suggests internal sulfur cycling within these habitats. Other phyla detected included Bacteroidetes, Actinobacteria, Chloroflexi, Firmicutes, Planctomycetes, Verrucomicrobia, and Deinococcus-Thermus. Statistically significant relationships between sequence library composition and habitat type suggest a predictable pattern for High Flow and Low Flow environments. Most sequences significantly more represented in High Flow libraries were related to sulfur and hydrogen oxidizers, while mainly heterotrophic groups were more represented in Low Flow libraries. Differences in temperature, available energy for metabolism, and stability between High Flow and Low Flow habitats potentially explain their distinct bacterial communities. PMID:23401293

  18. Activity re-assignment and microclimate selection of free-living Arabian oryx: responses that could minimise the effects of climate change on homeostasis?

    PubMed

    Hetem, Robyn S; Strauss, W Maartin; Fick, Linda G; Maloney, Shane K; Meyer, Leith C R; Shobrak, Mohammed; Fuller, Andrea; Mitchell, Duncan

    2012-12-01

    Predicting whether behaviour could buffer the effects of climate change on long-lived mammals requires a better understanding of the long-term behavioural responses of mammals to environmental stress. Using biologging, we measured locomotor activity and microclimate selection, over eight months, in five Arabian oryx (Oryx leucoryx) living free in a Saudi Arabian desert. The oryx displayed seasonal flexibility in activity patterns, shifting from a continuous 24-h activity pattern with crepuscular peaks in cooler months to a predominantly nocturnal activity pattern during the hottest months, without reducing the total 24-h activity level. The proportion of total 24-h activity that occurred during daylight hours was just 29±8% during the hottest months, versus 53±8% (mean±SD, n=5 oryx) in the other months. The attenuation in diurnal activity levels during the hot months was accompanied by the selection of cooler microclimates, presumably via shade seeking, during the heat of the day. Analysis of miniature black globe (miniglobe) temperature from a remote sensor on the collar of two female animals revealed that oryx selected microclimates cooler than the microclimates in direct sun at higher environmental heat loads across all periods, but with enhanced efficiency during the dry periods. We have quantified activity re-assignment and microclimate selection as responses to hot arid conditions in a free-living artiodactyl. Such flexible behavioural processes may act to buffer the adverse effects of the progressively hotter and drier conditions predicted to occur with climate change. PMID:23036437

  19. Associations of quality of life with physical activity, fruit and vegetable consumption, and physical inactivity in a free living, multiethnic population in Hawaii: a longitudinal study

    PubMed Central

    2010-01-01

    Introduction High intake of fruit and vegetables and being physically active are associated with reduced risk of chronic diseases. In the current study, we examined the associations of physical activity, fruit and vegetable consumption, and TV/video watching (indicator for physical inactivity) with perceived quality of life (QOL) in a sample of free living adults. Methods A cohort (N = 139) from a random, multi-ethnic sample of 700 adults living in Hawaii was evaluated at 3-month intervals for the first year and 6-month intervals for the second year. QOL was assessed from self-reports of mental or physical health at the end of the study. Results Overall, the cohort participants appeared to maintain relatively constant levels of physical activity, fruit and vegetable intake, and TV/video watching. Physical activity was positively related to mental health (p-values < 0.05), but not physical health, at all time points regardless of participants' fruit and vegetable consumption and hours of TV/video watching. Neither mental nor physical health was associated with fruit and vegetable intake or TV/video watching. Conclusion Our study supports that physical activity is positively associated with mental health. Fruit and vegetable consumption and TV/video watching may be too specific to represent an individual's overall nutritional status and physical inactivity, respectively. PMID:21092223

  20. Use of reverse transcriptase polymerase chain reaction (RT-PCR) in molecular screening of Newcastle disease virus in poultry and free-living bird populations.

    PubMed

    Carrasco, Adriano de Oliveira Torres; Rodrigues, Juliana Nogueira Martins; Seki, Meire Christina; de Moraes, Fabricio Edgar; Silva, Jaqueline Raymondi; Durigon, Edison Luis; Pinto, Aramis Augusto

    2013-02-01

    The aim of this study was to evaluate a simple molecular method of reverse transcriptase polymerase chain reaction (RT-PCR) to differentiate Newcastle disease virus strains according to their pathogenicity, in order to use it in molecular screening of Newcastle disease virus in poultry and free-living bird populations. Specific primers were developed to differentiate LaSota--LS--(vaccine strain) and Sao Joao do Meriti--SJM--strain (highly pathogenic strain). Chickens and pigeons were experimentally vaccinated/infected for an in vivo study to determine virus shedding in feces. Validation of sensitivity and specificity of the primers (SJM and LS) by experimental models used in the present study and results obtained in the molecular analysis of the primers by BLAST made it possible to generalize results. The development of primers that differentiate the level of pathogenicity of NDV stains is very important, mainly in countries where real-time RT-PCR is still not used as a routine test. These primers were able to determine the presence of the agent and to differentiate it according to its pathogenicity. PMID:22983878

  1. Seasonal changes in plasma testosterone and glucocorticosteroids in free-living male yellow-pine chipmunks and the response to capture and handling.

    PubMed

    Place, N J; Kenagy, G J

    2000-05-01

    We measured plasma levels of testosterone, corticosterone, and cortisol in free-living male yellow-pine chipmunks to demonstrate the patterns of seasonal variation and to assess the effects of capture and handling on hormone levels. We achieved the latter by modifying our standard trapping technique (blood samples collected within 1-3 h of capture) to obtain blood samples that allowed measurement of hormone levels within 3 min of capture (basal) and again 30 min later. By alternating the modified and standard trapping techniques over 7 months of the active season we demonstrated that seasonal patterns of variation in steroid hormone levels can be accurately described with the simpler, standard trapping technique. Basal and 30-min post-capture testosterone levels were high during mating and dropped to a persistently low level thereafter. Conversely, both cortisol and corticosterone were at their seasonal low during mating and climbed to peak levels in June following reproduction. Plasma glucocorticosteroid levels increased during the 30 min after capture and handling at all times of the active season, and these elevated levels were similar to the levels obtained by standard trapping. Testosterone levels during the mating period also increased in response to capture and handling. The contrasting patterns of seasonal variation in glucocorticosteroid and testosterone levels and the changes induced by capture and handling suggest that when testosterone concentration is high, adrenocortical activity is suppressed. PMID:10841266

  2. Efficacy of amitraz-impregnated collars on white-tailed deer (Artiodactyla: Cervidae) in reducing free-living populations of lone star ticks (Acari: Ixodidae).

    PubMed

    Pound, J M; Lohmeyer, K H; Davey, R B; Miller, J A; George, J E

    2012-12-01

    Over a 7 yr period, we monitored the effect of a commercially available, amitraz impregnated anti-tick collar in controlling free-living populations of lone star ticks, Amblyomma americanum (L.) when manually fitted around necks of white-tailed deer, Odocoileus virginianus (Zimmermann). Study animals in treatment and control groups were confined in 38.8 ha game-fenced and densely vegetated treatment plots in South Texas. Tick densities during years 1 and 7 served as untreated pre- and posttreatment comparisons and treatments occurred during years 2 through 5. Reductions in tick densities in the treatment plot were compared against tick densities in a control plot having similar vegetation and numbers of untreated deer. During years of treatment, indices of control pressure ranged from 18.2 to 82.6 for nymphs and 16.9-78.7 for adults, and efficacy, expressed as percentage control during the final year of treatment, was 77.2 and 85.0%, respectively, for nymphal and adult ticks. These data show that acaricidal collar treatments provide efficacies very similar to those achieved with the existing ivermectin-medicated bait and '4-Poster' topical treatment technologies to control ticks feeding on wild white-tailed deer. PMID:23356088

  3. Trophic restructuring (Wieser 1953) of free-living nematode in marine sediment experimentally enriched to increasing doses of pharmaceutical penicillin G.

    PubMed

    Nasri, Ahmed; Jouili, Soufiane; Boufahja, Fehmi; Hedfi, Amor; Saidi, Ibtihel; Mahmoudi, Ezzeddine; Aïssa, Patricia; Essid, Naceur; Hamouda, Beyrem

    2016-08-01

    Trophic structure of free living nematode from Bizerte lagoon was tested by a microcosmic study after 30 days of exposure with 5 increasing doses of pharmaceutical penicillin G (D1: 3 mg L(-1), D2: 30 mg L(-1), D3: 300 mg L(-1), D4: 600 mg L(-1), D5: 700 mg L(-1)). Results showed significant differences between nematode assemblages from undisturbed controls and those from penicillin G treatments. Selective deposit-feeders (1A) or nonselective deposit-feeders (1B), very abundant in the control microcosm, were significantly affected and their dominance declined significantly. Epistrate feeders (2A) were significantly gradual increase for all microcosms treated with penicillin G, appeared to be more tolerant to the antibiotic and to take advantage of the growing scarcity of other trophic groups. Compared to the control microcosms, omnivorous-carnivorous (2B) was found to be higher in all treated microcosms, with the exception of those treated with D5. Trophic index (Σθ(2)) was significantly reduced in all microcosms treated whereas trophic ratio 1B/2A appears to be insignificant. PMID:27230096

  4. Impact of a Traditional Dietary Supplement with Coconut Milk and Soya Milk on the Lipid Profile in Normal Free Living Subjects

    PubMed Central

    Ekanayaka, R. A. I.; Ekanayaka, N. K.; Perera, B.; De Silva, P. G. S. M.

    2013-01-01

    Background. The effects of coconut fat and soya fat on serum lipids are controversial. This study was designed to investigate the lipid effects of coconut milk and soya milk supplementation on the lipid profile of free living healthy subjects. Methods. Sixty (60) healthy volunteers aged 18–57 years were given coconut milk porridge (CMP) for 5 days of the week for 8 weeks, followed by a 2-week washout period, subsequent to which they received isoenergetic soya milk porridge (SMP) for 8 weeks. Results. The LDL (low density lipoprotein) levels decreased with CMP and reached statistical significance in the total study population and in the >130 baseline LDL group. The HDL (high density lipoprotein) levels rose significantly with CMP supplementation (P = 0.000). Conclusions. We conclude that coconut fat in the form of CM does not cause a detrimental effect on the lipid profile in the general population and in fact is beneficial due to the decrease in LDL and rise in HDL. SMP will be of benefit only in those whose baseline LDL levels are elevated. PMID:24282632

  5. Cooccurrence of Free-Living Amoebae and Nontuberculous Mycobacteria in Hospital Water Networks, and Preferential Growth of Mycobacterium avium in Acanthamoeba lenticulata

    PubMed Central

    Ovrutsky, Alida R.; Kartalija, Marinka; Bai, Xiyuan; Jackson, Mary; Gibbs, Sara; Falkinham, Joseph O.; Iseman, Michael D.; Reynolds, Paul R.; McDonnell, Gerald

    2013-01-01

    The incidence of lung and other diseases due to nontuberculous mycobacteria (NTM) is increasing. NTM sources include potable water, especially in households where NTM populate pipes, taps, and showerheads. NTM share habitats with free-living amoebae (FLA) and can grow in FLA as parasites or as endosymbionts. FLA containing NTM may form cysts that protect mycobacteria from disinfectants and antibiotics. We first assessed the presence of FLA and NTM in water and biofilm samples collected from a hospital, confirming the high prevalence of NTM and FLA in potable water systems, particularly in biofilms. Acanthamoeba spp. (genotype T4) were mainly recovered (8/17), followed by Hartmannella vermiformis (7/17) as well as one isolate closely related to the genus Flamella and one isolate only distantly related to previously described species. Concerning mycobacteria, Mycobacterium gordonae was the most frequently found isolate (9/17), followed by Mycobacterium peregrinum (4/17), Mycobacterium chelonae (2/17), Mycobacterium mucogenicum (1/17), and Mycobacterium avium (1/17). The propensity of Mycobacterium avium hospital isolate H87 and M. avium collection strain 104 to survive and replicate within various FLA was also evaluated, demonstrating survival of both strains in all amoebal species tested but high replication rates only in Acanthamoeba lenticulata. As A. lenticulata was frequently recovered from environmental samples, including drinking water samples, these results could have important consequences for the ecology of M. avium in drinking water networks and the epidemiology of disease due to this species. PMID:23475613

  6. Characterization of Low Pathogenic Avian Influenza Virus Subtype H9N2 Isolated from Free-Living Mynah Birds (Acridotheres tristis) in the Sultanate of Oman.

    PubMed

    Body, Mohammad H; Alrarawahi, Abdulmajeed H; Alhubsy, Saif S; Saravanan, Nirmala; Rajmony, Sunil; Mansoor, Muhammad Khalid

    2015-06-01

    A low pathogenic avian influenza virus was identified from free-living birds (mynah, Acridotheres tristis) of the starling family. Virus was isolated by inoculation of homogenized suspension from lung, tracheal, spleen, and cloacal swabs into the allantoic cavity of embryonated chicken eggs. Subtype of the isolate was characterized as H9N2 by hemagglutination inhibition test using monospecific chicken antisera to a wide range of influenza reference strain. Pathogenicity of the isolate was determined by intravenous pathogenicity index. The virus was reisolated from experimentally infected chicken. Additionally, the isolate was subjected to reverse transcriptase PCR using partial hemagglutinin (HA) gene-specific primers and yielded an amplicon of 487 bp. HA gene sequence analysis revealed 99% sequence homology among mynah and chicken isolates from Oman. On phylogenetic analysis, isolates from mynah (A/mynnah/Oman/AIVS6/2005) and chicken (A/chicken/Oman/AIVS3/2006; A/chicken/Oman/AIVS7/2006) clustered together tightly, indicating these free-flying birds may be a source of introduction of H9N2 subtype in poultry bird in Oman. Moreover, the HA gene of H9N2 isolates from Oman resembled those of viruses of the G1-like lineage and were very similar to those from United Arab Emirates. PMID:26473686

  7. Impacts of Organic and Conventional Crop Management on Diversity and Activity of Free-Living Nitrogen Fixing Bacteria and Total Bacteria Are Subsidiary to Temporal Effects

    PubMed Central

    Orr, Caroline H.; Leifert, Carlo; Cummings, Stephen P.; Cooper, Julia M.

    2012-01-01

    A three year field study (2007–2009) of the diversity and numbers of the total and metabolically active free-living diazotophic bacteria and total bacterial communities in organic and conventionally managed agricultural soil was conducted using the Nafferton Factorial Systems Comparison (NFSC) study, in northeast England. Fertility management appeared to have little impact on both diazotrophic and total bacterial communities. However, copy numbers of the nifH gene did appear to be negatively impacted by conventional crop protection measures across all years suggesting diazotrophs may be particularly sensitive to pesticides. Impacts of crop management were greatly overshadowed by the influence of temporal effects with diazotrophic communities changing on a year by year basis and from season to season. Quantitative analyses using qPCR of each community indicated that metabolically active diazotrophs were highest in year 1 but the population significantly declined in year 2 before recovering somewhat in the final year. The total bacterial population in contrast increased significantly each year. It appeared that the dominant drivers of qualitative and quantitative changes in both communities were annual and seasonal effects. Moreover, regression analyses showed activity of both communities was significantly affected by soil temperature and climatic conditions. PMID:23285218

  8. Molecular identification and characterization of Mycobacterium avium subspecies paratuberculosis in free living non-human primate (Rhesus macaques) from North India.

    PubMed

    Singh, S V; Singh, A V; Singh, P K; Kumar, A; Singh, B

    2011-05-01

    In recent years, Mycobacterium avium subspecies paratuberculosis (MAP) has emerged as major animal pathogen with significant zoonotic concerns, worldwide. MAP infection is endemic in domestic and wild ruminant population in India. However, information on MAP infection in free ranging animal species and non human primates is limited. Present study aimed to estimate the status of MAP infection in free living Rhesus macaques suffering with multiple clinical conditions (coughing and loose stool). A total of 25 stool samples were collected from six colonies of Rhesus macaques from Mathura region (North India) and screened for the presence of MAP, using microscopic examination and IS900 PCR, directly from stool samples. PCR positive DNA samples were further genotyped using IS1311 PCR-restriction enzyme analysis. Of the 25 stool samples, 10 (40.0%) and 2 (8.0%) were positive for MAP using microscopic examination and direct IS900 PCR, respectively. IS900 PCR positive DNA samples were genotyped as 'Indian Bison type', which is a major MAP genotype infecting domestic and wild ruminant species and human beings in India. Prevalence of MAP in Rhesus macaques (Indian monkeys) was moderately high and confirmed interspecies sharing of MAP between domestic livestock and non-human primates. Presence of MAP in non-human primates, support the etiological role of MAP in inflammatory bowel disease patients. Indian monkeys may serve as model for understanding the role of non-human primates in sustenance, transmission and pathogenesis of MAP infection. PMID:21255839

  9. Getting a feel for parameters: using interactive parallel plots as a tool for parameter identification in the new rainfall-runoff model WALRUS

    NASA Astrophysics Data System (ADS)

    Brauer, Claudia; Torfs, Paul; Teuling, Ryan; Uijlenhoet, Remko

    2015-04-01

    Recently, we developed the Wageningen Lowland Runoff Simulator (WALRUS) to fill the gap between complex, spatially distributed models often used in lowland catchments and simple, parametric models which have mostly been developed for mountainous catchments (Brauer et al., 2014ab). This parametric rainfall-runoff model can be used all over the world in both freely draining lowland catchments and polders with controlled water levels. The open source model code is implemented in R and can be downloaded from www.github.com/ClaudiaBrauer/WALRUS. The structure and code of WALRUS are simple, which facilitates detailed investigation of the effect of parameters on all model variables. WALRUS contains only four parameters requiring calibration; they are intended to have a strong, qualitative relation with catchment characteristics. Parameter estimation remains a challenge, however. The model structure contains three main feedbacks: (1) between groundwater and surface water; (2) between saturated and unsaturated zone; (3) between catchment wetness and (quick/slow) flowroute division. These feedbacks represent essential rainfall-runoff processes in lowland catchments, but increase the risk of parameter dependence and equifinality. Therefore, model performance should not only be judged based on a comparison between modelled and observed discharges, but also based on the plausibility of the internal modelled variables. Here, we present a method to analyse the effect of parameter values on internal model states and fluxes in a qualitative and intuitive way using interactive parallel plotting. We applied WALRUS to ten Dutch catchments with different sizes, slopes and soil types and both freely draining and polder areas. The model was run with a large number of parameter sets, which were created using Latin Hypercube Sampling. The model output was characterised in terms of several signatures, both measures of goodness of fit and statistics of internal model variables (such as the

  10. Reconstructing lead isotope exposure histories preserved in the growth layers of walrus teeth using the SHRIMP II ion microprobe

    SciTech Connect

    Stern, R.A.; Outridge, P.M.; Davis, W.J.; Stewart, R.E.A.

    1999-05-15

    Development of a microprobe technique to determine Pb isotope ratios within the growth layers of mammal teeth could have widespread applications in Pb toxicology, Pb pollution tracing, and human and animal ecology. Here, the SHRIMP II ion microprobe is shown to possess sufficient sensitivity, accuracy, and precision to satisfactorily determine Pb isotope ratios in the canine tooth cementum of a walrus (Odobenus rosmarus rosmarus), with a sampling resolution of 130 {micro}m. The tooth layers were estimated to contain only 1--3 {micro}g/gf Pb. By combining multiple replicates within each annual layer, the {+-}1 SE uncertainty was typically {+-}1% for {sup 206}Pb/{sup 207}Pb and {+-}0.5% for {sup 208}Pb/{sup 207}Pb. Significant isotopic differences were found between layers deposited at age 10 and ages 2, 27, and 30. This result, together with corroborative data on excised cementum fragments analyzed by thermal ionization mass spectrometry, indicates that the animal migrated into different geological terrains several times during its life. There was no evidence of exchange between the Pb deposited in early growth layers and more recent ambient Pb.

  11. Invasion biology in non-free-living species: interactions between abiotic (climatic) and biotic (host availability) factors in geographical space in crayfish commensals (Ostracoda, Entocytheridae)

    PubMed Central

    Mestre, Alexandre; Aguilar-Alberola, Josep A; Baldry, David; Balkis, Husamettin; Ellis, Adam; Gil-Delgado, Jose A; Grabow, Karsten; Klobučar, Göran; Kouba, Antonín; Maguire, Ivana; Martens, Andreas; Mülayim, Ayşegül; Rueda, Juan; Scharf, Burkhard; Soes, Menno; S Monrós, Juan; Mesquita-Joanes, Francesc

    2013-01-01

    In invasion processes, both abiotic and biotic factors are considered essential, but the latter are usually disregarded when modeling the potential spread of exotic species. In the framework of set theory, interactions between biotic (B), abiotic (A), and movement-related (M) factors in the geographical space can be hypothesized with BAM diagrams and tested using ecological niche models (ENMs) to estimate A and B areas. The main aim of our survey was to evaluate the interactions between abiotic (climatic) and biotic (host availability) factors in geographical space for exotic symbionts (i.e., non-free-living species), using ENM techniques combined with a BAM framework and using exotic Entocytheridae (Ostracoda) found in Europe as model organisms. We carried out an extensive survey to evaluate the distribution of entocytherids hosted by crayfish in Europe by checking 94 European localities and 12 crayfish species. Both exotic entocytherid species found, Ankylocythere sinuosa and Uncinocythere occidentalis, were widely distributed in W Europe living on the exotic crayfish species Procambarus clarkii and Pacifastacus leniusculus, respectively. No entocytherids were observed in the remaining crayfish species. The suitable area for A. sinuosa was mainly restricted by its own limitations to minimum temperatures in W and N Europe and precipitation seasonality in circum-Mediterranean areas. Uncinocythere occidentalis was mostly restricted by host availability in circum-Mediterranean regions due to limitations of P. leniusculus to higher precipitation seasonality and maximum temperatures. The combination of ENMs with set theory allows studying the invasive biology of symbionts and provides clues about biogeographic barriers due to abiotic or biotic factors limiting the expansion of the symbiont in different regions of the invasive range. The relative importance of abiotic and biotic factors on geographical space can then be assessed and applied in conservation plans. This

  12. Nocturnal sleep-related variables from 24-h free-living waist-worn accelerometry: International Study of Childhood Obesity, Lifestyle and the Environment

    PubMed Central

    Tudor-Locke, C; Mire, E F; Barreira, T V; Schuna, J M; Chaput, J-P; Fogelholm, M; Hu, G; Kurpad, A; Kuriyan, R; Lambert, E V; Maher, C; Maia, J; Matsudo, V; Olds, T; Onywera, V; Sarmiento, O L; Standage, M; Tremblay, M S; Zhao, P; Church, T S; Katzmarzyk, P T

    2015-01-01

    Objectives: We describe the process of identifying and defining nocturnal sleep-related variables (for example, movement/non-movement indicators of sleep efficiency, waking episodes, midpoint and so on) using the unique 24-h waist-worn free-living accelerometer data collected in the International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE). Methods: Seven consecutive days of 24-h waist-worn accelerometer (GT3X+, ActiGraph LLC) data were collected from over 500 children at each site. An expert subgroup of the research team with accelerometry expertize, frontline data collectors and data managers met on several occasions to categorize and operationally define nocturnal accelerometer signal data patterns. The iterative process was informed by the raw data drawn from a sub set of the US data, and culminated in a refined and replicable delineated definition for each identified nocturnal sleep-related variable. Ultimately based on 6318 participants from all 12 ISCOLE sites with valid total sleep episode time (TSET), we report average clock times for nocturnal sleep onset, offset and midpoint in addition to sleep period time, TSET and restful sleep efficiency (among other derived variables). Results: Nocturnal sleep onset occurred at 2218 hours and nocturnal sleep offset at 0707 hours. The mean midpoint was 0243 hours. The sleep period time of 529.6 min (8.8 h) was typically accumulated in a single episode, making the average TSET very similar in duration (529.0 min). The mean restful sleep efficiency ranged from 86.8% (based on absolute non-movement of 0 counts per minute) to 96.0% (based on relative non-movement of <100 counts per minute). Conclusions: These variables extend the potential of field-based 24-h waist-worn accelerometry to distinguish and categorize the underlying robust patterns of movement/non-movement signals conveying magnitude, duration, frequency and periodicity during the nocturnal sleep period. PMID:27152185

  13. The Passive Yet Successful Way of Planktonic Life: Genomic and Experimental Analysis of the Ecology of a Free-Living Polynucleobacter Population

    PubMed Central

    Hahn, Martin W.; Scheuerl, Thomas; Jezberová, Jitka; Koll, Ulrike; Jezbera, Jan; Šimek, Karel; Vannini, Claudia; Petroni, Giulio; Wu, Qinglong L.

    2012-01-01

    Background The bacterial taxon Polynucleobacter necessarius subspecies asymbioticus represents a group of planktonic freshwater bacteria with cosmopolitan and ubiquitous distribution in standing freshwater habitats. These bacteria comprise <1% to 70% (on average about 20%) of total bacterioplankton cells in various freshwater habitats. The ubiquity of this taxon was recently explained by intra-taxon ecological diversification, i.e. specialization of lineages to specific environmental conditions; however, details on specific adaptations are not known. Here we investigated by means of genomic and experimental analyses the ecological adaptation of a persistent population dwelling in a small acidic pond. Findings The investigated population (F10 lineage) contributed on average 11% to total bacterioplankton in the pond during the vegetation periods (ice-free period, usually May to November). Only a low degree of genetic diversification of the population could be revealed. These bacteria are characterized by a small genome size (2.1 Mb), a relatively small number of genes involved in transduction of environmental signals, and the lack of motility and quorum sensing. Experiments indicated that these bacteria live as chemoorganotrophs by mainly utilizing low-molecular-weight substrates derived from photooxidation of humic substances. Conclusions Evolutionary genome streamlining resulted in a highly passive lifestyle so far only known among free-living bacteria from pelagic marine taxa dwelling in environmentally stable nutrient-poor off-shore systems. Surprisingly, such a lifestyle is also successful in a highly dynamic and nutrient-richer environment such as the water column of the investigated pond, which was undergoing complete mixis and pronounced stratification in diurnal cycles. Obviously, metabolic and ecological versatility is not a prerequisite for long-lasting establishment of abundant bacterial populations under highly dynamic environmental conditions. Caution

  14. Effect of elevated CO2 on the dynamics of particle-attached and free-living bacterioplankton communities in an Arctic fjord

    NASA Astrophysics Data System (ADS)

    Sperling, M.; Piontek, J.; Gerdts, G.; Wichels, A.; Schunck, H.; Roy, A.-S.; La Roche, J.; Gilbert, J.; Nissimov, J. I.; Bittner, L.; Romac, S.; Riebesell, U.; Engel, A.

    2013-01-01

    In the frame of the European Project on Ocean Acidification (EPOCA), the response of an Arctic pelagic community (<3 mm) to a gradient of seawater pCO2 was investigated. For this purpose 9 large-scale in situ mesocosms were deployed in Kongsfjorden, Svalbard (78°56.2´ N, 11°53.6´ E), in 2010. The present study investigates effects on the communities of particle-attached (PA; >3 μm) and free-living (FL; < 3 μm > 0.2 μm) bacteria by Automated Ribosomal Intergenic Spacer Analysis (ARISA) in 6 of the mesocosms, ranging from 185 to 1050 μatm initial pCO2, and the surrounding fjord. ARISA was able to resolve, on average, 27 bacterial band classes per sample and allowed for a detailed investigation of the explicit richness and diversity. Both, the PA and the FL bacterioplankton community exhibited a strong temporal development, which was driven mainly by temperature and phytoplankton development. In response to the breakdown of a picophytoplankton bloom, numbers of ARISA band classes in the PA community were reduced at low and medium CO2 (~ 185-685 μatm) by about 25%, while they were more or less stable at high CO2 (~ 820-1050 μatm). We hypothesise that enhanced viral lysis and enhanced availability of organic substrates at high CO2 resulted in a more diverse PA bacterial community in the post-bloom phase. Despite lower cell numbers and extracellular enzyme activities in the post-bloom phase, bacterial protein production was enhanced in high CO2 mesocosms, suggesting a positive effect of community richness on this function and on carbon cycling by bacteria.

  15. Relationships between Free-Living Protozoa, Cultivable Legionella spp., and Water Quality Characteristics in Three Drinking Water Supplies in the Caribbean▿†

    PubMed Central

    Valster, Rinske M.; Wullings, Bart A.; van den Berg, Riemsdijk; van der Kooij, Dick

    2011-01-01

    The study whose results are presented here aimed at identifying free-living protozoa (FLP) and conditions favoring the growth of these organisms and cultivable Legionella spp. in drinking water supplies in a tropical region. Treated and distributed water (±30°C) of the water supplies of three Caribbean islands were sampled and investigated with molecular techniques, based on the 18S rRNA gene. The protozoan host Hartmannella vermiformis and cultivable Legionella pneumophila were observed in all three supplies. Operational taxonomic units (OTUs) with the highest similarity to the potential or candidate hosts Acanthamoeba spp., Echinamoeba exundans, E. thermarum, and an Neoparamoeba sp. were detected as well. In total, 59 OTUs of FLP were identified. The estimated protozoan richness did not differ significantly between the three supplies. In supply CA-1, the concentration of H. vermiformis correlated with the concentration of Legionella spp. and clones related to Amoebozoa predominated (82%) in the protozoan community. These observations, the low turbidity (<0.2 nephelometric turbidity units [NTU]), and the varying ATP concentrations (1 to 12 ng liter−1) suggest that biofilms promoted protozoan growth in this supply. Ciliophora represented 25% of the protozoan OTUs in supply CA-2 with elevated ATP concentrations (maximum, 55 ng liter−1) correlating with turbidity (maximum, 62 NTU) caused by corroding iron pipes. Cercozoan types represented 70% of the protozoan clones in supply CA-3 with ATP concentrations of <1 ng liter−1 and turbidity of <0.5 NTU in most samples of distributed water. The absence of H. vermiformis in most samples from supply CA-3 suggests that growth of this protozoan is limited at ATP concentrations of <1 ng liter−1. PMID:21873489

  16. Estimation of normal tear production in free-living Eurasian black vultures (Aegypius monachus) and griffon vultures (Gyps fulvus) in Dadia National Park, Greece.

    PubMed

    Komnenou, Anastasia T; Thomas, Angelos L N; Danika, Stefania E; Skartsi, Theodora; Vasilakis, Dimitris P; Cárcamo, Beatriz; Ofri, Ron

    2013-06-01

    The aim of this study was to record the Schirmer tear test I (STT I) measurements in free-living vultures in order to estimate normal values. The Eurasian black vulture (Aegypius monachus), which breeds in the Mediterranean region and Asia, is listed as near threatened; it is also classified as vulnerable at the European level and endangered in Greece. The griffon vulture (Gyps fulvus), once widespread across the continent, has undergone a dramatic decline which has led to its extinction in many regions. Sixty-two animals were examined in total including 54 black vultures and 8 griffon vultures. The birds were classified into five age groups while four age groups were then combined into one large group: free-flying. STT I measurements and complete ophthalmic examinations were performed. Mean STT I value for black vultures was 10.9 +/- 3.3 mm/min (right eye, oculus dexter, OD) and 11.9 +/- 3.3 mm/min (left eye, oculus sinister, OS) and for griffon vultures was 6.4 +/- 1.8 mm/min OD and 6.5 +/- 1.8 mm/min OS. In both eyes, STT I values in black vultures were significantly higher than those recorded in griffon vultures. Intraspecific comparisons yielded a significant difference between eyes of black vultures but not between those of griffon vultures, with OS producing higher STT I readings than did OD. When STT I was compared between OD and OS for each age group separately, a statistically significant difference was detected in the immature and free-flying black vultures. In addition, black vulture hatchlings had a significantly higher tear production than did free-flying juveniles, immatures, subadults, and adults. STT I values in black vultures are similar to those reported in other Accipitriformes but are lower in griffon vultures. This difference is probably related to anatomic, evolutionary, and feeding factors and requires further investigation. PMID:23805550

  17. Energy regulation in context: Free-living female arctic ground squirrels modulate the relationship between thyroid hormones and activity among life history stages.

    PubMed

    Wilsterman, Kathryn; Buck, C Loren; Barnes, Brian M; Williams, Cory T

    2015-09-01

    Thyroid hormones (THs), key regulators of lipid and carbohydrate metabolism, are likely modulators of energy allocation within and among animal life history stages. Despite their role in modulating metabolism, few studies have investigated whether THs vary among life history stages in free-living animals or if they exhibit stage-specific relationships to total energy expenditure and activity levels. We measured plasma total triiodothyronine (tT3) and thyroxine (tT4) at four, discrete life history stages of female arctic ground squirrels from two different populations in northern Alaska to test whether plasma THs correlate with life history stage-specific changes in metabolic rate and energy demand. We also tested whether THs explained individual variation in aboveground activity levels within life history stages. T3 peaked during lactation and was lowest during pre-hibernation fattening, consistent with known changes in basal metabolism and core body temperature. In contrast, T4 was elevated shortly after terminating hibernation but remained low and stable across other life-history stages in the active season. THs were consistently higher in the population that spent more time above-ground but the relationship between THs and activity varied among life history stages. T3 was positively correlated with activity only during lactation (r(2)=0.50) whereas T4 was positively correlated with activity immediately following lactation (r(2)=0.48) and during fattening (r(2)=0.53). Our results support the hypothesis that THs are an important modulator of basal metabolism but also suggest that the relationship between THs and activity varies among life history stages. PMID:26416501

  18. Sex differences in the long-term repeatability of the acute stress response in long-lived, free-living Florida scrub-jays (Aphelocoma coerulescens).

    PubMed

    Small, Thomas W; Schoech, Stephan J

    2015-01-01

    There is increasing evidence that individual differences in the physiological stress response are persistent traits in many animals. To test the hypothesis that the stress-induced CORT (SI-CORT) response is repeatable over the adult life span of Florida scrub-jays (Aphelocoma coerulescens), we sampled 32 male and 25 female free-living scrub-jays (aged 2-13 years) during a 9-year period (2004-2012). Each individual was sampled two to five times and samples were collected one or more years apart during the pre-breeding season (Jan-March). In addition, individuals sampled over the greatest time period (6-8 years) were analyzed separately to more closely assess long-term repeatability. SI-CORT was repeatable in females, but not males, when values were not corrected for confounding variables (agreement repeatability). However, when the year and time of day of sample collection were controlled (adjusted repeatability), SI-CORT was repeatable in both sexes. SI-CORT was also repeatable in the males and females sampled 6-8 years apart. Finally, baseline CORT levels of males, but not females, exhibited low but significant repeatability when adjusted for year. The results of this study demonstrate that differences in SI-CORT levels were repeatable within adult scrub-jays sampled up to 8 years apart. Further, the female SI-CORT response was more consistent between pre-breeding seasons than males, which may have resulted from males having higher SI-CORT plasticity in response to environmental conditions. These data support the hypothesis that the SI-CORT response of Florida scrub-jays develops before adulthood and persists throughout much, if not all, of their natural adult life span. PMID:25378217

  19. LIPGENE food-exchange model for alteration of dietary fat quantity and quality in free-living participants from eight European countries.

    PubMed

    Shaw, Danielle I; Tierney, Audrey C; McCarthy, Sinead; Upritchard, Jane; Vermunt, Susan; Gulseth, Hanne L; Drevon, Christian A; Blaak, Ellen E; Saris, Wim H M; Karlström, Brita; Helal, Olfa; Defoort, Catherine; Gallego, Raquel; López-Miranda, José; Siedlecka, Dominika; Malczewska-Malec, Małgorzata; Roche, Helen M; Lovegrove, Julie A

    2009-03-01

    Controlled human intervention trials are required to confirm the hypothesis that dietary fat quality may influence insulin action. The aim was to develop a food-exchange model, suitable for use in free-living volunteers, to investigate the effects of four experimental diets distinct in fat quantity and quality: high SFA (HSFA); high MUFA (HMUFA) and two low-fat (LF) diets, one supplemented with 1.24 g EPA and DHA/d (LFn-3). A theoretical food-exchange model was developed. The average quantity of exchangeable fat was calculated as the sum of fat provided by added fats (spreads and oils), milk, cheese, biscuits, cakes, buns and pastries using data from the National Diet and Nutrition Survey of UK adults. Most of the exchangeable fat was replaced by specifically designed study foods. Also critical to the model was the use of carbohydrate exchanges to ensure the diets were isoenergetic. Volunteers from eight centres across Europe completed the dietary intervention. Results indicated that compositional targets were largely achieved with significant differences in fat quantity between the high-fat diets (39.9 (sem 0.6) and 38.9 (sem 0.51) percentage energy (%E) from fat for the HSFA and HMUFA diets respectively) and the low-fat diets (29.6 (sem 0.6) and 29.1 (sem 0.5) %E from fat for the LF and LFn-3 diets respectively) and fat quality (17.5 (sem 0.3) and 10.4 (sem 0.2) %E from SFA and 12.7 (sem 0.3) and 18.7 (sem 0.4) %E MUFA for the HSFA and HMUFA diets respectively). In conclusion, a robust, flexible food-exchange model was developed and implemented successfully in the LIPGENE dietary intervention trial. PMID:18680629

  20. Rickettsia sp. strain colombianensi (Rickettsiales: Rickettsiaceae): a new proposed Rickettsia detected in Amblyomma dissimile (Acari: Ixodidae) from iguanas and free-living larvae ticks from vegetation.

    PubMed

    Miranda, Jorge; Portillo, Aránzazu; Oteo, José A; Mattar, Salim

    2012-07-01

    From January to December 2009, 55 Amblyomma dissimile (Koch) ticks removed from iguanas in the municipality of Monteria and 3,114 ticks [458 Amblyomma sp. larvae, 2,636 Rhipicephalus microplus (Canestrini) larvae and 20 Amblyomma sp. nymphs] collected over vegetation in Los Cordobas were included in the study. The ticks were pooled into groups from which DNA was extracted. For initial screening of Rickettsia sp., each pool was analyzed by gltA real-time polymerase chain reaction (PCR). Positive pools were further studied using gltA, ompA, and ompB conventional PCR assays. Sequencing and phylogenetic analysis were also conducted. Rickettsial DNA was found in 28 pools of ticks (16 A. dissimile pools and 12 free-living larvae pools) out of 113 (24.7%) using real-time PCR. The same 28 pools were also positive using conventional PCR assays aimed to amplify gltA, ompA, and ompB. For each gene analyzed, PCR products obtained from 4/28 pools (two pools of A. dissimile, one pool of Amblyomma sp. larvae and one pool of Rh. microplus larvae) were randomly chosen and sequenced twice. Nucleotide sequences generated were identical to each other for each of the rickettsial genes gltA, ompA, and ompB, and showed 99.4, 95.6, and 96.4% identity with those of Rickettsia tamurae. They were deposited in the GenBank database under accession numbers JF905456, JF905458, and JF905457, respectively. In conclusion, we present the first molecular evidence of a novel Rickettsia (Rickettsia sp. strain Colombianensi) infecting A. dissimile ticks collected from iguanas, and also Rh. microplus and unspeciated Amblyomma larvae from vegetation in Colombia. PMID:22897060

  1. Maternal Gestational Cortisol and Testosterone Are Associated with Trade-Offs in Offspring Sex and Number in a Free-Living Rodent (Urocitellus richardsonii)

    PubMed Central

    Ryan, Calen P.; Anderson, W. Gary; Berkvens, Charlene N.; Hare, James F.

    2014-01-01

    The adaptive manipulation of offspring sex and number has been of considerable interest to ecol