title: PeerJ description: Articles published in PeerJ link: https://peerj.com/articles/index.rss3?journal=peerj&page=1736 creator: info@peerj.com PeerJ errorsTo: info@peerj.com PeerJ language: en title: Isolation and characterization of human articular chondrocytes from surgical waste after total knee arthroplasty (TKA) link: https://peerj.com/articles/3079 last-modified: 2017-03-21 description: BackgroundCartilage tissue engineering is a fast-evolving field of biomedical engineering, in which the chondrocytes represent the most commonly used cell type. Since research in tissue engineering always consumes a lot of cells, simple and cheap isolation methods could form a powerful basis to boost such studies and enable their faster progress to the clinics. Isolated chondrocytes can be used for autologous chondrocyte implantation in cartilage repair, and are the base for valuable models to investigate cartilage phenotype preservation, as well as enable studies of molecular features, nature and scales of cellular responses to alterations in the cartilage tissue.MethodsIsolation and consequent cultivation of primary human adult articular chondrocytes from the surgical waste obtained during total knee arthroplasty (TKA) was performed. To evaluate the chondrogenic potential of the isolated cells, gene expression of collagen type 2 (COL2), collagen 1 (COL1) and aggrecan (ACAN) was evaluated. Immunocytochemical staining of all mentioned proteins was performed to evaluate chondrocyte specific production.ResultsCartilage specific gene expression of COL2 and ACAN has been shown that the proposed protocol leads to isolation of cells with a high chondrogenic potential, possibly even specific phenotype preservation up to the second passage. COL1 expression has confirmed the tendency of the isolated cells dedifferentiation into a fibroblast-like phenotype already in the second passage, which confirms previous findings that higher passages should be used with care in cartilage tissue engineering. To evaluate the effectiveness of our approach, immunocytochemical staining of the evaluated chondrocyte specific products was performed as well.DiscussionIn this study, we developed a protocol for isolation and consequent cultivation of primary human adult articular chondrocytes with the desired phenotype from the surgical waste obtained during TKA. TKA is a common and very frequently performed orthopaedic surgery during which both femoral condyles are removed. The latter present the ideal source for a simple and relatively cheap isolation of chondrocytes as was confirmed in our study. creator: Jakob Naranda creator: Lidija Gradišnik creator: Mario Gorenjak creator: Matjaž Vogrin creator: Uroš Maver uri: https://doi.org/10.7717/peerj.3079 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2017 Naranda et al. title: Can video playback provide social information for foraging blue tits? link: https://peerj.com/articles/3062 last-modified: 2017-03-21 description: Video playback is becoming a common method for manipulating social stimuli in experiments. Parid tits are one of the most commonly studied groups of wild birds. However, it is not yet clear if tits respond to video playback or how their behavioural responses should be measured. Behaviours may also differ depending on what they observe demonstrators encountering. Here we present blue tits (Cyanistes caeruleus) videos of demonstrators discovering palatable or aversive prey (injected with bitter-tasting Bitrex) from coloured feeding cups. First we quantify variation in demonstrators’ responses to the prey items: aversive prey provoked high rates of beak wiping and head shaking. We then show that focal blue tits respond differently to the presence of a demonstrator on a video screen, depending on whether demonstrators discover palatable or aversive prey. Focal birds faced the video screen more during aversive prey presentations, and made more head turns. Regardless of prey type, focal birds also hopped more frequently during the presence of a demonstrator (compared to a control video of a different coloured feeding cup in an empty cage). Finally, we tested if demonstrators’ behaviour affected focal birds’ food preferences by giving individuals a choice to forage from the same cup as a demonstrator, or from the cup in the control video. We found that only half of the individuals made their choice in accordance to social information in the videos, i.e., their foraging choices were not different from random. Individuals that chose in accordance with a demonstrator, however, made their choice faster than individuals that chose an alternative cup. Together, our results suggest that video playback can provide social cues to blue tits, but individuals vary greatly in how they use this information in their foraging decisions. creator: Liisa Hämäläinen creator: Hannah M. Rowland creator: Johanna Mappes creator: Rose Thorogood uri: https://doi.org/10.7717/peerj.3062 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2017 Hämäläinen et al. title: Temporal patterns and geographic heterogeneity of Zika virus (ZIKV) outbreaks in French Polynesia and Central America link: https://peerj.com/articles/3015 last-modified: 2017-03-21 description: BackgroundZika virus (ZIKV) transmission has been reported in 67 countries/territories in the Oceania region and the Americas since 2015, prompting the World Health Organization (WHO) to declare ZIKV as a Public Health Emergency of International Concern in February 2016, due to its strong association with medical complications such as microcephaly and Guillain–Barré Syndrome (GBS). However, a substantial gap in knowledge still exists regarding differing temporal pattern and potential of transmission of ZIKV in different regions of the world.MethodsWe use a phenomenological model to ascertain the temporal patterns and transmission potential of ZIKV in various countries/territories, by fitting the model to Zika case data from Yap Island and French Polynesia in the Oceania region and 11 countries/territories with confirmed case data, namely, Colombia, Ecuador, French Guiana, Guadeloupe, Guatemala, Mexico, Nicaragua, Panama, Puerto Rico, Saint Martin, and Suriname, to pinpoint the waves of infections in each country/territory and to estimate the respective basic reproduction number R0.ResultsSix of these time series datasets resulted in statistically significant model fit of at least one wave of reported cases, namely that of French Polynesia, Colombia, Puerto Rico, Guatemala, Suriname and Saint Martin. However, only Colombia and Guatemala exhibited two waves of cases while the others had only one wave. Temporal patterns of the second wave in Colombia and the single wave in Suriname are very similar, with the respective turning points separated by merely a week. Moreover, the mean estimates of R0 for Colombia, Guatemala and Suriname, all land-based populations, range between 1.05 and 1.75, while the corresponding mean estimates for R0 of island populations in French Polynesia, Puerto Rico and Saint Martin are significantly lower with a range of 5.70–6.89. We also fit the Richards model to Zika case data from six main archipelagos in French Polynesia, suggesting the outbreak in all six island populations occurred during the same time, albeit with different peak time, with mean R0 range of 3.09–5.05.DiscussionUsing the same modeling methodology, in this study we found a significant difference between transmissibility (as quantified by R0) in island populations as opposed to land-based countries/territories, possibly suggesting an important role of geographic heterogeneity in the spread of vector-borne diseases and its future course, which requires further monitoring. Our result has potential implications for planning respective intervention and control policies targeted for island and land-based populations. creator: Ying-Hen Hsieh uri: https://doi.org/10.7717/peerj.3015 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2017 Hsieh title: A multidisciplinary approach to digital mapping of dinosaurian tracksites in the Lower Cretaceous (Valanginian–Barremian) Broome Sandstone of the Dampier Peninsula, Western Australia link: https://peerj.com/articles/3013 last-modified: 2017-03-21 description: The abundant dinosaurian tracksites of the Lower Cretaceous (Valanginian–Barremian) Broome Sandstone of the Dampier Peninsula, Western Australia, form an important part of the West Kimberley National Heritage Place. Previous attempts to document these tracksites using traditional mapping techniques (e.g., surface overlays, transects and gridlines combined with conventional photography) have been hindered by the non-trivial challenges associated with working in this area, including, but not limited to: (1) the remoteness of many of the tracksites; (2) the occurrence of the majority of the tracksites in the intertidal zone; (3) the size and complexity of many of the tracksites, with some extending over several square kilometres. Using the historically significant and well-known dinosaurian tracksites at Minyirr (Gantheaume Point), we show how these issues can be overcome through the use of an integrated array of remote sensing tools. A combination of high-resolution aerial photography with both manned and unmanned aircraft, airborne and handheld high-resolution lidar imaging and handheld photography enabled the collection of large amounts of digital data from which 3D models of the tracksites at varying resolutions were constructed. The acquired data encompasses a very broad scale, from the sub-millimetre level that details individual tracks, to the multiple-kilometre level, which encompasses discontinuous tracksite exposures and large swathes of coastline. The former are useful for detailed ichnological work, while the latter are being employed to better understand the stratigraphic and temporal relationship between tracksites in a broader geological and palaeoecological context. These approaches and the data they can generate now provide a means through which digital conservation and temporal monitoring of the Dampier Peninsula’s dinosaurian tracksites can occur. As plans for the on-going management of the tracks in this area progress, analysis of the 3D data and 3D visualization will also likely provide an important means through which the broader public can experience these spectacular National Heritage listed landscapes. creator: Anthony Romilio creator: Jorg M. Hacker creator: Robert Zlot creator: George Poropat creator: Michael Bosse creator: Steven W. Salisbury uri: https://doi.org/10.7717/peerj.3013 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2017 Romilio et al. title: The Non-Recurrent Laryngeal Nerve: a meta-analysis and clinical considerations link: https://peerj.com/articles/3012 last-modified: 2017-03-21 description: BackgroundThe Non-Recurrent Laryngeal Nerve (NRLN) is a rare embryologically-derived variant of the Recurrent Laryngeal Nerve (RLN). The presence of an NRLN significantly increases the risk of iatrogenic injury and operative complications. Our aim was to provide a comprehensive meta-analysis of the overall prevalence of the NRLN, its origin, and its association with an aberrant subclavian artery.MethodsThrough March 2016, a database search was performed of PubMed, CNKI, ScienceDirect, EMBASE, BIOSIS, SciELO, and Web of Science. The references in the included articles were also extensively searched. At least two reviewers judged eligibility and assessed and extracted articles. MetaXL was used for analysis, with all pooled prevalence rates calculated using a random effects model. Heterogeneity among the included studies was assessed using the Chi2 test and the I2 statistic.ResultsFifty-three studies (33,571 right RLNs) reported data on the prevalence of a right NRLN. The pooled prevalence estimate was 0.7% (95% CI [0.6–0.9]). The NRLN was found to originate from the vagus nerve at or above the laryngotracheal junction in 58.3% and below it in 41.7%. A right NRLN was associated with an aberrant subclavian artery in 86.7% of cases.ConclusionThe NRLN is a rare yet very clinically relevant structure for surgeons and is associated with increased risk of iatrogenic injury, most often leading to temporary or permanent vocal cord paralysis. A thorough understanding of the prevalence, origin, and associated pathologies is vital for preventing injuries and complications. creator: Brandon Michael Henry creator: Silvia Sanna creator: Matthew J. Graves creator: Jens Vikse creator: Beatrice Sanna creator: Iwona M. Tomaszewska creator: R. Shane Tubbs creator: Jerzy A. Walocha creator: Krzysztof A. Tomaszewski uri: https://doi.org/10.7717/peerj.3012 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2017 Henry et al. title: Testing of microsatellite multiplexes for individual identification of Cape Parrots (Poicephalus robustus): paternity testing and monitoring trade link: https://peerj.com/articles/2900 last-modified: 2017-03-21 description: BackgroundIllegal trade in rare wildlife species is a major threat to many parrot species around the world. Wildlife forensics plays an important role in the preservation of endangered or threatened wildlife species. Identification of illegally harvested or traded animals through DNA techniques is one of the many methods used during forensic investigations. Natural populations of the South African endemic Cape Parrot (Poicephalus robustus) are negatively affected by the removal of eggs and chicks for the pet trade.MethodsIn this study, 16 microsatellite markers specifically designed for the South African endemic Cape Parrot (P. robustus) are assessed for their utility in forensic casework. Using these 16 loci, the genetic diversity of a subset of the captive Cape Parrot population was also assessed and compared to three wild Cape Parrot populations.ResultsIt was determined that the full 16 locus panel has sufficient discriminatory power to be used in parentage analyses and can be used to determine if a bird has been bred in captivity and so can be legally traded or if it has been illegally removed from the wild. In cases where birds have been removed from the wild, this study suggests that a reduced 12 locus microsatellite panel has sufficient power to assign confiscated birds to geographic population of origin.DiscussionThe level of genetic diversity observed within the captive Cape Parrot population was similar to that observed in the wild populations, which suggests that the captive population is not suffering from decreased levels of genetic diversity. The captive Cape Parrots did however have double the number of private alleles compared to that observed in the most genetically diverse wild population. This is probably due to the presence of rare alleles present in the founder population, which has not been lost due to genetic drift, as many of the individuals tested in this study are F1–F3 wild descendants. The results from this study provide a suit of markers that can be used to aid conservation and law enforcement authorities to better control legal and illegal trade of this South African endemic. creator: Willem G. Coetzer creator: Colleen T. Downs creator: Mike R. Perrin creator: Sandi Willows-Munro uri: https://doi.org/10.7717/peerj.2900 license: http://creativecommons.org/licenses/by/4.0/ rights: © 2017 Coetzer et al. title: Developmental and loco-like effects of a swainsonine-induced inhibition of α-mannosidase in the honey bee, Apis mellifera link: https://peerj.com/articles/3109 last-modified: 2017-03-16 description: BackgroundDeficiencies in lysosomal a-mannosidase (LAM) activity in animals, caused either by mutations or by consuming toxic alkaloids, lead to severe phenotypic and behavioural consequences. Yet, epialleles adversely affecting LAM expression exist in the honey bee population suggesting that they might be beneficial in certain contexts and cannot be eliminated by natural selection.MethodsWe have used a combination of enzymology, molecular biology and metabolomics to characterise the catalytic properties of honey bee LAM (AmLAM) and then used an indolizidine alkaloid swainsonine to inhibit its activity in vitro and in vivo.ResultsWe show that AmLAM is inhibited in vitro by swainsonine albeit at slightly higher concentrations than in other animals. Dietary exposure of growing larvae to swainsonine leads to pronounced metabolic changes affecting not only saccharides, but also amino acids, polyols and polyamines. Interestingly, the abundance of two fatty acids implicated in epigenetic regulation is significantly reduced in treated individuals. Additionally, swainsonie causes loco-like symptoms, increased mortality and a subtle decrease in the rate of larval growth resulting in a subsequent developmental delay in pupal metamorphosis.DiscussionWe consider our findings in the context of cellular LAM function, larval development, environmental toxicity and colony-level impacts. The observed developmental heterochrony in swainsonine-treated larvae with lower LAM activity offer a plausible explanation for the existence of epialleles with impaired LAM expression. Individuals carrying such epialleles provide an additional level of epigenetic diversity that could be beneficial for the functioning of a colony whereby more flexibility in timing of adult emergence might be useful for task allocation. creator: Laura Wedd creator: Regan Ashby creator: Sylvain Foret creator: Ryszard Maleszka uri: https://doi.org/10.7717/peerj.3109 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2017 Wedd et al. title: Plant growth-promoting endophytic bacteria versus pathogenic infections: an example of Bacillus amyloliquefaciens RWL-1 and Fusarium oxysporum f. sp. lycopersici in tomato link: https://peerj.com/articles/3107 last-modified: 2017-03-16 description: Fungal pathogenic attacks are one of the major threats to the growth and productivity of crop plants. Currently, instead of synthetic fungicides, the use of plant growth-promoting bacterial endophytes has been considered intriguingly eco-friendly in nature. Here, we aimed to investigate the in vitro and in vivo antagonistic approach by using seed-borne endophytic Bacillus amyloliquefaciens RWL-1 against pathogenic Fusarium oxysporum f. sp. lycopersici. The results revealed significant suppression of pathogenic fungal growth by Bacillus amyloliquefaciens in vitro. Further to this, we inoculated tomato plants with RWL-1 and F. oxysporum f. sp. lycopersici in the root zone. The results showed that the growth attributes and biomass were significantly enhanced by endophytic-inoculation during disease incidence as compared to F. oxysporum f. sp. lycopersici infected plants. Under pathogenic infection, the RWL-1-applied plants showed increased amino acid metabolism of cell wall related (e.g., aspartic acid, glutamic acid, serine (Ser), and proline (Pro)) as compared to diseased plants. In case of endogenous phytohormones, significantly lower amount of jasmonic acid (JA) and higher amount of salicylic acid (SA) contents was recorded in RWL-1-treated diseased plants. The phytohormones regulation in disease incidences might be correlated with the ability of RWL-1 to produce organic acids (e.g., succinic acid, acetic acid, propionic acid, and citric acid) during the inoculation and infection of tomato plants. The current findings suggest that RWL-1 inoculation promoted and rescued plant growth by modulating defense hormones and regulating amino acids. This suggests that bacterial endophytes could be used for possible control of F. oxysporum f. sp. lycopersici in an eco-friendly way. creator: Raheem Shahzad creator: Abdul Latif Khan creator: Saqib Bilal creator: Sajjad Asaf creator: In-Jung Lee uri: https://doi.org/10.7717/peerj.3107 license: http://creativecommons.org/licenses/by/4.0/ rights: © 2017 Shahzad et al. title: Evaluation of procedures for typing of group B Streptococcus: a retrospective study link: https://peerj.com/articles/3105 last-modified: 2017-03-16 description: BackgroundThis study evaluates two procedures for typing of Streptococcus agalactiae (group B streptococci; GBS) isolates, using retrospective typing data from the period 2010 to 2014 with a commercial latex agglutination test (latex test) and the Lancefield precipitation test (LP test). Furthermore, the genotype distribution of phenotypically non-typable (NT) GBS isolates is presented. We also raise the awareness, that the difference in typing results obtained by phenotypical methods and genotype based methods may have implications on vaccine surveillance in case a GBS vaccine is introduced.MethodsA total of 616 clinical GBS isolates from 2010 to 2014 were tested with both a latex test and the LP test. Among these, 66 isolates were genotyped by PCR, including 41 isolates that were phenotypically NT.ResultsThe latex test provided a serotype for 83.8% of the isolates (95% CI [80.7–86.6]) compared to 87.5% (95% CI [84.6–90.0]) obtained by the LP method. The two assays provided identical capsular identification for all sero-typeable isolates (excluding NT isolates). The PCR assay provided a genotype designation to the 41 isolates defined as phenotypically NT isolates.DiscussionWe found that the latex test showed a slightly lower identification percentage than the LP test. Our recommendation is to use the latex agglutination as the routine primary assay for GBS surveillance, and then use the more labour intensive precipitation test on the NT isolates to increase the serotyping rate. A genotype could be assigned to all the phenotypically NT isolates, however, as a consequence genotyping will overestimate the coverage from possible future capsular polysaccharide based GBS vaccines. creator: Hans-Christian Slotved creator: Steen Hoffmann uri: https://doi.org/10.7717/peerj.3105 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2017 Slotved and Hoffmann title: Climate-change-induced range shifts of three allergenic ragweeds (Ambrosia L.) in Europe and their potential impact on human health link: https://peerj.com/articles/3104 last-modified: 2017-03-16 description: Invasive allergenic plant species may have severe health-related impacts. In this study we aim to predict the effects of climate change on the distribution of three allergenic ragweed species (Ambrosia spp.) in Europe and discuss the potential associated health impact. We built species distribution models based on presence-only data for three ragweed species, using MAXENT software. Future climatic habitat suitability was modeled under two IPCC climate change scenarios (RCP 6.0 and RCP 8.5). We quantify the extent of the increase in ‘high allergy risk’ (HAR) areas, i.e., parts of Europe with climatic conditions corresponding to the highest quartile (25%) of present day habitat suitability for each of the three species. We estimate that by year 2100, the distribution range of all three ragweed species increases towards Northern and Eastern Europe under all climate scenarios. HAR areas will expand in Europe by 27–100%, depending on species and climate scenario. Novel HAR areas will occur mostly in Denmark, France, Germany, Russia and the Baltic countries, and overlap with densely populated cities such as Paris and St. Petersburg. We conclude that areas in Europe affected by severe ragweed associated allergy problems are likely to increase substantially by year 2100, affecting millions of people. To avoid this, management strategies must be developed that restrict ragweed dispersal and establishment of new populations. Precautionary efforts should limit the spread of ragweed seeds and reduce existing populations. Only by applying cross-countries management plans can managers mitigate future health risks and economical consequences of a ragweed expansion in Europe. creator: Karen Rasmussen creator: Jakob Thyrring creator: Robert Muscarella creator: Finn Borchsenius uri: https://doi.org/10.7717/peerj.3104 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2017 Rasmussen et al.