title: PeerJ
description:  Articles published in PeerJ
link: https://peerj.com/articles/index.rss3?journal=peerj&page=1453
creator: info@peerj.com PeerJ
errorsTo: info@peerj.com PeerJ
language: en

title: Appetitive reversal learning differences of two honey bee subspecies with different foraging behaviors
link: https://peerj.com/articles/5918
last-modified: 2018-11-21
description: We aimed to examine mechanistically the observed foraging differences across two honey bee, Apis mellifera, subspecies using the proboscis extension response assay. Specifically, we compared differences in appetitive reversal learning ability between honey bee subspecies: Apis mellifera caucasica (Pollman), and Apis mellifera syriaca (Skorikov) in a “common garden” apiary. It was hypothesized that specific learning differences could explain previously observed foraging behavior differences of these subspecies: A.m. caucasica switches between different flower color morphs in response to reward variability, and A.m. syriaca does not switch. We suggest that flower constancy allows reduced exposure by minimizing search and handling time, whereas plasticity is important when maximizing harvest in preparation for long winter is at a premium. In the initial or Acquisition phase of the test we examined specifically discrimination learning, where bees were trained to respond to a paired conditioned stimulus with an unconditioned stimulus and not to respond to a second conditioned stimulus that is not followed by an unconditioned stimulus. We found no significant differences among the subspecies in the Acquisition phase in appetitive learning. During the second, Reversal phase of the experiment, where flexibility in association was tested, the paired and unpaired conditioned stimuli were reversed. During the Reversal phase A.m. syriaca showed a reduced ability to learn the reverse association in the appetitive learning task. This observation is consistent with the hypothesis that A.m. syriaca foragers cannot change the foraging choice because of lack of flexibility in appetitive associations under changing contingencies. Interestingly, both subspecies continued responding to the previously rewarded conditioned stimulus in the reversal phase. We discuss potential ecological correlates and molecular underpinnings of these differences in learning across the two subspecies. In addition, in a supplemental experiment we demonstrated that these differences in appetitive reversal learning do not occur in other learning contexts.
creator: Eddie Pérez Claudio
creator: Yoselyn Rodriguez-Cruz
creator: Okan Can Arslan
creator: Tugrul Giray
creator: José Luis Agosto Rivera
creator: Meral Kence
creator: Harrington Wells
creator: Charles I. Abramson
uri: https://doi.org/10.7717/peerj.5918
license: http://creativecommons.org/licenses/by/4.0/
rights: © 2018 Pérez Claudio et al.

title: Broad cognitive complaints but subtle objective working memory impairment in fibromyalgia patients
link: https://peerj.com/articles/5907
last-modified: 2018-11-21
description: BackgroundCognitive dysfunction in fibromyalgia (FM) encompasses objective cognitive difficulties, as measured in neuropsychological tests, and self-reported cognitive complaints. Although it has been suggested that FM patients display problems in working memory, the data are inconsistent, and the overall working memory status of the patients is unclear. It is also not clear whether the working memory problems are related to cognitive complaints or how the dyscognition is affected by the characteristic clinical symptoms of FM.MethodsTo clarify these aspects, we explored the neuropsychological performance for different components of working memory and the subjective self-perception of cognitive status in a sample of 38 women with FM. They were compared with a matched group of 32 healthy women.ResultsOur findings suggested that the FM patients do not differ from healthy controls in their overall working memory functioning. Only a poor performance was found in a single task of visuospatial working memory, mediated by the presence of depressive symptoms, fatigue and pain. The FM patients also displayed a higher level of perception of cognitive difficulties than healthy controls, and this difference was mediated by depression and fatigue. Furthermore, cognitive complaints in FM patients were only associated with a lower verbal WM capacity.DiscussionFM patients have a subtle specific impairment in their working memory functioning, as well as elevated concern about their cognitive status. These findings suggest a disconnection between neuropsychological performance and subjective complaints. In FM patients, clinical variables such as pain, fatigue, and depression play an important role in dyscognition, as assessed by both objective and subjective measures, and should be taken into account in future research.
creator: Marina Pidal-Miranda
creator: Alberto Jacobo González-Villar
creator: María Teresa Carrillo-de-la-Peña
creator: Elena Andrade
creator: Dolores Rodríguez-Salgado
uri: https://doi.org/10.7717/peerj.5907
license: http://creativecommons.org/licenses/by/4.0/
rights: ©2018 Pidal-Miranda et al.

title: Hemodynamic effects of sex and handedness on the Wisconsin Card Sorting Test: the contradiction between neuroimaging and behavioural results
link: https://peerj.com/articles/5890
last-modified: 2018-11-21
description: This study investigated the potential role of sex and handedness on the performance of a computerised Wisconsin Card Sorting Test (WCST) in healthy participants by applying functional near-infrared spectroscopy (fNIRS). We demonstrated significant (p < 0.05) sex-related differences of hemodynamic response in the prefrontal cortex of 70 healthy participants (female, n = 35 and male, n = 35; right-handed, n = 40 and left-handed, n = 30). In contrast, behavioural results of the WCST do not show sex bias, which is consistent with previous literature. Because of this, we compared ours and sparse previous fNIRS studies on the WCST. We propose that, according to recent studies of neurovascular coupling, this contradiction between neuroimaging and behavioural results may be explained by normal variability in neurovascular dynamics.
creator: Sigita Cinciute
creator: Algis Daktariunas
creator: Osvaldas Ruksenas
uri: https://doi.org/10.7717/peerj.5890
license: http://creativecommons.org/licenses/by/4.0/
rights: © 2018 Cinciute et al.

title: First steps towards assessing the evolutionary history and phylogeography of a widely distributed Neotropical grassland bird (Motacillidae: Anthus correndera)
link: https://peerj.com/articles/5886
last-modified: 2018-11-21
description: Grasslands in southern South America are extensive ecosystems which harbor a unique biodiversity; however, studies on the evolution of their taxa are scarce. Here we studied the phylogeography and population history of the Correndera Pipit (Anthus correndera), a grassland specialist bird with a large breeding distribution in southern South America, with the goals of investigating its phylogeographic history and relate it to the historical development of South American grasslands. The mitochondrial NADH dehydrogenase subunit II gene (ND2) was sequenced in 66 individuals from 19 localities and the intron 9 of the sex-linked gene for aconitase (ACOI9) was sequenced from a subset of those individuals, including all five subspecies of A. correndera, as well as the closely related A. antarcticus. Phylogenetic analysis revealed two distinct lineages within the complex: the first (A) corresponding to Andean subspecies A. c. calcaratus and A. c. catamarcae and the second (B) including birds traditionally assigned to A. c. correndera, A. c. chilensis, A. c. grayi and some individuals of A. c. catamarcae. A. antarcticus is nested within this second lineage. These results were also supported by evidence of niche divergence for variables associated with precipitation. The oldest split between clade A and B was estimated at c. 0.37 Mya, during the middle Pleistocene. Species distribution models for the present and the Last Glacial Maximum (LGM) suggest that grassland areas in southern South America remained relatively stable, in contrast to the general view of a reduction in grassland cover in South America since the LGM. Recent divergences and low phylogeographic structure (for lowland vs. highland geographic groups, intra-population genetic variance was greater than inter-groups; e.g., for ACOI9: 95.47% and ND2: 51.51% respectively), suggest widespread gene flow between lowland populations.
creator: Heraldo V. Norambuena
creator: Paul Van Els
creator: Carlos P. Muñoz-Ramírez
creator: Pedro F. Victoriano
uri: https://doi.org/10.7717/peerj.5886
license: http://creativecommons.org/licenses/by/4.0/
rights: ©2018 Norambuena et al.

title: Seasonal and predator-prey effects on circadian activity of free-ranging mammals revealed by camera traps
link: https://peerj.com/articles/5827
last-modified: 2018-11-21
description: Endogenous circadian and seasonal activity patterns are adapted to facilitate effective utilisation of environmental resources. Activity patterns are shaped by physiological constraints, evolutionary history, circadian and seasonal changes and may be influenced by other factors, including ecological competition and interspecific interactions. Remote-sensing camera traps allow the collection of species presence data throughout the 24 h period and for almost indefinite lengths of time. Here, we collate data from 10 separate camera trap surveys in order to describe circadian and seasonal activity patterns of 10 mammal species, and, in particular, to evaluate interspecific (dis)associations of five predator-prey pairs. We recorded 8,761 independent detections throughout Northern Ireland. Badgers, foxes, pine martens and wood mice were nocturnal; European and Irish hares and European rabbits were crepuscular; fallow deer and grey and red squirrels were diurnal. All species exhibited significant seasonal variation in activity relative to the timing of sunrise/sunset. Foxes in particular were more crepuscular from spring to autumn and hares more diurnal. Lagged regression analyses of predator-prey activity patterns between foxes and prey (hares, rabbits and wood mice), and pine marten and prey (squirrel and wood mice) revealed significant annual and seasonal cross-correlations. We found synchronised activity patterns between foxes and hares, rabbits and wood mice and pine marten and wood mice, and asynchrony between squirrels and pine martens. Here, we provide fundamental ecological data on endemic, invasive, pest and commercially valuable species in Ireland, as well as those of conservation importance and those that could harbour diseases of economic and/or zoonotic relevance. Our data will be valuable in informing the development of appropriate species-specific methodologies and processes and associated policies.
creator: Anthony Caravaggi
creator: Maria Gatta
creator: Marie-Claire Vallely
creator: Kayleigh Hogg
creator: Marianne Freeman
creator: Erfan Fadaei
creator: Jaimie T.A. Dick
creator: W. Ian Montgomery
creator: Neil Reid
creator: David G. Tosh
uri: https://doi.org/10.7717/peerj.5827
license: http://creativecommons.org/licenses/by/4.0/
rights: © 2018 Caravaggi et al.

title: Genetic and phenotypic differentiation of lumpfish (Cyclopterus lumpus) across the North Atlantic: implications for conservation and aquaculture
link: https://peerj.com/articles/5974
last-modified: 2018-11-20
description: Demand for lumpfish (Cyclopterus lumpus) has increased exponentially over the last decade, both for their roe, which is used as a caviar substitute, and increasingly also as cleaner fish to control sea lice in salmon farming. The species is classified as Near Threatened by the IUCN and there are growing concerns that over-exploitation of wild stocks and translocation of hatchery-reared lumpfish may compromise the genetic diversity of native populations. We carried out a comparative analysis of genetic and phenotypic variation across the species’ range to estimate the level of genetic and phenotypic differentiation, and determined patterns of gene flow at spatial scales relevant to management. We found five genetically distinct groups located in the West Atlantic (USA and Canada), Mid Atlantic (Iceland), East Atlantic (Faroe Islands, Ireland, Scotland, Norway and Denmark), English Channel (England) and Baltic Sea (Sweden). Significant phenotypic differences were also found, with Baltic lumpfish growing more slowly, attaining a higher condition factor and maturing at a smaller size than North Atlantic lumpfish. Estimates of effective population size were consistently low across the North East Atlantic (Iceland, Faroe Islands and Norway), the area where most wild lumpfish are fished for their roe, and also for the aquaculture industry. Our study suggests that some lumpfish populations are very small and have low genetic diversity, which makes them particularly vulnerable to over-exploitation and genetic introgression. To protect them we advocate curtailing fishing effort, closing the breeding cycle of the species in captivity to reduce dependence on wild stocks, restricting the translocation of genetically distinct populations, and limiting the risk of farm escapes.
creator: Benjamin Alexander Whittaker
creator: Sofia Consuegra
creator: Carlos Garcia de Leaniz
uri: https://doi.org/10.7717/peerj.5974
license: http://creativecommons.org/licenses/by/4.0/
rights: ©2018 Whittaker et al.

title: Specific and reliable detection of Myosin 1C isoform A by RTqPCR in prostate cancer cells
link: https://peerj.com/articles/5970
last-modified: 2018-11-20
description: BackgroundProstate cancer (PC) diagnostics and treatment often present a challenging task due to cancer subtype heterogeneity and differential disease progression in patient subgroups. Hence, the critical issue is finding a reliable and sensitive diagnostic and prognostic PC marker, especially for cases of biopsies with low percentages of cancer cells. Isoform A of myosin 1C was shown to be expressed in PC cells and responsible for their invasive properties, however, its feasibility for diagnostic purposes remains to be elucidated.MethodsTo verify the role of myosin 1C isoform A mRNA expression as a putative prostate cancer marker we performed RT qPCR normalized by three reference genes (GAPDH, YWHAZ, HPRT1) on PC3, RWPE-1, LNCaP and 22Rv1 cell lines. Myosin 1C isoform A detection specificity was confirmed by immunofluorescence staining, cancer and non-cancer prostate cell lines were immunophenotyped by flow cytometry.ResultsMedian normalized mRNA expression level of myosin 1C isoform A in PC cells (PC3 and 22Rv1) is two orders of magnitude higher compared to RWPE-1 cells, which functionally correspond to benign prostate cells. Myosin 1C isoform A expression allows PC cell detection even at a dilution ratio of 1:1000 cancer to non-cancer cells. At the protein level, the mean fluorescence intensity of myosin 1C isoform A staining in PC3 nuclei was only twice as high as in RWPE-1, while the immunophenotypes of both cell lines were similar (CD44+/CD90-/CD133-/CD57-/CD24+-).ConclusionsWe report a distinct difference in myosin 1C isoform A mRNA levels in malignant (PC3) and benign (RWPE-1) prostate cell lines and suggest a combination of three reference genes for accurate data normalization. For the first time we provide an immunophenotype comparison of RWPE-1 and PC3 cells and demonstrate that RT qPCR analysis of MYO 1C A using appropriate reference genes is sufficient for PC detection even in low-abundance cancer specimens.
creator: Aleena A. Saidova
creator: Daria M. Potashnikova
creator: Anna V. Tvorogova
creator: Ivan V. Maly
creator: Wilma A. Hofmann
creator: Ivan A. Vorobjev
uri: https://doi.org/10.7717/peerj.5970
license: http://creativecommons.org/licenses/by/4.0/
rights: ©2018 Saidova et al.

title: Reassessing public opinion of captive cetacean attractions with a photo elicitation survey
link: https://peerj.com/articles/5953
last-modified: 2018-11-20
description: BackgroundCaptive cetacean attractions are growing in number globally, their operators citing entertainment, education, and conservation as benefits. Those for and against developing such attractions claim public support. Previous public opinion research, however, shows little consensus, partly due to the introduction of biases in study design that influence participants’ responses. Those involved in, or concerned with, developing and licensing these attractions need to better understand what drives the lack of consensus to take socially-acceptable decisions.MethodsWe reviewed previous research on public opinion of cetacean captivity, noting possible sources of bias. Survey question wording can be a major source of introduced bias, so we used an open-ended photo elicitation approach. We showed tourists in the Turks Caicos Islands (N = 292) images of a marine mammal park (MMP) killer whale show and a swim-with-the-dolphins (SWTD) attraction and asked for their qualitative comments on the potential development of each. They also indicated how likely they would be to visit each on a Likert scale.ResultsRespondents were generally against visiting MMP killer whale shows, with 60.9% not likely to visit. SWTD attractions were more popular; 60.3% were likely to visit. For SWTD, USA residents were more likely to visit; older respondents and those staying in all-inclusive resorts were less likely. Those staying in all-inclusive resorts were also less likely to visit MMP killer whale shows. The great majority of qualitative comments centred on either entertainment value or animal welfare concerns. There were very few, if any, comments on the education or conservation value of these attractions.DiscussionOur findings contradict several previous studies on public opinion of captive cetaceans that did not use photo elicitation. The support shown for MMP killer whale shows in this survey was well below that claimed by studies conducted on behalf of captive cetacean attraction operators. Opposition to SWTD was also noticeably lower than that found in surveys conducted with wild cetacean tourism participants. This difference can likely be attributed to the different survey populations and settings, but this variation is also very likely attributable to researcher-introduced bias. While photo selection can introduce bias, photo elicitation reduces reliance on pre-scripted questions and responses, and seems to effectively reduce other forms of bias. Allowing open-ended responses, where participants responded to an image, seems to have given a more representative understanding of what is at the forefront of the public’s mind than closed questioning. These conclusions, among others made in this study, suggest that development decisions for captive cetacean attractions are being made on imprecise data. Going forward, data collected via responder-led, open-ended, bias-minimising approaches should at least be considered when informing such decisions.
creator: Sophia N. Wassermann
creator: Edward J. Hind-Ozan
creator: Julia Seaman
uri: https://doi.org/10.7717/peerj.5953
license: http://creativecommons.org/licenses/by/4.0/
rights: ©2018 Wassermann et al.

title: De novo annotation of the transcriptome of the Northern Wheatear (Oenanthe oenanthe)
link: https://peerj.com/articles/5860
last-modified: 2018-11-20
description: We have sequenced a partial transcriptome of the Northern Wheatear (Oenanthe oenanthe), a species with one of the longest migrations on Earth. The transcriptome was constructed de novo using RNA-Seq sequence data from the pooled mRNA of six different tissues: brain, muscle, intestine, liver, adipose tissue and skin. The samples came from nine captive-bred wheatears collected at three different stages of the endogenous autumn migratory period: (1) lean birds prior the onset of migration, (2) during the fattening stage and (3) individuals at their migratory body mass plateau, when they have almost doubled their lean body mass. The sample structure used to build up the transcriptome of the Northern Wheatears concerning tissue composition and time guarantees the future survey of the regulatory genes involved in the development of the migratory phenotype. Through the pre-migratory period, birds accomplish outstanding physical and behavioural changes that involve all organ systems. Nevertheless, the molecular mechanisms through which birds synchronize and control hyperphagia, fattening, restlessness increase, immunity boosting and tuning the muscles for such endurance flight are still largely unknown. The use of RNA-Seq has emerged as a powerful tool to analyse complex traits on a broad scale, and we believe it can help to characterize the migratory phenotype of wheatears at an unprecedented level. The primary challenge to conduct quantitative transcriptomic studies in non-model species is the availability of a reference transcriptome, which we have constructed and described in this paper. The cDNA was sequenced by pyrosequencing using the Genome Sequencer Roche GS FLX System; with single paired-end reads of about 400 bp. We estimate the total number of genes at 15,640, of which  67% could be annotated using Turkey and Zebra Finch genomes, or protein sequence information from SwissProt and NCBI databases. With our study, we have made a first step towards understanding the migratory phenotype regarding gene expression of a species that has become a model to study birds long-distance migrations.
creator: Roberto Carlos Frias-Soler
creator: Lilian Villarín Pildaín
creator: Agnes Hotz-Wagenblatt
creator: Jonas Kolibius
creator: Franz Bairlein
creator: Michael Wink
uri: https://doi.org/10.7717/peerj.5860
license: http://creativecommons.org/licenses/by/4.0/
rights: ©2018 Frias-Soler et al.

title: Exploratory investigation of region level risk factors of Ebola Virus Disease in West Africa
link: https://peerj.com/articles/5888
last-modified: 2018-11-19
description: BackgroundEbola Virus Disease (EVD) is a highly infectious disease that has produced over 25,000 cases in the past 50 years. While many past outbreaks resulted in relatively few cases, the 2014 outbreak in West Africa was the most deadly occurrence of EVD to date, producing over 15,000 confirmed cases.ObjectiveIn this study, we investigated population level predictors of EVD risk at the regional level in Sierra Leone, Liberia, and Guinea.MethodsSpatial and descriptive analyses were conducted to assess distribution of EVD cases. Choropleth maps showing the spatial distribution of EVD risk across the study area were generated in ArcGIS. Poisson and negative binomial models were then used to investigate population and regional predictors of EVD risk.ResultsResults indicated that the risk of EVD was significantly lower in areas with higher proportions of: (a) the population living in urban areas, (b) households with a low quality or no toilets, and (c) married men working in blue collar jobs. However, risk of EVD was significantly higher in areas with high mean years of education.ConclusionsThe identified significant predictors of high risk were associated with areas with higher levels of urbanization. This may be due to higher population densities in the more urban centers and hence higher potential of infectious contact. However, there is need to better understand the role of urbanization and individual contact structure in an Ebola outbreak. We discuss shortcomings in available data and emphasize the need to consider spatial scale in future data collection and epidemiological studies.
creator: Benjamin Levy
creator: Agricola Odoi
uri: https://doi.org/10.7717/peerj.5888
license: http://creativecommons.org/licenses/by/4.0/
rights: ©2018 Levy and Odoi