title: PeerJ description: Articles published in PeerJ link: https://peerj.com/articles/index.rss3?journal=peerj&page=1497 creator: info@peerj.com PeerJ errorsTo: info@peerj.com PeerJ language: en title: Neural correlates of executive functions in patients with obesity link: https://peerj.com/articles/5002 last-modified: 2018-06-12 description: Obesity is one of the most challenging problems in human health and is recognized as an important risk factor for many chronic diseases. It remains unclear how the neural systems (e.g., the mesolimbic “reward” and the prefrontal “control” neural systems) are correlated with patients’ executive function (EF), conceptualized as the integration of “cool” EF and “hot” EF. “Cool” EF refers to relatively abstract, non-affective operations such as inhibitory control and mental flexibility. “Hot” EF refers to motivationally significant affective operations such as affective decision-making. We tried to find the correlation between structural and functional neuroimaging indices and EF in obese patients. The study population comprised seventeen patients with obesity (seven males and 10 females, BMI = 37.99 ± 5.40, age = 31.82 ± 8.75 year-old) preparing to undergo bariatric surgery. We used noninvasive diffusion tensor imaging, generalized q-sampling imaging, and resting-state functional magnetic resonance imaging to examine the neural correlations between structural and functional neuroimaging indices and EF performances in patients with obesity. We reported that many brain areas are correlated to the patients’ EF performances. More interestingly, some correlations may implicate the possible associations of EF and the incentive motivational effects of food. The neural correlation between the left precuneus and middle occipital gyrus and inhibitory control may suggest that patients with a better ability to detect appetitive food may have worse inhibitory control. Also, the neural correlation between the superior frontal blade and affective decision-making may suggest that patients’ affective decision-making may be associated with the incentive motivational effects of food. Our results provide evidence suggesting neural correlates of EF in patients with obesity. creator: Ming-Chou Ho creator: Vincent Chin-Hung Chen creator: Seh-Huang Chao creator: Ching-Tzu Fang creator: Yi-Chun Liu creator: Jun-Cheng Weng uri: https://doi.org/10.7717/peerj.5002 license: http://creativecommons.org/licenses/by/4.0/ rights: © 2018 Ho et al. title: The restoration of the endangered Sambucus palmensis after 30 years of conservation actions in the Garajonay National Park: genetic assessment and niche modeling link: https://peerj.com/articles/4985 last-modified: 2018-06-12 description: The translocation of individuals or the reinforcement of populations are measures in the genetic rescue of endangered species. Although it can be controversial to decide which and how many individuals must be reintroduced, populations can benefit from reinforcements. Sambucus palmensis is a critically endangered endemic to the Canary Islands. During the past 30 years, the Garajonay National Park (La Gomera) has carried out an intensive program of translocations using cuttings, due to the low germination rates of seeds. To assess the effect of the restorations on the population genetics of S. palmensis in La Gomera, we collected 402 samples from all the restored sites and all known natural individuals, which were genotyped with seven microsatellite markers. In addition, we conducted a species distribution modeling approach to assess how restorations fit the ecological niche of the species. Results show that there is a high proportion of clone specimens due to the propagation method, and the natural clonal reproduction of the species. Nonetheless, the observed heterozygosity has increased with the restorations and there still are private alleles and unique genotypes in the natural populations that have not been considered in the restorations. The population of Liria constitutes a very important genetic reservoir for the species. To optimize future reintroductions, we have proposed a list of specimens that are suitable for the extraction of seeds or cuttings in a greenhouse, as well as new suitable areas obtained by the species distribution models. creator: Priscila Rodríguez-Rodríguez creator: Alejandro G. Fernández de Castro creator: Pedro A. Sosa uri: https://doi.org/10.7717/peerj.4985 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2018 Rodríguez-Rodríguez et al. title: Biofilms and antibiotic susceptibility of multidrug-resistant bacteria from wild animals link: https://peerj.com/articles/4974 last-modified: 2018-06-12 description: BackgroundThe “One Health” concept recognizes that human health and animal health are interdependent and bound to the health of the ecosystem in which they (co)exist. This interconnection favors the transmission of bacteria and other infectious agents as well as the flow of genetic elements containing antibiotic resistance genes. This problem is worsened when pathogenic bacteria have the ability to establish as biofilms. Therefore, it is important to understand the characteristics and behaviour of microorganisms in both planktonic and biofilms states from the most diverse environmental niches to mitigate the emergence and dissemination of resistance.MethodsThe purpose of this work was to assess the antibiotic susceptibility of four bacteria (Acinetobacter spp., Klebsiella pneumoniae, Pseudomonas fluorescens and Shewanella putrefaciens) isolated from wild animals and their ability to form biofilms. The effect of two antibiotics, imipenem (IPM) and ciprofloxacin (CIP), on biofilm removal was also assessed. Screening of resistance genetic determinants was performed by PCR. Biofilm tests were performed by a modified microtiter plate method. Bacterial surface hydrophobicity was determined by sessile drop contact angles.ResultsThe susceptibility profile classified the bacteria as multidrug-resistant. Three genes coding for β-lactamases were detected in K. pneumoniae (TEM, SHV, OXA-aer) and one in P. fluorescens (OXA-aer). K. pneumoniae was the microorganism that carried more β-lactamase genes and it was the most proficient biofilm producer, while P. fluorescens demonstrated the highest adhesion ability. Antibiotics at their MIC, 5 × MIC and 10 × MIC were ineffective in total biofilm removal. The highest biomass reductions were found with IPM (54% at 10 × MIC) against K. pneumoniae biofilms and with CIP (40% at 10 × MIC) against P. fluorescens biofilms.DiscussionThe results highlight wildlife as important host reservoirs and vectors for the spread of multidrug-resistant bacteria and genetic determinants of resistance. The ability of these bacteria to form biofilms should increase their persistence. creator: Carla Dias creator: Anabela Borges creator: Diana Oliveira creator: Antonio Martinez-Murcia creator: Maria José Saavedra creator: Manuel Simões uri: https://doi.org/10.7717/peerj.4974 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2018 Dias et al. title: Biomechanical evidence suggests extensive eggshell thinning during incubation in the Sanagasta titanosaur dinosaurs link: https://peerj.com/articles/4971 last-modified: 2018-06-12 description: The reproduction of titanosaur dinosaurs is still a complex and debated topic. Their Late Cretaceous nesting sites are distributed worldwide and their eggs display substantial morphological variations according to the parent species. In contrast to the typical 1.3–2.0 mm thick shells common to eggs of most titanosaur species (e.g., those that nested in Auca Mahuevo, Tama, Toteşti or Boseong), the Cretaceous Sanagasta eggs of Argentina display an unusual shell thickness of up to 7.9 mm. Their oviposition was synchronous with a palaeogeothermal process, leading to the hypothesis that their extra thick eggshell was an adaptation to this particular nesting environment. Although this hypothesis has already been supported indirectly through several investigations, the mechanical implications of developing such thick shells and how this might have affected the success of hatching remains untested. Finite element analyses estimate that the breaking point of the thick-shelled Sanagasta eggs is 14–45 times higher than for other smaller and equally sized titanosaur eggs. The considerable energetic disadvantage for piping through these thick eggshells suggests that their dissolution during incubation would have been paramount for a successful hatching. creator: E. Martín Hechenleitner creator: Jeremías R. A. Taborda creator: Lucas E. Fiorelli creator: Gerald Grellet-Tinner creator: Segundo R. Nuñez-Campero uri: https://doi.org/10.7717/peerj.4971 license: http://creativecommons.org/licenses/by/4.0/ rights: © 2018 Hechenleitner et al. title: Odor-dependent temporal dynamics in Caenorhabitis elegans adaptation and aversive learning behavior link: https://peerj.com/articles/4956 last-modified: 2018-06-12 description: Animals sense an enormous number of cues in their environments, and, over time, can form learned associations and memories with some of these. The nervous system remarkably maintains the specificity of learning and memory to each of the cues. Here we asked whether the nematode Caenorhabditis elegans adjusts the temporal dynamics of adaptation and aversive learning depending on the specific odor sensed. C. elegans senses a multitude of odors, and adaptation and learned associations to many of these odors requires activity of the cGMP-dependent protein kinase EGL-4 in the AWC sensory neuron. We identified a panel of 17 attractive odors, some of which have not been tested before, and determined that the majority of these odors require the AWC primary sensory neuron for sensation. We then devised a novel assay to assess odor behavior over time for a single population of animals. We used this assay to evaluate the temporal dynamics of adaptation and aversive learning to 13 odors and find that behavior change occurs early in some odors and later in others. We then examined EGL-4 localization in early-trending and late-trending odors over time. We found that the timing of these behavior changes correlated with the timing of nuclear accumulation of EGL-4 in the AWC neuron suggesting that temporal changes in behavior may be mediated by aversive learning mechanisms. We demonstrate that temporal dynamics of adaptation and aversive learning in C. elegans can be used as a model to study the timing of memory formation to different sensory cues. creator: Jae Im Choi creator: Hee Kyung Lee creator: Hae Su Kim creator: So Young Park creator: Tong Young Lee creator: Kyoung-hye Yoon creator: Jin I. Lee uri: https://doi.org/10.7717/peerj.4956 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2018 Choi et al. title: A relationship between species richness and evenness that depends on specific relative abundance distribution link: https://peerj.com/articles/4951 last-modified: 2018-06-12 description: Although many ecologists focus on the relationship between species richness (S) and evenness (E), conflicts between observation and theory are difficult to reconcile. Empirical S–E relationships were not consistent, while relationships show strong correlation between S and E. Since E essentially depended on the relative abundance distribution (RAD), the hypothesis of this paper was that the S–E relationship should be determined by RAD. Theoretical S–E relationships for various RADs have already been reported, but they were rarely assessed by the raw data. This study constructed S–E relationships for a specific RAD, which indicated that if the community had a fractal distribution of rank abundance, E would decrease with S, and the S–E relationship would be unique for a given RAD. Such theoretical expectations were supported by three datasets with 82 samples, which suggested that the S–E relationship were controlled by RAD and inconsistent S–E relationships in statistical analyses could be accounted for by the variation of underlying RAD model between communities. From the perspective of RAD, it could be too early to split the diversity into S and E only based on the S–E relationship in statistical analyses. creator: Qiang Su uri: https://doi.org/10.7717/peerj.4951 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2018 Su title: RNA interference-mediated silencing of genes involved in the immune responses of the soybean pod borer Leguminivora glycinivorella (Lepidoptera: Olethreutidae) link: https://peerj.com/articles/4931 last-modified: 2018-06-12 description: RNA interference (RNAi) technology may be useful for developing new crop protection strategies against the soybean pod borer (SPB; Leguminivora glycinivorella), which is a critical soybean pest in northeastern Asia. Immune-related genes have been recently identified as potential RNAi targets for controlling insects. However, little is known about these genes or mechanisms underlying their expression in the SPB. In this study, we completed a transcriptome-wide analysis of SPB immune-related genes. We identified 41 genes associated with SPB microbial recognition proteins, immune-related effectors or signalling molecules in immune response pathways (e.g., Toll and immune deficiency pathways). Eleven of these genes were selected for a double-stranded RNA artificial feeding assay. The down-regulated expression levels of LgToll-5-1a and LgPGRP-LB2a resulted in relatively high larval mortality rates and abnormal development. Our data represent a comprehensive genetic resource for immune-related SPB genes, and may contribute to the elucidation of the mechanism regulating innate immunity in Lepidoptera species. Furthermore, two immune-related SPB genes were identified as potential RNAi targets, which may be used in the development of RNAi-mediated SPB control methods. creator: Ruixue Ran creator: Tianyu Li creator: Xinxin Liu creator: Hejia Ni creator: Wenbin Li creator: Fanli Meng uri: https://doi.org/10.7717/peerj.4931 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2018 Ran et al. title: Does bariatric surgery influence plasma levels of fetuin-A and leukocyte cell-derived chemotaxin-2 in patients with type 2 diabetes mellitus? link: https://peerj.com/articles/4884 last-modified: 2018-06-12 description: BackgroundFetuin-A and leukocyte cell-derived chemotaxin-2 (LECT-2) are liver-derived proteins. Fetuin-A is an independent risk factor for type 2 diabetes (T2D) and obese patients with T2D have higher plasma fetuin-A levels than those without T2D. LECT-2 has positive correlation with the severity of both obesity and insulin resistance. The changes in plasma fetuin-A are not consistent after bariatric surgery and no studies have investigated the changes in LECT-2 on the obese patients with T2D after bariatric surgery.MethodsOverall, 18 patients undergoing gastric bypass (GB) and 16 patients undergoing sleeve gastrectomy (SG) were enrolled. The fasting plasma fetuin-A and LECT-2 levels were measured at baseline, one week, three months, and one year after surgery.ResultsBoth the GB and SG groups significantly decreased the body mass index (BMI), waist-to-hip ratio, a body shape index; the triglyceride, fasting blood sugar (FBS), hemoglobin A1c, C-peptide levels; and homeostatic model assessment (HOMA-IR) one year after surgery. The SG group showed a decreasing trend in plasma fetuin-A levels one year after SG surgery. There are no significant changes in LECT-2 one year after either GB or SG. Fetuin-A had a near significant negative relationship with insulin (P = 0.056) and HOMA-IR (P = 0.050) in the SG group. Changes in fetuin-A had a significant positive relationship with changes in BMI (P = 0.031) and waist-to-hip ratio (P = 0.031) in the GB group and had a near significant positive correlation with FBS (P = 0.051) in the SG group.DiscussionNeither GB nor SG modifies plasma levels of plasma fetuin-A or LECT-2 in T2D patients after surgery. The changes in plasma fetuin-A have a positive correlation with those of the BMI and waist-to-hip ratio 12 months after GB. creator: Hsien-Hao Huang creator: Chun Yeh creator: Jung-Chien Chen creator: Tzong-Hsi Lee creator: Shu-Chun Chen creator: Wei-Jei Lee creator: Chih-Yen Chen uri: https://doi.org/10.7717/peerj.4884 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2018 Huang et al. title: Unfamiliar face matching with photographs of infants and children link: https://peerj.com/articles/5010 last-modified: 2018-06-11 description: BackgroundInfants and children travel using passports that are typically valid for five years (e.g. Canada, United Kingdom, United States and Australia). These individuals may also need to be identified using images taken from videos and other sources in forensic situations including child exploitation cases. However, few researchers have examined how useful these images are as a means of identification.MethodsWe investigated the effectiveness of photo identification for infants and children using a face matching task, where participants were presented with two images simultaneously and asked whether the images depicted the same child or two different children. In Experiment 1, both images showed an infant (<1 year old), whereas in Experiment 2, one image again showed an infant but the second image of the child was taken at 4–5 years of age. In Experiments 3a and 3b, we asked participants to complete shortened versions of both these tasks (selecting the most difficult trials) as well as the short version Glasgow face matching test. Finally, in Experiment 4, we investigated whether information regarding the sex of the infants and children could be accurately perceived from the images.ResultsIn Experiment 1, we found low levels of performance (72% accuracy) for matching two infant photos. For Experiment 2, performance was lower still (64% accuracy) when infant and child images were presented, given the significant changes in appearance that occur over the first five years of life. In Experiments 3a and 3b, when participants completed both these tasks, as well as a measure of adult face matching ability, we found lowest performance for the two infant tasks, along with mixed evidence of within-person correlations in sensitivities across all three tasks. The use of only same-sex pairings on mismatch trials, in comparison with random pairings, had little effect on performance measures. In Experiment 4, accuracy when judging the sex of infants was at chance levels for one image set and above chance (although still low) for the other set. As expected, participants were able to judge the sex of children (aged 4–5) from their faces.DiscussionIdentity matching with infant and child images resulted in low levels of performance, which were significantly worse than for an adult face matching task. Taken together, the results of the experiments presented here provide evidence that child facial photographs are ineffective for use in real-world identification. creator: Robin S.S. Kramer creator: Jerrica Mulgrew creator: Michael G. Reynolds uri: https://doi.org/10.7717/peerj.5010 license: http://creativecommons.org/licenses/by/4.0/ rights: © 2018 Kramer et al. title: Expressional and functional interactions of two Apis cerana cerana olfactory receptors link: https://peerj.com/articles/5005 last-modified: 2018-06-11 description: Apis cerana cerana relies on its sensitive olfactory system to perform foraging activities in the surrounding environment. Olfactory receptors (ORs) are a primary requirement for odorant recognition and coding. However, the molecular recognition of volatile compounds with ORs in A. cerana cerana is still not clear. Hence, in the present study, we achieved transient transfection and cell surface expression of A. cerana cerana ORs (AcerOr1 and AcerOr2; AcerOr2 is orthologous to the co-receptor) in Spodoptera frugiperda (Sf9) cells. AcerOr2 narrowly responded to N-(4-ethylphenyl)-2-((4-ethyl-5-(3-pyridinyl)-4H-1,2,4-triazol-3-yl) thio) acetamide (VUAA1), whereas AcerOr1 was sensitive to eugenol, lauric acid, ocimene, 1-nonanol, linolenic acid, hexyl acetate, undecanoic acid, 1-octyl alcohol, and nerol. Of the compounds tested, AcerOr1 showed the highest sensitivity to these odorants with EC50 values of 10−7 and 10−8 M, and AcerOr2 recognized VUAA1 with higher sensitivity [EC50 = (6.621 ± 0.26) × 10−8]. These results indicate that AcerOr2 is an essential gene for olfactory signaling, and AcerOr1 is a broadly tuned receptor. We discovered ligands that were useful for probing receptor activity during odor stimulation and validated three of them by electroantennography. The response increased with concentration of the odorant. The present study provides insight into the mechanism of olfactory discrimination in A. cerana cerana. creator: Lina Guo creator: Huiting Zhao creator: Yusuo Jiang uri: https://doi.org/10.7717/peerj.5005 license: http://creativecommons.org/licenses/by/4.0/ rights: © 2018 Guo et al.