bluuebunny/crossref_metadata_2025 huggingface dataset:
Beauty-in-averageness and its contextual modulations: A Bayesian statistical account
Authors: Ryali Chaitanya K. , Yu Angela J.
Published: July 2018

Understanding how humans perceive the likability of high-dimensional “objects” such as faces is an important problem in both cognitive science and AI/ML. Existing models of human preferences generally assume these preferences to be fixed. However, human assessment of facial attractiveness have been found to be highly context-dependent. Specifically, the classical Beauty-in-Averageness (BiA) effect, whereby a face blended from two original faces is judged to be more attractive than the originals, is significantly diminished or reversed when the original faces are recognizable, or when the morph is mixed-race/mixed gender and the attractiveness judgment is preceded by a race/gender categorization. This effect, dubbed Ugliness-in-Averageness (UiA), has previously been attributed to a disfluency account, which is both qualitative and clumsy in explaining BiA. We hypothesize, instead, that these contextual influences on face processing result from the dependence of attractiveness perception on an element of statistical typicality, and from an attentional mechanism that restricts face representation to a task-relevant subset of features, thus redefining typicality within that subspace. Furthermore, we propose a principled explanation of why statistically atypical objects are less likable: they incur greater encoding or processing cost associated with a greater prediction error, when the brain uses predictive coding to compare the actual stimulus properties with those expected from its associated categorical prototype. We use simulations to show our model provides a parsimonious, statistically grounded, and quantitative account of contextual dependence of attractiveness. We also validate our model using experimental data from a gender categorization task. Finally, we make model predictions for a proposed experiment that can disambiguate the previous disfluency account and our statistical typicality theory.
Constructing Predictive Cancer Systems Biology Models
Authors: Rohrs Jennifer A. , Makaryan Sahak Z. , Finley Stacey D.
Published: July 2018

Systems biology combines computational modeling with quantitative experimental measurements to study complex biological processes. Here, we outline an approach for parameterizing and validating a systems biology model to yield predictive tool that can generate testable hypotheses and expand biological understanding.
An immune-CNS axis activates remote hippocampal stem cells following Spinal Transection Injury
Authors: Dehler Sascha , Lou Pak-Kin , Skabkin Maxim , Laudenklos Sabrina , Neumann Andreas , Martin-Villalba Ana
Published: July 2018

External stimuli such as injury, learning, or stress influence the production of neurons by neural stem cells (NSCs) in the adult mammalian brain. These external stimuli directly impact stem cell activity by influencing areas directly connected or in close proximity to the neurogenic niches of the adult brain. However, very little is known on how distant injuries affect NSC activation state. In this study we demonstrate that a thoracic spinal transection injury activates the distally located hippocampal-NSCs. This activation leads to a transient increase production of neurons that functionally integrate to improve animal’s performance in hippocampal-related memory tasks. We further show that interferon-CD95 signaling is required to promote injury-mediated activation of remote NSCs. Thus, we identify an immune-CNS axis responsible for injury-mediated activation of remotely located NSCs.
Plan-based generalization shapes local implicit adaptation to opposing visuomotor transformations
Authors: Schween Raphael , Taylor Jordan , Hegele Mathias
Published: July 2018

The human ability to use different tools demonstrates our capability of forming and maintaining multiple, context specific motor memories. Experimentally, this ability has been investigated in dual adaptation, where participants adjust their reaching movements to opposing visuomotor transformations. Adaptation in these paradigms occurs by distinct processes, i.e. the development of explicit aiming strategies for each transformation and/or the implicit acquisition of distinct visuomotor mappings. The presence of distinct, transformation-dependent aftereffects has been interpreted as support for the latter. Alternatively, however, distinct aftereffects could reflect adaptation of a single visuomotor map, which is locally adjusted in different regions of the workspace. Indeed, recent studies suggest that explicit aiming strategies direct where in the workspace implicit adaptation occurs.

Disentangling these possibilities is critical to understanding how humans acquire and maintain separate motor memories for different skills and tools. We therefore investigated generalization of explicit and implicit adaptation to different directions after participants practiced two opposing cursor rotations, which were associated with separate visual workspaces. Whereas participants learned to compensate opposing rotations by explicit strategies that were specific to the visual workspace cue, aftereffects were not sensitive to visual workspace cues. Instead, aftereffects displayed bimodal generalization patterns that appeared to reflect locally limited learning of both transformations. By varying target arrangements and instructions, we show that these generalization patterns are consistent with implicit adaptation that generalizes locally around (explicit) movement plans associated with opposing visuomotor transformations. Our findings show that strategies can shape implicit adaptation in a complex manner.

New & Noteworthy

Visuomotor dual adaptation experiments have identified contextual cues that enable learning of separate visuomotor mappings, but little is known about the underlying representations of learning. We report that visual workspace separation as a contextual cue enables participants to compensate opposing cursor rotations by a combination of explicit and implicit processes: Learners developed context-dependent explicit aiming strategies while an implicit visuomotor map represented dual adaptation independent from context by local adaptation around the explicit movement plan.
A migration-associated supergene reveals loss of biocomplexity in Atlantic cod
Authors: Kess Tony , Bentzen Paul , Lehnert Sarah J. , Sylvester Emma V.A. , Lien Sigbjørn , Kent Matthew P. , Sinclair-Waters Marion , Morris Corey , Regular Paul , Fairweather Robert , Bradbury Ian R.
Published: July 2018

Intraspecific phenotypic diversity is integral to ecological resilience and the provision of ecosystem services1. Chromosome structural variation may underpin intraspecific diversity and complex phenotypes2 by reducing recombination within supergenes containing linked, co-adapted alleles. Connecting ecologically-relevant phenotypes to genomic variation can enable more precise conservation of exploited marine species by protecting important genetic diversity3,4. Here, using genome-wide association analysis of a 12K single nucleotide polymorphism (SNP) array we confirm that an ancient, derived chromosomal rearrangement consisting of two adjacent inversions is strongly associated with migratory phenotype and individual-level genetic structure in Atlantic cod (Gadus morhua) across the Northwest Atlantic. The presence of all identified migration-associated loci within this rearrangement indicates that pervasive variation in migration phenotype is in part controlled by a recombination-resistant supergene, facilitating fine-scale individual phenotypic variation within Northern cod. Furthermore, we reconstruct trends in effective population size over the last century, and find genomic signatures of population collapse, and different patterns of population expansion and decline among individuals based on supergene alleles. We demonstrate declines in effective population size consistent with the onset of industrialized harvest (post 1950) and substantially reduced effective size of individuals homozygous for the derived chromosomal rearrangement relative to heterozygous individuals or those homozygous for the ancestral version of this chromosomal region. These results illustrate how chromosomal structural diversity can mediate fine-scale genetic and phenotypic variation in a highly connected marine species, and suggest a loss of biocomplexity from a migration-associated supergene within Northern cod by overfishing.
Fluorescence Multiplexing with Spectral Imaging and Combinatorics
Authors: Holzapfel Hadassa Y. , Stern Alan D. , Bouhaddou Mehdi , Anglin Catilin M. , Putur Danielle , Comer Sarah , Birtwistle Marc R.
Published: July 2018

Ultraviolet-to-infrared fluorescence is a versatile and accessible assay modality, but is notoriously hard to multiplex due to overlap of wide emission spectra. We present an approach for fluorescence multiplexing using spectral imaging and combinatorics (MuSIC). MuSIC consists of creating new independent probes from covalently-linked combinations of individual fluorophores, leveraging the wide palette of currently available probes with the mathematical power of combinatorics. Probe levels in a mixture can be inferred from spectral emission scanning data. Theory and simulations suggest MuSIC can increase fluorescence multiplexing ~4-5 fold using currently available dyes and measurement tools. Experimental proof-of-principle demonstrates robust demultiplexing of nine solution-based probes using ~25% of the available excitation wavelength window (380-480 nm), consistent with theory. The increasing prevalence of white lasers, angle filter-based wavelength scanning, and large, sensitive multi-anode photo-multiplier tubes make acquisition of such MuSIC-compatible datasets increasingly attainable.
Architecture and organization of mouse posterior parietal cortex relative to extrastriate areas
Authors: Hovde Karoline , Gianatti Michele , Witter Menno P. , Whitlock Jonathan R.
Published: July 2018

The posterior parietal cortex (PPC) is a multifaceted region of cortex, contributing to several cognitive processes including sensorimotor integration and spatial navigation. Although recent years have seen a considerable rise in the use of rodents, particularly mice, to investigate PPC and related networks, a coherent anatomical definition of PPC in the mouse is still lacking. To address this, we delineated the mouse PPC using cyto- and chemoarchitectural markers from Nissl-, parvalbumin- and muscarinic acetylcholine receptor M2-staining. Additionally, we performed bilateral triple anterograde tracer injections in primary visual cortex (V1) and prepared flattened tangential sections from one hemisphere and coronal sections from the other, allowing us to co-register the cytoarchitectural features of PPC with V1 projections. In charting the location of extrastriate areas and the architectural features of PPC in the context of each other, we reconcile different, widely used conventions for demarcating PPC in the mouse. Furthermore, triple anterograde tracer injections in PPC showed strong projections to associative thalamic nuclei as well as higher visual areas, orbitofrontal, cingulate and secondary motor cortices. Retrograde circuit mapping with rabies virus further showed that all cortical connections were reciprocal. These combined approaches provide a coherent definition of mouse PPC that incorporates laminar architecture, extrastriate projections, thalamic, and cortico-cortical connections.
HIV-1 vaccine design through minimizing envelope metastability
Authors: He Linling , Kumar Sonu , Allen Joel D. , Huang Deli , Lin Xiaohe , Mann Colin J. , Saye-Francisco Karen L. , Copps Jeffrey , Sarkar Anita , Blizard Gabrielle S. , Ozorowski Gabriel , Sok Devin , Crispin Max , Ward Andrew B. , Nemazee David , Burton Dennis R. , Wilson Ian A. , Zhu Jiang
Published: July 2018

Overcoming envelope metastability is crucial to trimer-based HIV-1 vaccine design. Here, we present a coherent vaccine strategy by minimizing metastability. For ten strains across five clades, we demonstrate that gp41 ectodomain (gp41ECTO) is the main source of envelope metastability by replacing wild-type gp41ECTOwith BG505 gp41ECTOof the uncleaved prefusion-optimized (UFO) design. These gp41ECTO-swapped trimers can be produced in CHO cells with high yield and high purity. Crystal structure of a gp41ECTO-swapped trimer elucidates how a neutralization-resistant tier 3 virus evades antibody recognition of the V2 apex. UFO trimers of transmitted/founder (T/F) viruses and UFO trimers containing a consensus-based ancestral gp41ECTOsuggest an evolutionary root of the metastability. Gp41ECTO-stabilized trimers can be readily displayed on 24- and 60-meric nanoparticles, with incorporation of additional T cell help illustrated for a hyperstable 60-mer. In mice and rabbits, gp140 nanoparticles induced more effective tier 2 neutralizing antibody response than trimers with statistical significance.

HIGHLIGHTS

gp41 is the main source of HIV-1 envelope metastability

BG505 gp41 of the UFO design stabilizes gp140 trimers of diverse subtypes

gp41 stabilization facilitates gp140 nanoparticle assembly and improves production

Nanoparticles elicit tier 2 neutralizing antibodies more effectively than trimers
Regulatory networks of gene expression in maize (Zea mays) under drought stress and re-watering
Authors: Cao Liru , Lu Xiaomin , Zhang Pengyu , Ku Lixia , Wang Guorui , Yuan Zhen , Zhang Xin , Cui Jingyu , Han Jingli , Liu Ying , Cao Yangyong , Wei Li , Wang Tongchao
Published: July 2018

Drought can severely limit plant growth and production. However, few studies have investigated gene expression profiles in maize during drought/re-watering. We compared drought-treated and water-sufficient maize plants by measuring their leaf relative water content, superoxide dismutase and peroxidase activities, proline content, and leaf gas exchange parameters (photosynthetic rates, stomatal conductance, and transpiration rates). We conducted RNA sequencing analyses to elucidate gene expression profiles and identify miRNAs that might be related to drought resistance. A GO enrichment analysis showed that the common DEGs (differently expressed genes) between drought-treated and control plants were involved in response to stimulus, cellular process, metabolic process, cell part, and binding and catalytic activity. Analyses of gene expression profiles revealed that 26 of the DEGs under drought encoded 10 enzymes involved in proline synthesis, suggesting that increased proline synthesis was a key part of the drought response. We also investigated cell wall-related genes and transcription factors regulating abscisic acid-dependent and -independent pathways. The expression profiles of the miRNAs miR6214-3p, miR5072-3p, zma-miR529-5p, zma-miR167e-5p, zma-miR167f-5p, and zma-miR167j-5p and their relevant targets under drought conditions were analyzed. These results provide new insights into the molecular mechanisms of drought tolerance, and may identify new targets for breeding drought-tolerant maize lines.

Abbreviations

leaf relative water content: RWC, superoxide dismutase activity: SOD, peroxidase activity: POD, proline content: Pro, photosynthetic rates: Pn, stomatal conductance: Cond, transpiration rates: Tr.; quantitative real-time polymerase chain reaction: qPCR; abscisic acid; ABA; polyethylene glycol :PEG; Principal component analysis :PCA; polyacrylamide gel electrophoresis :PAGE

Highlight

The study of physiology and molecular mechanism of maize laid a theoretical foundation for drought resistance breeding under drought stress and re-watering.
DrosophilaDNA/RNA methyltransferase contributes to robust host defense in ageing animals by regulating sphingolipid metabolism
Authors: Abhyankar Varada , Kaduskar Bhagyashree , Kamat Siddhesh S. , Deobagkar Deepti , Ratnaparkhi Girish
Published: July 2018

Drosophilamethyltransferase (Mt2) has been implicated in methylation of both DNA and tRNA. In this study, we demonstrate that loss ofMt2activity leads to an age dependent decline of immune function in the adult fly. A newly eclosed adult has mild immune defects that exacerbate in a fifteen-day oldMt2−/−fly. The age dependent effects appear to be systemic, including disturbances in lipid metabolism, changes in cell shape of hemocytes and significant fold changes in levels of transcripts related to host defense. Lipid imbalance, as measured by quantitative lipidomics, correlates with immune dysfunction with high levels of immunomodulatory lipids, sphingosine-1phosphate (S1P) and ceramides, along with low levels of storage lipids. Activity assays on fly lysates confirm the age dependent increase in S1P and concomitant reduction of S1P lyase activity. We hypothesize thatMt2functions to regulate genetic loci such as S1P lyase and this regulation is essential for robust host defense as the animal ages. Our study uncovers novel links between age dependentMt2function, innate immune response and lipid homeostasis.
Population genomics supports clonal reproduction and multiple gains and losses of parasitic abilities in the most devastating nematode plant pest
Authors: Koutsovoulos Georgios D. , Marques Eder , Arguel Marie-Jeanne , Duret Laurent , Machado Andressa C.Z. , Carneiro Regina M.D.G. , Kozlowski Djampa K. , Bailly-Bechet Marc , Castagnone-Sereno Philippe , Albuquerque Erika V.S. , Danchin Etienne G.J.
Published: July 2018

The most devastating nematodes to worldwide agriculture are the root-knot nematodes withMeloidogyne incognitabeing the most widely distributed and damaging species. This parasitic and ecological success seem surprising given its supposed obligatory clonal reproduction. Clonal reproduction has been suspected based on cytological observations but, so far, never confirmed by population genomics data. At the species level,M. incognitais highly polyphagous with thousands of host plants. However, the host range varies among differentM. incognitaisolates that may present distinct and more restricted host compatibilities. Historically, four ‘host races’ had been defined as a function of ranges of compatible and incompatible plants. We sequenced the genomes of 11 isolates across Brazil, covering these four distinct races to assess (i) how clonal reproduction is and (ii) how the level of genome variability associates with biological traits such as the host races, affected agronomic culture, and geographical distribution. By aligning the genomic reads of the isolates to theM. incognitareference genome assembly, we identified SNV and small-scale insertions/deletions. Analysis of linkage disequilibrium and 4-gametes test, showed no sign of recombination, confirming the clonal mode of reproduction ofM. incognita.We showed that there are relatively few point variations between the different isolates, and these variations show no significant association with either the host races, the geographical origin of the samples or the host plant on which they have been collected. Due to the lack of phylogenetic signal underlying their existence, we recommend the discontinuation of the terminology ‘race’. Overall, these results suggest that multiple gains and losses of parasitic abilities and adaptations to different environmental conditions account for the broad host spectrum and wide geographic distribution ofM. incognita. Hence, this nematode constitutes a model species to study adaptability without sexual recombination and overall low genomic variations in animals.
Using the Weibull accelerated failure time regression model to predict time to health events
Authors: Liu Enwu , Lim Karen
Published: July 2018

We describe a statistical method protocol to use a Weibull accelerated failure time (AFT) model to predict time to a health-related event. This prediction method is quite common in engineering reliability research but rarely used for medical predictions such as survival time. A worked example for how to perform the prediction using a published dataset is included.
Mate choice and gene expression signatures associated with nutritional adaptation in the medfly (Ceratitis capitata)
Authors: Nash Will , Mohorianu Irina , Chapman Tracey
Published: July 2018

Evolutionary responses to nutrition are key to understanding host shifts and the potential for reproductive isolation. Previously, experimental evolution was used to describe responses of the medfly (Ceratitis capitata) to divergent larval diets. Within 30 generations there was divergence in larval development time, egg to adult survival and adaptation in adult body size. In this study, the gene expression signatures associated with these changes were examined, using mRNA-seq on males following 60 generations of nutritional selection. Variation in gene expression was also validated using qRT-PCR. The results showed observed an over-representation of differential expression in metabolism, oxidative phosphorylation and proteolysis genes. In addition, at generations 60 and 90, we tested whether these evolved patterns (differences in gene expression) were associated with mate choice. We found evidence for assortative mating by diet at generation 60, but not in mating tests within and between replicate lines at generation 90. Hence, there was no consistent evidence for assortative mating by diet, which emphasises the importance of replicate tests of evolutionary responses over time. Overall, the study provides the first genome-wide survey of the putative mechanisms underpinning evolved responses to nutritional adaptation.
The Enzymes that beyond Non-Oxidative Glycolysis
Authors: Xu Zixiang , Wu Qiaqing , Zhu Dunming
Published: July 2018

High yield is an important objective of cell factory. One or several genes cloned into the bacterial may make the synthetic pathway much more optimal, so can increase the yield. But the global benefit enzymes are rare, which can increase the yields of many chemical products for a cell factory such as E.coli. Two of these kinds of global benefit enzymes are the famous enzymes, D-fructose-6-phosphate D-erythrose-4-phosphate-lyase and D-Xylulose 5-phosphate D-glyceraldehyde-3-phosphate-lyase, of non-oxidative glycolysis (NOG) published in Nature, which can improve the utilization ratio of carbon. We expect to find other global benefit enzymes. We use an integrated model, which integrated in silico model of E.coli and KEGG. By computation, we analyze the effect of adding each reaction from KEGG on the theoretical yields of several products with E.coli and find 83 enzymes that may be potentially global benefit enzymes. By comparison, we find about 30 of the 83 enzymes are better in improving the theoretical yields than the two enzymes of NOG.

In order to compare the global benefit enzymes with NOG, as an example, we select “Glycerol:NADP+ oxidoreductase” (GNO) which can increase the supply of NADPH in E.coli. But To increase the supply of reducing power, such as NADPH will probably increase the yield of chemicals in a cell factory. We use flux balance analysis method to testify our assumption. By comparing the maximum yields of 80 products produced by E.coli with respectively using GNO and NOG, we find GNO has better performance in the product production of E.coli. So GNO is a global benefit enzyme which can increase the yields of many chemical products in E.coli.
Protein Deacetylase CobB Interplays with c-di-GMP
Authors: Xu Zhaowei , Zhang Hainan , Zhang Xingrun , Liu Chengxi , Jiang Hewei , Wu Fanlin , Qian Lili , Czajkowsky Daniel M. , Guo Shujuan , Bi Lijun , Wang Shihua , Li Haitao , Tan Minjia , Feng Lei , Hou Jingli , Tao Sheng-ce
Published: July 2018

As a ubiquitous bacterial secondary messenger, c-di-GMP plays key regulatory roles in processes such as bacterial motility and transcription regulation. CobB is the Sir2 family protein deacetylase that controls energy metabolism, chemotaxis and DNA supercoiling in many bacteria. Using anE.coliproteome microarray, we found that c-di-GMP strongly binds to CobB. Protein deacetylation assays showed that c-di-GMP inhibits CobB activity and thereby modulates the biogenesis of acetyl-CoA. Through mutagenesis studies, residues R8, R17 and E21 of CobB were shown to be required for c-di-GMP binding. Next, we found that CobB is an effective deacetylase of YdeH, a major diguanylate cyclase (DGC) ofE.colithat is endogenously acetylated. Mass spectrometry analysis identified YdeH K4 as the major site of acetylation, and it could be deacetylated by CobB. Interestingly, deacetylation of YdeH enhances its stability and cyclase activity in c-di-GMP production. Thus, our work establishes a novel negative feedback loop linking c-di-GMP biogenesis and CobB-mediated protein deacetylation.
Human back-tracking behaviour is associated with suppression of default-mode region activity and enhanced dorsal anterior cingulate activity
Authors: Javadi Amir-Homayoun , Patai Eva Zita , Marin-Garcia Eugenia , Margois Aaron , Tan Heng-Ru M. , Kumaran Dharshan , Nardini Marko , Penny Will , Duzel Emrah , Dayan Peter , Spiers Hugo J.
Published: July 2018

Central to the concept of the ‘cognitive map’ is that it confers behavioural flexibility, allowing animals to take efficient detours, exploit shortcuts and realise the need to back-track rather than persevere on a poorly chosen route. The neural underpinnings of such naturalistic and flexible behaviour remain unclear. During fMRI we tested human subjects on their ability to navigate to a set of goal locations in a virtual desert island riven by lava, which occasionally shifted to block selected paths (necessitating detours) or receded to open new paths (affording shortcuts). We found that during self-initiated back-tracking, activity increased in frontal regions and the dorsal anterior cingulate cortex, while activity in regions associated with the core default-mode network was suppressed. Detours activated a network of frontal regions compared to shortcuts. Activity in right dorsolateral prefrontal cortex specifically increased when participants encountered new plausible shortcuts but which in fact added to the path (false shortcuts). These results help inform current models as to how the brain supports navigation and planning in dynamic environments.

Significance Statement

Adaptation to change is important for survival. Although real-world spatial environments are prone to continual change, little is known about how the brain supports navigation in dynamic environments where flexible adjustments to route plans are needed. Here, we used fMRI to examine the brain activity elicited when humans took forced detours, identified shortcuts and spontaneously back-tracked along their recent path. Both externally and internally generated changes in the route activated the fronto-parietal attention network, whereas only internally generated changes generated increased activity in the dorsal anterior cingulate cortex with a concomitant disengagement in regions associated with the default-mode network. The results provide new insights into how the brain plans and re-plans in the face of a changing environment.
Life history evolution and phenotypic plasticity in parasitic eyebrights (Euphrasia, Orobanchaceae)
Authors: Twyford Alex D. , Frachon Natacha , Wong Edgar L. Y. , Metherell Chris , Brown Max R.
Published: July 2018

Premise of the study

Parasite lifetime reproductive success is determined by both genetic variation and phenotypically plastic life history traits that respond to host quality and external environment. Here, we use the generalist parasitic plant genus Euphrasia to investigate life history trait variation, in particular whether there is a trade-off between growth and reproduction, and how life history traits are affected by host quality.

Methods

We perform a common garden experiment to evaluate life history trait differences between eleven Euphrasia taxa grown on a common host, document phenotypic plasticity when a single Euphrasia species is grown on eight different hosts, and relate our observations to trait differences recorded in the wild.

Key results

Euphrasia exhibit a range of life history strategies that differ between species that transition rapidly to flower at the expense of early season growth, and those that invest in vegetative growth and delay flowering. Many life history traits show extensive phenotypic plasticity in response to host quality and demonstrate the costs of attaching to a low-quality host.

Conclusions

Common garden experiments reveal trait differences between taxonomically complex Euphrasia species that are characterised by postglacial speciation and hybridisation. Our experiments suggest life history strategies in this generalist parasitic plant genus are the product of natural selection on traits related to growth and flowering. However, host quality may be a primary determinant of lifetime reproductive success.
Flow stimuli reveal ecologically-appropriate responses in mouse visual cortex
Authors: Dyballa Luciano , Hoseini Mahmood S. , Dadarlat Maria C. , Zucker Steven W. , Stryker Michael P.
Published: July 2018

Assessments of the mouse visual system based on spatial frequency analysis imply that its visual capacity is low, with few neurons responding to spatial frequencies greater than 0.5 cycles/degree. However, visually-mediated behaviors, such as prey capture, suggest that the mouse visual system is more precise. We introduce a new stimulus class—visual flow patterns—that is more like what the mouse would encounter in the natural world than are sine-wave gratings but is more tractable for analysis than are natural images. We used 128-site silicon microelectrodes to measure the simultaneous responses of single neurons in the primary visual cortex (V1) of alert mice. While holding temporal-frequency content fixed, we explored a class of drifting patterns of black or white dots that have energy only at higher spatial frequencies. These flow stimuli evoke strong visually-mediated responses well beyond those predicted by spatial frequency analysis. Flow responses predominate in higher spatial-frequency ranges (0.15–1.6 cycles/degree); many are orientation- or direction-selective; and flow responses of many neurons depend strongly on sign of contrast. Many cells exhibit distributed responses across our stimulus ensemble. Together, these results challenge conventional linear approaches to visual processing and expand our understanding of the mouse’s visual capacity to behaviorally-relevant ranges.

Significance Statement

The visual system of the mouse is now widely studied as a model for development and disease in humans. Studies of its primary visual cortex (V1) using conventional grating stimuli to construct linear-nonlinear receptive fields suggest that the mouse must have very poor vision. Using novel stimuli resembling the flow of images across the retina as the mouse moves through the grass, we find that most V1 neurons respond reliably to very much finer details of the visual scene than previously believed. Our findings suggest that the conventional notion of a unique receptive field does not capture the operation of the neural network in mouse V1.
Dynamics of the Ghrelin/Growth Hormone Secretagogue Receptor System in the Human Heart Before and After Cardiac Transplantation
Authors: Sullivan Rebecca , Randhawa Varinder K , Stokes Anne , Wu Derek , Lalonde Tyler , Kiaii Bob , Luyt Leonard , Wisenberg Gerald , Dhanvantari Savita
Published: July 2018

Background

Currently, the early pre-clinical detection of left ventricular (LV) dysfunction is difficult as biomarkers are not specific for the cardiomyopathic process. The underlying molecular mechanisms leading to heart failure remain elusive, highlighting the need for identification of cardiac-specific markers. The growth hormone secretagogue receptor (GHSR) and its ligand ghrelin are present in cardiac tissue and are known to contribute to myocardial energetics. Here, we examined tissue ghrelin-GHSR levels as specific markers of cardiac dysfunction in patients who underwent cardiac transplantation.

Methods and Results

Samples of cardiac tissue were obtained from 10 cardiac transplant patients at the time of organ harvesting, and during serial post-transplant biopsies. Quantitative fluorescence microscopy using a novel fluorescent ghrelin analog was used to measure levels of GHSR, and immunofluorescence was used to measure levels of ghrelin, b-type natriuretic peptide (BNP) and tissue markers of cardiomyocyte contractility and growth. GHSR and ghrelin expression levels were highly variable in the explanted heart, less in the grafted heart biopsies. GHSR and ghrelin were strongly positively correlated, and both markers were negatively correlated with LV ejection fraction. Ghrelin had stronger positive correlations than BNP with the signaling markers for contractility and growth.

Conclusions

These data suggest that GHSR-ghrelin have potential use as an integrated marker of cardiac dysfunction. Interestingly, tissue ghrelin appeared to be a more sensitive indicator than BNP to the biochemical processes that are characteristic of heart failure. This work allows for further use of ghrelin-GHSR to interrogate cardiac-specific biochemical mechanisms in pre-clinical stages of HF.

Precis

This study shows the relationships between GHSR, ghrelin, and signaling molecules with relation to heart function in human heart failure with tissue from diseased heart and healthy heart biopsies.
The limits of long-term selection against Neandertal introgression
Authors: Petr Martin , Pääbo Svante , Kelso Janet , Vernot Benjamin
Published: July 2018

Several studies have suggested that introgressed Neandertal DNA was subjected to negative selection in modern humans due to deleterious alleles that had accumulated in the Neandertals after they split from the modern human lineage. A striking observation in support of this is an apparent monotonic decline in Neandertal ancestry observed in modern humans in Europe over the past 45 thousand years. Here we show that this apparent decline is an artifact caused by gene flow between West Eurasians and Africans, which is not taken into account by statistics previously used to estimate Neandertal ancestry. When applying a more robust statistic that takes advantage of two high-coverage Neandertal genomes, we find no evidence for a change in Neandertal ancestry in Western Europe over the past 45 thousand years. We use whole-genome simulations of selection and introgression to investigate a wide range of model parameters, and find that negative selection is not expected to cause a significant long-term decline in genome-wide Neandertal ancestry. Nevertheless, these models recapitulate previously observed signals of selection against Neandertal alleles, in particular a depletion of Neandertal ancestry in conserved genomic regions that are likely to be of functional importance. Thus, we find that negative selection against Neandertal ancestry has not played as strong a role in recent human evolution as had previously been assumed.
Trajectory planning for mini unmanned helicopter in obstacle and windy environments
Authors: Xiang Jinwu , Shen Tong , Li Daochun
Published: July 2018

Purpose

Obstacle and wind field are common environmental factors for mini unmanned helicopter (MUH) flight. This paper aims to develop a trajectory planning approach guiding MUH to avoid static and dynamic obstacles and to fly in steady uniform or boundary-layer wind field.

Design/methodology/approach

An optimal control model including a nonlinear flight dynamics model and a cubic obstacle model is established for MUH trajectory planning. Radau pseudospectral method is used to generate the optimal trajectory.

Findings

The approach can plan reasonable obstacle-avoiding trajectories in obstacle and windy environments. The simulation results show that high-speed wind fields increase the flight time and fluctuation of control inputs. If boundary-layer wind field exists, the trajectory deforms significantly and gets closer to the ground to escape from the strong wind.

Originality/value

The key innovations in this paper include a cubic obstacle model which is straightforward and practical for trajectory planning and MUH trajectory planning in steady uniform wind field and boundary-layer wind field. This study provides an efficient solution to the trajectory planning for MUH in obstacle and windy environments.
A shiitake mushroom extract as a viable alternative to NaCl for a reduction in sodium in beef burgers
Authors: Mattar Thayana Vilela , Gonçalves Carla Saraiva , Pereira Rafaela Corrêa , Faria Michelle Aparecida , de Souza Vanessa Rios , Carneiro João de Deus Souza
Published: July 2018

Purpose

The purpose of this paper is to evaluate a shiitake mushroom extract as a potential natural taste enhancer in low-sodium beef burgers by means of sensorial and physico-chemical assays because nowadays there is a trend in the market for the development of clean-label products.

Design/methodology/approach

Ten formulations of beef burgers were developed, varying in the percentage reduction in NaCl (0-75 per cent) and mushroom water extracts (obtained from a 5, 12.5, or 20 per cent mushroom homogenate). Sensory characterisation was performed by time-intensity (TI) and acceptance tests. In addition, physico-chemical analyses (pH, yield, shrinkage, shear force, and colour) were conducted.

Findings

Extracts obtained from 5, 12.5, or 20 per cent mushroom homogenate (E1, E2, and E3, respectively) did not enhance the salty taste in formulations with a 0 or 75 per cent reduction in NaCl. In formulations with a 50 per cent reduction in NaCl, all the extracts enhanced salinity perception, with E3 being the most effective. E3 also increased acceptance of colour, aroma, texture, flavour, and overall perception, although it caused changes in some physico-chemical characteristics (pH, yield, shrinkage, shear force, and colour).

Originality/value

The shiitake mushroom extract is a natural ingredient with a potential to serve as a taste enhancer in meat and other food products, for the purpose of reducing sodium content without compromising sensory acceptability. Therefore, this extract will enable the development of healthier products (owing to a reduction in sodium) with preserved sensory quality and will meet consumers’ requirements for the minimal use of chemical additives in food.
Linking strategic management accounting and quality management systems
Authors: Sedevich-Fons Leonardo
Published: July 2018

Purpose

Quality management is gradually becoming an area of interest among management accounting practitioners and scholars because of its significant effects on performance and increasing adoption by organizations. Therefore, the purpose of this paper is to explore the relationships between these two broad disciplines and provide guidelines for their joint consideration.

Design/methodology/approach

Two specific management innovations are analyzed in detail: strategic management accounting (SMA) and ISO 9000 quality management system (QMS). Such an analysis includes a literature review of both frameworks, the identification of benefits associated with their simultaneous application and the design of a comprehensive model integrating their individual principles.

Findings

It is concluded that these management schemes are compatible and complementary from a theoretical standpoint; and that, therefore, their combined implementation might help organizations improve overall performance. It is also argued here that their use in conjunction could facilitate the spread of SMA techniques and the full exploitation of QMSs.

Originality/value

A new management system proposing the incorporation of SMA tools into traditional QMSs is introduced, and some recommendations for its practical use are presented.
A novel framework for owner driven reconstruction projects to enhance disaster resilience in the long term
Authors: Vahanvati Mittul
Published: July 2018

Purpose

Post-disaster reconstruction poses a double-edged sword to its implementers as it demands addressing survivors’ need for speed as well as meeting the growing expectation to trigger resilience. While an owner-driven housing reconstruction (ODHR), inter-disciplinary and long-term approach has been promoted internationally; however, there is limited research focussed on the long-term impacts (>10 years after a disaster) of ODHR. Furthermore, there is no one accepted framework for practitioners to guide through the process of ODHR projects to carve pathways for disaster resilience. The purpose of this paper is to assimilate findings—contingent and generalisable—into a novel framework for future change in practice.

Design/methodology/approach

This paper deployed a mixed methods methodology with a comparative case study research method. Two case study projects were from the Indian state of Gujarat, 13 years after the 2001 earthquake and the other two from Bihar, 6 years since the 2008 Kosi river floods. Due to multi-disciplinary nature of research, empirical data collection relied on a mix of social sciences methods including 80 semi-structured interviews, and architectural research methods including the visual analysis of photographs and sketches. Three sample groups of agency members, beneficiaries and non-beneficiaries were purposively selected. Thematic content analysis was used for the data analysis.

Findings

The paper provides empirical insights on how ODHR projects in Indian states of Gujarat and Bihar succeeded at enhancing disaster resilience of communities. It suggests that the civil society organisations acted as “enablers” at four stages: envisioning strategically based on systemic understanding, building soft assets including community trust and dignity for social mobilisation prior to, proposing minor modifications to construction technology for its multi-hazard safety as well as cultural relevance, and sustaining capacity building efforts beyond reconstruction completion or beyond one project life-cycle.

Research limitations/implications

The author of this paper cautions that the spiral framework needs further development to make it flexibility and customisable to suit the specifics of a particular context.

Originality/value

The implications of the findings discussed in this paper are primarily for practitioners involved in disaster recovery and development sector. Since prevailing models or frameworks neither incorporate multi-disciplinary approach (demanded by socio-ecological systems resilience concept), nor represent project scale, a novel, four-pronged framework for ODHR has been proposed in this paper for strategic success. The framework has been illustrated in spiral and tabular forms, and has been kept abstract to provide practitioners the much-needed flexibility for adapting it to suit the specifics of a particular context.
Resource levelling optimization model considering float loss impact
Authors: El-Sayegh Sameh
Published: July 2018

Purpose

The purpose of this paper is to propose a Non-Linear Integer Programming (NLIP) model that solves the resource leveling problem while reducing the negative effect of the total float loss on risk.

Design/methodology/approach

An NLIP model is formulated to solve the resource leveling optimization problem incorporating float loss cost (FLC). The proposed model is implemented using “What’s Best solver” for Excel. The FLC is calculated using the float commodity approach. An example is solved using the proposed model in order to illustrate its applicability. Sensitivity analysis is also performed.

Findings

The results confirmed that resource leveling reduces the available float of non-critical activities; decreases schedule flexibility and reduces the probability of project completion. The probability of timely completion dropped from 50 percent (for the normal schedule with 32 resource fluctuations) to 13.5 percent for leveled resources with zero fluctuations. Using the proposed method, the number of resource fluctuations is 8 but the probability of completing the project on time improved to 20 percent.

Practical implications

The proposed model allows project managers to exercise new trade-offs between resource leveling and schedule flexibility which will ultimately improve the chances of successful project delivery.

Originality/value

Resource leveling techniques result in reducing the available total float for the non-critical activities. Existing methods focus on moving noncritical activities within their available float and ignore the impact of the resulting float loss. This reduces the schedule flexibility and increase the risk of project delays. The proposed model incorporates the FLC into the resource leveling optimization problem resulting in more efficient schedules with improved resource utilization while keeping some schedule flexibility.
The Grow parenting program: demonstrating proof of concept
Authors: Chesnut Ryan , DiNallo Jennifer M. , Czymoniewicz-Klippel Melina T. , Perkins Daniel F.
Published: July 2018

Purpose

Parent-focused interventions (PFIs) are a promising method for supporting parents and promoting children’s well-being. Few PFIs in the USA, however, include physical health promotion content and are universal programs. The purpose of this paper is to describe a universal health-promoting PFI for parents of elementary school-aged children and demonstrate proof of concept.

Design/methodology/approach

The program emphasizes positive parenting practices, stress management skills and physical health promotion strategies and recommendations, and is part of a larger initiative that includes a continuum of universal, developmentally appropriate, health-promoting PFIs for civilian and military parents. The program was implemented at two community sites in rural Pennsylvania with 20 civilian parents completing pretests and posttests. Study measures assessed parenting, stress and stress management and physical health promotion related outcomes.

Findings

Parents reported decreases in suboptimal discipline and feeding practices, stress and child internalizing behavior. They also reported increases in their sense of control in managing child behavior, coping socialization, child’s outdoor playtime and health recommendations met.

Research limitations/implications

While these preliminary findings may not be generalizable, they serve as proof of concept, which suggests that more rigorous research on the program is warranted.

Practical implications

Implementing a universal, health-promoting PFI within the USA is viable and has the potential to impact multiple short-term outcomes.

Originality/value

Parents are among their child’s earliest and most influential educators, and this study lends further support to their role as health educators. Given the significant public health benefits of holistically promoting child health, the time has come for universal PFIs to begin including physical health promotion content.