bluuebunny/crossref_metadata_2025 huggingface dataset:
Microstructural evidence for a disequilibrium condensation origin for hibonite‐spinel inclusions in the ALHA77307 CO3.0 chondrite
Authors: Han Jangmi , Brearley Adrian J. , Keller Lindsay P.
Published: November 2015

Two hibonite‐spinel inclusions (CAIs 03 and 08) in the ALHA77307 CO3.0 chondrite have been characterized in detail using the focused ion beam sample preparation technique combined with transmission electron microscopy. These hibonite‐spinel inclusions are irregularly shaped and porous objects and consist of randomly oriented hibonite laths enclosed by aggregates of spinel with fine‐grained perovskite inclusions finally surrounded by a partial rim of diopside. Melilite is an extremely rare phase in this type of CAI and occurs only in one inclusion (CAI 03) as interstitial grains between hibonite laths and on the exterior of the inclusion. The overall petrologic and mineralogical observations suggest that the hibonite‐spinel inclusions represent high‐temperature condensates from a cooling nebular gas. The textural relationships indicate that hibonite is the first phase to condense, followed by perovskite, spinel, and diopside. Texturally, melilite condensation appears to have occurred after spinel, suggesting that the condensation conditions were far from equilibrium. The crystallographic orientation relationships between hibonite and spinel provide evidence of epitaxial nucleation and growth of spinel on hibonite surfaces, which may have lowered the activation energy for spinel nucleation compared with that of melilite and consequently inhibited melilite condensation. Hibonite contains abundant stacking defects along the (001) plane consisting of different ratios of the spinel and Ca‐containing blocks within the ideal hexagonal hibonite structure. This modification of the stacking sequence is likely the result of accommodation of excess Al in the gas into hibonite due to incomplete condensation of corundum from a cooling gas under disequilibrium conditions. We therefore conclude that these two hibonite‐spinel inclusions in ALHA77307 formed by high‐temperature condensation under disequilibrium conditions.
40Ar/39Ar age of material returned from asteroid 25143 Itokawa
Authors: Park Jisun , Turrin Brent D. , Herzog Gregory F. , Lindsay Fara N. , Delaney Jeremy S. , Swisher Carl C. , Uesugi Masayuki , Karouji Yuzuru , Yada Toru , Abe Masanao , Okada Tatsuaki , Ishibashi Yukihiro
Published: November 2015

The Hayabusa mission to asteroid 25143, Itokawa, brought back 2000 small particles, which most closely resemble material found inLL4‐6 chondrites. We report an40Ar/39Ar age of 1.3 ± 0.3 Ga for a sample of Itokawa consisting of three grains with a total mass of ~2 μg. This age is lower than the >4.0 Ga ages measured for 75% ofLLchondrites but close to one for Y‐790964 and its pairs. The flat40Ar/39Ar release spectrum of the sample suggests complete degassing 1.3 Ga ago. Recent solar heating in Itokawa's current orbit does not appear likely to have reset that age. Solar or impact heating 1.3 Ga ago could have done so. If impact heating was responsible, then the 1.3 Ga age sets an upper bound on the time at which the Itokawa rubble pile was assembled and suggests that rubble pile creation was an ongoing process in the inner solar system for at least the first 3 billion years of solar system history.
Glass‐bearing inclusions in Shergotty and Chassigny: Consistent samples of a primary trapped melt?
Authors: Varela Maria Eugenia , Zinner Ernst
Published: November 2015

Glass‐bearing inclusions hosted by different mineral phases inSNCmeteorites provide important information on the conditions that prevailed during formation of early phases and/or on the composition of the primary trapped liquids/melts of these rocks. Although extensive previous work has been reported on such inclusions, several questions are still unresolved. We performed a chemical and petrographic study of the constituents (glasses and mineral assemblage) of glassy and multiphase inclusions in Shergotty and Chassigny. We focused on obtaining accurate trace element contents of glasses and co‐existing minerals and discussing their highly variableREEcontents. Our results reveal an unusual geochemistry of trace element contents that appear to be independent of their major element compositions. Chemical equilibrium between phases inside inclusions as well as between glasses and host minerals could not be established. TheLREEcontents of glasses in glass inclusions can vary by up to two orders of magnitude. The depletion in trace element abundances shown by glasses seem to be inconsistent with these phases being residual melts. The light lithophile element contents of glasses are highly variable with enrichment in incompatible elements (e.g., Be, Sr, Ba, andLREE) indicating some processes involving percolation of fluids. All of these features are incompatible with glass‐bearing inclusions in the host minerals acting as closed systems preserving unmodified primary liquids/melts. Glass‐bearing inclusions in Shergotty and Chassigny appear to have been altered (as was the rock itself) by different postformational processes (e.g., shock, metamorphism, metasomatic [?] fluids) that affected these meteorites with different degree of intensity. Our results indicate that these inclusions could not preserve a reliable sample of the primary trapped melt.
The Pillars of Hercules as a bathymetric barrier to gene flow promoting isolation in a global deep‐sea shark (Centroscymnus coelolepis)
Authors: Catarino Diana , Knutsen Halvor , Veríssimo Ana , Olsen Esben Moland , Jorde Per Erik , Menezes Gui , Sannæs Hanne , Stanković David , Company Joan Baptista , Neat Francis , Danovaro Roberto , Dell'Anno Antonio , Rochowski Bastien , Stefanni Sergio
Published: November 2015

Knowledge of the mechanisms limiting connectivity and gene flow in deep‐sea ecosystems is scarce, especially for deep‐sea sharks. The Portuguese dogfish (Centroscymnus coelolepis) is a globally distributed and near threatened deep‐sea shark. C. coelolepis population structure was studied using 11 nuclear microsatellite markers and a 497‐bp fragment from the mtDNA control region. High levels of genetic homogeneity across the Atlantic (ΦST = −0.0091, FST = 0.0024, P > 0.05) were found suggesting one large population unit at this basin. The low levels of genetic divergence between Atlantic and Australia (ΦST = 0.0744, P < 0.01; FST = 0.0015, P > 0.05) further suggested that this species may be able to maintain some degree of genetic connectivity even across ocean basins. In contrast, sharks from the Mediterranean Sea exhibited marked genetic differentiation from all other localities studied (ΦST = 0.3808, FST = 0.1149, P < 0.001). This finding suggests that the shallow depth of the Strait of Gibraltar acts as a barrier to dispersal and that isolation and genetic drift may have had an important role shaping the Mediterranean shark population over time. Analyses of life history traits allowed the direct comparison among regions providing a complete characterization of this shark's populations. Sharks from the Mediterranean had markedly smaller adult body size and size at maturity compared to Atlantic and Pacific individuals. Together, these results suggest the existence of an isolated and unique population of C. coelolepis inhabiting the Mediterranean that most likely became separated from the Atlantic in the late Pleistocene.
Landscape genetics in a changing world: disentangling historical and contemporary influences and inferring change
Authors: Epps Clinton W. , Keyghobadi Nusha
Published: November 2015

Landscape genetics seeks to determine the effect of landscape features on gene flow and genetic structure. Often, such analyses are intended to inform conservation and management. However, depending on the many factors that influence the time to reach equilibrium, genetic structure may more strongly represent past rather than contemporary landscapes. This well‐known lag between current demographic processes and population genetic structure often makes it challenging to interpret how contemporary landscapes and anthropogenic activity shape gene flow. Here, we review the theoretical framework for factors that influence time lags, summarize approaches to address this temporal disconnect in landscape genetic studies, and evaluate ways to make inferences about landscape change and its effects on species using genetic data alone or in combination with other data. Those approaches include comparing correlation of genetic structure with historical versus contemporary landscapes, using molecular markers with different rates of evolution, contrasting metrics of genetic structure and gene flow that reflect population genetic processes operating at different temporal scales, comparing historical and contemporary samples, combining genetic data with contemporary estimates of species distribution or movement, and controlling for phylogeographic history. We recommend using simulated data sets to explore time lags in genetic structure, and argue that time lags should be explicitly considered both when designing and interpreting landscape genetic studies. We conclude that the time lag problem can be exploited to strengthen inferences about recent landscape changes and to establish conservation baselines, particularly when genetic data are combined with other data.
Secondary contact and local adaptation contribute to genome‐wide patterns of clinal variation inDrosophila melanogaster
Authors: Bergland Alan O. , Tobler Ray , González Josefa , Schmidt Paul , Petrov Dmitri
Published: November 2015

Populations arrayed along broad latitudinal gradients often show patterns of clinal variation in phenotype and genotype. Such population differentiation can be generated and maintained by both historical demographic events and local adaptation. These evolutionary forces are not mutually exclusive and can in some cases produce nearly identical patterns of genetic differentiation among populations. Here, we investigate the evolutionary forces that generated and maintain clinal variation genome‐wide among populations ofDrosophila melanogastersampled in North America and Australia. We contrast patterns of clinal variation in these continents with patterns of differentiation among ancestral European and African populations. Using established and novel methods we derive here, we show that recently derived North America and Australia populations were likely founded by both European and African lineages and that this hybridization event likely contributed to genome‐wide patterns of parallel clinal variation between continents. The pervasive effects of admixture mean that differentiation at only several hundred loci can be attributed to the operation of spatially varying selection using anFSToutlier approach. Our results provide novel insight into the well‐studied system of clinal differentiation inD. melanogasterand provide a context for future studies seeking to identify loci contributing to local adaptation in a wide variety of organisms, including other invasive species as well as temperate endemics.
Influence of the larval phase on connectivity: strong differences in the genetic structure of brooders and broadcasters in the Ophioderma longicauda species complex
Authors: Weber A. A.‐T. , Mérigot B. , Valière S. , Chenuil A.
Published: November 2015

Closely related species with divergent life history traits are excellent models to infer the role of such traits in genetic diversity and connectivity. Ophioderma longicauda is a brittle star species complex composed of different genetic clusters, including brooders and broadcasters. These species diverged very recently and some of them are sympatric and ecologically syntopic, making them particularly suitable to study the consequences of their trait differences. At the scale of the geographic distribution of the broadcasters (Mediterranean Sea and northeastern Atlantic), we sequenced the mitochondrial marker COI and genotyped an intron (i51) for 788 individuals. In addition, we sequenced 10 nuclear loci newly developed from transcriptome sequences, for six sympatric populations of brooders and broadcasters from Greece. At the large scale, we found a high genetic structure within the brooders (COI: 0.07 < FST < 0.65) and no polymorphism at the nuclear locus i51. In contrast, the broadcasters displayed lower genetic structure (0 < FST < 0.14) and were polymorphic at locus i51. At the regional scale, the multilocus analysis confirmed the contrasting genetic structure between species, with no structure in the broadcasters (global FST < 0.001) and strong structure in the brooders (global FST = 0.49), and revealed a higher genetic diversity in broadcasters. Our study showed that the lecithotrophic larval stage allows on average a 50‐fold increase in migration rates, a 280‐fold increase in effective size and a threefold to fourfold increase in genetic diversity. Our work, investigating complementary genetic markers on sympatric and syntopic taxa, highlights the strong impact of the larval phase on connectivity and genetic diversity.
Evolutionary and demographic history of the Californian scrub white oak species complex: an integrative approach
Authors: Ortego Joaquín , Noguerales Víctor , Gugger Paul F. , Sork Victoria L.
Published: November 2015

Understanding the factors promoting species formation is a major task in evolutionary research. Here, we employ an integrative approach to study the evolutionary history of the Californian scrub white oak species complex (genus Quercus). To infer the relative importance of geographical isolation and ecological divergence in driving the speciation process, we (i) analysed inter‐ and intraspecific patterns of genetic differentiation and employed an approximate Bayesian computation (ABC) framework to evaluate different plausible scenarios of species divergence. In a second step, we (ii) linked the inferred divergence pathways with current and past species distribution models (SDMs) and (iii) tested for niche differentiation and phylogenetic niche conservatism across taxa. ABC analyses showed that the most plausible scenario is the one considering the divergence of two main lineages followed by a more recent pulse of speciation. Genotypic data in conjunction with SDMs and niche differentiation analyses support that different factors (geography vs. environment) and modes of speciation (parapatry, allopatry and maybe sympatry) have played a role in the divergence process within this complex. We found no significant relationship between genetic differentiation and niche overlap, which probably reflects niche lability and/or that multiple factors, have contributed to speciation. Our study shows that different mechanisms can drive divergence even among closely related taxa representing early stages of species formation and exemplifies the importance of adopting integrative approaches to get a better understanding of the speciation process.
Temporal variation of Bistorta vivipara‐associated ectomycorrhizal fungal communities in the High Arctic
Authors: Mundra Sunil , Bahram Mohammad , Tedersoo Leho , Kauserud Håvard , Halvorsen Rune , Eidesen Pernille Bronken
Published: November 2015

Ectomycorrhizal (ECM) fungi are important for efficient nutrient uptake of several widespread arctic plant species. Knowledge of temporal variation of ECM fungi, and the relationship of these patterns to environmental variables, is essential to understand energy and nutrient cycling in Arctic ecosystems. We sampled roots of Bistorta vivipara ten times over two years; three times during the growing‐season (June, July and September) and twice during winter (November and April) of both years. We found 668 ECM OTUs belonging to 25 different ECM lineages, whereof 157 OTUs persisted throughout all sampling time‐points. Overall, ECM fungal richness peaked in winter and species belonging to Cortinarius, Serendipita and Sebacina were more frequent in winter than during summer. Structure of ECM fungal communities was primarily affected by spatial factors. However, after accounting for spatial effects, significant seasonal variation was evident revealing correspondence with seasonal changes in environmental conditions. We demonstrate that arctic ECM richness and community structure differ between summer (growing‐season) and winter, possibly due to reduced activity of the core community, and addition of fungi adapted for winter conditions forming a winter‐active fungal community. Significant month × year interactions were observed both for fungal richness and community composition, indicating unpredictable between‐year variation. Our study indicates that addressing seasonal changes requires replication over several years.
Contrasting patterns of selection and drift between two categories of immune genes in prairie‐chickens
Authors: Bateson Zachary W. , Whittingham Linda A. , Johnson Jeff A. , Dunn Peter O.
Published: November 2015

Immune‐receptor genes of the adaptive immune system, such as the major histocompatibility complex (MHC), are involved in recognizing specific pathogens and are known to have high rates of adaptive evolution, presumably as a consequence of rapid co‐evolution between hosts and pathogens. In contrast, many ‘mediating’ genes of the immune system do not interact directly with specific pathogens and are involved in signalling (e.g. cytokines) or controlling immune cell growth. As a consequence, we might expect stronger selection at immune‐receptor than mediating genes, but these two types of genes have not been compared directly in wild populations. Here, we tested the hypothesis that selection differs between MHC (class I and II) and mediating genes by comparing levels of population differentiation across the range of greater prairie‐chickens (Tympanuchus cupido). As predicted, there was stronger population differentiation and isolation by distance at immune receptor (MHC) than at either mediating genes or neutral microsatellites, suggesting a stronger role of local adaptation at the MHC. In contrast, mediating genes displayed weaker differentiation between populations than neutral microsatellites, consistent with selection favouring similar alleles across populations for mediating genes. In addition to selection, drift also had a stronger effect on immune receptor (MHC) than mediating genes as indicated by the stronger decline of MHC variation in relation to population size. This is the first study in the wild to show that the effects of selection and drift on immune genes vary across populations depending on their functional role.
Divergence in DNA photorepair efficiency among genotypes from contrasting UV radiation environments in nature
Authors: Miner Brooks E. , Kulling Paige M. , Beer Karlyn D. , Kerr Benjamin
Published: November 2015

Populations of organisms routinely face abiotic selection pressures, and a central goal of evolutionary biology is to understand the mechanistic underpinnings of adaptive phenotypes. Ultraviolet radiation (UVR) is one of earth's most pervasive environmental stressors, potentially damaging DNA in any organism exposed to solar radiation. We explored mechanisms underlying differential survival following UVR exposure in genotypes of the water flea Daphnia melanica derived from natural ponds of differing UVR intensity. The UVR tolerance of a D. melanica genotype from a high‐UVR habitat depended on the presence of visible and UV‐A light wavelengths necessary for photoenzymatic repair of DNA damage, a repair pathway widely shared across the tree of life. We then measured the acquisition and repair of cyclobutane pyrimidine dimers, the primary form of UVR‐caused DNA damage, in D. melanica DNA following experimental UVR exposure. We demonstrate that genotypes from high‐UVR habitats repair DNA damage faster than genotypes from low‐UVR habitats in the presence of visible and UV‐A radiation necessary for photoenzymatic repair, but not in dark treatments. Because differences in repair rate only occurred in the presence of visible and UV‐A radiation, we conclude that differing rates of DNA repair, and therefore differential UVR tolerance, are a consequence of variation in photoenzymatic repair efficiency. We then rule out a simple gene expression hypothesis for the molecular basis of differing repair efficiency, as expression of the CPD photolyase gene photorepair did not differ among D. melanica lineages, in both the presence and absence of UVR.
Eco‐morphological differentiation in Lake Magadi tilapia, an extremophile cichlid fish living in hot, alkaline and hypersaline lakes in East Africa
Authors: Kavembe Geraldine D. , Kautt Andreas F. , Machado‐Schiaffino Gonzalo , Meyer Axel
Published: November 2015

Ecological diversification through divergent selection is thought to be a major force during the process of adaptive radiations. However, the large sizes and complexity of most radiations such as those of the cichlids in the African Great Lakes make it impossible to infer the exact evolutionary history of any population divergence event. The genusAlcolapia,a small cichlid lineage endemic to Lakes Magadi and Natron in East Africa, exhibits phenotypes similar to some of those found in cichlids of the radiations of the African Great Lakes. The simplicity withinAlcolapiamakes it an excellent model system to investigate ecological diversification and speciation. We used an integrated approach including population genomics based onRAD‐seq data, geometric morphometrics and stable isotope analyses to investigate the eco‐morphological diversification of tilapia in Lake Magadi and its satellite lake Little Magadi. Additionally, we reconstructed the demographic history of the species using coalescent simulations based on the joint site frequency spectrum. The population in Little Magadi has a characteristically upturned mouth—possibly an adaptation to feeding on prey from the water surface. Eco‐morphological differences between populations within Lake Magadi are more subtle, but are consistent with known ecological differences between its lagoons such as high concentrations of nitrogen attributable to extensive guano deposits in Rest of Magadi relative to Fish Springs Lagoon. All populations diverged simultaneously only about 1100 generations ago. Differences in levels of gene flow between populations and the effective population sizes have likely resulted in the inferred heterogeneous patterns of genome‐wide differentiation.
RAD sequencing reveals within‐generation polygenic selection in response to anthropogenic organic and metal contamination in North Atlantic Eels
Authors: Laporte M. , Pavey S. A. , Rougeux C. , Pierron F. , Lauzent M. , Budzinski H. , Labadie P. , Geneste E. , Couture P. , Baudrimont M. , Bernatchez L.
Published: November 2015

Measuring the effects of selection on the genome imposed by human‐altered environment is currently a major goal in ecological genomics. Given the polygenic basis of most phenotypic traits, quantitative genetic theory predicts that selection is expected to cause subtle allelic changes among covarying loci rather than pronounced changes at few loci of large effects. The goal of this study was to test for the occurrence of polygenic selection in both North Atlantic eels (European Eel, Anguilla anguilla and American Eel, A. rostrata), using a method that searches for covariation among loci that would discriminate eels from ‘control’ vs. ‘polluted’ environments and be associated with specific contaminants acting as putative selective agents. RAD‐seq libraries resulted in 23 659 and 14 755 filtered loci for the European and American Eels, respectively. A total of 142 and 141 covarying markers discriminating European and American Eels from ‘control’ vs. ‘polluted’ sampling localities were obtained using the Random Forest algorithm. Distance‐based redundancy analyses (db‐RDAs) were used to assess the relationships between these covarying markers and concentration of 34 contaminants measured for each individual eel. PCB153, 4′4′DDE and selenium were associated with covarying markers for both species, thus pointing to these contaminants as major selective agents in contaminated sites. Gene enrichment analyses suggested that sterol regulation plays an important role in the differential survival of eels in ‘polluted’ environment. This study illustrates the power of combining methods for detecting signals of polygenic selection and for associating variation of markers with putative selective agents in studies aiming at documenting the dynamics of selection at the genomic level and particularly so in human‐altered environments.
Targeted capture and resequencing of 1040 genes reveal environmentally driven functional variation in grey wolves
Authors: Schweizer Rena M. , Robinson Jacqueline , Harrigan Ryan , Silva Pedro , Galverni Marco , Musiani Marco , Green Richard E. , Novembre John , Wayne Robert K.
Published: November 2015

In an era of ever‐increasing amounts of whole‐genome sequence data for individuals and populations, the utility of traditional single nucleotide polymorphisms (SNPs) array‐based genome scans is uncertain. We previously performed a SNP array‐based genome scan to identify candidate genes under selection in six distinct grey wolf (Canis lupus) ecotypes. Using this information, we designed a targeted capture array for 1040 genes, including all exons and flanking regions, as well as 5000 1‐kb nongenic neutral regions, and resequenced these regions in 107 wolves. Selection tests revealed striking patterns of variation within candidate genes relative to noncandidate regions and identified potentially functional variants related to local adaptation. We found 27% and 47% of candidate genes from the previous SNP array study had functional changes that were outliers in sweed and bayenv analyses, respectively. This result verifies the use of genomewide SNP surveys to tag genes that contain functional variants between populations. We highlight nonsynonymous variants in APOB, LIPG and USH2A that occur in functional domains of these proteins, and that demonstrate high correlation with precipitation seasonality and vegetation. We find Arctic and High Arctic wolf ecotypes have higher numbers of genes under selection, which highlight their conservation value and heightened threat due to climate change. This study demonstrates that combining genomewide genotyping arrays with large‐scale resequencing and environmental data provides a powerful approach to discern candidate functional variants in natural populations.
Protein aggregation as an antibiotic design strategy
Authors: Bednarska Natalia G. , van Eldere Johan , Gallardo Rodrigo , Ganesan Ashok , Ramakers Meine , Vogel Isabel , Baatsen Pieter , Staes An , Goethals Marc , Hammarström Per , Nilsson K. Peter R. , Gevaert Kris , Schymkowitz Joost , Rousseau Frederic
Published: November 2015

Taking advantage of the xenobiotic nature of bacterial infections, we tested whether the cytotoxicity of protein aggregation can be targeted to bacterial pathogens without affecting their mammalian hosts. In particular, we examined if peptides encoding aggregation‐prone sequence segments of bacterial proteins can display antimicrobial activity by initiating toxic protein aggregation in bacteria, but not in mammalian cells. Unbiased in vitro screening of aggregating peptide sequences from bacterial genomes lead to the identification of several peptides that are strongly bactericidal against methicillin‐resistant Staphylococcus aureus. Upon parenteral administration in vivo, the peptides cured mice from bacterial sepsis without apparent toxic side effects as judged from histological and hematological evaluation. We found that the peptides enter and accumulate in the bacterial cytosol where they cause aggregation of bacterial polypeptides. Although the precise chain of events that leads to cell death remains to be elucidated, the ability to tap into aggregation‐prone sequences of bacterial proteomes to elicit antimicrobial activity represents a rich and unexplored chemical space to be mined in search of novel therapeutic strategies to fight infectious diseases.
Glucagon‐like peptide 2 counteracts the mucosal damage and the neuropathy induced by chronic treatment with cisplatin in the mouse gastric fundus
Authors: Pini A. , Garella R. , Idrizaj E. , Calosi L. , Baccari M. C. , Vannucchi M. G.
Published: November 2015

Background

Glucagon‐like peptide‐2 (GLP‐2) is a pleiotropic hormone synthesized and secreted by the enteroendocrine ‘L’ cells able to exert intestine‐trophic and anti‐inflammatory effects. The antineoplastic drug cisplatin causes gastrointestinal alterations with clinical symptoms (nausea and vomiting) that greatly affect the therapy compliance. Experimentally, it has been reported that chronic cisplatin treatment caused mucosal damage and enteric neuropathy in the rat colon.

Methods

We investigated, through a combined immunohistochemical and functional approach, whether [Gly2]GLP‐2, a GLP‐2 analog, was able to counteract the detrimental effects of long‐term cisplatin administration in the mucosa and myenteric neurons of mouse gastric fundus.

Key Results

Morphological experiments showed a reduction in the epithelium thickness in cisplatin‐treated mice, which was prevented by [Gly2]GLP‐2 co‐treatment. Immunohistochemistry demonstrated that cisplatin caused a significant decrease in myenteric neurons, mainly those expressing neuronal nitric oxide synthase (nNOS), that was prevented by [Gly2]GLP‐2 co‐treatment. In the functional experiments, [Gly2]GLP‐2 co‐treatment counteracted the increase in amplitude of the neurally induced contractions observed in strips from cisplatin‐treated animals. The NO synthesis inhibitor L‐NG‐nitro arginine caused an increase in amplitude of the contractile responses that was greater in preparations from cisplatin+[Gly2]GLP‐2 treated mice compared to the cisplatin‐treated ones.

Conclusions & Inferences

The results demonstrate that in cisplatin long‐term treated mice [Gly2]GLP‐2 is able to counteract both the mucosal gastric fundus damage, by preventing the epithelium thickness decrease, and the neuropathy, by protecting the nNOS neurons. Taken together, the present data suggest that [Gly2]GLP‐2 could represent an effective strategy to overcome the distressing gastrointestinal symptoms present during the anti‐neoplastic therapy.
Maximum upper esophageal sphincter (UES) admittance: a non‐specific marker of UES dysfunction
Authors: Cock C. , Besanko L. , Kritas S. , Burgstad C. M. , Thompson A. , Heddle R. , Fraser R. J. L. , Omari T. I.
Published: November 2015

Background

Assessment of upper esophageal sphincter (UES) motility is challenging, as functionally, UES relaxation and opening are distinct. We studied novel parameters, UES admittance (inverse of nadir impedance), and 0.2‐s integrated relaxation pressure (IRP), in patients with cricopharyngeal bar (CPB) and motor neuron disease (MND), as predictors of UES dysfunction.

Methods

Sixty‐six healthy subjects (n = 50 controls 20–80 years; n = 16 elderly >80 years), 11 patients with CPB (51–83 years) and 16 with MND (58–91 years) were studied using pharyngeal high‐resolution impedance manometry. Subjects received 5 × 5 mL liquid (L) and viscous (V) boluses. Admittance and IRP were compared by age and between groups. A p < 0.05 was considered significant.

Key Results

In healthy subjects, admittance was reduced (L: p = 0.005 and V: p = 0.04) and the IRP higher with liquids (p = 0.02) in older age. Admittance was reduced in MND compared to both healthy groups (Young: p < 0.0001 for both, Elderly L: p < 0.0001 and V: p = 0.009) and CPB with liquid (p = 0.001). Only liquid showed a higher IRP in MND patients compared to controls (p = 0.03), but was similar to healthy elderly and CPB patients. Only admittance differentiated younger controls from CPB (L: p = 0.0002 and V: p < 0.0001), with no differences in either parameter between CPB and elderly subjects.

Conclusions & Inferences

The effects of aging and pathology were better discriminated by UES maximum admittance, demonstrating greater statistical confidence across bolus consistencies as compared to 0.2‐s IRP. Maximum admittance may be a clinically useful determinate of UES dysfunction.
The relationship among gastroparetic symptoms, quality of life, and gastric emptying in patients referred for gastric emptying testing
Authors: DiBaise J. K. , Patel N. , Noelting J. , Dueck A. C. , Roarke M. , Crowell M. D.
Published: November 2015

Background

Symptoms suggestive of gastroparesis are non‐specific and conflicting reports exist regarding the ability of symptoms to predict the presence of gastroparesis. Our aim, therefore, was to evaluate the relationships between gastroparetic symptoms and their impact on quality of life and determine their relationship with clinical factors and gastric emptying.

Methods

Gastric emptying scintigraphy, sociodemographic features, health care resource utilization, gastroparetic symptoms, and quality of life using validated questionnaires were obtained from consecutive patients referred for gastric emptying testing (GET). Descriptive analyses were conducted and logistic regression was performed to evaluate associations with abnormal gastric emptying after controlling for other covariates.

Key Results

Two hundred and sixty‐six patients participated (195 females; mean age, 49.1 ± 17.6 years); 75% met Rome III criteria for functional dyspepsia. Gastric emptying was delayed in 28.2% at 4 h; the delay was mild in 48%, moderate in 20% and severe in 32%. Nausea/emesis and postprandial fullness, but not bloating, were significantly greater in those with delayed emptying. Postprandial fullness was most severe. Weak correlations were identified between symptom severity and the severity of gastric emptying delay. Quality of life was also lower in the delayed emptying group. Logistic regression analysis demonstrated associations between delayed gastric emptying and lower quality of life and increased symptom severity.

Conclusions & Inferences

In patients referred for GET, gastroparetic symptoms were more severe in those with delayed emptying. A decrease in quality of life in those with delayed gastric emptying was also present; this was not related to the severity of the delay in gastric emptying.
Functional implications of omnivory for dietary nutrient balance
Authors: Remonti Luigi , Balestrieri Alessandro , Raubenheimer David , Saino Nicola
Published: November 2015

Captive experiments have shown that many species regulate their macronutrient (i.e. protein, lipid and carbohydrate) intake by selecting complementary food types, but the relationships between foraging strategies in the wild and nutrient regulation remain poorly understood. Using the pine marten as a model species, we collated available data from the literature to investigate effects of seasonal and geographic variation in diet on dietary macronutrient balance. Our analysis showed that despite a high variety of foods comprising the diet, typical of a generalist predator, the macronutrient energy ratios of pine martens were limited to a range of 50–55% of protein, 38–42% of lipids and 5–10% of carbohydrates. This broad annual stabilisation of macronutrient ratios was achieved by using alternative animal foods to compensate for the high fluctuation of particular prey items, and sourcing non‐protein energy (carbohydrates and fats) from plant‐derived foods, particularly fruits. Macronutrient balance varied seasonally, with higher carbohydrate intake in summer–autumn, due to opportunistic fruit consumption, and higher protein intake in winter–spring. In terms of their proportional dietary carbohydrate intake the pine marten's nutritional strategy fell between that of true carnivores (e.g. the wolf) and more omnivorous feeders (e.g. the European badger). However, in terms of energy contributed by protein pine martens are equivalent to obligate carnivores such as the wolf and domesticated cat, and different to some omnivorous carnivores such as the domesticated dog and grizzly bears.
Highly unsaturated fatty acids in nature: what we know and what we need to learn
Authors: Twining Cornelia W. , Brenna J. Thomas , Hairston Nelson G. , Flecker Alexander S.
Published: November 2015

The supply and demand of omega‐3 highly unsaturated fatty acids (ω‐3 HUFA) in natural ecosystems may lead to resource limitation in a diverse array of animal taxa. Here, we review why food quality in terms of ω‐3 HUFAs is important, particularly for neural tissue, across a diversity of animal taxa ranging from invertebrate zooplankton to vertebrates (including humans). Our review is focused on ω‐3 HUFAs rather than other unsaturated fatty acids because these compounds are especially important biochemically, but scarce in nature. We discuss the dichotomy between ω‐3 HUFA availability between aquatic primary producers, which are often rich in these compounds, and terrestrial primary producers, which are contain little to none of them. We describe the use of fatty acids as qualitative and quantitative tracers for reconstructing animal diets in natural ecosystems. Next, we discuss both direct and indirect ecological implications of ω‐3 HUFA limitation at the individual, population, food web, and ecosystem scales, which include: changes in behavior, species composition, secondary production rates, trophic transfer efficiency and cross‐ecosystem subsidies. We finish by highlighting future research priorities including a need for more research on ω‐3 HUFAs in terrestrial systems, more research their importance for higher order consumers, and more research on the food web and ecosystem‐scale effects of ω‐3 HUFA limitation.

Synthesis

Mismatches between the supply of and demand for omega‐3 highly unsaturated fatty acids (ω‐3 HUFA) in natural ecosystems have the potential to result in resource limitation across a diverse array of ecosystems. We combined perspectives from ecology and nutritional science to develop a unified synthesis of ω‐3 HUFA ecology. We reviewed the importance of ω‐3 HUFAs for animals, the striking differences in ω‐3 HUFA availability at the base of terrestrial versus aquatic food webs, and the implications of ω‐3 HUFA limitation for food webs. We finished by highlighting research priorities in the field including more research on ω‐3 HUFAs in terrestrial systems, on higher order consumers, and at the food web and ecosystem‐scales.
Pain Self‐Efficacy and Fear of Movement are Similarly Associated with Pain Intensity and Disability in Italian Patients with Chronic Low Back Pain
Authors: Ferrari Silvano , Chiarotto Alessandro , Pellizzer Marta , Vanti Carla , Monticone Marco
Published: November 2015

The purpose of this study was to investigate cross‐sectional associations of pain self‐efficacy and fear of movement with pain intensity and disability in Italian patients with chronic low back pain (CLBP). One hundred and three adult outpatients with nonspecific CLBP were included in the study. Socio‐demographic and clinical characteristics were assessed, together with Italian versions of self‐reported questionnaires to measure the four constructs of interest. Multiple linear regression models were built with psychosocial constructs as main determinants, and pain intensity and disability as outcomes. Potential confounding of socio‐demographic and clinical characteristics was assessed. Pain self‐efficacy and fear of movement displayed moderate correlations with pain intensity (r = −0.41 and 0.42, respectively) and disability (−0.55 and 0.54). Association models adjusted for pain intensity showed that both pain self‐efficacy (β = −0.35, 95% CI = −0.5; −0.2, R2 = 41%) and fear of movement (β = 0.65, 95% CI = 0.36; 0.93, R2 = 40%) are significantly and strongly associated with disability. Pain self‐efficacy was no longer significantly associated with pain intensity when disability was added as a confounder to the model, whereas fear of movement retained its significant association (β = 0.06, 95% CI = 0.00;0.11, R2 = 30%). No other variables acted as confounders in these associations. Pain self‐efficacy and fear of movement are very similarly associated with main outcomes in this sample of Italian patients with CLBP. The results of this study suggest that both psychosocial constructs should be considered in clinical management. Future studies should investigate whether these findings can be replicated in other samples, in longitudinal designs and if other variables not measured in this study confound the associations.
Pathophysiological Mechanisms Involved in Vasomotor Disturbances in Complex Regional Pain Syndrome and Implications for Therapy: A Review
Authors: Kortekaas Minke C. , Niehof Sjoerd P. , Stolker Robert J. , Huygen Frank J.P.M.
Published: November 2015

Complex regional pain syndrome (CRPS) is characterized by continuous pain, disproportional to the initial trauma. It usually spreads to the distal parts of the affected limb. Besides continuing pain, a mix of sensory, sudo‐ and vasomotor disturbances, motor dysfunction, and trophic changes is responsible for physical complaints. Vasomotor disturbance is characterized by changes in skin temperature and color. In CRPS patients with a cold extremity, a decrease in blood flow can cause decreased tissue saturation and tissue acidosis, resulting in ischemic pain. The pathophysiology of vasomotor disturbances is not completely understood. Temperature asymmetry is generally assumed as a result of disturbance in the sympathetic nervous system. Vasodilating drugs and sympathetic blockade have been cornerstones of therapy in cold CRPS for years. However, only a limited part of these patients improve on this kind of therapies. Research has shown a pivotal role for inflammation in the pathophysiology of CRPS. Inflammation can result in endothelial dysfunction. Endothelial function plays an important role in the local regulation of vascular tone. Endothelial dysfunction could be another mechanism responsible for the vasomotor disturbances in cold CRPS. An important goal in the treatment of cold‐type CRPS is the restoration of a normal blood flow. Consequently it is important to distinguish the underlying pathophysiological mechanisms of vasomotor disturbances. A disturbance of the sympathetic nervous system may require another type of treatment than inflammation‐induced endothelial dysfunction. Diagnostic tools to distinguish these underlying pathophysiological mechanisms of vasomotor disturbances would enable a mechanism‐based treatment and improve clinical outcome.
A Novel Compound Analgesic Cream (Ketamine, Pentoxifylline, Clonidine, DMSO) for Complex Regional Pain Syndrome Patients
Authors: Russo Marc A. , Santarelli Danielle M.
Published: November 2015

Background

Evidence suggests that complex regional pain syndrome (CRPS) is a manifestation of microvascular dysfunction. Topical combinations of α2‐adrenergic receptor agonists or nitric oxide donors with phosphodiesterase or phosphatidic acid inhibitors formulated to treat microvascular dysfunction have been shown to reduce allodynia in a rat model of CRPS‐I. Driven by these findings, we assessed the outcomes of CRPS patients treated with a compound analgesic cream (CAC) consisting of ketamine 10%, pentoxifylline 6%, clonidine 0.2%, and dimethyl sulfoxide 6% to 10%.

Methods

An audit was conducted on 13 CRPS patients who trialed the CAC. A detailed report was compiled for each patient which comprised baseline characteristics, including CRPS description, previous treatments, and pain scores (numerical pain rating scale; 0 to 10). Recorded outcomes consisted of pain scores, descriptive outcomes, and concurrent medications/treatments, for which basic analysis was performed to determine the effectiveness of the CAC. Case reports are presented for 3 patients with varying outcomes.

Results

Nine patients (69%) reported pain/symptom reduction (4.4 ± 2.1 vs. 6.3 ± 1.9) with use of the CAC. Six patients reported sustained benefits after 2 months of CAC use, and 2 patients reported complete resolution of pain/symptoms: one had early CRPS‐I and the other received a partial CRPS diagnosis. An otherwise medication refractory and intolerant patient found partial benefit with the CAC.

Conclusions

These results demonstrate promise for this topical combination as a useful treatment in multimodal therapy for patients with CRPS, with the potential to resolve pain/symptoms in early CRPS patients.
Iris pigmentation as a quantitative trait: variation in populations of European, East Asian and South Asian ancestry and association with candidate gene polymorphisms
Authors: Edwards Melissa , Cha David , Krithika S. , Johnson Monique , Cook Gillian , Parra Esteban J.
Published: November 2015

In this study, we present a new quantitative method to measure iris colour based on high‐resolution photographs. We applied this method to analyse iris colour variation in a sample of individuals of East Asian, European and South Asian ancestry. We show that measuring iris colour using the coordinates of the CIELAB colour space uncovers a significant amount of variation that is not captured using conventional categorical classifications, such as ‘brown’, ‘blue’ or ‘green’. We tested the association of a selected panel of polymorphisms with iris colour in each population group. Six markers showed significant associations with iris colour in the European sample, three in the South Asian sample and two in the East Asian sample. We also observed that the marker HERC2 rs12913832, which is the main determinant of ‘blue’ versus ‘brown’ iris colour in European populations, is also significantly associated with central heterochromia in the European sample.
A Non‐Reciprocal Autosomal Translocation 64,XX, t(4;10)(q21;p15) in an Arabian Mare with Repeated Early Embryonic Loss
Authors: Ghosh S , Das PJ , Avila F , Thwaits BK , Chowdhary BP , Raudsepp T
Published: November 2015

Contents

Balanced autosomal translocations are a known cause for repeated early embryonic loss (REEL) in horses. In most cases, carriers of such translocations are phenotypically normal, but the chromosomal aberration negatively affects gametogenesis giving rise to both genetically balanced and unbalanced gametes. The latter, if involved in fertilization, result in REEL, whereas gametes with the balanced form of translocation will pass the defect into next generation. Therefore, in order to reduce the incidence of REEL, identification of translocation carriers is critical. Here, we report about a phenotypically normal 3‐year‐old Arabian mare that had repeated resorption of conceptuses prior to day 45 of gestation and was diagnosed with REEL. Conventional and molecular cytogenetic analyses revealed that the mare had normal chromosome number 64,XX but carried a non‐mosaic and non‐reciprocal autosomal translocation t(4;10)(q21;p15). This is a novel translocation described in horses with REEL and the first such report in Arabians. Previous cases of REEL due to autosomal translocations have exclusively involved Thoroughbreds. The findings underscore the importance of routine cytogenetic screening of breeding animals.