Apparent Overlap Research Articles

Lake Michigan trophic structure as revealed by stable C and N isotopes

Abstract The objectives of this study were to describe the current trophic structure of Lake Michigan's upper food web using stable C and N isotopes. We describe ontogenetic diet patterns for common Lake Michigan species as revealed by stable isotope analysis and compare these patterns during a major transitional period (2002–2003 to 2010–2012) for most trophic levels. Proportional prey assimilation for various fishes was described using a Bayesian mixing model approach, and ontogenetic patterns were described using an analysis of covariance. δ 13 C results reveal distinct separation between the offshore and nearshore food webs. Within the offshore food web, invertebrates and prey fishes exhibited a large range in mean δ 15 N values which resulted in an apparent overlap between these trophic levels. This overlap may be due to spatiotemporal variability in δ 15 N at the base of the food web. Within the nearshore food web, more distinct delineation of trophic levels was apparent in δ 15 N values. Non-dreissenid nearshore benthic invertebrates were very isotopically similar and were the primary prey for non-piscivorous nearshore fishes. Ontogenetic shifts in diet were observed for alewife, bloater, deepwater sculpin, lake trout, round goby and yellow perch. Furthermore ontogenetic diet patterns changed significantly during the study period for alewife and bloater. Our findings provide a trophic structure baseline that can inform management action and be used to evaluate further ecological change as community structure continues to evolve.

Spatiotemporal occurrence of loggerhead turtles (Caretta caretta) on the West Florida Shelf and apparent overlap with a commercial fishery

Information on the spatial and temporal distribution of protected marine species is critical for the development of conservation strategies. We examined a 12-year dataset describing the postnesting residence areas of 81 adult female loggerhead turtles (Caretta caretta) on the West Florida Shelf (WFS) in the northeastern Gulf of Mexico. The aggregation of loggerheads on the WFS represents at least four US recovery units for this protected species. We identified several seasonally persistent residence areas that were shared by multiple loggerheads on the WFS. The majority (69%) of individuals remained within a discrete residence area throughout the tracking period. We placed our results within the context of a related fishery management concern — loggerhead bycatch within the bottom longline component of the Gulf commercial reef-fish fishery. We characterized loggerhead residence areas and compared that information with fishing activity. Our results provide information on the distribution of WFS loggerhead residence areas and the extent to which residence areas overlap with areas of high fishing effort. Loggerheads were present year-round on portions of the WFS, within or near to areas with high fishing effort. Interactions among loggerheads and fishing activities could be reduced by conservation management strategies that consider these spatial and seasonal patterns of occurrence.

Researching the Psychosocial: An Introduction

This special issue explores key issues relevant to psychosocial research and presents innovative qualitative approaches for investigating this emerging field. The term ‘psychosocial’ is increasingly widely used and has become associated with its own ‘turn’ in social theorising and research. Such a turn would be consistent with a now-well established trajectory of academic innovation. It implies a Kuhnian leap and a major re-framing through which deficiencies and absences in current theory and research are recognised then remedied, opening up new directions and problems for investigation, as occurred in psychology with the ‘discursive turn’ of the 1980s and 90s. However, the status of a psychosocial turn is less clear-cut, first because of the very broad reference of the term ‘psychosocial’, second, because of the apparent overlap with the project of social psychology, and third, because of the odd relation of the psychosocial to psychology more generally, including the rejection of its main traditions of qualitative research. This introduction expands on these points and introduces the five central articles in this special issue, each of which contributes a particular resolution to the challenges of the new turn, and the commentaries in which two senior critical and social psychologists, Ian Parker and Margaret Wetherell, reflect on future directions for psychosocial research.

Nicotinic and muscarinic acetylcholine receptors shape ganglion cell response properties.

The purpose of this study was to evaluate the expression patterns of nicotinic and muscarinic ACh receptors (nAChRs and mAChRs, respectively) in relation to one another and to understand their effects on rabbit retinal ganglion cell response properties. Double-label immunohistochemistry revealed labeled inner-retinal cell bodies and complex patterns of nAChR and mAChR expression in the inner plexiform layer. Specifically, the expression patterns of m1, m4, and m5 muscarinic receptors overlapped with those of non-α7 and α7 nicotinic receptors in presumptive amacrine and ganglion cells. There was no apparent overlap in the expression patterns of m2 muscarinic receptors with α7 nicotinic receptors or of m3 with non-α7 nicotinic receptors. Patch-clamp recordings demonstrated cell type-specific effects of nicotinic and muscarinic receptor blockade. Muscarinic receptor blockade enhanced the center responses of brisk-sustained/G4 On and G4 Off ganglion cells, whereas nicotinic receptor blockade suppressed the center responses of G4 On-cells near the visual streak but enhanced the center responses of nonstreak G4 On-cells. Blockade of muscarinic or nicotinic receptors suppressed the center responses of brisk-sustained Off-cells and the center light responses of subsets of brisk-transient/G11 On- and Off-cells. Only nicotinic blockade affected the center responses of G10 On-cells and G5 Off-cells. These data indicate that physiologically and morphologically identified ganglion cell types have specific patterns of AChR expression. The cholinergic receptor signatures of these cells may have implications for understanding visual defects in disease states that result from decreased ACh availability.

Non-rhabdoid pediatric SMARCB1-deficient tumors: overlap between chordomas and malignant rhabdoid tumors?

Somatic alterations in the tumor suppressor gene SMARCB1 were first described in the malignant rhabdoid tumor (MRT) of infancy. Since then, SMARCB1 alterations have been found in other tumors, forming a varied group of SMARCB1-deficient tumors, which sometimes shares overlapping immunohistochemical and histological findings. Thus, the diagnosis is challenging. We report two cases of pediatric SMARCB1-deficient tumors from the clivus that illustrate the diagnostic difficulties. Both cases were strongly positive for epithelial markers associated with loss of BAF47 (INI1) expression, and were negative for S100 and CD34. Molecular analyses of the SMARCB1 gene found a deletion of all nine exons in both cases. In the first case, a 5-year-old girl presented with a thoracic metastasis of a clival tumor, which was diagnosed as MRT and treated accordingly. The morphological findings and the expression of brachyury would favor the diagnosis of a poorly differentiated chordoma. The second case was a quickly fatal clival tumor in a 2-year-old boy: This tumor was morphologically undifferentiated and raises the problem of differential diagnosis between an MRT, a malignant myoepithelial tumor, or an undifferentiated chordoma due to the location and the expression of brachyury. Studies of biological signatures, such as transcriptome profiling, could help to understand the apparent overlap between these tumors.

Bacterial phylogeny structures soil resistomes across habitats.

SummaryAncient and diverse antibiotic resistance genes (ARGs) have previously been identified from soil1–3, including genes identical to those in human pathogens4. Despite the apparent overlap between soil and clinical resistomes4–6, factors influencing ARG composition in soil and their movement between genomes and habitats remain largely unknown3. General metagenome functions often correlate with the underlying structure of bacterial communities7–12. However, ARGs are hypothesized to be highly mobile4,5,13, prompting speculation that resistomes may not correlate with phylogenetic signatures or ecological divisions13,14. To investigate these relationships, we performed functional metagenomic selections for resistance to 18 antibiotics from 18 agricultural and grassland soils. The 2895 ARGs we discovered were predominantly novel, and represent all major resistance mechanisms15. We demonstrate that distinct soil types harbor distinct resistomes, and that nitrogen fertilizer amendments strongly influenced soil ARG content. Resistome composition also correlated with microbial phylogenetic and taxonomic structure, both across and within soil types. Consistent with this strong correlation, mobility elements syntenic with ARGs were rare in soil compared to sequenced pathogens, suggesting that ARGs in the soil may not transfer between bacteria as readily as is observed in the clinic. Together, our results indicate that bacterial community composition is the primary determinant of soil ARG content, challenging previous hypotheses that horizontal gene transfer effectively decouples resistomes from phylogeny13,14.

Atrial Natriuretic Peptide Affects Cardiac Remodeling, Function, Heart Failure, and Survival in a Mouse Model of Dilated Cardiomyopathy

Dilated cardiomyopathy is a frequent cause of heart failure and death. Atrial natriuretic peptide (ANP) is a biomarker of dilated cardiomyopathy, but there is controversy whether ANP modulates the development of heart failure. Therefore, we examined whether ANP affects heart failure, cardiac remodeling, function, and survival in a well-characterized, transgenic model of dilated cardiomyopathy. Mice with dilated cardiomyopathy with normal ANP levels survived longer than mice with partial ANP (P<0.01) or full ANP deficiency (P<0.001). In dilated cardiomyopathy mice, ANP protected against the development of heart failure as indicated by reduced lung water, alveolar congestion, pleural effusions, etc. ANP improved systolic function and reduced cardiomegaly. Pathological cardiac remodeling was diminished in mice with normal ANP as indicated by decreased ventricular interstitial and perivascular fibrosis. Mice with dilated cardiomyopathy and normal ANP levels had better systolic function (P<0.001) than mice with dilated cardiomyopathy and ANP deficiency. Dilated cardiomyopathy was associated with diminished cardiac transcripts for NP receptors A and B in mice with normal ANP and ANP deficiency, but transcripts for NP receptor C and C-type natriuretic peptide were selectively altered in mice with dilated cardiomyopathy and ANP deficiency. Taken together, these data indicate that ANP has potent effects in experimental dilated cardiomyopathy that reduce the development of heart failure, prevent pathological remodeling, preserve systolic function, and reduce mortality. Despite the apparent overlap in physiological function between the NPs, these data suggest that the role of ANP in dilated cardiomyopathy and heart failure is not compensated physiologically by other NPs.

Habitat use patterns of the invasive red lionfish Pterois volitans : a comparison between mangrove and reef systems in San Salvador, Bahamas

The Indo-Pacific red lionfish Pterois volitans is widespread both in its native and its non-native habitats. The rapid invasion of this top predator has had a marked negative effect on fish populations in the Western Atlantic and the Caribbean. It is now well documented that lionfish are invading many tropical and sub-tropical habitats. However, there are fewer data available on the change in lionfish abundance over time and the variation of body size and diet across habitats. A recent study in San Salvador, Bahamas, found body size differences between individuals from mangrove and reef systems. That study further suggested that ontogenetic investigation of habitat use patterns could help clarify whether lionfish are using the mangrove areas of San Salvador as nurseries. The aim of the present study is to determine temporal trends in lionfish relative abundance in mangrove and reef systems in San Salvador, and to further assess whether there is evidence suggesting an ontogenetic shift from mangroves to reef areas. Accordingly, we collected lionfish from mangrove and reef habitats and calculated catch per unit effort (a proxy for relative abundance), compared body size distributions across these two systems, and employed a combination of stable isotope, stomach content, and genetic analyses of prey, to evaluate differences in lionfish trophic interactions and habitat use patterns. Our results show that populations may have increased in San Salvador during the last 4 years, and that there is a strong similarity in body size between habitats, stark differences in prey items, and no apparent overlap in the use of habitat and/or food resources. These results suggest that there is not evidence an for ontogenetic shift from mangroves to reefs, and support other studies that propose lionfish are opportunistic forages with little movement across habitats.

How generalists coexist: the role of floral phenotype and spatial factors in the pollination systems of two Ranunculus species

Aims Competition for pollinators between phenotypically similar flowers is believed to play an important role in floral trait diversification in the angiosperms. However, in many plant communities, species with apparently similar floral phenotypes and generalist pollination systems co-flower. Here, the pollination systems of Ranunculus acris L. and Ranunculus repens L. were investigated to determine the factors enabling the species to coexist within apparently over lapping pollination niches. Methods Sympatrically flowering populations of R. acris and R. repens were investigated at three study sites in West Wales. The floral phenotypes of the two species were compared using measurements of floral morphology and spectral analyses of petal reflectance, using principal component analysis and bee and fly colour-space models. Evidence of inter-specific discrimination by foraging insects was tested for in the field and using floral arrays. The relative roles of behavioural constancy and spatial patchiness in maintaining pollinator fidelity were estimated. Important Findings The floral phenotypes of R. acris and R. repens differed significantly. Social bees were highly constant when foraging at flowers of the two species and patchy floral distribution explained some of the observed fidelity. Dipterans visiting mixed floral arrays appeared to discriminate between the species, visiting more R. acris than R. repens flowers, but there was no difference in the number of visits to single-species arrays. Social bees were more likely to display constancy to flowers of R. repens in the field. Patchiness in floral distribution, subtle differences in floral phenotype, pollinator preferences and behavioural constancy are all likely to contribute to the continued coexistence of R. acris and R. repens, despite apparent overlap in their pollination niches. Such differences have the potential to facilitate the maintenance of species diversity in plant communities, even where plants appear to share similar floral phenotypes.

Unified dispersive approach to real and virtual photon-photon scattering at low energy

Previous representations of pion pair production amplitudes by two real photons at low energy, which combine dispersion theoretical constraints with elastic unitariy, chiral symmetry and soft photon constraints are generalized to the case where one photon is virtual. The constructed amplitudes display explicitly the dependence on the $\pi\pi$ phase-shifts, on pion form factors and on pion polarizabilities. They apply both for space-like and time-like virtualities despite the apparent overlap of the left and right-hand cuts, by implementing a definition of resonance exchange amplitudes complying with analyticity and consistent limiting prescriptions for the energy variables. Applications are made to the pion generalized polarizabilies, to vector meson radiative decays, and to the $\sigma\gamma$ electromagnetic form factor. Finally, and evaluation of the contribution of $\gamma\pi\pi$ states in the hadronic vacuum polarization to the muon $g-2$ is given, which should be less model dependent than previous estimates.

FRI0271 Stratification of sle patients for improved diagnosis and treatment

BackgroundSystemic autoimmune diseases (SAIDs) affect about 2 % of the population in Western countries. Sufficient diagnostic criteria are lacking due to the heterogeneity within diagnostic categories and apparent overlap regarding...

Fatal pyoderma gangrenosum in a patient with inflammatory bowel disease and hypogonadotropic hypogonadism: Case report

Pyoderma gangrenosum is an inflammatory disease that has been found to be associated with many systemic illnesses. Here we describe, first time to our knowledge of pyoderma gangrenosum as well as pyostomatitis vegetans in a patient with hypogonadotropic hypogonadism. Later on inflammatory bowel disease was also detected. The pyoderma lesions appeared as multiple outbreaks which resolved totally after several combined immunosuppressive treatment. The clinical course of pyoderma gangrenosum and inflammatory bowel disease appeared independent, with no apparent overlap in inflammatory activity or response to the drugs administered.

Eco-environmental implications of elemental and carbon isotope distributions in ornithogenic sediments from the Ross Sea region, Antarctica

Seabirds have substantial influence on geochemical circulation of elements, serving as a link for substance exchange between their foraging area and colonies. In this study, we investigated the elemental and carbon isotopic composition of five penguin-affected sediment profiles excavated from Ross Island and Beaufort Island in the Ross Sea region, Antarctica. Among the three main constituents of the sediments (including weathered bedrock, guano and algae), guano was the main source of organic matter and nutrients, causing selective enrichment of several elements in each of the sediment profiles. In the 22 measured elements, As, Cd, Cu, P, S, Se and Zn were identified as penguin bio-elements in the Ross Sea region through statistical analysis and comparison with local end-member environmental media such as weathered bedrock, fresh guano and fresh algae. Carbon isotopic composition in the ornithogenic sediments showed a mixing feature of guano and algae. Using a two-member isotope mixing equation, we were able to reconstruct the historical change of guano input and algal bio-mass. Compared with research in other parts of Antarctic, Arctic, and South China Sea, we found apparent overlap of avian bio-elements including As, Cd, Cu, P, Se, and Zn. Information on the composition and behavior of bio-elements in seabird guano on a global scale, and the role that bio-vectors play in the geochemical circulation between land and sea, will facilitate future research on avian ecology and paleoclimatic reconstruction.

Testes play a role in termination but not in initiation of the spring migration in the night-migratory blackheaded bunting

Day length regulates the development of seasonal phenotypes linked with both the spring migration (e.g., premigratory body fattening and intense nighttime restlessness, called Zugunruhe, in captive birds) and reproduction (e.g., gonadal growth and maturation). The apparent overlap in these photoinduced seasonal phenotypes could be taken to suggest that they are causally linked. The present study investigates this, using the night-migratory blackheaded bunting (Emberiza melanocephala). We continuously monitored activity of male buntings exposed for 19 weeks to short (8 h light : 16 h darkness; 8L : 16D) and long (16L : 8D) photoperiods. Long, but not short, days induced the spring migratory phenotype. Another experiment investigated the role of testes in spring migration by comparing the development of Zugunruhe between intact and castrated buntings held on natural day lengths, at Meerut (India, 29°01′N, 77°45′E) during the period from March to October, thus covering the times of both the spring and autumn migrations. Testes were not involved in induction of the migratory phenotype but probably influenced the end of the migratory season, since castrates delayed the termination of the Zugunruhe.

Cannabinoid-hypocretin cross-talk in the central nervous system: what we know so far

Emerging findings suggest the existence of a cross-talk between hypocretinergic and endocannabinoid systems. Although few studies have examined this relationship, the apparent overlap observed in the neuroanatomical distribution of both systems as well as their putative functions strongly point to the existence of such cross-modulation. In agreement, biochemical and functional studies have revealed the existence of heterodimers between CB1 cannabinoid receptor and hypocretin receptor-1, which modulates the cellular localization and downstream signaling of both receptors. Moreover, the activation of hypocretin receptor-1 stimulates the synthesis of 2-arachidonoyl glycerol culminating in the retrograde inhibition of neighboring cells and suggesting that endocannabinoids could contribute to some hypocretin effects. Pharmacological data indicate that endocannabinoids and hypocretins might have common physiological functions in the regulation of appetite, reward and analgesia. In contrast, these neuromodulatory systems seem to play antagonistic roles in the regulation of sleep/wake cycle and anxiety-like responses. The present review attempts to piece together what is known about this interesting interaction and describes its potential therapeutic implications.

Kr II laser-induced fluorescence for measuring plasma acceleration

We present the application of laser-induced fluorescence of singly ionized krypton as a diagnostic technique for quantifying the electrostatic acceleration within the discharge of a laboratory cross-field plasma accelerator also known as a Hall effect thruster, which has heritage as spacecraft propulsion. The 728.98 nm Kr II transition from the metastable 5d(4)D(7/2) to the 5p(4)P(5/2)(∘) state was used for the measurement of laser-induced fluorescence within the plasma discharge. From these measurements, it is possible to measure velocity as krypton ions are accelerated from near rest to approximately 21 km/s (190 eV). Ion temperature and the ion velocity distributions may also be extracted from the fluorescence data since available hyperfine splitting data allow for the Kr II 5d(4)D(7/2)-5p(4)P(5/2)(∘) transition lineshape to be modeled. From the analysis, the fluorescence lineshape appears to be a reasonable estimate for the relatively broad ion velocity distributions. However, due to an apparent overlap of the ion creation and acceleration regions within the discharge, the distributed velocity distributions increase ion temperature determination uncertainty significantly. Using the most probable ion velocity as a representative, or characteristic, measure of the ion acceleration, overall propellant energy deposition, and effective electric fields may be calculated. With this diagnostic technique, it is possible to nonintrusively characterize the ion acceleration both within the discharge and in the plume.

HIGH-RESOLUTION H I DISTRIBUTIONS AND MULTI-WAVELENGTH ANALYSES OF MAGELLANIC SPIRALS NGC 4618 AND NGC 4625

We present a detailed analysis of high resolution H I observations of the Magellanic spiral galaxies NGC 4618 and NGC 4625. While the H I disk of NGC 4625 is remarkably quiescent with a nearly uniform velocity dispersion and no evidence of H I holes, there is a dynamic interplay between star formation and the distribution of neutral hydrogen in NGC 4618. We calculate the critical density for widespread star formation in each galaxy and find that star formation proceeds even where the surface density of the atomic gas is well below the critical density necessary for global star formation. There are strong spatial correlations in NGC 4618 between UV emission, 1.4 GHz radio continuum emission, and peaks in the H I column density. Despite the apparent overlap of the outer disks of the two galaxies, we find that they are kinematically distinct, indicating that NGC 4618 and NGC 4625 are not interacting. The structure of NGC 4618 and, in particular, the nature of its outer ring, are highly suggestive of an interaction, but the timing and nature of such an interaction remain unclear.

Are executive function and impulsivity antipodes? A conceptual reconstruction with special reference to addiction

Although there is considerable interest in how either executive function (EF) or impulsivity relate to addiction, there is little apparent overlap between these research areas. The present paper aims to determine if components of these two constructs are conceptual antipodes--widely separated on a shared continuum. EFs and impulsivities were compared and contrasted. Specifically, the definitions of the components of EF and impulsivity, the methods used to measure the various components, the populations of drug users that show deficits in these components, and the neural substrates of these components were compared and contrasted. Each component of impulsivity had an antipode in EF. EF, however, covered a wider range of phenomena, including compulsivity. Impulsivity functions as an antipode of certain components of EF. Recognition of the relationship between EF and impulsivity may inform the scientific inquiry of behavioral problems such as addiction. Other theoretical implications are discussed.

A conceptual framework for understanding self-regulation in adults

Multiple models of self-regulation have been posited, yet despite the apparent overlap between them, there is no common theoretical framework to unite the many theories. Authors in the area of self-regulation research have noted the lack of cross-field communication due to the absence of a conceptual framework and of common terms to describe self-regulatory processes (Bandura, 2005; Boekaerts, Maes, & Karoly, 2005; Karoly, Boekaerts, & Maes, 2005). The objective of the current review is to propose a common lexicon and a comprehensive model to integrate and organize the extant self-regulation research, thereby facilitating the understanding of self-regulation. The proposed model revisits classic cybernetic theory (Wiener, 1948), and is composed of a reference, input, comparator, and output. Each of these components is represented in current self-regulation theory, and is discussed as it relates to self-regulation models and ongoing empirical research.

A Cryptic New Species of Thrush (Turdidae:Turdus) from Western Amazonia

Abstract. The taxonomy of Hauxwell's Thrush (Turdus hauxwelli) with respect to its relationship to the Cocoa Thrush (Turdus fumigatus) has been complicated. A confounding factor has been the morphological variation reported within T. hauxwelli and the apparent geographic overlap of the two taxa. Recent evidence shows that some of these factors may be explained by the existence of a cryptic, syntopic species, very similar in plumage to T. hauxwelli. The new species differs in minor plumage characters, in soft-part colors, and (especially) in voice. On the basis of vocal and molecular data, we propose that the new thrush is not particularly closely related to the T. fumigatus/hauxwelli complex but rather is the western Amazonian member of the Spectacled Thrush (T. nudigenis) complex. Our molecular phylogeny suggests that the new species is sister to the Unicolored Thrush (T. haplochrous) and also that the Ecuadorian Thrush (T. maculirostris) should be considered a species separate from the Spectacled Thrush...