Science.gov

Sample records for structures conspicuously absent

  1. Absent Apologies

    ERIC Educational Resources Information Center

    Drew, Paul; Hepburn, Alexa

    2016-01-01

    Absent apologies--apologies that were expected but are not forthcoming--are quite frequently identified and commented on, for instance in the media. In this article we discuss two kinds of evidence that apologies can be "noticeably" absent for participants in ordinary interactions. The first kind is the delays that can occur in the…

  2. PHACE without face? Infantile hemangiomas of the upper body region with minimal or absent facial hemangiomas and associated structural malformations.

    PubMed

    Nabatian, Adam S; Milgraum, Sandy S; Hess, Christopher P; Mancini, Anthony J; Krol, Alfons; Frieden, Ilona J

    2011-01-01

    Infantile hemangiomas can be associated with congenital anomalies such as PHACE syndrome with facial hemangiomas and genitourinary and spinal anomalies in the setting of lower body hemangiomas. We describe five infants in whom segmental hemangiomas involving the upper torso and extremities with absent or small facial hemangiomas were associated with structural anomalies similar to those reported with PHACE syndrome, including three with structural arterial anomalies of the subclavian arteries, three with aortic arch anomalies (right sided or narrowed arch), two with congenital heart disease (atrial septal defect and ventricular septal defect; tetralogy of Fallot), one with a retinal scar, and one with a sternal defect (scar). Two of five had small facial hemangiomas of the lower lip, but none had large segmental hemangiomas of the face. Three of five would have met diagnostic criteria for PHACE but lacked a facial hemangioma of 5 cm in diameter or greater. Patients with segmental arm and thorax hemangiomas may have associated structural abnormalities with overlapping features of PHACE, suggesting that a similar syndrome can occur in this clinical setting.

  3. 14 CFR 31.83 - Conspicuity.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... STANDARDS: MANNED FREE BALLOONS Operating Limitations and Information § 31.83 Conspicuity. The exterior... enough, and there are enough of them of contrasting color, to make the balloon conspicuous during flight....

  4. 14 CFR 31.83 - Conspicuity.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... STANDARDS: MANNED FREE BALLOONS Operating Limitations and Information § 31.83 Conspicuity. The exterior... enough, and there are enough of them of contrasting color, to make the balloon conspicuous during flight....

  5. 14 CFR 31.83 - Conspicuity.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... STANDARDS: MANNED FREE BALLOONS Operating Limitations and Information § 31.83 Conspicuity. The exterior... enough, and there are enough of them of contrasting color, to make the balloon conspicuous during flight....

  6. 14 CFR 31.83 - Conspicuity.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... STANDARDS: MANNED FREE BALLOONS Operating Limitations and Information § 31.83 Conspicuity. The exterior... enough, and there are enough of them of contrasting color, to make the balloon conspicuous during flight....

  7. 14 CFR 31.83 - Conspicuity.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... STANDARDS: MANNED FREE BALLOONS Operating Limitations and Information § 31.83 Conspicuity. The exterior... enough, and there are enough of them of contrasting color, to make the balloon conspicuous during flight....

  8. Visual conspicuity of objects in complex scenes

    NASA Astrophysics Data System (ADS)

    Boersema, Theo; Zwaga, Harm J. G.

    2000-06-01

    In many everyday situations people have to locate a particular object in a cluttered environment, for instance a routing sign among commercial signs in an airport terminal. The object's conspicuity determines the efficiency of the search. The literature on human visual search does not unequivocally answer the question how a cluttered environment affects target conspicuity. A method was developed and validated to measure target conspicuity and the effect of distractors, using the case of routing signs (blue with white lettering) and commercial signs (non-blue) in large public buildings as a vehicle. The stimulus fields are complex, computer-generated images, which mimic natural scenes in public buildings but have no apparent meaning. Target conspicuity is operationalized as the time a subject needs to locate the target; this search time is derived from the subject's eye movements. To avoid artifacts of perceptual learning, the number of trials per subject is limited. Experiments in which this method was used clearly demonstrated that conspicuity results from the combined action of the object's own physical properties in relation to those of its environment and of the observer's perceptual and cognitive properties and current intention. Thus, conspicuity never depends merely on the characteristics of the visual stimulus.

  9. The fish eye view: are cichlids conspicuous?

    PubMed

    Dalton, Brian E; Cronin, Thomas W; Marshall, N Justin; Carleton, Karen L

    2010-07-01

    The extent of animal colouration is determined by an interplay between natural and sexual selection. Both forces probably shape colouration in the speciose, rock-dwelling cichlids of Lake Malawi. Sexual selection is thought to drive male colouration, overcoming natural selection to create conspicuous colour patterns via female mate choice and male-male competition. However, natural selection should make female cichlids cryptic because they mouthbrood their young. We hypothesize that as a result of both sexual and natural selection, males will have colours that are more conspicuous than female colours. Cichlid spectral sensitivity, especially in the ultraviolet, probably influences how colours appear to them. Here we use simple models of the trichromatic colour space of cichlid visual systems to compare the conspicuousness of male and female nuptial colours of nine species. Conspicuousness of colours was evaluated as their Euclidian distance in colour space from environmental backgrounds and from other colours on the same fish. We find in six of the nine species that breeding males have colours that are statistically more conspicuous than female colours. These colours contrast strongly with each other or with the backgrounds, and they fall within a range of spectra best transmitted in the habitat. Female colour distances were sometimes smaller, suggesting that females of some species are more cryptic than males. Therefore, selection can differentially act to generate male colours that are more conspicuous than those in females. However, in two species, females had colours that were more conspicuous than male colours, suggesting that other selective forces and possibly sexual conflicts are acting in this system.

  10. 31 CFR 50.12 - Clear and conspicuous disclosure.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... requirement to provide clear and conspicuous disclosure as described in § 50.10 through use of appropriate... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Clear and conspicuous disclosure. 50... INSURANCE PROGRAM Disclosures as Conditions for Federal Payment § 50.12 Clear and conspicuous disclosure....

  11. Conspicuous and aposematic spines in the animal kingdom

    NASA Astrophysics Data System (ADS)

    Inbar, Moshe; Lev-Yadun, Simcha

    2005-04-01

    Spines serve as a common physical defence mechanism in both the plant and animal kingdoms. Here we argue that as in plants, defensive animal spines are often conspicuous (shape and colour) and should be considered aposematic. Conspicuous spines may evolve as signals or serve as a cue for potential predators. Spine conspicuousness in animals has evolved independently across and within phyla occupying aquatic and terrestrial ecosystems, indicating that this convergent phenomenon is highly adaptive. Still, many spines are cryptic, suggesting that conspicuity is not simply constrained by developmental factors such as differences in the chemical composition of the integument. Aposematism does not preclude the signalling role of conspicuous spines in the sexual arena.

  12. Conspicuous and aposematic spines in the animal kingdom.

    PubMed

    Inbar, Moshe; Lev-Yadun, Simcha

    2005-04-01

    Spines serve as a common physical defence mechanism in both the plant and animal kingdoms. Here we argue that as in plants, defensive animal spines are often conspicuous (shape and colour) and should be considered aposematic. Conspicuous spines may evolve as signals or serve as a cue for potential predators. Spine conspicuousness in animals has evolved independently across and within phyla occupying aquatic and terrestrial ecosystems, indicating that this convergent phenomenon is highly adaptive. Still, many spines are cryptic, suggesting that conspicuity is not simply constrained by developmental factors such as differences in the chemical composition of the integument. Aposematism does not preclude the signalling role of conspicuous spines in the sexual arena.

  13. Aposematic signals and the relationship between conspicuousness and distinctiveness.

    PubMed

    Merilaita, Sami; Ruxton, Graeme D

    2007-03-21

    It has long been recognized that prey that invest in toxic or other defenses often advertise these defenses by means of conspicuously coloured signals. One question that remains unanswered is why conspicuousness is such a universal trait of aposematic signals. Conspicuousness may allow more rapid avoidance learning by predators or improved retention of such learning. An alternative or complementary explanation is that defended species should adopt a conspicuous signal of their defence to make them visually distinct from inconspicuous undefended prey. Here, we use a neural network model of prey detection and attack decision making by a predator in combination with evolving, virtual prey to shed light on the relative importance of conspicuousness against the background and distinctiveness from other species as mechanisms underlying aposematic signalling. Our model suggests that prey conspicuousness may result from selection for distinctiveness, but that selection for distinctiveness does not result in maximization of conspicuousness. On the other hand, our model does not justify the exclusion of the possibility that conspicuousness as such may be a beneficial attribute of warning coloration. It is likely that the relative importance of the two selective forces (for conspicuousness and for distinctiveness) will differ on a case-by-case basis, however there is no empirical or logical reason for the current neglect of evolutionary pressure for distinctiveness. Thus, we suggest that description of aposematism as the teaming of a secondary defence with a conspicuous signal may be overly simplistic; we would rather that the signal were described as conspicuous and/or distinctive.

  14. Decoration Increases the Conspicuousness of Raptor Nests.

    PubMed

    Canal, David; Mulero-Pázmány, Margarita; Negro, Juan José; Sergio, Fabrizio

    2016-01-01

    Avian nests are frequently concealed or camouflaged, but a number of species builds noticeable nests or use conspicuous materials for nest decoration. In most cases, nest decoration has a role in mate choice or provides thermoregulatory or antiparasitic benefits. In territorial species however, decorations may serve additional or complementary functions, such as extended phenotypic signaling of nest-site occupancy and social status to potential intruders. The latter may benefit both signaler and receiver by minimizing the risk of aggressive interactions, especially in organisms with dangerous weaponry. Support for this hypothesis was recently found in a population of black kites (Milvus migrans), a territorial raptor that decorates its nest with white artificial materials. However, the crucial assumption that nest decorations increased nest-site visibility to conspecifics was not assessed, a key aspect given that black kite nests may be well concealed within the canopy. Here, we used an unmanned aircraft system to take pictures of black kite nests, with and without an experimentally placed decoration, from different altitudes and distances simulating the perspective of a flying and approaching, prospecting intruder. The pictures were shown to human volunteers through a standardized routine to determine whether detection rates varied according the nest decoration status and distance. Decorated nests consistently showed a higher detection frequency and a lower detection-latency, compared to undecorated versions of the same nests. Our results confirm that nest decoration in this species may act as a signaling medium that enhances nest visibility for aerial receivers, even at large distances. This finding complements previous work on this communication system, which showed that nest decoration was a threat informing trespassing conspecifics on the social dominance, territory quality and fighting capabilities of the signaler.

  15. Decoration Increases the Conspicuousness of Raptor Nests

    PubMed Central

    Canal, David; Mulero-Pázmány, Margarita; Negro, Juan José; Sergio, Fabrizio

    2016-01-01

    Avian nests are frequently concealed or camouflaged, but a number of species builds noticeable nests or use conspicuous materials for nest decoration. In most cases, nest decoration has a role in mate choice or provides thermoregulatory or antiparasitic benefits. In territorial species however, decorations may serve additional or complementary functions, such as extended phenotypic signaling of nest-site occupancy and social status to potential intruders. The latter may benefit both signaler and receiver by minimizing the risk of aggressive interactions, especially in organisms with dangerous weaponry. Support for this hypothesis was recently found in a population of black kites (Milvus migrans), a territorial raptor that decorates its nest with white artificial materials. However, the crucial assumption that nest decorations increased nest-site visibility to conspecifics was not assessed, a key aspect given that black kite nests may be well concealed within the canopy. Here, we used an unmanned aircraft system to take pictures of black kite nests, with and without an experimentally placed decoration, from different altitudes and distances simulating the perspective of a flying and approaching, prospecting intruder. The pictures were shown to human volunteers through a standardized routine to determine whether detection rates varied according the nest decoration status and distance. Decorated nests consistently showed a higher detection frequency and a lower detection-latency, compared to undecorated versions of the same nests. Our results confirm that nest decoration in this species may act as a signaling medium that enhances nest visibility for aerial receivers, even at large distances. This finding complements previous work on this communication system, which showed that nest decoration was a threat informing trespassing conspecifics on the social dominance, territory quality and fighting capabilities of the signaler. PMID:27455066

  16. Denoised and texture enhanced MVCT to improve soft tissue conspicuity

    SciTech Connect

    Sheng, Ke Qi, Sharon X.; Gou, Shuiping; Wu, Jiaolong

    2014-10-15

    Purpose: MVCT images have been used in TomoTherapy treatment to align patients based on bony anatomies but its usefulness for soft tissue registration, delineation, and adaptive radiation therapy is limited due to insignificant photoelectric interaction components and the presence of noise resulting from low detector quantum efficiency of megavoltage x-rays. Algebraic reconstruction with sparsity regularizers as well as local denoising methods has not significantly improved the soft tissue conspicuity. The authors aim to utilize a nonlocal means denoising method and texture enhancement to recover the soft tissue information in MVCT (DeTECT). Methods: A block matching 3D (BM3D) algorithm was adapted to reduce the noise while keeping the texture information of the MVCT images. Following imaging denoising, a saliency map was created to further enhance visual conspicuity of low contrast structures. In this study, BM3D and saliency maps were applied to MVCT images of a CT imaging quality phantom, a head and neck, and four prostate patients. Following these steps, the contrast-to-noise ratios (CNRs) were quantified. Results: By applying BM3D denoising and saliency map, postprocessed MVCT images show remarkable improvements in imaging contrast without compromising resolution. For the head and neck patient, the difficult-to-see lymph nodes and vein in the carotid space in the original MVCT image became conspicuous in DeTECT. For the prostate patients, the ambiguous boundary between the bladder and the prostate in the original MVCT was clarified. The CNRs of phantom low contrast inserts were improved from 1.48 and 3.8 to 13.67 and 16.17, respectively. The CNRs of two regions-of-interest were improved from 1.5 and 3.17 to 3.14 and 15.76, respectively, for the head and neck patient. DeTECT also increased the CNR of prostate from 0.13 to 1.46 for the four prostate patients. The results are substantially better than a local denoising method using anisotropic diffusion

  17. 21 CFR 369.10 - Conspicuousness of warning statements.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 5 2014-04-01 2014-04-01 false Conspicuousness of warning statements. 369.10... (CONTINUED) DRUGS FOR HUMAN USE INTERPRETATIVE STATEMENTS RE WARNINGS ON DRUGS AND DEVICES FOR OVER-THE-COUNTER SALE Definitions and Interpretations § 369.10 Conspicuousness of warning statements....

  18. 21 CFR 369.10 - Conspicuousness of warning statements.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 5 2012-04-01 2012-04-01 false Conspicuousness of warning statements. 369.10... (CONTINUED) DRUGS FOR HUMAN USE INTERPRETATIVE STATEMENTS RE WARNINGS ON DRUGS AND DEVICES FOR OVER-THE-COUNTER SALE Definitions and Interpretations § 369.10 Conspicuousness of warning statements....

  19. 21 CFR 369.10 - Conspicuousness of warning statements.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 5 2011-04-01 2011-04-01 false Conspicuousness of warning statements. 369.10... (CONTINUED) DRUGS FOR HUMAN USE INTERPRETATIVE STATEMENTS RE WARNINGS ON DRUGS AND DEVICES FOR OVER-THE-COUNTER SALE Definitions and Interpretations § 369.10 Conspicuousness of warning statements....

  20. 21 CFR 369.10 - Conspicuousness of warning statements.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Conspicuousness of warning statements. 369.10... (CONTINUED) DRUGS FOR HUMAN USE INTERPRETATIVE STATEMENTS RE WARNINGS ON DRUGS AND DEVICES FOR OVER-THE-COUNTER SALE Definitions and Interpretations § 369.10 Conspicuousness of warning statements....

  1. Change of region conspicuity in bilateral mammograms: potential impact on CAD performance

    NASA Astrophysics Data System (ADS)

    Zheng, Bin; Wang, Xiao Hui; Chang, Yuan-Hsiang; Hardesty, Lara A.; Ganott, Marie A.; Good, Walter F.; Gur, David

    2002-05-01

    In this study, we test a new method to automatically search for matched regions in bilateral digitized mammograms and to compute differences in region conspicuities in pairs of matched regions. One hundred pairs of bilateral images of the same view were selected for the experiment. Each pair of images depicted one verified mass. These 100 mass regions, along with 356 suspicious but actually negative mass regions, were first detected by a single-image-based CAD scheme. To find the matched regions in the corresponding bilateral images, a Procrustean-type technique was used to register the two images, which corrects the deformation of tissue structure between images by guaranteeing the registration of nipples, skin lines, and chest walls. Then, a region growth algorithm was applied to generate a growth region in the matched area, which has the same effective size as the suspicious region in the abnormal image. The conspicuities in the two matched regions, as well as their differences, were computed. Using the conspicuity in the original mass regions and the difference of conspicuities in the two matched regions as two identification indices to classify this set of 456 suspicious regions, the computed areas under the ROC curves (Az) were 0.77 and 0.75, respectively. This preliminary study indicates that by comparing the difference of conspicuities in two matched regions that a very useful feature for the CAD schemes can be extracted.

  2. Absent or occult pulmonary artery.

    PubMed Central

    Presbitero, P; Bull, C; Haworth, S G; de Leval, M R

    1984-01-01

    Of 12 patients with angiographically absent pulmonary artery, 11 were investigated surgically. The previously occult pulmonary artery was found in 10 patients, in five of whom a vestige of an intrapericardial artery was present and in five the artery was patent only at the hilus, a gap existing between the main pulmonary artery and the hilar vessel, and no artery was found in one. All patients with an intrapericardial artery had right ventricular outflow tract obstruction and a ductus descending vertically from underneath the aortic arch. In those without an intrapericardial vessel the occult artery was on the side opposite the aortic arch, and there was evidence of a ductus coming from the innominate artery on the side of the interruption. The occult pulmonary artery, where identified at operation, was usually joined initially to the systemic circulation. Ultimately, continuity between the hilar and main pulmonary artery may be established surgically. Where no intrapericardial vessel exists, however, a conduit may be required to bridge the gap. It seems advisable to search for the occult artery as early in life as is feasible in the hope that providing a blood supply will ensure development of the vessel and normal lung growth. Images PMID:6743435

  3. Predator feeding choice on conspicuous and non-conspicuous carabid beetles: first results.

    PubMed

    Bonacci, Teresa; Brandmayr, Pietro; Zetto Brandmayr, Tullia

    2011-01-01

    Insects use various types of behaviour, chemical defences, mimetic, aposematic or cryptic appearances as anti-predatory strategies. Among insects, carabid beetles of the genus Brachinus are distasteful prey because they discharge an irritating "cloud" of quinones when threatened. These beetles live in aggregations and adopt warning (conspicuous pattern) colours and chemicals to create a template that is easily learnt by predators. Another carabid beetle, Anchomenus dorsalis, mimics the colours and cuticular profile of Brachinus and is usually found in Brachinus aggregations. In this paper we report results from laboratory observations on feeding choice of the following natural predators - Crocidura leucodon (Insectivora: Soricidae), Ocypus olens (Coleoptera: Staphylinidae) and Podarcis sicula (Reptilia: Lacertidae) - on carabid beetle species. Comparing the number of attacks of predators towards aposematic and non-aposematic prey, there was a statistically significant preference towards non-aposematic prey.

  4. 21 CFR 740.2 - Conspicuousness of warning statements.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... (CONTINUED) COSMETICS COSMETIC PRODUCT WARNING STATEMENTS General § 740.2 Conspicuousness of warning... exemption pursuant to paragraph (b) of this section is established. (b) If the label of any cosmetic...

  5. 21 CFR 740.2 - Conspicuousness of warning statements.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... (CONTINUED) COSMETICS COSMETIC PRODUCT WARNING STATEMENTS General § 740.2 Conspicuousness of warning... exemption pursuant to paragraph (b) of this section is established. (b) If the label of any cosmetic...

  6. 21 CFR 740.2 - Conspicuousness of warning statements.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... (CONTINUED) COSMETICS COSMETIC PRODUCT WARNING STATEMENTS General § 740.2 Conspicuousness of warning... exemption pursuant to paragraph (b) of this section is established. (b) If the label of any cosmetic...

  7. 21 CFR 740.2 - Conspicuousness of warning statements.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... (CONTINUED) COSMETICS COSMETIC PRODUCT WARNING STATEMENTS General § 740.2 Conspicuousness of warning... exemption pursuant to paragraph (b) of this section is established. (b) If the label of any cosmetic...

  8. 21 CFR 740.2 - Conspicuousness of warning statements.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... (CONTINUED) COSMETICS COSMETIC PRODUCT WARNING STATEMENTS General § 740.2 Conspicuousness of warning... exemption pursuant to paragraph (b) of this section is established. (b) If the label of any cosmetic...

  9. Predator mimicry, not conspicuousness, explains the efficacy of butterfly eyespots.

    PubMed

    De Bona, Sebastiano; Valkonen, Janne K; López-Sepulcre, Andrés; Mappes, Johanna

    2015-05-07

    Large conspicuous eyespots on butterfly wings have been shown to deter predators. This has been traditionally explained by mimicry of vertebrate eyes, but recently the classic eye-mimicry hypothesis has been challenged. It is proposed that the conspicuousness of the eyespot, not mimicry, is what causes aversion due to sensory biases, neophobia or sensory overloads. We conducted an experiment to directly test whether the eye-mimicry or the conspicuousness hypothesis better explain eyespot efficacy. We used great tits (Parus major) as model predator, and tested their reaction towards animated images on a computer display. Birds were tested against images of butterflies without eyespots, with natural-looking eyespots, and manipulated spots with the same contrast but reduced resemblance to an eye, as well as images of predators (owls) with and without eyes. We found that mimetic eyespots were as effective as true eyes of owls and more efficient in eliciting an aversive response than modified, less mimetic but equally contrasting eyespots. We conclude that the eye-mimicry hypothesis explains our results better than the conspicuousness hypothesis and is thus likely to be an important mechanism behind the evolution of butterfly eyespots.

  10. Predator perception of Batesian mimicry and conspicuousness in a salamander.

    PubMed

    Kraemer, Andrew C; Adams, Dean C

    2014-04-01

    In Batesian mimicry a palatable mimic deceives predators by resembling an unpalatable model. The evolution of Batesian mimicry relies on the visual capabilities of the potential predators, as prey detection provides the selective force driving evolutionary change. We compared the visual capabilities of several potential predators to test predictions stemming from the hypothesis of Batesian mimicry between two salamanders: the model species Notophthalmus viridescens, and polymorphic mimic, Plethodon cinereus. First, we found mimicry to be restricted to coloration, but not brightness. Second, only bird predators appeared able to discriminate between the colors of models and nonmimic P. cinereus. Third, estimates of salamander conspicuousness were background dependent, corresponding to predictions only for backgrounds against which salamanders are most active. These results support the hypothesis that birds influence the evolution of Batesian mimicry in P. cinereus, as they are the only group examined capable of differentiating N. viridescens and nonmimetic P. cinereus. Additionally, patterns of conspicuousness suggest that selection from predators may drive the evolution of conspicuousness in this system. This study confirms the expectation that the visual abilities of predators may influence the evolution of Batesian mimicry, but the role of conspicuousness may be more complex than previously thought.

  11. 21 CFR 369.10 - Conspicuousness of warning statements.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 5 2013-04-01 2013-04-01 false Conspicuousness of warning statements. 369.10 Section 369.10 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... labeling in juxtaposition with the directions for use and, in any case, should appear on the label...

  12. Predator mimicry, not conspicuousness, explains the efficacy of butterfly eyespots

    PubMed Central

    De Bona, Sebastiano; Valkonen, Janne K.; López-Sepulcre, Andrés; Mappes, Johanna

    2015-01-01

    Large conspicuous eyespots on butterfly wings have been shown to deter predators. This has been traditionally explained by mimicry of vertebrate eyes, but recently the classic eye-mimicry hypothesis has been challenged. It is proposed that the conspicuousness of the eyespot, not mimicry, is what causes aversion due to sensory biases, neophobia or sensory overloads. We conducted an experiment to directly test whether the eye-mimicry or the conspicuousness hypothesis better explain eyespot efficacy. We used great tits (Parus major) as model predator, and tested their reaction towards animated images on a computer display. Birds were tested against images of butterflies without eyespots, with natural-looking eyespots, and manipulated spots with the same contrast but reduced resemblance to an eye, as well as images of predators (owls) with and without eyes. We found that mimetic eyespots were as effective as true eyes of owls and more efficient in eliciting an aversive response than modified, less mimetic but equally contrasting eyespots. We conclude that the eye-mimicry hypothesis explains our results better than the conspicuousness hypothesis and is thus likely to be an important mechanism behind the evolution of butterfly eyespots. PMID:25854889

  13. Does avian conspicuous colouration increase or reduce predation risk?

    PubMed

    Ruiz-Rodríguez, M; Avilés, J M; Cuervo, J J; Parejo, D; Ruano, F; Zamora-Muñoz, C; Sergio, F; López-Jiménez, L; Tanferna, A; Martín-Vivaldi, M

    2013-09-01

    Animals often announce their unprofitability to predators through conspicuous coloured signals. Here we tested whether the apparently conspicuous colour designs of the four European Coraciiformes and Upupiformes species may have evolved as aposematic signals, or whether instead they imply a cost in terms of predation risk. Because previous studies suggested that these species are unpalatable, we hypothesized that predators could avoid targeting them based on their colours. An experiment was performed where two artificial models of each bird species were exposed simultaneously to raptor predators, one painted so as to resemble the real colour design of these birds, and the other one painted using cryptic colours. Additionally, we used field data on the black kite's diet to compare the selection of these four species to that of other avian prey. Conspicuous models were attacked in equal or higher proportions than their cryptic counterparts, and the attack rate on the four species increased with their respective degree of contrast against natural backgrounds. The analysis of the predator's diet revealed that the two least attacked species were negatively selected in nature despite their abundance. Both conspicuous and cryptic models of one of the studied species (the hoopoe) received fewer attacks than cryptic models of the other three species, suggesting that predators may avoid this species for characteristics other than colour. Globally, our results suggest that the colour of coraciiforms and upupiforms does not function as an aposematic signal that advises predators of their unprofitability, but also that conspicuous colours may increase predation risk in some species, supporting thus the handicap hypothesis.

  14. Congenitally absent lumbar pedicle: a reappraisal

    SciTech Connect

    Wortzman, G.; Steinhardt, M.I.

    1984-09-01

    Three patients who had a diagnosis of congenitally absent lumbar pedicle underwent CT examination. Findings showed that each patient had an aberrant hypoplastic pedicle plus a retroisthmic defect in their ipsilateral lamina rather than an absent pedicle. Axial CT was the diagnostic modality of choice; reformated images were of little value. The differential diagnosis to be considered from the findings of plain film radiography includes pediculate thinning, neoplastic disease, neurofibroma, mesodermal dysplasia associated with neurofibromatosis, and vascular anomalies.

  15. Imperfect Batesian mimicry and the conspicuousness costs of mimetic resemblance.

    PubMed

    Speed, Michael P; Ruxton, Graeme D

    2010-07-01

    We apply signal detection methodology to make predictions about the evolution of Batesian mimicry. Our approach is novel in three ways. First, we applied a deterministic evolutionary modeling system that allows a large number of alternative mimetic morphs to coexist and compete. Second, we considered that there may be natural boundaries to phenotypic expression. Finally, we allowed increasing conspicuousness to impose an increasing detection cost on mimics. In some instances, the model predicts widespread variation in mimetic forms at evolutionary stability. In other situations, rather than a polymorphism the model predicts dimorphisms in which some prey were maximally cryptic and had minimal resemblance to the model, whereas many others were more conspicuous than the model. The biological implications of these results, particularly for our understanding of imperfect mimicry, are discussed.

  16. Conspicuity of target lights: The influence of color

    NASA Technical Reports Server (NTRS)

    Connors, M. M.

    1975-01-01

    The conspicuity (or attention-getting qualities) were investigated of foveally-equated, colored lights, when seen against a star background. Subjects who were periodically engaged in a distracting cockpit task were required to search a large visual field and report the appearance of a target light as quickly as possible. Targets were red, yellow, white, green, and blue, and appeared either as steady or as flashing lights. Results indicate that red targets were missed more frequently and responded to more slowly than lights of other hues. Yellow targets were acquired more slowly than white, green, or blue targets; responses to white targets were significantly slower than responses to green or blue targets. In general, flashing lights were superior to steady lights, but this was not found for all hues. For red, the 2 Hz flash was superior to all other flash rates and to the steady light, none of which differed significantly from each other. Over all hues, conspicuity was found to peak at 2-3 Hz. Response time was found to be fastest, generally, for targets appearing at between 3 and 8 from the center of the visual field. However, this pattern was not repeated for every hue. Conspicuity response times suggest a complex relationship between hue and position in the visual field that is explained only partially by retinal sensitivity.

  17. Making the most of conspicuous production in hospital marketing.

    PubMed

    Kassaye, W W; Mirmirani, S

    1994-01-01

    In today's marketplace, having an effective marketing strategy is key to changing a hospital's image as well as the nature of the product/service. To make the strategy effective, the focus of hospital administrators should be on getting the most out of the hospital's budget, and making a socially responsible decision that can maximize the contribution margin of all marketing expenditures. This article presents a model which attempts to maximize the contribution of various inputs toward a better image and conspicuousness of a hospital.

  18. Batesian mimics influence the evolution of conspicuousness in an aposematic salamander.

    PubMed

    Kraemer, A C; Serb, J M; Adams, D C

    2015-05-01

    Conspicuousness, or having high contrast relative to the surrounding background, is a common feature of unpalatable species. Several hypotheses have been proposed to explain the occurrence of conspicuousness, and while most involve the role of conspicuousness as a direct signal of unpalatability to potential predators, one hypothesis suggests that exaggerated conspicuousness may evolve in unpalatable species to reduce predator confusion with palatable species (potential Batesian mimics). This hypothesis of antagonistic coevolution between palatable and unpalatable species hinges on the 'cost of conspicuousness', in which conspicuousness increases the likelihood of predation more in palatable species than in unpalatable species. Under this mimicry scenario, four patterns are expected: (i) mimics will more closely resemble local models than models from other localities, (ii) there will be a positive relationship between mimic and model conspicuousness, (iii) models will be more conspicuous in the presence of mimics, and (iv) when models and mimics differ in conspicuousness, mimics will be less conspicuous than models. We tested these predictions in the salamander mimicry system involving Notophthalmus viridescens (model) and one colour morph of Plethodon cinereus (mimic). All predictions were supported, indicating that selection for Batesian mimicry not only influences the evolution of mimics, but also the evolution of the models they resemble. These findings indicate that mimicry plays a large role in the evolution of model warning signals, particularly influencing the evolution of conspicuousness.

  19. Importance of absent ductus arteriosus in tetralogy of Fallot with absent pulmonary valve syndrome.

    PubMed

    Qureshi, Muhammad Yasir; Burkhart, Harold M; Julsrud, Paul; Cetta, Frank

    2014-12-01

    Tetralogy of Fallot without pulmonary valve syndrome is almost always associated with an absent ductus arteriosus. Patients with right aortic arch and retroesophageal left subclavian artery have a vascular ring if the left ductus arteriosus or its remnant and the Kommerell diverticulum are present. We report the cases of 2 infants in whom the role of an absent ductus arteriosus or its remnant is noteworthy. Both patients had a combination of tetralogy of Fallot with absent pulmonary valve syndrome and right aortic arch with retroesophageal left subclavian artery without a vascular ring. The absence of the ductus arteriosus has a role in the pathogenesis of tetralogy of Fallot with absent pulmonary valve syndrome. The absence of a ductus arteriosus in the right aortic arch with retroesophageal left subclavian artery precludes a vascular ring.

  20. Genetic Architecture of Conspicuous Red Ornaments in Female Threespine Stickleback

    PubMed Central

    Yong, Lengxob; Peichel, Catherine L.; McKinnon, Jeffrey S.

    2015-01-01

    Explaining the presence of conspicuous female ornaments that take the form of male-typical traits has been a longstanding challenge in evolutionary biology. Such female ornaments have been proposed to evolve via both adaptive and nonadaptive evolutionary processes. Determining the genetic underpinnings of female ornaments is important for elucidating the mechanisms by which such female traits arise and persist in natural populations, but detailed information about their genetic basis is still scarce. In this study, we investigated the genetic architecture of two ornaments, the orange-red throat and pelvic spine, in the threespine stickleback (Gasterosteus aculeatus). Throat coloration is male-specific in ancestral marine populations but has evolved in females in some derived stream populations, whereas sexual dimorphism in pelvic spine coloration is variable among populations. We find that ornaments share a common genetic architecture between the sexes. At least three independent genomic regions contribute to red throat coloration, and harbor candidate genes related to pigment production and pigment cell differentiation. One of these regions is also associated with spine coloration, indicating that both ornaments might be mediated partly via pleiotropic genetic mechanisms. PMID:26715094

  1. Absent in Melanoma 2 proteins in SLE.

    PubMed

    Choubey, Divaker; Panchanathan, Ravichandran

    2017-03-01

    Type I interferons (IFN-α/β)-inducible PYRIN and HIN domain-containing protein family includes Absent in Melanoma 2 (murine Aim2 and human AIM2), murine p202, and human PYRIN-only protein 3 (POP3). The generation of Aim2-deficient mice indicated that the Aim2 protein is essential for inflammasome activation, resulting in the secretion of interleukin-1β (IL-1β) and IL-18 and cell death by pyroptosis. Further, Aim2-deficiency also increased constitutive expression of the IFN-β and expression of the p202 protein. Notably, an increased expression of p202 protein in female mice associated with the development of systemic lupus erythematosus (SLE). SLE in patients is characterized by a constitutive increase in serum levels of IFN-α and an increase in the expression IFN-stimulated genes. Recent studies indicate that p202 and POP3 proteins inhibit activation of the Aim2/AIM2 inflammasome and promote IFN-β expression. Therefore, we discuss the role of Aim2/AIM2 proteins in the suppression of type I IFNs production and lupus susceptibility.

  2. Genetic Influences Are Virtually Absent for Trust

    PubMed Central

    Van Lange, Paul A. M.; Vinkhuyzen, Anna A. E.; Posthuma, Danielle

    2014-01-01

    Over the past decades, numerous twin studies have revealed moderate to high heritability estimates for individual differences in a wide range of human traits, including cognitive ability, psychiatric disorders, and personality traits. Even factors that are generally believed to be environmental in nature have been shown to be under genetic control, albeit modest. Is such heritability also present in social traits that are conceptualized as causes and consequences of social interactions or in other ways strongly shaped by behavior of other people? Here we examine a population-based sample of 1,012 twins and relatives. We show that the genetic influence on generalized trust in other people (trust-in-others: h2 = 5%, ns), and beliefs regarding other people’s trust in the self (trust-in-self: h2 = 13%, ns), is virtually absent. As test-retest reliability for both scales were found to be moderate or high (r = .76 and r = .53, respectively) in an independent sample, we conclude that all variance in trust is likely to be accounted for by non-shared environmental influences. We show that, relative to cognitive abilities, psychiatric disorders, and classic personality variables, genetic influences are smaller for trust, and propose that experiences with or observations of the behavior of other people shape trust more strongly than other traits. PMID:24709897

  3. Communication about absent entities in great apes and human infants.

    PubMed

    Bohn, Manuel; Call, Josep; Tomasello, Michael

    2015-12-01

    There is currently debate about the extent to which non-linguistic beings such as human infants and great apes are capable of absent reference. In a series of experiments we investigated the flexibility and specificity of great apes' (N=36) and 12 month-old infants' (N=40) requests for absent entities. Subjects had the choice between requesting visible objects directly and using the former location of a depleted option to request more of these now-absent entities. Importantly, we systematically varied the quality of the present and absent options. We found that great apes as well as human infants flexibly adjusted their requests for absent entities to these contextual variations and only requested absent entities when the visible option was of lower quality than the absent option. These results suggest that the most basic cognitive capacities for absent reference do not depend on language and are shared by humans and their closest living relatives.

  4. 16 CFR 14.9 - Requirements concerning clear and conspicuous disclosures in foreign language advertising and...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... conspicuous disclosures in foreign language advertising and sales materials. 14.9 Section 14.9 Commercial... and conspicuous disclosures in foreign language advertising and sales materials. The Federal Trade... are being printed in foreign languages. In recent years the Commission has issued various...

  5. 49 CFR 229.133 - Interim locomotive conspicuity measures-auxiliary external lights.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Interim locomotive conspicuity measures-auxiliary external lights. 229.133 Section 229.133 Transportation Other Regulations Relating to Transportation... STANDARDS Safety Requirements Cabs and Cab Equipment § 229.133 Interim locomotive conspicuity...

  6. Subjective Well-Being in Rural India: The Curse of Conspicuous Consumption

    ERIC Educational Resources Information Center

    Linssen, Rik; van Kempen, Luuk; Kraaykamp, Gerbert

    2011-01-01

    Using data on 697 individuals from 375 rural low income households in India, we test expectations on the effects of relative income and conspicuous consumption on subjective well-being. The results of the multi-level regression analyses show that individuals who spent more on conspicuous consumption report lower levels of subjective well-being.…

  7. Absent Aortic Valve in DiGeorge Syndrome.

    PubMed

    Bertsch, Elizabeth C; Minturn, Lucy; Gotteiner, Nina L; Ernst, Linda M

    2016-01-01

    A 20-week-old fetus with the 22q11.2 deletion characteristic of DiGeorge syndrome is described with vertebral segmentation abnormalities and complex cardiovascular anomalies including an absent aortic valve. This is only the second known case of absent aortic valve in association with DiGeorge syndrome. We discuss the association of absent aortic valve with other conotruncal defects and the utility of fetal echocardiography in the diagnosis of DiGeorge syndrome.

  8. The role of conspicuity in preventing bicycle crashes involving a motor vehicle

    PubMed Central

    Woodward, Alistair; Ameratunga, Shanthi

    2015-01-01

    Background: Bicycle use, despite its proven health and other benefits, is rarely part of everyday travel for many people due to the perceived risk of injury from collision crashes. This article investigated the role of physical vs. attention conspicuity in preventing bicycle crashes involving a motor vehicle in New Zealand. Methods: The Taupo Bicycle Study involved 2590 adult cyclists recruited in 2006 (43.1% response rate) and followed for bicycle crash outcomes through linkage to four national databases. A composite measure of physical conspicuity was created using latent class analysis based on the use of fluorescent colours, lights and reflective materials, and the main colour of top, helmet and bike frame. Attention conspicuity was assessed based on regional differences in travel patterns and the amount of riding in a bunch. Cox regression modelling for repeated events was performed with multivariate adjustments. Results: During a median follow-up period of 6.4 years, 162 participants experienced 187 bicycle–motor vehicle crashes. The crash risk was not predicted by the four latent classes identified and the amount of bunch riding but was higher in Auckland, the region with the lowest level of bicycle use relative to car use. In subgroup analyses, compared to other latent classes, the most physically conspicuous group had a higher risk in Auckland but a lower risk in other regions. Conclusion: Conspicuity aids may not be effective in preventing bicycle–motor vehicle crashes in New Zealand, particularly in Auckland, where attention conspicuity is low. PMID:25085469

  9. Sibling Competition and Conspicuousness of Nestling Gapes in Altricial Birds: A Comparative Study

    PubMed Central

    Soler, Juan J.; Avilés, Jesús M.

    2010-01-01

    Background Nestlings of altricial birds capture parents' attention through conspicuous visual displays, including exposure of their gape coloration which informs parents about their level of need, competitive ability or health; information that parents use for deciding food allocation among their offspring. Thus, because nestlings compete with nest mates for parental care, nestling conspicuousness is expected to increase with level of sibling competition along bird phylogeny. Methodology/Principal Findings We test this prediction by jointly using information of brood reduction, clutch size and duration of nestling period as proxies for intensity of sibling competition, and visual models that assess detectability of nestlings by adult birds. As predicted, we found a positive association between nestling conspicuousness and intensity of brood reduction, while clutch size and duration of nestling period did not enter in the best models. Level of brood reduction was positively related with the achromatic component of nestling conspicuousness and body mass was negatively related with the chromatic component. Conclusions These associations are in agreement with the hypothesis that sibling competition for parental attention has driven the evolution of visual nestling conspicuousness in a context of parent-offspring communication in altricial birds. PMID:20463902

  10. Food quality and conspicuousness shape improvements in olfactory discrimination by mice.

    PubMed

    Price, Catherine J; Banks, Peter B

    2017-01-25

    How animals locate nutritious but camouflaged prey items with increasing accuracy is not well understood. Olfactory foraging is common in vertebrates and the nutritional desirability of food should influence the salience of odour cues. We used signal detection analysis to test the effect of nutritional value relative to the conspicuousness of food patches on rates of foraging improvement of wild house mice Mus musculus searching for buried food (preferred peanuts or non-preferred barley). Olfactory cues were arranged to make food patches conspicuous or difficult to distinguish using a novel form of olfactory camouflage. Regardless of food type or abundance, mice searching for conspicuous food patches performed significantly better than mice searching for camouflaged patches. However, food type influenced how mice responded to different levels of conspicuousness. Mice searching for peanuts improved by similar rates regardless of whether food was easy or hard to find, but mice searching for barley showed significant differences, improving rapidly when food was conspicuous but declining in accuracy when food was camouflaged. Our results demonstrate a fundamental tenet of olfactory foraging that nutritional desirability influences rates of improvement in odour discrimination, enabling nutritious but camouflaged prey to be located with increasing efficiency.

  11. Inferring Predator Behavior from Attack Rates on Prey-Replicas That Differ in Conspicuousness

    PubMed Central

    2012-01-01

    Behavioral ecologists and evolutionary biologists have long studied how predators respond to prey items novel in color and pattern. Because a predatory response is influenced by both the predator’s ability to detect the prey and a post-detection behavioral response, variation among prey types in conspicuousness may confound inference about post-prey-detection predator behavior. That is, a relatively high attack rate on a given prey type may result primarily from enhanced conspicuousness and not predators’ direct preference for that prey. Few studies, however, account for such variation in conspicuousness. In a field experiment, we measured predation rates on clay replicas of two aposematic forms of the poison dart frog Dendrobates pumilio, one novel and one familiar, and two cryptic controls. To ask whether predators prefer or avoid a novel aposematic prey form independently of conspicuousness differences among replicas, we first modeled the visual system of a typical avian predator. Then, we used this model to estimate replica contrast against a leaf litter background to test whether variation in contrast alone could explain variation in predator attack rate. We found that absolute predation rates did not differ among color forms. Predation rates relative to conspicuousness did, however, deviate significantly from expectation, suggesting that predators do make post-detection decisions to avoid or attack a given prey type. The direction of this deviation from expectation, though, depended on assumptions we made about how avian predators discriminate objects from the visual background. Our results show that it is important to account for prey conspicuousness when investigating predator behavior and also that existing models of predator visual systems need to be refined. PMID:23119039

  12. 16 CFR 1500.121 - Labeling requirements; prominence, placement, and conspicuousness.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., layout, or color with other printed matter on the label. This regulation contains the Commission's... all sides from other printed or graphic matter, with the exception of the declaration of net contents... any other printed matter in the accompanying literature and must be in conspicuous and legible type...

  13. 16 CFR 1500.121 - Labeling requirements; prominence, placement, and conspicuousness.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., layout, or color with other printed matter on the label. This regulation contains the Commission's... all sides from other printed or graphic matter, with the exception of the declaration of net contents... any other printed matter in the accompanying literature and must be in conspicuous and legible type...

  14. 16 CFR 1500.121 - Labeling requirements; prominence, placement, and conspicuousness.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., layout, or color with other printed matter on the label. This regulation contains the Commission's... all sides from other printed or graphic matter, with the exception of the declaration of net contents... any other printed matter in the accompanying literature and must be in conspicuous and legible type...

  15. Conspicuousness, color resemblance, and toxicity in geographically diverging mimicry: The pan-Amazonian frog Allobates femoralis.

    PubMed

    Amézquita, Adolfo; Ramos, Óscar; González, Mabel Cristina; Rodríguez, Camilo; Medina, Iliana; Simões, Pedro Ivo; Lima, Albertina Pimentel

    2017-01-09

    Predation risk is allegedly reduced in Batesian and Müllerian mimics, because their coloration resembles the conspicuous coloration of unpalatable prey. The efficacy of mimicry is thought to be affected by variation in the unpalatability of prey, the conspicuousness of the signals, and the visual system of predators that see them. Many frog species exhibit small colorful patches contrasting against an otherwise dark body. By measuring toxicity and color reflectance in a geographically variable frog species and the syntopic toxic species, we tested whether unpalatability was correlated with between-species color resemblance and whether resemblance was highest for the most conspicuous components of coloration pattern. Heterospecific resemblance in colorful patches was highest between species at the same locality, but unrelated to concomitant variation in toxicity. Surprisingly, resemblance was lower for the conspicuous femoral patches compared to the inconspicuous dorsum. By building visual models, we further tested whether resemblance was affected by the visual system of model predators. As predicted, mimic-model resemblance was higher under the visual system of simulated predators compared to no visual system at all. Our results indicate that femoral patches are aposematic signals and support a role of mimicry in driving phenotypic divergence or mimetic radiation between localities.

  16. An evaluation of the hypothesis that laser light is more conspicuous than incandescent light

    NASA Astrophysics Data System (ADS)

    Winslow, T. S.; Mandler, M. B.

    1986-05-01

    It has been thought that laser aids to navigation might appear more conspicuous than aids employing conventional light sources. Two experiments rigorously tested the hypothesis that laser light is more conspicuous than incandescent light. Incandescent and Helium Neon laser sources were optically filtered and adjusted to present the same illuminance and color to distant observers. Thirty-seven observers viewed 60 random presentations (2 source types, 2 illuminance levels) from a distance of 1500 yards. Group correct source discrimination percentages were 52.6 and 55.2 for the low and high illuminance levels, respectively. The experiment was repeated indoors at higher illuminances with resultant group correct source discrimination percentages of 57, 67.5, and 66 for the low, medium, and high illuminances, respectively. It was concluded that at practical design illuminance levels, no significant conspicuity advantage would be gained by replacing existing navigational aids with laser aids-to-navigation. Calculations show that a significant conspicuity advantage is likely to be obtained if the mariner uses a narrow bandpass filter (3 to 10 nm) centered at the laser wavelength. The illuminance from the laser will be relatively unaffected, while the illuminances from all background lights will be dramatically diminished. An additional section compares the electrical efficiency of a standard Coast Guard FA-240 range light with a laser aid configured for the same application. For equal input power, the FA-240 is shown to produce 10 times the luminous intensity of the laser aid.

  17. Minimal Absent Words in Four Human Genome Assemblies

    PubMed Central

    Garcia, Sara P.; Pinho, Armando J.

    2011-01-01

    Minimal absent words have been computed in genomes of organisms from all domains of life. Here, we aim to contribute to the catalogue of human genomic variation by investigating the variation in number and content of minimal absent words within a species, using four human genome assemblies. We compare the reference human genome GRCh37 assembly, the HuRef assembly of the genome of Craig Venter, the NA12878 assembly from cell line GM12878, and the YH assembly of the genome of a Han Chinese individual. We find the variation in number and content of minimal absent words between assemblies more significant for large and very large minimal absent words, where the biases of sequencing and assembly methodologies become more pronounced. Moreover, we find generally greater similarity between the human genome assemblies sequenced with capillary-based technologies (GRCh37 and HuRef) than between the human genome assemblies sequenced with massively parallel technologies (NA12878 and YH). Finally, as expected, we find the overall variation in number and content of minimal absent words within a species to be generally smaller than the variation between species. PMID:22220210

  18. Absent and Accounted For: Absenteeism and Cooperative Learning

    ERIC Educational Resources Information Center

    Koppenhaver, G. D.

    2006-01-01

    In a small section collaborative learning environment where student work teams promote mutual learning about investments, students limit the opportunity to learn from other students if they are absent from class. Absenteeism not only denies the student the opportunity to learn from others but also denies other members of the student's work team…

  19. The Production of Present and Absent Presences in Education

    ERIC Educational Resources Information Center

    Frelin, Anneli; Grannäs, Jan

    2013-01-01

    Drawing on the distinction between absent and present presences, this article contributes to our understanding of how new managerial and performative discourses are played out in a secondary school context in Sweden. The consequences of numerous educational reforms during the last 20 years include a surge of new independent schools and increased…

  20. Vampire Selfie: A Curious Case of an Absent Reflection

    ERIC Educational Resources Information Center

    Grossman, Joshua M.

    2014-01-01

    This article presents a puzzle for the optics section of an introductory course on reflections. A teacher could ask students to explain the phenomenon of the "vampire selfie" or the absent reflection. How could that be? What physics caused this curious phenomenon? The article explains light refraction and its effect on what we see and…

  1. PHACE syndrome and congenitally absent thyroid gland at MR imaging.

    PubMed

    Mamlouk, Mark D; Yu, John-Paul J; Asch, Sarah; Mathes, Erin F

    2016-01-01

    PHACE syndrome is a rare neurocutaneous disorder characterized by posterior fossa malformations, hemangiomas, arterial anomalies, cardiac defects, and abnormalities of the eye. Thyroid disorders associated with PHACE syndrome have been described, although there are limited reports of this rare occurrence. We report a case of PHACE syndrome with congenital hypothyroidism in an infant, for which absent thyroid gland was diagnosed at magnetic resonance imaging.

  2. Kaufman oculo-cerebro-facial syndrome in a child with small and absent terminal phalanges and absent nails.

    PubMed

    Kariminejad, Ariana; Ajeawung, Norbert Fonya; Bozorgmehr, Bita; Dionne-Laporte, Alexandre; Molidperee, Sirinart; Najafi, Kimia; Gibbs, Richard A; Lee, Brendan H; Hennekam, Raoul C; Campeau, Philippe M

    2017-04-01

    Kaufman oculo-cerebro-facial syndrome (KOS) is caused by recessive UBE3B mutations and presents with microcephaly, ocular abnormalities, distinctive facial morphology, low cholesterol levels and intellectual disability. We describe a child with microcephaly, brachycephaly, hearing loss, ptosis, blepharophimosis, hypertelorism, cleft palate, multiple renal cysts, absent nails, small or absent terminal phalanges, absent speech and intellectual disability. Syndromes that were initially considered include DOORS syndrome, Coffin-Siris syndrome and Dubowitz syndrome. Clinical investigations coupled with karyotype analysis, array-comparative genomic hybridization, exome and Sanger sequencing were performed to characterize the condition in this child. Sanger sequencing was negative for the DOORS syndrome gene TBC1D24 but exome sequencing identified a homozygous deletion in UBE3B (NM_183415:c.3139_3141del, p.1047_1047del) located within the terminal portion of the HECT domain. This finding coupled with the presence of characteristic features such as brachycephaly, ptosis, blepharophimosis, hypertelorism, short palpebral fissures, cleft palate and developmental delay allowed us to make a diagnosis of KOS. In conclusion, our findings highlight the importance of considering KOS as a differential diagnosis for patients under evaluation for DOORS syndrome and expand the phenotype of KOS to include small or absent terminal phalanges, nails, and the presence of hallux varus and multicystic dysplastic kidneys.

  3. Local adaptation and divergence in colour signal conspicuousness between monomorphic and polymorphic lineages in a lizard.

    PubMed

    McLean, C A; Moussalli, A; Stuart-Fox, D

    2014-12-01

    Population differences in visual environment can lead to divergence in multiple components of animal coloration including signalling traits and colour patterns important for camouflage. Divergence may reflect selection imposed by different receivers (conspecifics, predators), which depends in turn on the location of the colour patch. We tested for local adaptation of two genetically and phenotypically divergent lineages of a rock-inhabiting lizard, Ctenophorus decresii, by comparing the visual contrast of colour patches to different receivers in native and non-native environments. The lineages differ most notably in male throat coloration, which is polymorphic in the northern lineage and monomorphic in the southern lineage, but also differ in dorsal and lateral coloration, which is visible to both conspecifics and potential predators. Using models of animal colour vision, we assessed whether lineage-specific throat, dorsal and lateral coloration enhanced conspicuousness to conspecifics, increased crypsis to birds or both, respectively, when viewed against the predominant backgrounds from each lineage. Throat colours were no more conspicuous against native than non-native rock but contrasted more strongly with native lichen, which occurs patchily on rocks inhabited by C. decresii. Conversely, neck coloration (lateral) more closely matched native lichen. Furthermore, although dorsal coloration of southern males was consistently more conspicuous to birds than that of northern males, both lineages had similar absolute conspicuousness against their native backgrounds. Combined, our results are consistent with local adaptation of multiple colour traits in relation to multiple receivers, suggesting that geographic variation in background colour has influenced the evolution of lineage-specific coloration in C. decresii.

  4. Wall lizards display conspicuous signals to conspecifics and reduce detection by avian predators

    PubMed Central

    Stevens, Martin

    2014-01-01

    Visual signals are often under conflicting selection to be hidden from predators while being conspicuous to mates and rivals. Here, we investigated whether 3 different island populations of Aegean wall lizards (Podarcis erhardii) with variable coloration among diverse island habitats exhibit simultaneous camouflage and sexual signals. We examined whether signals appear better tuned to conspecific vision as opposed to that of avian predators, and whether background-matching camouflage and sexual signals are partitioned to specific body regions. This could facilitate both covert sexual signaling and camouflage according to the viewing perspectives of predators and conspecifics. We found that lizards typically appeared twice as conspicuous to conspecifics than to avian predators against the same visual background, largely due to lizards’ enhanced sensitivity to ultraviolet, suggesting that P. erhardii signals are tuned to conspecific vision to reduce detection by predators. Males were more conspicuous than females to both predators and conspecifics. In 2 populations, male backs were relatively more camouflaged to predators compared to signaling flanks, whereas in females, exposed and concealed surfaces were camouflaged to predators and generally did not differ in background matching. These findings indicate that lizard coloration evolves under the competing demands of natural and sexual selection to promote signals that are visible to conspecifics while being less perceptible to avian predators. They also elucidate how interactions between natural and sexual selection influence signal detectability and partitioning to different body regions, highlighting the importance of considering receiver vision, viewing perspectives, and signaling environments in studies of signal evolution. PMID:25419083

  5. On the relationship between human search strategies, conspicuity, and search performance

    NASA Astrophysics Data System (ADS)

    Hogervorst, Maarten A.; Bijl, Piet; Toet, Alexander

    2005-05-01

    We determined the relationship between search performance with a limited field of view (FOV) and several scanning- and scene parameters in human observer experiments. The observers (38 trained army scouts) searched through a large search sector for a target (a camouflaged person) on a heath. From trial to trial the target appeared at a different location. With a joystick the observers scanned through a panoramic image (displayed on a PC-monitor) while the scan path was registered. Four conditions were run differing in sensor type (visual or thermal infrared) and window size (large or small). In conditions with a small window size the zoom option could be used. Detection performance was highly dependent on zoom factor and deteriorated when scan speed increased beyond a threshold value. Moreover, the distribution of scan speeds scales with the threshold speed. This indicates that the observers are aware of their limitations and choose a (near) optimal search strategy. We found no correlation between the fraction of detected targets and overall search time for the individual observers, indicating that both are independent measures of individual search performance. Search performance (fraction detected, total search time, time in view for detection) was found to be strongly related to target conspicuity. Moreover, we found the same relationship between search performance and conspicuity for visual and thermal targets. This indicates that search performance can be predicted directly by conspicuity regardless of the sensor type.

  6. Apes Communicate about Absent and Displaced Objects: Methodology Matters

    PubMed Central

    Lyn, Heidi; Russell, Jamie L.; Leavens, David A.; Bard, Kim A.; Boysen, Sarah T.; Schaeffer, Jennifer A.; Hopkins, William D.

    2013-01-01

    Displaced reference is the ability to refer to an item that has been moved (displaced) in space and/or time, and has been called one of the true hallmarks of referential communication. Several studies suggest that nonhuman primates have this capability, but a recent experiment concluded that in a specific situation (absent entities) human infants display displaced reference but chimpanzees do not. Here we show that chimpanzees and bonobos of diverse rearing histories are capable of displaced reference to absent and displaced objects. It is likely that some of the conflicting findings from animal cognition studies are due to relatively minor methodological differences, but are compounded by interpretation errors. Comparative studies are of great importance in elucidating the evolution of human cognition, however, greater care must be taken with methodology and interpretation for these studies to accurately reflect species differences. PMID:23681052

  7. Congenital hypogonadotropic hypogonadism: implications of absent mini-puberty.

    PubMed

    Dwyer, Andrew A; Jayasena, Channa N; Quinton, Richard

    2016-06-01

    The phenomenon known as "mini-puberty" refers to activation of the neonatal hypothalamo-pituitary axis causing serum concentrations of gonadotrophins and testosterone (T) to approach adult male levels. This early neonatal period is a key proliferative window for testicular germ cells and immature Sertoli cells. Although failure to spontaneously initiate (adolescent) puberty is the most evident consequence of a defective gonadotropin-releasing hormone (GnRH) neurosecretory network, absent mini-puberty is also likely to have a major impact on the reproductive phenotype of men with congenital hypogonadotrophic hypogonadism (CHH). Furthermore, the phase of male mini-puberty represents a key window-of-opportunity to identify congenital GnRH deficiency (either isolated CHH, or as part of combined pituitary hormone deficiency) in childhood. Among male neonates exhibiting "red flag" indicators for CHH (i.e. maldescended testes with or without cryptorchidism) a single serum sample (between 4-8 weeks of life) can pinpoint congenital GnRH deficiency far more rapidly and with much greater accuracy than dynamic tests performed in later childhood or adolescence. Potential consequences for missing absent mini-puberty in a male neonate include the lack of monitoring of pubertal progression/lack of progression, and the missed opportunity for early therapeutic intervention. This article will review our current understanding of the mechanisms and clinical consequences of mini-puberty. Furthermore, evidence for the optimal clinical management of patients with absent mini-puberty will be discussed.

  8. The Absent Interpreter in Administrative Detention Center Medical Units.

    PubMed

    Rondeau-Lutz, Murielle; Weber, Jean-Christophe

    2017-03-01

    The particular situation of the French administrative detention center (ADC) medical units appears to be an exemplary case to study the difficulties facing medical practice. Indeed, the starting point of our inquiry was an amazing observation that needed to be addressed and understood: why are professional interpreters so seldom requested in ADC medical units, where one would expect that they would be "naturally" present? Aiming to fully explore the meanings of the "absent interpreter", this article takes into account the possible meanings of this situation: the recourse to professional interpreters in France is far from expected given cumulative evidence of its benefits; perceptions of illegal immigrants and medical habitus itself may both hamper the use of a third party; the ADCs are a very stressful place for healthcare professionals, with conflicting missions, political issues enmeshed with medical goals, and heavy affective burden that may lead to self-protection. Silencing voices of suffering others might be seen as the hidden indecent truth of the "absent interpreter". These reflections open a window to a larger issue with regard to the full range of medicine: what are the place, the role and the function of patient's words and narratives in contemporary medicine? The highly invested somatic perspective and its political corollary giving primacy to bare life harbor potential risks of obscuring speeches and undervaluing narratives.

  9. Absent without leave; a neuroenergetic theory of mind wandering

    PubMed Central

    Killeen, Peter R.

    2013-01-01

    Absent minded people are not under the control of task-relevant stimuli. According to the Neuroenergetics Theory of attention (NeT), this lack of control is often due to fatigue of the relevant processing units in the brain caused by insufficient resupply of the neuron's preferred fuel, lactate, from nearby astrocytes. A simple drift model of information processing accounts for response-time statistics in a paradigm often used to study inattention, the Sustained Attention to Response Task (SART). It is suggested that errors and slowing in this fast-paced, response-engaging task may have little to due with inattention. Slower-paced and less response-demanding tasks give greater license for inattention—aka absent-mindedness, mind-wandering. The basic NeT is therefore extended with an ancillary model of attentional drift and recapture. This Markov model, called NEMA, assumes probability λ of lapses of attention from 1 s to the next, and probability α of drifting back to the attentional state. These parameters measure the strength of attraction back to the task (α), or away to competing mental states or action patterns (λ); their proportion determines the probability of the individual being inattentive at any point in time over the long run. Their values are affected by the fatigue of the brain units they traffic between. The deployment of the model is demonstrated with a data set involving paced responding. PMID:23847559

  10. The evolution of colour pattern complexity: selection for conspicuousness favours contrasting within-body colour combinations in lizards.

    PubMed

    Pérez I de Lanuza, G; Font, E

    2016-05-01

    Many animals display complex colour patterns that comprise several adjacent, often contrasting colour patches. Combining patches of complementary colours increases the overall conspicuousness of the complex pattern, enhancing signal detection. Therefore, selection for conspicuousness may act not only on the design of single colour patches, but also on their combination. Contrasting long- and short-wavelength colour patches are located on the ventral and lateral surfaces of many lacertid lizards. As the combination of long- and short-wavelength-based colours generates local chromatic contrast, we hypothesized that selection may favour the co-occurrence of lateral and ventral contrasting patches, resulting in complex colour patterns that maximize the overall conspicuousness of the signal. To test this hypothesis, we performed a comparative phylogenetic study using a categorical colour classification based on spectral data and descriptive information on lacertid coloration collected from the literature. Our results demonstrate that conspicuous ventral (long-wavelength-based) and lateral (short-wavelength-based) colour patches co-occur throughout the lacertid phylogeny more often than expected by chance, especially in the subfamily Lacertini. These results suggest that selection promotes the evolution of the complex pattern rather than the acquisition of a single conspicuous colour patch, possibly due to the increased conspicuousness caused by the combination of colours with contrasting spectral properties.

  11. [Termites that build conspicuous nests in two areas of Atlantic Forest under different levels of anthropogenic disturbance].

    PubMed

    Vasconcellos, Alexandre; Bandeira, Adelmar G; Almeida, Waltécio O; Moura, Flávia M S

    2008-01-01

    The effects of selective logging on termite assemblages that build conspicuous nests were studied in two areas of semideciduous Atlantic Forest, located in the Reserva Biológica Guaribas, Northeastern Brazil. The two study areas went through selective logging until 1985 (A17) and 1972 (A30). In 2002, termite nests were studied in two plots of 1 ha (100 x 100 m), being one plot in each area. The nests were placed in each plot and the species were categorized in feeding groups. The structure of the study assemblages was different between the two areas. Diversity and richness of builder species were greater in the A30 area. Species that consume humus were more sensitive to selective logging. Nest abundance of humus feeding species was significantly higher in the A30 area, whereas nests of wood feeding species were significantly more abundant in the area A17. Nest ratio between humus and wood feeding species was 1:3 in the A30 area and 1:12 in the A17 area. Nests with greater volume were observed in the area A30, whereas abundance of inactive nests was significantly higher in A17. The time for habitat resilience after the selective logging influenced patterns of assemblage structure of termites in similar ways as described in other studies in tropical forests.

  12. Role of sensory and cognitive conspicuity in the prevention of collisions between motorcycles and trucks at T-intersections.

    PubMed

    Law, Teik Hua; Ghanbari, Mahshid; Hamid, Hussain; Abdul-Halin, Alfian; Ng, Choy Peng

    2016-11-01

    Motorcyclists are particularly vulnerable to injury in crashes with heavy vehicles due to substantial differences in vehicle mass, the degree of protection and speed. There is a considerable difference in height between motorcycles and trucks; motorcycles are viewed by truck drivers from downward angles, and shorter distances between them mean steeper downward angles. Hence, we anticipated that the effects of motorcycle conspicuity treatments would be different for truck drivers. Therefore, this study aims to evaluate the effects of motorcycle conspicuity treatments on the identification and detection of motorcycles by truck drivers. Two complementary experiments were performed; the first experiment assessed the impact of motorcycle sensory conspicuity on the ability of un-alerted truck drivers to detect motorcycles, and the second experiment assessed the motorcycle cognitive conspicuity to alerted truck drivers. The sensory conspicuity was measured in terms of motorcycle detection rates by un-alerted truck drivers when they were not anticipating a motorcycle within a realistic driving scene, while the cognitive conspicuity was determined by the time taken by alerted truck drivers to actively search for a motorcycle. In the first experiment, the participants were presented with 10 pictures and were instructed to report the kinds of vehicles that were presented in the pictures. Each picture was shown to the participants for 600ms. In the second experiment, the participants were presented with the same set of pictures and were instructed to respond by clicking the right button on a mouse as soon as they detected a motorcycle in the picture. The results indicate that the motorcycle detection rate increases, and the response time to search for a motorcycle decreases, as the distance between the targeted motorcycle and the viewer decreases. This is true regardless of the type of conspicuity treatment used. The use of daytime running headlights (DRH) was found to

  13. Formation of excitatory and inhibitory associations between absent events

    PubMed Central

    Holland, Peter C.; Sherwood, Andrew

    2010-01-01

    Considerable evidence indicates that associations may be formed between two events even when one or both of them is absent at the time of learning. Previously, some researchers asserted that excitatory associations are formed when associatively-activated representations for two events are paired, whereas others claimed that inhibitory associations are formed. In three experiments we investigated the nature of tone-sucrose learning when associatively-activated representations of those events were paired in the absence of either of the events themselves. Experiment 1 found substantial excitatory learning when the tone surrogate preceded the sucrose surrogate in training. Experimental 2 evaluated other accounts for the results of Experiment 1, and Experiment 3 found evidence for inhibitory tone-sucrose learning when the tone and sucrose surrogates were presented in simultaneous or backward order. The results indicated that the nature of representation-mediated learning is influenced by some of the same variables as more standard associative learning. PMID:18665716

  14. Is it safe to nest near conspicuous neighbours? Spatial patterns in predation risk associated with the density of American Golden-Plover nests

    PubMed Central

    Trottier-Paquet, Myriam; Bêty, Joël; Lamarre, Vincent; Lecomte, Nicolas

    2016-01-01

    Predation is one of the main factors explaining nesting mortality in most bird species. Birds can avoid nest predation or reduce predation pressure by breeding at higher latitude, showing anti-predator behaviour, selecting nest sites protected from predators, and nesting in association with protective species. American Golden-Plovers (Pluvialis dominica) defend their territory by using various warning and distraction behaviours displayed at varying levels of intensity (hereafter “conspicuous behaviour”), as well as more aggressive behaviours such as aerial attacks, but only in some populations. Such antipredator behaviour has the potential to repel predators and thus benefit the neighbouring nests by decreasing their predation risk. Yet, conspicuous behaviour could also attract predators by signalling the presence of a nest. To test for the existence of a protective effect associated with the conspicuous antipredator behaviour of American Golden-Plovers, we studied the influence of proximity to plover nests on predation risk of artificial nests on Igloolik Island (Nunavut, Canada) in July 2014. We predicted that the predation risk of artificial nests would decrease with proximity to and density of plover nests. We monitored 18 plover nests and set 35 artificial nests at 30, 50, 100, 200, and 500 m from seven of those plover nests. We found that the predation risk of artificial nests increases with the density of active plover nests. We also found a significant negative effect of the distance to the nearest active protector nest on predation risk of artificial nests. Understanding how the composition and structure of shorebird communities generate spatial patterns in predation risks represents a key step to better understand the importance of these species of conservation concern in tundra food webs. PMID:27602257

  15. Is it safe to nest near conspicuous neighbours? Spatial patterns in predation risk associated with the density of American Golden-Plover nests.

    PubMed

    Giroux, Marie-Andrée; Trottier-Paquet, Myriam; Bêty, Joël; Lamarre, Vincent; Lecomte, Nicolas

    2016-01-01

    Predation is one of the main factors explaining nesting mortality in most bird species. Birds can avoid nest predation or reduce predation pressure by breeding at higher latitude, showing anti-predator behaviour, selecting nest sites protected from predators, and nesting in association with protective species. American Golden-Plovers (Pluvialis dominica) defend their territory by using various warning and distraction behaviours displayed at varying levels of intensity (hereafter "conspicuous behaviour"), as well as more aggressive behaviours such as aerial attacks, but only in some populations. Such antipredator behaviour has the potential to repel predators and thus benefit the neighbouring nests by decreasing their predation risk. Yet, conspicuous behaviour could also attract predators by signalling the presence of a nest. To test for the existence of a protective effect associated with the conspicuous antipredator behaviour of American Golden-Plovers, we studied the influence of proximity to plover nests on predation risk of artificial nests on Igloolik Island (Nunavut, Canada) in July 2014. We predicted that the predation risk of artificial nests would decrease with proximity to and density of plover nests. We monitored 18 plover nests and set 35 artificial nests at 30, 50, 100, 200, and 500 m from seven of those plover nests. We found that the predation risk of artificial nests increases with the density of active plover nests. We also found a significant negative effect of the distance to the nearest active protector nest on predation risk of artificial nests. Understanding how the composition and structure of shorebird communities generate spatial patterns in predation risks represents a key step to better understand the importance of these species of conservation concern in tundra food webs.

  16. Social power, product conspicuousness, and the demand for luxury brand counterfeit products.

    PubMed

    Bian, Xuemei; Haque, Sadia; Smith, Andrew

    2015-03-01

    The aim of this article is twofold: (1) to achieve a better understanding of the psychological determinants of the demand for luxury brand counterfeit products (LBCP) through exploring the effects of social power; (2) to extend power literature by identifying boundary conditions of the relationship between social power and compensatory consumption identified by Rucker and Galinsky (2008, J. Consum. Res., 35, 257-267) and Rucker and Galinsky (2009, J. Exp. Soc. Psychol., 45, 549-555). Findings from three experiments demonstrate that social power holds key insights into understanding consumers' purchase propensity for LBCP; product conspicuousness moderates the effects of social power on purchase propensity for status products; these moderation effects are only observed when the status products are LBCP but not genuine products. This article, therefore, contributes to the literature regarding the demand for counterfeits as well as the social power and compensatory consumption literature.

  17. EFFECTS OF FLUID AND COMPUTED TOMOGRAPHIC TECHNICAL FACTORS ON CONSPICUITY OF CANINE AND FELINE NASAL TURBINATES

    PubMed Central

    Uosyte, Raimonda; Shaw, Darren J; Gunn-Moore, Danielle A; Fraga-Manteiga, Eduardo; Schwarz, Tobias

    2015-01-01

    Turbinate destruction is an important diagnostic criterion in canine and feline nasal computed tomography (CT). However decreased turbinate visibility may also be caused by technical CT settings and nasal fluid. The purpose of this experimental, crossover study was to determine whether fluid reduces conspicuity of canine and feline nasal turbinates in CT and if so, whether CT settings can maximize conspicuity. Three canine and three feline cadaver heads were used. Nasal slabs were CT-scanned before and after submerging them in a water bath; using sequential, helical, and ultrahigh resolution modes; with images in low, medium, and high frequency image reconstruction kernels; and with application of additional posterior fossa optimization and high contrast enhancing filters. Visible turbinate length was measured by a single observer using manual tracing. Nasal density heterogeneity was measured using the standard deviation (SD) of mean nasal density from a region of interest in each nasal cavity. Linear mixed-effect models using the R package ‘nlme’, multivariable models and standard post hoc Tukey pair-wise comparisons were performed to investigate the effect of several variables (nasal content, scanning mode, image reconstruction kernel, application of post reconstruction filters) on measured visible total turbinate length and SD of mean nasal density. All canine and feline water-filled nasal slabs showed significantly decreased visibility of nasal turbinates (P < 0.001). High frequency kernels provided the best turbinate visibility and highest SD of aerated nasal slabs, whereas medium frequency kernels were optimal for water-filled nasal slabs. Scanning mode and filter application had no effect on turbinate visibility. PMID:25867935

  18. EFFECTS OF FLUID AND COMPUTED TOMOGRAPHIC TECHNICAL FACTORS ON CONSPICUITY OF CANINE AND FELINE NASAL TURBINATES.

    PubMed

    Uosyte, Raimonda; Shaw, Darren J; Gunn-Moore, Danielle A; Fraga-Manteiga, Eduardo; Schwarz, Tobias

    2015-01-01

    Turbinate destruction is an important diagnostic criterion in canine and feline nasal computed tomography (CT). However decreased turbinate visibility may also be caused by technical CT settings and nasal fluid. The purpose of this experimental, crossover study was to determine whether fluid reduces conspicuity of canine and feline nasal turbinates in CT and if so, whether CT settings can maximize conspicuity. Three canine and three feline cadaver heads were used. Nasal slabs were CT-scanned before and after submerging them in a water bath; using sequential, helical, and ultrahigh resolution modes; with images in low, medium, and high frequency image reconstruction kernels; and with application of additional posterior fossa optimization and high contrast enhancing filters. Visible turbinate length was measured by a single observer using manual tracing. Nasal density heterogeneity was measured using the standard deviation (SD) of mean nasal density from a region of interest in each nasal cavity. Linear mixed-effect models using the R package 'nlme', multivariable models and standard post hoc Tukey pair-wise comparisons were performed to investigate the effect of several variables (nasal content, scanning mode, image reconstruction kernel, application of post reconstruction filters) on measured visible total turbinate length and SD of mean nasal density. All canine and feline water-filled nasal slabs showed significantly decreased visibility of nasal turbinates (P < 0.001). High frequency kernels provided the best turbinate visibility and highest SD of aerated nasal slabs, whereas medium frequency kernels were optimal for water-filled nasal slabs. Scanning mode and filter application had no effect on turbinate visibility.

  19. Thrombocytopenia-absent radius syndrome: a clinical genetic study

    PubMed Central

    Greenhalgh, K; Howell, R; Bottani, A; Ancliff, P; Brunner, H; Verschuuren-Bemel..., C; Vernon, E; Brown, K; Newbury-Ecob, R

    2002-01-01

    The thrombocytopenia-absent radius (TAR) syndrome is a congenital malformation syndrome characterised by bilateral absence of the radii and a thrombocytopenia. The lower limbs, gastrointestinal, cardiovascular, and other systems may also be involved. Shaw and Oliver in 1959 were the first to describe this condition, but it was Hall et al in 1969 who reported the first major series of patients. Since then most reports have been based on single or small numbers of cases. We report the results of a clinical study looking at the phenotype of 34 patients with TAR syndrome. All cases had a documented thrombocytopenia and bilateral radial aplasia, 47% had lower limb anomalies, 47% cow's milk intolerance, 23% renal anomalies, and 15% cardiac anomalies. Congenital anomalies not previously described in association with TAR syndrome included facial capillary haemangiomata, intracranial vascular malformation, sensorineural hearing loss, and scoliosis. Karyotype analysis, chromosome breakage studies including premature centromeric separation and fluorescence in situ hybridisation studies looking for a deletion of chromosome 22q11 were undertaken. Two abnormal karyotypes were identified. PMID:12471199

  20. Absent in melanoma 2 proteins in the development of cancer.

    PubMed

    Choubey, Divaker

    2016-12-01

    Recent studies utilizing chemical-induced colitis-associated and sporadic colon cancer in mouse models indicated a protective role for absent in melanoma 2 (Aim2) in colon epithelial cells. Accordingly, mutations in the human AIM2 gene have been found in colorectal cancer (CRC), and reduced expression of AIM2 in CRC is associated with its progression. Furthermore, the overexpression of AIM2 protein in human cancer cell lines inhibits cell proliferation. Interferon-inducible Aim2 and AIM2 are members of the PYHIN (PYRIN and HIN domain-containing) protein family and share ~57 % amino acid identity. The family also includes murine p202, human PYRIN-only protein 3, and IFI16, which negatively regulate Aim2/AIM2 functions. Because the CRC incidence and mortality rates are higher among men compared with women and the expression of Aim2/AIM2 proteins and their regulators is dependent upon age, gender, and sex hormones, we discuss the potential roles of Aim2/AIM2 in the development of cancer. An improved understanding of the biological functions of the AIM2 in the development of CRC will likely identify new therapeutic approaches to treat patients.

  1. Distinct Biochemical Activities of Eyes absent During Drosophila Eye Development.

    PubMed

    Jin, Meng; Mardon, Graeme

    2016-03-16

    Eyes absent (Eya) is a highly conserved transcriptional coactivator and protein phosphatase that plays vital roles in multiple developmental processes from Drosophila to humans. Eya proteins contain a PST (Proline-Serine-Threonine)-rich transactivation domain, a threonine phosphatase motif (TPM), and a tyrosine protein phosphatase domain. Using a genomic rescue system, we find that the PST domain is essential for Eya activity and Dac expression, and the TPM is required for full Eya function. We also find that the threonine phosphatase activity plays only a minor role during Drosophila eye development and the primary function of the PST and TPM domains is transactivation that can be largely substituted by the heterologous activation domain VP16. Along with our previous results that the tyrosine phosphatase activity of Eya is dispensable for normal Eya function in eye formation, we demonstrate that a primary function of Eya during Drosophila eye development is as a transcriptional coactivator. Moreover, the PST/TPM and the threonine phosphatase activity are not required for in vitro interaction between retinal determination factors. Finally, this work is the first report of an Eya-Ey physical interaction. These findings are particularly important because they highlight the need for an in vivo approach that accurately dissects protein function.

  2. Twelve- and 16-Month-Old Infants Recognize Properties of Mentioned Absent Things

    ERIC Educational Resources Information Center

    Saylor, Megan M.

    2004-01-01

    Absent reference comprehension is a critical achievement of early development, yet little is known about its emergence. In the current study, 12- and 16-month-old infants' recognition of properties of mentioned absent things was used as an index of absent reference comprehension. Infants were presented with displays matching the color and prior…

  3. Cytochrome 572 is a conspicuous membrane protein with iron oxidation activity purified directly from a natural acidophilic microbial community.

    PubMed

    Jeans, Chris; Singer, Steven W; Chan, Clara S; Verberkmoes, Nathan C; Shah, Manesh; Hettich, Robert L; Banfield, Jillian F; Thelen, Michael P

    2008-05-01

    Recently, there has been intense interest in the role of electron transfer by microbial communities in biogeochemical systems. We examined the process of iron oxidation by microbial biofilms in one of the most extreme environments on earth, where the inhabited water is pH 0.5-1.2 and laden with toxic metals. To approach the mechanism of Fe(II) oxidation as a means of cellular energy acquisition, we isolated proteins from natural samples and found a conspicuous and novel cytochrome, Cyt(572), which is unlike any known cytochrome. Both the character of its covalently bound prosthetic heme group and protein sequence are unusual. Extraction of proteins directly from environmental biofilm samples followed by membrane fractionation, detergent solubilization and gel filtration chromatography resulted in the purification of an abundant yellow-red protein. The purified protein has a cytochrome c-type heme binding motif, CxxCH, but a unique spectral signature at 572 nm, and thus is called Cyt(572). It readily oxidizes Fe(2+) in the physiologically relevant acidic regime, from pH 0.95-3.4. Other physical characteristics are indicative of a membrane-bound multimeric protein. Circular dichroism spectroscopy indicates that the protein is largely beta-stranded, and 2D Blue-Native polyacrylamide gel electrophoresis and chemical crosslinking independently point to a multi-subunit structure for Cyt(572). By analyzing environmental genomic information from biofilms in several distinctly different mine locations, we found multiple genetic variants of Cyt(572). MS proteomics of extracts from these biofilms substantiated the prevalence of these variants in the ecosystem. Due to its abundance, cellular location and Fe(2+) oxidation activity at very low pH, we propose that Cyt(572) provides a critical function for fitness within the ecological niche of these acidophilic microbial communities.

  4. Understanding Conspicuous Gravity Low Over the Koyna-Warna Seismogenic Region (Maharashtra, India) and Earthquake Nucleation: A Paradigm Shift

    NASA Astrophysics Data System (ADS)

    Vasanthi, A.; Satish Kumar, K.

    2016-06-01

    The continued seismicity in Koyna-Warna region of the western part of Maharastra (India) and its relationship with subsurface structures, concealed below thick volcanic sequences, are studied in detail using gravity field along with newly available deep scientific drilling results. This seismically active zone is marked by a large conspicuous negative gravity anomaly, the causes of which are yet to be fully understood. Recent findings from the boreholes drilled in the Koyna (G upta et al. in Int J Earth Sci 104:1511-1522, 2015) and Killari seismic zones, both of which penetrated the thick Deccan volcanic cover and the underlying Archean crystalline basement, have motivated us to revisit the Bouguer gravity field over this region, using a newly developed finite element method of regional-residual separation. Our study reveals the presence of two thick low-density/low-velocity crustal zones below the Koyna-Warna region, the shallower one between 5 and 13 km depth and the deeper one between 35 and 43 km depth just above the Moho. Both of these zones appear to contain mantle-metasomatised and fractionated magmatic material, respectively. Interestingly, the hypocenters of all M ≥ 5 Koyna earthquakes occur within the upper low-velocity/low-density zone. We also suggest high-order crustal exhumation below this region, which led to the removal of the entire sedimentary and granitic upper crustal column. This process has brought denser mid-crustal lithological facies close to the surface. Quaternary uplifting and movement of fault blocks along the old as well as newly created fault planes seem to be still continuing. A paleo-rift may have existed beneath this region below which Moho temperatures (~600 °C) and mantle heat flow (~31 mW/m2) are still high.

  5. A Conspicuous Clay Ovoid in Nakhla: Evidence for Subsurface Hydrothermal Alteration on Mars with Implications for Astrobiology

    PubMed Central

    Haigh, Sarah; Lyon, Ian

    2014-01-01

    Abstract A conspicuous biomorphic ovoid structure has been discovered in the Nakhla martian meteorite, made of nanocrystalline iron-rich saponitic clay and amorphous material. The ovoid is indigenous to Nakhla and occurs within a late-formed amorphous mesostasis region of rhyolitic composition that is interstitial to two clinopyroxene grains with Al-rich rims, and contains acicular apatite crystals, olivine, sulfides, Ti-rich magnetite, and a new mineral of the rhoenite group. To infer the origin of the ovoid, a large set of analytical tools was employed, including scanning electron microscopy and backscattered electron imaging, wavelength-dispersive X-ray analysis, X-ray mapping, Raman spectroscopy, time-of-flight secondary ion mass spectrometry analysis, high-resolution transmission electron microscope imaging, and atomic force microscope topographic mapping. The concentric wall of the ovoid surrounds an originally hollow volume and exhibits internal layering of contrasting nanotextures but uniform chemical composition, and likely inherited its overall shape from a preexisting vesicle in the mesostasis glass. A final fibrous layer of Fe-rich phases blankets the interior surfaces of the ovoid wall structure. There is evidence that the parent rock of Nakhla has undergone a shock event from a nearby bolide impact that melted the rims of pyroxene and the interstitial matter and initiated an igneous hydrothermal system of rapidly cooling fluids, which were progressively mixed with fluids from the melted permafrost. Sharp temperature gradients were responsible for the crystallization of Al-rich clinopyroxene rims, rhoenite, acicular apatites, and the quenching of the mesostasis glass and the vesicle. During the formation of the ovoid structure, episodic fluid infiltration events resulted in the precipitation of saponite rinds around the vesicle walls, altered pyrrhotite to marcasite, and then isolated the ovoid wall structure from the rest of the system by depositing a

  6. A conspicuous clay ovoid in Nakhla: evidence for subsurface hydrothermal alteration on Mars with implications for astrobiology.

    PubMed

    Chatzitheodoridis, Elias; Haigh, Sarah; Lyon, Ian

    2014-08-01

    Abstract A conspicuous biomorphic ovoid structure has been discovered in the Nakhla martian meteorite, made of nanocrystalline iron-rich saponitic clay and amorphous material. The ovoid is indigenous to Nakhla and occurs within a late-formed amorphous mesostasis region of rhyolitic composition that is interstitial to two clinopyroxene grains with Al-rich rims, and contains acicular apatite crystals, olivine, sulfides, Ti-rich magnetite, and a new mineral of the rhoenite group. To infer the origin of the ovoid, a large set of analytical tools was employed, including scanning electron microscopy and backscattered electron imaging, wavelength-dispersive X-ray analysis, X-ray mapping, Raman spectroscopy, time-of-flight secondary ion mass spectrometry analysis, high-resolution transmission electron microscope imaging, and atomic force microscope topographic mapping. The concentric wall of the ovoid surrounds an originally hollow volume and exhibits internal layering of contrasting nanotextures but uniform chemical composition, and likely inherited its overall shape from a preexisting vesicle in the mesostasis glass. A final fibrous layer of Fe-rich phases blankets the interior surfaces of the ovoid wall structure. There is evidence that the parent rock of Nakhla has undergone a shock event from a nearby bolide impact that melted the rims of pyroxene and the interstitial matter and initiated an igneous hydrothermal system of rapidly cooling fluids, which were progressively mixed with fluids from the melted permafrost. Sharp temperature gradients were responsible for the crystallization of Al-rich clinopyroxene rims, rhoenite, acicular apatites, and the quenching of the mesostasis glass and the vesicle. During the formation of the ovoid structure, episodic fluid infiltration events resulted in the precipitation of saponite rinds around the vesicle walls, altered pyrrhotite to marcasite, and then isolated the ovoid wall structure from the rest of the system by depositing a

  7. Detectability matters: conspicuous nestling mouth colours make prey transfer easier for parents in a cavity nesting bird.

    PubMed

    Dugas, Matthew B

    2015-11-01

    An often underappreciated function of signals is to notify receivers of the presence and position of senders. The colours that ornament the mouthparts of nestling birds, for example, have been hypothesized to evolve via selective pressure generated by parents' inability to efficiently detect and feed nestlings without such visually conspicuous targets. This proposed mechanism has primarily been evaluated with comparative studies and experimental tests for parental allocation bias, leaving untested the central assumption of this detectability hypothesis, that provisioning offspring is a visually challenging task for avian parents and conspicuous mouths help. To test this assumption, I manipulated the mouths of nestling house sparrows to appear minimally and maximally conspicuous, and quantified prey transfer difficulty as the total duration of a feeding event and the number of transfer attempts required. Prey transfer to inconspicuous nestlings was, as predicted, more difficult. While this suggests that detectability constraints could shape nestling mouth colour evolution, even minimally conspicuous nestlings were not prohibitively difficult for parents to feed, indicating that a more nuanced explanation for interspecific diversity in this trait is needed.

  8. Human search with a limited field of view: effects of scan speed, aperture size, and target conspicuity

    NASA Astrophysics Data System (ADS)

    Hogervorst, Maarten A.; Toet, Alexander; Bijl, Piet

    2013-04-01

    We investigate how human visual search performance with field of view (FOV) restrictions depends on scan speed, zoom factor, target location, and conspicuity. First, observers search a FOV that moves at a constant speed along a predefined path over a visual search scene (the field of regard, or FOR), and we measure the effects of scan speed, zoom factor, FOV size, target location, and conspicuity on search performance (detection time and probability). Then observers search either visual or thermal scenes by freely moving a joystick-controlled FOV over the FOR, while freely selecting the zoom factor in some conditions, and we measure the effects of the scan path characteristics and the use of different strategies on search performance. Search performance depends on the effective FOV size (the area where targets are expected to occur), but is largely independent of the display area. Both for visual and thermal imagery, various search performance measures correlate with target conspicuity. The results of both experiments suggest that observers can optimize their performance by adjusting their scanning behavior both to their visual limitations and to the expected target conspicuity. We present the outlines of a simple search model based on these current findings.

  9. The carotenoid-continuum: carotenoid-based plumage ranges from conspicuous to cryptic and back again

    PubMed Central

    2010-01-01

    Background Carotenoids are frequently used by birds to colour their plumage with green, yellow, orange or red hues, and carotenoid-based colours are considered honest signals of quality, although they may have other functions, such as crypsis. It is usually assumed that red through yellow colours have a signalling function while green is cryptic. Here we challenge this notion using the yellow and green colouration of blue tits (Cyanistes caeruleus), great tits (Parus major) and greenfinches (Carduelis chloris) as a model. Results The relationship between colouration (chroma, computed using visual sensitivities of conspecifics) and detectability (contrast against natural backgrounds as perceived by conspecifics and avian predators) followed a similar curvilinear pattern for yellow and green plumage with minimum detectability at intermediate levels of carotenoid deposition. Thus, for yellow and green plumage, colours at or close to the point of minimum detectability may aid in crypsis. This may be the case for blue and great tit green and yellow plumage, and greenfinch green plumage, all of which had comparably low levels of detectability, while greenfinch yellow plumage was more chromatic and detectable. As yellow and green blue tit colouration are strongly affected by carotenoid availability during moult, variation in pigment availability between habitats may affect the degree of background-matching or the costliness of producing cryptic plumage. Conclusions Increasing carotenoid-deposition in the integument does not always lead to more conspicuous colours. In some cases, such as in blue or great tits, carotenoid deposition may be selected through enhanced background-matching, which in turn suggests that producing cryptic plumage may entail costs. We stress however, that our data do not rule out a signalling function of carotenoid-based plumage in tits. Rather, it shows that alternative functions are plausible and that assuming a signalling function based solely on

  10. Combination of conspicuity improved synthetic mammograms and digital breast tomosynthesis: a promising approach for mass detection

    NASA Astrophysics Data System (ADS)

    Kim, Seong Tae; Kim, Dae Hoe; Ro, Yong Man

    2015-03-01

    In this study, a novel mass detection framework that utilizes the information from synthetic mammograms has been developed for detecting masses in digital breast tomosynthesis (DBT). In clinical study, it is demonstrated that the combination of DBT and full field digital mammography (FFDM) increases the reader performance. To reduce the radiation dose in this approach, synthetic mammogram has been developed in previous researches and it is demonstrated that synthetic mammogram can alternate the FFDM when it is used with DBT. In this study, we investigate the feasibility of the combined approach of DBT and synthetic mammogram in point of computer-aided detection (CAD). As a synthetic mammogram, two-dimensional image was generated by adopting conspicuous voxels of three-dimensional DBT volume in our study. The mass likelihood scores estimated for each mass candidates in synthetic mammogram and DBT are merged to differentiate masses and false positives (FPs) in combined approach. We compared the performance of detecting masses in the proposed combined approach and DBT alone. A clinical data set of 196 DBT volumes was used to evaluate the different detection schemes. The combined approach achieved sensitivity of 80% and 89% with 1.16 and 2.37 FPs per DBT volume. The DBT alone approach achieved same sensitivities with 1.61 and 3.46 FPs per DBT volume. Experimental results show that statistically significant improvement (p = 0.002) is achieved in combined approach compared to DBT alone. These results imply that the information fusion of synthetic mammogram and DBT is a promising approach to detect masses in DBT.

  11. The effect of metapopulation dynamics on the survival and spread of a novel, conspicuous prey.

    PubMed

    Lee, Thomas J; Speed, Michael P

    2010-12-07

    Animals that deploy chemical defences against predators often signal their unprofitability using bright colouration. This pairing of toxicity and conspicuous patterning is known as aposematism. Explaining the evolution and spread of aposematic traits in previously cryptic species has been the focus of much empirical and theoretical work over the last two decades. Existing research concerning the initial evolution of aposematism does not however properly consider that many aposematic species (such as members of the hymenoptera, the lepidoptera, and amphibia) are highly mobile. We argue in this paper that the evolution of aposematic displays is therefore often best understood within a metapopulation framework; hence in this paper we present the first explicit metapopulation model of the evolution of aposematism. Our most general finding is that migration tends to reduce the probability that an aposematic prey can increase from rarity and spread across a large population. Hence, the best case scenarios for the spread of aposematism required fixation of the aposematic form in one or more isolated sub-habitats prior to some event which subsequently enabled migration. We observed that changes in frequency of new aposematic forms within source habitats are likely to be nonmonotonic. First, aposematic prey tend to decline in frequency as they migrate outwards from the source habitat to neighbouring sink habitats, but subsequently they increase in relative abundance in the source, as the descendents of earlier migrants migrate back from newly converted sub-populations. This pattern of initial loss and subsequent gain between new source and neighbouring sink habitats is then repeated as the aposematic form spreads via a moving cline.

  12. The Economic Consequences of Absent Parents. JCPR Working Paper.

    ERIC Educational Resources Information Center

    Page, Marianne E.; Stevens, Ann Huff

    In recent years, the belief that marriage bestows large economic gains has generated enthusiasm for policy proposals that encourage the formation and continuation of two-parent families. This study examined the effects of family structure on economic resources, controlling for unobservable family background characteristics. Data were drawn from…

  13. Renal tubular dysgenesis, absent nipples, and multiple malformations in three brothers: a new, lethal syndrome.

    PubMed

    Hisama, F M; Reyes-Mugica, M; Wargowski, D S; Thompson, K J; Mahoney, M J

    1998-12-04

    We report on three brothers with renal tubular dysgenesis and absent nipples, each also had other malformations including pre-auricular pits and a preauricular tag, branchial clefts, choanal atresia, pulmonary lobation anomaly, ventricular septal defect, type IIB interrupted aortic arch, absent gallbladder, absent thymus, parathyroid gland, accessory spleen, imperforate anus, clinodactyly, and broad digits and small nails. All three infants died neonatally. This pattern of clinical malformations appears to be a previously unreported syndrome.

  14. Turner Syndrome and apparent absent uterus: a case report and review of the literature.

    PubMed

    Akierman, Sarah V; Skappak, Christopher D; Girgis, Rose; Ho, Josephine

    2013-01-01

    We report on a patient who initially presented with delayed puberty and an absent uterus on imaging with ultrasound and MRI. She was subsequently diagnosed with Turner Syndrome. Turner Syndrome typically presents with early loss of ovarian function and should be considered when primary ovarian insufficiency is present with apparent absent uterus on imaging. Follow-up imaging of the apparent absent uterus post-estrogen replacement therapy is important to confirm a normal uterus. A diagnosis of an absent uterus can be psychologically traumatic for patients and families, and can have significant implications for future fertility options.

  15. Causal Attributions as Predictors of Academic Achievement in Father-Absent Children.

    ERIC Educational Resources Information Center

    Salzman, Stephanie A.

    The purpose of this study was to examine the potential impact of maternal attributions and self-attributions on the academic achievement of father-absent children in comparison to commonly identified family interaction and demographic variables. Subjects included 33 male and 34 female father-absent sixth graders (mean age of 11.6 years) and their…

  16. Asymmetrical Sample Training Produces Asymmetrical Retention Functions in Feature-Present/Feature-Absent Matching in Pigeons

    ERIC Educational Resources Information Center

    Grant, Douglas S.; Blatz, Craig W.

    2004-01-01

    Pigeons were trained in a matching task in which samples involved presentation of a white line on a green background (feature-present) or on an otherwise dark key (feature-absent). After asymmetrical training in which one group was initially trained with the feature-present sample and another was initially trained with the feature-absent sample,…

  17. 42 CFR 410.175 - Alien absent from the United States.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 2 2014-10-01 2014-10-01 false Alien absent from the United States. 410.175... Alien absent from the United States. (a) Medicare does not pay Part B benefits for services furnished to... during the first full calendar month the alien is back in the United States....

  18. 42 CFR 410.175 - Alien absent from the United States.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Alien absent from the United States. 410.175... Alien absent from the United States. (a) Medicare does not pay Part B benefits for services furnished to... during the first full calendar month the alien is back in the United States....

  19. 42 CFR 410.175 - Alien absent from the United States.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 2 2013-10-01 2013-10-01 false Alien absent from the United States. 410.175... Alien absent from the United States. (a) Medicare does not pay Part B benefits for services furnished to... during the first full calendar month the alien is back in the United States....

  20. 42 CFR 410.175 - Alien absent from the United States.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 2 2012-10-01 2012-10-01 false Alien absent from the United States. 410.175... Alien absent from the United States. (a) Medicare does not pay Part B benefits for services furnished to... during the first full calendar month the alien is back in the United States....

  1. 42 CFR 410.175 - Alien absent from the United States.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 2 2011-10-01 2011-10-01 false Alien absent from the United States. 410.175... Alien absent from the United States. (a) Medicare does not pay Part B benefits for services furnished to... during the first full calendar month the alien is back in the United States....

  2. Successful Black Men from Absent-Father Homes and Their Resilient Single Mothers: A Phenomenological Study

    ERIC Educational Resources Information Center

    Wilson, Angie D.; Henriksen, Richard C.; Bustamante, Rebecca; Irby, Beverly

    2016-01-01

    The phenomenon of absent fathers is a common occurrence in today's homes that appears to be escalating, especially in Black households across the United States. The purpose of this study was to describe the lived experiences of successful Black men who were raised in absent-father homes as well as the lived experiences of their resilient single…

  3. Disneyland Dads, Disneyland Moms? How Nonresident Parents Spend Time with Absent Children.

    ERIC Educational Resources Information Center

    Stewart, Susan D.

    1999-01-01

    Examines gender differences in how nonresident parents spend time with their absent children. Results suggest that nonresident mothers and fathers exhibit a similar pattern of participation in activities with their absent children. Most nonresident parents either engage in only leisure activities with their children or have no contact. (Author/MKA)

  4. Sweating - absent

    MedlinePlus

    ... diseases or scarring of the skin that block sweat glands Trauma to sweat glands Use of certain drugs Home Care If there ... Miller JL. Diseases of the eccrine and apocrine sweat glands. In: Bolognia JL, Jorizzo JL, Schaffer JV, eds. ...

  5. Thirst - absent

    MedlinePlus

    ... to drink fluids, even when the body is low on water or has too much salt. ... do a detailed nervous system exam if a head injury or problem ... are dehydrated, fluids will likely be given through a vein (IV).

  6. Serum levels of IGF-1 are related to human skin characteristics including the conspicuousness of facial pores.

    PubMed

    Sugiyama-Nakagiri, Y; Naoe, A; Ohuchi, A; Kitahara, T

    2011-04-01

    Conspicuous facial pores are one type of serious aesthetic defects for many women. However, the mechanism(s) that underlie the conspicuousness of facial pores remains unclear. We previously characterized the epidermal architecture around facial pores that correlates with the appearance of those pores in various ethnic groups including Japanese. The goal of this study was to evaluate the possible relationships between facial pore size, the severity of impairment of epidermal architecture around facial pores and sebum output levels to investigate the possible role of IGF-1 in the pathogenesis of conspicuous facial pores. The subjects consisted of 38 healthy Japanese women (aged 22-41 years). IGF-1 was measured using immunoradiometric assay. Surface replicas were collected to compare pore sizes of cheek skin and horizontal cross-section images of cheek skin were obtained non-invasively from the same subjects using in vivo confocal laser scanning microscopy and the severity of impairment of epidermal architecture around facial pores was determined. The skin surface lipids of each subject were collected from their cheeks and lipid classes were determined using gas chromatography/flame ionization detection. The serum level of IGF-1 correlated significantly with total pore area (R = 0.36, P < 0.05), with the severity of impairment of epidermal architecture around facial pores (R = 0.43, P < 0.05) and with sebum output levels (R = 0.41, P < 0.01). The sebum output levels correlated with total pore area (R = 0.32, P < 0.05). Our study found that serum levels of IGF-1 are correlated with facial skin characteristics including facial pore size and with the severity of impairment of epidermal architecture around facial pores.

  7. Deceived by stripes: conspicuous patterning on vital anterior body parts can redirect predatory strikes to expendable posterior organs

    PubMed Central

    Kodandaramaiah, Ullasa

    2016-01-01

    Conspicuous coloration, which presumably makes prey more visible to predators, has intrigued researchers for long. Contrastingly coloured, conspicuous striped patterns are common among lizards and other animals, but their function is not well known. We propose and test a novel hypothesis, the ‘redirection hypothesis’, wherein longitudinal striped patterns, such as those found on the anterior body parts of most lacertilians, redirect attacks away from themselves during motion towards less vulnerable posterior parts, for example, the autotomous tail. In experiments employing human ‘predators’ attacking virtual prey on a touchscreen, we show that longitudinal striped patterns on the anterior half of prey decreased attacks to the anterior and increased attacks to the posterior. The position of stripes mattered—they worked best when they were at the anterior. By employing an adaptive psychophysical procedure, we show that prey with striped patterning are perceived to move slower, offering a mechanistic explanation for the redirective effect. In summary, our results suggest that the presence of stripes on the body (i.e. head and trunk) of lizards in combination with caudal autotomy can work as an effective anti-predator strategy during motion. PMID:27429765

  8. Amine templating effect absent in uranyl sulfates synthesized with 1,4-n-butyldiamine

    SciTech Connect

    Jouffret, Laurent J.; Wylie, Ernest M.; Burns, Peter C.

    2013-01-15

    Two new uranyl sulfates, (C{sub 4}H{sub 14}N{sub 2})[(UO{sub 2}){sub 2}(SO{sub 4}){sub 3}(H{sub 2}O)]{center_dot}2H{sub 2}O (NDUS2) and (C{sub 4}H{sub 14}N{sub 2})[(UO{sub 2})(SO{sub 4}){sub 2}(H{sub 2}O)]{center_dot}2H{sub 2}O (NDUS3), were synthesized and their crystal structures determined. NDUS2 was obtained in highly acidic media heat-treated at 373 K and subsequently maintained at 278 K until crystals formed after two months. NDUS3 results from the degradation of NDUS2 over the course of a few days. NDUS2 and NDUS3 crystallize in the monoclinic space group P2{sub 1}/n, a=10.9075(4) A, b=10.4513(4) A, c=17.7881(7) A, {beta}=97.908(2) Degree-Sign , V=2008.52(13) A{sup 3}, Z=4, at 140 K and a=8.8570(4) A, b=7.3299(3) A, c=20.4260(9) A, {beta}=95.140(2) Degree-Sign , V=1320.74(10) A{sup 3}, Z=4, at 140 K, respectively. The compounds contain interlayer 1,4-n-butyldiammonium cations that charge-balance the anionic structural units. - Graphical abstract: Amine templating effect absent in uranyl sulfates synthesized with 1,4-diaminobutane, as shown by the synthesis of two new uranyl sulfates, (C{sub 4}H{sub 14}N{sub 2})[(UO{sub 2}){sub 2}(SO{sub 4}){sub 3}(H{sub 2}O)]{center_dot}2H{sub 2}O (NDUS2) and (C{sub 4}H{sub 14}N{sub 2})[(UO{sub 2})(SO{sub 4}){sub 2}(H{sub 2}O)]{center_dot}2H{sub 2}O (NDUS3). Highlights: Black-Right-Pointing-Pointer Two layered uranyl sulfates were synthesized. Black-Right-Pointing-Pointer Amine molecules are located in the interlayers of the compounds. Black-Right-Pointing-Pointer No templating effect of the amine was observed. Black-Right-Pointing-Pointer Amine molecules are only charge balancing cations in the structures.

  9. Case Study: The Perception of Online Tutorials--Habitually Absent Students with Familial or Socioeconomic Circumstances

    ERIC Educational Resources Information Center

    Hudson, Glyniss A.

    2013-01-01

    This case study explored the perception of online tutorials by habitually absent students with familial or socioeconomic circumstances. Researched literature confirmed a link between absenteeism, and academic achievement. Research Questions were designed to determine (a) student perception of online tutorials, and (b) motivation to achieve…

  10. Eyeless initiates the expression of both sine oculis and eyes absent during Drosophila compound eye development.

    PubMed

    Halder, G; Callaerts, P; Flister, S; Walldorf, U; Kloter, U; Gehring, W J

    1998-06-01

    The Drosophila Pax-6 gene eyeless acts high up in the genetic hierarchy involved in compound eye development and can direct the formation of extra eyes in ectopic locations. Here we identify sine oculis and eyes absent as two mediators of the eye-inducing activity of eyeless. We show that eyeless induces and requires the expression of both genes independently during extra eye development. During normal eye development, eyeless is expressed earlier than and is required for the expression of sine oculis and eyes absent, but not vice versa. Based on the results presented here and those of others, we propose a model in which eyeless induces the initial expression of both sine oculis and eyes absent in the eye disc. sine oculis and eyes absent then appear to participate in a positive feedback loop that regulates the expression of all three genes. In contrast to the regulatory interactions that occur in the developing eye disc, we also show that in the embryonic head, sine oculis acts in parallel to eyeless and twin of eyeless, a second Pax-6 gene from Drosophila. Recent studies in vertebrate systems indicate that the epistatic relationships among the corresponding vertebrate homologs are very similar to those observed in Drosophila.

  11. When Familiar Is Not Better: 12-Month-Old Infants Respond to Talk about Absent Objects

    ERIC Educational Resources Information Center

    Osina, Maria A.; Saylor, Megan M.; Ganea, Patricia A.

    2013-01-01

    Three experiments that demonstrate a novel constraint on infants' language skills are described. Across the experiments it is shown that as babies near their 1st birthday, their ability to respond to talk about an absent object is influenced by a referent's spatiotemporal history: familiarizing infants with an object in 1 or several nontest…

  12. Reconstruction of a congenitally absent flexor pollicis longus in an adult

    PubMed Central

    Shamsian, Negin; Exton, Rebecca; Shibu, MM

    2010-01-01

    Congenital absence of the flexor pollicis longus (FPL) is an unusual finding that is frequently associated with thumb hypoplasia. Isolated FPL absence is the rarest of the congenital thumb anomalies. The present article describes a patient with a congenitally absent FPL, and discusses the chosen method of reconstruction. PMID:22131842

  13. A Conspicuous Absence

    ERIC Educational Resources Information Center

    Pluviose, David

    2006-01-01

    Every major city in every state in the country has a public community college, as do U.S. territories such as Guam and Puerto Rico. President Bush, Federal Reserve chairman Alan Greenspan and civic and business leaders of all stripes are increasingly talking up community colleges as critical to training U.S. workers for ever-changing job needs in…

  14. Increased conspicuousness can explain the match between visual sensitivities and blue plumage colours in fairy-wrens

    PubMed Central

    Delhey, Kaspar; Hall, Michelle; Kingma, Sjouke A.; Peters, Anne

    2013-01-01

    Colour signals are expected to match visual sensitivities of intended receivers. In birds, evolutionary shifts from violet-sensitive (V-type) to ultraviolet-sensitive (U-type) vision have been linked to increased prevalence of colours rich in shortwave reflectance (ultraviolet/blue), presumably due to better perception of such colours by U-type vision. Here we provide the first test of this widespread idea using fairy-wrens and allies (Family Maluridae) as a model, a family where shifts in visual sensitivities from V- to U-type eyes are associated with male nuptial plumage rich in ultraviolet/blue colours. Using psychophysical visual models, we compared the performance of both types of visual systems at two tasks: (i) detecting contrast between male plumage colours and natural backgrounds, and (ii) perceiving intraspecific chromatic variation in male plumage. While U-type outperforms V-type vision at both tasks, the crucial test here is whether U-type vision performs better at detecting and discriminating ultraviolet/blue colours when compared with other colours. This was true for detecting contrast between plumage colours and natural backgrounds (i), but not for discriminating intraspecific variability (ii). Our data indicate that selection to maximize conspicuousness to conspecifics may have led to the correlation between ultraviolet/blue colours and U-type vision in this clade of birds. PMID:23118438

  15. Discrete colour polymorphism in the tawny dragon lizard (Ctenophorus decresii) and differences in signal conspicuousness among morphs.

    PubMed

    Teasdale, L C; Stevens, M; Stuart-Fox, D

    2013-05-01

    Intraspecific colour variation is common in nature and can vary from the coexistence of discrete colour variants in polymorphic species to continuous variation. Whether coloration is continuous or discrete is often ambiguous and many species exhibit a combination of the two. The nature of the variation (discrete or continuous) has implications for both the genetic basis of the colour variation and the evolutionary processes generating and maintaining it. Consequently, it is important to qualify the existence of discrete morphs, particularly in relation to the animal's visual system. In this study, we quantified male throat colour variation in Ctenophorus decresii tawny dragon lizard and tested for morphological and ecological correlates of the colour variants. We confirmed that discrete throat colour morphs can be defined based on colour and pattern analyses independent of the human visual system. We also found that the colour variants differed in their conspicuousness from the background, to the lizard's visual system, which has implications for signalling. However, the morphs did not differ in morphology or microhabitat use, which suggests that these characteristics are not involved in the evolutionary maintenance of the polymorphism.

  16. Conspicuity of target lights: The influence of flash rate and brightness. [collision avoidance - visual discrimination/pilot performance, aircraft lights

    NASA Technical Reports Server (NTRS)

    Connors, M. M.

    1975-01-01

    The stimulus characteristics of lights that might aid a pilot to see and avoid, by alerting him to a potential threat were studied. The relative conspicuity of foveally equated, point-source, steady and flashing lights of several brightnesses, seen against a star background was examined. From the subject's viewpoint, these target lights could appear anywhere within a large (40 deg horizontal by 35 deg vertical) field of view. The lights appeared at random time intervals while the subject was periodically distracted by a simulated cockpit task. The results indicate that correct target detection increases and reaction time decreases with increased target intensity. Steady lights are missed more frequently and acquired more slowly than flashing lights, but no significant differences are found among the wide range of flash rates employed. The intensity of the light has a greater effect on both detection and reaction time to steady lights than to flashing lights. These results are compared with results of other researchers who used targets which appeared at fixed locations. The longest reaction times were recorded to lights which appeared either at the extremes or at the very center of the visual field.

  17. Conspicuous carotenoid-based pelvic spine ornament in three-spined stickleback populations—occurrence and inheritance

    PubMed Central

    Amundsen, CR; Gjøen, HM; Larsen, B; Egeland, ES

    2015-01-01

    Reports on reddish carotenoid-based ornaments in female three-spined sticklebacks (Gasterosteus aculeatus) are few, despite the large interest in the species’ behaviour, ornamentation, morphology and evolution. We sampled sticklebacks from 17 sites in north-western Europe in this first extensive study on the occurrence of carotenoid-based female pelvic spines and throat ornaments. The field results showed that females, and males, with reddish spines were found in all 17 populations. Specimens of both sexes with conspicuous red spines were found in several of the sites. The pelvic spines of males were more intensely red compared to the females’ spines, and large specimens were more red than small ones. Fish infected with the tapeworm (Schistocephalus solidus) had drabber spines than uninfected fish. Both sexes had red spines both during and after the spawning period, but the intensity of the red colour was more exaggerated during the spawning period. As opposed to pelvic spines, no sign of red colour at the throat was observed in any female from any of the 17 populations. A rearing experiment was carried out to estimate a potential genetic component of the pelvic spine ornament by artificial crossing and rearing of 15 family groups during a 12 months period. The results indicated that the genetic component of the red colour at the spines was low or close to zero. Although reddish pelvic spines seem common in populations of stickleback, the potential adaptive function of the reddish pelvic spines remains largely unexplained. PMID:25861558

  18. Sensory exploitation of prey: manipulation of the initial direction of prey escapes by a conspicuous "rare enemy".

    PubMed

    Jabłonski, P G

    2001-05-22

    The painted redstart (Myioborus pictus) represents a group of non-cryptic predators, the flush pursuers, who visually trigger prey escapes by spreading and pivoting their conspicuously patterned tails and wings. The prey are then chased in aerial pursuits. Such an exploitation of prey may be possible because the predation risk from redstarts is smaller than that from the predatory guild of insectivores and their neural pathways are adapted to helping prey avoid common predators rather than "rare enemies". I propose that the pivoting movements of flush pursuers direct insect escapes across the central field of vision of a predator, where it is easier to track and intercept the prey. Eighty per cent of chases by wild redstarts were in a direction suggesting that prey were entering the birds' area of stereoscopic vision. The redstart's fanned and raised tail creates a stronger visual stimulus than a redstart's head. Flies escaped away from the section of the fly's field of vision in which the model's tail was located and towards the area where the predator's stereoscopic vision is likely to be located, in front of a bird's forehead. The experiments suggested that redstarts may not only exploit the sensitivity of typical neural escape pathways, which are non-directionally sensitive, but that they may also exploit the sensitivity of some directionally sensitive neural pathways in prey.

  19. Mayer Rokitansky Kuster Hauser (MRKH) syndrome with absent thumbs and big toes.

    PubMed

    Yunus, Mahira

    2014-01-01

    Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome is a rare developmental failure of Müllerian ducts. Principle clinical features of MRKH syndrome are primary amenorrhoea associated with congenital absence of vagina, uterine anomalies, normal ovaries, 46 XX karyotype with normal female secondary sexual characteristics and frequent association with renal, skeletal, and other congenital anomalies. A case of a 3-year-old child with congenitally absent thumbs and big toes is reported herein; she was brought in with complaints of urinary incontinence. Radiological investigation (ultrasound and magnetic resonance imaging (MRI) scan) revealed absent uterus and vagina while both ovaries were normal. Intravenous urography (IVU) study showed bifid pelvicalyceal systems bilaterally. Karyotyping revealed a 46 XX female phenotype. Laparoscopy confirmed normal ovaries bilaterally and small unfused uterine buds lying beside both ovaries on each side of pelvis. Early diagnosis of MRKH syndrome is essential for timely planning of vaginal and (if possible) uterine reconstructive surgeries.

  20. A surviving infant with sirenomelia (Mermaid syndrome) associated with absent bladder.

    PubMed

    Stanton, Michael P; Penington, Elizabeth C; Hutson, John M

    2003-08-01

    The authors report a case of a surviving infant with sirenomelia (Mermaid syndrome). The child is now 4 years of age. The authors believe that this is only the fourth reported case of an infant with sirenomelia surviving beyond the neonatal period and the first associated with absent bladder. The abnormal distal aorta shown in this case supports the theory that sirenomelia is an extreme form of caudal dysgenesis rather than occurring secondary to vascular steal.

  1. Surgical treatment of tetralogy of Fallot with absent pulmonary valve syndrome.

    PubMed

    Tanaka, Yuki; Miyamoto, Takashi; Naito, Yuji; Yoshitake, Shuichi

    2016-06-01

    The patient was a 3-month-old girl weighting 3.6 kg, diagnosed with tetralogy of Fallot and absent pulmonary valve syndrome. We surgically repaired the tetralogy of Fallot by patch closure of the ventricular septal defect, right ventricular outflow tract reconstruction using an expanded polytetrafluoroethylene monocusp patch with a bulging sinus, and removal of the bronchial obstruction by anterior translocation of the pulmonary artery using the Lecompte maneuver.

  2. Force production and flow structure of the leading edge vortex on flapping wings at high and low Reynolds numbers.

    PubMed

    Birch, James M; Dickson, William B; Dickinson, Michael H

    2004-03-01

    The elevated aerodynamic performance of insects has been attributed in part to the generation and maintenance of a stable region of vorticity known as the leading edge vortex (LEV). One explanation for the stability of the LEV is that spiraling axial flow within the vortex core drains energy into the tip vortex, forming a leading-edge spiral vortex analogous to the flow structure generated by delta wing aircraft. However, whereas spiral flow is a conspicuous feature of flapping wings at Reynolds numbers (Re) of 5000, similar experiments at Re=100 failed to identify a comparable structure. We used a dynamically scaled robot to investigate both the forces and the flows created by a wing undergoing identical motion at Re of approximately 120 and approximately 1400. In both cases, motion at constant angular velocity and fixed angle of attack generated a stable LEV with no evidence of shedding. At Re=1400, flow visualization indicated an intense narrow region of spanwise flow within the core of the LEV, a feature conspicuously absent at Re=120. The results suggest that the transport of vorticity from the leading edge to the wake that permits prolonged vortex attachment takes different forms at different Re.

  3. The bulk and the tail of minimal absent words in genome sequences

    NASA Astrophysics Data System (ADS)

    Aurell, Erik; Innocenti, Nicolas; Zhou, Hai-Jun

    2016-04-01

    Minimal absent words (MAW) of a genomic sequence are subsequences that are absent themselves but the subwords of which are all present in the sequence. The characteristic distribution of genomic MAWs as a function of their length has been observed to be qualitatively similar for all living organisms, the bulk being rather short, and only relatively few being long. It has been an open issue whether the reason behind this phenomenon is statistical or reflects a biological mechanism, and what biological information is contained in absent words. In this work we demonstrate that the bulk can be described by a probabilistic model of sampling words from random sequences, while the tail of long MAWs is of biological origin. We introduce the concept of a core of a MAW, which are sequences present in the genome and closest to a given MAW. We show that in E. faecalis, E. coli and yeast the cores of the longest MAWs, which exist in two or more copies, are located in highly conserved regions the most prominent example being ribosomal RNAs. We also show that while the distribution of the cores of long MAWs is roughly uniform over these genomes on a coarse-grained level, on a more detailed level it is strongly enhanced in 3’ untranslated regions (UTRs) and, to a lesser extent, also in 5’ UTRs. This indicates that MAWs and associated MAW cores correspond to fine-tuned evolutionary relationships, and suggest that they can be more widely used as markers for genomic complexity.

  4. Gender-based violence and absent fathers: a scoping review protocol

    PubMed Central

    Sikweyiya, Yandisa; Nduna, Mzikazi; Khuzwayo, Nelisiwe; Mthombeni, Andile; Mashamba-Thompson, Tivani Phosa

    2016-01-01

    Introduction Gender-based violence (GBV) and absent fathers are two epidemics that affect women and children in sub-Saharan Africa. However, the understanding of the complex links between GBV and absent fathers is currently inadequate. The aim of the study is to provide an overview of documented evidence that links GBV and absent fathers as well as identifies areas that require systematic review and where more primary research is needed. Methods and analysis The search strategy for this scoping review study will involve electronic databases including: Academic Search Premier, Ingenta, Kluwer Online, PsycARTICLES (EBSCO), PsycINFO (EBSCO), Social Work Abstracts and Sociological Collection. The studies will be mapped in 2 stages: stage 1 will map studies descriptively by focus and method; stage 2 will involve additional inclusion criteria, quality assessment and data extraction undertaken by two reviewers in parallel. A thematic analysis of the studies will be carried out to extract relevant outcomes using NVIVO. Discussion We anticipate finding a large number of studies on GBV diagnostic interventions in sub-Saharan Africa which, once summarised, will be useful to guide future research. The protocol for the scoping review has been registered in PROSPERO. Dissemination The study will be disseminated electronically and in print. It will also be presented to conferences related to GBV, Father Connections and Children's Health. PROSPERO registration number CRD42015022094. PMID:27297007

  5. Cardiac-locked bursts of muscle sympathetic nerve activity are absent in familial dysautonomia

    PubMed Central

    Macefield, Vaughan G; Norcliffe-Kaufmann, Lucy; Axelrod, Felicia B; Kaufmann, Horacio

    2013-01-01

    Familial dysautonomia (Riley–Day syndrome) is an hereditary sensory and autonomic neuropathy (HSAN type III), expressed at birth, that is associated with reduced pain and temperature sensibilities and absent baroreflexes, causing orthostatic hypotension as well as labile blood pressure that increases markedly during emotional excitement. Given the apparent absence of functional baroreceptor afferents, we tested the hypothesis that the normal cardiac-locked bursts of muscle sympathetic nerve activity (MSNA) are absent in patients with familial dysautonomia. Tungsten microelectrodes were inserted percutaneously into muscle or cutaneous fascicles of the common peroneal nerve in 12 patients with familial dysautonomia. Spontaneous bursts of MSNA were absent in all patients, but in five patients we found evidence of tonically firing sympathetic neurones, with no cardiac rhythmicity, that increased their spontaneous discharge during emotional arousal but not during a manoeuvre that unloads the baroreceptors. Conversely, skin sympathetic nerve activity (SSNA), recorded in four patients, appeared normal. We conclude that the loss of phasic bursts of MSNA and the loss of baroreflex modulation of muscle vasoconstrictor drive contributes to the poor control of blood pressure in familial dysautonomia, and that the increase in tonic firing of muscle vasoconstrictor neurones contributes to the increase in blood pressure during emotional excitement. PMID:23165765

  6. Conspicuity of Malignant Lesions on PET/CT and Simultaneous Time-Of-Flight PET/MRI

    PubMed Central

    Minamimoto, Ryogo; Iagaru, Andrei; Jamali, Mehran; Holley, Dawn; Barkhodari, Amir; Vasanawala, Shreyas; Zaharchuk, Greg

    2017-01-01

    Purpose To compare the conspicuity of malignant lesions between FDG PET/CT and a new simultaneous, time-of-flight (TOF) enabled PET/MRI scanner. Methods All patients underwent a single-injection of FDG, followed by a dual imaging protocol consisting of PET/CT followed by TOF PET/MRI. PET/CT and PET/MRI images were evaluated by two readers independently for areas of FDG uptake compatible with malignancy, and then categorized into 5 groups (1: PET/MRI and PET/CT positive; 2: PET/MRI positive, PET/CT positive in retrospect; 3: PET/CT positive, PET/MRI positive in retrospect; 4: PET/MRI positive, PET/CT negative; 5: PET/MRI negative, PET/CT positive) by consensus. Patients with no lesions on either study or greater than 10 lesions based on either modality were excluded from the study. Results Fifty-two patients (mean±SD age: 58±14 years) underwent the dual imaging protocol; of these, 29 patients with a total of 93 FDG-avid lesions met the inclusion criteria. The majority of lesions (56%) were recorded prospectively in the same location on PET/CT and PET/MRI. About an equal small fraction of lesions were seen on PET/CT but only retrospectively on PET/MRI (9%) and vice versa (12%). More lesions were identified only on PET/MRI but not on PET/CT, even in retrospect (96% vs. 81%, respectively; p = 0.003). Discrepant lesions had lower maximum standardized uptake value (SUVmax) than concordant lesions on both modalities (p<0.001). Conclusions While most lesions were identified prospectively on both modalities, significantly more lesions were identified with PET/MRI than with PET/CT. PMID:28103230

  7. Conspicuous variation of the lattice unit cell in the pavonite homologous series and its relation with cation/anion occupational modulations

    SciTech Connect

    Perez-Mato, J.M.; Topa, Dan; Petříček, Václav; Madariaga, Gotzon

    2013-06-01

    Highlights: ► Strong non-uniform variation of unit cell parameters in the pavonite homologous series. ► Conspicuous unit cell variation due to an underlying sub-lattice with cation/anion occupation. ► A modulated model common to the whole series using the superspace formalism proposed. ► Model successfully applied to the {sup 7}P pavonite Ag{sub 3}(Bi,Pb){sub 7}S{sub 12}. ► The model can be applied in a predictive way to other members of the family. - Abstract: The pavonites is a homologous series of sulfosalts with galena-like modules of variable size. A survey of their unit cells reveals that they are severely constrained by the metrics of an underlying common average sublattice. The unit cell of any compound of the series accommodates with high precision an integer number of approximately equal subcells. This explains a peculiar non-uniform variation of the unit cell parameters within the series and evidences that the interface between the galena-like modules, despite having a very different topology, approximately maintains the subperiodicity of the modules, and must therefore be subject to strong steric restrictions. It also implies that cations and anions occupy the nodes of the observed common underlying average sublattice according to a striking alternate cation/anion occupational modulation. This is the starting point for a description of these materials as modulated structures, which can make a proficient use of the approximate atomic positional non-crystallographic correlations caused by their modular character. Under this approach only four parameters suffice to define a realistic approximate model of any member of the series. A full structural characterization of any of the compounds only requires the determination of additional small/smooth modulations. As an example, the case of the {sup 7}P pavonite Ag{sub 3}Bi{sub 6.2}Pb{sub 0.8}S{sub 12}, is analyzed.

  8. Anal atresia, abnormal genitalia, and absent thumb: congenital malformations associated with mosaic ring chromosome 13.

    PubMed

    Ocak, Z; Ozlu, T; Vural, M

    2013-01-01

    Because of the deletion of a segment of the chromosome during the formation of a ring, several clinical findings may be associated with ring chromosomes. Ring chromosome 13 is one of such disorders in which the genotype-phenotype correlation is stronger by virtue of the accumulating literature. It can be associated with multiple congenital abnormalities and severe mental retardation. We report a case with mosaic ring chromosome 13 whose prenatal ultrasound revealed bilateral ventriculomegaly. Anal atresia, unidentifiable external genitalia, and an absent thumb were observed in the postmortem examination.

  9. Lateral facial cleft associated with accessory mandible having teeth, absent parotid gland and peripheral facial weakness.

    PubMed

    Ozçelik, D; Toplu, G; Türkseven, A; Senses, D A; Yiğit, B

    2014-07-01

    Transverse facial cleft is a very rare malformation. The Tessier no. 7 cleft is a lateral facial cleft which emanates from oral cavity and extends towards the tragus, involving both soft tissue and skeletal components. Here, we present a case having transverse facial cleft, accessory mandible having teeth, absent parotid gland and ipsilateral peripheral facial nerve weakness. After surgical repair of the cleft in 2-month of age, improvement of the facial nerve function was detected in 3-year of age. Resection of the accessory mandible was planned in 5-6 years of age.

  10. Profuse congenital familial milia with absent dermatoglyphics (Basan's Syndrome): description of a new family.

    PubMed

    Luna, Paula Carolina; Larralde, Margarita

    2012-01-01

    Milia are common, small, keratin-containing cysts frequently seen in all age groups. They may arise spontaneously or develop after a variety of stimuli. They can be found alone or as part of syndromes. We present a female neonate born not only with profuse facial milia, but also with acral bullae and absent dermatoglyphics. Similar features were seen in several members of her family. These findings correspond to the syndrome known as Basan's syndrome, a rare autosomal-dominant inherited dermatosis characterized by profuse congenital milia, transient neonatal acral bullae, and absence of dermatoglyphics.

  11. [Tetralogy of Fallot with absent pulmonary valve in a newborn and infant. Complete surgical correction].

    PubMed

    Cabrera Duro, A; Rodrigo Carbonero, D; Martínez Corrales, P; Aramendi Gallardo, J; Alcíbar Villa, J; López de Heredia Goya, J; Romero Ibarra, C

    2004-02-01

    We report two patients, a newborn and a 7-month old infant, with tetralogy of Fallot and absent pulmonary valve syndrome. Both had severe obstruction at the level of the ring with aneurysmal pulmonary artery branches, which compressed and displaced the trachea and main bronchial tubes. The neonate required mechanical ventilation from birth. Treatment was aggressive in both patients with interventricular septum defect closure, arterioplasty of the branches and homograft in the infant, and resection of the truncus and pulmonary branches with posterior face suture of both branches associated with a valved conduit in orthotopic position in the neonate. We believe that early treatment avoids airway degeneration and right ventricle volume overload.

  12. Diatom assemblage responses to changing environment in the conspicuously eutrophic Kiuruvesi lake route, central-eastern Finland

    NASA Astrophysics Data System (ADS)

    Tammelin, Mira; Kauppila, Tommi

    2016-04-01

    Lakes and their water quality have been affected by anthropogenic actions for centuries. The most intensive changes have often occurred since the mid-19th century. Industrialization, modern agriculture, forest ditching and artificial lowering of water level are examples of these changes that have usually resulted in the deterioration of lake water quality. Many organisms, such as diatoms, are sensitive to these changes in their environmental conditions. Therefore, a marked species turnover is often seen between the pre and post human impact diatom assemblages. This turnover can be rapidly assessed simultaneously from many lakes by using multivariate methods and top-bottom sampling. Our study area consists of three adjacent lake routes in the grass cultivation and dairy production area of central-eastern Finland, where slash-and-burn cultivation and artificial water level lowering were common practice during the past centuries. The centermost Iisalmi lake route is particularly interesting because of the conspicuously eutrophic lakes in its Kiuruvesi subroute. We used the top-bottom approach to sample pre and post human impact samples from 47 lakes (50 sampling sites) located in the three lake routes. In addition, stratigraphic samples from the long cores of three lakes (one larger central basin and two small upstream lakes) in the Kiuruvesi subroute were studied in more detail. Multivariate methods were used to assess diatom assemblage change within the long cores and between the pre-disturbance and modern samples. The results indicate that most study lakes have undergone a marked shift in their diatom assemblages since the onset of human impact in the area. The lake routes are characterized by differing pre-impact diatom assemblages. However, human influence has reduced their natural variation. Similar diatom species are common in the modern samples of the heavily impacted lakes in all three lake routes. The detailed examination of the diatom assemblage turnover in

  13. Group velocity mismatch-absent nonlinear frequency conversions for mid-infrared femtosecond pulses generation

    PubMed Central

    Zhong, Haizhe; Zhang, Lifu; Li, Ying; Fan, Dianyuan

    2015-01-01

    A novel group velocity mismatch (GVM) absent scheme for nonlinear optical parametric procedure in mid-infrared was developed with type-I quasi phase matching by use of an off-digital nonlinear optical coefficient d31. This was achieved by matching of the group velocities of the pump and the signal waves, while the phase velocities were quasi phase matched. The system employs MgO-doped periodically poled LiNbO3 as the nonlinear medium. Desired group-velocity dispersion would be obtained via appropriately temperature regulation. To demonstrate its potential applications in ultrafast mid-infrared pulses generation, aiming at a typical mid-infrared wavelength of ~3.2 μm, design examples of two basic nonlinear frequency conversion procedures are studied for both the narrow-band seeding mid-IR optical parametric amplification (OPA) and the synchronously pumped femtosecond optical parametric oscillation (SPOPO). Compared with the conventional scheme of type-0 QPM, the quantum-efficiency can be more than doubled with nearly unlimited bandwidth. The proposed GVM- absent phase matching design may provide a promising route to efficient and broadband sub-100 fs mid-infrared ultrafast pulses generation without group-velocity walk-off. PMID:26099837

  14. Distractor Dwelling, Skipping, and Revisiting Determine Target Absent Performance in Difficult Visual Search

    PubMed Central

    Horstmann, Gernot; Herwig, Arvid; Becker, Stefanie I.

    2016-01-01

    Some targets in visual search are more difficult to find than others. In particular, a target that is similar to the distractors is more difficult to find than a target that is dissimilar to the distractors. Efficiency differences between easy and difficult searches are manifest not only in target-present trials but also in target-absent trials. In fact, even physically identical displays are searched through with different efficiency depending on the searched-for target. Here, we monitored eye movements in search for a target similar to the distractors (difficult search) versus a target dissimilar to the distractors (easy search). We aimed to examine three hypotheses concerning the causes of differential search efficiencies in target-absent trials: (a) distractor dwelling (b) distractor skipping, and (c) distractor revisiting. Reaction times increased with target similarity which is consistent with existing theories and replicates earlier results. Eye movement data indicated guidance in target trials, even though search was very slow. Dwelling, skipping, and revisiting contributed to low search efficiency in difficult search, with dwelling being the strongest factor. It is argued that differences in dwell time account for a large amount of total search time differences. PMID:27574510

  15. Distractor Dwelling, Skipping, and Revisiting Determine Target Absent Performance in Difficult Visual Search.

    PubMed

    Horstmann, Gernot; Herwig, Arvid; Becker, Stefanie I

    2016-01-01

    Some targets in visual search are more difficult to find than others. In particular, a target that is similar to the distractors is more difficult to find than a target that is dissimilar to the distractors. Efficiency differences between easy and difficult searches are manifest not only in target-present trials but also in target-absent trials. In fact, even physically identical displays are searched through with different efficiency depending on the searched-for target. Here, we monitored eye movements in search for a target similar to the distractors (difficult search) versus a target dissimilar to the distractors (easy search). We aimed to examine three hypotheses concerning the causes of differential search efficiencies in target-absent trials: (a) distractor dwelling (b) distractor skipping, and (c) distractor revisiting. Reaction times increased with target similarity which is consistent with existing theories and replicates earlier results. Eye movement data indicated guidance in target trials, even though search was very slow. Dwelling, skipping, and revisiting contributed to low search efficiency in difficult search, with dwelling being the strongest factor. It is argued that differences in dwell time account for a large amount of total search time differences.

  16. Examining Clinicians' Experiences Providing Sexual Health Services for LGBTQ Youth: Considering Social and Structural Determinants of Health in Clinical Practice

    ERIC Educational Resources Information Center

    Knight, R. E.; Shoveller, J. A.; Carson, A. M.; Contreras-Whitney, J. G.

    2014-01-01

    Although barriers related to lesbian, gay, bisexual, transgender and queer (LGBTQ) youth's experiences accessing sexual health services have been examined in detail, research into the experiences and perceptions of clinicians providing these services has been conspicuously absent. The aim of this article is to explore the perceptions and…

  17. Functional analysis of the role of eyes absent and sine oculis in the developing eye of the cricket Gryllus bimaculatus.

    PubMed

    Takagi, Akira; Kurita, Kazuki; Terasawa, Taiki; Nakamura, Taro; Bando, Tetsuya; Moriyama, Yoshiyuki; Mito, Taro; Noji, Sumihare; Ohuchi, Hideyo

    2012-02-01

    In the cricket Gryllus bimaculatus, a hemimetabolous insect, the compound eyes begin to form in the embryo and increase 5-6 fold in size during the postembryonic development of the nymphal stage. Retinal stem cells in the anteroventral proliferation zone (AVPZ) of the nymphal eye proliferate to increase retinal progenitors, which then differentiate to form new ommatidia in the anterior region of the eye. However, mechanisms underlying this type of eye formation have not been well elucidated yet. Here, we found that the homologues of the retinal determination transcription factor genes of eyes absent (eya) and sine oculis (so) are expressed during the cricket embryonic eye formation. eya is also expressed intensely in the AVPZ of the nymphal eye. To explore their functions, we performed knockdown by RNA interference (RNAi). Knockdown of Gb'eya resulted in loss of the embryonic eye. In the nymphal eye, RNAi against Gb'eya or Gb'so impaired retinal morphology by apparently transforming cornea structures into head cuticle. These results imply that Gb'eya and Gb'so are essential for the differentiation of the retinal progenitor cells and maintaining retinal structures during eye development.

  18. Unrepaired Tetralogy of Fallot with Absent Pulmonary Valve in a Mildly Symptomatic 16-Year-Old Boy

    PubMed Central

    Drogalis-Kim, Diana E.; Reemtsen, Brian L.

    2016-01-01

    Absent pulmonary valve is a rare and severe variant seen in only 3% to 6% of patients with tetralogy of Fallot. Fetuses with this combined condition who survive through birth typically need intervention in infancy or early childhood because of respiratory distress, heart failure, or failure to thrive. We describe the unusual case of a mildly symptomatic 16-year-old boy with these conditions who underwent successful primary repair. Our search of the medical literature yielded fewer than 5 cases of tetralogy of Fallot with absent pulmonary valve (or variants with an absent left pulmonary artery) and survival without repair into later adolescence or adulthood. PMID:28100972

  19. Computerized axial tomography of the chest for visualization of ''absent'' pulmonary arteries

    SciTech Connect

    Sondheimer, H.M.; Oliphant, M.; Schneider, B.; Kavey, R.E.W.; Blackman, M.S.; Parker, F.B. Jr.

    1982-05-01

    To expand the search for central pulmonary arteries in six patients with absence of cardiac-pulmonary continuity, computerized axial tomography (CAT) of the chest was performed. The CAT scans were compared with previous arteriograms and pulmonary vein wedge angiograms. Three patients with type IV truncus arteriosus were studied, and none had a central, right or left pulmonary artery on CAT scan. However, two patients with tetralogy of Fallot with pulmonary atresia and a patent ductus arteriosus to the right lung demonstrated the presence of a left pulmonary artery. In addition, one child with truncus arteriosus with ''absent'' left pulmonary artery demonstrated a left pulmonary artery on the CAT scan. The CAT scan may therefore enhance our ability to search for disconnected pulmonary arteries in children with complex cyanotic congenital heart disease.

  20. Absent or reversed end diastolic flow velocity in the umbilical artery and necrotising enterocolitis.

    PubMed Central

    Malcolm, G; Ellwood, D; Devonald, K; Beilby, R; Henderson-Smart, D

    1991-01-01

    Absent or reversed end diastolic flow (AREDF) velocities in the umbilical artery were identified in 25 high risk pregnancies. In six pregnancies the fetus was abnormal and all but one of these ended in perinatal death. Of the 19 morphologically normal fetuses, three died in utero and there were four neonatal or infant deaths. The mortality rate was 48% for all pregnancies and 37% for those with morphologically normal fetuses. There was a highly significant increased risk for the development of necrotising enterocolitis in these morphologically normal fetuses with AREDF (53%) compared with controls (6%) who did have umbilical artery end diastolic flow velocities in fetal life. There were no significant differences between the matched pairs for parameters of neonatal outcome chosen to reflect neonatal morbidity. These findings demonstrate the close association between AREDF and necrotising enterocolitis that appears to be independent of other variables such as degree of growth retardation, prematurity, and perinatal asphyxia. PMID:1863128

  1. Ejaculatory ducts opening into accessory urethral channel with hypospadias and absent verumontanum: a rare association.

    PubMed

    Ravi Kumar, Valkodai Ramanthan; Duraisami, Vijayagiri

    2013-12-01

    Ejaculatory ducts draining into accessory urethral channel opening into perineum is rare. This is a case report of a 27-year-old male who had hypospadias surgery at 3 years of age, presenting with discharge of semen through the perineal opening from adolescence. Cystoscopy and dye study showed that it was a short channel communicating with both ejaculatory ducts. Cystoscopy of the native urethra revealed that the vermontanum had not developed. The mucous lined accessory urethra was anastomosed to the bulbar urethra. Urethrogram done after one year showed that the accessory urethra was draining well into the bulbar urethra. Such type of accessory urethral channel communicating with ejaculatory ducts and associated with hypospadias and absent vermontanum has not been reported so far.

  2. Delayed emergence from anesthesia associated with absent brainstem reflexes following suboccipital craniotomy.

    PubMed

    Munis, James R; Marcukaitis, Anthony W; Sprung, Juraj

    2006-01-01

    One of the most feared complications after intracranial surgery is development of acute intracranial pathology, which may result in hypoperfusion and brain injury. Thus, early neurological assessment, performed in the operating room immediately after emergence from anesthesia, is a practice that may contribute to timely diagnosis of neurosurgical complications. Failure to awake after general anesthesia precludes conductance of neurological assessment. We report a patient who failed to emerge from anesthesia after suboccipital craniotomy and had absent brain-stem reflexes with fixed and dilated pupils consistent with severe brain injury. Approximately 60 minutes after termination of surgery, the patient suddenly woke up. After the fact, we discovered that the neurosurgeon performed a generous field block with bupivacaine along the neck incision line. We presume that our patient's failure to awaken was caused by paralysis of brain-stem caused by migration of bupivacaine from the site of the injection.

  3. Silent dropouts in health surveys: are nonrespondent absent teenagers different from those who participate in school-based health surveys?

    PubMed

    Michaud, P A; Delbos-Piot, I; Narring, F

    1998-04-01

    3324 in-school students aged 15-20 years randomly selected from high schools and professional centers in francophone Switzerland answered a self-administered questionnaire about their health problems, needs, and behavior. Their responses were compared with those of 96 absent students sampled via telephone on a shorter, but similar questionnaire. Relative to the absent students, a significantly higher percentage of in-school students reported skin problems, weight concerns, sleep problems, headaches, stomach aches, and vision or dental problems. The percentages of students reporting a need for help were also higher among present students than among those who were absent: nutrition, 21.8 vs. 9.4; stress, 44.2 vs. 31.3; depression, 28.4 vs. 18.9; sleep problems, 21.3 vs. 12.1; sports, 9.2 vs. 4.2; and love life, 31.5 vs. 14.5. The rates of hospitalization and injuries were lower among absent students, 28.2 vs. 40.1. A higher proportion of absent students were sexually active and they also had a tendency to use tobacco, alcohol, and cannabis more often than did present students. Absent students also more frequently partook of leisure and group activities. Study findings suggest that within the Swiss context, school absenteeism is probably related less to physical or chronic health problems than to hedonistic lifestyles which predispose some students skip part of the school hours.

  4. Once a Batesian mimic, not always a Batesian mimic: mimic reverts back to ancestral phenotype when the model is absent.

    PubMed

    Prudic, Kathleen L; Oliver, Jeffrey C

    2008-05-22

    Batesian mimics gain protection from predation through the evolution of physical similarities to a model species that possesses anti-predator defences. This protection should not be effective in the absence of the model since the predator does not identify the mimic as potentially dangerous and both the model and the mimic are highly conspicuous. Thus, Batesian mimics should probably encounter strong predation pressure outside the geographical range of the model species. There are several documented examples of Batesian mimics occurring in locations without their models, but the evolutionary responses remain largely unidentified. A mimetic species has four alternative evolutionary responses to the loss of model presence. If predation is weak, it could maintain its mimetic signal. If predation is intense, it is widely presumed the mimic will go extinct. However, the mimic could also evolve a new colour pattern to mimic another model species or it could revert back to its ancestral, less conspicuous phenotype. We used molecular phylogenetic approaches to reconstruct and test the evolution of mimicry in the North American admiral butterflies (Limenitis: Nymphalidae). We confirmed that the more cryptic white-banded form is the ancestral phenotype of North American admiral butterflies. However, one species, Limenitis arthemis, evolved the black pipevine swallowtail mimetic form but later reverted to the white-banded more cryptic ancestral form. This character reversion is strongly correlated with the geographical absence of the model species and its host plant, but not the host plant distribution of L. arthemis. Our results support the prediction that a Batesian mimic does not persist in locations without its model, but it does not go extinct either. The mimic can revert back to its ancestral, less conspicuous form and persist.

  5. Molecular genetic analysis of Drosophila eyes absent mutants reveals an eye enhancer element.

    PubMed Central

    Zimmerman, J E; Bui, Q T; Liu, H; Bonini, N M

    2000-01-01

    The eyes absent (eya) gene is critical for normal eye development in Drosophila and is highly conserved to vertebrates. To define regions of the gene critical for eye function, we have defined the mutations in the four viable eya alleles. Two of these mutations are eye specific and undergo transvection with other mutations in the gene. These were found to be deletion mutations that remove regulatory sequence critical for eye cell expression of the gene. Two other viable alleles cause a reduced eye phenotype and affect the function of the gene in additional tissues, such as the ocelli. These mutations were found to be insertion mutations of different transposable elements within the 5' UTR of the transcript. Detailed analysis of one of these revealed that the transposable element has become subject to regulation by eye enhancer sequences of the eya gene, disrupting normal expression of EYA in the eye. More extended analysis of the deletion region in the eye-specific alleles indicated that the deleted region defines an enhancer that activates gene expression in eye progenitor cells. This enhancer is responsive to ectopic expression of the eyeless gene. This analysis has defined a critical regulatory region required for proper eye expression of the eya gene. PMID:10628984

  6. Molecular analysis of Drosophila eyes absent mutants reveals features of the conserved Eya domain.

    PubMed Central

    Bui, Q T; Zimmerman, J E; Liu, H; Bonini, N M

    2000-01-01

    The eyes absent (eya) gene is critical to eye formation in Drosophila; upon loss of eya function, eye progenitor cells die by programmed cell death. Moreover, ectopic eya expression directs eye formation, and eya functionally synergizes in vivo and physically interacts in vitro with two other genes of eye development, sine oculis and dachshund. The Eya protein sequence, while highly conserved to vertebrates, is novel. To define amino acids critical to the function of the Eya protein, we have sequenced eya alleles. These mutations have revealed that loss of the entire Eya Domain is null for eya activity, but that alleles with truncations within the Eya Domain display partial function. We then extended the molecular genetic analysis to interactions within the Eya Domain. This analysis has revealed regions of special importance to interaction with Sine Oculis or Dachshund. Select eya missense mutations within the Eya Domain diminished the interactions with Sine Oculis or Dachshund. Taken together, these data suggest that the conserved Eya Domain is critical for eya activity and may have functional subregions within it. PMID:10835393

  7. Identification of Transcriptional Targets of the Dual Function Transcription Factor/Phosphatase Eyes Absent

    PubMed Central

    Jemc, Jennifer; Rebay, Ilaria

    2007-01-01

    Drosophila eye specification and development relies on a collection of transcription factors termed the retinal determination gene network (RDGN). Two members of this network, Eyes absent (EYA) and Sine oculis (SO), form a transcriptional complex in which EYA provides the transactivation function while SO provides the DNA binding activity. EYA also functions as a protein tyrosine phosphatase, raising the question of whether transcriptional output is dependent or independent of phosphatase activity. To explore this, we used microarrays together with binding site analysis, quantitative real-time PCR, chromatin immunoprecipitation, genetics and in vivo expression analysis to identify new EYA-SO targets. In parallel, we examined the expression profiles of tissue expressing phosphatase mutant eya and found that reducing phosphatase activity did not globally impair transcriptional output. Among the targets identified by our analysis was the cell cycle regulatory gene, string (stg), suggesting that EYA and SO may influence cell proliferation through transcriptional regulation of stg. Future investigation into the regulation of stg and other EYA-SO targets identified in this study will help elucidate the transcriptional circuitries whereby output from the RDGN integrates with other signaling inputs to coordinate retinal development. PMID:17714699

  8. Terminal hemimelia of the lower extremity: absent lateral ray and a normal fibula

    PubMed Central

    Kim, Jae Kwang; Chung, Moon Sang; Lee, Sang Ki

    2007-01-01

    Congenital lateral ray deficiency is considered to be a manifestation of fibular hemimelia. However, we have noted patients with absent lateral ray but stable knee and ankle joints, and named this condition terminal hemimelia of the lower extremity. This study was undertaken to further define this group of patients and to compare these patients with fibular hemimelia patients. Four boys and one girl of mean age six years two months were in the terminal hemimelic group and four boys and three girls of mean age eight years seven months in the fibular hemimelic group at the final evaluation. Clinical features commonly observed in the fibular hemimelia such as knee valgus, knee instability, tibial bowing, ball and socket ankle, ankle instability, tarsal coalition, leg length inequality were compared between both groups. Terminal hemimelia of the lower extremity was the same as fibular hemimelia in clinical features below the ankle joint. However, terminal hemimela was found to be milder than fibular hemimelia in terms of limb shortening. The clinical features above the ankle joint were different between both groups. Knees and ankles were stable, and gait disturbance were rarely noticed in patients with terminal hemimelia of the lower extremity. PMID:17558505

  9. Effect of absent end diastolic flow velocity in the fetal umbilical artery on subsequent outcome

    PubMed Central

    Adiotomre, P.; Johnstone, F.; Laing, I.

    1997-01-01

    Sixty babies, delivered over a six and a half year period, who had absent end diastolic frequency (AEDF) in the umbilical artery, were studied. Individually matched control pregnancies for gestational age, birthweight, maternal clinical condition and date of delivery, in whom umbilical artery recordings showed end diastolic frequency, were also studied.
  Matching was achieved in 36 cases. Neonates from case pregnancies showed no increase in necrotising enterocolitis, intraventricular haemorrhage, pneumo-thorax, neonatal death or bronchopulmonary dysplasia. However, they were significantly less likely to require ventilation for respiratory distress syndrome (P=0.02).
  Although AEDF indicates a fetus under vascular stress, this finding alone will include a spectrum of response in the baby, from the well compensated to the irreversibly damaged. Delivery at different points in the deteriorating fetal environment may explain discrepant study results. This intrauterine stress, by increasing fetal corticosteroid and thyroid hormones, may account for enhanced lung maturity. Predictions of neonatal course need to be based on more comprehensive awareness of fetal status.

 Keywords: high risk pregnancies; end diastolic flow velocity; ventilation; respiratory distress syndrome. PMID:9059184

  10. Axillary Meristem Formation in Rice Requires the WUSCHEL Ortholog TILLERS ABSENT1[OPEN

    PubMed Central

    Tanaka, Wakana; Ohmori, Yoshihiro; Ushijima, Tomokazu; Matsusaka, Hiroaki; Matsushita, Tomonao; Kumamaru, Toshihiro; Kawano, Shigeyuki; Hirano, Hiro-Yuki

    2015-01-01

    Axillary shoot formation is a key determinant of plant architecture. Formation of the axillary shoot is regulated by initiation of the axillary meristem or outgrowth of the axillary bud. Here, we show that rice (Oryza sativa) TILLERS ABSENT1 (TAB1; also known as Os WUS), an ortholog of Arabidopsis thaliana WUS, is required to initiate axillary meristem development. We found that formation of the axillary meristem in rice proceeds via a transient state, which we term the premeristem, characterized by the expression of OSH1, a marker of indeterminate cells in the shoot apical meristem. In the tab1-1 (wus-1) mutant, however, formation of the axillary meristem is arrested at various stages of the premeristem zone, and OSH1 expression is highly reduced. TAB1/WUS is expressed in the premeristem zone, where it shows a partially overlapping pattern with OSH1. It is likely, therefore, that TAB1 plays an important role in maintaining the premeristem zone and in promoting the formation of the axillary meristem by promoting OSH1 expression. Temporal expression patterns of WUSCHEL-RELATED HOMEOBOX4 (WOX4) indicate that WOX4 is likely to regulate meristem maintenance instead of TAB1 after establishment of the axillary meristem. Lastly, we show that the prophyll, the first leaf in the secondary axis, is formed from the premeristem zone and not from the axillary meristem. PMID:25841039

  11. Antibiotics conspicuously affect community profiles and richness, but not the density of bacterial cells associated with mucosa in the large and small intestines of mice.

    PubMed

    Puhl, Nathan J; Uwiera, Richard R E; Yanke, L Jay; Selinger, L Brent; Inglis, G Douglas

    2012-02-01

    The influence of three antibiotics (bacitracin, enrofloxacin, and neomycin sulfate) on the mucosa-associated enteric microbiota and the intestines of mice was examined. Antibiotics caused conspicuous enlargement of ceca and an increase in overall length of the intestine. However, there were no pathologic changes associated with increased cecal size or length of the intestine. Conspicuous reductions in the richness of mucosa-associated bacteria and changes to community profiles within the small (duodenum, proximal jejunum, middle jejunum, distal jejunum, and ileum) and large (cecum, ascending colon, and descending colon) intestine occurred in mice administered antibiotics. Communities in antibiotic-treated mice were dominated by a limited number of Clostridium-like (i.e. clostridial cluster XIVa) and Bacteroides species. The richness of mucosa-associated communities within the small and large intestine increased during the 14-day recovery period. However, community profiles within the large intestine did not return to baseline (i.e. relative to the control). Although antibiotic administration greatly reduced bacterial richness, densities of mucosa-associated bacteria were not reduced correspondingly. These data showed that the antibiotics, bacitracin, enrofloxacin, and neomycin sulfate, administered for 21 days to mice did not sterilize the intestine, but did impart a tremendous and prolonged impact on mucosa-associated bacterial communities throughout the small and large intestine.

  12. What explains rare and conspicuous colours in a snail? A test of time-series data against models of drift, migration or selection

    PubMed Central

    Johannesson, K; Butlin, R K

    2017-01-01

    It is intriguing that conspicuous colour morphs of a prey species may be maintained at low frequencies alongside cryptic morphs. Negative frequency-dependent selection by predators using search images (‘apostatic selection') is often suggested without rejecting alternative explanations. Using a maximum likelihood approach we fitted predictions from models of genetic drift, migration, constant selection, heterozygote advantage or negative frequency-dependent selection to time-series data of colour frequencies in isolated populations of a marine snail (Littorina saxatilis), re-established with perturbed colour morph frequencies and followed for >20 generations. Snails of conspicuous colours (white, red, banded) are naturally rare in the study area (usually <10%) but frequencies were manipulated to levels of ~50% (one colour per population) in 8 populations at the start of the experiment in 1992. In 2013, frequencies had declined to ~15–45%. Drift alone could not explain these changes. Migration could not be rejected in any population, but required rates much higher than those recorded. Directional selection was rejected in three populations in favour of balancing selection. Heterozygote advantage and negative frequency-dependent selection could not be distinguished statistically, although overall the results favoured the latter. Populations varied idiosyncratically as mild or variable colour selection (3–11%) interacted with demographic stochasticity, and the overall conclusion was that multiple mechanisms may contribute to maintaining the polymorphisms. PMID:27649616

  13. Late outcomes for the surgical management of absent pulmonary valve syndrome in infants

    PubMed Central

    Hu, Renjie; Zhang, Haibo; Xu, Zhiwei; Liu, Jinfen; Su, Zhaokang; Ding, Wenxiang

    2013-01-01

    OBJECTIVES Absent pulmonary valve syndrome (APVS) is a rare cardiac malformation that is usually associated with aneurysmal dilatation of pulmonary arteries and respiratory distress. The surgical mortality of neonates and infants with APVS has decreased tremendously, from 60% in 1980s to 10–20% recently. This study retrospectively reviews surgical outcomes of our 10-year experience in patients with APVS. METHODS From 2002 to 2012, 42 patients with APVS underwent surgical correction. Thirty-seven patients had APVS as a variant of tetralogy of Fallot, 4 with double outlet right ventricle and 1 with ventricular septal defect. Respiratory distress was present in 12 infants. Four patients needed continuous positive airway pressure and 5 required intubation with mechanical ventilation before surgery. RESULTS There was no hospital death and 3 late deaths. The mean follow-up time was 62.71 ± 34.31 months. Significant differences were found in the duration of postoperative ventilation between patients with or without respiratory distress (P = 0.009) and patients with left or right aortic arch (P = 0.012). The Kaplan–Meier curve indicated that overall survival at 5 and 10 years was 92.4%. The survival rates between patients with or without respiratory distress were 72.7 and 100%, respectively (P = 0.003). Overall mortality was associated with longer cardiopulmonary bypass time (P = 0.004) and lower weight at operation (P = 0.042). There were no significant differences in survival and postoperative data such as the duration of ventilation or intensive care unit stay and New York Heart Association class among the three methods of right ventricular outflow tract (RVOT) reconstruction. CONCLUSIONS Surgical treatment of APVS has got favourable outcomes in terms of mortality and reoperation rate. Different methods of RVOT reconstruction do not affect the surgical outcome. Patients required long-term follow-up for postoperative respiratory complications secondary to persistent

  14. Is CFTR-delF508 Really Absent from the Apical Membrane of the Airway Epithelium?

    PubMed Central

    Borthwick, Lee A.; Botha, Phil; Verdon, Bernard; Brodlie, Malcolm J.; Gardner, Aaron; Bourn, David; Johnson, Gail E.

    2011-01-01

    Background Understanding where mutant CFTR is localised in airway epithelia is essential in guiding the best therapeutic approach to correct the dysfunction of the CFTR protein. The widely held paradigm is that CF patients harbouring the commonest mutation, CFTR-delF508, trap CFTR within the endoplasmic reticulum and target it for degradation. However there are conflicting reports concerning expression and localisation of CFTR-delF508 in lung tissue. To attempt to resolve this fundamental issue we developed a novel approach to measure CFTR-delF508 in the lower airways of patients who have undergone lung transplantation for advanced CF. By sampling CF and non-CF epithelium simultaneously from the same individual, confounding factors of different airway microenvironments which may have influenced previous observations can be overcome. Methods Epithelia sampled by bronchial brushing above (CF) and below (non-CF) the bronchial anastomosis were stained for CFTR and the localisation and level of expression assessed (n = 12). Results There was no significant difference in the proportion of tall columnar cells showing CFTR immunostaining as a discrete band at the apical membrane in cells harbouring the CFTR-delF508 mutation compared to non-CF cells (p = 0.21, n = 12). However, the amount of CFTR expressed at the apical surface was reduced by ∼50% in CF cells compared to non-CF cells (p = 0.04, n = 5). Conclusions Our novel observation challenges the prevailing paradigm that CFTR is essentially absent from the apical membrane of respiratory cells harbouring the CFTR-delF508 mutation. Moreover, it raises the possibility that the new generation of CFTR potentiators may offer a realistic therapeutic option for CF patients. PMID:21826241

  15. Duck TRIM27-L enhances MAVS signaling and is absent in chickens and turkeys.

    PubMed

    Blaine, Alysson H; Miranzo-Navarro, Domingo; Campbell, Lee K; Aldridge, Jerry R; Webster, Robert G; Magor, Katharine E

    2015-10-01

    Wild waterfowl, including mallard ducks, are the natural reservoir of avian influenza A virus and they are resistant to strains that would cause fatal infection in chickens. Here we investigate potential involvement of TRIM proteins in the differential response of ducks and chickens to influenza. We examine a cluster of TRIM genes located on a single scaffold in the duck genome, which is a conserved synteny group with a TRIM cluster located in the extended MHC region in chickens and turkeys. We note a TRIM27-like gene is present in ducks, and absent in chickens and turkeys. Orthologous genes are predicted in many birds and reptiles, suggesting the gene has been lost in chickens and turkeys. Using quantitative real-time PCR (qPCR) we show that TRIM27-L, and the related TRIM27.1, are upregulated 5- and 9-fold at 1 day post-infection with highly pathogenic A/Vietnam/1203/2004. To assess whether TRIM27.1 or TRIM27-L are involved in modulation of antiviral gene expression, we overexpressed them in DF1 chicken cells, and neither show any direct effect on innate immune gene expression. However, when co-transfected with duck RIG-I-N (d2CARD) to constitutively activate the MAVS pathway, TRIM27.1 weakly decreases, while TRIM27-L strongly activates innate immune signaling leading to increased transcription of antiviral genes MX1 and IFN-β. Furthermore, when both are co-expressed, the activation of the MAVS signaling pathway by TRIM27-L over-rides the inhibition by TRIM27.1. Thus, ducks have an activating TRIM27-L to augment MAVS signaling following RIG-I detection, while chickens lack both TRIM27-L and RIG-I itself.

  16. Femoral hypoplasia-unusual facies syndrome with bifid hallux, absent tibia, and macrophallus: a report of a Bedouin baby.

    PubMed Central

    Sabry, M A; Obenbergerova, D; Al-Sawan, R; Saleh, Q A; Farah, S; Al-Awadi, S A; Farag, T I

    1996-01-01

    A male Bedouin baby with the clinical profile of femoral hypoplasia-unusual facies syndrome is described. The phenotype includes bilateral asymmetrical lower limb hypoplasia/aplasia with short remnants of both femora, absent right tibia, bifid right big toe, dysmorphic facies, thoracic/pelvic abnormalities, macrophallus, and bilateral cryptorchidism. This report re-emphasises the previously described rare association of femoral hypoplasia-unusual facies syndrome with preaxial polydactyly and suggests that the clinical spectrum of the syndrome could be stretched further to accommodate other unusual traits, for example, macrophallus and absent tibia. Images PMID:8929957

  17. 1H–NMR Metabolomic Biomarkers of Poor Outcome after Hemorrhagic Shock are Absent in Hibernators

    PubMed Central

    Bogren, Lori K.; Murphy, Carl J.; Johnston, Erin L.; Sinha, Neeraj; Serkova, Natalie J.; Drew, Kelly L.

    2014-01-01

    rats. These same biomarkers are absent in AGS after HS with warm I/R. PMID:25211248

  18. Deficits of Semantic Control Produce Absent or Reverse Frequency Effects in Comprehension: Evidence from Neuropsychology and Dual Task Methodology

    ERIC Educational Resources Information Center

    Almaghyuli, Azizah; Thompson, Hannah; Lambon Ralph, Matthew A.; Jefferies, Elizabeth

    2012-01-01

    Patients with multimodal semantic impairment following stroke (referred to here as "semantic aphasia" or SA) fail to show the standard effects of frequency in comprehension tasks. Instead, they show absent or even "reverse" frequency effects: i.e., better understanding of less common words. In addition, SA is associated with poor regulatory…

  19. The Concept of the Absent Curriculum: The Case of the Muslim Contribution and the English National Curriculum for History

    ERIC Educational Resources Information Center

    Wilkinson, Matthew L. N.

    2014-01-01

    This paper introduces the concept of the "absent curriculum" on the premise that the study of curriculum has been prone to privileging curricular presence to the exclusion of curricular absence. In order to address this imbalance and to articulate a theory of absence in the curriculum, the paper applies ideas derived from the philosophy…

  20. Crystallization and preliminary X-ray crystallographic investigations on a βγ-crystallin domain of absent in melanoma 1 (AIM1), a protein from Homo sapiens

    SciTech Connect

    Aravind, Penmatsa; Rajini, Bheemreddy; Sharma, Yogendra; Sankaranarayanan, Rajan

    2006-03-01

    The crystallization and preliminary X-ray diffraction analysis of AIM1g1, a βγ-crystallin domain of absent in melanoma (AIM1) protein from H. sapiens, is reported. AIM1g1 is a single βγ-crystallin domain from the protein absent in melanoma 1 (AIM1), which appears to play a role in the suppression of melanomas. This domain is known to bind calcium and its structure would help in identifying calcium-coordinating sites in vertebrate crystallins, which have hitherto been believed to have lost this ability during evolution. Crystallization of this domain was performed by the hanging-drop vapour-diffusion method. Crystals diffracted to a maximum resolution of 1.86 Å and were found to belong to space group P6{sub 1} or P6{sub 5}, with unit-cell parameters a = b = 54.98, c = 59.73 Å. Solvent-content analysis indicated the presence of one monomer per asymmetric unit.

  1. A highly conspicuous mineralized composite photonic architecture in the translucent shell of the blue-rayed limpet.

    PubMed

    Li, Ling; Kolle, Stefan; Weaver, James C; Ortiz, Christine; Aizenberg, Joanna; Kolle, Mathias

    2015-02-26

    Many species rely on diverse selections of entirely organic photonic structures for the manipulation of light and the display of striking colours. Here we report the discovery of a mineralized hierarchical photonic architecture embedded within the translucent shell of the blue-rayed limpet Patella pellucida. The bright colour of the limpet's stripes originates from light interference in a periodically layered zig-zag architecture of crystallographically co-oriented calcite lamellae. Beneath the photonic multilayer, a disordered array of light-absorbing particles provides contrast for the blue colour. This unique mineralized manifestation of a synergy of two distinct optical elements at specific locations within the continuum of the limpet's translucent protective shell ensures the vivid shine of the blue stripes, which can be perceived under water from a wide range of viewing angles. The stripes' reflection band coincides with the spectral range of minimal light absorption in sea water, raising intriguing questions regarding their functional significance.

  2. Effect of surface structure on the dynamic magnetic response in Ni-Zn ferrite nanoparticles

    NASA Astrophysics Data System (ADS)

    Poddar, P.; Swaminathan, R.

    2005-03-01

    Surface magnetic spin structure plays a dominant role in determining the effective anisotropy in magnetic nanostructures. To probe the anisotropy in nanoparticle systems, we have developed an RF transverse susceptibility technique based on a resonant tunnel-diode oscillator (TDO). Transverse susceptibility measurements were performed on NiZn ferrite nanoparticles (synthesized using a RF induction plasma torch) over a wide temperature range (10K to 300K) and magnetic fields (-10kOe to 10kOe). As-synthesized polydisperse nanoparticles showed broad peaks at the characteristic anisotropy fields that are attributed to the presence of both the (100) and (111) surfaces and their respective surface anisotropy contributions. The peak positions and heights were found to be sensitive to the particle size dispersion and surface magnetic spin structure. The polydisperse particles were coated with oleic acid and size-selected using ultra-centrifugation. The anisotropy peaks are conspicuously absent in the size-selected smaller nanoparticles. This is understood within the framework of a surface structure model based on isotropic canted triangular spin structures on the dominant (111) surfaces in the smallest nanoparticles. Work at USF supported by NSF through Grant No. CTS-0408933. RS and MEM thank the Institute of Complex Engineering Systems (ICES), CMU for support.

  3. A highly conspicuous mineralized composite photonic architecture in the translucent shell of the blue-rayed limpet

    PubMed Central

    Li, Ling; Kolle, Stefan; Weaver, James C.; Ortiz, Christine; Aizenberg, Joanna; Kolle, Mathias

    2015-01-01

    Many species rely on diverse selections of entirely organic photonic structures for the manipulation of light and the display of striking colours. Here we report the discovery of a mineralized hierarchical photonic architecture embedded within the translucent shell of the blue-rayed limpet Patella pellucida. The bright colour of the limpet’s stripes originates from light interference in a periodically layered zig-zag architecture of crystallographically co-oriented calcite lamellae. Beneath the photonic multilayer, a disordered array of light-absorbing particles provides contrast for the blue colour. This unique mineralized manifestation of a synergy of two distinct optical elements at specific locations within the continuum of the limpet’s translucent protective shell ensures the vivid shine of the blue stripes, which can be perceived under water from a wide range of viewing angles. The stripes’ reflection band coincides with the spectral range of minimal light absorption in sea water, raising intriguing questions regarding their functional significance. PMID:25716102

  4. A highly conspicuous mineralized composite photonic architecture in the translucent shell of the blue-rayed limpet

    DOE PAGES

    Li, Ling; Kolle, Stefan; Weaver, James C.; ...

    2015-02-26

    Many species rely on diverse selections of entirely organic photonic structures for the manipulation of light and the display of striking colours. Here we report the discovery of a mineralized hierarchical photonic architecture embedded within the translucent shell of the blue-rayed limpet Patella pellucida. The bright colour of the limpet’s stripes originates from light interference in a periodically layered zig-zag architecture of crystallographically co-oriented calcite lamellae. Beneath the photonic multilayer, a disordered array of light-absorbing particles provides contrast for the blue colour. This unique mineralized manifestation of a synergy of two distinct optical elements at specific locations within the continuummore » of the limpet’s translucent protective shell ensures the vivid shine of the blue stripes, which can be perceived under water from a wide range of viewing angles. The stripes’ reflection band coincides with the spectral range of minimal light absorption in sea water, raising intriguing questions regarding their functional significance.« less

  5. A highly conspicuous mineralized composite photonic architecture in the translucent shell of the blue-rayed limpet

    SciTech Connect

    Li, Ling; Kolle, Stefan; Weaver, James C.; Ortiz, Christine; Aizenberg, Joanna; Kolle, Mathias

    2015-02-26

    Many species rely on diverse selections of entirely organic photonic structures for the manipulation of light and the display of striking colours. Here we report the discovery of a mineralized hierarchical photonic architecture embedded within the translucent shell of the blue-rayed limpet Patella pellucida. The bright colour of the limpet’s stripes originates from light interference in a periodically layered zig-zag architecture of crystallographically co-oriented calcite lamellae. Beneath the photonic multilayer, a disordered array of light-absorbing particles provides contrast for the blue colour. This unique mineralized manifestation of a synergy of two distinct optical elements at specific locations within the continuum of the limpet’s translucent protective shell ensures the vivid shine of the blue stripes, which can be perceived under water from a wide range of viewing angles. The stripes’ reflection band coincides with the spectral range of minimal light absorption in sea water, raising intriguing questions regarding their functional significance.

  6. Cytochrome 572 is a conspicuous membrane protein with iron oxidation activity purified directly from a natural acidophilic microbial community

    SciTech Connect

    Verberkmoes, Nathan C; Singer, Steven; Shah, Manesh B; Thelen, Michael P.; Hettich, Robert {Bob} L; Banfield, Jillian F.

    2008-01-01

    We have discovered and characterized a novel membrane cytochrome of an iron oxidizing microbial biofilm obtained from the surface of extremely acidic mine water. This protein was initially identified through proteogenomic analysis as one of many novel gene products of Leptospirillum group II, the dominant bacterium of this community (Ram et al, 2005, Science 308, 1915-20). Extraction of proteins directly from environmental biofilm samples followed by membrane fractionation, detergent solubilization and gel filtration chromatography resulted in the purification of an abundant yellow-red protein. Covalently bound to heme, the purified cytochrome has a unique spectral signature at 572 nm and is thus called Cyt572. It readily oxidizes Fe2+ even in the presence of Fe3+ over a pH range from 0.95 to 3.4. Independent experiments involving 2D blue-native polyacrylamide gel electrophoresis and chemical crosslinking establish a homotetrameric structure for Cyt572. Also, circular dichroism spectroscopy indicates that the protein is largely beta-stranded, consistent with an outer membrane location. Although no significant sequence homology to the full-length cytochrome is detected in protein databases, environmental DNA sequences from both Leptospirillum groups II and III reveal at least 17 strain variants of Cyt572. Due to its abundance, cellular location and Fe2+ oxidation activity, we propose Cyt572 is the iron oxidase of the Leptospirillum bacteria, providing a critical function for fitness within the ecological niche of this acidophilic microbial community.

  7. Fetal MRI correlates with postnatal CT angiogram assessment of pulmonary anatomy in tetralogy of Fallot with absent pulmonary valve.

    PubMed

    Sun, Heather Y; Boe, Justin; Rubesova, Erika; Barth, Richard A; Tacy, Theresa A

    2014-01-01

    In tetralogy of Fallot with absent pulmonary valve, pulmonary stenosis and regurgitation results in significant pulmonary artery dilatation. Branch pulmonary artery dilatation often compresses the tracheobronchial tree, causing fluid trapping in fetal life and air trapping and/or atelectasis after birth. Prenatal diagnosis predicts poor prognosis, which depends on the degree of respiratory insufficiency from airway compromise and lung parenchymal disease after birth. Fetal magnetic resonance imaging (MRI) has been useful in evaluating the effects of congenital lung lesions on lung development and indicating severity of pulmonary hypoplasia. This report is the first demonstrating the utility of fetal MRI in tetralogy of Fallot/absent pulmonary valve patients, which predicted postnatal pulmonary artery size and visualized airway compression and lung parenchymal lesions. The distribution of lobar fluid trapping on fetal MRI correlated with air trapping on postnatal computed tomography angiogram.

  8. Crystallization and preliminary X-ray crystallographic investigations on a betagamma-crystallin domain of absent in melanoma 1 (AIM1), a protein from Homo sapiens.

    PubMed

    Aravind, Penmatsa; Rajini, Bheemreddy; Sharma, Yogendra; Sankaranarayanan, Rajan

    2006-03-01

    AIM1g1 is a single betagamma-crystallin domain from the protein absent in melanoma 1 (AIM1), which appears to play a role in the suppression of melanomas. This domain is known to bind calcium and its structure would help in identifying calcium-coordinating sites in vertebrate crystallins, which have hitherto been believed to have lost this ability during evolution. Crystallization of this domain was performed by the hanging-drop vapour-diffusion method. Crystals diffracted to a maximum resolution of 1.86 A and were found to belong to space group P6(1) or P6(5), with unit-cell parameters a = b = 54.98, c = 59.73 A. Solvent-content analysis indicated the presence of one monomer per asymmetric unit.

  9. Echinorhynchus salmonis Müller, 1784 absent in Britain and Ireland: re-identification of museum specimens.

    PubMed

    Chubb, James C

    2004-03-01

    Collections of 'Echinorhynchus salmonis' from Britain and Ireland deposited in The Natural History Museum, London (1921.7.19.3-12 and 1952.10.30.122-127) were re-identified as Acanthocephalus clavula and Acanthocephalus lucii respectively. The amphipod, Pontoporeia affinis, European intermediate host of E. salmonis, does not occur in the British Isles, so it is concluded that E. salmonis is absent from British and Irish freshwater fishes.

  10. American Art of Conspicuous Recycling.

    ERIC Educational Resources Information Center

    Gomez, Aurelia

    1999-01-01

    Characterizes the use of recycling "junk" as a means for creating art by exploring various recycling traditions that are present in the United States. Demonstrates to students that "junk" can be fashioned into beautiful works of art. Offers four works of art and provides discussion questions and project ideas for each artwork. (CMK)

  11. Pre-fusion F is absent on the surface of formalin-inactivated respiratory syncytial virus

    PubMed Central

    Killikelly, April M.; Kanekiyo, Masaru; Graham, Barney S.

    2016-01-01

    The lack of a licensed vaccine for respiratory syncytial virus (RSV) can be partly attributed to regulatory hurdles resulting from vaccine enhanced respiratory disease (ERD) subsequent to natural RSV infection that was observed in clinical trials of formalin-inactivated RSV (FI-RSV) in antigen-naïve infants. To develop an effective vaccine that does not enhance RSV illness, it is important to understand how formalin and heat inactivation affected the antigenicity and immunogenicity of FI-RSV compared to native virus. Informed by atomic structures of RSV fusion (F) glycoprotein in prefusion (pre-F) and postfusion (post-F) conformations, we demonstrate that FI-RSV predominately presents post-F on the virion surface, whereas infectious RSV presents both pre-F and post-F conformations. This significant antigenic distinction has not been previously appreciated. Thus, a stabilized pre-F antigen is more representative of live RSV than F in its post-F conformation, as displayed on the surface of FI-RSV. This finding has major implications for discriminating current pre-F-based immunogens from FI-RSV used in historical vaccine trials. PMID:27682426

  12. Comparison of Smoking, Drinking, and Marijuana Use between Students Present or Absent on the Day of a School-Based Survey

    ERIC Educational Resources Information Center

    Bovet, Pascal; Viswanathan, Bharathi; Faeh, David; Warren, Wick

    2006-01-01

    The aim of this population-based survey was to compare the prevalence of selected risk behaviors between students present or absent on the day of a school-based survey. The study population was a representative sample of all students of secondary schools in the Seychelles (Indian Ocean). Students absent on the day of the survey were traced and…

  13. Here! But What about Those Who Are Not? Reinforcement among Chronically Absent Elementary Students, Its Effectiveness, and the Why behind the Absences

    ERIC Educational Resources Information Center

    Bickelhaupt, Delane L.

    2011-01-01

    This paper is a description of an action research (AR) study done with chronically absent elementary school students. The AR sought to answer these questions: 1) do reinforcement and daily check-ins increase attendance and 2) why are some students absent? Related literature regarding attendance and the methods used for the study are described and…

  14. Bare lymphocyte syndrome. Consequences of absent class II major histocompatibility antigen expression for B lymphocyte differentiation and function.

    PubMed Central

    Clement, L T; Plaeger-Marshall, S; Haas, A; Saxon, A; Martin, A M

    1988-01-01

    The bare lymphocyte syndrome is a rare combined immunodeficiency disorder associated with the absence of class I and/or class II major histocompatibility (MHC) antigens. Although it has been inferred that the immune deficiency is a consequence of disordered MHC-restricted interactions among otherwise normal cells, the biological capabilities and differentiation of B lymphocytes deficient in class II MHC antigens have not been rigorously analyzed. We have examined the phenotypic and functional attributes of B cells with absent class II MHC antigens. Our data demonstrate that these B cells are intrinsically defective in their responses to membrane-mediated activation stimuli. In addition, virtually all the B cells had phenotypic evidence of arrested differentiation at an immature stage. Finally, these B cells also failed to express the C3d-EBV receptor normally present on all B lymphocytes. These data indicate that class II MHC molecules are vital participants in early events of the B cell activation cascade, and that other non-MHC membrane molecules may also be absent as a consequence of either arrested differentiation or as a result of the basic defect affecting the expression of MHC membrane antigens. PMID:3257764

  15. Absent or compressed basal cisterns on first CT scan: ominous predictors of outcome in severe head injury.

    PubMed

    Toutant, S M; Klauber, M R; Marshall, L F; Toole, B M; Bowers, S A; Seelig, J M; Varnell, J B

    1984-10-01

    The relationship of outcome to the appearance of the basal cisterns as seen on initial computerized tomography (CT) scanning was assessed in 218 consecutive severely head-injured patients entered into the second phase of the National Pilot Traumatic Coma Data Bank. Outcome could be directly related to the status of the basal cisterns on the initial CT scan. The mortality rates were 77%, 39%, and 22% among those with absent, compressed, and normal basal cisterns, respectively. This association between cisterns and outcome was shown to be strong after adjusting for Glasgow Coma Scale (GCS) score (p less than 0.001). The state of the cisterns was more important for those with higher GCS scores (scores 6 to 8) than for those with lower scores (scores 3 to 5). Patients with GCS scores of 6 to 8, with cisterns absent or not visualized, suffered nearly a fourfold additional risk of poor outcome, compared to those with normal cisterns. This indicates that the status of the cisterns can be used as an early noninvasive method of identifying patients at high risk of death or severe disability, in whom the initial neurological examination would potentially suggest otherwise.

  16. Structural Mapping of Folded Sedimentary Environments from Satellite Images: an Example from Central Asia

    NASA Technical Reports Server (NTRS)

    Leith, W.

    1985-01-01

    In the Tadjik Depression, in Soviet Central Asia, in the absence of existing geologic or topographic maps, an enhanced LANDSAT multispectral scanner image was used in combination with field data to produce a 1:250000 geologic map of the Vakhsh fold-and-thrust belt and adjacent autochthon. Several structural conclusions are reached as a result of this mapping. Deformation of the Cretaceous and Tertiary strata of the fold-and-thrust belt is, in the central Tadjik Depression, conspicuously absent north of a buried basement fault that marks the hinge-zone of the Late Mesozoic passive margin. But, in the eastern half of the depression, thrusting has moved coherent sheets northward, over the block fault, these sheets now lie flat atop the autochthon to the north. The crustal structure inherited from the Mesozoic extensional phase has strongly influenced the Late Cenozoic pattern of deformation, producing the fold-and-thrust belt that is markedly asymmetric. The development of the thrust system has included the progressive overlapping of thrust: the later thrusts apparently formed internal to the older thrusts, and subsequently overrode them.

  17. Sources of Variation in a Two-Step Monitoring Protocol for Species Clustered in Conspicuous Points: Dolichotis patagonum as a Case Study

    PubMed Central

    Alonso Roldán, Virginia; Bossio, Luisina; Galván, David E.

    2015-01-01

    In species showing distributions attached to particular features of the landscape or conspicuous signs, counts are commonly made by making focal observations where animals concentrate. However, to obtain density estimates for a given area, independent searching for signs and occupancy rates of suitable sites is needed. In both cases, it is important to estimate detection probability and other possible sources of variation to avoid confounding effects on measurements of abundance variation. Our objective was to assess possible bias and sources of variation in a two-step protocol in which random designs were applied to search for signs while continuously recording video cameras were used to perform abundance counts where animals are concentrated, using mara (Dolichotis patagonum) as a case study. The protocol was successfully applied to maras within the Península Valdés protected area, given that the protocol was logistically suitable, allowed warrens to be found, the associated adults to be counted, and the detection probability to be estimated. Variability was documented in both components of the two-step protocol. These sources of variation should be taken into account when applying this protocol. Warren detectability was approximately 80% with little variation. Factors related to false positive detection were more important than imperfect detection. The detectability for individuals was approximately 90% using the entire day of observations. The shortest sampling period with a similar detection capacity than a day was approximately 10 hours, and during this period, the visiting dynamic did not show trends. For individual mara, the detection capacity of the camera was not significantly different from the observer during fieldwork. The presence of the camera did not affect the visiting behavior of adults to the warren. Application of this protocol will allow monitoring of the near-threatened mara providing a minimum local population size and a baseline for

  18. Absent pulmonary valve

    MedlinePlus

    ... Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics . 20th ed. Philadelphia, PA: Elsevier; 2016:chap 428. ... Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics . 20th ed. Philadelphia, PA: Elsevier; 2016:chap 430. ...

  19. Characterization of the first intragenic SATB2 duplication in a girl with intellectual disability, nearly absent speech and suspected hypodontia.

    PubMed

    Kaiser, Ann-Sophie; Maas, Bianca; Wolff, Anna; Sutter, Christian; Janssen, Johannes W G; Hinderhofer, Katrin; Moog, Ute

    2015-05-01

    SATB2, a gene encoding a highly conserved DNA-binding protein, is known to have an important role in craniofacial and neuronal development. Only a few patients with SATB2 variants have been described so far. Recently, Döcker et al provided a summary of these patients and delineated the SAS (SATB2-associated syndrome). We here report on a girl with intellectual disability, nearly absent speech and suspected hypodontia who was shown to carry an intragenic SATB2 tandem duplication hypothesized to lead to haploinsufficiency of SATB2. Preliminary information on this patient had already been included in the article by Döcker et al. We want to give a detailed description of the patient's phenotype and genotype, providing further insight into the spectrum of the molecular mechanisms leading to SAS.

  20. Vestibular responses to linear acceleration are absent in otoconia-deficient C57BL/6JEi-het mice

    NASA Technical Reports Server (NTRS)

    Jones, S. M.; Erway, L. C.; Bergstrom, R. A.; Schimenti, J. C.; Jones, T. A.

    1999-01-01

    Vestibular evoked potentials (VsEPs) were measured in normal mice and in mice homozygous for the head tilt mutation (het/het, abbr. het). The het mice lack otoconia, the inertial mass critical for natural stimulation of inner ear gravity receptors. Our findings demonstrate that vestibular neural responses to pulsed linear acceleration are absent in het mice. The results: (1) confirm that adequate sensory stimuli fail to activate gravity receptors in the het model; and (2) serve as definitive evidence that far-field vestibular responses to pulsed linear acceleration depend critically on otolith end organs. The C57BL/6JEi-het mouse may be an excellent model of gravity receptor sensory deprivation.

  1. Rare Site of Parasitic Dermoid Cyst at Uterovesical Fold of Peritoneum with Absent One-Sided Adnexa

    PubMed Central

    Sehgal, Alka; Ballega, Puneeti; Punia, RPS

    2016-01-01

    Teratomas are the most common type of germ cell tumour. It can be congenital or acquired and are usually found in gonads (testes and ovaries). Parasitic dermoid cysts are rare and their actual incidence is unknown. We are reporting a case of 25-year-old gravida two, para one and one living child, who underwent emergency cesarean section in view of symptomatic placenta previa. A parasitic dermoid cyst was found incidently in front of uterus which was attached to uterovasical fold of bladder. This cyst did not show any connection to uterus or adnexa. Uterus, uterine cavity, right side tube and ovary were normal. Her left sided fallopian tube and ovary was completely absent. She did not have any symptoms related to the dermoid cyst. Histopathology confirmed parasitic mature dermoid cyst. PMID:28208952

  2. Rare Site of Parasitic Dermoid Cyst at Uterovesical Fold of Peritoneum with Absent One-Sided Adnexa.

    PubMed

    Dubey, Sunita; Sehgal, Alka; Ballega, Puneeti; Punia, Rps

    2016-12-01

    Teratomas are the most common type of germ cell tumour. It can be congenital or acquired and are usually found in gonads (testes and ovaries). Parasitic dermoid cysts are rare and their actual incidence is unknown. We are reporting a case of 25-year-old gravida two, para one and one living child, who underwent emergency cesarean section in view of symptomatic placenta previa. A parasitic dermoid cyst was found incidently in front of uterus which was attached to uterovasical fold of bladder. This cyst did not show any connection to uterus or adnexa. Uterus, uterine cavity, right side tube and ovary were normal. Her left sided fallopian tube and ovary was completely absent. She did not have any symptoms related to the dermoid cyst. Histopathology confirmed parasitic mature dermoid cyst.

  3. Examining clinicians' experiences providing sexual health services for LGBTQ youth: considering social and structural determinants of health in clinical practice.

    PubMed

    Knight, R E; Shoveller, J A; Carson, A M; Contreras-Whitney, J G

    2014-08-01

    Although barriers related to lesbian, gay, bisexual, transgender and queer (LGBTQ) youth's experiences accessing sexual health services have been examined in detail, research into the experiences and perceptions of clinicians providing these services has been conspicuously absent. The aim of this article is to explore the perceptions and experiences of clinicians providing sexual health services for LGBTQ youth. Drawing on in-depth, semi-structured interviews, this study examines 24 clinicians' experiences providing sexual health services to LGBTQ youth in five communities in British Columbia, Canada. Our findings reveal how many clinicians provide services to LGBTQ youth with a lack of cultural competency-either implicitly (e.g., by describing heteronormative practices) or explicitly (e.g., by expressing frustration that they had not been sufficiently provided with appropriate training related to LGBTQ youth sexual health). Institutional norms and values were identified as the dominant barriers in the effective provision of LGBTQ-tailored services. Many clinicians find themselves unprepared to provide culturally competent sexual health services that have both the capacity to address individual-level issues (e.g. promoting condom use) while considering (and adapting services to) the broader socio-cultural and structural conditions that can render LGBTQ youth socially vulnerable.

  4. The Histone Methyltransferase Gene Absent, Small, or Homeotic Discs-1 Like Is Required for Normal Hox Gene Expression and Fertility in Mice1

    PubMed Central

    Brinkmeier, Michelle L.; Geister, Krista A.; Jones, Morgan; Waqas, Meriam; Maillard, Ivan; Camper, Sally A.

    2015-01-01

    Chromatin remodeling influences gene expression in developing and adult organisms. Active and repressive marks of histone methylation dictate the embryonic expression boundaries of developmentally regulated genes, including the Hox gene cluster. Drosophila ash1 (absent, small or homeotic discs 1) gene encodes a histone methyltransferase essential for regulation of Hox gene expression that interacts genetically with other members of the trithorax group (TrxG). While mammalian members of the mixed lineage leukemia (Mll) family of TrxG genes have roles in regulation of Hox gene expression, little is known about the expression and function of the mammalian ortholog of the Drosophila ash1 gene, Ash1-like (Ash1l). Here we report the expression of mouse Ash1l gene in specific structures within various organs and provide evidence that reduced Ash1l expression has tissue-specific effects on mammalian development and adult homeostasis. Mutants exhibit partially penetrant postnatal lethality and failure to thrive. Surviving mutants have growth insufficiency, skeletal transformations, and infertility associated with developmental defects in both male and female reproductive organs. Specifically, expression of Hoxa11 and Hoxd10 are altered in the epididymis of Ash1l mutant males and Hoxa10 is reduced in the uterus of Ash1l mutant females. In summary, we show that the histone methyltransferase Ash1l is important for the development and function of several tissues and for proper expression of homeotic genes in mammals. PMID:26333994

  5. Retinal Expression of the Drosophila eyes absent Gene Is Controlled by Several Cooperatively Acting Cis-regulatory Elements

    PubMed Central

    Neuman, Sarah D.; Bashirullah, Arash; Kumar, Justin P.

    2016-01-01

    The eyes absent (eya) gene of the fruit fly, Drosophila melanogaster, is a member of an evolutionarily conserved gene regulatory network that controls eye formation in all seeing animals. The loss of eya leads to the complete elimination of the compound eye while forced expression of eya in non-retinal tissues is sufficient to induce ectopic eye formation. Within the developing retina eya is expressed in a dynamic pattern and is involved in tissue specification/determination, cell proliferation, apoptosis, and cell fate choice. In this report we explore the mechanisms by which eya expression is spatially and temporally governed in the developing eye. We demonstrate that multiple cis-regulatory elements function cooperatively to control eya transcription and that spacing between a pair of enhancer elements is important for maintaining correct gene expression. Lastly, we show that the loss of eya expression in sine oculis (so) mutants is the result of massive cell death and a progressive homeotic transformation of retinal progenitor cells into head epidermis. PMID:27930646

  6. The Accordion Maneuver: A Noninvasive Strategy for Absent or Delayed Callus Formation in Cases of Limb Lengthening

    PubMed Central

    Makhdom, Asim M.; Cartaleanu, Adrian Sever; Rendon, Juan Sebastian; Villemure, Isabelle; Hamdy, Reggie C.

    2015-01-01

    The distraction osteogenesis (DO) technique has been used worldwide to treat many orthopaedic conditions. Although successful, absent or delayed callus formation in the distraction gap can lead to significant morbidities. An alternate cycle of distraction-compression (accordion maneuver) is one approach to accelerate bone regeneration. The primary aim of our study is to report our experience with the accordion maneuver during DO and to provide a detailed description of this technique, as performed in our center. The secondary aim is to present a review of the literature regarding the use of accordion maneuver. We reviewed the database of all patients undergoing limb lengthening from the year of 1997 to 2012. Four patients (6.15%) out of 65 showed poor bone regenerate in their tibiae and therefore accordion maneuver was applied for a mean of 6.75 weeks. Of these, three patients have had successful outcome with this technique. The literature showed that this technique is successful approach to trigger bone healing. However, details of how and when to apply this combination of distraction-compression forces were lacking. In conclusion, the accordion technique is safe noninvasive approach to promote bone formation, thus avoiding more invasive surgical procedures in cases of poor callus formation in limb lengthening. PMID:26557996

  7. Increased Expression and Activation of Absent in Melanoma 2 Inflammasome Components in Lymphocytic Infiltrates of Abdominal Aortic Aneurysms

    PubMed Central

    Dihlmann, Susanne; Erhart, Philipp; Mehrabi, Arianeb; Nickkholgh, Arash; Lasitschka, Felix; Böckler, Dittmar; Hakimi, Maani

    2014-01-01

    Chronic vascular inflammation is a key hallmark in the pathogenesis of abdominal aortic aneurysm (AAA). Recent investigations have suggested that the inflammasome, a cytosolic multiprotein complex that recognizes pathogen-associated molecular patterns, plays a role in atherosclerosis. However, its role in AAA inflammation has not yet been investigated. This pilot study analyzed inflammasome activation and its intramural localization in 24 biopsy samples from 11 patients with asymptomatic AAA versus 12 aortic samples from apparently healthy controls. Using a histological inflammation scale, we identified grade 2/3 inflammatory changes with lymphoid aggregates/tertiary lymphoid organs in 21 out of 24 AAA samples, whereas only 7 of the 12 control samples exhibited local grade 1 inflammatory changes. Strong expression levels of “apoptosis-associated speck-like protein with a caspase recruitment domain” (ASC), caspase-1, caspase-5 and “absent in melanoma 2” (AIM2) were detected by immunohistochemistry in both sporadic infiltrating lymphoid cells and lymphoid aggregates located in the outer media and adventitia of AAA samples. In contrast, inflammasome-positive cells were restricted to cholesterol plaque–associated areas and to single infiltrating cells in control aortas. Analysis of gene expression using real-time polymerase chain reaction (PCR) revealed significantly increased median mRNA levels of the inflammasome core components PYCARD (ASC), CASP1 (Caspase-1) and IL1B (IL-1β) in AAA tissue compared with normal aorta. Moreover, significantly increased median amounts of AIM2 protein and mature caspase-5 (p20) were found in samples associated with high rupture risk compared with paired low rupture risk samples of the same AAA patient. We conclude from our data that AAA-associated lymphoid cells are capable of inflammasome signaling, suggesting that inflammasome activation is involved in the chronic inflammatory process driving AAA progression. PMID:24618883

  8. Proliferation of transformed somatotroph cells related to low or absent expression of protein kinase a regulatory subunit 1A protein.

    PubMed

    Lania, Andrea G; Mantovani, Giovanna; Ferrero, Stefano; Pellegrini, Caterina; Bondioni, Sara; Peverelli, Erika; Braidotti, Paola; Locatelli, Marco; Zavanone, Mario L; Ferrante, Emanuela; Bosari, Silvano; Beck-Peccoz, Paolo; Spada, Anna

    2004-12-15

    The two regulatory subunits (R1 and R2) of protein kinase A (PKA) are differentially expressed in cancer cell lines and exert diverse roles in growth control. Recently, mutations of the PKA regulatory subunit 1A gene (PRKAR1A) have been identified in patients with Carney complex. The aim of this study was to evaluate the expression of the PKA regulatory subunits R1A, R2A, and R2B in a series of 30 pituitary adenomas and the effects of subunit activation on cell proliferation. In these tumors, neither mutation of PRKAR1A nor loss of heterozygosity was identified. By real-time PCR, mRNA of the three subunits was detected in all of the tumors, R1A being the most represented in the majority of samples. By contrast, immunohistochemistry documented low or absent R1A levels in all tumors, whereas R2A and R2B were highly expressed, thus resulting in an unbalanced R1/R2 ratio. The low levels of R1A were, at least in part, due to proteasome-mediated degradation. The effect of the R1/R2 ratio on proliferation was assessed in GH3 cells, which showed a similar unbalanced pattern of R subunits expression, and in growth hormone-secreting adenomas. The R2-selective cAMP analog 8-Cl cAMP and R1A RNA silencing, stimulated cell proliferation and increased Cyclin D1 expression, respectively, in human and rat adenomatous somatotrophs. These data show that a low R1/R2 ratio promoted proliferation of transformed somatotrophs and are consistent with the Carney complex model in which R1A inactivating mutations further unbalance this ratio in favor of R2 subunits. These results suggest that low expression of R1A protein may favor cAMP-dependent proliferation of transformed somatotrophs.

  9. It only takes once: The absent-exempt heuristic and reactions to comparison-based sexual risk information

    PubMed Central

    Stock, Michelle L.; Gibbons, Frederick X.; Beekman, Janine B.; Gerrard, Meg

    2015-01-01

    Three studies (N = 545) investigated the effects of social comparison on a type of heuristic called “absent-exempt” (AE; feeling exempt from future risk). Study 1 examined how comparison with an infected peer (comparison target) who was similar or non-similar in terms of sexual risk (number of partners, lack of condom use), influenced willingness and intentions to engage in sex without a condom and conditional perceived vulnerability to a sexually transmitted disease (STD). Participants generally reported lower willingness and higher conditional vulnerability if they compared with a similar-risk level target. However, high-risk students who compared with a low-risk comparison target engaged in what appeared to be AE thinking, reporting the highest willingness and lowest conditional vulnerability. Intentions to have sex without a condom were not influenced. Study 2 included a direct measure of AE thinking, and compared the impact of a low-risk comparison target with a Public Service Announcement (PSA) stating that negative outcomes (e.g., STDs) can happen even to low-risk targets. Among high-risk participants, comparing with the low-risk target led to an increase in AE thinking. As expected, the effects in Studies 1 and 2 were strongest among participants high in tendencies to socially compare. Study 3 explored whether AE thinking could be decreased by encouraging more reasoned processing. Results indicated that asking participants to think about the illogicality of AE thinking reduces AE endorsement and increases STD testing intentions. Findings suggest that comparison-based information can have a stronger influence on health cognitions than analytic-based information (e.g., most PSAs). Implications for dual-processing models of decision-making and their applicability to interventions and health messages are discussed. PMID:26098587

  10. The "eyes absent" (eya) gene in the eye-bearing hydrozoan jellyfish Cladonema radiatum: conservation of the retinal determination network.

    PubMed

    Graziussi, Daria Federica; Suga, Hiroshi; Schmid, Volker; Gehring, Walter Jakob

    2012-06-01

    Eyes absent (Eya) is a member of the Retinal Determination Gene Network (RDGN), a set of genes responsible for eye specification in Drosophila. Eya is a dual function protein, working as a transcription factor in the nucleus and as a tyrosine phosphatase in the cytoplasm. It had been shown that Pax and Six family genes, main components of the RDGN, are present in the hydrozoan Cladonema radiatum and that they are expressed in the eye. However, nothing had been known about the Eya family in hydrozoan jellyfish. Here we report the presence of an Eya homologue (CrEya) in Cladonema. Real-time PCR analysis and in situ hybridization showed that CrEya is expressed in the eye. Furthermore, the comprehensive survey of eukaryote genomes revealed that the acquisition of the N-terminal transactivation domain, including the EYA Domain 2 and its adjacent sequence shared by all eumetazoans, happened early in evolution, before the separation of Cnidaria and Bilateria. Our results uncover the evolution of the two domains and show a conservation of the expression pattern of the Eya gene between Cnidaria and Bilateria, which, together with previous data, supports the hypothesis of the monophyletic origin of metazoans eyes. We additionally show that CrEya is also expressed in the oocytes, where two other members of the RDGN, CrPaxB, and Six4/5-Cr, are known to be expressed. These data suggest that several members of the RDGN have begun to be localized also into the different context of egg development early in the course of metazoan evolution.

  11. Migrant labor in South Africa: a comparative analysis of the academic achievement of father-present and father-absent adolescents.

    PubMed

    Mboya, M M; Nesengani, R I

    1999-01-01

    This study was designed to determine whether there are significant differences in academic achievement between father-present and father-absent (due to migrant labor) adolescents. Data were collected from 276 high school students in South Africa. Academic achievement was measured by the Human Sciences Research Council's (HSRC) Scholastic Achievement Test, covering biology, English (second language), and mathematics. Father-present students were found to score significantly higher than father-absent students. The findings suggest that a father's absence due to work conditions has deleterious effects on the scholastic performance of young people.

  12. The absent discourse of communication: understanding ethics of provider-patient relationship in six hospitals in urban India.

    PubMed

    Ghoshal, Rakhi; Madhiwalla, Neha; Jesani, Amar; Samant, Padmaja; Badhwar, Vijaya; Surve, Sweta

    2013-01-01

    Understanding the complexities of a provider-patient relationship is considered to be of critical importance especially in medical ethics. It is important to understand this relation from the perspectives of all stakeholders. This article derives from a qualitative study conducted across six obstetric care providing institutions in the cities of Mumbai and Navi Mumbai, India, over a period of 10 months. Thirty obstetricians were interviewed in-depth to understand what they perceived as the most important aspect in developing a good provider-patient relationship. The study found that while most providers highlighted the point of communication as the most critical part of the provider-patient relationship, they admitted that they could not engage in communication with the patients for various reasons. Obstetric consultants and residents said that they were too overburdened to spend time communicating with patients; providers working in public hospitals added that the lack of education of their patients posed a hindrance in effective communication. However, providers practicing in private institutions explained that they faced a challenge in communicating with patients because their patients came from educated families who tended to trust the provider less and were generally more critical of the provider's clinical judgement. The article shows how provider-patient communication exists as an idea among medical providers but is absent in daily clinical practice. This gives rise to a discourse shaped around an absence. The authors conclude by decoding the term 'communication' - they read the word against the context of its use in the interviews, and argue that for the providers 'communication' was not intended to be a trope towards setting up a dialogue-based, egalitarian provider-patient relationship. Providers used the word in lieu of 'counselling', 'guiding', 'talking to'. It concludes that, despite the providers' insisting on the significance of communication and

  13. Microstructures and crystallographic fabric evolution during melt-present and melt-absent conditions in the partially molten middle crust: the Patos shear zone (Borborema Province, NE Brazil)

    NASA Astrophysics Data System (ADS)

    Ferreira Viegas, Luís Gustavo; Archanjo, Carlos; Vauchez, Alain

    2013-04-01

    The Patos shear zone is an exposed segment of the partially molten middle crust characterized by a 600 km long, E-trending transcurrent structure that deforms the Precambrian rocks of the Borborema Province. High-temperature (HT) mylonites with low melt fractions (~ 5%) constitute most of the shear belt, while a narrow strip of highly strained mylonites to ultramylonites outlines its southern margin. Migmatites and "transitional" mylonites occur sandwiched between these tectonites. A progressive microfabric development is recorded from melt-bearing mylonites to high-strain ultramylonites. A microstructural study was carried out to understand the fabric evolution from melt-assisted to melt-absent deformation. Fabrics were investigated by optical and scanning electron microscopy (SEM), and crystallographic preferred orientations were measured by Electron Backscatter Diffraction (EBSD). Melt-bearing HT-mylonites display solid-state microstructures with coarse quartz ribbons and sutured grain boundaries. K-feldspar clasts are often fractured and show peripheral myrmekite. Towards the contact with anatexites the microfabric becomes typically magmatic with abundant interstitial quartz. Transitional mylonites, located immediately south of the migmatites, are marked by progressive grain size reduction of recrystallized felsic phases. High-strain mylonites have a fine-grained quartz-feldspar matrix with relics of quartz ribbons and fractured K-feldspar. Melt-bearing mylonites display quartz [0001] axes forming maxima mainly on Y, while quartz fabrics in the anatexite are weaker and diffuse, suggesting deformation in the magmatic state. In transitional and high-strain mylonites the measured quartz CPOs show [0001] concentrations between Z and Y. K-feldspar and plagioclase fabrics record mainly the activity of (010)[001] and (010)[100] slip systems in all rock types, with local activity of the (100)[010] slip system in the transitional mylonites. These data suggest that the

  14. Migrant Labor in South Africa: A Comparative Analysis of the Academic Achievement of Father-Present and Father-Absent Adolescents.

    ERIC Educational Resources Information Center

    Mboya, Mzobanzi M.; Nesengani, Ralintho I.

    1999-01-01

    Study seeks to determine whether there are significant differences in academic achievement between father-present and father-absent (due to migrant labor) adolescents. Academic achievement of 276 high school students in South Africa was measured covering biology, English (second language), and mathematics.. Father-present students were found to…

  15. Finding the Two-Way Street: Women from Mother-Present/Father-Absent Homes and Their Ability to Make Close Female Friendships

    ERIC Educational Resources Information Center

    Marote, Melissa A.

    2011-01-01

    This heuristic study involving seven coresearchers, which included the author, explores the experiences of women from mother-present/father-absent homes and their ability to form and maintain close female friendships. The heuristic research model was chosen to provide the opportunity to conduct research in a very personalized, collaborative way…

  16. Transcatheter closure of atrial septal defect in a patient with absent inferior caval vein connection: a novel technique using a steerable guide catheter.

    PubMed

    Takaya, Yoichi; Akagi, Teiji; Ito, Hiroshi

    2016-06-01

    An alternative approach for transcatheter closure of atrial septal defect is necessary in patients with absent inferior caval vein connection. In this report, we describe the successful transcatheter atrial septal defect closure via the transjugular approach using a steerable guide catheter.

  17. A genetic model for absent chylomicron formation: mice producing apolipoprotein B in the liver, but not in the intestine.

    PubMed Central

    Young, S G; Cham, C M; Pitas, R E; Burri, B J; Connolly, A; Flynn, L; Pappu, A S; Wong, J S; Hamilton, R L; Farese, R V

    1995-01-01

    The formation of chylomicrons by the intestine is important for the absorption of dietary fats and fat-soluble vitamins (e.g., retinol, alpha-tocopherol). Apo B plays an essential structural role in the formation of chylomicrons in the intestine as well as the VLDL in the liver. We have developed genetically modified mice that express apo B in the liver but not in the intestine. By electron microscopy, the enterocytes of these mice lacked nascent chylomicrons in the endoplasmic reticulum and Golgi apparatus. Because these mice could not form chylomicrons, the intestinal villus enterocytes were massively engorged with fat, which was contained in cytosolic lipid droplets. These mice absorbed D-xylose normally, but there was virtually no absorption of retinol palmitate or cholesterol. The levels of alpha-tocopherol in the plasma were extremely low. Of note, the absence of chylomicron synthesis in the intestine did not appear to have a significant effect on the plasma levels of the apo B-containing lipoproteins produced by the liver. The mice lacking intestinal apo B expression represent the first genetic model of defective absorption of fats and fat-soluble vitamins and provide a useful animal model for studying nutrition and lipoprotein metabolism. Images PMID:8675665

  18. Expression of the Na+/l- symporter (NIS) is markedly decreased or absent in gastric cancer and intestinal metaplastic mucosa of Barrett esophagus

    PubMed Central

    Altorjay, Áron; Dohán, Orsolya; Szilágyi, Anna; Paroder, Monika; Wapnir, Irene L; Carrasco, Nancy

    2007-01-01

    Background The sodium/iodide symporter (NIS) is a plasma membrane glycoprotein that mediates iodide (I-) transport in the thyroid, lactating breast, salivary glands, and stomach. Whereas NIS expression and regulation have been extensively investigated in healthy and neoplastic thyroid and breast tissues, little is known about NIS expression and function along the healthy and diseased gastrointestinal tract. Methods Thus, we investigated NIS expression by immunohistochemical analysis in 155 gastrointestinal tissue samples and by immunoblot analysis in 17 gastric tumors from 83 patients. Results Regarding the healthy Gl tract, we observed NIS expression exclusively in the basolateral region of the gastric mucin-producing epithelial cells. In gastritis, positive NIS staining was observed in these cells both in the presence and absence of Helicobacter pylori. Significantly, NIS expression was absent in gastric cancer, independently of its histological type. Only focal faint NIS expression was detected in the direct vicinity of gastric tumors, i.e., in the histologically intact mucosa, the expression becoming gradually stronger and linear farther away from the tumor. Barrett mucosa with junctional and fundic-type columnar metaplasia displayed positive NIS staining, whereas Barrett mucosa with intestinal metaplasia was negative. NIS staining was also absent in intestinalized gastric polyps. Conclusion That NIS expression is markedly decreased or absent in case of intestinalization or malignant transformation of the gastric mucosa suggests that NIS may prove to be a significant tumor marker in the diagnosis and prognosis of gastric malignancies and also precancerous lesions such as Barrett mucosa, thus extending the medical significance of NIS beyond thyroid disease. PMID:17214887

  19. Impact of a Federal Healthy Start Program on feto-infant morbidity associated with absent fathers: a quasi-experimental study

    PubMed Central

    Salihu, Hamisu M.; August, Euna M.; Mbah, Alfred K.; Alio, Amina P.; Berry, Estrellita “Lo”; Aliyu, Muktar H.

    2014-01-01

    Objectives The absence of fathers during pregnancy increases the risk of feto-infant morbidities, including low birth weight (LBW), preterm birth (PTB), and small-for-gestational age (SGA). Previous research has shown that the Central Hillsborough Healthy Start project (CHHS) – a federally funded initiative in Tampa, Florida – has effectively improved birth outcomes. This study explores the effectiveness of the CHHS project in ameliorating the adverse effects of fathers’ absence during pregnancy. Methods This retrospective cohort study used CHHS records linked to vital statistics and hospital discharge data (1998–2007). The study population consisted of women who had a singleton birth with an absent father during pregnancy. Women were categorized based on residence in the CHHS service area. Propensity score matching was used to match cases (CHHS) to controls (rest of Florida). Conditional logistic regression was employed to generate odds ratios (OR) and 95% confidence intervals (CI) for matched observations. Results Women residing in the CHHS service area were more likely to be high school graduates, black, younger (<35 years), and to have adequate prenatal care compared to controls (p<0.01). These differences disappeared after propensity score matching. Mothers with absent fathers in the CHHS service area had a reduced likelihood of LBW (OR=0.76, 95% CI=0.65–0.89), PTB (OR=0.72, 95% CI=0.62–0.84), very low birth weight (OR=0.50, 95% CI= 0.35–0.72) and very preterm birth (OR=0.48, 95% CI=0.34–0.69) compared to their counterparts in the rest of the state. Conclusions This study demonstrates that a Federal Healthy Start project contributed to a significant reduction in adverse fetal birth outcomes in families with absent fathers. PMID:24549651

  20. An Analytic Contemplation of the Conspicuous Vicissitudes in the Histomorphology of Corpuscles of Stannius of a Freshwater Catfish Mystus tengara (Hamilton, 1822) due to the Exposure of ZnS Nanoparticles

    PubMed Central

    Chatterjee, Nilanjana

    2015-01-01

    Enhanced surface photooxidation property associated with the ZnS nanoparticles caused the reduction of dissolved oxygen content in water in a dose dependent manner, when ZnS nanoparticles of different sizes are exposed to the water in various concentrations. This property was more prominent for ZnS nanoparticles with smaller sizes. Mystus tengara, exposed to ZnS nanoparticles, responded to hypoxia with varied behavioural, physiological, and cellular responses in order to maintain homeostasis and organ function in an oxygen-depleted environment. The histomorphology of corpuscles of Stannius of the fish showed conspicuous vicissitudes under exposure of ZnS nanoparticles. The population of the cell type with granular cytoplasm showed significant increase at the expense of the other that consisted of agranular cytoplasm with increasing nanoparticle concentration. This can be explained as the defence mechanism of the fish against ZnS nanoparticle induced hypoxia and environmental acidification. The altering histomorphology has been studied employing an analytical approach. PMID:26693386

  1. Shadows of an Absent Partner

    PubMed Central

    Corradi, Gerardo R.; de Tezanos Pinto, Felicitas; Mazzitelli, Luciana R.; Adamo, Hugo P.

    2012-01-01

    The P5-ATPases are important components of eukaryotic cells. They have been shown to influence protein biogenesis, folding, and transport. The knowledge of their biochemical properties is, however, limited, and the transported ions are still unknown. We expressed in Saccharomyces cerevisiae the yeast Spf1 P5A-ATPase containing the GFP fused at the N-terminal end. The GFP-Spf1 protein was localized in the yeast endoplasmic reticulum. Purified preparations of GFP-Spf1 hydrolyzed ATP at a rate of ∼0.3–1 μmol of Pi/mg/min and formed a phosphoenzyme in a simple reaction medium containing no added metal ions except Mg2+. No significant differences were found between the ATPase activity of GFP-Spf1 and recombinant Spf1. Omission of protease inhibitors from the purification buffers resulted in a high level of endogenous proteolysis at the C-terminal portion of the GFP-Spf1 molecule that abolished phosphoenzyme formation. The Mg2+ dependence of the GFP-Spf1 ATPase was similar to that of other P-ATPases where Mg2+ acts as a cofactor. The addition of Mn2+ to the reaction medium decreased the ATPase activity. The enzyme manifested optimal activity at a near neutral pH. When chased by the addition of cold ATP, 90% of the phosphoenzyme remained stable after 5 s. In contrast, the phosphoenzyme rapidly decayed to less than 20% when chased for 3 s by the addition of ADP. The greater effect of ADP accelerating the disappearance of EP suggests that GFP-Spf1 accumulated the E1∼P phosphoenzyme. This behavior may reflect a limiting countertransported substrate needed to promote turnover or a missing regulatory factor. PMID:22745129

  2. Tooth formation - delayed or absent

    MedlinePlus

    ... missing teeth they never developed. Cosmetic or orthodontic dentistry can correct this problem. Causes Specific diseases can ... process. In: Dean JA, ed. McDonald and Avery's Dentistry for the Child and Adolescent . 10th ed. St. ...

  3. Positive Family History, Infection, Low Absolute Lymphocyte Count (ALC) and Absent Thymic Shadow: Diagnostic Clues for all Molecular Forms of Severe Combined Immunodeficiency (SCID)

    PubMed Central

    McWilliams, Laurie M; Railey, Mary Dell; Buckley, Rebecca H

    2015-01-01

    Background Severe Combined Immunodeficiency (SCID) is a syndrome uniformly fatal during infancy unless recognized and treated successfully by bone marrow transplantation or gene therapy. Because SCID infants have no abnormal physical appearance, diagnosis is usually delayed unless newborn screening is performed. Objective In this study, we sought to evaluate the presenting features of all 172 SCID patients transplanted at this institution over the past 31 years. Methods We reviewed original charts from 172 consecutive classic SCID patients who received either T cell-depleted HLA-haploidentical (N=154) or HLA-identical (N=18) non-ablative related marrow transplants at Duke University Medical Center from 1982–2013. Results The mean age at presentation was 4.87 months. When there was a family history of early infant death or known SCID (63/172 or 37%), the mean presentation age was much earlier, 2.0 months compared to 6.6 months. Failure to thrive was common, with 84 patients (50%) having a weight less than the 5th percentile. The leading infections included oral moniliasis (43%), viral infections (61/172 35.5%) and Pneumocystis jiroveci (26%) pneumonia. The group mean ALC was 1454/cmm; 88% of the infants had an ALC less than 3000/cmm. Absent thymic shadow was seen in 92% of infants with electronic radiographic data available. An absence of T cell function was found in all patients. Conclusions SCID infants appear normal at birth but later present with failure to thrive and/or recurrent fungal, viral and bacterial infections. Low ALCs and absent thymic shadow on chest x-ray are key diagnostic clues. The absence of T cell function confirms the diagnosis. PMID:25824440

  4. Structural transitions in laterally compressed two-dimensional Coulomb clusters

    SciTech Connect

    Rancova, O.; Anisimovas, E.; Varanavicius, T.

    2011-03-15

    We model structural transitions of small-size Wigner crystals in laterally compressed two-dimensional traps. Ground and metastable configurations are calculated and their transformations are linked to conspicuous changes in the heat capacity of the system. We show that various types of structural transitions are reflected by characteristic features in the behavior of the heat capacity. For deeper understanding, results produced by the Monte Carlo numerical calculations are compared to predictions of simple one-dimensional models.

  5. Basement membrane of mouse bone marrow sinusoids shows distinctive structure and proteoglycan composition: a high resolution ultrastructural study.

    PubMed

    Inoue, S; Osmond, D G

    2001-11-01

    Venous sinusoids in bone marrow are the site of a large-scale traffic of cells between the extravascular hemopoietic compartment and the blood stream. The wall of the sinusoids consists solely of a basement membrane interposed between a layer of endothelial cells and an incomplete covering of adventitial cells. To examine its possible structural specialization, the basement membrane of bone marrow sinusoids has now been examined by high resolution electron microscopy of perfusion-fixed mouse bone marrow. The basement membrane layer was discontinuous, consisting of irregular masses of amorphous material within a uniform 60-nm-wide space between apposing endothelial cells and adventitial cell processes. At maximal magnifications, the material was resolved as a random arrangement of components lacking the "cord network" formation seen in basement membranes elsewhere. Individual components exhibited distinctive ultrastructural features whose molecular identity has previously been established. By these morphological criteria, the basement membrane contained unusually abundant chondroitin sulfate proteoglycan (CSPG) revealed by 3-nm-wide "double tracks," and moderate amounts of both laminin as dense irregular coils and type IV collagen as 1-1.5-nm-wide filaments, together with less conspicuous amounts of amyloid P forming pentagonal frames. In contrast, 4.5-5-nm-wide "double tracks" characteristic of heparan sulfate proteoglycan (HSPG) were absent. The findings demonstrate that, in comparison with "typical" basement membranes in other tissues, the bone marrow sinusoidal basement membrane is uniquely specialized in several respects. Its discontinuous nature, lack of network organization, and absence of HSPG, a molecule that normally helps to maintain membrane integrity, may facilitate disassembly and reassembly of basement membrane material in concert with movements of adventitial cell processes as maturing hemopoietic cells pass through the sinusoidal wall: the

  6. Structuralism.

    ERIC Educational Resources Information Center

    Piaget, Jean

    Provided is an overview of the analytical method known as structuralism. The first chapter discusses the three key components of the concept of a structure: the view of a system as a whole instead of so many parts; the study of the transformations in the system; and the fact that these transformations never lead beyond the system but always…

  7. [Prognostic factors of perinatal short-term outcome in severe placental insufficiency using Doppler sonography to assess end-diastolic absent and reverse blood flow in umbilical arteries].

    PubMed

    Frauenschuh, I; Wirbelauer, J; Karl, S; Girschick, G; Rehn, M; Zollner, U; Frambach, T; Dietl, J; Müller, T

    2015-02-01

    Significant placental insufficiency, indicated by Doppler ultrasound findings of absent or reverse end-diastolic flow velocities (AREDV), is associated with increased morbidity and mortality. Analysis of blood flow in the ductus venosus should assist in early intrauterine recognition of threatened foetuses. 58 high-risk pregnancies with umbilical AREDV were repeatedly examined (n=364). Doppler findings were correlated with neonatal signs of deterioration (ratio of normoblasts to leukocytes, pH, base excess, Apgar score), as well as short-term morbidity [need for intubation, duration of assisted respiration, evidence of respiratory distress syndrome (RDS), bronchopulmonary dysplasia (BPD), necrotising enterocolitis (NEC), intraventricular haemorrhage (IVH grade III+IV)] against the analysis of the blood flow findings (normal or increased pulsitility, absence or reverse end-diastolic flow) in the umbilical arteries (AU), the middle cerebral arteries (ACM) and ductus venosus (DV) relating these to birth weight and the duration of the pregnancy. The median period of observation was 12.8 days, 48% of the foetuses showed an abnormal ductus venosus flow and 26% an absent venous or reverse end-diastolic flow. The median date of delivery was 30 weeks, with a mean birth weight of 816 g. 93% were live births with 12% dying postnatally. Although the criteria for postnatal morbidity (BPD, NEC, IVH III+IV) and mortality did not correlate with changes in arterial and venous Doppler parameters in our group, there was a significant relationship between the normoblast count, known to be a marker of chronic hypoxia. The Apgar 10 minte score, umbilical arterial pH and base excess were correlated with changes in the DV flow curves. Healthy survival started, irrespective of arterial or venous blood flow criteria, from 27+0 weeks of pregnancy. If born between 27.0 and 30+6 weeks, the infants were more likely to be healthy the less the blood flow had been compromised. A birth weight

  8. Nociceptin/orphanin FQ (N/OFQ)-evoked bradycardia, hypotension, and diuresis are absent in N/OFQ peptide (NOP) receptor knockout mice.

    PubMed

    Burmeister, Melissa A; Ansonoff, Michael A; Pintar, John E; Kapusta, Daniel R

    2008-09-01

    Intracerebroventricular administration of the opioid-like peptide nociceptin/orphanin FQ (N/OFQ) produces bradycardia, hypotension, and diuresis in mice. We hypothesized that these responses are solely caused by selective activation of central N/OFQ peptide (NOP) receptors. To test this premise, we first examined whether i.c.v. N/OFQ produced dose-dependent diuretic and cardiovascular depressor responses in commercially available C57BL/6 mice. Next, using doses established in these studies, we examined the renal excretory and cardiovascular responses to i.c.v. N/OFQ in conscious transgenic NOP receptor knockout mice (NOP(-/-)). In metabolic studies, i.c.v. N/OFQ, but not saline vehicle, dose-dependently increased urine output (V) in NOP(+/+); this response was significant at 3 nmol (N/OFQ, V = 0.39 +/- 0.10 ml/2 h; saline, 0.08 +/- 0.05 ml/2 h). The N/OFQ-evoked diuresis was absent in littermate NOP(-/-) (N/OFQ, V = 0.06 +/- 0.06 ml/2 h; saline, 0.03 +/- 0.03 ml/2 h). There were no significant changes in urinary sodium or potassium excretion or free water clearance in either group. In telemetry studies, i.c.v. N/OFQ dose dependently lowered heart rate (HR) and mean arterial pressure (MAP). At 3 nmol N/OFQ, both HR and MAP were reduced in NOP(+/+) (peak DeltaHR = -217 +/- 31 bpm; peak DeltaMAP =-47 +/- 7 mm Hg) compared with saline (peak DeltaHR =-14 +/- 5 bpm; peak DeltaMAP = 2 +/- 3 mm Hg). These N/OFQ-evoked bradycardic and hypotensive responses were absent in NOP(-/-) (peak DeltaHR =-13 +/- 17 bpm; peak DeltaMAP =-2 +/- 4 mm Hg, respectively). Basal 24-h cardiovascular and renal excretory function were not different between NOP(-/-) and NOP(+/+) mice. These results establish that the bradycardia, hypotension and diuresis produced by centrally administered N/OFQ are mediated by selective activation of NOP receptors.

  9. Rendered invisible? The absent presence of egg providers in U.K. debates on the acceptability of research and therapy for mitochondrial disease.

    PubMed

    Haimes, Erica; Taylor, Ken

    2015-12-01

    Techniques for resolving some types of inherited mitochondrial diseases have recently been the subject of scientific research, ethical scrutiny, media coverage and regulatory initiatives in the UK. Building on research using eggs from a variety of providers, scientists hope to eradicate maternally transmitted mutations in mitochondrial DNA by transferring the nuclear DNA of a fertilised egg, created by an intending mother at risk of transmitting mitochondrial disease, and her male partner, into an enucleated egg provided by another woman. In this article we examine how egg providers for mitochondrial research and therapy have been represented in stakeholder debates. A systematic review of key documents and parliamentary debates shows that the balance of consideration tilts heavily towards therapeutic egg providers; research egg providers have been ignored and rendered invisible. However, mapping the various designations of therapeutic egg providers shows that their role is so heavily camouflaged that they have only an absent presence in discussions. We explore this puzzling ambivalence towards egg providers whose contributions are necessary to the success of current mitochondrial research and proposed therapies. We suggest that labels that diminish the contributions of egg providers serve certain governance objectives in managing possible future claims about, and by, therapeutic egg providers. We demonstrate that the social positioning of research egg providers is entangled within that of therapeutic egg providers which means that the former can also never receive their due recognition. This article contributes to the wider literature on the governance of new technological interventions.

  10. Don't it make my brown eyes blue: co-witness misinformation about a target's appearance can impair target-absent line-up performance.

    PubMed

    Zajac, Rachel; Henderson, Nicola

    2009-04-01

    Misinformation from another witness has been shown to impair eyewitness reports, but little is known about how it may influence eyewitness identification. In Experiment 1, adult pairs comprising one participant and one experimental confederate viewed a video clip of a staged theft. Half of the participants were then misinformed by the confederate that the thief's accomplice had blue eyes (in fact, they were brown). Next, individual participants described the accomplice and completed a target-absent photographic line-up task comprising blue-eyed members. Misinformed participants were several times more likely than controls to describe the accomplice as having blue eyes, and twice as likely to identify someone from the line-up. In Experiment 2, when line-up members' eye colour was digitally altered from blue to brown, the line-up effect disappeared, suggesting that the increase in identifications in Experiment 1 was not a generalised increase in willingness to choose from the line-up. In Experiment 3, we discounted the possibility that discussion alone could account for the line-up misinformation effect, by subjecting all participants to co-witness discussion.

  11. De novo analysis of the transcriptome of Pratylenchus zeae to identify transcripts for proteins required for structural integrity, sensation, locomotion and parasitism.

    PubMed

    Fosu-Nyarko, John; Tan, Jo-Anne C H; Gill, Reetinder; Agrez, Vaughan G; Rao, Uma; Jones, Michael G K

    2016-05-01

    The root lesion nematode Pratylenchus zeae, a migratory endoparasite, is an economically important pest of major crop plants (e.g. cereals, sugarcane). It enters host roots, migrates through root tissues and feeds from cortical cells, and defends itself against biotic and abiotic stresses in the soil and in host tissues. We report de novo sequencing of the P. zeae transcriptome using 454 FLX, and the identification of putative transcripts encoding proteins required for movement, response to stimuli, feeding and parasitism. Sequencing generated 347,443 good quality reads which were assembled into 10,163 contigs and 139,104 singletons: 65% of contigs and 28% of singletons matched sequences of free-living and parasitic nematodes. Three-quarters of the annotated transcripts were common to reference nematodes, mainly representing genes encoding proteins for structural integrity and fundamental biochemical processes. Over 15,000 transcripts were similar to Caenorhabditis elegans genes encoding proteins with roles in mechanical and neural control of movement, responses to chemicals, mechanical and thermal stresses. Notably, 766 transcripts matched parasitism genes employed by both migratory and sedentary endoparasites in host interactions, three of which hybridized to the gland cell region, suggesting that they might be secreted. Conversely, transcripts for effectors reported to be involved in feeding site formation by sedentary endoparasites were conspicuously absent. Transcripts similar to those encoding some secretory-excretory products at the host interface of Brugia malayi, the secretome of Meloidogyne incognita and products of gland cells of Heterodera glycines were also identified. This P. zeae transcriptome provides new information for genome annotation and functional analysis of possible targets for control of pratylenchid nematodes.

  12. Anti-viral gene induction is absent upon secondary challenge with double-stranded RNA in the Pacific oyster, Crassostrea gigas.

    PubMed

    Green, Timothy J; Benkendorff, Kirsten; Robinson, Nick; Raftos, David; Speck, Peter

    2014-08-01

    Oyster farming is one of the most important aquaculture industries in the world. However, its productivity is increasingly limited by viral disease and we do not yet have management practices, such as protective vaccination, that can control these disease outbreaks. Hence, in the current study we investigated the expression of known anti-viral genes in oysters (Crassostrea gigas) in response to primary and secondary encounter with a virus associated molecular pattern (dsRNA), and tested whether a common form of epigenetic gene regulation (DNA methylation) was associated with the expression of these anti-viral genes. Injection of dsRNA into the adductor muscle resulted in the rapid and transient expression of virus recognition receptors (TLR & MDA5), whereas several anti-viral signalling (IRF & SOC-1) and effector (PKR & viperin) genes were still up-regulated at one week post primary challenge (p < 0.05). This primary encounter with dsRNA appeared to deplete the immune system because anti-viral gene induction was absent in the gills when oysters were given a second injection of dsRNA at 1-week post-primary injection. The expression of DNA methylation genes (DNMT1, DNMT3b, TDG, TET2) and DNA methylation profiles up-stream of specific anti-viral genes (STING, SOC-1 & Viperin) did not change in response to dsRNA injection (p > 0.05). These results collectively suggest that C. gigas does not have an enhanced anti-viral gene response (immune-priming) to secondary dsRNA challenge and that the sustained up-regulation of anti-viral signalling and effector genes following primary challenge is unlikely to be associated with upstream DNA methylation levels.

  13. A rare P2X7 variant Arg307Gln with absent pore formation function protects against neuroinflammation in multiple sclerosis.

    PubMed

    Gu, Ben J; Field, Judith; Dutertre, Sébastien; Ou, Amber; Kilpatrick, Trevor J; Lechner-Scott, Jeannette; Scott, Rodney; Lea, Rodney; Taylor, Bruce V; Stankovich, Jim; Butzkueven, Helmut; Gresle, Melissa; Laws, Simon M; Petrou, Steven; Hoffjan, Sabine; Akkad, Denis A; Graham, Colin A; Hawkins, Stanley; Glaser, Anna; Bedri, Sahl Khalid; Hillert, Jan; Matute, Carlos; Antiguedad, Alfredo; Wiley, James S

    2015-10-01

    Multiple sclerosis (MS) is a chronic relapsing-remitting inflammatory disease of the central nervous system characterized by oligodendrocyte damage, demyelination and neuronal death. Genetic association studies have shown a 2-fold or greater prevalence of the HLA-DRB1*1501 allele in the MS population compared with normal Caucasians. In discovery cohorts of Australasian patients with MS (total 2941 patients and 3008 controls), we examined the associations of 12 functional polymorphisms of P2X7, a microglial/macrophage receptor with proinflammatory effects when activated by extracellular adenosine triphosphate (ATP). In discovery cohorts, rs28360457, coding for Arg307Gln was associated with MS and combined analysis showed a 2-fold lower minor allele frequency compared with controls (1.11% for MS and 2.15% for controls, P = 0.0000071). Replication analysis of four independent European MS case-control cohorts (total 2140 cases and 2634 controls) confirmed this association [odds ratio (OR) = 0.69, P = 0.026]. A meta-analysis of all Australasian and European cohorts indicated that Arg307Gln confers a 1.8-fold protective effect on MS risk (OR = 0.57, P = 0.0000024). Fresh human monocytes heterozygous for Arg307Gln have >85% loss of 'pore' function of the P2X7 receptor measured by ATP-induced ethidium uptake. Analysis shows Arg307Gln always occurred with 270His suggesting a single 307Gln-270His haplotype that confers dominant negative effects on P2X7 function and protection against MS. Modeling based on the homologous zP2X4 receptor showed Arg307 is located in a region rich in basic residues located only 12 Å from the ligand binding site. Our data show the protective effect against MS of a rare genetic variant of P2RX7 with heterozygotes showing near absent proinflammatory 'pore' function.

  14. The Depression Anxiety Stress Scales (DASS): detecting anxiety disorder and depression in employees absent from work because of mental health problems

    PubMed Central

    Nieuwenhuijsen, K; de Boer, A G E M; Verbeek, J; Blonk, R; van Dijk, F J H

    2003-01-01

    Aims: To (1) evaluate the psychometric properties and (2) examine the ability to detect cases with anxiety disorder and depression in a population of employees absent from work because of mental health problems. Methods: Internal consistency, construct validity, and criterion validity of the Depression Anxiety Stress Scales (DASS) were assessed. Furthermore, the ability to identify anxiety disorders or depression was evaluated by calculating posterior probabilities of these disorders following positive and negative test results for different cut off scores of the DASS-Depression and DASS-Anxiety subscales. Results: Internal consistency of the DASS subscales was high, with Cronbach's alphas of 0.94, 0.88, and 0.93 for depression, anxiety, and stress respectively. Factor analysis revealed a three factor solution, which corresponded well with the three subscales of the DASS. Construct validity was further supported by moderately high correlations of the DASS with indices of convergent validity (0.65 and 0.75), and lower correlations of the DASS with indices of divergent validity (range -0.22 to 0.07). Support for criterion validity was provided by a statistically significant difference in DASS scores between two diagnostic groups. A cut off score of 5 for anxiety and 12 for depression is recommended. The DASS showed probabilities of anxiety and depression after a negative test result of 0.05 and 0.06 respectively. Probabilities of 0.29 for anxiety disorder and 0.33 for depression after a positive test result reflect relatively low specificity of the DASS. Conclusion: The psychometric properties of the DASS are suitable for use in an occupational health care setting. The DASS can be helpful in ruling out anxiety disorder and depression in employees with mental health problems. PMID:12782751

  15. A 3.4-kb Copy-Number Deletion near EPAS1 Is Significantly Enriched in High-Altitude Tibetans but Absent from the Denisovan Sequence

    PubMed Central

    Lou, Haiyi; Lu, Yan; Lu, Dongsheng; Fu, Ruiqing; Wang, Xiaoji; Feng, Qidi; Wu, Sijie; Yang, Yajun; Li, Shilin; Kang, Longli; Guan, Yaqun; Hoh, Boon-Peng; Chung, Yeun-Jun; Jin, Li; Su, Bing; Xu, Shuhua

    2015-01-01

    Tibetan high-altitude adaptation (HAA) has been studied extensively, and many candidate genes have been reported. Subsequent efforts targeting HAA functional variants, however, have not been that successful (e.g., no functional variant has been suggested for the top candidate HAA gene, EPAS1). With WinXPCNVer, a method developed in this study, we detected in microarray data a Tibetan-enriched deletion (TED) carried by 90% of Tibetans; 50% were homozygous for the deletion, whereas only 3% carried the TED and 0% carried the homozygous deletion in 2,792 worldwide samples (p < 10−15). We employed long PCR and Sanger sequencing technologies to determine the exact copy number and breakpoints of the TED in 70 additional Tibetan and 182 diverse samples. The TED had identical boundaries (chr2: 46,694,276–46,697,683; hg19) and was 80 kb downstream of EPAS1. Notably, the TED was in strong linkage disequilibrium (LD; r2 = 0.8) with EPAS1 variants associated with reduced blood concentrations of hemoglobin. It was also in complete LD with the 5-SNP motif, which was suspected to be introgressed from Denisovans, but the deletion itself was absent from the Denisovan sequence. Correspondingly, we detected that footprints of positive selection for the TED occurred 12,803 (95% confidence interval = 12,075–14,725) years ago. We further whole-genome deep sequenced (>60×) seven Tibetans and verified the TED but failed to identify any other copy-number variations with comparable patterns, giving this TED top priority for further study. We speculate that the specific patterns of the TED resulted from its own functionality in HAA of Tibetans or LD with a functional variant of EPAS1. PMID:26073780

  16. Rod-like microglia are restricted to eyes with laser-induced ocular hypertension but absent from the microglial changes in the contralateral untreated eye.

    PubMed

    de Hoz, Rosa; Gallego, Beatriz I; Ramírez, Ana I; Rojas, Blanca; Salazar, Juan J; Valiente-Soriano, Francisco J; Avilés-Trigueros, Marcelino; Villegas-Perez, Maria P; Vidal-Sanz, Manuel; Triviño, Alberto; Ramírez, José M

    2013-01-01

    In the mouse model of unilateral laser-induced ocular hypertension (OHT) the microglia in both the treated and the normotensive untreated contralateral eye have morphological signs of activation and up-regulation of MHC-II expression in comparison with naïve. In the brain, rod-like microglia align to less-injured neurons in an effort to limit damage. We investigate whether: i) microglial activation is secondary to laser injury or to a higher IOP and; ii) the presence of rod-like microglia is related to OHT. Three groups of mice were used: age-matched control (naïve, n=15); and two lasered: limbal (OHT, n=15); and non-draining portion of the sclera (scleral, n=3). In the lasered animals, treated eyes as well as contralateral eyes were analysed. Retinal whole-mounts were immunostained with antibodies against, Iba-1, NF-200, MHC-II, CD86, CD68 and Ym1. In the scleral group (normal ocular pressure) no microglial signs of activation were found. Similarly to naïve eyes, OHT-eyes and their contralateral eyes had ramified microglia in the nerve-fibre layer related to the blood vessel. However, only eyes with OHT had rod-like microglia that aligned end-to-end, coupling to form trains of multiple cells running parallel to axons in the retinal surface. Rod-like microglia were CD68+ and were related to retinal ganglion cells (RGCs) showing signs of degeneration (NF-200+RGCs). Although MHC-II expression was up-regulated in the microglia of the NFL both in OHT-eyes and their contralateral eyes, no expression of CD86 and Ym1 was detected in ramified or in rod-like microglia. After 15 days of unilateral lasering of the limbal and the non-draining portion of the sclera, activated microglia was restricted to OHT-eyes and their contralateral eyes. However, rod-like microglia were restricted to eyes with OHT and degenerated NF-200+RGCs and were absent from their contralateral eyes. Thus, rod-like microglia seem be related to the neurodegeneration associated with HTO.

  17. Skin vasoreactivity to insulin iontophoresis is reduced in elderly subjects and is absent in treated non-insulin-dependent diabetes patients.

    PubMed

    Rossi, Marco; Cupisti, Adamasco; Ricco, Roberto; Santoro, Gino; Pentimone, Ferdinando; Carpi, Angelo

    2004-12-01

    subjects and show that this effect is reduced by aging and is absent in treated NIDDM patients. The local skin vasodilatatory effect induced by insulin seems to involve mechanisms different from those underlying the skin postischemic hyperemia.

  18. Anomalous origin of the right pulmonary artery from the ascending aorta accompanied by absent pulmonary valve syndrome and right-sided aortic arch: a rare case in adult congenital heart disease.

    PubMed

    Khajali, Zahra; Mohammadzadeh, Ali; Khayatzadeh, Marzieh

    2015-04-01

    We present a rare congenital heart disease in a 20-year-old man with anomalous origin of the right pulmonary artery from the ascending aorta, accompanied by absent pulmonary valve syndrome, and a right-sided aortic arch suspected initially in transthoracic echocardiography and subsequently confirmed by cardiac catheterisation and computed tomography angiography.

  19. From symbolizing to non-symbolizing within the scope of a link: from dreams to shouts of terror caused by an absent presence.

    PubMed

    Levy, Ruggero

    2012-08-01

    This article examines pathologies in the creation of symbols and those pathologies' ensuing consequences. It relies mainly on the vertices provided by Bion and Meltzer. It studies the different forms in which these lapses occur in symbolic processes, where they may create vacuums in symbolic networks or give rise to 'lies', and even destroy or de-symbolize established symbols. Based on Bion's concept of the minus-contained (-contained), I propose that when a symbol is attacked, a particular mental structure with its own peculiar characteristics comes about. This structure not only creates a vacuum in that mental zone, it ends up damaging the entire symbolization process. This contribution aims to describe that structure from the metapsychological point of view - contained. I end by synthesizing the possible widening of what could be a Bionian negative grid.

  20. Path integration absent in scent-tracking fimbria-fornix rats: evidence for hippocampal involvement in "sense of direction" and "sense of distance" using self-movement cues.

    PubMed

    Whishaw, I Q; Gorny, B

    1999-06-01

    Allothetic and idiothetic navigation strategies use very different cue constellations and computational processes. Allothetic navigation requires the use of the relationships between relatively stable external (visual, olfactory, auditory) cues, whereas idiothetic navigation requires the integration of cues generated by self-movement and/or efferent copy of movement commands. The flexibility with which animals can switch between these strategies and the neural structures that support these strategies are not well understood. By capitalizing on the proclivity of foraging rats to carry large food pellets back to a refuge for eating, the present study examined the contribution of the hippocampus to the use of allothetic versus idiothetic navigation strategies. Control rats and fimbria-fornix-ablated rats were trained to follow linear, polygonal, and octagonal scent trails that led to a piece of food. The ability of the rats to return to the refuge with the food via the shortest route using allothetic cues (visual cues and/or the odor trail available) or using ideothetic cues (the odor trail removed and the rats blindfolded or tested in infrared light) was examined. Control rats "closed the polygon" by returning directly home in all cue conditions. Fimbria-fornix rats successfully used allothetic cues (closed the polygon using visual cues or tracked back on the string) but were insensitive to the direction and distance of the refuge and were lost when restricted to idiothetic cues. The results support the hypothesis that the hippocampal formation is necessary for navigation requiring the integration of idiothetic cues.

  1. Caveolin-1 expression is variably displayed in astroglial-derived tumors and absent in oligodendrogliomas: concrete premises for a new reliable diagnostic marker in gliomas.

    PubMed

    Cassoni, Paola; Senetta, Rebecca; Castellano, Isabella; Ortolan, Erika; Bosco, Martino; Magnani, Ivana; Ducati, Alessandro

    2007-05-01

    Caveolins are basic constituents of flask-shaped cell membrane microdomains (caveolae), which are involved in many cell functions, including signalling, trafficking, and cellular growth control. The distribution of caveolae within the normal brain and in brain tumors is controversial. In the present study, we describe the expression of caveolin-1 (cav-1) in 64 brain tumors of different grade, of either astroglial or oligodendroglial origin. All studied astrocitomas of any grade (from II to IV) were cav-1 positive, displaying staining patterns and intensity specifically associated to the different tumor grades. In all glioblastomas and gliosarcomas, cav-1 staining was extremely intense, typically localized at the cell membrane and recognized a variable percentage of cells, including the majority of spindle cells and palisade-oriented perinecrotic cells. In anaplastic astrocytomas, a less intense membrane staining or a cytoplasmic dotlike immunoreactivity were present, the latter being almost the exclusive pattern observed in diffuse astrocitomas grade II. In contrast to astroglial tumors, the striking totality of grade II oligodendrogliomas and the large majority of grade III were lacking cav-1 expression. Interestingly, a cav-1 distribution overlapping the pattern described in tissues was observed also in primary cell cultures of human glioblastomas and astrocytomas, and also in one established glioblastoma cell line (U251 MG), analyzed by means of confocal microscopy and flow cytometry. In conclusion, among astroglial tumors cav-1 expression varies in distribution, pattern, and intensity specifically according to tumor types and grades. The association between tumor progression and a more structured membranous pattern of cav-1 expression could suggest the hypothesis of a neoplastic shift towards a mesenchymal phenotype, whose behavioral and biologic significance worth further studies. Finally, the lack of cav-1 immunoreactivity in oligodendrogliomas suggests its

  2. Coupling of proton flow to ATP synthesis in Rhodobacter capsulatus: F(0)F(1)-ATP synthase is absent from about half of chromatophores.

    PubMed

    Feniouk, B A; Cherepanov, D A; Junge, W; Mulkidjanian, A Y

    2001-11-01

    F(0)F(1)-ATP synthase (H(+)-ATP synthase, F(0)F(1)) utilizes the transmembrane protonmotive force to catalyze the formation of ATP from ADP and inorganic phosphate (P(i)). Structurally the enzyme consists of a membrane-embedded proton-translocating F(0) portion and a protruding hydrophilic F(1) part that catalyzes the synthesis of ATP. In photosynthetic purple bacteria a single turnover of the photosynthetic reaction centers (driven by a short saturating flash of light) generates protonmotive force that is sufficiently large to drive ATP synthesis. Using isolated chromatophore vesicles of Rhodobacter capsulatus, we monitored the flash induced ATP synthesis (by chemoluminescence of luciferin/luciferase) in parallel to the transmembrane charge transfer through F(0)F(1) (by following the decay of electrochromic bandshifts of intrinsic carotenoids). With the help of specific inhibitors of F(1) (efrapeptin) and of F(0) (venturicidin), we decomposed the kinetics of the total proton flow through F(0)F(1) into (i) those coupled to the ATP synthesis and (ii) the de-coupled proton escape through F(0). Taking the coupled proton flow, we calculated the H(+)/ATP ratio; it was found to be 3.3+/-0.6 at a large driving force (after one saturating flash of light) but to increase up to 5.1+/-0.9 at a smaller driving force (after a half-saturating flash). From the results obtained, we conclude that our routine chromatophore preparations contained three subsets of chromatophore vesicles. Chromatophores with coupled F(0)F(1) dominated in fresh material. Freezing/thawing or pre-illumination in the absence of ADP and P(i) led to an increase in the fraction of chromatophores with at least one de-coupled F(0)(F(1)). The disclosed fraction of chromatophores that lacked proton-conducting F(0)(F(1)) (approx. 40% of the total amount) remained constant upon these treatments.

  3. Absent fetal movement response with a blunted cardioacceleratory fetal response to external vibratory acoustic stimulation in a fetus with the Pena-Shokeir syndrome (fetal akinesia and hypokinesia sequence).

    PubMed

    Sherer, D M; Sanko, S R; Metlay, L A; Woods, J R

    1992-01-01

    We present a case that describes a partial fetal response to external vibratory acoustic stimulation in that, although no fetal movements were elicited, a blunted, brief positive cardioacceleratory response was noted. This fetus exhibited features of the Pena-Shokeir syndrome, characterized by skeletal neurogenic atrophy, yet with a normal auditory system at autopsy. This observation may suggest that the prolonged increase in the basal fetal heart noted after fetal vibratory acoustic stimulation is sustained by active fetal movements, absent in this fetus due to joint contractures.

  4. Blepharophimosis syndrome with absent tear production.

    PubMed

    Ng, Jacqueline K; Stout, Ann U; Aaby, Aazy A; Ng, John D

    2015-01-01

    The purpose of this report was to present a case of congenital alacrima in a patient with blepharophimosis-ptosis-epicanthus inversus syndrome (BPES). A 9-month-old boy presented with characteristic clinical findings of BPES confirmed by genetic testing. On further history taking and evaluation, the patient was noted to have no tear production, despite clinically present palpebral lobes of the lacrimal glands. BPES is an autosomal dominant condition characterized by narrowed horizontal palpebral fissures, severe bilateral symmetric ptosis, epicanthus inversus, and telecanthus. To the authors' knowledge, this represents the second reported case of congenital alacrima in this syndrome. The first case described in the literature was in a 9-month-old girl who had congenital absence of the lacrimal glands. BPES may present with alacrima requiring vigilant lifelong lubrication and careful consideration in decisions for eyelid surgery including ptosis repair.

  5. Fluid-absent metamorphism in the Adirondacks

    NASA Technical Reports Server (NTRS)

    Valley, J. W.

    1986-01-01

    Results on late Proterozoic metamorphism of granulite in the Adirondacks are presented. There more than 20,000 sq km of rock are at granulite facies. Low water fugacites are implied by orthopyroxene bearing assemblages and by stability of k'spar-plag-quartz assemblages. After mentioning the popular concept of infiltration of carbon dioxide into Precambrian rocks and attendent generation of granulite facies assemblages, several features of Adirondack rocks pertinent to carbon dioxide and water during their metamorphism are summarized: wollastonite occurs in the western lowlands; contact metamorphism by anorthosite preceeding granulite metamorphism is indicated by oxygen isotopes. Oxygen fugacity lies below that of the QFM buffer; total P sub water + P sub carbon dioxide determined from monticellite bearing assemblages are much less than P sub total (7 to 7.6 kb). These and other features indicate close spatial association of high- and low-P sub carbon dioxide assemblages and that a vapor phase was not present during metamorphism. Thus Adirondack rocks were not infiltrated by carbon dioxide vapor. Their metamorphism, at 625 to 775 C, occurred either when the protoliths were relatively dry or after dessication occurred by removal of a partial melt phase.

  6. An Absent Body in a Present Landscape

    ERIC Educational Resources Information Center

    Marcussen, Jens

    2012-01-01

    The wilderness expedition experience will always be a confluence of emotional, cognitive and bodily processes. The author wants to show that the body is an important but often forgotten part of the wilderness expedition experience. In society, the focus on the body is often polarised. Sometimes, there is an extreme focus on the thin and fit body…

  7. Cytokines in relapsing experimental autoimmune encephalomyelitis in DA rats: persistent mRNA expression of proinflammatory cytokines and absent expression of interleukin-10 and transforming growth factor-beta.

    PubMed

    Issazadeh, S; Lorentzen, J C; Mustafa, M I; Höjeberg, B; Müssener, A; Olsson, T

    1996-09-01

    Experimental autoimmune encephalomyelitis (EAE) in rats is typically a brief and monophasic disease with sparse demyelination. However, inbred DA rats develop a demyelinating, prolonged and relapsing encephalomyelitis after immunization with rat spinal cord in incomplete Freund's adjuvant. This model enables studies of mechanisms related to chronicity and demyelination, two hallmarks of multiple sclerosis (MS). Here we have investigated, in situ, the dynamics of cytokine mRNA expression in the central nervous system (CNS) and peripheral lymphoid organs (lymph node cells and splenocytes) of diseased DA rats. We demonstrate that peripheral lymphoid cells stimulated in vitro with encephalitogenic peptides 69-87 and 87-101 of myelin basic protein responded with high mRNA expression for proinflammatory cytokines; interferon-gamma, interleukin-12 (IL-12), tumour necrosis factors alpha and beta, IL-1 beta and cytolysin. A high expression of mRNA for these proinflammatory cytokines was also observed in the CNS where it was accompanied by classical signs of inflammation such as expression of major histocompatibility complex class I and II, CD4, CD8 and IL-2 receptor. The expression of mRNA for proinflammatory cytokines was remarkably long-lasting in DA rats as compared to LEW rats which display a brief and monophasic EAE. Furthermore, mRNAs for putative immunodownmodulatory cytokines, i.e. transforming growth factor-beta (TGF-beta), IL-10 and IL-4 were almost absent in DA rats, in both the CNS and in vitro stimulated peripheral lymphoid cells, while their levels were elevated in the CNS of LEW rats during the recovery phase. We conclude that the MS-like prolonged and relapsing EAE in DA rats is associated with a prolonged production of proinflammatory cytokines and/or low or absent production of immunodownmodulatory cytokines.

  8. Going green to be seen: status, reputation, and conspicuous conservation.

    PubMed

    Griskevicius, Vladas; Tybur, Joshua M; Van den Bergh, Bram

    2010-03-01

    Why do people purchase proenvironmental "green" products? We argue that buying such products can be construed as altruistic, since green products often cost more and are of lower quality than their conventional counterparts, but green goods benefit the environment for everyone. Because biologists have observed that altruism might function as a "costly signal" associated with status, we examined in 3 experiments how status motives influenced desire for green products. Activating status motives led people to choose green products over more luxurious nongreen products. Supporting the notion that altruism signals one's willingness and ability to incur costs for others' benefit, status motives increased desire for green products when shopping in public (but not private) and when green products cost more (but not less) than nongreen products. Findings suggest that status competition can be used to promote proenvironmental behavior.

  9. 31 CFR 50.12 - Clear and conspicuous disclosure.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ....12 Section 50.12 Money and Finance: Treasury Office of the Secretary of the Treasury TERRORISM RISK... a “surcharge.” (2) Premium to reflect definition of act of terrorism. If an insurer makes an initial..., consistent with the definition of an act of terrorism as amended by the Terrorism Risk Insurance...

  10. 31 CFR 50.12 - Clear and conspicuous disclosure.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ....12 Section 50.12 Money and Finance: Treasury Office of the Secretary of the Treasury TERRORISM RISK... a “surcharge.” (2) Premium to reflect definition of act of terrorism. If an insurer makes an initial..., consistent with the definition of an act of terrorism as amended by the Terrorism Risk Insurance...

  11. 31 CFR 50.12 - Clear and conspicuous disclosure.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ....12 Section 50.12 Money and Finance: Treasury Office of the Secretary of the Treasury TERRORISM RISK... a “surcharge.” (2) Premium to reflect definition of act of terrorism. If an insurer makes an initial..., consistent with the definition of an act of terrorism as amended by the Terrorism Risk Insurance...

  12. Conspicuous Invisibility: Shadowing as a Data Collection Strategy

    ERIC Educational Resources Information Center

    Quinlan, Elizabeth

    2008-01-01

    Shadowing entails a researcher closely following a subject over a period of time to investigate what people actually do in the course of their everyday lives, not what their roles dictate of them. Behaviors, opinions, actions, and explanations for those actions are reflected in the resulting thick, descriptive data. There is little written that…

  13. A case of gastric adenocarcinoma with conspicuous binuclear cytologic features.

    PubMed

    Ito, Hideaki; Furuya, Chiemi; Yamanouchi, Tsuyoshi; Ikemoto, Kenzo; Katoh, Tomoe; Onoda, Masahiko; Kondo, Tomoko; Oga, Atsunori

    2013-01-01

    Binuclear cells have been occasionally observed in nonneoplastic and carcinoma cells. However, in clinical cases, few reports have analyzed and discussed the origins and features, including the proliferative capacity, of binuclear cells. We describe the case of a 75-year-old man with gastric cancer with microscopically prominent binuclear cells in the resected tissue and ascitic fluid. Image cytometry and chromosomal analysis were performed on cells isolated from the ascitic fluid. The DNA histogram pattern showed aneuploidy and the fluorescence in situ hybridization pattern of centromeres 7 and 11 was similar to that of most other mononuclear cancer cells. Furthermore, the binuclear cells showed low proliferative capability based on 5-bromo-2'-deoxyuridine incorporation. Our results demonstrated that the binuclear cells were derived from mononuclear aneuploid cells through incomplete cell division, and, in this case, may have impaired proliferative capacity.

  14. Concealed by conspicuousness: distractive prey markings and backgrounds

    PubMed Central

    Dimitrova, Marina; Stobbe, Nina; Schaefer, H. Martin; Merilaita, Sami

    2009-01-01

    High-contrast markings, called distractive or dazzle markings, have been suggested to draw and hold the attention of a viewer, thus hindering detection or recognition of revealing prey characteristics, such as the body outline. We tested this hypothesis in a predation experiment with blue tits (Cyanistes caeruleus) and artificial prey. We also tested whether this idea can be extrapolated to the background appearance and whether high-contrast markings in the background would improve prey concealment. We compared search times for a high-contrast range prey (HC-P) and a low-contrast range prey (LC-P) in a high-contrast range background (HC-B) and a low-contrast range background (LC-B). The HC-P was more difficult to detect in both backgrounds, although it did not match the LC-B. Also, both prey types were more difficult to find in the HC-B than in the LC-B, in spite of the mismatch of the LC-P. In addition, the HC-P was more difficult to detect, in both backgrounds, when compared with a generalist prey, not mismatching either background. Thus, we conclude that distractive prey pattern markings and selection of microhabitats with distractive features may provide an effective way to improve camouflage. Importantly, high-contrast markings, both as part of the prey coloration and in the background, can indeed increase prey concealment. PMID:19324754

  15. Conspicuous Consumption in Higher Education: The Case of Academic Bling

    ERIC Educational Resources Information Center

    Vander Schee, Brian A.

    2011-01-01

    Spring is a time for gardening, blossoms, and baseball. At American college and universities, it is also a time for commencement ceremonies. Students are recognized for their scholastic achievements as faculty and staff close out another academic school year. Family and friends applaud the graduates and celebrate their success. Students show their…

  16. The c-di-GMP phosphodiesterase VmpA absent in Escherichia coli K12 strains affects motility and biofilm formation in the enterohemorrhagic O157:H7 serotype.

    PubMed

    Branchu, Priscilla; Hindré, Thomas; Fang, Xin; Thomas, Robynn; Gomelsky, Mark; Claret, Laurent; Harel, Josée; Gobert, Alain P; Martin, Christine

    2013-03-15

    Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is a foodborne pathogen that resists the acidic gastric environment, colonizes the gut epithelium, and causes hemorrhagic colitis and hemolytic-uremic syndrome, especially in children. The genomic island OI-47 of E. coli O157:H7 contains a gene, z1528, encoding an EAL-domain protein potentially involved in c-di-GMP hydrolysis that is absent in non-pathogenic E. coli. This gene, designated vmpA, is co-transcribed with ycdT, which is present in non pathogenic E. coli and encodes a diguanylate cyclase involved in c-di-GMP synthesis. To test for vmpA function, we constructed a vmpA knockout mutant. We also overexpressed vmpA, purified the VmpA protein and assayed for its activity in vitro. We found that VmpA possesses c-di-GMP phosphodiesterase activity and that the vmpA mutation results in increased biofilm formation, and reduced swimming motility, which is consistent with the function determined in vitro. Unexpectedly, suppressor mutations arise frequently in the vmpA background suggesting that VmpA plays an important regulatory role in E. coli O157:H7. These findings represent an example of remarkable flexibility in the organization of c-di-GMP signaling pathways in closely related species.

  17. De novo 9q gain in an infant with tetralogy of Fallot with absent pulmonary valve: Patient report and review of congenital heart disease in 9q duplication syndrome.

    PubMed

    Amarillo, Ina E; O'Connor, Shawn; Lee, Caroline K; Willing, Marcia; Wambach, Jennifer A

    2015-12-01

    Genomic disruptions, altered epigenetic mechanisms, and environmental factors contribute to the heterogeneity of congenital heart defects (CHD). In recent years, chromosomal microarray analysis (CMA) has led to the identification of numerous copy number variations (CNV) in patients with CHD. Genes disrupted by and within these CNVs thus represent excellent candidate genes for CHD. Microduplications of 9q (9q+) have been described in patients with CHD, however, the critical gene locus remains undetermined. Here we discuss an infant with tetralogy of Fallot with absent pulmonary valve, fetal hydrops, and a 3.76 Mb de novo contiguous gain of 9q34.2-q34.3 detected by CMA, and confirmed by karyotype and FISH studies. This duplicated interval disrupted RXRA (retinoid X receptor alpha; OMIM #180245) at intron 1. We also review CHD findings among previously reported patients with 9q (9q+) duplication syndrome. This is the first report implicating RXRA in CHD with 9q duplication, providing additional data in understanding the genetic etiology of tetralogy of Fallot, CHD, and disorders linked to 9q microduplication syndrome. This report also highlights the significance of CMA in the clinical diagnosis and genetic counseling of patients and families with complex CHD.

  18. Caste Structures and E-Governance in a Developing Country

    NASA Astrophysics Data System (ADS)

    de', Rahul

    Castes, or endogamous kinship relationships, are prevalent in communities across the world and particularly in developing countries. Caste plays a strong role in determining community structures and political power. However, the role of caste as a factor in shaping e-governance design and outcomes is absent in the literature. This paper addresses this particular gap by examining some cases from India.

  19. The panorama of future sick-leave diagnoses among young adults initially long-term sickness absent due to neck, shoulder, or back diagnoses. An 11-year prospective cohort study

    PubMed Central

    Vaez, Marjan; Hagberg, Jan; Alexanderson, Kristina

    2009-01-01

    Background Little is known about future sick-leave diagnoses among individuals on long-term sickness absence. The aim of this study was to describe the panorama of sick-leave diagnoses over time among young adults initially sick-listed for ≥ 28 days due to back, neck, or shoulder diagnoses Methods An 11-year prospective population-based cohort study including all 213 individuals in a Swedish municipality who, in 1985, were aged 25–34 years and had a new sick-leave spell ≥ 28 days due to neck, shoulder, or back diagnoses. Results Over the 11-year period, the young adults in this cohort had 176,825 sick-leave days in 7,878 sick-leave periods (in 4,610 sick-leave spells) due to disorders in 17 of the 18 ICD-8 diagnostic categories (International Classification of Diseases, Revision 8). Musculoskeletal or mental diagnoses accounted for most of the sick-leave days, whereas most of the sick-leave periods were due to musculoskeletal, respiratory, or infectious disorders, or to unclassified symptoms. Most cohort members had had four to eight different sick-leave diagnoses over the 11 years, although some had had up to 11 diagnoses. Only two individuals (1%) had been sickness absent solely due to musculoskeletal diagnoses. Conclusion Although the young adults initially were sick listed with back, neck, or shoulder diagnoses, their sickness absence during the follow up were due to a wide variety of other medical diagnoses. It might be that the ill-health content of sickness absence due to back pain is greater than usually assumed. More research on prognoses of sick-leave diagnoses among long-term sick listed is warranted.

  20. Structure and chemistry of silica, metal oxides, and phosphates

    SciTech Connect

    Heaney, P.J.; Banfield, J.A.

    1993-12-31

    This chapter addresses the structures and chemical properties of the rockforming oxides and phosphates. In one sense these materials are less complex than the chain and sheet silicates discussed previously. In general their unit cells are smaller and formulas shorter. Moreover, the baroque chemical variation that makes amphiboles a joy for mineralogists and a nightmare for health scientists is virtually absent within some oxides. Instead, the oxides express their individuality through structural permutation, illustrating the important concept of polymorphism. 230 refs., 25 figs.

  1. Deformed microbial mat structures in a semiarid temperate coastal setting

    NASA Astrophysics Data System (ADS)

    Cuadrado, Diana G.; Pan, Jerónimo; Gómez, Eduardo A.; Maisano, Lucía

    2015-07-01

    This study focuses on sedimentary structures formed by microbial consortia, in a particular coastal setting, an ancient tidal channel, separated from the ocean by a sandy spit and connected by a blind tidal channel at the opposite end. Most studies in modern and ancient environments consider water movement as the triggering mechanism acting in the formation and deformation of sedimentary structures. As such, the paper documents the presence of several microbial structures such as shrinkage cracks, flip-over mats, microbial chips, and multidirectional ripples which are related to tidal processes, while bulges and gas domes structures are formed after occasional inundation events. However, the more conspicuous structures covering a great area at the study site are folds and roll-ups, the product of deformation of microbially induced structures by the action of sporadic spring-tidal currents due to strong winds. Therefore, the objective of this research is to document modern sedimentary structures in a coastal area and to provide a mechanistic explanation for their formation, based on the interplaying effects of the moisture variation and high shear stress. Also, several microbial sedimentary structures are distinguished throughout vertical sediment cores, such as microbial chips, detached mat, sponge fabrics, tears, and concentric structures, which are identified in a sedimentary profile. Through the recognition and interpretation of modern sedimentary deformation structures, this study contributes empirical tools for the reconstruction of analogous paleoenvironments in fossil studies.

  2. Unusual crystalline structures in photoreceptors of Lonchoplanella axi (Plathelminthes, Rhabdocoela, 'Typhloplanoida'): functional aspects and phylogenetic implications.

    PubMed

    Sopott-Ehlers, B

    2000-10-01

    Lonchoplanella axi has a pair of small dot-like pigment-cup ocelli. Each eye is composed of a single cup cell and two sensory cells of the rhabdomeric type. The most conspicuous differentiations in the sensory cells are spindle-shaped crystalline structures accompanying the nuclei. These structures flank the dorsolateral, respectively ventrolateral side of the nucleus. It is supposed that these 'spindles' serve rather as an additional shading device than as dioptrics. Since such structures in photoreceptors have hitherto not been reported for representatives of the Plathelminthes, it is concluded that the spindle-shaped crystalline bodies in the eyes of Lonchoplanella axi are an autapomorphic feature of this species or even an autapomorphy of the taxon Mariplanellinae.

  3. Structure Topology Optimization of Brake Pad in Large- megawatt Wind Turbine Brake Considering Thermal- structural Coupling

    NASA Astrophysics Data System (ADS)

    Zhang, S. F.; Yin, J.; Liu, Y.; Sha, Z. H.; Ma, F. J.

    2016-11-01

    There always exists severe non-uniform wear of brake pad in large-megawatt wind turbine brake during the braking process, which has the brake pad worn out in advance and even threats the safety production of wind turbine. The root cause of this phenomenon is the non-uniform deformation caused by thermal-structural coupling effect between brake pad and disc while braking under the conditions of both high speed and heavy load. For this problem, mathematical model of thermal-structural coupling analysis is built. Based on the topology optimization method of Solid Isotropic Microstructures with Penalization, SIMP, structure topology optimization of brake pad is developed considering the deformation caused by thermal-structural coupling effect. The objective function is the minimum flexibility, and the structure topology optimization model of brake pad is established after indirect thermal- structural coupling analysis. Compared with the optimization result considering non-thermal- structural coupling, the conspicuous influence of thermal effect on brake pad wear and deformation is proven as well as the rationality of taking thermal-structural coupling effect as optimization condition. Reconstructed model is built according to the result, meanwhile analysis for verification is carried out with the same working condition. This study provides theoretical foundation for the design of high-speed and heavy-load brake pad. The new structure may provide design reference for improving the stress condition between brake pad and disc, enhancing the use ratio of friction material and increasing the working performance of large-megawatt wind turbine brake.

  4. Race Differences in Family Experience and Early Sexual Initiation: Dynamic Models of Family Structure and Family Change.

    ERIC Educational Resources Information Center

    Wu, Lawrence L.; Thomson, Elizabeth

    2001-01-01

    Examines the effects of family structure on age at first sexual intercourse before marriage for a recent cohort of women. For neither White nor Black women are results consistent with hypotheses positing earlier initiation of sexual activity for women with prolonged exposure to a single-mother or father-absent family. (BF)

  5. The (Absent) Politics of Neo-Liberal Education Policy

    ERIC Educational Resources Information Center

    Clarke, Matthew

    2012-01-01

    Despite its ideological saturation, recent neo-liberal education policy has been deeply depoliticising in the sense of reducing properly political concerns to matters of technical efficiency. This depoliticisation is reflected in the hegemony of a managerial discourse and the decontestation of terms like "quality" and…

  6. Consequences of retinal image clarity versus occlusion (absent) versus diffusion.

    PubMed Central

    Jampolsky, A

    1994-01-01

    A series of clinical questions and stated hypotheses suggested in the pre-1960s regarding the differences between stimuli of occlusion and diffusion are presented (Part I) and are answered and confirmed by a series of experiments and data in animals and humans. A diffusion stimulus is extremely destructive to development of the acuity system in an eye per se (as well as producing myopia), and a unilateral diffusion stimulus is also destructive to development of the binocular system. Real occlusion is a no-stimulus condition that can be used to preserve normal acuity and binocular development, and as a delay tactic to successfully counteract the detrimental effect of diffusion. Binocular input differences (especially if one is a diffusion stimulus) are a major cause of strabismus in both the immature and mature binocular systems. The hypothesis was proposed that preoperative full-time alternate occlusion in infantile esotropia enhanced the binocularity outcome (for which supportive experimental data in animals and humans from our laboratories are discussed in Part III). Animal experiments during the 1960s and 1970s are reviewed relative to the confusion and conflict generated (Part II), since many of these experiments were based on the false assumptions that the unilateral eyelid closure model was a no-stimulus condition (because of the small amount of light transmitted). In fact, it was a worst-case severe stimulus with both monocular and binocular detrimental consequences. And the unilateral eyelid closure model usually produced either undetected or ignored strabismus in the animal experiments, with such strabismus severely compounding the detrimental effects of the eyelid closure model. Further confusion was added by the amblyopia therapeutic model in animals of "reverse eyelid occlusion" (which was really reverse diffusion) and which the author maintains was a gross distortion of the clinician's real occlusive patch over the better eye in the therapy of amblyopia of the poorer eye. These confusions and conflicts were at variance with long-standing clinical percepts. Part III provides data from the series of animal and human experiments from our laboratories at Smith-Kettlewell Eye Research Institute, which clarify the confusion and conflicts of some of the animal experiments described. Our data support the original hypotheses (Part I) enabling the clinician to use occlusion measures in selected patients to expand the therapeutic timing options and to improve visual outcomes. Binocular system outcomes are shown to be improved by our recent data in animal and human experiments, thus supporting the beneficial sensory effects of preoperative full-time alternate occlusion regimes in infantile esotropia. PMID:7886872

  7. Archaeal Lineages within the Human Microbiome: Absent, Rare or Elusive?

    PubMed Central

    Horz, Hans-Peter

    2015-01-01

    Archaea are well-recognized components of the human microbiome. However, they appear to be drastically underrepresented compared to the high diversity of bacterial taxa which can be found on various human anatomic sites, such as the gastrointestinal environment, the oral cavity and the skin. As our “microbial” view of the human body, including the methodological concepts used to describe them, has been traditionally biased towards bacteria, the question arises whether our current knowledge reflects the actual ratio of archaea versus bacteria or whether we have failed so far to unravel the full diversity of human-associated archaea. This review article hypothesizes that distinct archaeal lineages within humans exist, which still await our detection. First, previously unrecognized taxa might be quite common but they have eluded conventional detection methods. Two recent prime examples are described that demonstrate that this might be the case for specific archaeal lineages. Second, some archaeal taxa might be overlooked because they are rare and/or in low abundance. Evidence for this exists for a broad range of phylogenetic lineages, however we currently do not know whether these sporadically appearing organisms are mere transients or important members of the so called “rare biosphere” with probably basic ecosystem functions. Lastly, evidence exists that different human populations harbor different archaeal taxa and/or the abundance and activity of shared archaeal taxa may differ and thus their impact on the overall microbiome. This research line is rather unexplored and warrants further investigation. While not recapitulating exhaustively all studies on archaeal diversity in humans, this review highlights pertinent recent findings that show that the choice of appropriate methodological approaches and the consideration of different human populations may lead to the detection of archaeal lineages previously not associated with humans. This in turn will help understand variations found in the overall microbiomes from different individuals and ultimately may lead to the emergence of novel concepts/mechanisms impacting human health. PMID:25950865

  8. Hyperactive Students Are Never Absent and Other Truths about Teaching

    ERIC Educational Resources Information Center

    Forsten, Char; Grant, Jim; Hollas, Betty; Reynolds, Laureen

    2008-01-01

    Teachers sometimes feel that much of what they learned about teaching was learned in the classroom---not the college classroom, but the room in which they teach. As every teacher knows--or eventually learns--a good sense of humor is essential to having a happy, healthy teaching experience. This book points out some of the things they always forget…

  9. Absent Audiences: Youth Identity Formation in Preparations for Performance

    ERIC Educational Resources Information Center

    Thompson, Carol C.

    2011-01-01

    This article explores the use of audiences in preparation for public presentation by an urban youth organization in Camden, New Jersey (U.S.). Camden is an impoverished city with few opportunities for youth. The organization, a hybrid of youth development, technology, business, and college preparation, prepared youth for good jobs or college.…

  10. Genetics Home Reference: thrombocytopenia-absent radius syndrome

    MedlinePlus

    ... gene provides instructions for making a protein called RNA-binding motif protein 8A. This protein is believed ... that cause TAR syndrome reduce the amount of RNA-binding motif protein 8A in cells. The deletions ...

  11. Clinical manifestations of the thrombocytopenia and absent radii (TAR) syndrome.

    PubMed

    Gounder, D S; Pullon, H W; Ockelford, P A; Nicol, R O

    1989-10-01

    Six patients with the classical features of the TAR syndrome were diagnosed at birth. In one case an older sibling was also affected. The characteristic features of foreshortened forearms and radially deviated hands were noted in all cases at presentation and confirmed radiologically. With one exception skeletal abnormalities of the lower limbs were also present. Varying degrees of thrombocytopenia were present at birth with three of the five patients having platelet counts below 50 x 10(9)/L. Bone marrow examination was performed in two patients and revealed an absence of normal megakaryocytes. Two patients with severe thrombocytopenia had bleeding complications during infancy requiring transfusion support. Severe gastroenteritis occurred in two patients, in one of whom it was attributed to cow's milk intolerance. In all patients the platelet count has risen progressively since birth. Orthopedic surgical procedures have been performed without hemorrhagic complications.

  12. Repeated bout effect is absent in resistance trained men

    PubMed Central

    Falvo, Michael J.; Schilling, Brian K.; Bloomer, Richard J.; Smith, Webb A.

    2009-01-01

    A prior bout of exercise is well known to confer protection from subsequent eccentric bouts (i.e. repeated bout effect; RBE), which may be fostered through neural adaptations, specifically a shift in the frequency content of the surface electromyogram (EMG). It is currently not clear whether chronically resistance trained men are capable of a RBE driven by neural adaptations. Eleven resistance trained men (23.5 ± 3.4 yrs) performed 100 eccentric actions of the barbell bench press exercise, followed by an equivalent bout 14 days later. Indirect markers of muscle damage (i.e. force production, soreness) along with surface EMG were measured before and through 48 h of recovery. Median frequency and maximal isometric force demonstrated time main effects (p > 0.05), but no RBE. A prior bout of eccentric exercise does not confer a RBE for indirect markers of muscle injury or elicit changes in the frequency content of the EMG signal in resistance trained men. PMID:19059793

  13. Lipid oxidation volatiles absent in milk after selected ultrasound processing.

    PubMed

    Juliano, Pablo; Torkamani, Amir Ehsan; Leong, Thomas; Kolb, Veronika; Watkins, Peter; Ajlouni, Said; Singh, Tanoj Kumar

    2014-11-01

    Ultrasonic processing can suit a number of potential applications in the dairy industry. However, the impact of ultrasound treatment on milk stability during storage has not been fully explored under wider ranges of frequencies, specific energies and temperature applications. The effect of ultrasonication on lipid oxidation was investigated in various types of milk. Four batches of raw milk (up to 2L) were sonicated at various frequencies (20, 400, 1000, 1600 and 2000kHz), using different temperatures (4, 20, 45 and 63°C), sonication times and ultrasound energy inputs up to 409kJ/kg. Pasteurized skim milk was also sonicated at low and high frequency for comparison. In selected experiments, non-sonicated and sonicated samples were stored at 4°C and were drawn periodically up to 14days for SPME-GCMS analysis. The cavitational yield, characterized in all systems in water, was highest between 400kHz and 1000kHz. Volatile compounds from milk lipid oxidation were detected and exceeded their odor threshold values at 400kHz and 1000kHz at specific energies greater than 271kJ/kg in raw milk. However, no oxidative volatile compounds were detected below 230kJ/kg in batch systems at the tested frequencies under refrigerated conditions. Skim milk showed a lower energy threshold for oxidative volatile formation. The same oxidative volatiles were detected after various passes of milk through a 0.3L flow cell enclosing a 20kHz horn and operating above 90kJ/kg. This study showed that lipid oxidation in milk can be controlled by decreasing the sonication time and the temperature in the system depending on the fat content in the sample among other factors.

  14. [Phenomenological study on the process to onset and the structure of symptoms in eating disorders].

    PubMed

    Yamada, Y; Itaya, Y; Yamada, T

    2000-01-01

    Psychogenic experiences occurring prior to the onset of eating disorders had previously been ignored as not corresponding to the symptoms. Recently, we have been considering these experiences as outbreak conditions, and have done phenomenological analysis of the experiences themselves with the following results. We found that patients have experienced 1.) "shame", and following that, and from the phenomenological consideration of the experience of "shame", we have observed 2.) "alienation" occurring in each patients, leading to "isolation." In "isolation", the patient is driven to despair due to existential anxiety, and as the ultimate in despair, the patient shows the attitude of 3.) "One wishing to be oneself in despair." (Kierkegaard, S.), or "haughtiness" which is the attitude of "a person who understands himself or herself to be a free design, and considers others as 'existence-others' reached through this design." (Sartre, J. P.) Here, the patient shows "consumption" as a symptom in either of the forms of surfeit (bulimia) or the consumption of one's own body (anorexia): wasting. 4.) These are defined as "conspicuous consumption" (Veblen, T. B.). 5.) Conspicuous consumption has been analyzed as a primitive form of exchange by Mauss, M., and has been mentioned repeatedly in the intellectual lineage of Bataille, G., Baudrillard, J., et al. This action is concerned with the acquisition of social status in order to save one's own face, and shows what forms the depth-psychological base stratum in the "class system" of human beings, as well as illuminating the "social functions of dignity and class distribution." We have discovered a continuous course from the psychogenic experiences occurring at the onset and previously considered trifling and therefore ignored, proceeding to the symptoms and to the structure of the symptoms. In particular, by using a phenomenological analysis of shame and symptom structure, we show a new hypothesis about the structure of symptoms

  15. The Mount Evans batholith in the Colorado Front Range: revision of its age and reinterpretation of its structure

    USGS Publications Warehouse

    Aleinikoff, J.N.; Reed, J.C.; Dewitt, E.

    1993-01-01

    The Mount Evans batholith is composed of a main phase of massive to conspicuously foliated monzogranite and granodiorite and undeformed aplite and pegmatite. The Mount Evans batholith was previously considered to be part of the 1.7 Ga Routt Plutonic Suite. New U-Pb zircon ages on four samples (granodiorite, monzogranite, and granite), however, indicate that the batholith was emplaced at 1442 ?? 2 Ma and belongs to the Berthoud Plutonic Suite. Most of the batholith has igneous textures and structures, except in the vicinity of the Idaho Springs-Ralston shear zone where those features are tectonically recrystallized and foliated. The Mount Evans batholith is anomalous in composition and structure compared to most other 1.4 Ga plutons of the southwestern US. The differences probably reflect different sources of partial melting; the specific tectonic setting where rocks of such disparate origin are temporally and spatially juxtaposed is not understood. -from Authors

  16. Genetic diversity and population structure of the Ethiopian sorghum [Sorghum bicolor (L.) Moench] germplasm collection maintained by the USDA-ARS, National Plant Germplasm System using SSR markers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genetic diversity and population structure present in the Ethiopia sorghum collection maintained by the USDA-ARS, National Plant Germplasm System (USDA-ARS-NPGS) is unknown. In addition, passport information is absent for 83% of these accessions which limit its evaluation and utility. Therefor...

  17. Particle accelerations and current structures of Weibel and Filamentation instabilities

    NASA Astrophysics Data System (ADS)

    Ryu, C. M.; Huynh, C. T.

    2015-12-01

    Particle accelerations of the Wibel instability (WI) and the Filamentation instability(FI) are studied by using PIC simuations, comparing them side-by-side. Although two instabilities are almost identical in the linear growth phase, significant differences are found in the nonlinear phase in their particle accelerations and current structures. The FI shows enhanced electron acceleration, whereas particle acceleration is almost absent in the WI. The different particle accelerations between the FI and the WI seem to be associated with their different current structures; a hollow electron current structure for the FI and a center filled current structure for that of the WI. Different electron distributions seem to bring in different current filament structures, eventually leading to different magnetic characteristics.

  18. Confinement in F4 Exceptional Gauge Group Using Domain Structures

    NASA Astrophysics Data System (ADS)

    Rafibakhsh, Shahnoosh; Shahlaei, Amir

    2017-03-01

    We calculate the potential between static quarks in the fundamental representation of the F4 exceptional gauge group using domain structures of the thick center vortex model. As non-trivial center elements are absent, the asymptotic string tension is lost while an intermediate linear potential is observed. SU(2) is a subgroup of F4. Investigating the decomposition of the 26 dimensional representation of F4 to the SU(2) representations, might explain what accounts for the intermediate linear potential, in the exceptional groups with no center element.

  19. Structural and mechanical architecture of the intestinal villi and crypts in the rat intestine: integrative reevaluation from ultrastructural analysis.

    PubMed

    Hosoyamada, Yasue; Sakai, Tatsuo

    2005-08-01

    The ultrastructure of the rat intestinal interstitium was analyzed from the viewpoint of mechanical dynamics to stabilize the intestinal villi, crypts and mucosal folds. In the rat, the small intestine lacks circular folds, but the large intestine possesses spiral folds. The intestinal villi, the largest in the duodenum, decreased in size in the jejunum and ileum successively, and were absent in the large intestine. The intestinal interstitium consisted of lamina propria mucosae (LPM) and tela submucosa (TSM) separated by muscularis mucosae (MM), the LPM was subdivided into an upper part within the villi and a lower part among the crypts in the small intestine. The light microscopic density of interstitium in the intestinal wall was lowest in the upper LPM, moderately dense in the lower LPM and highest in the TSM, and that among the intestinal region was highest in the duodenum and decreased successively in the jejunum and ileum. In the large intestine, the TSM bulged to form spiral folds with very low density. The intestinal epithelium in the villi possessed wide intercellular spaces and that in the crypts had closed intercellular spaces. At electron microscopic level, the upper and lower LPM contained subepithelial supportive meshwork that consisted of collagen fibrils and myofibroblast processes. The lower LPM and TSM contained conspicuous bundles of collagen fibrils and, in addition, TSM contained minor populations of scattered collagen fibrils near the smooth muscle layer (SML). The diameter of collagen fibrils was the largest in the bundles of TSM, and decreased from the duodenum through the jejunum and ileum to the large intestine. On the basis of these observations, we hypothesize that the intestinal villi are mechanically stabilized by the balance between the expansive interstitial pressure and inward pull by the subepithelial supportive meshwork. This hypothesis explains the hitherto neglected fact that the intestinal epithelium possesses wide

  20. Color signaling in conspicuous red sticklebacks: do ultraviolet signals surpass others?

    PubMed Central

    2008-01-01

    Background The use of ultraviolet (UV) signals for communication tasks is widespread in vertebrates. For instance, there is a UV component to mate choice in several species. Nevertheless, it remains unclear how the signal value of the UV wave band compares to that of other regions of the animal's visible spectrum. We investigated the relative importance of UV signals compared with signals of longer wavelengths in the threespine stickleback (Gasterosteus aculeatus), a species using UV wavelengths in female and male mate choice as well as in shoaling behavior. In a choice experiment, female sticklebacks were simultaneously presented with four male visual appearances manipulated by optical filters. Each male lacked one wavelength range of the stickleback's visible spectrum corresponding to the spectral sensitivities of the four cone types. The resulting male appearances thus had no UV (UV-), no short-wave (SW-), no medium-wave (MW-) or no long-wave (LW-) body reflectance. Results Males without UV wavelengths and long wavelengths ("red") were least preferred. In contrast, the removal of medium and most notably short wavelengths left male attractiveness to females rather unaffected. Using color metrics, the effects of the four optical filters on stickleback perception of three male body regions were illustrated as quantal catches calculated for the four single cones. Conclusion The removal of UV light (UV-) considerably reduced visual attractiveness of courting males to female three-spined sticklebacks particularly in comparison to the removal of short-wave light (SW-). We thus report first experimental evidence that the UV wave band clearly outranks at least one other part of an animal's visible spectrum (SW-) in the context of communication. In addition, females were also less attracted to males presented without long wavelengths (LW-) which supports the traditionally considered strong influence of the red color component on stickleback mate choice. Overall, the removal of medium wavelengths (MW-) and especially short (SW-) left male attractiveness for females rather unaffected. Our work suggests that, in addition to long wavelengths ("red"), the UV wave band contains important information for visual mate choice in sticklebacks. Hence, the previously suggested exclusive role of the characteristic red nuptial coloration in visual interactions between reproductively active stickleback conspecifics may be overestimated with UV wavelengths playing a more important role than previously suggested. PMID:18593461

  1. A Conspicuous Gap in Cultural Studies: Popular Music in the English Studies Classroom

    ERIC Educational Resources Information Center

    Knippling, Jim

    2013-01-01

    For the author, the key analytic question about a popular song is not "What does it mean?" or "What hidden or coded meaning does it express?" but "What does its popularity tell us about the cultural moment when it resonated with its public?" How did the song "create its audience," so to speak? Obviously, a 1973 hit song, if it could time-travel,…

  2. Conspicuous Strategies in Teaching Expressive Writing: A Quantitative Study Comparing Two Approaches to Process Writing

    ERIC Educational Resources Information Center

    Fontenot, Jennifer; Carney, Karen J.; Hansen, Kay

    2015-01-01

    A process-writing approach (BW) with novel concepts was developed by the authors to teach writing to elementary-level students. They believed the BW approach was effective but was particularly effective for special-needs students. Consequently, they decided to quantitatively test these assertions. Instead of testing students taught using the BW…

  3. Fast and Conspicuous? Quantifying Salience With the Theory of Visual Attention

    PubMed Central

    Krüger, Alexander; Tünnermann, Jan; Scharlau, Ingrid

    2016-01-01

    Particular differences between an object and its surrounding cause salience, guide attention, and improve performance in various tasks. While much research has been dedicated to identifying which feature dimensions contribute to salience, much less regard has been paid to the quantitative strength of the salience caused by feature differences. Only a few studies systematically related salience effects to a common salience measure, and they are partly outdated in the light of new findings on the time course of salience effects. We propose Bundesen’s Theory of Visual Attention (TVA) as a theoretical basis for measuring salience and introduce an empirical and modeling approach to link this theory to data retrieved from temporal-order judgments. With this procedure, TVA becomes applicable to a broad range of salience-related stimulus material. Three experiments with orientation pop-out displays demonstrate the feasibility of the method. A 4th experiment substantiates its applicability to the luminance dimension. PMID:27168868

  4. 49 CFR 229.133 - Interim locomotive conspicuity measures-auxiliary external lights.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... stroboscopic lights, each with “effective intensity,” as defined by the Illuminating Engineering Society's Guide for Calculating the Effective Intensity of Flashing Signal Lights (November 1964), of at least 500... external lights. 229.133 Section 229.133 Transportation Other Regulations Relating to...

  5. Validated novel software to measure the conspicuity index of lesions in DICOM images

    NASA Astrophysics Data System (ADS)

    Szczepura, K. R.; Manning, D. J.

    2016-03-01

    A novel software programme and associated Excel spreadsheet has been developed to provide an objective measure of the expected visual detectability of focal abnormalities within DICOM images. ROIs are drawn around the abnormality, the software then fits the lesion using a least squares method to recognize the edges of the lesion based on the full width half maximum. 180 line profiles are then plotted around the lesion, giving 360 edge profiles.

  6. 16 CFR 1500.121 - Labeling requirements; prominence, placement, and conspicuousness.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... name and place of business of the manufacturer, packer, distributor, or seller; statements of... business of the manufacturer, packer, distributor, or seller, all cautionary material required by the Act... a display panel elsewhere on the container. The name and place of business of the...

  7. 16 CFR 1500.121 - Labeling requirements; prominence, placement, and conspicuousness.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... name and place of business of the manufacturer, packer, distributor, or seller; statements of... business of the manufacturer, packer, distributor, or seller, all cautionary material required by the Act... a display panel elsewhere on the container. The name and place of business of the...

  8. Conspicuous disease: The surveillance of silicosis in South Africa, 1910-1970.

    PubMed

    Breckenridge, Keith Derek

    2015-11-01

    Scholarly understanding of the nature of the science around silicosis has been strongly influenced, in recent years, by the idea that the mine doctors were responsible for hiding an epidemic, on the mines and in the countryside. In this paper, I try to show that the opposite was in fact the case, and that the science and government institutions for the regulation of silicosis and tuberculosis in white and black male workers were distinctively elaborated, and very largely successful in tracking and controlling the disease. This singular visibility, funded by the mines, stands in marked contrast with disease in general in South Africa, and forms a major part of the explanation for the very strong association of silicosis with mine work.

  9. Status-Relevant Experiences and Conspicuous Consumption - the Moderating Role of Prenatal Androgen Exposure.

    PubMed

    Cornelissen, Gert; Palacios-Fenech, Javier

    2016-09-20

    In this paper we study consumers' interest in acquiring and displaying expensive luxury products. Based on recent insights in consumer psychology, which build on developments in evolutionary biology, we consider luxury products as "costly signals": wasteful and costly goods, whose purpose is to communicate one's biological fitness, and social status, to others. In line with previous research, we show that experiences that trigger mate attraction goals (Study 1: Exposure to others in bathing outfit) or status display goals (Study 2: Experiencing a vicarious victory of one's favorite sports team) can increase people's interest in luxury products. However, we demonstrate that some individuals are predictably more responsive to those experiences than others. We used a physiological measure (the proportion of the length of the index finger and ring finger of the right hand, 2D:4D) as a proxy for individual differences in exposure to prenatal androgens (i.e., testosterone). This measure has been related to dominant and competitive behavior later in life. We predict and find that individuals with a low 2D:4D (i.e., high exposure to prenatal androgens) were more responsive to the status-relevant experiences: they became more interested in luxury goods after these experiences. This was not the case for high 2D:4D individuals.

  10. 16 CFR 14.9 - Requirements concerning clear and conspicuous disclosures in foreign language advertising and...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... language-speaking consumers. As part of this special effort, advertisements, brochures and sales documents..., or other publication that is not in English, the disclosure shall appear in the predominant...

  11. 16 CFR 14.9 - Requirements concerning clear and conspicuous disclosures in foreign language advertising and...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... language-speaking consumers. As part of this special effort, advertisements, brochures and sales documents..., or other publication that is not in English, the disclosure shall appear in the predominant...

  12. 16 CFR 14.9 - Requirements concerning clear and conspicuous disclosures in foreign language advertising and...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... language-speaking consumers. As part of this special effort, advertisements, brochures and sales documents..., or other publication that is not in English, the disclosure shall appear in the predominant...

  13. 16 CFR 14.9 - Requirements concerning clear and conspicuous disclosures in foreign language advertising and...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... language-speaking consumers. As part of this special effort, advertisements, brochures and sales documents..., or other publication that is not in English, the disclosure shall appear in the predominant...

  14. The Anthropocene: a conspicuous stratigraphical signal of anthropogenic changes in production and consumption across the biosphere

    NASA Astrophysics Data System (ADS)

    Williams, Mark; Zalasiewicz, Jan; Waters, Colin N.; Edgeworth, Matt; Bennett, Carys; Barnosky, Anthony D.; Ellis, Erle C.; Ellis, Michael A.; Cearreta, Alejandro; Haff, Peter K.; Ivar do Sul, Juliana A.; Leinfelder, Reinhold; McNeill, John R.; Odada, Eric; Oreskes, Naomi; Revkin, Andrew; Richter, Daniel deB; Steffen, Will; Summerhayes, Colin; Syvitski, James P.; Vidas, Davor; Wagreich, Michael; Wing, Scott L.; Wolfe, Alexander P.; Zhisheng, An

    2016-03-01

    Biospheric relationships between production and consumption of biomass have been resilient to changes in the Earth system over billions of years. This relationship has increased in its complexity, from localized ecosystems predicated on anaerobic microbial production and consumption to a global biosphere founded on primary production from oxygenic photoautotrophs, through the evolution of Eukarya, metazoans, and the complexly networked ecosystems of microbes, animals, fungi, and plants that characterize the Phanerozoic Eon (the last ˜541 million years of Earth history). At present, one species, Homo sapiens, is refashioning this relationship between consumption and production in the biosphere with unknown consequences. This has left a distinctive stratigraphy of the production and consumption of biomass, of natural resources, and of produced goods. This can be traced through stone tool technologies and geochemical signals, later unfolding into a diachronous signal of technofossils and human bioturbation across the planet, leading to stratigraphically almost isochronous signals developing by the mid-20th century. These latter signals may provide an invaluable resource for informing and constraining a formal Anthropocene chronostratigraphy, but are perhaps yet more important as tracers of a biosphere state that is characterized by a geologically unprecedented pattern of global energy flow that is now pervasively influenced and mediated by humans, and which is necessary for maintaining the complexity of modern human societies.

  15. Morbid Obesity in Disasters: Bringing the “Conspicuously Invisible” into Focus

    PubMed Central

    Gray, Lesley; MacDonald, Carol

    2016-01-01

    It is a frightening reality for some people to be caught up in the midst of a disaster, alone and vulnerable due to their relative size, shape or weight. A literature search failed to find any empirical reports of data specific to body mass index (BMI) in disaster situations. A handful of largely anecdotal reports described situations in which people categorised as morbidly obese were negatively impacted in disasters because of their size and/or weight. While a small number of toolkits and training resources were found, there remains a paucity of research in relation to obesity and emergency planning or disaster risk reduction. This is somewhat surprising, considering the concern about increasing levels of obesity globally. Research is urgently needed to prioritise and address the specific considerations of people with morbid obesity and how communities plan, prepare, respond, and recover from disasters and public health emergencies. PMID:27775636

  16. Critique of medicinal conspicuousness of Parsley(Petroselinum crispum): a culinary herb of Mediterranean region.

    PubMed

    Mahmood, Sidra; Hussain, Shahzad; Malik, Farnaz

    2014-01-01

    WHO estimates, around 80% of the especially developing world is indigent on complementary and alternative medicines which are prodigiously derived from herbal material. Parsley (Petroselinum crispum) is an important culinary herb originated from the Mediterranean region. It possesses small and dark seeds with volatile oil content. Petroselinum crispum is now planted throughout the world due to its usage in food industry, perfume manufacturing, soaps, and creams. Its main constituents subsume coumarins, furanocoumarins (bergapten, imperatori), ascorbic acid, carotenoids, flavonoids, apiole, various terpenoic compounds, phenyl propanoids, phathalides, and tocopherol. Due to these constituents, it has been annunciated to possess a number of possible medicinal emblematics including, antimicrobial, antianemic, menorrhagic, anticoagulant, antihyperlipidemic, antihepatotoxic, antihypertensive, diuretic effects, hypoglycaemic, hypouricemic, anti oxidative and estrogenic activities. In Morocco, Parsley is mostly used as an elixir to treat arterial hypertension, diabetes, cardiac and renal diseases. Antioxidant and antibacterial activities of parsley, made it propitious in food systems. Its ELI17 gene has been corroborated as a particularly fast-responding gene. There is a requisite for extensive research to avail the maximal benefits of this significant medicinal plant. The aim of this review paper is to divulge the chemical constituents of parsley that are explicitly related to substantial medicinal facets.

  17. Selection of a conspicuous male genitalic trait in the seedbug Lygaeus simulans

    PubMed Central

    Tadler, A.

    1999-01-01

    Phenotypic selection of a male genitalic trait based on insemination success in the seedbug Lygaeus simulans, Deckert 1985, was demonstrated in this study. In a laboratory experiment, 97 pairs of virgin animals copulated once. The females consisted of six groups of full sisters, all sisters of a group having been raised in the same box. Related females were used in order to lower the variance of female preferences and to thereby increase the chances of detecting selection of male traits by female choice. The males were independent, i.e. each male descended from a unique pair of parents. Multiple regressions of insemination success on linear and nonlinear terms of a male genitalic trait (processus gonopori length) and male weight revealed stabilizing selection on the genitalic trait. According to functional considerations this selection is most probably the result of female choice of male processus length.

  18. The structure of APG turbulent boundary layers

    NASA Astrophysics Data System (ADS)

    Gungor, Ayse G.; Maciel, Yvan; Simens, Mark P.; Soria, Julio

    2013-11-01

    A boundary layer under influence of a strong APG is studied using DNS. Transition to turbulence is triggered using a trip wire which is modelled using the immersed boundary method. The Reynolds number close to the exit of the numerical domain is Reθ = 2175 and the shape-factor H = 2 . 5 . Two dimensional two-point spatial correlation functions are obtained in this region and close to the transition region. Cvu with a reference point close to the transition region shows a flow periodicity until Reθ ~ 1600 . This periodicity is related to the shear layer instability of the separation bubble created as a result of the APG. The Cvv and Cww correlations obtained far from the transition region at Reθ = 2175 and at y / δ = 0 . 4 coincide with results obtained for a ZPG boundary layer. Implying that the structure of the v , w fluctuations is the same as in ZPG. However, Cuu indicates that the structure of the u fluctuation in an APG boundary layer is almost twice as short as the ZPG structures. The APG structures are also less correlated with the flow at the wall. The near wall structure of strong APG flows is different from ZPG flows in that streaks are much shorter or absent. Funded in part by ITU, NSERC of Canada, ARC Discovery Grant, and Multiflow program of the ERC.

  19. Cranial Bosses of Choerosaurus dejageri (Therapsida, Therocephalia): Earliest Evidence of Cranial Display Structures in Eutheriodonts

    PubMed Central

    Benoit, Julien; Manger, Paul R.; Fernandez, Vincent; Rubidge, Bruce S.

    2016-01-01

    Choerosaurus dejageri, a non-mammalian eutheriodont therapsid from the South African late Permian (~259 Ma), has conspicuous hemispheric cranial bosses on the maxilla and the mandible. These bosses, the earliest of this nature in a eutheriodont, potentially make C. dejageri a key species for understanding the evolutionary origins of sexually selective behaviours (intraspecific competition, ritualized sexual and intimidation displays) associated with cranial outgrowths at the root of the clade that eventually led to extant mammals. Comparison with the tapinocephalid dinocephalian Moschops capensis, a therapsid in which head butting is strongly supported, shows that the delicate structure of the cranial bosses and the gracile structure of the skull of Choerosaurus would be more suitable for display and low energy combat than vigorous head butting. Thus, despite the fact that Choerosaurus is represented by only one skull (which makes it impossible to address the question of sexual dimorphism), its cranial bosses are better interpreted as structures involved in intraspecific selection, i.e. low-energy fighting or display. Display structures, such as enlarged canines and cranial bosses, are widespread among basal therapsid clades and are also present in the putative basal therapsid Tetraceratops insignis. This suggests that sexual selection may have played a more important role in the distant origin and evolution of mammals earlier than previously thought. Sexual selection may explain the subsequent independent evolution of cranial outgrowths and pachyostosis in different therapsid lineages (Biarmosuchia, Dinocephalia, Gorgonopsia and Dicynodontia). PMID:27548428

  20. Structural ceramics

    SciTech Connect

    Wachtman, J.B. Jr.

    1989-01-01

    The present work discusses opportunities for application of structural ceramics in heat engines, industrial-wear parts, prosthetics and bearings; conceptual and detailed design principles for structural ceramics; the processing, consolidation, and properties of members of the SiC family of structural ceramics; and the silicon nitride and sialon families of hot-pressed, sintered, and reaction-bonded, structural ceramics. Also discussed are partially-stabilized zirconia and zirconia-toughened ceramics for structural applications, the processing methods and mechanisms of fiber-reinforcement in ceramic-matrix fiber-reinforced composites, and the tribological properties of structural ceramics.

  1. Structure and diversity in mammalian accessory olfactory bulb.

    PubMed

    Meisami, E; Bhatnagar, K P

    1998-12-15

    The accessory olfactory bulb (AOB) is the first neural integrative center for the olfactory-like vomeronasal sensory system. In this article, we first briefly present an overview of vomeronasal system organization and review the history of the discovery of mammalian AOB. Next, we briefly review the evolution of the vomeronasal system in vertebrates, in particular the reptiles. Following these introductory aspects, the structure of the rodent AOB, as typical of the well-developed mammalian AOB, is presented, detailing laminar organization and cell types as well as aspects of the homology with the main olfactory bulb. Then, the evolutionary origin and diversity of the AOB in mammalian orders and species is discussed, describing structural, phylogenetic, and species-specific variation in the AOB location, shape, and size and morphologic differentiation and development. The AOB is believed to be absent in fishes but present in terrestrial tetrapods including amphibians; among the reptiles AOB is absent in crocodiles, present in turtles, snakes, and some lizards where it may be as large or larger than the main bulb. The AOB is absent in bird and in the aquatic mammals (whales, porpoises, manatees). Among other mammals, AOB is present in the monotremes and marsupials, edentates, and in the majority of the placental mammals like carnivores, herbivores, as well as rodents and lagomorphs. Most bat species do not have an AOB and among those where one is found, it shows marked variation in size and morphologic development. Among insectivores and primates, AOB shows marked variation in occurrence, size, and morphologic development. It is small in shrews and moles, large in hedgehogs and prosimians; AOB continues to persist in New World monkeys but is not found in the adults of the higher primates such as the Old World monkeys, apes, and humans. In many species where AOB is absent in the adult, it often develops in the embryo and fetus but regresses in later stages of

  2. Website Structure

    ERIC Educational Resources Information Center

    Jackson, Larry S.

    2009-01-01

    This dissertation reports the results of an exploratory data analysis investigation of the relationship between the structures used for information organization and access and the associated storage structures within state government websites. Extending an earlier claim that hierarchical directory structures are both the preeminent information…

  3. A remarkable new species of Euragallia from Peru (Insecta, Hemiptera, Cicadellidae, Agalliini), including the description of a peculiar structure of the male genitalia

    PubMed Central

    Rodrigues, Luiz G.; Gonçalves, Ana Clara; Mejdalani, Gabriel

    2012-01-01

    Abstract A new species of Euragallia Oman, 1938 from Peru (Pasco Department) is described and illustrated. Euragallia batmani sp. n. can be distinguished from the other species of the genus by the very posteriorly pronounced male pygofer, with an apical hook-like projection, and by the well-developed dorsal area of the aedeagal base, resembling the open wings of a bat. With the addition of Euragallia batmani sp. n., the number of Euragallia species is increased to 21. Only one additional species of the genus is recorded from Peru (Euragallia prion Kramer, 1976). A comparison between the new species and Euragallia prion is provided. A conspicuous structure, which connects the subgenital plates to the styles, is described in detail and named. PMID:22539879

  4. Novel structure in sciaenid fish skulls indicates continuous production of the cephalic neuromast cupula

    PubMed Central

    Pombo, Maíra; Turra, Alexander

    2016-01-01

    The presence of a conspicuous and frequent but never-described structure in the skull cavities of sciaenid fish was noted during population studies in an urbanized bay. The ultrastructure closely resembles the cupula of neuromasts, an organ associated with the perception of the environment in teleost fish. The bodies were recorded detached in both preserved and freshly sampled individuals and without associated cilia. Prominent characteristics are acellularity, the elliptic-conic shape composed of stack-like protein lamellas, and a mesh-like appearance in cross section. These acellular lamellar cephalic bodies (ALCBs) were more abundant in larger individuals and showed temporal peaks of abundance independently of the fish size. The conic and lamellar features suggest that the deposition of protein layers follows fish growth, and the bimodality of the size of these structures in individuals indicates temporal peaks of production. These results indicate that these ALCBs are a consequence of the accretion of the cupula of neuromasts at a faster rate than they degrade. Given the novelty of this structure and the increasing records of diseases of marine organisms worldwide, an important question is whether these bodies occur subsequently to some environmental change and whether their accumulation in the skull cavities has consequences to fish health. PMID:27876848

  5. Correlatively Dependent Lattice and Electronic Structural Evolutions in Compressed Monolayer Tungsten Disulfide.

    PubMed

    Han, Bo; Li, Fangfei; Li, Liang; Huang, Xiaoli; Gong, Yuanbo; Fu, Xinpeng; Gao, Hanxue; Zhou, Qiang; Cui, Tian

    2017-03-02

    Transition-metal dichalcogenides (TMDs) are promising materials for optoelectronic devices. Their lattice and electronic structural evolutions under high strain conditions and their relations remain open questions. We exert pressure on WS2 monolayers on different substrates, namely, Si/SiO2 substrate and diamond anvil surface up to ∼25 GPa. Structural distortions in various degree are disclosed based on the emergence of Raman-inactive B mode. Splits of out-of-plane B and A1' modes are only observed on Si/SiO2 substrate due to extra strain imported from volume decrease in Si and corrugation of SiO2 surface, and its photoluminescence (PL) quenches quickly because of decreased K-K transition by conspicuous distortion of Brillouin zone. While diamond anvil surface provides better hydrostatic environment, combined analysis of PL and absorption proves that pressure effectively tunes PL emission energy and enhances Coulomb interactions. Knowledge of these distinct pressure tunable characteristics of monolayer WS2 improves further understanding of structural and optical properties of TMDs.

  6. Phylogeographic structure and northward range expansion in the barnacle Chthamalus fragilis.

    PubMed

    Govindarajan, Annette F; Bukša, Filip; Bockrath, Katherine; Wares, John P; Pineda, Jesús

    2015-01-01

    The barnacle Chthamalus fragilis is found along the US Atlantic seaboard historically from the Chesapeake Bay southward, and in the Gulf of Mexico. It appeared in New England circa 1900 coincident with warming temperatures, and is now a conspicuous member of rocky intertidal communities extending through the northern shore of Cape Cod, Massachusetts. The origin of northern C. fragilis is debated. It may have spread to New England from the northern end of its historic range through larval transport by ocean currents, possibly mediated by the construction of piers, marinas, and other anthropogenic structures that provided new hard substrate habitat. Alternatively, it may have been introduced by fouling on ships originating farther south in its historic distribution. Here we examine mitochondrial cytochrome c oxidase I sequence diversity and the distribution of mitochondrial haplotypes of C. fragilis from 11 localities ranging from Cape Cod, to Tampa Bay, Florida. We found significant genetic structure between northern and southern populations. Phylogenetic analysis revealed three well-supported reciprocally monophyletic haplogroups, including one haplogroup that is restricted to New England and Virginia populations. While the distances between clades do not suggest cryptic speciation, selection and dispersal barriers may be driving the observed structure. Our data are consistent with an expansion of C. fragilis from the northern end of its mid-19th century range into Massachusetts.

  7. Potential field constraints on the deep structure of the Lugo gneiss dome (NW Spain)

    NASA Astrophysics Data System (ADS)

    Ayarza, Puy; Martínez Catalán, José R.

    2007-07-01

    The Lugo gneiss dome, in the NW Iberian Massif (Spain) is a Variscan structure developed during late stages of orogenic collapse. Crustal extension was mainly accomplished by two kilometre-scale conjugate extensional shear zones and by the late development of the dome and a huge normal fault. These structures overprint previous contractional recumbent folds and a thrust fault. The Lugo dome and its southward continuation, the Sanabria dome, are the site of the conspicuous Eastern Galicia Magnetic Anomaly (EGMA), a N-S band, 50 km wide and 190 km long, with a maximum amplitude of 190 nT. Integrated potential field modelling of the EGMA and its corresponding gravity signature have been carried out aided by constraints provided by the measurement of c. 900 magnetic susceptibilities and by previous geophysical data, mainly seismic refraction and reflection profiles. Results suggest that a large volume of low-density migmatites and associated inhomogeneous granites are the main source of the magnetic anomaly. Small massifs of basic and ultrabasic rocks inside the migmatites and high-susceptibility iron ore bodies sparsely distributed in low-grade Middle Ordovician slates are also thought to contribute to the anomaly but to a minor extent. Although otherwise similar to other gneiss domes, the Lugo dome is accompanied by a striking magnetic anomaly whose origin is discussed in terms of the tectonic evolution of this structure and the provenance of the magnetite-bearing migmatites and inhomogeneous granites that core it.

  8. Crustal structure of the Kapuskasing Uplift from LITHOPROBE near-vertical/wide-angle seismic reflection data

    NASA Astrophysics Data System (ADS)

    Wu, Jianjun; Mereu, Robert F.

    1992-11-01

    Reprocessing of one LITHOPROBE Kapuskasing deep seismic reflection profile discloses significant new information on the structure of the Kapuskasing Uplift (KU). The shallow structure of the Ivanhoe Lake fault zone (ILFZ), along which the high-grade granulites of the KU were thrust to the surface, is conspicuously imaged on a seismic section as a series of prominent northwest-dipping reflections with listric geometry. The new images show that the ILFZ is a steep fault (about 50 deg) near the surface which quickly flattens out at shallow depths. These reflections coincide with bright positive aeromagnetic anomalies over the fault zone. Direct correlation with geological observations indicates that the high reflectivity and high magnetism associated with the fault zone likely originate from mylonites. The reprocessing also reveals a pronounced midcrustal reflector within the Abitibi greenstone belt (AGB), dipping northwest and plunging under the KU. The existence of such a reflector is independently confirmed by wide-angle reflection data acquired from a cross-profile. This reflector is apparently also detected on two other reflection profiles crossing the ILFZ about 80 km to the southwest. Its concave-down shape and broad lateral extent suggest that it represents underthrusting of the AGB beneath the KU. With these new results, a more complete structural cross-section is constructed.

  9. Phylogeographic structure and northward range expansion in the barnacle Chthamalus fragilis

    PubMed Central

    Bukša, Filip; Bockrath, Katherine; Wares, John P.; Pineda, Jesús

    2015-01-01

    The barnacle Chthamalus fragilis is found along the US Atlantic seaboard historically from the Chesapeake Bay southward, and in the Gulf of Mexico. It appeared in New England circa 1900 coincident with warming temperatures, and is now a conspicuous member of rocky intertidal communities extending through the northern shore of Cape Cod, Massachusetts. The origin of northern C. fragilis is debated. It may have spread to New England from the northern end of its historic range through larval transport by ocean currents, possibly mediated by the construction of piers, marinas, and other anthropogenic structures that provided new hard substrate habitat. Alternatively, it may have been introduced by fouling on ships originating farther south in its historic distribution. Here we examine mitochondrial cytochrome c oxidase I sequence diversity and the distribution of mitochondrial haplotypes of C. fragilis from 11 localities ranging from Cape Cod, to Tampa Bay, Florida. We found significant genetic structure between northern and southern populations. Phylogenetic analysis revealed three well-supported reciprocally monophyletic haplogroups, including one haplogroup that is restricted to New England and Virginia populations. While the distances between clades do not suggest cryptic speciation, selection and dispersal barriers may be driving the observed structure. Our data are consistent with an expansion of C. fragilis from the northern end of its mid-19th century range into Massachusetts. PMID:25945315

  10. Novel structure in sciaenid fish skulls indicates continuous production of the cephalic neuromast cupula

    NASA Astrophysics Data System (ADS)

    Pombo, Maíra; Turra, Alexander

    2016-11-01

    The presence of a conspicuous and frequent but never-described structure in the skull cavities of sciaenid fish was noted during population studies in an urbanized bay. The ultrastructure closely resembles the cupula of neuromasts, an organ associated with the perception of the environment in teleost fish. The bodies were recorded detached in both preserved and freshly sampled individuals and without associated cilia. Prominent characteristics are acellularity, the elliptic-conic shape composed of stack-like protein lamellas, and a mesh-like appearance in cross section. These acellular lamellar cephalic bodies (ALCBs) were more abundant in larger individuals and showed temporal peaks of abundance independently of the fish size. The conic and lamellar features suggest that the deposition of protein layers follows fish growth, and the bimodality of the size of these structures in individuals indicates temporal peaks of production. These results indicate that these ALCBs are a consequence of the accretion of the cupula of neuromasts at a faster rate than they degrade. Given the novelty of this structure and the increasing records of diseases of marine organisms worldwide, an important question is whether these bodies occur subsequently to some environmental change and whether their accumulation in the skull cavities has consequences to fish health.

  11. Magnetic and electronic structure of Mn nanostructures on Ag(111) and Au(111)

    NASA Astrophysics Data System (ADS)

    Cardias, R.; Bezerra-Neto, M. M.; Ribeiro, M. S.; Bergman, A.; Szilva, A.; Eriksson, O.; Klautau, A. B.

    2016-01-01

    We present results of the electronic and magnetic structure of Mn nanowires adsorbed on Ag(111) and Au(111) surfaces. For finite Mn nanowires on Ag(111) and Au(111) surfaces, our ab initio results show that the large difference between the spin-orbit splitting of these two surfaces leads to completely different magnetic configurations. The magnetic ordering for Mn nanowires adsorbed on Ag(111) is governed by the strong exchange interaction between Mn adatoms. For Mn nano-chains on Au(111), the competition between Heisenberg and Dzyaloshinskii-Moriya interactions leads to a complex magnetic structure of the clusters considered here. Among the more conspicuous results we note a spin-spiral helical type for the nanowire with seven atoms, and a complex magnetic configuration incommensurate with the substrate lattice for a double-sized Mn wire. The effect of the structural relaxation is also investigated, showing sensitivity of the exchange interactions to the bond distance to the substrate. We also demonstrate that small changes in the band filling of these Mn chains results in drastically different changes of the interatomic exchange. Finally, we show that dispersion of the electronic energy spectrum is possible even in nanostructures with bounded spatial extension.

  12. Establishment, sex structure and breeding system of an exotic riparian willow, Salix X rubens

    USGS Publications Warehouse

    Shafroth, Patrick B.; Scott, Michael L.; Friedman, Jonathan M.; Laven, Richard D.

    1994-01-01

    Several Eurasian tree willows (Salix spp.) have become naturalized in riparian areas outside of their native range. Salix x rubens is a Eurasian willow that is conspicuous along streams in the high plains of Colorado. We examined establishment of seedlings and cuttings, the sex structure and the breeding system of S. x rubens. An experiment was conducted on establishment and growth of seedlings and cuttings under a range of hydrologic conditions. Seedlings became established under all conditions except when flooded, although many fewer seedlings became established where soil surface conditions were relatively dry. Cuttings became established under all experimental conditions, but most frequently where soil moisture was highest. The sex structure of S. x rubens was determined along several streams in the Colorado high plains. Of 2175 trees surveyed, >99% (2172) were female. Salix x rubens produce viable seed apparently as a result of hybridization with another Eurasian willow, S. alba var. vitellina. Salix x rubens often reproduces vegetatively, which, combined with low hybrid seedling survival in the field, may explain the unusual sex structure. Salix x rubens will likely continue to spread vegetatively in high plains riparian areas, and the potential for spread through hybridization could increase if males of compatible Salix spp. are planted near extant S. x rubens.

  13. Population structure and genetic diversity of Indian Major Carp, Labeo rohita (Hamilton, 1822) from three phylo-geographically isolated riverine ecosystems of India as revealed by mtDNA cytochrome b region sequences.

    PubMed

    Behera, Bijay Kumar; Baisvar, Vishwamitra Singh; Kunal, Swaraj Priyaranjan; Meena, Dharmendra Kumar; Panda, Debarata; Pakrashi, Sudip; Paria, Prasenjit; Das, Pronob; Bhakta, Dibakar; Debnath, Dipesh; Roy, Suvra; Suresh, V R; Jena, J K

    2016-12-26

    The population structure and genetic diversity of Rohu (Labeo rohita Hamilton, 1822) was studied by analysis of the partial sequences of mitochondrial DNA cytochrome b region. We examined 133 samples collected from six locations in three geographically isolated rivers of India. Analysis of 11 haplotypes showed low haplotype diversity (0.00150), nucleotide diversity (π) (0.02884) and low heterogeneity value (0.00374). Analysis of molecular variance (AMOVA) revealed the genetic diversity of L. rohita within population is very high than between the populations. The Fst scores (-0.07479 to 0.07022) were the indication of low genetic structure of L. rohita populations of three rivers of India. Conspicuously, Farakka-Bharuch population pair Fst score of 0.0000, although the sampling sites are from different rivers. The phylogenetic reconstruction of unique haplotypes revealed sharing of a single central haplotype (Hap_1) by all the six populations with a point mutations ranging from 1-25 nucleotides.

  14. The role of zonally asymmetric heating in the vertical and temporal structure of the global scale flow fields during FGGE SOP-1. [First Global Atmospheric Research Program Global Experiment (FGGE); Special Observing Period (SOP)

    NASA Technical Reports Server (NTRS)

    Paegle, J.; Kalnay-Rivas, E.; Baker, W. E.

    1981-01-01

    By examining the vertical structure of the low order spherical harmonics of the divergence and vorticity fields, the relative contribution of tropical and monsoonal circulations upon the global wind fields was estimated. This indicates that the overall flow over North America and the Pacific between January and February is quite distinct both in the lower and upper troposphere. In these longitudes there is a stronger tropical overturning and subtropical jet stream in January than February. The divergent flow reversed between 850 and 200 mb. Poleward rotational flow at upper levels is associated with an equatorward rotational flow at low levels. This suggests that the monsoon and other tropical circulations project more amplitude upon low order (global scale) representations of the flow than do the typical midlatitude circulations and that their structures show conspicuous changes on a time scale of a week or less.

  15. Fabrication of porous bioceramics with porosity gradients similar to the bimodal structure of cortical and cancellous bone.

    PubMed

    Hsu, Y H; Turner, I G; Miles, A W

    2007-12-01

    The aim of this study was to fabricate porous implant materials with graded pore structures similar to the bimodal structure of cortical and cancellous bone. Porous hydroxyapatite/tricalcium phosphate (HA/TCP) bioceramics with interconnected porosity and controlled pore sizes required to simulate natural bone tissue morphology were fabricated by a novel technique of vacuum impregnation of reticulated polymeric foams with ceramic slip. Functionally gradient materials (FGMs) with porosity gradients were made by joining different pore per inch (ppi) foams together by either stitching or pressfitting to form templates. Post production, no defects could be seen at the interface between the two different porosity sections. The macropore sizes of the HA/TCP bioceramics were larger than 100 mum which is appropriate for bone ingrowth. A sample with a graded porous structure which is close to the human bone morphology was also developed. The two component structures were conspicuously different but joined together firmly. Four point bend testing of FGM samples showed them to have similar mechanical properties to homogeneous ceramics based on foam templates with uniform pore sizes, with no evidence of interfacial weakness. Many potential biomedical applications could be developed utilising graded porous structures. The ease of processing will make it possible to fabricate a range of complex shapes for different applications.

  16. Reconfigurable structure

    NASA Technical Reports Server (NTRS)

    Curtis, Steven A. (Inventor)

    2010-01-01

    A reconfigurable structure includes a plurality of selectively extensible and retractable limbs, at least one node pivotably receiving respective ends of at least two limbs, and an actuator associated with each limb for extending and retracting the limb. The structure may further include an addressable module associated with each actuator to control the actuator.

  17. Structural Ceramics

    NASA Technical Reports Server (NTRS)

    1986-01-01

    This publication is a compilation of abstracts and slides of papers presented at the NASA Lewis Structural Ceramics Workshop. Collectively, these papers depict the scope of NASA Lewis' structural ceramics program. The technical areas include monolithic SiC and Si3N4 development, ceramic matrix composites, tribology, design methodology, nondestructive evaluation (NDE), fracture mechanics, and corrosion.

  18. Tau Structures

    PubMed Central

    Avila, Jesus; Jiménez, Juan S.; Sayas, Carmen L.; Bolós, Marta; Zabala, Juan C.; Rivas, Germán; Hernández, Felix

    2016-01-01

    Tau is a microtubule-associated protein that plays an important role in axonal stabilization, neuronal development, and neuronal polarity. In this review, we focus on the primary, secondary, tertiary, and quaternary tau structures. We describe the structure of tau from its specific residues until its conformation in dimers, oligomers, and larger polymers in physiological and pathological situations. PMID:27877124

  19. Protein Structure

    ERIC Educational Resources Information Center

    Asmus, Elaine Garbarino

    2007-01-01

    Individual students model specific amino acids and then, through dehydration synthesis, a class of students models a protein. The students clearly learn amino acid structure, primary, secondary, tertiary, and quaternary structure in proteins and the nature of the bonds maintaining a protein's shape. This activity is fun, concrete, inexpensive and…

  20. On Structure.

    ERIC Educational Resources Information Center

    Acland, Henry

    Structure as an aspect of educational setting is discussed and illustrated in the course of an argument indicating that efforts to change schools, including Project Follow Through, should aim to change structures rather than people. It is asserted that educational reform in America usually attempts to change people, especially children, and that…

  1. Organisational Structure

    ERIC Educational Resources Information Center

    National Centre for Vocational Education Research (NCVER), 2006

    2006-01-01

    An understanding of organisational structure can provide guidance for organisations that want to change and innovate. Many writers agree that this understanding allows organisations to shape how their work is done to ultimately achieve their business goals--and that too often structure is given little consideration in business strategy and…

  2. Hierarchically structured hematite architectures achieved by growth in a silica hydrogel.

    PubMed

    Asenath-Smith, Emily; Hovden, Robert; Kourkoutis, Lena F; Estroff, Lara A

    2015-04-22

    Biomineralization strategies include the use of hydrogels to direct the formation of composite, single-crystal-like structures with unique structure-property profiles. Application of similar synthetic approaches to transition-metal oxides has the promise to yield low-temperature routes to hierarchically structured crystals that are optimized for a range of applications. Here, growth of hematite (α-Fe2O3) within a silica hydrogel resulted in hierarchical, mosaic crystals preferentially expressing catalytically active {110} facets, which are absent in solution-grown controls. Quantitative structural and compositional analysis reveals architectural changes that begin with the incorporation of silicon into the hematite lattice and propagate through to the nanoscale domain structure and assembly, leading to microscale morphologies that show improved photocatalytic performance. This work demonstrates the potential of applying bioinspired crystallization techniques to design functional oxides with multiscale architectural features.

  3. The structure and composition of Holocene coral reefs in the Middle Florida Keys

    USGS Publications Warehouse

    Toth, Lauren T.; Stathakopoulos, Anastasios; Kuffner, Ilsa B.

    2016-07-21

    The Florida Keys reef tract (FKRT) is the largest coral-reef ecosystem in the continental United States. The modern FKRT extends for 362 kilometers along the coast of South Florida from Dry Tortugas National Park in the southwest, through the Florida Keys National Marine Sanctuary (FKNMS), to Fowey Rocks reef in Biscayne National Park in the northeast. Most reefs along the FKRT are sheltered by the exposed islands of the Florida Keys; however, large channels are located between the islands of the Middle Keys. These openings allow for tidal transport of water from Florida Bay onto reefs in the area. The characteristics of the water masses coming from Florida Bay, which can experience broad swings in temperature, salinity, nutrients, and turbidity over short periods of time, are generally unfavorable or “inimical” to coral growth and reef development.Although reef habitats are ubiquitous throughout most of the Upper and Lower Keys, relatively few modern reefs exist in the Middle Keys most likely because of the impacts of inimical waters from Florida Bay. The reefs that are present in the Middle Keys generally are poorly developed compared with reefs elsewhere in the region. For example, Acropora palmata has been the dominant coral on shallow-water reefs in the Caribbean over the last 1.5 million years until populations of the coral declined throughout the region in recent decades. Although A. palmata was historically abundant in the Florida Keys, it was conspicuously absent from reefs in the Middle Keys. Instead, contemporary reefs in the Middle Keys have been dominated by occasional massive (that is, boulder or head) corals and, more often, small, non-reef-building corals.Holocene reef cores have been collected from many locations along the FKRT; however, despite the potential importance of the history of reefs in the Middle Florida Keys to our understanding of the environmental controls on reef development throughout the FKRT, there are currently no published

  4. Mode of formation and structural features of DNA-cationic liposome complexes used for transfection.

    PubMed

    Gershon, H; Ghirlando, R; Guttman, S B; Minsky, A

    1993-07-20

    Complexes formed between cationic liposomes and nucleic acids represent a highly efficient vehicle for delivery of DNA and RNA molecules into a large variety of eukaryotic cells. By using fluorescence, gel electrophoresis, and metal-shadowing electron microscopy techniques, the factors that affect the, yet unclear, interactions between DNA and cationic liposomes as well as the structural features of the resulting complexes have been elucidated. A model is suggested according to which cationic liposomes bind initially to DNA molecules to form clusters of aggregated vesicles along the nucleic acids. At a critical liposome density, two processes occur, namely, DNA-induced membrane fusion, indicated by lipid mixing studies, and liposome-induced DNA collapse, pointed out by the marked cooperativity of the encapsulation processes, by their modulations by DNA-condensing agents, and also by their conspicuous independence upon DNA length. The DNA collapse leads to the formation of condensed structures which can be completely encapsulated within the fused lipid bilayers in a fast, highly cooperative process since their exposed surface is substantially smaller than that of extended DNA molecules. The formation of the transfecting DNA-liposome complexes in which the nucleic acids are fully encapsulated within a positively-charged lipid bilayer is proposed, consequently, to be dominated by mutual effects exerted by the DNA and the cationic liposomes, leading to interrelated lipid fusion and DNA collapse.

  5. Spacecraft Structures

    NASA Video Gallery

    This activity challenges students to solve a real-world problem that is part of the space program using creativity, cleverness and scientific knowledge while learning about forces, structures and e...

  6. Structural Analysis

    NASA Technical Reports Server (NTRS)

    1991-01-01

    After an 800-foot-tall offshore oil recovery platform collapsed, the engineers at Engineering Dynamics, Inc., Kenner, LA, needed to learn the cause of the collapse, and analyze the proposed repairs. They used STAGSC-1, a NASA structural analysis program with geometric and nonlinear buckling analysis. The program allowed engineers to determine the deflected and buckling shapes of the structural elements. They could then view the proposed repairs under the pressure that caused the original collapse.

  7. Inhibitors of the kinase IspE: structure-activity relationships and co-crystal structure analysis.

    PubMed

    Hirsch, Anna K H; Alphey, Magnus S; Lauw, Susan; Seet, Michael; Barandun, Luzi; Eisenreich, Wolfgang; Rohdich, Felix; Hunter, William N; Bacher, Adelbert; Diederich, François

    2008-08-07

    Enzymes of the non-mevalonate pathway for isoprenoid biosynthesis are therapeutic targets for the treatment of important infectious diseases. Whereas this pathway is absent in humans, it is used by plants, many eubacteria and apicomplexan protozoa, including major human pathogens such as Plasmodium falciparum and Mycobacterium tuberculosis. Herein, we report on the design, preparation and biological evaluation of a new series of ligands for IspE protein, a kinase from this pathway. These inhibitors were developed for the inhibition of IspE from Escherichia coli, using structure-based design approaches. Structure-activity relationships (SARs) and a co-crystal structure of Aquifex aeolicus IspE bound to a representative inhibitor validate the proposed binding mode. The crystal structure shows that the ligand binds in the substrate-rather than the adenosine 5'-triphosphate (ATP)-binding pocket. As predicted, a cyclopropyl substituent occupies a small cavity not used by the substrate. The optimal volume occupancy of this cavity is explored in detail. In the co-crystal structure, a diphosphate anion binds to the Gly-rich loop, which normally accepts the triphosphate moiety of ATP. This structure provides useful insights for future structure-based developments of inhibitors for the parasite enzymes.

  8. Structures research

    NASA Technical Reports Server (NTRS)

    Abu-Saba, Elias; Mcginley, Williams; Shen, Ji-Yao

    1992-01-01

    The main objective of the structures group is to provide quality aerospace research with the Center for Aerospace Research - A NASA Center for Excellence at North Carolina Agricultural and Technical State University. The group includes dedicated faculty and students who have a proven record in the area of structures, in particular space structures. The participating faculty developed accurate mathematical models and effective computational algorithms to characterize the flexibility parameters of joint dominated beam-truss structures. Both experimental and theoretical modelling has been applied to the dynamic mode shapes and mode frequencies for a large truss system. During the past few months, the above procedures has been applied to the hypersonic transport plane model. The plane structure has been modeled as a lumped mass system by Doctor Abu-Saba while Doctor Shen applied the transfer matrix method with a piecewise continuous Timoshenko tapered beam model. Results from both procedures compare favorably with those obtained using the finite element method. These two methods are more compact and require less computer time than the finite element method. The group intends to perform experiments on structural systems including the hypersonic plane model to verify the results from the theoretical models.

  9. Structures Division

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The NASA Lewis Research Center Structures Division is an international leader and pioneer in developing new structural analysis, life prediction, and failure analysis related to rotating machinery and more specifically to hot section components in air-breathing aircraft engines and spacecraft propulsion systems. The research consists of both deterministic and probabilistic methodology. Studies include, but are not limited to, high-cycle and low-cycle fatigue as well as material creep. Studies of structural failure are at both the micro- and macrolevels. Nondestructive evaluation methods related to structural reliability are developed, applied, and evaluated. Materials from which structural components are made, studied, and tested are monolithics and metal-matrix, polymer-matrix, and ceramic-matrix composites. Aeroelastic models are developed and used to determine the cyclic loading and life of fan and turbine blades. Life models are developed and tested for bearings, seals, and other mechanical components, such as magnetic suspensions. Results of these studies are published in NASA technical papers and reference publication as well as in technical society journal articles. The results of the work of the Structures Division and the bibliography of its publications for calendar year 1995 are presented.

  10. Centriole structure

    PubMed Central

    Winey, Mark; O'Toole, Eileen

    2014-01-01

    Centrioles are among the largest protein-based structures found in most cell types, measuring approximately 250 nm in diameter and approximately 500 nm long in vertebrate cells. Here, we briefly review ultrastructural observations about centrioles and associated structures. At the core of most centrioles is a microtubule scaffold formed from a radial array of nine triplet microtubules. Beyond the microtubule triplets of the centriole, we discuss the critically important cartwheel structure and the more enigmatic luminal density, both found on the inside of the centriole. Finally, we discuss the connectors between centrioles, and the distal and subdistal appendages outside of the microtubule scaffold that reflect centriole age and impart special functions to the centriole. Most of the work we review has been done with electron microscopy or electron tomography of resin-embedded samples, but we also highlight recent work performed with cryoelectron microscopy, cryotomography and subvolume averaging. Significant opportunities remain in the description of centriolar structure, both in mapping of component proteins within the structure and in determining the effect of mutations on components that contribute to the structure and function of the centriole. PMID:25047611

  11. Sperm structure and phylogeny of Astigmata.

    PubMed

    Liana, Marcin; Witaliński, Wojciech

    2005-09-01

    The Astigmata, a large and variable group, is still a subject of taxonomic dispute. Particularly, their origin from ancestors of the lower oribatid mites (e.g., Malaconothroidea) seems well documented by many lines of evidence. The structure of spermatozoa has been successfully applied to phylogenetic investigations in many animal groups. The aim of our study was to provide new data on spermatozoon structure in Astigmata and to consider its appropriateness in phylogenetic studies. The study reveals information on spermatozoa in 17 species of Astigmata (11 species studied for the first time) extending our knowledge to 18 species (one species known only from the literature) representing 12 families and 7 superfamilies. Spermatozoa have the same basic structure in all species: cells are multiform and the chromatin forms thin threads embedded directly in the cytoplasm; the acrosome is absent. The cytoplasm in most species contains electron-dense lamellae, varying in both number and arrangement within the cell. In Sarcoptoidea, electron-dense tubules in contact with lamellae margins were also observed in Psoroptidae (Psoroptes equi), whereas in two representatives of Sarcoptidae (Notoedres cati and Sarcoptes scabiei), only electron-dense tubules were found. In two species, Canestrinia sellnicki (Canestrinioidea: Canestriniidae) and Scutulanyssus obscurus (Analgoidea: Pteronyssidae), neither lamellae nor tubules were present. The mitochondria in a spermatozoon are usually gathered at the cell periphery and their structure is usually modified to form so-called mitochondrial derivatives. The chromatin threads are an autapomorphy strongly supporting the monophyly of Astigmata. As spermatozoa vary considerably between species in Astigmata, we deduce that sperm structure may be useful for phylogenetic analyses within the group. Several conclusions concerning the affinities within Astigmata are presented. Spermatology seems to be unhelpful, however, in questions on the origin

  12. Ash Shutbah: A possible impact structure in Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Gnos, Edwin; Hofmann, Beda A.; Schmieder, Martin; Al-Wagdani, Khalid; Mahjoub, Ayman; Al-Solami, Abdulaziz A.; Habibullah, Siddiq N.; Matter, Albert; Alwmark, Carl

    2014-10-01

    We have investigated the Ash Shutbah circular structure in central Saudi Arabia (21°37'N 45°39'E) using satellite imagery, field mapping, thin-section petrography, and X-ray diffraction of collected samples. The approximately 2.1 km sized structure located in flat-lying Jurassic Tuwaiq Mountain Limestone has been nearly peneplained by erosional processes. Satellite and structural data show a central area consisting of Dhruma Formation sandstones with steep bedding and tight folds plunging radially outward. Open folding occurs in displaced, younger Tuwaiq Mountain Limestone Formation blocks surrounding the central area, but is absent outside the circular structure. An approximately 60 cm thick, unique folded and disrupted orthoquartzitic sandstone marker bed occurring in the central area of the structure is found 140 m deeper in undisturbed escarpment outcrops located a few hundred meters west of the structure. With exception of a possible concave shatter cone found in the orthoquartzite of the central area, other diagnostic shock features are lacking. Some quartz-rich sandstones from the central area show pervasive fracturing of quartz grains with common concussion fractures. This deformation was followed by an event of quartz dissolution and calcite precipitation consistent with local sea- or groundwater heating. The combination of central stratigraphic uplift of 140 m, concussion features in discolored sandstone, outward-dipping concentric folds in the central area, deformation restricted to the rocks of the ring structure, a complex circular structure of 2.1 km diameter that appears broadly consistent with what one would expect from an impact structure in sedimentary targets, and a possible shatter cone all point to an impact origin of the Ash Shutbah structure. In fact, the Ash Shutbah structure appears to be a textbook example of an eroded, complex impact crater located in flat-lying sedimentary rocks, where the undisturbed stratigraphic section can be

  13. Composite structural materials. [aircraft structures

    NASA Technical Reports Server (NTRS)

    Ansell, G. S.; Loewy, R. G.; Wiberley, S. E.

    1980-01-01

    The use of filamentary composite materials in the design and construction of primary aircraft structures is considered with emphasis on efforts to develop advanced technology in the areas of physical properties, structural concepts and analysis, manufacturing, and reliability and life prediction. The redesign of a main spar/rib region on the Boeing 727 elevator near its actuator attachment point is discussed. A composite fabrication and test facility is described as well as the use of minicomputers for computer aided design. Other topics covered include (1) advanced structural analysis methids for composites; (2) ultrasonic nondestructive testing of composite structures; (3) optimum combination of hardeners in the cure of epoxy; (4) fatigue in composite materials; (5) resin matrix characterization and properties; (6) postbuckling analysis of curved laminate composite panels; and (7) acoustic emission testing of composite tensile specimens.

  14. Study of molecular structure and interactions in partially fluorinated liquid crystal by infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Yakubov, A. A.

    2000-02-01

    The influence of fluorination of mesogens on their molecular structure and interactions were studied by the example of 4- n-(4,4,4-trifluorobutyl) benzoic acid. It was shown, that the inductive influence of the CF 3-group is experienced only by the nearest to it CH 2-groups, and in benzene ring and in carboxyl group its influence is absent. In crystalline phase the intermolecular hydrogen bonds of the C-F…H-C type are formed between CF 3 group and benzene ring. This leads to the increase of intermolecular interactions and, as a result, to increase of melting temperature.

  15. The A-nucleotide preference of HIV-1 in the context of its structured RNA genome

    PubMed Central

    van Hemert, Formijn J.; van der Kuyl, Antoinette C.; Berkhout, Ben

    2013-01-01

    A bipartition of HIV-1 RNA genome sequences into single- and double-stranded nucleotides is possible based on the secondary structure model of a complete 9 kb genome. Subsequent analysis revealed that the well-known lentiviral property of A-accumulation is profoundly present in single-stranded domains, yet absent in double-stranded domains. Mutational rate analysis by means of an unrestricted model of nucleotide substitution suggests the presence of an evolutionary equilibrium to preserve this biased nucleotide distribution. PMID:23235488

  16. Polymorphous-Crystalloid Structure and Relaxation Processes in Some Chalcogenide Glass-Forming Substances

    DTIC Science & Technology

    2001-06-01

    structure is absent. Azoulay in 1975 [21], heating glasses of Ge-Se system with 15-30 at.% Ge content up to temperatures of 280-300 0C, discovered in...at.% Ge only GeSe 2 phase can be formed. Therefore, Azoulay appears to be the first who discovered LTPM GeSe2 and observed the phase transition LTPM...HTPM which can be interpreted as the process of relaxation of crystalline GeSe 2 at temperature increase. The confirmation of the fact that Azoulay

  17. Adenovirus structure.

    PubMed

    Rux, John J; Burnett, Roger M

    2004-12-01

    Structural studies continue to play an essential role as the focus of adenovirus research shifts in emphasis from basic biology to adenovirus-based vector technologies. A crucial step in developing novel therapeutics for gene replacement, cancer, and vaccines is often to modify the virion. Such engineered changes are designed to retarget the virus, or to reduce the immunological responses to infection. These efforts are far more effective when they are based on detailed structural knowledge. This minireview provides a brief summary of the wealth of information that has been obtained from the combined application of X-ray crystallography and electron microscopy. This knowledge now includes a good working model for the architectural organization of the virion, and atomic resolution molecular structures for all the major capsid proteins, hexon, penton, and fiber. We highlight new developments, which include the structure of the penton base and the discovery that adenovirus has several relatives. We sketch how the structural information can be used to engineer novel virions and conclude with the prospects for future progress.

  18. Tension Structure

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The fabric structure pictured is the Campus Center of La Verne College, La Verne, California. Unlike the facilities shown on the preceding pages, it is not air-supported. It is a "tension structure," its multi-coned fabric membrane supported by a network of cables attached to steel columns which function like circus tent poles. The spider-web in the accompanying photo is a computer graph of the tension pattern. The designers, Geiger-Berger Associates PC, of New York City, conducted lengthy computer analysis to determine the the best placement of columns and cables. The firm also served as structural engineering consultant on the Pontiac Silverdome and a number of other large fabric structures. Built by Birdair Structures, Inc., Buffalo, New York, the La Verne Campus Center was the first permanent facility in the United States enclosed by the space-spinoff fabric made of Owens-Corning Beta fiber glass coated with Du Pont Teflon TFE. The flexible design permits rearrangement of the interior to accommodate athletic events, student activities, theatrical productions and other recreational programs. Use of fabric covering reduced building cost 30 percent below conventional construction.

  19. Capturing Hammerhead Ribozyme Structures in Action by Modulating General Base Catalysis

    PubMed Central

    Chi, Young-In; Martick, Monika; Lares, Monica; Kim, Rosalind; Scott, William G; Kim, Sung-Hou

    2008-01-01

    We have obtained precatalytic (enzyme–substrate complex) and postcatalytic (enzyme–product complex) crystal structures of an active full-length hammerhead RNA that cleaves in the crystal. Using the natural satellite tobacco ringspot virus hammerhead RNA sequence, the self-cleavage reaction was modulated by substituting the general base of the ribozyme, G12, with A12, a purine variant with a much lower pKa that does not significantly perturb the ribozyme's atomic structure. The active, but slowly cleaving, ribozyme thus permitted isolation of enzyme–substrate and enzyme–product complexes without modifying the nucleophile or leaving group of the cleavage reaction, nor any other aspect of the substrate. The predissociation enzyme-product complex structure reveals RNA and metal ion interactions potentially relevant to transition-state stabilization that are absent in precatalytic structures. PMID:18834200

  20. Structural Insight into Processive Human Mitochondrial DNA Synthesis and Disease-Related Polymerase Mutations

    SciTech Connect

    Lee, Young-Sam; Kennedy, W. Dexter; Yin, Y. Whitney

    2010-09-07

    Human mitochondrial DNA polymerase (Pol {gamma}) is the sole replicase in mitochondria. Pol {gamma} is vulnerable to nonselective antiretroviral drugs and is increasingly associated with mutations found in patients with mitochondriopathies. We determined crystal structures of the human heterotrimeric Pol {gamma} holoenzyme and, separately, a variant of its processivity factor, Pol {gamma}B. The holoenzyme structure reveals an unexpected assembly of the mitochondrial DNA replicase where the catalytic subunit Pol {gamma}A interacts with its processivity factor primarily via a domain that is absent in all other DNA polymerases. This domain provides a structural module for supporting both the intrinsic processivity of the catalytic subunit alone and the enhanced processivity of holoenzyme. The Pol {gamma} structure also provides a context for interpreting the phenotypes of disease-related mutations in the polymerase and establishes a foundation for understanding the molecular basis of toxicity of anti-retroviral drugs targeting HIV reverse transcriptase.

  1. Structural basis for cooperative oxygen binding and bracelet-assisted assembly of Lumbricus terrestris hemoglobin

    PubMed Central

    Chen, Wei-Ting; Chen, Yu-Chuen; Liou, Horng-Huei; Chao, Chih-Yu

    2015-01-01

    The iron-containing hemoglobins (Hbs) are essential proteins to serve as oxygen transporters in the blood. Among various kinds of Hbs, the earthworm Hbs are the champions in carrying oxygen due to not only their large size but also the unusually high cooperativity of ligand binding. However, the cooperative oxygen binding mechanisms are still mostly unknown. Here we report the cryo-electron microscopy structure of Lumbricus terrestris Hb in its native, oxygenated state at 9.1 Å resolution, showing remarkable differences from the carbon monoxide-binding X-ray structure. Our structural analysis first indicates that the cooperative ligand binding of L. terrestris Hb requires tertiary and quaternary transitions in the heme pocket and a global subunit movement facilitated by intra-ring and inter-ring contacts. Moreover, the additional sinusoidal bracelet provides the confirmation for the long-standing debate about the additional electron densities absent in the X-ray crystal structure. PMID:25897633

  2. Structures protection

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Materials of which an aircraft is made and the methods used to hold these materials together forming the aircraft structure were studied as factors important in protecting a modern aircraft from hazardous natural environments. Since all-metal aircraft are being replaced by aircraft constructed partly of fiber reinforced plastics with desirable light weight and high strength properties but with poor electrical conductivity, the danger of lightning strikes has become more serious. Lightning effects on metal structures were reviewed and design protection was discussed. The expected lightning effects on nonmetallic materials such as fiberglass and advanced composites were also reviewed.

  3. High conformational stability of secreted eukaryotic catalase-peroxidases: answers from first crystal structure and unfolding studies.

    PubMed

    Zámocký, Marcel; García-Fernández, Queralt; Gasselhuber, Bernhard; Jakopitsch, Christa; Furtmüller, Paul G; Loewen, Peter C; Fita, Ignacio; Obinger, Christian; Carpena, Xavi

    2012-09-14

    Catalase-peroxidases (KatGs) are bifunctional heme enzymes widely spread in archaea, bacteria, and lower eukaryotes. Here we present the first crystal structure (1.55 Å resolution) of an eukaryotic KatG, the extracellular or secreted enzyme from the phytopathogenic fungus Magnaporthe grisea. The heme cavity of the homodimeric enzyme is similar to prokaryotic KatGs including the unique distal (+)Met-Tyr-Trp adduct (where the Trp is further modified by peroxidation) and its associated mobile arginine. The structure also revealed several conspicuous peculiarities that are fully conserved in all secreted eukaryotic KatGs. Peculiarities include the wrapping at the dimer interface of the N-terminal elongations from the two subunits and cysteine residues that cross-link the two subunits. Differential scanning calorimetry and temperature- and urea-mediated unfolding followed by UV-visible, circular dichroism, and fluorescence spectroscopy combined with site-directed mutagenesis demonstrated that secreted eukaryotic KatGs have a significantly higher conformational stability as well as a different unfolding pattern when compared with intracellular eukaryotic and prokaryotic catalase-peroxidases. We discuss these properties with respect to the structure as well as the postulated roles of this metalloenzyme in host-pathogen interactions.

  4. Effective electron-density map improvement and structure validation on a Linux multi-CPU web cluster: The TB Structural Genomics Consortium Bias Removal Web Service.

    PubMed

    Reddy, Vinod; Swanson, Stanley M; Segelke, Brent; Kantardjieff, Katherine A; Sacchettini, James C; Rupp, Bernhard

    2003-12-01

    Anticipating a continuing increase in the number of structures solved by molecular replacement in high-throughput crystallography and drug-discovery programs, a user-friendly web service for automated molecular replacement, map improvement, bias removal and real-space correlation structure validation has been implemented. The service is based on an efficient bias-removal protocol, Shake&wARP, and implemented using EPMR and the CCP4 suite of programs, combined with various shell scripts and Fortran90 routines. The service returns improved maps, converted data files and real-space correlation and B-factor plots. User data are uploaded through a web interface and the CPU-intensive iteration cycles are executed on a low-cost Linux multi-CPU cluster using the Condor job-queuing package. Examples of map improvement at various resolutions are provided and include model completion and reconstruction of absent parts, sequence correction, and ligand validation in drug-target structures.

  5. Structural evolution

    SciTech Connect

    Burr, M.T.

    1993-03-01

    In this special report, financial executives discuss key trends in power project finance, new funding sources and evolving project structures. Industry wide, financial firms and developers are striving to improve the cost-effectiveness and efficiency of project financing, for projects in both greenfield development and the growing secondary market.

  6. Nanocrystal structures

    DOEpatents

    Eisler, Hans J.; Sundar, Vikram C.; Walsh, Michael E.; Klimov, Victor I.; Bawendi, Moungi G.; Smith, Henry I.

    2006-12-19

    A structure including a grating and a semiconductor nanocrystal layer on the grating, can be a laser. The semiconductor nanocrystal layer can include a plurality of semiconductor nanocrystals including a Group II–VI compound, the nanocrystals being distributed in a metal oxide matrix. The grating can have a periodicity from 200 nm to 500 nm.

  7. Structural Adaptation

    ERIC Educational Resources Information Center

    Crowley, Julianne; Titmus, Morgan

    2016-01-01

    This article explores an alternative conception held by high school and first-year university biology students regarding the structure of the left and right ventricles of the heart and the significance of the left ventricular wall being thicker than the right. The left ventricular wall of the heart is thicker than the right ventricular wall due to…

  8. Lightweight Structures.

    ERIC Educational Resources Information Center

    Shaver and Co., Michigan City, IN.

    One of the newest and most promising developments in architecture has been the use of lightweight structures for encapsulating space. Using this new technology, builders can enclose large and small areas at a fraction of the cost of conventional construction and at the same time provide interior space that is totally flexible. This brochure shows…

  9. Lake whitefish and lake herring population structure and niche in ten south-central Ontario lakes

    USGS Publications Warehouse

    Carl, Leon M.; McGuiness, Fiona

    2006-01-01

    This study compares simple fish communities of ten oligotrophic lakes in south-central Ontario. Species densities and population size structure vary significantly among these lake communities depending on fish species present beyond the littoral zone. Lake whitefish are fewer and larger in the presence of lake herring than in their absence. Diet analysis indicates that lake whitefish shift from feeding on both plankton and benthic prey when lake herring are absent to a primarily benthic feeding niche in the presence of lake herring. When benthic round whitefish are present, lake whitefish size and density decline and they move lower in the lake compared to round whitefish. Burbot are also fewer and larger in lakes with lake herring than in lakes without herring. Burbot, in turn, appear to influence the population structure of benthic coregonine species. Lower densities of benthic lake whitefish and round whitefish are found in lakes containing large benthic burbot than in lakes with either small burbot or where burbot are absent. Predation on the pelagic larvae of burbot and lake whitefish by planktivorous lake herring alters the size and age structure of these populations. As life history theory predicts, those species with poor larval survival appear to adopt a bet-hedging life history strategy of long-lived individuals as a reproductive reserve.

  10. Geomorphic indicators of deeper seated structure on the southern margin, East Texas basin

    SciTech Connect

    Lemons, D.

    1985-02-01

    Surface geomorphic features are frequently difficult to relate to potential productive structures, but in the East Texas basin there appears to be a significant correlation between surface features and oil fields. The surface topography overlying the East Texas basin gives little indication of subsurface structure. However, conspicuous to southeastern Houston County on the southern margin of the East Texas basin, and to a large part of the entire basin, is a series of northwest- and northeast-trending stream and topographic alignments. These mappable linear geomorphic features (termed lineaments) may indicate fracturing, faulting, and jointing, and thus may be a clue to subsurface structure. The lineaments of southeastern Houston County were mapped and analyzed on a local scale, and those of Houston, Cherokee, Trinity, and Angelina Counties were mapped and analyzed on a more regional scale. Both the local and regional scale lineament analyses indicated preferential orientations of north 30/sup 0/ west and north 30/sup 0/ east. These lineaments are thought to reflect fracturing and faulting although field reconnaissance could not confirm this. It is suggested that gravity slide of the East Texas basin gulfward from the updip edge of the Lousann Salt provided the tensional forces necessary for major lineament formation. However on a more local scale there is a correlation between lineaments and productive fields. Areas of minimum lineament density on the lineament-density contour maps represent subtle subsurface structural highs and, conversely, areas of maximum lineament density on the lineament density contour maps represent subtle subsurface structural lows. Therefore, petroleum potential is generally limited to areas of minimum lineament density.

  11. Stability of Brillouin Flow in Slow-Wave Structures

    NASA Astrophysics Data System (ADS)

    Simon, David; Lau, Y. Y.; Greening, Geoffrey; Wong, Patrick; Gilgenbach, Ronald; Hoff, Brad

    2016-10-01

    For the first time, we include a slow-wave structure (SWS) to study the stability of Brillouin flow in the conventional, planar, and inverted magnetron geometry. The resonant interaction of the SWS circuit mode and the corresponding smooth-bore diocotron-like mode is found to be the dominant cause for instability, overwhelming the intrinsic negative (positive) mass property of electrons in the inverted (conventional) magnetron geometry. It severely restricts the wavenumber for instability to the narrow range in which the cold tube frequency of the SWS is within a few percent of the corresponding smooth bore diocotron-like mode in the Brillouin flow. This resonant interaction is absent in a smooth bore magnetron. Work supported by ONR N00014-13-1-0566 and N00014-16-1-2353, AFOSR FA9550-15-1-0097, and L-3 Communications Electron Device Division.

  12. Periplasmic Structure in Saccharomyces rouxii (Boutroux), an Osmophil

    PubMed Central

    Arnold, Wilfred N.; Garrison, Robert G.; Boyd, Karen S.

    1974-01-01

    Electron micrographs of ultrathin sections of S. rouxii displayed electrondense, membrane-circumscribed structures between the protoplasmic membrane and the cell wall. These periplasmic bodies were numerous in cells from a 3-day culture and absent or rare in older cells. Periplasmic bodies were fewer and smaller (flattened) in specimens grown in a medium fortified with 10% sucrose; they were not detected in cells grown in 20% sucrose. A brief treatment with ethyl acetate caused the periplasmic bodies of young cells to become electron light. Periplasmic bodies were most prevalent in the regions of the bud scars and were often accommodated within large invaginations in the protoplasmic membrane. In general, conditions which favor the prevalence and electron density of periplasmic bodies are those which also mask the activity of β-fructofuranosidase in this species. Images PMID:4451363

  13. Lightweight Structures

    NASA Technical Reports Server (NTRS)

    Whittenberger, J. Daniel

    2001-01-01

    Present structural concepts for hot static structures are conventional "sheet & stringer" or truss core construction. More weight-efficient concepts such as honeycomb and lattice block are being investigated, in combination with both conventional superalloys and TiAl. Development efforts for components made from TiAl sheet are centered on lower cost methods for sheet and foil production, plus alloy development for higher temperature capability. A low-cost casting technology recently developed for aluminum and steel lattice blocks has demonstrated the required higher strength and stiffness, with weight efficiency approach- ing honeycombs. The current effort is based on extending the temperature capability by developing lattice block materials made from IN-718 and Mar-M247.

  14. Superconducting structure

    DOEpatents

    Kwon, Chuhee; Jia, Quanxi; Foltyn, Stephen R.

    2003-04-01

    A superconductive structure including a dielectric oxide substrate, a thin buffer layer of a superconducting material thereon; and, a layer of a rare earth-barium-copper oxide superconducting film thereon the thin layer of yttrium-barium-copper oxide, the rare earth selected from the group consisting of samarium, gadolinium, ytterbium, erbium, neodymium, dysprosium, holmium, lutetium, a combination of more than one element from the rare earth group and a combination of one or more elements from the rare earth group with yttrium, the buffer layer of superconducting material characterized as having chemical and structural compatibility with the dielectric oxide substrate and the rare earth-barium-copper oxide superconducting film is provided.

  15. Superconducting Structure

    DOEpatents

    Kwon, Chuhee; Jia, Quanxi; Foltyn, Stephen R.

    2005-09-13

    A superconductive structure including a dielectric oxide substrate, a thin buffer layer of a superconducting material thereon; and, a layer of a rare earth-barium-copper oxide superconducting film thereon the thin layer of yttrium-barium-copper oxide, the rare earth selected from the group consisting of samarium, gadolinium, ytterbium, erbium, neodymium, dysprosium, holmium, lutetium, a combination of more than one element from the rare earth group and a combination of one or more elements from the rare earth group with yttrium, the buffer layer of superconducting material characterized as having chemical and structural compatibility with the dielectric oxide substrate and the rare earth-barium-copper oxide superconducting film is provided.

  16. Structural Geology

    NASA Astrophysics Data System (ADS)

    Weber, John; Frankel, Kurt L.

    2011-05-01

    Structural geology and continental tectonics were ushered in to the modern quantitative age of geosciences with the arrival of the global plate tectonics paradigm (circa 1968), derived using new data from the oceans' depths, and John Ramsay's 1967 seminal work, Folding and Fracturing of Rocks. Fossen is to be applauded for crafting a unique, high-caliber, and accessible undergraduate textbook on structural geology that faithfully reflects this advance and the subsequent evolution of the discipline. This well-written text draws on Fossen's wealth of professional experience, including his broad and diverse academic research and experience in the petroleum industry. This book is beautifully illustrated, with excellent original color diagrams and with impressive color field photographs that are all keyed to locations and placed into geologic context.

  17. Terminal structure

    DOEpatents

    Schmidt, Frank; Allais, Arnaud; Mirebeau, Pierre; Ganhungu, Francois; Lallouet, Nicolas

    2009-10-20

    A terminal structure (2) for a superconducting cable (1) is described. It consists of a conductor (2a) and an insulator (2b) that surrounds the conductor (2a), wherein the superconducting cable (1) has a core with a superconducting conductor (5) and a layer of insulation that surrounds the conductor (5), and wherein the core is arranged in such a way that it can move longitudinally in a cryostat. The conductor (2a) of the terminal structure (2) is electrically connected with the superconducting conductor (5) or with a normal conductor (6) that is connected with the superconducting conductor (5) by means of a tubular part (7) made of an electrically conductive material, wherein the superconducting conductor (5) or the normal conductor (6) can slide in the part (7) in the direction of the superconductor.

  18. Detection of damage in welded structure using experimental modal data

    NASA Astrophysics Data System (ADS)

    Abu Husain, N.; Ouyang, H.

    2011-07-01

    A typical automotive structure could contain thousands of spot weld joints that contribute significantly to the vehicle's structural stiffness and dynamic characteristics. However, some of these joints may be imperfect or even absent during the manufacturing process and they are also highly susceptible to damage due to operational and environmental conditions during the vehicle lifetime. Therefore, early detection and estimation of damage are important so necessary actions can be taken to avoid further problems. Changes in physical parameters due to existence of damage in a structure often leads to alteration of vibration modes; thus demonstrating the dependency between the vibration characteristics and the physical properties of structures. A sensitivity-based model updating method, performed using a combination of MATLAB and NASTRAN, has been selected for the purpose of this work. The updating procedure is regarded as parameter identification which aims to bring the numerical prediction to be as closely as possible to the measured natural frequencies and mode shapes data of the damaged structure in order to identify the damage parameters (characterised by the reductions in the Young's modulus of the weld patches to indicate the loss of material/stiffness at the damage region).

  19. Deciphering Supramolecular Structures with Protein-Protein Interaction Network Modeling

    PubMed Central

    Tsuji, Toshiyuki; Yoda, Takao; Shirai, Tsuyoshi

    2015-01-01

    Many biological molecules are assembled into supramolecules that are essential to perform complicated functions in the cell. However, experimental information about the structures of supramolecules is not sufficient at this point. We developed a method of predicting and modeling the structures of supramolecules in a biological network by combining structural data of the Protein Data Bank (PDB) and interaction data in IntAct databases. Templates for binary complexes in IntAct were extracted from PDB. Modeling was attempted by assembling binary complexes with superposed shared subunits. A total of 3,197 models were constructed, and 1,306 (41% of the total) contained at least one subunit absent from experimental structures. The models also suggested 970 (25% of the total) experimentally undetected subunit interfaces, and 41 human disease-related amino acid variants were mapped onto these model-suggested interfaces. The models demonstrated that protein-protein interaction network modeling is useful to fill the information gap between biological networks and structures. PMID:26549015

  20. The 2.3-Angstrom Structure of Porcine Circovirus 2

    SciTech Connect

    Khayat, Reza; Brunn, Nicholas; Speir, Jeffrey A.; Hardham, John M.; Ankenbauer, Robert G.; Schneemann, Anette; Johnson, John E.

    2012-10-25

    Porcine circovirus 2 (PCV2) is a T = 1 nonenveloped icosahedral virus that has had severe impact on the swine industry. Here we report the crystal structure of an N-terminally truncated PCV2 virus-like particle at 2.3-{angstrom} resolution, and the cryo-electron microscopy (cryo-EM) image reconstruction of a full-length PCV2 virus-like particle at 9.6-{angstrom} resolution. This is the first atomic structure of a circovirus. The crystal structure revealed that the capsid protein fold is a canonical viral jelly roll. The loops connecting the strands of the jelly roll define the limited features of the surface. Sulfate ions interacting with the surface and electrostatic potential calculations strongly suggest a heparan sulfate binding site that allows PCV2 to gain entry into the cell. The crystal structure also allowed previously determined epitopes of the capsid to be visualized. The cryo-EM image reconstruction showed that the location of the N terminus, absent in the crystal structure, is inside the capsid. As the N terminus was previously shown to be antigenic, it may externalize through viral 'breathing'.

  1. Microplastic Structures

    NASA Astrophysics Data System (ADS)

    Feely, Wayne E.

    1986-07-01

    Thick coatings (5-15μm) of a new dual image, aqueous developable photoresist can be exposed using a light attenuating photomask consisting of clear, opaque and grey areas and then processed to yield thermally stable 3-dimensional structures which are potentially useful as mechanical and optical components of devices. In the positive mode, relief and intaglio images are produced by processing similar to positive novolak based resists with 1- 2μm resolution and with the added feature that the images can be made thermally stable to temperatures >300° C. Negative mode processing of coated wafers imaged with the special mask produces thermally stable structures with tunnels or hollow chambers as well as cantilever beams. Because these structures are crosslinked at the time of development, processing in the negative mode shows much wider latitude than is the case in the positive mode. Images by negative mode processing are capable of submicron resolution, higher aspect ratio (>3 vs <1.6), and inward sloping wall profiles adjustable by exposure. The acid hardening resin compositions cover a broad range of compositions so that resins can be tailored to meet specific property requirements.

  2. THE FINE STRUCTURE OF SYMPATHETIC NEURONS IN X-IRRADIATED FROGS

    PubMed Central

    Pick, Joseph

    1965-01-01

    The effects of whole body x-irradiation on the fine structure of sympathetic neurons were studied in 15 unanesthetized adult frogs (Rana pipiens), as seen at intervals ranging from 1 hour to 2 weeks after single exposures to 1000 r and 2000 r. Using standard procedures, the lumbar sympathetic ganglia of experimental and 20 control animals were prepared for electron microscope examination. Radiation produced conspicuous but irregular and variable deterioration, swelling, and clearing of neuronal lysosomes. These changes may have been due to an increased permeability of lysosomal membranes, causing the entry of fluid into lysosomes and their swelling and deterioration, but a pronounced escape of lysosomal enzymes into the cytoplasm was questionable. Less frequent were the dilatation and the parallel layering or complete fusion and tight packing of the rough-edged endoplasmic reticulum. The number of vacuoles, probably derived from Golgi cisternae, was somewhat increased. These vacuoles were conjectured to serve the "sequestration" of damaged cytoplasmic areas. Abnormal amounts of presumptive glycogen granules occupied some axons of myelinated and unmyelinated fibers, especially of presynaptic nerve fibers. This was assumed to be due to a decreased breakdown of glycogen and probably caused the interruption of the transmission of nerve impulses in presynaptic fibers. The maximal incidence of these alterations seemingly occurred 8 days after exposure to 1000 r, and 1 hour after x-irradiation with 2000 r. Signs of recovery appeared 2 weeks after exposure to 2000 r. PMID:5865928

  3. Structural polarity and dynamics of male germline stem cells in the milkweed bug (Oncopeltus fasciatus).

    PubMed

    Schmidt, Esther D; Dorn, August

    2004-11-01

    The male germline stem cells (GSCs) of the milkweed bug present an extraordinary structural polarity that is, to our knowledge, unequalled by any other type of stem cells. They consist of a perikaryon and numerous projections arising from the cell pole directed toward the apical cells, the proposed niche of the GSCs. The projections can traverse a considerable distance until their terminals touch the apical cells. From hatching until death, the GSC projections undergo conspicuous changes, the sequence of which has been deduced from observations of all developmental stages. Projection formation starts from lobular cell protrusions showing trabecular ingrowths of the cell membrane. Finger-like projections result from a process of growth and "carving out". The newly formed projections contain mostly only free ribosomes other than a few mitochondria. A stereotyped degradation process commences in the projection terminals: profiles of circular, often concentric, cisternae of rough endoplasmic reticulum appear and turn into myelin bodies, whereas mitochondria become more numerous. The cytoplasm vesiculates, lysosomal bodies appear, and mitochondria become swollen. At the same time, the projection terminals are segregated by transverse ingrowths of the cell membrane. Finally, autophagic vacuoles and myelin bodies fill the segregated terminals, which then rupture. Simultaneously, new projections seem to sprout from the perikaryon of the GSCs. These dynamics, which are not synchronized among the GSCs, indicate that a novel type of signal exchange and transduction between the stem cells and their niche is involved in the regulation of asymmetric versus symmetric division of GSCs.

  4. Original Size of the Sudbury Structure: Evidence from Field Investigations and Imaging Radar

    NASA Technical Reports Server (NTRS)

    Lowmman, Paul D., Jr.

    1999-01-01

    This paper summarizes results of continuing studies of the original size of the Sudbury impact structure, including imaging radar and field investigations of supposed "Sudbury breccia" north of the Sudbury Igneous Comples (SIC). Imaging radar acquired from Canada Centre for Remote Sensing (CCRS) aircraft, European Space Agency Remote Sensing Satellite (ERS-1), and RADARSAT shows no evidence of outer rings concentric with the North Range. Illumination directions are such that these rings, presumably extension fractures, would be conspicuous by look azimuth highlighting if they existed. Field mapping supports this interpretation, showing that supposed ring fractures occupied by Huronian sediments are essentially synclines older than the 1850 Ma impact and are not related to the impact. Field investigations of "Sudbury breccia" north of the SIC shows that most if not all of it is inside or along contacts with diabase dykes of the Sudbury Swarm (ca. 1238 Ma), and hence is far too young to be related to the impact. A recently-discovered occurrence of "Sudbury breccia" south of the SIC, near Creighton, is similarly associated with a NW-trending diabase dyke cutting the SIC, supporting the post-impact age of the breccia. It is concluded that the original north rim of the Sudbury crater was not more than 5 to 10 km north of the present North Range SIC contact, and that published estimates of the crater size (ca 200 km diameter) are incorrect.

  5. A Study of Middle Atmospheric Thermal Structure over Western India: Satellite and Model Perspectives

    NASA Astrophysics Data System (ADS)

    Sharma, Som Kumar; Vaishnav, Rajesh; Kumar, Prashant; Jethava, Chintan

    2016-07-01

    Long term variations of middle atmospheric thermal structure in the upper stratosphere and lower mesosphere (20 km to 90 km) have been studied over Ahmedabad (23.1o N, 72.3o E, 55 m amsl), India using SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) onboard TIMED (Thermosphere, Ionosphere, Mesosphere, Energetics and Dynamics)observations during year 2002 to year 2014. For the same period, three different atmospheric models show over-estimation of temperature (~10 K) in stratopause and in upper mesosphere, and a signature of under-estimation is seen above mesopause when compared against SABER measured temperature profile. Estimation of monthly temperature anomalies reveals a downward trend of lower temperature from mesosphere to stratosphere during January to December. Moreover, Lomb Scargle periodogram (LSP) and Wavelet transform techniques are employed to characterize the semi-annual, annual and quasi-biennial oscillations to diagnose the wave dynamics in the stratosphere-mesosphere system. Results suggested that semi-annual, annual and quasi-biennial oscillations are exist in stratosphere, whereas, semi-annual and annual oscillations are observed in mesosphere. In lower mesosphere, LSP analyses revealed conspicuous absence of annual oscillations in altitude range of ~55 to 65 km, and semi-annual oscillations are not exist in 35 to 45 km. Four monthly oscillations are also reported in the altitude range of about 45 to 65 km.The temporal localization of oscillations using wavelet analysis shows strong annual oscillation during year 2004-2006 and 2009-2011.

  6. Petrophysical and paleomagnetic data of drill cores from the Bosumtwi impact structure, Ghana

    NASA Astrophysics Data System (ADS)

    Elbra, T.; Kontny, A.; Pesonen, L. J.; Schleifer, N.; Schell, C.

    Physical properties from rocks of the Bosumtwi impact structure, Ghana, Central Africa, are essential to understand the formation of the relatively young (1.07 Ma) and small (10.5 km) impact crater and to improve its geophysical modeling. Results of our petrophysical studies of deep drill cores LB-07A and LB-08A reveal distinct lithological patterns but no depth dependence. The most conspicuous difference between impactites and target lithologies are the lower bulk densities and significantly higher porosities of the suevite and lithic breccia units compared to meta-graywacke and metapelites of target lithologies. Magnetic susceptibility shows mostly paramagnetic values (200-500 × 10-6 SI) throughout the core, with an exception of a few metasediment samples, and correlates positively with natural remanent magnetization (NRM) and Q values. These data indicate that magnetic parameters are related to inhomogeneously distributed ferrimagnetic pyrrhotite. The paleomagnetic data reveals that the characteristic direction of NRM has shallow normal (in a few cases shallow reversed) polarity, which is in agreement with the Lower Jaramillo N-polarity chron direction, and is carried by ferrimagnetic pyrrhotite. However, our study has not revealed the expected high magnetization body required from previous magnetic modeling. Furthermore, the LB-07A and LB08-A drill cores did not show the predicted high content of melt in the rocks, requiring a new interpretation model for magnetic data.

  7. Glycoconjugates in sweat glands and other structures of skin from normal and cystic fibrosis subjects.

    PubMed

    Hazen-Martin, D J; Sens, D A; Spicer, S S

    1986-12-01

    In this study, glycoconjugates of human skin varied in structure between cell types in an individual and often between individuals for a given cell type. Stored secretory material in dark cells of the sweat gland coil contained complex carbohydrate with terminal alpha-galactose, N-acetylgalactosamine, fucose, or sialic acid. The plasmalemma of clear cells in the secretory coil stained conspicuously for terminal alpha-N-acetylgalactosamine, and the cytosol of clear cells contained lectin-reactive glycogen in the majority of specimens. Superficial and deep cells of the sweat duct evidenced plasmalemmal glycoconjugate with terminal N-acetylgalactosamine. However, only the superficial cell plasmalemma in the duct stained for terminal alpha-N-acetylgalactosamine, fucose, and sialic acid. In several specimens, only the deep cells in the sweat duct revealed plasmalemmal glycoconjugate with terminal beta-galactose. Sebaceous glands alone displayed lectin affinity demonstrative of terminal alpha-galactose and like other sites stained for terminal beta-galactose and alpha-N-acetylgalactosamine. The epithelium in epidermis and hair follicles appeared similar, except for epidermis failing to evidence fucose and alpha-N-acetylgalactosamine with certain lectins. Both underwent changes in glycoconjugate composition with cell maturation. Skin from control subjects and patients with cystic fibrosis did not differ in lectin-binding properties. Abnormalities observed in cystic fibrosis specimens included decreased volume of sebaceous glands and, in two cases, increased infiltration of macrophages staining for terminal N-acetylgalactosamine.

  8. The first description of oarfish Regalecus glesne (Regalecus russellii Cuvier 1816) ageing structures

    USGS Publications Warehouse

    Midway, S.R.; Wagner, Tyler

    2016-01-01

    Despite being a large, conspicuous teleost with a worldwide tropical and temperate distribution, the giant oarfish Regalecus spp. remain very rare fish species in terms of scientific sampling. Subsequently, very little biological information is known about Regalecus spp. and almost nothing has been concluded in the field of age and growth (Roberts, 2012). No studies of otoliths or temporal (annual) markings on any hard structures have been reported, and to our knowledge otoliths have never been recovered from any specimens (Tyson Roberts, personal communication),although a few texts do provide illustrations of Regalecus sp. otoliths (Lin and Chang, 2012; Nolf, 2013). Further inferential difficulty comes from the fact that age and growth studies of any Lampridiforme species are rare. Lampris guttatus is perhaps the only Lampridiforme species for which any biological information has been reported(Francis et al., 2004), which stems from the species commercial value. In order to begin understanding any species (for later purposes of management, conservation, etc.), basic biological information is needed. In the present study, we examine not only the first Regalecus russellii otolith, but provide suggestions toward future work that should direct data collection that can be used to generate basic biological information for this species.

  9. Formation mechanism of primary phases and eutectic structures within undercooled Pb-Sb-Sn ternary alloys

    NASA Astrophysics Data System (ADS)

    Wang, Weili; Dai, Fuping; Wei, Bingbo

    2007-08-01

    The solidification characteristics of three types of Pb-Sb-Sn ternary alloys with different primary phases were studied under substantial undercooling conditions. The experimental results show that primary (Pb) and SbSn phases grow in the dendritic mode, whereas primary (Sb) phase exhibits faceted growth in the form of polygonal blocks and long strips. (Pb) solid solution phase displays strong affinity with SbSn intermetallic compound so that they produce various morphologies of pseudobinary eutectics, but it can only grow in the divorced eutectic mode together with (Sb) phase. Although (Sb) solid solution phase and SbSn intermetallic compound may grow cooperatively within ternary eutectic microstructures, they seldom form pseudobinary eutectics independently. The (Pb)+(Sb)+SbSn ternary eutectic structure usually shows lamellar morphology, but appears as anomalous eutectic when its volume fraction becomes small. EDS analyses reveal that all of the three primary (Pb), (Sb) and SbSn phases exhibit conspicuous solute trapping effect during rapid solidification, which results in the remarkable extension of solute solubility.

  10. Endoskeletal structure in Cheirolepis (Osteichthyes, Actinopterygii), An early ray-finned fish.

    PubMed

    Giles, Sam; Coates, Michael I; Garwood, Russell J; Brazeau, Martin D; Atwood, Robert; Johanson, Zerina; Friedman, Matt

    2015-09-01

    As the sister lineage of all other actinopterygians, the Middle to Late Devonian (Eifelian-Frasnian) Cheirolepis occupies a pivotal position in vertebrate phylogeny. Although the dermal skeleton of this taxon has been exhaustively described, very little of its endoskeleton is known, leaving questions of neurocranial and fin evolution in early ray-finned fishes unresolved. The model for early actinopterygian anatomy has instead been based largely on the Late Devonian (Frasnian) Mimipiscis, preserved in stunning detail from the Gogo Formation of Australia. Here, we present re-examinations of existing museum specimens through the use of high-resolution laboratory- and synchrotron-based computed tomography scanning, revealing new details of the neuro-cranium, hyomandibula and pectoral fin endoskeleton for the Eifelian Cheirolepis trailli. These new data highlight traits considered uncharacteristic of early actinopterygians, including an uninvested dorsal aorta and imperforate propterygium, and corroborate the early divergence of Cheirolepis within actinopterygian phylogeny. These traits represent conspicuous differences between the endoskeletal structure of Cheirolepis and Mimipiscis. Additionally, we describe new aspects of the parasphenoid, vomer and scales, most notably that the scales display peg-and-socket articulation and a distinct neck. Collectively, these new data help clarify primitive conditions within ray-finned fishes, which in turn have important implications for understanding features likely present in the last common ancestor of living osteichthyans.

  11. Structural representation of data structures

    NASA Astrophysics Data System (ADS)

    Cantoni, Virginio; Gaggia, Alessandro; Gatti, Riccardo; Lombardi, Luca

    2014-06-01

    Study of the morphology of proteins, and their 3D structure, supports investigations of their functions and represents an initial step towards protein-based drug design. The goal of this paper is to define techniques, based on the geometrical and topological structure of protein surfaces, for the detection and analysis of sites of potential protein-protein and protein-ligand interactions. Two protein representation modalities based on the Concavity Tree (CT) and the Enriched Complex Extended Gaussian Image (EC-EGI) are considered. In particular, the concavity tree, in which the interface is usually extended and roughly planar, is considered to be better suited to protein-protein interaction studies. Instead, the EGI is more suited to protein-ligand interactions, in which the small ligand molecule usually has to fit into the protein cavity. In fact, the histogram of the orientations is better suited to representing a mainly convex object and its dual matching region (the cavity). Both these data structures are open, and can be easily integrated with biochemical features.

  12. Shear induced structures in crystallizing cocoa butter

    NASA Astrophysics Data System (ADS)

    Mazzanti, Gianfranco; Guthrie, Sarah E.; Sirota, Eric B.; Marangoni, Alejandro G.; Idziak, Stefan H. J.

    2004-03-01

    Cocoa butter is the main structural component of chocolate and many cosmetics. It crystallizes in several polymorphs, called phases I to VI. We used Synchrotron X-ray diffraction to study the effect of shear on its crystallization. A previously unreported phase (phase X) was found and a crystallization path through phase IV under shear was observed. Samples were crystallized under shear from the melt in temperature controlled Couette cells, at final crystallization temperatures of 17.5^oC, 20^oC and 22.5^oC in Beamline X10A of NSLS. The formation of phase X was observed at low shear rates (90 s-1) and low crystallization temperature (17.5^oC), but was absent at high shear (720 s-1) and high temperature (20^oC). The d-spacing and melting point suggest that this new phase is a mixture rich on two of the three major components of cocoa butter. We also found that, contrary to previous reports, the transition from phase II to phase V can happen through the intermediate phase IV, at high shear rates and temperature.

  13. Airfoil structure

    DOEpatents

    Frey, G.A.; Twardochleb, C.Z.

    1998-01-13

    Past airfoil configurations have been used to improve aerodynamic performance and engine efficiencies. The present airfoil configuration further increases component life and reduces maintenance by reducing internal stress within the airfoil itself. The airfoil includes a chord and a span. Each of the chord and the span has a bow being summed to form a generally ``C`` configuration of the airfoil. The generally ``C`` configuration includes a compound bow in which internal stresses resulting from a thermal temperature gradient are reduced. The structural configuration reduces internal stresses resulting from thermal expansion. 6 figs.

  14. Airfoil structure

    DOEpatents

    Frey, Gary A.; Twardochleb, Christopher Z.

    1998-01-01

    Past airfoil configurations have been used to improve aerodynamic performance and engine efficiencies. The present airfoil configuration further increases component life and reduces maintenance by reducing internal stress within the airfoil itself. The airfoil includes a chord and a span. Each of the chord and the span has a bow being summed to form a generally "C" configuration of the airfoil. The generally "C" configuration includes a compound bow in which internal stresses resulting from a thermal temperature gradient are reduced. The structural configuration reduces internal stresses resulting from thermal expansion.

  15. The cortical analysis of speech-specific temporal structure revealed by responses to sound quilts

    PubMed Central

    Overath, Tobias; McDermott, Josh H; Zarate, Jean Mary; Poeppel, David

    2016-01-01

    Speech contains temporal structure that the brain must analyze to enable linguistic processing. To investigate the neural basis of this analysis, we used sound quilts, stimuli constructed by shuffling segments of a natural sound, approximately preserving its properties on short timescales while disrupting them on longer scales. We generated quilts from foreign speech to eliminate language cues and manipulated the extent of natural acoustic structure by varying the segment length. Using functional magnetic resonance imaging, we identified bilateral regions of the superior temporal sulcus (STS) whose responses varied with segment length. This effect was absent in primary auditory cortex and did not occur for quilts made from other natural sounds or acoustically matched synthetic sounds, suggesting tuning to speech-specific spectrotemporal structure. When examined parametrically, the STS response increased with segment length up to ~500 ms. Our results identify a locus of speech analysis in human auditory cortex that is distinct from lexical, semantic or syntactic processes. PMID:25984889

  16. Identification and Structural Analysis of Amino Acid Substitutions that Increase the Stability and Activity of Aspergillus niger Glucose Oxidase

    PubMed Central

    Marín-Navarro, Julia; Roupain, Nicole; Talens-Perales, David; Polaina, Julio

    2015-01-01

    Glucose oxidase is one of the most conspicuous commercial enzymes due to its many different applications in diverse industries such as food, chemical, energy and textile. Among these applications, the most remarkable is the manufacture of glucose biosensors and in particular sensor strips used to measure glucose levels in serum. The generation of ameliorated versions of glucose oxidase is therefore a significant biotechnological objective. We have used a strategy that combined random and rational approaches to isolate uncharacterized mutations of Aspergillus niger glucose oxidase with improved properties. As a result, we have identified two changes that increase significantly the enzyme's thermal stability. One (T554M) generates a sulfur-pi interaction and the other (Q90R/Y509E) introduces a new salt bridge near the interphase of the dimeric protein structure. An additional double substitution (Q124R/L569E) has no significant effect on stability but causes a twofold increase of the enzyme's specific activity. Our results disclose structural motifs of the protein which are critical for its stability. The combination of mutations in the Q90R/Y509E/T554M triple mutant yielded a version of A. niger glucose oxidase with higher stability than those previously described. PMID:26642312

  17. Brain structure volumes in the mole rat, Spalax ehrenbergi (Spalacidae, Rodentia) in comparison to the rat and subterrestrial insectivores.

    PubMed

    Frahm, H D; Rehkämper, G; Nevo, E

    1997-01-01

    Natural blindness and a subterranean, digging mode of life demand peculiar adaptations of the central nervous system in the mole rat Spalax ehrenbergi, which are the focus of this quantitative investigation. Volumes of 25 brain structures in Spalax were evaluated allometrically, using the least encephalized mammalian species, the Madagassian hedgehog-like tenrecs (Tenrecinae) as a reference base, and their sizes compared with those of the rat (as a more generalized representative of rodents) and of some subterranean Insectivora. The allometric approach reveals that Spalax has a larger brain than tenrecs and the rat. Within the brain, the neocortex and diencephalon are well developed, an observation also made in other mammalian species with a relatively high encephalization. An unique feature in Spalax is the enlargement of motor structures of the brain, such as the cerebellum (and cerebellar nuclei), and the striatum. Most conspicuous is the large size of the nucleus motorius nervi trigemini, reflecting the importance of masticatory muscles for the special digging technique, which demand an intense use of the teeth for loosening the soil.

  18. Structures of

    PubMed

    Kirik; Solovyov; Blokhin; Yakimov

    2000-06-01

    Crystal structures of [Pd(NH3)2X2] complexes, where X = Br or I, diamminediiodo-/-dibromopalladium(II), have been studied by X-ray powder diffraction. The series consists of five complexes: cis-[Pd(NH3)2Br2] (I) [a = 13.3202 (7), b = 12.7223 (6), c = 7.05854 (3) A, Z = 8, space group Pbca], trans-[Pd(NH3)2Br2] (II) [a = 6.7854 (3), b = 7.1057 (3), c = 6.6241 (2) A, alpha = 103.221 (3), beta = 102.514 (2), gamma = 100.386 (3) degrees, Z = 2, space group P1], beta-trans-[Pd(NH3)2Br2] (III) [a = 8.4315 (3), b = 8.4206 (3), c = 8.0916 (2) A, Z = 4, space group Pbca], cis-[Pd(NH3)2I2] (IV) [a = 13.9060 (8), b = 13.5035 (8), c = 7.5050 (4) A, Z = 8, space group Pbca], and beta-trans-[Pd(NH3)2I2] (V) [a = 8.8347 (5), b = 8.8410 (5), c = 8.6081 (2) A, Z = 4, space group Pbca]. Patterson synthesis and Rietveld refinement have been used for structural determination. Molecular structures with column- or parquet-type packing of flat complexes are characteristic of these substances. Corresponding cis- and beta-trans compounds are isostructural. The thermal transformations cis-->trans-->beta-trans (cis-->beta-trans in the case of iodine) are considered. Cl derivatives are also discussed. The transformations proceed irreversibly and are accompanied by decreasing specific volume. Owing to these features, they can be classified as chemical reactions. High-temperature X-ray powder diffraction was used to study the transformations in air. The set of data is consistent with a solid state transformation from cis to trans. According to this model, the columns of molecules remain intact during the process, and the transformation proceeds via the breaking of Pd...X and Pd...N intermolecular bonds. The powder diffraction data have been deposited in ICDD-JCPDS (45-0596, 46-0876, 46-0879, 47-1690, 48-1185).

  19. Patterns of inner chorion structure in Anastrepha (Diptera: Tephritidae) eggs.

    PubMed

    Figueiredo, Julia V A; Perondini, André L P; Selivon, Denise

    2017-03-01

    The inner chorion structure of Anastrepha eggs from 16 species of various infrageneric taxonomic groups is described by scanning and transmission electron microscopy. The layers of the chorion, the outer egg membrane, are structurally similar. Furthermore, an additional trabecular layer (ATL) that exists in some species, together with other characteristics, facilitates the recognition of four patterns of chorion structuring: Pattern I, in which the ATL layer is absent, is found in Anastrepha amita, the Anastrepha fraterculus complex, Anastrepha obliqua, Anastrepha sororcula, Anastrepha suspensa and Anastrepha zenildae (fraterculus group), and Anastrepha bistrigata and Anastrepha striata (striata group); Pattern II in Anastrepha serpentina (serpentina group), Anastrepha grandis (grandis group) and Anastrepha pseudoparallela (pseudoparallela group), in which the ATL presents large open spaces with pillars; Pattern III, found in Anastrepha consobrina (pseudoparallela group), in which the ATL is composed of round cavities; and Pattern IV, found in Anastrepha alveata and Anastrepha pickeli (spatulata group), where the large ATL cavities are reticulated. Comparatively, the chorion structure in Anastrepha eggs is more complex than in eggs of other fruit flies, e.g., Bactrocera, Rhagoletis and Ceratitis.

  20. Digital structural

    USGS Publications Warehouse

    Dohm, J.M.; Anderson, R.C.; Tanaka, K.L.

    1998-01-01

    Magmatic and tectonic activity have both contributed significantly to the surface geology of Mars. Digital structural mapping techniques have now been used to classify and date centers of tectonic activity in the western equatorial region. For example, our results show a center of tectonic activity at Valles Marineris, which may be associated with uplift caused by intrusion. Such evidence may help explain, in part, the development of the large troughs and associated outflow channels and chaotic terrain. We also find a local centre of tectonic activity near the source region of Warrego Valles. Here, we suggest that the valley system may have resulted largely from intrusive-related hydrothermal activity. We hope that this work, together with the current Mars Global Surveyor mission, will lead to a better understanding of the geological processes that shaped the Martian surface.

  1. Armor structures

    DOEpatents

    Chu, Henry Shiu-Hung [Idaho Falls, ID; Lacy, Jeffrey M [Idaho Falls, ID

    2008-04-01

    An armor structure includes first and second layers individually containing a plurality of i-beams. Individual i-beams have a pair of longitudinal flanges interconnected by a longitudinal crosspiece and defining opposing longitudinal channels between the pair of flanges. The i-beams within individual of the first and second layers run parallel. The laterally outermost faces of the flanges of adjacent i-beams face one another. One of the longitudinal channels in each of the first and second layers faces one of the longitudinal channels in the other of the first and second layers. The channels of the first layer run parallel with the channels of the second layer. The flanges of the first and second layers overlap with the crosspieces of the other of the first and second layers, and portions of said flanges are received within the facing channels of the i-beams of the other of the first and second layers.

  2. Mapping domain structures in silks from insects and spiders related to protein assembly.

    PubMed

    Bini, Elisabetta; Knight, David P; Kaplan, David L

    2004-01-02

    The exceptional solubility in vivo (20-30%, w/v) of the silk proteins of insects and spiders is dictated by both the need to produce solid fibres with a high packing fraction and the high mesogen concentration required for lyotropic liquid crystalline spinning. A further design requirement for silk proteins is a strong predominance of hydrophobic amino acid residues to provide for the hydrophobic interactions, water exclusion, and beta-crystallite formation required to produce strong insoluble threads. Thus, the domain structure of silk proteins needs to enable nanoscale phase separation to achieve high solubility of hydrophobic proteins in aqueous solutions. Additionally, silk proteins need to avoid premature precipitation as beta-sheets during storage and processing. Here we use mapping of domain types, sizes and distributions in silks to identify consistent design features that have evolved to meet these requirements. We show that silk proteins consist of conspicuously hydrophilic terminal domains flanking a very long central portion constructed from hydrophobic blocks separated by hydrophilic ones, discussing the domain structure in detail. The general rules of construction for silk proteins based on our observations should give a useful guide to the way in which Nature has solved the problem of processing hydrophobic proteins in water and how this can be copied industrially. Following these rules may also help in obtaining adequate expression, soluble products and controllable conformational switches in the production of genetically engineered or chemically synthesized silk analogues. Thus these insights have implications for structural biology and relevance to fundamental and applied questions in material science and engineering.

  3. Crystal structure of pentapeptide-independent chemotaxis receptor methyltransferase (CheR) reveals idiosyncratic structural determinants for receptor recognition.

    PubMed

    Batra, Monu; Sharma, Rajesh; Malik, Anjali; Dhindwal, Sonali; Kumar, Pravindra; Tomar, Shailly

    2016-12-01

    Chemotactic methyltransferase, CheR catalyse methylation of specific glutamate residues in the cytoplasmic domain of methyl-accepting chemotactic protein receptors (MCPRs). The methylation of MCPRs is essential for the chemical sensing and chemotactic bacterial mobility towards favorable chemicals or away from unfavorable ones. In this study, crystal structure of B. subtilis CheR (BsCheR) in complex with S-adenosyl-l-homocysteine (SAH) has been determined to 1.8Å resolution. This is the first report of crystal structure belonging to the pentapeptide-independent CheR (PICheR) class. Till date, only one crystal structure of CheR from S. typhimurium (StCheR) belonging to pentapeptide-dependent CheR (PDCheR) class is available. Structural analysis of BsCheR reveals a helix-X-helix motif (HXH) with Asp53 as the linker residue in the N-terminal domain. The key structural features of the PDCheR β-subdomain involved in the formation of a tight complex with the pentapeptide binding motif in MCPRs were found to be absent in the structure of BsCheR. Additionally, isothermal titration calorimetry (ITC) experiments were performed to investigate S-adenosyl-(l)-methionine (SAM) binding affinity and KD was determined to be 0.32mM. The structure of BsCheR reveals that mostly residues of the large C-terminal domain contribute to SAH binding, with contributions of few residues from the linker region and the N-terminal domain. Structural investigations and sequence analysis carried out in this study provide critical insights into the distinct receptor recognition mechanism of the PDCheR and PICheR methyltransferase classes.

  4. Crystal Structures of Trypanosoma brucei Oligopeptidase B Broaden the Paradigm of Catalytic Regulation in Prolyl Oligopeptidase Family Enzymes

    PubMed Central

    Morty, Rory E.; Fülöp, Vilmos

    2013-01-01

    Oligopeptidase B cleaves after basic amino acids in peptides up to 30 residues. As a virulence factor in bacteria and trypanosomatid pathogens that is absent in higher eukaryotes, this is a promising drug target. Here we present ligand-free open state and inhibitor-bound closed state crystal structures of oligopeptidase B from Trypanosoma brucei, the causative agent of African sleeping sickness. These (and related) structures show the importance of structural dynamics, governed by a fine enthalpic and entropic balance, in substrate size selectivity and catalysis. Peptides over 30 residues cannot fit the enzyme cavity, preventing the complete domain closure required for a key propeller Asp/Glu to fix the catalytic His and Arg in the catalytically competent conformation. This size exclusion mechanism protects larger peptides and proteins from degradation. Similar bacterial prolyl endopeptidase and archael acylaminoacyl peptidase structures demonstrate this mechanism is conserved among oligopeptidase family enzymes across all three domains of life. PMID:24265767

  5. Crystal structures of Trypanosoma brucei oligopeptidase B broaden the paradigm of catalytic regulation in prolyl oligopeptidase family enzymes.

    PubMed

    Canning, Peter; Rea, Dean; Morty, Rory E; Fülöp, Vilmos

    2013-01-01

    Oligopeptidase B cleaves after basic amino acids in peptides up to 30 residues. As a virulence factor in bacteria and trypanosomatid pathogens that is absent in higher eukaryotes, this is a promising drug target. Here we present ligand-free open state and inhibitor-bound closed state crystal structures of oligopeptidase B from Trypanosoma brucei, the causative agent of African sleeping sickness. These (and related) structures show the importance of structural dynamics, governed by a fine enthalpic and entropic balance, in substrate size selectivity and catalysis. Peptides over 30 residues cannot fit the enzyme cavity, preventing the complete domain closure required for a key propeller Asp/Glu to fix the catalytic His and Arg in the catalytically competent conformation. This size exclusion mechanism protects larger peptides and proteins from degradation. Similar bacterial prolyl endopeptidase and archael acylaminoacyl peptidase structures demonstrate this mechanism is conserved among oligopeptidase family enzymes across all three domains of life.

  6. Surgical anatomy and morphologic variations of umbilical structures.

    PubMed

    Fathi, Amir H; Soltanian, Hooman; Saber, Alan A

    2012-05-01

    The umbilicus is the main access route to the abdominal cavity in laparoscopic surgeries. However, its anatomical configuration is rarely studied in the surgical and anatomical literature. With introduction of laparoendoscopic single-site surgery and considering the significant number of primary and postoperative umbilical hernias, we felt the necessity to comprehensively study the umbilical structures and analyze their protective function against hernias. Twenty-four embalmed cadavers were studied in the anatomy laboratory of Case Western Reserve University. Round hepatic, median and medial ligaments, umbilical ring, umbilical and umbilicovesicular fasciae, and pattern of attachment to the ring were dissected and measured. Mean age was 82.1 years, ranging between 56 and 96 years, with a male-to-female ratio of 1.4:1. Ninety-two per cent was white and 8 per cent black adults. According to shape and attachment pattern of ligaments, umbilical ring is classified into five types. Hernia incidence was 25 per cent. All hernia cases lacked the umbilical fascia and the round hepatic ligament was not attached to the inferior border of the ring. The umbilical ring and its morphologic relation with adjacent ligaments are described and classified into five types. In contrary to sparse existing literature, we propose that umbilical fascia is continuation and condensation of umbilicovesicular rather than transversalis fascia. It was absent in cadavers forming conjoined median and medial ligaments with a single insertion site to the ring. Round ligament insertion to the inferior border of the ring provides another protective factor. These two protective measures were absent in all the observed umbilical hernias.

  7. Anatomy of the antennal dorsal organ in female of Neodryinus typhlocybae (Hymenoptera: Dryinidae): A peculiar sensory structure possibly involved in perception of host vibration.

    PubMed

    Riolo, Paola; Isidoro, Nunzio; Ruschioni, Sara; Minuz, Roxana L; Bin, Ferdinando; Romani, Roberto

    2016-01-01

    Neodryinus typhlocybae (Hymenoptera: Dryinidae) is a natural enemy of the planthopper Metcalfa pruinosa, which was introduced from North America into Europe and has become established in various regions as a pest species. Vibrational signals play a crucial role in the communication of M. pruinosa, which appears to be exploited by N. typhlocybae. Scanning and transmission electron microscopy have shown that the antennae of N. typhlocybae females have peculiar and complex sensory structures: deep longitudinal grooves that house long sensilla trichodea, termed here "Antennal Dorsal Organs." Such structures were not present on male antennae. These sensilla extend for the length of the grooves, without contact with the groove cuticle. Their hair shaft is empty and aporous, and inserted into a specialized socket, underneath which there is a cuticular ampulla-like chamber. Each sensillum is associated with two sensory neurons: one terminates at the proximal end of the dendritic sheath; the other continues into the sensillum sinus and is enclosed in the dendritic sheath. This second sensory neuron then enters the ampulla-like chamber through the circular opening, and then terminates with a conspicuous tubular body at the shaft base. The possible involvement of this peculiar structure in the context of host recognition mechanism is discussed.

  8. Crustal structure of the Bighorn Mountains region: Precambrian influence on Laramide shortening and uplift in north-central Wyoming

    NASA Astrophysics Data System (ADS)

    Worthington, Lindsay L.; Miller, Kate C.; Erslev, Eric A.; Anderson, Megan L.; Chamberlain, Kevin R.; Sheehan, Anne F.; Yeck, William L.; Harder, Steven H.; Siddoway, Christine S.

    2016-01-01

    The crustal structure of north-central Wyoming records a history of complex lithospheric evolution from Precambrian accretion to Cretaceous-Paleogene Laramide shortening. We present two active source P wave velocity model profiles collected as part of the Bighorn Arch Seismic Experiment in 2010. Analyses of these velocity models and single-fold reflection data, together with potential field modeling of regional gravity and magnetic signals, constrain crustal structure and thickness of the Bighorn region. We image a west dipping reflection boundary and model a sharp magnetic contact east of the Bighorn Arch that together may delineate a previously undetected Precambrian suture zone. Localized patches of a high-velocity, high-density lower crustal layer (the "7.× layer") occur across the study area but are largely absent beneath the Bighorn Arch culmination. Moho topography is relatively smooth with no large-scale offsets, with depths ranging from ~50 to 37 km, and is largely decoupled from Laramide basement topography. These observations suggest that (1) the edge of the Archean Wyoming craton lies just east of the Bighorn Mountains, approximately 300 km west of previous interpretations, and (2) Laramide deformation localized in an area with thin or absent 7.× layer, due to its relatively weak lower crust, leading to detachment faulting. Our findings show that Precambrian tectonics in northern Wyoming may be more complicated than previously determined and subsequent Laramide deformation may have been critically dependent on laterally heterogeneous crustal structure that can be linked to Precambrian origins.

  9. Gossiping Girls, Insider Boys, A-List Achievement: Examining and Exposing Young Adult Novels Consumed by Conspicuous Consumption

    ERIC Educational Resources Information Center

    Glenn, Wendy

    2008-01-01

    This article employs critical discourse analysis methods to (a) apply Marxist and critical literacy theories to recently published young adult novels that feature wealthy New York teens whose privilege grants them lives of leisure and (b) discuss the implications of using these texts in the classroom to encourage students to read (and consume)…

  10. Conspicuous Coloration in Males of the Damselfly Nehalennia irene (Zygoptera: Coenagrionidae): Do Males Signal Their Unprofitability to Other Males?

    PubMed Central

    Beatty, Christopher D.; Andrés, José A.; Sherratt, Thomas N.

    2015-01-01

    In damselflies, sexual colour dimorphism is commonly explained as a consequence of selection on traits that increase male attractiveness to females. However, while many species in the damselfly family Coenagrionidae (Insecta: Odonata) are sexually dimorphic, the males do not engage in displays, and male competition for mates resembles a “scramble”. An alternative explanation for the sexual differences in coloration within these species is that sexual dimorphism has evolved as a sex-related warning signal, with males signalling their uprofitability as mates to other males, thereby avoiding harassment from conspecifics. We evaluated an underlying assumption of the theory that male-male harassment rate is influenced by colour by comparing harassment of males of the species Nehalennia irene that had been painted to make them appear: (i) similar to an unaltered male (blue), (ii) different from a male (orange) and (iii) more similar to a female (black). When caged together we found that blue-painted males experienced significantly lower harassment than black-painted males. When unpainted males were caged with each type of painted male we found that blue-painted males and the unpainted males housed in the same cages experienced lower rates of harassment than males housed in cages where some males were painted black, suggesting that a single, reliable signal of unprofitability may benefit the individuals that carry it. While our results do not in themselves demonstrate that sexual colour dimorphism originally evolved as an intra-specific warning signal, they do show that harassment is influenced by coloration, and that such selection could conceivably maintain male coloration as a warning signal. PMID:26587979

  11. Conspicuous effect on treatment of mild-to-moderate COPD by combining deep-breathing exercise with oxygen inhalation.

    PubMed

    Liu, Yong-Qiang; Yan, Ling-Xian; Zhang, Li-Yan; Song, Qing-Hua; Xu, Rong-Mei

    2015-01-01

    Chronic obstructive pulmonary disease (COPD) can lead to respiratory failure, but current pharmacological treatments focus on symptom relief or slowing disease progression. Here, the effectiveness of an alternative therapy combining deep-breathing exercises and oxygen inhalation therapy was assessed in mild-to-moderate COPD patients. Forty-two male mild-to-moderate COPD patients were randomly divided into a deep-breathing training group, an oxygen inhalation group, and a combination group (n=14 in each). In the deep-breathing training group, the patients were treated only by the deep-breathing exercise; in the oxygen inhalation group, the patients were treated only by oxygen inhalation; in the combination group, the patients were treated by combining the deep-breathing exercises with oxygen inhalation. Before treatment, there were no statistical differences in the general characteristics or lung function indexes between the three groups of patients (P > 0.05). However, after treatment, patients in the combination group had significantly better lung function indexes than they did before treatment, and their improvement was also superior to that of patients from the deep-breathing training group and the oxygen inhalation group (P < 0.01 and P < 0.05, respectively). Thus, a treatment method combining deep-breathing exercise with oxygen inhalation offers more significant lung function improvement in COPD patients than either the deep-breathing exercise or oxygen inhalation alone. This approach should be further explored for use in the clinic.

  12. Commentary: The Conspicuous Invisibility of Black Ways of Being--Missing Data in New Models of Children's Mental Health

    ERIC Educational Resources Information Center

    Stevenson, Howard C.

    2003-01-01

    The work of Atkins and his colleagues (2003) have provided a wonderful beginning to the development of models that broaden the role of community and school psychology as well as the role of intervention research in the schools. Unfortunately, this work is not easily supported by institutions of academic psychology where more control of extraneous…

  13. Can red flowers be conspicuous to bees? Bombus dahlbomii and South American temperate forest flowers as a case in point.

    PubMed

    Martínez-Harms, J; Palacios, A G; Márquez, N; Estay, P; Arroyo, M T K; Mpodozis, J

    2010-02-15

    It has been argued that trichromatic bees with photoreceptor spectral sensitivity peaks in the ultraviolet (UV), blue and green areas of the spectrum are blind to long wavelengths (red to humans). South American temperate forests (SATF) contain a large number of human red-looking flowers that are reported to be visited by the bumblebee Bombus dahlbomii. In the present study, B. dahlbomii's spectral sensitivity was measured through electroretinogram (ERG) recordings. No extended sensitivity to long wavelengths was found in B. dahlbomii. The spectral reflectance curves from eight plant species with red flowers were measured. The color loci occupied by these flowers in the bee color space was evaluated using the receptor noise-limited model. Four of the plant species have pure red flowers with low levels of chromatic contrast but high levels of negative L-receptor contrast. Finally, training experiments were performed in order to assess the role of achromatic cues in the detection and discrimination of red targets by B. dahlbomii. The results of the training experiments suggest that the bumblebee relies on achromatic contrast provided by the L-receptor to detect and discriminate red targets. These findings are discussed in the context of the evolutionary background under which the relationship between SATF species and their flower visitors may have evolved.

  14. When young are more conspicuous than adults: a new ranid species (Anura: Ranidae) revealed by its tadpole.

    PubMed

    Grosjean, Stéphane; Bordoloi, Sabitry; Chuaynkern, Yodchaiy; Chakravarty, Paramita; Ohler, Annemarie

    2015-12-18

    Tadpoles of Clinotarsus alticola collected nearby the type locality in Assam, India are barcoded and described. A detailed morphological and morphometrical description of the specimens, along with a study of the anatomy of the buccal cavity are provided. A comparison of these tadpoles with "Clinotarsus alticola" tadpoles from peninsular Thailand and of the genetic variation of a fragment of their mtDNA 16S gene led us to assign the population of peninsular Thailand to a new species, Clinotarsus penelope sp. n. The holotype of the new species is chosen among the tadpole series as no adult could be found in the type locality. Presumed conspecific adults of nearby localities are morphologically described and compared to barcoded adults of Clinotarsus alticola, waiting for further molecular confirmation. The tadpole of the new species differs from that of C. alticola by a much greater size at comparative stages (e.g., 77.7 mm vs. 53.3 mm in stage 36, respectively), a black coloration (vs. a yellow-olive tinge), several ocelli on the tail muscle (vs. only one), a rounded snout (vs. a more pointed snout) and a different Keratodont Row Formula (KRF; nine keratodonts rows maximum on both labia in C. penelope vs. eight maximum in C. alticola). A discussion about the choice of the holotype, the assignment of adult specimens and the future confirmation of this assignment are provided, as well as a comparison with older descriptions of "Clinotarsus alticola" sensu lato tadpoles and with Clinotarsus curtipes tadpoles from Karnataka, India. The lectotype of Clinotarsus alticola is redescribed.

  15. Asteroid structure

    NASA Astrophysics Data System (ADS)

    Asphaug, E.

    2014-07-01

    Even before the first space missions to asteroids, in the mid-1990s, it was known that asteroids have weird structures. Photometry indicated complicated shapes, and the pioneering radar investigations by Ostro and colleagues followed by adaptive optics campaigns and flybys showed odd binary forms, and confirmed the common presence of satellites, and indications of highly varying surface roughness. Some asteroids turned out to be dominated by a single major cratering event, while others showed no evidence of a major crater, or perhaps for global crater erasure. The first space mission to orbit an asteroid, NEAR, found a mixture of heavily cratered terrains and geomorphically active 'ponds', and indicated evidence for global seismicity from impact. The next mission to orbit an asteroid, Hayabusa, found what most agree is a rubble pile, with no major craters and an absence of fines. There is to date no direct evidence of asteroid interior geology, other than measurements of bulk density, and inferences made for mass distribution asymmetry based on dynamics, and inferences based on surface lineaments. Interpolating from the surface to the interior is always risky and usually wrong, but of course the answer is important since we are someday destined to require this knowledge in order to divert a hazardous asteroid from impact with the Earth. Even considering the near-subsurface, here we remain as ignorant as we were about the Moon in the early 1960s, whether the surface will swallow us up in dust, or will provide secure landing and anchoring points. Laboratory experimentation in close to zero-G is still in its early stages. Adventures such as mining and colonization will surely have to wait until we better know these things. How do we get from here to there? I will focus on 3 areas of progress: (1) asteroid cratering seismology, where we use the surface craters to understand what is going on inside; (2) numerical modeling of collisions, which predicts the internal

  16. Structural Changes in the Antennapedia Complex of Drosophila Pseudoobscura

    PubMed Central

    Randazzo, F. M.; Seeger, M. A.; Huss, C. A.; Sweeney, M. A.; Cecil, J. K.; Kaufman, T. C.

    1993-01-01

    The discovery of the striking positional conservation between the Antennapedia and Bithorax homeotic gene complexes (ANT-C and BX-C) in Drosophila melanogaster and the murine Hox and human HOX clusters has had a substantial impact on our understanding of the evolution of development and its genetic regulation. Structural differences do exist among the mammalian Hox complexes and the ANT-C in D. melanogaster. To gain further insight into the evolutionary changes among these complexes, the ANT-C was cloned in the closely related species, Drosophila pseudoobscura. The overall structure of the ANT-C in D. pseudoobscura is highly similar to its D. melanogaster counterpart; however, two differences in the organization of the ANT-C have been identified. First, the z2 gene, a member of the ANT-C in D. melanogaster, is not present in the D. pseudoobscura ANT-C and is possibly absent from the D. pseudoobscura genome. Second, the orientation of the Deformed gene is inverted in D. pseudoobscura, providing it with a 5' to 3' direction of transcription identical to the remaining ANT-C homeobox genes with the exception of fushi tarazu. These differences demonstrate that subtle changes can occur in ANT-C structure during relatively short periods of evolutionary divergence, although the fundamental organization of the complex is conserved. These observations and others suggest that the complex is not absolutely rigid but that selective pressures have maintained this organization of genes for some functional reason that remains elusive. PMID:8099892

  17. Structural conservation of chemotaxis machinery across Archaea and Bacteria.

    PubMed

    Briegel, Ariane; Ortega, Davi R; Huang, Audrey N; Oikonomou, Catherine M; Gunsalus, Robert P; Jensen, Grant J

    2015-06-01

    Chemotaxis allows cells to sense and respond to their environment. In Bacteria, stimuli are detected by arrays of chemoreceptors that relay the signal to a two-component regulatory system. These arrays take the form of highly stereotyped super-lattices comprising hexagonally packed trimers-of-receptor-dimers networked by rings of histidine kinase and coupling proteins. This structure is conserved across chemotactic Bacteria, and between membrane-bound and cytoplasmic arrays, and gives rise to the highly cooperative, dynamic nature of the signalling system. The chemotaxis system, absent in eukaryotes, is also found in Archaea, where its structural details remain uncharacterized. Here we provide evidence that the chemotaxis machinery was not present in the last archaeal common ancestor, but rather was introduced in one of the waves of lateral gene transfer that occurred after the branching of Eukaryota but before the diversification of Euryarchaeota. Unlike in Bacteria, the chemotaxis system then evolved largely vertically in Archaea, with very few subsequent successful lateral gene transfer events. By electron cryotomography, we find that the structure of both membrane-bound and cytoplasmic chemoreceptor arrays is conserved between Bacteria and Archaea, suggesting the fundamental importance of this signalling architecture across diverse prokaryotic lifestyles.

  18. Morphology of supposed cellulose-synthesizing structures in higher plants

    SciTech Connect

    Willison, J.H.M.

    1983-01-01

    The structure, frequency of occurrence, and distribution of structures, revealed by freeze fracturing plasma membranes and claimed to be associated with cellulose microfibril biosynthesis/bioassembly, is presented. P. fracture face ''rosettes'' are shown to consist of six equivalent particles. It is argued that rosettes are not involved with microfibril biosynthesis and assembly because they are absent from isolated protoplasts known to be assembling microfibrils; their frequency is 2.5 to 6 times lower than that of ''terminal globules'' in root tissues and cotton fibres; and they are not microfibril terminal. It is reasoned that E fracture face terminal globules constitute evidence of microfibril tip growth (an involvement of the globules with microfibril biosynthesis/bioassembly is a valid hypothesis) in view of their attachment to microfibril tips. Since terminal globules appear to vary in the intimacy of their association with the plasma membrane, it is argued that an integral association between the terminal globule and the plasma membrane may be inessential for microfibril bioassembly. Not all microfibril tips have terminal globules, and it is speculated that different types of microfibrils may have different types of terminal synthetic structures. 40 references, 11 figures, 1 table.

  19. The structure and inhibition of human diamine oxidase†,‡

    PubMed Central

    McGrath, Aaron P; Hilmer, Kimberly M; Collyer, Charles A; Shepard, Eric M; Elmore, Bradley O.; Brown, Doreen E; Dooley, David M; Guss, J Mitchell

    2009-01-01

    Humans have three functioning genes that code for copper-containing amine oxidases. The product of the AOC1 gene is a so-called diamine oxidase (hDAO), named for its substrate preference for diamines, particularly histamine. hDAO has been cloned and expressed in insect cells and the structure of the native enzyme determined by X-ray crystallography to a resolution of 1.8 Å. The homodimeric structure has the archetypal amine oxidase fold. Two active sites, one in each subunit, are characterized by the presence of a copper ion and a topaquinone residue formed by the post-translational modification of a tyrosine. Although hDAO shares 37.9 % sequence identity with another human copper amine oxidase, semicarbazide sensitive amine oxidase or vascular adhesion protein-1, its substrate binding pocket and entry channel are distinctly different in accord with the different substrate specificities. The structures of two inhibitor complexes of hDAO, berenil and pentamidine, have been refined to resolutions of 2.1 Å and 2.2 Å, respectively. They bind non-covalently in the active site channel. The inhibitor binding suggests that an aspartic acid residue, conserved in all diamine oxidases but absent from other amine oxidases, is responsible for the diamine specificity by interacting with the second amino group of preferred diamine substrates. PMID:19764817

  20. Identification of silver cubic structures during ultrasonication of chitosan AgNO3 solution.

    PubMed

    Raghavendra, Gownolla Malegowd; Jung, Jeyoung; Kim, Dowan; Varaprasad, Kokkarachedu; Seo, Jongchul

    2016-11-05

    During ultrasonication of chitosan AgNO3 solution (10mM), silver cubic structures were identified along with other dispersed silver nanoparticles. Temperature influenced the formation of the cubic structures. Formation of the silver cubic structures occurred via initial formation of 'four petal flower-like' structures that underwent transformation to the "cubic morphology" in the latter stages. Aging of the reaction mixture led to formation of complete dendrites. These dendrites comprised a large quantity of silver nanoparticles. Upon repetition of the experiment with starch instead of chitosan, the identified silver cubic structures were completely absent, indicating that formation of the 'silver cubic structures' is dependent on the polysaccharide used. It is believed that the structural features of chitosan facilitate the formation of 'silver cubic structures' under ultrasonic conditions. The phenomena occurring during the experiments were evaluated via scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), ultraviolet-visible (UV-vis) spectra, transmission electron microscopy (TEM), and selected area electron diffraction (SAED) analysis.

  1. Simultaneous characterization of cellular RNA structure and function with in-cell SHAPE-Seq

    PubMed Central

    Watters, Kyle E.; Abbott, Timothy R.; Lucks, Julius B.

    2016-01-01

    Many non-coding RNAs form structures that interact with cellular machinery to control gene expression. A central goal of molecular and synthetic biology is to uncover design principles linking RNA structure to function to understand and engineer this relationship. Here we report a simple, high-throughput method called in-cell SHAPE-Seq that combines in-cell probing of RNA structure with a measurement of gene expression to simultaneously characterize RNA structure and function in bacterial cells. We use in-cell SHAPE-Seq to study the structure–function relationship of two RNA mechanisms that regulate translation in Escherichia coli. We find that nucleotides that participate in RNA–RNA interactions are highly accessible when their binding partner is absent and that changes in RNA structure due to RNA–RNA interactions can be quantitatively correlated to changes in gene expression. We also characterize the cellular structures of three endogenously expressed non-coding RNAs: 5S rRNA, RNase P and the btuB riboswitch. Finally, a comparison between in-cell and in vitro folded RNA structures revealed remarkable similarities for synthetic RNAs, but significant differences for RNAs that participate in complex cellular interactions. Thus, in-cell SHAPE-Seq represents an easily approachable tool for biologists and engineers to uncover relationships between sequence, structure and function of RNAs in the cell. PMID:26350218

  2. Gravitational Effects on Near Field Flow Structure of Low Density Gas Jets

    NASA Technical Reports Server (NTRS)

    Yep, Tze-Wing; Agrawal, Ajay K.; Griffin, DeVon; Salzman, Jack (Technical Monitor)

    2001-01-01

    Experiments were conducted in Earth gravity and microgravity to acquire quantitative data on near field flow structure of helium jets injected into air. Microgravity conditions were simulated in the 2.2-second drop tower at NASA Glenn Research Center. The jet flow was observed by quantitative rainbow schlieren deflectometry, a non-intrusive line of site measurement technique for the whole field. The flow structure was characterized by distributions of angular deflection and helium mole percentage obtained from color schlieren images taken at 60 Hz. Results show that the jet flow was significantly influenced by the gravity. The jet in microgravity was up to 70 percent wider than that in Earth gravity. The jet flow oscillations observed in Earth gravity were absent in microgravity, providing direct experimental evidence that the flow instability in the low density jet was buoyancy induced. The paper provides quantitative details of temporal flow evolution as the experiment undergoes a change in gravity in the drop tower.

  3. Gravitational Effects on Near-Field Flow Structure of Low-Density Gas Jets

    NASA Technical Reports Server (NTRS)

    Yep, Tze-Wing; Agrawal, Ajay K.; Griffin, DeVon

    2004-01-01

    Experiments were conducted in earth gravity and micro gravity to acquire quantitative data on near field flow structure of helium jets injected into air. Microgravity conditions were simulated in the 2.2 s drop tower at NASA John H. Glenn Research Center. The jet flow was observed by quantitative rainbow schlieren deflectometry, a non-intrusive line of sight measurement technique suited for the microgravity environment. The flow structure was characterized by distribution of helium mole fraction obtained from color schlieren images taken at 60 Hz. Results show that the jet in microgravity was up to 70% wider than that in Earth gravity. Experiments reveal that the global flow oscillations observed in Earth are absent in microgravity. Quantitative deatails are provided of the evolution as the experiment undergoes changes in gravity in the drop tower.

  4. Gravitational Effects on Near Field Flow Structure of Low Density Gas Jets

    NASA Technical Reports Server (NTRS)

    Griffin, D. W.; Yep, T. W.; Agrawal, A. K.

    2005-01-01

    Experiments were conducted in Earth gravity and microgravity to acquire quantitative data on near field flow structure of helium jets injected into air. Microgravity conditions were simulated in the 2.2- second drop tower at NASA Glenn Research Center. The jet flow was observed by quantitative rainbow schlieren deflectometry, a non-intrusive line of site measurement technique for the whole field. The flow structure was characterized by distributions of angular deflection and helium mole percentage obtained from color schlieren images taken at 60 Hz. Results show that the jet in microgravity was up to 70 percent wider than that in Earth gravity. The global jet flow oscillations observed in Earth gravity were absent in microgravity, providing direct experimental evidence that the flow instability in the low density jet was buoyancy induced. The paper provides quantitative details of temporal flow evolution as the experiment undergoes change in gravity in the drop tower.

  5. Structure and orientation of small particles of platinum deposited on NaCl and mica

    NASA Technical Reports Server (NTRS)

    Renou, A.; Gillet, M.

    1979-01-01

    The structure of small platinum particles condensed in vacuum onto NaCl (001), NaCl (111) and mica substrates was studied by electron diffraction and electron microscopy. Results show that above a certain substrate temperature decahedral or icosahedral particles are formed. These particles are practically absent with substrates cleaved in high vacuum. They are always much less numerous than in gold films prepared under the same conditions. Assumptions made to explain this phenomenon are: (1) the initial growth of an abnormal structure of the nuclei as opposed by the substrate; (2) the particles disappear before they attain a size which corresponds to the observations; and (3) the particles result from a coalescence mechanism leading to multiple twinned particles.

  6. Structure of the human smoothened receptor 7TM bound to an antitumor agent

    PubMed Central

    Wang, Chong; Wu, Huixian; Katritch, Vsevolod; Han, Gye Won; Huang, Xi-Ping; Liu, Wei; Siu, Fai Yiu; Roth, Bryan L.; Cherezov, Vadim; Stevens, Raymond C.

    2013-01-01

    The smoothened (SMO) receptor, a key signal transducer in the Hedgehog (Hh) signaling pathway is both responsible for the maintenance of normal embryonic development and implicated in carcinogenesis. The SMO receptor is classified as a class Frizzled (class F) G protein-coupled receptor (GPCR), although the canonical Hh signaling pathway involves the transcription factor Gli and the sequence similarity with class A GPCRs is less than 10%. Here we report the crystal structure at 2.5 Å resolution of the transmembrane domain of the human SMO receptor bound to the small molecule antagonist LY2940680. Although the SMO receptor shares the seven transmembrane helical (7TM) fold, most conserved motifs for class A GPCRs are absent, and the structure reveals an unusually complex arrangement of long extracellular loops stabilized by four disulfide bonds. The ligand binds at the extracellular end of the 7TM bundle and forms extensive contacts with the loops. PMID:23636324

  7. Raman scattering and Medium Range Structure of (BaO)x(B2O3)100-x -glasses

    NASA Astrophysics Data System (ADS)

    Holbrook, Chad; Chbier, Ralph; Czaja, Andrew; Boolchand, Punit

    In Raman scattering of titled glasses we observe a triad of modes (770 cm-1, 750 cm-1, 705 cm-1) on the low frequency side of the famous Boroxyl-Ring (BR) mode (808 cm-1) as the BaO content x increases in the 0 conspicuous absence of these mixed-ring modes is consistent with the composition range representing the immiscibility range. At x >15%, the 770 cm-1 mode scattering strength grows precipitously to show a maximum near xc = 20%, consistent with presence of Ba-tetraborate structural grouping (SG). At x >15%, we also observe scattering strength of the 750 cm-1 mode to increase with x and show a maximum near xc = 33%, consistent with formation of Ba-diborate SG. Finally, a mode near 705 cm-1, whose scattering strength increases linearly with x in the 15%

  8. Structural Biology Fact Sheet

    MedlinePlus

    ... Home > Science Education > Structural Biology Fact Sheet Structural Biology Fact Sheet Tagline (Optional) Middle/Main Content Area What is structural biology? Structural biology is a field of science focused ...

  9. Structural consequences of cohesion in gravitational instabilities triggered by fluid overpressure: Analytical derivation and experimental testing

    NASA Astrophysics Data System (ADS)

    Mourgues, R.; Costa, A. C. G.; Marques, F. O.; Lacoste, A.; Hildenbrand, A.

    2016-06-01

    The critical taper theory of Coulomb wedges has been classically applied to compressive regimes (accretionary prisms/fold-and-thrust belts), and more recently to gravitational instabilities. Following the initial hypothesis of the theory, we provide an alternative expression of the exact solution for a non-cohesive wedge by considering the balance of forces applied to the external surfaces. Then, we use this approach to derive a solution for the case of cohesive wedges. We show that cohesion has conspicuous structural effects, including a minimum length required for sliding and the formation of listric faults. The stabilizing effect of cohesion is accentuated in the foremost thin domain of the wedge, defining a required Minimum Failure Length (MFL), and producing sliding of a rigid mass above the detachment. This MFL decreases with less cohesion, a smaller coefficient of internal friction, larger fluid overpressure ratio, and steeper upper and basal surfaces for the wedge. Listricity of the normal faults depends on the fluid overpressure magnitude within the wedge. For moderate fluid overpressure, normal faults are curved close to the surface, and become straight at depth. In contrast, where fluid overpressure exceeds a critical value corresponding to the fluid pressure required to destabilize the surface of a noncohesive wedge, the state of stress changes and rotates at depth. The faults are straight close to the surface and listric at depth, becoming parallel to the upper surface if the wedge is thick enough. We tested some of these structural effects of a cohesive wedge on gravitational instabilities using analogue models where cohesive material was subjected to pore-fluid pressure. The shape of the faults obtained in the models is consistent with the predictions of the theory.

  10. Evolutionary snowdrift game incorporating costly punishment in structured populations

    NASA Astrophysics Data System (ADS)

    Chan, Nat W. H.; Xu, C.; Tey, Siew Kian; Yap, Yee Jiun; Hui, P. M.

    2013-01-01

    The role of punishment and the effects of a structured population in promoting cooperation are important issues. Within a recent model of snowdrift game (SG) incorporating a costly punishing strategy (P), we study the effects of a population connected through a square lattice. The punishers, who carry basically a cooperative (C) character, are willing to pay a cost α so as to punish a non-cooperative (D) opponent by β. Depending on α, β, the cost-to-benefit ratio r in SG, and the initial conditions, the system evolves into different phases that could be homogeneous or inhomogeneous. The spatial structure imposes geometrical constraint on how one agent is affected by neighboring agents. Results of extensive numerical simulations, both for the steady state and the dynamics, are presented. Possible phases are identified and discussed, and isolated phases in the r-β space are identified as special local structures of strategies that are stable due to the lattice structure. In contrast to a well-mixed population where punishers are suppressed due to the cost of punishment, the altruistic punishing strategy can flourish and prevail for appropriate values of the parameters, implying an enhancement in cooperation by imposing punishments in a structured population. The system could evolve to a phase corresponding to the coexistence of C, D, and P strategies at some particular payoff parameters, and such a phase is absent in a well-mixed population. The pair approximation, a commonly used analytic approach, is extended from a two-strategy system to a three-strategy system. We show that the pair approximation can, at best, capture the numerical results only qualitatively. Due to the improper way of including spatial correlation imposed by the lattice structure, the approximation does not give the frequencies of C, D, and P accurately and fails to give the homogeneous AllD and AllP phases.

  11. NMR solution structures of actin depolymerizing factor homology domains

    PubMed Central

    Goroncy, Alexander K; Koshiba, Seizo; Tochio, Naoya; Tomizawa, Tadashi; Sato, Manami; Inoue, Makato; Watanabe, Satoru; Hayashizaki, Yoshihide; Tanaka, Akiko; Kigawa, Takanori; Yokoyama, Shigeyuki

    2009-01-01

    Actin is one of the most conserved proteins in nature. Its assembly and disassembly are regulated by many proteins, including the family of actin-depolymerizing factor homology (ADF-H) domains. ADF-H domains can be divided into five classes: ADF/cofilin, glia maturation factor (GMF), coactosin, twinfilin, and Abp1/drebrin. The best-characterized class is ADF/cofilin. The other four classes have drawn much less attention and very few structures have been reported. This study presents the solution NMR structure of the ADF-H domain of human HIP-55-drebrin-like protein, the first published structure of a drebrin-like domain (mammalian), and the first published structure of GMF β (mouse). We also determined the structures of mouse GMF γ, the mouse coactosin-like domain and the C-terminal ADF-H domain of mouse twinfilin 1. Although the overall fold of the five domains is similar, some significant differences provide valuable insights into filamentous actin (F-actin) and globular actin (G-actin) binding, including the identification of binding residues on the long central helix. This long helix is stabilized by three or four residues. Notably, the F-actin binding sites of mouse GMF β and GMF γ contain two additional β-strands not seen in other ADF-H structures. The G-actin binding site of the ADF-H domain of human HIP-55-drebrin-like protein is absent and distorted in mouse GMF β and GMF γ. PMID:19768801

  12. Perspectives for a Framework to Understand Aril Initiation and Development.

    PubMed

    Silveira, Sylvia R; Dornelas, Marcelo C; Martinelli, Adriana P

    2016-01-01

    A differentiated structure called "aril" has been described in seeds of several plant species during the course of evolution and might be considered as a supernumerary integument. Besides its ecological function in seed dispersal, the structure also represents a relevant character for systematic classification and exhibits important properties that impart agronomic value in certain species. Little is known about the molecular pathways underlying this morphological innovation because it is absent in currently used model species. A remarkable feature of the seeds of Passiflora species is the presence of a conspicuous aril. This genus is known for the ornamental, medicinal, and food values of its species. In view of the molecular resources and tools available for some Passiflora species, we highlight the potential of these species as models for developmental studies of the aril.

  13. Perspectives for a Framework to Understand Aril Initiation and Development

    PubMed Central

    Silveira, Sylvia R.; Dornelas, Marcelo C.; Martinelli, Adriana P.

    2016-01-01

    A differentiated structure called “aril” has been described in seeds of several plant species during the course of evolution and might be considered as a supernumerary integument. Besides its ecological function in seed dispersal, the structure also represents a relevant character for systematic classification and exhibits important properties that impart agronomic value in certain species. Little is known about the molecular pathways underlying this morphological innovation because it is absent in currently used model species. A remarkable feature of the seeds of Passiflora species is the presence of a conspicuous aril. This genus is known for the ornamental, medicinal, and food values of its species. In view of the molecular resources and tools available for some Passiflora species, we highlight the potential of these species as models for developmental studies of the aril. PMID:28066474

  14. Liquid proteins--a new frontier for biomolecule-based nanoscience.

    PubMed

    Perriman, Adam W; Mann, Stephen

    2011-08-23

    Solid, liquid, or gas? The physical states adopted by nano-objects such as proteins are critically dependent on the size and range of the intermolecular attractive forces, and as a consequence, pure liquids comprising solventless melts of structurally intact, discrete functional nanoconstructs are conspicuously absent. Here we describe how globular proteins can be surface-engineered such that anhydrous powders of these nanoscale objects melt at close to room temperature to produce solvent-free liquids comprising exceedingly high concentrations of structurally and functionally intact biomolecules. These liquids offer unprecedented opportunities in bionanomaterials research, represent a new phase for protein chemistry, and challenge the existing paradigm on the role of water molecules in protein folding and function.

  15. Magnetic multilayer structure

    DOEpatents

    Herget, Philipp; O'Sullivan, Eugene J.; Romankiw, Lubomyr T.; Wang, Naigang; Webb, Bucknell C.

    2017-03-21

    A mechanism is provided for an integrated laminated magnetic device. A substrate and a multilayer stack structure form the device. The multilayer stack structure includes alternating magnetic layers and diode structures formed on the substrate. Each magnetic layer in the multilayer stack structure is separated from another magnetic layer in the multilayer stack structure by a diode structure.

  16. Magnetic multilayer structure

    SciTech Connect

    Herget, Philipp; O'Sullivan, Eugene J.; Romankiw, Lubomyr T.; Wang, Naigang; Webb, Bucknell C.

    2016-07-05

    A mechanism is provided for an integrated laminated magnetic device. A substrate and a multilayer stack structure form the device. The multilayer stack structure includes alternating magnetic layers and diode structures formed on the substrate. Each magnetic layer in the multilayer stack structure is separated from another magnetic layer in the multilayer stack structure by a diode structure.

  17. Sexual differences in microhabitat selection of breeding little bustards Tetrax tetrax: Ecological segregation based on vegetation structure

    NASA Astrophysics Data System (ADS)

    Morales, M. B.; Traba, J.; Carriles, E.; Delgado, M. P.; de la Morena, E. L. García

    2008-11-01

    We examined sexual differences in patterns of vegetation structure selection in the sexually dimorphic little bustard. Differences in vegetation structure between male, female and non-used locations during reproduction were examined and used to build a presence/absence model for each sex. Ten variables were measured in each location, extracting two PCA factors (PC1: a visibility-shelter gradient; PC2: a gradient in food availability) used as response variables in GLM explanatory models. Both factors significantly differed between female, male and control locations. Neither study site nor phenology was significant. Logistic regression was used to model male and female presence/absence. Female presence was positively associated to cover of ground by vegetation litter, as well as overall vegetation cover, and negatively to vegetation density over 30 cm above ground. Male presence was positively related to litter cover and short vegetation and negatively to vegetation density over 30 cm above ground. Models showed good global performance and robustness. Female microhabitat selection and distribution seems to be related to the balance between shelter and visibility for surveillance. Male microhabitat selection would be related mainly to the need of conspicuousness for courtship. Accessibility to food resources seems to be equally important for both sexes. Differences suggest ecological sexual segregation resulting from different ecological constraints. These are the first detailed results on vegetation structure selection in both male and female little bustards, and are useful in designing management measures addressing vegetation structure irrespective of landscape composition. Similar microhabitat approaches can be applied to manage the habitat of many declining farmland birds.

  18. Modeling Equity for Alternative Water Rate Structures

    NASA Astrophysics Data System (ADS)

    Griffin, R.; Mjelde, J.

    2011-12-01

    The rising popularity of increasing block rates for urban water runs counter to mainstream economic recommendations, yet decision makers in rate design forums are attracted to the notion of higher prices for larger users. Among economists, it is widely appreciated that uniform rates have stronger efficiency properties than increasing block rates, especially when volumetric prices incorporate intrinsic water value. Yet, except for regions where water market purchases have forced urban authorities to include water value in water rates, economic arguments have weakly penetrated policy. In this presentation, recent evidence will be reviewed regarding long term trends in urban rate structures while observing economic principles pertaining to these choices. The main objective is to investigate the equity of increasing block rates as contrasted to uniform rates for a representative city. Using data from four Texas cities, household water demand is established as a function of marginal price, income, weather, number of residents, and property characteristics. Two alternative rate proposals are designed on the basis of recent experiences for both water and wastewater rates. After specifying a reasonable number (~200) of diverse households populating the city and parameterizing each household's characteristics, every household's consumption selections are simulated for twelve months. This procedure is repeated for both rate systems. Monthly water and wastewater bills are also computed for each household. Most importantly, while balancing the budget of the city utility we compute the effect of switching rate structures on the welfares of households of differing types. Some of the empirical findings are as follows. Under conditions of absent water scarcity, households of opposing characters such as low versus high income do not have strong preferences regarding rate structure selection. This changes as water scarcity rises and as water's opportunity costs are allowed to

  19. Visualizing viral protein structures in cells using genetic probes for correlated light and electron microscopy.

    PubMed

    Ou, Horng D; Deerinck, Thomas J; Bushong, Eric; Ellisman, Mark H; O'Shea, Clodagh C

    2015-11-15

    Structural studies of viral proteins most often use high-resolution techniques such as X-ray crystallography, nuclear magnetic resonance, single particle negative stain, or cryo-electron microscopy (EM) to reveal atomic interactions of soluble, homogeneous viral proteins or viral protein complexes. Once viral proteins or complexes are separated from their host's cellular environment, their natural in situ structure and details of how they interact with other cellular components may be lost. EM has been an invaluable tool in virology since its introduction in the late 1940's and subsequent application to cells in the 1950's. EM studies have expanded our knowledge of viral entry, viral replication, alteration of cellular components, and viral lysis. Most of these early studies were focused on conspicuous morphological cellular changes, because classic EM metal stains were designed to highlight classes of cellular structures rather than specific molecular structures. Much later, to identify viral proteins inducing specific structural configurations at the cellular level, immunostaining with a primary antibody followed by colloidal gold secondary antibody was employed to mark the location of specific viral proteins. This technique can suffer from artifacts in cellular ultrastructure due to compromises required to provide access to the immuno-reagents. Immunolocalization methods also require the generation of highly specific antibodies, which may not be available for every viral protein. Here we discuss new methods to visualize viral proteins and structures at high resolutions in situ using correlated light and electron microscopy (CLEM). We discuss the use of genetically encoded protein fusions that oxidize diaminobenzidine (DAB) into an osmiophilic polymer that can be visualized by EM. Detailed protocols for applying the genetically encoded photo-oxidizing protein MiniSOG to a viral protein, photo-oxidation of the fusion protein to yield DAB polymer staining, and

  20. Visualizing Viral Protein Structures in Cells Using Genetic Probes for Correlated Light and Electron Microscopy

    PubMed Central

    Ou, Horng D.; Deerinck, Thomas J.; Bushong, Eric; Ellisman, Mark H.; O’Shea, Clodagh C.

    2015-01-01

    Structural studies of viral proteins most often use high-resolution techniques such as X-ray crystallography, nuclear magnetic resonance, single particle negative stain, or cryo-electron microscopy (EM) to reveal atomic interactions of soluble, homogeneous viral proteins or viral protein complexes. Once viral proteins or complexes are separated from their host’s cellular environment, their natural in-situ structure and details of how they interact with other cellular components may be lost. EM has been an invaluable tool in virology since its introduction in the late 1940’s and subsequent application to cells in the 1950’s. EM studies have expanded our knowledge of viral entry, viral replication, alteration of cellular components, and viral lysis. Most of these early studies were focused on conspicuous morphological cellular changes, because classic EM metal stains were designed to highlight classes of cellular structures rather than specific molecular structures. Much later, to identify viral proteins inducing specific structural configurations at the cellular level, immunostaining with a primary antibody followed by colloidal gold secondary antibody was employed to mark the location of specific viral proteins. This technique can suffer from artifacts in cellular ultrastructure due to compromises required to provide access to the immuno-reagents. Immunolocalization methods also require the generation of highly specific antibodies, which may not be available for every viral protein. Here we discuss new methods to visualize viral proteins and structures at high resolutions in-situ using correlated light and electron microscopy (CLEM). We discuss the use of genetically encoded protein fusions that oxidize diaminobenzidine (DAB) into an osmiophilic polymer that can be visualized by EM. Detailed protocols for applying the genetically encoded photo-oxidizing protein MiniSOG to a viral protein, photo-oxidation of the fusion protein to yield DAB polymer staining

  1. Large-insert genome analysis technology detects structural variation in Pseudomonas aeruginosa clinical strains from cystic fibrosis patients.

    PubMed

    Hayden, Hillary S; Gillett, Will; Saenphimmachak, Channakhone; Lim, Regina; Zhou, Yang; Jacobs, Michael A; Chang, Jean; Rohmer, Laurence; D'Argenio, David A; Palmieri, Anthony; Levy, Ruth; Haugen, Eric; Wong, Gane K S; Brittnacher, Mitch J; Burns, Jane L; Miller, Samuel I; Olson, Maynard V; Kaul, Rajinder

    2008-06-01

    Large-insert genome analysis (LIGAN) is a broadly applicable, high-throughput technology designed to characterize genome-scale structural variation. Fosmid paired-end sequences and DNA fingerprints from a query genome are compared to a reference sequence using the Genomic Variation Analysis (GenVal) suite of software tools to pinpoint locations of insertions, deletions, and rearrangements. Fosmids spanning regions that contain new structural variants can then be sequenced. Clonal pairs of Pseudomonas aeruginosa isolates from four cystic fibrosis patients were used to validate the LIGAN technology. Approximately 1.5 Mb of inserted sequences were identified, including 743 kb containing 615 ORFs that are absent from published P. aeruginosa genomes. Six rearrangement breakpoints and 220 kb of deleted sequences were also identified. Our study expands the "genome universe" of P. aeruginosa and validates a technology that complements emerging, short-read sequencing methods that are better suited to characterizing single-nucleotide polymorphisms than structural variation.

  2. The Crystal Structures of the Open and Catalytically Competent Closed Conformation of Escherichia coli Glycogen Synthase

    SciTech Connect

    Sheng, Fang; Jia, Xiaofei; Yep, Alejandra; Preiss, Jack; Geiger, James H.

    2009-07-06

    Escherichia coli glycogen synthase (EcGS, EC 2.4.1.21) is a retaining glycosyltransferase (GT) that transfers glucose from adenosine diphosphate glucose to a glucan chain acceptor with retention of configuration at the anomeric carbon. EcGS belongs to the GT-B structural superfamily. Here we report several EcGS x-ray structures that together shed considerable light on the structure and function of these enzymes. The structure of the wild-type enzyme bound to ADP and glucose revealed a 15.2 degrees overall domain-domain closure and provided for the first time the structure of the catalytically active, closed conformation of a glycogen synthase. The main chain carbonyl group of His-161, Arg-300, and Lys-305 are suggested by the structure to act as critical catalytic residues in the transglycosylation. Glu-377, previously thought to be catalytic is found on the alpha-face of the glucose and plays an electrostatic role in the active site and as a glucose ring locator. This is also consistent with the structure of the EcGS(E377A)-ADP-HEPPSO complex where the glucose moiety is either absent or disordered in the active site

  3. Crystal structure of the carbapenem intrinsic resistance protein CarG.

    PubMed

    Tichy, E M; Luisi, B F; Salmond, G P C

    2014-05-01

    In the Gram-negative enterobacterium Erwinia (Pectobacterium) and Serratia sp. ATCC 39006, intrinsic resistance to the carbapenem antibiotic 1-carbapen-2-em-3-carboxylic acid is mediated by the CarF and CarG proteins, by an unknown mechanism. Here, we report a high-resolution crystal structure for the Serratia sp. ATCC 39006 carbapenem resistance protein CarG. This structure of CarG is the first in the carbapenem intrinsic resistance (CIR) family of resistance proteins from carbapenem-producing bacteria. The crystal structure shows the protein to form a homodimer, in agreement with results from analytical gel filtration. The structure of CarG does not show homology with any known antibiotic resistance proteins nor does it belong to any well-characterised protein structural family. However, it is a close structural homologue of the bacterial inhibitor of invertebrate lysozyme, PliI-Ah, with some interesting structural variations, including the absence of the catalytic site responsible for lysozyme inhibition. Both proteins show a unique β-sandwich fold with short terminal α-helices. The core of the protein is formed by stacked anti-parallel sheets that are individually very similar in the two proteins but differ in their packing interface, causing the splaying of the two sheets in CarG. Furthermore, a conserved cation binding site identified in CarG is absent from the homologue.

  4. Removing shore protection structures to facilitate migration of landforms and habitats on the bayside of a barrier spit

    NASA Astrophysics Data System (ADS)

    Nordstrom, Karl F.; Jackson, Nancy L.

    2013-10-01

    Coastal landforms and habitats require space to reform in response to storm damage to increase the likelihood of long-term sustainability. The purpose of this study is to evaluate the potential for removing shore protection structures to allow natural shoreline processes to prevail as part of a strategy to adapt to sea level rise associated with climate change. The location of the study was Sandy Hook Spit, New Jersey, a site managed by the U.S. National Park Service (NPS). A field investigation was conducted to identify the structures that impede migration of landforms and habitats, the function of each structure in protecting resources, and the opportunities to facilitate landform migration by removing the structures or allowing them to deteriorate. Nineteen shore-parallel walls are present along the ocean and bay shore of a 10 km long portion of the spit. Most of the shore protection structures were built when the spit was formerly used by the US Army, and many bulkheads on the bay shore have deteriorated. Sediment will become available to the longshore transport system where protection structures are removed, contributing to spit growth at the ends of drift cells, possibly mimicking the spits that were more conspicuous on the bay shore prior to human alterations. Observations indicate that new habitat can be created by loss and re-creation in a different location by longshore extension, not just by landward migration. Allowing shore protection structures to deteriorate will leave human infrastructure in the landscape. Removing these structures is more costly but can result in a more rapid reversion to a natural system. The time horizon is critical in determining the social, political and economic feasibility of removing structures and the expectations for geomorphic and habitat change. The feasibility of protecting threatened buildings and roads will decrease in the future as sea level rises and the existing protection structures degrade or fall below new

  5. Structure-related optical behavior of nanoscale GaN island, tip, tube and cone arrays formed by inductively coupled plasmas etching

    NASA Astrophysics Data System (ADS)

    Lin, Chih-Ming; Huang, Pei-Hsing; Cheng, Nai-Jen; Hung, Shang-Chao

    2016-03-01

    We introduce a one-step self-assembled technique to form various nanostructures on N-type GaN film and then present an optical characterization of a series of low-dimensional GaN nanostructures by using low-temperature photoluminescence (LTPL) spectroscopy. Nanoscale GaN island, tip, tube and cone-like structures of diameters ranging from 50 to 190 nm were self-assembled on a c-axis perpendicular to substrate surface with uniform diameter and uniform length by inductively coupled plasmas etching process without lithography. Optical LTPL measurements on nanostructures show consistent variations in the properties of the fabricated GaN structures as a function of surface area of GaN nanostructures. LTPL mapping gives an evidence for defect-induced donors and/or acceptors near the facets of the ICP-etched nanostructure. Our results indicate that a higher concentration of donor-related defects is introduced on the surface of GaN nanotubes. In particular, the nanotubes sample exhibits a conspicuous increased in yellow luminescence intensity compared to the other nanostructure samples. This result may support more information for the application of nanotubes on nanogenerators.

  6. The structure and ultrastructure of the sinus venosus in the mature dogfish (Scyliorhinus canicula): the endocardium, the epicardium and the subepicardial space.

    PubMed

    Ramos, C

    2004-12-01

    The sinus venosus of fish is the most caudal chamber of the heart. It is often reduced in teleosts but well developed in elasmobranchs. The sinus venosus of the dogfish (Scyliorhinus canicula) is vital, since it harbours key elements such as a little known neuroendocrine system and the nodal tissue. However, the study of its structure is still incomplete. We examined the endocardium, epicardium and subepicardium of the sinus venosus in mature dogfishes. The wall is 100-250 microm thick and comprises three main layers. Large bundles of myocardial cells occupy the middle layer. The endothelial ensheathing is composed of thin endocardial cells with prominent nuclei towards the lumen, whose cytoplasm contains numerous dense bodies and moderately dense bodies, 150-800 nm in diameter and large vacuoles. The possible functions of these organelles are discussed. The outermost layer is made of a robust sheet of cuboidal epicardial cells separated from the subepicardium by a conspicuous basal lamina. Numerous microvilli towards the pericardial cavity and elliptical vesicles are located in the apex of epicardial cells. A thick layer richly endowed with dense bundles of collagen fibres forms the subepicardial space. This structure should be contrasted with the venous return mechanism of elasmobranchs.

  7. Structural characterization and molecular identification of arbuscular mycorrhiza morphotypes of Alzatea verticillata (Alzateaceae), a prominent tree in the tropical mountain rain forest of South Ecuador.

    PubMed

    Beck, Adela; Haug, Ingeborg; Oberwinkler, Franz; Kottke, Ingrid

    2007-10-01

    The vast majority of the highly diverse trees in the tropical mountain rain forest of South Ecuador form arbuscular mycorrhizas, and previous molecular investigations revealed a high diversity of fungi. In this study, we present a first trial to link fungal DNA-sequences with defined morphotypes characterized on the basis of partly new mycelial features obtained from field material of one tree species, Alzatea verticillata. Fine roots were halved lengthwise to study the mycelium anatomy on one half and to obtain fungal nuclear rDNA coding for the small subunit rRNA of Glomeromycota from the other half. Light microscopy revealed conspicuously large amounts of mycelium attaching to the surface of the rootlets. The mycelium formed fine- or large-branched appressoria-like plates, vesicles of regular or irregular shape, and very fine, multibranched structures ensheathed by septate hyphae. These previously undescribed features of the supraradical mycelia combined with intraradical mycelium structures were used for distinguishing of four main morphogroups and subordinate 14 morphotypes. DNA sequences of Glomus group A, Acaulospora and Gigaspora, were obtained and linked to three morphogroups. Two sequence types within Glomus group A could be tentatively associated to subordinate morphotypes.

  8. What Is Present and Absent in Critical Analyses of Neoliberalism in Education

    ERIC Educational Resources Information Center

    Apple, Michael W.

    2017-01-01

    In "Can Education Change Society?" (Apple, 2013), Apple described a number of tasks in which the critical scholar/activist needs to engage. Among them are telling the truth about what is happening in the creation of inequalities, illuminating spaces of possibility, and acting as the critical secretary of the movements and people who…

  9. Epithelial Label-Retaining Cells Are Absent during Tooth Cycling in Salmo salar and Polypterus senegalus

    PubMed Central

    Vandenplas, Sam; Willems, Maxime; Witten, P. Eckhard; Hansen, Tom; Fjelldal, Per Gunnar; Huysseune, Ann

    2016-01-01

    The Atlantic salmon (Salmo salar) and African bichir (Polypterus senegalus) are both actinopterygian fish species that continuously replace their teeth without the involvement of a successional dental lamina. Instead, they share the presence of a middle dental epithelium: an epithelial tier enclosed by inner and outer dental epithelium. It has been hypothesized that this tier could functionally substitute for a successional dental lamina and might be a potential niche to house epithelial stem cells involved in tooth cycling. Therefore, in this study we performed a BrdU pulse chase experiment on both species to (1) determine the localization and extent of proliferating cells in the dental epithelial layers, (2) describe cell dynamics and (3) investigate if label-retaining cells are present, suggestive for the putative presence of stem cells. Cells proliferate in the middle dental epithelium, outer dental epithelium and cervical loop at the lingual side of the dental organ to form a new tooth germ. Using long chase times, both in S. salar (eight weeks) and P. senegalus (eight weeks and twelve weeks), we could not reveal the presence of label-retaining cells in the dental organ. Immunostaining of P. senegalus dental organs for the transcription factor Sox2, often used as a stem cell marker, labelled cells in the zone of outer dental epithelium which grades into the oral epithelium (ODE transition zone) and the inner dental epithelium of a successor only. The location of Sox2 distribution does not provide evidence for epithelial stem cells in the dental organ and, more specifically, in the middle dental epithelium. Comparison of S. salar and P. senegalus reveals shared traits in tooth cycling and thus advances our understanding of the developmental mechanism that ensures lifelong replacement. PMID:27049953

  10. Why Are Teachers Absent? Probing Service Delivery in Peruvian Primary Schools

    ERIC Educational Resources Information Center

    Alcazar, Lorena; Rogers, F. Halsey; Chaudhury, Nazmul; Hammer, Jeffrey; Kremer, Michael; Muralidharan, Karthik

    2006-01-01

    A high rate of absence of teachers from their posts is a serious obstacle to delivery of education in many developing countries, but hard evidence on the problem has been scarce. This study, carried out as part of a new multi-country survey project, is the first systematic investigation in Peru into the extent and causes of teachers' absence from…

  11. Molecular mechanism of male differentiation is conserved in the SRY-absent mammal, Tokudaia osimensis.

    PubMed

    Otake, Tomofumi; Kuroiwa, Asato

    2016-09-09

    The sex-determining gene SRY induces SOX9 expression in the testes of eutherian mammals via two pathways. SRY binds to testis-specific enhancer of Sox9 (TESCO) with SF1 to activate SOX9 transcription. SRY also up-regulates ER71 expression, and ER71 activates Sox9 transcription. After the initiation of testis differentiation, SOX9 enhances Amh expression by binding to its promoter with SF1. SOX8, SOX9 and SOX10, members of the SOXE gene family, also enhance the activities of the Amh promoter and TESCO. In this study, we investigated the regulation of these sexual differentiation genes in Tokudaia osimensis, which lacks a Y chromosome and the SRY gene. The activity of the AMH promoter was stimulated by SOXE genes and SF1. Mutant AMH promoters, with mutations in its SOX and SF1 binding sites, did not show significant activity by SOX9 and SF1. These results indicate that AMH expression was regulated by the binding of SOX9 and SF1. By contrast, SOXE genes could not enhance TESCO activity. These results indicate that TESCO enhancer activity was lost in this species. Furthermore, the activity of the SOX9 promoter was enhanced by ER71, indicating that ER71 may play an important role in the testis-specific expression of SOX9.

  12. Cattle ticks in Cameroon: is Rhipicephalus (Boophilus) microplus absent in Cameroon and the Central African region?

    PubMed

    Awa, D N; Adakal, H; Luogbou, N D D; Wachong, K H; Leinyuy, I; Achukwi, M D

    2015-03-01

    In most parts of the world, ticks are rapidly developing resistance to commonly used acaricides thus rendering control difficult. This constraint is further compounded by the introduction of new species in areas where they did not exist before. Such is the case with the introduction into and rapid spread of Rhipicephalus (Boophilus) microplus in some countries of West Africa. With the looming threat of its further spread in the region, the objective of the present study was to update knowledge on cattle ticks in Cameroon. Among 19,189 ticks collected monthly from 60 animals in 5 herds from March 2012 to February 2013, Rh. (B.) decoloratus was the most abundant species with a relative prevalence of 62.2%, followed by Amblyomma variegatum (28.4%), Rh. (B.) annulatus (0.2%), Rh. (B.) geigyi (0.03%), other Rhipicephalus spp. (8.4%) and Hyalomma spp. (0.3%). Rh. (B.) decoloratus and A. variegatum were also the most widely distributed in space. Infestation rate was generally high, with average tick count/animal of about 80 during peak periods. Tick distribution and abundance in the different sites was as varied as the underlying factors, among which the most important were management systems and climatic factors. The effects of rainfall and temperature were confounded by other factors and difficult to evaluate. However, it appears tick development depends among other factors, on a humidity threshold, above which there is not much more effect. Rh. microplus was not found during this study, but more extensive tick collections have to be done to confirm this. In conclusion, cattle tick infestation in Cameroon remains an important cause for concern. Farmers need assistance in the use and management of acaricides in order to increase their efficiency and reduce the development of resistance. Although Rh. microplus was not found, its introduction from other West African countries is imminent if adequate measures, especially in the control and limitation of animal movements, are not taken.

  13. Technology: So Pervasive in Jewish Living, so Absent from Jewish Educational Research

    ERIC Educational Resources Information Center

    Schein, Jeffrey

    2016-01-01

    The Jewish world, like the world civilization that hosts it, is awash in new technologies. Appropriately, there is a great deal of attention paid to how to improve the Jewish world and Jewish identity through technology. Paradoxically there is a paucity of literature characterizing the relationship of Jews and Judaism to technology. This article…

  14. Bad bones, absent smell, selfish testes: the pleiotropic consequences of human FGF receptor mutations.

    PubMed

    Wilkie, Andrew O M

    2005-04-01

    The discovery in 1994 that highly specific mutations of fibroblast growth factor (FGF) receptor 3 caused the most common form of human short-limbed dwarfism, achondroplasia, heralded a new era in FGF receptor (FGFR) biology. A decade later, the purpose of this review is to survey how the study of humans with FGFR mutations continues to provide insights into FGFR function in health and disease, and the clinical applications of these findings. Amongst the most interesting recent discoveries have been the description of novel phenotypes associated with FGFR1 and FGFR3 mutations; identification of fundamental differences in the cellular mechanisms of mutant FGFR2 and FGFR3 action; and the direct identification of FGFR2 and FGFR3 mutations in sperm. These clinical observations illustrate the pleiotropism of FGFR action and fuel ongoing efforts to understand the rich biology and pathophysiology of the FGF signalling system.

  15. Molecular mechanism of male differentiation is conserved in the SRY-absent mammal, Tokudaia osimensis

    PubMed Central

    Otake, Tomofumi; Kuroiwa, Asato

    2016-01-01

    The sex-determining gene SRY induces SOX9 expression in the testes of eutherian mammals via two pathways. SRY binds to testis-specific enhancer of Sox9 (TESCO) with SF1 to activate SOX9 transcription. SRY also up-regulates ER71 expression, and ER71 activates Sox9 transcription. After the initiation of testis differentiation, SOX9 enhances Amh expression by binding to its promoter with SF1. SOX8, SOX9 and SOX10, members of the SOXE gene family, also enhance the activities of the Amh promoter and TESCO. In this study, we investigated the regulation of these sexual differentiation genes in Tokudaia osimensis, which lacks a Y chromosome and the SRY gene. The activity of the AMH promoter was stimulated by SOXE genes and SF1. Mutant AMH promoters, with mutations in its SOX and SF1 binding sites, did not show significant activity by SOX9 and SF1. These results indicate that AMH expression was regulated by the binding of SOX9 and SF1. By contrast, SOXE genes could not enhance TESCO activity. These results indicate that TESCO enhancer activity was lost in this species. Furthermore, the activity of the SOX9 promoter was enhanced by ER71, indicating that ER71 may play an important role in the testis-specific expression of SOX9. PMID:27611740

  16. Absent Presences: The Recognition of Social Class and Gender Dimensions within Peer Assessment Interactions

    ERIC Educational Resources Information Center

    Crossouard, Barbara

    2012-01-01

    This article focuses on the discursive characteristics of peer assessment interactions, drawing upon recent research into formative assessment within a task design involving extended project-based work tackled in groups by pupils. Case studies were conducted within two schools in socially deprived areas of Scotland. They included classroom…

  17. How absent negativity relates to affect and motivation: an integrative relief model

    PubMed Central

    Deutsch, Roland; Smith, Kevin J. M.; Kordts-Freudinger, Robert; Reichardt, Regina

    2015-01-01

    The present paper concerns the motivational underpinnings and behavioral correlates of the prevention or stopping of negative stimulation – a situation referred to as relief. Relief is of great theoretical and applied interest. Theoretically, it is tied to theories linking affect, emotion, and motivational systems. Importantly, these theories make different predictions regarding the association between relief and motivational systems. Moreover, relief is a prototypical antecedent of counterfactual emotions, which involve specific cognitive processes compared to factual or mere anticipatory emotions. Practically, relief may be an important motivator of addictive and phobic behaviors, self destructive behaviors, and social influence. In the present paper, we will first provide a review of conflicting conceptualizations of relief. We will then present an integrative relief model (IRMO) that aims at resolving existing theoretical conflicts. We then review evidence relevant to distinctive predictions regarding the moderating role of various procedural features of relief situations. We conclude that our integrated model results in a better understanding of existing evidence on the affective and motivational underpinnings of relief, but that further evidence is needed to come to a more comprehensive evaluation of the viability of IRMO. PMID:25806008

  18. From Absent to Active Voices: Securing Disability Equality within Higher Education

    ERIC Educational Resources Information Center

    Beauchamp-Pryor, Karen

    2012-01-01

    This article discusses the representation and participation of disabled students in the development of higher education policy and provision within the UK, at both a national and institutional level. Findings are drawn from a doctoral study, which identified the importance of student participation in securing equality and inclusion. Power…

  19. Why the Unskilled Are Unaware: Further Explorations of (Absent) Self-Insight Among the Incompetent

    PubMed Central

    Ehrlinger, Joyce; Johnson, Kerri; Banner, Matthew; Dunning, David; Kruger, Justin

    2009-01-01

    People are typically overly optimistic when evaluating the quality of their performance on social and intellectual tasks. In particular, poor performers grossly overestimate their performances because their incompetence deprives them of the skills needed to recognize their deficits. Five studies demonstrated that poor performers lack insight into their shortcomings even in real world settings and when given incentives to be accurate. An additional meta-analysis showed that it was lack of insight into their own errors (and not mistaken assessments of their peers) that led to overly optimistic estimates among poor performers. Along the way, these studies ruled out recent alternative accounts that have been proposed to explain why poor performers hold such positive impressions of their performance. PMID:19568317

  20. Absent but Not Gone: Interdependence in Couples' Quality of Life Persists After a Partner's Death.

    PubMed

    Bourassa, Kyle J; Knowles, Lindsey M; Sbarra, David A; O'Connor, Mary-Frances

    2016-02-01

    Spouses influence each other's psychological functioning and quality of life. To explore whether this interdependence continues after a person becomes widowed, we tested whether deceased spouses' characteristics were associated with their widowed partners' later quality of life using couples drawn from a multinational sample of aging adults. Independent subsamples (ns = 221 and 325) were assessed before and after a spouse's death. Regressions revealed that deceased partners' quality of life prior to their death positively predicted their spouses' quality of life after the partners' death, even when we controlled for spouses' prior quality of life to account for environmental factors shared within couples. Further, widowed participants' quality of life was lower than nonwidowed couples' 2 years before and after their partners' death, but was equivalent 4 years prior. Finally, the strength of the association between partners' earlier quality of life and participants' later quality of life did not differ between widowed and nonwidowed participants. These findings suggest that interdependence in quality of life continues after one's partner has passed away.

  1. Absent movement-related cortical potentials in children with primary motor stereotypies.

    PubMed

    Houdayer, Elise; Walthall, Jessica; Belluscio, Beth A; Vorbach, Sherry; Singer, Harvey S; Hallett, Mark

    2014-08-01

    The underlying pathophysiologic mechanism for complex motor stereotypies in children is unknown, with hypotheses ranging from an arousal to a motor control disorder. Movement-related cortical potentials (MRCPs), representing the activation of cerebral areas involved in the generation of movements, precede and accompany self-initiated voluntary movements. The goal of this study was to compare cerebral activity associated with stereotypies to that seen with voluntary movements in children with primary complex motor stereotypies. Electroencephalographic (EEG) activity synchronized with video recording was recorded in 10 children diagnosed with primary motor stereotypies and 7 controls. EEG activity related to stereotypies and self-paced arm movements were analyzed for presence or absence of early or late MRCP, a steep negativity beginning about 1 second before the onset of a voluntary movement. Early MRCPs preceded self-paced arm movements in 8 of 10 children with motor stereotypies and in 6 of 7 controls. Observed MRCPs did not differ between groups. No MRCP was identified before the appearance of a complex motor stereotypy. Unlike voluntary movements, stereotypies are not preceded by MRCPs. This indicates that premotor areas are likely not involved in the preparation of these complex movements and suggests that stereotypies are initiated by mechanisms different from voluntary movements. Further studies are required to determine the site of the motor control abnormality within cortico-striatal-thalamo-cortical pathways and to identify whether similar findings would be found in children with secondary stereotypies.

  2. Absent bystanders and cognitive dissonance: a comment on Timmins & de Vries.

    PubMed

    Paley, John

    2015-04-01

    Timmins & de Vries are more sympathetic to my editorial than other critics, but they take issue with the details. They doubt whether the bystander phenomenon applies to Mid Staffs nurses; they believe that cognitive dissonance is a better explanation of why nurses fail to behave compassionately; and they think that I am 'perhaps a bit rash' to conclude that 'teaching compassion may be fruitless'. In this comment, I discuss all three points. I suggest that the bystander phenomenon is irrelevant; that Timmins & de Vries give an incomplete account of cognitive dissonance; and that it isn't rash to propose that educating nurses 'for compassion' is a red herring. Additionally, I comment on the idea that I wish to mount a 'defence of healthcare staff'.

  3. PACSIN 1 interacts with huntingtin and is absent from synaptic varicosities in presymptomatic Huntington's disease brains.

    PubMed

    Modregger, Jan; DiProspero, Nicholas A; Charles, Vinod; Tagle, Danilo A; Plomann, Markus

    2002-10-01

    Huntington's disease (HD) is caused by a pathological expansion of a CAG repeat in the first exon of the gene coding for huntingtin, resulting in an abnormally long polyglutamine stretch. Despite its widespread expression, mutant huntingtin leads to selective neuronal loss in the striatum and cortex. Here we report that the neurospecific phosphoprotein PACSIN 1, which has been implicated as playing a central role in synaptic vesicle recycling, interacts with huntingtin via its C-terminal SH3 domain. Moreover, two other isoforms, PACSIN 2 and 3, which show a wider tissue distribution including the brain, do not interact with huntingtin despite a highly conserved SH3 domain. Furthermore, this interaction is repeat-length-dependent and is enhanced with mutant huntingtin, possibly causing the sequestration of PACSIN 1. Normally, PACSIN 1 is located along neurites and within synaptic boutons, but in HD patient neurons, there is a progressive loss of PACSIN 1 immunostaining in synaptic varicosities, beginning in presymptomatic and early-stage HD. Further, PACSIN 1 immunostaining of HD patient tissue reveals a more cytoplasmic distribution of the protein, with particular concentration in the perinuclear region coincident with mutant huntingtin. Thus, the specific interaction of huntingtin with the neuronal PACSIN isoform, PACSIN 1, and its altered intracellular distribution in pathological tissue, together with the observed differences in the binding behavior, suggest a role for PACSIN 1 during early stages of the selective neuropathology of HD.

  4. Superinfection exclusion is absent during acute Junin virus infection of Vero and A549 cells

    PubMed Central

    Gaudin, Raphaël; Kirchhausen, Tomas

    2015-01-01

    Many viruses have evolved strategies of so-called “superinfection exclusion” to prevent re-infection of a cell that the same virus has already infected. Although Old World arenavirus infection results in down-regulation of its viral receptor and thus superinfection exclusion, whether New World arenaviruses have evolved such a mechanism remains unclear. Here we show that acute infection by the New World Junin virus (JUNV) failed to down-regulate the transferrin receptor and did not induce superinfection exclusion. We observed that Vero cells infected by a first round of JUNV (Candid1 strain) preserve an ability to internalize new incoming JUNV particles that is comparable to that of non-infected cells. Moreover, we developed a dual infection assay with the wild-type Candid1 JUNV and a recombinant JUNV-GFP virus to discriminate between first and second infections at the transcriptional and translational levels. We found that Vero and A549 cells already infected by JUNV were fully competent to transcribe viral RNA from a second round of infection. Furthermore, flow cytometry analysis of viral protein expression indicated that viral translation was normal, regardless of whether cells were previously infected or not. We conclude that in acutely infected cells, Junin virus lacks a superinfection exclusion mechanism. PMID:26549784

  5. Extant or Absent: Formation Water in New York State Drinking Water Wells

    NASA Astrophysics Data System (ADS)

    Christian, K.; Lautz, L. K.

    2013-12-01

    The current moratorium on hydraulic fracturing in New York State (NYS) provides an opportunity to collect baseline shallow groundwater quality data pre-hydraulic fracturing, which is essential for determining the natural variability of groundwater chemistry and to evaluate future claims of impaired groundwater quality if hydraulic fracturing occurs in the State. Concerns regarding the future environmental impact of shale gas extraction in NYS include potential shallow groundwater contamination due to migration of methane or formation water from shale gas extraction sites. Treatment, storage and disposal of saline flowback fluids after gas extraction could also be a source of water contamination. In this study, we combine southern NYS shallow groundwater chemistry data from Project Shale-Water Interaction Forensic Tools (SWIFT, n=60), the National Uranium Resource Evaluation program (NURE, n=684), and the USGS 305(b) Ambient Groundwater Quality Monitoring program (USGS, n=89) to examine evidence of formation water mixing with groundwater using the methodology of Warner et al. (2012). Groundwater characterized as low salinity (<20 mg/L Cl-) accounted for 72% of samples and 28% of samples had high salinity (>20 mg/L Cl-). A plot of bromide versus chloride shows high salinity groundwater samples with Br/Cl ratios >0.0001 fall on the mixing line between low salinity groundwater and Appalachian Basin formation water. Based on the observed linear relationship between bromide and chloride, it appears there is up to 1% formation water mixing with shallow groundwater in the region. The presence of formation water in shallow groundwater would indicate the existence of natural migratory pathways between deep formation wells and shallow groundwater aquifers. A plot of sodium versus chloride also illustrates a linear trend for Type D waters (R^2= 0.776), but the relationship is weaker than that for bromide versus chloride (R^2= 0.924). Similar linear relationships are not observed between other ions and chloride, including Mg, Ca, and Sr. If high salinity groundwater samples from NYS contain small percentages of formation water, we expect linear relationships between chloride and these other, generally conservative ions. The absence of these linear relationships suggests high salinity could be associated with contamination by landfill leachate, septic effluent, road salt, or other potential sources of elevated salt. Future work needs to determine if mixing of shallow groundwater with other potential sources of salinity, such as road deicers, can explain the observed linear relationships. Strontium isotopes from shallow groundwater samples will also be compared to those for NY formation water.

  6. Taurine is absent from amino components in fruits of Opuntia ficus-indica.

    PubMed

    Ali, Hatem Salama Mohamed; Al-Khalifa, Abdulrahman Saleh; Brückner, Hans

    2014-01-01

    Juices of edible fruits from Opuntia ficus-indica (L.) Miller, commonly named prickly pears or Indian figs, were analysed for amino acids using an automated amino acid analyser run in the high-resolution physiological mode. Emphasis was put on the detection of free taurine (Tau), but Tau could be detected neither in different cultivars of prickly pears from Italy, South Africa and the Near East nor in commercially available prickly pear juices from the market.

  7. Does orthographic training on a phonemic contrast absent in the listener's dialect influence word recognition?

    PubMed

    Dufour, Sophie; Nguyen, Noël; Pattamadilok, Chotiga; Frauenfelder, Ulrich Hans

    2016-09-01

    This study examined whether the ability of southern French speakers to discriminate between standard French word forms such as /pike/ and /pikε/ can be improved by a training procedure in which participants were exposed to the orthographic representations of words forming /e/-/ε/ minimal pairs. The results of the training procedure showed that southern French speakers were able to perceive the /e/-/ε/ contrast in word final position when they associated words containing these vowels with their correct spelled form. Further, participants in a priming experiment, which was run immediately after training, no longer showed the priming effect on the trained minimal pairs that they had shown in the pre-test. However, a priming effect on the untrained minimal pairs was still observed immediately after training, showing that this training failed to transfer to untrained items. Finally, the benefits of the training procedure were no longer observed the day after training, since southern French speakers once again showed a priming effect on the trained minimal pair of words in a one day post-test. Implications of these findings for the locus of the difficulties of the southern French speakers with the word-final /e/-/ε/ contrast are discussed.

  8. Ocular albinism with absent foveal pits but without nystagmus, photophobia, or severely reduced vision.

    PubMed

    Kubal, Anup; Dagnelie, Gislin; Goldberg, Morton

    2009-12-01

    A 9-year-old Caucasian girl of northern European ancestry presented with findings suggestive of ocular albinism, although she maintains good visual acuity and lacks nystagmus and photophobia. DNA analysis revealed that the patient is a compound heterozygote for mutations in the tyrosinase gene, which is typically associated with overt, generalized oculocutaneous albinism and severe ocular symptoms. Her particular genotype confers no apparent cutaneous disease and only mild ocular features.

  9. Emergency Preparedness as Public Pedagogy: The Absent-Presence of Race in "Preparing for Emergencies"

    ERIC Educational Resources Information Center

    Preston, John; Avery, Barry; Chakrabarty, Namita; Edmonds, Casey

    2011-01-01

    Emergency preparedness can be considered to be a form of lifelong learning and public pedagogy with implications for race equality. The paper is based on an ESRC project "Preparedness pedagogies and race: an interdisciplinary approach" considering the policy process around the construction of the "Preparing for Emergencies"…

  10. Achievement for Students Who Are Persistently Absent: Missing School, Missing Out?

    ERIC Educational Resources Information Center

    Arthurs, Nikie; Patterson, Jonathan; Bentley, Alex

    2014-01-01

    This article, written by three research-active teachers with the support of their academic partner, interrogates the achievement-attendance link in the most recent government quantitative data for secondary schools in England: persistent absentees stands at 6.6% for all children, but it raises to 9% for students who are classed as "Pupil…

  11. The "Absent Presence" of Part-Time Senior Secondary Study: A Research and Policy Challenge

    ERIC Educational Resources Information Center

    Ramsay, Eleanor

    2008-01-01

    Part-time engagement is a significant feature of senior secondary study for large numbers of students, in a context which includes high level policy pressures to achieve better outcomes for many more and a wider proportion of the schooling population, and significant policy and practice shifts at school, system and accreditation authority levels.…

  12. Genome and transcriptome sequencing of the halophilic fungus Wallemia ichthyophaga: haloadaptations present and absent

    PubMed Central

    2013-01-01

    Background The basidomycete Wallemia ichthyophaga from the phylogenetically distinct class Wallemiomycetes is the most halophilic fungus known to date. It requires at least 10% NaCl and thrives in saturated salt solution. To investigate the genomic basis of this exceptional phenotype, we obtained a de-novo genome sequence of the species type-strain and analysed its transcriptomic response to conditions close to the limits of its lower and upper salinity range. Results The unusually compact genome is 9.6 Mb large and contains 1.67% repetitive sequences. Only 4884 predicted protein coding genes cover almost three quarters of the sequence. Of 639 differentially expressed genes, two thirds are more expressed at lower salinity. Phylogenomic analysis based on the largest dataset used to date (whole proteomes) positions Wallemiomycetes as a 250-million-year-old sister group of Agaricomycotina. Contrary to the closely related species Wallemia sebi, W. ichthyophaga appears to have lost the ability for sexual reproduction. Several protein families are significantly expanded or contracted in the genome. Among these, there are the P-type ATPase cation transporters, but not the sodium/ hydrogen exchanger family. Transcription of all but three cation transporters is not salt dependent. The analysis also reveals a significant enrichment in hydrophobins, which are cell-wall proteins with multiple cellular functions. Half of these are differentially expressed, and most contain an unusually large number of acidic amino acids. This discovery is of particular interest due to the numerous applications of hydrophobines from other fungi in industry, pharmaceutics and medicine. Conclusions W. ichthyophaga is an extremophilic specialist that shows only low levels of adaptability and genetic recombination. This is reflected in the characteristics of its genome and its transcriptomic response to salt. No unusual traits were observed in common salt-tolerance mechanisms, such as transport of inorganic ions or synthesis of compatible solutes. Instead, various data indicate a role of the cell wall of W. ichthyophaga in its response to salt. Availability of the genomic sequence is expected to facilitate further research into this unique species, and shed more light on adaptations that allow it to thrive in conditions lethal to most other eukaryotes. PMID:24034603

  13. Absent portal vein bifurcation: a rare variant and its clinical significance

    PubMed Central

    Kumar Panda, Sitansu; Bahinipati, Pravakar

    2014-01-01

    Portal vein branching anomaly occurs due to aberration of normal anastomotic patterns and involution of vitelline veins during development of portal vein. Anatomical knowledge of portal vein and its branching pattern is important for hepatobiliary surgeon and gastrointestinal intervention radiologist. We are reporting a case of absence of portal vein bifurcation showing single main intrahepatic portal vein with gradual decreasing caliber distally, in a young female patient on contrast-enhanced computed tomography study of abdomen. Few cases of absence of portal bifurcation have been reported in literature so far. PMID:25276482

  14. RNA editing is absent in a single mitochondrial gene of Didymium iridis.

    PubMed

    Hendrickson, Peter G; Silliker, Margaret E

    2010-01-01

    An open reading frame (ORF) was found in the mitochondrial genome of the Pan2-16 strain of Didymium iridis that showed high similarity to the NADH dehydrogenase subunit 3 (nad3) gene in other organisms. So far all other typical mitochondrial genes identified in this organism require RNA editing to generate ORFs capable of directing protein synthesis. The D. iridis sequence was compared to the putative nad3 gene in the related myxomycete Physarum polycephalum, which would require editing. Based on this comparison, editing sites could be predicted for the P. polycelphalum gene that would result in the synthesis of a highly conserved ND3 protein between the two organisms. To determine the editing status of the nad3 gene in other D. iridis strains, PCR was used to amplify this region from eight other independent isolates of the A1 Central American interbreeding series. In each case a 378 base pair ORF was detected by PCR amplification and sequencing. Three patterns of sequence variation were observed; however all base substitutions were in the third codon position and silent with respect to the amino acids encoded. The distribution of the sequence variants was mapped geographically. The requirement for RNA editing in all other typical mitochondrial genes of D. iridis and P. polycephalum and the presence of RNA editing in the nad3 gene of P. polycephalum suggest that the D. iridis nad3 gene might have been edited at one time. We propose that the D. iridis nad3 gene may have lost the requirement for RNA editing by reverse transcription of an edited transcript that subsequently was inserted into the genome.

  15. Multidisciplinary team decision-making in cancer and the absent patient: a qualitative study

    PubMed Central

    Hamilton, D W; Heaven, B; Thomson, R G; Wilson, J A; Exley, C

    2016-01-01

    Objective To critically examine the process of multidisciplinary team (MDT) decision-making with a particular focus on patient involvement. Design Ethnographic study using direct non-participant observation of 35 MDT meetings and 37 MDT clinics, informal interviews and formal, semistructured interviews with 20 patients and 9 MDT staff members. Setting Three head and neck cancer centres in the north of England. Participants Patients with a diagnosis of new or recurrent head and neck cancer and staff members who attend the head and neck cancer MDT. Results Individual members of the MDT often have a clear view of which treatment they consider to be ‘best’ in any clinical situation. When disagreement occurs, the MDT has to manage how it presents this difference of opinion to the patient. First, this is because the MDT members recognise that the clinician selected to present the treatment choice to the patient may ‘frame’ their description of the treatment options to fit their own view of best. Second, many MDT members feel that any disagreement and difference of opinion in the MDT meeting should be concealed from the patient. This leads to much of the work of decision-making occurring in the MDT meeting, thus excluding the patient. MDT members seek to counteract this by introducing increasing amounts of information about the patient into the MDT meeting, thus creating an ‘evidential patient’. Often, only highly selected or very limited information of this type can be available or known and it can easily be selectively reported in order to steer the discussion in a particular direction. Conclusions The process of MDT decision-making presents significant barriers to effective patient involvement. If patients are to be effectively involved in cancer decision-making, the process of MDT decision-making needs substantial review. PMID:27443554

  16. The Earth is flat when personally significant experiences with the sphericity of the Earth are absent.

    PubMed

    Carbon, Claus-Christian

    2010-07-01

    Participants with personal and without personal experiences with the Earth as a sphere estimated large-scale distances between six cities located on different continents. Cognitive distances were submitted to a specific multidimensional scaling algorithm in the 3D Euclidean space with the constraint that all cities had to lie on the same sphere. A simulation was run that calculated respective 3D configurations of the city positions for a wide range of radii of the proposed sphere. People who had personally experienced the Earth as a sphere, at least once in their lifetime, showed a clear optimal solution of the multidimensional scaling (MDS) routine with a mean radius deviating only 8% from the actual radius of the Earth. In contrast, the calculated configurations for people without any personal experience with the Earth as a sphere were compatible with a cognitive concept of a flat Earth.

  17. The Earth Is Flat when Personally Significant Experiences with the Sphericity of the Earth Are Absent

    ERIC Educational Resources Information Center

    Carbon, Claus-Christian

    2010-01-01

    Participants with personal and without personal experiences with the Earth as a sphere estimated large-scale distances between six cities located on different continents. Cognitive distances were submitted to a specific multidimensional scaling algorithm in the 3D Euclidean space with the constraint that all cities had to lie on the same sphere. A…

  18. Exploring What's Missing: What Do Target Absent Trials Reveal about Autism Search Superiority?

    ERIC Educational Resources Information Center

    Keehn, Brandon; Joseph, Robert M.

    2016-01-01

    We used eye-tracking to investigate the roles of enhanced discrimination and peripheral selection in superior visual search in autism spectrum disorder (ASD). Children with ASD were faster at visual search than their typically developing peers. However, group differences in performance and eye-movements did not vary with the level of difficulty of…

  19. The Body and Pedagogy: Beyond Absent, Moving Bodies in Pedagogic Practice

    ERIC Educational Resources Information Center

    Ivinson, Gabrielle

    2012-01-01

    Following the corporeal turn in social theory, this paper explores how the body is implicated in pedagogic practice and leaning. Focusing on the body has usually been recognised as part of the regulative rather than instructional discourse in schools. Work has begun to redress the mind-body imbalance through the "corporeal device" developed from…

  20. Absent Authority: Failure to Plan Funding and Command Authorities in USAF Security Assistance Units

    DTIC Science & Technology

    2013-03-01

    the USAF took partners who were 58 Ken Arteaga , “Air Advisor Education & Training Information...2 Feb 2012. Arteaga , Ken. “Air Advisor Education & Training Information Brief.” San Antonio TX: Headquarters Air Education and Training Command

  1. Type 2 inflammation in asthma — present in most, absent in many

    PubMed Central

    Fahy, John V.

    2015-01-01

    Asthma is one of the most common chronic immunological diseases in humans, affecting people from childhood to old age. Progress in treating asthma has been relatively slow and treatment guidelines have mostly recommended empirical approaches on the basis of clinical measures of disease severity rather than on the basis of the underlying mechanisms of pathogenesis. An important molecular mechanism of asthma is type 2 inflammation, which occurs in many but not all patients. In this Opinion article, I explore the role of type 2 inflammation in asthma, including lessons learnt from clinical trials of inhibitors of type 2 inflammation. I consider how dichotomizing asthma according to levels of type 2 inflammation — into ‘T helper 2 (TH2)-high’ and ‘TH2-low’ subtypes (endotypes) — has shaped our thinking about the pathobiology of asthma and has generated new interest in understanding the mechanisms of disease that are independent of type 2 inflammation. PMID:25534623

  2. Complement, Kinins, and Hereditary Angioedema: Mechanisms of Plasma Instability when C1 Inhibitor is Absent.

    PubMed

    Kaplan, Allen P; Joseph, Kusumam

    2016-10-01

    Plasma of patients with types I and II hereditary angioedema is unstable if incubated in a plastic (i.e., inert) vessel at 37 °C manifested by progressively increasing formation of bradykinin. There is also a persistent low level of C4 in 95 % of patients even when they are symptomatic. These phenomena are due to the properties of the C1r subcomponent of C1, factor XII, and the bimolecular complex of prekallikrein with high molecular weight kininogen (HK). Purified C1r auto-activates in physiologic buffers, activates C1s, which in turn depletes C4. This occurs when C1 inhibitor is deficient. The complex of prekallikrein-HK acquires an inducible active site not present in prekallikrein which in Tris-type buffers cleaves HK stoichiometrically to release bradykinin, or in phosphate buffer auto-activates to generate kallikrein and bradykinin. Thus immunologic depletion of C1 inhibitor from factor XII-deficient plasma (phosphate is the natural buffer) auto-activates on incubation to release bradykinin. Normal C1 inhibitor prevents this from occurring. During attacks of angioedema, if factor XII auto-activates on surfaces, the initial factor XIIa formed converts prekallikrein to kallikrein, and kallikrein cleaves HK to release bradykinin. Kallikrein also rapidly activates most remaining factor XII to factor XIIa. Additional cleavages convert factor XIIa to factor XIIf and factor XIIf activates C1r enzymatically so that C4 levels approach zero, and C2 is depleted. There is also a possibility that kallikrein is generated first as a result of activation of the prekallikrein-HK complex by heat shock protein 90 released from endothelial cells, followed by kallikrein activation of factor XII.

  3. Iron-Nitride Alloy Magnets: Transformation Enabled Nitride Magnets Absent Rare Earths (TEN Mare)

    SciTech Connect

    2012-01-01

    REACT Project: Case Western is developing a highly magnetic iron-nitride alloy to use in the magnets that power electric motors found in EVs and renewable power generators. This would reduce the overall price of the motor by eliminating the expensive imported rare earth minerals typically found in today’s best commercial magnets. The iron-nitride powder is sourced from abundant and inexpensive materials found in the U.S. The ultimate goal of this project is to demonstrate this new magnet system, which contains no rare earths, in a prototype electric motor. This could significantly reduce the amount of greenhouse gases emitted in the U.S. each year by encouraging the use of clean alternatives to oil and coal.

  4. Absent movement-related cortical potentials in children with primary motor stereotypies

    PubMed Central

    Houdayer, Elise; Walthall, Jessica; Belluscio, Beth A.; Vorbach, Sherry; Singer, Harvey S.; Hallett, Mark

    2013-01-01

    Background The underlying pathophysiologic mechanism for complex motor stereotypies in children is unknown with hypotheses ranging from an arousal to a motor control disorder. Movement-related cortical potentials (MRCPs), representing the activation of cerebral areas involved in the generation of movements, precede and accompany self-initiated voluntary movements. The goal of this study was to compare cerebral activity associated with stereotypies to that seen with voluntary movements in children with primary complex motor stereotypies. Methods Electroencephalographic (EEG) activity synchronized with video recording was recorded in 10 children diagnosed with primary motor stereotypies and 7 controls. EEG activity related to stereotypies and self-paced arm movements were analyzed for presence or absence of early or late MRCP, a steep negativity beginning about one second before the onset of a voluntary movement. Results Early MRCPs preceded self-paced arm movements in 8 out of 10 children with motor stereotypies and in 6 out of 7 controls. Observed MRCPs did not differ between groups. No MRCP was identified before the appearance of a complex motor stereotypy. Conclusions Unlike voluntary movements, stereotypies are not preceded by MRCPs. This indicates that premotor areas are likely not involved in the preparation of these complex movements and suggests that stereotypies are initiated by mechanisms different from voluntary movements. Further studies are required to determine the site of the motor control abnormality within cortico-striatal-thalamo-cortical pathways and to identify whether similar findings would be found in children with secondary stereotypies. PMID:24259275

  5. Challenging Some Contemporary Views of Coronal Mass Ejections. II. The Case for Absent Filaments

    NASA Astrophysics Data System (ADS)

    Howard, T. A.; DeForest, C. E.; Schneck, U. G.; Alden, C. R.

    2017-01-01

    When a coronal mass ejection (CME) appears in a coronagraph it often exhibits three parts. This “classic” three-part configuration consists of a bright leading edge, a dark circular- or teardrop-shaped cavity, and a bright core within the cavity. It is generally accepted that these are manifestations of coronal plasma pileup, the driving magnetic flux rope, and the associated eruptive filament, respectively. The latter has become accepted by the community since coronagraph CMEs have been commonly associated with eruptive filaments for over 40 years. In this second part of our series challenging views on CMEs, we present the case that the inner core of the three-part coronagraph CME may not be, and in the most common cases is not, a filament. We present our case in the form of four exhibits showing that most of the CMEs in a broad survey are not associated with an eruptive filament at the Sun, and that the cores of those CMEs that are filament-associated do not geometrically resemble or consist of material from the associated filament. We conclude with a discussion on the possible causes of the bright CME core and what happens to the filament material postlaunch. We discuss how the CME core could arise spontaneously from the eruption of a flux rope from the Sun, or could be the result of a mathematical caustic produced by the geometric projection of a twisted flux rope.

  6. An Absent Presence: Women Professors at the University of New Zealand 1911-1961

    ERIC Educational Resources Information Center

    Fitzgerald, Tanya

    2007-01-01

    The historiography of women's higher education has almost exclusively charted women's admission to universities, institutional responses to increasing numbers of women students and women's struggles to claim a presence as academics and administrators. Less attention has however been paid to the history and agency of women professors who were…

  7. Adaptive Associations between Social Cognition and Emotion Regulation are Absent in Schizophrenia and Bipolar Disorder.

    PubMed

    Rowland, Jesseca E; Hamilton, Meelah K; Vella, Nicholas; Lino, Bianca J; Mitchell, Philip B; Green, Melissa J

    2012-01-01

    Schizophrenia (SZ) and bipolar disorder (BD) are associated with impairments in facial emotion perception and Theory of Mind (ToM). These social cognitive skills deficits may be related to a reduced capacity to effectively regulate one's own emotions according to the social context. We therefore set out to examine the relationship between social cognitive abilities and the use of cognitive strategies for regulating negative emotion in SZ and BD. Participants were 56 SZ, 33 BD, and 58 healthy controls (HC) who completed the Ekman 60-faces test of facial emotion recognition; a sub-set of these participants also completed The Awareness of Social Inference Test (TASIT) and the Cognitive Emotion Regulation Questionnaire (CERQ). SZ participants demonstrated impairments in emotion perception on both the Ekman and the TASIT Emotion Evaluation tests relative to BD and HC. While both SZ and BD patients showed ToM deficits (i.e., perception of sarcasm and lie) compared to HC, SZ patients demonstrated significantly greater ToM impairment compared to BD. There were also distinct patterns of cognitive strategies used to regulate emotion in both patient groups: those with SZ were more likely to engage in catastrophizing and rumination, while BD subjects were more likely to blame themselves and were less likely to engage in positive reappraisal, relative to HC. In addition, those with SZ were more likely to blame others compared to BD. Associations between social cognition and affect regulation were revealed for HC only: TASIT performance was negatively associated with more frequent use of rumination, catastrophizing, and blaming others, such that more frequent use of maladaptive cognitive emotion regulation strategies was associated with poor social cognitive performance. These associations were not present in either patient group. However, both SZ and BD patients demonstrated poor ToM performance and aberrant use of emotion regulation strategies consistent with previous studies. SZ also showed basic emotion recognition deficits relative to BD and HC. That there were no associations between social cognition and the capacity to self-regulate negative emotion in SZ and BD (in the context of poor social cognition and maladaptive regulatory strategies) suggests that dysfunction in fronto-limbic brain networks may underpin both social cognitive deficits and the use of maladaptive cognitive strategies in these disorders, albeit by potentially different routes.

  8. Intrafibrillar Mineral May be Absent in Dentinogenesis Imperfecta Type II (DI-II)

    SciTech Connect

    Pople, John A.

    2001-03-29

    High-resolution synchrotron radiation computed tomography (SRCT) and small angle x-ray scattering (SAXS) were performed on normal and dentinogenesis imperfecta type II (DI-II) teeth. Three normal and three DI-II human third molars were used in this study. The normal molars were unerupted and had intact enamel; donors were female and ranged in age from 18-21y. The DI-II specimens, which were also unerupted with intact enamel, came from a single female donor age 20y. SRCT showed that the mineral concentration was 33% lower on average in the DI-II dentin with respect to normal dentin. The SAXS spectra from normal dentin exhibited low-angle diffraction peaks at harmonics of 67.6 nm, consistent with nucleation and growth of the apatite phase within gaps in the collagen fibrils (intrafibrillar mineralization). In contrast, the low-angle peaks were almost nonexistent in the DI-II dentin. Crystallite thickness was independent of location in both DI-II and normal dentin, although the crystallites were significantly thicker in DI-II dentin (6.8 nm (s.d. = 0.5) vs 5.1 nm (s.d. = 0.6)). The shape factor of the crystallites, as determined by SAXS, showed a continuous progression in normal dentin from roughly one-dimensional (needle-like) near the pulp to two-dimensional (plate-like) near the dentin-enamel junction. The crystallites in DI-II dentin, on the other hand, remained needle-like throughout. The above observations are consistent with an absence of intrafibrillar mineral in DI-II dentin.

  9. Normal body scheme and absent phantom limb experience in amputees while dreaming.

    PubMed

    Alessandria, Maria; Vetrugno, Roberto; Cortelli, Pietro; Montagna, Pasquale

    2011-12-01

    While dreaming amputees often experience a normal body image and the phantom limb may not be present. However, dreaming experiences in amputees have mainly been collected by questionnaires. We analysed the dream reports of amputated patients with phantom limb collected after awakening from REM sleep during overnight videopolysomnography (VPSG). Six amputated patients underwent overnight VPSG study. Patients were awakened during REM sleep and asked to report their dreams. Three patients were able to deliver an account of a dream. In all dreaming recalls, patients reported that the amputated limbs were intact and completely functional and they no longer experienced phantom limb sensations. Phantom limb experiences, that during wake result from a conflict between a pre-existing body scheme and the sensory information on the missing limb, were suppressed during sleep in our patients in favour of the image of an intact body accessed during dream.

  10. Superinfection exclusion is absent during acute Junin virus infection of Vero and A549 cells.

    PubMed

    Gaudin, Raphaël; Kirchhausen, Tomas

    2015-11-09

    Many viruses have evolved strategies of so-called "superinfection exclusion" to prevent re-infection of a cell that the same virus has already infected. Although Old World arenavirus infection results in down-regulation of its viral receptor and thus superinfection exclusion, whether New World arenaviruses have evolved such a mechanism remains unclear. Here we show that acute infection by the New World Junin virus (JUNV) failed to down-regulate the transferrin receptor and did not induce superinfection exclusion. We observed that Vero cells infected by a first round of JUNV (Candid1 strain) preserve an ability to internalize new incoming JUNV particles that is comparable to that of non-infected cells. Moreover, we developed a dual infection assay with the wild-type Candid1 JUNV and a recombinant JUNV-GFP virus to discriminate between first and second infections at the transcriptional and translational levels. We found that Vero and A549 cells already infected by JUNV were fully competent to transcribe viral RNA from a second round of infection. Furthermore, flow cytometry analysis of viral protein expression indicated that viral translation was normal, regardless of whether cells were previously infected or not. We conclude that in acutely infected cells, Junin virus lacks a superinfection exclusion mechanism.

  11. Misdiagnosing Absent Pedicle of Cervical Spine in the Acute Trauma Setting

    PubMed Central

    Rossel, Felipe; Nooh, Anas; Jarzem, Peter

    2015-01-01

    Congenital absence of cervical spine pedicle can be easily misdiagnosed as facet dislocation on plain radiographs especially in the acute trauma setting. Additional imaging, including computed tomography (CT)-scan with careful interpretation is required in order to not misdiagnose cervical posterior arch malformation with subsequent inappropriate management. A 39-year-old patient presented to the emergency unit of our university hospital after being trampled by a cow over her back and head followed by loss of consciousness, retrograde amnesia and neck pain. Her initial cervical CT-scan showed possible C5-C6 dislocation, then, it became clear that her problem was a misdiagnosed congenital cervical abnormality. Patient was treated symptomatically without consequences. The congenital absence of a cervical pedicle is a very unusual condition that is easily misdiagnosed. Diagnosis can be accurately confirmed with a CT-scan of the cervical spine. Symptomatic conservative treatment will result in resolution of the symptoms. PMID:26605026

  12. Presence, Absence, and the Presently-Absent: Ethics and the Pedagogical Possibilities of Photographs

    ERIC Educational Resources Information Center

    Stern, Mark

    2012-01-01

    One of the fundamental pedagogical questions in teaching about human rights, war, and global citizenship is how to educate students to care about strangers whom they may never know and whom they may assume they have nothing in common with. At its core, this is an ethical question that highlights a problem in articulating relations between self and…

  13. Good, Bad or Absent: Discourses of Parents with Disabilities in Australian News Media

    ERIC Educational Resources Information Center

    Fraser, Vikki; Llewellyn, Gwynnyth

    2015-01-01

    Background: News media frames public perceptions. As such, news media becomes a useful source of analysis to understand the presence (or otherwise) of people with disabilities, particularly intellectual disabilities, within parenting discourses in Australia. Method: Using Critical Discourse Analysis, this article examines major Australian…

  14. Teaching Experimental Method Using the Feature-Present/Feature-Absent Effect

    ERIC Educational Resources Information Center

    Balch, William R.

    2010-01-01

    To determine whether a classroom experiment improved the learning of experimental method, at the start of the semester 2 introductory psychology classes took a 10-question multiple-choice pretest on experimental method. Two days later, before the instructor covered the relevant material in the course, 1 class took part in a classroom experiment on…

  15. Parent-Absent Children: A Demographic Analysis of Children and Adolescents Living Apart from Their Parents.

    ERIC Educational Resources Information Center

    Montemayor, Raymond; Leigh, Geoffrey K.

    1982-01-01

    Presents a profile of children and adolescents living apart from their parents. Indicates that in 1980 3.7 percent of all unmarried, noninstitutionalized children were not living with either parent. A large majority were living with relatives, and a minority were living in group quarters, such as boarding schools. (Author)

  16. Why Teachers Are Absent: An Examination of Teacher Absences in Broward County Public Schools.

    ERIC Educational Resources Information Center

    Green, Laura R.; Blasik, Katherine A.; Varela-Russo, Carmen

    1999-01-01

    An absenteeism study found that the largest percentage of teacher absences was due to professional development activities, illness, and vacant positions. High schools had lower absence rates than elementary and middle schools and centers. Absenteeism was also related to number of kids eligible for free-lunch programs. (Contains 20 references.)…

  17. Prenatal diagnosis of a case with anencephaly-omphalocele-unilateral absent radial ray.

    PubMed

    Ceylaner, S; Ceylaner, G; Altun, M; Coşkun, A; Danisman, N

    2009-01-01

    We report here a female fetus with anencephaly, omphalocele and unilateral radial aplasia. The combination of two of these three malformations were reported in a number of patients diagnosed as Gershoni-Barush syndrome, ORR phenotype, VATER association, Schisis association, OEIS complex, Schinzel phocomelia syndrome and Acalvaria but they have not been reported all together in the same patient up to date. We hypothesize that, some or all these syndromes given above may be related etiologically.

  18. The right coronary artery is absent in the chinchilla (Chinchilla lanigera).

    PubMed

    Ozdemir, V; Cevik-Demirkan, A; Turkmenoglu, I

    2008-04-01

    A total of 10 adult, healthy, male chinchillas (Chinchilla lanigera) were used to investigate the origin, course, and termination of the coronary arteries. Coloured latex was injected into the carotid arteries following conventional anatomical applications. In all the chinchillas examined, the left coronary artery was the single coronary artery. The right coronary artery was missing. Additionally, a small vessel originating from the cranial border of the aorta was observed in one chinchilla. The left coronary artery divided into the paraconal, interventricular and left circumflex rami. The left marginis ventricular ramus arose from the paraconal interventricular ramus in eight chinchillas, and from the left circumflex ramus in two. The ventricular and septal branches of the left coronary artery ran subepicardially at the beginning mostly parallel to the muscle fibres, also surrounded by a thin adipose tissue. It was concluded that the only left coroner artery supplied blood to the heart in the chinchilla.

  19. Motor hysteresis in a sequential grasping and pointing task is absent in task-critical joints.

    PubMed

    Schütz, Christoph; Weigelt, Matthias; Schack, Thomas

    2017-03-01

    In a prior study (Schütz et al. in Exp Brain Res 2016. doi: 10.1007/s00221-016-4608-6 ), we demonstrated that the cognitive cost of motor planning did not differ in a vertical pointing and grasping task. It was unclear whether the similar cost implied that both tasks required the same number of independent degrees of freedom (IDOFs) or that the number of IDOFs did not affect motor planning. To differentiate between both cases, a reanalysis of the prior data was conducted. The number of IDOFs in the pointing and grasping tasks was computed by factor analysis. In both tasks, two IDOFs were used, which was the minimum number required for position control. This indicates that hand alignment in the grasping task did not require an additional IDOF. No conclusions regarding the link between the cognitive cost of motor planning and the number of IDOFs could be drawn. A subset of task-critical joint angles was not affected by motor hysteresis. This indicates that a joint's susceptibility to motor hysteresis depends on its relevance to the task goal. In task-critical joints, planning cost minimization by motor plan reuse is suppressed in favor of the task goal.

  20. Absent Peers in Elementary Years: The Negative Classroom Effects of Unexcused Absences on Standardized Testing Outcomes

    ERIC Educational Resources Information Center

    Gottfried, Michael A.

    2011-01-01

    Background/Context: This article addresses the classroom contextual effects of absences on student achievement. Previous research on peer effects has predominantly focused on peer socioeconomic status or classroom academic ability and its effects on classmates. However, the field has been limited by not discerning the individual-level academic…

  1. Gender and sexual orientation in relation to hypothalamic structures.

    PubMed

    Swaab, D F; Gooren, L J; Hofman, M A

    1992-01-01

    Animal experiments have provided evidence for the presence of sex differences from the synaptic level up to behaviour. Although sex differences in the human brain may have been presumed implicitly since the days of Aristotle, research on the presence of functional and structural sex differences of the human brain started only relatively recently. The most conspicuous sex difference in the mammalian brain was described by Gorski et al. [1978] in the preoptic area (POA) of the rat hypothalamus. We found that the volume of a putative homologue of this sexually dimorphic nucleus (SDN) in the adult human hypothalamus was more than twice as large in men as in women and contained about twice as many cells. Recently a similar sex difference and volume has been described for the human bed nucleus of the stria terminalis and 'interstitial nuclei of the hypothalamus' (INAH). Sexual differentiation of the hypothalamus was generally believed to take place between 4 and 7 months of gestation. A life span study on the SDN of more than 100 subjects revealed, however, that only after the age of 2-4 years postnatally sexual differentiation becomes manifest by a decrease in volume and cell number in the female SDN. If sexual differentiation of the brain indeed takes place postnatally, not only chemical and hormonal factors may influence this process but also social factors. A prominent theory on the development of sexual orientation is that it develops as a result of an interaction between the developing brain and sex hormones. According to Dörner's hypothesis, male homosexuals have a female differentiation of the hypothalamus. This hypothesis was not supported by our observations on the SDN. Neither the SDN volume nor the cell number in the hypothalamus of homosexual men differed from that of heterosexual men. However, a difference in SCN cell number was observed in relation to sexual orientation. The volume and cell number of the SCN of homosexual men was twice as large as that of

  2. Crystal structure of homoisocitrate dehydrogenase from Schizosaccharomyces pombe

    SciTech Connect

    Bulfer, Stacie L.; Hendershot, Jenna M.; Trievel, Raymond C.

    2013-09-18

    Lysine biosynthesis in fungi, euglena, and certain archaebacteria occurs through the {alpha}-aminoadipate pathway. Enzymes in the first steps of this pathway have been proposed as potential targets for the development of antifungal therapies, as they are absent in animals but are conserved in several pathogenic fungi species, including Candida, Cryptococcus, and Aspergillus. One potential antifungal target in the {alpha}-aminoadipate pathway is the third enzyme in the pathway, homoisocitrate dehydrogenase (HICDH), which catalyzes the divalent metal-dependent conversion of homoisocitrate to 2-oxoadipate (2-OA) using nicotinamide adenine dinucleotide (NAD{sup +}) as a cofactor. HICDH belogns to a family of {beta}-hydroxyacid oxidative decarboxylases that includes malate dehydrogenase, tartrate dehydrogenase, 6-phosphogluconate dehydrogenase, isocitrate dehydrogenase (ICDH), and 3-isopropylmalte dehydrogenase (IPMDH). ICDH and IPMDH are well-characterized enzymes that catalyze the decarboxylation of isocitrate to yield 2-oxoglutarate (2-OG) in the citric acid cycle and the conversion of 3-isopropylmalate to 2-oxoisovalerate in the leucine biosynthetic pathway, respectively. Recent structural and biochemical studies of HICDH reveal that this enzyme shares sequence, structural, and mechanistic homology with ICDH and IPMDH. To date, the only published structures of HICDH are from the archaebacteria Thermus thermophilus (TtHICDH). Fungal HICDHs diverge from TtHICDH in several aspects, including their thermal stability, oligomerization state, and substrate specificity, thus warranting further characterization. To gain insights into these differences, they determined crystal structures of a fungal Schizosaccharomyces pombe HICDH (SpHICDH) as an apoenzyme and as a binary complex with additive tripeptide glycyl-glycyl-glycine (GGG) to 1.55 {angstrom} and 1.85 {angstrom} resolution, respectively. Finally, a comparison of the SpHICDH and TtHICDH structures reveal differences in

  3. Shatter cones at the Keurusselkä impact structure and their relation to local jointing

    NASA Astrophysics Data System (ADS)

    Hasch, Maximilian; Reimold, Wolf Uwe; Raschke, Ulli; Zaag, Patrice Tristan

    2016-08-01

    Shatter cones are the only distinct meso- to macroscopic recognition criterion for impact structures, yet not all is known about their formation. The Keurusselkä impact structure, Finland, is interesting in that it presents a multitude of well-exposed shatter cones in medium- to coarse-grained granitoids. The allegedly 27 km wide Keurusselkä impact structure was formed about 1150 Ma ago in rocks of the Central Finland Granitoid Complex. Special attention was paid in this work to possible relationships between shatter cones and local, as well as regionally occurring, fracture or joint systems. A possible shatter cone find outside the previously suggested edge of the structure could mean that the Keurusselkä impact structure is larger than previously thought. The spacing between joints/fractures from regional joint systems was influenced by the impact, but impact-induced fractures strongly follow the regional joint orientation trends. There is a distinct relationship between shatter cones and joints: shatter cones occur on and against joint surfaces of varied orientations and belonging to the regional orientation trends. Planar fractures (PF) and planar deformation features (PDF) were found in three shatter cone samples from the central-most part of the impact structure, whereas other country rock samples from the same level of exposure but further from the assumed center lack shock deformation features. PDF occurrence is enhanced within 5 mm of shatter cone surfaces, which is interpreted to suggest that shock wave reverberation at preimpact joints could be responsible for this local enhancement of shock deformation. Some shatter cone surfaces are coated with a quasi-opaque material which is also found in conspicuous veinlets that branch off from shatter cone surfaces and resemble pseudotachylitic breccia veins. The vein-filling is composed of two mineral phases, one of which could be identified as a montmorillonitic phyllosilicate. The second phase could not be

  4. Predator-guided sampling reveals biotic structure in the bathypelagic.

    PubMed

    Benoit-Bird, Kelly J; Southall, Brandon L; Moline, Mark A

    2016-02-24

    We targeted a habitat used differentially by deep-diving, air-breathing predators to empirically sample their prey's distributions off southern California. Fine-scale measurements of the spatial variability of potential prey animals from the surface to 1,200 m were obtained using conventional fisheries echosounders aboard a surface ship and uniquely integrated into a deep-diving autonomous vehicle. Significant spatial variability in the size, composition, total biomass, and spatial organization of biota was evident over all spatial scales examined and was consistent with the general distribution patterns of foraging Cuvier's beaked whales (Ziphius cavirostris) observed in separate studies. Striking differences found in prey characteristics between regions at depth, however, did not reflect differences observed in surface layers. These differences in deep pelagic structure horizontally and relative to surface structure, absent clear physical differences, change our long-held views of this habitat as uniform. The revelation that animals deep in the water column are so spatially heterogeneous at scales from 10 m to 50 km critically affects our understanding of the processes driving predator-prey interactions, energy transfer, biogeochemical cycling, and other ecological processes in the deep sea, and the connections between the productive surface mixed layer and the deep-water column.

  5. Wake structure and kinematics in two insectivorous bats.

    PubMed

    Hubel, Tatjana Y; Hristov, Nickolay I; Swartz, Sharon M; Breuer, Kenneth S

    2016-09-26

    We compare kinematics and wake structure over a range of flight speeds (4.0-8.2 m s(-1)) for two bats that pursue insect prey aerially, Tadarida brasiliensis and Myotis velifer Body mass and wingspan are similar in these species, but M. velifer has broader wings and lower wing loading. By using high-speed videography and particle image velocimetry of steady flight in a wind tunnel, we show that three-dimensional kinematics and wake structure are similar in the two species at the higher speeds studied, but differ at lower speeds. At lower speeds, the two species show significant differences in mean angle of attack, body-wingtip distance and sweep angle. The distinct body vortex seen at low speed in T. brasiliensis and other bats studied to date is considerably weaker or absent in M. velifer We suggest that this could be influenced by morphology: (i) the narrower thorax in this species probably reduces the body-induced discontinuity in circulation between the two wings and (ii) the wing loading is lower, hence the lift coefficient required for weight support is lower. As a result, in M. velifer, there may be a decreased disruption in the lift generation between the body and the wing, and the strength of the characteristic root vortex is greatly diminished, both suggesting increased flight efficiency.This article is part of the themed issue 'Moving in a moving medium: new perspectives on flight'.

  6. Predator-guided sampling reveals biotic structure in the bathypelagic

    PubMed Central

    Southall, Brandon L.; Moline, Mark A.

    2016-01-01

    We targeted a habitat used differentially by deep-diving, air-breathing predators to empirically sample their prey's distributions off southern California. Fine-scale measurements of the spatial variability of potential prey animals from the surface to 1 200 m were obtained using conventional fisheries echosounders aboard a surface ship and uniquely integrated into a deep-diving autonomous vehicle. Significant spatial variability in the size, composition, total biomass, and spatial organization of biota was evident over all spatial scales examined and was consistent with the general distribution patterns of foraging Cuvier's beaked whales (Ziphius cavirostris) observed in separate studies. Striking differences found in prey characteristics between regions at depth, however, did not reflect differences observed in surface layers. These differences in deep pelagic structure horizontally and relative to surface structure, absent clear physical differences, change our long-held views of this habitat as uniform. The revelation that animals deep in the water column are so spatially heterogeneous at scales from 10 m to 50 km critically affects our understanding of the processes driving predator–prey interactions, energy transfer, biogeochemical cycling, and other ecological processes in the deep sea, and the connections between the productive surface mixed layer and the deep-water column. PMID:26888030

  7. Brillouin resonance broadening due to structural variations in nanoscale waveguides

    NASA Astrophysics Data System (ADS)

    Wolff, C.; Van Laer, R.; Steel, M. J.; Eggleton, B. J.; Poulton, C. G.

    2016-02-01

    We study the impact of structural variations (that is slowly varying geometry aberrations and internal strain fields) on the width and shape of the stimulated Brillouin scattering (SBS) resonance in nanoscale waveguides. We find that they lead to an inhomogeneous resonance broadening through two distinct mechanisms: firstly, the acoustic frequency is directly influenced via mechanical nonlinearities; secondly, the optical wave numbers are influenced via the opto-mechanical nonlinearity leading to an additional acoustic frequency shift via the phase-matching condition. We find that this second mechanism is proportional to the opto-mechanical coupling and, hence, related to the SBS-gain itself. It is absent in intra-mode forward SBS, while it plays a significant role in backward scattering. In backward SBS increasing the opto-acoustic overlap beyond a threshold defined by the fabrication tolerances will therefore no longer yield the expected quadratic increase in overall Stokes amplification. Finally, we illustrate in a numerical example that in backward SBS and inter-mode forward SBS the existence of two broadening mechanisms with opposite sign also opens the possibility to compensate the effect of geometry-induced broadening. Our results can be transferred to other micro- and nano-structured waveguide geometries such as photonic crystal fibres.

  8. Crystal structure of a maltogenic amylase provides insights into a catalytic versatility.

    PubMed

    Kim, J S; Cha, S S; Kim, H J; Kim, T J; Ha, N C; Oh, S T; Cho, H S; Cho, M J; Kim, M J; Lee, H S; Kim, J W; Choi, K Y; Park, K H; Oh, B H

    1999-09-10

    Amylases catalyze the hydrolysis of starch material and play central roles in carbohydrate metabolism. Compared with many different amylases that are able to hydrolyze only alpha-D-(1,4)-glycosidic bonds, maltogenic amylases exhibit catalytic versatility: hydrolysis of alpha-D-(1,4)- and alpha-D-(1,6)-glycosidic bonds and transglycosylation of oligosaccharides to C3-, C4-, or C6-hydroxyl groups of various acceptor mono- or disaccharides. It has been speculated that the catalytic property of the enzymes is linked to the additional approximately 130 residues at the N terminus that are absent in other typical alpha-amylases. The crystal structure of a maltogenic amylase from a Thermus strain was determined at 2.8 A. The structure, an analytical centrifugation, and a size exclusion column chromatography proved that the enzyme is a dimer in solution. The N-terminal segment of the enzyme folds into a distinct domain and comprises the enzyme active site together with the central (alpha/beta)(8) barrel of the adjacent subunit. The active site is a narrow and deep cleft suitable for binding cyclodextrins, which are the preferred substrates to other starch materials. At the bottom of the active site cleft, an extra space, absent in the other typical alpha-amylases, is present whose size is comparable with that of a disaccharide. The space is most likely to host an acceptor molecule for the transglycosylation and to allow binding of a branched oligosaccharide for hydrolysis of alpha-D-(1,4)-glycosidic or alpha-D-(1,6)-glycosidic bond. The (alpha/beta)(8) barrel of the enzyme is the preserved scaffold in all the known amylases. The structure represents a novel example of how an enzyme acquires a different substrate profile and a catalytic versatility from a common active site and represents a framework for explaining the catalytic activities of transglycosylation and hydrolysis of alpha-D-(1,6)-glycosidic bond.

  9. Common structure-balance between spacetime structure and massenergy structure

    NASA Astrophysics Data System (ADS)

    Cao, Daqing; Cao, Dayong

    2017-01-01

    According to Einstein field equation, there is a balance between spacetime structure and massenergy structure. nd the paper consider it as a common structurewhich was brought forward by Daqing Cao in 2011 ecause it is general structure in the universe and everything have the same model of structure in their one system. The Jovian planets is spacetime structure of solar system because they are gas-sphere and they have more density of spacetime (spacetime/massenergy) than the density of massenergy (massenergy/spacetime). The terrestrial planets is massenergy structure of solar system because they are rock-ball and they have more density of massenergy than the density of spacetime. That can explain of that the Jovian planets of big mass is far away from sun. With the idea that the wave is spacetime and the wave effect is spacetime structure, the planets have elliptic orbits and the same direction of their revolution. Because sun is like a massenergy center of the massenergy structure and the terrestrial planets, the paper supposes there is a dark sun-a dark hole who has a spacetime center of spacetime structure and influences on the orbits of the Jovian planets. http://meetings.aps.org/Meeting/APR16/Session/M13.8

  10. Ostrich crystallins. Structural characterization of delta-crystallin with enzymic activity.

    PubMed Central

    Chiou, S H; Lo, C H; Chang, C Y; Itoh, T; Kaji, H; Samejima, T

    1991-01-01

    Lens crystallins from the African ostrich (Struthio camelus) were isolated and characterized. Four crystallin fractions corresponding to alpha-, delta/beta- and beta-crystallins similar to those of duck crystallins were isolated, but epsilon-crystallin was found to be absent. The native molecular masses and subunit structures of the purified fractions were analysed by gel filtration. SDS/PAGE and isoelectric focusing, revealing various extents of heterogeneity in each orthologous crystallin class. An ion-exchange chromatographic method was used for the large-scale preparation of delta-crystallin suitable for structural and enzymic studies. It was unexpectedly found that the purified native delta-crystallin of ostrich lens possessed high argininosuccinate lyase activity, in contrast with chicken delta-crystallin. The c.d. spectra indicated a predominant beta-sheet structure in alpha- and beta-crystallins, and a significant contribution of alpha-helical structure in the delta-crystallin fraction. The estimate of secondary structures from c.d. spectroscopy for each crystallin class bears a resemblance to that of duck crystallins, except that ostrich delta-crystallin possesses much less helical content than duck delta-crystallin. Comparison of crystallin compositions and structures from aquatic and terrestrial birds revealed distinct differences. Images Fig. 1. Fig. 2. Fig. 3. PMID:1991029

  11. Genetic population structure of US atlantic coastal striped bass (Morone saxatilis).

    PubMed

    Gauthier, David T; Audemard, Corinne A; Carlsson, Jeanette E L; Darden, Tanya L; Denson, Michael R; Reece, Kimberly S; Carlsson, Jens

    2013-01-01

    Genetic population structure of anadromous striped bass along the US Atlantic coast was analyzed using 14 neutral nuclear DNA microsatellites. Young-of-the-year and adult striped bass (n = 1114) were sampled from Hudson River, Delaware River, Chesapeake Bay, North Carolina, and South Carolina. Analyses indicated clear population structure with significant genetic differentiation between all regions. Global multilocus F ST was estimated at 0.028 (P < 0.001). Population structure followed an isolation-by-distance model and temporal sampling indicated a stable population structure more than 2 years at all locations. Significant structure was absent within Hudson River, whereas weak but significant genetic differences were observed between northern and southern samples in Chesapeake Bay. The largest and smallest effective striped bass population sizes were found in Chesapeake Bay and South Carolina, respectively. Coalescence analysis indicated that the highest historical gene flow has been between Chesapeake Bay and Hudson River populations, and that exchange has not been unidirectional. Bayesian analysis of contemporary migration indicated that Chesapeake Bay serves as a major source of migrants for Atlantic coastal regions from Albemarle Sound northward. In addition to examining population genetic structure, the data acquired during this project were capable of serving as a baseline for assigning fish with unknown origin to source region.

  12. Biochemical functional predictions for protein structures of unknown or uncertain function.

    PubMed

    Mills, Caitlyn L; Beuning, Penny J; Ondrechen, Mary Jo

    2015-01-01

    With the exponential growth in the determination of protein sequences and structures via genome sequencing and structural genomics efforts, there is a growing need for reliable computational methods to determine the biochemical function of these proteins. This paper reviews the efforts to address the challenge of annotating the function at the molecular level of uncharacterized proteins. While sequence- and three-dimensional-structure-based methods for protein function prediction have been reviewed previously, the recent trends in local structure-based methods have received less attention. These local structure-based methods are the primary focus of this review. Computational methods have been developed to predict the residues important for catalysis and the local spatial arrangements of these residues can be used to identify protein function. In addition, the combination of different types of methods can help obtain more information and better predictions of function for proteins of unknown function. Global initiatives, including the Enzyme Function Initiative (EFI), COMputational BRidges to EXperiments (COMBREX), and the Critical Assessment of Function Annotation (CAFA), are evaluating and testing the different approaches to predicting the function of proteins of unknown function. These initiatives and global collaborations will increase the capability and reliability of methods to predict biochemical function computationally and will add substantial value to the current volume of structural genomics data by reducing the number of absent or inaccurate functional annotations.

  13. Crystal structures of human IPP isomerase: new insights into the catalytic mechanism.

    PubMed

    Zhang, Cheng; Liu, Lin; Xu, Hang; Wei, Zhiyi; Wang, Yanli; Lin, Yajing; Gong, Weimin

    2007-03-09

    Type I isopentenyl diphosphate (IPP): dimethylally diphosphate (DMAPP) isomerase is an essential enzyme in human isoprenoid biosynthetic pathway. It catalyzes isomerization of the carbon-carbon double bonds in IPP and DMAPP, which are the basic building blocks for the subsequent biosynthesis. We have determined two crystal structures of human IPP isomerase I (hIPPI) under different crystallization conditions. High similarity between structures of human and Escherichia coli IPP isomerases proves the conserved catalytic mechanism. Unexpectedly, one of the hIPPI structures contains a natural substrate analog ethanol amine pyrophosphate (EAPP). Based on this structure, a water molecule is proposed to be the direct proton donor for IPP and different conformations of IPP and DMAPP bound in the enzyme are also proposed. In addition, structures of human IPPI show a flexible N-terminal alpha-helix covering the active pocket and blocking the entrance, which is absent in E. coli IPPI. Besides, the active site conformation is not the same in the two hIPPI structures. Such difference leads to a hypothesis that substrate binding induces conformational change in the active site. The inhibition mechanism of high Mn(2+) concentrations is also discussed.

  14. Biochemical functional predictions for protein structures of unknown or uncertain function

    PubMed Central

    Mills, Caitlyn L.; Beuning, Penny J.; Ondrechen, Mary Jo

    2015-01-01

    With the exponential growth in the determination of protein sequences and structures via genome sequencing and structural genomics efforts, there is a growing need for reliable computational methods to determine the biochemical function of these proteins. This paper reviews the efforts to address the challenge of annotating the function at the molecular level of uncharacterized proteins. While sequence- and three-dimensional-structure-based methods for protein function prediction have been reviewed previously, the recent trends in local structure-based methods have received less attention. These local structure-based methods are the primary focus of this review. Computational methods have been developed to predict the residues important for catalysis and the local spatial arrangements of these residues can be used to identify protein function. In addition, the combination of different types of methods can help obtain more information and better predictions of function for proteins of unknown function. Global initiatives, including the Enzyme Function Initiative (EFI), COMputational BRidges to EXperiments (COMBREX), and the Critical Assessment of Function Annotation (CAFA), are evaluating and testing the different approaches to predicting the function of proteins of unknown function. These initiatives and global collaborations will increase the capability and reliability of methods to predict biochemical function computationally and will add substantial value to the current volume of structural genomics data by reducing the number of absent or inaccurate functional annotations. PMID:25848497

  15. Nonlinear Structural Analysis

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Nonlinear structural analysis techniques for engine structures and components are addressed. The finite element method and boundary element method are discussed in terms of stress and structural analyses of shells, plates, and laminates.

  16. Study of Boundary Structures.

    DTIC Science & Technology

    1982-09-01

    THEORY OF ABC-CBA STACKING BOUNDARY IN fcc STRUCTURE .......... 11 - 4 TRANSITIONS AND PHASE EQUILIBRIA AMONG GRAIN BOUNDARY STRUCTURES...19 B THEORY OF ABC-CBA STACKING BOUNDARY IN fcc STRUCTURE .......... 37 C TRANSITIONS AND PHASE EQUILIBRIA AMONG GRAIN BOUNDARY...layer structure. 10 SECTION 3 THEORY OF ABC-CBA STACKING BOUNDARY IN fcc STRUCTURE The (111) planes of the fcc structure is stacked as ABCABC... as

  17. Structurally divergent histone H1 variants in chromosomes containing highly condensed interphase chromatin.

    PubMed

    Schulze, E; Nagel, S; Gavenis, K; Grossbach, U

    1994-12-01

    Condensed and late-replicating interphase chromatin in the Dipertan insect Chironomus contains a divergent type of histone H1 with an inserted KAP-KAP repeat that is conserved in single H1 variants of Caenorhabditis elegans and Volvox carteri. H1 peptides comprising the insertion interact specifically with DNA. The Chironomid Glyptotendipes exhibits a corresponding correlation between the presence of condensed chromosome sections and the appearance of a divergent H1 subtype. The centromere regions and other sections of Glyptotendipes barbipes chromosomes are inaccessible to immunodecoration by anti-H2B and anti-H1 antibodies one of which is known to recognize nine different epitopes in all domains of the H1 molecule. Microelectrophoresis of the histones from manually isolated unfixed centromeres revealed the presence of H1 and core histones. H1 genes of G. barpipes were sequenced and found to belong to two groups. H1 II and H1 III are rather similar but differ remarkably from H1 I. About 30% of the deduced amino acid residues were found to be unique to H1 I. Most conspicuous is the insertion, SPAKSPGR, in H1 I that is lacking in H1 II and H1 III and at its position gives rise to the sequence repeat SPAKSPAKSPGR. The homologous H1 I gene in Glyptotendipes salinus encodes the very similar repeat TPAKSPAKSPGR. Both sequences are structurally related to the KAPKAP repeat in H1 I-1 specific for condensed chromosome sites in Chironomus and to the SPKKSPKK repeat in sea urchin sperm H1, lie at almost the same distance from the central globular domain, and could interact with linker DNA in packaging condensed chromatin.

  18. Stratigraphy and structure of the Miners Mountain area, Wayne County, Utah

    USGS Publications Warehouse

    Luedke, Robert G.

    1953-01-01

    The Miners Mountain area includes about 85 square miles in Wayne County, south-central Utah. The area is semiarid and characterized by cliffs and deep canyons. Formations range in age from Permian to Upper Jurassic and have an aggregate thickness of about 3,500 feet. Permian formations are the buff Coconino sandstone and the overlying white, limy, shert-containing Kaibab limestone. Unconformably overlying the Kaihab is the lower Triassic Moenkopi formation of reddish-brown and yellow mudstone, siltstone, and sandstone; it contains the Sinbad limestone member (?) in the lower part. Thin, lenticular Shinarump conglomerate unconformably overlies the Moenkopi, but grades upward into the Upper Triassic Chinle formation of variegated mudstone with some interbedded sandstone and limestone lenses. Uncomformably overlying the Chinle are the Wingate sandstone, Kayenta formation, and Navajo sandstone of the Jurassic (?) Glen Canyon group, which consist of red to white sandstone. Only the lower part of the Carmel formation of the Upper Jurassic San Rafael group is exposed in the area; it consists of variegated siltstone, sandstone, limestone, and gypsum. The conspicuous structural feature in the area is the Teasdale anticline which trends northwest, is about 14 miles long, and is asymmetric with a steeper west flank. Bounding the anticline on the northeast and east is the Capitol Reef monocline, the northern part of the Waterpocket Fold. Strata in the area are broken by steeply-dipping normal faults with small displacements, except for the Teasdale fault which has a maximum displacement of over 1,000 feet. Jointing is prominent in some formations. The major orogenic movement in the area is believed to be late Upper Cretaceous to early Tertiary. Epeirogenic uplift occurred intermittently throughout Tertiary and perhaps Quaternary time.

  19. Fatty Acid Composition and Community Structure of Plankton from the San Lorenzo Channel, Gulf of California

    NASA Astrophysics Data System (ADS)

    Lavaniegos, B. E.; López-Cortés, D.

    1997-12-01

    The structure of the plankton community and fatty acid composition of nano-, micro- and zooplankton are described during four seasons of 1994 from the San Lorenzo Channel. During August, the warmest temperature in the surface water was observed and a thermocline developed between 20 and 30 m. In the remaining months, a well-mixed layer occurred in the upper 30 m. The chlorophyllacontent of the nanoplankton fraction (<38 μm) was higher than the microplanktonic fraction (38-200 μm) year round. Maximal chlorophyll values (1·5-3 μ l-1) occurred in January, which may be associated with organic matter, since phytoplankton was lower than at other seasons. The relative abundance of diatoms increased from January (57% of phytoplankton) to November (99%). The increment was mainly due toNitzschiaandChaetoceros. Dinoflagellates were always low (0·03-1·36 cells ml-1). Copepods (mainlyEucalanus) dominated the zooplankton in winter and fall, while in spring and summer, the abundance of doliolids was similar to the copepods (Nannocalanus minordominated). Four fatty acids (16:0, 16:1, 18:0, 18:1) were the most conspicuous in the plankton, representing usually between 40 and 80% of the total fatty acids throughout the water column. In winter, higher fatty acid content and higher relative amounts of 16:0 and 16:1 were observed than in the warm months. Stearic acid (18:0) peaked during fall. The major seasonal differences occurred in the nanoplankton, which had peaks of 20:5 during January, and 16:4 in April. A strong decrease in polyunsaturated fatty acids (PUFA) occurred during the warm months. The fatty acid composition of microplankton and larger zooplankton was similar in winter-spring. Individual copepods of selected species (Eucalanus sewelli,Rhincalanus nasutus,Centropages furcatusandLabidocera acuta) showed fatty acid profiles similar to the mixed zooplankton, with some differences in content of PUFA.

  20. Paleogeographic and structural setting of Miocene strata in central western Nevada

    SciTech Connect

    Stewart, J.H. )

    1993-04-01

    Late Cenozoic sedimentary rocks as old as 19 Ma are widely distributed in central western Nevada. They are greatly more abundant than older Cenozoic strata and are commonly interpreted to have formed in fault-bounded basins that mark the onset of widespread extension in the Basin and Range Province. Miocene strata are largely coeval with a magmatic arc that extended south southeast near the boundary of the Basin and Range and Sierra Nevada Provinces. This arc produced voluminous andesitic flows and lahars that locally interfinger with the Miocene strata. Miocene depositional basins apparently varied greatly in size. The largest that can be defined clearly is the Esmeralda Basin that was at least 65 km long and 45 km wide. Other basins may have been larger but are difficult to reconstruct; still other basins may be small and isolated, particularly within the magmatic arc. Lacustrine deposits and minor interfingering deltaic and distal fluvial units predominate; near-source, coarse alluvial-fan and megabreccia landslide deposits are locally conspicuous. coarse near-source deposits, particularly landslide deposits, are interpreted to be adjacent to basin-bounding normal faults. The Esmeralda, Coal Valley, and Gabbs Valley-Stewart Valley-Tonopah Basins are interpreted to be related to large-scale Miocene extension. Other basins may be (1) pull-apart structures related to strike-slip faults, (2) downdropped blocks in areas of cross-cutting normal and/or strike-slip faults related to changes in the extension direction or (3) grabens or half-grabens related to uniform extension. Younger Cenozoic basins, including present-day basins, overprint and cut across the Miocene basins.

  1. Proper Cellular Reorganization during Drosophila Spermatid Individualization Depends on Actin Structures Composed of Two Domains, Bundles and Meshwork, That Are Differentially Regulated and Have Different Functions

    PubMed Central

    Noguchi, Tatsuhiko; Lenartowska, Marta; Rogat, Aaron D.; Frank, Deborah J.

    2008-01-01

    During spermatid individualization in Drosophila, actin structures (cones) mediate cellular remodeling that separates the syncytial spermatids into individual cells. These actin cones are composed of two structural domains, a front meshwork and a rear region of parallel bundles. We show here that the two domains form separately in time, are regulated by different sets of actin-associated proteins, can be formed independently, and have different roles. Newly forming cones were composed only of bundles, whereas the meshwork formed later, coincident with the onset of cone movement. Polarized distributions of myosin VI, Arp2/3 complex, and the actin-bundling proteins, singed (fascin) and quail (villin), occurred when movement initiated. When the Arp2/3 complex was absent, meshwork formation was compromised, but surprisingly, the cones still moved. Despite the fact that the cones moved, membrane reorganization and cytoplasmic exclusion were abnormal and individualization failed. In contrast, when profilin, a regulator of actin assembly, was absent, bundle formation was greatly reduced. The meshwork still formed, but no movement occurred. Analysis of this actin structure's formation and participation in cellular reorganization provides insight into how the mechanisms used in cell motility are modified to mediate motile processes within specialized cells. PMID:18353976

  2. Structure of the trypanosome cyanide-insensitive alternative oxidase

    PubMed Central

    Shiba, Tomoo; Kido, Yasutoshi; Sakamoto, Kimitoshi; Inaoka, Daniel Ken; Tsuge, Chiaki; Tatsumi, Ryoko; Takahashi, Gen; Balogun, Emmanuel Oluwadare; Nara, Takeshi; Aoki, Takashi; Honma, Teruki; Tanaka, Akiko; Inoue, Masayuki; Matsuoka, Shigeru; Saimoto, Hiroyuki; Moore, Anthony L.; Harada, Shigeharu; Kita, Kiyoshi

    2013-01-01

    In addition to haem copper oxidases, all higher plants, some algae, yeasts, molds, metazoans, and pathogenic microorganisms such as Trypanosoma brucei contain an additional terminal oxidase, the cyanide-insensitive alternative oxidase (AOX). AOX is a diiron carboxylate protein that catalyzes the four-electron reduction of dioxygen to water by ubiquinol. In T. brucei, a parasite that causes human African sleeping sickness, AOX plays a critical role in the survival of the parasite in its bloodstream form. Because AOX is absent from mammals, this protein represents a unique and promising therapeutic target. Despite its bioenergetic and medical importance, however, structural features of any AOX are yet to be elucidated. Here we report crystal structures of the trypanosomal alternative oxidase in the absence and presence of ascofuranone derivatives. All structures reveal that the oxidase is a homodimer with the nonhaem diiron carboxylate active site buried within a four-helix bundle. Unusually, the active site is ligated solely by four glutamate residues in its oxidized inhibitor-free state; however, inhibitor binding induces the ligation of a histidine residue. A highly conserved Tyr220 is within 4 Å of the active site and is critical for catalytic activity. All structures also reveal that there are two hydrophobic cavities per monomer. Both inhibitors bind to one cavity within 4 Å and 5 Å of the active site and Tyr220, respectively. A second cavity interacts with the inhibitor-binding cavity at the diiron center. We suggest that both cavities bind ubiquinol and along with Tyr220 are required for the catalytic cycle for O2 reduction. PMID:23487766

  3. Determinants of fish assemblage structure in Northwestern Great Plains streams

    USGS Publications Warehouse

    Mullen, J.A.; Bramblett, R.G.; Guy, C.S.; Zale, A.V.; Roberts, D.W.

    2011-01-01

    Prairie streams are known for their harsh and stochastic physical conditions, and the fish assemblages therein have been shown to be temporally variable. We assessed the spatial and temporal variation in fish assemblage structure in five intermittent, adventitious northwestern Great Plains streams representing a gradient of watershed areas. Fish assemblages and abiotic conditions varied more spatially than temporally. The most important variables explaining fish assemblage structure were longitudinal position and the proportion of fine substrates. The proportion of fine substrates increased proceeding upstream, approaching 100% in all five streams, and species richness declined upstream with increasing fine substrates. High levels of fine substrate in the upper reaches appeared to limit the distribution of obligate lithophilic fish species to reaches further downstream. Species richness and substrates were similar among all five streams at the lowermost and uppermost sites. However, in the middle reaches, species richness increased, the amount of fine substrate decreased, and connectivity increased as watershed area increased. Season and some dimensions of habitat (including thalweg depth, absolute distance to the main-stem river, and watershed size) were not essential in explaining the variation in fish assemblages. Fish species richness varied more temporally than overall fish assemblage structure did because common species were consistently abundant across seasons, whereas rare species were sometimes absent or perhaps not detected by sampling. The similarity in our results among five streams varying in watershed size and those from other studies supports the generalization that spatial variation exceeds temporal variation in the fish assemblages of prairie and warmwater streams. Furthermore, given longitudinal position, substrate, and stream size, general predictions regarding fish assemblage structure and function in prairie streams are possible. ?? American

  4. Structural and functional properties of hemp seed protein products.

    PubMed

    Malomo, Sunday A; He, Rong; Aluko, Rotimi E

    2014-08-01

    The effects of pH and protein concentration on some structural and functional properties of hemp seed protein isolate (HPI, 84.15% protein content) and defatted hemp seed protein meal (HPM, 44.32% protein content) were determined. The HPI had minimum protein solubility (PS) at pH 4.0, which increased as pH was decreased or increased. In contrast, the HPM had minimum PS at pH 3.0, which increased at higher pH values. Gel electrophoresis showed that some of the high molecular weight proteins (>45 kDa) present in HPM were not well extracted by the alkali and were absent or present in low ratio in the HPI polypeptide profile. The amino acid composition showed that the isolation process increased the Arg/Lys ratio of HPI (5.52%) when compared to HPM (3.35%). Intrinsic fluorescence and circular dichroism data indicate that the HPI proteins had a well-defined structure at pH 3.0, which was lost as pH value increased. The differences in structural conformation of HPI at different pH values were reflected as better foaming capacity at pH 3.0 when compared to pH 5.0, 7.0, and 9.0. At 10 and 25 mg/mL protein concentrations, emulsions formed by the HPM had smaller oil droplet sizes (higher quality), when compared to the HPI-formed emulsions. In contrast at 50 mg/mL protein concentration, the HPI-formed emulsions had smaller oil droplet sizes (except at pH 3.0). We conclude that the functional properties of hemp seed protein products are dependent on structural conformations as well as protein concentration and pH.

  5. Extensively Reversible Thermal Transformations of a Bistable, Fluorescence-Switchable Molecular Solid: Entry into Functional Molecular Phase-Change Materials.

    PubMed

    Srujana, P; Radhakrishnan, T P

    2015-06-15

    Functional phase-change materials (PCMs) are conspicuously absent among molecular materials in which the various attributes of inorganic solids have been realized. While organic PCMs are primarily limited to thermal storage systems, the amorphous-crystalline transformation of materials like Ge-Sb-Te find use in advanced applications such as information storage. Reversible amorphous-crystalline transformations in molecular solids require a subtle balance between robust supramolecular assembly and flexible structural elements. We report novel diaminodicyanoquinodimethanes that achieve this transformation by interlinked helical assemblies coupled with conformationally flexible alkoxyalkyl chains. They exhibit highly reversible thermal transformations between bistable (crystalline/amorphous) forms, along with a prominent switching of the fluorescence emission energy and intensity.

  6. Ascidian recruitment patterns on an artificial reef in Eilat (Red Sea).

    PubMed

    Shenkar, Noa; Zeldman, Yael; Loya, Yossi

    2008-01-01

    Although ascidians are conspicuous members of the fouling community not much is known regarding their recruitment patterns in coral reefs. A 1-year study was carried out along the Red Sea coast of Israel to examine the effects of season and spatial distribution on ascidian recruitment to artificial marine structures. In general, autumn and spring were characterized by higher coverage with a significantly higher percentage of cover of Didemnum granulatum in autumn and higher numbers of Herdmania momus in spring. These species contributed the most to similarity between treatments consequently setting the pattern for each group (colonial and solitary). Halocynthia spinosa had significantly higher numbers during winter and Phallusia nigra was absent in spring and winter. H. momus showed a preference for horizontal surfaces. P. nigra and Ascidia cannelata showed a preference for floating units. It is concluded that the ascidian recruitment patterns are species-specific and vary between seasons, orientation and position on the substrata and in the water column.

  7. Resolving mantle structure beneath the Pacific Northwest

    NASA Astrophysics Data System (ADS)

    Darold, A. P.; Humphreys, E.; Schmandt, B.; Gao, H.

    2011-12-01

    Cenozoic tectonics of the Pacific Northwest (PNW) and the associated mantle structures are remarkable, the latter revealed only recently by EarthScope seismic data. Over the last ~66 Ma this region experienced a wide range of tectonic and magmatic conditions: Laramide compression, ~75-53 Ma, involving Farallon flat-slab subduction, regional uplift, and magmatic quiescence. With the ~53 Ma accretion of Siletzia ocean lithosphere within the Columbia Embayment, westward migration of subduction beginning Cascadia, along with initiation of the Cascade volcanic arc. Within the continental interior the Laramide orogeny was quickly followed by a period of extension involving metamorphic core complexes and the associated initial ignimbrite flare-up (both in northern Washington, Idaho, and western Montana); interior magmo-tectonic activity is attributed to flat-slab removal and (to the south) slab rollback. Rotation of Siletzia created new crust on SE Oregon and, at ~16 Ma, the Columbia River Flood Basalt (CRB) eruptions renewed vigorous magmatism. We have united several EarthScope studies in the Pacific Northwest and have focused on better resolving the major mantle structures that have been discovered. We have tomographically modeled the body waves with teleseismic, finite-frequency code under the constraints of ambient noise tomography and teleseismic receiver function models of Gao et al. (2011), and teleseismic anisotropy models of Long et al. (2009) in order to resolve structures continuously from the surface to the base of the upper mantle. We now have clear imaging of two episodes of subduction: Juan De Fuca slab deeper than ~250 km is absent across much of the PNW, and it has an E-W tear located beneath northern Oregon; Farallon slab (the "Siletzia curtain") is still present, hanging vertically just inboard of the core complexes, and with a basal tear causing the structure to extend deeper (~600 km) beneath north-central Idaho than beneath south-central Idaho and

  8. Structure of capsule around acanthocephalan Corynosoma strumosum from uncommon paratenic hosts-lizards of two species.

    PubMed

    Skorobrechova, Ekaterina M; Nikishin, Vladimir P; Lisitsyna, Olga I

    2012-01-01

    Micromorphology and ultrastructure of capsule forming around acanthocephalan Corynosoma strumosum in uncommon paratenic hosts-lizards Lacerta agilis and Lacerta viridis-have been studied. Experimental infestation of the lizards by acanthocephalans obtained from naturally infested sea fishes showed that only small amount of parasites occurred in the intestine of the host was able to migrate into body cavity and to be encapsulated. Micromorphology of capsules of different ages from different species of lizards and micromorphology and ultrastructure of capsules at the age of 1.5 and 10 days appeared to be similar. In the capsule's structure cells of inflammatory rank were prevailing: mononuclear and multinuclear macrophages, eosinophils, and basophils. Fibroblasts were not numerous and were located only in the outer part of a capsule; exocellular collagen fibers were absent. Inflammatory character of capsule confirms the idea that lizards are unsuitable paratenic hosts for corynosomes.

  9. Electron opaque structures in human platelets: which are or are not dense bodies?

    PubMed

    White, James G

    2008-09-01

    The dense bodies, also referred to as delta (delta) granules, present in human platelets are the storage sites for adenine nucleotides and serotonin. Stored products released following activation are important for platelet aggregation during hemostasis. Dense bodies are easily detected in thin sections of properly fixed platelets and in unfixed, unstained whole mount preparations. It is important to determine their presence and frequency with accuracy because they are absent or markedly reduced in platelet storage pool deficiency disorders. The present study has demonstrated that identification of dense bodies as not a simple matter. There are electron dense structures, including dense rings, glycosomes, "fuzzy" balls, chains, clusters and other dense elements, that may confuse the determination of true dense bodies. Even some alpha granules are sufficiently electron dense to be confused with delta granules when using densitometric techniques. The present work may prevent investigators from making diagnostic errors.

  10. Corrections to the Eckhaus' stability criterion for one-dimensional stationary structures

    NASA Astrophysics Data System (ADS)

    Malomed, B. A.; Staroselsky, I. E.; Konstantinov, A. B.

    1989-01-01

    Two amendments to the well-known Eckhaus' stability criterion for small-amplitude non-linear structures generated by weak instability of a spatially uniform state of a non-equilibrium one-dimensional system against small perturbations with finite wavelengths are obtained. Firstly, we evaluate small corrections to the main Eckhaus' term which, on the contrary so that term, do not have a universal form. Comparison of those non-universal corrections with experimental or numerical results gives a possibility to select a more relevant form of an effective nonlinear evolution equation. In particular, the comparison with such results for convective rolls and Taylor vortices gives arguments in favor of the Swift-Hohenberg equation. Secondly, we derive an analog of the Eckhaus criterion for systems degenerate in the sense that in an expansion of their non-linear parts in powers of dynamical variables, the second and third degree terms are absent.

  11. Identification of relaxing structural defects in densified B2O3 glasses

    NASA Astrophysics Data System (ADS)

    Carini, Giovanni; Carini, Giuseppe; D'Angelo, Giovanna; Fioretto, Daniele; Tripodo, Gaspare

    2014-10-01

    Sound propagation has been investigated at megahertz and gigahertz frequencies in B2O3 solids which have been pressure quenched to go through different glassy phases having growing density until the crystalline state. Over the temperature range between 10 and 300 K, the attenuation and velocity of sound in glasses are regulated by classical activation over potential barriers of structural defects and vibrational anharmonicity. The defect states are absent in the crystalline phase whose acoustic behavior is determined only by the anharmonic coupling between sound waves and thermal vibrations. Our study leads to identification of the specific superstructural units subjected to thermally activated motions in vitreous B2O3 . These molecular groups are the boroxol rings which are formed due to the poor atomic packing of glassy networks and are missing in the crystal.

  12. Pole structure of the Λ(1405) in a recent QCD simulation

    DOE PAGES

    Molina, R.; Doring, M.

    2016-09-27

    The Λ(1405) baryon is difficult to detect in experiment, absent in many quark model calculations, and supposedly manifested through a two-pole structure. Its uncommon properties made it subject to numerous experimental and theoretical studies in recent years. Lattice-QCD eigenvalues for different quark masses were recently reported by the Adelaide group. We compare these eigenvalues to predictions of a model based on Unitary Chiral Perturbation Theory. The UχPT calculation predicts the quark mass dependence remarkably well. It also explains the overlap pattern with different meson-baryon components, mainly πΣ and K¯N, at different quark masses. As a result, more accurate lattice QCDmore » data are required to draw definite conclusions on the nature of the Λ(1405).« less

  13. Structure and Expression of a Novel Compact Myelin Protein - Small VCP-Interacting Protein (SVIP)

    PubMed Central

    Wu, Jiawen; Peng, Dungeng; Voehler, Markus; Sanders, Charles R.; Li, Jun

    2013-01-01

    SVIP (small p97/VCP-interacting protein) was initially identified as one of many cofactors regulating the valosin containing protein (VCP), an AAA+ ATPase involved in endoplasmic-reticulum-associated protein degradation (ERAD). Our previous study showed that SVIP is expressed exclusively in the nervous system. In the present study, SVIP and VCP were seen to be co-localized in neuronal cell bodies. Interestingly, we also observed that SVIP co-localizes with myelin basic protein (MBP) in compact myelin, where VCP was absent. Furthermore, using nuclear magnetic resonance (NMR) and circular dichroism (CD) spectroscopic measurements, we determined that SVIP is an intrinsically disordered protein (IDP). However, upon binding to the surface of membranes containing a net negative charge, the helical content of SVIP increases dramatically. These findings provide structural insight into interactions between SVIP and myelin membranes. PMID:24055875

  14. Crystal Structure Analyses of the Fosmidomycin-Target Enzyme from Plasmodium Falciparum

    NASA Astrophysics Data System (ADS)

    Umeda, Tomonobu; Kusakabe, Yoshio; Tanaka, Nobutada

    The human malaria parasite Plasmodium falciparum is responsible for the death of more than a million people each year. Fosmidomycin has proved to be efficient in the treatment of P. falciparum malaria through the inhibition of 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DXR), an enzyme of the non-mevalonate pathway of isoprenoid biosynthesis, which is absent in humans. Crystal structure analyses of P. falciparum DXR (PfDXR) revealed that (i) an intrinsic flexibility of the PfDXR molecule accounts for the induced-fit movement to accommodate the bound inhibitor in the active site, and (ii) a cis arrangement of the oxygen atoms of the hydroxamate group of the bound inhibitor is essential for tight binding of the inhibitor to the active site metal. We believe that our study will serve as a useful guide to develop more potent PfDXR inhibitors.

  15. Structure of the intermediate Zr/sub 2/Br/sub 2/H by neutron diffraction and its structural and bonding relationships to other phases

    SciTech Connect

    Wijeyesekera, S.D.; Corbett, J.D.

    1986-12-17

    The structures of the isomorphous Zr/sub 2/Br/sub 2/D and Zr/sub 2/Br/sub 2/H have been solved and refined by using Rietveld techniques on pulsed neutron diffraction data obtained from the powdered samples at 14 K (C2/m, a = 19.437 (3) A, b = 3.5253 (4) A, c = 5.9036 (6) A, ..beta.. = 100.98 (1)/sup 0/, R(profile)/R(expected) = 2.44 for the deuteride). The structure consists of layers sequenced Br-Zr-H-H-Zr-Br and arranged such that hydride lies in zigzag chains of distorted metal tetrahedra (or butterflies) (d(Zr-D) = 2.03-2.20 A; d(D-D) = 2.93 A). The structure is intermediate between ZrBr (ccp) and ZrBrH (hcp heavy atoms, double H in trigonal-antiprismatic interstices) and can be generated by concerted intraslab slippage from either. The hemihydride effectively retains most of the strong Zr-Zr bonding of the ZrBr parent while tetrahedral bonding of hydrogen to metal is gained that is absent in ZrBrH. The energetics associated with the contrasting structures of YClH/sub x/ (ZrBr type) and ZrBrH are considered in terms of the results of extended-Hueckel band calculations. 25 references, 7 figures, 3 tables.

  16. Electromagnetic modeling of periodically-structured fiber-reinforced single-layer laminate with multiple fibers missing

    NASA Astrophysics Data System (ADS)

    Liu, Z.-C.; Li, C.-Y.; Lesselier, D.; Zhong, Y.

    2016-12-01

    Modeling of periodically-structured, fiber-reinforced laminates with fibers missing is investigated, this applying as well to similarly disorganized photonic crystals at optical frequencies. Parallel cylindrical fibers are periodically embedded within a layer sandwiched between two half-spaces. Absent fibers destroy the periodicity. The supercell concept involving an auxiliary periodic structure provides subsidiary solutions, wherein plane-wave illumination can be analyzed with the help of the Floquet theorem, while the field response due to a line source can be calculated from the pertinent plane-wave expansion. Accuracy, computational efficacy and versatility of the above approaches are illustrated by comprehensive numerical simulations with in particular comparisons to results provided by a finite-element code, all-purpose but computationally demanding, this work seen as the first step to the localization of missing fibers in a damaged laminate and imaging thereof.

  17. Local structural distortions and their role in superconductivity in SmFeAsO1-xFx superconductors

    NASA Astrophysics Data System (ADS)

    Ingle, Kapil; Priolkar, K. R.; Pal, Anand; Awana, V. P. S.; Emura, S.

    2014-07-01

    EXAFS studies at the As K edge as a function of temperature were carried out in SmFeAsO1-xFx (x = 0 and 0.2) compounds to understand the role of local structural distortions in superconductivity observed in F-doped compounds. A significant correlation between the thermal variation of local structural parameters such as anion height and superconducting onset is found in the fluorinated compounds. Such a variation in anion height is absent in the non-superconducting compound. An increase in the Fe-As bond distance just below the superconducting onset temperature indicates a similarity between the distortions observed in the high-T_{C} cuprates and these Fe-based superconductors.

  18. Exciton-plasmon interaction in hybrid quantum dot/metal cluster structures fabricated by molecular-beam epitaxy

    NASA Astrophysics Data System (ADS)

    Lyamkina, A. A.; Moshchenko, S. P.; Dmitriev, D. V.; Toropov, A. I.; Shamirzaev, T. S.

    2014-04-01

    Hybrid structures consisting of InAs/AlGaAs quantum dots and In clusters on the surface separated by an AlGaAs spacer with a specified thickness are investigated. The enhancement of the photoluminescence signal in the long-wavelength region manifesting itself in the appearance of a new narrow emission line is observed. This line is absent in the control structure with a quantum-dot array and no metal clusters. It also disappears with increasing thickness of the dielectric spacer between the layers. These results are explained in terms of a model taking into account the resonance interaction of excitons in quantum dots with localized surface plasmons in metal clusters.

  19. Further dicentric X isochromosomes and deletions, and a new structure i(X)(pter to q2102 to pter).

    PubMed Central

    Daniel, A; Saville, T; Southall, D B

    1979-01-01

    A new dicentric X isochromosome i(X)(pter to q2102 to pter) of similar size to a normal X is described in a girl with gonadal dysgenesis. In this non-mosaic case with an X short arm duplication, most of the stigmata associated with Turner's syndrome were absent. This structure was compared with that of six i(Xq) and three del(X). The del(Xq) structures all possessed a regular sized C band, but in the i(Xq) this was double sized in each case. Phenotypic comparisons are made in the Xq deletions, and some presumptive short arm isochromosomes are reinterpreted as Xq deletions. Incomplete centromeric suppression is suggested as the causal mechanism of mosaicism of sex isochromosomes with 45,X cells, and it is argued that an exchange event between homologoues is an unlikely mechanism to explain sex isochromosome origin. Images PMID:490580

  20. An unusual triangle structure associated with thrust front development in the thin-skinned Eastern Jura Mountains

    NASA Astrophysics Data System (ADS)

    Malz, Alexander; Madritsch, Herfried; Meier, Beat; Heuberger, Stefan; Kley, Jonas

    2014-05-01

    The Late Miocene to Early Pliocene Jura fold-and-thrust belt, stretching across northern Switzerland and eastern France, is a classical example of a thin-skinned foreland fold-and-thrust belt, its basal décollement being located in Mid- to Upper Triassic evaporites. The arcuate mountain range referred to as the Folded Jura is formed by mainly N-vergent thrusts and associated folds. In our study area, comprising the easternmost part of the thrust belt, the border between the Folded Jura and the non-detached autochthonous foreland (Tabular Jura) is not clearly defined. In most interpretations, the frontal thrust is taken to coincide with the northernmost anticline of the Folded Jura visible at the surface. Newly reprocessed, depth-migrated reflection seismic sections allow us to closer analyse the regional structural framework of the thrust front. Constant line-length and area cross section balancing techniques are applied to verify geometry of the interpreted structures. The best matching interpretation of the thin-skinned thrust belt front is a complex triangle structure, which traces an offset of the basal décollement by an inherited pre-exisiting normal fault that was previously associated with the border fault of a Late Paleozoic trough. This "unusual" triangle structure is defined by a number of (at least two) thrusts and backthrusts above each other associated with several secondary faults. The most characteristic feature of the fault zone is its low width with respect to the stratigraphic thickness influenced by the fault. The triangle structure shows a very uniform amount of shortening over much of its length. We interpret this uniform shortening to suggest that the configuration of the structure represents a maximum attainable, "saturated" amount of deformation achieved during an initial phase of Jura folding. To the west of our study area the triangle structure merges with the northernmost Jura anticline, which shows a conspicuous change in strike from