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Sample records for structures conspicuously absent

  1. Sources and Structures of Mitotic Crossovers That Arise When BLM Helicase Is Absent in Drosophila

    PubMed Central

    LaFave, Matthew C.; Andersen, Sabrina L.; Stoffregen, Eric P.; Holsclaw, Julie K.; Kohl, Kathryn P.; Overton, Lewis J.; Sekelsky, Jeff

    2014-01-01

    The Bloom syndrome helicase, BLM, has numerous functions that prevent mitotic crossovers. We used unique features of Drosophila melanogaster to investigate origins and properties of mitotic crossovers that occur when BLM is absent. Induction of lesions that block replication forks increased crossover frequencies, consistent with functions for BLM in responding to fork blockage. In contrast, treatment with hydroxyurea, which stalls forks, did not elevate crossovers, even though mutants lacking BLM are sensitive to killing by this agent. To learn about sources of spontaneous recombination, we mapped mitotic crossovers in mutants lacking BLM. In the male germline, irradiation-induced crossovers were distributed randomly across the euchromatin, but spontaneous crossovers were nonrandom. We suggest that regions of the genome with a high frequency of mitotic crossovers may be analogous to common fragile sites in the human genome. Interestingly, in the male germline there is a paucity of crossovers in the interval that spans the pericentric heterochromatin, but in the female germline this interval is more prone to crossing over. Finally, our system allowed us to recover pairs of reciprocal crossover chromosomes. Sequencing of these revealed the existence of gene conversion tracts and did not provide any evidence for mutations associated with crossovers. These findings provide important new insights into sources and structures of mitotic crossovers and functions of BLM helicase. PMID:24172129

  2. Absent pulmonary valve

    MedlinePlus

    ... can occur with absent pulmonary valve include: Abnormal tricuspid valve Atrial septal defect Double outlet right ventricle Ductus arteriosis Endocardial cushion defect Marfan syndrome Tricuspid atresia Heart problems that occur with absent pulmonary ...

  3. Absent pulmonary valve

    MedlinePlus

    ... absent pulmonary valve syndrome associated with bronchial obstruction. Ann Thoracic Surg. 2006;82:2221-2226. PMID: 17126138 ... of airway compression in absent pulmonary valve syndrome. Ann Thorac Surg . 2006;81:1802-1807. PMID: 16631676 ...

  4. 14 CFR 31.83 - Conspicuity.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... surface of the envelope must be of a contrasting color or colors so that it will be conspicuous during... 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, 2010 CFR

    2010-01-01

    ... surface of the envelope must be of a contrasting color or colors so that it will be conspicuous during... enough, and there are enough of them of contrasting color, to make the balloon conspicuous during flight....

  6. Tooth formation - delayed or absent

    MedlinePlus

    Delayed or absent tooth formation; Teeth - delayed or absent formation ... The age at which the tooth comes in varies. Most infants get their first tooth between 6 and 9 months, but it may be earlier or later. ...

  7. 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. PMID:20543123

  8. Engineering the Electronic Structure of 2D WS2 Nanosheets Using Co Incorporation as Cox W(1- x ) S2 for Conspicuously Enhanced Hydrogen Generation.

    PubMed

    Shifa, Tofik Ahmed; Wang, Fengmei; Liu, Kaili; Xu, Kai; Wang, Zhenxing; Zhan, Xueying; Jiang, Chao; He, Jun

    2016-07-01

    Transition metal dichalcogenides (TMDs), as one of potential electrocatalysts for hydrogen evolution reaction (HER), have been extensively studied. Such TMD-based ternary materials are believed to engender optimization of hydrogen adsorption free energy to thermoneutral value. Theoretically, cobalt is predicted to actively promote the catalytic activity of WS2 . However, experimentally it requires systematic approach to form Cox W(1- x ) S2 without any concomitant side phases that are detrimental for the intended purpose. This study reports a rational method to synthesize pure ternary Cox W(1- x ) S2 nanosheets for efficiently catalyzing HER. Benefiting from the modification in the electronic structure, the resultant material requires overpotential of 121 mV versus reversible hydrogen electrode (RHE) to achieve current density of 10 mA cm(-2) and shows Tafel slope of 67 mV dec(-1) . Furthermore, negligible loss of activity is observed over continues electrolysis of up to 2 h demonstrating its fair stability. The finding provides noticeable experimental support for other computational reports and paves the way for further works in the area of HER catalysis based on ternary materials. PMID:27322598

  9. 16 CFR 500.20 - Conspicuousness.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 1 2014-01-01 2014-01-01 false Conspicuousness. 500.20 Section 500.20 Commercial Practices FEDERAL TRADE COMMISSION RULES, REGULATIONS, STATEMENT OF GENERAL POLICY OR INTERPRETATION AND EXEMPTIONS UNDER THE FAIR PACKAGING AND LABELING ACT REGULATIONS UNDER SECTION 4 OF THE...

  10. 16 CFR 500.20 - Conspicuousness.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 1 2013-01-01 2013-01-01 false Conspicuousness. 500.20 Section 500.20 Commercial Practices FEDERAL TRADE COMMISSION RULES, REGULATIONS, STATEMENT OF GENERAL POLICY OR INTERPRETATION AND EXEMPTIONS UNDER THE FAIR PACKAGING AND LABELING ACT REGULATIONS UNDER SECTION 4 OF THE...

  11. 16 CFR 500.20 - Conspicuousness.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... INTERPRETATION AND EXEMPTIONS UNDER THE FAIR PACKAGING AND LABELING ACT REGULATIONS UNDER SECTION 4 OF THE FAIR PACKAGING AND LABELING ACT § 500.20 Conspicuousness. The statement of net quantity of contents shall appear..., color, embossing, or molding) to other matter on the package; except that a statement of net...

  12. 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.

  13. 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 Section 369.10 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...-COUNTER SALE Definitions and Interpretations § 369.10 Conspicuousness of warning statements....

  14. 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

  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. 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. PMID:27455066

  17. 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. PMID:15761732

  18. Allograft Replacement for Absent Native Tissue

    PubMed Central

    Chaudhury, Salma; Wanivenhaus, Florian; Fox, Alice J.; Warren, Russell F.; Doyle, Maureen; Rodeo, Scott A.

    2013-01-01

    Context: Structural instability due to poor soft tissue quality often requires augmentation. Allografts are important biological substitutes that are used for the symptomatic patient in the reconstruction of deficient ligaments, tendons, menisci, and osteochondral defects. Interest in the clinical application of allografts has arisen from the demand to obtain stable anatomy with restoration of function and protection against additional injury, particularly for high-demand patients who participate in sports. Traditionally, allografts were employed to reinforce weakened tissue. However, they can also be employed to substitute deficient or functionally absent tissue, particularly in the sports medicine setting. Objective: This article presents a series of 6 cases that utilized allografts to restore functionally deficient anatomic architecture, rather than just simply augmenting the degenerated or damaged native tissue. Detailed discussions are presented of the use of allografts as a successful treatment strategy to replace functionally weakened tissue, often after failed primary repairs. PMID:24427387

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. Using biological motion to enhance the conspicuity of roadway workers.

    PubMed

    Wood, Joanne M; Tyrrell, Richard A; Marszalek, Ralph; Lacherez, Philippe; Chaparro, Alex; Britt, Thomas W

    2011-05-01

    This study examined whether the conspicuity of road workers at night can be enhanced by distributing retroreflective strips across the body to present a pattern of biological motion (biomotion). Twenty visually normal drivers (mean age = 40.3 years) participated in an experiment conducted at two open-road work sites (one suburban and one freeway) at night-time. At each site, four road workers walked in place wearing a standard road worker night vest either (a) alone, (b) with additional retroreflective strips on thighs, (c) with additional retroreflective strips on ankles and knees, or (d) with additional retroreflective strips on eight moveable joints (full biomotion). Participants, seated in stationary vehicles at three different distances (80 m, 160 m, 240 m), rated the relative conspicuity of the four road workers. Road worker conspicuity was maximized by the full biomotion configuration at all distances and at both sites. The addition of ankle and knee markings also provided significant benefits relative to the standard vest alone. The effects of clothing configuration were more evident at the freeway site and at shorter distances. Overall, the full biomotion configuration was ranked to be most conspicuous and the vest least conspicuous. These data provide the first evidence that biomotion effectively enhances conspicuity of road workers at open-road work sites. PMID:21376898

  5. Infants Interpret Ambiguous Requests for Absent Objects

    ERIC Educational Resources Information Center

    Saylor, Megan M.; Ganea, Patricia

    2007-01-01

    The current studies investigated 2 skills involved in 14- to 20-month-olds' ability to interpret ambiguous requests for absent objects: tracking others' experiences (Study 1) and representing links between speakers and object features across present and absent reference episodes (Study 2). In the basic task, 2 experimenters played separately with…

  6. Cryptic and conspicuous coloration in the pelagic environment.

    PubMed

    Johnsen, Sönke

    2002-02-01

    Despite the importance of cryptic and conspicuous coloration in pelagic ecosystems, few researchers have investigated the optimal reflectance spectra for either trait. In this study, the underwater radiance distribution in tropical oceanic water was modelled using measured inherent optical properties and radiative transfer calculations. The modelled light field was then used to predict the reflectance spectra that resulted in minimal or maximal object contrast as a function of depth, viewing angle, azimuth and solar elevation. The results matched commonly observed trends in the coloration of many pelagic organisms and showed that optimal coloration for either crypticity or conspicuity is a complex function of the parameters examined. The effects of viewing angle and depth were substantial and non-intuitive, showing that red coloration is most cryptic at depth. The effects of viewing azimuth were less significant and the effects of solar elevation were minor. White coloration and black coloration were equally cryptic/conspicuous when viewed from below. Although conspicuous objects viewed from below had the lowest contrast when viewed from a short distance, they had the longest sighting distances. The contrast of maximally conspicuous objects viewed from short distances was greatest at wavelengths displaced from the wavelength of maximum light penetration. PMID:11839193

  7. Surgical Management of Absent Pulmonary Valve Syndrome.

    PubMed

    Jonas, Richard A

    2016-09-01

    The author's approach to the management of tetralogy of Fallot with absent pulmonary valve is described, including the technique of homograft replacement of the central pulmonary arteries for the neonate who presents with profound respiratory compromise. PMID:27587495

  8. 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

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

    PubMed

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

    2015-05-01

    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

  10. Omphalocele major with absent lower limb.

    PubMed

    Kundal, Vijay Kumar; Gajdhar, Mufique; Kundal, Raksha; Ahmed, Reyaz; Agrawal, Leela Dhar

    2015-02-01

    A newborn delivered by Caesarian section presented with an absent anterior abdominal wall and visible bowel loops and liver. The defect was covered by a thin membrane. The patient had associated absent left lower limb and right foot fusion defect. The patient was haemodynamically stable; general condition was average. No genito-urinary abnormality was detected. The anal opening was present normally, and the patient passed meconium immediately after birth. A diagnosis of omphalocele major with amelia was made. The patient was initially managed by topical application of povidone-iodine for eschar formation and epithelisation of the sac. The patient was discharged after 1 week with advice for regular follow-up. PMID:25829718

  11. 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.

  12. Two notions of conspicuity and the classification of phyllotaxis.

    PubMed

    Reick, Christian H

    2002-04-01

    Invoking cylindrical Bravais lattices, Adler (1974, 1977) proposed a mathematically precise definition for the botanical classification of phyllotaxis. It is based on opposed pairs of parastichy families, that are conspicuous and visible. Jean (1988) generalized this concept to non-opposed pairs of parastichy families. In the present paper it is shown that this generalization implies a notion of conspicuity different from Adler's. This is made obvious by redefining the key terms of the two approaches. Both classifications are well defined. For Adler's, this is shown by presenting a general proof for his conjecture that conspicuous (in the sense of Adler) opposed pairs of parastichy families are visible. There are indications that in applications to models of phyllotaxis (van Iterson model, inhibitor models) their solutions are better characterized by Jean's classification. The differences between Adler's and Jean's classification show up only in very rare cases, so that the practice of pattern determination is only insignificantly touched by the present results. It turns out that the widely used contact parastichy method to determine phyllotactic patterns gives results according to Jean's classification rather than Adler's. PMID:12054835

  13. Fusion of digital breast tomosynthesis images via wavelet synthesis for improved lesion conspicuity

    NASA Astrophysics Data System (ADS)

    Hariharan, Harishwaran; Pomponiu, Victor; Zheng, Bin; Whiting, Bruce; Gur, David

    2014-03-01

    Full-field digital mammography (FFDM) is the most common screening procedure for detecting early breast cancer. However, due to complications such as overlapping breast tissue in projection images, the efficacy of FFDM reading is reduced. Recent studies have shown that digital breast tomosynthesis (DBT), in combination with FFDM, increases detection sensitivity considerably while decreasing false-positive, recall rates. There is a huge interest in creating diagnostically accurate 2-D interpretations from the DBT slices. Most of the 2-D syntheses rely on visualizing the maximum intensities (brightness) from each slice through different methods. We propose a wavelet based fusion method, where we focus on preserving holistic information from larger structures such as masses while adding high frequency information that is relevant and helpful for diagnosis. This method enables the spatial generation of a 2D image from a series of DBT images, each of which contains both smooth and coarse structures distributed in the wavelet domain. We believe that the wavelet-synthesized images, generated from their DBT image datasets, provide radiologists with improved lesion and micro-calcification conspicuity as compared with FFDM images. The potential impact of this fusion method is (1) Conception of a device-independent, data-driven modality that increases the conspicuity of lesions, thereby facilitating early detection and potentially reducing recall rates; (2) Reduction of the accompanying radiation dose to the patient.

  14. Semen searching when sperm is absent.

    PubMed

    Martínez, Pilar; Santiago, Begoña; Alcalá, Belén; Atienza, Inmaculada

    2015-03-01

    Sexual assault cases have varying factors that may mask semen findings when analysing evidence at the forensic laboratory. Semenogelin (Sg) is a potential marker for the identification of semen even at azoospermy or when few sperm cells are found. The current study examined Sg in normospermic and azoospermic donors as an internal evaluation of sensitivity, specificity and interference. The impact of a historical review of 53 judicial sexual assault cases over a five-year period was also analysed. The use of varying tests was of importance to prioritize certain samples within cases. Semen findings by Sg were then compared to prostate-specific antigen (PSA), phosphatase enzyme (AP) and Y-chromosome presence, the latter being used in an attempt to link semen fluid identification with obtaining a male DNA profile. Test findings were the highest ever registered for Sg (1:400,000), PSA (1:800,000), AP (1:25,000) and sperm cytology (SC) (1:50,000). Our results demonstrated the usefulness of using the Sg marker to avoid a false semen-negative result (6% cases), particularly in cases where sperm was absent or scarce (11% spermatozoa positive cases). Results were expressed in categories according to the set: Sg-PSA-AP. Thus, categories I (full positive, 46%), VI (full negative, 27%) and III (Sg/PSA positive; 11%) were the most frequent and Y-chromosome was obtained in 59%, 12% and 12% ratios, respectively. In conclusion, Sg was recommended for the workflow procedure of semen investigation when sperm absence is expected either from azoospermic/oligospermic or normospermic semen, especially before/after ejaculation. PMID:25753997

  15. 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

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

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 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... language-speaking consumers. As part of this special effort, advertisements, brochures and sales...

  17. 16 CFR 14.9 - Requirements concerning clear and conspicuous disclosures in foreign language advertising and...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 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... language-speaking consumers. As part of this special effort, advertisements, brochures and sales...

  18. 16 CFR 14.9 - Requirements concerning clear and conspicuous disclosures in foreign language advertising and...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 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... language-speaking consumers. As part of this special effort, advertisements, brochures and sales...

  19. 16 CFR 14.9 - Requirements concerning clear and conspicuous disclosures in foreign language advertising and...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 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... language-speaking consumers. As part of this special effort, advertisements, brochures and sales...

  20. 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.…

  1. 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... language-speaking consumers. As part of this special effort, advertisements, brochures and sales...

  2. 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. PMID:26230226

  3. The Eyes Absent proteins in development and disease.

    PubMed

    Tadjuidje, Emmanuel; Hegde, Rashmi S

    2013-06-01

    The Eyes Absent (EYA) proteins, first described in the context of fly eye development, are now implicated in processes as disparate as organ development, innate immunity, DNA damage repair, photoperiodism, angiogenesis, and cancer metastasis. These functions are associated with an unusual combination of biochemical activities: tyrosine phosphatase and threonine phosphatase activities in separate domains, and transactivation potential when associated with a DNA-binding partner. EYA mutations are linked to multiorgan developmental disorders, as well as to adult diseases ranging from dilated cardiomyopathy to late-onset sensorineural hearing loss. With the growing understanding of EYA biochemical and cellular activity, biological function, and association with disease, comes the possibility that the EYA proteins are amenable to the design of targeted therapeutics. The availability of structural information, direct links to disease states, available animal models, and the fact that they utilize unconventional reaction mechanisms that could allow specificity, suggest that EYAs are well-positioned for drug discovery efforts. This review provides a summary of EYA structure, activity, and function, as they relate to development and disease, with particular emphasis on recent findings. PMID:22971774

  4. Subjective Well-being in Rural India: The Curse of Conspicuous Consumption

    PubMed Central

    van Kempen, Luuk; Kraaykamp, Gerbert

    2010-01-01

    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. Surprisingly an individual’s relative income position does not affect feelings of well-being. Motivated by positional concerns, people do not passively accept their relative rank but instead consume conspicuous goods to keep up with the Joneses. Conspicuous consumption always comes at the account of the consumption of basic needs. Our analyses point at a positional treadmill effect of the consumption of status goods. PMID:21423323

  5. 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

  6. Using reflective clothing to enhance the conspicuity of bicyclists at night.

    PubMed

    Wood, Joanne M; Tyrrell, Richard A; Marszalek, Ralph; Lacherez, Philippe; Carberry, Trent; Chu, Byoung Sun

    2012-03-01

    Bicycling at night is more dangerous than in the daytime and poor conspicuity is likely to be a contributing factor. The use of reflective markings on a pedestrian's major joints to facilitate the perception of biological motion has been shown to greatly enhance pedestrian conspicuity at night, but few corresponding data exist for bicyclists. Twelve younger and twelve older participants drove around a closed-road circuit at night and indicated when they first recognized a bicyclist who wore black clothing either alone, or together with a reflective bicycling vest, or a vest plus ankle and knee reflectors. The bicyclist pedalled in place on a bicycle that had either a static or flashing light, or no light on the handlebars. Bicyclist clothing significantly affected conspicuity; drivers responded to bicyclists wearing the vest plus ankle and knee reflectors at significantly longer distances than when the bicyclist wore the vest alone or black clothing without a vest. Older drivers responded to bicyclists less often and at shorter distances than younger drivers. The presence of a bicycle light, whether static or flashing, did not enhance the conspicuity of the bicyclist; this may result in bicyclists who use a bicycle light being overconfident of their own conspicuity at night. The implications of our findings are that ankle and knee markings are a simple and very effective approach for enhancing bicyclist conspicuity at night. PMID:22269563

  7. Numerical solution of a conspicuous consumption model with constant control delay☆

    PubMed Central

    Huschto, Tony; Feichtinger, Gustav; Hartl, Richard F.; Kort, Peter M.; Sager, Sebastian; Seidl, Andrea

    2011-01-01

    We derive optimal pricing strategies for conspicuous consumption products in periods of recession. To that end, we formulate and investigate a two-stage economic optimal control problem that takes uncertainty of the recession period length and delay effects of the pricing strategy into account. This non-standard optimal control problem is difficult to solve analytically, and solutions depend on the variable model parameters. Therefore, we use a numerical result-driven approach. We propose a structure-exploiting direct method for optimal control to solve this challenging optimization problem. In particular, we discretize the uncertainties in the model formulation by using scenario trees and target the control delays by introduction of slack control functions. Numerical results illustrate the validity of our approach and show the impact of uncertainties and delay effects on optimal economic strategies. During the recession, delayed optimal prices are higher than the non-delayed ones. In the normal economic period, however, this effect is reversed and optimal prices with a delayed impact are smaller compared to the non-delayed case. PMID:22267871

  8. Breast mass detection using slice conspicuity in 3D reconstructed digital breast volumes

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

    In digital breast tomosynthesis, the three dimensional (3D) reconstructed volumes only provide quasi-3D structure information with limited resolution along the depth direction due to insufficient sampling in depth direction and the limited angular range. The limitation could seriously hamper the conventional 3D image analysis techniques for detecting masses because the limited number of projection views causes blurring in the out-of-focus planes. In this paper, we propose a novel mass detection approach using slice conspicuity in the 3D reconstructed digital breast volumes to overcome the above limitation. First, to overcome the limited resolution along the depth direction, we detect regions of interest (ROIs) on each reconstructed slice and separately utilize the depth directional information to combine the ROIs effectively. Furthermore, we measure the blurriness of each slice for resolving the degradation of performance caused by the blur in the out-of-focus plane. Finally, mass features are extracted from the selected in focus slices and analyzed by a support vector machine classifier to reduce the false positives. Comparative experiments have been conducted on a clinical data set. Experimental results demonstrate that the proposed approach outperforms the conventional 3D approach by achieving a high sensitivity with a small number of false positives.

  9. Minimal absent words in four human genome assemblies.

    PubMed

    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

  10. 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

  11. Modelling of conspicuity-related motorcycle accidents in Seremban and Shah Alam, Malaysia.

    PubMed

    Radin, U R; Mackay, M G; Hills, B L

    1996-05-01

    Preliminary analysis of the short-term impact of a running headlights intervention revealed that there has been a significant drop in conspicuity-related motorcycle accidents in the pilot areas, Seremban and Shah Alam, Malaysia. This paper attempts to look in more detail at conspicuity-related accidents involving motorcycles. The aim of the analysis was to establish a statistical model to describe the relationship between the frequency of conspicuity-related motorcycle accidents and a range of explanatory variables so that new insights can be obtained into the effects of introducing a running headlight campaign and regulation. The exogenous variables in this analysis include the influence of time trends, changes in the recording and analysis system, the effect of fasting activities during Ramadhan and the "Balik Kampong" culture, a seasonal cultural-religious holiday activity unique to Malaysia. The model developed revealed that the running headlight intervention reduced the conspicuity-related motorcycle accidents by about 29%. It is concluded that the intervention has been successful in improving conspicuity-related motorcycle accidents in Malaysia. PMID:8799436

  12. Blatant benevolence and conspicuous consumption: when romantic motives elicit strategic costly signals.

    PubMed

    Griskevicius, Vladas; Tybur, Joshua M; Sundie, Jill M; Cialdini, Robert B; Miller, Geoffrey F; Kenrick, Douglas T

    2007-07-01

    Conspicuous displays of consumption and benevolence might serve as "costly signals" of desirable mate qualities. If so, they should vary strategically with manipulations of mating-related motives. The authors examined this possibility in 4 experiments. Inducing mating goals in men increased their willingness to spend on conspicuous luxuries but not on basic necessities. In women, mating goals boosted public--but not private--helping. Although mating motivation did not generally inspire helping in men, it did induce more helpfulness in contexts in which they could display heroism or dominance. Conversely, although mating motivation did not lead women to conspicuously consume, it did lead women to spend more publicly on helpful causes. Overall, romantic motives seem to produce highly strategic and sex-specific self-presentations best understood within a costly signaling framework. PMID:17605591

  13. 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

  14. 42 CFR 31.6 - Personnel absent without leave.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Personnel absent without leave. 31.6 Section 31.6 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICAL CARE AND EXAMINATIONS MEDICAL CARE FOR CERTAIN PERSONNEL OF THE COAST GUARD, NATIONAL OCEAN SURVEY, PUBLIC...

  15. 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…

  16. Investigating Whether Contacting Absent Students Increases Course Success

    ERIC Educational Resources Information Center

    Stucky, Thomas D.

    2008-01-01

    Studies suggest that student attendance in college classes increases course success. Yet, surprisingly few studies have examined strategies to increase student attendance. The goal of the current study is to consider whether contacting consistently absent students increases success in an undergraduate research methods course. Results of this…

  17. 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…

  18. Conspicuous male coloration impairs survival against avian predators in Aegean wall lizards, Podarcis erhardii.

    PubMed

    Marshall, Kate L A; Philpot, Kate E; Stevens, Martin

    2015-09-01

    Animal coloration is strikingly diverse in nature. Within-species color variation can arise through local adaptation for camouflage, sexual dimorphism and conspicuous sexual signals, which often have conflicting effects on survival. Here, we tested whether color variation between two island populations of Aegean wall lizards (Podarcis erhardii) is due to sexual dimorphism and differential survival of individuals varying in appearance. On both islands, we measured attack rates by wild avian predators on clay models matching the coloration of real male and female P. erhardii from each island population, modeled to avian predator vision. Avian predator attack rates differed among model treatments, although only on one island. Male-colored models, which were more conspicuous against their experimental backgrounds to avian predators, were accordingly detected and attacked more frequently by birds than less conspicuous female-colored models. This suggests that female coloration has evolved primarily under selection for camouflage, whereas sexually competing males exhibit costly conspicuous coloration. Unexpectedly, there was no difference in avian attack frequency between local and non-local model types. This may have arisen if the models did not resemble lizard coloration with sufficient precision, or if real lizards behaviorally choose backgrounds that improve camouflage. Overall, these results show that sexually dimorphic coloration can affect the risk of predator attacks, indicating that color variation within a species can be caused by interactions between natural and sexual selection. However, more work is needed to determine how these findings depend on the island environment that each population inhabits. PMID:26442582

  19. Australian Teacher Education 1900-1950: Conspicuous and Inconspicuous International Networks

    ERIC Educational Resources Information Center

    Vick, Malcolm

    2007-01-01

    Australian historiography has often portrayed Australian education as dependent and isolated. Starting from Foucault's notion of power as capillary, this paper traces two ways in which Australian teacher training in the first half of the twentieth century was tied into international networks. It documents some conspicuous links between key…

  20. 16 CFR 1500.121 - Labeling requirements; prominence, placement, and conspicuousness.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 2 2012-01-01 2012-01-01 false Labeling requirements; prominence, placement, and conspicuousness. 1500.121 Section 1500.121 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS HAZARDOUS SUBSTANCES AND ARTICLES; ADMINISTRATION AND ENFORCEMENT REGULATIONS § 1500.121...

  1. 49 CFR 229.133 - Interim locomotive conspicuity measures-auxiliary external lights.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Interim locomotive conspicuity measures-auxiliary external lights. 229.133 Section 229.133 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Cabs and...

  2. Nepotism absent in insect societies - or is it?

    PubMed

    Wenseleers, Tom

    2007-08-01

    Inclusive fitness theory, put forward by English biologist William Hamilton in 1964, is considered by many as the most important addition to the theory of natural selection since Darwin. One prediction of the theory is that animals should often show a tendency to nepotistically favour close relatives. Goodisman et al. (2007) test this theory for the first time using molecular methods in a vespine wasp, the eastern yellowjacket, Vespula maculifrons. Somewhat surprisingly, nepotism was found to be absent. This begs the question why nepotism is predicted by theory, yet in a growing list of species is shown to be absent. Is inclusive fitness theory in trouble? As we show, it is not: costs and constraints explain the general absence of queen rearing nepotism, and nepotism in insect societies in fact is well supported in the context of male rearing and manipulation of colony sex ratios. PMID:17651186

  3. 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

  4. 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. PMID:26995578

  5. Thrombocytopenia with absent radius in a boy and his uncle.

    PubMed

    Schnur, R E; Eunpu, D L; Zackai, E H

    1987-09-01

    We report a boy and his maternal uncle who have Thrombocytopenia-Absent Radius (TAR) syndrome. The mother of the propositus is normal. A maternal aunt has mild radial hypoplasia, possibly representing partial expression of the syndrome. A review of the literature shows several pedigrees in which relatives other than sibs were affected with TAR. Thus, autosomal recessive inheritance may not account for all cases and alternate modes of transmission should be considered. PMID:3314504

  6. 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. PMID:27213784

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

    NASA Astrophysics Data System (ADS)

    Grossman, Joshua M.

    2014-11-01

    During a recent ride in an elevator, I was startled by an observation. Once the door closed, the features on the back wall of the elevator were evident in a reflection on the door; however, my own reflection appeared absent (see Fig. 1). How could that be? What physics caused this curious phenomenon? The elevator had wooden molding, including horizontal strips that ran all the way around the back and sides (see Fig. 2). These horizontal strips were what showed up most clearly in the reflection. The door's surface was brushed metal with the brush marks all running vertically. Therein lay the solution.

  8. Investigation of five types of switchable retroreflector films for enhanced visible and infrared conspicuity applications.

    PubMed

    Schultz, P; Cumby, B; Heikenfeld, J

    2012-06-10

    We report on the physics, design, characterization, and demonstration of five viable techniques for switchable retroreflectors, including integrated electrowetting scattering, integrated and external electrowetting light valves, external liquid crystal light valve, and external liquid crystal scattering. All techniques were evaluated for use in conspicuity applications spanning wavelengths in the visible and IR (night vision). Achieved performance includes high optical efficiencies up to nearly 30% (out of a maximum 35%), visibly fast switching speeds of <100 ms, low to moderate operating voltages ranging from 5 to 60 V, more than ±45 deg of operation angle, and implementation with pressure-sensitive, adhesive-backed films of 0.7 to 1 mm thickness for flexibility and impact resistance. Each approach has unique strengths and weaknesses, which will also be discussed for applications ranging from commercial to military conspicuity. PMID:22695651

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

    PubMed

    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. 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

  11. Transvection at the Eyes Absent Gene of Drosophila

    PubMed Central

    Leiserson, W. M.; Bonini, N. M.; Benzer, S.

    1994-01-01

    The Drosophila eyes absent (eya) gene is required for survival and differentiation of eye progenitor cells. Loss of gene function in the eye results in reduction or absence of the adult compound eye. Certain combinations of eya alleles undergo partial complementation, with dramatic restoration of eye size. This interaction is sensitive to the relative positions of the two alleles in the genome; rearrangements predicted to disrupt pairing of chromosomal homologs in the eya region disrupt complementation. Ten X-ray-induced rearrangements that suppress the interaction obey the same general rules as those tha disrupt transvection at the bithorax complex and the decapentaplegic gene. Moreover, like transvection in those cases, the interaction at eya depends on the presence of normal zeste function. The discovery of transvection at eya suggests that transvection interactions of this type may be more prevalent than generally thought. PMID:7896099

  12. Tetralogy of Fallot with absent pulmonary valve. A continuing challenge.

    PubMed

    Jekel, L; Benatar, A; Bennink, G B; Woolley, S R; van de Wal, H J

    1998-01-01

    Absent pulmonary valve syndrome (APVS); the combination of tetralogy of Fallot (TOF) with agenesis of the pulmonary valve, is a relatively rare cardiac malformation. Despite the anatomic similarity with classic TOF, the pathophysiology is strikingly different. Data on 10 patients (3 male, 7 female) with APVS, treated between January 1978 and December 1995, were retrospectively reviewed. During this period a total of 2920 children underwent correction of a variety of congenital cardiac anomalies, of which 246 patients (8%) had a correction for TOF. Two patients with APVS presented within the first four months of life with severe cardiorespiratory distress and required several operative procedures. The remaining eight patients had only mild to moderate respiratory and/or cardiac symptoms and elective intracardiac repair was performed on those between the ages of 10 months and 9.5 years. Associated cardiac anomalies seen in five patients included aberrant coronary artery, absent or interrupted left pulmonary artery, partial AVSD and aberrant azygos continuation. In those electively corrected, the strategies used were ventriculotomy (7), pulmonary homograft (3) and aneurysmorrhaphy (2). There were two deaths, one in each group of patients, as a result of progressive respiratory insufficiency and cardiac tamponade, respectively. The follow-up of the eight survivors ranged from 2 to 11 years (median 6.75). All have a normal effort tolerance; only one child is on digoxin therapy, and one child continues to suffer bronchospastis episodes. Our experience with infants with this lesion is limited but underlines the different approaches required, depending on the age of presentation. PMID:9802139

  13. Bicyclists overestimate their own night-time conspicuity and underestimate the benefits of retroreflective markers on the moveable joints.

    PubMed

    Wood, Joanne M; Tyrrell, Richard A; Marszalek, Ralph; Lacherez, Philippe; Carberry, Trent

    2013-06-01

    Conspicuity limitations make bicycling at night dangerous. This experiment quantified bicyclists' estimates of the distance at which approaching drivers would first recognize them. Twenty five participants (including 13 bicyclists who rode at least once per week, and 12 who rode once per month or less) cycled in place on a closed-road circuit at night-time and indicated when they were confident that an approaching driver would first recognize that a bicyclist was present. Participants wore black clothing alone or together with a fluorescent bicycling vest, a fluorescent bicycling vest with additional retroreflective tape, or the fluorescent retroreflective vest plus ankle and knee reflectors in a modified 'biomotion' configuration. The bicycle had a light mounted on the handlebars which was either static, flashing or off. Participants judged that black clothing made them least visible, retroreflective strips on the legs in addition to a retroreflective vest made them most visible and that adding retroreflective materials to a fluorescent vest provides no conspicuity benefits. Flashing bicycle lights were associated with higher conspicuity than static lights. Additionally, occasional bicyclists judged themselves to be more visible than did frequent bicyclists. Overall, bicyclists overestimated their conspicuity compared to previously collected recognition distances and underestimated the conspicuity benefits of retroreflective markings on their ankles and knees. Participants mistakenly judged that a fluorescent vest that did not include retroreflective material would enhance their night-time conspicuity. These findings suggest that bicyclists have dangerous misconceptions concerning the magnitude of the night-time conspicuity problem and the potential value of conspicuity treatments. PMID:23542135

  14. 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. PMID:26801820

  15. Beyond re-membering: phantom sensations of congenitally absent limbs.

    PubMed

    Brugger, P; Kollias, S S; Müri, R M; Crelier, G; Hepp-Reymond, M C; Regard, M

    2000-05-23

    Phantom limbs are traditionally conceptualized as the phenomenal persistence of a body part after deafferentation. Previous clinical observations of subjects with phantoms of congenitally absent limbs are not compatible with this view, but, in the absence of experimental work, the neural basis of such "aplasic phantoms" has remained enigmatic. In this paper, we report a series of behavioral, imaging, and neurophysiological experiments with a university-educated woman born without forearms and legs, who experiences vivid phantom sensations of all four limbs. Visuokinesthetic integration of tachistoscopically presented drawings of hands and feet indicated an intact somatic representation of these body parts. Functional magnetic resonance imaging of phantom hand movements showed no activation of primary sensorimotor areas, but of premotor and parietal cortex bilaterally. Movements of the existing upper arms produced activation expanding into the hand territories deprived of afferences and efferences. Transcranial magnetic stimulation of the sensorimotor cortex consistently elicited phantom sensations in the contralateral fingers and hand. In addition, premotor and parietal stimulation evoked similar phantom sensations, albeit in the absence of motor evoked potentials in the stump. These data indicate that body parts that have never been physically developed can be represented in sensory and motor cortical areas. Both genetic and epigenetic factors, such as the habitual observation of other people moving their limbs, may contribute to the conscious experience of aplasic phantoms. PMID:10801982

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

    PubMed Central

    Jin, Meng; Mardon, Graeme

    2016-01-01

    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. PMID:26980695

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

    PubMed

    Jin, Meng; Mardon, Graeme

    2016-01-01

    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. PMID:26980695

  18. 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. PMID:27602257

  19. 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

  20. Turbulent Sediment Suspension and Induced Ripple Dynamics Absent Mean Shear

    NASA Astrophysics Data System (ADS)

    Johnson, B. A.; Cowen, E.

    2014-12-01

    The uprush and backwash phases in the swash zone, the region of the beach that is alternately covered and uncovered by wave run-up, are fundamentally different events. Backwash is dominated by a growing boundary layer where the turbulence is set by the bed shear stress. In this phase traditional boundary layer turbulence models and Shields-type critical stress pickup functions work well. However, the uprush phase, while often viewed in the context of traditional boundary layer turbulence models, has little in common with the backwash phase. During uprush, the entire water column is turbulent, as it rapidly advects well-stirred highly turbulent flow generated offshore from breaking waves or collapsing bores. Turbulence levels in the uprush are several times higher than turbulent boundary layer theory would predict and hence the use of a boundary layer model to predict turbulence levels during uprush grossly under predicts the turbulence and subsequent sediment suspension in the swash zone. To study the importance of this advected turbulence to sediment suspension we conduct experiments in a water tank designed to generate horizontally homogeneous isotropic turbulence absent mean shear using randomly actuated synthetic jet arrays suspended above both a solid glass plate and a narrowly graded sediment bed. Using jet arrays with different jet spacings allows the generation of high Reynolds number turbulence with variable integral length scales, which we hypothesize control the characteristic length scales in the induced ripple field. Particle image velocimetry and acoustic Doppler velocimetry measurements are used to characterize the near-bed flow and this unique turbulent boundary layer. Metrics include the mean flow and turbulence intensities and stresses, temporal and spatial spectra, dissipation of turbulent kinetic energy, and integral length scales of the turbulence. We leverage our unique dataset to compare the flows over impermeable fixed and permeable mobile

  1. Minding the Absent: Arguments for the Full Competence Hypothesis.

    ERIC Educational Resources Information Center

    Borer, Hagit; Rohrbacher, Bernhard

    2002-01-01

    Suggests that the systematic omission of functional material by young children, contrary to current beliefs, argues for the presence of functional structure,because in the absence of such structure what is expected is not a systematic omission of functional material but rather its random use. (Author/VWL)

  2. 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. PMID:24823942

  3. 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

  4. 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. PMID:25867935

  5. Configuring retroreflective markings to enhance the night-time conspicuity of road workers.

    PubMed

    Wood, Joanne M; Marszalek, Ralph; Lacherez, Philippe; Tyrrell, Richard A

    2014-09-01

    This study investigated whether the night-time conspicuity of road workers can be enhanced by positioning retroreflective strips on the moveable joints in patterns that convey varying degrees of biological motion. Participants were 24 visually normal adults (12 young M=26.8 years; 12 older M=72.9 years). Visual acuity, contrast sensitivity and glare sensitivity were recorded for each participant. Experimenters acting as road workers walked in place on a closed road circuit within simulated road work sites, facing either the oncoming driver or the roadway (presenting sideways to the driver) and wearing one of four clothing conditions: (i) standard road worker vest; (ii) standard vest plus thigh-mounted retroreflective strips; (iii) standard vest plus retroreflective strips on ankles and knees; (iv) standard vest plus retroreflective strips positioned on the extremities in a configuration that conveyed biological motion ("biomotion"). As they drove along the closed road participants were instructed to press a button to indicate when they first recognized that a road worker was present. The results demonstrated that regardless of the direction of walking, road workers wearing biomotion clothing were recognized at significantly (p<0.05) longer distances (3×), relative to the standard vest alone. Response distances were significantly shorter for the older drivers. Contrast sensitivity was a better predictor of the ability to recognize road workers than was visual acuity or glare sensitivity. We conclude that adding retroreflective strips in the biomotion configuration can significantly improve road worker conspicuity regardless of the road worker's orientation and the age of the driver. PMID:24816151

  6. Conspicuity of Bone Metastases on Fast Dixon-Based Multisequence Whole Body MRI: Clinical Utility per Sequence

    PubMed Central

    Costelloe, Colleen M.; Madewell, John E.; Kundra, Vikas; Harrell, Robyn K.; Bassett, Roland L.; Ma, Jingfei

    2013-01-01

    Purpose To evaluate the conspicuity of bone metastases on each of the numerous sequences produced by fast Dixon-based multisequence whole-body (WB) MRI scanning in order to determine the most clinically useful sequences overall and per anatomic region. Materials and Methods Twenty-seven breast cancer patients with bone metastases were prospectively studied with fast Dixon-based WB MRI including head/neck, chest, abdominal, pelvic, thigh, calf/feet, and either cervical, thoracic and lumbar or cervical/thoracic and thoracic/lumbar regions. Sequences included coronal T2, axial T1 without and with intravenous gadolinium (+C), sagittal T1 spine +C, each associated fat only (FO) and fat saturated (FS) sequence, axial DWI and STIR. Blinded reviewers evaluated lesion conspicuity, a surrogate of clinical utility, on a 5 point scale per anatomic region. Sequences were compared using ANOVA, differences detected with Tukey’s HSD, and the four sequences with highest mean conspicuity were compared to the remainder overall and per anatomic region. Results Overall, a significant lesion conspicuity difference was found (P<0.0001), and lesion conspicuity was significantly higher on FS T1 +C, FO T1 +C, T1 +C sagittal, FS T1 +C axial sequences (P<0.0001). Per region results were the same in head/neck. Other sequences overlapped with these and included: Chest/abdomen-FO T2, DWI; pelvis- DWI, FO T2; thigh-FS T2, FO T2, FO T1 +C; calf/feet-FS T2, DWI, FO T2, STIR. Conclusion Overall, bone lesions were most conspicuous on FS T1 +C sagittal, FO T1 +C sagittal, T1 +C sagittal and FS T1 +C axial fast Dixon WB MRI sequences. PMID:23290478

  7. 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…

  8. Structure of aldose reductase from Giardia lamblia

    PubMed Central

    Ferrell, M.; Abendroth, J.; Zhang, Y.; Sankaran, B.; Edwards, T. E.; Staker, B. L.; Van Voorhis, W. C.; Stewart, L. J.; Myler, P. J.

    2011-01-01

    Giardia lamblia is an anaerobic aerotolerant eukaryotic parasite of the intestines. It is believed to have diverged early from eukarya during evolution and is thus lacking in many of the typical eukaryotic organelles and biochemical pathways. Most conspicuously, mitochondria and the associated machinery of oxidative phosphorylation are absent; instead, energy is derived from substrate-level phosphorylation. Here, the 1.75 Å resolution crystal structure of G. lamblia aldose reductase heterologously expressed in Escherichia coli is reported. As in other oxidoreductases, G. lamblia aldose reductase adopts a TIM-barrel conformation with the NADP+-binding site located within the eight β-strands of the interior. PMID:21904059

  9. 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.

  10. 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.

    2016-02-01

    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 (Guc(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.

  11. 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

  12. 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

  13. An experimental and theoretical model of children’s search behavior in relation to target conspicuity and spatial distribution

    NASA Astrophysics Data System (ADS)

    Rosetti, Marcos Francisco; Pacheco-Cobos, Luis; Larralde, Hernán; Hudson, Robyn

    2010-11-01

    This work explores search trajectories of children attempting to find targets distributed on a playing field. This task, of ludic nature, was developed to test the effect of conspicuity and spatial distribution of targets on the searcher’s performance. The searcher’s path was recorded by a Global Positioning System (GPS) device attached to the child’s waist. Participants were not rewarded nor their performance rated. Variation in the conspicuity of the targets influenced search performance as expected; cryptic targets resulted in slower searches and longer, more tortuous paths. Extracting the main features of the paths showed that the children: (1) paid little attention to the spatial distribution and at least in the conspicuous condition approximately followed a nearest neighbor pattern of target collection, (2) were strongly influenced by the conspicuity of the targets. We implemented a simple statistical model for the search rules mimicking the children’s behavior at the level of individual (coarsened) steps. The model reproduced the main features of the children’s paths without the participation of memory or planning.

  14. 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. PMID:26538540

  15. The long search for conspicuous orbits (French Title: La longue recherche des orbites remarquables)

    NASA Astrophysics Data System (ADS)

    Hoynant, G.

    2004-12-01

    1-Theoretical basis : This first part of a series of papers on conspicuous orbits is an historical survey, from Kepler to Einstein, of different theories of gravitation implemented for the description of the motion of several bodies in gravitational interaction. 2-The restricted three bodies problem : The restricted 3 body problem ( 2 massive bodies and one body with a neglectable mass in 2D ), was intensively studied by algebra. Numeric computation allows to describe a very large number of systems . One dozen of these systems, selected for their typical constitution, are graphically presented. 3-The three bodies problem and some related cases : The basic systems with 3 massive bodies were discovered by Lagrange (equilateral configuration) and by Euler (colinear configuration) utilising classical algebra. Polygonal and pyramidal configurations appear as consequences of the equilateral configuration. Symmetry is the fundamental component of all systems based upon the equilateral configuration: numerical modelisation must be adjusted in order not to deteriorate the symmetry during each step of computation.

  16. Improved Liver Lesion Conspicuity With Iterative Reconstruction in Computed Tomography Imaging.

    PubMed

    Jensen, Kristin; Andersen, Hilde Kjernlie; Tingberg, Anders; Reisse, Claudius; Fosse, Erik; Martinsen, Anne Catrine T

    2016-01-01

    Studies on iterative reconstruction techniques on computed tomographic (CT) scanners show reduced noise and changed image texture. The purpose of this study was to address the possibility of dose reduction and improved conspicuity of lesions in a liver phantom for different iterative reconstruction algorithms. An anthropomorphic upper abdomen phantom, specially designed for receiver operating characteristic analysis was scanned with 2 different CT models from the same vendor, GE CT750 HD and GE Lightspeed VCT. Images were obtained at 3 dose levels, 5, 10, and 15mGy, and reconstructed with filtered back projection (FBP), and 2 different iterative reconstruction algorithms; adaptive statistical iterative reconstruction and Veo. Overall, 5 interpreters evaluated the images and receiver operating characteristic analysis was performed. Standard deviation and the contrast to noise ratio were measured. Veo image reconstruction resulted in larger area under curves compared with those adaptive statistical iterative reconstruction and FBP image reconstruction for given dose levels. For the CT750 HD, iterative reconstruction at the 10mGy dose level resulted in larger or similar area under curves compared with FBP at the 15mGy dose level (0.88-0.95 vs 0.90). This was not shown for the Lightspeed VCT (0.83-0.85 vs 0.92). The results in this study indicate that the possibility for radiation dose reduction using iterative reconstruction techniques depends on both reconstruction technique and the CT scanner model used. PMID:26790606

  17. Eavesdropping parasitoids do not cause the evolution of less conspicuous signalling behaviour in a field cricket

    PubMed Central

    Beckers, Oliver M.; Wagner, William E.

    2013-01-01

    Males of many species produce conspicuous mating signals to attract females, but these signals can also attract eavesdropping predators and parasites. Males are thus expected to evolve signalling behaviours that balance the sexual selection benefits and the natural selection costs. In the variable field cricket, Gryllus lineaticeps, males sing to attract females, but these songs also attract the lethal parasitoid fly Ormia ochracea. The flies use male crickets as hosts for their larvae, primarily search for hosts during a 2 h period following sunset and prefer the same song types as female crickets. We tested whether males from high-risk populations reduce the risk of parasitism by singing less frequently or by shifting their singing activity to a time of the night when the risk of parasitism is low. We compared male singing activity and its temporal pattern between six high-risk and six low-risk populations that were reared in a common environment. There was no effect of parasitism risk on either total male singing activity or the temporal pattern of male singing activity. Males from high-risk populations thus sang as frequently as males from low-risk populations. These results suggest that sexual selection on male singing behaviour may be substantially stronger in high-risk populations than in low-risk populations. It is possible that other traits may have evolved to reduce parasitism risk without compromising mate attraction. PMID:23888083

  18. Prevalence of eating disorders in three Cambridge general practices: hidden and conspicuous morbidity.

    PubMed Central

    Whitehouse, A M; Cooper, P J; Vize, C V; Hill, C; Vogel, L

    1992-01-01

    The aims of this study were to investigate the prevalence of anorexia nervosa, bulimia nervosa and partial syndromes in women general practice attenders to establish the relative proportions of 'conspicuous' and 'hidden' morbidity. A consecutive series of 540 women patients aged 16-35 years attending their family doctor were screened using a specially devised questionnaire, the weight and dietary practices survey. A total of 115 patients were selected for further assessment and of these 101 patients were interviewed using a standardized diagnostic interview for DSM III-R eating disorders. The prevalence of anorexia nervosa was 0.2% (one case), of bulimia nervosa 1.5% (eight cases) and of partial syndrome bulimia nervosa 5.4% (29 cases). Half of the cases of bulimia nervosa had not been identified by the general practitioner and two of these patients had been referred to specialists for treatment of secondary complications of the eating disorder. Hidden cases of bulimia nervosa or partial syndromes are relatively common in general practice. Certain key questions could be used by general practitioners in order to identify women with eating disorders. PMID:1493006

  19. 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…

  20. 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…

  1. 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....

  2. 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....

  3. 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....

  4. 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....

  5. 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....

  6. 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)

  7. 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.

  8. Thirst - absent

    MedlinePlus

    ... fluids? Did the loss of thirst follow a head injury? Do you have other symptoms such as abdominal ... do a detailed nervous system exam if a head injury or problem with the hypothalamus is suspected. Tests ...

  9. Pretreatment Evaluation with Contrast-Enhanced Ultrasonography for Percutaneous Radiofrequency Ablation of Hepatocellular Carcinomas with Poor Conspicuity on Conventional Ultrasonography

    PubMed Central

    Kim, Ah Yeong; Rhim, Hyunchul; Cha, Dong Ik; Choi, Dongil; Kim, Young-sun; Lim, Hyo Keun; Cho, Seong Whi

    2013-01-01

    Objective To determine whether pretreatment evaluation with contrast-enhanced ultrasonography (CEUS) is effective for percutaneous radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC) with poor conspicuity on conventional ultrasonography (US). Materials and Methods This retrospective study was approved by the institutional review board and informed consent was waived. From June 2008 to July 2011, 82 patients having HCCs (1.2 ± 0.4 cm) with poor conspicuity on planning US for RFA were evaluated with CEUS prior to percutaneous RFA. We analyzed our database, radiologic reports, and US images in order to determine whether the location of HCC candidates on planning US coincide with that on CEUS. To avoid incomplete ablation, percutaneous RFA was performed only when HCC nodules were identified on CEUS. The rate of technical success was assessed. The cumulative rate of local tumor progression was estimated with the use of the Kaplan-Meier method (mean follow-up: 24.0 ± 13.0 months). Results Among 82 patients, 73 (89%) HCCs were identified on CEUS, whereas 9 (11%) were not. Of 73 identifiable HCCs on CEUS, the location of HCC on planning US corresponded with that on CEUS in 64 (87.7%), whereas the location did not correspond in 9 (12.3%) HCCs. Technical success was achieved for all 73 identifiable HCCs on CEUS in a single (n = 72) or two (n = 1) RFA sessions. Cumulative rates of local tumor progression were estimated as 1.9% and 15.4% at 1 and 3 years, respectively. Conclusion Pretreatment evaluation with CEUS is effective for percutaneous RFA of HCCs with poor conspicuity on conventional US. PMID:24043968

  10. The hydrodynamically relevant endothelial cell glycocalyx observed in vivo is absent in vitro.

    PubMed

    Potter, Daniel R; Damiano, Edward R

    2008-04-11

    In recent years, the endothelial cell surface glycocalyx has emerged as a structure of fundamental importance to a broad range of phenomena that determine cardiovascular health and disease. This new understanding of the functional significance of the glycocalyx has been made possible through recently developed experimental techniques using intravital microscopy that are capable of directly probing the glycocalyx in vivo. Using fluorescent microparticle image velocimetry in venules and endothelialized cylindrical collagen microchannels, we show that the hydrodynamically relevant endothelial cell glycocalyx surface layer observed in microvessels in vivo (0.52+/-0.28 microm thickness), which is a fundamental determinant of the hydrodynamic and mechanical environment at the endothelial cell surface, is absent from human umbilical vein (0.03+/-0.04 microm thickness) and bovine aortic (0.02+/-0.04 microm thickness) endothelial cells grown and maintained under standard cell culture conditions in vitro. An endothelial surface-bound glycosaminoglycan layer, not necessarily indicative of but having similar hydrodynamic properties to the endothelial glycocalyx observed in vivo, was detected (0.21+/-0.27 microm thickness) only after hyaluronan and chondroitin sulfate were added to the cell culture media at hyperphysiological concentrations (0.2 mg/mL perfused for 75 minutes). The implications of this glycocalyx deficiency under standard cell culture conditions in these pervasive in vitro models broadly impact a myriad of studies involving endothelial cell monolayers in which inferences are made that may depend on endothelial cell surface chemistry. In light of these findings, conclusions drawn from such studies in the areas of microvascular permeability, inflammation, mechanotransduction, and atherosclerosis must be carefully reconsidered. PMID:18258858

  11. Supernumerary and absent limbs and digits of the lower limb: a review of the literature.

    PubMed

    Klaassen, Zachary; Shoja, Mohammadali M; Tubbs, R Shane; Loukas, Marios

    2011-07-01

    Anatomical history over centuries includes description of a wide variety of malformations involving the lower limbs. This article offers an organized review of these diverse abnormalities, including new understanding of mechanisms through recent discoveries in genetics and molecular biology. In 19th century Europe, a number of unique anomalies were reported, as well as evidence of foot amputations occurring in ancient Peruvian culture. Embryologically, the limbs develop early, with the lower limb being recognizable for the first time at stage 13 of development. By stage 23, the toes are clearly defined and by birth, although the legs appear bowed, the tibia and fibula are straight. Removal of the apical ectodermal ridge results in cessation of limb development, conversely, a second apical ectodermal ridge results in duplication of distal structures. Supernumerary limbs have been documented to occur as part of a teratoma with unique morphology and accompanying blood supply. Additionally, many examples of polydactyly occur in the foot postulating that deletion of chromosome 22q11 is involved in postaxial polydactyly. Such deletions occur near the middle of the chromosome at a location designated q11.2 (i.e., on the long arm of one of the pair of chromosomes 22) and this syndrome is also referred to as DiGeorge syndrome, which has a prevalence estimated at 1:4,000. Absence of the lower limbs has also been noted, with hypoplasia of the fibula being the most common manifestation of congenital bone absences in the lower limb. In addition to fibular aplasia, cases of tibial aplasia have been reported. This article is important for surgeons attempting correctional repair of lower limb anomalies, as well as providing analysis of the historical, anatomical and clinical aspects of supernumerary and absent limbs and digits for the lower limb. PMID:21647959

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

    PubMed

    Murali, Gopal; Kodandaramaiah, Ullasa

    2016-06-01

    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

  13. The role of nocturnal vision in mate choice: females prefer conspicuous males in the European tree frog (Hyla arborea)

    PubMed Central

    Gomez, Doris; Richardson, Christina; Lengagne, Thierry; Plenet, Sandrine; Joly, Pierre; Léna, Jean-Paul; Théry, Marc

    2009-01-01

    Nocturnal frog species rely extensively on vocalization for reproduction. But recent studies provide evidence for an important, though long overlooked, role of visual communication. In many species, calling males exhibit a conspicuous pulsing vocal sac, a signal bearing visually important dynamic components. Here, we investigate female preference for male vocal sac coloration—a question hitherto unexplored—and male colour pattern in the European tree frog (Hyla arborea). Under nocturnal conditions, we conducted two-choice experiments involving video playbacks of calling males with identical calls and showing various naturally encountered colour signals, differing in their chromatic and brightness components. We adjusted video colours to match the frogs' visual perception, a crucial aspect not considered in previous experiments. Females prefer males with a colourful sac and a pronounced flank stripe. Both signals probably enhance male conspicuousness and facilitate detection and localization by females. This study provides the first experimental evidence of a preference for specific vocal sac spectral properties in a nocturnal anuran species. Vocal sac coloration is based on carotenoids and may convey information about male quality worthwhile for females to assess. The informative content of the flank stripe remains to be demonstrated. PMID:19324736

  14. 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

  15. 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…

  16. Aortic coarctation associated with an absent segment of the proximal right subclavian artery.

    PubMed

    Jasper, A; Keshava, S N

    2014-01-01

    Coarctation of the aorta is a congenital anomaly of the thoracic aorta with many known associations. We describe the case of a young man referred for management of subarachnoid hemorrhage, in whom subsequent work-up revealed the previously undescribed combination of severe postductal aortic coarctation and an absent segment of the proximal right subclavian artery. PMID:25370550

  17. Absent Does Not Equal Uninvolved: Predictors of Fathering in Teen Mother Families.

    ERIC Educational Resources Information Center

    Danziger, Sandra K.; Radin, Norma

    1990-01-01

    Examined effects of several predictors of father involvement in large sample of single-parent, teenage mother families (N=289). The results of telephone interviews indicated that work behavior of absent fathers had a significant direct effect on participation in childrearing and that minority mothers reported higher rates of paternal involvement.…

  18. The Absent Father: Gender Identity Considerations for Art Therapists Working with Adolescent Boys.

    ERIC Educational Resources Information Center

    Haeseler, Martha

    1996-01-01

    Recent research has shown that boys from father-absent homes exhibit greater feminine role identification, delinquency, mental disorders, poor academic performance, and poor self-esteem. This article presents case studies that demonstrate crises of masculine identification for adolescent boys whose lives lack either a present father or male…

  19. Aortic root replacement with absent left-main coronary artery: how to do it.

    PubMed

    Saha, Kamales Kumar; Parate, Bhupesh; Jagiasi, Bharat

    2015-02-01

    Aortic root replacement in patient with a coronary artery anomaly can be challenging. We describe aortic root replacement in a patient with annuloaortic ectasia and coarctation, who had an absent left main coronary artery. There were separate origins of the left anterior descending and left circumflex coronary arteries from the aorta. The technical modification employed in this case is discussed. PMID:24887871

  20. 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…

  1. Exploring What's Missing: What Do Target Absent Trials Reveal About Autism Search Superiority?

    PubMed

    Keehn, Brandon; Joseph, Robert M

    2016-05-01

    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 discrimination or selection. Rather, consistent with prior ASD research, group differences were mainly the effect of faster performance on target-absent trials. Eye-tracking revealed a lack of left-visual-field search asymmetry in ASD, which may confer an additional advantage when the target is absent. Lastly, ASD symptomatology was positively associated with search superiority, the mechanisms of which may shed light on the atypical brain organization that underlies social-communicative impairment in ASD. PMID:26762114

  2. Absent upper blind Pouch in a case of tracheo-esophageal fistula.

    PubMed

    Harjai, Man Mohan; Badal, Sachendra; Khanna, Sangeeta; Singh, Ajit Kumar

    2015-01-01

    A common upper airway and digestive tract is a rare congenital anomaly that is usually fatal and its exact incidence is not known. It is a diagnostic challenge as it requires high index of suspicion. It should be considered in a neonate with respiratory distress in a non-vigorous baby requiring endotracheal intubation, which is difficult even in expert hand. We present a newborn with suspected tracheo-esophageal fistula that was diagnosed intraoperatively to have absent upper blind pouch of the esophagus and on autopsy found to have laryngeal atresia with absent vocal cords and a common aerodigestive tract continuing distally with trachea. The neonate was ventilated with endotracheal tube (ETT) placement which in retrospect we came to know that it was in the esophagus. The neonate also had associated multiple congenital anomalies of VACTERL association. The importance of teamwork between neonatologist, pediatric surgeon, anesthesiologist, and radiologist is highlighted for diagnosis and management of such rare cases. PMID:25552830

  3. PHACE(S) Syndrome With Absent Intracranial Internal Carotid Artery and Anomalous Circle of Willis.

    PubMed

    Winter, Pieta R; Itinteang, Tinte; Leadbitter, Philip; FitzJohn, Trevor; Tan, Swee T

    2015-06-01

    The authors present a case of PHACE(S) (posterior fossa malformations, hemangioma, arterial anomalies, cardiac defects, eye anomalies, and sternal cleft or supraumbilical raphe) syndrome with a right-sided segmental infantile hemangioma, and describe in detail, the associated absent ipsilateral intracranial internal carotid artery and anomalous Circle of Willis. Propranolol therapy led to accelerated, complete involution. Nadolol may reduce the theoretical risk of treating PHACE(S) patients with β-blockers. PMID:26080245

  4. 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. PMID:25792545

  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. 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

  7. 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.

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

    PubMed

    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. PMID:27043075

  9. The effect of breast compression on mass conspicuity in digital mammography

    SciTech Connect

    Saunders, Robert S. Jr; Samei, Ehsan

    2008-10-15

    This study analyzed how the inherent quality of diagnostic information in digital mammography could be affected by breast compression. A digital mammography system was modeled using a Monte Carlo algorithm based on the Penelope program, which has been successfully used to model several medical imaging systems. First, the Monte Carlo program was validated against previous measurements and simulations. Once validated, the Monte Carlo software modeled a digital mammography system by tracking photons through a voxelized software breast phantom, containing anatomical structures and breast masses, and following photons until they were absorbed by a selenium-based flat-panel detector. Simulations were performed for two compression conditions (standard compression and 12.5% reduced compression) and three photon flux conditions (constant flux, constant detector signal, and constant glandular dose). The results showed that reduced compression led to higher scatter fractions, as expected. For the constant photon flux condition, decreased compression also reduced glandular dose. For constant glandular dose, the SdNR for a 4 cm breast was 0.60{+-}0.11 and 0.62{+-}0.11 under standard and reduced compressions, respectively. For the 6 cm case with constant glandular dose, the SdNR was 0.50{+-}0.11 and 0.49{+-}0.10 under standard and reduced compressions, respectively. The results suggest that if a particular imaging system can handle an approximately 10% increase in total tube output and 10% decrease in detector signal, breast compression can be reduced by about 12% in terms of breast thickness with little impact on image quality or dose.

  10. Conspicuous involvement of desmin tail mutations in diverse cardiac and skeletal myopathies.

    PubMed

    Bär, Harald; Goudeau, Bertrand; Wälde, Sarah; Casteras-Simon, Monique; Mücke, Norbert; Shatunov, Alexey; Goldberg, Y Paul; Clarke, Charles; Holton, Janice L; Eymard, Bruno; Katus, Hugo A; Fardeau, Michel; Goldfarb, Lev; Vicart, Patrick; Herrmann, Harald

    2007-04-01

    Myofibrillar myopathy (MFM) encompasses a genetically heterogeneous group of human diseases caused by mutations in genes coding for structural proteins of muscle. Mutations in the intermediate filament (IF) protein desmin (DES), a major cytoskeletal component of myocytes, lead to severe forms of "desminopathy," which affects cardiac, skeletal, and smooth muscle. Most mutations described reside in the central alpha-helical rod domain of desmin. Here we report three novel mutations--c.1325C>T (p.T442I), c.1360C>T (p.R454W), and c.1379G>T (p.S460I)--located in desmin's non-alpha-helical carboxy-terminal "tail" domain. We have investigated the impact of these and four--c.1237G>A (p.E413K), c.1346A>C (p.K449T), c.1353C>G (p.I451M), and c.1405G>A (p.V469M)--previously described "tail" mutations on in vitro filament formation and on the generation of ordered cytoskeletal arrays in transfected myoblasts. Although all but two mutants (p.E413K, p.R454W) assembled into IFs in vitro and all except p.E413K were incorporated into IF arrays in transfected C2C12 cells, filament properties differed significantly from wild-type desmin as revealed by viscometric assembly assays. Most notably, when coassembled with wild-type desmin, these mutants revealed a severe disturbance of filament-formation competence and filament-filament interactions, indicating an inherent incompatibility of mutant and wild-type protein to form mixed filaments. The various clinical phenotypes observed may reflect altered interactions of desmin's tail domain with different components of the myoblast cytoskeleton leading to diminished biomechanical properties and/or altered metabolism of the individual myocyte. Our in vitro assembly regimen proved to be a very sensible tool to detect if a particular desmin mutation is able to cause filament abnormalities. PMID:17221859

  11. Syndrome of absent abdominal muscles: two cases with microcephaly, polymicrogyria, and cerebellar malformations

    PubMed Central

    Heffner, Reid R.

    1970-01-01

    Two unique cases of the syndrome of absent abdominal muscles with central nervous system involvement are presented. Microcephaly, polymicrogyria, and cerebellar heterotopiae were present in both. In case 1 there was also absence of the corpus callosum and agenesis of the cerebellar vermis. In case 2 a count of anterior horn cells in the spinal cord showed a reduction of approximately 50% in the lower thoracic region. The pertinent literature is briefly discussed. The findings in the nervous system suggest that the syndrome is the result of defective embryogenesis during the first trimester. Images PMID:4250700

  12. Leg ulceration in chronic venous insufficiency caused by an absent inferior vena cava.

    PubMed

    Amano, Hiroo; Nagai, Yayoi; Endo, Yukie; Iwasaki, Tomoko; Ishikawa, Osamu

    2009-01-01

    We report here the case of a 55-year-old Japanese man with a one-year history of multiple ulcers on the left crural region. He had had pronounced varicose veins on both legs and the abdominal region for 35 years. Computed tomography images of the thoracic and abdominal regions showed the absence of an inferior vena cava, with pronounced dilatation of paravertebral venous plexus, cutaneous and azygous veins. Conservative topical treatments led to complete healing of the ulcers in one month. An absent inferior vena cava is an uncommon abnormality, often complicated by cardiac and other visceral malformations. It is a rare cause of chronic leg ulcers. PMID:19734977

  13. 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. PMID:27574510

  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. Mourning the dead, mourning the disappeared: the enigma of the absent-presence.

    PubMed

    Taiana, Cecilia

    2014-12-01

    Freud's interest in the impact of death on the living goes back further than Mourning and Melancholia (1917e, [1915]). In Totem and Taboo (1912-13) Freud noted the ambivalence of the emotions we experience in relation to the dead. In this paper, I focus on Mourning and Melancholia as a landmark in the understanding of both the normal and psychopathological aspects of mourning and depressive processes in human beings. Mourning and Melancholia bridges Freud's first and second topographic theories of the psychic apparatus and constitutes for many authors the foundation of his theory of internal object relations. With this psychoanalytic understanding of mourning as a framework, I discuss 'special mourning processes,' such as the those confronted by psychoanalysts in Argentina when treating the relatives of thousands of people who were 'disappeared' by the military dictatorship in the 1970s; they are 'special' in the sense that the external reality [which] constitutes the starting point of the psychic mourning process, as described by Freud, is absent. I argue that the 'absent-presence' of the body as an enigmatic message initiates a special mourning process that bears certain characteristics of, and is isomorphic to, Laplanche's seduction theory. PMID:25363451

  16. 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

  17. 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. PMID:11375085

  18. 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

  19. The use of conspicuity aids by cyclists and risk of crashes involving other road users: a protocol for a population based case-control study

    PubMed Central

    2010-01-01

    Background Regular cycling has been shown to improve health and has a role in tackling the threats posed by obesity and inactivity. Cycle collisions, particularly those involving motorised vehicles, can lead to significant mortality and morbidity and are currently a barrier to wider uptake of cycling. There is evidence that the conspicuity of cyclists is a factor in many injury collisions. Low-cost, easy to use retro-reflective and fluorescent clothing and accessories ('conspicuity aids') are available. Their effectiveness in reducing cycling collisions is unknown. The study is designed to investigate the relationship between the use of conspicuity aids and risk of collision or evasion crashes for utility and commuter cyclists in the UK. Methods/Design A matched case-control study is proposed. Cases are adult commuter and utility cyclists involved in a crash resulting from a collision or attempted evasion of a collision with another road user recruited at a UK emergency department. Controls are commuter and utility cyclists matched by journey purpose, time and day of travel and geographical area recruited at public and private cycle parking sites. Data on the use of conspicuity aids, crash circumstances, demographics, cycling experience, safety equipment use, journey characteristics and route will be collected using self-completed questionnaires and maps. Conditional logistic regression will be used to calculate adjusted odds ratios and 95% confidence intervals of the risk of a crash when using any item of fluorescent or reflective clothing or equipment. Discussion This study will provide information on the effectiveness of conspicuity aids in reducing the risk of injury to cyclists resulting from crashes involving other road users. PMID:20105286

  20. Combined Use of Automatic Tube Voltage Selection and Current Modulation with Iterative Reconstruction for CT Evaluation of Small Hypervascular Hepatocellular Carcinomas: Effect on Lesion Conspicuity and Image Quality

    PubMed Central

    Lv, Peijie; Liu, Jie; Zhang, Rui; Jia, Yan

    2015-01-01

    Objective To assess the lesion conspicuity and image quality in CT evaluation of small (≤ 3 cm) hepatocellular carcinomas (HCCs) using automatic tube voltage selection (ATVS) and automatic tube current modulation (ATCM) with or without iterative reconstruction. Materials and Methods One hundred and five patients with 123 HCC lesions were included. Fifty-seven patients were scanned using both ATVS and ATCM and images were reconstructed using either filtered back-projection (FBP) (group A1) or sinogram-affirmed iterative reconstruction (SAFIRE) (group A2). Forty-eight patients were imaged using only ATCM, with a fixed tube potential of 120 kVp and FBP reconstruction (group B). Quantitative parameters (image noise in Hounsfield unit and contrast-to-noise ratio of the aorta, the liver, and the hepatic tumors) and qualitative visual parameters (image noise, overall image quality, and lesion conspicuity as graded on a 5-point scale) were compared among the groups. Results Group A2 scanned with the automatically chosen 80 kVp and 100 kVp tube voltages ranked the best in lesion conspicuity and subjective and objective image quality (p values ranging from < 0.001 to 0.004) among the three groups, except for overall image quality between group A2 and group B (p = 0.022). Group A1 showed higher image noise (p = 0.005) but similar lesion conspicuity and overall image quality as compared with group B. The radiation dose in group A was 19% lower than that in group B (p = 0.022). Conclusion CT scanning with combined use of ATVS and ATCM and image reconstruction with SAFIRE algorithm provides higher lesion conspicuity and better image quality for evaluating small hepatic HCCs with radiation dose reduction. PMID:25995682

  1. 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…

  2. EYA4, a novel vertebrate gene related to Drosophila eyes absent.

    PubMed

    Borsani, G; DeGrandi, A; Ballabio, A; Bulfone, A; Bernard, L; Banfi, S; Gattuso, C; Mariani, M; Dixon, M; Donnai, D; Metcalfe, K; Winter, R; Robertson, M; Axton, R; Brown, A; van Heyningen, V; Hanson, I

    1999-01-01

    We have isolated a family of four vertebrate genes homologous to eyes absent (eya), a key regulator of ocular development in Drosophila. Here we present the detailed characterization of the EYA4 gene in human and mouse. EYA4 encodes a 640 amino acid protein containing a highly conserved C-terminal domain of 271 amino acids which in Drosophila eya is known to mediate developmentally important protein-protein interactions. Human EYA4 maps to 6q23 and mouse Eya4 maps to the predicted homology region near the centromere of chromosome 10. In the developing mouse embryo, Eya4 is expressed primarily in the craniofacial mesenchyme, the dermamyotome and the limb. On the basis of map position and expression pattern, EYA4 is a candidate for oculo-dento-digital (ODD) syndrome, but no EYA4 mutations were found in a panel of ODD patients. PMID:9887327

  3. Characterization of the threonine-phosphatase of mouse eyes absent 3.

    PubMed

    Sano, Teruyuki; Nagata, Shigekazu

    2011-09-01

    Eyes absent (EYA) has tyrosine- and threonine-phosphatase activities in their C-terminal and N-terminal regions, respectively. Using various mutants of mouse EYA3, we showed that the 68-amino acid domain between positions 53 and 120 was necessary and sufficient for its threonine-phosphatase activity. Point mutations were then introduced, and residues Cys-56, Tyr-77, His-79, and Tyr-90 were essential for the EYA3s threonine-phosphatase. The 68-amino acid domain is not well conserved among the four mouse EYA members, but is evolutionally highly conserved in the orthologous EYA members of different species, suggesting that the threonine-phosphatase of EYA3 has a function distinct from that of the other EYAs. PMID:21821028

  4. Invasive sinonasal adenocarcinoma with an absent olfactory bulb: a case report.

    PubMed

    Newman, Thomas H; Tipper, Geoffrey A; Hussain, Zakier

    2016-01-01

    Sinonasal adenocarcinomas are rare, locally invasive tumours. In this case the symptomatic profile was unusual and the diagnosis was missed at the primary care stage. Interestingly this would be the first documented case with an absent ipsilateral olfactory bulb. A 55-year old male presented with symptoms of behavioural change and mild headaches. He was later found to have a large Sinonasal adenocarcinoma which penetrated the skull base. This was treated by a combined craniotomy and endonasal approach. Sinonasal adenocarcinomas are unusual tumours and further research is required in order to clarify management strategies and prognosis. This interesting case was more unusual again given its presentation, extent and absence of the olfactory bulb. Importantly for primary care physicians the initial diagnosis was considered psychiatric rather than organic; despite there being specific features of the presentation which were suggestive of an intra-cranial lesion. PMID:27402540

  5. Invasive sinonasal adenocarcinoma with an absent olfactory bulb: a case report

    PubMed Central

    Newman, Thomas H.; Tipper, Geoffrey A.; Hussain, Zakier

    2016-01-01

    Sinonasal adenocarcinomas are rare, locally invasive tumours. In this case the symptomatic profile was unusual and the diagnosis was missed at the primary care stage. Interestingly this would be the first documented case with an absent ipsilateral olfactory bulb. A 55-year old male presented with symptoms of behavioural change and mild headaches. He was later found to have a large Sinonasal adenocarcinoma which penetrated the skull base. This was treated by a combined craniotomy and endonasal approach. Sinonasal adenocarcinomas are unusual tumours and further research is required in order to clarify management strategies and prognosis. This interesting case was more unusual again given its presentation, extent and absence of the olfactory bulb. Importantly for primary care physicians the initial diagnosis was considered psychiatric rather than organic; despite there being specific features of the presentation which were suggestive of an intra-cranial lesion. PMID:27402540

  6. 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.

  7. The post-syrinx syndrome: stable central myelopathy and collapsed or absent syrinx.

    PubMed

    Bogdanov, E I; Heiss, John D; Mendelevich, E G

    2006-06-01

    Among 168 cases with neurologic findings of cervicothoracic syringomyelia and MRI findings of Chiari 1 malformation and/or underdevelopment of the posterior cranial fossa, 15 patients (9.1 %) had collapsed, flat syrinxes and 14 patients (8.3 %) did not have syrinxes. Both groups of patients had clinical findings of central myelopathy that had been stable for at least 3 years. Magnetic resonance imaging detected atrophy of the cervical spinal cord in both groups and spontaneous communications between the syrinx and the subarachnoid space in 3 patients of the group with collapsed syrinxes. Analysis of these results and review of the literature suggest that patients with clinical signs of syringomyelia and Chiari 1 malformation or underdeveloped posterior fossa, but with small or absent syringomyelitic cavities, have the "postsyrinx" state as a result of spontaneous collapse of distended syrinxes. PMID:16511636

  8. 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…

  9. 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.

  10. Proximal hypospadias with skin-covered shaft of penis and absent urethral plate: An unknown variant and its management

    PubMed Central

    Rashid, Kumar A.; Bhat, Nisar A.

    2011-01-01

    We report a case of proximal hypospadias with an absent urethral plate having intact ventral shaft skin with hooded dorsal prepuce and a good glans groove. Such a variant of hypospadias has not been reported in the literature. PMID:22121320

  11. 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. PMID:9561465

  12. [Umbilical Absent and Reverse End-Diastolic Flow Velocity Waveforms Already Present Prior to Viability do not Exclude Long-Term Foetal Surveillance: A Report of Two Cases].

    PubMed

    Müller, T; Wirbelauer, J; Frauenschuh, I; Frambach, T; Zollner, U; Dietl, J

    2015-04-01

    The finding of absent or reverse end-diastolic flow velocities (AREDV) in the umbilical artery already prior to viability corresponds to the most severe end of the clinical spectrum of placental insufficiency. However, there is little or no experience or published literature with regard to perinatal outcome. We report 2 cases in which structurally and chromosomally normal foetuses showed severe early onset retardation but were continuing to grow. These gestations could be prolonged by 62 and 64 days, respectively. Perinatal outcome was good in both following Caesarean section at 32+3 and 31+5 gestational weeks respectively. PMID:25901870

  13. Magnetic Resonance Evaluation of Multiple Myeloma at 3.0 Tesla: How Do Bone Marrow Plasma Cell Percentage and Selection of Protocols Affect Lesion Conspicuity?

    PubMed Central

    Takasu, Miyuki; Tamura, Takayuki; Kaichi, Yoko; Tanitame, Keizo; Akiyama, Yuji; Date, Shuji; Sakai, Akira; Kuroda, Yoshiaki; Awai, Kazuo

    2014-01-01

    Purpose To compare various pulse sequences in terms of percent contrast and contrast-to-noise ratio (CNR) for detection of focal multiple myeloma lesions and to assess the dependence of lesion conspicuity on the bone marrow plasma cell percent (BMPC%). Materials and Methods Sagittal T1-weighted FSE, fat-suppressed T2-weighted FSE (FS- T2 FSE), fast STIR and iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) imaging of the lumbar spine were performed (n = 45). Bone marrow (BM)-focal myeloma lesion percent contrast and CNR were calculated. Spearman rank correlation coefficients were obtained between percent contrast, CNR and BMPC%. Percent contrasts and CNRs were compared among the three imaging sequences. Results BM-focal lesion percent contrasts, CNRs and BMPC% showed significant negative correlations in the three fat-suppression techniques. Percent contrast and CNRs were significantly higher for FS- T2 FSE than for STIR (P<0.01, P<0.05, respectively), but no significant differences were found among the three fat-suppression methods in the low tumor load BM group. Conclusion The higher BMPC% was within BM, the less conspicuous the focal lesion was on fat-suppressed MRI. The most effective protocol for detecting focal lesions was FS- T2 FSE. In the high tumor load BM group, no significant differences in lesion conspicuity were identified among the three fat-suppression techniques. PMID:24489680

  14. NMR Structure of Conserved Eukaryotic Protein ZK652.3 from C. elegans: a Ubiquitin-like Fold

    SciTech Connect

    Cort, John R. ); Chiang, Yiwen; Zheng, Deyou; Kennedy, Michael A. ); Montelione, Gaetano

    2002-09-01

    Structural proteomics aims to provide one or more representative 3D structures for every structural domain family in nature. As part of an international effort in structural proteomics, the Northeast Structural Genomics Consortium has targeted clusters of strongly conserved eukaryotic protein families for structural and functional analysis. On this basis, protein ZK652.3 (nesg WR41 / YOY3{_}CAEEL / Swiss-Prot P34661 / gi|17557033) from Caenorhabditis elegans was selected for structure determination. Expression of the ZK652.3 gene has been observed in a transcriptional profile of C. elegans genes, where it was one of a cluster of 89 genes whose expression levels co-varied during development1. The biochemical function of this protein is presently unknown. Sequencing of cDNA libraries shows that homologues of ZK652.3 occur widely in vertebrates and plants (Fig. 1). However, ZK652.3 homologues are conspicuously absent from the yeast and Drosophila genomes. Here we describe the three-dimensional structure of ZK652.3 determined by NMR spectroscopy and discuss structural similarities with other proteins which provide clues to potential biochemical functions.

  15. 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

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

    PubMed Central

    Prudic, Kathleen L; Oliver, Jeffrey C

    2008-01-01

    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. PMID:18285285

  17. Inhibition of Eyes Absent Homolog 4 expression induces malignant peripheral nerve sheath tumor necrosis.

    PubMed

    Miller, S J; Lan, Z D; Hardiman, A; Wu, J; Kordich, J J; Patmore, D M; Hegde, R S; Cripe, T P; Cancelas, J A; Collins, M H; Ratner, N

    2010-01-21

    Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive sarcomas without effective therapeutics. Bioinformatics was used to identify potential therapeutic targets. Paired Box (PAX), Eyes Absent (EYA), Dachsund (DACH) and Sine Oculis (SIX) genes, which form a regulatory interactive network in Drosophila, were found to be dysregulated in human MPNST cell lines and solid tumors. We identified a decrease in DACH1 expression, and increases in the expressions of PAX6, EYA1, EYA2, EYA4, and SIX1-4 genes. Consistent with the observation that half of MPNSTs develop in neurofibromatosis type 1 (NF1) patients, subsequent to NF1 mutation, we found that exogenous expression of the NF1-GTPase activating protein-related domain normalized DACH1 expression. EYA4 mRNA was elevated more than 100-fold as estimated by quantitative real-time PCR in most MPNST cell lines. In vitro, suppression of EYA4 expression using short hairpin RNA reduced cell adhesion and migration and caused cellular necrosis without affecting cell proliferation or apoptotic cell death. MPNST cells expressing shEYA4 either failed to form tumors in nude mice or formed very small tumors, with extensive necrosis but similar levels of proliferation and apoptosis as control cells. Our findings identify a role of EYA4 and possibly interacting SIX and DACH proteins in MPNSTs and suggest the EYA4 pathway as a rational therapeutic target. PMID:19901965

  18. Cloning and characterization of two vertebrate homologs of the Drosophila eyes absent gene.

    PubMed

    Zimmerman, J E; Bui, Q T; Steingrímsson, E; Nagle, D L; Fu, W; Genin, A; Spinner, N B; Copeland, N G; Jenkins, N A; Bucan, M; Bonini, N M

    1997-02-01

    The Drosophila eyes absent (eya) gene plays an essential role in the events that lead to proper development of the fly eye and embryo. Here we report the analysis of two human and two mouse homologs of the fly eya gene. Sequence comparison reveals a large domain of approximately 270 amino acids in the carboxyl terminus of the predicted mammalian proteins that shows 53% identity between the fly sequence and all of the vertebrate homologs. This Eya-homology domain is of novel sequence, with no previously identified motifs. RNA hybridization studies indicate that the mouse genes are expressed during embryogenesis and in select tissues of the adult. Both mouse Eya genes are expressed in the eye, suggesting that these genes may function in eye development in vertebrates as eya does in the fly. The mouse Eya2 gene maps to chromosome 2 in the region syntenic with human chromosome 20q13, and the mouse Eya2 gene maps to chromosome 4 in the region syntenic with human chromosome 1p36. Our findings support the notion that several families of genes (Pax-6/eyeless, Six-3/sine oculis, and Eya) play related and critical roles in the eye for both files and vertebrates. PMID:9049631

  19. A CD45 polymorphism associated with abnormal splicing is absent in African populations.

    PubMed

    Tchilian, Elma Z; Dawes, Ritu; Ramaley, Patricia A; Whitworth, James A; Yuldasheva, Nadira; Wells, R Spencer; Watera, Christine; French, Neil; Gilks, Charles F; Kunachiwa, Warunee; Ruzibakiev, Ruslan; Leetrakool, Nipapan; Carrington, Christine V F; Ramdath, D Dan; Gotch, Frances; Stephens, Henry A; Hill, Adrian V; Beverley, Peter C L

    2002-02-01

    The CD45 antigen is essential for normal antigen receptor-mediated signalling in lymphocytes, and different patterns of splicing of CD45 are associated with distinct functions in lymphocytes. Abnormal CD45 splicing has been recognized in humans, caused by a C77G transversion in the gene encoding CD45 (PTPRC). Recently the C77G polymorphism has been associated with multiple sclerosis and increased susceptibility to HIV-1 infection. These studies suggest that the regulation of CD45 splicing may be critical for the proper function of the immune system. Because of these data we examined the frequency of the C77G allele in African and Asian populations from countries with high or low prevalence of HIV infection. Here we report that the variant CD45 C77G allele is absent in African populations. We further show that populations living in the Pamir mountains of Central Asia have a very high prevalence of the C77G variant. PMID:11862398

  20. Regulation of the innate immune response by threonine-phosphatase of Eyes absent.

    PubMed

    Okabe, Yasutaka; Sano, Teruyuki; Nagata, Shigekazu

    2009-07-23

    Innate immunity is stimulated not only by viral or bacterial components, but also by non-microbial danger signals (damage-associated molecular patterns). One of the damage-associated molecular patterns is chromosomal DNA that escapes degradation. In programmed cell death and erythropoiesis, DNA from dead cells or nuclei expelled from erythroblasts is digested by DNase II in the macrophages after they are engulfed. DNase II(-/-) (also known as Dnase2a(-/-)) mice suffer from severe anaemia or chronic arthritis due to interferon-beta (IFN-beta) and tumour necrosis factor-alpha (TNF-alpha) produced from the macrophages carrying undigested DNA in a Toll-like receptor (TLR)-independent mechanism. Here we show that Eyes absent 4 (EYA4), originally identified as a co-transcription factor, stimulates the expression of IFN-beta and CXCL10 in response to the undigested DNA of apoptotic cells. EYA4 enhanced the innate immune response against viruses (Newcastle disease virus and vesicular stomatitis virus), and could associate with signalling molecules (IPS-1 (also known as MAVS), STING (TMEM173) and NLRX1). Three groups have previously shown that EYA has phosphatase activity. We found that mouse EYA family members act as a phosphatase for both phosphotyrosine and phosphothreonine. The haloacid dehalogenase domain at the carboxy terminus contained the tyrosine-phosphatase, and the amino-terminal half carried the threonine-phosphatase. Mutations of the threonine-phosphatase, but not the tyrosine-phosphatase, abolished the ability of EYA4 to enhance the innate immune response, suggesting that EYA regulates the innate immune response by modulating the phosphorylation state of signal transducers for the intracellular pathogens. PMID:19561593

  1. Frequent methylation of eyes absent 4 gene in Barrett's esophagus and esophageal adenocarcinoma.

    PubMed

    Zou, Hongzhi; Osborn, Neal K; Harrington, Jonathan J; Klatt, Kristie K; Molina, Julian R; Burgart, Lawrence J; Ahlquist, David A

    2005-04-01

    Most esophageal adenocarcinomas arise within Barrett's esophagus but the cause of this increasingly prevalent condition remains unknown. Early detection improves survival and discriminant screening markers for Barrett's esophagus and cancer are needed. This study was designed to explore the natural history of eyes absent 4 (EYA4) gene methylation in the neoplastic progression of Barrett's esophagus and to evaluate methylated EYA4 as a candidate marker. Aberrant promoter methylation of EYA4 was studied by methylation-specific PCR using bisulfite-treated DNA from esophageal adenocarcinomas, Barrett's esophagus, and normal epithelia, and then confirmed by sequencing. Eight cancer cell lines were treated with the demethylation agent 5-aza-2'-deoxycytidine, and EYA4 mRNA expression with and without treatment was quantified by real-time reverse-transcription PCR. EYA4 hypermethylation was detected in 83% (33 of 40) of esophageal adenocarcinomas and 77% (27 of 35) of Barrett's tissues, but only in 3% (2 of 58) of normal esophageal and gastric mucosa samples (P < 0.001). The unmethylated cancer cell lines had much higher EYA4 mRNA expression than the methylated cancer cell lines. Demethylation caused by 5-aza-2'-deoxycytidine increased the mRNA expression level by a median of 3.2-fold in methylated cells, but its effect on unmethylated cells was negligible. Results indicate that aberrant promoter methylation of EYA4 is very common during tumorigenesis in Barrett's esophagus, occurs in early metaplasia, seems to be an important mechanism of down-regulating EYA4 expression, and represents an intriguing candidate marker for Barrett's metaplasia and esophageal cancer. PMID:15824152

  2. 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

  3. Drosophila Eyes Absent Is Required for Normal Cone and Pigment Cell Development

    PubMed Central

    Karandikar, Umesh C.; Jin, Meng; Jusiak, Barbara; Kwak, SuJin; Chen, Rui; Mardon, Graeme

    2014-01-01

    In Drosophila, development of the compound eye is orchestrated by a network of highly conserved transcriptional regulators known as the retinal determination (RD) network. The retinal determination gene eyes absent (eya) is expressed in most cells within the developing eye field, from undifferentiated retinal progenitors to photoreceptor cells whose differentiation begins at the morphogenetic furrow (MF). Loss of eya expression leads to an early block in retinal development, making it impossible to study the role of eya expression during later steps of retinal differentiation. We have identified two new regulatory regions that control eya expression during retinal development. These two enhancers are necessary to maintain eya expression anterior to the MF (eya-IAM) and in photoreceptors (eya-PSE), respectively. We find that deleting these enhancers affects developmental events anterior to the MF as well as retinal differentiation posterior to the MF. In line with previous results, we find that reducing eya expression anterior to the MF affects several early steps during early retinal differentiation, including cell cycle arrest and expression of the proneural gene ato. Consistent with previous observations that suggest a role for eya in cell proliferation during early development we find that deletion of eya-IAM leads to a marked reduction in the size of the adult retinal field. On the other hand, deletion of eya-PSE leads to defects in cone and pigment cell development. In addition we find that eya expression is necessary to activate expression of the cone cell marker Cut and to regulate levels of the Hedgehog pathway effector Ci. In summary, our study uncovers novel aspects of eya-mediated regulation of eye development. The genetic tools generated in this study will allow for a detailed study of how the RD network regulates key steps in eye formation. PMID:25057928

  4. Mismatch Negativity of Sad Syllables Is Absent in Patients with Major Depressive Disorder

    PubMed Central

    Pang, Xiaomei; Xu, Jing; Chang, Yi; Tang, Di; Zheng, Ya; Liu, Yanhua; Sun, Yiming

    2014-01-01

    Background Major depressive disorder (MDD) is an important and highly prevalent mental disorder characterized by anhedonia and a lack of interest in everyday activities. Additionally, patients with MDD appear to have deficits in various cognitive abilities. Although a number of studies investigating the central auditory processing of low-level sound features in patients with MDD have demonstrated that this population exhibits impairments in automatic processing, the influence of emotional voice processing has yet to be addressed. To explore the automatic processing of emotional prosodies in patients with MDD, we analyzed the ability to detect automatic changes using event-related potentials (ERPs). Method This study included 18 patients with MDD and 22 age- and sex-matched healthy controls. Subjects were instructed to watch a silent movie but to ignore the afferent acoustic emotional prosodies presented to both ears while continuous electroencephalographic activity was synchronously recorded. Prosodies included meaningless syllables, such as “dada” spoken with happy, angry, sad, or neutral tones. The mean amplitudes of the ERPs elicited by emotional stimuli and the peak latency of the emotional differential waveforms were analyzed. Results The sad MMN was absent in patients with MDD, whereas the happy and angry MMN components were similar across groups. The abnormal sad emotional MMN component was not significantly correlated with the HRSD-17 and HAMA scores, respectively. Conclusion The data indicate that patients with MDD are impaired in their ability to automatically process sad prosody, whereas their ability to process happy and angry prosodies remains normal. The dysfunctional sad emotion-related MMN in patients with MDD were not correlated with depression symptoms. The blunted MMN of sad prosodies could be considered a trait of MDD. PMID:24658084

  5. Absent Left Main Coronary Artery and Separate Ostia of Left Coronary System in a Patient with Holt-Oram Syndrome and Sinus Node Dysfunction

    PubMed Central

    Aung, Thein Tun; Roberto, Edward Samuel; Wase, Abdul

    2016-01-01

    Patient: Male, 41 Final Diagnosis: Sick Sinus Syndrome and absent left main coronary artery • separate ostia of left anterior descending and circumflex arteries in Holt-Oram Syndrome Symptoms: Conduction disturbance • seizure-like activity • upper extremity malformations Medication: — Clinical Procedure: Electro physiology study • coronary catheterization • pacemaker Specialty: Cardiology Objective: Congenital defects/diseases Background: Holt-Oram syndrome (HOS) is a rare but significant syndrome consisting of structural heart defects, conduction abnormalities, and upper extremity anomalies. It was first described in the British Heart Journal in 1960 by Mary Holt and Samuel Oram as a report of atrial septal defect, conduction disturbances, and hand malformations occurring in family members. Patients can present with heart blocks or symptoms of underlying congenital heart defects. Case Report: A 41-year-old man with Holt-Oram syndrome presented with seizure-like activity and was found to have an underlying conduction disturbance. Physical exam showed bilateral atrophic upper extremities with anatomic disfiguration, and weakness of the intrinsic hand muscles. Cardiovascular exam revealed a slow heart rate with irregular rhythm. EKG showed sinus arrest with junctional escape rhythm. Cardiac catheterization revealed coronary anomalies, including absent left main coronary artery and separate ostia of the left anterior ascending and left circumflex coronary artery. Coronary arteries were patent. Following electrophysiology study, sick sinus syndrome and AV block were diagnosed, and the patient received implantation of a permanent pacemaker. Conclusions: This patient presented with a seizure-like episode attributed to hypoxia during asystole from an underlying cardiac conduction defect associated with Holt-Oram syndrome. Arrhythmias and heart blocks are seen in these patients, and conduction defects are highly associated with congenital heart defects. Holt

  6. Changes in 99mTechnegas ventilation lung scan in a newborn with absent pulmonary valve syndrome.

    PubMed

    Takahashi, K; Kuwahara, T; Nagatsu, M

    2001-11-01

    A newborn infant with tetralogy of Fallot and absent pulmonary valve was successfully corrected in two stages. Absent pulmonary valve syndrome presenting in early infancy manifests severe respiratory symptoms that still make challenging both management and surgical treatment. This is ascribed to tracheobronchial compression by the extremely dilated pulmonary arteries, and to the resultant pulmonary obstructive lesions. We report herein the first findings of 99mTechnegas ventilation lung scanning in an infant with the syndrome to assess the pulmonary obstructive lesions. PMID:11813924

  7. Dopamine D2 receptor bands in normal human temporal cortex are absent in Alzheimer's disease.

    PubMed

    Joyce, J N; Myers, A J; Gurevich, E

    1998-02-16

    A modular organization of bands enriched in high concentrations of D2 receptors are observed throughout the rostral to caudal aspects of the temporal cortex of the normal human at postmortem, but are most frequently observed in the inferior and superior temporal cortices [S. Goldsmith, J.N. Joyce, Dopamine D2 receptors are organized in bands in normal human temporal cortex, Neuroscience 74 (1996) 435-451]. In the tissue derived at postmortem from Alzheimer's disease cases (AD), these D2 receptor-enriched modules were found to be largely absent at rostral and mid-levels of the temporal cortex. Regions exhibiting this loss of receptor binding also showed a marked reduction in the number of pyramidal neurons stained for D2 mRNA. In addition, the AD material exhibited numerous thioflavin-positive plaques and tangle-filled extraneuronal (ghost) pyramidal neurons that were D2 mRNA-negative. Regions that are the earliest affected and most susceptible to classical AD pathology are also most sensitive to the loss of D2 receptors. These results, along with our previous data [J.N. Joyce, C. Kaeger, H. Ryoo, S. Goldsmith, Dopamine D2 receptors in the hippocampus and amygdala in Alzheimer's disease, Neurosci. Lett. 154 (1993) 171-174; H. Ryoo, J. N. Joyce, The loss of dopamine D2 receptors varies along the rostrocaudal axis of the hippocampal complex in Alzheimer's disease, J. Comp. Neurol. 348 (1994) 94-110], indicate that specific pathways enriched with D2 receptors, including that within modules of higher order association cortices of the temporal lobe and continued through segregated pathways within the parahippocampus and hippocampus, are particularly susceptible to the loss in AD. These dopamine D2 receptor-enriched modules may play an important role in the reciprocal activity of large groups of neurons in these high-order association cortical regions. Hence, the loss of the D2 receptor-enriched modules in Alzheimer's disease contributes to disturbances in information

  8. 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

  9. 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…

  10. 25 CFR 15.106 - May a probate case be initiated when an owner of an interest has been absent?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false May a probate case be initiated when an owner of an interest has been absent? 15.106 Section 15.106 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR PROBATE PROBATE OF INDIAN ESTATES, EXCEPT FOR MEMBERS OF THE OSAGE NATION AND THE FIVE...

  11. 25 CFR 15.106 - May a probate case be initiated when an owner of an interest has been absent?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false May a probate case be initiated when an owner of an interest has been absent? 15.106 Section 15.106 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR PROBATE PROBATE OF INDIAN ESTATES, EXCEPT FOR MEMBERS OF THE OSAGE NATION AND THE FIVE...

  12. 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…

  13. 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.

  14. 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. PMID:22185696

  15. Bone metastases from prostate, breast and multiple myeloma: differences in lesion conspicuity at short-tau inversion recovery and diffusion-weighted MRI

    PubMed Central

    Pearce, T; Philip, S; Brown, J; Koh, D M; Burn, P R

    2012-01-01

    Objectives The objective of this study was to compare the relative conspicuity of bone metastases on short-tau inversion recovery (STIR) and diffusion-weighted MRI (DWI) whole-body MR sequences for breast, prostate and myeloma malignancies. Methods 44 whole-body MRI scans were reviewed retrospectively (coronal T1 weighted, STIR and DWI with b=800). On each scan, up to four of the largest bone lesions were identified on T1 weighting, and the region of interest signal intensity was measured on STIR and DWI, as well as the background signal intensity. The mean lesion signal to background ratio was calculated for each patient and then for each malignancy group. Results In prostate cancer patients, the DWI signal/background ratio was greater than that of STIR in 22 out of 24 patients (mean DWI lesion/background ratio 3.91, mean STIR lesion/background ratio 2.31; p=0.0001). In multiple myeloma, the DWI ratio was higher in 6/7 patients (DWI group mean ratio 7.59, STIR group mean ratio 3.7; p=0.0366). In 13 breast cancer patients, mean STIR and DWI signal/background were similar (DWI group mean ratio 4.13, group mean STIR ratio 4.26; p=0.8587). Conclusion Bone lesion conspicuity measured by lesion/background signal intensity was higher on DWI b=800 than on STIR in patients with prostate cancer and multiple myeloma. DWI should be used in whole-body MR oncology protocols in these conditions to maximise lesion detection. PMID:22457319

  16. 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…

  17. A symptomatic neonate with tetralogy of Fallot, an absent pulmonary valve, and a single coronary artery with a major fistula.

    PubMed

    Kajihara, Noriyoshi; Asou, Toshihide; Takeda, Yuko; Kosaka, Yoshimichi; Matsuhama, Minoru; Onakatomi, Yasuko; Yanagi, Sadamitsu; Yasui, Seiyo

    2009-11-01

    We present a case with a rare combination of tetralogy of Fallot with an absent pulmonary valve, and a single coronary artery with a major fistula to the main pulmonary artery. Myocardial ischemia developed in response to increasing shunt flow through the coronary fistula, resulting in heart failure. We ligated the coronary fistula and plicated the anterior wall of the dilated pulmonary arteries during the neonatal period. Complete repair through a transatrial-transpulmonary approach was performed at the age of 17 months. The postoperative course was excellent and the patient maintained a stable hemodynamic and respiratory state with no evidence of myocardial ischemia. PMID:19853139

  18. Absent husbands, single wives: success, domesticity, and seminuclear families in the nineteenth-century Great Lakes world.

    PubMed

    Nutting, P Bradley

    2010-01-01

    The industrial and transportation revolutions of nineteenth-century America separated work from home (at least for the growing middle class) and intensified the development of masculine and feminine spheres devoted to success and domesticity, respectively. This development tended to reduce the husband's traditional patriarchal roles to that of provider only, while leaving the wife and mother with enhanced authority over household management and child rearing, a development with consequences for feminism. This article examines two extreme cases of separation of work from home: absent husbands, respected professional men, who left their wives alone for months or years and, while they provided financial support, surrendered all household authority to "single" wives. PMID:21105493

  19. 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.

  20. Head Direction Cell Activity Is Absent in Mice without the Horizontal Semicircular Canals

    PubMed Central

    Valerio, Stephane

    2016-01-01

    Head direction (HD) cells fire when an animal faces a particular direction in its environment, and they are thought to represent the neural correlate of the animal's perceived spatial orientation. Previous studies have shown that vestibular information is critical for generating the HD signal but have not delineated whether information from all three semicircular canals or just the horizontal canals, which are primarily sensitive to angular head rotation in the horizontal (yaw) plane, are critical for the signal. Here, we monitored cell activity in the anterodorsal thalamus (ADN), an area known to contain HD cells, in epstatic circler (Ecl) mice, which have a bilateral malformation of the horizontal (lateral) semicircular canals. Ecl mice and their littermates that did not express the mutation (controls) were implanted with recording electrodes in the ADN. Results confirm the important role the horizontal canals play in forming the HD signal. Although normal HD cell activity (Raleigh's r > 0.4) was recorded in control mice, no such activity was found in Ecl mice, although some cells had activity that was mildly modulated by HD (0.4 > r > 0.2). Importantly, we also observed activity in Ecl mice that was best characterized as bursty—a pattern of activity similar to an HD signal but without any preferred firing direction. These results suggest that the neural structure for the HD network remains intact in Ecl mice, but the absence of normal horizontal canals results in an inability to control the network properly and brings about an unstable HD signal. SIGNIFICANCE STATEMENT Cells in the anterior dorsal thalamic nucleus normally fire in relation to the animal's directional heading with respect to the environment—so-called head direction cells. To understand how these head direction cells generate their activity, we recorded single-unit activity from the anterior dorsal thalamus in transgenic mice that lack functional horizontal semicircular canals. We show that

  1. Head Direction Cell Activity Is Absent in Mice without the Horizontal Semicircular Canals.

    PubMed

    Valerio, Stephane; Taube, Jeffrey S

    2016-01-20

    Head direction (HD) cells fire when an animal faces a particular direction in its environment, and they are thought to represent the neural correlate of the animal's perceived spatial orientation. Previous studies have shown that vestibular information is critical for generating the HD signal but have not delineated whether information from all three semicircular canals or just the horizontal canals, which are primarily sensitive to angular head rotation in the horizontal (yaw) plane, are critical for the signal. Here, we monitored cell activity in the anterodorsal thalamus (ADN), an area known to contain HD cells, in epstatic circler (Ecl) mice, which have a bilateral malformation of the horizontal (lateral) semicircular canals. Ecl mice and their littermates that did not express the mutation (controls) were implanted with recording electrodes in the ADN. Results confirm the important role the horizontal canals play in forming the HD signal. Although normal HD cell activity (Raleigh's r > 0.4) was recorded in control mice, no such activity was found in Ecl mice, although some cells had activity that was mildly modulated by HD (0.4 > r > 0.2). Importantly, we also observed activity in Ecl mice that was best characterized as bursty--a pattern of activity similar to an HD signal but without any preferred firing direction. These results suggest that the neural structure for the HD network remains intact in Ecl mice, but the absence of normal horizontal canals results in an inability to control the network properly and brings about an unstable HD signal. Significance statement: Cells in the anterior dorsal thalamic nucleus normally fire in relation to the animal's directional heading with respect to the environment--so-called head direction cells. To understand how these head direction cells generate their activity, we recorded single-unit activity from the anterior dorsal thalamus in transgenic mice that lack functional horizontal semicircular canals. We show that the

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

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

    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.

  3. 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.

  4. 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.

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

    DOE PAGESBeta

    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 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

  6. 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

  7. The retinal determination gene eyes absent is regulated by the EGF receptor pathway throughout development in Drosophila.

    PubMed

    Salzer, Claire L; Elias, Yair; Kumar, Justin P

    2010-01-01

    Members of the Eyes absent (Eya) protein family play important roles in tissue specification and patterning by serving as both transcriptional activators and protein tyrosine phosphatases. These activities are often carried out in the context of complexes containing members of the Six and/or Dach families of DNA binding proteins. eyes absent, the founding member of the Eya family is expressed dynamically within several embryonic, larval, and adult tissues of the fruit fly, Drosophila melanogaster. Loss-of-function mutations are known to result in disruptions of the embryonic head and central nervous system as well as the adult brain and visual system, including the compound eyes. In an effort to understand how eya is regulated during development, we have carried out a genetic screen designed to identify genes that lie upstream of eya and govern its expression. We have identified a large number of putative regulators, including members of several signaling pathways. Of particular interest is the identification of both yan/anterior open and pointed, two members of the EGF Receptor (EGFR) signaling cascade. The EGFR pathway is known to regulate the activity of Eya through phosphorylation via MAPK. Our findings suggest that this pathway is also used to influence eya transcriptional levels. Together these mechanisms provide a route for greater precision in regulating a factor that is critical for the formation of a wide range of diverse tissues. PMID:19884307

  8. The Retinal Determination Gene eyes absent Is Regulated by the EGF Receptor Pathway Throughout Development in Drosophila

    PubMed Central

    Salzer, Claire L.; Elias, Yair; Kumar, Justin P.

    2010-01-01

    Members of the Eyes absent (Eya) protein family play important roles in tissue specification and patterning by serving as both transcriptional activators and protein tyrosine phosphatases. These activities are often carried out in the context of complexes containing members of the Six and/or Dach families of DNA binding proteins. eyes absent, the founding member of the Eya family is expressed dynamically within several embryonic, larval, and adult tissues of the fruit fly, Drosophila melanogaster. Loss-of-function mutations are known to result in disruptions of the embryonic head and central nervous system as well as the adult brain and visual system, including the compound eyes. In an effort to understand how eya is regulated during development, we have carried out a genetic screen designed to identify genes that lie upstream of eya and govern its expression. We have identified a large number of putative regulators, including members of several signaling pathways. Of particular interest is the identification of both yan/anterior open and pointed, two members of the EGF Receptor (EGFR) signaling cascade. The EGFR pathway is known to regulate the activity of Eya through phosphorylation via MAPK. Our findings suggest that this pathway is also used to influence eya transcriptional levels. Together these mechanisms provide a route for greater precision in regulating a factor that is critical for the formation of a wide range of diverse tissues. PMID:19884307

  9. Absent right and persistent left superior vena cava: troubleshooting during a challenging pacemaker implant: a case report

    PubMed Central

    2014-01-01

    Background Venous anomalies of the thorax can occur in isolation or in association with complex congenital heart disease. The incidence of an absent right superior vena cava in the setting of a persistent left superior vena cava is very rare in the general population with only a dozen cases documented in the medical literature. Such venous anomalies can make for very challenging electronic cardiac device implantation. We report our challenging dual chamber pacemaker implant in a patient with such complex anatomy and focus on our implantation technique that helped achieve adequate lead positioning. Case presentation A 73-year-old Caucasian female with degenerative complete heart block presented for dual chamber permanent pacemaker implant. Lead implantation was very challenging due to abnormal and rare vena cava anatomy; a persistent left superior vena cava drained directly into the coronary sinus and the right brachiocephalic vein drained directly into the left persistent superior vena cava as the patient had an absent right superior vena cava . Adequate right ventricular lead positioning was achieved following numerous lead-stylet manipulations and careful looping in the atria to redirect its trajectory to the ventricular apex. Conclusion Abnormal superior vena cava development is uncommon and can lead to technical challenges when venous access is required during various interventional procedures. Pre-operative imaging can help identify such challenging anatomy allowing appropriate operative planning; careful patient selection is warranted for venography given the risk of contrast nephrotoxicity. PMID:25047923

  10. Condition at birth of infants with previously absent or reverse umbilical artery end-diastolic flow velocities.

    PubMed

    Weiss, E; Ulrich, S; Berle, P

    1992-01-01

    In a case control study we assessed 47 fetuses with absent or reverse end-diastolic flow velocities (AREDFV) of the umbilical artery with respect to the mode of delivery, fetal acidosis, and abnormal neurological evaluations at the time of discharge from the department of pediatrics. We also studied a control group which was matched for gestational age and had normal umbilical artery flow velocity waveforms. Fetuses with AREDFV were delivered almost exclusively by cesarean section which was usually done for fetal distress. The number of fetuses with abnormal neurological signs was significantly increased compared to the control group. Fetuses with AREDFV showed an increased incidence of fetal acidosis. Forty per cent of these fetuses were delivered within one day of the first abnormal flow measurement; Sixty per cent were observed clinically for up to four weeks before delivery. PMID:1417086

  11. 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.

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

    PubMed Central

    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 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. PMID:24412811

  13. 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)

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

    PubMed

    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

  15. 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

  16. Nemo phosphorylates Eyes absent and enhances output from the Eya-Sine oculis transcriptional complex during Drosophila retinal determination

    PubMed Central

    Morillo, Santiago A.; Braid, Lorena R.; Verheyen, Esther M.; Rebay, Ilaria

    2013-01-01

    The retinal determination gene network comprises a collection of transcription factors that respond to multiple signaling inputs to direct Drosophila eye development. Previous genetic studies have shown that nemo (nmo), a gene encoding a proline-directed serine/threonine kinase, can promote retinal specification through interactions with the retinal determination gene network, although the molecular point of cross-talk was not defined. Here, we report that the Nemo kinase positively and directly regulates Eyes absent (Eya). Genetic assays show that Nmo catalytic activity enhances Eya-mediated ectopic eye formation and potentiates induction of the Eya-Sine oculis (So) transcriptional targets dachshund and lozenge. Biochemical analyses demonstrate that Nmo forms a complex with and phosphorylates Eya at two consensus mitogen-activated protein kinase (MAPK) phosphorylation sites. These same sites appear crucial for Nmo-mediated activation of Eya function in vivo. Thus, we propose that Nmo phosphorylation of Eya potentiates its transactivation function to enhance transcription of Eya-So target genes during eye specification and development. PMID:22394486

  17. Mandibuloacral dysplasia and LMNA A529V mutation in Turkish patients with severe skeletal changes and absent breast development.

    PubMed

    Ozer, Leyla; Unsal, Evrim; Aktuna, Suleyman; Baltaci, Volkan; Celikkol, Pelin; Akyigit, Fatma; Sen, Askin; Ayvaz, Ozge; Balci, Sevim

    2016-07-01

    Mandibuloacral dysplasia (MAD) is an autosomal recessive disorder characterized by acroosteolysis (resorption of terminal phalanges), skin changes (hyperpigmentation), clavicular hypoplasia, craniofascial anomalies, a hook nose and prominent eyes, delayed closures of the cranial sutures, lipodystrophy, alopecia, and skeletal anomalies. MAD patients are classified according to lipodystrophy patterns: type A and type B. The vast majority of MAD cases are caused by LMNA gene mutations. MAD patients with type A lipodystrophy (MADA) have been reported to have LMNA R527H, A529V, or A529T mutations. In this report, we describe two MADA patients with progressive skeletal changes, absent breast development, and cataract in addition to the classical MAD phenotype. Both patients were found to be homozygous for the Ala529Val mutation of the LMNA gene. Our female patient is the oldest MADA patient (59 years old) who has ever been reported with the LMNA mutation and also the LMNA Ala529Val mutation. This study is the second report on MADA patients with a homozygous Ala529Val mutation. PMID:27100822

  18. Absent in Melanoma 2 (AIM2) limits pro-inflammatory cytokine transcription in cardiomyocytes by inhibiting STAT1 phosphorylation.

    PubMed

    Furrer, Antonia; Hottiger, Michael O; Valaperti, Alan

    2016-06-01

    Interferon (IFN)-γ is highly upregulated during heart inflammation and enhances the production of pro-inflammatory cytokines. Absent in Melanoma 2 (AIM2) is an IFN-inducible protein implicated as a component of the inflammasome. Here we seek to determine the role of AIM2 during inflammation in cardiac cells. We found that the presence of AIM2, but not of the other inflammasome components Nod-like receptor (NLR) NLRP3 or NLRC4, specifically limited the transcription of the pro-inflammatory cytokines interleukin (IL)-6, IP-10, and tumor necrosis factor (TNF)-α in HL-1 mouse cardiomyocytes stimulated with IFN-γ and lipopolysaccharides (LPS). Similarly, AIM2 reduced pro-inflammatory cytokine transcription in primary mouse neonatal cardiomyocytes (MNC), but not in primary mouse neonatal cardiac fibroblasts (MNF). Interestingly, AIM2-dependent reduction of pro-inflammatory cytokines in cardiomyocytes was independent of Caspase-1. Mechanistically, AIM2 reduced pro-inflammatory cytokine transcription in cardiomyocytes by interacting with and inhibiting the phosphorylation of STAT1. In AIM2-depleted cardiomyocytes, increased STAT1 phosphorylation enhanced the NF-κB pathway by promoting NF-κB p65 phosphorylation and acetylation. These results show for the first time that AIM2 plays an important anti-inflammatory, yet inflammasome-independent function in cardiomyocytes. Our findings will help to further understand how the various heart cell types differently react to inflammatory stimuli. PMID:27148820

  19. 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

  20. 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. PMID:22821862

  1. Identification of novel direct targets of Drosophila Sine oculis and Eyes absent by integration of genome-wide data sets.

    PubMed

    Jin, Meng; Aibar, Sara; Ge, Zhongqi; Chen, Rui; Aerts, Stein; Mardon, Graeme

    2016-07-01

    Drosophila eye development is a complex process that involves many transcription factors (TFs) and interactions with their cofactors and targets. The TF Sine oculis (So) and its cofactor Eyes absent (Eya) are highly conserved and are both necessary and sufficient for eye development. Despite their many important roles during development, the direct targets of So are still largely unknown. Therefore the So-dependent regulatory network governing eye determination and differentiation is poorly understood. In this study, we intersected gene expression profiles of so or eya mutant eye tissue prepared from three different developmental stages and identified 1731 differentially expressed genes across the Drosophila genome. A combination of co-expression analyses and motif discovery identified a set of twelve putative direct So targets, including three known and nine novel targets. We also used our previous So ChIP-seq data to assess motif predictions for So and identified a canonical So binding motif. Finally, we performed in vivo enhancer reporter assays to test predicted enhancers from six candidate target genes and find that at least one enhancer from each gene is expressed in the developing eye disc and that their expression patterns overlap with that of So. We furthermore confirmed that the expression level of predicted direct So targets, for which antibodies are available, are reduced in so or eya post-mitotic knockout eye discs. In summary, we expand the set of putative So targets and show for the first time that the combined use of expression profiling of so with its cofactor eya is an effective method to identify novel So targets. Moreover, since So is highly conserved throughout the metazoa, our results provide the basis for future functional studies in a wide variety of organisms. PMID:27178668

  2. Neural processes mediating the preparation and release of focal motor output are suppressed or absent during imagined movement

    PubMed Central

    Eagles, Jeremy S.; Carlsen, Anthony N.

    2016-01-01

    Movements that are executed or imagined activate a similar subset of cortical regions, but the extent to which this activity represents functionally equivalent neural processes is unclear. During preparation for an executed movement, presentation of a startling acoustic stimulus (SAS) evokes a premature release of the planned movement with the spatial and temporal features of the tasks essentially intact. If imagined movement incorporates the same preparatory processes as executed movement, then a SAS should release the planned movement during preparation. This hypothesis was tested using an instructed-delay cueing paradigm during which subjects were required to rapidly release a handheld weight while maintaining the posture of the arm or to perform first-person imagery of the same task while holding the weight. In a subset of trials, a SAS was presented at 1500, 500, or 200 ms prior to the release cue. Task-appropriate preparation during executed and imagined movements was confirmed by electroencephalographic recording of a contingent negative variation waveform. During preparation for executed movement, a SAS often resulted in premature release of the weight with the probability of release progressively increasing from 24 % at −1500 ms to 80 % at −200 ms. In contrast, the SAS rarely (<2 % of trials) triggered a release of the weight during imagined movement. However, the SAS frequently evoked the planned postural response (suppression of bicep brachii muscle activity) irrespective of the task or timing of stimulation (even during periods of postural hold without preparation). These findings provide evidence that neural processes mediating the preparation and release of the focal motor task (release of the weight) are markedly attenuated or absent during imagined movement and that postural and focal components of the task are prepared independently. PMID:25744055

  3. Human hepatocytes express absent in melanoma 2 and respond to hepatitis B virus with interleukin-18 expression.

    PubMed

    Pan, Xingfei; Xu, Haixia; Zheng, Changlong; Li, Mei; Zou, Xiaofang; Cao, Hong; Xu, Qihuan

    2016-08-01

    Absent in melanoma 2 (AIM2) is a recently recognized cytoplasmic receptor which could sense cytoplasmic double-stranded DNA (dsDNA). After AIM2 detects the presence of parasitic nucleic acids (dsDNA) derived from invasive bacteria or viral genomes (for example, vaccinia virus and cytomegalovirus) within infected cells, AIM2 inflammasome could be formed. The formed AIM2 inflammasome could induce innate immune response and increase expressions of IL-1β and IL-18. Hepatitis B virus (HBV) is a hepatotropic, non-cytopathic double-stranded DNA virus. The immune response to viral antigens or virus is thought to be responsible for both liver damage and viral clearance in patients with HBV infection. However, there are no reports about whether AIM2 inflammasome exists in hepatocytes. In the present study, we investigated the presence and activity of AIM2 inflammasome in human hepatocytes. We found that AIM2 was expressed in cytoplasm of hepatocytes, and IL-18 expression was increased after AIM2 sensed HBV in hepatocytes in vitro. These results showed that AIM2 inflammasome was active in hepatocytes. We also found that hepatic AIM2 expression of chronic hepatitis B (CHB) patients was higher than that of controls. Hepatic AIM2 expression levels were positively correlated to the severity of liver inflammation. IL-18 is already considered to be associated with hepatic injury during HBV infection. In conclusion, we, therefore, believe that AIM2 inflammasome in hepatocytes might play an important role in the development and maintenance of HBV-related hepatitis. PMID:27094165

  4. 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

  5. Intralimb Coordination Patterns in Absent, Mild, and Severe Stages of Diabetic Neuropathy: Looking Beyond Kinematic Analysis of Gait Cycle

    PubMed Central

    Yi, Liu Chiao; Sartor, Cristina D.; Souza, Francis Trombini; Sacco, Isabel C. N.

    2016-01-01

    Aim Diabetes Mellitus progressively leads to impairments in stability and joint motion and might affect coordination patterns, mainly due to neuropathy. This study aims to describe changes in intralimb joint coordination in healthy individuals and patients with absent, mild and, severe stages of neuropathy. Methods Forty-seven diabetic patients were classified into three groups of neuropathic severity by a fuzzy model: 18 without neuropathy (DIAB), 7 with mild neuropathy (MILD), and 22 with moderate to severe neuropathy (SVRE). Thirteen healthy subjects were included as controls (CTRL). Continuous relative phase (CRP) was calculated at each instant of the gait cycle for each pair of lower limb joints. Analysis of Variance compared each frame of the CRP time series and its standard deviation among groups (α = 5%). Results For the ankle-hip CRP, the SVRE group presented increased variability at the propulsion phase and a distinct pattern at the propulsion and initial swing phases compared to the DIAB and CTRL groups. For the ankle-knee CRP, the 3 diabetic groups presented more anti-phase ratios than the CTRL group at the midstance, propulsion, and terminal swing phases, with decreased variability at the early stance phase. For the knee-hip CRP, the MILD group showed more in-phase ratio at the early stance and terminal swing phases and lower variability compared to all other groups. All diabetic groups were more in-phase at early the midstance phase (with lower variability) than the control group. Conclusion The low variability and coordination differences of the MILD group showed that gait coordination might be altered not only when frank evidence of neuropathy is present, but also when neuropathy is still incipient. The ankle-knee CRP at the initial swing phase showed distinct patterns for groups from all degrees of neuropathic severity and CTRLs. The ankle-hip CRP pattern distinguished the SVRE patients from other diabetic groups, particularly in the transitional

  6. Phylogeny and in situ identification of a morphologically conspicuous bacterium, Candidatus Magnospira bakii, present at very low frequency in activated sludge.

    PubMed

    Snaidr, J; Fuchs, B; Wallner, G; Wagner, M; Schleifer, K H; Amann, R

    1999-04-01

    A morphologically conspicuous bacterium that constituted a very small fraction (< 0.01%) of the total microbial community of activated sludge was enriched and analysed phylogenetically by a combination of cultivation-independent molecular and physical methods. The large, corkscrew-shaped, filamentous bacteria were first detected in municipal activated sludge by light microscopy owing to their unusual rotating gliding motility. Various attempts at microbiological enrichment and pure culture isolation with traditional techniques failed, as did attempts to retrieve the morphotype of interest by micromanipulation. In situ hybridization with the group-specific, rRNA-targeted oligonucleotide probe CF319a indicated a phylogenetic affiliation to the Cytophaga-Flexibacter group of the Cytophaga-Flavobacterium-Bacteroides phylum. Based on strong morphological resemblance to members of the genus Saprospira, additional 16S rRNA-targeted oligonucleotides with more narrow specificity were designed and evaluated for in situ hybridization to the morphotype of interest. Flow cytometric cell sorting based on the fluorescence conferred by probe SGR1425 and forward scatter enabled a physical enrichment of the helical coiled cells. Subsequent polymerase chain reaction (PCR) amplification of 16S rDNA fragments from whole fixed sorted cells with a primer pair based on probes CF319a and SGR1425 resulted in the retrieval of 12 almost identical partial 16S rDNA fragments with sequence similarities among each other of more than 99.2%. In situ hybridizations proved that the sequences that showed the highest similarity (88.4%) to the 16S rRNA of Saprospira grandis were indeed retrieved from the corkscrew-shaped filaments. The bacterium is likely to be a member of a genus of which no species has been cultured hitherto. It was consequently tentatively named 'Magnospira bakii' and has the taxonomic rank of Candidatus Magnospira bakii, as the ultimate taxonomic placement has to await its

  7. Unusual variant of scimitar syndrome associated with an absent right pulmonary artery, stenosis of the inferior vena cava, hemi-azygous continuation and the VACTERL association.

    PubMed

    Takawira, Farirai F; Omar, Fareed

    2013-04-01

    We report on a two-month-old infant with an unusual form of scimitar syndrome, associated with an absent right pulmonary artery, obstructed inferior vena cava, hemi-azygous continuation and the VACTERL association. The infant posed a major management problem and eventually died from a lower respiratory tract infection. PMID:23728126

  8. 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…

  9. 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. PMID:27161147

  10. The simian varicella virus genome contains an invertible 665 base pair terminal element that is absent in the varicella zoster virus genome

    PubMed Central

    Mahalingam, Ravi; Gray, Wayne L.

    2007-01-01

    Simian varicella virus (SVV) causes chickenpox in monkeys, establishes latency, and reactivates to produce zoster thus providing a model to study human varicella zoster virus (VZV) infection. Sequence analysis of a recombinant cosmid clone containing the left end of the SVV genome revealed a 665 base pair (bp) segment that is absent in VZV DNA. This segment inverts and contains 507 bp of unique sequences flanked on either side by 79 bp inverted repeats, making the SVV genome to be 124,785 bp in size. Part of the inverted repeat sequence (64 bp) is also present at the junction of the long and short segments of the SVV genome. The terminal DNA sequences are conserved among different SVV isolates and present in tissues from infected monkeys. The terminal region is transcriptionally active and is also present in the genomes of other animal varicelloviruses, but absent in the VZV genome. PMID:17555785

  11. Compression of the left main coronary artery by a pulmonary artery aneurysm in a patient with tetralogy of Fallot and an absent pulmonary valve.

    PubMed

    Khante, Vishal; Agarwal, Saket; Satyarthi, Subodh; Upretti, Lalendra; Satsangi, Deepak K

    2011-05-01

    A case of a 16-year-old female with tetralogy of Fallot and absent pulmonary valve is presented, who on coronary angiography and computerized tomography (CT) angiography had severe compression of the left main coronary artery by the dilated main pulmonary artery. The patient was successfully managed by surgical correction of the intracardiac defect, with right ventricular outflow tract reconstruction by the Contegra(®) bovine jugular vein conduit.  PMID:21447083

  12. Phosphoglucomutase is absent in Trypanosoma brucei and redundantly substituted by phosphomannomutase and phospho-N-acetylglucosamine mutase

    PubMed Central

    Bandini, Giulia; Mariño, Karina; Güther, M Lucia Sampaio; Wernimont, Amy K; Kuettel, Sabine; Qiu, Wei; Afzal, Shamshad; Kelner, Anna; Hui, Raymond; Ferguson, Michael A J

    2012-01-01

    The enzymes phosphomannomutase (PMM), phospho-N-acetylglucosamine mutase (PAGM) and phosphoglucomutase (PGM) reversibly catalyse the transfer of phosphate between the C6 and C1 hydroxyl groups of mannose, N-acetylglucosamine and glucose respectively. Although genes for a candidate PMM and a PAGM enzymes have been found in the Trypanosoma brucei genome, there is, surprisingly, no candidate gene for PGM. The TbPMM and TbPAGM genes were cloned and expressed in Escherichia coli and the TbPMM enzyme was crystallized and its structure solved at 1.85 Å resolution. Antibodies to the recombinant proteins localized endogenous TbPMM to glycosomes in the bloodstream form of the parasite, while TbPAGM localized to both the cytosol and glycosomes. Both recombinant enzymes were able to interconvert glucose-phosphates, as well as acting on their own definitive substrates. Analysis of sugar nucleotide levels in parasites with TbPMM or TbPAGM knocked down by RNA interference (RNAi) suggests that, in vivo, PGM activity is catalysed by both enzymes. This is the first example in any organism of PGM activity being completely replaced in this way and it explains why, uniquely, T. brucei has been able to lose its PGM gene. The RNAi data for TbPMM also showed that this is an essential gene for parasite growth. PMID:22676716

  13. The Arabidopsis ABHD11 Mutant Accumulates Polar Lipids in Leaves as a Consequence of Absent Acylhydrolase Activity1[OPEN

    PubMed Central

    Vijayakumar, Anitha; Vijayaraj, Panneerselvam; Vijayakumar, Arun Kumar; Rajasekharan, Ram

    2016-01-01

    Alpha/beta hydrolase domain (ABHD)-containing proteins are structurally related with diverse catalytic activities. In various species, some ABHD proteins have been characterized and shown to play roles in lipid homeostasis. However, little is known about ABHD proteins in plants. Here, we characterized AT4G10030 (AtABHD11), an Arabidopsis (Arabidopsis thaliana) homolog of a human ABHD11 gene. In silico analyses of AtABHD11 revealed homology with other plant species with a conserved GXSXG lipid motif. Interestingly, Arabidopsis abhd11 mutant plants exhibited an enhanced growth rate compared with wild-type plants. Quantitative analyses of the total lipids showed that the mutant abhd11 has a high amount of phospholipid and galactolipid in Arabidopsis leaves. The overexpression of AtABHD11 in Escherichia coli led to a reduction in phospholipid levels. The bacterially expressed recombinant AtABHD11 hydrolyzed lyso(phospho)lipid and monoacylglycerol. Furthermore, using whole-genome microarray and real-time PCR analyses of abhd11 and wild-type plants, we noted the up-regulation of MGD1, -2, and -3 and DGD1. Together, these findings suggested that AtABHD11 is a lyso(phospho)lipase. The disruption of AtABHD11 caused the accumulation of the polar lipids in leaves, which in turn promoted a higher growth rate compared with wild-type plants. PMID:26589672

  14. Genomic Subtractive Hybridization and Selective Capture of Transcribed Sequences Identify a Novel Salmonella typhimurium Fimbrial Operon and Putative Transcriptional Regulator That Are Absent from the Salmonella typhi Genome

    PubMed Central

    Morrow, Brian J.; Graham, James E.; Curtiss, Roy

    1999-01-01

    Salmonella typhi, the etiologic agent of typhoid fever, is adapted to the human host and unable to infect nonprimate species. The genetic basis for host specificity in S. typhi is unknown. The avirulence of S. typhi in animal hosts may result from a lack of genes present in the broad-host-range pathogen Salmonella typhimurium. Genomic subtractive hybridization was successfully employed to isolate S. typhimurium genomic sequences which are absent from the S. typhi genome. These genomic subtracted sequences mapped to 17 regions distributed throughout the S. typhimurium chromosome. A positive cDNA selection method was then used to identify subtracted sequences which were transcribed by S. typhimurium following macrophage phagocytosis. A novel putative transcriptional regulator of the LysR family was identified as transcribed by intramacrophage S. typhimurium. This putative transcriptional regulator was absent from the genomes of the human-adapted serovars S. typhi and Salmonella paratyphi A. Mutations within this gene did not alter the level of S. typhimurium survival within macrophages or virulence within mice. A subtracted genomic fragment derived from the ferrichrome operon also hybridized to the intramacrophage cDNA. Nucleotide sequence analysis of S. typhimurium and S. typhi chromosomal sequences flanking the ferrichrome operon identified a novel S. typhimurium fimbrial operon with a high level of similarity to sequences encoding Proteus mirabilis mannose-resistant fimbriae. The novel fimbrial operon was absent from the S. typhi genome. The absence of specific genes may have allowed S. typhi to evolve as a highly invasive, systemic human pathogen. PMID:10496884

  15. 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

  16. Cochleo-saccular degeneration in one of three sisters with hereditary deafness, absent gastric motility, small bowel diverticulitis and progressive sensory neuropathy.

    PubMed

    Igarashi, M; MacRae, D; O-Uchi, T; Alford, B R

    1981-01-01

    This is a report of cochleo-saccular degeneration found in temporal bones from a patient who had suffered from slowly progressive and total sensorineural deafness which had an inherited origin. At age 8, this patient began to complain of hearing loss, and by age 10 she was totally deaf. The patient was 1 of 3 female siblings who have suffered from an exactly identical progressive disease: deafness, absent gastric motility, small bowel diverticulitis and ulceration, and sensory neuropathy. The temporal bone pathology found in this case was the degenerative change in the cochlear duct and sacculus. No pathology was found in the utriculus and semicircular canals. PMID:6937848

  17. 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

  18. fH-dependent complement evasion by disease-causing meningococcal strains with absent fHbp genes or frameshift mutations.

    PubMed

    Giuntini, Serena; Vu, David M; Granoff, Dan M

    2013-08-28

    Meningococci bind human fH to down-regulate complement, which enhances survival of the bacteria in serum. A major fH ligand is the vaccine candidate, factor H-binding protein (fHbp). Although fHbp has been considered an essential meningococcal virulence factor, rarely, invasive isolates with absent fHbp genes or frameshift mutations have been identified. In previous studies fH binding to these isolates was not detected. The aim of the present study was to investigate fH binding and complement evasion by invasive meningococcal serogroup B clinical isolates with absent fHbp genes or frameshift mutations. Four of the seven isolates tested bound human fH by flow cytometry and survived in IgG-depleted human serum. In all four, fH binding was decreased after inactivating the gene encoding NspA. Binding of fH to fHbp and NspA is specific for human fH. To investigate fH-dependent evasion of host defenses, human fH transgenic infant rats, or control littermates negative for human fH, were challenged IP with 10(3)-10(4)CFU of two of the isolates with no detectable fH binding by flow cytometry. At 6h, bacteremia caused by both strains was higher in human fH transgenic rats than in control rats (P<0.002). In conclusion, six of the seven isolates had evidence of fH binding and/or human fH-dependent complement evasion in transgenic rats. In four, NspA was as an alternative fH ligand. fHbp vaccination may select for mutants that do not require fHbp for complement evasion. Inclusion of additional target antigens in vaccines containing fHbp may delay emergence of these mutants. PMID:23791680

  19. 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

  20. 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

  1. 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…

  2. 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

    Chatterjee, Nilanjana; Bhattacharjee, Baibaswata

    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

  3. 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

  4. [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

  5. Absent otoacoustic emissions predict otitis media in young Aboriginal children: A birth cohort study in Aboriginal and non-Aboriginal children in an arid zone of Western Australia

    PubMed Central

    Lehmann, Deborah; Weeks, Sharon; Jacoby, Peter; Elsbury, Dimity; Finucane, Janine; Stokes, Annette; Monck, Ruth; Coates, Harvey

    2008-01-01

    Background Otitis media (OM) is the most common paediatric illness for which antibiotics are prescribed. In Australian Aboriginal children OM is frequently asymptomatic and starts at a younger age, is more common and more likely to result in hearing loss than in non-Aboriginal children. Absent transient evoked otoacoustic emissions (TEOAEs) may predict subsequent risk of OM. Methods 100 Aboriginal and 180 non-Aboriginal children in a semi-arid zone of Western Australia were followed regularly from birth to age 2 years. Tympanometry was conducted at routine field follow-up from age 3 months. Routine clinical examination by an ENT specialist was to be done 3 times and hearing assessment by an audiologist twice. TEOAEs were measured at ages <1 and 1–2 months. Cox proportional hazards model was used to investigate the association between absent TEOAEs and subsequent risk of OM. Results At routine ENT specialist clinics, OM was detected in 55% of 184 examinations in Aboriginal children and 26% of 392 examinations in non-Aboriginal children; peak prevalence was 72% at age 5–9 months in Aboriginal children and 40% at 10–14 months in non-Aboriginal children. Moderate-severe hearing loss was present in 32% of 47 Aboriginal children and 7% of 120 non-Aboriginal children aged 12 months or more. TEOAE responses were present in 90% (46/51) of Aboriginal children and 99% (120/121) of non-Aboriginal children aged <1 month and in 62% (21/34) and 93% (108/116), respectively, in Aboriginal and non-Aboriginal children at age 1–2 months. Aboriginal children who failed TEOAE at age 1–2 months were 2.6 times more likely to develop OM subsequently than those who passed. Overall prevalence of type B tympanograms at field follow-up was 50% (n = 78) in Aboriginal children and 20% (n = 95) in non-Aboriginal children. Conclusion The burden of middle ear disease is high in all children, but particularly in Aboriginal children, one-third of whom suffer from moderate-severe hearing

  6. Improving motorcycle conspicuity through innovative headlight configurations.

    PubMed

    Ranchet, Maud; Cavallo, Viola; Dang, Nguyen-Thong; Vienne, Fabrice

    2016-09-01

    Most motorcycle crashes involve another vehicle that violated the motorcycle's right-of-way at an intersection. Two kinds of perceptual failures of other road users are often the cause of such accidents: motorcycle-detection failures and motion-perception errors. The aim of this study is to investigate the effect of different headlight configurations on motorcycle detectability when the motorcycle is in visual competition with cars. Three innovative headlight configurations were tested: (1) standard yellow (central yellow headlight), (2) vertical white (one white light on the motorcyclist's helmet and two white lights on the fork in addition to the central white headlight), and (3) vertical yellow (same configuration as (2) with yellow lights instead of white). These three headlight configurations were evaluated in comparison to the standard configuration (central white headlight) in three environments containing visual distractors formed by car lights: (1) daytime running lights (DRLs), (2) low beams, or (3) DRLs and low beams. Video clips of computer-generated traffic situations were displayed briefly (250ms) to 57 drivers. The results revealed a beneficial effect of standard yellow configuration and the vertical yellow configuration on motorcycle detectability. However, this effect was modulated by the car-DRL environment. Findings and practical recommendations are discussed with regard to possible applications for motorcycles. PMID:27280780

  7. The C. elegans eyes absent ortholog EYA-1 is required for tissue differentiation and plays partially redundant roles with PAX-6.

    PubMed

    Furuya, Miwa; Qadota, Hiroshi; Chisholm, Andrew D; Sugimoto, Asako

    2005-10-15

    eyes absent/Eya is a conserved transcriptional coactivator involved in development of various tissues and organs in arthropods and vertebrates. In Drosophila eye development, eya functions as part of the transcriptional regulatory network along with eyeless/Pax6, sine oculis/Six and dachshund/Dach. Here, we present the first functional study of the C. elegans Eya homolog, EYA-1. Loss of EYA-1 function by RNAi and deletion mutations resulted in early larval lethality with incomplete penetrance, associated with defects of differentiation and morphogenesis of several tissues and organs. In late embryogenesis, morphological defect in the head region, pharyngeal malformation and excess cell deaths in the anterior region were observed. Consistently, EYA-1 was expressed in the nuclei of a subset of anterior cells including pharyngeal and body wall muscle cells, starting from the morphogenesis stage in embryogenesis. Interestingly, eya-1 and pax-6/Pax6 mutants showed a strong genetic interaction for larval viability and embryonic anterior morphogenesis. Thus, eya-1 appears to play a partially redundant role with pax-6 during C. elegans embryogenesis. PMID:16154558

  8. Aberrant promoter hypermethylation of PBRM1, BAP1, SETD2, KDM6A and other chromatin-modifying genes is absent or rare in clear cell RCC

    PubMed Central

    Ibragimova, Ilsiya; Maradeo, Marie E.; Dulaimi, Essel; Cairns, Paul

    2013-01-01

    Recent sequencing studies of clear cell (conventional) renal cell carcinoma (ccRCC) have identified inactivating point mutations in the chromatin-modifying genes PBRM1, KDM6A/UTX, KDM5C/JARID1C, SETD2, MLL2 and BAP1. To investigate whether aberrant hypermethylation is a mechanism of inactivation of these tumor suppressor genes in ccRCC, we sequenced the promoter region within a bona fide CpG island of PBRM1, KDM6A, SETD2 and BAP1 in bisulfite-modified DNA of a representative series of 50 primary ccRCC, 4 normal renal parenchyma specimens and 5 RCC cell lines. We also interrogated the promoter methylation status of KDM5C and ARID1A in the Cancer Genome Atlas (TCGA) ccRCC Infinium data set. PBRM1, KDM6A, SETD2 and BAP1 were unmethylated in all tumor and normal specimens. KDM5C and ARID1A were unmethylated in the TCGA 219 ccRCC and 119 adjacent normal specimens. Aberrant promoter hypermethylation of PBRM1, BAP1 and the other chromatin-modifying genes examined here is therefore absent or rare in ccRCC. PMID:23644518

  9. Absent in melanoma 2 (AIM2) expressed in human dental pulp mediates IL-1β secretion in response to cytoplasmic DNA.

    PubMed

    Huang, Shuheng; Song, Zhi; Jiang, Lan; Chen, Lingling; Wang, Runfu; Qin, Wei; Liu, Pengcheng; Lin, Zhengmei

    2015-04-01

    The inflammasome has been determined to play an important role in inflammatory diseases in recent years. Absent in melanoma 2 (AIM2), an inflammasome that recognizes cytoplasmic DNA, has recently been identified as a critical regulator of immune responses. In this study, we explored whether AIM2 was expressed in human dental pulp and defined the role of AIM2 in regulating interleukin (IL)-1β secretion. We demonstrated that AIM2 was only detected in the odontoblast layer of healthy dental pulp, whereas strong expression was observed in inflamed dental pulp. Stimulation with interferon gamma (IFN-γ) and cytoplasmic DNA significantly activated the AIM2 inflammasome and increased IL-1β secretion in human dental pulp cells (HDPCs) in a time- and dose-dependent manner. Moreover, the knockdown of AIM2 downregulated both cleaved-caspase-1 expression and IL-1β release in HDPCs. These results suggest that AIM2 expressed in human dental pulp plays an important role in the immune defense by activating the inflammasome signaling pathway. PMID:24986444

  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. PMID:19156565

  11. 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. PMID:26712608

  12. Absent smooth muscle actin immunoreactivity of the small bowel muscularis propria circular layer in association with chromosome 15q11 deletion in megacystis-microcolon-intestinal hypoperistalsis syndrome.

    PubMed

    Szigeti, Reka; Chumpitazi, Bruno P; Finegold, Milton J; Ranganathan, Sarangarajan; Craigen, William J; Carter, Beth A; Tatevian, Nina

    2010-01-01

    Megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS; OMIM%249210) is a rare and severe form of congenital intestinal and urinary dysfunction and malformation. Histologic studies suggest that the predominant intestinal manifestation is smooth muscle myopathy. Molecular observations have linked the disease to the neuronal nicotinic acetylcholine receptor (ηAChR), namely the absence of a functional α3 subunit of the ηAChR in patients with MMIHS. We describe a case of MMIHS in association with a de novo deletion of the proximal long arm of chromosome 15 (15q11.2). Histologic evaluation revealed an appropriate light microscopic appearance of both the circular and longitudinal layers of the small bowel muscularis propria. Immunohistochemical staining for smooth muscle actin, however, was selectively absent in the circular layer, demonstrating isolated absence in a unique and previously undescribed pattern. These observations raise the possibility that the proximal long arm of chromosome 15 (15q11) may be of clinical significance in MMIHS. PMID:20028211

  13. 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. PMID:26292651

  14. 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

  15. Mutations in SDCCAG8/NPHP10 Cause Bardet-Biedl Syndrome and Are Associated with Penetrant Renal Disease and Absent Polydactyly

    PubMed Central

    Schaefer, E.; Zaloszyc, A.; Lauer, J.; Durand, M.; Stutzmann, F.; Perdomo-Trujillo, Y.; Redin, C.; Bennouna Greene, V.; Toutain, A.; Perrin, L.; Gérard, M.; Caillard, S.; Bei, X.; Lewis, R.A.; Christmann, D.; Letsch, J.; Kribs, M.; Mutter, C.; Muller, J.; Stoetzel, C.; Fischbach, M.; Marion, V.; Katsanis, N.; Dollfus, H.

    2011-01-01

    The ciliopathies are an expanding group of disorders caused by mutations in genes implicated in the biogenesis and function of primary cilia. Bardet-Biedl syndrome (BBS) is a model ciliopathy characterized by progressive retinal degeneration, obesity, polydactyly, cognitive impairment, kidney anomalies and hypogonadism. Mutations in SDCCAG8(NPHP10) were described recently in patients with nephronophthisis and retinal degeneration (Senior-Loken syndrome; SLS). Given the phenotypic and genetic overlap between known ciliopathy genes, we hypothesized that mutations in SDCCAG8 might also contribute alleles to more severe, multisystemic ciliopathies. We performed genetic and phenotypic analyses of 2 independent BBS cohorts. Subsequent to mutation screening, we made a detailed phenotypic analysis of 5 families mutated for SDCCAG8 (3 homozygous and 2 compound heterozygous mutations) and conducted statistical analyses across both cohorts to examine possible phenotype-genotype correlations with mutations at this locus. All patients with mutations in SDCCAG8 fulfilled the diagnostic criteria for BBS (retinal degeneration, obesity, cognitive defects, renal failure, hypogonadism). Interestingly, none of the patients with primary SDCCAG8 mutations had polydactyly, a frequent but not obligatory BBS feature. In contrast, the same patients displayed early-onset renal failure, obesity, as well as recurrent pulmonary and ENT infections. Comparison of the phenotypes of these families with our entire BBS cohort indicated that renal impairment and absent polydactyly correlated significantly with causal SDCCAG8 mutations. Thus, SDCCAG8 mutations are sufficient to cause BBS in 1–2% of our combined cohorts, and define this gene as the sixteenth BBS locus (BBS16). The absence of polydactyly and the concomitant, apparently fully penetrant association with early kidney failure represents the first significant genotype-phenotype correlation in BBS that potentially represents an indicator for

  16. Mutations in SDCCAG8/NPHP10 Cause Bardet-Biedl Syndrome and Are Associated with Penetrant Renal Disease and Absent Polydactyly.

    PubMed

    Schaefer, E; Zaloszyc, A; Lauer, J; Durand, M; Stutzmann, F; Perdomo-Trujillo, Y; Redin, C; Bennouna Greene, V; Toutain, A; Perrin, L; Gérard, M; Caillard, S; Bei, X; Lewis, R A; Christmann, D; Letsch, J; Kribs, M; Mutter, C; Muller, J; Stoetzel, C; Fischbach, M; Marion, V; Katsanis, N; Dollfus, H

    2011-09-01

    The ciliopathies are an expanding group of disorders caused by mutations in genes implicated in the biogenesis and function of primary cilia. Bardet-Biedl syndrome (BBS) is a model ciliopathy characterized by progressive retinal degeneration, obesity, polydactyly, cognitive impairment, kidney anomalies and hypogonadism. Mutations in SDCCAG8(NPHP10) were described recently in patients with nephronophthisis and retinal degeneration (Senior-Loken syndrome; SLS). Given the phenotypic and genetic overlap between known ciliopathy genes, we hypothesized that mutations in SDCCAG8 might also contribute alleles to more severe, multisystemic ciliopathies. We performed genetic and phenotypic analyses of 2 independent BBS cohorts. Subsequent to mutation screening, we made a detailed phenotypic analysis of 5 families mutated for SDCCAG8 (3 homozygous and 2 compound heterozygous mutations) and conducted statistical analyses across both cohorts to examine possible phenotype-genotype correlations with mutations at this locus. All patients with mutations in SDCCAG8 fulfilled the diagnostic criteria for BBS (retinal degeneration, obesity, cognitive defects, renal failure, hypogonadism). Interestingly, none of the patients with primary SDCCAG8 mutations had polydactyly, a frequent but not obligatory BBS feature. In contrast, the same patients displayed early-onset renal failure, obesity, as well as recurrent pulmonary and ENT infections. Comparison of the phenotypes of these families with our entire BBS cohort indicated that renal impairment and absent polydactyly correlated significantly with causal SDCCAG8 mutations. Thus, SDCCAG8 mutations are sufficient to cause BBS in 1-2% of our combined cohorts, and define this gene as the sixteenth BBS locus (BBS16). The absence of polydactyly and the concomitant, apparently fully penetrant association with early kidney failure represents the first significant genotype-phenotype correlation in BBS that potentially represents an indicator for

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

    PubMed

    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

    2015-07-01

    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; r(2) = 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

  18. Epigenetic Silencing of Eyes Absent 4 Gene by Acute Myeloid Leukemia 1-Eight-twenty-one Oncoprotein Contributes to Leukemogenesis in t(8;21) Acute Myeloid Leukemia

    PubMed Central

    Huang, Sai; Jiang, Meng-Meng; Chen, Guo-Feng; Qian, Kun; Gao, Hong-Hao; Guan, Wei; Shi, Jin-Long; Liu, An-Qi; Liu, Jing; Wang, Bian-Hong; Li, Yong-Hui; Yu, Li

    2016-01-01

    Background: The acute myeloid leukemia 1 (AML1)-eight-twenty-one (ETO) fusion protein generated by the t(8;21)(q22;q22) translocation is considered to display a crucial role in leukemogenesis in AML. By focusing on the anti-leukemia effects of eyes absent 4 (EYA4) gene on AML cells, we investigated the biologic and molecular mechanism associated with AML1-ETO expressed in t(8;21) AML. Methods: Qualitative polymerase chain reaction (PCR), quantitative reverse transcription PCR (RT-PCR), and Western blotting analysis were used to observe the mRNA and protein expression levels of EYA4 in cell lines. Different plasmids (including mutant plasmids) of dual luciferase reporter vector were built to study the binding status of AML1-ETO to the promoter region of EYA4. Chromatin immunoprecipitation assay was used to study the epigenetic silencing mechanism of EYA4. Bisulfite sequencing was applied to detect the methylation status in EYA4 promoter region. The influence of EYA4 gene in the cell proliferation, apoptosis, and cell clone-forming ability was detected by the technique of Cell Counting Kit-8, flow cytometry, and clonogenic assay. Results: EYA4 gene was hypermethylated in AML1-ETO+ patients and its expression was down-regulated by 6-fold in Kasumi-1 and SKNO-1 cells, compared to HL-60 and SKNO-1-siA/E cells, respectively. We demonstrated that AML1-ETO triggered the epigenetic silencing of EYA4 gene by binding at AML1-binding sites and recruiting histone deacetylase 1 and DNA methyltransferases. Enhanced EYA4 expression levels inhibited cellular proliferation and suppressed cell colony formation in AML1-ETO+ cell lines. We also found EYA4 transfection increased apoptosis of Kasumi-1 and SKNO-1 cells by 1.6-fold and 1.4-fold compared to negative control, respectively. Conclusions: Our study identified EYA4 gene as targets for AML1-ETO and indicated it as a novel tumor suppressor gene. In addition, we provided evidence that EYA4 gene might be a novel therapeutic target

  19. 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. PMID:15589063

  20. Rod-Like Microglia Are Restricted to Eyes with Laser-Induced Ocular Hypertension but Absent from the Microglial Changes in the Contralateral Untreated Eye

    PubMed Central

    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. PMID:24367610

  1. 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. PMID:24367610

  2. Absent in Melanoma 2 (AIM2) is an important mediator of interferon-dependent and -independent HLA-DRA and HLA-DRB gene expression in colorectal cancers.

    PubMed

    Lee, J; Li, L; Gretz, N; Gebert, J; Dihlmann, S

    2012-03-01

    Absent in Melanoma 2 (AIM2) is a member of the HIN-200 family of hematopoietic, IFN-inducible, nuclear proteins, associated with both, infection defense and tumor pathology. Recently, AIM2 was found to act as a DNA sensor in innate immunity. In addition, we and others have previously demonstrated a high frequency of AIM2-alterations in microsatellite unstable (MSI-H) tumors. To further elucidate AIM2 function in colorectal tumors, we here addressed AIM2-responsive target genes by microarray based gene expression profiling of 22 244 human genes. A total of 111 transcripts were significantly upregulated, whereas 80 transcripts turned out to be significantly downregulated in HCT116 cells, constitutively expressing AIM2, compared with AIM2-negative cells. Among the upregulated genes that were validated by quantitative PCR and western blotting we recognized several interferon-stimulated genes (ISGs: IFIT1, IFIT2, IFIT3, IFI6, IRF7, ISG15, HLA-DRA, HLA-DRB, TLR3 and CIITA), as well as genes involved in intercellular adhesion and matrix remodeling. Expression of ISGs correlated with expression of AIM2 in 10 different IFN-γ treated colorectal cancer cell lines. Moreover, small interfering RNA-mediated knock-down of AIM2 resulted in reduced expression of HLA-DRA, HLA-DRB and CIITA in IFN-γ-treated cells. IFN-γ independent induction of HLA-DR genes and their encoded proteins was also demonstrated upon doxycyclin-regulated transient induction of AIM2. Luciferase reporter assays revealed induction of the HLA-DR promoter upon AIM2 transfection in different cell lines. STAT-signaling was not involved in IFN-γ independent induction of ISGs, arguing against participation of cytokines released in an autostimulating manner. Our data indicate that AIM2 mediates both IFN-γ dependent and independent induction of several ISGs, including genes encoding the major histocompatibility complex (MHC) class II antigens HLA-DR-α and -β. This suggests a novel role of the IFN/AIM2/ISG

  3. A Report to the President of the United States [from the] Intergovernmental Advisory Council on Education, National Networking Conference [on] The Absent Parent (Washington, D.C. May 9-10, 1988).

    ERIC Educational Resources Information Center

    Intergovernmental Advisory Council on Education (ED), Washington, DC.

    This report on child care and the Federal government's role in child care is based on the National Networking Conference on the Absent Parent which was held May 9-10, 1988 under the sponsorship of the President's Intergovernmental Advisory Council on Education (IACE). The report begins with 12 recommendations concerning day care and latchkey…

  4. [Spatial heterogeneity of community structure of Picea crassifolia forest in Qilian Mountains, China].

    PubMed

    Zhao, Wei-jun; Liu, Xian-de; Jing, Wen-mao; Xu, Li-heng; Niu, Yun; Qi, Peng; Zhao, Yong-hong

    2015-09-01

    We selected the grid of 5 m x 5 m in a dynamic monitoring plot (340 m x 300 m) as the sampling unites and chose 5 structural characteristics (density, average crown breadth, coverage, conspicuousness and average height) to study the spatial heterogeneity of community structure of Picea crassifolia forest in Dayekou Basin of Qilian Mountains by the fractal geometry and geostatistics methods. The results showed that the order of spatial variation in these characteristics was: density > average crown breadth > conspicuousness > coverage > average height, with the variation coefficient ranging from 43.7% to 79.6%. Moran's I index indicated that the structural variables had different degrees of spatial autocorrelation, and the order of autocorrelation was density > average height> coverage > average crown breadth > conspicuousness, with the range of -0.047-0.382. The exponential semivariation model well fitted the spatial variability in different structural features, and the range was 24.6-68.1 m. The variables displayed moderate spatial autocorrelation except for coverage, while the other variables had strong spatial autocorrelation, and the fractal dimension of the variables was close to 2, indicating a low spatial dependence among variables. The variables presented a superposing characteristic of zonal and patchy structures except for density and coverage, while the other variables presented strong patchiness property. Density and coverage had a certain spatial dependence on average crown breadth, conspicuousness and average height. Density and coverage for the spatial heterogeneity of community structural of P. crassifolia forests were 10 m and 0.5 hm2, respectively. PMID:26785538

  5. 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. PMID:22900552

  6. Human sterile alpha motif domain 9, a novel gene identified as down-regulated in aggressive fibromatosis, is absent in the mouse

    PubMed Central

    Li, Catherine F; MacDonald, Jeffrey R; Wei, Robert Y; Ray, Jocelyn; Lau, Kimberly; Kandel, Christopher; Koffman, Rachel; Bell, Sherilyn; Scherer, Stephen W; Alman, Benjamin A

    2007-01-01

    Background Neoplasia can be driven by mutations resulting in dysregulation of transcription. In the mesenchymal neoplasm, aggressive fibromatosis, subtractive hybridization identified sterile alpha motif domain 9 (SAMD9) as a substantially down regulated gene in neoplasia. SAMD9 was recently found to be mutated in normophosphatemic familial tumoral calcinosis. In this study, we studied the gene structure and function of SAMD9, and its paralogous gene, SAMD9L, and examined these in a variety of species. Results SAMD9 is located on human chromosome 7q21.2 with a paralogous gene sterile alpha motif domain 9 like (SAMD9L) in the head-to-tail orientation. Although both genes are present in a variety of species, the orthologue for SAMD9 is lost in the mouse lineage due to a unique genomic rearrangement. Both SAMD9 and SAMD9L are ubiquitously expressed in human tissues. SAMD9 is expressed at a lower level in a variety of neoplasms associated with β-catenin stabilization, such as aggressive fibromatosis, breast, and colon cancers. SAMD9 and SAMD9L contain an amino-terminal SAM domain, but the remainder of the predicted protein structure does not exhibit substantial homology to other known protein motifs. The putative protein product of SAMD9 localizes to the cytoplasm. In vitro data shows that SAMD9 negatively regulates cell proliferation. Over expression of SAMD9 in the colon cancer cell line, SW480, reduces the volume of tumors formed when transplanted into immune-deficient mice. Conclusion SAMD9 and SAMD9L are a novel family of genes, which play a role regulating cell proliferation and suppressing the neoplastic phenotype. This is the first report as far as we know about a human gene that exists in rat, but is lost in mouse, due to a mouse specific rearrangement, resulting in the loss of the SAMD9 gene. PMID:17407603

  7. Synthesis and molecular structure of gold triarylcorroles.

    PubMed

    Thomas, Kolle E; Alemayehu, Abraham B; Conradie, Jeanet; Beavers, Christine; Ghosh, Abhik

    2011-12-19

    A number of third-row transition-metal corroles have remained elusive as synthetic targets until now, notably osmium, platinum, and gold corroles. Against this backdrop, we present a simple and general synthesis of β-unsubstituted gold(III) triarylcorroles and the first X-ray crystal structure of such a complex. Comparison with analogous copper and silver corrole structures, supplemented by extensive scalar-relativistic, dispersion-corrected density functional theory calculations, suggests that "inherent saddling" may occur for of all coinage metal corroles. The degree of saddling, however, varies considerably among the three metals, decreasing conspicuously along the series Cu > Ag > Au. The structural differences reflect significant differences in metal-corrole bonding, which are also reflected in the electrochemistry and electronic absorption spectra of the complexes. From Cu to Au, the electronic structure changes from noninnocent metal(II)-corrole(•2-) to relatively innocent metal(III)-corrole(3-). PMID:22111600

  8. Physics of structural colors

    NASA Astrophysics Data System (ADS)

    Kinoshita, S.; Yoshioka, S.; Miyazaki, J.

    2008-07-01

    In recent years, structural colors have attracted great attention in a wide variety of research fields. This is because they are originated from complex interaction between light and sophisticated nanostructures generated in the natural world. In addition, their inherent regular structures are one of the most conspicuous examples of non-equilibrium order formation. Structural colors are deeply connected with recent rapidly growing fields of photonics and have been extensively studied to clarify their peculiar optical phenomena. Their mechanisms are, in principle, of a purely physical origin, which differs considerably from the ordinary coloration mechanisms such as in pigments, dyes and metals, where the colors are produced by virtue of the energy consumption of light. It is generally recognized that structural colors are mainly based on several elementary optical processes including thin-layer interference, diffraction grating, light scattering, photonic crystals and so on. However, in nature, these processes are somehow mixed together to produce complex optical phenomena. In many cases, they are combined with the irregularity of the structure to produce the diffusive nature of the reflected light, while in some cases they are accompanied by large-scale structures to generate the macroscopic effect on the coloration. Further, it is well known that structural colors cooperate with pigmentary colors to enhance or to reduce the brilliancy and to produce special effects. Thus, structure-based optical phenomena in nature appear to be quite multi-functional, the variety of which is far beyond our understanding. In this article, we overview these phenomena appearing particularly in the diversity of the animal world, to shed light on this rapidly developing research field.

  9. 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…

  10. Fluid-absent metamorphism in the Adirondacks

    NASA Astrophysics Data System (ADS)

    Valley, J. W.

    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.

  11. 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.

  12. 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.

  13. Absent minds and absent agents: attention-lapse induced alienation of agency.

    PubMed

    Cheyne, James Allan; Carriere, Jonathan S A; Smilek, Daniel

    2009-06-01

    We report a novel task designed to elicit transient attention-lapse induced alienation (ALIA) of agency experiences in normal participants. When attention-related action slips occur during the task, participants reported substantially decreased self control as well as a high degree of perceived agency attributed to the errant hand. In addition, participants reported being surprised by, and annoyed with, the actions of the errant hand. We argue that ALIA experiences occur because of constraints imposed by the close and precise temporal relations between intention formation and a contrary action employed in this paradigm. We note similarities between ALIA experiences and anarchic hand sign (AHS) and argue that, despite important differences, both ALIA experiences and AHS phenomenology reflect failures of executive control to intervene and cancel contrary affordance-driven habitual motor plans. PMID:19264515

  14. Conspicuous impacts of inconspicuous hosts on the Lyme disease epidemic

    PubMed Central

    Brisson, Dustin; Dykhuizen, Daniel E; Ostfeld, Richard S

    2007-01-01

    Emerging zoonotic pathogens are a constant threat to human health throughout the world. Control strategies to protect public health regularly fail, due in part to the tendency to focus on a single host species assumed to be the primary reservoir for a pathogen. Here, we present evidence that a diverse set of species can play an important role in determining disease risk to humans using Lyme disease as a model. Host-targeted public health strategies to control the Lyme disease epidemic in North America have focused on interrupting Borrelia burgdorferi sensu stricto (ss) transmission between blacklegged ticks and the putative dominant reservoir species, white-footed mice. However, B. burgdorferi ss infects more than a dozen vertebrate species, any of which could transmit the pathogen to feeding ticks and increase the density of infected ticks and Lyme disease risk. Using genetic and ecological data, we demonstrate that mice are neither the primary host for ticks nor the primary reservoir for B. burgdorferi ss, feeding 10% of all ticks and 25% of B. burgdorferi-infected ticks. Inconspicuous shrews feed 35% of all ticks and 55% of infected ticks. Because several important host species influence Lyme disease risk, interventions directed at a multiple host species will be required to control this epidemic. PMID:18029304

  15. 31 CFR 50.12 - Clear and conspicuous disclosure.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... circumstances of the disclosure. See § 50.17 for model forms. (b)(1) Description of premium. An insurer may... offer of coverage, or offers to renew an existing policy on or after December 26, 2007, the disclosure... available coverage for insured losses in a new policy or policy renewal in Program Year 3 for...

  16. 31 CFR 50.12 - Clear and conspicuous disclosure.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... circumstances of the disclosure. See § 50.17 for model forms. (b)(1) Description of premium. An insurer may... offer of coverage, or offers to renew an existing policy on or after December 26, 2007, the disclosure... available coverage for insured losses in a new policy or policy renewal in Program Year 3 for...

  17. 31 CFR 50.12 - Clear and conspicuous disclosure.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... circumstances of the disclosure. See § 50.17 for model forms. (b)(1) Description of premium. An insurer may... offer of coverage, or offers to renew an existing policy on or after December 26, 2007, the disclosure... available coverage for insured losses in a new policy or policy renewal in Program Year 3 for...

  18. 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…

  19. 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…

  20. 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. PMID:20175620

  1. 31 CFR 50.12 - Clear and conspicuous disclosure.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ....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...

  2. 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...

  3. The nervous and the immune systems: conspicuous physiological analogies.

    PubMed

    Sotelo, Julio

    2015-02-01

    From all biological constituents of complex organisms, two are highly sophisticated: the nervous and the immune systems. Interestingly, their goals and processes appear to be distant from each other; however, their physiological mechanisms keep notorious similarities. Both construct intelligence, learn from experience, and keep memory. Their precise responses to innumerable stimuli are delicately modulated, and the exposure of the individual to thousands of potential challenges integrates their functionality; they use a large part of their constituents not in excitatory activities but in the maintenance of inhibitory mechanisms to keep silent vast intrinsic potentialities. The nervous and immune systems are integrated by a basic cell lineage (neurons and lymphocytes, respectively) but each embodies countless cell subgroups with different and specialized deeds which, in contrast with cells from other organs, labyrinthine molecular arrangements conduct to "one cell, one function". Also, nervous and immune actions confer identity that differentiates every individual from countless others in the same species. Both systems regulate and potentiate their responses aided by countless biological resources of variable intensity: hormones, peptides, cytokines, pro-inflammatory molecules, etc. How the immune and the nervous systems buildup memory, learning capability, and exquisite control of excitatory/inhibitory mechanisms constitute major intellectual challenges for contemporary research. PMID:25398574

  4. 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.

  5. Public Investments in Training: Perspectives on Macro-Level Structural Issues and Micro-Level Delivery Systems. EQW Working Papers WP24.

    ERIC Educational Resources Information Center

    Cascio, Wayne F.

    Training issues can be examined from at least two perspectives: the structural level (macro-level) and the micro-level. Structural issues in the delivery of training include the following: absent or uneven corporate commitment, inadequate expenditures by businesses, degrees awarded by schools that do not guarantee skill mastery, poaching of…

  6. Novel structures in secreting the androgenic gland hormone.

    PubMed

    Negishi, S; Hasegawa, Y; Nakajima, Y

    2001-12-01

    The secretory granules in the androgenic gland of the terrestrial isopod Armadillidium vulgare, which have been indistinct for long time because of vulnerable structures, were revealed by using the rapid-freezing and freeze-substitution method. The fine structure of the androgenic gland is conspicuous by the distribution of numerous particular organelles in the cytoplasm consisting of the endoplasmic reticulum and the Golgi complex, and by having a number of highly organized structures developed between the androgenic gland cells. The structures connect to the intercellular space, which is seen as intercellular canaliculi for exporting the androgenic gland hormone. The plasma membranes near the particular structure of the intercellular canaliculi in the androgenic gland are often specialized to form cellular junctions. The secretory granules including the electron-dense materials, which are supposed to be peptides of androgenic gland hormone, are distributed beside the particular structure of the intercellular canaliculi. Some of the granules are seen to fuse with the plasma membranes. This observation suggests that, in the Armadillidium vulgare, the secretory granules containing androgenic gland hormone are transferred to the extracellular space through the intercellular canaliculi particularly developed for exporting the peptide hormone. This is the first evidence to show the secretory mechanism of the androgenic gland hormone in the Isopoda. PMID:11911080

  7. Potent inhibitors of HIV-1 integrase display a two-step, slow-binding inhibition mechanism which is absent in a drug-resistant T66I/M154I mutant.

    PubMed

    Garvey, Edward P; Schwartz, Benjamin; Gartland, Margaret J; Lang, Scott; Halsey, Wendy; Sathe, Ganesh; Carter, H Luke; Weaver, Kurt L

    2009-02-24

    Two-metal binding HIV-1 integrase inhibitors (INIs) are potent inhibitors of HIV-1 in vitro and in patients. We report here for the first time the kinetics of inhibition of integrase-catalyzed strand transfer. First, the IC(50) values for each of six structurally distinct INIs decreased when a preincubation was included: S-1360 (1.3 microM vs 0.12 microM), L-731,988 (130 nM vs 9 nM), L-870,810 (130 nM vs 4 nM), raltegravir (300 nM vs 9 nM), elvitegravir (90 nM vs 6 nM), and GSK364735 (90 nM vs 6 nM). When reactions with these INIs were initiated with integrase, progress curve analyses indicated time-dependent inhibition, which could be fitted to a two-step mechanism of binding. Overall fitted K(i) values matched the IC(50) values measured with a preincubation: S-1360 (0.17 microM), L-731,988 (34 nM), L-870,810 (2.4 nM), raltegravir (10 nM), elvitegravir (4.0 nM), and GSK364735 (2.5 nM). To begin to understand the mechanism for this slow onset of inhibition and its possible impact on drug resistance, studies of resistance mutations were initiated. T66I/M154I exhibited little if any time-dependent inhibition by any of the six INIs, as measured by differences in potency upon preincubation or by progress curve analysis. These data demonstrate that slow binding is a signature of two-metal binding INIs, and that the second slow step is required for full potency. We discuss a possible structural explanation of the second slow step of inhibition and also the relationship between loss of time-dependent inhibition and drug resistance of this important new class of HIV-1 antiretroviral drugs. PMID:19178153

  8. A further polymorphism of the Gd locus for glucose-6-phosphate dehydrogenase present among blacks (Nigerians) and apparently absent among Caucasoids: the quantitative isoelectrophoretic variation of the Gd+ allele.

    PubMed

    Modiano, G; Ciminelli, B M; Malaspina, P; Santolamazza, P; Sedran, L; Meloni, T; Forteleoni, G; Mela, G

    1991-01-01

    A structural but isoelectrophoretic moderate variation of glucose-6-phosphate dehydrogenase (G6PD) activity is common among Nigerians (a black population exposed to a long-lasting intense Plasmodium falciparum malarial endemia). It had never even been searched for among Caucasoids and Mongoloids. In the present work, we attempted to ascertain whether this polymorphism exists among Caucasoids. With this purpose, two Caucasoid male populations were studied: Sardinians and Romans, who respectively did and did not experience an evolutionarily effective exposure to P. falciparum. The approach adopted here consisted in comparing the variations of G6PD activity observed between brothers who certainly received their Gd gene from the same grandparent (hence Gd genes identical by descent) with those between brothers who received it (in the Roman series) or may have received it (in the Sardinian series) from different grandparents. No evidence for common moderate G6PD activity variations segregating with the Gd gene was found either in Romans or Sardinians, who have both been studied with much larger samples and more sensitive approaches than those which detected such type of polymorphism among Nigerians. The upper 95% confidence limit of such zero estimates for the frequency of the isoelectrophoretic quantitative Gd variant alleles were about 0.04 and 0.025 for Romans and Sardinians, respectively. This is the first example of a genetic region (the Gd gene with its flanking sequences) apparently monomorphic in a major race and with several (four) polymorphic sites in another major race. PMID:1797629

  9. [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

  10. Divisions of potential fracture permeability, based on distribution of structures and lineaments, in sedimentary rocks of the Rocky Mountains-High Plains region, Western United States

    USGS Publications Warehouse

    Cooley, Maurice E.

    1986-01-01

    Fractures--joints and faults--affect the movement of fluids in rocks. Fracture permeability is important in sedimentary rocks that otherwise transmit water slowly, particularly limestone, dolomite, and fine-grained sandstone. A map of fracture traces may be used in assessing the spatial distribution of groundwater. The principal map in this report (scale 1:2,500 ,000) shows geologic structures and lineaments that affect the distribution of fracture traces in the sedimentary rocks of the High Plains and some adjacent areas. Potential fracture permeability is indicated on the map by 5 divisions, ranging from division 1 (smallest) to division 5 (largest potential fracture permeability). Geologic structure was the basis for delineating division boundaries. Generally, rocks in structurally uplifted areas and near conspicuous lineaments are more extensively fractured and have greater secondary permeability than rocks of structural basins. (USGS)

  11. When You're Absent: Preparing for the Substitute.

    ERIC Educational Resources Information Center

    Fox, Brian A.

    1988-01-01

    Suggests ways classroom teachers can prepare for absences and help make substitute teaching productive. Recommends forming a list of preferred substitutes at the beginning of the school year; clarifying with students expected behavior; and preparing a permanent substitute packet. (LS)

  12. 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.…

  13. 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 ...

  14. 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…

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

    PubMed

    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 on 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

  16. Bioaerosol exposure to personnel in a clinical environment absent patients.

    PubMed

    Heimbuch, Brian K; Wallace, William H; Balzli, Charles L; Laning, Michelle L; Harnish, Delbert A; Wander, Joseph D

    2016-01-01

    Nosocomial infections pose a significant and escalating threat to both patients and healthcare workers (HCWs). By their nature, hospitals induce antibiotic resistance in virulent and commensal strains, leading to increasingly severe hospital-acquired infections. This study measured environmental exposure experienced by domestic staff cleaning vacated patient rooms of a community hospital to bacteria in ambient bioaerosols. While they cleaned the room, participants wore an N95 filtering facepiece respirator (FFR), from which coupons were cut and bacteria were extracted, cultured and enumerated. Extrapolation to the full area of the respirator yielded measured exposures of 0.2-1.4 × 10(4) colony-forming units/hour, of which ∼97% collected on the front layer of the N95, suggesting a possible role for minimal respiratory protection in nonpatient environments. Random resistance testing of 1.6% of the isolates showed that ∼70% of both Gram-positive and Gram-negative organisms exhibited resistance to oxacillin and ∼9% of the Gram-positives displayed resistance to vancomycin. These data provide an estimate for mask bioaerosol loading that can be used in risk modeling and to refine strategies for reuse of FFRs during critical shortages. PMID:26375496

  17. 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. PMID:24704065

  18. Structure and ultrastructure of leaf and calyx glands in Galphimia brasiliensis (Malpighiaceae).

    PubMed

    Castro, M A; Vega, A S; Múlgura, M E

    2001-11-01

    The present study describes the anatomical structure of calyx and leaf glands in Galphimia brasiliensis and analyzes the mechanism of secretion. The glands are marginal and suprabasal, cup-shaped, sessile, and scarcely visible with the naked eye. Light microscopy reveals the following features: a thin, smooth cuticle; unistratified secretory cells; subglandular parenchyma; and vascular bundle supply composed of phloem and xylem with abundant druses of calcium oxalate. Transmission electron microscopy reveals the presence of secretory cells with conspicuous nuclei, dense cytoplasm, lipid droplets, numerous vesicles, mitochondria, Golgi, rough endoplasmic reticulum (RER), and elongated plastids with osmiophilic contents. The secretion reaches the apoplastic space and accumulates beneath the cuticle. Finally, the viscous, translucent exudate is eliminated by mechanical rupture of the cuticle. Histochemical analysis confirms that lipids are the main constituent. Small amounts of polysaccharides were also identified. PMID:21669626

  19. Discovery of a Novel Accessory Structure of the Pitviper Infrared Receptor Organ (Serpentes: Viperidae)

    PubMed Central

    Bolívar-G, Wilmar; Antoniazzi, Marta M.; Grant, Taran; Jared, Carlos

    2014-01-01

    The facial pits of rattlesnakes, copperheads, lanceheads, bushmasters and other American and Asian pitvipers (Crotalinae) are highly innervated and densely vascularized infrared (IR) receptor organs. For over a century, studies have focused on a small sample of model species from North America and Asia. Based on an expanded survey of Central and South American crotalines, we report a conspicuous accessory structure composed of well-defined papillae that project from the anterior orbital adnexa. The papillae are continuous with the inner chamber of the IR receptor organ and our histological and ultrastructural data suggest that they possess a well-developed nervous network and extensive vascularization; however, they lack the characteristic IR-sensitive terminal nerve masses found in the IR-receptive pit membrane. The function of the IR receptor organ papillae is unknown. PMID:24595025

  20. 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...

  1. 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., Jr.; 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

  2. Some structural determinants of melody recall.

    PubMed

    Boltz, M

    1991-05-01

    Sophisticated musicians were asked to recall, using musical notation, a set of unfamiliar folk tunes that varied in rhythmic structure and referents of tonality. The results showed that memory was facilitated by tonic triad members marking phrase endings, but only when their presence was highlighted by a corresponding pattern of temporal accents. Conversely, recall significantly declined when tonal information was either absent or obscured by rhythmic structure. Error analyses further revealed that the retention of overall pitch contour and information at phrase ending points varied as a function of these manipulations. The results are discussed in terms of a framework that links the acts of perceiving and remembering to a common attentional scheme. PMID:1861610

  3. The structure and nature of the Moho beneath Central Iberia

    NASA Astrophysics Data System (ADS)

    Ehsan, Siddique Akhtar; Carbonell, Ramon; Ayarza, Puy; Martí, David; Poyatos, David Martínez; Pérez-Estaún, Andrés

    2015-11-01

    The Moho is the most conspicuous feature in the ALCUDIA deep normal incidence and wide-angle seismic reflection datasets acquired across the Central Iberia Zone. This discontinuity appears to be sub-horizontal with a slight dip toward the center of the Iberian Peninsula, beneath the Tajo Basin. Densely spaced wide-angle seismic reflection data reveal conspicuous PmP and SmS reflections in the shot records. These reflections, arriving over a 1.5 s time window and characterized by a relatively low frequency content, are used to infer the internal structure and characteristics of this crustal boundary in an effort to place constraints on its nature beneath the studied area. The wide-angle shot records were processed in order to generate low-fold stacks that reveal gradual deepening of Moho PmP phases from 10.2 s TWT (~ 31 km) in the Central Iberian Zone to 11.8 s TWT (~ 36 km) beneath the Tajo Basin. The Moho seismic signature was the main objective of a series of 1-D and 2-D synthetic modeling simulations. Reflectivity modeling was used as the 1-D modeling approach and an elastic finite difference scheme was used for the 2-D modeling. The Moho can be considered to be a self-similar/fractal heterogeneous media with a bimodal velocity distribution, alternating crustal and mantle values, with horizontal correlation lengths that range between 1 and 4 km and vertical correlation lengths that range from 0.2 to 1 km. The depth of this boundary is most probably the result of late to post-variscan re-equilibration processes affecting a previously deformed and laminated lower crust. The mechanisms that took part in this process might have differed to the north and south of the sampled Central Iberian Zone, being more thermally induced to the north, near the Central System. Processes leading to the layered structure of the Moho boundary, either tectonic or magmatic, should be further investigated.

  4. Distribution and dynamics of epibiota on hard structures for coastal protection

    NASA Astrophysics Data System (ADS)

    Bacchiocchi, Francesca; Airoldi, Laura

    2003-04-01

    Hard structures for protection against erosion of shores are some of the most common human-made constructions in coastal areas. Nevertheless, little is known as to how marine organisms respond to their presence. The composition and distribution of intertidal epibiota at different positions around different types of defence structures (groynes and breakwaters) at three stations along the Emilia Romagna coast (Italy) were analysed. Sampling covered a range of scales: meters (distance among replicate plots), hundreds of meters (distance among replicate areas) and tens of kilometres (distance among stations). The colonisation and dynamics of conspicuous species over 1 year, following maintenance works on two structures, were also quantified. Assemblages on defence structures were characterised by a notably low richness of species, by strong spatial dominance of mussels and green ephemeral algae, and by high rates of colonisation. Abundance of mussels, Enteromorpha intestinalis and filamentous algae differed significantly among nearby areas within stations. Mussels were significantly less abundant along the landward side of breakwaters compared with all other positions on both groynes and breakwaters. Overall, however, fewer differences, than expected, were observed in the distribution of species at different positions around groynes and breakwaters, probably as a consequence of the low complexity of the colonising assemblages. Possible factors explaining the patterns of distribution observed are discussed, including the roles of harvesting of mussels and frequent maintenance works on the structures. The implications of the low richness of species observed in terms of management of defence structures and other human-made constructions are discussed.

  5. Design of structurally distinct proteins using strategies inspired by evolution.

    PubMed

    Jacobs, T M; Williams, B; Williams, T; Xu, X; Eletsky, A; Federizon, J F; Szyperski, T; Kuhlman, B

    2016-05-01

    Natural recombination combines pieces of preexisting proteins to create new tertiary structures and functions. We describe a computational protocol, called SEWING, which is inspired by this process and builds new proteins from connected or disconnected pieces of existing structures. Helical proteins designed with SEWING contain structural features absent from other de novo designed proteins and, in some cases, remain folded at more than 100°C. High-resolution structures of the designed proteins CA01 and DA05R1 were solved by x-ray crystallography (2.2 angstrom resolution) and nuclear magnetic resonance, respectively, and there was excellent agreement with the design models. This method provides a new strategy to rapidly create large numbers of diverse and designable protein scaffolds. PMID:27151863

  6. Structure and Development of Glia in Drosophila

    PubMed Central

    Hartenstein, Volker

    2014-01-01

    Insect glia represents a conspicuous and diverse population of cells and plays a role in controlling neuronal progenitor proliferation, axonal growth, neuronal differentiation and maintenance, and neuronal function. Genetic studies in Drosophila have elucidated many aspects of glial structure, function and development. Just as in vertebrates, it appears as if different classes of glial cells are specialized for different functions. Based on topology and cell shape, glial cells of the central nervous system fall into three classes (Fig. 1A–C): (i) surface glia that extend sheath-like processes to wrap around the entire brain; (ii) cortex glia (also called cell body-associated glia) that encapsulate neuronal somata and neuroblasts which form the outer layer (cortex) of the central nervous system; (iii) neuropile glia that are located at the interface between the cortex and the neuropile, the central domain of the nervous system formed by the highly branched neuronal processes and their synaptic contacts. Surface glia is further subdivided into an outer, perineurial layer, and an inner, subperineurial layer. Likewise, neuropile glia comprises a class of cells that remain at the surface of the neuropile (ensheathing glia), and a second class that forms profuse lamellar processes around nerve fibers within the neuropile (astrocyte-like or reticular glia). Glia also surrounds the peripheral nerves and sensory organs; here, one also recognizes perineurial and subperineurial glia, and a third type called “wrapping glia” that most likely corresponds to the ensheathing glia of the central nervous system. Much more experimental work is needed to determine how fundamental these differences between classes of glial cells are, or how and when during development they are specified. To aid in this work the following review will briefly summarize our knowledge of the classes of glial cells encountered in the Drosophila nervous system, and then survey their development from

  7. Structural controllability of unidirectional bipartite networks

    NASA Astrophysics Data System (ADS)

    Nacher, Jose C.; Akutsu, Tatsuya

    2013-04-01

    The interactions between fundamental life molecules, people and social organisations build complex architectures that often result in undesired behaviours. Despite all of the advances made in our understanding of network structures over the past decade, similar progress has not been achieved in the controllability of real-world networks. In particular, an analytical framework to address the controllability of bipartite networks is still absent. Here, we present a dominating set (DS)-based approach to bipartite network controllability that identifies the topologies that are relatively easy to control with the minimum number of driver nodes. Our theoretical calculations, assisted by computer simulations and an evaluation of real-world networks offer a promising framework to control unidirectional bipartite networks. Our analysis should open a new approach to reverting the undesired behaviours in unidirectional bipartite networks at will.

  8. Cell Structure

    MedlinePlus

    ... Cells, Tissues, & Membranes Cell Structure & Function Cell Structure Cell Function Body Tissues Epithelial Tissue Connective Tissue Muscle Tissue ... apparatus , and lysosomes . « Previous (Cell Structure & Function) Next (Cell Function) » Contact Us | Privacy Policy | Accessibility | FOIA | File Formats ...

  9. Detection of Structural Faults by Modal Data, Lower Bounds and Shadow Sites

    NASA Astrophysics Data System (ADS)

    Contursi, T.; Mangialardi, L. M.; Messina, A.

    1998-02-01

    Different algorithms have recently been developed for the diagnosis of many types of civil and mechanical structures using modal data, such as natural frequencies and mode shapes. Although many solutions have been proposed, some important questions seem to be absent in the technical literature. If changes in a structure's modal parameters are able to reflect structural faults, it is important to know what is the smallest detectable physical change in that structure.It is suggested that damage detection by means of modal data can be useful for macro-damage rather than for micro-damage. This resulted from numerical and experimental tests using a simple correlation between measurement noise and sensitivity of modal data, with respect to structural changes in different parts of a system. An automatic sensitivity approach is presented to obtain the lower bound of structural faults for the particular structure under study. The same automatic procedure is able to detect possible shadow sites within the frequency range analyzed.

  10. Coloration and structure of Taiwanese bronze scarab (Anomala expansa)

    NASA Astrophysics Data System (ADS)

    Wu, Min-Nan; Chen, Chien-Yen; Pan, Wei

    2015-12-01

    The structure and optical properties of the elytra of Taiwanese bronze scarabs (Anomala expansa) were investigated. The elytron is composed by a scale-like texture on the surface and a repeated bi-layers underneath. The reflectivity spectrum shows iridescence that the peaks shifts from yellow to green color regions as long as the incident angle (θ) increases. A shoulder peak at 600 nm (θ = 20o) is absent after gently scraping the surface, which indicates that the yellow color is contributed by the scale-like texture. The remaining peak at 550 nm (θ = 20o) in the spectrum resembles the simulated spectrum by assuming the refractive index of n = 1.54 and n = 1 for the adjacent bi-layered structure. This implies that the multi-layered structure contributes to the green coloration as well as the iridescent effect.

  11. 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

  12. Characterization of the structure and DNA complexity of mung bean mitochondrial nucleoids.

    PubMed

    Lo, Yih-Shan; Hsiao, Lin-June; Cheng, Ning; Litvinchuk, Alexandra; Dai, Hwa

    2011-03-01

    Electron microscopic images of mitochondrial nucleoids isolated from mung bean seedlings revealed a relatively homogeneous population of particles, each consisting of a chromatin-like structure associated with a membrane component. Association of F-actin with mitochondrial nucleoids was also observed. The mitochondrial nucleoid structure identified in situ showed heterogeneous genomic organization. After pulsed-field gel electrophoresis (PFGE), a large proportion of the mitochondrial nucleoid DNA remained in the well, whereas the rest migrated as a 50-200 kb smear zone. This PFGE migration pattern was not affected by high salt, topoisomerase I or latrunculin B treatments; however, the mobility of a fraction of the fast-moving DNA decreased conspicuously following an in-gel ethidium-enhanced UV-irradiation treatment, suggesting that molecules with intricately compact structures were present in the 50-200 kb region. Approximately 70% of the mitochondrial nucleoid DNA molecules examined via electron microscopy were open circles, supercoils, complex forms, and linear molecules with interspersed sigma-shaped structures and/or loops. Increased sensitivity of mtDNA to DNase I was found after mitochondrial nucleoids were pretreated with high salt. This result indicates that some loosely bound or peripheral DNA binding proteins protected the mtDNA from DNase I degradation. PMID:21347700

  13. Transient structures of the human fetal brain: subplate, thalamic reticular complex, ganglionic eminence.

    PubMed

    Ulfig, N; Neudörfer, F; Bohl, J

    2000-07-01

    Morphological features of the subplate, the thalamic reticular complex and the ganglionic eminence, which represent three major transient structures of the human fetal forebrain, are summarized with special reference to their functional roles. The subplate harboring various neuronal types is an outstandingly wide zone subjacent to the cortical plate in the human fetal brain. Within the subplate various cortical afferents establish synaptic contacts for a prolonged period before entering the cortical plate. Therefore, the subplate is regarded as a "waiting compartment" which is required for the formation of mature cortical connections. Next to the thalamic reticular nucleus, within the fibers of internal capsule, the perireticular nucleus is located which has been established as a distinct entity during development. Its various neuronal types express a number of different neuroactive substances. Perinatally, the perireticular nucleus is drastically reduced in size. It is involved in the guidance of corticofugal and thalamocortical fibers. The ganglionic eminence is a conspicuous proliferative area that persists throughout nearly the entire fetal period. In the human fetal brain it extends medially upon the dorsal thalamic nuclei which receive precursor cells from the ganglionic eminence. Postmitotic cells in the marginal zone of the ganglionic eminence serve as an intermediate target for growing axons. On the whole, all three structures establish transient neural circuitries that may be essential for the formation of adult projections. The characteristics of the three transient structures are particularly relevant for developmental neuropathology as these structures may be damaged in disorders that preferentially occur in preterm infants. PMID:10963122

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

    PubMed

    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

  15. Structure of a Complete Mediator-RNA Polymerase II Pre-Initiation Complex.

    PubMed

    Robinson, Philip J; Trnka, Michael J; Bushnell, David A; Davis, Ralph E; Mattei, Pierre-Jean; Burlingame, Alma L; Kornberg, Roger D

    2016-09-01

    A complete, 52-protein, 2.5 million dalton, Mediator-RNA polymerase II pre-initiation complex (Med-PIC) was assembled and analyzed by cryo-electron microscopy and by chemical cross-linking and mass spectrometry. The resulting complete Med-PIC structure reveals two components of functional significance, absent from previous structures, a protein kinase complex and the Mediator-activator interaction region. It thereby shows how the kinase and its target, the C-terminal domain of the polymerase, control Med-PIC interaction and transcription. PMID:27610567

  16. Information Structure and Linguistic Structure.

    ERIC Educational Resources Information Center

    Zierer, Ernesto

    1972-01-01

    This document describes a format for analyzing the information content of sentences and the language patterns that accompany particular information content. The author writes in terms of information structures, each information structure having a corresponding linguistic structure composed of distinctive features. The information structure of a…

  17. Evolution of sensory structures in basal metazoa.

    PubMed

    Jacobs, Dave K; Nakanishi, Nagayasu; Yuan, David; Camara, Anthony; Nichols, Scott A; Hartenstein, Volker

    2007-11-01

    Cnidaria have traditionally been viewed as the most basal animals with complex, organ-like multicellular structures dedicated to sensory perception. However, sponges also have a surprising range of the genes required for sensory and neural functions in Bilateria. Here, we: (1) discuss "sense organ" regulatory genes, including; sine oculis, Brain 3, and eyes absent, that are expressed in cnidarian sense organs; (2) assess the sensory features of the planula, polyp, and medusa life-history stages of Cnidaria; and (3) discuss physiological and molecular data that suggest sensory and "neural" processes in sponges. We then develop arguments explaining the shared aspects of developmental regulation across sense organs and between sense organs and other structures. We focus on explanations involving divergent evolution from a common ancestral condition. In Bilateria, distinct sense-organ types share components of developmental-gene regulation. These regulators are also present in basal metazoans, suggesting evolution of multiple bilaterian organs from fewer antecedent sensory structures in a metazoan ancestor. More broadly, we hypothesize that developmental genetic similarities between sense organs and appendages may reflect descent from closely associated structures, or a composite organ, in the common ancestor of Cnidaria and Bilateria, and we argue that such similarities between bilaterian sense organs and kidneys may derive from a multifunctional aggregations of choanocyte-like cells in a metazoan ancestor. We hope these speculative arguments presented here will stimulate further discussion of these and related questions. PMID:21669752

  18. Classifying structures

    SciTech Connect

    Buslov, V.M.; Krahl, N.W.

    1985-01-01

    61 concepts are categorized and divided by structure type into bottom-mounted, floating, and island structures. They are either permanent systems or moving systems. They are further subdivided and listed in this paper. The structural designs are all distinguished by the consideration of sea ice. Bottom-mounted structures have been built in water depths from 30 to about 500 feet. To date, only a few steel or concrete structures have been built, but a number are being planned. A list of concrete structures now in operation is provided.

  19. Distribution patterns of vimentin-immunoreactive structures in the human prosencephalon during the second half of gestation.

    PubMed

    Ulfig, N; Neudörfer, F; Bohl, J

    1999-07-01

    Neuronal migration is guided by long radially oriented glial fibres. During late stages of development radial glial cells are transformed into astrocytes. A predominant intermediate filament protein within radial glial cells and immature astrocytes is vimentin. In this study fetal brain sections were used to demonstrate the transient features of vimentin-positive radial glia. In the lower half of the cerebral wall of the 6th gestational month bundles, curvature, and crossing of vimentin-positive fibres are regularly seen. Moreover, fibres terminating on vessels are observed. In the upper half fibres are radially oriented; when ascending towards the pial surface the number and diameter of fibres appears conspicuously decreased. Radially aligned fibres display numerous varicosities. In the 8th month the bulk of vimentin-positive fibres is encountered next to the ganglionic eminence and below isocortical cerebral fissures. The dentate gyrus is conspicuous due to its high amount of immunolabelled fibres. Furthermore, densely packed fibres are visible within the internal and external capsule and in the vicinity of the anterior commissure. Radial glial somata are found in the proliferative areas as well as in the adjacent white matter. In the latter location bipolar, monopolar and stellate vimentin-positive cells are present. The results demonstrate an area-specific distribution pattern of vimentin-positive structures which can be correlated with migrational events. Areas maturing late in development for instance, reveal dense immunolabelling in the 8th month. The orientation and position of radial fibres point to an additional developmental role of these fibres, i.e. their involvement in the guidance of growing axons. Moreover, the arrangement and morphology of vimentin-positive fibres, such as retraction of fibres or occurrence of varicosities, are indicative of degenerative events. Accordingly, a transformation of radial glial somata, their displacement towards the

  20. Distribution patterns of vimentin-immunoreactive structures in the human prosencephalon during the second half of gestation

    PubMed Central

    ULFIG, NORBERT; NEUDÖRFER, FRANK; BOHL, JÜRGEN

    1999-01-01

    Neuronal migration is guided by long radially oriented glial fibres. During late stages of development radial glial cells are transformed into astrocytes. A predominant intermediate filament protein within radial glial cells and immature astrocytes is vimentin. In this study fetal brain sections were used to demonstrate the transient features of vimentin-positive radial glia. In the lower half of the cerebral wall of the 6th gestational month bundles, curvature, and crossing of vimentin-positive fibres are regularly seen. Moreover, fibres terminating on vessels are observed. In the upper half fibres are radially oriented; when ascending towards the pial surface the number and diameter of fibres appears conspicuously decreased. Radially aligned fibres display numerous varicosities. In the 8th month the bulk of vimentin-positive fibres is encountered next to the ganglionic eminence and below isocortical cerebral fissures. The dentate gyrus is conspicuous due to its high amount of immunolabelled fibres. Furthermore, densely packed fibres are visible within the internal and external capsule and in the vicinity of the anterior commissure. Radial glial somata are found in the proliferative areas as well as in the adjacent white matter. In the latter location bipolar, monopolar and stellate vimentin-positive cells are present. The results demonstrate an area-specific distribution pattern of vimentin-positive structures which can be correlated with migrational events. Areas maturing late in development for instance, reveal dense immunolabelling in the 8th month. The orientation and position of radial fibres point to an additional developmental role of these fibres, i.e. their involvement in the guidance of growing axons. Moreover, the arrangement and morphology of vimentin-positive fibres, such as retraction of fibres or occurrence of varicosities, are indicative of degenerative events. Accordingly, a transformation of radial glial somata, their displacement towards the

  1. 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…

  2. 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

  3. 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.

  4. Crystal structure of type I 3-dehydroquinate dehydratase of Aquifex aeolicus suggests closing of active site flap is not essential for enzyme action.

    PubMed

    Devi, Aribam Swarmistha; Ebihara, Akio; Kuramitsu, Seiki; Yokoyama, Shigeyuki; Kumarevel, Thirumananseri; Ponnuraj, Karthe

    2013-03-01

    Structural analyses of enzymes involved in biosynthetic pathways that are present in micro-organisms, but absent from mammals (for example Shikimate pathway) are important in developing anti-microbial drugs. Crystal structure of the Shikimate pathway enzyme, type I 3-dehydroquinate dehydratase (3-DHQase) from the hyperthermophilic bacterium Aquifex aeolicus was solved both as an apo form and in complex with a ligand. The complex structure revealed an interesting structural difference when compared to other ligand-bound type I 3-DHQases suggesting that closure of the active site loop is not essential for catalysis. This provides new insights into the catalytic mechanism of type I 3-DHQases. PMID:23396056

  5. 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.

  6. 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.

  7. 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

  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. PMID:26509750

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

    PubMed

    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

  10. 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.

  11. [The endocrine status of clinically conspicuous mares during the peripartum period].

    PubMed

    Meinecke, B; Gips, H

    1990-10-01

    The aim of the present investigations was to characterize the endocrine changes in the peripheral plasma during the periparturient phase of mares with a known history of obstetrical disorders. Blood plasma samples from 9 mares (8 mares during parturition, 1 mare during abortion) were collected and the following steroid hormones were radioimmunologically determined: progesterone (P4), dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEA-S), estrone (E1), estrone sulfate (E1-S), estradiol-17 beta (E2), estriol (E3), cortisol and transcortin. In general, with the exception of cortisol, DHEA and transcortin, all steroid hormone levels declined significantly after parturition. Mean plasma concentrations of DHEA-S, the direct fetal precursor of estrone, were 6 times higher than DHEA. However, DHEA-S levels varied considerably between all mares as well as between daily values of the same mare. Levels of E1-S were found to be about thousand times higher than those of E1, E2, and E3. The rather low concentrations of E3 suggest that this hormone is mainly produced by peripheral conversion and that in the horse fetus the 16 alpha-hydroxylation of DHEA-S is lacking. Despite the fact that most of the examined mares showed signs of severe disease none of the investigated steroid hormones indicated any disturbances of gestation. It is concluded that, from the clinical point of view, serial determinations of E1-S plasma levels are the best way to prove the fetal well-being. However, it should be stressed, that even the E1-S values are no indicators for the onset of parturition or abortion. PMID:2264056

  12. 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,…

  13. Conspicuous Female Ornamentation and Tests of Male Mate Preference in Threespine Sticklebacks (Gasterosteus aculeatus)

    PubMed Central

    Wright, Daniel Shane; Pierotti, Michele E. R.; Rundle, Howard D.; McKinnon, Jeffrey S.

    2015-01-01

    Sexual selection drives the evolution of exaggerated male ornaments in many animal species. Female ornamentation is now acknowledged also to be common but is generally less well understood. One example is the recently documented red female throat coloration in some threespine stickleback (Gasterosteus aculeatus) populations. Although female sticklebacks often exhibit a preference for red male throat coloration, the possibility of sexual selection on female coloration has been little studied. Using sequential and simultaneous mate choice trials, we examined male mate preferences for female throat color, as well as pelvic spine color and standard length, using wild-captured threespine sticklebacks from the Little Campbell River, British Columbia. In a multivariate analysis, we found no evidence for a population-level mate preference in males, suggesting the absence of directional sexual selection on these traits arising from male mate choice. Significant variation was detected among males in their preference functions, but this appeared to arise from differences in their mean responsiveness across mating trials and not from variation in the strength (i.e., slope) of their preference, suggesting the absence of individual-level preferences as well. When presented with conspecific intruder males, male response decreased as intruder red throat coloration increased, suggesting that males can discriminate color and other aspects of phenotype in our experiment and that males may use these traits in intrasexual interactions. The results presented here are the first to explicitly address male preference for female throat color in threespine sticklebacks. PMID:25806520

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

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... beam that depicts a circle or a horizontal figure “8” to the front, about the longitudinal centerline... location on the front of the locomotive, that flash alternately with beams within five degrees horizontally... at least 200,000 candela in a moving beam that depicts a circle or a horizontal figure “8” to...

  16. At the Crossroads of Conspicuous and Concealable: What Race Categories Communicate about Sexual Orientation

    PubMed Central

    Johnson, Kerri L.; Ghavami, Negin

    2011-01-01

    We found that judgments of a perceptually ambiguous social category, sexual orientation, varied as a function of a perceptually obvious social category, race. Sexual orientation judgments tend to exploit a heuristic of gender inversion that often promotes accuracy. We predicted that an orthogonal social category that is itself gendered, race, would impact both sexual orientation categorizations and their accuracy. Importantly, overlaps in both the phenotypes and stereotypes associated with specific race and sex categories (e.g., the categories Black and Men and the categories Asian and Women) lead race categories to be decidedly gendered. Therefore, we reasoned that race categories would bias judgments of sexual orientation and their accuracy because of the inherent gendered nature. Indeed, both gay and straight perceivers in the United States were more likely to judge targets to be gay when target race was associated with gender-atypical stereotypes or phenotypes (e.g., Asian Men). Perceivers were also most accurate when judging the sexual orientation of the most strongly gender-stereotyped groups (i.e., Asian Women and Black Men), but least accurate when judging the sexual orientation of counter-stereotypical groups (i.e., Asian men and Black Women). Signal detection analyses confirmed that this pattern of accuracy was achieved because of heightened sensitivity to cues in groups who more naturally conform to gendered stereotypes (Asian Women and Black Men). Implications for social perception are discussed. PMID:21483863

  17. Conspicuous female ornamentation and tests of male mate preference in threespine sticklebacks (Gasterosteus aculeatus).

    PubMed

    Wright, Daniel Shane; Pierotti, Michele E R; Rundle, Howard D; McKinnon, Jeffrey S

    2015-01-01

    Sexual selection drives the evolution of exaggerated male ornaments in many animal species. Female ornamentation is now acknowledged also to be common but is generally less well understood. One example is the recently documented red female throat coloration in some threespine stickleback (Gasterosteus aculeatus) populations. Although female sticklebacks often exhibit a preference for red male throat coloration, the possibility of sexual selection on female coloration has been little studied. Using sequential and simultaneous mate choice trials, we examined male mate preferences for female throat color, as well as pelvic spine color and standard length, using wild-captured threespine sticklebacks from the Little Campbell River, British Columbia. In a multivariate analysis, we found no evidence for a population-level mate preference in males, suggesting the absence of directional sexual selection on these traits arising from male mate choice. Significant variation was detected among males in their preference functions, but this appeared to arise from differences in their mean responsiveness across mating trials and not from variation in the strength (i.e., slope) of their preference, suggesting the absence of individual-level preferences as well. When presented with conspecific intruder males, male response decreased as intruder red throat coloration increased, suggesting that males can discriminate color and other aspects of phenotype in our experiment and that males may use these traits in intrasexual interactions. The results presented here are the first to explicitly address male preference for female throat color in threespine sticklebacks. PMID:25806520

  18. 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. PMID:24374449

  19. 16 CFR 1500.121 - Labeling requirements; prominence, placement, and conspicuousness.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... sections 2(p)(1) of the FHSA (repeated in 16 CFR 1500.3(b)(14)(i) or by the regulations which require..., 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...

  20. 16 CFR 1500.121 - Labeling requirements; prominence, placement, and conspicuousness.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... sections 2(p)(1) of the FHSA (repeated in 16 CFR 1500.3(b)(14)(i) or by the regulations which require..., 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...

  1. 16 CFR 1500.121 - Labeling requirements; prominence, placement, and conspicuousness.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... sections 2(p)(1) of the FHSA (repeated in 16 CFR 1500.3(b)(14)(i) or by the regulations which require..., 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...

  2. 49 CFR 229.133 - Interim locomotive conspicuity measures-auxiliary external lights.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... apart, and at least 36 inches above the top of the rail. (2) Oscillating light. (i) An oscillating light shall consist of: (A) One steadily burning white light producing at least 200,000 candela in a moving... to either side of the longitudinal centerline of the locomotive. (ii) An oscillating light...

  3. 49 CFR 229.133 - Interim locomotive conspicuity measures-auxiliary external lights.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... light shall produce at least 200,000 candela, either steadily burning or alternately flashing. (v) The... the locomotive. (4) Oscillating light. (i) An oscillating light shall consist of: (A) One steadily burning white light producing at least 200,000 candela in a moving beam that depicts a circle or...

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

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... apart, and at least 36 inches above the top of the rail. (2) Oscillating light. (i) An oscillating light shall consist of: (A) One steadily burning white light producing at least 200,000 candela in a moving... to either side of the longitudinal centerline of the locomotive. (ii) An oscillating light...

  5. 16 CFR 1500.121 - Labeling requirements; prominence, placement, and conspicuousness.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... sections 2(p)(1) of the FHSA (repeated in 16 CFR 1500.3(b)(14)(i) or by the regulations which require..., layout, or color with other printed matter on the label. This regulation contains the Commission's... required under the Fair Packaging and Labeling Act, 15 U.S.C. 1453(a) (2) and (3), by a border line or by...

  6. Defining the structural relationship between kainate receptor deactivation and desensitization

    PubMed Central

    Dawe, G. Brent; Musgaard, Maria; Andrews, Elizabeth D.; Daniels, Bryan A.; Aurousseau, Mark R.P.; Biggin, Philip C.; Bowie, Derek

    2016-01-01

    Desensitization is an important mechanism that curtails the activity of ligand-gated ion-channels (LGICs). Although the structural basis of desensitization is not fully resolved, it is thought to be governed by the physicochemical properties of the bound ligand. Here, we show the importance of an allosteric cation binding pocket in controlling transitions between activated and desensitized states of rat kainate-type (KAR) ionotropic glutamate receptors (iGluRs). Tethering a positive charge to this pocket sustains KAR activation, preventing desensitization, whereas mutations that disrupt cation binding eliminate channel gating. These different outcomes explain the structural distinction between deactivation and desensitization. Deactivation occurs when the ligand unbinds before the cation, whereas desensitization proceeds if a ligand is bound without cation pocket occupancy. This sequence of events is absent from AMPA-type iGluRs, identifying cations as gatekeepers of KAR gating, a role unique among even closely-related LGICs. PMID:23955023

  7. Coilgun structures

    NASA Astrophysics Data System (ADS)

    Andrews, J. A.

    1993-01-01

    Recent research into the optimal design of 'coilgun' structures has indicated that structural requirements are strong functions of launcher classification as well as acceleration mode. Attention is presently given to both closed-form and numerical analytical techniques for coaxial DC accelerator (DCA) structural-design calculations. The DCA is a multistage pulsed-induction launcher that makes extensive use of composite materials technology; measured plastic deformations of the armature after a high energy experiment are compared to FEM analysis predictions.

  8. Aeropropulsion structures

    NASA Technical Reports Server (NTRS)

    Nichols, Lester D.

    1987-01-01

    The structural engineer is faced with unique problems when dealing with aeropropulsion systems. He is faced with extremes in operating temperatures, rotational effects, and behaviors of advanced material systems which combine into complexities that require advances in many scientific disciplines involved in structural analysis and design procedures. This presentation provides an overview of the complexities of aeropropulsion structures and the theoretical, computational, and experimental research conducted to achieve the needed advances.

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

    USGS Publications Warehouse

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

    2016-01-01

    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

  10. Structural crashworthiness

    SciTech Connect

    Jones, N.; Wierzbicki, T.

    1983-01-01

    Behind the quest for safety in all forms of transport lies a complex technology of which structural crashworthiness forms an important part. This volume contains the work of over twenty experts whose interests range from the fundamental principles of structural collapse to the application of those principles to the design of ships, aircraft, road vehicles, and rail vehicles. The text focuses on the application of analytical and experimental techniques to predict energy dissipation characteristics of thin-walled structures and structural members under quasi-static and dynamic loadings.

  11. 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. PMID:25822466

  12. Multiple structure alignment with msTALI

    PubMed Central

    2012-01-01

    Background Multiple structure alignments have received increasing attention in recent years as an alternative to multiple sequence alignments. Although multiple structure alignment algorithms can potentially be applied to a number of problems, they have primarily been used for protein core identification. A method that is capable of solving a variety of problems using structure comparison is still absent. Here we introduce a program msTALI for aligning multiple protein structures. Our algorithm uses several informative features to guide its alignments: torsion angles, backbone Cα atom positions, secondary structure, residue type, surface accessibility, and properties of nearby atoms. The algorithm allows the user to weight the types of information used to generate the alignment, which expands its utility to a wide variety of problems. Results msTALI exhibits competitive results on 824 families from the Homstrad and SABmark databases when compared to Matt and Mustang. We also demonstrate success at building a database of protein cores using 341 randomly selected CATH domains and highlight the contribution of msTALI compared to the CATH classifications. Finally, we present an example applying msTALI to the problem of detecting hinges in a protein undergoing rigid-body motion. Conclusions msTALI is an effective algorithm for multiple structure alignment. In addition to its performance on standard comparison databases, it utilizes clear, informative features, allowing further customization for domain-specific applications. The C++ source code for msTALI is available for Linux on the web at http://ifestos.cse.sc.edu/mstali. PMID:22607234

  13. 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.

  14. 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.

  15. 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…

  16. 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…

  17. Fine Structure and Molecular Phylogeny of Parametopidium circumlabens (Ciliophora: Armophorea), Endocommensal of Sea Urchins.

    PubMed

    da Silva-Neto, Inácio Domingos; da Silva Paiva, Thiago; do Nascimento Borges, Bárbara; Harada, Maria Lúcia

    2016-01-01

    Metopid armophoreans are ciliates commonly found in anaerobic environments worldwide; however, very little is known of their fine structure. In this study, the metopid Parametopidium circumlabens (Biggar and Wenrich 1932) Aescht, 1980, a common endocommensal of sea urchins, is investigated for the first time with emphasis on transmission electron microscopy, revealing several previously unknown elements of its morphology. Somatic dikinetids of P. circumlabens have a typical ribbon of transverse microtubules, an isolated microtubule near triplets 4 and 5 of the anterior kinetosome, plus two other microtubules between anterior and posterior kinetosomes, a short kinetodesmal striated fiber and long postciliary microtubules. In the dikinetids of the perizonal stripe, the kinetodesmal fiber is very pronounced, and there is a conspicuous microfibrillar network system associated with the kinetosomes. A new structure, shaped as a dense, roughly cylindrical mass surrounded by microtubules, is found associated with the posterior kinetosome of perizonal dikinetids. The paroral membrane is diplostichomonad and the adoral membranelles are of the "paramembranelle" type. Bayesian inference and maximum-likelihood analysis of the 18S-rDNA gene unambiguously placed P. circumlabens as sister group of the cluster formed by ((Atopospira galeata, Atopospira violacea) Metopus laminarius) + Clevelandellida, corroborating its classification within the Metopida. PMID:26111546

  18. Structural and physical properties of Ni-Tb-Fe-O system

    SciTech Connect

    Khan, M. Azhar Islam, M.U.; Ishaque, M.; Rahman, I.Z.; Genson, A.; Hampshire, S.

    2009-01-15

    A series of soft ferrites in the system Ni{sub 1-x}Tb{sub x}Fe{sub 2}O{sub 4} (0 {<=} x {<=} 0.2), was prepared by a standard ceramic technique. The influence of terbium content was investigated by means of X-ray diffraction, Fourier Transform Infrared (FTIR) spectroscopy and scanning electron microscopy. The X-ray diffraction analysis reveals that the samples have a cubic spinel (single phase) structure for 0 {<=} x {<=} 0.08; for x > 0.08 a small peak of orthorhombic phase (TbFeO{sub 3}) appears and becomes more conspicuous with increased terbium substitution. The lattice parameter changes in a non-linear way as a function of terbium content which may be attributed to differences in the ionic radii of the cations involved and the solubility limit of terbium ions. A gradual increase in the bulk density was observed with the increase of terbium concentration, from 5.13 g/cm{sup 3} to 5.69 g/cm{sup 3}. FTIR absorption spectra of the Ni-Tb-Fe-O system were investigated in the wave number range 370-1500 cm{sup -1}. Each spectrum exhibited two main absorption bands, thereby confirming the spinel structure.

  19. On the evolution of harming and recognition in finite panmictic and infinite structured populations.

    PubMed

    Lehmann, Laurent; Feldman, Marcus W; Rousset, François

    2009-11-01

    Natural selection may favor two very different types of social behaviors that have costs in vital rates (fecundity and/or survival) to the actor: helping behaviors, which increase the vital rates of recipients, and harming behaviors, which reduce the vital rates of recipients. Although social evolutionary theory has mainly dealt with helping behaviors, competition for limited resources creates ecological conditions in which an actor may benefit from expressing behaviors that reduce the vital rates of neighbors. This may occur if the reduction in vital rates decreases the intensity of competition experienced by the actor or that experienced by its offspring. Here, we explore the joint evolution of neutral recognition markers and marker-based costly conditional harming whereby actors express harming, conditional on actor and recipient bearing different conspicuous markers. We do so for two complementary demographic scenarios: finite panmictic and infinite structured populations. We find that marker-based conditional harming can evolve under a large range of recombination rates and group sizes under both finite panmictic and infinite structured populations. A direct comparison with results for the evolution of marker-based conditional helping reveals that, if everything else is equal, marker-based conditional harming is often more likely to evolve than marker-based conditional helping. PMID:19624725

  20. High-order spoof localized surface plasmons supported on a complementary metallic spiral structure

    NASA Astrophysics Data System (ADS)

    Gao, Zhen; Gao, Fei; Zhang, Baile

    2016-04-01

    We experimentally demonstrate that multiple high-order spoof localized surface plasmons (spoof-LSPs) modes can be supported on a complementary metallic spiral structure, which were absent in the previously reported spoof-LSPs modes. Through exact numerical simulations and near-field imaging experiments, we directly observe these high-order spoof-LSPs modes at microwave frequencies. We also show that these higher-order spoof-LSPs modes exhibit larger frequency shifts caused by the local environmental refractive index change than the previously reported low-order spoof-LSPs modes. Hence the complementary MSS may find potential applications as plasmonic sensor in the microwave and terahertz frequencies.

  1. Structured light in structured media

    NASA Astrophysics Data System (ADS)

    Zeng, Jinwei

    The objective of this dissertation is to investigate fundamental optical phenomena at the interface between two emerging fields of modern optics - structured light and micro/nano-structured optical materials. Until recently, these fields were developing in parallel yet independently. A majority of researchers in the field of metamaterials and photonic crystals considered "simple" linearly or circularly polarized light or Gaussian beam propagation in "structured" materials with properties not found in nature. However, in addition to conventional polarization states, light beams can be radially or azimuthally polarized and carry orbital angular momentum (OAM). A fascinating example of a beam carrying OAM is the optical vortex---a donut-shaped beam with a helical phase front. Similarly, the structured light community largely focused on complex light propagation in rather simple homogeneous, isotropic, transparent media. In this dissertation, we explore fundamentals and applications of light-matter interactions that involve both complex light and complex media. The central question that we aim to tackle is: How may the synergy of these two fields lead to a breakthrough in modern photonics? Structured materials, including metamaterials and photonic bandgap structures, realize unprecedented control over light propagation and design flexibility. They can enable new optical properties and functionalities, including new regimes of wave guiding, negative index of refraction, magnetism at optical frequencies, and subwavelength imaging to name a few. We demonstrate how nearly unlimited possibilities in engineering the properties of structured media can be used for generation and manipulation of structured light. Also, we show how the unique properties of structured light could be used for characterization of structured media.

  2. Coagulation factor XII protease domain crystal structure

    PubMed Central

    Pathak, M; Wilmann, P; Awford, J; Li, C; Hamad, BK; Fischer, PM; Dreveny, I; Dekker, LV; Emsley, J

    2015-01-01

    Background Coagulation factor XII is a serine protease that is important for kinin generation and blood coagulation, cleaving the substrates plasma kallikrein and FXI. Objective To investigate FXII zymogen activation and substrate recognition by determining the crystal structure of the FXII protease domain. Methods and results A series of recombinant FXII protease constructs were characterized by measurement of cleavage of chromogenic peptide and plasma kallikrein protein substrates. This revealed that the FXII protease construct spanning the light chain has unexpectedly weak proteolytic activity compared to β-FXIIa, which has an additional nine amino acid remnant of the heavy chain present. Consistent with these data, the crystal structure of the light chain protease reveals a zymogen conformation for active site residues Gly193 and Ser195, where the oxyanion hole is absent. The Asp194 side chain salt bridge to Arg73 constitutes an atypical conformation of the 70-loop. In one crystal form, the S1 pocket loops are partially flexible, which is typical of a zymogen. In a second crystal form of the deglycosylated light chain, the S1 pocket loops are ordered, and a short α-helix in the 180-loop of the structure results in an enlarged and distorted S1 pocket with a buried conformation of Asp189, which is critical for P1 Arg substrate recognition. The FXII structures define patches of negative charge surrounding the active site cleft that may be critical for interactions with inhibitors and substrates. Conclusions These data provide the first structural basis for understanding FXII substrate recognition and zymogen activation. PMID:25604127

  3. Deep Crustal Structure beneath Large Igneous Provinces and the Petrologic Evolution of Flood Basalts

    NASA Astrophysics Data System (ADS)

    Richards, M. A.; Ridley, V. A.

    2010-12-01

    We present a review of seismological constraints on deep crustal structures underlying large igneous provinces (LIPs), largely from wide-angle seismic refraction surveys. The main purpose of this review is to ascertain whether this seismic evidence is consistent with, or contrary to, petrological models for the genesis of flood basalt lavas. Where high-quality data are available beneath continental flood basalt (CFB) provinces (Emeishan, Columbia River, Deccan, Siberia), high-velocity structures (Vp ~6.9-7.5 km/sec) are typically found immediately overlying the Moho in layers of order ~5-15 km thick. Oceanic plateau (OP) LIPs exhibit similar layers, with a conspicuous layer of very high crustal velocity (Vp~7.7 km/sec) beneath the enormous Ontong-Java plateau. These structures are similar to inferred ultramafic underplating structures seen beneath active hotspots such as Hawaii, the Marquesas, and La Reunion. Petrogenetic models for flood basalt volcanism based on hot plume melting beneath mature lithosphere suggest that these deep seismic structures may consist in large part of cumulate bodies of olivine and clinopyroxene which result from ponding and deep-crustal fractionation of ultramafic primary melts. Such fractionation is necessary to produce basalts with typical MgO contents of ~6-8%, as observed for the vast bulk of observed flood basalts, from primary melts with MgO contents of order ~15-18% (or greater) such as result from hot, deep melting beneath the lithosphere. The volumes of cumulate bodies and ultramafic intrusions in the lowermost crust, often described in the literature as “underplating,” are comparable to those of the overlying basaltic formations, also consistent with petrological models. Further definition of the deep seismic structure beneath such prominent LIPs as the Ontong-Java Plateau could place better constraints on flood basalt petrogenesis by determining the relative volumes of ultramafic bodies and basaltic lavas, thereby better

  4. Deep Crustal Structure beneath Large Igneous Provinces and the Petrologic Evolution of Flood Basalts

    NASA Astrophysics Data System (ADS)

    Richards, Mark; Ridley, Victoria

    2010-05-01

    We present a review of seismological constraints on deep crustal structures underlying large igneous provinces (LIPs), largely from wide-angle seismic refraction surveys. The main purpose of this review is to ascertain whether this seismic evidence is consistent with, or contrary to, petrological models for the genesis of flood basalt lavas. Where high-quality data are available beneath continental flood basalt (CFB) provinces (Emeishan, Columbia River, Deccan, Siberia), high-velocity structures (Vp ~6.9-7.5 km/sec) are typically found immediately overlying the Moho in layers of order ~5-15 km thick. Oceanic plateau (OP) LIPs exhibit similar layers, with a conspicuous layer of very high crustal velocity (Vp~7.7 km/sec) beneath the enormous Ontong-Java plateau. These structures are similar to inferred ultramafic underplating structures seen beneath active hotspots such as Hawaii, the Marqueses, and La Reunion. Petrogenetic models for flood basalt volcanism based on hot plume melting beneath mature lithosphere suggest that these deep seismic structures may consist in large part of cumulate bodies of olivine and clinopyroxene which result from ponding and deep-crustal fractionation of ultramafic primary melts. Such fractionation is necessary to produce basalts with typical MgO contents of ~6-8%, as observed for the vast bulk of observed flood basalts, from primary melts with MgO contents of order ~15-18% (or greater) such as result from hot, deep melting beneath the lithosphere. The volumes of cumulate bodies and ultramafic intrusions in the lowermost crust, often described in the literature as "underplating," are comparable to those of the overlying basaltic formations, also consistent with petrological models. Further definition of the deep seismic structure beneath such prominent LIPs as the Ontong-Java Plateau could place better constraints on flood basalt petrogenesis by determining the relative volumes of ultramafic bodies and basaltic lavas, thereby better

  5. Deep crustal structure beneath large igneous provinces and the petrologic evolution of flood basalts

    NASA Astrophysics Data System (ADS)

    Ridley, Victoria A.; Richards, Mark A.

    2010-09-01

    We present a review of seismological constraints on deep crustal structures underlying large igneous provinces (LIPs), largely from wide-angle seismic refraction surveys. The main purpose of this review is to ascertain whether this seismic evidence is consistent with, or contrary to, petrological models for the genesis of flood basalt lavas. Where high-quality data are available beneath continental flood basalt (CFB) provinces (Emeishan, Columbia River, Deccan, Siberia), high-velocity structures (Vp ˜ 6.9-7.5 km/sec) are typically found immediately overlying the Moho in layers of order ˜5-15 km thick. Oceanic plateau (OP) LIPs exhibit similar layers, with a conspicuous layer of very high crustal velocity (Vp ˜ 7.7 km/sec) beneath the enormous Ontong-Java plateau. These structures are similar to inferred ultramafic underplating structures seen beneath active hot spots such as Hawaii, the Marquesas, and La Reunion. Petrogenetic models for flood basalt volcanism based on hot plume melting beneath mature lithosphere suggest that these deep seismic structures may consist in large part of cumulate bodies of olivine and clinopyroxene which result from ponding and deep-crustal fractionation of ultramafic primary melts. Such fractionation is necessary to produce basalts with typical MgO contents of ˜6-8%, as observed for the vast bulk of observed flood basalts, from primary melts with MgO contents of order ˜15-18% (or greater) such as result from hot, deep melting beneath the lithosphere. The volumes of cumulate bodies and ultramafic intrusions in the lowermost crust, often described in the literature as "underplating," are comparable to those of the overlying basaltic formations, also consistent with petrological models. Further definition of the deep seismic structure beneath such prominent LIPs as the Ontong-Java Plateau could place better constraints on flood basalt petrogenesis by determining the relative volumes of ultramafic bodies and basaltic lavas, thereby

  6. 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...

  7. 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.

  8. 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

  9. Structural biology.

    PubMed Central

    Holmes, K C

    1999-01-01

    Protein crystallography has become a major technique for understanding cellular processes. This has come about through great advances in the technology of data collection and interpretation, particularly the use of synchrotron radiation. The ability to express eukaryotic genes in Escherichia coli is also important. Analysis of known structures shows that all proteins are built from about 1000 primeval folds. The collection of all primeval folds provides a basis for predicting structure from sequence. At present about 450 are known. Of the presently sequenced genomes only a fraction can be related to known proteins on the basis of sequence alone. Attempts are being made to determine all (or as many as possible) of the structures from some bacterial genomes in the expectation that structure will point to function more reliably than does sequence. Membrane proteins present a special problem. The next 20 years may see the experimental determination of another 40,000 protein structures. This will make considerable demands on synchrotron sources and will require many more biochemists than are currently available. The availability of massive structure databases will alter the way biochemistry is done. PMID:10670018

  10. 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.

  11. 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.

  12. 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.

  13. 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

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

    PubMed

    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

  15. Structure of three Zlatoust bulats (Damascus-steel blades)

    NASA Astrophysics Data System (ADS)

    Schastlivtsev, V. M.; Gerasimov, V. Yu.; Rodionov, D. P.

    2008-08-01

    Chemical composition, structure, and hardness of samples of three Zlatoust bulats (Damascus steels), namely, an Anosov bulat blade (1841), Obukhov bulat blade (1859), and a Shvetsov forged bulat-steel blank (crucible steel) have been investigated. The Anosov bulat possesses all signs of the classical Damascus steel; this is a hypereutectoid carbon steel with a structure formed from chains of carbides against the background of fine pearlite (troostite). A banded pattern is revealed on the surface of the blade. The Obukhov blade cannot be referred to classical Damascus steel. The pattern on the surface of the blade is absent, despite the fact that the initial steel is hypereutectoid. The structure of the blade does not correspond to the structure of classical Damascus steel; this is bainite with numerous cementite particles. The Shvetsov sample cannot be regarded as Damascus steel since it is made from a hypereutectoid steel alloyed by managanese and tungsten. The pattern on the surface of the metal is a consequence of the dendritic structure of the ingot which is developed during forging. The structure of this pattern differs from classical damascene pattern, since the latter is formed due to a specific arrangement of a variety of carbide particles against the pearlitic or some other background obtained during heat treatment.

  16. 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.

  17. The structure and distribution of nasal glands in four marsupial species.

    PubMed

    Kratzing, J E

    1984-10-01

    The structure and distribution of nasal glands in four marsupial species were studied by light and electron microscopy. The species studied were the honey possum (Tarsipes rostratus), the bandicoot (Isoodon macrourus), the koala (Phascolarctos cinereus) and the agile wallaby (Macropus agilis). Glands were grouped and described according to their location. Those of general distribution (goblet cells and olfactory glands) were similar in structures and distribution in all specimens. Glands of the lateral nasal wall include the lateral nasal, maxillary sinus and turbinate glands. The lateral nasal and maxillary sinus glands were absent in the adult koala but occupied large areas in the other species. Turbinate glands were best developed rostrally and ventrally in the nasal cavity. On the nasal septum, Tarsipes and Isoodon had well developed glands associated with vascular 'swell bodies'. These were poorly developed to Macropus though septal glands were abundant. 'Swell bodies' were absent in Phascolarctos and glands were sparse. Tubular vomeronasal glands were present in all species and most extensive in Tarsipes. In Isoodon, there was a posterior ventral septal gland associated with the septal olfactory organ. The fine structural features of secretory cells and ducts are described and their potential role discussed in terms of chemoreception and temperature and humidity control. PMID:6490535

  18. The structure and distribution of nasal glands in four marsupial species.

    PubMed Central

    Kratzing, J E

    1984-01-01

    The structure and distribution of nasal glands in four marsupial species were studied by light and electron microscopy. The species studied were the honey possum (Tarsipes rostratus), the bandicoot (Isoodon macrourus), the koala (Phascolarctos cinereus) and the agile wallaby (Macropus agilis). Glands were grouped and described according to their location. Those of general distribution (goblet cells and olfactory glands) were similar in structures and distribution in all specimens. Glands of the lateral nasal wall include the lateral nasal, maxillary sinus and turbinate glands. The lateral nasal and maxillary sinus glands were absent in the adult koala but occupied large areas in the other species. Turbinate glands were best developed rostrally and ventrally in the nasal cavity. On the nasal septum, Tarsipes and Isoodon had well developed glands associated with vascular 'swell bodies'. These were poorly developed to Macropus though septal glands were abundant. 'Swell bodies' were absent in Phascolarctos and glands were sparse. Tubular vomeronasal glands were present in all species and most extensive in Tarsipes. In Isoodon, there was a posterior ventral septal gland associated with the septal olfactory organ. The fine structural features of secretory cells and ducts are described and their potential role discussed in terms of chemoreception and temperature and humidity control. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 PMID:6490535

  19. Functional silicene and stanene nanoribbons compared to graphene: electronic structure and transport

    NASA Astrophysics Data System (ADS)

    van den Broek, B.; Houssa, M.; Iordanidou, K.; Pourtois, G.; Afanas'ev, V. V.; Stesmans, A.

    2016-03-01

    Since the advent of graphene, other 2D materials have garnered interest; notably the single element materials silicene, germanene, and stanene. We investigate the ballistic current-voltage (I-V) characteristics of armchair silicene and stanene armchair nanoribbons (AXNRs with X = Si, Sn) using a combination of density functional theory and non-equilibrium Green’s functions. The impact of out-of-plane electric field and in-plane uniaxial strain on the ribbon geometries, electronic structure, and (I-V)s are considered and contrasted with graphene. Since silicene and stanene are sp2/sp3 buckled layers, the electronic structure can be tuned by an electric field that breaks the sublattice symmetry, an effect absent in graphene. This decreases the current by ˜50% for Sn, since it has the largest buckling. Uniaxial straining of the ballistic channel affects the AXNR electronic structure in multiple ways: it changes the bandgap and associated effective carrier mass, and creates a local buckling distortion at the lead-channel interface which induces a interface dipole. Due to the increasing sp3 hybridization character with increasing element mass, large reconstructions rectify the strained systems, an effect absent in sp2 bonded graphene. This results in a smaller strain effect on the current: a decrease of 20% for Sn at 15% tensile strain compared to a ˜75% decrease for C.

  20. 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.

  1. 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.

  2. Infundibulocystic Structures and Prominent Squamous Metaplasia in Sebaceoma-A Rare Feature. A Clinicopathologic Study of 10 Cases.

    PubMed

    Flux, Katharina; Kutzner, Heinz; Rütten, Arno; Plaza, Jose A; Gasparov, Slavko; Michal, Michal; Guenova, Emmanuella; Kazakov, Dmitry V

    2016-09-01

    The authors describe 10 cases of sebaceoma that manifested prominent infundibulocystic structures in all cases and, additionally, conspicuous squamous metaplasia in 6 neoplasms. All tumors occurred on the scalp or the face (2 cases lacked clinical information) and presented as a solitary lesion, measuring from 5 to 20 mm. The patients' age ranged from 22 to 89 years. The main component of all tumors was small, uniform basaloid cells (immature sebocytes) intermixed with mature sebocytes clearly arranged in nodules, classifying the lesions as a sebaceoma. In all neoplasms, the tumor cells showed organoid growth patterns of sebaceoma, including rippled, sinusoidal/labyrinthine, and carcinoid-like, occurring alone or in combination. Additionally, numerous infundibulocystic structures were readily noticed and were either distributed multifocally or unilocular within the tumors. In some cases, they were segregated from the main tumor bulk. The authors posit that these structures, which are different from both sebaceous ductal differentiation and squamous metaplasia, represent an authentic follicular differentiation. The infundibulocystic features (combined with squamous metaplasia), when prominent and in a limited biopsy specimen, may cause a confusion with trichoadenoma or even microcystic adnexal carcinoma. PMID:26760686

  3. 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.

  4. Structure of Railroad Valley, Nye County, Nevada

    SciTech Connect

    Ehni, W.J.

    1987-08-01

    In 1976, the second oil field in Nevada - Trap Springs - was discovered in Railroad Valley. Since then, more than 100 oil wells have been drilled in Nye County, and most of these have been in Railroad Valley. This well-control helped to unravel the complex structure of Railroad Valley and enabled the construction of more accurate maps of this valley than any other. This information can be used to construct models for exploring other valleys in the Basin and Range Province of eastern Nevada. The basic stratigraphy of the valley consists of Paleozoic carbonates and shales overlain by Tertiary volcanics, overlain, in turn, by valley fill. The areal extent of Tertiary volcanics, which can be a good reservoir rock, is controlled by tensional normal faulting and paleotopography. In some areas, these volcanics can be in excess of 5000 ft thick, but absent within a few miles, owing to paleotopography and/or faulting. The Paleozoic rocks are deformed by a pre-basin and range compressional history that folded and faulted them. As a result, the structure within the Paleozoics is more complex. Thrust faulting played an important role in the deformation of these rocks. Crystalline basement rocks can be found juxtaposed between Paleozoic outcrops in the flanks of the valley, and Paleozoic rocks found in well control farther out in the valley. The geothermal history of Railroad Valley plays an important role in constructing a structural map of the valley, taking into account the Mesozoic thrust faulting and Tertiary normal faulting. Air photos, combined with good well control and published reports, assist in mapping the geologic structure in Railroad Valley.

  5. 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

  6. Larval dispersal drives trophic structure across Pacific coral reefs.

    PubMed

    Stier, Adrian C; Hein, Andrew M; Parravicini, Valeriano; Kulbicki, Michel

    2014-01-01

    Top predators are a critical part of healthy ecosystems. Yet, these species are often absent from spatially isolated habitats leading to the pervasive view that fragmented ecological communities collapse from the top down. Here we study reef fish from coral reef communities across the Pacific Ocean. Our analysis shows that species richness of reef fish top predators is relatively stable across habitats that vary widely in spatial isolation and total species richness. In contrast, species richness of prey reef fish declines rapidly with increasing isolation. By consequence, species-poor communities from isolated islands have three times as many predator species per prey species as near-shore communities. We develop and test a colonization-extinction model to reveal how larval dispersal patterns shape this ocean-scale gradient in trophic structure. PMID:25412873

  7. 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…

  8. 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.

  9. Nanocrystal structures

    SciTech Connect

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

    2008-12-30

    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.

  10. 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.

  11. 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).

  12. 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

  13. Structure and electronic properties of (+)-catechin: aqueous solvent effects.

    PubMed

    Bentz, Erika N; Pomilio, Alicia B; Lobayan, Rosana M

    2014-02-01

    We report a study of the structure of (+)-catechin, which belongs to the family of the flavan-3-ols-one of the five most widely distributed phenolic groups. The biological activities and pharmaceutical utility of these compounds are related to antioxidant activity due to their ability to scavenge free radicals. A breakthrough in the study of the conformational space of this compound, so far absent in the literature, is presented herein. A detailed analysis of the electronic distribution, charge delocalization effects, and stereoelectronic effects is presented following application of the theory of atoms in molecules (AIM) and natural bond orbital analysis. The stability order, and the effects of electron delocalization in the structures were analyzed in depth. The molecular electrostatic potential (MEP) was also obtained, assessing changes in the electronic distribution in aqueous solution, the effects of the solvent on the intrinsic electronic properties, and molecular geometry. The effect of the aqueous solvent on MEP was also quantified, and rationalized by charge delocalization mechanisms, relating them to structural changes and topological properties of the electronic charge density. To further analyze the effects of the aqueous solvent, as well as investigating the molecular and structural properties of these compounds in a biological environment, the polarizabilities for all conformers characterized were also calculated. All results were interpreted on the basis of our accumulated knowledge on (4α→6", 2α→O→1")-phenylflavans in previous reports, thus enriching and deepening the analysis of both types of structure. PMID:24526380

  14. 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'.

  15. Processing Coordinate Structures in Chinese: Evidence from Eye Movements

    PubMed Central

    Qingrong, Chen; Yan, Huang

    2012-01-01

    This article reports the results of an eye-tracking experiment that investigated the processing of coordinate structures in Chinese sentence comprehension. The study tracked the eye movements of native Chinese readers as they read sentences consisting of two independent clauses connected by the word huo zhe. The data strongly confirmed readers' preference for an initial noun phrase (NP)-coordination parsing in Chinese coordination structure. When huo zhe was absent from the beginning of a sentence, we identified a cost associated with abandoning the NP-coordination analysis, which was evident with regard to the second NP when the coordination was unambiguous. Otherwise, this cost was evident with regard to the verb, the syntactically disambiguating region, when the coordination was ambiguous. However, the presence of a sentence-initial huo zhe reduced reading times and regressions in the huo zhe NP and the verb regions. We believe that the word huo zhe at the beginning of a sentence helps the reader predict that the sentence contains a parallel structure. Before the corresponding phrases appear, the readers can use the word huo zhe and the language structure thereafter to predicatively construct the syntactic structure. Such predictive capability can eliminate the reader's preference for NP-coordination analysis. Implications for top-down parsing theory and models of initial syntactic analysis and reanalysis are discussed. PMID:22558163

  16. 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.

  17. 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.

  18. 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.

  19. Structure of the Crust and Uppermost Mantle Beneath Hudson Bay Based on Ambient- Noise Tomography

    NASA Astrophysics Data System (ADS)

    Pawlak, A.; Eaton, D. W.

    2008-12-01

    Hudson Bay is a vast inland sea that penetrates deeply into north-central Canada, forming a conspicuous element of the North American coastline. The Bay conceals several fundamental tectonic elements of North America, including most of the Paleoproterozoic Trans Hudson orogen, the Paleozoic Hudson Bay basin and a large part of the lithospheric root beneath the Precambrian core of North America. This study is focused on regional crustal structure based on ambient-noise tomography. Twenty-one months of continuous ambient- noise recordings have been acquired from 31 broadband seismograph stations that encircle Hudson Bay. These stations are part of the Hudson Bay Lithospheric Experiment (HuBLE), an international project that is currently operating more than 40 broadband seismograph stations around the periphery of Hudson Bay. Following established processing procedures that include trace normalization and spectral whitening, cross- correlations are computed for all possible station pairs. The resulting waveforms are treated as Green functions, from which group velocity dispersion measurements can be made. Since Hudson Bay freezes during winter months, there is a pronounced asymmetry to the Green functions indicative of noise sources along the Atlantic seaboard. Preliminary results indicate shield-like conditions in most areas, but reduced crustal velocities beneath the Hudson Bay basin.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. The cortical analysis of speech-specific temporal structure revealed by responses to sound quilts.

    PubMed

    Overath, Tobias; McDermott, Josh H; Zarate, Jean Mary; Poeppel, David

    2015-06-01

    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

  8. Influence of time lag and noncolocation on integrated structural/control system designs

    NASA Technical Reports Server (NTRS)

    Manning, R. A.; Schmit, L. A.

    1989-01-01

    Recent research efforts have led to the development of simultaneous structural/control system design procedures. Absent in any of the work is the time delay present in the control system sensors and actuators and the computational time delay for synthesizing actuator commands from sensor measurements. Madden has shown that the time delay present in the control system can have profound effects on the resulting system performance and stability regardless of its source. In addition, many of the simultaneous structural/control system design procedures have used colocated sensors and actuators for implementation of the control system. In actual practice, colocation in not always possible. The issue of stability degradation when using noncolocated sensor and actuators was raised. The integrated structural/control system design procedure is extended to include the effects of time lag and noncolocation of sensors and actuators on the resulting optimum designs.

  9. 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

  10. 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.

  11. Structure/antileishmanial activity relationship study of naphthoquinones and dependency of the mode of action on the substitution patterns.

    PubMed

    Ali, Ahmad; Assimopoulou, Andreana Nikolaos; Papageorgiou, Vassilios Peter; Kolodziej, Herbert

    2011-12-01

    A series of naphthoquinones was tested for activity against both extracellular promastigote and intracellular amastigote Leishmania major GFP in vitro. In parallel, the compounds were evaluated for cytotoxic effects against bone marrow-derived macrophages (BMM Φ) as a mammalian host cell control. Most of the compounds noticeably inhibited the growth of extracellular parasites (IC (50) 0.5 to 6 µM) and the intracellular survival of L. major GFP amastigotes (IC (50) 1 to 7 µM) when compared with the antileishmanial drug amphotericin B (IC (50) of 2.5 and 0.2 µM, respectively). In general, antiprotozoal activity and host cell cytotoxicity seemed to increase in parallel. Conspicuously, the cytotoxic effect was less pronounced on infected host cells when compared with that on noninfected cells. Concerning structure/activity relationships for the tested naphthoquinones, some interesting structural features emerged from this study. Introduction of a methyl or methoxyl group at C-2 of the parent 1,4-naphthoquinone slightly increased the antileishmanial activity against clinically relevant amastigotes, while the presence of a hydroxyl function in this position dramatically reduced the effectiveness. In contrast, hydroxylation at C-5 and dihydroxy substitution at C-5 and C-8 significantly enhanced the antiprotozoal activity. Similarly, the presence of a side chain hydroxyl group PERI to a carbonyl function as represented in the series of shikonin/alkannin derivatives increased the activity when compared with substituted analogs. Within the series of naphthoquinones tested, the dimeric mixture of vaforhizin and isovaforhizin showed the highest activity IN VITRO against the clinically relevant intracellular amastigote with an IC (50) of 1.1 µM. With IC (50) values mostly in the range of 1-3 µM, the shikonin/alkannin derivatives proved to be similarly considerably leishmanicidal. None of the compounds tested was capable to induce NO production known to play a

  12. Structure and evolutionary history of DISC1.

    PubMed

    Sanchez-Pulido, Luis; Ponting, Chris P

    2011-10-15

    Evolutionary and protein structural analyses can provide functional insights into genes implicated in human psychiatric diseases. Even eukaryotic organisms lacking nervous systems contain homologues of many key signalling molecules of animal neurons implying that human cognition derives, in part, from modifications of ancestral molecules and complexes. One protein whose evolutionary origin is obscure is DISC1 (disrupted in schizophrenia 1) whose gene locus has been associated with many psychiatric conditions including schizophrenia, clinical depression and bipolar disorder. This protein's rapid evolution and its unusual amino acid and α-helix composition have hindered searches for DISC1 homologues in species other than vertebrates. Here, we review the evolution and structure of the DISC1 protein in the light of in-depth sequence analyses. These predict DISC1 orthologues in diverse eukaryotic organisms, including early-branching animals such as amphioxus, sea anemone, amoebas and Trichoplax, and in plants and algae. DISC1 thus is widespread among eukaryotes, although it remains absent from fungi, nematodes and Diptera, including fruit flies. These observations now permit studies of DISC1 function in simple non-vertebrate model organisms. Surprisingly, these analyses also identify between two and four sequence repeats in DISC1 orthologues. The first two of these repeats show significant sequence similarity to the UVR family of globular domains. These UVR-like repeats are predicted to contain, not coiled coil structures, but rather two closely associated antiparallel α-helices. One common missense variant in DISC1 (L607F) lies within the second DISC1 UVR-like domain. These observations should assist in delineating the functional regions of the DISC1 protein. PMID:21852244

  13. On the changes in the physical properties of the ionized region around the Weigelt structures in η Carinae over the 5.54-yr spectroscopic cycle

    NASA Astrophysics Data System (ADS)

    Teodoro, Mairan; Gull, Theodore R.; Bautista, Manuel; Hillier, Desmond John; Weigelt, Gerd

    2015-01-01

    We present HST/STIS observations and analysis of two prominent nebular structures around the central source of η Carinae, the so-called Weigelt blobs C and D. The former is brighter than the latter for emission lines from intermediate or high ionization potential ions. The brightness of lines from intermediate and high ionization potential ions significantly decreases at phases around periastron. We do not see conspicuous changes in the brightness of lines from low ionization potential ions over the orbital period. Line ratios suggest that the total extinction towards the Weigelt structures is AV=2.0. Weigelt C and D are characterized by an electron density of 106.9 cm-3 that does not significantly change throughout the orbital cycle. The electron temperature varies from 5500 K (around periastron) to 7200 K (around apastron). The relative changes in the brightness of He0 lines are well reproduced by the variations in the electron temperature alone. We found that, at phases around periastron, the electron temperature seems to be higher for Weigelt C than that of D. The Weigelt structures are located close to the Homunculus equatorial plane, at a distance of about 1240 AU from the central source. From the analysis of proper motion and age, the Weigelt complex can be associated with the equatorial structure called `Butterfly Nebula' surrounding the central binary system.

  14. 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

  15. Tracing the structural evolution of eukaryotic ATP binding cassette transporter superfamily

    PubMed Central

    Xiong, Jie; Feng, Jinmei; Yuan, Dongxia; Zhou, Jun; Miao, Wei

    2015-01-01

    The ATP binding cassette (ABC) transporters superfamily is one of the largest classes of membrane proteins. The core of the ABC transporter protein is composed of transmembrane domains (TMDs) and nucleotide binding domains (NBD). Eukaryotes ABC transporters are classified into seven main families (ABCA to ABCG) based on sequence similarity and domain organizations. With different domain number and domain organizations, eukaryote ABC transporters show diverse structures: the single structure (NBD or TMD), the ABC2 structure (NBD-NBD), the half structure (TMD-NBD or NBD-TMD) and the full structure (TMD-NBD-TMD-NBD or NBD-TMD-NBD-TMD). However, studies on how various ABC transporter gene structures evolved is still absent. Therefore, in this study, we comprehensively investigated the structural evolution of eukaryotic ABC transporters. The seven eukaryote ABC transporter families (A to G) fell into three groups: A&G group, B,C&D group and E&F group. There were at least four times the number of NBD and TMD fusion events in the origin of the half structure transporter. Two fusion modes were found in the full and ABC2 structure origination. Based on these findings, we present a putative structural evolutionary path of eukaryote ABC transporters that will increase our understanding on their origin, divergence and function. PMID:26577702

  16. Extension and inversion structures in the Tethys-Atlantic linkage zone, Algarve Basin, Portugal

    NASA Astrophysics Data System (ADS)

    Ramos, Adrià; Fernández, Oscar; Terrinha, Pedro; Muñoz, Josep Anton

    2016-07-01

    The Algarve Basin is a Meso-Cenozoic sedimentary basin overlying Carboniferous basement, located in the southwestern margin of the Iberian Peninsula. Its structure reveals a protracted tectonic history comprising various pulses of Mesozoic extension followed by Cenozoic compression. This work deals with the structure along the northern margin, where the Mesozoic extensional structures and Cenozoic inversion structures crop out. The strike of the extensional structures ranges from E-W to N-S, as controlled by a shift from Tethyan-dominated extension in the east to Atlantic-dominated extension in the west. Contractional structures are inverted extensional structures, following their same trends. It is argued that the thickness of the Hettangian evaporite layer exerts a strong control on the structural style throughout the basin during the extensional and inversion episodes. The basin is affected by thick-skinned deformation along the northern margin, where salt is thin or absent, basement involved fault systems and short-cut structures. Basinward, as the Hettangian salt thickens, the margin is affected by thin-skinned deformation, with listric and down-to-the-basin growth faults, diapirism and salt-cored detachment folds. The aim was to discuss the key tectonic features, the relevance of salt, and understand the nature, timing, and significance of all these structures in the regional tectonic evolution.

  17. Extension and inversion structures in the Tethys-Atlantic linkage zone, Algarve Basin, Portugal

    NASA Astrophysics Data System (ADS)

    Ramos, Adrià; Fernández, Oscar; Terrinha, Pedro; Muñoz, Josep Anton

    2015-12-01

    The Algarve Basin is a Meso-Cenozoic sedimentary basin overlying Carboniferous basement, located in the southwestern margin of the Iberian Peninsula. Its structure reveals a protracted tectonic history comprising various pulses of Mesozoic extension followed by Cenozoic compression. This work deals with the structure along the northern margin, where the Mesozoic extensional structures and Cenozoic inversion structures crop out. The strike of the extensional structures ranges from E-W to N-S, as controlled by a shift from Tethyan-dominated extension in the east to Atlantic-dominated extension in the west. Contractional structures are inverted extensional structures, following their same trends. It is argued that the thickness of the Hettangian evaporite layer exerts a strong control on the structural style throughout the basin during the extensional and inversion episodes. The basin is affected by thick-skinned deformation along the northern margin, where salt is thin or absent, basement involved fault systems and short-cut structures. Basinward, as the Hettangian salt thickens, the margin is affected by thin-skinned deformation, with listric and down-to-the-basin growth faults, diapirism and salt-cored detachment folds. The aim was to discuss the key tectonic features, the relevance of salt, and understand the nature, timing, and significance of all these structures in the regional tectonic evolution.

  18. Ultrafast magnetization and structural dynamics in the intercalated transition metal dichalcogenides Fe0.25TaS2 and Mn0.25TaS2

    NASA Astrophysics Data System (ADS)

    Liu, Q.; Zhu, X. D.; Wang, L. H.; Cheong, S.-W.; Tobey, R. I.

    2016-05-01

    We measure magnetization and structural dynamics in two intercalant-ordered transition metal dichalcogenides: Fe0.25TaS2 and Mn0.25TaS2. The structurally equivalent materials allow us to probe the effect of orbital angular momentum which is active in Fe0.25TaS2 and absent in Mn0.25TaS2. Interestingly, we find that the magnetooptics dynamics are nearly indistinguishable in these two materials, in contradiction to conventional explanations of a spin–lattice mechanism. We compare our results to other materials where spin–lattice demagnetization has been put forth as a demagnetization channel.

  19. 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.

  20. 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.

  1. 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

  2. Simultaneous characterization of cellular RNA structure and function with in-cell SHAPE-Seq.

    PubMed

    Watters, Kyle E; Abbott, Timothy R; Lucks, Julius B

    2016-01-29

    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

  3. Intercohort size structure dynamics of fire salamander larvae in ephemeral habitats: a mesocosm experiment.

    PubMed

    Sadeh, Asaf; Polevikov, Antonina; Mangel, Marc; Blaustein, Leon

    2015-10-01

    The size structure of a larval population facilitates interaction asymmetries that, in turn, influence the dynamics of size-structure. In species that exhibit conspicuous aggressive interactions, the competitive effects of the smaller individuals may be overlooked. We manipulated initial size differences between two larval cohorts and young-cohort density of Salamandra infraimmaculata in mesocosms to determine: (1) whether young individuals function primarily as prey or as competitors of older and larger individuals; (2) the resulting dynamics of size variation; and (3) recruitment to the postmetamorph population. Intercohort size differences generally remained constant over time at low young-cohort densities, but reduced over time at high densities due to retardation of the old-cohort growth rate. This suggests a competitive advantage to the young cohort that outweighs the interference advantage of older cohorts previously documented in this species. The increase in mortality from desiccation due to high young-cohort density was an order of magnitude greater in the old cohort than in the young-cohort, further indicating size-dependent vulnerability to competition. However, the conditions least favorable to most of the old-cohort larvae (large size difference and high young-cohort density) promoted cannibalism. Among cannibals, mortality and time to metamorphosis decreased and sizes at metamorphosis increased substantially. Thus, a balance between the competitive advantage to young cohorts, and the interference and cannibalism advantage to old cohorts shapes larval size-structure dynamics. Larval densities and individual expression of cannibalism can shift this balance in opposite directions and alter relative recruitment rates from different cohorts. PMID:26080758

  4. 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.

  5. 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.

  6. 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. PMID:26460191

  7. 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

  8. Fine structure of adhesive devices of Strepsiptera (Insecta).

    PubMed

    Pohl, Hans; Beutel, Rolf G

    2004-01-01

    Legs and other body parts of males, females and first instar larvae of almost all recognised families of Strepsiptera (Insecta) were examined. Descriptions of tibial, tarsal and pretarsal adhesive structures for each family are presented. These and attachment devices not associated with the legs are discussed. Strepsiptera evolved two strictly different types of tarsal attachment structures: hairy surfaces in the males and smooth flexible pads in the first instar larvae. Additional adhesive devices are present in several subgroups: mushroom-shaped microtrichia on the maxillary palp of males of Bohartillidae and acute pointed tibiae, or tarsal segments of males in different families. First instar larvae have evolved adhesive hairs on the ventral side of the body and on the podomeres. Specialised adhesive hairs are absent in the groundplan of adult males of Strepsiptera, but have evolved with the adoption of permanent endoparasitism of females. The most elaborate attachment structures, both in males and first instar larvae, are present in parasites of fast flying hymenopteran hosts (Aculeata). PMID:18089021

  9. Analysis of the crystal structure of an active MCM hexamer

    PubMed Central

    Miller, Justin M; Arachea, Buenafe T; Epling, Leslie B; Enemark, Eric J

    2014-01-01

    In a previous Research article (Froelich et al., 2014), we suggested an MCM helicase activation mechanism, but were limited in discussing the ATPase domain because it was absent from the crystal structure. Here we present the crystal structure of a nearly full-length MCM hexamer that is helicase-active and thus has all features essential for unwinding DNA. The structure is a chimera of Sulfolobus solfataricus N-terminal domain and Pyrococcus furiosus ATPase domain. We discuss three major findings: 1) a novel conformation for the A-subdomain that could play a role in MCM regulation; 2) interaction of a universally conserved glutamine in the N-terminal Allosteric Communication Loop with the AAA+ domain helix-2-insert (h2i); and 3) a recessed binding pocket for the MCM ssDNA-binding motif influenced by the h2i. We suggest that during helicase activation, the h2i clamps down on the leading strand to facilitate strand retention and regulate ATP hydrolysis. DOI: http://dx.doi.org/10.7554/eLife.03433.001 PMID:25262915

  10. 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.

  11. Structures of Trypanosome Vacuolar Soluble Pyrophosphatases: Antiparasitic Drug Targets.

    PubMed

    Yang, Yunyun; Ko, Tzu-Ping; Chen, Chun-Chi; Huang, Guozhong; Zheng, Yingying; Liu, Weidong; Wang, Iren; Ho, Meng-Ru; Hsu, Shang-Te Danny; O'Dowd, Bing; Huff, Hannah C; Huang, Chun-Hsiang; Docampo, Roberto; Oldfield, Eric; Guo, Rey-Ting

    2016-05-20

    Trypanosomatid parasites are the causative agents of many neglected tropical diseases, including the leishmaniases, Chagas disease, and human African trypanosomiasis. They exploit unusual vacuolar soluble pyrophosphatases (VSPs), absent in humans, for cell growth and virulence and, as such, are drug targets. Here, we report the crystal structures of VSP1s from Trypanosoma cruzi and T. brucei, together with that of the T. cruzi protein bound to a bisphosphonate inhibitor. Both VSP1s form a hybrid structure containing an (N-terminal) EF-hand domain fused to a (C-terminal) pyrophosphatase domain. The two domains are connected via an extended loop of about 17 residues. Crystallographic analysis and size exclusion chromatography indicate that the VSP1s form tetramers containing head-to-tail dimers. Phosphate and diphosphate ligands bind in the PPase substrate-binding pocket and interact with several conserved residues, and a bisphosphonate inhibitor (BPH-1260) binds to the same site. On the basis of Cytoscape and other bioinformatics analyses, it is apparent that similar folds will be found in most if not all trypanosomatid VSP1s, including those found in insects (Angomonas deanei, Strigomonas culicis), plant pathogens (Phytomonas spp.), and Leishmania spp. Overall, the results are of general interest since they open the way to structure-based drug design for many of the neglected tropical diseases. PMID:26907161

  12. Coupled and extended quintessence: Theoretical differences and structure formation

    NASA Astrophysics Data System (ADS)

    Pettorino, Valeria; Baccigalupi, Carlo

    2008-05-01

    The case of a coupling between dark energy and matter [coupled quintessence (CQ)] or gravity [extended quintessence (EQ)] has recently attracted a deep interest and has been widely investigated both in the Einstein and in the Jordan frames (EF, JF), within scalar-tensor theories. Focusing on the simplest models proposed so far, in this paper we study the relation existing between the two scenarios, isolating the Weyl scaling which allows one to express them in the EF and JF. Moreover, we perform a comparative study of the behavior of linear perturbations in both scenarios, which turn out to behave in a markedly different way. In particular, while the clustering is enhanced in the considered CQ models with respect to the corresponding quintessence ones where the coupling is absent and to the ordinary cosmologies with a cosmological constant and cold dark matter (ΛCDM), structures in EQ models may grow slower. This is likely to have direct consequences on the inner properties of nonlinear structures, like cluster concentration, as well as on the weak lensing shear on large scales. Finally, we specialize our study for interfacing linear dynamics and N-body simulations in these cosmologies, giving a recipe for the corrections to be included in N-body codes in order to take into account the modifications to the expansion rate, growth of structures, and strength of gravity.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. Identification of silver cubic structures during ultrasonication of chitosan AgNO3 solution.

    PubMed

    Raghavendra, Gownolla Malegowd; Jung, Jeyoung; Kim, Dowan; Varaprasad, Kokkarachedu; Seo, Jongchul

    2016-11-01

    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. PMID:27516304

  19. 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. PMID:21749034

  20. Analytical framework for reconstructing heterogeneous environmental variables from mammal community structure.

    PubMed

    Louys, Julien; Meloro, Carlo; Elton, Sarah; Ditchfield, Peter; Bishop, Laura C

    2015-01-01

    We test the performance of two models that use mammalian communities to reconstruct multivariate palaeoenvironments. While both models exploit the correlation between mammal communities (defined in terms of functional groups) and arboreal heterogeneity, the first uses a multiple multivariate regression of community structure and arboreal heterogeneity, while the second uses a linear regression of the principal components of each ecospace. The success of these methods means the palaeoenvironment of a particular locality can be reconstructed in terms of the proportions of heavy, moderate, light, and absent tree canopy cover. The linear regression is less biased, and more precisely and accurately reconstructs heavy tree canopy cover than the multiple multivariate model. However, the multiple multivariate model performs better than the linear regression for all other canopy cover categories. Both models consistently perform better than randomly generated reconstructions. We apply both models to the palaeocommunity of the Upper Laetolil Beds, Tanzania. Our reconstructions indicate that there was very little heavy tree cover at this site (likely less than 10%), with the palaeo-landscape instead comprising a mixture of light and absent tree cover. These reconstructions help resolve the previous conflicting palaeoecological reconstructions made for this site. PMID:25480104

  1. Effect of Zn substitution on the structural and magnetic properties of copper based divanadates

    NASA Astrophysics Data System (ADS)

    Chattopadhyay, Bidisa; Ahmed, Md. A.; Bandyopadhyay, S.; Mandal, P.

    2016-05-01

    We have prepared a series of polycrystalline Cu(2-x)ZnxV2O7 samples for x = 0.0, 0.05, 0.1, 0.15,0.2 a 0.3. X-ray structural studies show that there is a Zn mediated polymorphic phase transition from α-Cu2V2O7 to β-Cu2V2O7 phase beyond x=0.15. The static magnetic susceptibility shows a steep upturn as the temperature lowers indicating a transition to a magnetically ordered state. This behavior continues up to Zn concentration x=0.15. The field dependence of magnetization behavior M(H) also show hysteresis below transition temperature for x=0.0,0.1,0.15 samples. But hysteresis is absent for all other samples below transition temperatures confirming the idea that the undoped compound Cu2V2O7 as well as Cu(2-x)ZnxV2O7 up to x=0.15, are antiferromagnetic with canted spins leading to weak ferromagnetism which is absent beyond x=0.15 in the β-phase.

  2. Actin Grips: Circular Actin-Rich Cytoskeletal Structures that Mediate the Wrapping of Polymeric Microfibers by Endothelial Cells

    PubMed Central

    Jones, Desiree; Park, DoYoung; Anghelina, Mirela; Pecot, Thierry; Machiraju, Raghu; Xue, Ruipeng; Lannutti, John; Thomas, Jessica; Cole, Sara; Moldovan, Leni; Moldovan, Nicanor I.

    2015-01-01

    Interaction of endothelial-lineage cells with three-dimensional substrates was much less studied than that with flat culture surfaces. We investigated the in vitro attachment of both mature endothelial cells (ECs) and of less differentiated EC colony-forming cells to poly-e-capro-lactone (PCL) fibers with diameters in 5–20 μm range (‘scaffold microfibers’, SMFs). We found that notwithstanding the poor intrinsic adhesiveness to PCL, both cell types completely wrapped the SMFs after long-term cultivation, thus attaining a cylindrical morphology. In this system, both EC types grew vigorously for more than a week and became increasingly more differentiated, as shown by multiplexed gene expression. Three-dimensional reconstructions from multiphoton confocal microscopy images using custom software showed that the filamentous (F) actin bundles took a conspicuous ring-like organization around the SMFs. Unlike the classical F-actin-containing stress fibers, these rings were not associated with either focal adhesions or intermediate filaments. We also demonstrated that plasma membrane boundaries adjacent to these circular cytoskeletal structures were tightly yet dynamically apposed to the SMFs, for which reason we suggest to call them ‘actin grips’. In conclusion, we describe a particular form of F-actin assembly with relevance for cytoskeletal organization in response to biomaterials, for endothelial-specific cell behavior in vitro and in vivo, and for tissue engineering. PMID:25818446

  3. Fine-structural characterization and phylogeny of Peridinium polonicum, type species of the recently described genus Naiadinium (Dinophyceae).

    PubMed

    Craveiro, Sandra C; Daugbjerg, Niels; Moestrup, Øjvind; Calado, António J

    2015-08-01

    Peridinium polonicum is a freshwater peridinioid with an unusual tabulation that includes one or two anterior intercalary plates in the mid-dorsal axis, and in such a low position that it seems inset in precingular Plate 4. Although the species has been classified in both Peridinium and Peridiniopsis, evidence from nucleotide sequences consistently shows that its closest relatives are within the Scrippsiella group. The genus Naiadinium Carty has been recently described with P. polonicum as its type species. However, Naiadinium was separated from other peridinioids only on the basis of shape and plate arrangements and these characters do not allow reliable determination of its closest phylogenetic relatives. Serial section fine-structural analysis revealed the presence of a small peduncle supported by a conspicuous microtubular basket that extended far into the cell; a complex pusular system that included a collecting chamber from which about 70 pusular tubes radiated; a flagellar apparatus with general peridinioid characters but with an unusually large distance of nearly 700 nm between basal bodies. An ITS1-5.8S-ITS2 rDNA-based phylogenetic analysis grouped, with high statistical support, Naiadinium polonicum with three species currently placed in Scrippsiella, viz. S. irregularis, S. precaria and S. ramonii. PMID:26094011

  4. 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

  5. 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.

  6. Population Structure, Genetic Variation, and Linkage Disequilibrium in Perennial Ryegrass Populations Divergently Selected for Freezing Tolerance

    PubMed Central

    Kovi, Mallikarjuna Rao; Fjellheim, Siri; Sandve, Simen R.; Larsen, Arild; Rudi, Heidi; Asp, Torben; Kent, Matthew Peter; Rognli, Odd Arne

    2015-01-01

    Low temperature is one of the abiotic stresses seriously affecting the growth of perennial ryegrass (Lolium perenne L.), and freezing tolerance is a complex trait of major agronomical importance in northern and central Europe. Understanding the genetic control of freezing tolerance would aid in the development of cultivars of perennial ryegrass with improved adaptation to frost. The plant material investigated in this study was an experimental synthetic population derived from pair-crosses among five European perennial ryegrass genotypes, representing adaptations to a range of climatic conditions across Europe. A total number of 80 individuals (24 of High frost [HF]; 29 of Low frost [LF], and 27 of Unselected [US]) from the second generation of the two divergently selected populations and an unselected (US) control population were genotyped using 278 genome-wide SNPs derived from perennial ryegrass transcriptome sequences. Our studies investigated the genetic diversity among the three experimental populations by analysis of molecular variance and population structure, and determined that the HF and LF populations are very divergent after selection for freezing tolerance, whereas the HF and US populations are more similar. Linkage disequilibrium (LD) decay varied across the seven chromosomes and the conspicuous pattern of LD between the HF and LF population confirmed their divergence in freezing tolerance. Furthermore, two Fst outlier methods; finite island model (fdist) by LOSITAN and hierarchical structure model using ARLEQUIN, both detected six loci under directional selection. These outlier loci are most probably linked to genes involved in freezing tolerance, cold adaptation, and abiotic stress. These six candidate loci under directional selection for freezing tolerance might be potential marker resources for breeding perennial ryegrass cultivars with improved freezing tolerance. PMID:26617611

  7. Computational structural mechanics for engine structures

    NASA Technical Reports Server (NTRS)

    Chamis, Christos C.

    1989-01-01

    The computational structural mechanics (CSM) program at Lewis encompasses the formulation and solution of structural mechanics problems and the development of integrated software systems to computationally simulate the performance, durability, and life of engine structures. It is structured to supplement, complement, and, whenever possible, replace costly experimental efforts. Specific objectives are to investigate unique advantages of parallel and multiprocessing for reformulating and solving structural mechanics and formulating and solving multidisciplinary mechanics and to develop integrated structural system computational simulators for predicting structural performance, evaluating newly developed methods, and identifying and prioritizing improved or missing methods.

  8. Computational structural mechanics for engine structures

    NASA Technical Reports Server (NTRS)

    Chamis, Christos C.

    1988-01-01

    The computational structural mechanics (CSM) program at Lewis encompasses the formulation and solution of structural mechanics problems and the development of integrated software systems to computationally simulate the performance, durability, and life of engine structures. It is structured to supplement, complement, and, whenever possible, replace costly experimental efforts. Specific objectives are to investigate unique advantages of parallel and multiprocessing for reformulating and solving structural mechanics and formulating and solving multidisciplinary mechanics and to develop integrated structural system computational simulators for predicting structural performance, evaluating newly developed methods, and identifying and prioritizing improved or missing methods.

  9. Adaptive Space Structures

    NASA Technical Reports Server (NTRS)

    Wada, B.

    1993-01-01

    The term adaptive structures refers to a structural control approach in which sensors, actuators, electronics, materials, structures, structural concepts, and system-performance-validation strategies are integrated to achieve specific objectives.

  10. 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 ...

  11. 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

  12. 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

  13. Crystal Structure of the Carbapenem Intrinsic Resistance Protein CarG

    PubMed Central

    Tichy, E.M.; Luisi, B.F.; Salmond, G.P.C.

    2015-01-01

    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. PMID:24583229

  14. Crystal structure of arcelin-5, a lectin-like defense protein from Phaseolus vulgaris.

    PubMed

    Hamelryck, T W; Poortmans, F; Goossens, A; Angenon, G; Van Montagu, M; Wyns, L; Loris, R

    1996-12-20

    In the seeds of the legume plants, a class of sugar-binding proteins with high structural and sequential identity is found, generally called the legume lectins. The seeds of the common bean (Phaseolus vulgaris) contain, besides two such lectins, a lectin-like defense protein called arcelin, in which one sugar binding loop is absent. Here we report the crystal structure of arcelin-5 (Arc5), one of the electrophoretic variants of arcelin, solved at a resolution of 2.7 A. The R factor of the refined structure is 20.6%, and the free R factor is 27.1%. The main difference between Arc5 and the legume lectins is the absence of the metal binding loop. The bound metals are necessary for the sugar binding capabilities of the legume lectins and stabilize an Ala-Asp cis-peptide bond. Surprisingly, despite the absence of the metal binding site in Arc5, this cis-peptide bond found in all legume lectin structures is still present, although the Asp residue has been replaced by a Tyr residue. Despite the high identity between the different legume lectin sequences, they show a broad range of quaternary structures. The structures of three different dimers and three different tetramers have been solved. Arc5 crystallized as a monomer, bringing the number of known quaternary structures to seven. PMID:8955116

  15. Structured Data in Structural Analysis Software

    NASA Technical Reports Server (NTRS)

    Kunz, Donald L.; Hopkins, Stewart

    1987-01-01

    This paper discusses the use of computer data structures in finite-element structural analysis programs. A number of data structure types that have been shown to be useful in such programs are introduced and described. A simple finite-element model is used to demonstrate how the given set of data structure types naturally lend themselves to developing software for the model. Different methods of implementing data structures in the context of a program are discussed.

  16. 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

  17. Probing local structure in the yellow phosphor LaSr[subscript 2]AlO[subscript 5]:Ce[superscript 3+], by the maximum entropy method and pair distribution function analysis

    SciTech Connect

    Im, Won Bin; Page, Katharine; DenBaars, Steven P.; Seshadri, Ram

    2011-08-04

    The compound LaSr{sub 2}AlO{sub 5} was recently introduced as a competitive Ce{sup 3+} host material for blue-pumped yellow phosphors for use in white light emitting diodes. A crucial feature of the crystal structure of LaSr{sub 2}AlO{sub 5} is that La, which is the host site for Ce{sup 3+}, is located in the 8h positions of the I4/mcm crystal structure, a site equally shared with Sr. While the average crystal structure of LaSr{sub 2}AlO{sub 5} as revealed by Rietveld analysis of laboratory and synchrotron X-ray diffraction data suggests nothing untoward, maximum entropy method analysis of the synchrotron X-ray data reveals the existence of conspicuous non-sphericity of the electron density. Pair distribution function analysis of the data suggests that despite their occupying the same crystallographic site, La and Sr possess distinct coordination environments, and the environment around La is more compact and regular than the environment suggested by the Rietveld refinement of the average structure. The absorption and emission from Ce{sup 3+} centers is controlled by the local coordination and symmetry, and the use of powerful new tools in unraveling details of these strengthens the rational search for new phosphors for solid state white lighting.

  18. Magnetic multilayer structure

    DOEpatents

    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.

  19. Collapsible Geostrut Structure

    NASA Technical Reports Server (NTRS)

    Robertson, Glen A.

    1994-01-01

    Portable truss structure collapsible into smaller volume for storage and transportation. At new site, reerected quickly, without need to reassemble parts. Structure could be tent, dome, tunnel, or platform. Key element in structure joint, called "geostrut joint," includes internal cable. Structure is network of struts attached to geostrut joints. Pulling cables taut in all joints makes structure rigid. Releasing cables relaxes structure.

  20. 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

  1. Structural and magnetic properties of Co2Ti1-xFexAl (0 ≤ x ≤ 0.5) alloys

    NASA Astrophysics Data System (ADS)

    Pal, Lakhan; Gupta, Sachin; Suresh, K. G.

    2014-04-01

    In this work we studied the effect of partial Fe substitution for Ti on the structural and magnetic properties of the Co2TiAl. X-ray diffraction analysis indicates the presence of B2 type disorder for x > 0, (111) reflections are absent for x > 0 which is the characteristic of B2 type disorder. XRD analysis also shows presence of second phase. Magnetization measurements also confirm the presence of dual phase. Curie temperature of the alloys increases with increase in Fe concentration. Saturation magnetic moments agree very well with those calculated by Slater-Pauling rule.

  2. Structural models of mammalian mitochondrial transcription factor B2.

    PubMed

    Moustafa, Ibrahim M; Uchida, Akira; Wang, Yao; Yennawar, Neela; Cameron, Craig E

    2015-08-01

    Mammalian mitochondrial DNA (mtDNA) encodes 13 core proteins of oxidative phosphorylation, 12S and 16S ribosomal RNAs, and 22 transfer RNAs. Mutations and deletions of mtDNA and/or nuclear genes encoding mitochondrial proteins have been implicated in a wide range of diseases. Thus, cell survival and health of the organism require some steady-state level of the mitochondrial genome and its expression. In mammalian systems, the mitochondrial transcription factor B2 (mtTFB2 or TFB2M) is indispensable for transcription initiation. TFB2M along with two other proteins, mitochondrial RNA polymerase (mtRNAP or POLRMT) and mitochondrial transcription factor A (mtTFA or TFAM), are key components of the core mitochondrial transcription apparatus. Structural information for POLRMT and TFAM from humans is available; however, there is no available structure for TFB2M. In the present study, three-dimensional structure of TFB2M from humans was modeled using a combination of homology modeling and small-angle X-ray scattering (SAXS). The TFB2M structural model adds substantively to our understanding of TFB2M function. An explanation for the low or absent RNA methyltransferase activity is provided. A putative nucleic acid-binding site is revealed. The amino and carboxy termini, while likely lacking defined secondary structure, appear to adopt compact, globular conformations, thus "capping" the ends of the protein. Finally, sites of interaction of TFB2M with other factors, protein and/or nucleic acid, are suggested by the identification of species-specific clusters on the surface of the protein. PMID:26066983

  3. 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

  4. 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.

  5. 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. PMID:26888030

  6. 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'. PMID:27528775

  7. [The structure of the cercarian tegument of microphallid trematodes].

    PubMed

    Galaktionov, K V; Malkova, I I

    1990-01-01

    The tegument of mature cercariae of Microphallus sp. Podlipajev, 1979, M. claviformis, Levinseniella brachysoma and Maritrema subdolum consists of the outer syncytial layer filled with several types of secretory inclusions. Cytons and subtegumental cell ducts are absent. Covers of Microphallus cercariae have structure typical of larvae of trematodes. The tegument surface of L. brachysoma cercariae carries lamelli, spines are divided into two parts: short massive body sharpened at fore end and long thin stalk connected with basal membrane. The tegument surface of M. subdolum larvae forms tongue-like protrusions, modified spines serve as their frame. The development of tegument of the above species during cercaria morphogenesis has been traced. It is shown that at first in embryos syncytial lamina of the tegument is formed. Within it rudiments of spines have been detected as narrow transversal columns of mediate electron density. Henceforward syncytial layer has thickened, provisional spines have become conical, their matrix has become fibrous. Then the joining of protrusions of subtegumental glandular cells to outer syncytium has begun. These cells have been arranged into three types depending on the character of secret produced. The spines have acquired the species-specific structure. In members of the genus Microphallus they have become massive, and both in L. brachysoma and M. subdolum they have lengthened and subdivided into body and stalk. Spines of M. subdolum have flattened appreciably, their bodies have been found within tegumental tongue-like protrusions. PMID:2259525

  8. 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

  9. Daddy's Gone to Colorado: Male-Staffed Child Care for Father-Absent Boys.

    ERIC Educational Resources Information Center

    Brody, Steve

    1978-01-01

    The article presents the goals, methods, and case examples of The Nutury, a predominantly male-staffed child care center serving single-parent children. The primary goal is to provide consistent relationships with men for children without a male model in their home. Clinical observations reveal positive life-styles and attitudes. (LPG)

  10. 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…

  11. 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.

  12. Epithelial Label-Retaining Cells Are Absent during Tooth Cycling in Salmo salar and Polypterus senegalus.

    PubMed

    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

  13. Early Absent Pupillary Light Reflexes After Cardiac Arrest in Patients Treated with Therapeutic Hypothermia.

    PubMed

    Dhakal, Laxmi P; Sen, Ayan; Stanko, Carlene M; Rawal, Bhupendra; Heckman, Michael G; Hoyne, Jonathan B; Dimberg, Elliot L; Freeman, Michelle L; Ng, Lauren K; Rabinstein, Alejandro A; Freeman, William D

    2016-08-01

    Loss of pupillary light reactivity is one recognized indicator of poor prognosis after cardiopulmonary resuscitation (CPR). However, drug overdose, low cardiac output, and/or resuscitation drugs can lead to impaired pupillary light reflex. To investigate pupillary light reflex status before therapeutic hypothermia (TH) in relation to neurological outcome, we retrospectively reviewed the data of a prospectively implemented TH protocol in patients with cardiac arrest (CA) at Mayo Clinic in Jacksonville, Florida (January 2006-January 2012), and Mayo Clinic in Scottsdale, Arizona (August 2010-March 2014). During this period, all CA patients who underwent hypothermia were included. These patients were selected from an institutional database and hypothermia data set. The Cerebral Performance Category (CPC) at time of discharge was our primary outcome measure. A CPC of 1 to 2 was defined as good outcome and a CPC from 3 to 5 was defined as poor outcome. We identified 99 patients who had CA treated with TH. Twenty-nine patients (29%) had pupils that were nonreactive to light on admission examination before TH, eight of whom later had return of pupil reactivity by day 3. Two of these 29 patients (6.9%) had good outcome, compared to 24 of 70 patients (34.3%) with pupils that were reactive to light (p = 0.005). Both of these patients had CA after illicit drug overdose. Early nonreactive pupils occurred in almost a third of patients after CPR and before TH in our patient population. Recovery of pupillary light reactivity is possible, and in a small minority of those cases (particularly when CA is preceded by the use of illicit drugs), a good outcome can be achieved. PMID:27135180

  14. The memory enhancement effect of emotion is absent in conceptual implicit memory.

    PubMed

    Ramponi, Cristina; Handelsman, Gemma; Barnard, Philip J

    2010-04-01

    Memory for emotional stimuli is superior to memory for neutral stimuli. This study investigated whether this memory advantage is present in implicit memory. Memory was tested with a test of explicit memory (associate cued recall) and a test of conceptual implicit memory (free association) identical in all respects apart from the retrieval instructions. After studying emotional and neutral paired associates, participants saw the first member of the pair, the cue; in the test of explicit memory participants were instructed to recall the associate; in the test of implicit memory participants were instructed to generate the first word coming to mind associated to the word. Depth of study processing dissociated performance in the tests, confirming that the free-association test was not contaminated by an intentional retrieval strategy. Emotional pairs were better recalled than neutral pairs in the test of explicit memory but not in the equivalent test of implicit memory. The absence of an emotion effect in implicit memory implies that emotional material does not have a privileged global mnemonic status; intentional retrieval is necessary for observing the emotion-related memory advantage. PMID:20364908

  15. 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

  16. Activity-dependent hyperpolarization of EGABA is absent in cutaneous DRG neurons from inflamed rats

    PubMed Central

    Zhu, Yi; Zhang, Xiu-Lin; Gold, Michael S.

    2013-01-01

    A shift in GABAA signaling from inhibition to excitation in primary afferent neurons appears to contribute to the inflammation-induced increase in afferent input to the central nervous system (CNS). An activity-dependent depolarization of the GABA equilibrium potential (EGABA) has been described in CNS neurons which drives a shift in GABAA signaling from inhibition to excitation. The purpose of the present study was to determine if such an activity-dependent depolarization of EGABA occurs in primary afferents and whether the depolarization is amplified with persistent inflammation. Acutely dissociated retrogradely labeled cutaneous DRG neurons from naïve and inflamed rats were studied with gramicidin perforated patch recording. Rather than a depolarization, 200 action potentials delivered at 2 Hz resulted in a ~10 mV hyperpolarization of EGABA in cutaneous neurons from naïve rats. No such hyperpolarization was observed in neurons from inflamed rats. The shift in EGABA was not blocked by 10 µM bumetanide. Furthermore, because activity-dependent hyperpolarization of EGABA was fully manifest in the absence of HCO3− in the bath solution, this shift was not dependent on a change in HCO3−-Cl− exchanger activity, despite evidence of HCO3−-Cl− exchangers in DRG neurons that may contribute to the establishment of EGABA in the presence of HCO3−. While the mechanism underlying the activity-dependent hyperpolarization of EGABA has yet to be identified, because this mechanism appears to function as a form of feedback inhibition, facilitating GABA mediated inhibition of afferent activity, it may serve as a novel target for the treatment of inflammatory pain. PMID:24135545

  17. Exaggerated object affordance and absent automatic inhibition in alien hand syndrome

    PubMed Central

    McBride, Jennifer; Sumner, Petroc; Jackson, Stephen R.; Bajaj, Nin; Husain, Masud

    2013-01-01

    Patients with alien hand syndrome (AHS) experience making apparently deliberate and purposeful movements with their hand against their will. However, the mechanisms contributing to these involuntary actions remain poorly understood. Here, we describe two experimental investigations in a patient with corticobasal syndrome (CBS) with alien hand behaviour in her right hand. First, we show that responses with the alien hand are made significantly more quickly to images of objects which afford an action with that hand compared to objects which afford an action with the unaffected hand. This finding suggests that involuntary grasping behaviours in AHS might be due to exaggerated, automatic motor activation evoked by objects which afford actions with that limb. Second, using a backwards masked priming task, we found normal automatic inhibition of primed responses in the patient's unaffected hand, but importantly there was no evidence of such suppression in the alien limb. Taken together, these findings suggest that grasping behaviours in AHS may result from exaggerated object affordance effects, which might potentially arise from disrupted inhibition of automatically evoked responses. PMID:23433243

  18. Absent or low rate of adult neurogenesis in the hippocampus of bats (Chiroptera).

    PubMed

    Amrein, Irmgard; Dechmann, Dina K N; Winter, York; Lipp, Hans-Peter

    2007-01-01

    Bats are the only flying mammals and have well developed navigation abilities for 3D-space. Even bats with comparatively small home ranges cover much larger territories than rodents, and long-distance migration by some species is unique among small mammals. Adult proliferation of neurons, i.e., adult neurogenesis, in the dentate gyrus of rodents is thought to play an important role in spatial memory and learning, as indicated by lesion studies and recordings of neurons active during spatial behavior. Assuming a role of adult neurogenesis in hippocampal function, one might expect high levels of adult neurogenesis in bats, particularly among fruit- and nectar-eating bats in need of excellent spatial working memory. The dentate gyrus of 12 tropical bat species was examined immunohistochemically, using multiple antibodies against proteins specific for proliferating cells (Ki-67, MCM2), and migrating and differentiating neurons (Doublecortin, NeuroD). Our data show a complete lack of hippocampal neurogenesis in nine of the species (Glossophaga soricina, Carollia perspicillata, Phyllostomus discolor, Nycteris macrotis, Nycteris thebaica, Hipposideros cyclops, Neoromicia rendalli, Pipistrellus guineensis, and Scotophilus leucogaster), while it was present at low levels in three species (Chaerephon pumila, Mops condylurus and Hipposideros caffer). Although not all antigens were recognized in all species, proliferation activity in the subventricular zone and rostral migratory stream was found in all species, confirming the appropriateness of our methods for detecting neurogenesis. The small variation of adult hippocampal neurogenesis within our sample of bats showed no indication of a correlation with phylogenetic relationship, foraging strategy, type of hunting habitat or diet. Our data indicate that the widely accepted notion of adult neurogenesis supporting spatial abilities needs to be considered carefully. Given their astonishing longevity, certain bat species may be useful subjects to compare adult neurogenesis with other long-living species, such as monkeys and humans, showing low rates of adult hippocampal neurogenesis. PMID:17520014

  19. 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. PMID:25485199

  20. Intraflagellar transport is essential for mammalian spermiogenesis but is absent in mature sperm

    PubMed Central

    San Agustin, Jovenal T.; Pazour, Gregory J.; Witman, George B.

    2015-01-01

    Drosophila sperm are unusual in that they do not require the intraflagellar transport (IFT) system for assembly of their flagella. In the mouse, the IFT proteins are very abundant in testis, but we here show that mature sperm are completely devoid of them, making the importance of IFT to mammalian sperm development unclear. To address this question, we characterized spermiogenesis and fertility in the Ift88Tg737Rpw mouse. This mouse has a hypomorphic mutation in the gene encoding the IFT88 subunit of the IFT particle. This mutation is highly disruptive to ciliary assembly in other organs. Ift88−/− mice are completely sterile. They produce ∼350-fold fewer sperm than wild-type mice, and the remaining sperm completely lack or have very short flagella. The short flagella rarely have axonemes but assemble ectopic microtubules and outer dense fibers and accumulate improperly assembled fibrous sheath proteins. Thus IFT is essential for the formation but not the maintenance of mammalian sperm flagella. PMID:26424803

  1. 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

  2. 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…

  3. 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'. PMID:25549986

  4. 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

  5. Heavy-light, absent-present: rethinking the 'weight' of imprisonment.

    PubMed

    Crewe, Ben; Liebling, Alison; Hulley, Susie

    2014-09-01

    Since King and McDermott (1995), following Downes (1988), defined the psychological oppressiveness of incarceration in terms of 'weight', little has been written about the 'weight of imprisonment'. None the less, it is generally assumed that prisons that are 'light' are preferable to those that are 'heavy' - in part because of an assumption among many penologists that power, and its application, is dangerous and antagonistic. This article does not dispute that 'heavy' prisons are undesirable. Its argument is that there can also be dangers if prisons are excessively light. Many of these dangers are linked to the under-use of power. The tone and quality of prison life depends on the combined effects of institutional weight with the 'absence' or 'presence' of staff power. Drawing on prisoners' descriptions of their experiences in public and private sector prisons, and their assessments of important aspects of their quality of life, the article outlines what these concepts mean in practice. The authors develop a four-quadrant framework for conceptualizeng penal legitimacy and the experience of penal authority. PMID:25251137

  6. 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…

  7. 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

  8. Novel, congenital iliac arterial anatomy: Absent common iliac arteries and left internal iliac artery

    PubMed Central

    Green, Christopher S.; Helmy, Mohammed A.

    2015-01-01

    Congenital anomalies of the iliac arterial system are rare and can be associated with ischemia. With an increase in vascular imaging and interventions, such anomalies are likely to be encountered with greater frequency. We present the case of a 25-year-old female who was incidentally found to have absence of the common iliac arteries bilaterally and the left internal iliac artery, a constellation not previously reported in the literature. We present relevant imaging findings, review embryonic vascular development, and discuss potential clinical implications.

  9. Furin inhibition results in absent or decreased invasiveness and tumorigenicity of human cancer cells

    PubMed Central

    Bassi, Daniel E.; Lopez De Cicco, Ricardo; Mahloogi, Haleh; Zucker, Stanley; Thomas, Gary; Klein-Szanto, Andres J. P.

    2001-01-01

    Pro-protein convertases such as furin are expressed in many human tumor lines and primary tumors. Furin processes stromelysin-3, membrane type 1 matrix metalloproteinase (MMPs) involved in tumor cell invasiveness, as well as growth factors such as transforming growth factor β1. Evaluation of furin expression in head and neck squamous cell carcinoma (HNSCC) cells exhibiting different invasive ability showed that furin overexpression correlated with their respective invasiveness. The use of a selective furin inhibitor, alpha 1-PDX (PDX) was studied in three furin-expressing invasive HNSCC cell lines. The effects of PDX transfection were evaluated in vivo and in vitro to determine changes in the malignant phenotype. Transfection of HNSCC cell lines with PDX resulted in significant decrease or absence of tumorigenicity after s.c. inoculation into severe combined immunodeficient mice. Likewise, in vitro invasiveness was reduced ≈50%. The in vivo invasion assay using tracheal xenotransplants showed even more drastic reductions of the invasive ability of PDX-transfected cells (up to an 80% decrease). PDX-transfected cells did not invade or penetrated less into the tracheal wall tissues than their vector alone-transfected counterparts. In addition, the former cells showed a remarkable decrease in MMP-2 processing and activity. After PDX transfection the cells were less efficient in processing the tumor progression-associated furin substrates transforming growth factor β1 and pro-membrane type 1-MMP. These findings indicate that furin inhibition is a feasible approach to attenuate and even abolish certain critical attributes of the advanced malignant phenotype. Thus, furin should be considered as a promising target for cancer therapy. PMID:11517338

  10. 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…

  11. 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…

  12. 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…

  13. A receptor-like kinase mutant with absent endodermal diffusion barrier displays selective nutrient homeostasis defects

    PubMed Central

    Pfister, Alexandre; Barberon, Marie; Alassimone, Julien; Kalmbach, Lothar; Lee, Yuree; Vermeer, Joop EM; Yamazaki, Misako; Li, Guowei; Maurel, Christophe; Takano, Junpei; Kamiya, Takehiro; Salt, David E; Roppolo, Daniele; Geldner, Niko

    2014-01-01

    The endodermis represents the main barrier to extracellular diffusion in plant roots, and it is central to current models of plant nutrient uptake. Despite this, little is known about the genes setting up this endodermal barrier. In this study, we report the identification and characterization of a strong barrier mutant, schengen3 (sgn3). We observe a surprising ability of the mutant to maintain nutrient homeostasis, but demonstrate a major defect in maintaining sufficient levels of the macronutrient potassium. We show that SGN3/GASSHO1 is a receptor-like kinase that is necessary for localizing CASPARIAN STRIP DOMAIN PROTEINS (CASPs)—major players of endodermal differentiation—into an uninterrupted, ring-like domain. SGN3 appears to localize into a broader band, embedding growing CASP microdomains. The discovery of SGN3 strongly advances our ability to interrogate mechanisms of plant nutrient homeostasis and provides a novel actor for localized microdomain formation at the endodermal plasma membrane. DOI: http://dx.doi.org/10.7554/eLife.03115.001 PMID:25233277

  14. Does the Over-Claiming Questionnaire measure overclaiming? Absent convergent validity in a large community sample.

    PubMed

    Ludeke, Steven G; Makransky, Guido

    2016-06-01

    The Over-Claiming Questionnaire (OCQ) aims to provide a practical and cost-effective method of assessing individual differences in the tendency to misrepresent oneself in self-reports. OCQ bias measures have strong theoretical appeal but limited empirical demonstrations of validity. Using a sample of 704 adult community members, we found minimal support for the OCQ as an assessment of misrepresentation. We assessed misrepresentation by comparing self-reports of personality and cognitive ability against other criterion indicators of these trait levels (peer reports of personality and performance on a cognitive ability measure). OCQ bias measures bore no relationship with either of these self-criterion discrepancy measures, and were also unassociated with self-deceptive enhancement scores. One OCQ index bore a modest relationship to narcissism. OCQ bias measures were instead consistently and sometimes even highly related to measures of careless responding. However, statistically controlling for careless responding only minimally improved the convergent validity of OCQ bias indices. (PsycINFO Database Record PMID:26372263

  15. 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. PMID:25575435

  16. Acute audiovestibular deficit with complete ocular tilt reaction and absent VEMPs.

    PubMed

    Goto, Fumiyuki; Ban, Yumiko; Tsutumi, Tomoko

    2011-07-01

    A patient presenting with vertical diplopia along with ocular tilt reaction (OTR) due to peripheral vestibular dysfunction is a rare occurrence. OTR is an eye-head postural reaction consisting of head tilt, skew deviation, conjugated eye cyclotorsion, and alteration of vertical perception, and is thought to occur with central lesions, mainly brainstem lesions. Here, we report a case of a patient who was suffering from left acute peripheral cochleovestibular loss. He had profound deafness and absence of caloric response on the left side. No central lesion was observed on magnetic resonance images. Neuro-ophthalmological examination showed OTR consisting of head tilt, skew deviation with left hypotropia, excyclotorsion, and tilt of the static visual vertical directed to the left side. Both utricular and saccular dysfunctions were identified by the absence of cervical vestibular evoked myogenic potential (cVEMP) and ocular VEMP (oVEMP) on the left side. Within a month, the OTR disappeared completely probably because of vestibular compensation. This is the first report to state that the peripheral otolith dysfunction causing reversible vertical diplopia was identified by objective examinations (VEMP). PMID:21431953

  17. Molecular mechanism of male differentiation is conserved in the SRY-absent mammal, Tokudaia osimensis.

    PubMed

    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

  18. 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" (PFE) campaign. This…

  19. 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

  20. 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.

  1. 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

  2. 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…

  3. 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.…

  4. How absent negativity relates to affect and motivation: an integrative relief model.

    PubMed

    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

  5. 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…

  6. Absent effect of zinc deficiency on the oxidative stress of erythrocytes in chronic uremic rats.

    PubMed

    Chen, Shu-Ming; Wang, Ching-Chu; Lin, Fanny; Young, Tze-Kong

    2002-03-31

    Both anemia and zinc deficiency are commonly observed in patients with chronic uremia. Oxidative stress of red blood cells (RBC) has been suggested to participate in the development of anemia in these patients with chronic uremia due to reduced life span of RBC. Whether zinc deficiency aggravates the effect of oxidative stress on RBC of chronic uremia is still not understood. We thus performed the study to determine the influence of zinc deficiency on the oxidative stress of RBC in uremic rats. Zinc deficiency was induced by long-term dietary zinc deficiency. Five-sixth nephrectomy (5/6 Nx) was used to produce chronic uremia. Experiment was carried out in the following five groups: normal control (NL), chronic uremia (Nx), chronic uremia + dietary zinc deficiency (Nx-D), Nx-D + zinc supplement (Nx-DZ) and Chronic uremia + pair-fed (Nx-PF). Osmotic fragility and lipid peroxidation of RBC were used to evaluate the oxidative stress of RBC. Five weeks after 5/6 nephrectomy (Nx), 5/6 Nx rats present a syndrome of uremia to elevate the levels of plasma creatinine and urea, and reduce the level of plasma zinc (1.12 +/- 0.08 vs 1.35 +/- 0.05 ug/ml). But they does not find to produce anemia and to increase osmotic fragility and lipid peroxidation in RBC. Dietary zinc deficiency in Nx-D group produced severe anorexia and reduced plasma zinc and selenium levels and the activity of RBC-GPX. Yet in Nx-D rats, osmotic fragility and susceptibility of lipid peroxidation in red cells did not increase, because of the increase of plasma copper level (1.85 +/- 0.3 vs 1.41 +/- 0.05 microg/ml) and RBC-SOD activity (1.95 +/- 0.27 vs 0.78 +/- 0.05 unit/g Hb). Zinc supplement in Nx-D rats (Nx-DZ group) recovered the appetite and normalized the levels of plasma zinc, copper and selenium. Food restriction in 5/6 Nx rats (Nx-PF group) decreased plasma copper level and increased osmotic fragility of RBC and elevated the susceptibility of lipid peroxidation after stressing RBC with H2O2 Because Nx-PF rats presented a lower RBC-SOD activity (0.44 +/- 0.11 vs 0.78 +/- 0.05 unit/g Hb) and a lower plasma copper level. We further found a positive relationship (r=0. 802,p<0.01) between plasma copper level and RBC-SOD activity in normal and uremic rats. This study suggests that RBC-SOD activity may play an important role in preventing RBC oxidative stress. Plasma copper level may be a marker of RBC-SOD activity. We conclude, in chronic uremia, zinc deficiency doses not result in RBC oxidative stress as plasma copper level is normal, but may affect the absorption of intestinal nutrition. PMID:12005352

  7. Strategy Effects Counteract Distractor Inhibition: Negative Priming with Constantly Absent Probe Distractors

    ERIC Educational Resources Information Center

    Frings, Christian; Wentura, Dirk

    2006-01-01

    It is an accepted, albeit puzzling finding that negative priming (NP) hinges on the presence of distractors in probe displays. In three experiments without probe distractors, the authors yielded evidence that response-biasing processes based on the contingency between prime and probe displays may have caused this finding. It is argued that it is…

  8. Misdiagnosing Absent Pedicle of Cervical Spine in the Acute Trauma Setting.

    PubMed

    Abduljabbar, Fahad H; Rossel, Felipe; Nooh, Anas; Jarzem, Peter

    2015-09-28

    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

  9. 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…

  10. Absent CNKSR2 causes seizures and intellectual, attention, and language deficits.

    PubMed

    Vaags, Andrea K; Bowdin, Sarah; Smith, Mary-Lou; Gilbert-Dussardier, Brigitte; Brocke-Holmefjord, Katja S; Sinopoli, Katia; Gilles, Cindy; Haaland, Tove B; Vincent-Delorme, Catherine; Lagrue, Emmanuelle; Harbuz, Radu; Walker, Susan; Marshall, Christian R; Houge, Gunnar; Kalscheuer, Vera M; Scherer, Stephen W; Minassian, Berge A

    2014-11-01

    Synaptic function is central to brain function. Understanding the synapse is aided by studies of patients lacking individual synaptic proteins. Common neurological diseases are genetically complex. Their understanding is likewise simplified by studies of less common monogenic forms. We detail the disease caused by absence of the synaptic protein CNKSR2 in 8 patients ranging from 6 to 62 years old. The disease is characterized by intellectual disability, attention problems, and abrupt lifelong language loss following a brief early childhood epilepsy with continuous spike-waves in sleep. This study describes the phenotype of CNKSR2 deficiency and its involvement in systems underlying common neurological disorders. PMID:25223753

  11. 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. PMID:26710822

  12. 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…

  13. Large-scale remapping of visual cortex is absent in adult humans with macular degeneration.

    PubMed

    Baseler, Heidi A; Gouws, André; Haak, Koen V; Racey, Christopher; Crossland, Michael D; Tufail, Adnan; Rubin, Gary S; Cornelissen, Frans W; Morland, Antony B

    2011-05-01

    The occipital lobe contains retinotopic representations of the visual field. The representation of the central retina in early visual areas (V1-3) is found at the occipital pole. When the central retina is lesioned in both eyes by macular degeneration, this region of visual cortex at the occipital pole is accordingly deprived of input. However, even when such lesions occur in adulthood, some visually driven activity in and around the occipital pole can be observed. It has been suggested that this activity is a result of remapping of this area so that it now responds to inputs from intact, peripheral retina. We evaluated whether or not remapping of visual cortex underlies this activity. Our functional magnetic resonance imaging results provide no evidence of remapping, questioning the contemporary view that early visual areas of the adult human brain have the capacity to reorganize extensively. PMID:21441924

  14. 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…

  15. 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

  16. 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

    2016-07-01

    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

  17. Geophysical characterization of two circular structures at Bajada del Diablo (Patagonia, Argentina): Indication of impact origin

    NASA Astrophysics Data System (ADS)

    Prezzi, Claudia B.; Orgeira, María Julia; Acevedo, Rogelio D.; Ponce, Juan Federico; Martinez, Oscar; Rabassa, Jorge O.; Corbella, Hugo; Vásquez, Carlos; González-Guillot, Mauricio; Subías, Ignacio

    2012-02-01

    An impact origin has been proposed for the circular structures found in Bajada del Diablo, Patagonia, Argentina. Taking into account its extension and the number of impact structures, Bajada del Diablo would be the largest meteoritic impact areas known on Earth, being an extremely interesting area for the research of impact events and processes. Moreover, the global distribution of known impact structures shows a surprising asymmetry. Particularly, South America has only seven described areas. It is evident that this situation is an artifact, highlighting the importance of intensifying the research in the least studied areas such as Argentina. Circular structures in Bajada del Diablo have been identified on two rock types: the Quiñelaf eruptive complex and Pampa Sastre Formation. In the first case, circular structures are placed in olivine basalts. On the other hand, Pampa Sastre Formation (late Pliocene/early Pleistocene) corresponds to conglomerate layers with basalt clasts boulder and block in size in a coarse sandy matrix. With the aim of further the investigation of the proposed impact origin for these circular structures, we carried out detailed topographic, magnetic and electromagnetic ground surveys in two circular structures ("8" and "A") found in Pampa Sastre conglomerates. Both circular structures are simple, bowl-shaped with rim diameters of 300 m and maximum depths of 10 m. They have been partially filled in by debris flows from the rims and wind-blown sands. Two preliminary magnetic profiles have also been carried out in circular structure "G" found in Quiñelaf basalts. The magnetic anomalies show a circular pattern with a slightly negative and relatively flat signal in the circular structures' bases. Furthermore in the circular structures' rims, high-amplitude, conspicuous and localized (short wavelength) anomalies are observed. Such large amplitude and short wavelength anomalies are not detected outside the circular structures. For all used

  18. Computational structural mechanics for engine structures

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.

    1989-01-01

    The computational structural mechanics (CSM) program at Lewis encompasses: (1) fundamental aspects for formulating and solving structural mechanics problems, and (2) development of integrated software systems to computationally simulate the performance/durability/life of engine structures. It is structured to mainly supplement, complement, and whenever possible replace, costly experimental efforts which are unavoidable during engineering research and development programs. Specific objectives include: investigate unique advantages of parallel and multiprocesses for: reformulating/solving structural mechanics and formulating/solving multidisciplinary mechanics and develop integrated structural system computational simulators for: predicting structural performances, evaluating newly developed methods, and for identifying and prioritizing improved/missing methods needed. Herein the CSM program is summarized with emphasis on the Engine Structures Computational Simulator (ESCS). Typical results obtained using ESCS are described to illustrate its versatility.

  19. Structure-specificity relationships of an intracellular xylanase from Geobacillus stearothermophilus.

    PubMed

    Solomon, V; Teplitsky, A; Shulami, S; Zolotnitsky, G; Shoham, Y; Shoham, G

    2007-08-01

    Geobacillus stearothermophilus T-6 is a thermophilic Gram-positive bacterium that produces two selective family 10 xylanases which both take part in the complete degradation and utilization of the xylan polymer. The two xylanases exhibit significantly different substrate specificities. While the extracellular xylanase (XT6; MW 43.8 kDa) hydrolyzes the long and branched native xylan polymer, the intracellular xylanase (IXT6; MW 38.6 kDa) preferentially hydrolyzes only short xylo-oligosaccharides. In this study, the detailed three-dimensional structure of IXT6 is reported, as determined by X-ray crystallography. It was initially solved by molecular replacement and then refined at 1.45 A resolution to a final R factor of 15.0% and an R(free) of 19.0%. As expected, the structure forms the classical (alpha/beta)(8) fold, in which the two catalytic residues (Glu134 and Glu241) are located on the inner surface of the central cavity. The structure of IXT6 was compared with the highly homologous extracellular xylanase XT6, revealing a number of structural differences between the active sites of the two enzymes. In particular, structural differences derived from the unique subdomain in the carboxy-terminal region of XT6, which is completely absent in IXT6. These structural modifications may account for the significant differences in the substrate specificities of these otherwise very similar enzymes. PMID:17642511

  20. 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. PMID:23682125