WorldWideScience

Sample records for naked mole-rat brain

  1. Extreme hypoxia tolerance of naked mole-rat brain.

    Science.gov (United States)

    Larson, John; Park, Thomas J

    2009-12-09

    Mammalian brains have extremely high levels of aerobic metabolism and typically suffer irreversible damage after brief periods of oxygen deprivation such as occur during stroke or cardiac arrest. Here we report that brain tissue from naked mole-rats, rodents that live in a chronically low-oxygen environment, is remarkably resistant to hypoxia: naked mole-rat neurons maintain synaptic transmission much longer than mouse neurons and can recover from periods of anoxia exceeding 30 min. We suggest that brain tolerance to hypoxia may result from slowed or arrested brain development in these extremely long-lived animals.

  2. Distribution of vasopressin in the brain of the eusocial naked mole-rat.

    Science.gov (United States)

    Rosen, Greta J; De Vries, Geert J; Goldman, Sharry L; Goldman, Bruce D; Forger, Nancy G

    2007-02-20

    Naked mole-rats are eusocial rodents that live in large subterranean colonies in which one queen breeds with one to three males. All other animals are nonbreeding subordinates. The external features of male and female subordinates, including their genitalia, are remarkably monomorphic, as is their behavior. Because vasopressin (VP) is associated with social behaviors and sex differences in other species, its distribution in naked mole-rats was of interest. We used immunohistochemistry to examine VP in the brains of subordinate and breeding naked mole-rats of both sexes. As in other mammals, VP-immunoreactive (-ir) somata were found in the paraventricular (PVN) and supraoptic nuclei (SON) and VP-ir projections from these nuclei ran through the internal and external zone of the median eminence. However, naked mole-rats had very few VP-ir cells in the bed nucleus of the stria terminalis (BST) and none in the suprachiasmatic nucleus (SCN); the extensive network of fine-caliber VP-ir fibers usually seen in projection sites of the BST and SCN were also absent. Equally unexpected was the abundance of large-caliber VP-ir fibers in the dorsomedial septum. VP immunoreactivity was generally similar in all groups, with the exception of VP-ir cell number in the dorsomedial hypothalamus (DMH). Breeders had a population of labeled cells in the DMH that was absent, or nearly absent, in subordinates. Future studies on the function of VP in these areas are needed to determine how the atypical distribution of VP immunoreactivity relates to eusociality and the unusual physiology of naked mole-rats.

  3. Multidimensional MRI-CT atlas of the naked mole-rat brain (Heterocephalus glaber).

    Science.gov (United States)

    Seki, Fumiko; Hikishima, Keigo; Nambu, Sanae; Okanoya, Kazuo; Okano, Hirotaka J; Sasaki, Erika; Miura, Kyoko; Okano, Hideyuki

    2013-01-01

    Naked mole-rats have a variety of distinctive features such as the organization of a hierarchical society (known as eusociality), extraordinary longevity, and cancer resistance; thus, it would be worthwhile investigating these animals in detail. One important task is the preparation of a brain atlas database that provide comprehensive information containing multidimensional data with various image contrasts, which can be achievable using a magnetic resonance imaging (MRI). Advanced MRI techniques such as diffusion tensor imaging (DTI), which generates high contrast images of fiber structures, can characterize unique morphological properties in addition to conventional MRI. To obtain high spatial resolution images, MR histology, DTI, and X-ray computed tomography were performed on the fixed adult brain. Skull and brain structures were segmented as well as reconstructed in stereotaxic coordinates. Data were also acquired for the neonatal brain to allow developmental changes to be observed. Moreover, in vivo imaging of naked mole-rats was established as an evaluation tool of live animals. The data obtained comprised three-dimensional (3D) images with high tissue contrast as well as stereotaxic coordinates. Developmental differences in the visual system were highlighted in particular by DTI. Although it was difficult to delineate optic nerves in the mature adult brain, parts of them could be distinguished in the immature neonatal brain. From observation of cortical thickness, possibility of high somatosensory system development replaced to the visual system was indicated. 3D visualization of brain structures in the atlas as well as the establishment of in vivo imaging would promote neuroimaging researches towards detection of novel characteristics of eusocial naked mole-rats.

  4. Multidimensional MRI-CT atlas of the naked mole-rat brain

    Directory of Open Access Journals (Sweden)

    Fumiko eSeki

    2013-12-01

    Full Text Available Naked mole-rats have a variety of distinctive features such as the organisation of a hierarchical society (known as eusociality, extraordinary longevity, and cancer resistance; thus, it would be worthwhile investigating these animals in detail. One important task is the preparation of a brain atlas database that provide comprehensive information containing multidimensional data with various image contrasts, which can be achievable using a magnetic resonance imaging (MRI. Advanced MRI techniques such as diffusion tensor imaging (DTI, which generates high contrast images of fibre structures, can characterise unique morphological properties in addition to conventional MRI. To obtain high spatial resolution images, MR histology, DTI, and X-ray computed tomography (CT were performed on the fixed adult brain. Skull and brain structures were segmented as well as reconstructed in stereotaxic coordinates. Data were also acquired for the neonatal brain to allow developmental changes to be observed. Moreover, in vivo imaging of naked mole-rats was established as an evaluation tool of live animals. The data obtained comprised three-dimensional (3D images with high tissue contrast as well as stereotaxic coordinates. Developmental differences in the visual system were highlighted in particular by DTI. Although it was difficult to delineate optic nerves in the mature adult brain, parts of them could be distinguished in the immature neonatal brain. From observation of cortical thickness, possibility of high somatosensory system development replaced to the visual system was indicated. 3D visualisation of brain structures in the atlas as well as the establishment of in vivo imaging would promote neuroimaging researches towards detection of novel characteristics of eusocial naked mole-rats.

  5. Adult naked mole-rat brain retains the NMDA receptor subunit GluN2D associated with hypoxia tolerance in neonatal mammals.

    Science.gov (United States)

    Peterson, Bethany L; Park, Thomas J; Larson, John

    2012-01-11

    Adult naked mole-rats show a number of systemic adaptations to a crowded underground habitat that is low in oxygen and high in carbon dioxide. Remarkably, brain slice tissue from adult naked mole-rats also is extremely tolerant to oxygen deprivation as indicated by maintenance of synaptic transmission under hypoxic conditions as well as by a delayed neuronal depolarization during anoxia. These characteristics resemble hypoxia tolerance in brain slices from neonates in a variety of mammal species. An important component of neonatal tolerance to hypoxia involves the subunit composition of NMDA receptors. Neonates have a high proportion of NMDA receptors with GluN2D subunits which are protective because they retard calcium entry into neurons during hypoxic episodes. Therefore, we hypothesized that adult naked mole-rats retain a protective, neonatal-like, NMDA receptor subunit profile. We used immunoblotting to assess age-related changes in NMDA receptor subunits in naked mole-rats and mice. The results show that adult naked mole-rat brain retains a much greater proportion of the hypoxia-protective GluN2D subunit compared to adult mice. However, age-related changes in other subunits (GluN2A and GluN2B) from the neonatal period to adulthood were comparable in mice and naked mole-rats. Hence, adult naked mole-rat brain only retains the neonatal NMDA receptor subunit that is associated with hypoxia tolerance. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  6. Social status and sex independently influence androgen receptor expression in the eusocial naked mole-rat brain.

    Science.gov (United States)

    Holmes, Melissa M; Goldman, Bruce D; Forger, Nancy G

    2008-08-01

    Naked mole-rats (Heterocephalus glaber) are eusocial rodents that live in large subterranean colonies including a single breeding female and 1-3 breeding males; all other members of the colony, known as subordinates, are reproductively suppressed. We recently found that naked mole-rats lack many of the sex differences in the brain and spinal cord commonly found in other rodents. Instead, neural morphology is influenced by breeding status, such that breeders, regardless of sex, have more neurons than subordinates in the ventromedial nucleus of the hypothalamus (VMH), and larger overall volumes of the bed nucleus of the stria terminalis (BST), paraventricular nucleus (PVN) and medial amygdala (MeA). To begin to understand how breeding status influences brain morphology, we examined the distribution of androgen receptor (AR) immunoreactivity in gonadally intact breeders and subordinates of both sexes. All animals had AR+ nuclei in many of the same regions positive for AR in other mammals, including the VMH, BST, PVN, MeA, and the ventral portion of the premammillary nucleus (PMv). We also observed diffuse labeling throughout the preoptic area, demonstrating that distribution of the AR protein in presumptive reproductive brain nuclei is well-conserved, even in a species that exhibits remarkably little sexual dimorphism. In contrast to other rodents, however, naked mole-rats lacked AR+ nuclei in the suprachiasmatic nucleus and hippocampus. Males had more AR+ nuclei in the MeA, VMH, and PMv than did females. Surprisingly, breeders had significantly fewer AR+ nuclei than subordinates in all brain regions examined (VMH, BST, PVN, MeA, and PMv). Thus, social status is strongly correlated with AR immunoreactivity in this eusocial species.

  7. Metabolic clues to salubrious longevity in the brain of the longest-lived rodent: the naked mole-rat.

    Science.gov (United States)

    Triplett, Judy C; Swomley, Aaron; Kirk, Jessime; Lewis, Katilyn; Orr, Miranda; Rodriguez, Karl; Cai, Jian; Klein, Jon B; Buffenstein, Rochelle; Butterfield, D Allan

    2015-08-01

    Naked mole-rats (NMRs) are the oldest-living rodent species. Living underground in a thermally stable ecological niche, NMRs have evolved certain exceptional traits, resulting in sustained health spans, negligible cognitive decline, and a pronounced resistance to age-related disease. Uncovering insights into mechanisms underlying these extraordinary traits involved in successful aging may conceivably provide crucial clues to extend the human life span and health span. One of the most fundamental processes inside the cell is the production of ATP, which is an essential fuel in driving all other energy-requiring cellular activities. Not surprisingly, a prominent hallmark in age-related diseases, such as neurodegeneration and cancer, is the impairment and dysregulation of metabolic pathways. Using a two-dimensional polyacrylamide gel electrophoresis proteomics approach, alterations in expression and phosphorylation levels of metabolic proteins in the brains of NMRs, aged 2-24 years, were evaluated in an age-dependent manner. We identified 13 proteins with altered levels and/or phosphorylation states that play key roles in various metabolic pathways including glycolysis, β-oxidation, the malate-aspartate shuttle, the Tricarboxylic Acid Cycle (TCA) cycle, the electron transport chain, NADPH production, as well as the production of glutamate. New insights into potential pathways involved in metabolic aspects of successful aging have been obtained by the identification of key proteins through which the NMR brain responds and adapts to the aging process and how the NMR brain adapted to resist age-related degeneration. This study examines the changes in the proteome and phosphoproteome in the brain of the naked mole-rat aged 2-24 years. We identified 13 proteins (labeled in red) with altered expression and/or phosphorylation levels that are conceivably associated with sustained metabolic functions in the oldest NMRs that may promote a sustained health span and life span.

  8. Genome Stability Maintenance in Naked Mole-Rat.

    Science.gov (United States)

    Petruseva, I O; Evdokimov, A N; Lavrik, O I

    2017-01-01

    The naked mole-rat ( Heterocephalus glaber ) is one of the most promising models used to study genome maintenance systems, including the effective repair of damage to DNA. The naked mole-rat is the longest lived rodent species, which is extraordinarily resistant to cancer and has a number of other unique phenotypic traits. For at least 80% of its lifespan, this animal shows no signs of aging or any increased likelihood of death and retains the ability to reproduce. The naked mole-rat draws the heightened attention of researchers who study the molecular basis of lengthy lifespan and cancer resistance. Despite the fact that the naked mole-rat lives under genotoxic stress conditions (oxidative, etc.), the main characteristics of its genome and proteome are a high stability and effective functioning. Replicative senescence in the somatic cells of naked mole-rats is missing, while an additional p53/pRb-dependent mechanism of early contact inhibition has been revealed in its fibroblasts, which controls cell proliferation and its mechanism of arf- dependent aging. The unique traits of phenotypic and molecular adaptations found in the naked mole-rat speak to a high stability and effective functioning of the molecular machinery that counteract damage accumulation in its genome. This review analyzes existing results in the study of the molecular basis of longevity and high cancer resistance in naked mole-rats.

  9. Removal of reproductive suppression reveals latent sex differences in brain steroid hormone receptors in naked mole-rats, Heterocephalus glaber.

    Science.gov (United States)

    Swift-Gallant, Ashlyn; Mo, Kaiguo; Peragine, Deane E; Monks, D Ashley; Holmes, Melissa M

    2015-01-01

    Naked mole-rats are eusocial mammals, living in large colonies with a single breeding female and 1-3 breeding males. Breeders are socially dominant, and only the breeders exhibit traditional sex differences in circulating gonadal steroid hormones and reproductive behaviors. Non-reproductive subordinates also fail to show sex differences in overall body size, external genital morphology, and non-reproductive behaviors. However, subordinates can transition to breeding status if removed from their colony and housed with an opposite-sex conspecific, suggesting the presence of latent sex differences. Here, we assessed the expression of steroid hormone receptor and aromatase messenger RNA (mRNA) in the brains of males and females as they transitioned in social and reproductive status. We compared in-colony subordinates to opposite-sex subordinate pairs that were removed from their colony for either 1 day, 1 week, 1 month, or until they became breeders (i.e., produced a litter). Diencephalic tissue was collected and mRNA of androgen receptor (Ar), estrogen receptor alpha (Esr1), progesterone receptor (Pgr), and aromatase (Cyp19a1) was measured using qPCR. Testosterone, 17β-estradiol, and progesterone from serum were also measured. As early as 1 week post-removal, males exhibited increased diencephalic Ar mRNA and circulating testosterone, whereas females had increased Cyp19a1 mRNA in the diencephalon. At 1 month post-removal, females exhibited increased 17β-estradiol and progesterone. The largest changes in steroid hormone receptors were observed in breeders. Breeding females had a threefold increase in Cyp19a1 and fivefold increases in Esr1 and Pgr, whereas breeding males had reduced Pgr and increased Ar. These data demonstrate that sex differences in circulating gonadal steroids and hypothalamic gene expression emerge weeks to months after subordinate animals are removed from reproductive suppression in their home colony.

  10. Fructose-driven glycolysis supports anoxia resistance in the naked mole-rat.

    Science.gov (United States)

    Park, Thomas J; Reznick, Jane; Peterson, Bethany L; Blass, Gregory; Omerbašić, Damir; Bennett, Nigel C; Kuich, P Henning J L; Zasada, Christin; Browe, Brigitte M; Hamann, Wiebke; Applegate, Daniel T; Radke, Michael H; Kosten, Tetiana; Lutermann, Heike; Gavaghan, Victoria; Eigenbrod, Ole; Bégay, Valérie; Amoroso, Vince G; Govind, Vidya; Minshall, Richard D; Smith, Ewan St J; Larson, John; Gotthardt, Michael; Kempa, Stefan; Lewin, Gary R

    2017-04-21

    The African naked mole-rat's ( Heterocephalus glaber ) social and subterranean lifestyle generates a hypoxic niche. Under experimental conditions, naked mole-rats tolerate hours of extreme hypoxia and survive 18 minutes of total oxygen deprivation (anoxia) without apparent injury. During anoxia, the naked mole-rat switches to anaerobic metabolism fueled by fructose, which is actively accumulated and metabolized to lactate in the brain. Global expression of the GLUT5 fructose transporter and high levels of ketohexokinase were identified as molecular signatures of fructose metabolism. Fructose-driven glycolytic respiration in naked mole-rat tissues avoids feedback inhibition of glycolysis via phosphofructokinase, supporting viability. The metabolic rewiring of glycolysis can circumvent the normally lethal effects of oxygen deprivation, a mechanism that could be harnessed to minimize hypoxic damage in human disease. Copyright © 2017, American Association for the Advancement of Science.

  11. Extended postnatal brain development in the longest-lived rodent: prolonged maintenance of neotenous traits in the naked mole-rat brain

    Directory of Open Access Journals (Sweden)

    Miranda E. Orr

    2016-11-01

    Full Text Available The naked mole-rat (NMR is the longest-lived rodent with a maximum lifespan >31 years. Intriguingly, fully-grown naked mole-rats (NMRs exhibit many traits typical of neonatal rodents. However, little is known about NMR growth and maturation, and we question whether sustained neotenous features when compared to mice, reflect an extended developmental period, commensurate with their exceptionally long life. We tracked development from birth to three years of age in the slowest maturing organ, the brain, by measuring mass, neural stem cell proliferation, axonal and dendritic maturation, synaptogenesis and myelination. NMR brain maturation was compared to data from similar sized rodents, mice, and to that of long-lived mammals, humans and non-human primates. We found that at birth, NMR brains are significantly more developed than mice, and rather are more similar to those of newborn primates, with clearly laminated hippocampi and myelinated white matter tracts. Despite this more mature brain at birth than mice, postnatal NMR brain maturation occurs at a far slower rate than mice, taking four-times longer than required for mice to fully complete brain development. At four months of age, NMR brains reach 90% of adult size with stable neuronal cytostructural protein expression whereas myelin protein expression does not plateau until nine months of age in NMRs, and synaptic protein expression continues to change throughout the first three years of life. Intriguingly, NMR axonal composition is more similar to humans than mice whereby NMRs maintain expression of three-repeat (3R tau even after brain growth is complete; mice experience an abrupt downregulation of 3R tau by postnatal day 8 which continues to diminish through six weeks of age. We have identified key ages in NMR cerebral development and suggest that the long-lived NMR may provide neurobiologists an exceptional model to study brain developmental processes that are compressed in common short

  12. Extended Postnatal Brain Development in the Longest-Lived Rodent: Prolonged Maintenance of Neotenous Traits in the Naked Mole-Rat Brain.

    Science.gov (United States)

    Orr, Miranda E; Garbarino, Valentina R; Salinas, Angelica; Buffenstein, Rochelle

    2016-01-01

    The naked mole-rat (NMR) is the longest-lived rodent with a maximum lifespan >31 years. Intriguingly, fully-grown naked mole-rats (NMRs) exhibit many traits typical of neonatal rodents. However, little is known about NMR growth and maturation, and we question whether sustained neotenous features when compared to mice, reflect an extended developmental period, commensurate with their exceptionally long life. We tracked development from birth to 3 years of age in the slowest maturing organ, the brain, by measuring mass, neural stem cell proliferation, axonal, and dendritic maturation, synaptogenesis and myelination. NMR brain maturation was compared to data from similar sized rodents, mice, and to that of long-lived mammals, humans, and non-human primates. We found that at birth, NMR brains are significantly more developed than mice, and rather are more similar to those of newborn primates, with clearly laminated hippocampi and myelinated white matter tracts. Despite this more mature brain at birth than mice, postnatal NMR brain maturation occurs at a far slower rate than mice, taking four-times longer than required for mice to fully complete brain development. At 4 months of age, NMR brains reach 90% of adult size with stable neuronal cytostructural protein expression whereas myelin protein expression does not plateau until 9 months of age in NMRs, and synaptic protein expression continues to change throughout the first 3 years of life. Intriguingly, NMR axonal composition is more similar to humans than mice whereby NMRs maintain expression of three-repeat (3R) tau even after brain growth is complete; mice experience an abrupt downregulation of 3R tau by postnatal day 8 which continues to diminish through 6 weeks of age. We have identified key ages in NMR cerebral development and suggest that the long-lived NMR may provide neurobiologists an exceptional model to study brain developmental processes that are compressed in common short-lived laboratory animal models.

  13. Blunted neuronal calcium response to hypoxia in naked mole-rat hippocampus.

    Directory of Open Access Journals (Sweden)

    Bethany L Peterson

    Full Text Available Naked mole-rats are highly social and strictly subterranean rodents that live in large communal colonies in sealed and chronically oxygen-depleted burrows. Brain slices from naked mole-rats show extreme tolerance to hypoxia compared to slices from other mammals, as indicated by maintenance of synaptic transmission under more hypoxic conditions and three fold longer latency to anoxic depolarization. A key factor in determining whether or not the cellular response to hypoxia is reversible or leads to cell death may be the elevation of intracellular calcium concentration. In the present study, we used fluorescent imaging techniques to measure relative intracellular calcium changes in CA1 pyramidal cells of hippocampal slices during hypoxia. We found that calcium accumulation during hypoxia was significantly and substantially attenuated in slices from naked mole-rats compared to slices from laboratory mice. This was the case for both neonatal (postnatal day 6 and older (postnatal day 20 age groups. Furthermore, while both species demonstrated more calcium accumulation at older ages, the older naked mole-rats showed a smaller calcium accumulation response than even the younger mice. A blunted intracellular calcium response to hypoxia may contribute to the extreme hypoxia tolerance of naked mole-rat neurons. The results are discussed in terms of a general hypothesis that a very prolonged or arrested developmental process may allow adult naked mole-rat brain to retain the hypoxia tolerance normally only seen in neonatal mammals.

  14. Blunted neuronal calcium response to hypoxia in naked mole-rat hippocampus.

    Science.gov (United States)

    Peterson, Bethany L; Larson, John; Buffenstein, Rochelle; Park, Thomas J; Fall, Christopher P

    2012-01-01

    Naked mole-rats are highly social and strictly subterranean rodents that live in large communal colonies in sealed and chronically oxygen-depleted burrows. Brain slices from naked mole-rats show extreme tolerance to hypoxia compared to slices from other mammals, as indicated by maintenance of synaptic transmission under more hypoxic conditions and three fold longer latency to anoxic depolarization. A key factor in determining whether or not the cellular response to hypoxia is reversible or leads to cell death may be the elevation of intracellular calcium concentration. In the present study, we used fluorescent imaging techniques to measure relative intracellular calcium changes in CA1 pyramidal cells of hippocampal slices during hypoxia. We found that calcium accumulation during hypoxia was significantly and substantially attenuated in slices from naked mole-rats compared to slices from laboratory mice. This was the case for both neonatal (postnatal day 6) and older (postnatal day 20) age groups. Furthermore, while both species demonstrated more calcium accumulation at older ages, the older naked mole-rats showed a smaller calcium accumulation response than even the younger mice. A blunted intracellular calcium response to hypoxia may contribute to the extreme hypoxia tolerance of naked mole-rat neurons. The results are discussed in terms of a general hypothesis that a very prolonged or arrested developmental process may allow adult naked mole-rat brain to retain the hypoxia tolerance normally only seen in neonatal mammals.

  15. High molecular weight hyaluronan mediates the cancer resistance of the naked mole-rat

    OpenAIRE

    Tian, Xiao; Azpurua, Jorge; Hine, Christopher; Vaidya, Amita; Myakishev-Rempel, Max; Ablaeva, Julia; Mao, Zhiyong; Nevo, Eviatar; Gorbunova, Vera; Seluanov, Andrei

    2013-01-01

    The naked mole-rat displays exceptional longevity, with a maximum lifespan exceeding 30 years 1–3 . This is the longest reported lifespan for a rodent species and is especially striking considering the small body mass of the naked mole-rat. In comparison, a similarly sized house mouse has a maximum lifespan of 4 years 4,5 . In addition to their longevity, naked mole-rats show an unusual resistance to cancer. Multi-year observations of large naked mole-rat colonies did not detect a single inci...

  16. Naked mole-rat cortical neurons are resistant to acid-induced cell death

    OpenAIRE

    Husson, Zoé; Smith, Ewan S

    2018-01-01

    Abstract Regulation of brain pH is a critical homeostatic process and changes in brain pH modulate various ion channels and receptors and thus neuronal excitability. Tissue acidosis, resulting from hypoxia or hypercapnia, can activate various proteins and ion channels, among which acid-sensing ion channels (ASICs) a family of primarily Na+ permeable ion channels, which alongside classical excitotoxicity causes neuronal death. Naked mole-rats (NMRs, Heterocephalus glaber) are ...

  17. High molecular weight hyaluronan mediates the cancer resistance of the naked mole-rat

    Science.gov (United States)

    Tian, Xiao; Azpurua, Jorge; Hine, Christopher; Vaidya, Amita; Myakishev-Rempel, Max; Ablaeva, Julia; Mao, Zhiyong; Nevo, Eviatar; Gorbunova, Vera; Seluanov, Andrei

    2013-01-01

    The naked mole-rat displays exceptional longevity, with a maximum lifespan exceeding 30 years1–3. This is the longest reported lifespan for a rodent species and is especially striking considering the small body mass of the naked mole-rat. In comparison, a similarly sized house mouse has a maximum lifespan of 4 years4,5. In addition to their longevity, naked mole-rats show an unusual resistance to cancer. Multi-year observations of large naked mole-rat colonies did not detect a single incidence of cancer2,6. Here we identify a mechanism responsible for the naked mole-rat’s cancer resistance. We found that naked mole-rat fibroblasts secrete extremely high molecular weight hyaluronan (HA), which is over five times larger than human or mouse HA. This high molecular weight HA accumulates abundantly in naked mole rat tissues due to the decreased activity of HA-degrading enzymes and a unique sequence of hyaluronan synthase 2 (HAS2). Furthermore, the naked mole-rat cells are more sensitive to HA signaling, as the naked mole rat cells have a higher affinity to HA than the mouse or human cells. Perturbation of the signaling pathways sufficient for malignant transformation of mouse fibroblasts fails to transform naked mole-rat cells. However, once high molecular weight HA is removed by either knocking down HAS2 or overexpressing the HA-degrading enzyme, Hyal2, naked mole-rat cells become susceptible to malignant transformation and readily form tumors in mice. We speculate that naked mole-rats have evolved a higher concentration of HA in the skin to provide skin elasticity needed for life in underground tunnels. This trait may have then been co-opted to provide cancer resistance and longevity to this species. PMID:23783513

  18. High-molecular-mass hyaluronan mediates the cancer resistance of the naked mole rat.

    Science.gov (United States)

    Tian, Xiao; Azpurua, Jorge; Hine, Christopher; Vaidya, Amita; Myakishev-Rempel, Max; Ablaeva, Julia; Mao, Zhiyong; Nevo, Eviatar; Gorbunova, Vera; Seluanov, Andrei

    2013-07-18

    The naked mole rat (Heterocephalus glaber) displays exceptional longevity, with a maximum lifespan exceeding 30 years. This is the longest reported lifespan for a rodent species and is especially striking considering the small body mass of the naked mole rat. In comparison, a similarly sized house mouse has a maximum lifespan of 4 years. In addition to their longevity, naked mole rats show an unusual resistance to cancer. Multi-year observations of large naked mole-rat colonies did not detect a single incidence of cancer. Here we identify a mechanism responsible for the naked mole rat's cancer resistance. We found that naked mole-rat fibroblasts secrete extremely high-molecular-mass hyaluronan (HA), which is over five times larger than human or mouse HA. This high-molecular-mass HA accumulates abundantly in naked mole-rat tissues owing to the decreased activity of HA-degrading enzymes and a unique sequence of hyaluronan synthase 2 (HAS2). Furthermore, the naked mole-rat cells are more sensitive to HA signalling, as they have a higher affinity to HA compared with mouse or human cells. Perturbation of the signalling pathways sufficient for malignant transformation of mouse fibroblasts fails to transform naked mole-rat cells. However, once high-molecular-mass HA is removed by either knocking down HAS2 or overexpressing the HA-degrading enzyme, HYAL2, naked mole-rat cells become susceptible to malignant transformation and readily form tumours in mice. We speculate that naked mole rats have evolved a higher concentration of HA in the skin to provide skin elasticity needed for life in underground tunnels. This trait may have then been co-opted to provide cancer resistance and longevity to this species.

  19. Sex, social status, and CRF receptor densities in naked mole-rats.

    Science.gov (United States)

    Beery, Annaliese K; Bicks, Lucy; Mooney, Skyler J; Goodwin, Nastacia L; Holmes, Melissa M

    2016-02-01

    Naked mole-rats (Heterocephalus glaber) live in groups that are notable for their large size and caste structure, with breeding monopolized by a single female and a small number of males. Recent studies have demonstrated substantial differences between the brains of breeders and subordinates induced by changes in social standing. Corticotropin-releasing factor (CRF) receptors-which bind the hormone CRF as well as related peptides-are important regulators of stress and anxiety, and are emerging as factors affecting social behavior. We conducted autoradiographic analyses of CRF1 and CRF2 receptor binding densities in female and male naked mole-rats varying in breeding status. Both globally and in specific brain regions, CRF1 receptor densities varied with breeding status. CRF1 receptor densities were higher in subordinates across brain regions, and particularly in the piriform cortex and cortical amygdala. Sex differences were present in CRF2 receptor binding densities, as is the case in multiple vole species. CRF2 receptor densities were higher in females, both globally and in the cortical amygdala and lateral amygdalar nucleus. These results provide novel insights into the neurobiology of social hierarchy in naked mole-rats, and add to a growing body of work that links changes in the CRF system with social behavior. © 2015 Wiley Periodicals, Inc.

  20. Genome sequencing reveals insights into physiology and longevity of the naked mole rat

    DEFF Research Database (Denmark)

    Kim, Eun Bae; Fang, Xiaodong; Fushan, Alexey A

    2011-01-01

    The naked mole rat (Heterocephalus glaber) is a strictly subterranean, extraordinarily long-lived eusocial mammal. Although it is the size of a mouse, its maximum lifespan exceeds 30 years, making this animal the longest-living rodent. Naked mole rats show negligible senescence, no age......-related increase in mortality, and high fecundity until death. In addition to delayed ageing, they are resistant to both spontaneous cancer and experimentally induced tumorigenesis. Naked mole rats pose a challenge to the theories that link ageing, cancer and redox homeostasis. Although characterized...... by significant oxidative stress, the naked mole rat proteome does not show age-related susceptibility to oxidative damage or increased ubiquitination. Naked mole rats naturally reside in large colonies with a single breeding female, the 'queen', who suppresses the sexual maturity of her subordinates. They also...

  1. The Naked Mole Rat Genome Resource: facilitating analyses of cancer and longevity-related adaptations.

    Science.gov (United States)

    Keane, Michael; Craig, Thomas; Alföldi, Jessica; Berlin, Aaron M; Johnson, Jeremy; Seluanov, Andrei; Gorbunova, Vera; Di Palma, Federica; Lindblad-Toh, Kerstin; Church, George M; de Magalhães, João Pedro

    2014-12-15

    The naked mole rat (Heterocephalus glaber) is an exceptionally long-lived and cancer-resistant rodent native to East Africa. Although its genome was previously sequenced, here we report a new assembly sequenced by us with substantially higher N50 values for scaffolds and contigs. We analyzed the annotation of this new improved assembly and identified candidate genomic adaptations which may have contributed to the evolution of the naked mole rat's extraordinary traits, including in regions of p53, and the hyaluronan receptors CD44 and HMMR (RHAMM). Furthermore, we developed a freely available web portal, the Naked Mole Rat Genome Resource (http://www.naked-mole-rat.org), featuring the data and results of our analysis, to assist researchers interested in the genome and genes of the naked mole rat, and also to facilitate further studies on this fascinating species. © The Author 2014. Published by Oxford University Press.

  2. Cutaneous and periodontal inputs to the cerebellum of the naked mole-rat (Heterocephalus glaber).

    Science.gov (United States)

    Sarko, Diana K; Leitch, Duncan B; Catania, Kenneth C

    2013-01-01

    The naked mole-rat (Heterocephalus glaber) is a small fossorial rodent with specialized dentition that is reflected by the large cortical area dedicated to representation of the prominent incisors. Due to naked mole-rats' behavioral reliance on the incisors for digging and for manipulating objects, as well as their ability to move the lower incisors independently, we hypothesized that expanded somatosensory representations of the incisors would be present within the cerebellum in order to accommodate a greater degree of proprioceptive, cutaneous, and periodontal input. Multiunit electrophysiological recordings targeting the ansiform lobule were used to investigate tactile inputs from receptive fields on the entire body with a focus on the incisors. Similar to other rodents, a fractured somatotopy appeared to be present with discrete representations of the same receptive fields repeated within each folium of the cerebellum. These findings confirm the presence of somatosensory inputs to a large area of the naked mole-rat cerebellum with particularly extensive representations of the lower incisors and mystacial vibrissae. We speculate that these extensive inputs facilitate processing of tactile cues as part of a sensorimotor integration network that optimizes how sensory stimuli are acquired through active exploration and in turn adjusts motor outputs (such as independent movement of the lower incisors). These results highlight the diverse sensory specializations and corresponding brain organizational schemes that have evolved in different mammals to facilitate exploration of and interaction with their environment.

  3. Selective inflammatory pain insensitivity in the African naked mole-rat (Heterocephalus glaber).

    Science.gov (United States)

    Park, Thomas J; Lu, Ying; Jüttner, René; Smith, Ewan St J; Hu, Jing; Brand, Antje; Wetzel, Christiane; Milenkovic, Nevena; Erdmann, Bettina; Heppenstall, Paul A; Laurito, Charles E; Wilson, Steven P; Lewin, Gary R

    2008-01-01

    In all mammals, tissue inflammation leads to pain and behavioral sensitization to thermal and mechanical stimuli called hyperalgesia. We studied pain mechanisms in the African naked mole-rat, an unusual rodent species that lacks pain-related neuropeptides (e.g., substance P) in cutaneous sensory fibers. Naked mole-rats show a unique and remarkable lack of pain-related behaviors to two potent algogens, acid and capsaicin. Furthermore, when exposed to inflammatory insults or known mediators, naked mole-rats do not display thermal hyperalgesia. In contrast, naked mole-rats do display nocifensive behaviors in the formalin test and show mechanical hyperalgesia after inflammation. Using electrophysiology, we showed that primary afferent nociceptors in naked mole-rats are insensitive to acid stimuli, consistent with the animal's lack of acid-induced behavior. Acid transduction by sensory neurons is observed in birds, amphibians, and fish, which suggests that this tranduction mechanism has been selectively disabled in the naked mole-rat in the course of its evolution. In contrast, nociceptors do respond vigorously to capsaicin, and we also show that sensory neurons express a transient receptor potential vanilloid channel-1 ion channel that is capsaicin sensitive. Nevertheless, the activation of capsaicin-sensitive sensory neurons in naked mole-rats does not produce pain-related behavior. We show that capsaicin-sensitive nociceptors in the naked mole-rat are functionally connected to superficial dorsal horn neurons as in mice. However, the same nociceptors are also functionally connected to deep dorsal horn neurons, a connectivity that is rare in mice. The pain biology of the naked mole-rat is unique among mammals, thus the study of pain mechanisms in this unusual species can provide major insights into what constitutes "normal" mammalian nociception.

  4. Selective inflammatory pain insensitivity in the African naked mole-rat (Heterocephalus glaber.

    Directory of Open Access Journals (Sweden)

    Thomas J Park

    2008-01-01

    Full Text Available In all mammals, tissue inflammation leads to pain and behavioral sensitization to thermal and mechanical stimuli called hyperalgesia. We studied pain mechanisms in the African naked mole-rat, an unusual rodent species that lacks pain-related neuropeptides (e.g., substance P in cutaneous sensory fibers. Naked mole-rats show a unique and remarkable lack of pain-related behaviors to two potent algogens, acid and capsaicin. Furthermore, when exposed to inflammatory insults or known mediators, naked mole-rats do not display thermal hyperalgesia. In contrast, naked mole-rats do display nocifensive behaviors in the formalin test and show mechanical hyperalgesia after inflammation. Using electrophysiology, we showed that primary afferent nociceptors in naked mole-rats are insensitive to acid stimuli, consistent with the animal's lack of acid-induced behavior. Acid transduction by sensory neurons is observed in birds, amphibians, and fish, which suggests that this tranduction mechanism has been selectively disabled in the naked mole-rat in the course of its evolution. In contrast, nociceptors do respond vigorously to capsaicin, and we also show that sensory neurons express a transient receptor potential vanilloid channel-1 ion channel that is capsaicin sensitive. Nevertheless, the activation of capsaicin-sensitive sensory neurons in naked mole-rats does not produce pain-related behavior. We show that capsaicin-sensitive nociceptors in the naked mole-rat are functionally connected to superficial dorsal horn neurons as in mice. However, the same nociceptors are also functionally connected to deep dorsal horn neurons, a connectivity that is rare in mice. The pain biology of the naked mole-rat is unique among mammals, thus the study of pain mechanisms in this unusual species can provide major insights into what constitutes "normal" mammalian nociception.

  5. Assessment of naked mole-rat distribution and threats in Eastern Ethiopia

    Directory of Open Access Journals (Sweden)

    Mengistu Wale

    2016-08-01

    Full Text Available Objective: To identify the distribution, threats and community attitudes towards naked molerat in Eastern Ethiopia. Methods: Data were collected through direct observation and interview and Chi-square at 95% confidence interval was used for significance test. Results: Naked mole-rat was identified in Fafan, City/Shinele, Eastern Hararghe Zone and Dire Dawa Administrative. The main threats of naked mole-rat identified were agricultural expansion, human killing and lack of awareness. From a total of 100 respondents, 92% of them considered naked mole-rat as pest as a result that 46% of them participated in direct killing. Literacy rate significantly affects the willingness to participate in the conservation of naked mole-rat (χ2 = 7.478, df = 1, P < 0.05. From a total of 26% respondents who did not show the willingness to participate in the conservation, 80.8% of them were illiterate. Conclusions: Naked mole-rat is fairly common in many of the study sites. However, rapid shift from nomadic life style to cultivation of crops and lacks of awareness were the main threats of naked mole-rat. Therefore, since there is no conservation action currently, further comprehensive study is required to design conservation plan for this species.

  6. Hypersensitivity to contact inhibition provides a clue to cancer resistance of naked mole-rat.

    Science.gov (United States)

    Seluanov, Andrei; Hine, Christopher; Azpurua, Jorge; Feigenson, Marina; Bozzella, Michael; Mao, Zhiyong; Catania, Kenneth C; Gorbunova, Vera

    2009-11-17

    The naked mole-rat is the longest living rodent with a maximum lifespan exceeding 28 years. In addition to its longevity, naked mole-rats have an extraordinary resistance to cancer as tumors have never been observed in these rodents. Furthermore, we show that a combination of activated Ras and SV40 LT fails to induce robust anchorage-independent growth in naked mole-rat cells, while it readily transforms mouse fibroblasts. The mechanisms responsible for the cancer resistance of naked mole-rats were unknown. Here we show that naked mole-rat fibroblasts display hypersensitivity to contact inhibition, a phenomenon we termed "early contact inhibition." Contact inhibition is a key anticancer mechanism that arrests cell division when cells reach a high density. In cell culture, naked mole-rat fibroblasts arrest at a much lower density than those from a mouse. We demonstrate that early contact inhibition requires the activity of p53 and pRb tumor suppressor pathways. Inactivation of both p53 and pRb attenuates early contact inhibition. Contact inhibition in human and mouse is triggered by the induction of p27(Kip1). In contrast, early contact inhibition in naked mole-rat is associated with the induction of p16(Ink4a). Furthermore, we show that the roles of p16(Ink4a) and p27(Kip1) in the control of contact inhibition became temporally separated in this species: the early contact inhibition is controlled by p16(Ink4a), and regular contact inhibition is controlled by p27(Kip1). We propose that the additional layer of protection conferred by two-tiered contact inhibition contributes to the remarkable tumor resistance of the naked mole-rat.

  7. The Naked Mole Rat Genome Resource : facilitating analyses of cancer and longevity-related adaptations

    OpenAIRE

    Keane, Michael; Craig, Thomas; Alfoldi, Jessica; Berlin, Aaron M; Johnson, Jeremy; Seluanov, Andrei; Gorbunova, Vera; Di Palma, Federica; Lindblad-Toh, Kerstin; Church, George M; de Magalhaes, Joao Pedro

    2014-01-01

    MOTIVATION: The naked mole rat (Heterocephalus glaber) is an exceptionally long-lived and cancer-resistant rodent native to East Africa. Although its genome was previously sequenced, here we report a new assembly sequenced by us with substantially higher N50 values for scaffolds and contigs. RESULTS: We analyzed the annotation of this new improved assembly and identified candidate genomic adaptations which may have contributed to the evolution of the naked mole rat's extraordinary traits, inc...

  8. High Autophagy in the Naked Mole Rat may Play a Significant Role in Maintaining Good Health

    Directory of Open Access Journals (Sweden)

    Shanmin Zhao

    2014-02-01

    Full Text Available Background/Aims: The maximum lifespan of the naked mole rat is over 28.3 years, which exceeds that of any other rodent species, suggesting that age-related changes in its body composition and functionality are either attenuated or delayed in this extraordinarily long-lived species. However, the mechanisms underlying the aging process in this species are poorly understood. In this study, we investigated whether long-lived naked mole rats display more autophagic activity than short-lived mice. Methods: Hepatic stellate cells isolated from naked mole rats were treated with 50 nM rapamycin or 20 mM 3-methyladenine (3-MA for 12 or 24 h. Expression of the autophagy marker proteins LC3-II and beclin 1 was measured with western blotting and immunohistochemistry. The induction of apoptosis was analyzed by flow cytometry. Results: Our results demonstrate that one-day-old naked mole rats have higher levels of autophagy than one-day-old short-lived C57BL/6 mice, and that both adult naked mole rats (eight months old and adult C57BL/6 mice (eight weeks old have high basal levels of autophagy, which may be an important mechanism inhibiting aging and reducing the risk of age-related diseases. Conclusion: Here, we report that autophagy facilitated the survival of hepatic stellate cells from the naked mole rat, and that treatment with 3-MA or rapamycin increased the ratio of apoptotic cells to normal hepatic stellate cells.

  9. The naked mole-rat response to oxidative stress: just deal with it.

    Science.gov (United States)

    Lewis, Kaitlyn N; Andziak, Blazej; Yang, Ting; Buffenstein, Rochelle

    2013-10-20

    The oxidative stress theory of aging has been the most widely accepted theory of aging providing insights into why we age and die for over 50 years, despite mounting evidence from a multitude of species indicating that there is no direct relationship between reactive oxygen species (ROS) and longevity. Here we explore how different species, including the longest lived rodent, the naked mole-rat, have defied the most predominant aging theory. In the case of extremely long-lived naked mole-rat, levels of ROS production are found to be similar to mice, antioxidant defenses unexceptional, and even under constitutive conditions, naked mole-rats combine a pro-oxidant intracellular milieu with high, steady state levels of oxidative damage. Clearly, naked mole-rats can tolerate this level of oxidative stress and must have mechanisms in place to prevent its translation into potentially lethal diseases. In addition to the naked mole-rat, other species from across the phylogenetic spectrum and even certain mouse strains do not support this theory. Moreover, overexpressing or knocking down antioxidant levels alters levels of oxidative damage and even cancer incidence, but does not modulate lifespan. Perhaps, it is not oxidative stress that modulates healthspan and longevity, but other cytoprotective mechanisms that allow animals to deal with high levels of oxidative damage and stress, and nevertheless live long, relatively healthy lifespans. Studying these mechanisms in uniquely long-lived species, like the naked mole-rat, may help us tease out the key contributors to aging and longevity.

  10. Cutaneous and periodontal inputs to the cerebellum of the naked mole-rat (Heterocephalus glaber

    Directory of Open Access Journals (Sweden)

    Diana K Sarko

    2013-11-01

    Full Text Available The naked mole-rat (Heterocephalus glaber is a small fossorial rodent with specialized dentition that is reflected by the large cortical area dedicated to representation of the prominent incisors. Due to naked mole-rats’ behavioral reliance on the incisors for digging and for manipulating objects, as well as their ability to move the lower incisors independently, we hypothesized that expanded somatosensory representations of the incisors would be present within the cerebellum in order to accommodate a greater degree of proprioceptive, cutaneous, and periodontal input. Multiunit electrophysiological recordings targeting the ansiform lobule were used to investigate tactile inputs from receptive fields on the entire body with a focus on the incisors. Similar to other rodents, a fractured somatotopy appeared to be present with discrete representations of the same receptive fields repeated within each folium of the cerebellum. These findings confirm the presence of somatosensory inputs to a large area of the naked mole-rat cerebellum with particularly extensive representations of the lower incisors and mystacial vibrissae. We speculate that these extensive inputs facilitate processing of tactile cues as part of a sensorimotor integration network that optimizes how sensory stimuli are acquired through active exploration and in turn adjusts motor outputs (such as independent movement of the lower incisors. These results highlight the diverse sensory specializations and corresponding brain organizational schemes that have evolved in different mammals to facilitate exploration of and interaction with their environment.

  11. Androgen receptor distribution in the social decision-making network of eusocial naked mole-rats.

    Science.gov (United States)

    Holmes, Melissa M; Van Mil, Spencer; Bulkowski, Camila; Goldman, Sharry L; Goldman, Bruce D; Forger, Nancy G

    2013-11-01

    Naked mole-rats are highly social rodents that live in large groups and exhibit a strict reproductive and social hierarchy. Only a few animals in each colony breed; the remainder are non-reproductive and are socially subordinate to breeders. We have examined androgen receptor immunoreactive (AR+) cells in brain regions comprising the recently described social decision-making network in subordinate and breeder naked mole-rats of both sexes. We find that subordinates have a significantly higher percentage of AR+ cells in all brain regions expressing this protein. By contrast, there were no significant effects of sex and no sex-by-status interactions on the percentage of AR+ cells. Taken together with previous findings, the present data complete a systematic assessment of the distribution of AR protein in the social decision-making network of the eusocial mammalian brain and demonstrate a significant role for social status in the regulation of this protein throughout many nodes of this network. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Expression of acid-sensing ion channels and selection of reference genes in mouse and naked mole rat.

    Science.gov (United States)

    Schuhmacher, Laura-Nadine; Smith, Ewan St John

    2016-12-13

    Acid-sensing ion channels (ASICs) are a family of ion channels comprised of six subunits encoded by four genes and they are expressed throughout the peripheral and central nervous systems. ASICs have been implicated in a wide range of physiological and pathophysiological processes: pain, breathing, synaptic plasticity and excitotoxicity. Unlike mice and humans, naked mole-rats do not perceive acid as a noxious stimulus, even though their sensory neurons express functional ASICs, likely an adaptation to living in a hypercapnic subterranean environment. Previous studies of ASIC expression in the mammalian nervous system have often not examined all subunits, or have failed to adequately quantify expression between tissues; to date there has been no attempt to determine ASIC expression in the central nervous system of the naked mole-rat. Here we perform a geNorm study to identify reliable housekeeping genes in both mouse and naked mole-rat and then use quantitative real-time PCR to estimate the relative amounts of ASIC transcripts in different tissues of both species. We identify RPL13A (ribosomal protein L13A) and CANX (calnexin), and β-ACTIN and EIF4A (eukaryotic initiation factor 4a) as being the most stably expressed housekeeping genes in mouse and naked mole-rat, respectively. In both species, ASIC3 was most highly expressed in dorsal root ganglia (DRG), and ASIC1a, ASIC2b and ASIC3 were more highly expressed across all brain regions compared to the other subunits. We also show that ASIC4, a proton-insensitive subunit of relatively unknown function, was highly expressed in all mouse tissues apart from DRG and hippocampus, but was by contrast the lowliest expressed ASIC in all naked mole-rat tissues.

  13. Central visual system of the naked mole-rat (Heterocephalus glaber).

    Science.gov (United States)

    Crish, Samuel D; Dengler-Crish, Christine M; Catania, Kenneth C

    2006-02-01

    Naked mole-rats are fossorial rodents native to eastern Africa that spend their lives in extensive subterranean burrows where visual cues are poor. Not surprisingly, they have a degenerated eye and optic nerve, suggesting they have poor visual abilities. However, little is known about their central visual system. To investigate the organization of their central visual system, we injected a neuronal tracer into the eyes of naked mole-rats and mice to compare the neural structures mediating vision. We found that the superior colliculus and lateral geniculate nucleus were severely atrophied in the naked mole-rat. The olivary pretectal nucleus was reduced but still retained its characteristic morphology, possibly indicating a role in light detection. In addition, the suprachiasmatic nucleus is well innervated and resembles the same structure in other rodents. The naked mole-rat appears to have selectively lost structures that mediate form vision while retaining structures needed for minimal entrainment of circadian rhythms. Similar results have been reported for other mole-rat species. Taken together, these data suggest that light detection may still play an important role in the lives of these "blind" animals: most likely for circadian entrainment or setting seasonal rhythms.

  14. Unraveling the message: insights into comparative genomics of the naked mole-rat.

    Science.gov (United States)

    Lewis, Kaitlyn N; Soifer, Ilya; Melamud, Eugene; Roy, Margaret; McIsaac, R Scott; Hibbs, Matthew; Buffenstein, Rochelle

    2016-08-01

    Animals have evolved to survive, and even thrive, in different environments. Genetic adaptations may have indirectly created phenotypes that also resulted in a longer lifespan. One example of this phenomenon is the preternaturally long-lived naked mole-rat. This strictly subterranean rodent tolerates hypoxia, hypercapnia, and soil-based toxins. Naked mole-rats also exhibit pronounced resistance to cancer and an attenuated decline of many physiological characteristics that often decline as mammals age. Elucidating mechanisms that give rise to their unique phenotypes will lead to better understanding of subterranean ecophysiology and biology of aging. Comparative genomics could be a useful tool in this regard. Since the publication of a naked mole-rat genome assembly in 2011, analyses of genomic and transcriptomic data have enabled a clearer understanding of mole-rat evolutionary history and suggested molecular pathways (e.g., NRF2-signaling activation and DNA damage repair mechanisms) that may explain the extraordinarily longevity and unique health traits of this species. However, careful scrutiny and re-analysis suggest that some identified features result from incorrect or imprecise annotation and assembly of the naked mole-rat genome: in addition, some of these conclusions (e.g., genes involved in cancer resistance and hairlessness) are rejected when the analysis includes additional, more closely related species. We describe how the combination of better study design, improved genomic sequencing techniques, and new bioinformatic and data analytical tools will improve comparative genomics and ultimately bridge the gap between traditional model and nonmodel organisms.

  15. The molecular basis of acid insensitivity in the African naked mole-rat.

    Science.gov (United States)

    Smith, Ewan St John; Omerbašić, Damir; Lechner, Stefan G; Anirudhan, Gireesh; Lapatsina, Liudmila; Lewin, Gary R

    2011-12-16

    Acid evokes pain by exciting nociceptors; the acid sensors are proton-gated ion channels that depolarize neurons. The naked mole-rat (Heterocephalus glaber) is exceptional in its acid insensitivity, but acid sensors (acid-sensing ion channels and the transient receptor potential vanilloid-1 ion channel) in naked mole-rat nociceptors are similar to those in other vertebrates. Acid inhibition of voltage-gated sodium currents is more profound in naked mole-rat nociceptors than in mouse nociceptors, however, which effectively prevents acid-induced action potential initiation. We describe a species-specific variant of the nociceptor sodium channel Na(V)1.7, which is potently blocked by protons and can account for acid insensitivity in this species. Thus, evolutionary pressure has selected for an Na(V)1.7 gene variant that tips the balance from proton-induced excitation to inhibition of action potential initiation to abolish acid nociception.

  16. Stress Resistance in the Naked Mole-Rat: The Bare Essentials – A Mini-Review

    Science.gov (United States)

    Lewis, Kaitlyn N.; Mele, James; Hornsby, Peter J.; Buffenstein, Rochelle

    2012-01-01

    Background Studies comparing similar-sized species with disparate longevity may elucidate novel mechanisms that abrogate aging and prolong good health. We focus on the longest living rodent, the naked mole-rat. This mouse-sized mammal lives ∼8 times longer than do mice and, despite high levels of oxidative damage evident at a young age, it is not only very resistant to spontaneous neoplasia but also shows minimal decline in age-associated physiological traits. Objectives We assess the current status of stress resistance and longevity, focusing in particular on the molecular and cellular responses to cytotoxins and other stressors between the short-lived laboratory mouse and the naked mole-rat. Results Like other experimental animal models of lifespan extension, naked mole-rat fibroblasts are extremely tolerant of a broad spectrum of cytotoxins including heat, heavy metals, DNA-damaging agents and xenobiotics, showing LD50 values between 2- and 20-fold greater than those of fibroblasts of shorter-lived mice. Our new data reveal that naked mole-rat fibroblasts stop proliferating even at low doses of toxin whereas those mouse fibroblasts that survive treatment rapidly re-enter the cell cycle and may proliferate with DNA damage. Naked mole-rat fibroblasts also show significantly higher constitutive levels of both p53 and Nrf2 protein levels and activity, and this increases even further in response to toxins. Conclusion Enhanced cell signaling via p53 and Nrf2 protects cells against proliferating with damage, augments clearance of damaged proteins and organelles and facilitates the maintenance of both genomic and protein integrity. These pathways collectively regulate a myriad of mechanisms which may contribute to the attenuated aging profile and sustained healthspan of the naked mole-rat. Understanding how these are regulated may be also integral to sustaining positive human healthspan well into old age and may elucidate novel therapeutics for delaying the onset and

  17. Stress resistance in the naked mole-rat: the bare essentials - a mini-review.

    Science.gov (United States)

    Lewis, Kaitlyn N; Mele, James; Hornsby, Peter J; Buffenstein, Rochelle

    2012-01-01

    Studies comparing similar-sized species with disparate longevity may elucidate novel mechanisms that abrogate aging and prolong good health. We focus on the longest living rodent, the naked mole-rat. This mouse-sized mammal lives ~8 times longer than do mice and, despite high levels of oxidative damage evident at a young age, it is not only very resistant to spontaneous neoplasia but also shows minimal decline in age-associated physiological traits. We assess the current status of stress resistance and longevity, focusing in particular on the molecular and cellular responses to cytotoxins and other stressors between the short-lived laboratory mouse and the naked mole-rat. Like other experimental animal models of lifespan extension, naked mole-rat fibroblasts are extremely tolerant of a broad spectrum of cytotoxins including heat, heavy metals, DNA-damaging agents and xenobiotics, showing LD(50) values between 2- and 20-fold greater than those of fibroblasts of shorter-lived mice. Our new data reveal that naked mole-rat fibroblasts stop proliferating even at low doses of toxin whereas those mouse fibroblasts that survive treatment rapidly re-enter the cell cycle and may proliferate with DNA damage. Naked mole-rat fibroblasts also show significantly higher constitutive levels of both p53 and Nrf2 protein levels and activity, and this increases even further in response to toxins. Enhanced cell signaling via p53 and Nrf2 protects cells against proliferating with damage, augments clearance of damaged proteins and organelles and facilitates the maintenance of both genomic and protein integrity. These pathways collectively regulate a myriad of mechanisms which may contribute to the attenuated aging profile and sustained healthspan of the naked mole-rat. Understanding how these are regulated may be also integral to sustaining positive human healthspan well into old age and may elucidate novel therapeutics for delaying the onset and progression of physiological declines

  18. Reduced Utilization of Selenium by Naked Mole Rats Due to a Specific Defect in GPx1 Expression*

    OpenAIRE

    Kasaikina, Marina V.; Lobanov, Alexei V.; Malinouski, Mikalai Y.; Lee, Byung Cheon; Seravalli, Javier; Fomenko, Dmitri E.; Turanov, Anton A.; Finney, Lydia; Vogt, Stefan; Park, Thomas J.; Miller, Richard A.; Hatfield, Dolph L.; Gladyshev, Vadim N.

    2011-01-01

    Naked mole rat (MR) Heterocephalus glaber is a rodent model of delayed aging because of its unusually long life span (>28 years). It is also not known to develop cancer. In the current work, tissue imaging by x-ray fluorescence microscopy and direct analyses of trace elements revealed low levels of selenium in the MR liver and kidney, whereas MR and mouse brains had similar selenium levels. This effect was not explained by uniform selenium deficiency because methionine sulfoxide reductase act...

  19. Comparative analysis of genome maintenance genes in naked mole rat, mouse, and human

    NARCIS (Netherlands)

    S.L. Macrae (Sheila L.); Q. Zhang (Quanwei); C. Lemetre (Christophe); I. Seim (Inge); R.B. Calder (Robert B.); J.H.J. Hoeijmakers (Jan); Y. Suh (Yousin); V.N. Gladyshev (Vadim N.); A. Seluanov (Andrei); V. Gorbunova (Vera); J. Vijg (Jan); Z.D. Zhang (Zhengdong D.)

    2015-01-01

    textabstractGenome maintenance (GM) is an essential defense system against aging and cancer, as both are characterized by increased genome instability. Here, we compared the copy number variation and mutation rate of 518 GM-associated genes in the naked mole rat (NMR), mouse, and human genomes. GM

  20. Blunted behavioral and c Fos responses to acidic fumes in the African naked mole-rat.

    Science.gov (United States)

    LaVinka, Pamela Colleen; Park, Thomas J

    2012-01-01

    Acidosis in the skin triggers activation of pain pathways and behaviors indicative of pain in vertebrates. The exception is the naked mole-rat, the only known vertebrate to show physiological and behavioral insensitivity to acid pain in the skin. The goal of the present study was to determine behavioral and physiological responses of this species to airborne acidic fumes, which would be expected to affect the trigeminal pain pathway in other species. Behaviorally, naked mole-rats did not avoid fumes from moderately high concentrations of acetic acid (10 and 20%), and c Fos labeling showed no increase in activity in the trigeminal nuclei and nucleus tractus solitarius. In contrast, these concentrations triggered behavioral aversion and increased Fos activity in other laboratory rodents. For a very high concentration of acetic acid (50%), naked mole-rats showed significant avoidance behavior and increased Fos labeling in the nucleus tractus solitarius caudal region, which receives vagal chemosensory information. However, there was no increase in trigeminal labeling, and in fact, activity significantly decreased. This pattern is opposite of that associated with another irritant, ammonia fumes, which elicited an increase in trigeminal but not nucleus tractus solitarius Fos labeling, and no behavioral avoidance. Behavioral avoidance of acidic fumes, but no increased labeling in the trigeminal pain nucleus is consistent with the notion of adaptations to blunt acid pain, which would be advantageous for naked mole-rats as they normally live under chronically high levels of acidosis-inducing CO(2).

  1. Blunted behavioral and c Fos responses to acidic fumes in the African naked mole-rat.

    Directory of Open Access Journals (Sweden)

    Pamela Colleen LaVinka

    Full Text Available Acidosis in the skin triggers activation of pain pathways and behaviors indicative of pain in vertebrates. The exception is the naked mole-rat, the only known vertebrate to show physiological and behavioral insensitivity to acid pain in the skin. The goal of the present study was to determine behavioral and physiological responses of this species to airborne acidic fumes, which would be expected to affect the trigeminal pain pathway in other species. Behaviorally, naked mole-rats did not avoid fumes from moderately high concentrations of acetic acid (10 and 20%, and c Fos labeling showed no increase in activity in the trigeminal nuclei and nucleus tractus solitarius. In contrast, these concentrations triggered behavioral aversion and increased Fos activity in other laboratory rodents. For a very high concentration of acetic acid (50%, naked mole-rats showed significant avoidance behavior and increased Fos labeling in the nucleus tractus solitarius caudal region, which receives vagal chemosensory information. However, there was no increase in trigeminal labeling, and in fact, activity significantly decreased. This pattern is opposite of that associated with another irritant, ammonia fumes, which elicited an increase in trigeminal but not nucleus tractus solitarius Fos labeling, and no behavioral avoidance. Behavioral avoidance of acidic fumes, but no increased labeling in the trigeminal pain nucleus is consistent with the notion of adaptations to blunt acid pain, which would be advantageous for naked mole-rats as they normally live under chronically high levels of acidosis-inducing CO(2.

  2. Investigation of the presence and antinociceptive function of muscarinic acetylcholine receptors in the African naked mole-rat (Heterocephalus glaber)

    DEFF Research Database (Denmark)

    Jørgensen, Kristine B.; Krogh-Jensen, Karen; Pickering, Darryl S

    2016-01-01

    The present study investigated the cholinergic system in the African naked mole-rat (Heterocephalus glaber) with focus on the muscarinic acetylcholine receptor subtypes M1 and M4. The protein sequences for the subtypes m 1–5 of the naked mole-rat were compared to that of the house mouse (Mus...... musculus) using basic local alignment search tool (BLAST). The presence and function of M1 and M4 was investigated in vivo, using the formalin test with the muscarinic receptor agonists xanomeline and VU0152100. Spinal cord tissue from the naked mole-rat was used for receptor saturation binding studies...

  3. Digital dissection of the masticatory muscles of the naked mole-rat, Heterocephalus glaber (Mammalia, Rodentia

    Directory of Open Access Journals (Sweden)

    Philip G. Cox

    2014-06-01

    Full Text Available The naked mole-rat, Heterocephalus glaber, of the family Bathyergidae is a subterranean rodent that feeds on underground roots and tubers and digs extensive tunnel systems with its incisors. It is a highly unusual mammal with regard to its social structure, longevity, pain insensitivity and cancer resistance, all of which have made it the subject of a great deal of research in recent years. Yet, much of the basic anatomy of this species remains undocumented. In this paper, we describe the morphology of the jaw-closing musculature of the naked mole-rat, as revealed by contrast-enhanced micro-computed tomography. This technique uses an iodine stain to enable the imaging of soft tissues with microCT. The iodine-enhanced scans were used to create 3D reconstructions of the naked mole-rat masticatory muscles from which muscle masses were calculated. The jaw-closing musculature of Heterocephalus glaber is relatively very large compared to other rodents and is dominated by the superficial masseter, the deep masseter and the temporalis. The temporalis in particular is large for a rodent, covering the entirety of the braincase and much of the rear part of the orbit. The morphology of the masseter complex described here differs from two other published descriptions of bathyergid masticatory muscles, but is more similar to the arrangement seen in other rodent families. The zygomaticomandibularis (ZM muscle does not protrude through the infraorbital foramen on to the rostrum and thus the naked mole-rat should be considered protrogomorphous rather than hystricomorphous, and the morphology is consistent with secondarily lost hystricomorphy as has been previously suggested for Bathyergidae. Overall, the morphology of the masticatory musculature indicates a species with a high bite force and a wide gape–both important adaptations for a life dominated by digging with the incisors.

  4. Naked mole-rat mortality rates defy Gompertzian laws by not increasing with age

    Science.gov (United States)

    Ruby, J Graham; Smith, Megan

    2018-01-01

    The longest-lived rodent, the naked mole-rat (Heterocephalus glaber), has a reported maximum lifespan of >30 years and exhibits delayed and/or attenuated age-associated physiological declines. We questioned whether these mouse-sized, eusocial rodents conform to Gompertzian mortality laws by experiencing an exponentially increasing risk of death as they get older. We compiled and analyzed a large compendium of historical naked mole-rat lifespan data with >3000 data points. Kaplan-Meier analyses revealed a substantial portion of the population to have survived at 30 years of age. Moreover, unlike all other mammals studied to date, and regardless of sex or breeding-status, the age-specific hazard of mortality did not increase with age, even at ages 25-fold past their time to reproductive maturity. This absence of hazard increase with age, in defiance of Gompertz’s law, uniquely identifies the naked mole-rat as a non-aging mammal, confirming its status as an exceptional model for biogerontology. PMID:29364116

  5. Investigation of the presence and antinociceptive function of muscarinic acetylcholine receptors in the African naked mole-rat (Heterocephalus glaber).

    Science.gov (United States)

    Jørgensen, Kristine B; Krogh-Jensen, Karen; Pickering, Darryl S; Kanui, Titus I; Abelson, Klas S P

    2016-01-01

    The present study investigated the cholinergic system in the African naked mole-rat (Heterocephalus glaber) with focus on the muscarinic acetylcholine receptor subtypes M1 and M4. The protein sequences for the subtypes m 1-5 of the naked mole-rat were compared to that of the house mouse (Mus musculus) using basic local alignment search tool (BLAST). The presence and function of M1 and M4 was investigated in vivo, using the formalin test with the muscarinic receptor agonists xanomeline and VU0152100. Spinal cord tissue from the naked mole-rat was used for receptor saturation binding studies with [(3)H]-N-methylscopolamine. The BLAST test revealed 95 % protein sequence homology showing the naked mole-rat to have the genetic potential to express all five muscarinic acetylcholine receptor subtypes. A significant reduction in pain behavior was demonstrated after administration of 8.4 mg/kg in the formalin test. Administration of 50 mg/kg VU0152100 resulted in a non-significant tendency towards antinociception. The antinociceptive effects were reversed by the muscarinic acetylcholine receptor antagonist atropine. Binding studies indicated presence of muscarinic acetylcholine receptors with a radioligand affinity comparable to that reported in mice. In conclusion, muscarinic acetylcholine receptor subtypes are present in the naked mole-rat and contribute to antinociception in the naked mole-rat.

  6. Hypofunctional TrkA Accounts for the Absence of Pain Sensitization in the African Naked Mole-Rat.

    Science.gov (United States)

    Omerbašić, Damir; Smith, Ewan St J; Moroni, Mirko; Homfeld, Johanna; Eigenbrod, Ole; Bennett, Nigel C; Reznick, Jane; Faulkes, Chris G; Selbach, Matthias; Lewin, Gary R

    2016-10-11

    The naked mole-rat is a subterranean rodent lacking several pain behaviors found in humans, rats, and mice. For example, nerve growth factor (NGF), an important mediator of pain sensitization, fails to produce thermal hyperalgesia in naked mole-rats. The sensitization of capsaicin-sensitive TRPV1 ion channels is necessary for NGF-induced hyperalgesia, but naked mole-rats have fully functional TRPV1 channels. We show that exposing isolated naked mole-rat nociceptors to NGF does not sensitize TRPV1. However, the naked mole-rat NGF receptor TrkA displays a reduced ability to engage signal transduction pathways that sensitize TRPV1. Between one- and three-amino-acid substitutions in the kinase domain of the naked mole-rat TrkA are sufficient to render the receptor hypofunctional, and this is associated with the absence of heat hyperalgesia. Our data suggest that evolution has selected for a TrkA variant that abolishes a robust nociceptive behavior in this species but is still compatible with species fitness. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  7. Hypofunctional TrkA Accounts for the Absence of Pain Sensitization in the African Naked Mole-Rat

    Directory of Open Access Journals (Sweden)

    Damir Omerbašić

    2016-10-01

    Full Text Available The naked mole-rat is a subterranean rodent lacking several pain behaviors found in humans, rats, and mice. For example, nerve growth factor (NGF, an important mediator of pain sensitization, fails to produce thermal hyperalgesia in naked mole-rats. The sensitization of capsaicin-sensitive TRPV1 ion channels is necessary for NGF-induced hyperalgesia, but naked mole-rats have fully functional TRPV1 channels. We show that exposing isolated naked mole-rat nociceptors to NGF does not sensitize TRPV1. However, the naked mole-rat NGF receptor TrkA displays a reduced ability to engage signal transduction pathways that sensitize TRPV1. Between one- and three-amino-acid substitutions in the kinase domain of the naked mole-rat TrkA are sufficient to render the receptor hypofunctional, and this is associated with the absence of heat hyperalgesia. Our data suggest that evolution has selected for a TrkA variant that abolishes a robust nociceptive behavior in this species but is still compatible with species fitness.

  8. Absence of histamine-induced itch in the African naked mole-rat and "rescue" by Substance P.

    Science.gov (United States)

    Smith, Ewan St John; Blass, Gregory R C; Lewin, Gary R; Park, Thomas J

    2010-05-24

    Recent research has proposed a pathway in which sensory neurons expressing the capsaicin activated ion channel TRPV1 are required for histamine-induced itch and subsequent scratching behavior. We examined histamine-induced itch in the African naked mole-rat (Heterocephalus glaber) and found that although naked mole-rats display innate scratching behavior, histamine was unable to evoke increased scratching as is observed in most mouse strains. Using calcium imaging, we examined the histamine sensitivity of naked mole-rat dorsal root ganglia (DRG) neurons and identified a population of small diameter neurons activated by histamine, the majority of which are also capsaicin-sensitive. This suggested that naked mole-rat sensory neurons are activated by histamine, but that spinal dorsal horn processing of sensory information is not the same as in other rodents. We have previously shown that naked mole-rats naturally lack substance P (SP) in cutaneous C-fibers, but that the neurokinin-1 receptor is expressed in the superficial spinal cord. This led us to investigate if SP deficiency plays a role in the lack of histamine-induced scratching in this species. After intrathecal administration of SP into the spinal cord we observed robust scratching behavior in response to histamine injection. Our data therefore support a model in which TRPV1-expressing sensory neurons are important for histamine-induced itch. In addition, we demonstrate a requirement for active, SP-induced post-synaptic drive to enable histamine sensitive afferents to drive itch-related behavior in the naked mole-rat. These results illustrate that it is altered dorsal horn connectivity of nociceptors that underlies the lack of itch and pain-related behavior in the naked mole-rat.

  9. Absence of histamine-induced itch in the African naked mole-rat and "rescue" by Substance P

    Directory of Open Access Journals (Sweden)

    Lewin Gary R

    2010-05-01

    Full Text Available Abstract Recent research has proposed a pathway in which sensory neurons expressing the capsaicin activated ion channel TRPV1 are required for histamine-induced itch and subsequent scratching behavior. We examined histamine-induced itch in the African naked mole-rat (Heterocephalus glaber and found that although naked mole-rats display innate scratching behavior, histamine was unable to evoke increased scratching as is observed in most mouse strains. Using calcium imaging, we examined the histamine sensitivity of naked mole-rat dorsal root ganglia (DRG neurons and identified a population of small diameter neurons activated by histamine, the majority of which are also capsaicin-sensitive. This suggested that naked mole-rat sensory neurons are activated by histamine, but that spinal dorsal horn processing of sensory information is not the same as in other rodents. We have previously shown that naked mole-rats naturally lack substance P (SP in cutaneous C-fibers, but that the neurokinin-1 receptor is expressed in the superficial spinal cord. This led us to investigate if SP deficiency plays a role in the lack of histamine-induced scratching in this species. After intrathecal administration of SP into the spinal cord we observed robust scratching behavior in response to histamine injection. Our data therefore support a model in which TRPV1-expressing sensory neurons are important for histamine-induced itch. In addition, we demonstrate a requirement for active, SP-induced post-synaptic drive to enable histamine sensitive afferents to drive itch-related behavior in the naked mole-rat. These results illustrate that it is altered dorsal horn connectivity of nociceptors that underlies the lack of itch and pain-related behavior in the naked mole-rat.

  10. Naked mole-rat acid-sensing ion channel 3 forms nonfunctional homomers, but functional heteromers.

    Science.gov (United States)

    Schuhmacher, Laura-Nadine; Callejo, Gerard; Srivats, Shyam; Smith, Ewan St John

    2018-02-02

    Acid-sensing ion channels (ASICs) form both homotrimeric and heterotrimeric ion channels that are activated by extracellular protons and are involved in a wide range of physiological and pathophysiological processes, including pain and anxiety. ASIC proteins can form both homotrimeric and heterotrimeric ion channels. The ASIC3 subunit has been shown to be of particular importance in the peripheral nervous system with pharmacological and genetic manipulations demonstrating a role in pain. Naked mole-rats, despite having functional ASICs, are insensitive to acid as a noxious stimulus and show diminished avoidance of acidic fumes, ammonia, and carbon dioxide. Here we cloned naked mole-rat ASIC3 (nmrASIC3) and used a cell-surface biotinylation assay to demonstrate that it traffics to the plasma membrane, but using whole-cell patch clamp electrophysiology we observed that nmrASIC3 is insensitive to both protons and the non-proton ASIC3 agonist 2-guanidine-4-methylquinazoline. However, in line with previous reports of ASIC3 mRNA expression in dorsal root ganglia neurons, we found that the ASIC3 antagonist APETx2 reversibly inhibits ASIC-like currents in naked mole-rat dorsal root ganglia neurons. We further show that like the proton-insensitive ASIC2b and ASIC4, nmrASIC3 forms functional, proton-sensitive heteromers with other ASIC subunits. An amino acid alignment of ASIC3s between 9 relevant rodent species and human identified unique sequence differences that might underlie the proton insensitivity of nmrASIC3. However, introducing nmrASIC3 differences into rat ASIC3 (rASIC3) produced only minor differences in channel function, and replacing the nmrASIC3 sequence with that of rASIC3 did not produce a proton-sensitive ion channel. Our observation that nmrASIC3 forms nonfunctional homomers may reflect a further adaptation of the naked mole-rat to living in an environment with high-carbon dioxide levels. © 2018 by The American Society for Biochemistry and Molecular

  11. Dominance and queen succession in captive colonies of the eusocial naked mole-rat, Heterocephalus glaber.

    Science.gov (United States)

    Clarke, F M; Faulkes, C G

    1997-07-22

    Naked mole-rat colonies exhibit a high reproductive skew, breeding being typically restricted to one female (the 'queen') and one to three males. Other colony members are reproductively suppressed, although this suppression can be reversed following the removal or death of the queen. We examined dominance and queen succession within captive colonies to investigate the relationship between urinary testosterone and cortisol, dominance rank and reproductive status; and to determine if behavioural and/or physiological parameters can be used as predictors of queen succession. Social structure was characterized by a linear dominance hierarchy before and after queen removal. Prior to queen removal, dominance rank was negatively correlated with body weight and urinary testosterone and cortisol titres in males and females. Queen removal results in social instability and aggression between high ranking individuals. Dominance rank appears to be a good predictor of reproductive status: queens are the highest ranking colony females and are succeeded by the next highest ranking females. The intense dominance-related aggression that accompanies reproductive succession in naked mole-rats provides empirical support for optimal skew theory.

  12. Differential effects of chronic fluoxetine on the behavior of dominant and subordinate naked mole-rats.

    Science.gov (United States)

    Mongillo, Daniel L; Kosyachkova, Ekaterina A; Nguyen, Tam M; Holmes, Melissa M

    2014-01-01

    Naked mole-rats are eusocial rodents that live in large subterranean colonies with a strict reproductive and social hierarchy. The breeding female (referred to as the queen) and 1 to 3 breeding males are the only reproductive members of the colony. Breeders are socially dominant and all other colony members are non-reproductive subordinates. The effects of manipulating the serotonergic neurotransmitter system on aggression and dominance behaviors are well studied in many species, but not in eusocial rodents like the naked mole-rat. The current study investigated how the serotonergic system influences aggressive/dominant behaviors in this species. To do this, two separate but related experiments were conducted: the effects of fluoxetine hydrochloride (FLX) on status-specific behaviors of subordinates (Experiment 1) and dominant queens (Experiment 2) were evaluated both in-colony and in a social-pairing paradigm. In accordance with our main hypothesis, chronic treatment of FLX attenuated the frequency and duration of aggression in queens, but not subordinates, when paired with an unfamiliar conspecific. Further exploration of pharmacological manipulation on status-specific behaviors of this eusocial species may elucidate the neurobiological mechanisms underlying their unique and rigid social hierarchy. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Retinal ganglion cell survival and axon regeneration after optic nerve injury in naked mole-rats.

    Science.gov (United States)

    Park, Kevin K; Luo, Xueting; Mooney, Skyler J; Yungher, Benjamin J; Belin, Stephane; Wang, Chen; Holmes, Melissa M; He, Zhigang

    2017-02-01

    In the adult mammalian central nervous system (CNS), axonal damage often triggers neuronal cell death and glial activation, with very limited spontaneous axon regeneration. In this study, we performed optic nerve injury in adult naked mole-rats, the longest living rodent, with a maximum life span exceeding 30 years, and found that injury responses in this species are quite distinct from those in other mammalian species. In contrast to what is seen in other mammals, the majority of injured retinal ganglion cells (RGCs) survive with relatively high spontaneous axon regeneration. Furthermore, injured RGCs display activated signal transducer and activator of transcription-3 (STAT3), whereas astrocytes in the optic nerve robustly occupy and fill the lesion area days after injury. These neuron-intrinsic and -extrinsic injury responses are reminiscent of those in "cold-blooded" animals, such as fish and amphibians, suggesting that the naked mole-rat is a powerful model for exploring the mechanisms of neuronal injury responses and axon regeneration in mammals. J. Comp. Neurol. 525:380-388, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  14. Endocrine function and neurobiology of the longest-living rodent, the naked mole-rat.

    Science.gov (United States)

    Edrey, Yael H; Park, Thomas J; Kang, Hyesin; Biney, Adriana; Buffenstein, Rochelle

    2011-01-01

    Animals that have evolved exceptional capabilities, such as extraordinary longevity may reveal pertinent and potentially critical insights into biomedical research that are not readily apparent in standard laboratory animals. Naked mole-rats (Heterocephalus glaber; NMRs) are extremely long-lived (30 years) mouse-sized rodents. They clearly have evolved superior anti-aging mechanisms as evident by the markedly attenuated age-related decline in physiological function, sustained reproductive capacity and pronounced cancer resistance throughout their long-lives. These eusocial rodents, like the social insects, live in colonies with breeding restricted to one female and a few males. Subordinates are sexually monomorphic, yet retain the ability to become breeders, and can undergo growth surges and neural modifications at any time throughout their life. This plasticity in physiological and behavioral aspects may have contributed to their long-lives. Naked mole-rats show numerous adaptations to life underground including extreme tolerance of hypoxia, acid insensitivity, as well as independence of photoendocrine systems. Here we review what is known about their unique social structure, sensory systems, endocrinology and neurobiology, and highlight areas that may be pertinent to biogerontology. Copyright © 2010 Elsevier Inc. All rights reserved.

  15. Bilateral lesions of the medial frontal cortex disrupt recognition of social hierarchy during antiphonal communication in naked mole-rats (Heterocephalus glaber).

    Science.gov (United States)

    Yosida, Shigeto; Okanoya, Kazuo

    2012-02-01

    Generation of the motor patterns of emotional sounds in mammals occurs in the periaqueductal gray matter of the midbrain and is not directly controlled by the cortex. The medial frontal cortex indirectly controls vocalizations, based on the recognition of social context. We examined whether the medial frontal cortex was responsible for antiphonal vocalization, or turn-taking, in naked mole-rats. In normal turn-taking, naked mole-rats vocalize more frequently to dominant individuals than to subordinate ones. Bilateral lesions of the medial frontal cortex disrupted differentiation of call rates to the stimulus animals, which had varied social relationships to the subject. However, medial frontal cortex lesions did not affect either the acoustic properties of the vocalizations or the timing of the vocal exchanges. This suggests that the medial frontal cortex may be involved in social cognition or decision making during turn-taking, while other regions of the brain regulate when animals vocalize and the vocalizations themselves.

  16. The effects of oxotremorine, epibatidine, atropine, mecamylamine and naloxone in the tail-flick, hot-plate, and formalin tests in the naked mole-rat (Heterocephalus glaber)

    DEFF Research Database (Denmark)

    Dulu, Thomas D; Kanui, Titus I; Towett, Philemon K

    2014-01-01

    The naked mole-rat (Heterocephalus glaber) is a promising animal model for the study of pain mechanisms, therefore a thorough characterization of this species is essential. The aim of the present study was to establish the naked mole-rat as a model for studying the cholinergic receptor system in ...

  17. Subcaste differences in neural activation suggest a prosocial role for oxytocin in eusocial naked mole-rats.

    Science.gov (United States)

    Hathaway, Georgia A; Faykoo-Martinez, Mariela; Peragine, Deane E; Mooney, Skyler J; Holmes, Melissa M

    2016-03-01

    The neuropeptide oxytocin (OT) influences prosocial behavior(s), aggression, and stress responsiveness, and these diverse effects are regulated in a species- and context-specific manner. The naked mole-rat (Heterocephalus glaber) is a unique species with which to study context-dependent effects of OT, exhibiting a strict social hierarchy with behavioral specialization within the subordinate caste: soldiers are aggressive and defend colonies against unfamiliar conspecifics while workers are prosocial and contribute to in-colony behaviors such as pup care. To determine if OT is involved in subcaste-specific behaviors, we compared behavioral responses between workers and soldiers of both sexes during a modified resident/intruder paradigm, and quantified activation of OT neurons in the hypothalamic paraventricular nucleus (PVN) and supraoptic nucleus (SON) using the immediate-early-gene marker c-fos co-localized with OT neurons. Resident workers and soldiers were age-matched with unfamiliar worker stimulus animals as intruders, and encounters were videorecorded and scored for aggressive behaviors. Colony-matched controls were left in their home colony for the duration of the encounters. Brains were extracted and cell counts were conducted for OT immunoreactive (ir), c-fos-ir, and percentage of OT-c-fos double-labeled cells. Results indicate that resident workers were less aggressive but showed greater OT neural activity than soldiers. Furthermore, a linear model including social treatment, cortisol, and subcaste revealed that subcaste was the only significant predictor of OT-c-fos double-labeled cells in the PVN. These data suggest that in naked mole-rats OT promotes prosocial behaviors rather than aggression and that even within subordinates status exerts robust effects on brain and behavior. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Comparative analysis of genome maintenance genes in naked mole rat, mouse, and human.

    Science.gov (United States)

    MacRae, Sheila L; Zhang, Quanwei; Lemetre, Christophe; Seim, Inge; Calder, Robert B; Hoeijmakers, Jan; Suh, Yousin; Gladyshev, Vadim N; Seluanov, Andrei; Gorbunova, Vera; Vijg, Jan; Zhang, Zhengdong D

    2015-04-01

    Genome maintenance (GM) is an essential defense system against aging and cancer, as both are characterized by increased genome instability. Here, we compared the copy number variation and mutation rate of 518 GM-associated genes in the naked mole rat (NMR), mouse, and human genomes. GM genes appeared to be strongly conserved, with copy number variation in only four genes. Interestingly, we found NMR to have a higher copy number of CEBPG, a regulator of DNA repair, and TINF2, a protector of telomere integrity. NMR, as well as human, was also found to have a lower rate of germline nucleotide substitution than the mouse. Together, the data suggest that the long-lived NMR, as well as human, has more robust GM than mouse and identifies new targets for the analysis of the exceptional longevity of the NMR. © 2015 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  19. Functional neurokinin and NMDA receptor activity in an animal naturally lacking substance P: the naked mole-rat.

    Directory of Open Access Journals (Sweden)

    Antje Brand

    Full Text Available Naked mole-rats are extremely unusual among mammals in that their cutaneous C-fibers lack the neuropeptide Substance P (SP. In other mammals, SP plays an important role in nociception: it is released from C-fibers onto spinal neurons where it facilitates NMDA receptor activity and causes sensitization that can last for minutes, hours or days. In the present study, we tested the effects of intrathecal application of: 1 SP, 2 an SP antagonist (GR-82334, and 3 an NMDA antagonist (APV on heat-evoked foot withdrawal. In the naked mole-rat, at a high enough concentration, application of SP caused a large, immediate, and long-lasting sensitization of foot withdrawal latency that was transiently reversed by application of either antagonist. However, neither SP nor NMDA antagonists had an effect when administered alone to naïve animals. In contrast, both antagonists induced an increase in basal withdrawal latency in mice. These results indicate that spinal neurons in naked mole-rats have functional SP and NMDA receptors, but that these receptors do not participate in heat-evoked foot withdrawal unless SP is experimentally introduced. We propose that the natural lack of SP in naked mole-rat C-fibers may have resulted during adaptation to living in a chronically high carbon dioxide, high ammonia environment that, in other mammals, would stimulate C-fibers and evoke nocifensive behavior.

  20. Four Cases of Spontaneous Neoplasia in the Naked Mole-Rat (Heterocephalus glaber), A Putative Cancer-Resistant Species.

    Science.gov (United States)

    Taylor, Kyle R; Milone, Nicholas A; Rodriguez, Carlos E

    2017-01-01

    The naked mole-rat (Heterocephalus glaber) is widely acclaimed to be cancer-resistant and of considerable research interest based on a paucity of reports of neoplasia in this species. We have, however, encountered four spontaneous cases of neoplasia and one presumptive case of neoplasia through routine necropsy and biopsy of individuals in a zoo collection of nonhybrid naked mole-rats bred from a single pair. One case each of metastasizing hepatocellular carcinoma, nephroblastoma (Wilms' tumor), and multicentric lymphosarcoma, as well as presumptive esophageal adenocarcinoma (Barrett's esophagus-like) was identified postmortem among 37 nonautolyzed necropsy submissions of naked mole-rats over 1-year-old that were submitted for necropsy between 1998 and August 2015. One incidental case of cutaneous hemangioma was also identified antemortem by skin biopsy from one naked mole-rat examined for trauma. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. A cytosolic protein factor from the naked mole-rat activates proteasomes of other species and protects these from inhibition

    Science.gov (United States)

    Rodriguez, Karl A.; Osmulski, Pawel A.; Pierce, Anson; Weintraub, Susan T.; Gaczynska, Maria; Buffenstein, Rochelle

    2015-01-01

    The naked mole-rat maintains robust proteostasis and high levels of proteasome-mediated proteolysis for most of its exceptional (~31y) life span. Here, we report that the highly active proteasome from the naked mole-rat liver resists attenuation by a diverse suite of proteasome-specific small molecule inhibitors. Moreover, mouse, human, and yeast proteasomes exposed to the proteasome-depleted, naked mole-rat cytosolic fractions, recapitulate the observed inhibition resistance, and mammalian proteasomes also show increased activity. Gel filtration coupled with mass spectrometry and atomic force microscopy indicates that these traits are supported by a protein factor that resides in the cytosol. This factor interacts with the proteasome and modulates its activity. Although HSP72 and HSP40 (Hdj1) are among the constituents of this factor, the observed phenomenon, such as increasing peptidase activity and protecting against inhibition cannot be reconciled with any known chaperone functions. This novel function may contribute to the exceptional protein homeostasis in the naked mole-rat and allow it to successfully defy aging. PMID:25018089

  2. Functional neurokinin and NMDA receptor activity in an animal naturally lacking substance P: the naked mole-rat.

    Science.gov (United States)

    Brand, Antje; Smith, Ewan St J; Lewin, Gary R; Park, Thomas J

    2010-12-21

    Naked mole-rats are extremely unusual among mammals in that their cutaneous C-fibers lack the neuropeptide Substance P (SP). In other mammals, SP plays an important role in nociception: it is released from C-fibers onto spinal neurons where it facilitates NMDA receptor activity and causes sensitization that can last for minutes, hours or days. In the present study, we tested the effects of intrathecal application of: 1) SP, 2) an SP antagonist (GR-82334), and 3) an NMDA antagonist (APV) on heat-evoked foot withdrawal. In the naked mole-rat, at a high enough concentration, application of SP caused a large, immediate, and long-lasting sensitization of foot withdrawal latency that was transiently reversed by application of either antagonist. However, neither SP nor NMDA antagonists had an effect when administered alone to naïve animals. In contrast, both antagonists induced an increase in basal withdrawal latency in mice. These results indicate that spinal neurons in naked mole-rats have functional SP and NMDA receptors, but that these receptors do not participate in heat-evoked foot withdrawal unless SP is experimentally introduced. We propose that the natural lack of SP in naked mole-rat C-fibers may have resulted during adaptation to living in a chronically high carbon dioxide, high ammonia environment that, in other mammals, would stimulate C-fibers and evoke nocifensive behavior.

  3. Ear Structures of the Naked Mole-Rat, Heterocephalus glaber, and Its Relatives (Rodentia: Bathyergidae.

    Directory of Open Access Journals (Sweden)

    Matthew J Mason

    Full Text Available Although increasingly popular as a laboratory species, very little is known about the peripheral auditory system of the naked mole-rat, Heterocephalus glaber. In this study, middle and inner ears of naked mole-rats of a range of ages were examined using micro-computed tomography and dissection. The ears of five other bathyergid species (Bathyergus suillus, Cryptomys hottentotus, Fukomys micklemi, Georychus capensis and Heliophobius argenteocinereus were examined for comparative purposes. The middle ears of bathyergids show features commonly found in other members of the Ctenohystrica rodent clade, including a fused malleus and incus, a synovial stapedio-vestibular articulation and the loss of the stapedius muscle. Heterocephalus deviates morphologically from the other bathyergids examined in that it has a more complex mastoid cavity structure, poorly-ossified processes of the malleus and incus, a 'columelliform' stapes and fewer cochlear turns. Bathyergids have semicircular canals with unusually wide diameters relative to their radii of curvature. How the lateral semicircular canal reaches the vestibule differs between species. Heterocephalus has much more limited high-frequency hearing than would be predicted from its small ear structures. The spongy bone forming its ossicular processes, the weak incudo-stapedial articulation, the columelliform stapes and (compared to other bathyergids reduced cochlear coiling are all potentially degenerate features which might reflect a lack of selective pressure on its peripheral auditory system. Substantial intraspecific differences were found in certain middle and inner ear structures, which might also result from relaxed selective pressures. However, such interpretations must be treated with caution in the absence of experimental evidence.

  4. Social condition and oxytocin neuron number in the hypothalamus of naked mole-rats (Heterocephalus glaber).

    Science.gov (United States)

    Mooney, S J; Holmes, M M

    2013-01-29

    The naked mole-rat is a subterranean colonial rodent. In each colony, which can grow to as many as 300 individuals, there is only one female and 1-3 males that are reproductive and socially dominant. The remaining animals are reproductively suppressed subordinates that contribute to colony survival through their cooperative behaviors. Oxytocin is a peptide hormone that has shown relatively widespread effects on prosocial behaviors in other species. We examined whether social status affects the number of oxytocin-immunoreactive neurons in the paraventricular nucleus and the supraoptic nucleus by comparing dominant breeding animals to subordinate non-breeding workers from intact colonies. We also examined these regions in subordinate animals that had been removed from their colony and paired with an opposite- or same-sex conspecific for 6 months. Stereological analyses indicated that subordinates had significantly more oxytocin neurons in the paraventricular nucleus than breeders. Animals in both opposite- and same-sex pairs showed a decreased oxytocin neuron number compared to subordinates suggesting that status differences may be due to social condition rather than the reproductive activity of the animal per se. The effects of social status appear to be region specific as no group differences were found for oxytocin neuron number in the supraoptic nucleus. Given that subordinate naked mole-rats are kept reproductively suppressed through antagonism by the queen, we speculate that status differences are due either to oxytocin's anxiolytic properties to combat the stress of this antagonism or to its ability to promote the prosocial behaviors of subordinates. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

  5. Ear Structures of the Naked Mole-Rat, Heterocephalus glaber, and Its Relatives (Rodentia: Bathyergidae).

    Science.gov (United States)

    Mason, Matthew J; Cornwall, Hannah L; Smith, Ewan St J

    2016-01-01

    Although increasingly popular as a laboratory species, very little is known about the peripheral auditory system of the naked mole-rat, Heterocephalus glaber. In this study, middle and inner ears of naked mole-rats of a range of ages were examined using micro-computed tomography and dissection. The ears of five other bathyergid species (Bathyergus suillus, Cryptomys hottentotus, Fukomys micklemi, Georychus capensis and Heliophobius argenteocinereus) were examined for comparative purposes. The middle ears of bathyergids show features commonly found in other members of the Ctenohystrica rodent clade, including a fused malleus and incus, a synovial stapedio-vestibular articulation and the loss of the stapedius muscle. Heterocephalus deviates morphologically from the other bathyergids examined in that it has a more complex mastoid cavity structure, poorly-ossified processes of the malleus and incus, a 'columelliform' stapes and fewer cochlear turns. Bathyergids have semicircular canals with unusually wide diameters relative to their radii of curvature. How the lateral semicircular canal reaches the vestibule differs between species. Heterocephalus has much more limited high-frequency hearing than would be predicted from its small ear structures. The spongy bone forming its ossicular processes, the weak incudo-stapedial articulation, the columelliform stapes and (compared to other bathyergids) reduced cochlear coiling are all potentially degenerate features which might reflect a lack of selective pressure on its peripheral auditory system. Substantial intraspecific differences were found in certain middle and inner ear structures, which might also result from relaxed selective pressures. However, such interpretations must be treated with caution in the absence of experimental evidence.

  6. Peripheral administration of oxytocin increases social affiliation in the naked mole-rat (Heterocephalus glaber).

    Science.gov (United States)

    Mooney, Skyler J; Douglas, Natasha R; Holmes, Melissa M

    2014-04-01

    The neuropeptide oxytocin regulates a wide variety of social behaviors across diverse species. However, the types of behaviors that are influenced by this hormone are constrained by the species in question and the social organization that a particular species exhibits. Therefore, the present experiments investigated behaviors regulated by oxytocin in a eusocial mammalian species by using the naked mole-rat (Heterocephalus glaber). In Experiment 1, adult non-breeding mole-rats were given intraperitoneal injections of either oxytocin (1mg/kg or 10mg/kg) or saline on alternate days. Animals were then returned to their colony and behavior was recorded for minutes 15-30 post-injection. Both doses of oxytocin increased huddling behavior during this time period. In Experiment 2, animals received intraperitoneal injections of either oxytocin (1mg/kg), an oxytocin-receptor antagonist (0.1mg/kg), a cocktail of oxytocin and the antagonist, or saline across 4 testing days in a counterbalanced design. Animals were placed in either a 2-chamber arena with a familiar conspecific or in a small chamber with 1week old pups from their home colony and behaviors were recorded for minutes 15-30 post-injection. Oxytocin increased investigation of, and time spent in close proximity to, a familiar conspecific; these effects were blocked by the oxytocin antagonist. No effects were seen on pup-directed behavior. These data suggest that oxytocin is capable of modulating affiliative-like behavior in this eusocial species. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. RNA sequencing reveals differential expression of mitochondrial and oxidation reduction genes in the long-lived naked mole-rat when compared to mice.

    Science.gov (United States)

    Yu, Chuanfei; Li, Yang; Holmes, Andrew; Szafranski, Karol; Faulkes, Chris G; Coen, Clive W; Buffenstein, Rochelle; Platzer, Matthias; de Magalhães, João Pedro; Church, George M

    2011-01-01

    The naked mole-rat (Heterocephalus glaber) is a long-lived, cancer resistant rodent and there is a great interest in identifying the adaptations responsible for these and other of its unique traits. We employed RNA sequencing to compare liver gene expression profiles between naked mole-rats and wild-derived mice. Our results indicate that genes associated with oxidoreduction and mitochondria were expressed at higher relative levels in naked mole-rats. The largest effect is nearly 300-fold higher expression of epithelial cell adhesion molecule (Epcam), a tumour-associated protein. Also of interest are the protease inhibitor, alpha2-macroglobulin (A2m), and the mitochondrial complex II subunit Sdhc, both ageing-related genes found strongly over-expressed in the naked mole-rat. These results hint at possible candidates for specifying species differences in ageing and cancer, and in particular suggest complex alterations in mitochondrial and oxidation reduction pathways in the naked mole-rat. Our differential gene expression analysis obviated the need for a reference naked mole-rat genome by employing a combination of Illumina/Solexa and 454 platforms for transcriptome sequencing and assembling transcriptome contigs of the non-sequenced species. Overall, our work provides new research foci and methods for studying the naked mole-rat's fascinating characteristics.

  8. RNA sequencing reveals differential expression of mitochondrial and oxidation reduction genes in the long-lived naked mole-rat when compared to mice.

    Directory of Open Access Journals (Sweden)

    Chuanfei Yu

    Full Text Available The naked mole-rat (Heterocephalus glaber is a long-lived, cancer resistant rodent and there is a great interest in identifying the adaptations responsible for these and other of its unique traits. We employed RNA sequencing to compare liver gene expression profiles between naked mole-rats and wild-derived mice. Our results indicate that genes associated with oxidoreduction and mitochondria were expressed at higher relative levels in naked mole-rats. The largest effect is nearly 300-fold higher expression of epithelial cell adhesion molecule (Epcam, a tumour-associated protein. Also of interest are the protease inhibitor, alpha2-macroglobulin (A2m, and the mitochondrial complex II subunit Sdhc, both ageing-related genes found strongly over-expressed in the naked mole-rat. These results hint at possible candidates for specifying species differences in ageing and cancer, and in particular suggest complex alterations in mitochondrial and oxidation reduction pathways in the naked mole-rat. Our differential gene expression analysis obviated the need for a reference naked mole-rat genome by employing a combination of Illumina/Solexa and 454 platforms for transcriptome sequencing and assembling transcriptome contigs of the non-sequenced species. Overall, our work provides new research foci and methods for studying the naked mole-rat's fascinating characteristics.

  9. Sociality and the telencephalic distribution of corticotrophin-releasing factor, urocortin 3, and binding sites for CRF type 1 and type 2 receptors: A comparative study of eusocial naked mole-rats and solitary Cape mole-rats.

    Science.gov (United States)

    Coen, Clive W; Kalamatianos, Theodosis; Oosthuizen, Maria K; Poorun, Ravi; Faulkes, Christopher G; Bennett, Nigel C

    2015-11-01

    Various aspects of social behavior are influenced by the highly conserved corticotrophin-releasing factor (CRF) family of peptides and receptors in the mammalian telencephalon. This study has mapped and compared the telencephalic distribution of the CRF receptors, CRF1 and CRF2 , and two of their ligands, CRF and urocortin 3, respectively, in African mole-rat species with diametrically opposed social behavior. Naked mole-rats live in large eusocial colonies that are characterized by exceptional levels of social cohesion, tolerance, and cooperation in burrowing, foraging, defense, and alloparental care for the offspring of the single reproductive female. Cape mole-rats are solitary; they tolerate conspecifics only fleetingly during the breeding season. The telencephalic sites at which the level of CRF1 binding in naked mole-rats exceeds that in Cape mole-rats include the basolateral amygdaloid nucleus, hippocampal CA3 subfield, and dentate gyrus; in contrast, the level is greater in Cape mole-rats in the shell of the nucleus accumbens and medial habenular nucleus. For CRF2 binding, the sites with a greater level in naked mole-rats include the basolateral amygdaloid nucleus and dentate gyrus, but the septohippocampal nucleus, lateral septal nuclei, amygdalostriatal transition area, bed nucleus of the stria terminalis, and medial habenular nucleus display a greater level in Cape mole-rats. The results are discussed with reference to neuroanatomical and behavioral studies of various species, including monogamous and promiscuous voles. By analogy with findings in those species, we speculate that the abundance of CRF1 binding in the nucleus accumbens of Cape mole-rats reflects their lack of affiliative behavior. © 2015 Wiley Periodicals, Inc.

  10. Naked Mole Rat Cells Have a Stable Epigenome that Resists iPSC Reprogramming

    Directory of Open Access Journals (Sweden)

    Li Tan

    2017-11-01

    Full Text Available Naked mole rat (NMR is a valuable model for aging and cancer research due to its exceptional longevity and cancer resistance. We observed that the reprogramming efficiency of NMR fibroblasts in response to OSKM was drastically lower than that of mouse fibroblasts. Expression of SV40 LargeT antigen (LT dramatically improved reprogramming of NMR fibroblasts. Inactivation of Rb alone, but not p53, was sufficient to improve reprogramming efficiency, suggesting that NMR chromatin may be refractory to reprogramming. Analysis of the global histone landscape revealed that NMR had higher levels of repressive H3K27 methylation marks and lower levels of activating H3K27 acetylation marks than mouse. ATAC-seq revealed that in NMR, promoters of reprogramming genes were more closed than mouse promoters, while expression of LT led to massive opening of the NMR promoters. These results suggest that NMR displays a more stable epigenome that resists de-differentiation, contributing to the cancer resistance and longevity of this species.

  11. Renal Pathology in a Nontraditional Aging Model: The Naked Mole-Rat (Heterocephalus glaber).

    Science.gov (United States)

    Delaney, M A; Kinsel, M J; Treuting, P M

    2016-03-01

    The naked mole-rat (NMR; Heterocephalus glaber) is growing in popularity as a model for aging research due to its extreme longevity (up to 30 years), highly adapted physiology, and resistance to cancer, particularly when compared with traditional aging models such as laboratory mice and rats. Despite the NMR's seemingly lengthy health span, several age-related lesions have been documented. During a 15-year retrospective evaluation of a zoo-housed population, histologic changes in the kidneys were reported in 127 of 138 (92%) adult NMRs. Of these, renal tubular mineralization was very common (115 of 127; 90.6%) and found in NMRs without concurrent renal lesions (36 of 127; 28.3%). Many of the other described lesions were considered progressive stages of a single process, generally referred to as chronic nephritis or nephropathy, and diagnosed in 73 of 127 (57.5%), while end-stage renal disease was reported in only 12 (9.4%) NMRs. Renal lesions of these NMRs were comparable to disease entities reported in laboratory rats and certain strains of inbred and noninbred mice. Although many lesions of NMR kidneys were similar to those found in aged laboratory rodents, some common urinary diseases were not represented in the examined colonies. The goal of this study was to describe renal lesions in NMRs from a zoologic setting to familiarize investigators and pathologists with an apparently common and presumably age-related disease in this nontraditional model. © The Author(s) 2015.

  12. Naked Mole Rat Induced Pluripotent Stem Cells and Their Contribution to Interspecific Chimera

    Directory of Open Access Journals (Sweden)

    Sang-Goo Lee

    2017-11-01

    Full Text Available Naked mole rats (NMRs are exceptionally long-lived, cancer-resistant rodents. Identifying the defining characteristics of these traits may shed light on aging and cancer mechanisms. Here, we report the generation of induced pluripotent stem cells (iPSCs from NMR fibroblasts and their contribution to mouse-NMR chimeric embryos. Efficient reprogramming could be observed under N2B27+2i conditions. The iPSCs displayed a characteristic morphology, expressed pluripotent markers, formed embryoid bodies, and showed typical differentiation patterns. Interestingly, NMR embryonic fibroblasts and the derived iPSCs had propensity for a tetraploid karyotype and were resistant to forming teratomas, but within mouse blastocysts they contributed to both interspecific placenta and fetus. Gene expression patterns of NMR iPSCs were more similar to those of human than mouse iPSCs. Overall, we uncovered unique features of NMR iPSCs and report a mouse-NMR chimeric model. The iPSCs and associated cell culture systems can be used for a variety of biological and biomedical applications.

  13. Functional characteristics of the naked mole rat μ-opioid receptor.

    Directory of Open Access Journals (Sweden)

    Melanie Busch-Dienstfertig

    Full Text Available While humans and most animals respond to µ-opioid receptor (MOR agonists with analgesia and decreased aggression, in the naked mole rat (NMR opioids induce hyperalgesia and severe aggression. Single nucleotide polymorphisms in the human mu-opioid receptor gene (OPRM1 can underlie altered behavioral responses to opioids. Therefore, we hypothesized that the primary structure of the NMR MOR may differ from other species. Sequencing of the NMR oprm1 revealed strong homology to other mammals, but exposed three unique amino acids that might affect receptor-ligand interactions. The NMR and rat oprm1 sequences were cloned into mammalian expression vectors and transfected into HEK293 cells. Radioligand binding and 3'-5'-cyclic adenosine monophosphate (cAMP enzyme immunoassays were used to compare opioid binding and opioid-mediated cAMP inhibition. At normalized opioid receptor protein levels we detected significantly lower [3H]DAMGO binding to NMR compared to rat MOR, but no significant difference in DAMGO-induced cAMP inhibition. Strong DAMGO-induced MOR internalization was detectable using radioligand binding and confocal imaging in HEK293 cells expressing rat or NMR receptor, while morphine showed weak or no effects. In summary, we found minor functional differences between rat and NMR MOR suggesting that other differences e.g. in anatomical distribution of MOR underlie the NMR's extreme reaction to opioids.

  14. Cardiac function of the naked mole-rat: ecophysiological responses to working underground.

    Science.gov (United States)

    Grimes, Kelly M; Voorhees, Andrew; Chiao, Ying Ann; Han, Hai-Chao; Lindsey, Merry L; Buffenstein, Rochelle

    2014-03-01

    The naked mole-rat (NMR) is a strictly subterranean rodent with a low resting metabolic rate. Nevertheless, it can greatly increase its metabolic activity to meet the high energetic demands associated with digging through compacted soils in its xeric natural habitat where food is patchily distributed. We hypothesized that the NMR heart would naturally have low basal function and exhibit a large cardiac reserve, thereby mirroring the species' low basal metabolism and large metabolic scope. Echocardiography showed that young (2-4 yr old) healthy NMRs have low fractional shortening (28 ± 2%), ejection fraction (43 ± 2%), and cardiac output (6.5 ± 0.4 ml/min), indicating low basal cardiac function. Histology revealed large NMR cardiomyocyte cross-sectional area (216 ± 10 μm(2)) and cardiac collagen deposition of 2.2 ± 0.4%. Neither of these histomorphometric traits was considered pathological, since biaxial tensile testing showed no increase in passive ventricular stiffness. NMR cardiomyocyte fibers showed a low degree of rotation, contributing to the observed low NMR cardiac contractility. Interestingly, when the exercise mimetic dobutamine (3 μg/g ip) was administered, NMRs showed pronounced increases in fractional shortening, ejection fraction, cardiac output, and stroke volume, indicating an increased cardiac reserve. The relatively low basal cardiac function and enhanced cardiac reserve of NMRs are likely to be ecophysiological adaptations to life in an energetically taxing environment.

  15. Challenging the inbreeding hypothesis in a eusocial mammal: population genetics of the naked mole-rat, Heterocephalus glaber.

    Science.gov (United States)

    Ingram, Colleen M; Troendle, Nicholas J; Gill, Clare A; Braude, Stanton; Honeycutt, Rodney L

    2015-10-01

    The role of genetic relatedness in the evolution of eusociality has been the topic of much debate, especially when contrasting eusocial insects with vertebrates displaying reproductive altruism. The naked mole-rat, Heterocephalus glaber, was the first described eusocial mammal. Although this discovery was based on an ecological constraints model of eusocial evolution, early genetic studies reported high levels of relatedness in naked mole-rats, providing a compelling argument that low dispersal rates and consanguineous mating (inbreeding as a mating system) are the driving forces for the evolution of this eusocial species. One caveat to accepting this long-held view is that the original genetic studies were based on limited sampling from the species' geographic distribution. A growing body of evidence supports a contrary view, with the original samples not representative of the species-rather reflecting a single founder event, establishing a small population south of the Athi River. Our study is the first to address these competing hypotheses by examining patterns of molecular variation in colonies sampled from north and south of the Athi and Tana rivers, which based on our results, serve to isolate genetically distinct populations of naked mole-rats. Although colonies south of the Athi River share a single mtDNA haplotype and are fixed at most microsatellite loci, populations north of the Athi River are considerably more variable. Our findings support the position that the low variation observed in naked mole-rat populations south of the Athi River reflects a founder event, rather than a consequence of this species' unusual mating system. © 2015 John Wiley & Sons Ltd.

  16. Naked mole-rats maintain healthy skeletal muscle and Complex IV mitochondrial enzyme function into old age.

    Science.gov (United States)

    Stoll, Elizabeth A; Karapavlovic, Nevena; Rosa, Hannah; Woodmass, Michael; Rygiel, Karolina; White, Kathryn; Turnbull, Douglass M; Faulkes, Chris G

    2016-12-19

    The naked mole-rat (NMR) Heterocephalus glaber is an exceptionally long-lived rodent, living up to 32 years in captivity. This extended lifespan is accompanied by a phenotype of negligible senescence, a phenomenon of very slow changes in the expected physiological characteristics with age. One of the many consequences of normal aging in mammals is the devastating and progressive loss of skeletal muscle, termed sarcopenia, caused in part by respiratory enzyme dysfunction within the mitochondria of skeletal muscle fibers. Here we report that NMRs avoid sarcopenia for decades. Muscle fiber integrity and mitochondrial ultrastructure are largely maintained in aged animals. While mitochondrial Complex IV expression and activity remains stable, Complex I expression is significantly decreased. We show that aged naked mole-rat skeletal muscle tissue contains some mitochondrial DNA rearrangements, although the common mitochondrial DNA deletions associated with aging in human and other rodent skeletal muscles are not present. Interestingly, NMR skeletal muscle fibers demonstrate a significant increase in mitochondrial DNA copy number. These results have intriguing implications for the role of mitochondria in aging, suggesting Complex IV, but not Complex I, function is maintained in the long-lived naked mole rat, where sarcopenia is avoided and healthy muscle function is maintained for decades.

  17. Membrane phospholipid composition may contribute to exceptional longevity of the naked mole-rat (Heterocephalus glaber): a comparative study using shotgun lipidomics.

    Science.gov (United States)

    Mitchell, Todd W; Buffenstein, Rochelle; Hulbert, A J

    2007-11-01

    Phospholipids containing highly polyunsaturated fatty acids are particularly prone to peroxidation and membrane composition may therefore influence longevity. Phospholipid molecules, in particular those containing docosahexaenoic acid (DHA), from the skeletal muscle, heart, liver and liver mitochondria were identified and quantified using mass-spectrometry shotgun lipidomics in two similar-sized rodents that show an approximately 9-fold difference in maximum lifespan. The naked mole rat is the longest-living rodent known with a maximum lifespan of >28 years. Total phospholipid distribution is similar in tissues of both species; DHA is only found in phosphatidylcholines (PC), phosphatidylethanolamines (PE) and phosphatidylserines (PS), and DHA is relatively more concentrated in PE than PC. Naked mole-rats have fewer molecular species of both PC and PE than do mice. DHA-containing phospholipids represent 27-57% of all phospholipids in mice but only 2-6% in naked mole-rats. Furthermore, while mice have small amounts of di-polyunsaturated PC and PE, these are lacking in naked mole-rats. Vinyl ether-linked phospholipids (plasmalogens) are higher in naked mole-rat tissues than in mice. The lower level of DHA-containing phospholipids suggests a lower susceptibility to peroxidative damage in membranes of naked mole-rats compared to mice. Whereas the high level of plasmalogens might enhance membrane antioxidant protection in naked mole-rats compared to mice. Both characteristics possibly contribute to the exceptional longevity of naked mole-rats and may indicate a special role for peroxisomes in this extended longevity.

  18. Naked mole-rat has increased translational fidelity compared with the mouse, as well as a unique 28S ribosomal RNA cleavage.

    Science.gov (United States)

    Azpurua, Jorge; Ke, Zhonghe; Chen, Iris X; Zhang, Quanwei; Ermolenko, Dmitri N; Zhang, Zhengdong D; Gorbunova, Vera; Seluanov, Andrei

    2013-10-22

    The naked mole-rat (Heterocephalus glaber) is a subterranean eusocial rodent with a markedly long lifespan and resistance to tumorigenesis. Multiple data implicate modulation of protein translation in longevity. Here we report that 28S ribosomal RNA (rRNA) of the naked mole-rat is processed into two smaller fragments of unequal size. The two breakpoints are located in the 28S rRNA divergent region 6 and excise a fragment of 263 nt. The excised fragment is unique to the naked mole-rat rRNA and does not show homology to other genomic regions. Because this hidden break site could alter ribosome structure, we investigated whether translation rate and amino acid incorporation fidelity were altered. We report that naked mole-rat fibroblasts have significantly increased translational fidelity despite having comparable translation rates with mouse fibroblasts. Although we cannot directly test whether the unique 28S rRNA structure contributes to the increased fidelity of translation, we speculate that it may change the folding or dynamics of the large ribosomal subunit, altering the rate of GTP hydrolysis and/or interaction of the large subunit with tRNA during accommodation, thus affecting the fidelity of protein synthesis. In summary, our results show that naked mole-rat cells produce fewer aberrant proteins, supporting the hypothesis that the more stable proteome of the naked mole-rat contributes to its longevity.

  19. Cessation of reproduction-related spine elongation after multiple breeding cycles in female naked mole-rats.

    Science.gov (United States)

    Dengler-Crish, Christine M; Catania, Kenneth C

    2009-01-01

    The breeding female or "queen" naked mole-rat has a uniquely elongated body morphology attributed to the lengthening of the lumbar vertebral column that occurs during pregnancy. It is unknown whether this vertebral growth is a continuous process, or associated only with early reproductive experience. We compared pregnancy-related bone elongation in nascent primiparous queens and established queens to determine if this vertebral expansion was a lifelong process in these females. We also investigated the impact of lactation on vertebral elongation in these mole-rats because it is known to be a time of significant bone loss in other mammals. Our data show that after eight or more pregnancies, established queens no longer experienced a net gain in lumbar spine length over the reproductive cycle, whereas the nascent breeders demonstrated significant spine lengthening over this time. Despite the lack of net spine lengthening in established breeders, our results indicated that these queens still experienced some pregnancy-specific vertebral elongation. In naked mole-rats, pregnancy-induced bone elongation may serve the dual purposes of first lengthening the spine, and then once optimal spine size is achieved, serving as a homeostatic mechanism that prepares the spine for the mineral demands of lactation. Anat Rec, 2009. (c) 2008 Wiley-Liss, Inc.

  20. The Insulin-Like Growth Factor System in the Long-Lived Naked Mole-Rat.

    Directory of Open Access Journals (Sweden)

    Malene Brohus

    Full Text Available Naked mole-rats (Heterocephalus glaber (NMRs are the longest living rodents known. They show negligible senescence, and are resistant to cancers and certain damaging effects associated with aging. The insulin-like growth factors (IGFs have pluripotent actions, influencing growth processes in virtually every system of the body. They are established contributors to the aging process, confirmed by the demonstration that decreased IGF signaling results in life-extending effects in a variety of species. The IGFs are likewise involved in progression of cancers by mediating survival signals in malignant cells. This report presents a full characterization of the IGF system in the NMR: ligands, receptors, IGF binding proteins (IGFBPs, and IGFBP proteases. A particular emphasis was placed on the IGFBP protease, pregnancy-associated plasma protein-A (PAPP-A, shown to be an important lifespan modulator in mice. Comparisons of IGF-related genes in the NMR with human and murine sequences indicated no major differences in essential parts of the IGF system, including PAPP-A. The protease was shown to possess an intact active site despite the report of a contradictory genome sequence. Furthermore, PAPP-A was expressed and translated in NMRs cells and retained IGF-dependent proteolytic activity towards IGFBP-4 and IGF-independent activity towards IGFBP-5. However, experimental data suggest differential regulatory mechanisms for PAPP-A expression in NMRs than those described in humans and mice. This overall description of the IGF system in the NMR represents an initial step towards elucidating the complex molecular mechanisms underlying longevity, and how these animals have evolved to ensure a delayed and healthy aging process.

  1. Initial Case Reports of Cancer in Naked Mole-rats (Heterocephalus glaber).

    Science.gov (United States)

    Delaney, M A; Ward, J M; Walsh, T F; Chinnadurai, S K; Kerns, K; Kinsel, M J; Treuting, P M

    2016-05-01

    Naked mole-rats (NMRs;Heterocephalus glaber) are highly adapted, eusocial rodents renowned for their extreme longevity and resistance to cancer. Because cancer has not been formally described in this species, NMRs have been increasingly utilized as an animal model in aging and cancer research. We previously reported the occurrence of several age-related diseases, including putative pre-neoplastic lesions, in zoo-housed NMR colonies. Here, we report for the first time 2 cases of cancer in zoo-housed NMRs. In Case No. 1, we observed a subcutaneous mass in the axillary region of a 22-year-old male NMR, with histologic, immunohistochemical (pancytokeratin positive, rare p63 immunolabeling, and smooth muscle actin negative), and ultrastructural characteristics of an adenocarcinoma possibly of mammary or salivary origin. In Case No. 2, we observed a densely cellular, poorly demarcated gastric mass of polygonal cells arranged in nests with positive immunolabeling for synaptophysin and chromogranin indicative of a neuroendocrine carcinoma in an approximately 20-year-old male NMR. We also include a brief discussion of other proliferative growths and pre-cancerous lesions diagnosed in 1 zoo colony. Although these case reports do not alter the longstanding observation of cancer resistance, they do raise questions about the scope of cancer resistance and the interpretation of biomedical studies in this model. These reports also highlight the benefit of long-term disease investigations in zoo-housed populations to better understand naturally occurring disease processes in species used as models in biomedical research. © The Author(s) 2016.

  2. The Insulin-Like Growth Factor System in the Long-Lived Naked Mole-Rat.

    Science.gov (United States)

    Brohus, Malene; Gorbunova, Vera; Faulkes, Chris G; Overgaard, Michael T; Conover, Cheryl A

    2015-01-01

    Naked mole-rats (Heterocephalus glaber) (NMRs) are the longest living rodents known. They show negligible senescence, and are resistant to cancers and certain damaging effects associated with aging. The insulin-like growth factors (IGFs) have pluripotent actions, influencing growth processes in virtually every system of the body. They are established contributors to the aging process, confirmed by the demonstration that decreased IGF signaling results in life-extending effects in a variety of species. The IGFs are likewise involved in progression of cancers by mediating survival signals in malignant cells. This report presents a full characterization of the IGF system in the NMR: ligands, receptors, IGF binding proteins (IGFBPs), and IGFBP proteases. A particular emphasis was placed on the IGFBP protease, pregnancy-associated plasma protein-A (PAPP-A), shown to be an important lifespan modulator in mice. Comparisons of IGF-related genes in the NMR with human and murine sequences indicated no major differences in essential parts of the IGF system, including PAPP-A. The protease was shown to possess an intact active site despite the report of a contradictory genome sequence. Furthermore, PAPP-A was expressed and translated in NMRs cells and retained IGF-dependent proteolytic activity towards IGFBP-4 and IGF-independent activity towards IGFBP-5. However, experimental data suggest differential regulatory mechanisms for PAPP-A expression in NMRs than those described in humans and mice. This overall description of the IGF system in the NMR represents an initial step towards elucidating the complex molecular mechanisms underlying longevity, and how these animals have evolved to ensure a delayed and healthy aging process.

  3. Transcriptome sequencing of the naked mole rat (Heterocephalus glaber and identification of hypoxia tolerance genes

    Directory of Open Access Journals (Sweden)

    Bang Xiao

    2017-12-01

    Full Text Available The naked mole rat (NMR; Heterocephalus glaber is a small rodent species found in regions of Kenya, Ethiopia and Somalia. It has a high tolerance for hypoxia and is thus considered one of the most important natural models for studying hypoxia tolerance mechanisms. The various mechanisms underlying the NMR's hypoxia tolerance are beginning to be understood at different levels of organization, and next-generation sequencing methods promise to expand this understanding to the level of gene expression. In this study, we examined the sequence and transcript abundance data of the muscle transcriptome of NMRs exposed to hypoxia using the Illumina HiSeq 2500 system to clarify the possible genomic adaptive responses to the hypoxic underground surroundings. The RNA-seq raw FastQ data were mapped against the NMR genome. We identified 2337 differentially expressed genes (DEGs by comparison of the hypoxic and control groups. Functional annotation of the DEGs by gene ontology (GO analysis revealed enrichment of hypoxia stress-related GO categories, including ‘biological regulation’, ‘cellular process’, ‘ion transport’ and ‘cell-cell signaling’. Enrichment of DEGs in signaling pathways was analyzed against the Kyoto Encyclopedia of Genes and Genomes (KEGG database to identify possible interactions between DEGs. The results revealed significant enrichment of DEGs in focal adhesion, the mitogen-activated protein kinase (MAPK signaling pathway and the glycine, serine and threonine metabolism pathway. Furthermore, inhibition of DEGs (STMN1, MAPK8IP1 and MAPK10 expression induced apoptosis and arrested cell growth in NMR fibroblasts following hypoxia. Thus, this global transcriptome analysis of NMRs can provide an important genetic resource for the study of hypoxia tolerance in mammals. Furthermore, the identified DEGs may provide important molecular targets for biomedical research into therapeutic strategies for stroke and cardiovascular diseases.

  4. Reduced Utilization of Selenium by Naked Mole Rats Due to a Specific Defect in GPx1 Expression*

    Science.gov (United States)

    Kasaikina, Marina V.; Lobanov, Alexei V.; Malinouski, Mikalai Y.; Lee, Byung Cheon; Seravalli, Javier; Fomenko, Dmitri E.; Turanov, Anton A.; Finney, Lydia; Vogt, Stefan; Park, Thomas J.; Miller, Richard A.; Hatfield, Dolph L.; Gladyshev, Vadim N.

    2011-01-01

    Naked mole rat (MR) Heterocephalus glaber is a rodent model of delayed aging because of its unusually long life span (>28 years). It is also not known to develop cancer. In the current work, tissue imaging by x-ray fluorescence microscopy and direct analyses of trace elements revealed low levels of selenium in the MR liver and kidney, whereas MR and mouse brains had similar selenium levels. This effect was not explained by uniform selenium deficiency because methionine sulfoxide reductase activities were similar in mice and MR. However, glutathione peroxidase activity was an order of magnitude lower in MR liver and kidney than in mouse tissues. In addition, metabolic labeling of MR cells with 75Se revealed a loss of the abundant glutathione peroxidase 1 (GPx1) band, whereas other selenoproteins were preserved. To characterize the MR selenoproteome, we sequenced its liver transcriptome. Gene reconstruction revealed standard selenoprotein sequences except for GPx1, which had an early stop codon, and SelP, which had low selenocysteine content. When expressed in HEK 293 cells, MR GPx1 was present in low levels, and its expression could be rescued neither by removing the early stop codon nor by replacing its SECIS element. In addition, GPx1 mRNA was present in lower levels in MR liver than in mouse liver. To determine if GPx1 deficiency could account for the reduced selenium content, we analyzed GPx1 knock-out mice and found reduced selenium levels in their livers and kidneys. Thus, MR is characterized by the reduced utilization of selenium due to a specific defect in GPx1 expression. PMID:21372135

  5. Immunohistochemical characterization of the chemosensory pulmonary neuroepithelial bodies in the naked mole-rat reveals a unique adaptive phenotype.

    Directory of Open Access Journals (Sweden)

    Jie Pan

    Full Text Available The pulmonary neuroepithelial bodies (NEBs constitute polymodal airway chemosensors for monitoring and signaling ambient gas concentrations (pO2, pCO2/H+ via complex innervation to the brain stem controlling breathing. NEBs produce the bioactive amine, serotonin (5-HT, and a variety of peptides with multiple effects on lung physiology and other organ systems. NEBs in mammals appear prominent and numerous during fetal and neonatal periods, and decline in the post-natal period suggesting an important role during perinatal adaptation. The naked mole-rat (NMR, Heterocephalus glaber, has adapted to the extreme environmental conditions of living in subterranean burrows in large colonies (up to 300 colony mates. The crowded, unventilated burrows are environments of severe hypoxia and hypercapnia. However, NMRs adjust readily to above ground conditions. The chemosensory NEBs of this species were characterized and compared to those of the conventional Wistar rat (WR to identify similarities and differences that could explain the NMR's adaptability to environments. A multilabel immunohistochemical analysis combined with confocal microscopy revealed that the expression patterns of amine, peptide, neuroendocrine, innervation markers and chemosensor component proteins in NEBs of NMR were similar to that of WR. However, we found the following differences: 1 NEBs in both neonatal and adult NMR lungs were significantly larger and more numerous as compared to WR; 2 NEBs in NMR had a more variable compact cell organization and exhibited significant differences in the expression of adhesion proteins; 3 NMR NEBs showed a significantly greater ratio of 5-HT positive cells with an abundance of 5-HT; 4 NEBs in NMR expressed the proliferating cell nuclear antigen (PCNA and the neurogenic gene (MASH1 indicating active proliferation and a state of persistent differentiation. Taken together our findings suggest that NEBs in lungs of NMR are in a hyperactive, functional

  6. Immunohistochemical characterization of the chemosensory pulmonary neuroepithelial bodies in the naked mole-rat reveals a unique adaptive phenotype.

    Science.gov (United States)

    Pan, Jie; Park, Thomas J; Cutz, Ernest; Yeger, Herman

    2014-01-01

    The pulmonary neuroepithelial bodies (NEBs) constitute polymodal airway chemosensors for monitoring and signaling ambient gas concentrations (pO2, pCO2/H+) via complex innervation to the brain stem controlling breathing. NEBs produce the bioactive amine, serotonin (5-HT), and a variety of peptides with multiple effects on lung physiology and other organ systems. NEBs in mammals appear prominent and numerous during fetal and neonatal periods, and decline in the post-natal period suggesting an important role during perinatal adaptation. The naked mole-rat (NMR), Heterocephalus glaber, has adapted to the extreme environmental conditions of living in subterranean burrows in large colonies (up to 300 colony mates). The crowded, unventilated burrows are environments of severe hypoxia and hypercapnia. However, NMRs adjust readily to above ground conditions. The chemosensory NEBs of this species were characterized and compared to those of the conventional Wistar rat (WR) to identify similarities and differences that could explain the NMR's adaptability to environments. A multilabel immunohistochemical analysis combined with confocal microscopy revealed that the expression patterns of amine, peptide, neuroendocrine, innervation markers and chemosensor component proteins in NEBs of NMR were similar to that of WR. However, we found the following differences: 1) NEBs in both neonatal and adult NMR lungs were significantly larger and more numerous as compared to WR; 2) NEBs in NMR had a more variable compact cell organization and exhibited significant differences in the expression of adhesion proteins; 3) NMR NEBs showed a significantly greater ratio of 5-HT positive cells with an abundance of 5-HT; 4) NEBs in NMR expressed the proliferating cell nuclear antigen (PCNA) and the neurogenic gene (MASH1) indicating active proliferation and a state of persistent differentiation. Taken together our findings suggest that NEBs in lungs of NMR are in a hyperactive, functional and

  7. The anti-tumorigenic activity of A2M-A lesson from the naked mole-rat.

    Directory of Open Access Journals (Sweden)

    Susanne Kurz

    Full Text Available Cancer resistance is a major cause for longevity of the naked mole-rat. Recent liver transcriptome analysis in this animal compared to wild-derived mice revealed higher expression of alpha2-macroglobulin (A2M and cell adhesion molecules, which contribute to the naked mole-rat's cancer resistance. Notably, A2M is known to dramatically decrease with age in humans. We hypothesize that this might facilitate tumour development. Here we found that A2M modulates tumour cell adhesion, migration and growth by inhibition of tumour promoting signalling pathways, e.g. PI3K / AKT, SMAD and up-regulated PTEN via down-regulation of miR-21, in vitro and in tumour xenografts. A2M increases the expression of CD29 and CD44 but did not evoke EMT. Transcriptome analysis of A2M-treated tumour cells, xenografts and mouse liver demonstrated a multifaceted regulation of tumour promoting signalling pathways indicating a less tumorigenic environment mediated by A2M. By virtue of these multiple actions the naturally occurring A2M has strong potential as a novel therapeutic agent.

  8. The anti-tumorigenic activity of A2M-A lesson from the naked mole-rat.

    Science.gov (United States)

    Kurz, Susanne; Thieme, René; Amberg, Ronny; Groth, Marco; Jahnke, Heinz-Georg; Pieroh, Philipp; Horn, Lars-Christian; Kolb, Marlen; Huse, Klaus; Platzer, Matthias; Volke, Daniela; Dehghani, Faramarz; Buzdin, Anton; Engel, Kathrin; Robitzki, Andrea; Hoffmann, Ralf; Gockel, Ines; Birkenmeier, Gerd

    2017-01-01

    Cancer resistance is a major cause for longevity of the naked mole-rat. Recent liver transcriptome analysis in this animal compared to wild-derived mice revealed higher expression of alpha2-macroglobulin (A2M) and cell adhesion molecules, which contribute to the naked mole-rat's cancer resistance. Notably, A2M is known to dramatically decrease with age in humans. We hypothesize that this might facilitate tumour development. Here we found that A2M modulates tumour cell adhesion, migration and growth by inhibition of tumour promoting signalling pathways, e.g. PI3K / AKT, SMAD and up-regulated PTEN via down-regulation of miR-21, in vitro and in tumour xenografts. A2M increases the expression of CD29 and CD44 but did not evoke EMT. Transcriptome analysis of A2M-treated tumour cells, xenografts and mouse liver demonstrated a multifaceted regulation of tumour promoting signalling pathways indicating a less tumorigenic environment mediated by A2M. By virtue of these multiple actions the naturally occurring A2M has strong potential as a novel therapeutic agent.

  9. Negligible senescence in the longest living rodent, the naked mole-rat: insights from a successfully aging species.

    Science.gov (United States)

    Buffenstein, Rochelle

    2008-05-01

    Aging refers to a gradual deterioration in function that, over time, leads to increased mortality risk, and declining fertility. This pervasive process occurs in almost all organisms, although some long-lived trees and cold water inhabitants reportedly show insignificant aging. Negligible senescence is characterized by attenuated age-related change in reproductive and physiological functions, as well as no observable age-related gradual increase in mortality rate. It was questioned whether the longest living rodent, the naked mole-rat, met these three strict criteria. Naked mole-rats live in captivity for more than 28.3 years, approximately 9 times longer than similar-sized mice. They maintain body composition from 2 to 24 years, and show only slight age-related changes in all physiological and morphological characteristics studied to date. Surprisingly breeding females show no decline in fertility even when well into their third decade of life. Moreover, these animals have never been observed to develop any spontaneous neoplasm. As such they do not show the typical age-associated acceleration in mortality risk that characterizes every other known mammalian species and may therefore be the first reported mammal showing negligible senescence over the majority of their long lifespan. Clearly physiological and biochemical processes in this species have evolved to dramatically extend healthy lifespan. The challenge that lies ahead is to understand what these mechanisms are.

  10. The naked mole-rat exhibits an unusual cardiac myofilament protein profile providing new insights into heart function of this naturally subterranean rodent.

    Science.gov (United States)

    Grimes, Kelly M; Barefield, David Y; Kumar, Mohit; McNamara, James W; Weintraub, Susan T; de Tombe, Pieter P; Sadayappan, Sakthivel; Buffenstein, Rochelle

    2017-12-01

    The long-lived, hypoxic-tolerant naked mole-rat well-maintains cardiac function over its three-decade-long lifespan and exhibits many cardiac features atypical of similar-sized laboratory rodents. For example, they exhibit low heart rates and resting cardiac contractility, yet have a large cardiac reserve. These traits are considered ecophysiological adaptations to their dank subterranean atmosphere of low oxygen and high carbon dioxide levels and may also contribute to negligible declines in cardiac function during aging. We asked if naked mole-rats had a different myofilament protein signature to that of similar-sized mice that commonly show both high heart rates and high basal cardiac contractility. Adult mouse ventricles predominantly expressed α-myosin heavy chain (97.9 ± 0.4%). In contrast, and more in keeping with humans, β myosin heavy chain was the dominant isoform (79.0 ± 2.0%) in naked mole-rat ventricles. Naked mole-rat ventricles diverged from those of both humans and mice, as they expressed both cardiac and slow skeletal isoforms of troponin I. This myofilament protein profile is more commonly observed in mice in utero and during cardiomyopathies. There were no species differences in phosphorylation of cardiac myosin binding protein-C or troponin I. Phosphorylation of both ventricular myosin light chain 2 and cardiac troponin T in naked mole-rats was approximately half that observed in mice. Myofilament function was also compared between the two species using permeabilized cardiomyocytes. Together, these data suggest a cardiac myofilament protein signature that may contribute to the naked mole-rat's suite of adaptations to its natural subterranean habitat.

  11. Reaching Out to Send a Message: Proteins Associated with Neurite Outgrowth and Neurotransmission are Altered with Age in the Long-Lived Naked Mole-Rat.

    Science.gov (United States)

    Triplett, Judy C; Swomley, Aaron M; Kirk, Jessime; Grimes, Kelly M; Lewis, Kaitilyn N; Orr, Miranda E; Rodriguez, Karl A; Cai, Jian; Klein, Jon B; Buffenstein, Rochelle; Butterfield, D Allan

    2016-07-01

    Aging is the greatest risk factor for developing neurodegenerative diseases, which are associated with diminished neurotransmission as well as neuronal structure and function. However, several traits seemingly evolved to avert or delay age-related deterioration in the brain of the longest-lived rodent, the naked mole-rat (NMR). The NMR remarkably also exhibits negligible senescence, maintaining an extended healthspan for ~75 % of its life span. Using a proteomic approach, statistically significant changes with age in expression and/or phosphorylation levels of proteins associated with neurite outgrowth and neurotransmission were identified in the brain of the NMR and include: cofilin-1; collapsin response mediator protein 2; actin depolymerizing factor; spectrin alpha chain; septin-7; syntaxin-binding protein 1; synapsin-2 isoform IIB; and dynamin 1. We hypothesize that such changes may contribute to the extended lifespan and healthspan of the NMR.

  12. Disparate patterns of age-related changes in lipid peroxidation in long-lived naked mole-rats and shorter-lived mice.

    Science.gov (United States)

    Andziak, Blazej; Buffenstein, Rochelle

    2006-12-01

    A key tenet of the oxidative stress theory of aging is that levels of accrued oxidative damage increase with age. Differences in damage generation and accumulation therefore may underlie the natural variation in species longevity. We compared age-related profiles of whole-organism lipid peroxidation (urinary isoprostanes) and liver lipid damage (malondialdehyde) in long living naked mole-rats [maximum lifespan (MLS) > 28.3 years] and shorter-living CB6F1 hybrid mice (MLS approximately 3.5 years). In addition, we compared age-associated changes in liver non-heme iron to assess how intracellular conditions, which may modulate oxidative processes, are affected by aging. Surprisingly, even at a young age, concentrations of both markers of lipid peroxidation, as well as of iron, were at least twofold (P naked mole tats than in mice. This refutes the hypothesis that prolonged naked mole-rat longevity is due to superior protection against oxidative stress. The age-related profiles of all three parameters were distinctly species specific. Rates of lipid damage generation in mice were maintained throughout adulthood, while accrued damage in old animals was twice that of young mice. In naked mole-rats, urinary isoprostane excretion declined by half with age (P naked mole-rats is independent of oxidative stress parameters.

  13. Walking the oxidative stress tightrope: a perspective from the naked mole-rat, the longest-living rodent.

    Science.gov (United States)

    Rodriguez, Karl A; Wywial, Ewa; Perez, Viviana I; Lambert, Adriant J; Edrey, Yael H; Lewis, Kaitlyn N; Grimes, Kelly; Lindsey, Merry L; Brand, Martin D; Buffenstein, Rochelle

    2011-01-01

    Reactive oxygen species (ROS), by-products of aerobic metabolism, cause oxidative damage to cells and tissue and not surprisingly many theories have arisen to link ROS-induced oxidative stress to aging and health. While studies clearly link ROS to a plethora of divergent diseases, their role in aging is still debatable. Genetic knock-down manipulations of antioxidants alter the levels of accrued oxidative damage, however, the resultant effect of increased oxidative stress on lifespan are equivocal. Similarly the impact of elevating antioxidant levels through transgenic manipulations yield inconsistent effects on longevity. Furthermore, comparative data from a wide range of endotherms with disparate longevity remain inconclusive. Many long-living species such as birds, bats and mole-rats exhibit high-levels of oxidative damage, evident already at young ages. Clearly, neither the amount of ROS per se nor the sensitivity in neutralizing ROS are as important as whether or not the accrued oxidative stress leads to oxidative-damage-linked age-associated diseases. In this review we examine the literature on ROS, its relation to disease and the lessons gleaned from a comparative approach based upon species with widely divergent responses. We specifically focus on the longest lived rodent, the naked mole-rat, which maintains good health and provides novel insights into the paradox of maintaining both an extended healthspan and lifespan despite high oxidative stress from a young age.

  14. Resistance to experimental tumorigenesis in cells of a long-lived mammal, the naked mole-rat (Heterocephalus glaber).

    Science.gov (United States)

    Liang, Sitai; Mele, James; Wu, Yuehong; Buffenstein, Rochelle; Hornsby, Peter J

    2010-08-01

    The naked mole-rat (NMR, Heterocephalus glaber) is a long-lived mammal in which spontaneous cancer has not been observed. To investigate possible mechanisms for cancer resistance in this species, we studied the properties of skin fibroblasts from the NMR following transduction with oncogenes that cause cells of other mammalian species to form malignant tumors. Naked mole-rat fibroblasts were transduced with a retrovirus encoding SV40 large T antigen and oncogenic Ras(G12V). Following transplantation of transduced cells into immunodeficient mice, cells rapidly entered crisis, as evidenced by the presence of anaphase bridges, giant cells with enlarged nuclei, multinucleated cells, and cells with large number of chromosomes or abnormal chromatin material. In contrast, similarly transduced mouse and rat fibroblasts formed tumors that grew rapidly without crisis. Crisis was also observed after > 40 population doublings in SV40 TAg/Ras-expressing NMR cells in culture. Crisis in culture was prevented by additional infection of the cells with a retrovirus encoding hTERT (telomerase reverse transcriptase). SV40 TAg/Ras/hTERT-expressing NMR cells formed tumors that grew rapidly in immunodeficient mice without evidence of crisis. Crisis could also be induced in SV40 TAg/Ras-expressing NMR cells by loss of anchorage, but after hTERT transduction, cells were able to proliferate normally following loss of anchorage. Thus, rapid crisis is a response of oncogene-expressing NMR cells to growth in an in vivo environment, which requires anchorage independence, and hTERT permits cells to avoid crisis and to achieve malignant tumor growth. The unique reaction of NMR cells to oncogene expression may form part of the cancer resistance of this species.

  15. Altered composition of liver proteasome assemblies contributes to enhanced proteasome activity in the exceptionally long-lived naked mole-rat.

    Science.gov (United States)

    Rodriguez, Karl A; Edrey, Yael H; Osmulski, Pawel; Gaczynska, Maria; Buffenstein, Rochelle

    2012-01-01

    The longest-lived rodent, the naked mole-rat (Bathyergidae; Heterocephalus glaber), maintains robust health for at least 75% of its 32 year lifespan, suggesting that the decline in genomic integrity or protein homeostasis routinely observed during aging, is either attenuated or delayed in this extraordinarily long-lived species. The ubiquitin proteasome system (UPS) plays an integral role in protein homeostasis by degrading oxidatively-damaged and misfolded proteins. In this study, we examined proteasome activity in naked mole-rats and mice in whole liver lysates as well as three subcellular fractions to probe the mechanisms behind the apparently enhanced effectiveness of UPS. We found that when compared with mouse samples, naked mole-rats had significantly higher chymotrypsin-like (ChT-L) activity and a two-fold increase in trypsin-like (T-L) in both whole lysates as well as cytosolic fractions. Native gel electrophoresis of the whole tissue lysates showed that the 20S proteasome was more active in the longer-lived species and that 26S proteasome was both more active and more populous. Western blot analyses revealed that both 19S subunits and immunoproteasome catalytic subunits are present in greater amounts in the naked mole-rat suggesting that the observed higher specific activity may be due to the greater proportion of immunoproteasomes in livers of healthy young adults. It thus appears that proteasomes in this species are primed for the efficient removal of stress-damaged proteins. Further characterization of the naked mole-rat proteasome and its regulation could lead to important insights on how the cells in these animals handle increased stress and protein damage to maintain a longer health in their tissues and ultimately a longer life.

  16. Altered composition of liver proteasome assemblies contributes to enhanced proteasome activity in the exceptionally long-lived naked mole-rat.

    Directory of Open Access Journals (Sweden)

    Karl A Rodriguez

    Full Text Available The longest-lived rodent, the naked mole-rat (Bathyergidae; Heterocephalus glaber, maintains robust health for at least 75% of its 32 year lifespan, suggesting that the decline in genomic integrity or protein homeostasis routinely observed during aging, is either attenuated or delayed in this extraordinarily long-lived species. The ubiquitin proteasome system (UPS plays an integral role in protein homeostasis by degrading oxidatively-damaged and misfolded proteins. In this study, we examined proteasome activity in naked mole-rats and mice in whole liver lysates as well as three subcellular fractions to probe the mechanisms behind the apparently enhanced effectiveness of UPS. We found that when compared with mouse samples, naked mole-rats had significantly higher chymotrypsin-like (ChT-L activity and a two-fold increase in trypsin-like (T-L in both whole lysates as well as cytosolic fractions. Native gel electrophoresis of the whole tissue lysates showed that the 20S proteasome was more active in the longer-lived species and that 26S proteasome was both more active and more populous. Western blot analyses revealed that both 19S subunits and immunoproteasome catalytic subunits are present in greater amounts in the naked mole-rat suggesting that the observed higher specific activity may be due to the greater proportion of immunoproteasomes in livers of healthy young adults. It thus appears that proteasomes in this species are primed for the efficient removal of stress-damaged proteins. Further characterization of the naked mole-rat proteasome and its regulation could lead to important insights on how the cells in these animals handle increased stress and protein damage to maintain a longer health in their tissues and ultimately a longer life.

  17. Specific paucity of unmyelinated C-fibers in cutaneous peripheral nerves of the African naked-mole rat: comparative analysis using six species of Bathyergidae.

    Science.gov (United States)

    St John Smith, Ewan; Purfürst, Bettina; Grigoryan, Tamara; Park, Thomas J; Bennett, Nigel C; Lewin, Gary R

    2012-08-15

    In mammalian peripheral nerves, unmyelinated C-fibers usually outnumber myelinated A-fibers. By using transmission electron microscopy, we recently showed that the saphenous nerve of the naked mole-rat (Heterocephalus glaber) has a C-fiber deficit manifested as a substantially lower C:A-fiber ratio compared with other mammals. Here we determined the uniqueness of this C-fiber deficit by performing a quantitative anatomical analysis of several peripheral nerves in five further members of the Bathyergidae mole-rat family: silvery (Heliophobius argenteocinereus), giant (Fukomys mechowii), Damaraland (Fukomys damarensis), Mashona (Fukomys darlingi), and Natal (Cryptomys hottentotus natalensis) mole-rats. In the largely cutaneous saphenous and sural nerves, the naked mole-rat had the lowest C:A-fiber ratio (∼1.5:1 compared with ∼3:1), whereas, in nerves innervating both skin and muscle (common peroneal and tibial) or just muscle (lateral/medial gastrocnemius), this pattern was mostly absent. We asked whether lack of hair follicles alone accounts for the C-fiber paucity by using as a model a mouse that loses virtually all its hair as a consequence of conditional deletion of the β-catenin gene in the skin. These β-catenin loss-of function mice (β-cat LOF mice) displayed only a mild decrease in C:A-fiber ratio compared with wild-type mice (4.42 compared with 3.81). We suggest that the selective cutaneous C-fiber deficit in the cutaneous nerves of naked mole-rats is unlikely to be due primarily to lack of skin hair follicles. Possible mechanisms contributing to this unique peripheral nerve anatomy are discussed. Copyright © 2012 Wiley Periodicals, Inc.

  18. A distinct role of the queen in coordinated workload and soil distribution in eusocial naked mole-rats.

    Directory of Open Access Journals (Sweden)

    Nobuyuki Kutsukake

    Full Text Available We investigated how group members achieve collective decision-making, by considering individual intrinsic behavioural rules and behavioural mechanisms for maintaining social integration. Using a simulated burrow environment, we investigated the behavioural rules of coordinated workload for soil distribution in a eusocial mammal, the naked mole-rat (Heterocephalus glaber. We tested two predictions regarding a distinct role of the queen, a socially dominant individual in the caste system: the presence of a queen would increase the workload of other caste individuals, and the cues by a queen would affect the soil distribution. In experiment 1, we placed four individuals of various castes from the same colony into an experimental burrow. Workers exhibited the highest frequency of workload compared to other castes. The presence of a queen activated the workload by other individuals. Individuals showed a consistent workload in a particular direction so as to bias the soil distribution. These results suggest that individuals have a consensus on soil distribution and that the queen plays a distinct role. In experiment 2, we placed the odour of a queen in one of four cells and observed its effect on other individuals' workload and soil distribution. Relative to other cells, individuals frequently dug in the queen cell so the amount of soil in the queen cell decreased. These results suggest that queen odour is an important cue in coordinated workload and soil distribution in this species.

  19. Low sulfide levels and a high degree of cystathionine β-synthase (CBS) activation by S-adenosylmethionine (SAM) in the long-lived naked mole-rat.

    Science.gov (United States)

    Dziegelewska, Maja; Holtze, Susanne; Vole, Christiane; Wachter, Ulrich; Menzel, Uwe; Morhart, Michaela; Groth, Marco; Szafranski, Karol; Sahm, Arne; Sponholz, Christoph; Dammann, Philip; Huse, Klaus; Hildebrandt, Thomas; Platzer, Matthias

    2016-08-01

    Hydrogen sulfide (H2S) is a gaseous signalling molecule involved in many physiological and pathological processes. There is increasing evidence that H2S is implicated in aging and lifespan control in the diet-induced longevity models. However, blood sulfide concentration of naturally long-lived species is not known. Here we measured blood sulfide in the long-lived naked mole-rat and five other mammalian species considerably differing in lifespan and found a negative correlation between blood sulfide and maximum longevity residual. In addition, we show that the naked mole-rat cystathionine β-synthase (CBS), an enzyme whose activity in the liver significantly contributes to systemic sulfide levels, has lower activity in the liver and is activated to a higher degree by S-adenosylmethionine compared to other species. These results add complexity to the understanding of the role of H2S in aging and call for detailed research on naked mole-rat transsulfuration. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  20. Low sulfide levels and a high degree of cystathionine β-synthase (CBS activation by S-adenosylmethionine (SAM in the long-lived naked mole-rat

    Directory of Open Access Journals (Sweden)

    Maja Dziegelewska

    2016-08-01

    Full Text Available Hydrogen sulfide (H2S is a gaseous signalling molecule involved in many physiological and pathological processes. There is increasing evidence that H2S is implicated in aging and lifespan control in the diet-induced longevity models. However, blood sulfide concentration of naturally long-lived species is not known. Here we measured blood sulfide in the long-lived naked mole-rat and five other mammalian species considerably differing in lifespan and found a negative correlation between blood sulfide and maximum longevity residual. In addition, we show that the naked mole-rat cystathionine β-synthase (CBS, an enzyme whose activity in the liver significantly contributes to systemic sulfide levels, has lower activity in the liver and is activated to a higher degree by S-adenosylmethionine compared to other species. These results add complexity to the understanding of the role of H2S in aging and call for detailed research on naked mole-rat transsulfuration.

  1. The effects of oxotremorine, epibatidine, atropine, mecamylamine and naloxone in the tail-flick, hot-plate, and formalin tests in the naked mole-rat (Heterocephalus glaber).

    Science.gov (United States)

    Dulu, Thomas D; Kanui, Titus I; Towett, Philemon K; Maloiy, Geoffrey M; Abelson, Klas S P

    2014-01-01

    The naked mole-rat (Heterocephalus glaber) is a promising animal model for the study of pain mechanisms, therefore a thorough characterization of this species is essential. The aim of the present study was to establish the naked mole-rat as a model for studying the cholinergic receptor system in antinociception by investigating the involvement of muscarinic, nicotinic and opioid receptors in nociceptive tests in this species. The effects of systemic administration of the muscarinic receptor agonist oxotremorine and the nicotinic receptor agonist epibatidine were investigated in the tail-flick, the hot-plate, and the formalin tests. The effects of co-administration of the muscarinic receptor antagonist atropine, the nicotinic receptor antagonist mecamylamine, and the opioid receptor antagonist naloxone were also investigated. Oxotremorine and epibatidine induced a significant, dose-dependent antinociceptive effect in the tail-flick, hot-plate, and formalin tests, respectively. The effects of oxotremorine and epibatidine were blocked by atropine and mecamylamine, respectively. In all three nociceptive tests, naloxone in combination with oxotremorine or epibatidine enhanced the antinociceptive effects of the drugs. The present study demonstrated that stimulation of muscarinic and nicotinic receptors produces antinociceptive effects in the naked-mole rat. The reversal effect of atropine and mecamylamine suggests that this effect is mediated by cholinergic receptors. As naloxone increases the antinociceptive effects of cholinergic agonists, it is suggested that the cholinergic antinociception acts via a gateway facilitated by opioid receptor blockage; however, the precise interaction between these receptor systems needs further investigation.

  2. A window into extreme longevity; the circulating metabolomic signature of the naked mole-rat, a mammal that shows negligible senescence.

    Science.gov (United States)

    Lewis, Kaitlyn N; Rubinstein, Nimrod D; Buffenstein, Rochelle

    2018-04-20

    Mouse-sized naked mole-rats (Heterocephalus glaber), unlike other mammals, do not conform to Gompertzian laws of age-related mortality; adults show no age-related change in mortality risk. Moreover, we observe negligible hallmarks of aging with well-maintained physiological and molecular functions, commonly altered with age in other species. We questioned whether naked mole-rats, living an order of magnitude longer than laboratory mice, exhibit different plasma metabolite profiles, which could then highlight novel mechanisms or targets involved in disease and longevity. Using a comprehensive, unbiased metabolomics screen, we observe striking inter-species differences in amino acid, peptide, and lipid metabolites. Low circulating levels of specific amino acids, particularly those linked to the methionine pathway, resemble those observed during the fasting period at late torpor in hibernating ground squirrels and those seen in longer-lived methionine-restricted rats. These data also concur with metabolome reports on long-lived mutant mice, including the Ames dwarf mice and calorically restricted mice, as well as fruit flies, and even show similarities to circulating metabolite differences observed in young human adults when compared to older humans. During evolution, some of these beneficial nutrient/stress response pathways may have been positively selected in the naked mole-rat. These observations suggest that interventions that modify the aging metabolomic profile to a more youthful one may enable people to lead healthier and longer lives.

  3. The long gestation of the small naked mole-rat (Heterocephalus glaber Rüppell, 1842) studied with ultrasound biomicroscopy and 3D-ultrasonography.

    Science.gov (United States)

    Roellig, Kathleen; Drews, Barbara; Goeritz, Frank; Hildebrandt, Thomas Bernd

    2011-03-07

    The naked mole-rat (Heterocephalus glaber) is one of the two known mammalian species that live in a eusocial population structure. Here we investigate the exceptionally long gestation period of 70 days observed in the mole-rat queen. The course of seven successful pregnancies in two individuals was recorded in a colony of captive naked mole-rats using ultrasound biomicroscopy (UBM) and 3D-ultrasonography. We establish a catalogue of basic reference ultrasound data for this species by describing the ultrasonographic appearance of reproductive organs, calculating growth curves to predict gestational age and defining ultrasonographic milestones to characterize pregnancy stages. Mean litter size was 10.9±2.7, of which 7.2±1.5 survived the weaning period. Mean interbirth interval was 128.8±63.0 days. The reproductive success in our colony did not differ from previously published data. In the queen the active corpora lutea had an anechoic, fluid filled centre. Using UBM, pregnancy could be detected 53 days before parturition. The period of embryonic development is assumed to last until 30 days before parturition. Embryonic resorptions were detected frequently in the queen, indicating that this might be an ordinary event in this species. We discuss the extraordinary long gestation period of this small rodent and postulate that the long gestation is beneficial to both the eusocial structure and longevity. An increased litter size, twice as large as for other rodents of similar size, seemingly compensates for the doubling of pregnancy length. We demonstrate that the lifetime reproductive effort of a naked mole-rat queen is equivalent to the mass of offspring that would be produced if all of the females of a colony would be reproducing.

  4. The long gestation of the small naked mole-rat (Heterocephalus glaber Ruppell, 1842 studied with ultrasound biomicroscopy and 3D-ultrasonography.

    Directory of Open Access Journals (Sweden)

    Kathleen Roellig

    Full Text Available The naked mole-rat (Heterocephalus glaber is one of the two known mammalian species that live in a eusocial population structure. Here we investigate the exceptionally long gestation period of 70 days observed in the mole-rat queen. The course of seven successful pregnancies in two individuals was recorded in a colony of captive naked mole-rats using ultrasound biomicroscopy (UBM and 3D-ultrasonography. We establish a catalogue of basic reference ultrasound data for this species by describing the ultrasonographic appearance of reproductive organs, calculating growth curves to predict gestational age and defining ultrasonographic milestones to characterize pregnancy stages. Mean litter size was 10.9±2.7, of which 7.2±1.5 survived the weaning period. Mean interbirth interval was 128.8±63.0 days. The reproductive success in our colony did not differ from previously published data. In the queen the active corpora lutea had an anechoic, fluid filled centre. Using UBM, pregnancy could be detected 53 days before parturition. The period of embryonic development is assumed to last until 30 days before parturition. Embryonic resorptions were detected frequently in the queen, indicating that this might be an ordinary event in this species. We discuss the extraordinary long gestation period of this small rodent and postulate that the long gestation is beneficial to both the eusocial structure and longevity. An increased litter size, twice as large as for other rodents of similar size, seemingly compensates for the doubling of pregnancy length. We demonstrate that the lifetime reproductive effort of a naked mole-rat queen is equivalent to the mass of offspring that would be produced if all of the females of a colony would be reproducing.

  5. Amyloid beta and the longest-lived rodent: the naked mole-rat as a model for natural protection from Alzheimer's disease.

    Science.gov (United States)

    Edrey, Yael H; Medina, David X; Gaczynska, Maria; Osmulski, Pawel A; Oddo, Salvatore; Caccamo, Antonella; Buffenstein, Rochelle

    2013-10-01

    Amyloid beta (Aβ) is implicated in Alzheimer's disease (AD) as an integral component of both neural toxicity and plaque formation. Brains of the longest-lived rodents, naked mole-rats (NMRs) approximately 32 years of age, had levels of Aβ similar to those of the 3xTg-AD mouse model of AD. Interestingly, there was no evidence of extracellular plaques, nor was there an age-related increase in Aβ levels in the individuals examined (2-20+ years). The NMR Aβ peptide showed greater homology to the human sequence than to the mouse sequence, differing by only 1 amino acid from the former. This subtle difference led to interspecies differences in aggregation propensity but not neurotoxicity; NMR Aβ was less prone to aggregation than human Aβ. Nevertheless, both NMR and human Aβ were equally toxic to mouse hippocampal neurons, suggesting that Aβ neurotoxicity and aggregation properties were not coupled. Understanding how NMRs acquire and tolerate high levels of Aβ with no plaque formation could provide useful insights into AD, and may elucidate protective mechanisms that delay AD progression. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Theoretical paper: exploring overlooked natural mitochondria-rejuvenative intervention: the puzzle of bowhead whales and naked mole rats.

    Science.gov (United States)

    Prokopov, Arkadi F

    2007-12-01

    There is an imperative need for exploring and implementing mitochondria-rejuvenative interventions that can bridge the current gap toward the step-by step realization of strategies for engineered negligible senescence (SENS) agenda. Recently discovered in mammals, natural mechanism mitoptosis-a selective "suicide" of mutated mitochondria-can facilitate continuous purification of mitochondrial pool in an organism from the most reactive oxygen species (ROS)-producing mitochondria. Mitoptosis, which is considered to be the first stage of ROS-induced apoptosis, underlies follicular atresia (a "quality control" mechanism in female germline cells that eliminates most germinal follicles in female embryos). Mitoptosis can be also activated in adult postmitotic somatic cells by evolutionary conserved phenotypic adaptations to intermittent oxygen restriction (IOR) and synergistically acting intermittent caloric restriction (ICR). IOR and ICR are common in mammals and seem to underlie extraordinary longevity and augmented cancer resistance in bowhead whales (Balena mysticetus) and naked mole rats (Heterocephalus glaber). Furthermore, in mammals IOR can facilitate continuous stromal stem cells-de-pendent tissue repair. A comparative analysis of IOR and ICR mechanisms in both mammals, in conjunction with the experience of decades of biomedical and clinical research on emerging preventative, therapeutic, and rehabilitative modality-the intermittent hypoxic training/therapy (IHT)-indicates that the notable clinical efficiency of IHT is based on the universal adaptational mechanisms that are common in mammals. Further exploration of natural mitochondria-preserving and -rejuvenating strategies can help refinement of IOR- and ICR-based synergistic protocols, having value in clinical human rejuvenation.

  7. Structural Changes and Lack of HCN1 Channels in the Binaural Auditory Brainstem of the Naked Mole-Rat (Heterocephalus glaber).

    Science.gov (United States)

    Gessele, Nikodemus; Garcia-Pino, Elisabet; Omerbašić, Damir; Park, Thomas J; Koch, Ursula

    2016-01-01

    Naked mole-rats (Heterocephalus glaber) live in large eu-social, underground colonies in narrow burrows and are exposed to a large repertoire of communication signals but negligible binaural sound localization cues, such as interaural time and intensity differences. We therefore asked whether monaural and binaural auditory brainstem nuclei in the naked mole-rat are differentially adjusted to this acoustic environment. Using antibody stainings against excitatory and inhibitory presynaptic structures, namely the vesicular glutamate transporter VGluT1 and the glycine transporter GlyT2 we identified all major auditory brainstem nuclei except the superior paraolivary nucleus in these animals. Naked mole-rats possess a well structured medial superior olive, with a similar synaptic arrangement to interaural-time-difference encoding animals. The neighboring lateral superior olive, which analyzes interaural intensity differences, is large and elongated, whereas the medial nucleus of the trapezoid body, which provides the contralateral inhibitory input to these binaural nuclei, is reduced in size. In contrast, the cochlear nucleus, the nuclei of the lateral lemniscus and the inferior colliculus are not considerably different when compared to other rodent species. Most interestingly, binaural auditory brainstem nuclei lack the membrane-bound hyperpolarization-activated channel HCN1, a voltage-gated ion channel that greatly contributes to the fast integration times in binaural nuclei of the superior olivary complex in other species. This suggests substantially lengthened membrane time constants and thus prolonged temporal integration of inputs in binaural auditory brainstem neurons and might be linked to the severely degenerated sound localization abilities in these animals.

  8. Structural Changes and Lack of HCN1 Channels in the Binaural Auditory Brainstem of the Naked Mole-Rat (Heterocephalus glaber.

    Directory of Open Access Journals (Sweden)

    Nikodemus Gessele

    Full Text Available Naked mole-rats (Heterocephalus glaber live in large eu-social, underground colonies in narrow burrows and are exposed to a large repertoire of communication signals but negligible binaural sound localization cues, such as interaural time and intensity differences. We therefore asked whether monaural and binaural auditory brainstem nuclei in the naked mole-rat are differentially adjusted to this acoustic environment. Using antibody stainings against excitatory and inhibitory presynaptic structures, namely the vesicular glutamate transporter VGluT1 and the glycine transporter GlyT2 we identified all major auditory brainstem nuclei except the superior paraolivary nucleus in these animals. Naked mole-rats possess a well structured medial superior olive, with a similar synaptic arrangement to interaural-time-difference encoding animals. The neighboring lateral superior olive, which analyzes interaural intensity differences, is large and elongated, whereas the medial nucleus of the trapezoid body, which provides the contralateral inhibitory input to these binaural nuclei, is reduced in size. In contrast, the cochlear nucleus, the nuclei of the lateral lemniscus and the inferior colliculus are not considerably different when compared to other rodent species. Most interestingly, binaural auditory brainstem nuclei lack the membrane-bound hyperpolarization-activated channel HCN1, a voltage-gated ion channel that greatly contributes to the fast integration times in binaural nuclei of the superior olivary complex in other species. This suggests substantially lengthened membrane time constants and thus prolonged temporal integration of inputs in binaural auditory brainstem neurons and might be linked to the severely degenerated sound localization abilities in these animals.

  9. Social structure predicts genital morphology in African mole-rats.

    Directory of Open Access Journals (Sweden)

    Marianne L Seney

    2009-10-01

    Full Text Available African mole-rats (Bathyergidae, Rodentia exhibit a wide range of social structures, from solitary to eusocial. We previously found a lack of sex differences in the external genitalia and morphology of the perineal muscles associated with the phallus in the eusocial naked mole-rat. This was quite surprising, as the external genitalia and perineal muscles are sexually dimorphic in all other mammals examined. We hypothesized that the lack of sex differences in naked mole-rats might be related to their unusual social structure.We compared the genitalia and perineal muscles in three African mole-rat species: the naked mole-rat, the solitary silvery mole-rat, and the Damaraland mole-rat, a species considered to be eusocial, but with less reproductive skew than naked mole-rats. Our findings support a relationship between social structure, mating system, and sexual differentiation. Naked mole-rats lack sex differences in genitalia and perineal morphology, silvery mole-rats exhibit sex differences, and Damaraland mole-rats are intermediate.The lack of sex differences in naked mole-rats is not an attribute of all African mole-rats, but appears to have evolved in relation to their unusual social structure and reproductive biology.

  10. Social structure predicts genital morphology in African mole-rats.

    Science.gov (United States)

    Seney, Marianne L; Kelly, Diane A; Goldman, Bruce D; Sumbera, Radim; Forger, Nancy G

    2009-10-15

    African mole-rats (Bathyergidae, Rodentia) exhibit a wide range of social structures, from solitary to eusocial. We previously found a lack of sex differences in the external genitalia and morphology of the perineal muscles associated with the phallus in the eusocial naked mole-rat. This was quite surprising, as the external genitalia and perineal muscles are sexually dimorphic in all other mammals examined. We hypothesized that the lack of sex differences in naked mole-rats might be related to their unusual social structure. We compared the genitalia and perineal muscles in three African mole-rat species: the naked mole-rat, the solitary silvery mole-rat, and the Damaraland mole-rat, a species considered to be eusocial, but with less reproductive skew than naked mole-rats. Our findings support a relationship between social structure, mating system, and sexual differentiation. Naked mole-rats lack sex differences in genitalia and perineal morphology, silvery mole-rats exhibit sex differences, and Damaraland mole-rats are intermediate. The lack of sex differences in naked mole-rats is not an attribute of all African mole-rats, but appears to have evolved in relation to their unusual social structure and reproductive biology.

  11. Socially regulated reproductive development: analysis of GnRH-1 and kisspeptin neuronal systems in cooperatively breeding naked mole-rats (Heterocephalus glaber).

    Science.gov (United States)

    Zhou, Shuzhi; Holmes, Melissa M; Forger, Nancy G; Goldman, Bruce D; Lovern, Matthew B; Caraty, Alain; Kalló, Imre; Faulkes, Christopher G; Coen, Clive W

    2013-09-01

    In naked mole-rat (NMR) colonies, breeding is monopolized by the queen and her consorts. Subordinates experience gonadal development if separated from the queen. To elucidate the neuroendocrine factors underlying reproductive suppression/development in NMRs, we quantified plasma gonadal steroids and GnRH-1- and kisspeptin-immunoreactive (ir) neurons in subordinate adults and in those allowed to develop into breeders, with or without subsequent gonadectomy. In males and females, respectively, plasma testosterone and progesterone are higher in breeders than in subordinates. No such distinction occurs for plasma estradiol; its presence after gonadectomy and its positive correlation with adrenal estradiol suggest an adrenal source. Numbers of GnRH-1-ir cell bodies do not differ between gonad-intact breeders and subordinates within or between the sexes. As in phylogenetically related guinea pigs, kisspeptin-ir processes pervade the internal and external zones of the median eminence. Their distribution is consistent with actions on GnRH-1 neurons at perikaryal and/or terminal levels. In previously investigated species, numbers of kisspeptin-ir cell bodies vary from substantial to negligible according to sex and/or reproductive state. NMRs are exceptional: irrespective of sex, reproductive state, or presence of gonads, substantial numbers of kisspeptin-ir cell bodies are detected in the rostral periventricular region of the third ventricle (RP3V) and in the anterior periventricular (PVa), arcuate, and dorsomedial hypothalamic nuclei. Nevertheless, the greater number in the RP3V/PVa of female breeders compared with female subordinates or male breeders suggests that emergence from a hypogonadotrophic state in females may involve kisspeptin-related mechanisms similar to those underlying puberty or seasonal breeding in other species. Copyright © 2013 Wiley Periodicals, Inc.

  12. And the beat goes on: maintained cardiovascular function during aging in the longest-lived rodent, the naked mole-rat.

    Science.gov (United States)

    Grimes, Kelly M; Reddy, Anilkumar K; Lindsey, Merry L; Buffenstein, Rochelle

    2014-08-01

    The naked mole-rat (NMR) is the longest-lived rodent known, with a maximum lifespan potential (MLSP) of >31 years. Despite such extreme longevity, these animals display attenuation of many age-associated diseases and functional changes until the last quartile of their MLSP. We questioned if such abilities would extend to cardiovascular function and structure in this species. To test this, we assessed cardiac functional reserve, ventricular morphology, and arterial stiffening in NMRs ranging from 2 to 24 years of age. Dobutamine echocardiography (3 μg/g ip) revealed no age-associated changes in left ventricular (LV) function either at baseline or with exercise-like stress. Baseline and dobutamine-induced LV pressure parameters also did not change. Thus the NMR, unlike other mammals, maintains cardiac reserve with age. NMRs showed no cardiac hypertrophy, evidenced by no increase in cardiomyocyte cross-sectional area or LV dimensions with age. Age-associated arterial stiffening does not occur since there are no changes in aortic blood pressures or pulse-wave velocity. Only LV interstitial collagen deposition increased 2.5-fold from young to old NMRs (P < 0.01). However, its effect on LV diastolic function is likely minor since NMRs experience attenuated age-related increases in diastolic dysfunction in comparison with other species. Overall, these findings conform to the negligible senescence phenotype, as NMRs largely stave off cardiovascular changes for at least 75% of their MLSP. This suggests that using a comparative strategy to find factors that change with age in other mammals but not NMRs could provide novel targets to slow or prevent cardiovascular aging in humans.

  13. Social status and sex effects on neural morphology in Damaraland mole-rats, Fukomys damarensis.

    Science.gov (United States)

    Anyan, Jeff J; Seney, Marianne L; Holley, Amanda; Bengston, Lynn; Goldman, Bruce D; Forger, Nancy G; Holmes, Melissa M

    2011-01-01

    We previously reported that in a eusocial rodent, the naked mole-rat (Heterocephalus glaber), traditional neural sex differences were absent; instead, neural dimorphisms were associated with breeding status. Here we examined the same neural regions previously studied in naked mole-rats in a second eusocial species, the Damaraland mole-rat (Fukomys damarensis). Damaraland mole-rats live in social groups with breeding restricted to a small number of animals. However, colony sizes are much smaller in Damaraland mole-rats than in naked mole-rats and there is consequently less reproductive skew. In this sense, Damaraland mole-rats may be considered intermediate in social organization between naked mole-rats and more traditional laboratory rodents. We report that, as in naked mole-rats, breeding Damaraland mole-rats have larger volumes of the principal nucleus of the bed nucleus of the stria terminalis and paraventricular nucleus of the hypothalamus than do subordinates, with no effect of sex on these measures. Thus, these structures may play special roles in breeders of eusocial species. However, in contrast to what was seen in naked mole-rats, we also found sex differences in Damaraland mole-rats: volume of the medial amygdala and motoneuron number in Onuf's nucleus were both greater in males than in females, with no significant effect of breeding status. Thus, both sex and breeding status influence neural morphology in Damaraland mole-rats. These findings are in accord with the observed sex differences in body weight and genitalia in Damaraland but not naked mole-rats. We hypothesize that the increased sexual dimorphism in Damaraland mole-rats relative to naked mole-rats is related to reduced reproductive skew. 2011 S. Karger AG, Basel.

  14. Analysis of Alpha-2 Macroglobulin from the Long-Lived and Cancer-Resistant Naked Mole-Rat and Human Plasma.

    Science.gov (United States)

    Thieme, René; Kurz, Susanne; Kolb, Marlen; Debebe, Tewodros; Holtze, Susanne; Morhart, Michaela; Huse, Klaus; Szafranski, Karol; Platzer, Matthias; Hildebrandt, Thomas B; Birkenmeier, Gerd

    2015-01-01

    The naked mole-rat (NMR) is a long-lived and cancer resistant species. Identification of potential anti-cancer and age related mechanisms is of great interest and makes this species eminent to investigate anti-cancer strategies and understand aging mechanisms. Since it is known that the NMR expresses higher liver mRNA-levels of alpha 2-macroglobulin than mice, nothing is known about its structure, functionality or expression level in the NMR compared to the human A2M. Here we show a comprehensive analysis of NMR- and human plasma-A2M, showing a different prediction in glycosylation of NMR-A2M, which results in a higher molecular weight compared to human A2M. Additionally, we found a higher concentration of A2M (8.3±0.44 mg/mL vs. and 4.4±0.20 mg/mL) and a lower total plasma protein content (38.7±1.79 mg/mL vs. 61.7±3.20 mg/mL) in NMR compared to human. NMR-A2M can be transformed by methylamine and trypsin resulting in a conformational change similar to human A2M. NMR-A2M is detectable by a polyclonal antibody against human A2M. Determination of tryptic and anti-tryptic activity of NMR and human plasma revealed a higher anti-tryptic activity of the NMR plasma. On the other hand, less proteolytic activity was found in NMR plasma compared to human plasma. We found transformed NMR-A2M binding to its specific receptor LRP1. We could demonstrate lower protein expression of LRP1 in the NMR liver tissue compared to human but higher expression of A2M. This was accompanied by a higher EpCAM protein expression as central adhesion molecule in cancer progression. NMR-plasma was capable to increase the adhesion in human fibroblast in vitro most probably by increasing CD29 protein expression. This is the first report, demonstrating similarities as well as distinct differences between A2M in NMR and human plasma. This might be directly linked to the intriguing phenotype of the NMR and suggests that A2M might probably play an important role in anti-cancer and the anti

  15. Analysis of Alpha-2 Macroglobulin from the Long-Lived and Cancer-Resistant Naked Mole-Rat and Human Plasma.

    Directory of Open Access Journals (Sweden)

    René Thieme

    Full Text Available The naked mole-rat (NMR is a long-lived and cancer resistant species. Identification of potential anti-cancer and age related mechanisms is of great interest and makes this species eminent to investigate anti-cancer strategies and understand aging mechanisms. Since it is known that the NMR expresses higher liver mRNA-levels of alpha 2-macroglobulin than mice, nothing is known about its structure, functionality or expression level in the NMR compared to the human A2M.Here we show a comprehensive analysis of NMR- and human plasma-A2M, showing a different prediction in glycosylation of NMR-A2M, which results in a higher molecular weight compared to human A2M. Additionally, we found a higher concentration of A2M (8.3±0.44 mg/mL vs. and 4.4±0.20 mg/mL and a lower total plasma protein content (38.7±1.79 mg/mL vs. 61.7±3.20 mg/mL in NMR compared to human. NMR-A2M can be transformed by methylamine and trypsin resulting in a conformational change similar to human A2M. NMR-A2M is detectable by a polyclonal antibody against human A2M. Determination of tryptic and anti-tryptic activity of NMR and human plasma revealed a higher anti-tryptic activity of the NMR plasma. On the other hand, less proteolytic activity was found in NMR plasma compared to human plasma.We found transformed NMR-A2M binding to its specific receptor LRP1. We could demonstrate lower protein expression of LRP1 in the NMR liver tissue compared to human but higher expression of A2M. This was accompanied by a higher EpCAM protein expression as central adhesion molecule in cancer progression. NMR-plasma was capable to increase the adhesion in human fibroblast in vitro most probably by increasing CD29 protein expression. This is the first report, demonstrating similarities as well as distinct differences between A2M in NMR and human plasma. This might be directly linked to the intriguing phenotype of the NMR and suggests that A2M might probably play an important role in anti-cancer and the

  16. H2O2 treatment or serum deprivation induces autophagy and apoptosis in naked mole-rat skin fibroblasts by inhibiting the PI3K/Akt signaling pathway.

    Science.gov (United States)

    Zhao, Shanmin; Li, Li; Wang, Shiyong; Yu, Chenlin; Xiao, Bang; Lin, Lifang; Cong, Wei; Cheng, Jishuai; Yang, Wenjing; Sun, Wei; Cui, Shufang

    2016-12-20

    Naked mole-rats (NMR; Heterocephalus glaber) display extreme longevity and resistance to cancer. Here, we examined whether autophagy contributes to the longevity of NMRs by assessing the effects of the PI3K/Akt pathway inhibitor LY294002 and the autophagy inhibitor chloroquine (CQ) on autophagy and apoptosis in NMR skin fibroblasts. Serum starvation, H2O2 treatment, and LY294002 treatment all increased the LC3-II/LC3-I ratio and numbers of double-membraned autophagosomes and autophagic vacuoles, and decreased levels of p70S6K, p-AktSer473, and p-AktThr308. By contrast, CQ treatment decreased p70S6K, AktSer473, and AktThr308 levels. The Bax/Bcl-2 ratio increased after 12 h of exposure to LY294002 or CQ. These data show that inhibiting the Akt pathway promotes autophagy and apoptosis in NMR skin fibroblasts. Furthermore, LY294002 or CQ treatment decreased caspase-3, p53, and HIF1-α levels, suggesting that serum starvation or H2O2 treatment increase autophagy and apoptosis in NMR skin fibroblasts by inhibiting the PI3K/Akt pathway. CQ-induced inhibition of late autophagy stages also prevented Akt activation and induced apoptosis. Finally, the HIF-1α and p53 pathways were involved in serum starvation- or H2O2-induced autophagy in NMR skin fibroblasts.

  17. Adult neurogenesis and its anatomical context in the hippocampus of three mole-rat species

    Directory of Open Access Journals (Sweden)

    Irmgard eAmrein

    2014-05-01

    Full Text Available African mole-rats (family Bathyergidae are small to medium sized, long-lived and strictly subterranean rodents that became valuable animal models as a result of their longevity and diversity in social organization. The formation and integration of new hippocampal neurons in adult mammals (adult hippocampal neurogenesis, AHN correlates negatively with age and positively with habitat complexity. Here we present quantitative data on AHN in wild-derived mole-rats of one year and older, and briefly describe its anatomical context including markers of neuronal function (calbindin and parvalbumin. Solitary Cape mole-rats (Georychus capensis, social highveld mole-rats (Cryptomys hottentotus pretoriae, and eusocial naked mole-rats (Heterocephalus glaber were assessed. Compared to other rodents, the hippocampal formation in mole-rats is small, but shows a distinct cytoarchitecture in the dentate gyrus and CA1. Distributions of the calcium-binding proteins differ from those seen in rodents; e.g., calbindin in CA3 of naked mole-rats distributes similar to the pattern seen in early primate development, and calbindin staining extends into the stratum lacunosum-moleculare of Cape mole-rats. Proliferating cells and young neurons are found in low numbers in the hippocampus of all three mole-rat species. Resident granule cell numbers are low as well. Proliferating cells expressed as a percentage of resident granule cells are in the range of other rodents, while the percentage of young neurons is lower than that observed in surface dwelling rodents. Between mole-rat species, we observed no difference in the percentage of proliferating cells. The percentages of young neurons are high in social highveld and naked mole-rats, and low in solitary Cape mole-rats. The findings support that proliferation is regulated independently of average life expectancy and habitat. Instead, neuronal differentiation reflects species-specific demands, which appear lower in subterranean

  18. Adult neurogenesis and its anatomical context in the hippocampus of three mole-rat species.

    Science.gov (United States)

    Amrein, Irmgard; Becker, Anton S; Engler, Stefanie; Huang, Shih-Hui; Müller, Julian; Slomianka, Lutz; Oosthuizen, Maria K

    2014-01-01

    African mole-rats (family Bathyergidae) are small to medium sized, long-lived, and strictly subterranean rodents that became valuable animal models as a result of their longevity and diversity in social organization. The formation and integration of new hippocampal neurons in adult mammals (adult hippocampal neurogenesis, AHN) correlates negatively with age and positively with habitat complexity. Here we present quantitative data on AHN in wild-derived mole-rats of 1 year and older, and briefly describe its anatomical context including markers of neuronal function (calbindin and parvalbumin). Solitary Cape mole-rats (Georychus capensis), social highveld mole-rats (Cryptomys hottentotus pretoriae), and eusocial naked mole-rats (Heterocephalus glaber) were assessed. Compared to other rodents, the hippocampal formation in mole-rats is small, but shows a distinct cytoarchitecture in the dentate gyrus and CA1. Distributions of the calcium-binding proteins differ from those seen in rodents; e.g., calbindin in CA3 of naked mole-rats distributes similar to the pattern seen in early primate development, and calbindin staining extends into the stratum lacunosum-moleculare of Cape mole-rats. Proliferating cells and young neurons are found in low numbers in the hippocampus of all three mole-rat species. Resident granule cell numbers are low as well. Proliferating cells expressed as a percentage of resident granule cells are in the range of other rodents, while the percentage of young neurons is lower than that observed in surface dwelling rodents. Between mole-rat species, we observed no difference in the percentage of proliferating cells. The percentages of young neurons are high in social highveld and naked mole-rats, and low in solitary Cape mole-rats. The findings support that proliferation is regulated independently of average life expectancy and habitat. Instead, neuronal differentiation reflects species-specific demands, which appear lower in subterranean rodents.

  19. Trading new neurons for status: Adult hippocampal neurogenesis in eusocial Damaraland mole-rats.

    Science.gov (United States)

    Oosthuizen, M K; Amrein, I

    2016-06-02

    Diversity in social structures, from solitary to eusocial, is a prominent feature of subterranean African mole-rat species. Damaraland mole-rats are eusocial, they live in colonies that are characterized by a reproductive division of labor and a subdivision into castes based on physiology and behavior. Damaraland mole-rats are exceptionally long lived and reproductive animals show delayed aging compared to non-reproductive animals. In the present study, we described the hippocampal architecture and the rate of hippocampal neurogenesis of wild-derived, adult Damaraland mole-rats in relation to sex, relative age and social status or caste. Overall, Damaraland mole-rats were found to have a small hippocampus and low rates of neurogenesis. We found no correlation between neurogenesis and sex or relative age. Social status or caste was the most prominent modulator of neurogenesis. An inverse relationship between neurogenesis and social status was apparent, with queens displaying the lowest neurogenesis while the worker mole-rats had the most. As there is no natural progression from one caste to another, social status within a colony was relatively stable and is reflected in the level of neurogenesis. Our results correspond to those found in the naked mole-rat, and may reflect an evolutionary and environmentally conserved trait within social mole-rat species. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  20. Plasticity and constraints on social evolution in African mole-rats: ultimate and proximate factors.

    Science.gov (United States)

    Faulkes, Chris G; Bennett, Nigel C

    2013-05-19

    Here, we review comparative studies of African mole-rats (family Bathyergidae) to explain how constraints acting at the ultimate (environmental) and proximate (organismal) levels have led to convergent gains and losses of sociality within this extensive adaptive radiation of subterranean rodents endemic to sub-Saharan Africa. At the ultimate level, living in environments that range from mesic through to arid has led to both variation and flexibility in social organization among species, culminating in the pinnacle of social evolution in the eusocial naked and Damaraland mole-rats (Heterocephalus glaber and Fukomys damarensis). The common mole-rat (Cryptomys hottentotus) provides a model example of how plasticity in social traits exists within a single species inhabiting areas with different ecological constraint. At the proximate level, reproductive strategies and cooperative breeding may be constrained by the correlated evolution of a suite of traits including physiological suppression of reproduction, the development of physiological and morphological castes, and the mode of ovulatory control and seasonality in breeding. Furthermore, recent neurobiological advances indicate that differential patterns of neurotransmitter expression within the forebrain may underpin (and limit) either a solitary or group living/cooperative lifestyle not only in mole-rats, but also more widely among disparate mammalian taxa.

  1. Morphological divergence of breeders and helpers in wild Damaraland mole-rat societies.

    Science.gov (United States)

    Young, Andrew J; Bennett, Nigel C

    2010-11-01

    The specialization of body shape to an individual's role within society represents a pinnacle of social evolution. Although commonplace among social insects, divergence in the body shapes of breeders and helpers has to date been documented in just one social vertebrate, the naked mole-rat, Heterocephalus glaber; an extraordinary species in which large colony size and frequent inbreeding may have favored the evolution of such specialization. Here, we present new evidence of morphological divergence between breeders and helpers in the Damaraland mole-rat, Fukomys damarensis; a much less socially extreme species that reflects an independent evolutionary origin of sociality. Using longitudinal data from wild populations, we show that dominant female Damaraland mole-rats, like many social insect queens, have a significantly more elongate body shape than subordinates. This difference arises not from a pre-existing difference in the body shapes of subordinates that do, and those that do not, become dominant, but from a modification to the growth trajectory of subordinates on dominance acquisition. Our findings reveal a wider role for morphological divergence within vertebrate societies and, as Damaraland mole-rats neither live in unusually large groups nor inbreed, suggest that circumstances favoring the evolution of such specializations may be more widespread among vertebrates than previously supposed. © 2010 The Author(s). Evolution© 2010 The Society for the Study of Evolution.

  2. Adaptations to a Subterranean Environment and Longevity Revealed by the Analysis of Mole Rat Genomes

    Directory of Open Access Journals (Sweden)

    Xiaodong Fang

    2014-09-01

    Full Text Available Subterranean mammals spend their lives in dark, unventilated environments that are rich in carbon dioxide and ammonia and low in oxygen. Many of these animals are also long-lived and exhibit reduced aging-associated diseases, such as neurodegenerative disorders and cancer. We sequenced the genome of the Damaraland mole rat (DMR, Fukomys damarensis and improved the genome assembly of the naked mole rat (NMR, Heterocephalus glaber. Comparative genome analyses, along with the transcriptomes of related subterranean rodents, revealed candidate molecular adaptations for subterranean life and longevity, including a divergent insulin peptide, expression of oxygen-carrying globins in the brain, prevention of high CO2-induced pain perception, and enhanced ammonia detoxification. Juxtaposition of the genomes of DMR and other more conventional animals with the genome of NMR revealed several truly exceptional NMR features: unusual thermogenesis, an aberrant melatonin system, pain insensitivity, and unique processing of 28S rRNA. Together, these genomes and transcriptomes extend our understanding of subterranean adaptations, stress resistance, and longevity.

  3. Cancer resistance in the blind mole rat is mediated by concerted necrotic cell death mechanism

    Science.gov (United States)

    Gorbunova, Vera; Hine, Christopher; Tian, Xiao; Ablaeva, Julia; Gudkov, Andrei V.; Nevo, Eviatar; Seluanov, Andrei

    2012-01-01

    Blind mole rats Spalax (BMR) are small subterranean rodents common in the Middle East. BMR is distinguished by its adaptations to life underground, remarkable longevity (with a maximum documented lifespan of 21 y), and resistance to cancer. Spontaneous tumors have never been observed in spalacids. To understand the mechanisms responsible for this resistance, we examined the growth of BMR fibroblasts in vitro of the species Spalax judaei and Spalax golani. BMR cells proliferated actively for 7–20 population doublings, after which the cells began secreting IFN-β, and the cultures underwent massive necrotic cell death within 3 d. The necrotic cell death phenomenon was independent of culture conditions or telomere shortening. Interestingly, this cell behavior was distinct from that observed in another long-lived and cancer-resistant African mole rat, Heterocephalus glaber, the naked mole rat in which cells display hypersensitivity to contact inhibition. Sequestration of p53 and Rb proteins using SV40 large T antigen completely rescued necrotic cell death. Our results suggest that cancer resistance of BMR is conferred by massive necrotic response to overproliferation mediated by p53 and Rb pathways, and triggered by the release of IFN-β. Thus, we have identified a unique mechanism that contributes to cancer resistance of this subterranean mammal extremely adapted to life underground. PMID:23129611

  4. Photic induction of Fos in the suprachiasmatic nucleus of African mole-rats: responses to increasing irradiance.

    Science.gov (United States)

    Oosthuizen, Maria K; Bennett, Nigel C; Cooper, Howard M

    2010-09-01

    African mole-rats (family Bathyergidae) are strictly subterranean rodent species that are rarely exposed to environmental light. Morphological and physiological adaptations to the underground environment include a severely reduced eye size and regressed visual system. Responses of the circadian system to light, however, appear to be intact, since mole-rats are able to entrain their circadian activity rhythms to the light-dark cycle and light induces Fos expression in the suprachiasmatic nucleus (SCN). Social organization varies from solitary species to highly elaborated eusocial structures, characterized by a distinct division of labor and in which one reproductive female regulates the behavior and reproductive physiology of other individuals in the colony. The authors studied light-induced Fos expression in the SCN to increasing light intensities in four mole-rat species, ranging from strictly solitary to highly social. In the solitary Cape mole-rat, light induces significant Fos expression in the SCN, and the number of Fos-immunopositive cells increases with increasing light intensity. In contrast, Fos induction in the SCN of social species was slightly greater than, but not statistically different from, the dark-control animals as is typical of most rodents. One species showed a trend for an increase in expression with increased light, whereas a second species showed no trend in expression. In the naked mole-rat, Fos expression appeared higher in the dark-controls than in the animals exposed to light, although the differences in Fos expression were not significant. These results suggest a gradient in the sensitivity of the circadian system to light in mole-rats, with a higher percentage of individuals that are unresponsive to light in correlation with the degree of sociality. In highly social species, such as the naked mole-rat that live in a relatively stable subterranean milieu in terms of food availability, temperature, constant darkness, and devoid of 24-h

  5. Burrow architecture of the Damaraland mole-rat ( Fukomys ...

    African Journals Online (AJOL)

    The burrow architecture (length, internal dimensions, fractal dimension of tunnel systems, number of nesting chambers and surface mounds) was investigated in the Damaraland mole-rat (Fukomys damarensis). A total of 31 animals were caught from five different colonies and their burrow systems were excavated in their ...

  6. Sleep in the Cape Mole Rat: A Short-Sleeping Subterranean Rodent.

    Science.gov (United States)

    Kruger, Jean-Leigh; Gravett, Nadine; Bhagwandin, Adhil; Bennett, Nigel C; Archer, Elizabeth K; Manger, Paul R

    2016-01-01

    The Cape mole rat Georychus capensis is a solitary subterranean rodent found in the western and southern Cape of South Africa. This approximately 200-gram bathyergid rodent shows a nocturnal circadian rhythm, but sleep in this species is yet to be investigated. Using telemetric recordings of the electroencephalogram (EEG) and electromyogram (EMG) in conjunction with video recordings, we were able to show that the Cape mole rat, like all other rodents, has sleep periods composed of both rapid eye movement (REM) and slow-wave (non-REM) sleep. These mole rats spent on average 15.4 h awake, 7.1 h in non-REM sleep and 1.5 h in REM sleep each day. Cape mole rats sleep substantially less than other similarly sized terrestrial rodents but have a similar percentage of total sleep time occupied by REM sleep. In addition, the duration of both non-REM and REM sleep episodes was markedly shorter in the Cape mole rat than has been observed in terrestrial rodents. Interestingly, these features (total sleep time and episode duration) are similar to those observed in another subterranean bathyergid mole rat, i.e. Fukomys mechowii. Thus, there appears to be a bathyergid type of sleep amongst the rodents that may be related to their environment and the effect of this on their circadian rhythm. Investigating further species of bathyergid mole rats may fully define the emerging picture of sleep in these subterranean African rodents. © 2016 S. Karger AG, Basel.

  7. Transcriptome sequencing of the blind subterranean mole rat, Spalax galili: Utility and potential for the discovery of novel evolutionary patterns

    KAUST Repository

    Malik, Assaf

    2011-08-12

    The blind subterranean mole rat (Spalax ehrenbergi superspecies) is a model animal for survival under extreme environments due to its ability to live in underground habitats under severe hypoxic stress and darkness. Here we report the transcriptome sequencing of Spalax galili, a chromosomal type of S. ehrenbergi. cDNA pools from muscle and brain tissues isolated from animals exposed to hypoxic and normoxic conditions were sequenced using Sanger, GS FLX, and GS FLX Titanium technologies. Assembly of the sequences yielded over 51,000 isotigs with homology to ~12,000 mouse, rat or human genes. Based on these results, it was possible to detect large numbers of splice variants, SNPs, and novel transcribed regions. In addition, multiple differential expression patterns were detected between tissues and treatments. The results presented here will serve as a valuable resource for future studies aimed at identifying genes and gene regions evolved during the adaptive radiation associated with underground life of the blind mole rat. 2011 Malik et al.

  8. case of natural queen succession in a captive colony of naked mole ...

    African Journals Online (AJOL)

    Naked mole-rats occur in large colonies where usually a single queen monopolizes reproduction. Queen succession occurs from within usually as a result of aggressive encounters with subordinate females that queue for reproductive succession following colony instability, which inevitably results in death of either the ...

  9. Extended longevity of reproductives appears to be common in Fukomys mole-rats (Rodentia, Bathyergidae.

    Directory of Open Access Journals (Sweden)

    Philip Dammann

    Full Text Available African mole-rats (Bathyergidae, Rodentia contain several social, cooperatively breeding species with low extrinsic mortality and unusually high longevity. All social bathyergids live in multigenerational families where reproduction is skewed towards a few breeding individuals. Most of their offspring remain as reproductively inactive "helpers" in their natal families, often for several years. This "reproductive subdivision" of mole-rat societies might be of interest for ageing research, as in at least one social bathyergid (Ansell's mole-rats Fukomys anselli, breeders have been shown to age significantly slower than non-breeders. These animals thus provide excellent conditions for studying the epigenetics of senescence by comparing divergent longevities within the same genotypes without the inescapable short-comings of inter-species comparisons. It has been claimed that many if not all social mole-rat species may have evolved similar ageing patterns, too. However, this remains unclear on account of the scarcity of reliable datasets on the subject. We therefore analyzed a 20-year breeding record of Giant mole-rats Fukomys mechowii, another social bathyergid species. We found that breeders indeed lived significantly longer than helpers (ca. 1.5-2.2fold depending on the sex, irrespective of social rank or other potentially confounding factors. Considering the phylogenetic positions of F. mechowii and F. anselli and unpublished data on a third Fukomys-species (F. damarensis showing essentially the same pattern, it seems probable that the reversal of the classic trade-off between somatic maintenance and sexual reproduction is characteristic of the whole genus and hence of the vast majority of social mole-rats.

  10. Influence of spatial environment on maze learning in an African mole-rat

    CSIR Research Space (South Africa)

    Du Toit, L

    2012-05-01

    Full Text Available -1 Anim Cogn DOI 10.1007/s10071-012-0503-0 Influence of spatial environment on maze learning in an African mole-rat Lydia du Toit ? Nigel C. Bennett ? Alecia Nickless ? Martin J. Whiting L. du Toit , A. Nickless , M. J. Whiting (email) School...

  11. The eye of the African mole-rat Cryptomys anselli : to see or not to see?

    NARCIS (Netherlands)

    Cernuda-Cernuda, R; Garcia-Fernandez, JM; Gordijn, MCM; Bovee-Geurts, PHM; DeGrip, WJ; de Grip, W.J.

    In an attempt to clarify its possible physiological role, we studied the eye of the Zambian mole rat Cryptomys anselli by light, electron and confocal microscopy using conventional staining as well as immunolabelling with rod and cone cell markers. The small eyes of Cryptomys are located

  12. The eye of the african mole-rat Cryptomys anselli: to see or not to see?

    NARCIS (Netherlands)

    Cernuda-Cernuda, R.; Garcia-Fernandez, J.M.; Gordijn, M.C.; Bovee-Geurts, P.H.M.; Grip, W.J. de

    2003-01-01

    In an attempt to clarify its possible physiological role, we studied the eye of the Zambian mole rat Cryptomys anselli by light, electron and confocal microscopy using conventional staining as well as immunolabelling with rod and cone cell markers. The small eyes of Cryptomys are located

  13. The reproductive biology of the giant Zambian mole-rat, Cryptomys ...

    African Journals Online (AJOL)

    1994-09-29

    Sep 29, 1994 ... gala (12° 27'S, 2T51'E) in the Copperbelt of northern Zam- hia. ... mole-rat, a pair of animals and a group comprising one male and three females .... Figure 1 Changes In bouy mass of a captive female Cr.vptom.vs mechowi ... The sex distribution was .... 'Ine social Cryptomys species are chmacteril,ed hy.

  14. Locomotor Activity and Body Temperature Patterns over a Temperature Gradient in the Highveld Mole-Rat (Cryptomys hottentotus pretoriae).

    Science.gov (United States)

    Haupt, Meghan; Bennett, Nigel C; Oosthuizen, Maria K

    2017-01-01

    African mole-rats are strictly subterranean mammals that live in extensive burrow systems. High humidity levels in the burrows prevent mole-rats from thermoregulating using evaporative cooling. However, the relatively stable environment of the burrows promotes moderate temperatures and small daily temperature fluctuations. Mole-rats therefore display a relatively wide range of thermoregulation abilities. Some species cannot maintain their body temperatures at a constant level, whereas others employ behavioural thermoregulation. Here we test the effect of ambient temperature on locomotor activity and body temperature, and the relationship between the two parameters, in the highveld mole-rat. We exposed mole-rats to a 12L:12D and a DD light cycle at ambient temperatures of 30°C, 25°C and 20°C while locomotor activity and body temperature were measured simultaneously. In addition, we investigated the endogenous rhythms of locomotor activity and body temperature at different ambient temperatures. Mole-rats displayed nocturnal activity at all three ambient temperatures and were most active at 20°C, but least active at 30°C. Body temperature was highest at 30°C and lowest at 20°C, and the daily cycle was highly correlated with locomotor activity. We show that the mole-rats have endogenous rhythms for both locomotor activity and body temperature. However, the endogenous body temperature rhythm appears to be less robust compared to the locomotor activity rhythm. Female mole-rats appear to be more sensitive to temperature changes than males, increased heterothermy is evident at lower ambient temperatures, whilst males show smaller variation in their body temperatures with changing ambient temperatures. Mole-rats may rely more heavily on behavioural thermoregulation as it is more energy efficient in an already challenging environment.

  15. O2 binding and CO2 sensitivity in haemoglobins of subterranean African mole rats

    DEFF Research Database (Denmark)

    Weber, Roy E.; Jarvis, Jennifer U. M.; Fago, Angela

    2017-01-01

    that predictably safeguard pulmonary loading under hypoxic and hypercapnic burrow conditions. The O2 binding characteristics are discussed in relation to available information on the primary structure of Hbs from adult and developmental stages of mammals subjected to hypoxia and hypercapnia and the molecular......Inhabiting deep and sealed subterranean burrows, mole rats exhibit a remarkable suite of specializations, including eusociality (living in colonies with single breeding queens), extraordinary longevity, cancer immunity and poikilothermy, and extreme tolerance of hypoxia and hypercapnia. With little...... and 2,3-diphosphoglycerate (DPG, the major allosteric modulator of Hb-O2 affinity in red blood cells) in four social and two solitary species of African mole rats (family Bathyergidae) originating from different biomes and soil types across Central and Southern Africa. We found no consistent patterns...

  16. Effects of ultraviolet radiation on mole rats kidney: A histopathologic and ultrastructural study

    Directory of Open Access Journals (Sweden)

    Hüseyin Türker

    2014-04-01

    Full Text Available The purpose of this study was to realize the ultrastructural effects of ultraviolet radiation on the kidney tissue cells of mole rats (Spalax leucodon. The mole rats of 180–200 g body weight were divided into the control and radiation-trial groups. The control group was not given any radiation. The other groups were irradiated with artificially produced UVC radiation for 14, 28 and 60 days. The kidney tissue samples were prepared at the end of experiments and analyzed by the light and electron microscope. Several effects were observed in the kidney tissues cells analyzed in accordance with the dose magnitude of radiation. These results clearly show the detrimental effects of UVC radiation on kidney tissue cells in exposure periods dependent on radiation dose and exposure time.

  17. Family Wide Molecular Adaptations to Underground Life in African Mole-Rats Revealed by Phylogenomic Analysis.

    Science.gov (United States)

    Davies, Kalina T J; Bennett, Nigel C; Tsagkogeorga, Georgia; Rossiter, Stephen J; Faulkes, Christopher G

    2015-12-01

    During their evolutionary radiation, mammals have colonized diverse habitats. Arguably the subterranean niche is the most inhospitable of these, characterized by reduced oxygen, elevated carbon dioxide, absence of light, scarcity of food, and a substrate that is energetically costly to burrow through. Of all lineages to have transitioned to a subterranean niche, African mole-rats are one of the most successful. Much of their ecological success can be attributed to a diet of plant storage organs, which has allowed them to colonize climatically varied habitats across sub-Saharan Africa, and has probably contributed to the evolution of their diverse social systems. Yet despite their many remarkable phenotypic specializations, little is known about molecular adaptations underlying these traits. To address this, we sequenced the transcriptomes of seven mole-rat taxa, including three solitary species, and combined new sequences with existing genomic data sets. Alignments of more than 13,000 protein-coding genes encompassed, for the first time, all six genera and the full spectrum of ecological and social variation in the clade. We detected positive selection within the mole-rat clade and along ancestral branches in approximately 700 genes including loci associated with tumorigenesis, aging, morphological development, and sociality. By combining these results with gene ontology annotation and protein-protein networks, we identified several clusters of functionally related genes. This family wide analysis of molecular evolution in mole-rats has identified a suite of positively selected genes, deepening our understanding of the extreme phenotypic traits exhibited by this group. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  18. Genetic signatures for enhanced olfaction in the African mole-rats.

    Directory of Open Access Journals (Sweden)

    Sofia Stathopoulos

    Full Text Available The Olfactory Receptor (OR superfamily, the largest in the vertebrate genome, is responsible for vertebrate olfaction and is traditionally subdivided into 17 OR families. Recent studies characterising whole-OR subgenomes revealed a 'birth and death' model of evolution for a range of species, however little is known about fine-scale evolutionary dynamics within single-OR families. This study reports the first assessment of fine-scale OR evolution and variation in African mole-rats (Bathyergidae, a family of subterranean rodents endemic to sub-Saharan Africa. Because of the selective pressures of life underground, enhanced olfaction is proposed to be fundamental to the evolutionary success of the Bathyergidae, resulting in a highly diversified OR gene-repertoire. Using a PCR-sequencing approach, we analysed variation in the OR7 family across 14 extant bathyergid species, which revealed enhanced levels of functional polymorphisms concentrated across the receptors' ligand-binding region. We propose that mole-rats are able to recognise a broad range of odorants and that this diversity is reflected throughout their OR7 gene repertoire. Using both classic tests and tree-based methods to test for signals of selection, we investigate evolutionary forces across the mole-rat OR7 gene tree. Four well-supported clades emerged in the OR phylogeny, with varying signals of selection; from neutrality to positive and purifying selection. Bathyergid life-history traits and environmental niche-specialisation are explored as possible drivers of adaptive OR evolution, emerging as non-exclusive contributors to the positive selection observed at OR7 genes. Our results reveal unexpected complexity of evolutionary mechanisms acting within a single OR family, providing insightful perspectives into OR evolutionary dynamics.

  19. The Predictive Power of Evolutionary Biology and the Discovery of Eusociality in the Naked Mole-Rat.

    Science.gov (United States)

    Braude, Stanton

    1997-01-01

    Discusses how biologists use evolutionary theory and provides examples of how evolutionary biologists test hypotheses on specific modes of selection and evolution. Presents an example of the successful predictive power of one evolutionary hypothesis. Contains 38 references. (DDR)

  20. Sex- and brain region-specific patterns of gene expression associated with socially-mediated puberty in a eusocial mammal.

    Directory of Open Access Journals (Sweden)

    Mariela Faykoo-Martinez

    Full Text Available The social environment can alter pubertal timing through neuroendocrine mechanisms that are not fully understood; it is thought that stress hormones (e.g., glucocorticoids or corticotropin-releasing hormone influence the hypothalamic-pituitary-gonadal axis to inhibit puberty. Here, we use the eusocial naked mole-rat, a unique species in which social interactions in a colony (i.e. dominance of a breeding female suppress puberty in subordinate animals. Removing subordinate naked mole-rats from this social context initiates puberty, allowing for experimental control of pubertal timing. The present study quantified gene expression for reproduction- and stress-relevant genes acting upstream of gonadotropin-releasing hormone in brain regions with reproductive and social functions in pre-pubertal, post-pubertal, and opposite sex-paired animals (which are in various stages of pubertal transition. Results indicate sex differences in patterns of neural gene expression. Known functions of genes in brain suggest stress as a key contributing factor in regulating male pubertal delay. Network analysis implicates neurokinin B (Tac3 in the arcuate nucleus of the hypothalamus as a key node in this pathway. Results also suggest an unappreciated role for the nucleus accumbens in regulating puberty.

  1. Adaptation of pelage color and pigment variations in Israeli subterranean blind mole rats, Spalax ehrenbergi [corrected].

    Directory of Open Access Journals (Sweden)

    Natarajan Singaravelan

    Full Text Available Concealing coloration in rodents is well established. However, only a few studies examined how soil color, pelage color, hair-melanin content, and genetics (i.e., the causal chain synergize to configure it. This study investigates the causal chain of dorsal coloration in Israeli subterranean blind mole rats, Spalax ehrenbergi.We examined pelage coloration of 128 adult animals from 11 populations belonging to four species of Spalax ehrenbergi superspecies (Spalax galili, Spalax golani, Spalax carmeli, and Spalax judaei and the corresponding coloration of soil samples from the collection sites using a digital colorimeter. Additionally, we quantified hair-melanin contents of 67 animals using HPLC and sequenced the MC1R gene in 68 individuals from all four mole rat species.Due to high variability of soil colors, the correlation between soil and pelage color coordinates was weak and significant only between soil hue and pelage lightness. Multiple stepwise forward regression revealed that soil lightness was significantly associated with all pelage color variables. Pelage color lightness among the four species increased with the higher southward aridity in accordance to Gloger's rule (darker in humid habitats and lighter in arid habitats. Darker and lighter pelage colors are associated with darker basalt and terra rossa, and lighter rendzina soils, respectively. Despite soil lightness varying significantly, pelage lightness and eumelanin converged among populations living in similar soil types. Partial sequencing of the MC1R gene identified three allelic variants, two of which were predominant in northern species (S. galili and S. golani, and the third was exclusive to southern species (S. carmeli and S. judaei, which might have caused the differences found in pheomelanin/eumelanin ratio.Darker dorsal pelage in darker basalt and terra rossa soils in the north and lighter pelage in rendzina and loess soils in the south reflect the combined results of

  2. Vocalisations of the silvery mole-rat: comparasion of vocal repertoires in subterrane an rodents with different socials systems

    Czech Academy of Sciences Publication Activity Database

    Knotková, E.; Veitl, S.; Šumbera, R.; Sedláček, František; Burda, H.

    2009-01-01

    Roč. 18, č. 3 (2009), s. 241-257 ISSN 0952-4622 Institutional research plan: CEZ:AV0Z60870520 Keywords : silvery mole-rat * bathyergidae * vocal communication Subject RIV: EG - Zoology Impact factor: 1.050, year: 2009

  3. Region-specific associations between sex, social status, and oxytocin receptor density in the brains of eusocial rodents.

    Science.gov (United States)

    Mooney, S J; Coen, C W; Holmes, M M; Beery, A K

    2015-09-10

    Naturally occurring variations in neuropeptide receptor distributions in the brain contribute to numerous mammalian social behaviors. In naked mole-rats, which live in large social groups and exhibit remarkable reproductive skew, colony-related social behaviors vary with reproductive status. Here we examined whether variation in social status is associated with variations in the location and/or density of oxytocin binding in this species. Autoradiography was performed to assess forebrain oxytocin receptor (OTR) densities in breeding and non-breeding naked mole-rats of both sexes. Overall, males exhibited higher OTR binding in the medial amygdala in comparison to females. While there were no main effects of reproductive status in any region, a sex difference in OTR binding in the nucleus accumbens was mediated by status. Specifically, breeding males tended to have more OTR binding than breeding females in the nucleus accumbens, while no sex difference was observed in subordinates. These effects suggest that oxytocin may act in a sex- and region-specific way that corresponds to reproductive status and associated social behaviors. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  4. Retinal S-opsin dominance in Ansell's mole-rats (Fukomys anselli) is a consequence of naturally low serum thyroxine.

    Science.gov (United States)

    Henning, Yoshiyuki; Mladěnková, Nella; Burda, Hynek; Szafranski, Karol; Begall, Sabine

    2018-03-12

    Mammals usually possess a majority of medium-wavelength sensitive (M-) and a minority of short-wavelength sensitive (S-) opsins in the retina, enabling dichromatic vision. Unexpectedly, subterranean rodents from the genus Fukomys exhibit an S-opsin majority, which is exceptional among mammals, albeit with no apparent adaptive value. Because thyroid hormones (THs) are pivotal for M-opsin expression and metabolic rate regulation, we have, for the first time, manipulated TH levels in the Ansell's mole-rat (Fukomys anselli) using osmotic pumps. In Ansell's mole-rats, the TH thyroxine (T4) is naturally low, likely as an adaptation to the harsh subterranean ecological conditions by keeping resting metabolic rate (RMR) low. We measured gene expression levels in the eye, RMR, and body mass (BM) in TH-treated animals. T4 treatment increased both, S- and M-opsin expression, albeit M-opsin expression at a higher degree. However, this plasticity was only given in animals up to approximately 2.5 years. Mass-specific RMR was not affected following T4 treatment, although BM decreased. Furthermore, the T4 inactivation rate is naturally higher in F. anselli compared to laboratory rodents. This is the first experimental evidence that the S-opsin majority in Ansell's mole-rats is a side effect of low T4, which is downregulated to keep RMR low.

  5. Non-invasive assessment of glucocorticoid and androgen metabolite levels in cooperatively breeding Damaraland mole-rats (Fukomys damarensis).

    Science.gov (United States)

    Medger, Katarina; Bennett, Nigel C; Lutermann, Heike; Ganswindt, Andre

    2018-05-18

    Dominant females of cooperative breeding species often use aggression to suppress reproduction of subordinate females, resulting in subordinates experiencing stress-related increases in glucocorticoid levels, which may cause reproductive down-regulation. This would suggest a general pattern with higher glucocorticoid levels in subordinate compared to dominant individuals; however, the opposite was found in a number of cooperatively breeding species. Furthermore, breeding females of the cooperatively breeding Damaraland mole-rats (Fukomys damarensis) exhibit very high androgen concentrations during the wet season, presumably to support their breeding monopoly. Hormone analysis in Damaraland mole-rats have typically been measured using plasma and urine, but faecal analysis offers additional advantages especially for field studies on this species. The present study examines the suitability of Damaraland mole-rat faecal samples for determining glucocorticoid metabolite (fGCM) and androgen metabolite (fAM) concentrations using enzyme immunoassays. Using these assays, we further evaluated the effects of breeding status on fGCM and fAM concentrations in wild-caught and captive Damaraland mole-rats. Wild-caught breeding and non-breeding males and females exhibited no differences in fAM concentrations. Immunoreactive fGCM concentrations were only high in male breeders and comparatively low in non-breeders and breeding females. Concentrations of fAMs and fGCMs were similar in captive males and females, but fAM concentrations were elevated in captive compared to wild-caught individuals, which may be related to a higher reproductive activity due to removal from the breeding female. The relatively uniform fAM and fGCM concentrations found in wild-caught mole-rats may be explained by a stable colony structure during the dry season during which this study was conducted. Limited dispersal opportunities result in lower aggression and stress levels within a colony and as a result

  6. Unusual ratio between free thyroxine and free triiodothyronine in a long-lived mole-rat species with bimodal ageing.

    Science.gov (United States)

    Henning, Yoshiyuki; Vole, Christiane; Begall, Sabine; Bens, Martin; Broecker-Preuss, Martina; Sahm, Arne; Szafranski, Karol; Burda, Hynek; Dammann, Philip

    2014-01-01

    Ansell's mole-rats (Fukomys anselli) are subterranean, long-lived rodents, which live in eusocial families, where the maximum lifespan of breeders is twice as long as that of non-breeders. Their metabolic rate is significantly lower than expected based on allometry, and their retinae show a high density of S-cone opsins. Both features may indicate naturally low thyroid hormone levels. In the present study, we sequenced several major components of the thyroid hormone pathways and analyzed free and total thyroxine and triiodothyronine in serum samples of breeding and non-breeding F. anselli to examine whether a) their thyroid hormone system shows any peculiarities on the genetic level, b) these animals have lower hormone levels compared to euthyroid rodents (rats and guinea pigs), and c) reproductive status, lifespan and free hormone levels are correlated. Genetic analyses confirmed that Ansell's mole-rats have a conserved thyroid hormone system as known from other mammalian species. Interspecific comparisons revealed that free thyroxine levels of F. anselli were about ten times lower than of guinea pigs and rats, whereas the free triiodothyronine levels, the main biologically active form, did not differ significantly amongst species. The resulting fT4:fT3 ratio is unusual for a mammal and potentially represents a case of natural hypothyroxinemia. Comparisons with total thyroxine levels suggest that mole-rats seem to possess two distinct mechanisms that work hand in hand to downregulate fT4 levels reliably. We could not find any correlation between free hormone levels and reproductive status, gender or weight. Free thyroxine may slightly increase with age, based on sub-significant evidence. Hence, thyroid hormones do not seem to explain the different ageing rates of breeders and non-breeders. Further research is required to investigate the regulatory mechanisms responsible for the unusual proportion of free thyroxine and free triiodothyronine.

  7. Unusual ratio between free thyroxine and free triiodothyronine in a long-lived mole-rat species with bimodal ageing.

    Directory of Open Access Journals (Sweden)

    Yoshiyuki Henning

    Full Text Available Ansell's mole-rats (Fukomys anselli are subterranean, long-lived rodents, which live in eusocial families, where the maximum lifespan of breeders is twice as long as that of non-breeders. Their metabolic rate is significantly lower than expected based on allometry, and their retinae show a high density of S-cone opsins. Both features may indicate naturally low thyroid hormone levels. In the present study, we sequenced several major components of the thyroid hormone pathways and analyzed free and total thyroxine and triiodothyronine in serum samples of breeding and non-breeding F. anselli to examine whether a their thyroid hormone system shows any peculiarities on the genetic level, b these animals have lower hormone levels compared to euthyroid rodents (rats and guinea pigs, and c reproductive status, lifespan and free hormone levels are correlated. Genetic analyses confirmed that Ansell's mole-rats have a conserved thyroid hormone system as known from other mammalian species. Interspecific comparisons revealed that free thyroxine levels of F. anselli were about ten times lower than of guinea pigs and rats, whereas the free triiodothyronine levels, the main biologically active form, did not differ significantly amongst species. The resulting fT4:fT3 ratio is unusual for a mammal and potentially represents a case of natural hypothyroxinemia. Comparisons with total thyroxine levels suggest that mole-rats seem to possess two distinct mechanisms that work hand in hand to downregulate fT4 levels reliably. We could not find any correlation between free hormone levels and reproductive status, gender or weight. Free thyroxine may slightly increase with age, based on sub-significant evidence. Hence, thyroid hormones do not seem to explain the different ageing rates of breeders and non-breeders. Further research is required to investigate the regulatory mechanisms responsible for the unusual proportion of free thyroxine and free triiodothyronine.

  8. Gis-approach for variability assessment of soil electric conductivity under pedoturbation activity of mole rat (Spalax microphthalmus

    Directory of Open Access Journals (Sweden)

    T. М. Konovalova

    2010-06-01

    Full Text Available The results of the investigation of the impact of the mole rat’s activity on soil electric conductivity have been presented. GIS-technology have been shown to be effective for assessment of the pedoturbation activity effect on the soil surface heterogeneity formation. Method of the one-dimension spatial coordinated array transformation into matrix form has been proposed for following multidimension statistic analysis application. The quantity estimation of the mole rats role in formation of the habitat nanorelief-level diversity has been obtained by means of indexes of the landscape complexity and diversity.

  9. Fos expression in the suprachiasmatic nucleus in response to light stimulation in a solitary and social species of African mole-rat (family Bathyergidae).

    Science.gov (United States)

    Oosthuizen, M K; Bennett, N C; Cooper, H M

    2005-01-01

    Mole-rats are strictly subterranean rodents that are rarely exposed to environmental light. They are well adapted to their environment and have reduced eyes and a severely regressed visual system. It has been shown, however, that mole-rats do exhibit endogenous circadian rhythms that can be entrained, suggesting an intact and functional circadian system. To determine whether light is the entraining agent in these animals, Fos expression in response to light pulses at different circadian times was investigated to obtain phase response curves. Light is integrated effectively in the suprachiasmatic nucleus of the Cape mole-rat (Georychus capensis), and Fos expression is gated according to the phase of the circadian clock. The Fos response in the Cape mole-rat was comparable to that of aboveground rodents. In contrast, the highveld mole-rat (Cryptomys hottentotus pretoriae) was less sensitive to light and did not show a selective Fos response according to the phase of the circadian cycle. Social species appear to be less sensitive to light than their solitary counterparts, which compares well with results from locomotor activity studies.

  10. Exceptional Chromosomal Evolution and Cryptic Speciation of Blind Mole Rats Nannospalax leucodon (Spalacinae, Rodentia from South-Eastern Europe

    Directory of Open Access Journals (Sweden)

    Ivo Savić

    2017-10-01

    Full Text Available Mole rats are exclusively subterranean and highly specialized rodents. Their long lifespans, remarkable anti-cancer mechanisms, and various distinctive adaptive features make them a useful research model. Moreover, opposing convergence of morphological traits, they have developed extremely high karyotype variability. Thus, 74 chromosomal forms have been described so far and new ones are being revealed continuously. These evolved during the process of rapid radiation and occur in different biogeographical regions. During research into their reproductive biology we have already provided substantial evidence for species-level separation of these taxa. Here, we review diverse chromosomal forms of the lesser blind mole rat, Mediterranean Nannospalax leucodon, distributed in South-eastern Europe, their karyotype records, biogeography, origin, and phylogeny from our extensive research. In the light of new data from molecular genetic studies, we question some former valuations and propose a cryptospecies rank for seven reproductively isolated chromosomal forms with sympatric and parapatric distribution and clear ecogeographical discrepances in their habitats, as well as new experimental and theoretical methods for understanding the courses of speciation of these unique fossorial mammals.

  11. Spatial and temporal activity patterns of the free-living giant mole-rat (Fukomys mechowii, the largest social bathyergid.

    Directory of Open Access Journals (Sweden)

    Matěj Lövy

    Full Text Available Despite the considerable attention devoted to the biology of social species of African mole-rats (Bathyergidae, Rodentia, knowledge is lacking about their behaviour under natural conditions. We studied activity of the largest social bathyergid, the giant mole-rat Fukomys mechowii, in its natural habitat in Zambia using radio-telemetry. We radio-tracked six individuals during three continuous 72-h sessions. Five of these individuals, including a breeding male, belonged to a single family group; the remaining female was probably a solitary disperser. The non-breeders of the family were active (i.e. outside the nest 5.8 hours per 24h-day with the activity split into 6.5 short bouts. The activity was more concentrated in the night hours, when the animals also travelled longer distances from the nest. The breeding male spent only 3.2 hours per day outside the nest, utilizing less than 20% of the whole family home range. The dispersing female displayed a much different activity pattern than the family members. Her 8.0 hours of outside-nest activity per day were split into 4.6 bouts which were twice as long as in the family non-breeders. Her activity peak in the late afternoon coincided with the temperature maximum in the depth of 10 cm (roughly the depth of the foraging tunnels. Our results suggest that the breeding individuals (at least males contribute very little to the work of the family group. Nevertheless, the amount of an individual's activity and its daily pattern are probably flexible in this species and can be modified in response to actual environmental and social conditions.

  12. Parentage analysis of Ansell’s mole-rat family groups indicates a high reproductive skew despite relatively relaxed ecological constraints on dispersal

    Czech Academy of Sciences Publication Activity Database

    Patzenhauerová, Hana; Šklíba, J.; Bryja, Josef; Šumbera, R.

    2013-01-01

    Roč. 22, č. 19 (2013), s. 4988-5000 ISSN 0962-1083 R&D Projects: GA AV ČR IAA601410802; GA ČR GAP506/10/0983 Institutional support: RVO:68081766 Keywords : African mole-rat * dispersal * eusociality * Fukomys * mating system * reproductive skew Subject RIV: EH - Ecology, Behaviour Impact factor: 5.840, year: 2013

  13. Variability of space-use patterns in a free living eusocial rodent, Ansell’s mole-rat indicates age-based rather than caste polyethism

    Czech Academy of Sciences Publication Activity Database

    Šklíba, Jan; Lövy, M.; Burda, H.; Šumbera, R.

    2016-01-01

    Roč. 6, DEC 06 (2016), č. článku 37497. ISSN 2045-2322 EU Projects: European Commission(XE) 669609 - Diversity6continents Institutional support: RVO:60077344 Keywords : eusocial rodent * mole-rats * Fukomys anselli Subject RIV: EG - Zoology OBOR OECD: Zoology Impact factor: 4.259, year: 2016 https://www.nature.com/articles/srep37497

  14. Effects of laboratory housing on exploratory behaviour, novelty discrimination and spatial reference memory in a subterranean, solitary rodent, the Cape mole-rat (Georychus capensis).

    Science.gov (United States)

    Oosthuizen, Maria Kathleen; Scheibler, Anne-Gita; Bennett, Nigel Charles; Amrein, Irmgard

    2013-01-01

    A large number of laboratory and field based studies are being carried out on mole-rats, both in our research group and others. Several studies have highlighted the development of adverse behaviours in laboratory animals and have emphasised the importance of enrichment for captive animals. Hence we were interested in evaluating how laboratory housing would affect behavioural performance in mole-rats. We investigated exploratory behaviour, the ability to discriminate between novel and familiar environments and reference memory in the solitary Cape mole-rat (Georychus capensis). Our data showed that both wild and captive animals readily explore open spaces and tunnels. Wild animals were however more active than their captive counterparts. In the Y maze two trial discrimination task, wild animals failed to discriminate between novel and familiar environments, while laboratory housed mole-rats showed preferential spatial discrimination in terms of the length of time spent in the novel arm. The performance of the laboratory and wild animals were similar when tested for reference memory in the Y maze, both groups showed a significant improvement compared to the first day, from the 3rd day onwards. Wild animals made more mistakes whereas laboratory animals were slower in completing the task. The difference in performance between wild and laboratory animals in the Y-maze may be as a result of the lower activity of the laboratory animals. Laboratory maintained Cape mole-rats show classic behaviours resulting from a lack of stimulation such as reduced activity and increased aggression. However, they do display an improved novelty discrimination compared to the wild animals. Slower locomotion rate of the laboratory animals may increase the integration time of stimuli, hence result in a more thorough inspection of the surroundings. Unlike the captive animals, wild animals show flexibility in their responses to unpredictable events, which is an important requirement under

  15. Sperm structure and motility in the eusocial naked mole-rat, Heterocephalus glaber: a case of degenerative orthogenesis in the absence of sperm competition?

    Directory of Open Access Journals (Sweden)

    van der Horst Gerhard

    2011-12-01

    Full Text Available Abstract Background We have studied sperm structure and motility in a eusocial rodent where reproduction is typically restricted to a single male and behaviourally dominant queen. Males rarely compete for access to the queen during her estrus cycle, suggesting little or no role for sperm competition. Results Our results revealed an atypical mammalian sperm structure with spermatozoa from breeding, subordinate and disperser males being degenerate and almost completely lacking a "mammalian phylogenetic stamp". Sperm structure is characterized by extreme polymorphism with most spermatozoa classified as abnormal. Sperm head shapes include round, oval, elongated, lobed, asymmetrical and amorphous. At the ultrastructural level, the sperm head contains condensed to granular chromatin with large open spaces between the chromatin. Nuclear chromatin seems disorganized since chromatin condensation is irregular and extremely inconsistent. The acrosome forms a cap (ca 35% over the anterior part of the head. A well defined nuclear fossa and neck with five minor sets of banded protein structures are present. The midpiece is poorly organized and contains only 5 to 7 round to oval mitochondria. The flagellar pattern is 9+9+2. A distinct degenerative feature of the tail principal piece is the absence of the fibrous sheath. Only 7% motile spermatozoa were observed which had exceptionally slow swimming speeds. Conclusion In this species, sperm form has simplified and degenerated in many aspects and represents a specialised form of degenerative orthogenesis at the cellular level.

  16. They live in the land down under: thyroid function and basal metabolic rate in the Blind Mole Rat, Spalax.

    Science.gov (United States)

    Avivi, Aaron; Nevo, Eviatar; Cohen, Keren; Sotnichenko, Nick; Hercbergs, Aleck; Band, Mark; Davis, Paul J; Ellis, Martin; Ashur-Fabian, Osnat

    2014-01-01

    The Israeli blind subterranean mole rat (Spalax ehrenbergi superspecies) lives in sealed underground burrows under extreme, hypoxic conditions. The four Israeli Spalax allospecies have adapted to different climates, the cool-humid (Spalax galili, 2 n = 52 chromosomes), semihumid (S. golani, 2 n = 54) north regions, warm-humid (S. carmeli, 2 n = 58) central region and the warm-dry S. judaei, 2 n = 60) southern regions. A dramatic interspecies decline in basal metabolic rate (BMR) from north to south, even after years of captivity, indicates a genetic basis for this BMR trait. We examined the possibility that the genetically-conditioned interspecies BMR difference was expressed via circulating thyroid hormone. An unexpected north to south increase in serum free thyroxine (FT4) and total 3, 5, 3'-triiodo-L-thyronine (T3) (p BMR measurements. The increases in serum FT4 and T3 were symmetrical, so that the T3:FT4 ratio - interpretable as an index of conversion of T4 to T3 in nonthyroidal tissues - did not support relative decrease in production of T3 as a contributor to BMR. Increased north-to-south serum FT4 and T3 levels also correlated negatively with hemoglobin/hematocrit. North-to-south adaptations in spalacids include decreased BMR and hematocrit/hemoglobin in the face of increasing thyroid hormone levels, arguing for independent control of hormone secretion and BMR/hematocrit/hemoglobin. But the significant inverse relationship between thyroid hormone levels and BMR/hematocrit/hemoglobin is also consistent with a degree of cellular resistance to thyroid hormone action that protects against hormone-induced increase in oxygen consumption in a hostile, hypoxic environment.

  17. Reproduction is associated with a tissue-dependent reduction of oxidative stress in eusocial female Damaraland mole-rats (Fukomys damarensis.

    Directory of Open Access Journals (Sweden)

    Christina M Schmidt

    Full Text Available Oxidative stress has been implicated as both a physiological cost of reproduction and a driving force on an animal's lifespan. Since increased reproductive effort is generally linked with a reduction in survival, it has been proposed that oxidative stress may influence this relationship. Support for this hypothesis is inconsistent, but this may, in part, be due to the type of tissues that have been analyzed. In Damaraland mole-rats the sole reproducing female in the colony is also the longest lived. Therefore, if oxidative stress does impact the trade-off between reproduction and survival in general, this species may possess some form of enhanced defense. We assessed this relationship by comparing markers of oxidative damage (malondialdehyde, MDA; protein carbonyls, PC and antioxidants (total antioxidant capacity, TAC; superoxide dismutase, SOD in various tissues including plasma, erythrocytes, heart, liver, kidney and skeletal muscle between wild-caught reproductive and non-reproductive female Damaraland mole-rats. Reproductive females exhibited significantly lower levels of PC across all tissues, and lower levels of MDA in heart, kidney and liver relative to non-reproductive females. Levels of TAC and SOD did not differ significantly according to reproductive state. The reduction in oxidative damage in breeding females may be attributable to the unusual social structure of this species, as similar relationships have been observed between reproductive and non-reproductive eusocial insects.

  18. How attractive is the girl next door? An assessment of spatial mate acquisition and paternity in the solitary Cape dune mole-rat, Bathyergus suillus.

    Directory of Open Access Journals (Sweden)

    Timothy C Bray

    Full Text Available Behavioural observations of reproduction and mate choice in wild fossorial rodents are extremely limited and consequently indirect methods are typically used to infer mating strategies. We use a combination of morphological, reproductive, spatial, and genetic data to investigate the reproductive strategy of a solitary endemic species, the Cape dune mole-rat Bathyergus suillus. These data provide the first account on the population dynamics of this species. Marked sexual dimorphism was apparent with males being both significantly larger and heavier than females. Of all females sampled 36% had previously reproduced and 12% were pregnant at the time of capture. Post-partum sex ratio was found to be significantly skewed in favour of females. The paternity of fifteen litters (n = 37 was calculated, with sires assigned to progeny using both categorical and full probability methods, and including a distance function. The maximum distance between progeny and a putative sire was determined as 2149 m with males moving between sub-populations. We suggest that above-ground movement should not be ignored in the consideration of mate acquisition behaviour of subterranean mammals. Estimated levels of multiple paternity were shown to be potentially as high as 26%, as determined using sibship and sire assignment methods. Such high levels of multiple paternity have not been found in other solitary mole-rat species. The data therefore suggest polyandry with no evidence as yet for polygyny.

  19. Timelike naked singularity

    International Nuclear Information System (INIS)

    Goswami, Rituparno; Joshi, Pankaj S.; Vaz, Cenalo; Witten, Louis

    2004-01-01

    We construct a class of spherically symmetric collapse models in which a naked singularity may develop as the end state of collapse. The matter distribution considered has negative radial and tangential pressures, but the weak energy condition is obeyed throughout. The singularity forms at the center of the collapsing cloud and continues to be visible for a finite time. The duration of visibility depends on the nature of energy distribution. Hence the causal structure of the resulting singularity depends on the nature of the mass function chosen for the cloud. We present a general model in which the naked singularity formed is timelike, neither pointlike nor null. Our work represents a step toward clarifying the necessary conditions for the validity of the Cosmic Censorship Conjecture

  20. No oxygen? No problem! Intrinsic brain tolerance to hypoxia in vertebrates

    Science.gov (United States)

    Larson, John; Drew, Kelly L.; Folkow, Lars P.; Milton, Sarah L.; Park, Thomas J.

    2014-01-01

    Many vertebrates are challenged by either chronic or acute episodes of low oxygen availability in their natural environments. Brain function is especially vulnerable to the effects of hypoxia and can be irreversibly impaired by even brief periods of low oxygen supply. This review describes recent research on physiological mechanisms that have evolved in certain vertebrate species to cope with brain hypoxia. Four model systems are considered: freshwater turtles that can survive for months trapped in frozen-over lakes, arctic ground squirrels that respire at extremely low rates during winter hibernation, seals and whales that undertake breath-hold dives lasting minutes to hours, and naked mole-rats that live in crowded burrows completely underground for their entire lives. These species exhibit remarkable specializations of brain physiology that adapt them for acute or chronic episodes of hypoxia. These specializations may be reactive in nature, involving modifications to the catastrophic sequelae of oxygen deprivation that occur in non-tolerant species, or preparatory in nature, preventing the activation of those sequelae altogether. Better understanding of the mechanisms used by these hypoxia-tolerant vertebrates will increase appreciation of how nervous systems are adapted for life in specific ecological niches as well as inform advances in therapy for neurological conditions such as stroke and epilepsy. PMID:24671961

  1. Naked Black Hole Firewalls.

    Science.gov (United States)

    Chen, Pisin; Ong, Yen Chin; Page, Don N; Sasaki, Misao; Yeom, Dong-Han

    2016-04-22

    In the firewall proposal, it is assumed that the firewall lies near the event horizon and should not be observable except by infalling observers, who are presumably terminated at the firewall. However, if the firewall is located near where the horizon would have been, based on the spacetime evolution up to that time, later quantum fluctuations of the Hawking emission rate can cause the "teleological" event horizon to have migrated to the inside of the firewall location, rendering the firewall naked. In principle, the firewall can be arbitrarily far outside the horizon. This casts doubt about the notion that firewalls are the "most conservative" solution to the information loss paradox.

  2. Naked Black Hole Firewalls

    Science.gov (United States)

    Chen, Pisin; Ong, Yen Chin; Page, Don N.; Sasaki, Misao; Yeom, Dong-han

    2016-04-01

    In the firewall proposal, it is assumed that the firewall lies near the event horizon and should not be observable except by infalling observers, who are presumably terminated at the firewall. However, if the firewall is located near where the horizon would have been, based on the spacetime evolution up to that time, later quantum fluctuations of the Hawking emission rate can cause the "teleological" event horizon to have migrated to the inside of the firewall location, rendering the firewall naked. In principle, the firewall can be arbitrarily far outside the horizon. This casts doubt about the notion that firewalls are the "most conservative" solution to the information loss paradox.

  3. Are naked singularities really visible

    Energy Technology Data Exchange (ETDEWEB)

    Calvani, M [Padua Univ. (Italy). Ist. di Astronomia; De Felice, F [Alberta Univ., Edmonton (Canada); Nobili, L [Padua Univ. (Italy). Ist. di Fisica

    1978-12-09

    The question whether a Kerr naked singularity is actually visible from infinity is investigated; it is shown that in fact any signal which could be emitted from the singularity is infinitely red-shifted. This implies that naked singularities would be indistinguishable from a black hole.

  4. Transcriptome sequencing of the blind subterranean mole rat, Spalax galili: Utility and potential for the discovery of novel evolutionary patterns

    KAUST Repository

    Malik, Assaf; Korol, Abraham; Hü bner, Sariel; Hernandez, Alvaro G.; Thimmapuram, Jyothi; Ali, Shahjahan; Glaser, Fabian; Paz, Arnon; Avivi, Aaron; Band, Mark

    2011-01-01

    sequencing of Spalax galili, a chromosomal type of S. ehrenbergi. cDNA pools from muscle and brain tissues isolated from animals exposed to hypoxic and normoxic conditions were sequenced using Sanger, GS FLX, and GS FLX Titanium technologies. Assembly

  5. Characterization of gonadotrophin-releasing hormone precursor cDNA in the Old World mole-rat Cryptomys hottentotus pretoriae: high degree of identity with the New World guinea pig sequence.

    Science.gov (United States)

    Kalamatianos, T; du Toit, L; Hrabovszky, E; Kalló, I; Marsh, P J; Bennett, N C; Coen, C W

    2005-05-01

    Regulation of pituitary gonadotrophins by the decapeptide gonadotrophin-releasing hormone 1 (GnRH1) is crucial for the development and maintenance of reproductive functions. A common amino acid sequence for this decapeptide, designated as 'mammalian' GnRH, has been identified in all mammals thus far investigated with the exception of the guinea pig, in which there are two amino acid substitutions. Among hystricognath rodents, the members of the family Bathyergidae regulate reproduction in response to diverse cues. Thus, highveld mole-rats (Cryptomys hottentotus pretoriae) are social bathyergids in which breeding is restricted to a particular season in the dominant female, but continuously suppressed in subordinate colony members. Elucidation of reproductive control in these animals will be facilitated by characterization of their GnRH1 gene. A partial sequence of GnRH1 precursor cDNA was isolated and characterized. Comparative analysis revealed the highest degree of identity (86%) to guinea pig GnRH1 precursor mRNA. Nevertheless, the deduced amino acid sequence of the mole-rat decapeptide is identical to the 'mammalian' sequence rather than that of guinea pigs. Successful detection of GnRH1-synthesizing neurones using either a guinea pig GnRH1 riboprobe or an antibody against the 'mammalian' decapeptide is consistent with the guinea pig-like sequence for the precursor and the classic 'mammalian' form for the decapeptide. The high degree of identity in the GnRH1 precursor sequence between this Old World mole-rat and the New World guinea pig is consistent with the theory that caviomorphs and phiomorphs originated from a common ancestral line in the Palaeocene to mid Eocene, some 63-45 million years ago.

  6. Non-image Forming Light Detection by Melanopsin, Rhodopsin, and Long-Middlewave (L/W) Cone Opsin in the Subterranean Blind Mole Rat, Spalax Ehrenbergi: Immunohistochemical Characterization, Distribution, and Connectivity

    DEFF Research Database (Denmark)

    Esquiva, Gema; Avivi, Aaron; Hannibal, Jens

    2016-01-01

    The blind mole rat, Spalax ehrenbergi, can, despite severely degenerated eyes covered by fur, entrain to the daily light/dark cycle and adapt to seasonal changes due to an intact circadian timing system. The present study demonstrates that the Spalax retina contains a photoreceptor layer, an outer...... marker RNA-binding protein with multiple splicing (RBPMS) it was shown that the Spalax eye contains 890 ± 62 RGCs. Of these, 87% (752 ± 40) contain melanopsin (cell density 788 melanopsin RGCs/mm2). The remaining RGCs were shown to co-store Brn3a and calretinin. The melanopsin cells were located mainly...... synapses, both rods and L/M cone ribbons containing pedicles in the OPL were found in close apposition with melanopsin dendrites in the outer plexus suggesting direct synaptic contact. A subset of cone bipolar cells and all photoreceptor cells contain recoverin while a subset of bipolar and amacrine cells...

  7. Quantum dress for a naked singularity

    Directory of Open Access Journals (Sweden)

    Marc Casals

    2016-09-01

    Full Text Available We investigate semiclassical backreaction on a conical naked singularity space–time with a negative cosmological constant in (2+1-dimensions. In particular, we calculate the renormalized quantum stress–energy tensor for a conformally coupled scalar field on such naked singularity space–time. We then obtain the backreacted metric via the semiclassical Einstein equations. We show that, in the regime where the semiclassical approximation can be trusted, backreaction dresses the naked singularity with an event horizon, thus enforcing (weak cosmic censorship.

  8. Dressing up a Kerr naked singularity

    Energy Technology Data Exchange (ETDEWEB)

    Calvani, M [Padua Univ. (Italy). Ist. di Astronomia; Nobili, L [Padua Univ. (Italy). Ist. di Fisica

    1979-06-11

    The evolution of a naked singularity surrounded by an accreting disk of matter is studied; two kinds of disks are considered: the standard thin-disk model and the thick barytropic model, for several initial conditions. It is shown that any Kerr naked singularity slows down in a finite time to a maximal Kerr black hole. The final mass, the luminosity and the time of evolution of the singularity are evaluated.

  9. Naked singularity, firewall, and Hawking radiation.

    Science.gov (United States)

    Zhang, Hongsheng

    2017-06-21

    Spacetime singularity has always been of interest since the proof of the Penrose-Hawking singularity theorem. Naked singularity naturally emerges from reasonable initial conditions in the collapsing process. A recent interesting approach in black hole information problem implies that we need a firewall to break the surplus entanglements among the Hawking photons. Classically, the firewall becomes a naked singularity. We find some vacuum analytical solutions in R n -gravity of the firewall-type and use these solutions as concrete models to study the naked singularities. By using standard quantum theory, we investigate the Hawking radiation emitted from the black holes with naked singularities. Here we show that the singularity itself does not destroy information. A unitary quantum theory works well around a firewall-type singularity. We discuss the validity of our result in general relativity. Further our result demonstrates that the temperature of the Hawking radiation still can be expressed in the form of the surface gravity divided by 2π. This indicates that a naked singularity may not compromise the Hakwing evaporation process.

  10. Early caries naked-eyed examination

    International Nuclear Information System (INIS)

    Bakhmutov, D; Gonchukov, S; Voytenok, O; Kharchenko, O; Zubov, B

    2008-01-01

    In view of its potential for dental diagnostics, noninvasive optical methods have been the object of research for the last years. Different techniques (spectroscopy, microscopy, and tomography) are used to discriminate between caries and sound enamel. The main aim of this paper is to determine a simple way to see incipient caries with the naked eye

  11. Naked-eye astronomy in mass tourism

    Directory of Open Access Journals (Sweden)

    Tadić Milutin

    2016-01-01

    Full Text Available This paper considers the possibility of developing astro-tourism in small countries such as Serbia and other Balkan countries, with "discreet" astro-tourism reduced to naked-eye astronomy as part of mass tourism rather than elite tourism that is realized through specialized programs with spacecraft and space stations, spectacular planetariums and observatories with giant telescopes. The specific relationship between the virtual and the real world is highlighted in this paper especially when considering younger generations. Furthermore, the differences in the way stars are perceived by astronomers and "ordinary" tourists or non-astronomers is also emphasized. Tourists are not enchanted by celestial bodies themselves, but by a complete scene, which consists of integrated skyscapes and landscapes, as a complex stage where in various combinations and forms these celestial bodies are observed, and of their own experience. These complex sky-earth landscapes, astro-landscapes, present astro-tourism resources of the small countries like Serbia, provided that a tourist can "read" their astronomical text. In this regard, Belgrade was used as the example for drafting a "package" of astronomical information that can be easily prepared and adapted according to the needs of a particular group, so that every tourist may know what can be seen, where and when. With the help of a rotating star map (planisphere, visitors may observe the sky with the naked eye.

  12. Naked singularities and cosmic censorship: comment on the current situation

    International Nuclear Information System (INIS)

    Seifert, H.J.

    1979-01-01

    The current discussion is mainly concerned with how, or indeed, whether space-times possessing naked singularities can be ruled out as being too unrealistic or not being singular at all. The present position is summarized, with references, under the following headings: the Hawking-Penrose existence theorems, hydrodynamical singularities and the strength of naked singularities. (UK)

  13. Naked singularities in higher dimensional Vaidya space-times

    International Nuclear Information System (INIS)

    Ghosh, S. G.; Dadhich, Naresh

    2001-01-01

    We investigate the end state of the gravitational collapse of a null fluid in higher-dimensional space-times. Both naked singularities and black holes are shown to be developing as the final outcome of the collapse. The naked singularity spectrum in a collapsing Vaidya region (4D) gets covered with the increase in dimensions and hence higher dimensions favor a black hole in comparison to a naked singularity. The cosmic censorship conjecture will be fully respected for a space of infinite dimension

  14. Naked singularities in self-similar spherical gravitational collapse

    International Nuclear Information System (INIS)

    Ori, A.; Piran, T.

    1987-01-01

    We present general-relativistic solutions of self-similar spherical collapse of an adiabatic perfect fluid. We show that if the equation of state is soft enough (Γ-1<<1), a naked singularity forms. The singularity resembles the shell-focusing naked singularities that arise in dust collapse. This solution increases significantly the range of matter fields that should be ruled out in order that the cosmic-censorship hypothesis will hold

  15. Productive performance of naked neck, frizzle and dwarf laying hens ...

    African Journals Online (AJOL)

    The productive performance of major genes for feather reduction (naked neck and frizzle) and body size reduction (dwarf) in a dual-purpose layer strain was evaluated in the subtropical coastal region of southeast Africa (Maputo, Mozambique). The experimental material consisted of ight different genetic groups, two diets ...

  16. Two-Laser Interference Visible to the Naked Eye

    Science.gov (United States)

    Kawalec, Tomasz; Bartoszek-Bober, Dobroslawa

    2012-01-01

    An experimental setup allowing the observation of two-laser interference by the naked eye is described. The key concept is the use of an electronic phase lock between two external cavity diode lasers. The experiment is suitable both for undergraduate and graduate students, mainly in atomic physics laboratories. It gives an opportunity for…

  17. On the nature of naked singularities in Vaidya spacetimes

    Energy Technology Data Exchange (ETDEWEB)

    Dwivedi, I.H. (Aligarh Muslim Univ. (India). Dept. of Physics); Joshi, P.S. (Tata Inst. of Fundamental Research, Bombay (India))

    1989-11-01

    The Vaidya-Papapetrou model containing a naked singularity is analysed for outgoing causal geodesics joining the singularity. The curvature growth along these trajectories is examined to show that this is a strong curvature singularity, providing a counter-example to certain forms of cosmic censorship hypotheses. (author).

  18. Papapetrou's naked singularity is a strong curvature singularity

    International Nuclear Information System (INIS)

    Hollier, G.P.

    1986-01-01

    Following Papapetrou [1985, a random walk in General Relativity ed. J. Krishna-Rao (New Delhi: Wiley Eastern)], a spacetime with a naked singularity is analysed. This singularity is shown to be a strong curvature singularity and thus a counterexample to a censorship conjecture. (author)

  19. On the nature of naked singularities in Vaidya spacetimes

    International Nuclear Information System (INIS)

    Dwivedi, I.H.

    1989-01-01

    The Vaidya-Papapetrou model containing a naked singularity is analysed for outgoing causal geodesics joining the singularity. The curvature growth along these trajectories is examined to show that this is a strong curvature singularity, providing a counter-example to certain forms of cosmic censorship hypotheses. (author)

  20. Perfect fluid tori orbiting Kehagias-Sfetsos naked singularities

    Science.gov (United States)

    Stuchlík, Z.; Pugliese, D.; Schee, J.; Kučáková, H.

    2015-09-01

    We construct perfect fluid tori in the field of the Kehagias-Sfetsos (K-S) naked singularities. These are spherically symmetric vacuum solutions of the modified Hořava quantum gravity, characterized by a dimensionless parameter ω M^2, combining the gravitational mass parameter M of the spacetime with the Hořava parameter ω reflecting the role of the quantum corrections. In dependence on the value of ω M^2, the K-S naked singularities demonstrate a variety of qualitatively different behavior of their circular geodesics that is fully reflected in the properties of the toroidal structures, demonstrating clear distinction to the properties of the torii in the Schwarzschild spacetimes. In all of the K-S naked singularity spacetimes the tori are located above an "antigravity" sphere where matter can stay in a stable equilibrium position, which is relevant for the stability of the orbiting fluid toroidal accretion structures. The signature of the K-S naked singularity is given by the properties of marginally stable tori orbiting with the uniform distribution of the specific angular momentum of the fluid, l= const. In the K-S naked singularity spacetimes with ω M^2 > 0.2811, doubled tori with the same l= const can exist; mass transfer between the outer torus and the inner one is possible under appropriate conditions, while only outflow to the outer space is allowed in complementary conditions. In the K-S spacetimes with ω M^2 < 0.2811, accretion from cusped perfect fluid tori is not possible due to the non-existence of unstable circular geodesics.

  1. Perfect fluid tori orbiting Kehagias-Sfetsos naked singularities

    Energy Technology Data Exchange (ETDEWEB)

    Stuchlik, Z.; Pugliese, D.; Schee, J.; Kucakova, H. [Silesian University in Opava, Faculty of Philosophy and Science, Institute of Physics and Research Centre of Theoretical Physics and Astrophysics, Opava (Czech Republic)

    2015-09-15

    We construct perfect fluid tori in the field of the Kehagias-Sfetsos (K-S) naked singularities. These are spherically symmetric vacuum solutions of the modified Horava quantum gravity, characterized by a dimensionless parameter ωM{sup 2}, combining the gravitational mass parameter M of the spacetime with the Horava parameter ω, reflecting the role of the quantum corrections. In dependence on the value of ωM{sup 2}, the K-S naked singularities demonstrate a variety of qualitatively different behavior of their circular geodesics that is fully reflected in the properties of the toroidal structures, demonstrating clear distinction to the properties of the torii in the Schwarzschild spacetimes. In all of the K-S naked singularity spacetimes the tori are located above an @gantigravity@h sphere where matter can stay in a stable equilibrium position, which is relevant for the stability of the orbiting fluid toroidal accretion structures. The signature of the K-S naked singularity is given by the properties of marginally stable tori orbiting with the uniform distribution of the specific angular momentum of the fluid, l = const. In the K-S naked singularity spacetimes with ωM{sup 2} > 0.2811, doubled tori with the same l = const can exist; mass transfer between the outer torus and the inner one is possible under appropriate conditions, while only outflow to the outer space is allowed in complementary conditions. In the K-S spacetimes with ωM{sup 2} < 0.2811, accretion from cusped perfect fluid tori is not possible due to the non-existence of unstable circular geodesics. (orig.)

  2. Structural studies of human Naked2: A biologically active intrinsically unstructured protein

    International Nuclear Information System (INIS)

    Hu Tianhui; Krezel, Andrzej M.; Li Cunxi; Coffey, Robert J.

    2006-01-01

    Naked1 and 2 are two mammalian orthologs of Naked Cuticle, a canonical Wnt signaling antagonist in Drosophila. Naked2, but not Naked1, interacts with transforming growth factor-α (TGFα) and escorts TGFα-containing vesicles to the basolateral membrane of polarized epithelial cells. Full-length Naked2 is poorly soluble. Since most functional domains, including the Dishevelled binding region, EF-hand, vesicle recognition, and membrane targeting motifs, reside in the N-terminal half of the protein, we expressed and purified the first 217 residues of human Naked2 and performed a functional analysis of this fragment. Its circular dichroism (CD) and nuclear magnetic resonance (NMR) spectra showed no evidence of secondary and/or tertiary structure. The fragment did not bind calcium or zinc. These results indicate that the N-terminal half of Naked2 behaves as an intrinsically unstructured protein

  3. Naked singularity formation in Brans-Dicke theory

    Energy Technology Data Exchange (ETDEWEB)

    Ziaie, Amir Hadi; Atazadeh, Khedmat [Department of Physics, Shahid Beheshti University, Evin, Tehran 19839 (Iran, Islamic Republic of); Tavakoli, Yaser, E-mail: am.ziaie@mail.sbu.ac.i, E-mail: k-atazadeh@sbu.ac.i, E-mail: tavakoli@ubi.p [Departamento de Fisica, Universidade da Beira Interior, Rua Marques d' Avila e Bolama, 6200 Covilha (Portugal)

    2010-04-07

    Gravitational collapse of the Brans-Dicke scalar field with non-zero potential in the presence of matter fluid obeying the barotropic equation of state, p = wrho, is studied. Utilizing the concept of the expansion parameter, it is seen that the cosmic censorship conjecture may be violated for w=-1/3 and w=-2/3 which correspond to the cosmic string and domain wall, respectively. We have shown that physically, it is the rate of collapse that governs the formation of a black hole or a naked singularity as the final fate of dynamical evolution and only for these two cases can the singularity be naked as the collapse end state. Also the weak energy condition is satisfied by the collapsing configuration.

  4. David Cronenberg, author of naked lunch: Intersemiotic translation as transcreation

    Directory of Open Access Journals (Sweden)

    Rosângela Fachel de Medeiros

    2016-05-01

    Full Text Available This paper presents and analyzes the intersemiotic translation process performed by filmmaker David Cronenberg of William Burroughs' novel Naked Lunch, and the intertextual bifurcations involved in this process. Investigating the similarities and differences between the creative worlds of both artists and how they reframe each other. For this, are used as the theoretical the idea of transcreation proposed by Haroldo de Campos, and the notion of the translator as a reader proposed by Jorge Luis Borges.

  5. Invariant identification of naked singularities in spherically symmetric spacetimes

    International Nuclear Information System (INIS)

    Torres, R

    2012-01-01

    The study of generic naked singularities and their implications for the cosmic censorship conjecture is still an open issue in the framework of general relativity. One of the obstacles can be traced to the procedures for identifying naked singularities. Usually, the methods applied are not only model and coordinate dependent, but they very often rely in some strong assumptions on the degree of differentiability of the physical magnitudes of the model (such as the mass, density, etc) in the singularity. In this paper, we present a coordinate independent framework for identifying naked singularities based on invariants which is also devoid of strong differentiability requirements. The approach is intended to analyse whole families of models and to provide general results related to the cosmic censorship conjecture. Moreover, since the framework has a strict geometrical nature it can be used with alternative theories of gravitation as long as they assume the existence of a Lorentzian manifold. We exemplify its strength by applying it to the study of the collapse of radiation in radiative coordinates and the collapse of dust in comoving coordinates. (paper)

  6. Naked singularities in four-dimensional string backgrounds

    International Nuclear Information System (INIS)

    Mohammedi, N.

    1993-04-01

    It is shown that gauged nonlinear sigma models can be always deformed by terms proportional to the field strength of the gauge fields (nonminimal gauging). These deformations can be interpreted as perturbations, by marginal operators, of conformal coset models. When applied to the SL(2, R)xSU(2)/U(1)xU(1)) WZWN model, a large class of four-dimensional curved spacetime backgrounds are obtained. In particular, a naked singularity may form at a time when the volume of the universe is different from zero. (orig.)

  7. Naked singularities are not singular in distorted gravity

    Energy Technology Data Exchange (ETDEWEB)

    Garattini, Remo, E-mail: Remo.Garattini@unibg.it [Università degli Studi di Bergamo, Facoltà di Ingegneria, Viale Marconi 5, 24044 Dalmine (Bergamo) (Italy); I.N.F.N. – sezione di Milano, Milan (Italy); Majumder, Barun, E-mail: barunbasanta@iitgn.ac.in [Indian Institute of Technology Gandhinagar, Ahmedabad, Gujarat 382424 (India)

    2014-07-15

    We compute the Zero Point Energy (ZPE) induced by a naked singularity with the help of a reformulation of the Wheeler–DeWitt equation. A variational approach is used for the calculation with Gaussian Trial Wave Functionals. The one loop contribution of the graviton to the ZPE is extracted keeping under control the UltraViolet divergences by means of a distorted gravitational field. Two examples of distortion are taken under consideration: Gravity's Rainbow and Noncommutative Geometry. Surprisingly, we find that the ZPE is no more singular when we approach the singularity.

  8. Naked singularities are not singular in distorted gravity

    Science.gov (United States)

    Garattini, Remo; Majumder, Barun

    2014-07-01

    We compute the Zero Point Energy (ZPE) induced by a naked singularity with the help of a reformulation of the Wheele-DeWitt equation. A variational approach is used for the calculation with Gaussian Trial Wave Functionals. The one loop contribution of the graviton to the ZPE is extracted keeping under control the UltraViolet divergences by means of a distorted gravitational field. Two examples of distortion are taken under consideration: Gravity's Rainbow and Noncommutative Geometry. Surprisingly, we find that the ZPE is no more singular when we approach the singularity.

  9. Naked singularities are not singular in distorted gravity

    International Nuclear Information System (INIS)

    Garattini, Remo; Majumder, Barun

    2014-01-01

    We compute the Zero Point Energy (ZPE) induced by a naked singularity with the help of a reformulation of the Wheeler–DeWitt equation. A variational approach is used for the calculation with Gaussian Trial Wave Functionals. The one loop contribution of the graviton to the ZPE is extracted keeping under control the UltraViolet divergences by means of a distorted gravitational field. Two examples of distortion are taken under consideration: Gravity's Rainbow and Noncommutative Geometry. Surprisingly, we find that the ZPE is no more singular when we approach the singularity

  10. Is it really naked? On cosmic censorship in string theory

    International Nuclear Information System (INIS)

    Frolov, Andrei V.

    2004-01-01

    We investigate the possibility of cosmic censorship violation in string theory using a characteristic double-null code, which penetrates horizons and is capable of resolving the spacetime all the way to the singularity. We perform high-resolution numerical simulations of the evolution of negative mass initial scalar field profiles, which were argued to provide a counterexample to cosmic censorship conjecture for AdS-asymptotic spacetimes in five-dimensional supergravity. In no instances formation of naked singularity is seen. Instead, numerical evidence indicates that black holes form in the collapse. Our results are consistent with earlier numerical studies, and explicitly show where the 'no black hole' argument breaks

  11. The starry room naked eye astronomy in the intimate universe

    CERN Document Server

    Schaaf, Fred

    2002-01-01

    This inspiring and enriching book, a collection of essays that evokes the beauty and wonder of the night sky, explains to beginning skywatchers how to find and where to look for specific celestial objects. Author Fred Schaaf, once described as a naturalist in the tradition of Henry David Thoreau and John Burroughs, reveals an intense love of his subject and a keen knowledge of the optimum ways of viewing astronomical phenomena with the naked eye. Schaaf not only describes such special sights as an eyelash-thin moon, a shooting star, streaking comets, and a lunar eclipse, but he also explains w

  12. ACTIVITY PATTERNS IN THE MOLE-RATS TACHYORYCTES ...

    African Journals Online (AJOL)

    Heilophoblus spends over 50 % of the day out of its nest, Tachyoryctes, ..... Surface foraging through an open hole and mole-hill formation could be directly ..... Heliophobius fed at irregular intervals throughout the day and night (Jarvis, ...

  13. Constraints on the structure of naked singularities in classical general relativity

    International Nuclear Information System (INIS)

    Newman, R.P.A.; Joshi, P.S.

    1988-01-01

    The known examples of naked singularities in general relativity are, in a certain sense, either gravitationally or causally innocuous. A cosmic censorship theorem is formulated and proved to the effect that this behaviour is characteristic of naked singularities in general spacetimes which do not deviate too far from spherical symmetry. copyright 1988 Academic Press, Inc

  14. Study of Biometric Identification Method Based on Naked Footprint

    Directory of Open Access Journals (Sweden)

    Raji Rafiu King

    2013-10-01

    Full Text Available The scale of deployment of biometric identity-verification systems has recently seen an enormous increase owing to the need for more secure and reliable way of identifying people. Footprint identification which can be defined as the measurement of footprint features for recognizing the identity of a user has surfaced recently. This study is based on a biometric personal identification method using static footprint features viz. friction ridge / texture and foot shape / silhouette. To begin with, naked footprints of users are captured; images then undergo pre processing followed by the extraction of two features; shape using Gradient Vector Flow (GVF) snake model and minutiae extraction respectively. Matching is then effected based on these two features followed by a fusion of these two results for either a reject or accept decision. Our shape matching feature is based on cosine similarity while the texture one is based on miniature score matching. The results from our research establish that the naked footprint is a credible biometric feature as two barefoot impressions of an individual match perfectly while that of two different persons shows a great deal of dissimilarity. Normal 0 false false false IN X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Doi: 10.12777/ijse.5.2.29-35 How to cite this article: King

  15. Naked Gold Nanoparticles and hot Electrons in Water.

    Science.gov (United States)

    Ghandi, Khashayar; Wang, Furong; Landry, Cody; Mostafavi, Mehran

    2018-05-08

    The ionizing radiation in aqueous solutions of gold nanoparticles, stabilized by electrostatic non-covalent intermolecular forces and steric interactions, with antimicrobial compounds, are investigated with picosecond pulse radiolysis techniques. Upon pulse radiolysis of an aqueous solution containing very low concentrations of gold nanoparticles with naked surfaces available in water (not obstructed by chemical bonds), a change to Cerenkov spectrum over a large range of wavelengths are observed and pre-solvated electrons are captured by gold nanoparticles exclusively (not by ionic liquid surfactants used to stabilize the nanoparticles). The solvated electrons are also found to decay rapidly compared with the decay kinetics in water. These very fast reactions with electrons in water could provide an enhanced oxidizing zone around gold nanoparticles and this could be the reason for radio sensitizing behavior of gold nanoparticles in radiation therapy.

  16. Naked singularity in the global structure of critical collapse spacetimes

    International Nuclear Information System (INIS)

    Frolov, Andrei V.; Pen, U.-L.

    2003-01-01

    We examine the global structure of scalar field critical collapse spacetimes using a characteristic double-null code. It can integrate past the horizon without any coordinate problems, due to the careful choice of constraint equations used in the evolution. The limiting sequence of sub- and supercritical spacetimes presents an apparent paradox in the expected Penrose diagrams, which we address in this paper. We argue that the limiting spacetime converges pointwise to a unique limit for all r>0, but not uniformly. The r=0 line is different in the two limits. We interpret that the two different Penrose diagrams differ by a discontinuous gauge transformation. We conclude that the limiting spacetime possesses a singular event, with a future removable naked singularity

  17. Trial watch: Naked and vectored DNA-based anticancer vaccines.

    Science.gov (United States)

    Bloy, Norma; Buqué, Aitziber; Aranda, Fernando; Castoldi, Francesca; Eggermont, Alexander; Cremer, Isabelle; Sautès-Fridman, Catherine; Fucikova, Jitka; Galon, Jérôme; Spisek, Radek; Tartour, Eric; Zitvogel, Laurence; Kroemer, Guido; Galluzzi, Lorenzo

    2015-05-01

    One type of anticancer vaccine relies on the administration of DNA constructs encoding one or multiple tumor-associated antigens (TAAs). The ultimate objective of these preparations, which can be naked or vectored by non-pathogenic viruses, bacteria or yeast cells, is to drive the synthesis of TAAs in the context of an immunostimulatory milieu, resulting in the (re-)elicitation of a tumor-targeting immune response. In spite of encouraging preclinical results, the clinical efficacy of DNA-based vaccines employed as standalone immunotherapeutic interventions in cancer patients appears to be limited. Thus, efforts are currently being devoted to the development of combinatorial regimens that allow DNA-based anticancer vaccines to elicit clinically relevant immune responses. Here, we discuss recent advances in the preclinical and clinical development of this therapeutic paradigm.

  18. Stationary spherical shells around Kerr-Newman naked singularities

    International Nuclear Information System (INIS)

    Zdenek Stuchlik; Stanislav Hledik

    1998-01-01

    It is shown that in the field of some Kerr-Newman naked singularities a stationary spherical shell of charged dust can exist, with the specific charge being the same for all particles of the dusty shell. Gravitational attractions acting on the particles are balanced by electromagnetic repulsion in such a way that the shell is stable against radial perturbations. Particles of the shell move along orbits with constant latitude and radius. Rotation of the shell is differential. The shell is corotating relative to static observers at infinity, but it is counter rotating relative to the family of locally non-rotating observers. No such a shell can exist in the field of Kerr-Newman black holes. (authors)

  19. Naked-eye sensor for rapid determination of mercury ion.

    Science.gov (United States)

    Liu, Jing; Wu, Dapeng; Yan, Xiaohui; Guan, Yafeng

    2013-11-15

    A naked-eye paper sensor for rapid determination of trace mercury ion in water samples was designed and demonstrated. The mercury-sensing rhodamine B thiolactone was immobilized in silica matrices and the silica matrices were impregnated firmly and uniformly in the filter paper. As water samples flow through the filter paper, the membrane color will change from white to purple red, which could be observed obviously with naked eye, when concentration of mercury ions equals to or exceeds 10nM, the maximum residue level in drinking water recommended by U.S. EPA. The color change can also be recorded by a flatbed scanner and then digitized, reducing the detection limit of Hg(2+) down to 1.2 nM. Moreover, this method is extremely specific for Hg(2+) and shows a high tolerance ratio of interferent coexisting ions. The presence of Na(+) (2 mM), K(+) (2 mM), Fe(3+) (0.1 mM), Zn(2+) (0.1 mM), Mg(2+) (0.1 mM), Ni(2+) (50 μM), Co(2+) (50 μM), Cd(2+) (50 μM), Pb(2+) (50 μM), Cu(2+) (50 μM) and Ag(+) (3.5 μM) did not interfere with the detection of Hg(2+) (25 nM). Finally, the present method was applied in the detection of Hg(2+) in mineral water, tap water and pond water. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Agronomic performance of naked oat (Avena nuda L. and faba bean intercropping

    Directory of Open Access Journals (Sweden)

    Agnieszka Klimek-Kopyra

    2015-06-01

    Full Text Available The most common cereals for faba bean (Vicia faba L. used in intercrops is conventional oat (Avena sativa L. An alternative to oat may be naked oat (Avena nuda L., whose oil content and quality is double. Here, intercropping of naked oat with two different faba bean cultivars (determinate-high tannin and indeterminate-low tannin was compared with sole crops of each species in 2006-2008. The treatments were: sole naked oat at 500 kernels m², indeterminate sole faba bean at 50 seeds m², determinate sole faba bean at 70 seeds m², and an additive series of 25%, 50%, and 75% of faba bean seeding rate mixed with the naked oat seeding rate. Our results demonstrated that intercropping increased the Land Equivalent Ratio by +3% to +9% over sole cropping. Raising the faba bean seeding rate in a mixture from 25% to 75% reduced oat grain yield from 630 (determinate cultivar to 760 kg ha-1 (indeterminate cultivar but increased faba bean grain yield from 760 kg ha-1. Higher yield and leaf area index (LAI and photosynthetically active radiation (PAR values show that the indeterminate cultivar of faba bean is more suitable in mixture with naked oat. The high value of competition index (CR > 1 indicates domination and aggressiveness of faba bean towards naked oat. Regardless of cultivar type, mixture of faba bean with naked oat is less productive than pure sowing.

  1. Incisors as digging tools in molerats (Bathyergidae)

    African Journals Online (AJOL)

    1998-03-26

    Xa and Vb) at which the upper and lower incisors (lines a- ..... JARVIS. JU.M., BENNETT. N.C. 1991. Introducing the Alriean mole-rats (family Bathyergidae). In: The biology of the naked mole-rat: 66 - 96. (Eds) Sherman. R. W ..

  2. Rapid micromotor-based naked-eye immunoassay.

    Science.gov (United States)

    de Ávila, Berta Esteban-Fernández; Zhao, Mingjiao; Campuzano, Susana; Ricci, Francesco; Pingarrón, José M; Mascini, Marcello; Wang, Joseph

    2017-05-15

    A dynamic micromotor-based immunoassay, exemplified by cortisol detection, based on the use of tubular micromotors functionalized with a specific antibody is described. The use of antibody-functionalized micromotors offers huge acceleration of both direct and competitive cortisol immunoassays, along with greatly enhanced sensitivity of direct and competitive immunoassays. The dramatically improved speed and sensitivity reflect the greatly increased likelihood of antibody-cortisol contacts and fluid mixing associated with the dynamic movement of these microtube motors and corresponding bubble generation that lead to a highly efficient and rapid recognition process. Rapid naked-eye detection of cortisol in the sample is achieved in connection to use of horseradish peroxidase (HRP) tag and TMB/H 2 O 2 system. Key parameters of the competitive immunoassay (e.g., incubation time and reaction volume) were optimized. This fast visual micromotor-based sensing approach enables "on the move" specific detection of the target cortisol down to 0.1μgmL -1 in just 2min, using ultrasmall (50µL) sample volumes. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Seeing Beyond the Naked Eye in a Planetarium

    Science.gov (United States)

    Fairall, A.

    2005-12-01

    I have a philosophy that the traditional naked-eye sky, as usually shown in planetariums, should only be an introductory step in portraying the Universe. Consequently, over the years I have produced 'inter alia' various versions of an enhanced Milky Way (the latest based on Axel Mellenger's panorama), the extragalactic sky and the radio sky for projection on planetarium domes. I also put together a three-dimensional planetarium show-the audience being equipped with ChromDepth(tm) spectacles- which stepped from the Solar System to the cosmic microwave background. The advent of digital technology now makes all this much easier. Currently, Labyrinth, a visualization program developed in-house, serves much the same function as the Hayden Planetarium's Partiview, but also permits rendering and fl y-throughs of large-scale structures. It allows viewers to explore local cosmography. Labyrinth can produce images that operate with the 3-D spectacles; we have also produced a version of Partiview that does the same.

  4. Naked Hair Shafts as a Marker of Cicatricial Alopecia.

    Science.gov (United States)

    Doytcheva, Kristina; Tan, Timothy; Guitart, Joan; Gerami, Pedram; Yazdan, Pedram

    2018-07-01

    Naked hair shafts (NHS) are free-floating hair shafts devoid of surrounding epithelium, supporting structures, and/or embedded in inflammation that may result from destruction of hair follicles by scarring processes such as inflammation and fibroplasia. Extensive examination of NHS has not been performed in scalp biopsies of alopecia. We retrospectively evaluated 622 scalp biopsies of alopecia [345 cicatricial alopecias (central centrifugal cicatricial alopecia, lichen planopilaris, discoid lupus erythematosus, acne keloidalis nuchae, and folliculitis decalvans] and 277 non-cicatricial alopecias [alopecia areata, androgenic alopecia, telogen effluvium, and psoriatic alopecia)] for the presence of NHS. NHS occurred in 0.72% (2/277) of non-cicatricial alopecias (1/102 of alopecia areata, 1/150 of androgenic alopecia, 0/17 of telogen effluvium, and 0/8 of psoriatic alopecia) and 20% (72/345) of cicatricial alopecias (27/118 of central centrifugal cicatricial alopecia, 29/109 of lichen planopilaris, 2/75 of discoid lupus erythematosus, 11/16 of acne keloidalis nuchae, and 3/27 of folliculitis decalvans). The presence of NHS was significantly increased in cicatricial alopecias in comparison with non-cicatricial alopecias; P value <0.0001. Among the cicatricial alopecias, 26% (92/345) had mild inflammation and/or fibrosis, of which 9% (9/92) had NHS. There were 73% (253/345) that had moderate to severe inflammation and/or fibrosis, of which 24% (63/253) had NHS, indicating that as the severity of inflammation and fibrosis increases, so does the presence of NHS. NHS rarely occurs in non-cicatricial alopecias. This variation may result from destruction of hair follicles by the inflammatory and scarring processes. The presence of NHS may be a useful adjunctive histopathologic feature in the diagnosis of cicatricial alopecia.

  5. Stemcell Information: SKIP000887 [SKIP Stemcell Database[Archive

    Lifescience Database Archive (English)

    Full Text Available NICATIONS 2015 7 11471 ... http://www.ncbi.nlm.nih.gov/pubmed/27161380 ... ...Tumour resistance in induced pluripotent stem cells derived from naked mole-rats. Shingo Miyawaki, Hideyuki Okano et al. NATURE COMMU

  6. Proč rypoši nestárnou?

    OpenAIRE

    Jelínková, Alena

    2016-01-01

    Naked mole rat and blind mole rat are useful model organisms for human age-associated diaseases studies. Unlike human, their long lifespan is not accompanied by physical health impairment. In both species, the genes involved in aging process or carcinogenesis are under positive selection or their regulation differs from the regulatory pattern known in other rodents or human. Some genes are present in higher number of copies, missing or entirely new and not observed in other organisms. In nake...

  7. Naked-eye 3D imaging employing a modified MIMO micro-ring conjugate mirrors

    Science.gov (United States)

    Youplao, P.; Pornsuwancharoen, N.; Amiri, I. S.; Thieu, V. N.; Yupapin, P.

    2018-03-01

    In this work, the use of a micro-conjugate mirror that can produce the 3D image incident probe and display is proposed. By using the proposed system together with the concept of naked-eye 3D imaging, a pixel and a large volume pixel of a 3D image can be created and displayed as naked-eye perception, which is valuable for the large volume naked-eye 3D imaging applications. In operation, a naked-eye 3D image that has a large pixel volume will be constructed by using the MIMO micro-ring conjugate mirror system. Thereafter, these 3D images, formed by the first micro-ring conjugate mirror system, can be transmitted through an optical link to a short distance away and reconstructed via the recovery conjugate mirror at the other end of the transmission. The image transmission is performed by the Fourier integral in MATLAB and compares to the Opti-wave program results. The Fourier convolution is also included for the large volume image transmission. The simulation is used for the manipulation, where the array of a micro-conjugate mirror system is designed and simulated for the MIMO system. The naked-eye 3D imaging is confirmed by the concept of the conjugate mirror in both the input and output images, in terms of the four-wave mixing (FWM), which is discussed and interpreted.

  8. The fields of a naked singularity and a black hole in mutual equilibrium

    Science.gov (United States)

    Paolino, Armando; Pizzi, Marco

    2008-01-01

    Recently Alekseev and Belinski have presented a new exact solution of the Einstein-Maxwell equation which describes two Reissner-Nordstrom (RN) sources in reciprocal equilibrium (no struts nor strings) one source is a naked singularity, the other is a black hole. In this paper we use the Alekseev-Belinki solution in the special case in which the charge of the black hole is zero-therefore we have a naked singularity near a neutral black hole. We give the plots of the electric force lines in both the cases in which the naked singularity has a mass comparable with the black hole and in which it is much smaller. The analysis of this latter case confirm the goodness of the Hanni-Ruffini approximation.

  9. Intrathecal injection of naked plasmid DNA provides long-term expression of secreted proteins.

    Science.gov (United States)

    Hughes, Travis S; Langer, Stephen J; Johnson, Kirk W; Chavez, Raymond A; Watkins, Linda R; Milligan, Erin D; Leinwand, Leslie A

    2009-01-01

    Therapeutic benefit has been reported to result from intrathecal (i.t.) injection of transgene vectors, including naked DNA. However, most studies using naked DNA have measured only the transgene expression of intracellular proteins. Here we demonstrate that i.t. injection of naked DNA can result in long-term expression of secreted proteins. Plasmids expressing either secreted alkaline phosphatase (SEAP) or human interleukin-10 (hIL-10) were injected into the i.t. space in rats, and transgene products were repeatedly measured in the cerebrospinal fluid (CSF). Both SEAP and hIL-10 were maximal at 1 and 2 days after the injection and still detectable at 4 months. The utilization of a plasmid having two features that are hypothesized to increase gene expression (matrix attachment regions (MARs) and lack of CpG dinucleotides) resulted in a significant increase in gene expression. Reinjection of SEAP or hIL-10 plasmids after 4 months significantly increased protein levels at 1 and 14 days after the reinjection. SEAP was uniformly distributed between the DNA delivery site (approximately vertebral level T13) and the lumbar puncture site (L5/L6 inter-vertebral space), was reduced at the cisterna magna, and was detectable, though at much lower levels, in serum. These data suggest that naked DNA has the potential to be used as a therapeutic tool for applications that require long-term release of transgenes into the CSF.

  10. Virtually naked: virtual environment reveals sex-dependent nature of skin disclosure.

    Directory of Open Access Journals (Sweden)

    Anna M Lomanowska

    Full Text Available The human tendency to reveal or cover naked skin reflects a competition between the individual propensity for social interactions related to sexual appeal and interpersonal touch versus climatic, environmental, physical, and cultural constraints. However, due to the ubiquitous nature of these constraints, isolating on a large scale the spontaneous human tendency to reveal naked skin has remained impossible. Using the online 3-dimensional virtual world of Second Life, we examined spontaneous human skin-covering behavior unhindered by real-world climatic, environmental, and physical variables. Analysis of hundreds of avatars revealed that virtual females disclose substantially more naked skin than virtual males. This phenomenon was not related to avatar hypersexualization as evaluated by measurement of sexually dimorphic body proportions. Furthermore, analysis of skin-covering behavior of a population of culturally homogeneous avatars indicated that the propensity of female avatars to reveal naked skin persisted despite explicit cultural norms promoting less revealing attire. These findings have implications for further understanding how sex-specific aspects of skin disclosure influence human social interactions in both virtual and real settings.

  11. Papapetrou's naked singularity is a strong curvature singularity

    Energy Technology Data Exchange (ETDEWEB)

    Hollier, G.P.

    1986-11-01

    Following Papapetrou (1985, a random walk in General Relativity ed. J. Krishna-Rao (New Delhi: Wiley Eastern)), a spacetime with a naked singularity is analysed. This singularity is shown to be a strong curvature singularity and thus a counterexample to a censorship conjecture.

  12. Oviposition and egg quality traits of dwarf and naked neck layers ...

    African Journals Online (AJOL)

    Oviposition and egg quality traits were studied in dwarf and naked neck layers in Maputo (Mozambique) during a 28-d period at 35 weeks of age. Birds were caged individually in a laying house with natural light and ventilation. Average daylight length during the study was 11.2 hr and minimum and maximum temperature ...

  13. effects of naked-neck and frizzle genes on growth performance and ...

    African Journals Online (AJOL)

    User

    cockerels (birds) do not reach their full genetic potential in terms of growth, body weight or carcass yields because their feathers hinder the dissipation of their excessively produced inter- nal heat. It is against this background that the use of major heat-tolerant genes like naked- neck and frizzle is advocated (Horst and.

  14. The Dual Role of an ESCRT-0 Component HGS in HBV Transcription and Naked Capsid Secretion

    Science.gov (United States)

    Chou, Shu-Fan; Tsai, Ming-Lin; Huang, Jyun-Yuan; Chang, Ya-Shu; Shih, Chiaho

    2015-01-01

    The Endosomal Sorting Complex Required for Transport (ESCRT) is an important cellular machinery for the sorting and trafficking of ubiquitinated cargos. It is also known that ESCRT is required for the egress of a number of viruses. To investigate the relationship between ESCRT and hepatitis B virus (HBV), we conducted an siRNA screening of ESCRT components for their potential effect on HBV replication and virion release. We identified a number of ESCRT factors required for HBV replication, and focused our study here on HGS (HRS, hepatocyte growth factor-regulated tyrosine kinase substrate) in the ESCRT-0 complex. Aberrant levels of HGS suppressed HBV transcription, replication and virion secretion. Hydrodynamic delivery of HGS in a mouse model significantly suppressed viral replication in the liver and virion secretion in the serum. Surprisingly, overexpression of HGS stimulated the release of HBV naked capsids, irrespective of their viral RNA, DNA, or empty contents. Mutant core protein (HBc 1–147) containing no arginine-rich domain (ARD) failed to secrete empty virions with or without HGS. In contrast, empty naked capsids of HBc 1–147 could still be promoted for secretion by HGS. HGS exerted a strong positive effect on the secretion of naked capsids, at the expense of a reduced level of virions. The association between HGS and HBc appears to be ubiquitin-independent. Furthermore, HBc is preferentially co-localized with HGS near the cell periphery, instead of near the punctate endosomes in the cytoplasm. In summary, our work demonstrated the importance of an optimum level of HGS in HBV propagation. In addition to an effect on HBV transcription, HGS can diminish the pool size of intracellular nucleocapsids with ongoing genome maturation, probably in part by promoting the secretion of naked capsids. The secretion routes of HBV virions and naked capsids can be clearly distinguished based on the pleiotropic effect of HGS involved in the ESCRT-0 complex. PMID

  15. The Dual Role of an ESCRT-0 Component HGS in HBV Transcription and Naked Capsid Secretion.

    Directory of Open Access Journals (Sweden)

    Shu-Fan Chou

    2015-10-01

    Full Text Available The Endosomal Sorting Complex Required for Transport (ESCRT is an important cellular machinery for the sorting and trafficking of ubiquitinated cargos. It is also known that ESCRT is required for the egress of a number of viruses. To investigate the relationship between ESCRT and hepatitis B virus (HBV, we conducted an siRNA screening of ESCRT components for their potential effect on HBV replication and virion release. We identified a number of ESCRT factors required for HBV replication, and focused our study here on HGS (HRS, hepatocyte growth factor-regulated tyrosine kinase substrate in the ESCRT-0 complex. Aberrant levels of HGS suppressed HBV transcription, replication and virion secretion. Hydrodynamic delivery of HGS in a mouse model significantly suppressed viral replication in the liver and virion secretion in the serum. Surprisingly, overexpression of HGS stimulated the release of HBV naked capsids, irrespective of their viral RNA, DNA, or empty contents. Mutant core protein (HBc 1-147 containing no arginine-rich domain (ARD failed to secrete empty virions with or without HGS. In contrast, empty naked capsids of HBc 1-147 could still be promoted for secretion by HGS. HGS exerted a strong positive effect on the secretion of naked capsids, at the expense of a reduced level of virions. The association between HGS and HBc appears to be ubiquitin-independent. Furthermore, HBc is preferentially co-localized with HGS near the cell periphery, instead of near the punctate endosomes in the cytoplasm. In summary, our work demonstrated the importance of an optimum level of HGS in HBV propagation. In addition to an effect on HBV transcription, HGS can diminish the pool size of intracellular nucleocapsids with ongoing genome maturation, probably in part by promoting the secretion of naked capsids. The secretion routes of HBV virions and naked capsids can be clearly distinguished based on the pleiotropic effect of HGS involved in the ESCRT-0 complex.

  16. Seasonal abundances of naked amoebae in biofilms on shells of zebra mussels (Dreissena polymorpha) with comparative data from rock scrapings.

    Science.gov (United States)

    Bischoff, Paul J; Wetmore, Scott

    2009-01-01

    In North America, zebra mussels (Dreissena polymorpha) are notoriously known as invasive species. The abundance of naked amoebae sampled from the shells of zebra mussels was compared with abundances from rock scrapings at approximately monthly intervals for 1 year. The sites were 2 km apart along the same shoreline. No significant difference in abundance of naked amoebae (F = 1.44; P naked amoebae in winter, followed by peaks in early spring. The percent encysted increased from a low of 1% in the summer to 80% in early winter.

  17. Performance and Heterosis of Indigenous Chicken Crossbreed (Naked Neck x Frizzled Feather In The Humid Tropics

    Directory of Open Access Journals (Sweden)

    Jeremiah Monday Nwenya

    2017-12-01

    Full Text Available Forty-four (44 birds (about 50 weeks old male and female inbred naked necked and frizzle feathered chickens were crossed to generate F1 crossbred chicken that were used to evaluate the performance and heterosis effects. Data taken on 180 chicks (97 NN and 83 FF day-old chick weight (BWT0, body weight (BWT, daily average feed intake (AFI, feed conversion ratio (FCR, brooding and rearing mortalities, linear body measurements (LBM: body length, wing length, keel length, shank length and breast width were used to estimate heterosis and performance of F1 progenies. Results of the experiment showed positive heterosis with significant differences among the F1 progenies over their parents in body weight, average feed intake and feed conversion ratio. The reciprocal cross (i.e. frizzle feather rooster x naked neck hen showed a significant improvement in their performances genetically, explaining that better results are achieved through crossbreeding of these indigenous breeds. With reference to their body linear parameters, the reciprocal cross of naked neck and frizzle feathered chickens developed higher body length, whereas the main crosses performed better in their wing length, keel length, shank length and body width respectively, mainly after 8 weeks suggesting that earlier performance was attributable to maternal influences.

  18. Optical effects related to Keplerian discs orbiting Kehagias-Sfetsos naked singularities

    Science.gov (United States)

    Stuchlík, Zdeněk; Schee, Jan

    2014-10-01

    We demonstrate possible optical signatures of the Kehagias-Sfetsos (KS) naked singularity spacetimes representing a spherically symmetric vacuum solution of the modified Hořava gravity. In such spacetimes, accretion structures significantly different from those present in standard black hole spacetimes occur due to the ‘antigravity’ effect, which causes an internal static sphere surrounded by Keplerian discs. We focus our attention on the optical effects related to the Keplerian accretion discs, constructing the optical appearance of the Keplerian discs, the spectral continuum due to their thermal radiation, and the spectral profiled lines generated in the innermost parts of such discs. The KS naked singularity signature is strongly encoded in the characteristics of predicted optical effects, especially in cases where the spectral continuum and spectral lines are profiled by the strong gravity of the spacetimes due to the vanishing region of the angular velocity gradient influencing the effectiveness of the viscosity mechanism. We can conclude that optical signatures of KS naked singularities can be well distinguished from the signatures of standard black holes.

  19. Optical effects related to Keplerian discs orbiting Kehagias–Sfetsos naked singularities

    International Nuclear Information System (INIS)

    Stuchlík, Zdeněk; Schee, Jan

    2014-01-01

    We demonstrate possible optical signatures of the Kehagias–Sfetsos (KS) naked singularity spacetimes representing a spherically symmetric vacuum solution of the modified Hořava gravity. In such spacetimes, accretion structures significantly different from those present in standard black hole spacetimes occur due to the ‘antigravity’ effect, which causes an internal static sphere surrounded by Keplerian discs. We focus our attention on the optical effects related to the Keplerian accretion discs, constructing the optical appearance of the Keplerian discs, the spectral continuum due to their thermal radiation, and the spectral profiled lines generated in the innermost parts of such discs. The KS naked singularity signature is strongly encoded in the characteristics of predicted optical effects, especially in cases where the spectral continuum and spectral lines are profiled by the strong gravity of the spacetimes due to the vanishing region of the angular velocity gradient influencing the effectiveness of the viscosity mechanism. We can conclude that optical signatures of KS naked singularities can be well distinguished from the signatures of standard black holes. (paper)

  20. Burrow architecture, family composition and habitat characteristics of the largest social African mole-rat: the giant mole-rat constructs really giant burrow systems

    Czech Academy of Sciences Publication Activity Database

    Šumbera, R.; Mazoch, V.; Patzenhauerová, Hana; Lövy, M.; Šklíba, J.; Bryja, Josef; Burda, H.

    2012-01-01

    Roč. 57, č. 2 (2012), s. 121-130 ISSN 0001-7051 R&D Projects: GA AV ČR IAA601410802 Institutional research plan: CEZ:AV0Z60930519 Keywords : Fukomys mechowii * subterranean rodent * burrow system * kin structure * Bathyergidae Subject RIV: EG - Zoology Impact factor: 0.949, year: 2012

  1. Naked-Eye Detection of Glucose in Saliva with Bienzymatic Paper-Based Sensor

    Directory of Open Access Journals (Sweden)

    Luis A. Santana-Jiménez

    2018-04-01

    Full Text Available The high incidence of Diabetes Mellitus in low-income regions has promoted the development of low-cost alternatives to replace blood-based procedures. In this work, we present a bienzymatic paper-based sensor suitable for the naked-eye detection of glucose in saliva samples. The sensor was obtained by a stamping procedure and modified with chitosan to improve the colorimetric readout. The bienzymatic reaction of GOx-HRP coupled with 2,4,6-tribromo-3-hydroxy benzoic acid was applied for the detection of glucose within a range from 0 to 180 mgdL−1 in buffer and artificial saliva solutions. The visual readout was perceived by the naked eye and registered with an office scanner to evaluate the analytical performance. The results showed a limit of detection of 0.37 mgdL−1 (S/N = 3 with an R.S.D. of 1.69% and a linear range from 1 to 22.5 mgdL−1 with an R2 of 0.99235. The analysis of human saliva samples was performed without pre-processing, achieving recoveries from 92 to 114%. The naked-eye detection was evaluated under two different light settings, showing average recoveries of 108.58 and 90.65% for standard and low illumination. The proposed device showed potential for easy-to-use, sensitive, low-cost, fast, and device-free detection of salivary glucose suitable for untrained personnel operation and limited facilities.

  2. Dew inspired breathing-based detection of genetic point mutation visualized by naked eye

    Science.gov (United States)

    Xie, Liping; Wang, Tongzhou; Huang, Tianqi; Hou, Wei; Huang, Guoliang; Du, Yanan

    2014-09-01

    A novel label-free method based on breathing-induced vapor condensation was developed for detection of genetic point mutation. The dew-inspired detection was realized by integration of target-induced DNA ligation with rolling circle amplification (RCA). The vapor condensation induced by breathing transduced the RCA-amplified variances in DNA contents into visible contrast. The image could be recorded by a cell phone for further or even remote analysis. This green assay offers a naked-eye-reading method potentially applied for point-of-care liver cancer diagnosis in resource-limited regions.

  3. Naked eye picometer resolution in a Michelson interferometer using conjugated twisted beams.

    Science.gov (United States)

    Emile, Olivier; Emile, Janine

    2017-01-15

    Michelson interferometry is one of the most widely used techniques for accuracy measurements. Its main characteristic feature is to infer a displacement in one of the arms of the interferometer from a phase measurement. Two different twisted beams, also called vortex beams, with opposite twisted rotations in each arm of the interferometer interfere in a daisy flower-like pattern. The number of petals is twice the topological charge. Their position depends on the relative phase of the beams. Naked eye detection of 44 pm displacements is achieved. The sensitivity of such an interferometer together with possible further improvements, and applications are then discussed.

  4. A preliminary phylogeny of the Palearctic naked-toed geckos (Reptilia: Squamata: Gekkonidae) with taxonomic implications.

    Science.gov (United States)

    Bauer, Aaron M; Masroor, Rafaqat; Titus-McQuillan, James; Heinicke, Matthew P; Daza, Juan D; Jackman, Todd R

    2013-01-08

    Palearctic naked-toed geckos are a group of gekkonid geckos that range from North Africa to northern India and western China, with their greatest diversity in Iran and Pakistan. Relationships among the constituent genera remain incompletely resolved and the monophyly of key genera remains unverified. Further, competing classifications are in current use and many species have been allocated to different genera by different authors. We used both mitochondrial (ND2) and nuclear genes (RAG1, PDC) to explore relationships among representatives of all but one genus in the group (Rhinogecko), including four genera not previously included in phylogenetic analyses (Asiocolotes, Altigekko, Indogekko, and Siwaligekko). Siwaligekko (and presumably other Tibeto-Himalayan species often referred to Cyrtopodion) are more closely related to tropical Asian Cyrtodactylus than to Palearctic naked-toed geckos. Sampled species of Asiocolotes and Altigekko are sister taxa, but both genera are here considered junior subjective synonyms of Altiphylax. Cyrtopodion sensu lato is non-monophyletic; Mediodactylus and Tenuidactylus, which have variably been considered as subgenera or synonyms of Cyrtopodion are both valid genera. Indogekko is embedded within Cyrtopodion and is here treated as a subgenus. Bunopus and Crossobamon are closely related to one-another, and with Agamura are interdigitated among taxa previously assigned to Cyrtopodion. Our data confirm the previous identification of a Saharo-Arabian Stenodactylus/Tropiocolotes/Pseudoceramodactylus clade and verify that Microgecko and Alsophylax are not members of the main clade of Palearctic naked-toed geckos. Osteological differences between Tropiocolotes and Microgecko, formerly treated as congeneric, are discussed and illustrated. The divergence between Cyrtodactylus and the Palearctic naked-toed clade predates the initial collision of the Indian and Eurasian plates, but deeper divergences within both groups are

  5. In vivo silencing of alpha-synuclein using naked siRNA

    Directory of Open Access Journals (Sweden)

    Charisse Klaus

    2008-11-01

    Full Text Available Abstract Background Overexpression of α-synuclein (SNCA in families with multiplication mutations causes parkinsonism and subsequent dementia, characterized by diffuse Lewy Body disease post-mortem. Genetic variability in SNCA contributes to risk of idiopathic Parkinson's disease (PD, possibly as a result of overexpression. SNCA downregulation is therefore a valid therapeutic target for PD. Results We have identified human and murine-specific siRNA molecules which reduce SNCA in vitro. As a proof of concept, we demonstrate that direct infusion of chemically modified (naked, murine-specific siRNA into the hippocampus significantly reduces SNCA levels. Reduction of SNCA in the hippocampus and cortex persists for a minimum of 1 week post-infusion with recovery nearing control levels by 3 weeks post-infusion. Conclusion We have developed naked gene-specific siRNAs that silence expression of SNCA in vivo. This approach may prove beneficial toward our understanding of the endogenous functional equilibrium of SNCA, its role in disease, and eventually as a therapeutic strategy for α-synucleinopathies resulting from SNCA overexpression.

  6. In vivo silencing of alpha-synuclein using naked siRNA

    Science.gov (United States)

    Lewis, Jada; Melrose, Heather; Bumcrot, David; Hope, Andrew; Zehr, Cynthia; Lincoln, Sarah; Braithwaite, Adam; He, Zhen; Ogholikhan, Sina; Hinkle, Kelly; Kent, Caroline; Toudjarska, Ivanka; Charisse, Klaus; Braich, Ravi; Pandey, Rajendra K; Heckman, Michael; Maraganore, Demetrius M; Crook, Julia; Farrer, Matthew J

    2008-01-01

    Background Overexpression of α-synuclein (SNCA) in families with multiplication mutations causes parkinsonism and subsequent dementia, characterized by diffuse Lewy Body disease post-mortem. Genetic variability in SNCA contributes to risk of idiopathic Parkinson's disease (PD), possibly as a result of overexpression. SNCA downregulation is therefore a valid therapeutic target for PD. Results We have identified human and murine-specific siRNA molecules which reduce SNCA in vitro. As a proof of concept, we demonstrate that direct infusion of chemically modified (naked), murine-specific siRNA into the hippocampus significantly reduces SNCA levels. Reduction of SNCA in the hippocampus and cortex persists for a minimum of 1 week post-infusion with recovery nearing control levels by 3 weeks post-infusion. Conclusion We have developed naked gene-specific siRNAs that silence expression of SNCA in vivo. This approach may prove beneficial toward our understanding of the endogenous functional equilibrium of SNCA, its role in disease, and eventually as a therapeutic strategy for α-synucleinopathies resulting from SNCA overexpression. PMID:18976489

  7. FARINOGRAPHIC EVALUATION OF WHEAT DOUGH ENRICHED WITH INULIN, NAKED BARLEY, MALT AND POTEX ADDITION

    Directory of Open Access Journals (Sweden)

    Marián Tokár

    2015-02-01

    Full Text Available One of the most important biological substances consumed in insufficient quantity is fibre that is often deficient in the diet. In general, dietary fibre is edible part of plants, or similar carbohydrates, that are resistant to digestion and absorption in the small intestine. Nowadays, there are many sources of fibre available for bakery industry, whether through addition of non-traditional bread cereals or through isolated form as additives. Except to supposed increase the nutritional value of bakery products with added fiber and raw materials containing fiber is necessary to think about their technological quality and rheological properties of dough. The aim of this experimental work was to investigate the effect of the addition of selected polysaccharides (inulin, Potex - potato fiber and non-bakery crops (naked barley, malt containing significant polysaccharides used in the mixture with wheat flour type T-650 in different ratios on the basis of farinographic evaluations. Based on the results of rheological measurements we found out that quality of dough was deteriorating proportionally to the amount of used additives. On the other hand, positively could be considered the increase of water absorption with addition of Potex and naked barley.

  8. Productive performance of naked neck chickens that were fed leaf meal shrubs

    Directory of Open Access Journals (Sweden)

    Santos M Herrera G.

    2015-12-01

    Full Text Available Objective. To compare the productive performance of naked neck chickens (phases of initiation, growth and final that were fed meals Gliricidia sepium, Cajanus cajan and Morus alba leaves. Materials and methods. 192 chickens, 1-84 days of age were distributed in a randomized block design with three experimental groups (5% of shrub in the diet, 48 animals/ group, eight replicates/ treatment, six animals/ reply and three animals/ sex in each replicate were used. The control group consumed diet based on corn and soybeans. They were reared on floor. Weighed every seven days. Weight gain, voluntary intake, conversion, balance and efficiency of feed utilization were calculated. Results. The highest total feed intake and average daily gain in rearing were 37.43g 9509.96 g respectively for M. alba (p<0.05, which also presented the best efficiency of energy and protein. Meanwhile, G. sepium showed the lowest values. Conclusions. It is possible to replace 5% of corn and soy in the diet of naked neck chickens, with the inclusion of leaf meal M. alba and get a favorable productive behavior.

  9. Ultra-low-energy (<10 eV/u) ion beam bombardment effect on naked DNA

    Energy Technology Data Exchange (ETDEWEB)

    Thopan, P. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thongkumkoon, P. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Prakrajang, K. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Faculty of Science, Maejo University, Chiang Mai 50290 (Thailand); Suwannakachorn, D. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, L.D., E-mail: yuld@thep-center.org [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

    2014-05-01

    Highlights: • Decelerated ultra-low energy ion beam bombarded naked DNA. • DNA form change induced by ion bombardment was investigated. • N-ion bombardment at 32 eV induced DNA single and double strand breaks. • Ar-ion bombardment at a-few-hundreds eV induced DNA single strand break. - Abstract: Since ion energy deposition in the ion-bombarded materials dominantly occurs in the low-energy range, it is very interesting to know effects from ultra-low-energy ion interaction with DNA for understanding ion-beam-induced genetic mutation. Tens-keV Ar- and N-ion beams were decelerated to ultra-low energy ranging from 20 to 100 eV, or only a few to 10 eV/u, to bombard naked plasmid DNA. The bombarded DNA was analyzed using gel electrophoresis for DNA form changes. The original DNA supercoiled form was found to change to relaxed and linear forms, indicating single or double strand breaks after bombarded by tens-eV ion beam. N-ion beam was found more effective in inducing DNA change and mutation than Ar-ion beam. The study demonstrated that the ion bombardment with energy as low as several-tens eV was able to break DNA strands and thus potentially to cause genetic modification of biological cells. The experimental results were discussed in terms of direct atomic collision between the ions and DNA atoms.

  10. Very low-energy and low-fluence ion beam bombardment of naked plasmid DNA

    International Nuclear Information System (INIS)

    Norarat, R.; Semsang, N.; Anuntalabhochai, S.; Yu, L.D.

    2009-01-01

    Ion beam bombardment of biological organisms has been recently applied to mutation breeding of both agricultural and horticultural plants. In order to explore relevant mechanisms, this study employed low-energy ion beams to bombard naked plasmid DNA. The study aimed at simulation of the final stage of the process of the ion beam bombardment of real cells to check whether and how very low-energy and low-fluence of ions can induce mutation. Argon and nitrogen ions at 5 keV and 2.5 keV respectively bombarded naked plasmid DNA pGFP to very low-fluences, an order of 10 13 ions/cm 2 . Subsequently, DNA states were analyzed using electrophoresis. Results provided evidences that the very low-energy and low-fluence ion bombardment indeed altered the DNA structure from supercoil to short linear fragments through multiple double strand breaks and thus induced mutation, which was confirmed by transfer of the bombarded DNA into bacteria Escherichia coli and subsequent expression of the marker gene.

  11. Ultra-low-energy (<10 eV/u) ion beam bombardment effect on naked DNA

    International Nuclear Information System (INIS)

    Thopan, P.; Thongkumkoon, P.; Prakrajang, K.; Suwannakachorn, D.; Yu, L.D.

    2014-01-01

    Highlights: • Decelerated ultra-low energy ion beam bombarded naked DNA. • DNA form change induced by ion bombardment was investigated. • N-ion bombardment at 32 eV induced DNA single and double strand breaks. • Ar-ion bombardment at a-few-hundreds eV induced DNA single strand break. - Abstract: Since ion energy deposition in the ion-bombarded materials dominantly occurs in the low-energy range, it is very interesting to know effects from ultra-low-energy ion interaction with DNA for understanding ion-beam-induced genetic mutation. Tens-keV Ar- and N-ion beams were decelerated to ultra-low energy ranging from 20 to 100 eV, or only a few to 10 eV/u, to bombard naked plasmid DNA. The bombarded DNA was analyzed using gel electrophoresis for DNA form changes. The original DNA supercoiled form was found to change to relaxed and linear forms, indicating single or double strand breaks after bombarded by tens-eV ion beam. N-ion beam was found more effective in inducing DNA change and mutation than Ar-ion beam. The study demonstrated that the ion bombardment with energy as low as several-tens eV was able to break DNA strands and thus potentially to cause genetic modification of biological cells. The experimental results were discussed in terms of direct atomic collision between the ions and DNA atoms

  12. Naked gene therapy of hepatocyte growth factor for dextran sulfate sodium-induced colitis in mice

    International Nuclear Information System (INIS)

    Kanbe, Takamasa; Murai, Rie; Mukoyama, Tomoyuki; Murawaki, Yoshiyuki; Hashiguchi, Ko-ichi; Yoshida, Yoko; Tsuchiya, Hiroyuki; Kurimasa, Akihiro; Harada, Ken-ichi; Yashima, Kazuo; Nishimuki, Eiji; Shabana, Noriko; Kishimoto, Yukihiro; Kojyo, Haruhiko; Miura, Kunihiko; Murawaki, Yoshikazu; Kawasaki, Hironaka; Shiota, Goshi

    2006-01-01

    Ulcerative colitis (UC) is progressive and relapsing disease. To explore the therapeutic effects of naked gene therapy of hepatocyte growth factor (HGF) on UC, the SRα promoter driving HGF gene was intrarectally administered to the mice in which colitis was induced by dextran sulfate sodium (DSS). Expression of the transgene was seen in surface epithelium, lamina propria, and muscularis mucosae. The HGF-treated mice showed reduced colonic mucosal damage and increased body weights, compared with control mice (P < 0.01 and P < 0.05, respectively). The HGF-treated mice displayed increased number of PCNA-positive cells and decreased number of apoptotic cells than in control mice (P < 0.01, each). Phosphorylated AKT was dramatically increased after HGF gene administration, however, phosphorylated ERK1/2 was not altered. Microarray analysis revealed that HGF induced expression of proliferation- and apoptosis-associated genes. These data suggest that naked HGF gene delivery causes therapeutic effects through regulation of many downstream genes

  13. Phage-mediated counting by the naked eye of miRNA molecules at attomolar concentrations in a Petri dish

    Science.gov (United States)

    Zhou, Xin; Cao, Peng; Zhu, Ye; Lu, Wuguang; Gu, Ning; Mao, Chuanbin

    2015-10-01

    The ability to count biomolecules such as cancer-biomarker miRNAs with the naked eye is seemingly impossible in molecular diagnostics. Here, we show an ultrasensitive naked-eye-counting strategy for quantifying miRNAs by employing T7 phage--a bacteria-specific virus nanoparticle--as a surrogate. The phage is genetically engineered to become fluorescent and capable of binding a miRNA-capturing gold nanoparticle (GNP) in a one-to-one manner. Target miRNAs crosslink the resultant phage-GNP couple and miRNA-capturing magnetic microparticles, forming a sandwich complex containing equimolar phage and miRNA. The phage is then released from the complex and developed into one macroscopic fluorescent plaque in a Petri dish by plating it in a host bacterial medium. Counting the plaques by the naked eye enables the quantification of miRNAs with detection limits of ~3 and ~5 aM for single-target and two-target miRNAs, respectively. This approach offers ultrasensitive and convenient quantification of disease biomarkers by the naked eye.

  14. First 10 kg of naked Germanium detectors in liquid nitrogen installed in the GENIUS-Test-Facility

    International Nuclear Information System (INIS)

    Klapdor-Kleingrothaus, H.V.; Chkvorets, O.; Krivosheina, I.V.; Strecker, H.; Tomei, C.

    2003-01-01

    The first four naked high-purity Germanium detectors were installed successfully in liquid nitrogen in the GENIUS-Test-Facility in the GRAN SASSO Underground Laboratory on May 5, 2003. This is the first time ever that this novel technique aiming at extreme background reduction in search for rare decays is going to be tested underground. First operational parameters are presented

  15. Naked (C5Me5)(2)M cations (M = Sc, Ti, and V) and their fluoroarene complexes

    NARCIS (Netherlands)

    Bouwkamp, MW; Budzelaar, PHM; Gercama, J; Morales, ID; de Wolf, J; Meetsma, A; Troyanov, SI; Teuben, JH; Hessen, B; Budzelaar, Peter H.M.; Hierro Morales, Isabel Del; Troyanov, Sergei I.

    2005-01-01

    The ionic metallocene complexes [Cp*M-2][BPh4] (CP* = C5Me5) of the trivalent 3d metals Sc, Ti, and V were synthesized and structurally characterized. For M Sc, the anion interacts weakly with the metal center through one of the phenyl groups, but for M = Ti and V, the cations are naked. They each

  16. The perception of (naked only) bodies and faceless heads relies on holistic processing: Evidence from the inversion effect.

    Science.gov (United States)

    Bonemei, Rob; Costantino, Andrea I; Battistel, Ilenia; Rivolta, Davide

    2018-05-01

    Faces and bodies are more difficult to perceive when presented inverted than when presented upright (i.e., stimulus inversion effect), an effect that has been attributed to the disruption of holistic processing. The features that can trigger holistic processing in faces and bodies, however, still remain elusive. In this study, using a sequential matching task, we tested whether stimulus inversion affects various categories of visual stimuli: faces, faceless heads, faceless heads in body context, headless bodies naked, whole bodies naked, headless bodies clothed, and whole bodies clothed. Both accuracy and inversion efficiency score results show inversion effects for all categories but for clothed bodies (with and without heads). In addition, the magnitude of the inversion effect for face, naked body, and faceless heads was similar. Our findings demonstrate that the perception of faces, faceless heads, and naked bodies relies on holistic processing. Clothed bodies (with and without heads), on the other side, may trigger clothes-sensitive rather than body-sensitive perceptual mechanisms. © 2017 The British Psychological Society.

  17. Development of a Textile Nanocomposite as Naked Eye Indicator of the Exposition to Strong Acids

    Directory of Open Access Journals (Sweden)

    Isabel Pallás

    2017-09-01

    Full Text Available Chemical burns, mainly produced by acids, are a topic of concern. A new sensing material for the detection of strong acids able to be incorporated into textiles has been developed. The material is prepared by the covalent attachment of 2,2′,4,4′,4″-pentamethoxy triphenyl methanol to a mesoporous material which further is included in a nitro resin to obtain a colourless composite. The response of this composite to diverse acid solutions was tested showing the appearance of an intense purple colour (with a colour difference higher than 160 that can be monitored by the naked eye or could be easily digitised to feed an instrumental sensor. Reversibility and resistance to washing cycles were studied with positive results. Finally, the response of the sensing composite to acid vapours was assayed, observing a colour change similar to that found in solution.

  18. X-ray sources in regions of star formation. I. The naked T Tauri stars

    International Nuclear Information System (INIS)

    Walter, F.M.

    1986-01-01

    Einstein X-ray observations of regions of active star formation in Taurus, Ophiuchus, and Corona Australis show a greatly enhanced surface density of stellar X-ray sources over that seen in other parts of the sky. Many of the X-ray sources are identified with low-mass, pre-main-sequence stars which are not classical T Tauri stars. The X-ray, photometric, and spectroscopic data for these stars are discussed. Seven early K stars in Oph and CrA are likely to be 1-solar-mass post-T Tauri stars with ages of 10-million yr. The late K stars in Taurus are not post-T Tauri, but naked T Tauri stars, which are coeval with the T Tauri stars, differing mainly in the lack of a circumstellar envelope. 72 references

  19. "All in the Day's Work": Cold War Doctoring and Its Discontents in William Burroughs's Naked Lunch.

    Science.gov (United States)

    Jarvis, Michael

    In Naked Lunch, the institutions and practices of science and medicine, specifically with regard to psychiatry/psychology, are symptoms of a bureaucratic system of control that shapes, constructs, defines, and makes procrustean alterations to both the mind and body of human subjects. Using sickness and junk (or heroin) as convenient metaphors for both a Cold War binary mentality and the mandatory consumption of twentieth-century capitalism, Burroughs presents modern man as fundamentally alienated from any sense of a personal self. Through policing the health of citizens, the doctors are some of the novel's most overt "Senders," or agents of capital-C Control, commodifying and exploiting the individual's humanity (mind and body) as a raw material in the generation of a knowledge that functions only in the legitimation and reinforcement of itself as authoritative.

  20. Magnetic purification of curcumin from Curcuma longa rhizome by novel naked maghemite nanoparticles.

    Science.gov (United States)

    Magro, Massimiliano; Campos, Rene; Baratella, Davide; Ferreira, Maria Izabela; Bonaiuto, Emanuela; Corraducci, Vittorino; Uliana, Maíra Rodrigues; Lima, Giuseppina Pace Pereira; Santagata, Silvia; Sambo, Paolo; Vianello, Fabio

    2015-01-28

    Naked maghemite nanoparticles, namely, surface active maghemite nanoparticles (SAMNs), characterized by a diameter of about 10 nm, possessing peculiar colloidal stability, surface chemistry, and superparamagnetism, present fundamental requisites for the development of effective magnetic purification processes for biomolecules in complex matrices. Polyphenolic molecules presenting functionalities with different proclivities toward iron chelation were studied as probes for testing SAMN suitability for magnetic purification. Thus, the binding efficiency and reversibility on SAMNs of phenolic compounds of interest in the pharmaceutical and food industries, namely, catechin, tyrosine, hydroxytyrosine, ferulic acid, coumaric acid, rosmarinic acid, naringenin, curcumin, and cyanidin-3-glucoside, were evaluated. Curcumin emerged as an elective compound, suitable for magnetic purification by SAMNs from complex matrices. A combination of curcumin, demethoxycurcumin, and bis-demethoxycurcumin was recovered by a single magnetic purification step from extracts of Curcuma longa rhizomes, with a purity >98% and a purification yield of 45%, curcumin being >80% of the total purified curcuminoids.

  1. Review of Naked Statistics: Stripping the Dread from Data by Charles Wheelan

    Directory of Open Access Journals (Sweden)

    Michael T. Catalano

    2015-01-01

    Full Text Available Wheelan, Charles. Naked Statistics: Stripping the Dread from Data (New York, NY, W. W. Norton & Company, 2014. 282 pp. ISBN 978-0-393-07195-5 In his review of What Numbers Say and The Numbers Game, Rob Root (Numeracy 3(1: 9 writes “Popular books on quantitative literacy need to be easy to read, reasonably comprehensive in scope, and include examples that are thought-provoking and memorable.” Wheelan’s book certainly meets this description, and should be of interest to both the general public and those with a professional interest in numeracy. A moderately diligent learner can get a decent understanding of basic statistics from the book. Teachers of statistics and quantitative literacy will find a wealth of well-related examples and stories to use in their classes.

  2. A genetic linkage map of hexaploid naked oat constructed with SSR markers

    Directory of Open Access Journals (Sweden)

    Gaoyuan Song

    2015-08-01

    Full Text Available Naked oat is a unique health food crop in China. Using 202 F2 individuals derived from a hybrid between the variety 578 and the landrace Sanfensan, we constructed a genetic linkage map consisting of 22 linkage groups covering 2070.50 cM and including 208 simple sequence repeat (SSR markers. The minimum distance between adjacent markers was 0.01 cM and the average was 9.95 cM. Each linkage group contained 2–22 markers. The largest linkage group covered 174.40 cM and the shortest one covered 36.80 cM, with an average of 94.11 cM. Thirty-six markers (17.3% showing distorted segregation were distributed across linkage groups LG5 to LG22. This map complements published oat genetic maps and is applicable for quantitative trait locus analysis, gene cloning and molecular marker-assisted selection.

  3. On the variably-charged black holes in general relativity: Hawking's radiation and naked singularities

    International Nuclear Information System (INIS)

    Ibohal, Ng

    2002-01-01

    In this paper variably-charged non-rotating Reissner-Nordstrom and rotating Kerr-Newman black holes are discussed. Such a variable charge e with respect to the polar coordinate r in the field equations is referred to as an electrical radiation of the black hole. It is shown that every electrical radiation e(r) of the non-rotating black hole leads to a reduction in its mass M by some quantity. If one considers such electrical radiation taking place continuously for a long time, then a continuous reduction of the mass may take place in the black-hole body and the original mass of the black hole may be evaporated completely. At that stage, the gravity of the object may depend only on the electromagnetic field, not on the mass. Immediately after the complete evaporation of the mass, if the next radiation continues, there may be creation of a new mass leading to the formation of a negative mass naked singularity. It appears that this new mass of the naked singularity would never decrease, but might increase gradually as the radiation continues forever. A similar investigation is also discussed in the case of a variably-charged rotating Kerr-Newman black hole. Thus, it has been shown by incorporating Hawking's evaporation of radiating black holes in the form of spacetime metrics, every electrical radiation of variably-charged rotating and non-rotating black holes may produce a change in the mass of the body without affecting the Maxwell scalar

  4. Covalently bound DNA on naked iron oxide nanoparticles: Intelligent colloidal nano-vector for cell transfection.

    Science.gov (United States)

    Magro, Massimiliano; Martinello, Tiziana; Bonaiuto, Emanuela; Gomiero, Chiara; Baratella, Davide; Zoppellaro, Giorgio; Cozza, Giorgio; Patruno, Marco; Zboril, Radek; Vianello, Fabio

    2017-11-01

    Conversely to common coated iron oxide nanoparticles, novel naked surface active maghemite nanoparticles (SAMNs) can covalently bind DNA. Plasmid (pDNA) harboring the coding gene for GFP was directly chemisorbed onto SAMNs, leading to a novel DNA nanovector (SAMN@pDNA). The spontaneous internalization of SAMN@pDNA into cells was compared with an extensively studied fluorescent SAMN derivative (SAMN@RITC). Moreover, the transfection efficiency of SAMN@pDNA was evaluated and explained by computational model. SAMN@pDNA was prepared and characterized by spectroscopic and computational methods, and molecular dynamic simulation. The size and hydrodynamic properties of SAMN@pDNA and SAMN@RITC were studied by electron transmission microscopy, light scattering and zeta-potential. The two nanomaterials were tested by confocal scanning microscopy on equine peripheral blood-derived mesenchymal stem cells (ePB-MSCs) and GFP expression by SAMN@pDNA was determined. Nanomaterials characterized by similar hydrodynamic properties were successfully internalized and stored into mesenchymal stem cells. Transfection by SAMN@pDNA occurred and GFP expression was higher than lipofectamine procedure, even in the absence of an external magnetic field. A computational model clarified that transfection efficiency can be ascribed to DNA availability inside cells. Direct covalent binding of DNA on naked magnetic nanoparticles led to an extremely robust gene delivery tool. Hydrodynamic and chemical-physical properties of SAMN@pDNA were responsible of the successful uptake by cells and of the efficiency of GFP gene transfection. SAMNs are characterized by colloidal stability, excellent cell uptake, persistence in the host cells, low toxicity and are proposed as novel intelligent DNA nanovectors for efficient cell transfection. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. An ion beam deceleration lens for ultra-low-energy ion bombardment of naked DNA

    Energy Technology Data Exchange (ETDEWEB)

    Thopan, P.; Prakrajang, K. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thongkumkoon, P. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Suwannakachorn, D. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, L.D., E-mail: yuldyuld@gmail.com [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

    2013-07-15

    Highlights: ► An ion beam deceleration lens was designed and constructed. ► The deceleration lens was installed and tested. ► The decelerated ion beam energy was measured using an electrical field. ► Decelerated ultra-low-energy ion beam bombarded naked DNA. ► Ion beam with energy of a few tens of eV could break DNA strands. -- Abstract: Study of low-energy ion bombardment effect on biological living materials is of significance. High-energy ion beam irradiation of biological materials such as organs and cells has no doubt biological effects. However, ion energy deposition in the ion-bombarded materials dominantly occurs in the low-energy range. To investigate effects from very-low-energy ion bombardment on biological materials, an ion beam deceleration lens is necessary for uniform ion energy lower than keV. A deceleration lens was designed and constructed based on study of the beam optics using the SIMION program. The lens consisted of six electrodes, able to focus and decelerate primary ion beam, with the last one being a long tube to obtain a parallel uniform exiting beam. The deceleration lens was installed to our 30-kV bioengineering-specialized ion beam line. The final decelerated-ion energy was measured using a simple electrostatic field to bend the beam to range from 10 eV to 1 keV controlled by the lens parameters and the primary beam condition. In a preliminary test, nitrogen ion beam at 60 eV decelerated from a primary 20-keV beam bombarded naked plasmid DNA. The original DNA supercoiled form was found to change to relaxed and linear forms, indicating single or double strand breaks. The study demonstrated that the ion bombardment with energy as low as several-tens eV was possible to break DNA strands and thus potential to cause genetic modification of biological cells.

  6. An ion beam deceleration lens for ultra-low-energy ion bombardment of naked DNA

    International Nuclear Information System (INIS)

    Thopan, P.; Prakrajang, K.; Thongkumkoon, P.; Suwannakachorn, D.; Yu, L.D.

    2013-01-01

    Highlights: ► An ion beam deceleration lens was designed and constructed. ► The deceleration lens was installed and tested. ► The decelerated ion beam energy was measured using an electrical field. ► Decelerated ultra-low-energy ion beam bombarded naked DNA. ► Ion beam with energy of a few tens of eV could break DNA strands. -- Abstract: Study of low-energy ion bombardment effect on biological living materials is of significance. High-energy ion beam irradiation of biological materials such as organs and cells has no doubt biological effects. However, ion energy deposition in the ion-bombarded materials dominantly occurs in the low-energy range. To investigate effects from very-low-energy ion bombardment on biological materials, an ion beam deceleration lens is necessary for uniform ion energy lower than keV. A deceleration lens was designed and constructed based on study of the beam optics using the SIMION program. The lens consisted of six electrodes, able to focus and decelerate primary ion beam, with the last one being a long tube to obtain a parallel uniform exiting beam. The deceleration lens was installed to our 30-kV bioengineering-specialized ion beam line. The final decelerated-ion energy was measured using a simple electrostatic field to bend the beam to range from 10 eV to 1 keV controlled by the lens parameters and the primary beam condition. In a preliminary test, nitrogen ion beam at 60 eV decelerated from a primary 20-keV beam bombarded naked plasmid DNA. The original DNA supercoiled form was found to change to relaxed and linear forms, indicating single or double strand breaks. The study demonstrated that the ion bombardment with energy as low as several-tens eV was possible to break DNA strands and thus potential to cause genetic modification of biological cells

  7. Poikilothermic traits in Mashona mole-rat (Fukomys darlingi). Reality or myth?

    Czech Academy of Sciences Publication Activity Database

    Zemanová, Milada; Šumbera, R.; Okrouhlík, J.

    2012-01-01

    Roč. 37, č. 7 (2012), s. 485-489 ISSN 0306-4565 Institutional support: RVO:60077344 Keywords : subterranean rodent * Bathyergidae * poikilothermy Subject RIV: ED - Physiology OBOR OECD: Biology (theoretical, mathematical, thermal, cryobiology, biological rhythm), Evolutionary biology Impact factor: 1.376, year: 2012 http://www.sciencedirect.com/science/article/pii/S0306456512000824

  8. The banded karyotype of the 2n=58 chromosomal race of mole rats from Erzincan, Turkey

    Czech Academy of Sciences Publication Activity Database

    Arslan, A.; Zima, Jan

    2013-01-01

    Roč. 62, č. 1 (2013), s. 19-23 ISSN 0139-7893 Institutional support: RVO:68081766 Keywords : Ag-NOR staining * C-banding * Nannospalax xanthodon Subject RIV: EG - Zoology Impact factor: 0.741, year: 2013 http://hdl.handle.net/11104/0221259

  9. Review of chromosome races in blind mole rats (Spalax and Nannospalax)

    Czech Academy of Sciences Publication Activity Database

    Arslan, A.; Kryštufek, B.; Matur, F.; Zima, Jan

    2016-01-01

    Roč. 65, č. 4 (2016), s. 249-301 ISSN 0139-7893 Institutional support: RVO:68081766 Keywords : karyotype * evolution * cytotypes * speciation Subject RIV: EG - Zoology Impact factor: 0.739, year: 2016

  10. Kinship structure and mating system in a solitary subterranean rodent, the silvery mole-rat

    Czech Academy of Sciences Publication Activity Database

    Patzenhauerová, Hana; Bryja, Josef; Šumbera, R.

    2010-01-01

    Roč. 64, č. 5 (2010), s. 757-767 ISSN 0340-5443 R&D Projects: GA AV ČR IAA601410802 Institutional research plan: CEZ:AV0Z60930519 Keywords : subterranean rodent * kinship structure * mating system * dispersal Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.565, year: 2010

  11. The reproductive biology of the giant Zambian mole-rat, Cryptomys ...

    African Journals Online (AJOL)

    Cryptomys mechowi occurs in the mesic Miombo tropical woodland and savanna of Zambia, Zaïre and Angola. It is a colonial balhyergid in which reproduction is restricted lo a single female. Courtship and copulation are initiated by the female. Copulation is brief and does not involve multiple bouts. The gestation length is ...

  12. Seismic communication in demon African mole rat Tachyoryctes daemon from Tanzania

    Czech Academy of Sciences Publication Activity Database

    Hrouzková, E.; Dvořáková, V.; Jedlička, Petr; Šumbera, R.

    2013-01-01

    Roč. 31, č. 3 (2013), s. 255-259 ISSN 0289-0771 Institutional support: RVO:67985530 Keywords : seismic communication * substrate-borne vibration * subterranean mammal Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 0.790, year: 2013

  13. Oxygen-Binding Characteristics of Hemoglobins from Hypoxia and Hypercapnia Tolerant African Mole Rats

    DEFF Research Database (Denmark)

    Weber, Roy E.; Jarvis, Jennifer U. M; Fago, Angela

    2016-01-01

    ) originating from a range of different biomes and soil types. The study shows no evidence for distinguishing interspecific differences in hematological characters (e.g. DPG and Hb levels and isoHb differentiation). Additionally small differences observed in Hb’s intrinsic O2 affinity and in the effects of p...

  14. The initial value problem for linearized gravitational perturbations of the Schwarzschild naked singularity

    Energy Technology Data Exchange (ETDEWEB)

    Dotti, Gustavo; Gleiser, Reinaldo J [Facultad de Matematica, AstronomIa y Fisica (FaMAF), Universidad Nacional de Cordoba, Ciudad Universitaria, 5000 Cordoba (Argentina)

    2009-11-07

    The coupled equations for the scalar modes of the linearized Einstein equations around Schwarzschild's spacetime were reduced by Zerilli to a (1+1) wave equation partial deriv{sup 2}PSI{sub z} /partial derivt{sup 2} +HPSI{sub z} =0, where H= -partial deriv{sup 2} /partial derivx{sup 2} + V(x) is the Zerilli 'Hamiltonian' and x is the tortoise radial coordinate. From its definition, for smooth metric perturbations the field PSI{sub z} is singular at r{sub s} = -6M/(l - 1)(l +2), with l being the mode harmonic number. The equation PSI{sub z} obeys is also singular, since V has a second-order pole at r{sub s}. This is irrelevant to the black hole exterior stability problem, where r > 2M > 0, and r{sub s} < 0, but it introduces a non-trivial problem in the naked singular case where M < 0, then r{sub s} > 0, and the singularity appears in the relevant range of r (0 < r < infinity). We solve this problem by developing a new approach to the evolution of the even mode, based on a new gauge invariant function, PSI-circumflex, that is a regular function of the metric perturbation for any value of M. The relation of PSI-circumflex to PSI{sub z} is provided by an intertwiner operator. The spatial pieces of the (1 + 1) wave equations that PSI-circumflex and PSI{sub z} obey are related as a supersymmetric pair of quantum Hamiltonians H and H-circumflex. For M < 0,H-circumflex has a regular potential and a unique self-adjoint extension in a domain D defined by a physically motivated boundary condition at r = 0. This allows us to address the issue of evolution of gravitational perturbations in this non-globally hyperbolic background. This formulation is used to complete the proof of the linear instability of the Schwarzschild naked singularity, by showing that a previously found unstable mode belongs to a complete basis of H-circumflex in D, and thus is excitable by generic initial data. This is further illustrated by numerically solving the linearized equations for

  15. Particle Collision Near 1 + 1-Dimensional Horava-Lifshitz Black Hole and Naked Singularity

    Directory of Open Access Journals (Sweden)

    M. Halilsoy

    2017-01-01

    Full Text Available The unbounded center-of-mass (CM energy of oppositely moving colliding particles near horizon emerges also in 1+1-dimensional Horava-Lifshitz gravity. This theory has imprints of renormalizable quantum gravity characteristics in accordance with the method of simple power counting. Surprisingly the result obtained is not valid for a 1-dimensional Compton-like process between an outgoing photon and an infalling massless/massive particle. It is possible to achieve unbounded CM energy due to collision between infalling photons and particles. The source of outgoing particles may be attributed to an explosive process just outside the horizon for a black hole and the naturally repulsive character for the case of a naked singularity. It is found that absence of angular momenta in 1+1-dimension does not yield unbounded energy for collisions in the vicinity of naked singularities.

  16. Self-similar cosmological solutions with dark energy. II. Black holes, naked singularities, and wormholes

    International Nuclear Information System (INIS)

    Maeda, Hideki; Harada, Tomohiro; Carr, B. J.

    2008-01-01

    We use a combination of numerical and analytical methods, exploiting the equations derived in a preceding paper, to classify all spherically symmetric self-similar solutions which are asymptotically Friedmann at large distances and contain a perfect fluid with equation of state p=(γ-1)μ with 0<γ<2/3. The expansion of the Friedmann universe is accelerated in this case. We find a one-parameter family of self-similar solutions representing a black hole embedded in a Friedmann background. This suggests that, in contrast to the positive pressure case, black holes in a universe with dark energy can grow as fast as the Hubble horizon if they are not too large. There are also self-similar solutions which contain a central naked singularity with negative mass and solutions which represent a Friedmann universe connected to either another Friedmann universe or some other cosmological model. The latter are interpreted as self-similar cosmological white hole or wormhole solutions. The throats of these wormholes are defined as two-dimensional spheres with minimal area on a spacelike hypersurface and they are all nontraversable because of the absence of a past null infinity

  17. Cerebellar Expression of the Neurotrophin Receptor p75 in Naked-Ataxia Mutant Mouse

    Directory of Open Access Journals (Sweden)

    Maryam Rahimi Balaei

    2016-01-01

    Full Text Available Spontaneous mutation in the lysosomal acid phosphatase 2 (Acp2 mouse (nax—naked-ataxia mutant mouse correlates with severe cerebellar defects including ataxia, reduced size and abnormal lobulation as well as Purkinje cell (Pc degeneration. Loss of Pcs in the nax cerebellum is compartmentalized and harmonized to the classic pattern of gene expression of the cerebellum in the wild type mouse. Usually, degeneration starts in the anterior and posterior zones and continues to the central and nodular zones of cerebellum. Studies have suggested that the p75 neurotrophin receptor (NTR plays a role in Pc degeneration; thus, in this study, we investigated the p75NTR pattern and protein expression in the cerebellum of the nax mutant mouse. Despite massive Pc degeneration that was observed in the nax mouse cerebellum, p75NTR pattern expression was similar to the HSP25 pattern in nax mice and comparable with wild type sibling cerebellum. In addition, immunoblot analysis of p75NTR protein expression did not show any significant difference between nax and wild type sibling (p > 0.5. In comparison with wild type counterparts, p75NTR pattern expression is aligned with the fundamental cytoarchitecture organization of the cerebellum and is unchanged in the nax mouse cerebellum despite the severe neurodevelopmental disorder accompanied with Pc degeneration.

  18. Synthesis and characterization of azo-guanidine based alcoholic media naked eye DNA sensor

    Science.gov (United States)

    Hashmat, Uzma; Yousaf, Muhammad; Lal, Bhajan; Ullah, Shafiq; Holder, Alvin A.; Badshah, Amin

    2016-01-01

    DNA sensing always has an open meadow of curiosity for biotechnologists and other researchers. Recently, in this field, we have introduced an emerging class of molecules containing azo and guanidine functionalities. In this study, we have synthesized three new compounds (UA1, UA6 and UA7) for potential application in DNA sensing in alcoholic medium. The synthesized materials were characterized by elemental analysis, FTIR, UV-visible, 1H NMR and 13C NMR spectroscopies. Their DNA sensing potential were investigated by UV-visible spectroscopy. The insight of interaction with DNA was further investigated by electrochemical (cyclic voltammetry) and hydrodynamic (viscosity) studies. The results showed that compounds have moderate DNA binding properties, with the binding constants range being 7.2 × 103, 2.4 × 103 and 0.2 × 103 M−1, for UA1, UA6 and UA7, respectively. Upon binding with DNA, there was a change in colour (a blue shift in the λmax value) which was observable with a naked eye. These results indicated the potential of synthesized compounds as DNA sensors with detection limit 1.8, 5.8 and 4.0 ng µl−1 for UA1, UA6 and UA7, respectively. PMID:28018613

  19. Electrochromic Asymmetric Supercapacitor Windows Enable Direct Determination of Energy Status by the Naked Eye.

    Science.gov (United States)

    Zhong, Ying; Chai, Zhisheng; Liang, Zhimin; Sun, Peng; Xie, Weiguang; Zhao, Chuanxi; Mai, Wenjie

    2017-10-04

    Because of the popularity of smart electronics, multifunctional energy storage devices, especially electrochromic supercapacitors (SCs), have attracted tremendous research interest. Herein, a solid-state electrochromic asymmetric SC (ASC) window is designed and fabricated by introducing WO 3 and polyaniline as the negative and positive electrodes, respectively. The two complementary materials contribute to the outstanding electrochemical and electrochromic performances of the fabricated device. With an operating voltage window of 1.4 V and an areal capacitance of 28.3 mF cm -2 , the electrochromic devices show a high energy density of 7.7 × 10 -3 mW h cm -2 . Meanwhile, they exhibit an obvious and reversible color transition between light green (uncharged state) and dark blue (charged state), with an optical transmittance change between 55 and 12% at a wavelength of 633 nm. Hence, the energy storage level of the ASC is directly related to its color and can be determined by the naked eye, which means it can be incorporated with other energy cells to visual display their energy status. Particularly, a self-powered and color-indicated system is achieved by combining the smart windows with commercial solar cell panels. We believe that the novel electrochromic ASC windows will have great potential application for both smart electronics and smart buildings.

  20. Physical properties of naked DNA influence nucleosome positioning and correlate with transcription start and termination sites in yeast

    Directory of Open Access Journals (Sweden)

    Soler-López Montserrat

    2011-10-01

    Full Text Available Abstract Background In eukaryotic organisms, DNA is packaged into chromatin structure, where most of DNA is wrapped into nucleosomes. DNA compaction and nucleosome positioning have clear functional implications, since they modulate the accessibility of genomic regions to regulatory proteins. Despite the intensive research effort focused in this area, the rules defining nucleosome positioning and the location of DNA regulatory regions still remain elusive. Results Naked (histone-free and nucleosomal DNA from yeast were digested by microccocal nuclease (MNase and sequenced genome-wide. MNase cutting preferences were determined for both naked and nucleosomal DNAs. Integration of their sequencing profiles with DNA conformational descriptors derived from atomistic molecular dynamic simulations enabled us to extract the physical properties of DNA on a genomic scale and to correlate them with chromatin structure and gene regulation. The local structure of DNA around regulatory regions was found to be unusually flexible and to display a unique pattern of nucleosome positioning. Ab initio physical descriptors derived from molecular dynamics were used to develop a computational method that accurately predicts nucleosome enriched and depleted regions. Conclusions Our experimental and computational analyses jointly demonstrate a clear correlation between sequence-dependent physical properties of naked DNA and regulatory signals in the chromatin structure. These results demonstrate that nucleosome positioning around TSS (Transcription Start Site and TTS (Transcription Termination Site (at least in yeast is strongly dependent on DNA physical properties, which can define a basal regulatory mechanism of gene expression.

  1. Circular geodesics of naked singularities in the Kehagias-Sfetsos metric of Hořava's gravity

    Science.gov (United States)

    Vieira, Ronaldo S. S.; Schee, Jan; Kluźniak, Włodek; Stuchlík, Zdeněk; Abramowicz, Marek

    2014-07-01

    We discuss photon and test-particle orbits in the Kehagias-Sfetsos (KS) metric of Hořava's gravity. For any value of the Hořava parameter ω, there are values of the gravitational mass M for which the metric describes a naked singularity, and this is always accompanied by a vacuum "antigravity sphere" on whose surface a test particle can remain at rest (in a zero angular momentum geodesic), and inside which no circular geodesics exist. The observational appearance of an accreting KS naked singularity in a binary system would be that of a quasistatic spherical fluid shell surrounded by an accretion disk, whose properties depend on the value of M, but are always very different from accretion disks familiar from the Kerr-metric solutions. The properties of the corresponding circular orbits are qualitatively similar to those of the Reissner-Nordström naked singularities. When event horizons are present, the orbits outside the Kehagias-Sfetsos black hole are qualitatively similar to those of the Schwarzschild metric.

  2. An empirical examination of the relationship between naked shorting and share prices around the announcement of a firm’s need for external capital

    Directory of Open Access Journals (Sweden)

    Austin Murphy

    2012-12-01

    Full Text Available This research finds some empirical evidence that the sale of stock without delivering shares can contribute to pressuring down the equity prices of companies seeking to raise capital. By allowing for the delayed effects on prices of limit orders by naked shorts, a significant negative impact on equity value per share is discovered but only for naked short selling by market makers and only on stocks of firms in urgent need of external financing.

  3. Carcass characteristics, physical property and chemical composition of Naked-Neck and Thai indigenous chickens muscles reared under backyard production systems

    Directory of Open Access Journals (Sweden)

    Songsang, A.

    2007-03-01

    Full Text Available The objective of this study was to obtain basic knowledge regarding carcass characteristics, physical property and chemical composition of the muscle meat of Naked-Neck and indigenous chickens reared underthe backyard production systems. Ninety heads each of Naked-Neck and indigenous chickens of both sexes at 1.3, 1.5 and 1.8 kg of live weight were used in the study. From this study, there were no significant differences (P>0.05 in the chilled carcass percentage between the two breeds and two sexes. The Naked-Neckchickens had lower breast (Pectoralis major, fillet (Pectoralis minor (P0.05 in drip loss and cooking loss values. The shear value of cooked breast and thigh muscles of Naked-Neck chickens was significantly lower (P0.05, redness (a* (P0.05 in moisture, protein, fat and ash contents. The Naked-Neck chicken contained higher (P0.05 between breeds in soluble collagen percentage of both types of muscles. For the fatty acid composition ofNaked-Neck and indigenous chickens, both breast and thigh muscles contained more saturated fatty acids than unsaturated fatty acids.

  4. Q2122-444: A NAKED ACTIVE GALACTIC NUCLEUS FULLY DRESSED

    International Nuclear Information System (INIS)

    Gliozzi, M.; Satyapal, S.; Panessa, F.; Franca, F. La; Saviane, I.; Monaco, L.; Foschini, L.; Kedziora-Chudczer, L.; Sambruna, R. M.

    2010-01-01

    Based on previous spectral and temporal optical studies, Q2122-444 has been classified as a naked active galactic nucleus (AGN) or true type 2 AGN, that is, an AGN that genuinely lacks a broad-line region (BLR). Its optical spectrum seemed to possess only narrow forbidden emission lines that are typical of type 2 (obscured) AGNs, but the long-term optical light curve, obtained from a monitoring campaign over more than two decades, showed strong variability, apparently ruling out the presence of heavy obscuration. Here we present the results from a ∼40 ks XMM-Newton observation of Q2122-444 carried out to shed light on the energetics of this enigmatic AGN. The X-ray analysis was complemented with Australia Telescope Compact Array radio data to assess the possible presence of a jet, and with new NTT/EFOSC2 optical spectroscopic data to verify the actual absence of a BLR. The higher-quality optical data revealed the presence of strong and broad Balmer lines that are at odds with the previous spectral classification of this AGN. The lack of detection of radio emission rules out the presence of a jet. The X-ray data combined with simultaneous UV observations carried out by the Optical Monitor (OM) aboard XMM-Newton confirm that Q2122-444 is a typical type 1 AGN without any significant intrinsic absorption. New estimates of the black hole mass independently obtained from the broad Balmer lines and from a new scaling technique based on X-ray spectral data suggest that Q2122-444 is accreting at a relatively high rate in Eddington units.

  5. CONSTRAINTS ON THE EMISSION MODEL OF THE 'NAKED-EYE BURST' GRB 080319B

    International Nuclear Information System (INIS)

    Abdo, A. A.; Abeysekara, A. U.; Linnemann, J. T.; Allen, B. T.; Chen, C.; Aune, T.; Berley, D.; Goodman, J. A.; Christopher, G. E.; Kolterman, B. E.; Mincer, A. I.; DeYoung, T.; Dingus, B. L.; Hoffman, C. M.; Ellsworth, R. W.; Gonzalez, M. M.; Granot, J.; Hays, E.; McEnery, J. E.; Hüntemeyer, P. H.

    2012-01-01

    On 2008 March 19, one of the brightest gamma-ray bursts (GRBs) ever recorded was detected by several ground- and space-based instruments spanning the electromagnetic spectrum from radio to gamma rays. With a peak visual magnitude of 5.3, GRB 080319B was dubbed the 'naked-eye' GRB, as an observer under dark skies could have seen the burst without the aid of an instrument. Presented here are results from observations of the prompt phase of GRB 080319B taken with the Milagro TeV observatory. The burst was observed at an elevation angle of 47°. Analysis of the data is performed using both the standard air shower method and the scaler or single-particle technique, which results in a sensitive energy range that extends from ∼5 GeV to >20 TeV. These observations provide the only direct constraints on the properties of the high-energy gamma-ray emission from GRB 080319B at these energies. No evidence for emission is found in the Milagro data, and upper limits on the gamma-ray flux above 10 GeV are derived. The limits on emission between ∼25 and 200 GeV are incompatible with the synchrotron self-Compton model of gamma-ray production and disfavor a corresponding range (2 eV-16 eV) of assumed synchrotron peak energies. This indicates that the optical photons and soft (∼650 keV) gamma rays may not be produced by the same electron population.

  6. Regional differences in the surface temperature of Naked Neck laying hens in a semi-arid environment.

    Science.gov (United States)

    de Souza, João Batista Freire; de Arruda, Alex Martins Varela; Domingos, Hérica Girlane Tertulino; de Macedo Costa, Leonardo Lelis

    2013-05-01

    The aim of this study was to evaluate the regional differences in the surface temperature of Naked Neck hens that were subjected to different temperatures in a semi-arid environment. The surface temperature was measured in four body regions (face, neck, legs and feathered area) of 60 Naked Neck hens. The following environmental variables were measured at the center of the shed: the black globe temperature (T G ), air temperature (T A ), wind speed (U) and relative humidity (R H ). The T A was divided into three classes: 1 (24.0-26.0 °C), 2 (26.1-28.9 °C) and 3 (29.0-31.0 °C). An analysis of variance was performed by the least squares method and a comparison of the means by the Tukey-Kramer test. The results showed a significant effect of T A class, the body region and the interaction between these two effects on the surface temperature. There was no significant difference between the T A classes for the face and neck. The legs and feathered area showed significant differences between the T A classes. Regarding the effect of body regions within each T A class, there was a significant difference among all regions in the three T A classes. In all T A classes the neck had the highest average followed by the face and legs. The feathered area showed the lowest average of the different T A classes. In conclusion, this study showed that there are regional differences in the surface temperature of Naked Neck hens, with the legs acting as thermal windows.

  7. First 10 kg of naked germanium detectors installed in liquid nitrogen in GENIUS Test-Facility in GRAN-SASSO

    Energy Technology Data Exchange (ETDEWEB)

    Klapdor-Kleingrothaus, H.V. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

    2004-07-01

    The GENIUS Test Facility has come into operation in Gran Sasso on May 5, 2003 with its first ten kg of naked Ge detectors in liquid nitrogen. This is the first time that this novel technique for extreme background reduction in search for rare decays is applied under the background conditions of an underground laboratory. GENIUS-TF has the potential to check the DAMA evidence for cold dark matter by modulation, and possibly, to improve the accuracy of the recently observed first signal for neutrinoless double beta decay. (orig.)

  8. First 10 kg of naked germanium detectors installed in liquid nitrogen in GENIUS Test-Facility in GRAN-SASSO

    International Nuclear Information System (INIS)

    Klapdor-Kleingrothaus, H.V.

    2004-01-01

    The GENIUS Test Facility has come into operation in Gran Sasso on May 5, 2003 with its first ten kg of naked Ge detectors in liquid nitrogen. This is the first time that this novel technique for extreme background reduction in search for rare decays is applied under the background conditions of an underground laboratory. GENIUS-TF has the potential to check the DAMA evidence for cold dark matter by modulation, and possibly, to improve the accuracy of the recently observed first signal for neutrinoless double beta decay. (orig.)

  9. THE “NAKED FACE” OF SECULAR EXCLUSION: BILL 94 AND THE PRIVATIZATION OF BELIEF

    Directory of Open Access Journals (Sweden)

    Pascale Fournier

    2012-02-01

    Full Text Available This article will consider the case study of Québec’s Bill 94 (An Act to establish guidelines governing accommodation requests within the Administration and certain institutions, introduced in March 2010, one of many recent bans imposed on the wearing of the niqab in the West. Citing the importance of “the right to gender equality and the principle of religious neutrality of the State,” Bill 94 emphasizes the necessity of “un visage découvert” or “naked face” when giving or receiving a broad range of public services in Québec, including all government services, childcare centres, hospitals, and health and social service agencies. According to section 6 of the Act, “If an accommodation involves an adaptation of that practice and reasons of security, communication or identification warrant it, the accommodation must be denied.” While quasi-neutral, this bill clearly has a disproportionate impact on religious women who wear the niqab. In fact, as a direct result of the legislation, Muslim women will likely disappear from the public sphere and be restricted to the private home where they might effectively be dependent on male family members to navigate the “market place” on their behalf. Borrowing from Charles Taylor’s A Secular Age, this paper will consider the distributive consequences of the niqab ban, a critical juncture of “religion-state relations” in which belief is more and more relegated to the private sphere in Quebec. The article will use Bill 94 to explore this peculiar manifestation of “secularism” with the concurrent existence of “governance feminism”— how the privatization of belief goes hand in hand and is perversely reinforced by a colonial discourse on gender equality, leaving some already marginalized women out of the public gaze. Is this legislated demand for a “naked face” truly the logical outcome of a successful feminist movement (as some have asserted or isthis erasure of religious

  10. Journal of Biosciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Clipboard: Of pungency, pain, and naked mole rats: chili peppers revisited · Renee M Borges · More Details Fulltext PDF. Volume 34 Issue 4 October 2009 pp 605-611 Articles. Phenotypic plasticity and longevity in plants and animals: cause and effect? Renee M Borges · More Details Abstract Fulltext PDF. Immobile plants ...

  11. Novel cellulose-based halochromic test strips for naked-eye detection of alkaline vapors and analytes.

    Science.gov (United States)

    Abou-Yousef, Hussein; Khattab, Tawfik A; Youssef, Yehia A; Al-Balakocy, Naser; Kamel, Samir

    2017-08-01

    A simple, portable and highly sensitive naked-eye test strip is successfully prepared for optical detection of gaseous and aqueous alkaline analytes. Novel pH-sensory tricyanofuran-hydrazone (TCFH) disperse colorant containing a hydrazone recognition functional moiety is successfully synthesized via azo-coupling reaction between active methyl-containing tricyanofuran (TCF) heterocycle and diazonium salt of 4-aminobenzaldehyde followed by Knoevenagel condensation with malononitrile. UV-vis absorption spectra display solvatochromism and reversible color changes of the TCFH solution in dimethyl sulfoxide in response to pH variations. We investigate the preparation of hydrophobic cellulose/polyethylene terephthalate composites characterized by their high affinity for disperse dyes. Composite films made from CA, Cell/CA, PET/CA, and Cell/PET-CA are produced via solvent-casting procedure using 10-30% modified cellulose or modified polyethylene terephthalate. The mechanical properties and morphologies of these composite films are investigated. The prepared pH-sensory hydrazone-based disperse dye is then applied to dye the produced cellulose-based composite films employing the high temperature pressure dyeing procedure. The produced halochromic PET-CA-TCFH test strip provide an instant visible signal from orange to purple upon exposure to alkaline conditions as proved by the coloration measurements. The sensor strip exhibits high sensitivity and quick detection toward ammonia in both of aqueous and vapor phases by naked-eye observations at room temperature and atmospheric pressure. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Seasonal variation in plasma and corpus luteum oestradiol.17[3and ...

    African Journals Online (AJOL)

    Flemming 1993) and, in males, with circulating sex steroid concentrations ..... biology of the Cape mole-rat, Georychus capensis (Rodentia. Bathycrgidac), j, Zool" ... brain. and behavior: an emerging discipline in herpetology. In: Biology of the ...

  13. TIM1 (HAVCR1 Is Not Essential for Cellular Entry of Either Quasi-enveloped or Naked Hepatitis A Virions

    Directory of Open Access Journals (Sweden)

    Anshuman Das

    2017-09-01

    Full Text Available Receptor molecules play key roles in the cellular entry of picornaviruses, and TIM1 (HAVCR1 is widely accepted to be the receptor for hepatitis A virus (HAV, an unusual, hepatotropic human picornavirus. However, its identification as the hepatovirus receptor predated the discovery that hepatoviruses undergo nonlytic release from infected cells as membrane-cloaked, quasi-enveloped HAV (eHAV virions that enter cells via a pathway distinct from naked, nonenveloped virions. We thus revisited the role of TIM1 in hepatovirus entry, examining both adherence and infection/replication in cells with clustered regularly interspaced short palindromic repeat (CRISPR/Cas9-engineered TIM1 knockout. Cell culture-derived, gradient-purified eHAV bound Huh-7.5 human hepatoma cells less efficiently than naked HAV at 4°C, but eliminating TIM1 expression caused no difference in adherence of either form of HAV, nor any impact on infection and replication in these cells. In contrast, TIM1-deficient Vero cells showed a modest reduction in quasi-enveloped eHAV (but not naked HAV attachment and replication. Thus, TIM1 facilitates quasi-enveloped eHAV entry in Vero cells, most likely by binding phosphatidylserine (PtdSer residues on the eHAV membrane. Both Tim1−/− Ifnar1−/− and Tim4−/− Ifnar1−/− double-knockout mice were susceptible to infection upon intravenous challenge with infected liver homogenate, with fecal HAV shedding and serum alanine aminotransferase (ALT elevations similar to those in Ifnar1−/− mice. However, intrahepatic HAV RNA and ALT elevations were modestly reduced in Tim1−/−Ifnar1−/− mice compared to Ifnar1−/− mice challenged with a lower titer of gradient-purified HAV or eHAV. We conclude that TIM1 is not an essential hepatovirus entry factor, although its PtdSer-binding activity may contribute to the spread of quasi-enveloped virus and liver injury in mice.

  14. Brain herniation

    Science.gov (United States)

    ... herniation; Uncal herniation; Subfalcine herniation; Tonsillar herniation; Herniation - brain ... Brain herniation occurs when something inside the skull produces pressure that moves brain tissues. This is most ...

  15. Naked singularities, branes and Chern-Simons couplings: The dark side of the 2+1 black hole

    International Nuclear Information System (INIS)

    Zanelli, Jorge

    2010-01-01

    Branes are naked singularities, analogous to linear or planar defects in crystals. Zero-branes in AdS spacetimes are n egative mass black holes , which can be generalized to higher-dimensional branes. When these solutions are endowed with angular momentum, the extremal spinning branes correspond to BPS states. On the other hand, the 2p-branes, spanning a (2p + 1)-dimensional worldsheet, provide a naturally coupling to CS field theories defined on a D-dimensional spacetime, with D > 2p + 1. In this picture, the field that lives in the D-dimensional spacetime, as well as the sources that couple to it are made out of the same stuff -an SO(D - 1,2) connection. The fact that on the brane the AdS group is necessarily broken down to SO(2p, 2), brings in a number of tensor fields that play the role of charged matter living on the brane.

  16. TIM1 (HAVCR1) Is Not Essential for Cellular Entry of Either Quasi-enveloped or Naked Hepatitis A Virions.

    Science.gov (United States)

    Das, Anshuman; Hirai-Yuki, Asuka; González-López, Olga; Rhein, Bethany; Moller-Tank, Sven; Brouillette, Rachel; Hensley, Lucinda; Misumi, Ichiro; Lovell, William; Cullen, John M; Whitmire, Jason K; Maury, Wendy; Lemon, Stanley M

    2017-09-05

    Receptor molecules play key roles in the cellular entry of picornaviruses, and TIM1 (HAVCR1) is widely accepted to be the receptor for hepatitis A virus (HAV), an unusual, hepatotropic human picornavirus. However, its identification as the hepatovirus receptor predated the discovery that hepatoviruses undergo nonlytic release from infected cells as membrane-cloaked, quasi-enveloped HAV (eHAV) virions that enter cells via a pathway distinct from naked, nonenveloped virions. We thus revisited the role of TIM1 in hepatovirus entry, examining both adherence and infection/replication in cells with clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9-engineered TIM1 knockout. Cell culture-derived, gradient-purified eHAV bound Huh-7.5 human hepatoma cells less efficiently than naked HAV at 4°C, but eliminating TIM1 expression caused no difference in adherence of either form of HAV, nor any impact on infection and replication in these cells. In contrast, TIM1-deficient Vero cells showed a modest reduction in quasi-enveloped eHAV (but not naked HAV) attachment and replication. Thus, TIM1 facilitates quasi-enveloped eHAV entry in Vero cells, most likely by binding phosphatidylserine (PtdSer) residues on the eHAV membrane. Both Tim1 -/- Ifnar1 -/- and Tim4 -/- Ifnar1 -/- double-knockout mice were susceptible to infection upon intravenous challenge with infected liver homogenate, with fecal HAV shedding and serum alanine aminotransferase (ALT) elevations similar to those in Ifnar1 -/- mice. However, intrahepatic HAV RNA and ALT elevations were modestly reduced in Tim1 -/- Ifnar1 -/- mice compared to Ifnar1 -/- mice challenged with a lower titer of gradient-purified HAV or eHAV. We conclude that TIM1 is not an essential hepatovirus entry factor, although its PtdSer-binding activity may contribute to the spread of quasi-enveloped virus and liver injury in mice. IMPORTANCE T cell immunoglobulin and mucin-containing domain protein 1 (TIM1) was reported more than

  17. ENERGETIC VALUE OF FORAGES FROM SEMI-ARID REGION AND DIGESTIBILITY OF RATIONS FOR NAKED NECK PULLETS

    Directory of Open Access Journals (Sweden)

    ALEX MARTINS VARELA DE ARRUDA

    2014-01-01

    Full Text Available The feeding programs for naked neck chickens in semi-intensive production system from brazilian equatorial semi-arid environment, must consider regional food availability and respective nutritional values. Thus, to evaluate the digestibility and metabolizable energy of alternative forages, it was used 240 naked neck pullets (Isa Label lineage receiving water and ration ad libitum, pair-housed in cages for total collection of excreta on conventional warehouse. It was used a completely randomized design with factorial arrangement (5x2: one control ration (corn and soy meal and other four experimental rations with silk flower hay (Calotropis procera, cassava leafs hay (Manihot esculenta, kills pasture hay (Senna obtusifolia or leucaena leafs hay (Leucaena leucocephala, and all rations were balanced for two growing phases, between 8 and 10 weeks (young pullets and between 14 and 16 weeks of age (old pullets. The values of apparent digestibility of nutrients for all experimental rations were lower than control ration (P <0.05 and it was observed general means of 72.18% for dry matter, 78.12% for crude protein, 66.90% for ether extract, 28.08% for neutral detergent fiber, 18.51% for the acid detergent fiber, 71.64% for gross energy and availability of 15.61% for mineral matter. The general mean of apparent and corrected metabolizable energy of alternative forages was 1217 kcal/ kg and 1108 kcal/kg, respectively, and the higher value was determined for leucaena hay and the lower value for silk flower hay (P <0.05.

  18. The naked truth: the face and body sensitive N170 response is enhanced for nude bodies.

    Directory of Open Access Journals (Sweden)

    Jari K Hietanen

    Full Text Available Recent event-related potential studies have shown that the occipitotemporal N170 component--best known for its sensitivity to faces--is also sensitive to perception of human bodies. Considering that in the timescale of evolution clothing is a relatively new invention that hides the bodily features relevant for sexual selection and arousal, we investigated whether the early N170 brain response would be enhanced to nude over clothed bodies. In two experiments, we measured N170 responses to nude bodies, bodies wearing swimsuits, clothed bodies, faces, and control stimuli (cars. We found that the N170 amplitude was larger to opposite and same-sex nude vs. clothed bodies. Moreover, the N170 amplitude increased linearly as the amount of clothing decreased from full clothing via swimsuits to nude bodies. Strikingly, the N170 response to nude bodies was even greater than that to faces, and the N170 amplitude to bodies was independent of whether the face of the bodies was visible or not. All human stimuli evoked greater N170 responses than did the control stimulus. Autonomic measurements and self-evaluations showed that nude bodies were affectively more arousing compared to the other stimulus categories. We conclude that the early visual processing of human bodies is sensitive to the visibility of the sex-related features of human bodies and that the visual processing of other people's nude bodies is enhanced in the brain. This enhancement is likely to reflect affective arousal elicited by nude bodies. Such facilitated visual processing of other people's nude bodies is possibly beneficial in identifying potential mating partners and competitors, and for triggering sexual behavior.

  19. Brain Tumors

    Science.gov (United States)

    A brain tumor is a growth of abnormal cells in the tissues of the brain. Brain tumors can be benign, with no cancer cells, ... cancer cells that grow quickly. Some are primary brain tumors, which start in the brain. Others are ...

  20. Interaction of Thermus thermophilus ArsC enzyme and gold nanoparticles naked-eye assays speciation between As(III) and As(V)

    International Nuclear Information System (INIS)

    Politi, Jane; De Stefano, Luca; Spadavecchia, Jolanda; Casale, Sandra; Fiorentino, Gabriella; Antonucci, Immacolata

    2015-01-01

    The thermophilic bacterium Thermus thermophilus HB27 encodes chromosomal arsenate reductase (TtArsC), the enzyme responsible for resistance to the harmful effects of arsenic. We report on adsorption of TtArsC onto gold nanoparticles for naked-eye monitoring of biomolecular interaction between the enzyme and arsenic species. Synthesis of hybrid biological–metallic nanoparticles has been characterized by transmission electron microscopy (TEM), ultraviolet-visible (UV–vis), dynamic light scattering (DLS) and phase modulated infrared reflection absorption (PM-IRRAS) spectroscopies. Molecular interactions have been monitored by UV–vis and Fourier transform-surface plasmon resonance (FT-SPR). Due to the nanoparticles’ aggregation on exposure to metal salts, pentavalent and trivalent arsenic solutions can be clearly distinguished by naked-eye assay, even at 85 μM concentration. Moreover, the assay shows partial selectivity against other heavy metals. (paper)

  1. The chromosome banding pattern in two cytotypes (2n = 36 and 38) of blind mole rats from Turkey (Mammalia: Spalaxidae)

    Czech Academy of Sciences Publication Activity Database

    Arslan, A.; Arisoy, A.; Zima, Jan

    2013-01-01

    Roč. 59, č. 2 (2013), s. 95-100 ISSN 0939-7140 Institutional support: RVO:68081766 Keywords : Nannospalax xanthodon * Ag-NOR staining * C-banding * Aydin * Manisa * western Anatolia Subject RIV: EG - Zoology Impact factor: 0.524, year: 2013

  2. Phylogeny of species and cytotypes of mole rats (Spalacidae) in Turkey inferred from mitochondrial cytochrome b gene sequencees

    Czech Academy of Sciences Publication Activity Database

    Kandemir, I.; Sozen, M.; Matur, F.; Kankilic, T.; Martínková, Natália; Colak, F.; Ozkurt, S. O.; Colak, E.

    2012-01-01

    Roč. 61, č. 1 (2012), s. 25-33 ISSN 0139-7893 Institutional support: RVO:68081766 Keywords : Nannospalax * molecular phylogeny * chromosomal form * Anatolia * Thrace Subject RIV: EG - Zoology Impact factor: 0.494, year: 2012

  3. Burrow systems of mole-rats as refuges for frogs in the Miombo woodlands of south-east Africa

    Czech Academy of Sciences Publication Activity Database

    Šklíba, J.; Jirků, Miloslav; Šumbera, R.

    2016-01-01

    Roč. 32, MAR (2016), s. 158-161 ISSN 0266-4674 R&D Projects: GA ČR GB14-36098G Institutional support: RVO:60077344 Keywords : aestivation * Anura * Bathyergidae * commensalism * ecosystem engineer * Malawi * subterranean rodent * Zambia Subject RIV: EG - Zoology Impact factor: 1.041, year: 2016

  4. The visual system in subterranean African mole-rats (Rodentia, Bathyergidae): Retina, subcortical visual nuclei and primary visual cortex

    Czech Academy of Sciences Publication Activity Database

    Němec, P.; Cveková, P.; Benada, Oldřich; Wielkopolska, E.; Olkowitz, S.; Turlejski, K.; Burda, H.; Bennett, N. C.; Peichl, L.

    2008-01-01

    Roč. 75, 2-4 (2008), s. 356-364 ISSN 0361-9230 Grant - others:GA AV ČR(CZ) GA206/06/1469; ZA(ZA) 2069070 Institutional research plan: CEZ:AV0Z50200510 Keywords : microphthalmia * ocular regression * subterranean mammals Subject RIV: EE - Microbiology, Virology Impact factor: 2.281, year: 2008

  5. A maze-lover's dream: Burrow architecture, natural history and habitat characteristics of Ansell's mole-rat (Fukomys anselli)

    Czech Academy of Sciences Publication Activity Database

    Šklíba, J.; Mazoch, V.; Patzenhauerová, Hana; Hrouzková, E.; Lövy, M.; Kott, O.; Šumbera, R.

    2012-01-01

    Roč. 77, č. 6 (2012), s. 420-427 ISSN 1616-5047 R&D Projects: GA AV ČR IAA601410802 Institutional support: RVO:68081766 Keywords : Bathyergidae * Burrow system * Sociality * Habitat characteristics * Subterranean mammal * Fukomys anselli Subject RIV: EG - Zoology Impact factor: 1.246, year: 2012

  6. Variation in C-heterochromatin and NOR distribution among chromosomal races of mole rats (Spalacidae) from Central Anatolia,Turkey

    Czech Academy of Sciences Publication Activity Database

    Arslan, A.; Sükrüye, A.; Zima, Jan

    2011-01-01

    Roč. 76, č. 1 (2011), s. 28-35 ISSN 1616-5047 R&D Projects: GA MŠk LC06073 Institutional research plan: CEZ:AV0Z60930519 Keywords : Nannospalax nehringi * Karyotype evolution * Speciation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.609, year: 2011

  7. Spatial variability of soil electrical conductivity under the mole rats (Spalax microphthalmus digging activity at the different scales

    Directory of Open Access Journals (Sweden)

    A. V. Zhukov

    2012-07-01

    Full Text Available The soil mounds emerged owing to the mole rats’ digging activity have been shown to be characterised by less electrical conductivity than surrounded soil. This effect is due to the changes of the mounds bulk’s density and moisture. The effect of the mole rats’ digging activity on the soil electrical conductivity has been found not to be restricted by the geometrical border of the mounds. The mounds are surrounded by 1–1.5 m halo of increased soil electrical conductivity. The halo size is increased with the aging of the mound and with the compacting of their aggregation.

  8. Otolith microchemistry of modern versus well-dated ancient naked carp Gymnocypris przewalskii: Implication for water evolution of Lake Qinghai

    Science.gov (United States)

    Zhou, Ling; Jin, Zhangdong; Wang, Chia-Hui; Li, Fuchun; Wang, Yujiao; Wang, Xulong; Zhang, Fei; Chen, Liumei; Du, Jinhua

    2015-06-01

    There is ongoing debate over how the water level and composition of the water in Lake Qinghai changed in the past and might change in future. This study of the microchemistry of otoliths from ancient naked carp explores the chemistry of a relict lake isolated from Lake Qinghai during the Little Ice Age (LIA). A close correlation between the ages measured on fish bone and otoliths by AMS-14C, and by optically stimulated luminescence on overlying sediments, confirms a high water level in Lake Qinghai before 680-300 years ago. The contrasting compositions of the ancient otoliths relative to modern otoliths and waters indicate that the relict lake became enriched in 18O, Mg, Li, B and to a lesser extent Ba, but depleted in 13C, owing to strong evaporation, authigenic carbonates precipitation, (micro-)organism activity, and less fresh water input after it was isolated. If there were long-term fresh water input, however, a reverse trend might occur. The most important observation is that, because the waters have been supersaturated with respect to carbonates, authigenic carbonate precipitation would result in low but consistent Sr/Ca ratios in the lakes, as recorded by both the ancient and modern otoliths. The geochemical records of ancient versus modern biogenic carbonates provide insights into the long-term hydroclimatic evolution processes of an inland water body.

  9. In vivo expression of ß-galactosidase by rat oviduct exposed to naked DNA or messenger RNA

    Directory of Open Access Journals (Sweden)

    MARIANA RIOS

    2002-01-01

    Full Text Available Intra-oviductal administration of RNA obtained from oviducts of estradiol-treated rats resulted in accelerated egg transport (Ríos et al., 1997. It is probable that estradiol-induced messenger RNA (mRNA entered oviductal cells and was translated into the proteins involved in accelerated egg transport. In order to test this interpretation we deposited in vivo 50 µg of pure ß-galactosidase (ß-gal mRNA, 50 µg of pure DNA from the reporter gene ß-gal under SV40 promoter or the vehicle (control oviducts into the oviductal lumen of rats. Twenty four hours later the ß-gal activity was assayed in oviductal tissue homogenates using o-nitrophenyl-ß-D-galactopyranoside as a substrate. The administration of ß-gal mRNA and pSVBgal plasmid increased ß-gal activity by 71% and 142%, respectively, over the control oviducts. These results indicate that naked DNA and mRNA coding for ß-gal can enter oviductal cells and be translated into an active enzyme. They are consistent with the interpretation that embryo transport acceleration caused by the injection of estradiol-induced RNA in the oviduct involves translation of the injected mRNA

  10. Low-Dose Gene Therapy for Murine PKU Using Episomal Naked DNA Vectors Expressing PAH from Its Endogenous Liver Promoter

    Directory of Open Access Journals (Sweden)

    Hiu Man Grisch-Chan

    2017-06-01

    Full Text Available Limited duration of transgene expression, insertional mutagenesis, and size limitations for transgene cassettes pose challenges and risk factors for many gene therapy vectors. Here, we report on physiological expression of liver phenylalanine hydroxylase (PAH by delivery of naked DNA/minicircle (MC-based vectors for correction of homozygous enu2 mice, a model of human phenylketonuria (PKU. Because MC vectors lack a defined size limit, we constructed a MC vector expressing a codon-optimized murine Pah cDNA that includes a truncated intron and is under the transcriptional control of a 3.6-kb native Pah promoter/enhancer sequence. This vector, delivered via hydrodynamic injection, yielded therapeutic liver PAH activity and sustained correction of blood phenylalanine comparable to viral or synthetic liver promoters. Therapeutic efficacy was seen with vector copy numbers of 95% loss of vector genomes and PAH activity in liver, demonstrating that MC vectors had not integrated into the liver genome. In conclusion, MC vectors, which do not have a defined size-limitation, offer a favorable safety profile for hepatic gene therapy due to their non-integration in combination with native promoters.

  11. Evidence for a new particle with naked ''beauty'' and for its associated production in high-energy (pp) interactions

    International Nuclear Information System (INIS)

    Basile, M.; Bonvicini, G.; Cara Romeo, G.; Cifarelli, L.; Contin, A.; D'Ali, G.; Di Cesare, P.; Esposito, B.; Giusti, P.; Massam, T.; Nania, R.; Palmonari, F.; Sartorelli, G.; Valenti, G.; Zichichi, A.; Bologna Univ.; Perugia Univ.

    1981-01-01

    Evidence is reported for the existence, with six standard deviations significance, of a new particle: the heaviest baryon observed so far, whose mass is measured to be m = (5,425 +- 75 175 ) MeV/c 2 . Its width is compatible with zero. It is electrically neutral and it decays into a proton, a D 0 , and a π - . This particle is produced in association with a hadronic state whose semileptonic decay contains a positive electron. The partial cross section for the observed effect is δσ = (3.8 +- 1.2) x 10 - 35 cm 2 . The interpretation of these results is in terms of the associated production of naked ''beauty'' states in (pp) interactions at √s = 62 GeV c.m. energy. The new particle is identified as the first ''beauty''-flavoured baryon with quark composition (udb), i.e. the #betta# 0 sub(b). The discrimination power of the experiment against ''known'' physics, is of the order of 10 - 10 . (author)

  12. Yield reduction caused by a soil-borne disease of naked, dwarf, and conventional oat in Finland

    Directory of Open Access Journals (Sweden)

    P. PELTONEN-SAINIO

    2008-12-01

    Full Text Available A severe disease occurred in the field plots of naked (cv. Salomon, dwarf (cv. Pal, and conventional oat (cvs. Jalostettu maatiainen and Salo at the Viikki Experimental Farm of the University of Helsinki, Finland, in 1994 and 1995. Symptoms were expressed as grayish-brown necrotic areas on the lower leaves which killed plants from the seedling to heading stage, the effect being cultivar dependent. The proportion of plants killed plants from the seedling to heading stage, the effect being cultivar dependent. The proportion of plants killed contributed to the yield losses. The infection also resulted in less grains per panicle and lower weight of both panicle and vegetative above-ground biomass. From a total of 57 fungal isolates obtained from infected leaves, Fusarium culmorum (W.G.Sm. Sacc. and F. sambucinum Fuck. Dominated and subsequently caused infection (particularly foot and root rot in oat in laboratory tests. These two Fusarium spp. Were considered to be the primary causal agents of the symptoms observed in the field, although other pathogens may have been present. The disease was probably soil-borne. The results of this study suggested that the unusually dry and warm weather during late June and in July was the principal factor behind the severe disease outbreak. ;

  13. Performance comparison of dwarf laying hens segregating for the naked neck gene in temperate and subtropical environments

    Directory of Open Access Journals (Sweden)

    Bordas André

    2009-01-01

    Full Text Available Abstract This study compares laying performances between two environments of dwarf laying hen lines segregating for the naked neck mutation (NA locus, a selected dwarf line of brown-egg layers and its control line. Layers with one of the three genotypes at the NA locus were produced from 11 sires from the control line and 12 sires from the selected line. Two hatches produced 216 adult hens in Taiwan and 297 hens in France. Genetic parameters for laying traits were estimated in each environment and the ranking of sire breeding values was compared between environments. Laying performance was lower, and mortality was higher in Taiwan than in France. The line by environment interaction was highly significant for body weight at 16 weeks, clutch length and egg number, with or without Box-Cox transformation. The selected line was more sensitive to environmental change but in Taiwan it could maintain a higher egg number than the control line. Estimated heritability values in the selected line were higher in France than in Taiwan, but not for all the traits in the control line. The rank correlations between sire breeding values were low within the selected line and slightly higher in the control line. A few sire families showed a good ranking in both environments, suggesting that some families may adapt better to environmental change.

  14. Platyamoeba pseudovannellida n. sp., a naked amoeba with wide salt tolerance isolated from the Salton Sea, California.

    Science.gov (United States)

    Hauer, G; Rogerson, A; Anderson, O R

    2001-01-01

    A new species of naked amoeba, Platyamoeba pseudovannellida n.sp., is described on the basis of light microscopic and fine structural features. The amoeba was isolated from the Salton Sea, California, from water at a salinity of ca. 44%. Locomotive amoebae occasionally had a spatulate outline and floating cells had radiating pseudopodia, sometimes with pointed tips. Both these features are reminiscent of the genus Vannella. However, the surface coat (glycocalyx) as revealed by TEM indicates that this is a species of Platyamoeba. Although salinity was not used as a diagnostic feature, this species was found to have remarkable tolerance to fluctuating salinity levels, even when changes were rapid. Amoebae survived over the range 0 per thousand to 150 per thousand salt and grew within the range 0 per thousand to 138 per thousand salt. The generation time of cells averaged 29 h and was not markedly affected by salt concentration. This is longer than expected for an amoeba of this size and suggests a high energetic cost of coping with salinity changes. The morphology of cells changed with increasing salinity: at 0 per thousand cells were flattened and active and at the other extreme (138 per thousand) amoebae were wrinkled and domed and cell movement was very slow. At the ultrastructural level, the cytoplasm of cells grown at high salinity (98 per thousand was considerably denser than that of cells reared at 0 per thousand.

  15. Brain surgery

    Science.gov (United States)

    Craniotomy; Surgery - brain; Neurosurgery; Craniectomy; Stereotactic craniotomy; Stereotactic brain biopsy; Endoscopic craniotomy ... cut depends on where the problem in the brain is located. The surgeon creates a hole in ...

  16. Brain Malformations

    Science.gov (United States)

    Most brain malformations begin long before a baby is born. Something damages the developing nervous system or causes it ... medicines, infections, or radiation during pregnancy interferes with brain development. Parts of the brain may be missing, ...

  17. A phenolic acid based colourimetric 'naked-eye' chemosensor for the rapid detection of Cu(II) ions

    Science.gov (United States)

    Sengupta, Priti; Ganguly, Aniruddha; Bose, Adity

    2018-06-01

    The crucial role of chemosensor for the immediate recognition of environment pollutant motivates the researchers to develop variety of sensing protocols. Of various chemosensory protocols, the colour change observed by the naked eye is considered to be a conceivable and on-site way to indicate the presence of an analyte. We herein report a colourimetric and commercially available absorption probe, sinapic acid (SA) that is completely ready to use for "on-site" visual determination of copper ions. The molecule, SA is well-known phenolic acid, often utilized for its antibacterial activity. In this work, for the first time, we are exploring its ability to work as an efficient Cu2+ sensor. This sensor molecule selectively detected Cu2+ ions by changing its colour from colourless to pink within detection limit of 64.5 nM, which is much lower than other reported sensor molecules and the suggested limit by World Health Organization (WHO) and U. S. Environmental Protection Agency (EPA) guidelines. The sensing mechanism was investigated through UV-vis and 1H NMR titration along with ESI-MS spectroscopy and further confirmed by DFT computational studies. Studies revealed the participation of hydroxyl group (sbnd OH) and methoxy group (sbnd OMe) of SA in complexation with Cu2+. The binding stoichiometry of SA to Cu2+ was found to be 1:2 through Job's plot and ESI-MS analysis. Importantly, paper strips of SA were prepared which could be used for a rapid "on-site" determination of Cu2+ containing samples.

  18. Effect of particle size on solubility, dissolution rate, and oral bioavailability: evaluation using coenzyme Q10 as naked nanocrystals

    Directory of Open Access Journals (Sweden)

    Sun J

    2012-11-01

    Full Text Available Jiao Sun,1 Fan Wang,1,2 Yue Sui,1 Zhennan She,1 Wenjun Zhai,1 Chunling Wang,1 Yihui Deng11College of Pharmacy, Shenyang Pharmaceutical University, Shenyang, China; 2Beijing Zhijianjinrui Applied Pharmaceutical Science Inc, Beijing, ChinaAbstract: In this paper work, four naked nanocrystals (size range 80–700 nm were prepared without any surfactant or polymer using the solvent/nonsolvent method. The effects of particle size on their solubility, dissolution, and oral bioavailability were investigated. Solubility and dissolution testing were performed in three types of dissolution medium, and the studies demonstrated that the equilibrium solubilities of coenzyme Q10 nanocrystals and bulk drugs were not affected by the dissolution media but the kinetic solubilities were. Kinetic solubility curves and changes in particle size distribution were determined and well explained by the proposed solubilization model for the nanocrystals and bulk drugs. The particle size effect on dissolution was clearly influenced by the diffusion coefficients of the various dissolution media, and the dissolution velocity of coenzyme Q10 increased as particle size decreased. The bioavailability of coenzyme Q10 after oral administration in beagle dogs was improved by reducing the particle size. For 700 nm nanocrystals, the AUC0–48 was 4.4-fold greater than that for the coarse suspensions, but a further decrease in particle size from 700 nm to 120 nm did not contribute to improvement in bioavailability until the particle size was reduced to 80 nm, when bioavailability was increased by 7.3-fold.Keywords: particle size, solubility, dissolution, nanocrystal, bioavailability, coenzyme Q10

  19. Feasibilty of in utero DNA vaccination following naked gene transfer into pig fetal muscle: transgene expression, immunity and safety.

    Science.gov (United States)

    Rinaldi, Monica; Signori, Emanuela; Rosati, Paolo; Cannelli, Giorgio; Parrella, Paola; Iannace, Enrico; Monego, Giovanni; Ciafrè, Silvia Anna; Farace, Maria Giulia; Iurescia, Sandra; Fioretti, Daniela; Rasi, Guido; Fazio, Vito Michele

    2006-05-22

    The high toll of death among first-week infants is due to infections occurring at the end of pregnancy, during birth or by breastfeeding. This problem significantly concerns industrialized countries also. To prevent the typical "first-week infections", a vaccine would be protective as early as at the birth. In utero DNA immunization has demonstrated the effectiveness in inducing specific immunity in newborns. We have already published results of a 2-year follow-up showing long-term safety, protective antibody titers at birth and long-term immune memory, following intramuscular in utero anti-HBV DNA immunization in 90-days pig fetuses. We have now analyzed further parameters of short-term safety. Two different reporter genes were injected in the thigh muscles of 90-days fetuses. At 8 days following DNA injection, we found high-level of transgenes expression in all injected fetuses. A step gradient of expression from the area of injection was observed with both reporter genes. CMV promoter/enhancer produced higher levels of expression compared to SV40 promoter/enhancer. Moreover, no evidence of local or systemic flogistic alterations or fetal malformations, mortality or haemorrhage following intramuscular injection were observed. A single anti-HBV s-antigen DNA immunization in 90-days fetuses supported protective antibody levels in all immunized newborns, lasting at least up to 4 months after birth. Our report further sustains safety and efficacy of intramuscular in utero naked gene transfer and immunization. This approach may support therapeutic or prophylactic procedure in many early life-threatening pathologic conditions.

  20. Covalent Binding of Antibodies to Cellulose Paper Discs and Their Applications in Naked-eye Colorimetric Immunoassays.

    Science.gov (United States)

    Peng, Yanfen; Gelder, Victor Van; Amaladoss, Anburaj; Patel, Kadamb Haribhai

    2016-10-21

    This report presents two methods for the covalent immobilization of capture antibodies on cellulose filter paper grade No. 1 (medium-flow filter paper) discs and grade No. 113 (fast-flow filter paper) discs. These cellulose paper discs were grafted with amine functional groups through a silane coupling technique before the antibodies were immobilized on them. Periodate oxidation and glutaraldehyde cross-linking methods were used to graft capture antibodies on the cellulose paper discs. In order to ensure the maximum binding capacity of the capture antibodies to their targets after immobilization, the effects of various concentrations of sodium periodate, glutaraldehyde, and capture antibodies on the surface of the paper discs were investigated. The antibodies that were coated on the amine-functionalized cellulose paper discs through a glutaraldehyde cross-linking agent showed enhanced binding activity to the target when compared to the periodate oxidation method. IgG (in mouse reference serum) was used as a reference target in this study to test the application of covalently immobilized antibodies through glutaraldehyde. A new paper-based, enzyme-linked immunosorbent assay (ELISA) was successfully developed and validated for the detection of IgG. This method does not require equipment, and it can detect 100 ng/ml of IgG. The fast-flow filter paper was more sensitive than the medium-flow filter paper. The incubation period of this assay was short and required small sample volumes. This naked-eye, colorimetric immunoassay can be extended to detect other targets that are identified with conventional ELISA.

  1. Ultrasound-mediated gene delivery of naked plasmid DNA in skeletal muscles: a case for bolus injections.

    Science.gov (United States)

    Sanches, Pedro Gomes; Mühlmeister, Mareike; Seip, Ralf; Kaijzel, Eric; Löwik, Clemens; Böhmer, Marcel; Tiemann, Klaus; Grüll, Holger

    2014-12-10

    Localized gene delivery has many potential clinical applications. However, the nucleic acids (e.g. pDNA and siRNA) are incapable of passively crossing the endothelium, cell membranes and other biological barriers which must be crossed to reach their intracellular targets. A possible solution is the use of ultrasound to burst circulating microbubbles inducing transient permeabilization of surrounding tissues which mediates nucleic acid extravasation and cellular uptake. In this study we report on an optimization of the ultrasound gene delivery technique. Naked pDNA (200 μg) encoding luciferase and SonoVue® microbubbles were co-injected intravenously in mice. The hindlimb skeletal muscles were exposed to ultrasound from a non-focused transducer (1 MHz, 1.25 MPa, PRI 30s) and injection protocols and total amounts as well as ultrasound parameters were systemically varied. Gene expression was quantified relative to a control using a bioluminescence camera system at day 7 after sonication. Bioluminescence ratios in sonicated/control muscles of up to 101× were obtained. In conclusion, we were able to specifically deliver genetic material to the selected skeletal muscles and overall, the use of bolus injections and high microbubble numbers resulted in increased gene expression reflected by stronger bioluminescence signals. Based on our data, bolus injections seem to be required in order to achieve transient highly concentrated levels of nucleic acids and microbubbles at the tissue of interest which upon ultrasound exposure should lead to increased levels of gene delivery. Thus, ultrasound mediated gene delivery is a promising technique for the clinical translation of localized drug delivery. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Microbial Populations in Naked Neck Chicken Ceca Raised on Pasture Flock Fed with Commercial Yeast Cell Wall Prebiotics via an Illumina MiSeq Platform.

    Directory of Open Access Journals (Sweden)

    Si Hong Park

    Full Text Available Prebiotics are non-digestible carbohydrate dietary supplements that selectively stimulate the growth of one or more beneficial bacteria in the gastrointestinal tract of the host. These bacteria can inhibit colonization of pathogenic bacteria by producing antimicrobial substances such as short chain fatty acids (SCFAs and competing for niches with pathogens within the gut. Pasture flock chickens are generally raised outdoors with fresh grass, sunlight and air, which represents different environmental growth conditions compared to conventionally raised chickens. The purpose of this study was to evaluate the difference in microbial populations from naked neck chicken ceca fed with commercial prebiotics derived from brewer's yeast cell wall via an Illumina MiSeq platform. A total of 147 day-of-hatch naked neck chickens were distributed into 3 groups consisted of 1 C: control (no prebiotic, 2 T1: Biolex® MB40 with 0.2%, and 3 T2: Leiber® ExCel with 0.2%, consistently supplemented prebiotics during the experimental period. At 8 weeks, a total of 15 birds from each group were randomly selected and ceca removed for DNA extraction. The Illumina Miseq platform based on V4 region of 16S rRNA gene was applied for microbiome analysis. Both treatments exhibited limited impact on the microbial populations at the phylum level, with no significant differences in the OTU number of Bacteroidetes among groups and an increase of Proteobacteria OTUs for the T1 (Biolex® MB40 group. In addition there was a significant increase of genus Faecalibacterium OTU, phylum Firmicutes. According to the development of next generation sequencing (NGS, microbiome analysis based on 16S rRNA gene proved to be informative on the prebiotic impact on poultry gut microbiota in pasture-raised naked neck birds.

  3. Microbial Populations in Naked Neck Chicken Ceca Raised on Pasture Flock Fed with Commercial Yeast Cell Wall Prebiotics via an Illumina MiSeq Platform.

    Science.gov (United States)

    Park, Si Hong; Lee, Sang In; Ricke, Steven C

    2016-01-01

    Prebiotics are non-digestible carbohydrate dietary supplements that selectively stimulate the growth of one or more beneficial bacteria in the gastrointestinal tract of the host. These bacteria can inhibit colonization of pathogenic bacteria by producing antimicrobial substances such as short chain fatty acids (SCFAs) and competing for niches with pathogens within the gut. Pasture flock chickens are generally raised outdoors with fresh grass, sunlight and air, which represents different environmental growth conditions compared to conventionally raised chickens. The purpose of this study was to evaluate the difference in microbial populations from naked neck chicken ceca fed with commercial prebiotics derived from brewer's yeast cell wall via an Illumina MiSeq platform. A total of 147 day-of-hatch naked neck chickens were distributed into 3 groups consisted of 1) C: control (no prebiotic), 2) T1: Biolex® MB40 with 0.2%, and 3) T2: Leiber® ExCel with 0.2%, consistently supplemented prebiotics during the experimental period. At 8 weeks, a total of 15 birds from each group were randomly selected and ceca removed for DNA extraction. The Illumina Miseq platform based on V4 region of 16S rRNA gene was applied for microbiome analysis. Both treatments exhibited limited impact on the microbial populations at the phylum level, with no significant differences in the OTU number of Bacteroidetes among groups and an increase of Proteobacteria OTUs for the T1 (Biolex® MB40) group. In addition there was a significant increase of genus Faecalibacterium OTU, phylum Firmicutes. According to the development of next generation sequencing (NGS), microbiome analysis based on 16S rRNA gene proved to be informative on the prebiotic impact on poultry gut microbiota in pasture-raised naked neck birds.

  4. Status of GENIUS-TF-II and TF-III-The long-term stability of naked detectors in liquid nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    Klapdor-Kleingrothaus, H.V. [Max-Planck-Institut fuer Kernphysik, P.O. Box 10 39 80, D-69029 Heidelberg (Germany)]. E-mail: H.Klapdor@mpi-hd.mpg.de; Krivosheina, I.V. [Max-Planck-Institut fuer Kernphysik, P.O. Box 10 39 80, D-69029 Heidelberg (Germany)

    2006-10-15

    GENIUS-TF-II is a setup of six naked high purity Ge detectors (15kg) in liquid nitrogen in Gran Sasso. It has been installed in October, 2004-after the first four naked Ge detectors had been installed on May 5, 2003 (GENIUS-TF-I). The GENIUS-Test-Facility (GENIUS-TF) is the first and up to now only setup ever testing the novel technique aiming at extreme background reduction in search for rare decays in particular underground. The goal of GENIUS-TF was to test some key operational parameters of the full GENIUS project proposal in 1997 [H.V. Klapdor-Kleingrothaus, Int. J. Mod. Phys. A 13 (1998) 3953; H.V. Klapdor-Kleingrothaus, J. Hellmig, M. Hirsch, GENIUS-Proposal, 20 November 1997; J. Hellmig and H.V. Klapdor-Kleingrothaus, Z. Phys. A 359 ( 1997) 351 and nucl-ex/9801004; H.V. Klapdor-Kleingrothaus, M. Hirsch, Z. Phys. A 359 (1997) 361; H.V. Klapdor-Kleingrothaus, J. Hellmig, M. Hirsch, J. Phys. G 24 (1998) 483; H.V. Klapdor-Kleingrothaus, CERN Courier, November 1997, pp. 16-18]. Simultaneous physical goal is to search for the annual modulation of the Dark Matter signal [H.V. Klapdor-Kleingrothaus, et al., Nucl. Instr. and Meth. A 481 (2002) 149; C. Tomei, A. Dietz, I. Krivosheina, H.V. Klapdor-Kleingrothaus, Nucl. Instr. and Meth. 508 (2003) 343]. After operation of GENIUS-TF over three years with finally six naked Ge detectors (15kg) in liquid nitrogen in Gran Sasso we realize serious problems for realization of a full-size GENIUS-like experiment: (1) Background from Rn222 diffusing into the setup, on a level far beyond the expectation. (2) Limited long-term stability of naked detectors in liquid nitrogen as result of increasing leakage current. None of the six detectors is running after three years with the nominal leakage current. Three of the six detectors do not work any more at all. The results of our three years of investigation of the long-term stability may cast doubt on the possibility to perform full GENIUS-like projects.

  5. Status of GENIUS-TF-II and TF-III-The long-term stability of naked detectors in liquid nitrogen

    International Nuclear Information System (INIS)

    Klapdor-Kleingrothaus, H.V.; Krivosheina, I.V.

    2006-01-01

    GENIUS-TF-II is a setup of six naked high purity Ge detectors (15kg) in liquid nitrogen in Gran Sasso. It has been installed in October, 2004-after the first four naked Ge detectors had been installed on May 5, 2003 (GENIUS-TF-I). The GENIUS-Test-Facility (GENIUS-TF) is the first and up to now only setup ever testing the novel technique aiming at extreme background reduction in search for rare decays in particular underground. The goal of GENIUS-TF was to test some key operational parameters of the full GENIUS project proposal in 1997 [H.V. Klapdor-Kleingrothaus, Int. J. Mod. Phys. A 13 (1998) 3953; H.V. Klapdor-Kleingrothaus, J. Hellmig, M. Hirsch, GENIUS-Proposal, 20 November 1997; J. Hellmig and H.V. Klapdor-Kleingrothaus, Z. Phys. A 359 ( 1997) 351 and nucl-ex/9801004; H.V. Klapdor-Kleingrothaus, M. Hirsch, Z. Phys. A 359 (1997) 361; H.V. Klapdor-Kleingrothaus, J. Hellmig, M. Hirsch, J. Phys. G 24 (1998) 483; H.V. Klapdor-Kleingrothaus, CERN Courier, November 1997, pp. 16-18]. Simultaneous physical goal is to search for the annual modulation of the Dark Matter signal [H.V. Klapdor-Kleingrothaus, et al., Nucl. Instr. and Meth. A 481 (2002) 149; C. Tomei, A. Dietz, I. Krivosheina, H.V. Klapdor-Kleingrothaus, Nucl. Instr. and Meth. 508 (2003) 343]. After operation of GENIUS-TF over three years with finally six naked Ge detectors (15kg) in liquid nitrogen in Gran Sasso we realize serious problems for realization of a full-size GENIUS-like experiment: (1) Background from Rn222 diffusing into the setup, on a level far beyond the expectation. (2) Limited long-term stability of naked detectors in liquid nitrogen as result of increasing leakage current. None of the six detectors is running after three years with the nominal leakage current. Three of the six detectors do not work any more at all. The results of our three years of investigation of the long-term stability may cast doubt on the possibility to perform full GENIUS-like projects

  6. Silencing the Honey Bee (Apis mellifera) Naked Cuticle Gene (nkd) Improves Host Immune Function and Reduces Nosema ceranae Infections

    Science.gov (United States)

    Li, Wenfeng; Evans, Jay D.; Huang, Qiang; Rodríguez-García, Cristina; Liu, Jie; Hamilton, Michele; Grozinger, Christina M.; Webster, Thomas C.; Su, Songkun

    2016-01-01

    ABSTRACT Nosema ceranae is a new and emerging microsporidian parasite of European honey bees, Apis mellifera, that has been implicated in colony losses worldwide. RNA interference (RNAi), a posttranscriptional gene silencing mechanism, has emerged as a potent and specific strategy for controlling infections of parasites and pathogens in honey bees. While previous studies have focused on the silencing of parasite/pathogen virulence factors, we explore here the possibility of silencing a host factor as a mechanism for reducing parasite load. Specifically, we used an RNAi strategy to reduce the expression of a honey bee gene, naked cuticle (nkd), which is a negative regulator of host immune function. Our studies found that nkd mRNA levels in adult bees were upregulated by N. ceranae infection (and thus, the parasite may use this mechanism to suppress host immune function) and that ingestion of double-stranded RNA (dsRNA) specific to nkd efficiently silenced its expression. Furthermore, we found that RNAi-mediated knockdown of nkd transcripts in Nosema-infected bees resulted in upregulation of the expression of several immune genes (Abaecin, Apidaecin, Defensin-1, and PGRP-S2), reduction of Nosema spore loads, and extension of honey bee life span. The results of our studies clearly indicate that silencing the host nkd gene can activate honey bee immune responses, suppress the reproduction of N. ceranae, and improve the overall health of honey bees. This study represents a novel host-derived therapeutic for honey bee disease treatment that merits further exploration. IMPORTANCE Given the critical role of honey bees in the pollination of agricultural crops, it is urgent to develop strategies to prevent the colony decline induced by the infection of parasites/pathogens. Targeting parasites and pathogens directly by RNAi has been proven to be useful for controlling infections in honey bees, but little is known about the disease impacts of RNAi silencing of host factors

  7. Gene expression in the muscle and central nervous system following intramuscular inoculation of encapsidated or naked poliovirus replicons

    International Nuclear Information System (INIS)

    Jackson, Cheryl A.; Messinger, Jeff; Palmer, Matthew T.; Peduzzi, Jean D.; Morrow, Casey D.

    2003-01-01

    The spread of intramuscularly inoculated poliovirus to the central nervous system (CNS) has been documented in humans, monkeys, and mice transgenic for the human poliovirus receptor. Poliovirus spread is thought to be due to infection of the peripheral nerve and retrograde transport of poliovirus through the axon to the neuron cell body, where final virus uncoating occurs and translation/replication ensues. In previous studies, we have shown that polio-based vectors (replicons) can be used for gene delivery to motor neurons of the CNS. Using a replicon that encodes green fluorescent protein (GFP), we found that following intrathecal inoculation, GFP expression was confined to motorneurons of the spinal cord. To further characterize the gene expression of poliovirus in the periphery and CNS, we have intramuscularly inoculated transgenic mice with poliovirus replicons encoding GFP. Expression of GFP was demonstrated in the muscle, sciatic nerve, dorsal root ganglion, and the ventral horn motorneurons following intramuscular inoculation. There was no evidence of paralysis or behavioral abnormalities in the mice following intramuscular inoculation of the replicon encoding GFP. Injection of replicon RNA alone (naked RNA) into the muscle of transgenic mice or rats, which do not express the poliovirus receptor, also resulted in expression of GFP in the muscle, sciatic nerve, dorsal root ganglion, and ventral horn motorneurons, indicating that transport of the replicon RNA from the periphery to CNS had occurred. GFP expression was found in the muscles and sciatic nerve as early as 6 h after injection of replicons or replicon RNA, even after sciatic nerve section. Analysis at longer times postinjection revealed GFP expression similar to 6 h levels in the cut sciatic nerves and robust expression in the nerves of uncut animals. The infection and expression of GFP in the CNS following intramuscular inoculation of encapsidated replicons encoding GFP occurred in juvenile or

  8. Silencing the Honey Bee (Apis mellifera) Naked Cuticle Gene (nkd) Improves Host Immune Function and Reduces Nosema ceranae Infections.

    Science.gov (United States)

    Li, Wenfeng; Evans, Jay D; Huang, Qiang; Rodríguez-García, Cristina; Liu, Jie; Hamilton, Michele; Grozinger, Christina M; Webster, Thomas C; Su, Songkun; Chen, Yan Ping

    2016-11-15

    Nosema ceranae is a new and emerging microsporidian parasite of European honey bees, Apis mellifera, that has been implicated in colony losses worldwide. RNA interference (RNAi), a posttranscriptional gene silencing mechanism, has emerged as a potent and specific strategy for controlling infections of parasites and pathogens in honey bees. While previous studies have focused on the silencing of parasite/pathogen virulence factors, we explore here the possibility of silencing a host factor as a mechanism for reducing parasite load. Specifically, we used an RNAi strategy to reduce the expression of a honey bee gene, naked cuticle (nkd), which is a negative regulator of host immune function. Our studies found that nkd mRNA levels in adult bees were upregulated by N. ceranae infection (and thus, the parasite may use this mechanism to suppress host immune function) and that ingestion of double-stranded RNA (dsRNA) specific to nkd efficiently silenced its expression. Furthermore, we found that RNAi-mediated knockdown of nkd transcripts in Nosema-infected bees resulted in upregulation of the expression of several immune genes (Abaecin, Apidaecin, Defensin-1, and PGRP-S2), reduction of Nosema spore loads, and extension of honey bee life span. The results of our studies clearly indicate that silencing the host nkd gene can activate honey bee immune responses, suppress the reproduction of N. ceranae, and improve the overall health of honey bees. This study represents a novel host-derived therapeutic for honey bee disease treatment that merits further exploration. Given the critical role of honey bees in the pollination of agricultural crops, it is urgent to develop strategies to prevent the colony decline induced by the infection of parasites/pathogens. Targeting parasites and pathogens directly by RNAi has been proven to be useful for controlling infections in honey bees, but little is known about the disease impacts of RNAi silencing of host factors. Here, we demonstrate

  9. The Naked Blunder

    CERN Multimedia

    Computer Security Team

    2013-01-01

    In the past, we have published many different articles on a multitude of aspects of computer security and on the risk to CERN and to you when you use your computer at CERN or at home. Some were relevant to all of us, others only to a minority. This time, we would like to raise a rather delicate and fortunately rare issue: the consultation of pornographic websites and why it is forbidden at CERN.   With 10,000 people at CERN of different cultural and professional backgrounds, some working outside traditional working hours and some staying in one of the three CERN hostels, it is a natural fact that behaviours, interests, perceptions and attitudes vary significantly. CERN highly values the diversity of its personnel and users and the interaction between them. In this respect, the CERN campus is comparable to a small city and, as in every small city, some citizens are attracted to pornography. It is not easy to find a common definition of pornography. It depends on our cultural roots, our value...

  10. The naked experts

    International Nuclear Information System (INIS)

    Martin, B.

    1982-01-01

    In an article critical of experts, the cases argued for and against nuclear power are discussed under the headings: environmental hazards arising from the nuclear fuel cycle; proliferation of nuclear weapons capabilities via expansion of the nuclear power industry; political and social threats and restraints of a nuclear society (terrorism, reduction in civil liberties, centralised political and economic power); economic and employment disadvantages of nuclear power; impact of uranium mining on (Australian) aboriginal culture; inadequacy of nuclear power as a solution to energy problems; advantages of a 'soft energy path' based around conservation and renewable energy technologies. (U.K.)

  11. The Naked Manager

    DEFF Research Database (Denmark)

    Meier Sørensen, Bent; Villadsen, Kaspar

    2015-01-01

    expressive and ‘liberated’ bodily comportment—is used tactically to shape the space of conduct of others in the company. The study foregrounds the managerial body as ‘signifier’ in its own right. Empirically, this is done through an analysis of video material produced by the film company Zentropa about...

  12. Why Is She Naked?

    DEFF Research Database (Denmark)

    Rodil, Kasper; Winschiers-Theophilus, Heike

    2018-01-01

    with a refinement of the previously presented Tripartite Digitisation Model (TDM). We begin by providing a short recapitulation of the TDM originally published in Vol. 10, with an emphasis on the role of evaluations. This model is exemplified with a concrete example of digitisation of ICH together with an Ova...

  13. Naked black holes

    International Nuclear Information System (INIS)

    Horowitz, G.T.; Ross, S.F.

    1997-01-01

    It is shown that there are large static black holes for which all curvature invariants are small near the event horizon, yet any object which falls in experiences enormous tidal forces outside the horizon. These black holes are charged and near extremality, and exist in a wide class of theories including string theory. The implications for cosmic censorship and the black hole information puzzle are discussed. copyright 1997 The American Physical Society

  14. Brain Diseases

    Science.gov (United States)

    The brain is the control center of the body. It controls thoughts, memory, speech, and movement. It regulates the function of many organs. When the brain is healthy, it works quickly and automatically. However, ...

  15. Brain Aneurysm

    Science.gov (United States)

    A brain aneurysm is an abnormal bulge or "ballooning" in the wall of an artery in the brain. They are sometimes called berry aneurysms because they ... often the size of a small berry. Most brain aneurysms produce no symptoms until they become large, ...

  16. Brain Development

    Science.gov (United States)

    ... Become a Member Home Early Development & Well-Being Brain Development A child’s brain undergoes an amazing period of development from birth ... neural connections each second. The development of the brain is influenced by many factors, including a child’s ...

  17. Transferrin-bearing polypropylenimine dendrimer for targeted gene delivery to the brain.

    Science.gov (United States)

    Somani, Sukrut; Blatchford, David R; Millington, Owain; Stevenson, M Lynn; Dufès, Christine

    2014-08-28

    The possibility of using genes as medicines to treat brain diseases is currently limited by the lack of safe and efficacious delivery systems able to cross the blood-brain barrier, thus resulting in a failure to reach the brain after intravenous administration. On the basis that iron can effectively reach the brain by using transferrin receptors for crossing the blood-brain barrier, we propose to investigate if a transferrin-bearing generation 3-polypropylenimine dendrimer would allow the transport of plasmid DNA to the brain after intravenous administration. In vitro, the conjugation of transferrin to the polypropylenimine dendrimer increased the DNA uptake by bEnd.3 murine brain endothelioma cells overexpressing transferrin receptors, by about 1.4-fold and 2.3-fold compared to that observed with the non-targeted dendriplex and naked DNA. This DNA uptake appeared to be optimal following 2h incubation with the treatment. In vivo, the intravenous injection of transferrin-bearing dendriplex more than doubled the gene expression in the brain compared to the unmodified dendriplex, while decreasing the non-specific gene expression in the lung. Gene expression was at least 3-fold higher in the brain than in any tested peripheral organs and was at its highest 24h following the injection of the treatments. These results suggest that transferrin-bearing polypropylenimine dendrimer is a highly promising gene delivery system to the brain. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Left Brain. Right Brain. Whole Brain

    Science.gov (United States)

    Farmer, Lesley S. J.

    2004-01-01

    As the United States student population is becoming more diverse, library media specialists need to find ways to address these distinctive needs. However, some of these differences transcend culture, touching on variations in the brain itself. Most people have a dominant side of the brain, which can affect their personality and learning style.…

  19. Brain Basics: Know Your Brain

    Science.gov (United States)

    ... however, the brain is beginning to relinquish its secrets. Scientists have learned more about the brain in ... through the activity of these lobes. At the top of each temporal lobe is an area responsible ...

  20. Large-area, uniform and low-cost dual-mode plasmonic naked-eye colorimetry and SERS sensor with handheld Raman spectrometer.

    Science.gov (United States)

    Xu, Zhida; Jiang, Jing; Wang, Xinhao; Han, Kevin; Ameen, Abid; Khan, Ibrahim; Chang, Te-Wei; Liu, Gang Logan

    2016-03-21

    We demonstrated a highly-sensitive, wafer-scale, highly-uniform plasmonic nano-mushroom substrate based on plastic for naked-eye plasmonic colorimetry and surface-enhanced Raman spectroscopy (SERS). We gave it the name FlexBrite. The dual-mode functionality of FlexBrite allows for label-free qualitative analysis by SERS with an enhancement factor (EF) of 10(8) and label-free quantitative analysis by naked-eye colorimetry with a sensitivity of 611 nm RIU(-1). The SERS EF of FlexBrite in the wet state was found to be 4.81 × 10(8), 7 times stronger than in the dry state, making FlexBrite suitable for aqueous environments such as microfluid systems. The label-free detection of biotin-streptavidin interaction by both SERS and colorimetry was demonstrated with FlexBrite. The detection of trace amounts of the narcotic drug methamphetamine in drinking water by SERS was implemented with a handheld Raman spectrometer and FlexBrite. This plastic-based dual-mode nano-mushroom substrate has the potential to be used as a sensing platform for easy and fast analysis in chemical and biological assays.

  1. Interrelation between the Author and the Text in W. S. Burroughs’s Naked Lunch and Chuck Palahniuk’s Fight Club

    Directory of Open Access Journals (Sweden)

    Viktoria Grivina

    2014-11-01

    Full Text Available Article adopts Jacques Lacan’s concept of the “mirror stage” to study the mechanisms of the way the Author’s identity evolves in W. Burroughs’s Naked Lunch and Ch. Palahniuk’s Fight Club. Evolution of the Author is set against general process of personal growth. The study is primarily concerned with features of the Author’s evolution within transgressive fiction, as Chuck Palahniuk and William Burroughs are the key figures of this genre. Transgression presupposes addressing social taboos by explicating them, thus creating strong reactions within the readership. We argue and find evidence that Burroughs and Palahniuk in the process of facing their perfect images of the Author digress from what Lacan would consider normal development. When they are given a chance to produce a unified body of text, the writers chose unconscious strive for fragmentation instead. Fragmented images invade Naked Lunch and Fight Club. However the mirror stage in the case of Palahniuk and in the case of Burroughs differ. While Burroughs in the myth of the Interzone ends up rejecting the notion of unique Author as such, Palahniuk accepts the fact that he managed to form a new niche for transgressive fiction and stays true to this niche, continuing similar aesthetics in the works that follow.

  2. An efficient probe for rapid detection of cyanide in water at parts per billion levels and naked-eye detection of endogenous cyanide.

    Science.gov (United States)

    Kumari, Namita; Jha, Satadru; Bhattacharya, Santanu

    2014-03-01

    A new molecular probe based on an oxidized bis-indolyl skeleton has been developed for rapid and sensitive visual detection of cyanide ions in water and also for the detection of endogenously bound cyanide. The probe allows the "naked-eye" detection of cyanide ions in water with a visual color change from red to yellow (Δλmax =80 nm) with the immediate addition of the probe. It shows high selectivity towards the cyanide ion without any interference from other anions. The detection of cyanide by the probe is ratiometric, thus making the detection quantitative. A Michael-type addition reaction of the probe with the cyanide ion takes place during this chemodosimetric process. In water, the detection limit was found to be at the parts per million level, which improved drastically when a neutral micellar medium was employed, and it showed a parts-per-billion-level detection, which is even 25-fold lower than the permitted limits of cyanide in water. The probe could also efficiently detect the endogenously bound cyanide in cassava (a staple food) with a clear visual color change without requiring any sample pretreatment and/or any special reaction conditions such as pH or temperature. Thus the probe could serve as a practical naked-eye probe for "in-field" experiments without requiring any sophisticated instruments. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Molecular and Physiological Factors of Neuroprotection in Hypoxia-tolerant Models: Pharmacological Clues for the Treatment of Stroke

    Directory of Open Access Journals (Sweden)

    Thomas I. Nathaniel

    2015-01-01

    Full Text Available The naked mole-rat possesses several unique physiological and molecular features that underlie their remarkably and exceptional resistance to tissue hypoxia. Elevated pattern of Epo, an erythropoietin (Epo factor; c-fos; vascular endothelial growth factor (VEGF; and hypoxia-inducible factors (HIF-1α contribute to the adaptive strategy to cope with hypoxic stress. Moreover, the naked mole-rat has a lower metabolic rate than any other eutherian mammal of comparable size that has been studied. The ability to actively reduce metabolic rate represents a strategy widely used in the face of decreased tissue oxygen availability. Understanding the different molecular and physiological factors that induce metabolic suppression could guide the development of pharmacological agents for the clinical management of stroke patient.

  4. Cellular Basis for Learning Impairment in Fragile X Syndrome

    Science.gov (United States)

    2014-08-01

    advances in therapy for neurological conditions such as stroke and epilepsy. KEY WORDS: Arctic ground squirrel, Cetacean, Hypoxia, Naked mole-rat...including migration and hibernation. Oxygen levels also vary widely, with animals adapted to sea level, high-altitude, underground and aquatic habitats...adapted for life in specific ecological niches as well as inform advances in therapy for neurological conditions such as stroke and epilepsy. Down for

  5. Brain glycogen

    DEFF Research Database (Denmark)

    Obel, Linea Lykke Frimodt; Müller, Margit S; Walls, Anne B

    2012-01-01

    Glycogen is a complex glucose polymer found in a variety of tissues, including brain, where it is localized primarily in astrocytes. The small quantity found in brain compared to e.g., liver has led to the understanding that brain glycogen is merely used during hypoglycemia or ischemia....... In this review evidence is brought forward highlighting what has been an emerging understanding in brain energy metabolism: that glycogen is more than just a convenient way to store energy for use in emergencies-it is a highly dynamic molecule with versatile implications in brain function, i.e., synaptic...... activity and memory formation. In line with the great spatiotemporal complexity of the brain and thereof derived focus on the basis for ensuring the availability of the right amount of energy at the right time and place, we here encourage a closer look into the molecular and subcellular mechanisms...

  6. Brain imaging

    International Nuclear Information System (INIS)

    Mishkin, F.S.

    1978-01-01

    The techniques of brain imaging and results in perfusion studies and delayed images are outlined. An analysis of the advantages and disadvantages of the brain scan in a variety of common problems is discussed, especially as compared with other available procedures. Both nonneoplastic and neoplastic lesions are considered. (Auth/C.F.)

  7. Employing a hydrazine linked asymmetric double naphthalene hybrid for efficient naked eye detection of F-: Crystal structure with real application for F-

    Science.gov (United States)

    Bhattacharyya, Arghyadeep; Makhal, Subhash Chandra; Ghosh, Soumen; Guchhait, Nikhil

    2018-06-01

    An asymmetric hydrazide, (12E, 13E)-2-((naphthalen-1-yl) methylene)-1-(1-(2-hydroxynaphthalen-6-yl) ethylidene) hydrazine (abbreviated as AH) is synthesized and characterized by standard techniques and crystal structure of AH has been obtained. The naked eye detection of F- in aqueous acetonitrile (acetonitrile: water = 7:3/v:v) by AH has been investigated by UV-Visible titration and in presence of other anions, the limit of detection being 1.31 × 10-6(M). The mechanism of F- sensing has been explored by 1H NMR titration. AH undergoes hydrogen bonding with F- followed by deprotonation. The practical utility of AH has been explored by successful test kit response and color change in toothpaste solution.

  8. A rapid, naked-eye detection of hypochlorite and bisulfite using a robust and highly-photostable indicator dye Quinaldine Red in aqueous medium

    Science.gov (United States)

    Dutta, Tanoy; Chandra, Falguni; Koner, Apurba L.

    2018-02-01

    A ;naked-eye; detection of health hazardous bisulfite (HSO3-) and hypochlorite (ClO-) using an indicator dye (Quinaldine Red, QR) in a wide range of pH is demonstrated. The molecule contains a quinoline moiety linked to an N,N-dimethylaniline moiety with a conjugated double bond. Treatment of QR with HSO3- and ClO-, in aqueous solution at near-neutral pH, resulted in a colorless product with high selectivity and sensitivity. The detection limit was 47.8 μM and 0.2 μM for HSO3- and ClO- respectively. However, ClO- was 50 times more sensitive and with 2 times faster response compared to HSO3-. The detail characterization and related analysis demonstrate the potential of QR for a rapid, robust and highly efficient colorimetric sensor for the practical applications to detect hypochlorite in water samples.

  9. A dual-responsive colorimetric and fluorescent chemosensor based on diketopyrrolopyrrole derivative for naked-eye detection of Fe3 + and its practical application

    Science.gov (United States)

    Zhang, Shanshan; Sun, Tao; Xiao, Dejun; Yuan, Fang; Li, Tianduo; Wang, Enhua; Liu, Haixia; Niu, Qingfen

    2018-01-01

    A novel dual-responsive colorimetric and fluorescent chemosensor L based on diketopyrrolopyrrole derivative for Fe3 + detection was designed and synthesized. In presence of Fe3 +, sensor L displayed strong colorimetric response as amaranth to rose pink and significant fluorescence enhancement and chromogenic change, which served as a naked-eye indicator by an obvious color change from purple to red. The binding constant for L-Fe3 + complex was found as 2.4 × 104 with the lower detection limit of 14.3 nM. The sensing mechanism was investigated in detail by fluorescence measurements, IR and 1H NMR spectra. Sensor L for Fe3 + detection also exhibited high anti-interference performance, good reversibility, wide pH response range and instantaneous response time. Furthermore, the sensor L has been used to quantify Fe3 + ions in practical water samples with good recovery.

  10. Brain tumor - primary - adults

    Science.gov (United States)

    ... Vestibular schwannoma (acoustic neuroma) - adults; Meningioma - adults; Cancer - brain tumor (adults) ... Primary brain tumors include any tumor that starts in the brain. Primary brain tumors can start from brain cells, ...

  11. Brain Stimulation Therapies

    Science.gov (United States)

    ... Magnetic Seizure Therapy Deep Brain Stimulation Additional Resources Brain Stimulation Therapies Overview Brain stimulation therapies can play ... for a shorter recovery time than ECT Deep Brain Stimulation Deep brain stimulation (DBS) was first developed ...

  12. Brain radiation - discharge

    Science.gov (United States)

    Radiation - brain - discharge; Cancer - brain radiation; Lymphoma - brain radiation; Leukemia - brain radiation ... Decadron) while you are getting radiation to the brain. It may make you hungrier, cause leg swelling ...

  13. Brain abscess

    Science.gov (United States)

    ... found. However, the most common source is a lung infection. Less often, a heart infection is the cause. The following raise your chance of developing a brain abscess: A weakened immune system (such as in people ...

  14. Brain imaging and brain function

    International Nuclear Information System (INIS)

    Sokoloff, L.

    1985-01-01

    This book is a survey of the applications of imaging studies of regional cerebral blood flow and metabolism to the investigation of neurological and psychiatric disorders. Contributors review imaging techniques and strategies for measuring regional cerebral blood flow and metabolism, for mapping functional neural systems, and for imaging normal brain functions. They then examine the applications of brain imaging techniques to the study of such neurological and psychiatric disorders as: cerebral ischemia; convulsive disorders; cerebral tumors; Huntington's disease; Alzheimer's disease; depression and other mood disorders. A state-of-the-art report on magnetic resonance imaging of the brain and central nervous system rounds out the book's coverage

  15. Brain SPECT

    International Nuclear Information System (INIS)

    Feistel, H.

    1991-01-01

    Brain SPECT investigations have gained broad acceptance since the introduction of the lipophilic tracer Tc-99m-HMPAO. Depending on equipment and objectives in different departments, the examinations can be divided into three groups: 1. Under normal conditions and standardised patient preparation the 'rest' SPECT can be performed in every department with a tomographic camera. In cerebrovascular disease there is a demand for determination of either the perfusion reserve in reversible ischemia or prognostic values in completed stroke. In cases of dementia, SPECT may yield useful results according to differential diagnosis. Central cerebral system involvement in immunologic disease may be estimated with higher sensitivity than in conventional brain imaging procedures. In psychiatric diseases there is only a relative indication for brain SPECT, since results during recent years have been contradictory and may be derived only in interventional manner. In brain tumor diagnostics SPECT with Tl-201 possibly permits grading. In inflammatory disease, especially in viral encephalitis, SPECT may be used to obtain early diagnosis. Normal pressure hydrocephalus can be distinguished from other forms of dementia and, consequently, the necessity for shunting surgery can be recognised. 2. In departments equipped for emergency cases an 'acute' SPECT can be performed in illnesses with rapid changing symptoms such as different forms of migraine, transient global amnesia, epileptic seizures (so-called 'ictal SPECT') or urgent forms like trauma. 3. In cooperation with several departments brain SPECT can be practised as an interventional procedure in clinical and in scientific studies. (orig./MG) [de

  16. Sustainable Utilization of Bio waste towards the Green Synthesis of Nanoparticles and its Utility in the Naked Eye Detection of Metals Coupled with its Larvicidal and Antimicrobial Properties

    Science.gov (United States)

    Nikhila, P. S.; Satheesh, Namitha; Sreejitha, V. S.; Pillai, Anandu R.; Saritha, A.; Smitha Chandran, S.

    2018-02-01

    Green synthesis of nanoparticles has become a prominent zone of attention in the field of nanotechnology, as it is a nontoxic, economically feasible and green approach. In the present work we have developed an eco-friendly and zero cost method for the synthesis of silver nanoparticles using common a bio waste banana blossom peel. The well-known characteristic phenomenon of surface Plasmon resonance (SPR) has been exploited towards the characterization of the green synthesized nanoparticles. The aforementioned nanoparticles were characterized by UV spectroscopy and the behaviour of these particles towards naked eye detection of metal ions were observed. The sensitivity of the nanoparticles towards the detection of metal ions was carefully monitored by the shift in the SPR band. Moreover the larvicidal potential of these green synthesized silver nanoparticles were evaluated as per WHO standards. The synthesized silver nanoparticles were found to be an effective antibacterial agent against Gram negative bacteria-E.coli. The method we followed for the synthesis of silver nanoparticles is economically feasible as well as environment friendly and also capable of rapid synthesis of nanoparticles at ambient conditions.

  17. Cell-penetrating DNA-binding protein as a safe and efficient naked DNA delivery carrier in vitro and in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun-Sung; Yang, Seung-Woo [Department of Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Hong, Dong-Ki; Kim, Woo-Taek [Department of Biology, Yonsei University, Seoul 120-749 (Korea, Republic of); Kim, Ho-Guen [Department of Pathology, Yonsei Medical School, Seoul 120-752 (Korea, Republic of); Lee, Sang-Kyou, E-mail: sjrlee@yonsei.ac.kr [Department of Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of)

    2010-01-29

    Non-viral gene delivery is a safe and suitable alternative to viral vector-mediated delivery to overcome the immunogenicity and tumorigenesis associated with viral vectors. Using the novel, human-origin Hph-1 protein transduction domain that can facilitate the transduction of protein into cells, we developed a new strategy to deliver naked DNA in vitro and in vivo. The new DNA delivery system contains Hph-1-GAL4 DNA-binding domain (DBD) fusion protein and enhanced green fluorescent protein (EGFP) reporter plasmid that includes the five repeats of GAL4 upstream activating sequence (UAS). Hph-1-GAL4-DBD protein formed complex with plasmid DNA through the specific interaction between GAL4-DBD and UAS, and delivered into the cells via the Hph-1-PTD. The pEGFP DNA was successfully delivered by the Hph-1-GAL4 system, and the EGFP was effectively expressed in mammalian cells such as HeLa and Jurkat, as well as in Bright Yellow-2 (BY-2) plant cells. When 10 {mu}g of pEGFP DNA was intranasally administered to mice using Hph-1-GAL4 protein, a high level of EGFP expression was detected throughout the lung tissue for 7 days. These results suggest that an Hph-1-PTD-mediated DNA delivery strategy may be an useful non-viral DNA delivery system for gene therapy and DNA vaccines.

  18. ESTIMATION OF THE DEVELOPMENT STANDARD OF NEURAL TUBE IN EMBRYOS FROM TRANSYLVANIAN NAKED NECK AND PLYMOUTH ROCK HEN BREEDS, DURING EARLY EMBRYOGENESIS

    Directory of Open Access Journals (Sweden)

    D. DRONCA

    2007-05-01

    Full Text Available In Romania, the Transylvanian Naked Neck hen breed is considered to be an“endangered” population, reason for which we consider that a special attentionshould have been given until now. Plymouth Rock breed was imported for the firsttime to Romania from the Studler Company, France in 1969. This paper is aimingto perform a profound analysis of the development patterns of the neural tube inthe two breeds, by measurements carried out at 30, 40, 50, and 60 hours ofincubation. Observations show that the closure of the neural canal and itstransformation into a tube follows an undulatory pattern, of which positive andnegative curls are diametrically opposed in the two breeds, while the developmentspeed during the whole studied period have a relative similar value between thetwo breeds. We estimate that the two breeds have a good combinative capacity,which recommend the utilization of these genetic materials to obtain hybrids forproducing “peasant-type” chicken meat, very well-appreciated by the Europeansbetween the two World Wars.

  19. A simple, reversible, colorimetric and water-soluble fluorescent chemosensor for the naked-eye detection of Cu2 + in 100% aqueous media and application to real samples

    Science.gov (United States)

    Sun, Tao; Niu, Qingfen; Li, Tianduo; Guo, Zongrang; Liu, Haixia

    2018-01-01

    A simple, reversible, colorimetric and water-soluble fluorescent chemosensor ADA for the naked-eye detection of Cu2 + was developed. Sensor ADA showed high selectivity and sensitivity toward Cu2 + in 100% aqueous media over wide pH range. Sensor ADA exhibited a red-shift in the absorption spectra from 466 to 480 nm that is accompanied by significant color change from light yellow to yellowish brown instantaneously. The Cu2 + recognition is based on the chelation-enhanced fluorescence quenching (CHEQ) effect of the paramagnetic nature. The lowest detection limit is determined to be 15.8 nM, which is much lower than the allowable level of Cu2 + in drinking water set by U.S. Environmental Protection Agency ( 20 μM) and the World Health Organization ( 30 μM). The 1:1 binding process was confirmed by fluorescence measurements, IR analysis and DFT studies. Moreover, sensor ADA was successfully applied for determination of trace level of Cu2 + with 4 reuse cycles in various water samples, which affords promising potential in ion-detection field.

  20. Cell-penetrating DNA-binding protein as a safe and efficient naked DNA delivery carrier in vitro and in vivo

    International Nuclear Information System (INIS)

    Kim, Eun-Sung; Yang, Seung-Woo; Hong, Dong-Ki; Kim, Woo-Taek; Kim, Ho-Guen; Lee, Sang-Kyou

    2010-01-01

    Non-viral gene delivery is a safe and suitable alternative to viral vector-mediated delivery to overcome the immunogenicity and tumorigenesis associated with viral vectors. Using the novel, human-origin Hph-1 protein transduction domain that can facilitate the transduction of protein into cells, we developed a new strategy to deliver naked DNA in vitro and in vivo. The new DNA delivery system contains Hph-1-GAL4 DNA-binding domain (DBD) fusion protein and enhanced green fluorescent protein (EGFP) reporter plasmid that includes the five repeats of GAL4 upstream activating sequence (UAS). Hph-1-GAL4-DBD protein formed complex with plasmid DNA through the specific interaction between GAL4-DBD and UAS, and delivered into the cells via the Hph-1-PTD. The pEGFP DNA was successfully delivered by the Hph-1-GAL4 system, and the EGFP was effectively expressed in mammalian cells such as HeLa and Jurkat, as well as in Bright Yellow-2 (BY-2) plant cells. When 10 μg of pEGFP DNA was intranasally administered to mice using Hph-1-GAL4 protein, a high level of EGFP expression was detected throughout the lung tissue for 7 days. These results suggest that an Hph-1-PTD-mediated DNA delivery strategy may be an useful non-viral DNA delivery system for gene therapy and DNA vaccines.

  1. A comparative study on low-energy ion beam and neutralized beam modifications of naked DNA and biological effect on mutation

    Science.gov (United States)

    Sarapirom, S.; Thongkumkoon, P.; Prakrajang, K.; Anuntalabhochai, S.; Yu, L. D.

    2012-02-01

    DNA conformation change or damage induced by low-energy ion irradiation has been of great interest owing to research developments in ion beam biotechnology and ion beam application in biomedicine. Mechanisms involved in the induction of DNA damage may account for effect from implanting ion charge. In order to check this effect, we used both ion beam and neutralized beam at keV energy to bombard naked DNA. Argon or nitrogen ion beam was generated and extracted from a radiofrequency (RF) ion source and neutralized by microwave-driven plasma in the beam path. Plasmid DNA pGFP samples were irradiated with the ion or neutralized beam in vacuum, followed by gel electrophoresis to observe changes in the DNA conformations. It was revealed that the ion charge played a certain role in inducing DNA conformation change. The subsequent DNA transfer into bacteria Escherichia coli ( E. coli) for mutation analysis indicated that the charged ion beam induced DNA change had high potential in mutation induction while neutralized beam did not. The intrinsic reason was attributed to additional DNA deformation and contortion caused by ion charge exchange effect so that the ion beam induced DNA damage could hardly be completely repaired, whereas the neutralized beam induced DNA change could be more easily recoverable owing to absence of the additional DNA deformation and contortion.

  2. A comparative study on low-energy ion beam and neutralized beam modifications of naked DNA and biological effect on mutation

    International Nuclear Information System (INIS)

    Sarapirom, S.; Thongkumkoon, P.; Prakrajang, K.; Anuntalabhochai, S.; Yu, L.D.

    2012-01-01

    DNA conformation change or damage induced by low-energy ion irradiation has been of great interest owing to research developments in ion beam biotechnology and ion beam application in biomedicine. Mechanisms involved in the induction of DNA damage may account for effect from implanting ion charge. In order to check this effect, we used both ion beam and neutralized beam at keV energy to bombard naked DNA. Argon or nitrogen ion beam was generated and extracted from a radiofrequency (RF) ion source and neutralized by microwave-driven plasma in the beam path. Plasmid DNA pGFP samples were irradiated with the ion or neutralized beam in vacuum, followed by gel electrophoresis to observe changes in the DNA conformations. It was revealed that the ion charge played a certain role in inducing DNA conformation change. The subsequent DNA transfer into bacteria Escherichia coli (E. coli) for mutation analysis indicated that the charged ion beam induced DNA change had high potential in mutation induction while neutralized beam did not. The intrinsic reason was attributed to additional DNA deformation and contortion caused by ion charge exchange effect so that the ion beam induced DNA damage could hardly be completely repaired, whereas the neutralized beam induced DNA change could be more easily recoverable owing to absence of the additional DNA deformation and contortion.

  3. A simple, reversible, colorimetric and water-soluble fluorescent chemosensor for the naked-eye detection of Cu2+ in ~100% aqueous media and application to real samples.

    Science.gov (United States)

    Sun, Tao; Niu, Qingfen; Li, Tianduo; Guo, Zongrang; Liu, Haixia

    2018-01-05

    A simple, reversible, colorimetric and water-soluble fluorescent chemosensor ADA for the naked-eye detection of Cu 2+ was developed. Sensor ADA showed high selectivity and sensitivity toward Cu 2+ in ~100% aqueous media over wide pH range. Sensor ADA exhibited a red-shift in the absorption spectra from 466 to 480nm that is accompanied by significant color change from light yellow to yellowish brown instantaneously. The Cu 2+ recognition is based on the chelation-enhanced fluorescence quenching (CHEQ) effect of the paramagnetic nature. The lowest detection limit is determined to be 15.8nM, which is much lower than the allowable level of Cu 2+ in drinking water set by U.S. Environmental Protection Agency (~20μM) and the World Health Organization (~30μM). The 1:1 binding process was confirmed by fluorescence measurements, IR analysis and DFT studies. Moreover, sensor ADA was successfully applied for determination of trace level of Cu 2+ with 4 reuse cycles in various water samples, which affords promising potential in ion-detection field. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Controlled formation of Ni(DMG)2 microrods/tubes by manipulating the kinetics of chemical reactions and their application in naked-eye sensors.

    Science.gov (United States)

    Qin, Jianli; Wang, Bo; Zhang, Xiujuan; Zhang, Xiaohong

    2012-08-01

    We have demonstrated controlled preparation of Ni(DMG)2 microrods/tubes via chemical reaction method. By manipulating the reaction kinetics via the concentration of reactants, shapes of the resulting microstructures can be easily tuned from microrods to microtubes. Size of the resulting products can also be controlled through changing the reaction temperatures. It was proposed that under high reactants' concentrations, molecules will prefer to grow at corners or edges of nuclei with high free energies, to reduce the total energy in the system, which would lead to partial or complete hollow interiors and eventually resulted in mircotubes. The fact that DMG show high selectivity with Ni2+ and accompanied with obvious color change enable us to fabricate test strip for naked-eye detection of Ni2+. Benefit from the large surface areas of DMG nanoparticles on the test strip, the detection limit is improved by two orders over that of conventional solution method. This strategy is sensitive, simple and easy to handle, thus expected to possess potentials for the practical Ni2+ detection applications.

  5. Brain Fog

    Science.gov (United States)

    ... relationship with your doctor(s): • Always report changes in cognition/memory and mood (depression, anxiety). • Make sure your physician ... joint pain. • Exercise regularly. Adequate physical exercise enhances cognition/memory. • Train the Brain! “If you don’t use ...

  6. Robot brains

    NARCIS (Netherlands)

    Babuska, R.

    2011-01-01

    The brain hosts complex networks of neurons that are responsible for behavior in humans and animals that we generally call intelligent. I is not easy to give an exact definition of intelligence – for the purpose of this talk it will suffice to say that we refer to intelligence as a collection of

  7. Understanding Brain Tumors

    Science.gov (United States)

    ... to Know About Brain Tumors . What is a Brain Tumor? A brain tumor is an abnormal growth
 ... Tumors” from Frankly Speaking Frankly Speaking About Cancer: Brain Tumors Download the full book Questions to ask ...

  8. Brain tumor - children

    Science.gov (United States)

    ... children; Neuroglioma - children; Oligodendroglioma - children; Meningioma - children; Cancer - brain tumor (children) ... The cause of primary brain tumors is unknown. Primary brain tumors may ... (spread to nearby areas) Cancerous (malignant) Brain tumors ...

  9. Brain Tumors (For Parents)

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Brain Tumors KidsHealth / For Parents / Brain Tumors What's in ... radiation therapy or chemotherapy, or both. Types of Brain Tumors There are many different types of brain ...

  10. Brain and Nervous System

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Brain and Nervous System KidsHealth / For Parents / Brain and ... healthy, and remove waste products. All About the Brain The brain is made up of three main ...

  11. The Creative Brain.

    Science.gov (United States)

    Herrmann, Ned

    1982-01-01

    Outlines the differences between left-brain and right-brain functioning and between left-brain and right-brain dominant individuals, and concludes that creativity uses both halves of the brain. Discusses how both students and curriculum can become more "whole-brained." (Author/JM)

  12. Brain imaging

    International Nuclear Information System (INIS)

    Greenfield, L.D.; Bennett, L.R.

    1976-01-01

    Imaging with radionuclides should be used in a complementary fashion with other neuroradiologic techniques. It is useful in the early detection and evaluation of intracranial neoplasm, cerebrovascular accident and abscess, and in postsurgical follow-up. Cisternography yields useful information about the functional status of cerebrospinal fluid pathways. Computerized axial tomography is a new technique of great promise that produced a cross-sectional image of the brain

  13. Brain imaging

    International Nuclear Information System (INIS)

    Bradshaw, J.R.

    1989-01-01

    This book presents a survey of the various imaging tools with examples of the different diseases shown best with each modality. It includes 100 case presentations covering the gamut of brain diseases. These examples are grouped according to the clinical presentation of the patient: headache, acute headache, sudden unilateral weakness, unilateral weakness of gradual onset, speech disorders, seizures, pituitary and parasellar lesions, sensory disorders, posterior fossa and cranial nerve disorders, dementia, and congenital lesions

  14. Near-infrared chemodosimetric probes based on heptamethine cyanine dyes for the “naked-eye” detection of cyanide in aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Dali [College of Chemistry, Xiangtan University, Xiangtan 411105, Hunan Province (China); Liu, Yijiang, E-mail: liuyijiang84@iccas.ac.cn [College of Chemistry, Xiangtan University, Xiangtan 411105, Hunan Province (China); Li, Mengnan [State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Chen, Hongbiao, E-mail: chhb606@163.com [College of Chemistry, Xiangtan University, Xiangtan 411105, Hunan Province (China); Li, Huaming [College of Chemistry, Xiangtan University, Xiangtan 411105, Hunan Province (China)

    2017-05-15

    Two simple chemodosimetric probes (P1 and P2) based on heptamethine cyanine dyes have been synthesized for highly sensitive and selective detection of cyanide anions (CN{sup −}) in aqueous media. The probes with an immobilized indolium salt as the specifically nucleophilic addition reaction site for CN{sup −} exhibit absorption bands in the near-infrared (NIR) region (650–850 nm). Upon the addition of CN{sup −}, the probes display a blue-shifted spectrum and result in apparent color change from green to brilliant yellow that can be easily observed by the naked eye even in the presence of other interfering anions such as F{sup −}, AcO{sup −}, Br{sup −}, NO{sub 2}{sup −}, Cl{sup −}, SO{sub 4}{sup 2−} and I{sup −}. There are good linear relationships between the fluorescence intensity of the probes and CN{sup −} concentrations, and the detection limits for P1 and P2 are estimated to be 0.017 μM and 0.2 μM, respectively. The sensing mechanism of the nucleophilic addition is confirmed by {sup 1}H NMR and mass spectroscopic analysis. In addition, the probe P2 is employed for cell imaging and the detection of CN{sup −} in living cells L929 is successfully realized. - Graphical abstract: Simple chemodosimetric probes based on heptamethine cyanine dye were synthesized and applied to detect CN{sup −} in aqueous media with colorimetric and fluorescent dual channel recognition.

  15. Rhodamine B immobilized on hollow Au-HMS material for naked-eye detection of Hg{sup 2+} in aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Na [State Key Laboratory of Fine Chemicals, College of Chemical Engineering, Dalian University of Technology, Dalian, 116024 (China); Li, Gang, E-mail: liganghg@dlut.edu.cn [State Key Laboratory of Fine Chemicals, College of Chemical Engineering, Dalian University of Technology, Dalian, 116024 (China); Cheng, Zhuhong [State Key Laboratory of Fine Chemicals, College of Chemical Engineering, Dalian University of Technology, Dalian, 116024 (China); Zuo, Xiujin [Key Laboratory of Bio-organic Chemistry, College of Environmental and Chemical Engineering, Dalian University, Dalian, 116622 (China)

    2012-08-30

    Graphical abstract: Au-HMS-Probe with worm-like mesoporous framework for detection of Hg{sup 2+} in aqueous media has been simply and effectively synthesized by immobilizing a Rhodamine B derivative on Au-HMS via Au-N groups under room temperature. Highlights: Black-Right-Pointing-Pointer Au-HMS-Probe is prepared via Au-N bonds. Black-Right-Pointing-Pointer Gold nanoparticles are chosen as connectors instead of silane agents. Black-Right-Pointing-Pointer Au-HMS is chosen as carrier for the first time. Black-Right-Pointing-Pointer The immobilization method of Au-HMS-Probe is very simple and effective. Black-Right-Pointing-Pointer Au-HMS-Probe shows excellent ability for detecting Hg{sup 2+} by naked-eye. - Abstract: A simple, effective method has been demonstrated to immobilize Rhodamine B (RhB) probes on mesoporous silica (Au-HMS). The prepared chemosensor (Au-HMS-Probe) was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), UV-vis spectrum and Fourier transform infrared spectroscopy (FT-IR). Further application of Au-HMS-Probe in sensing Hg{sup 2+} was confirmed by fluorescence titration experiment. Au-HMS-Probe afforded 'turn-on' fluorescence enhancement and displayed high brightness in water, and it also showed excellent selectivity for Hg{sup 2+} over alkali (Na{sup +}, K{sup +}), alkaline earth (Mg{sup 2+}, Ca{sup 2+}) and other heavy metal ions (Ag{sup +}, Cd{sup 2+}, Co{sup 2+}, Pb{sup 2+}, Ni{sup 2+}, Cu{sup 2+}, Fe{sup 2+}). Importantly, Au-HMS-Probe could be regenerated by treatment with tetrapropylammonium hydroxide solution.

  16. Estimation of genetic variability and selection response for clutch length in dwarf brown-egg layers carrying or not the naked neck gene

    Directory of Open Access Journals (Sweden)

    Tixier-Boichard Michèle

    2003-03-01

    Full Text Available Abstract In order to investigate the possibility of using the dwarf gene for egg production, two dwarf brown-egg laying lines were selected for 16 generations on average clutch length; one line (L1 was normally feathered and the other (L2 was homozygous for the naked neck gene NA. A control line from the same base population, dwarf and segregating for the NA gene, was maintained during the selection experiment under random mating. The average clutch length was normalized using a Box-Cox transformation. Genetic variability and selection response were estimated either with the mixed model methodology, or with the classical methods for calculating genetic gain, as the deviation from the control line, and the realized heritability, as the ratio of the selection response on cumulative selection differentials. Heritability of average clutch length was estimated to be 0.42 ± 0.02, with a multiple trait animal model, whereas the estimates of the realized heritability were lower, being 0.28 and 0.22 in lines L1 and L2, respectively. REML estimates of heritability were found to decline with generations of selection, suggesting a departure from the infinitesimal model, either because a limited number of genes was involved, or their frequencies were changed. The yearly genetic gains in average clutch length, after normalization, were estimated to be 0.37 ± 0.02 and 0.33 ± 0.04 with the classical methods, 0.46 ± 0.02 and 0.43 ± 0.01 with animal model methodology, for lines L1 and L2 respectively, which represented about 30% of the genetic standard deviation on the transformed scale. Selection response appeared to be faster in line L2, homozygous for the NA gene, but the final cumulated selection response for clutch length was not different between the L1 and L2 lines at generation 16.

  17. Baby Brain Map

    Science.gov (United States)

    ... a Member Home Resources & Services Professional Resource Baby Brain Map Mar 17, 2016 The Brain Map was adapted in 2006 by ZERO TO ... supports Adobe Flash Player. To view the Baby Brain Map, please visit this page on a browser ...

  18. Pediatric Brain Tumor Foundation

    Science.gov (United States)

    ... navigate their brain tumor diagnosis. WATCH AND SHARE Brain tumors and their treatment can be deadly so ... Pediatric Central Nervous System Cancers Read more >> Pediatric Brain Tumor Foundation 302 Ridgefield Court, Asheville, NC 28806 ...

  19. That's Using Your Brain!

    Science.gov (United States)

    Visser, Dana R.

    1996-01-01

    Discusses new adult learning theories, including those of Roger Sperry (left brain/right brain), Paul McLean (triune brain), and Howard Gardner (multiple intelligences). Relates adult learning theory to training. (JOW)

  20. Site remediation: The naked truth

    International Nuclear Information System (INIS)

    Calloway, J.M.

    1991-01-01

    The objective of any company faced with an environmental site remediation project is to perform the cleanup effectively at the lowest possible cost. Today, there are a variety of techniques being applied in the remediation of sites involving soils and sludges. The most popular include: stabilization, incineration, bioremediation and off-site treatment. Dewatering may also play an integral role in a number of these approaches. Selecting the most cost-effective technique for remediation of soils and sludges can be a formidable undertaking, namely because it is often difficult to quantify certain expenses in advance of the project. In addition to providing general cost guidelines for various aspects of soil and sludge remediation, this paper will show how some significant cost factors can be affected by conditions related to specific remediation projects and the cleanup technology being applied

  1. Gravitational collapse and naked singularities

    Indian Academy of Sciences (India)

    Suppose we have a one-parameter family of initial data sets ... the scaling law MBH ∝ |p − p∗|γ, where γ is a positive constant called a critical exponent. ... by more straightforward work [19], in which the causal structure of the critical solution ...

  2. Brain SPECT in children

    International Nuclear Information System (INIS)

    Guyot, M.; Baulieu, J.L.

    1996-01-01

    Brain SPECT in child involves specific trends regarding the patient cooperation, irradiation, resolution and especially interpretation because of the rapid scintigraphic modifications related to the brain maturation. In a general nuclear medicine department, child brain SPECT represents about 2 % of the activity. The choice indications are the perfusion children: thallium and MIBI in brain tumours, pharmacological and neuropsychological interventions. In the future, brain dedicated detectors and new radiopharmaceuticals will promote the development of brain SPECT in children. (author)

  3. Revisiting Einstein's brain in Brain Awareness Week.

    Science.gov (United States)

    Chen, Hao; Chen, Su; Zeng, Lidan; Zhou, Lin; Hou, Shengtao

    2014-10-01

    Albert Einstein's brain has long been an object of fascination to both neuroscience specialists and the general public. However, without records of advanced neuro-imaging of his brain, conclusions regarding Einstein's extraordinary cognitive capabilities can only be drawn based on the unique external features of his brain and through comparison of the external features with those of other human brain samples. The recent discovery of 14 previously unpublished photographs of Einstein's brain taken at unconventional angles by Dr. Thomas Stoltz Harvey, the pathologist, ignited a renewed frenzy about clues to explain Einstein's genius. Dr. Dean Falk and her colleagues, in their landmark paper published in Brain (2013; 136:1304-1327), described in such details about the unusual features of Einstein's brain, which shed new light on Einstein's intelligence. In this article, we ask what are the unique structures of his brain? What can we learn from this new information? Can we really explain his extraordinary cognitive capabilities based on these unique brain structures? We conclude that studying the brain of a remarkable person like Albert Einstein indeed provides us a better example to comprehensively appreciate the relationship between brain structures and advanced cognitive functions. However, caution must be exercised so as not to over-interpret his intelligence solely based on the understanding of the surface structures of his brain.

  4. Tissue hypoxia during ischemic stroke: adaptive clues from hypoxia-tolerant animal models.

    Science.gov (United States)

    Nathaniel, Thomas I; Williams-Hernandez, Ashley; Hunter, Anan L; Liddy, Caroline; Peffley, Dennis M; Umesiri, Francis E; Imeh-Nathaniel, Adebobola

    2015-05-01

    The treatment and prevention of hypoxic/ischemic brain injury in stroke patients remain a severe and global medical issue. Numerous clinical studies have resulted in a failure to develop chemical neuroprotection for acute, ischemic stroke. Over 150 estimated clinical trials of ischemic stroke treatments have been done, and more than 200 drugs and combinations of drugs for ischemic and hemorrhagic strokes have been developed. Billions of dollars have been invested for new scientific breakthroughs with only limited success. The revascularization of occluded cerebral arteries such as anti-clot treatments of thrombolysis has proven effective, but it can only be used in a 3-4.5h time frame after the onset of a stroke, and not for every patient. This review is about novel insights on how to resist tissue hypoxia from unconventional animal models. Ability to resist tissue hypoxia is an extraordinary ability that is not common in many laboratory animals such as rat and mouse models. For example, we can learn from a naked mole-rat, Chrysemys picta, how to actively regulate brain metabolic activity to defend the brain against fluctuating oxygen tension and acute bouts of oxidative stress following the onset of a stroke. Additionally, a euthermic arctic ground squirrel can teach us how the brain of a stroke patient can remain well oxygenated during tissue hypoxia with no evidence of cellular stress. In this review, we discuss how these animals provide us with a system to gain insight into the possible mechanisms of tissue hypoxia/ischemia. This issue is of clinical significance to stroke patients. We describe specific physiological and molecular adaptations employed by different animals' models of hypoxia tolerance in aquatic and terrestrial environments. We highlight how these adaptations might provide potential clues on strategies to adapt for the clinical management of tissue hypoxia during conditions such as stroke where oxygen demand fails to match the supply. Copyright

  5. Left brain, right brain: facts and fantasies.

    Science.gov (United States)

    Corballis, Michael C

    2014-01-01

    Handedness and brain asymmetry are widely regarded as unique to humans, and associated with complementary functions such as a left-brain specialization for language and logic and a right-brain specialization for creativity and intuition. In fact, asymmetries are widespread among animals, and support the gradual evolution of asymmetrical functions such as language and tool use. Handedness and brain asymmetry are inborn and under partial genetic control, although the gene or genes responsible are not well established. Cognitive and emotional difficulties are sometimes associated with departures from the "norm" of right-handedness and left-brain language dominance, more often with the absence of these asymmetries than their reversal.

  6. Brain Cancer—Patient Version

    Science.gov (United States)

    Brain cancer refers to growths of malignant cells in tissues of the brain. Tumors that start in the brain are called primary brain tumors. Tumors that spread to the brain are called metastatic brain tumors. Start here to find information on brain cancer treatment, research, and statistics.

  7. Neuroscience, brains, and computers

    Directory of Open Access Journals (Sweden)

    Giorno Maria Innocenti

    2013-07-01

    Full Text Available This paper addresses the role of the neurosciences in establishing what the brain is and how states of the brain relate to states of the mind. The brain is viewed as a computational deviceperforming operations on symbols. However, the brain is a special purpose computational devicedesigned by evolution and development for survival and reproduction, in close interaction with theenvironment. The hardware of the brain (its structure is very different from that of man-made computers.The computational style of the brain is also very different from traditional computers: the computationalalgorithms, instead of being sets of external instructions, are embedded in brain structure. Concerningthe relationships between brain and mind a number of questions lie ahead. One of them is why andhow, only the human brain grasped the notion of God, probably only at the evolutionary stage attainedby Homo sapiens.

  8. FROM BRAIN DRAIN TO BRAIN NETWORKING

    Directory of Open Access Journals (Sweden)

    Irina BONCEA

    2015-06-01

    Full Text Available Scientific networking is the most accessible way a country can turn the brain drain into brain gain. Diaspora’s members offer valuable information, advice or financial support from the destination country, without being necessary to return. This article aims to investigate Romania’s potential of turning brain drain into brain networking, using evidence from the medical sector. The main factors influencing the collaboration with the country of origin are investigated. The conclusions suggest that Romania could benefit from the diaspora option, through an active implication at institutional level and the implementation of a strategy in this area.

  9. Mapping Ad Hoc Communications Network of a Large Number Fixed-Wing UAV Swarm

    Science.gov (United States)

    2017-03-01

    shows like "Agents of S.H.I.E.L.D". Inspiration can come from the imaginative minds of people or from the world around us. Swarms have demonstrated a...high degree of success. Bees , ants, termites, and naked mole rats maintain large groups that distribute tasks among individuals in order to achieve...the application layer and not the transport layer. Real- world vehicle-to-vehicle packet delivery rates for the 50-UAV swarm event were de- scribed in

  10. Left brain, right brain: facts and fantasies.

    Directory of Open Access Journals (Sweden)

    Michael C Corballis

    2014-01-01

    Full Text Available Handedness and brain asymmetry are widely regarded as unique to humans, and associated with complementary functions such as a left-brain specialization for language and logic and a right-brain specialization for creativity and intuition. In fact, asymmetries are widespread among animals, and support the gradual evolution of asymmetrical functions such as language and tool use. Handedness and brain asymmetry are inborn and under partial genetic control, although the gene or genes responsible are not well established. Cognitive and emotional difficulties are sometimes associated with departures from the "norm" of right-handedness and left-brain language dominance, more often with the absence of these asymmetries than their reversal.

  11. Biomechanics of the brain

    CERN Document Server

    Miller, Karol

    2011-01-01

    With contributions from scientists at major institutions, this book presents an introduction to brain anatomy for engineers and scientists. It provides, for the first time, a comprehensive resource in the field of brain biomechanics.

  12. Brain Basics: Understanding Sleep

    Science.gov (United States)

    ... You are here Home » Disorders » Patient & Caregiver Education Brain Basics: Understanding Sleep Anatomy of Sleep Sleep Stages ... t form or maintain the pathways in your brain that let you learn and create new memories, ...

  13. Aneurysm in the brain

    Science.gov (United States)

    ... gov/ency/article/001414.htm Aneurysm in the brain To use the sharing features on this page, ... aneurysm occurs in a blood vessel of the brain, it is called a cerebral, or intracranial, aneurysm. ...

  14. Brain injury - discharge

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000163.htm Brain injury - discharge To use the sharing features on ... know was in the hospital for a serious brain injury. At home, it will take time for ...

  15. Genetic Brain Disorders

    Science.gov (United States)

    A genetic brain disorder is caused by a variation or a mutation in a gene. A variation is a different form ... mutation is a change in a gene. Genetic brain disorders affect the development and function of the ...

  16. Childhood Brain Tumors

    Science.gov (United States)

    Brain tumors are abnormal growths inside the skull. They are among the most common types of childhood ... still be serious. Malignant tumors are cancerous. Childhood brain and spinal cord tumors can cause headaches and ...

  17. Brain aneurysm repair

    Science.gov (United States)

    ... aneurysm repair; Dissecting aneurysm repair; Endovascular aneurysm repair - brain; Subarachnoid hemorrhage - aneurysm ... Your scalp, skull, and the coverings of the brain are opened. A metal clip is placed at ...

  18. Children's Brain Tumor Foundation

    Science.gov (United States)

    ... 2 Family Donate Volunteer Justin's Hope Fund Children’s Brain Tumor Foundation, A non-profit organization, was founded ... and the long term outlook for children with brain and spinal cord tumors through research, support, education, ...

  19. Brain aneurysm repair - discharge

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000123.htm Brain aneurysm repair - discharge To use the sharing features ... this page, please enable JavaScript. You had a brain aneurysm . An aneurysm is a weak area in ...

  20. Numbers and brains.

    Science.gov (United States)

    Gallistel, C R

    2017-12-01

    The representation of discrete and continuous quantities appears to be ancient and pervasive in animal brains. Because numbers are the natural carriers of these representations, we may discover that in brains, it's numbers all the way down.

  1. Protect Your Brain

    Centers for Disease Control (CDC) Podcasts

    At least three and a half million people in the U.S. sustained a traumatic brain injury (TBI), either with or without other injuries. This podcast discusses the importance of early diagnosis and treatment of brain injuries.

  2. Traumatic Brain Injury

    Science.gov (United States)

    ... brain injury Some traumatic brain injuries have lasting effects, and some do not. You may be left with disabilities. These can be physical, behavioral, communicative, and/or mental. Customized treatment helps you to have as full ...

  3. Right Brain Drawing.

    Science.gov (United States)

    Whalen, Adryce C.

    1985-01-01

    The author describes activities of a weekly enrichment class providing right-brain tasks to gifted elementary students. Activities, which centered on artistic creativity, were taken from "Drawing On the Right Side of the Brain" by B. Edwards. (CL)

  4. Insulin and the Brain

    Directory of Open Access Journals (Sweden)

    Grosu Cristina

    2017-12-01

    Full Text Available The brain represents an important site for the action of insulin. Besides the traditionally known importance in glucoregulation, insulin has significant neurotrophic properties and influences the brain activity: insulin influences eating behavior, regulates the storage of energy and several aspects concerning memory and knowledge. Insulin resistance and hyperinsulinism could be associated with brain aging, vascular and metabolic pathologies. Elucidating the pathways and metabolism of brain insulin could have a major impact on future targeted therapies.

  5. Brain cancer spreads

    DEFF Research Database (Denmark)

    Perryman, Lara; Erler, Janine Terra

    2014-01-01

    The discovery that ~20% of patients with brain cancer have circulating tumor cells breaks the dogma that these cells are confined to the brain and has important clinical implications (Müller et al., this issue).......The discovery that ~20% of patients with brain cancer have circulating tumor cells breaks the dogma that these cells are confined to the brain and has important clinical implications (Müller et al., this issue)....

  6. Neuromythology of Einstein's brain.

    Science.gov (United States)

    Hines, Terence

    2014-07-01

    The idea that the brain of the great physicist Albert Einstein is different from "average" brains in both cellular structure and external shape is widespread. This belief is based on several studies examining Einstein's brain both histologically and morphologically. This paper reviews these studies and finds them wanting. Their results do not, in fact, provide support for the claim that the structure of Einstein's brain reflects his intellectual abilities. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Brain imaging and schizophrenia

    International Nuclear Information System (INIS)

    Martinot, J.L.; Dao-Castellana, M.H.

    1991-01-01

    Brain structures and brain function have been investigated by the new brain imaging techniques for more than ten years. In Psychiatry, these techniques could afford a new understanding of mental diseases. In schizophrenic patients, CAT scanner and RMI pointed out statistically significant ventricular enlargments which are presently considered as evidence for abnormalities in brain maturation. Functional imaging techniques reported metabolic dysfunctions in the cortical associative areas which are probably linked to the cognitive features of schizophrenics [fr

  8. Brain atrophy during aging

    International Nuclear Information System (INIS)

    Matsuzawa, Taiju; Takeda, Shumpei; Hatazawa, Jun

    1985-01-01

    Age-related brain atrophy was investigated in thousands of persons with no neurologic disturbances using X-CT and NMR-CT and following results were obtained. Brain atrophy was minimal in 34 -- 35 years old in both sexes, increased exponentially to the increasing age after 34 -- 35 years, and probably resulted in dementia, such as vascular or multiinfarct dementia. Brain atrophy was significantly greater in men than in women at all ages. Brain volumes were maximal in 34 -- 35 years old in both sexes with minimal individual differences which increased proportionally to the increasing age. Remarkable individual differences in the extents of brain atrophy (20 -- 30 %) existed among aged subjects. Some aged subjects had little or no atrophy of their brains, as seen in young subjects, and others had markedly shrunken brains associated with senility. From these results there must be pathological factors promoting brain atrophy with a great individual difference. We have studied the relation of intelligence to brain volume, and have ascertained that progression of brain atrophy was closely related to loss of mental activities independently of their ages. Our longitudinal study has revealed that the most important factors promoting brain atrophy during aging was decrease in the cerebral blood flow. MNR-CT can easily detected small infarction (lacunae) and edematous lesions resulting from ischemia and hypertensive encephalopathy, while X-CT can not. Therefore NMR-CT is very useful for detection of subtle changes in the brain. (J.P.N.)

  9. Brain Migration Revisited

    Science.gov (United States)

    Vinokur, Annie

    2006-01-01

    The "brain drain/brain gain" debate has been going on for the past 40 years, with irresolvable theoretical disputes and unenforceable policy recommendations that economists commonly ascribe to the lack of reliable empirical data. The recent report of the World Bank, "International migration, remittances and the brain drain", documents the…

  10. Radiopharmaceuticals for brain - SPECT

    International Nuclear Information System (INIS)

    Moretti, J.L.

    1992-01-01

    Perfusion tracers for brain SPECT imaging suitable for regional cerebral blood flow measurement and regional cerebral blood volume determination, with respect to their ability to pass the blood-brain-barrier, are described. Problems related t the use of specific radiotracers to map receptors distribution in the brain are also discussed in this lecture. 9 figs, 6 tabs

  11. Brain Research and Learning.

    Science.gov (United States)

    Claycomb, Mary

    Current research on brain activity has many implications for educators. The triune brain concept and the left and right hemisphere concepts are among the many complex theories evolving from experimentation and observation. The triune brain concept suggests that the human forebrain has expanded while retaining three structurally unique formations…

  12. Primary lymphoma of the brain

    Science.gov (United States)

    Brain lymphoma; Cerebral lymphoma; Primary lymphoma of the central nervous system; Lymphoma - brain ... The cause of primary brain lymphoma is not known. People with a weakened immune system are at high risk for primary lymphoma of the brain. ...

  13. Brain atrophy during aging

    International Nuclear Information System (INIS)

    Matsuzawa, Taiju; Yamada, Kenji; Yamada, Susumu; Ono, Shuichi; Takeda, Shunpei; Hatazawa, Jun; Ito, Masatoshi; Kubota, Kazuo

    1985-01-01

    Age-related brain atrophy was investigated in thousands of persons with no neurologic disturbances using X-CT and NMR-CT. Brain atrophy was minimal in 34-35 years old in both sexes, increased exponentially to the increasing age after 34-35 years, and probably resulted in dementia, such as vascular or multi-infarct dementia. Brain atrophy was significantly greater in men than in women at all ages. Brain volumes were maximal in 34-35 years old in both sexes with minimal individual differences which increased proportionally to the increasing age. Remarkable individual differences in the extent of brain atrophy (20 - 30 %) existed among aged subjects. Progression of brain atrophy was closely related to loss of mental activities independently of their ages. Our longitudinal study has revealed that the most important factors promoting brain atrophy during aging was the decrease in the cerebral blood flow. We have classified brain atrophy into sulcal and cisternal enlargement type (type I), ventricular enlargement type (type II) and mixed type (type III) according to the clinical study using NMR-CT. Brain atrophy of type I progresses significantly in almost all of the geriatric disorders. This type of brain atrophy progresses significantly in heavy smokers and drinkers. Therefore this type of brain atrophy might be caused by the decline in the blood flow in anterior and middle cerebral arteries. Brain atrophy of type II was caused by the disturbance of cerebrospinal fluid circulation after cerebral bleeding and subarachnoid bleeding. Brain atrophy of type III was seen in vascular dementia or multi-infarct dementia which was caused by loss of brain matter after multiple infarction, and was seen also in dementia of Alzheimer type in which degeneration of nerve cells results in brain atrophy. NMR-CT can easily detect small infarction (lacunae) and edematous lesions resulting from ischemia and hypertensive encephalopathy. (J.P.N.)

  14. Instant BrainShark

    CERN Document Server

    Li, Daniel

    2013-01-01

    Filled with practical, step-by-step instructions and clear explanations for the most important and useful tasks. ""Instant BrainShark"" is a step-by-step guide to creating online presentations using BrainShark. The book covers digital marketing best practices alongside tips for sales conversions. The book is written in an easy-to-read style for anybody to easily pick up and get started with BrainShark.Instant BrainShark is for anyone who wants to use BrainShark to create presentations online and share them around the community. The book is also useful for developers who are looking to explore

  15. David Ferrier: brain drawings and brain maps.

    Science.gov (United States)

    Lazar, J Wayne

    2013-01-01

    This chapter has two emphases, one is about the men who influenced the visual representations that David Ferrier (1843-1928) used to illustrate his work on localization of brain functions during the years 1873-1875, namely, Alexander Ecker, John C. Galton, and Ernest Waterlow, and the other is about the nature of medical representations and of Ferrier's illustrations in particular. Medical illustrations are characterized either as pictures, line drawings, or brain maps. Ferrier's illustrations will be shown to be increasingly sophisticated brain maps that contrast with early nineteenth-century standards of medical illustrations, as exemplified by John Bell (1763-1829). © 2013 Elsevier B.V. All rights reserved.

  16. Endothelial cell marker PAL-E reactivity in brain tumor, developing brain, and brain disease

    NARCIS (Netherlands)

    Leenstra, S.; Troost, D.; Das, P. K.; Claessen, N.; Becker, A. E.; Bosch, D. A.

    1993-01-01

    The endothelial cell marker PAL-E is not reactive to vessels in the normal brain. The present study concerns the PAL-E reactivity in brain tumors in contrast to normal brain and nonneoplastic brain disease. A total of 122 specimens were examined: brain tumors (n = 94), nonneoplastic brain disease (n

  17. Mapping brain function to brain anatomy

    International Nuclear Information System (INIS)

    Valentino, D.J.; Huang, H.K.; Mazziotta, J.C.

    1988-01-01

    In Imaging the human brain, MRI is commonly used to reveal anatomical structure, while PET is used to reveal tissue function. This paper presents a protocol for correlating data between these two imaging modalities; this correlation can provide in vivo regional measurements of brain function which are essential to our understanding of the human brain. The authors propose a general protocol to standardize the acquisition and analysis of functional image data. First, MR and PET images are collected to form three-dimensional volumes of structural and functional image data. Second, these volumes of image data are corrected for distortions inherent in each imaging modality. Third, the image volumes are correlated to provide correctly aligned structural and functional images. The functional images are then mapped onto the structural images in both two-dimensional and three-dimensional representations. Finally, morphometric techniques can be used to provide statistical measures of the structure and function of the human brain

  18. Brain imaging during seizure: ictal brain SPECT

    International Nuclear Information System (INIS)

    Kottamasu, Sambasiva Rao

    1997-01-01

    The role of single photon computed tomography (SPECT) in presurgical localization of medically intractable complex partial epilepsy (CPE) in children is reviewed. 99m Technetium neurolite, a newer lipophylic agent with a high first pass brain extraction and little or no redistribution is injected during a seizure, while the child is monitored with a video recording and continuous EEG and SPECT imaging is performed in the next 1-3 hours with the images representing regional cerebral profusion at the time of injection. On SPECT studies performed with radiopharmaceutical injected during a seizure, ictal focus is generally hypervascular. Other findings on ictal brain SPECT include hypoperfusion of adjacent cerebral cortex and white matter, hyperperfusion of contralateral motor cortex, hyperperfusion of ipsilateral basal ganglia and thalamus, brain stem and contralateral cerebellum. Ictal brain SPECT is non-invasive, cost effective and highly sensitive for localization of epileptic focus in patients with intractable CPE. (author)

  19. Handbook of Brain Connectivity

    CERN Document Server

    Jirsa, Viktor K

    2007-01-01

    Our contemporary understanding of brain function is deeply rooted in the ideas of the nonlinear dynamics of distributed networks. Cognition and motor coordination seem to arise from the interactions of local neuronal networks, which themselves are connected in large scales across the entire brain. The spatial architectures between various scales inevitably influence the dynamics of the brain and thereby its function. But how can we integrate brain connectivity amongst these structural and functional domains? Our Handbook provides an account of the current knowledge on the measurement, analysis and theory of the anatomical and functional connectivity of the brain. All contributors are leading experts in various fields concerning structural and functional brain connectivity. In the first part of the Handbook, the chapters focus on an introduction and discussion of the principles underlying connected neural systems. The second part introduces the currently available non-invasive technologies for measuring struct...

  20. Mapping the brain

    International Nuclear Information System (INIS)

    Begley, S.; Wright, L.; Church, V.; Hager, M.

    1992-01-01

    With powerful new technologies such as positron tomography and superconducting quantum interference device that peer through the skull and see the brain at work, neuroscientists seek the wellsprings of thoughts and emotions, the genesis of intelligence and language. A functional map of the brain is thus obtained and its challenge is to move beyond brain structure to create a detailed diagram of which part do what. For that the brain's cartographers rely on a variety of technologies such as positron tomography and superconducting quantum interference devices. Their performances and uses are briefly reviewed. ills

  1. Mild Traumatic Brain Injury

    Science.gov (United States)

    ... mild Traumatic Brain Injury Resilience Families with Kids Depression Families & Friendships Tobacco Life Stress Spirituality Anger Physical Injury Stigma Health & Wellness Work Adjustment Community Peer-2-Peer Forum ...

  2. Brain spect imaging

    International Nuclear Information System (INIS)

    Lee, R.G.L.; Hill, T.C.; Holman, B.L.

    1989-01-01

    This paper discusses how the rapid development of single-photon radiopharmaceuticals has given new life to tomographic brain imaging in nuclear medicine. Further developments in radiopharmaceuticals and refinements in neuro-SPECT (single-photon emission computed tomography) instrumentation should help to reinstate brain scintigraphy as an important part of neurologic diagnosis. SPECT of the brain evolved from experimentation using prototype instrumentation during the early 1960s. Although tomographic studies provided superior diagnostic accuracy when compared to planar techniques, the arrival of X-ray CT of the head resulted in the rapid demise of technetium brain imaging

  3. A novel piperazine-bis(rhodamine-B)-based chemosensor for highly sensitive and selective naked-eye detection of Cu{sup 2+} and its application as an INHIBIT logic device

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Zebin; Li, Haizhen; Guo, Dan; Liu, Yan; Tian, Zhang; Yan, Shiqiang, E-mail: yansq@lzu.edu.cn

    2015-11-15

    Abstact: We report the design and synthesis of a new piperazine-bis(rhodamine-B) (RB-P-RB)-based indicator for selective detection of Cu{sup 2+} ion. Optical sensing behavior toward various metal ions including alkali, alkaline earth and transition metal ions (Na{sup +}, K{sup +}, Ba{sup 2+}, Mg{sup 2+}, Ca{sup 2+}, Zn{sup 2+}, Cd{sup 2+}, Mn{sup 2+}, Co{sup 2+}, Ni{sup 2+}, Pb{sup 2+}, Cu{sup 2+}, Hg{sup 2+}, and Ag{sup +}) were investigated by UV–vis and fluorescence spectroscopy in ethassnol solution. The indicator showed highly selective and sensitive colorimetric and “turn-on” fluorescence enhancement responses toward Cu{sup 2+} ion owing to the ring-opening structure of the rhodamine spirolactam. The significant change from colorless to pink upon the addition of Cu{sup 2+} could make it a suitable “naked-eye” indicator for Cu{sup 2+}. Furthermore, a possible ring-opening mechanism (off-on) of the rhodamine spirolactam induced by Cu{sup 2+} binding is supported by Job plot, ESI-mass, FT-IR, and {sup 1}H NMR. More significantly, the probe displayed highly selective Cu{sup 2+}-amplified absorption in the presence of Cu{sup 2+} ions. Finally, using Cu{sup 2+} and EDTA as inputs and the fluorescence emission intensity as output, an INHIBIT logic gate can be constructed at the molecular level. - Highlights: • A novel piperazine-bis(rhodamine-B)-based sensor for selective detection of Cu{sup 2+} ion was synthesized via simple synthetic procedures. • The probe exhibited highly selective and sensitive colorimetric and “turn on” fluorescence enhancement responses to Cu{sup 2+}. • The probe can serve as a reversible and selective “naked eye” indicator for Cu{sup 2+} ions in ethanol solution. • The probe can be utilized to construct an INHIBIT logic gate at the molecular level. • The probe displays highly selective Cu{sup 2+}-amplified absorption in ethanol solution.

  4. MRI of 'brain death'

    International Nuclear Information System (INIS)

    Nishino, Shigeki; Itoh, Takahiko; Tuchida, Shohei; Kinugasa, Kazushi; Asari, Shoji; Nishimoto, Akira; Sanou, Kazuo.

    1990-01-01

    Magnetic resonance imaging (MRI) was undertaken for two patients who suffered from severe cerebrovascular diseases and were clinically brain dead. The MRI system we used was Resona (Yokogawa Medical Systems, superconductive system 0.5 T) and the CT apparatus was Toshiba TCT-300. Initial CT and MRI were undertaken as soon as possible after admission, and repeated sequentially. After diagnosis of brain death, we performed angiography to determine cerebral circulatory arrest, and MRI obtained at the same time was compared with the angiogram and CT. Case 1 was a 77-year-old man who was admitted in an unconscious state. CT and MRI on the second day after hospitalization revealed cerebellar infarction. He was diagnosed as brain dead on day 4. Case 2 was a 35-year-old man. When he was transferred to our hospital, he was in cardiorespiratory arrested. Cardiac resuscitation was successful but no spontaneous respiration appeared. CT and MRI on admission revealed right intracerebral hemorrhage. Angiography revealed cessation of contrast medium in intracranial vessels in both of the patients. We found no 'flow signal void sign' in the bilateral internal carotid and basilar arteries on MRI images in both cases after brain death. MRI, showing us the anatomical changes of the brain, clearly revealed brain herniations, even though only nuclear findings of 'brain tamponade' were seen on CT. But in Case 1, we could not see the infarct lesions in the cerebellum on MR images obtained after brain death. This phenomenon was caused by the whole brain ischemia masking the initial ischemic lesions. We concluded that MRI was useful not only the anatomical display of lesions and brain herniation with high contrast resolution but for obtaining information on cerebral circulation of brain death. (author)

  5. The multilingual brain

    OpenAIRE

    Engel de Abreu, Pascale

    2013-01-01

    The multilingual brain. Is a multilingual education beneficial for children? What are the optimal conditions under which a child can become perfectly multilingual? The given lecture will focus on the "cognitive advantages" of multilingualism and illustrate the impact that being multilingual has on the cognitive organisation of the brain. Practical questions regarding multilingual education will also be discussed.

  6. The Resilient Brain

    Science.gov (United States)

    Brendtro, Larry K.; Longhurst, James E.

    2005-01-01

    Brain research opens new frontiers in working with children and youth experiencing conflict in school and community. Blending this knowledge with resilience science offers a roadmap for reclaiming those identified as "at risk." This article applies findings from resilience research and recent brain research to identify strategies for reaching…

  7. Brain PET scan

    Science.gov (United States)

    ... results on a PET scan. Blood sugar or insulin levels may affect the test results in people with diabetes . PET scans may be done along with a CT scan. This combination scan is called a PET/CT. Alternative Names Brain positron emission tomography; PET scan - brain References Chernecky ...

  8. What a Brain!

    Science.gov (United States)

    Love, Kim

    1997-01-01

    Outlines basic concepts about how the brain develops and considers how Head Start teachers and parents can take full advantage of the brain's multisensory learning approach to develop more effective ways to interact with children. Focuses on the critical developmental period for stimulating neurons and developing neural connections. Suggests…

  9. Baby brain atlases.

    Science.gov (United States)

    Oishi, Kenichi; Chang, Linda; Huang, Hao

    2018-04-03

    The baby brain is constantly changing due to its active neurodevelopment, and research into the baby brain is one of the frontiers in neuroscience. To help guide neuroscientists and clinicians in their investigation of this frontier, maps of the baby brain, which contain a priori knowledge about neurodevelopment and anatomy, are essential. "Brain atlas" in this review refers to a 3D-brain image with a set of reference labels, such as a parcellation map, as the anatomical reference that guides the mapping of the brain. Recent advancements in scanners, sequences, and motion control methodologies enable the creation of various types of high-resolution baby brain atlases. What is becoming clear is that one atlas is not sufficient to characterize the existing knowledge about the anatomical variations, disease-related anatomical alterations, and the variations in time-dependent changes. In this review, the types and roles of the human baby brain MRI atlases that are currently available are described and discussed, and future directions in the field of developmental neuroscience and its clinical applications are proposed. The potential use of disease-based atlases to characterize clinically relevant information, such as clinical labels, in addition to conventional anatomical labels, is also discussed. Copyright © 2018. Published by Elsevier Inc.

  10. Migraine and brain changes

    NARCIS (Netherlands)

    Meinders, I.H.

    2018-01-01

    This thesis describes the longitudinal population-based CAMERA-study on the association between migraine and brain changes (e.g. white matter hyperintensities, infarct-like and other lesions) and possible causes and consequences of those brain changes. Women with migraine showed higher incidence of

  11. Brain imaging in psychiatry

    International Nuclear Information System (INIS)

    Morihisa, J.M.

    1984-01-01

    This book contains the following five chapters: Positron Emission Tomography (PET) in Psychiatry; Regional Cerebral Blood Flow (CBF) in Psychiatry: Methodological Issues; Regional Cerebral Blood Flow in Psychiatry: Application to Clinical Research; Regional Cerebral Blood Flow in Psychiatry: The Resting and Activated Brains of Schizophrenic Patients; and Brain Electrical Activity Mapping (BEAM) in Psychiatry

  12. Inside the Adolescent Brain

    Science.gov (United States)

    Drury, Stacy S.

    2009-01-01

    Dr. Jay Giedd says that the main alterations in the adolescent brain are the inverted U-shaped developmental trajectories with late childhood/early teen peaks for gray matter volume among others. Giedd adds that the adolescent brain is vulnerable to substances that artificially modulate dopamine levels since its reward system is in a state of flux.

  13. One brain, two selves

    NARCIS (Netherlands)

    Reinders, AATS; Nijenhuis, ERS; Paans, AMJ; Korf, J; Willemsen, ATM; den Boer, JA

    2003-01-01

    Having a sense of self is an explicit and high-level functional specialization of the human brain. The anatomical localization of self-awareness and the brain mechanisms involved in consciousness were investigated by functional neuroimaging different emotional mental states of core consciousness in

  14. Coping changes the brain

    Directory of Open Access Journals (Sweden)

    Jordan M. Nechvatal

    2013-02-01

    Full Text Available One of the earliest and most consistent findings in behavioral neuroscience research is that learning changes the brain. Here we consider how learning as an aspect of coping in the context of stress exposure induces neuroadaptations that enhance emotion regulation and resilience. A systematic review of the literature identified 15 brain imaging studies in which humans with specific phobias or posttraumatic stress disorder were randomized to stress exposure therapies that diminished subsequent indications of anxiety. Most of these studies focused on functional changes in the amygdala and anterior corticolimbic brain circuits that control cognitive, motivational, and emotional aspects of physiology and behavior. Corresponding structural brain changes and the timing, frequency, and duration of stress exposure required to modify brain functions remain to be elucidated in future research. These studies will advance our understanding of coping as a learning process and provide mechanistic insights for the development of new interventions that promote stress coping skills.

  15. Epilepsy and Brain Tumors

    Institute of Scientific and Technical Information of China (English)

    Zhi-yi Sha

    2009-01-01

    @@ Epidemiology It is estimated 61,414 new cases of primary brain tumors are expected to be diagnosed in 2009 in the U.S. The incidence statistic of 61,414 persons diagnosed per year includes both malignant (22,738) and non-malignant (38,677) brain tumors. (Data from American Brain Tumor Association). During the years 2004-2005, approximately 359,000 people in the United States were living with the diagnosis of a primary brain or central nervous system tumor. Specifically, more than 81,000 persons were living with a malignant tumor, more than 267,000 persons with a benign tumor. For every 100,000 people in the United States, approximately 131 are living following the diagnosis of a brain tumor. This represents a prevalence rate of 130.8 per 100,000 person years[1].

  16. Brain-computer interfaces

    DEFF Research Database (Denmark)

    Treder, Matthias S.; Miklody, Daniel; Blankertz, Benjamin

    quality measure'. We were able to show that for stimuli close to the perceptual threshold, there was sometimes a discrepancy between overt responses and brain responses, shedding light on subjects using different response criteria (e.g., more liberal or more conservative). To conclude, brain-computer...... of perceptual and cognitive biases. Furthermore, subjects can only report on stimuli if they have a clear percept of them. On the other hand, the electroencephalogram (EEG), the electrical brain activity measured with electrodes on the scalp, is a more direct measure. It allows us to tap into the ongoing neural...... auditory processing stream. In particular, it can tap brain processes that are pre-conscious or even unconscious, such as the earliest brain responses to sounds stimuli in primary auditory cortex. In a series of studies, we used a machine learning approach to show that the EEG can accurately reflect...

  17. Inside the Diabetic Brain

    Directory of Open Access Journals (Sweden)

    Chomova M.

    2014-12-01

    Full Text Available CNS complications resulting from diabetes mellitus (DM are a problem gaining more acceptance and attention in the recent years. Both types 1 and 2 DM represent an significant risk factor for decreased cognitive functions, memory and learning deficits as well as development of Alzheimer’s disease. Chronic hyperglycemia through protein glycation and increased oxidative stress contributes to brain dysfunction, however increasing evidences suggest that the pathology of DM in the brain involves a progressive and coordinated disruption of insulin signaling, with profound consequences for brain function and plasticity. Since many of the CNS changes observed in diabetic patients and animal models of DM are reminiscent of the changes seen in aging, the theory of advanced brain aging in DM has been proposed. This review summarizes the findings of the literature regarding the effects of DM on the brain in the terms of diabetes-related metabolic derangements and intracellular signaling.

  18. Modeling Structural Brain Connectivity

    DEFF Research Database (Denmark)

    Ambrosen, Karen Marie Sandø

    The human brain consists of a gigantic complex network of interconnected neurons. Together all these connections determine who we are, how we react and how we interpret the world. Knowledge about how the brain is connected can further our understanding of the brain’s structural organization, help...... improve diagnosis, and potentially allow better treatment of a wide range of neurological disorders. Tractography based on diffusion magnetic resonance imaging is a unique tool to estimate this “structural connectivity” of the brain non-invasively and in vivo. During the last decade, brain connectivity...... has increasingly been analyzed using graph theoretic measures adopted from network science and this characterization of the brain’s structural connectivity has been shown to be useful for the classification of populations, such as healthy and diseased subjects. The structural connectivity of the brain...

  19. Exploring the brain

    International Nuclear Information System (INIS)

    Bloch, G.; Vernier, P.; Le Bihan, D.; Comtat, C.; Van Wassenhove, V.; Texier, I.; Planat-Chretien, A.; Poher, V.; Dinten, J.M.; Pannetier-lecoeur, M.; Trebossen, R.; Lethimonnier, F.; Eger, E.; Thirion, B.; Dehaene-Lambertz, G.; Piazza, M.; Mangin, J.F.; Dehaene, S.; Pallier, C.; Marti, S.; Klein, E.; Martinot, J.L.; Paillere, M.L.; Artiges, E.; Lemaitre, H.; Karila, L.; Houenou, J.; Sarrazin, S.; Hantraye, P.; Aron Badin, R.; Mergui, S.; Palfi, S.; Bemelmans, A.; Berger, F.; Frouin, V.; Pinel, J.F.; Crivello, F.; Mazoyer, B.; Flury-Herard, A.

    2014-01-01

    CEA (French Alternative Energies and Atomic Energy Commission) has been involved in brain research for over 50 years and this 62. issue of 'Clefs CEA' is the best occasion to come back on the latest advances in this wide field. The purpose is to show how neuroimaging combined with neuro sciences and computational sciences has shed light on various aspects of the brain life and experience such as for instance learning (with highlights on dyslexia and dyscalculia), vision, the feeling of time, consciousness, addictions, ageing, and neuro-degenerative diseases. This document is divided into 6 parts: 1) non-invasive exploration of the brain, 2) development, learning and plasticity of the brain, 3) cognitive architecture and the brain, 4) mental health and vulnerability, 5) neuro-degenerative diseases, and 6) identifying bio-markers for cerebral disorders. (A.C.)

  20. Brain Aneurysm Statistics and Facts

    Science.gov (United States)

    ... Statistics and Facts A- A A+ Brain Aneurysm Statistics and Facts An estimated 6 million people in ... Understanding the Brain Warning Signs/ Symptoms Brain Aneurysm Statistics and Facts Seeking Medical Attention Risk Factors Aneurysm ...

  1. The negative brain scintiscan in brain tumours

    International Nuclear Information System (INIS)

    Dalke, K.G.

    1978-01-01

    On the basis of 53 histologically verified and two histologically unidentified brain tumours, the author examined the reasons for these wrongly negative scintiscans. EEGs and angiographies carried out at about the same time were taken into account and compared with the scintigraphic findings. (orig.) [de

  2. The northern naked-tailed armadillo in the Lacandona rainforest, Mexico: new records and potential threats Armadillo de cola desnuda en la selva lacandona, México: nuevos registros y amenazas potenciales

    Directory of Open Access Journals (Sweden)

    Arturo González-Zamora

    2012-06-01

    Full Text Available We review historic occurrences in Mexico of one of the least known Xenarthra of Mesoamerica - the northern naked-tailed armadillo (Cabassous centralis Miller, 1899. We document 6 new records in the Lacandona rainforest, southern Mexico, and through interviews with local people, we assess potential threats for this species in the region. In addition to being locally rare, our results show that hunting and death by road-kill may be major threats to this species in the region.Se revisaron los registros históricos en México de uno de los xenartros menos conocidos de Mesoamérica - el armadillo de cola desnuda (Cabassous centralis Miller, 1899. Se documentan 6 nuevos registros en la selva lacandona, sur de México. A través de entrevistas con pobladores locales, se evaluaron las amenazas potenciales para esta especie en la región. Además de ser localmente rara, nuestros resultados muestran que la cacería y las muertes por atropellamiento pueden ser las principales amenazas para esta especie en la región.

  3. Effectively simultaneous naked-eye detection of Cu(II), Pb(II), Al(III) and Fe(III) using cyanidin extracted from red cabbage as chelating agent

    Science.gov (United States)

    Khaodee, Warangkhana; Aeungmaitrepirom, Wanlapa; Tuntulani, Thawatchai

    Simultaneous determination of Cu(II), Pb(II), Al(III) and Fe(III) using cyanidin as a chelating agent was investigated in terms of both quantitative and qualitative detections. Cyanidin was extracted and purified from red cabbage which is a local plant in Thailand. The selectivity of this method was examined by regulating the pH of cyanidin solution operated together with masking agents. It was found that Cu(II), Pb(II), Al(III) and Fe(III) simultaneously responded with the color change at pH 7, pH 6, pH 5 and pH 4, respectively. KF, DMG and the mixture of KF and DMG were used as masking agents for the determination of Fe(III), Al(III) and Pb(II), respectively. Results from naked-eye detection were evaluated by comparing with those of inductively coupled plasma (ICP), and there was no significant difference noticed. Cyanidin using as a multianalyte reagent could be employed for simultaneous determination of Cu(II), Pb(II), Al(III) and Fe(III) at the lowest concentration at 50, 80, 50 and 200 μM, respectively, by slightly varying pHs. Moreover, the proposed method could be potentially applied for real water samples with simplicity, rapidity, low cost and environmental safety.

  4. Persistent Dystrophin Protein Restoration 90 Days after a Course of Intraperitoneally Administered Naked 2′OMePS AON and ZM2 NP-AON Complexes in mdx Mice

    Directory of Open Access Journals (Sweden)

    Elena Bassi

    2012-01-01

    Full Text Available In Duchenne muscular dystrophy, the exon-skipping approach has obtained proof of concept in animal models, myogenic cell cultures, and following local and systemic administration in Duchenne patients. Indeed, we have previously demonstrated that low doses (7.5 mg/Kg/week of 2′-O-methyl-phosphorothioate antisense oligoribonucleotides (AONs adsorbed onto ZM2 nanoparticles provoke widespread dystrophin restoration 7 days after intraperitoneal treatment in mdx mice. In this study, we went on to test whether this dystrophin restoration was still measurable 90 days from the end of the same treatment. Interestingly, we found that both western blot and immunohistochemical analysis (up to 7% positive fibres were still able to detect dystrophin protein in the skeletal muscles of ZM2-AON-treated mice at this time, and the level of exon-23 skipping could still be assessed by RT real-time PCR (up to 10% of skipping percentage. In contrast, the protein was undetectable by western blot analysis in the skeletal muscles of mdx mice treated with an identical dose of naked AON, and the percentage of dystrophin-positive fibres and exon-23 skipping were reminiscent of those of untreated mdx mice. Our data therefore demonstrate the long-term residual efficacy of this systemic low-dose treatment and confirm the protective effect nanoparticles exert on AON molecules.

  5. Selective vulnerability in brain hypoxia

    DEFF Research Database (Denmark)

    Cervos-Navarro, J.; Diemer, Nils Henrik

    1991-01-01

    Neuropathology, selective vulnerability, brain hypoxia, vascular factors, excitotoxicity, ion homeostasis......Neuropathology, selective vulnerability, brain hypoxia, vascular factors, excitotoxicity, ion homeostasis...

  6. Insulin and the brain.

    Science.gov (United States)

    Derakhshan, Fatemeh; Toth, Cory

    2013-03-01

    Mainly known for its role in peripheral glucose homeostasis, insulin has also significant impact within the brain, functioning as a key neuromodulator in behavioral, cellular, biochemical and molecular studies. The brain is now regarded as an insulin-sensitive organ with widespread, yet selective, expression of the insulin receptor in the olfactory bulb, hypothalamus, hippocampus, cerebellum, amygdala and cerebral cortex. Insulin receptor signaling in the brain is important for neuronal development, glucoregulation, feeding behavior, body weight, and cognitive processes such as with attention, executive functioning, learning and memory. Emerging evidence has demonstrated insulin receptor signaling to be impaired in several neurological disorders. Moreover, insulin receptor signaling is recognized as important for dendritic outgrowth, neuronal survival, circuit development, synaptic plasticity and postsynaptic neurotransmitter receptor trafficking. We review the multiple roles of insulin in the brain, as well as its endogenous trafficking to the brain or its exogenous intervention. Although insulin can be directly targeted to the brain via intracerebroventricular (ICV) or intraparenchymal delivery, these invasive techniques are with significant risk, necessitating repeated surgical intervention and providing potential for systemic hypoglycemia. Another method, intranasal delivery, is a non-invasive, safe, and alternative approach which rapidly targets delivery of molecules to the brain while minimizing systemic exposure. Over the last decades, the delivery of intranasal insulin in animal models and human patients has evolved and expanded, permitting new hope for associated neurodegenerative and neurovascular disorders.

  7. Lutein and Brain Function

    Directory of Open Access Journals (Sweden)

    John W. Erdman

    2015-10-01

    Full Text Available Lutein is one of the most prevalent carotenoids in nature and in the human diet. Together with zeaxanthin, it is highly concentrated as macular pigment in the foveal retina of primates, attenuating blue light exposure, providing protection from photo-oxidation and enhancing visual performance. Recently, interest in lutein has expanded beyond the retina to its possible contributions to brain development and function. Only primates accumulate lutein within the brain, but little is known about its distribution or physiological role. Our team has begun to utilize the rhesus macaque (Macaca mulatta model to study the uptake and bio-localization of lutein in the brain. Our overall goal has been to assess the association of lutein localization with brain function. In this review, we will first cover the evolution of the non-human primate model for lutein and brain studies, discuss prior association studies of lutein with retina and brain function, and review approaches that can be used to localize brain lutein. We also describe our approach to the biosynthesis of 13C-lutein, which will allow investigation of lutein flux, localization, metabolism and pharmacokinetics. Lastly, we describe potential future research opportunities.

  8. Cannabinoids on the Brain

    Directory of Open Access Journals (Sweden)

    Andrew J. Irving

    2002-01-01

    Full Text Available Cannabis has a long history of consumption both for recreational and medicinal uses. Recently there have been significant advances in our understanding of how cannabis and related compounds (cannabinoids affect the brain and this review addresses the current state of knowledge of these effects. Cannabinoids act primarily via two types of receptor, CB1 and CB2, with CB1 receptors mediating most of the central actions of cannabinoids. The presence of a new type of brain cannabinoid receptor is also indicated. Important advances have been made in our understanding of cannabinoid receptor signaling pathways, their modulation of synaptic transmission and plasticity, the cellular targets of cannabinoids in different central nervous system (CNS regions and, in particular, the role of the endogenous brain cannabinoid (endocannabinoid system. Cannabinoids have widespread actions in the brain: in the hippocampus they influence learning and memory; in the basal ganglia they modulate locomotor activity and reward pathways; in the hypothalamus they have a role in the control of appetite. Cannabinoids may also be protective against neurodegeneration and brain damage and exhibit anticonvulsant activity. Some of the analgesic effects of cannabinoids also appear to involve sites within the brain. These advances in our understanding of the actions of cannabinoids and the brain endocannabinoid system have led to important new insights into neuronal function which are likely to result in the development of new therapeutic strategies for the treatment of a number of key CNS disorders.

  9. Human brain imaging

    International Nuclear Information System (INIS)

    Kuhar, M.J.

    1987-01-01

    Just as there have been dramatic advances in the molecular biology of the human brain in recent years, there also have been remarkable advances in brain imaging. This paper reports on the development and broad application of microscopic imaging techniques which include the autoradiographic localization of receptors and the measurement of glucose utilization by autoradiography. These approaches provide great sensitivity and excellent anatomical resolution in exploring brain organization and function. The first noninvasive external imaging of receptor distributions in the living human brain was achieved by positron emission tomography (PET) scanning. Developments, techniques and applications continue to progress. Magnetic resonance imaging (MRI) is also becoming important. Its initial clinical applications were in examining the structure and anatomy of the brain. However, more recent uses, such as MRI spectroscopy, indicate the feasibility of exploring biochemical pathways in the brain, the metabolism of drugs in the brain, and also of examining some of these procedures at an anatomical resolution which is substantially greater than that obtainable by PET scanning. The issues will be discussed in greater detail

  10. A Trickster in Disguise: Hyaluronan’s Ambivalent Roles in the Matrix

    Directory of Open Access Journals (Sweden)

    Lena Bohaumilitzky

    2017-10-01

    Full Text Available Hyaluronan (HA is a simple but diverse glycosaminoglycan. It plays a major role in aging, cellular senescence, cancer, and tissue homeostasis. In which way HA affects the surrounding tissues greatly depends on the molecular weight of HA. Whereas high molecular weight HA is associated with homeostasis and protective effects, HA fragments tend to be linked to the pathologic state. Furthermore, the interaction of HA with its binding partners, the hyaladherins, such as CD44, is essential for sustaining tissue integrity and is likewise related to cancer. The naked mole rat, a rodent species, possesses a special form of very high molecular weight (vHMW HA, which is associated with the extraordinary cancer resistance and longevity of those animals. This review addresses HA and its diverse facets: from HA synthesis to degradation, from oligomeric HA to vHMW-HA and from its beneficial properties to the involvement in pathologies. We further discuss the functions of HA in the naked mole rat and compare them to human conditions. Though intensively researched, this simple polymer bears some secrets that may hold the key for a better understanding of cellular processes and the development of diseases, such as cancer.

  11. Repeated functional convergent effects of NaV1.7 on acid insensitivity in hibernating mammals.

    Science.gov (United States)

    Liu, Zhen; Wang, Wei; Zhang, Tong-Zuo; Li, Gong-Hua; He, Kai; Huang, Jing-Fei; Jiang, Xue-Long; Murphy, Robert W; Shi, Peng

    2014-02-07

    Hibernating mammals need to be insensitive to acid in order to cope with conditions of high CO2; however, the molecular basis of acid tolerance remains largely unknown. The African naked mole-rat (Heterocephalus glaber) and hibernating mammals share similar environments and physiological features. In the naked mole-rat, acid insensitivity has been shown to be conferred by the functional motif of the sodium ion channel NaV1.7. There is now an opportunity to evaluate acid insensitivity in other taxa. In this study, we tested for functional convergence of NaV1.7 in 71 species of mammals, including 22 species that hibernate. Our analyses revealed a functional convergence of amino acid sequences, which occurred at least six times independently in mammals that hibernate. Evolutionary analyses determined that the convergence results from both parallel and divergent evolution of residues in the functional motif. Our findings not only identify the functional molecules responsible for acid insensitivity in hibernating mammals, but also open new avenues to elucidate the molecular underpinnings of acid insensitivity in mammals.

  12. Usefulness of brain SPECT

    International Nuclear Information System (INIS)

    Raynaud, C.; Rancurel, G.; Kieffer, E.; Ricard, S.; Askienazy, S.; Moretti, J.L.; Bourdoiseau, M.; Rapin, J.; Soussaline, F.

    1983-01-01

    Brain SPECT was not effectively exploited until I-123 isopropyl amphetamine (IAMP), indicator able to penetrate the blood brain barrier, became available. Although the experience of research teams working with IAMP is quite restricted due to the high cost of the indicator, some applications now appear to be worth the cost and in some cases provide data which cannot be obtained with routine techniques, especially in cerebrovascular patients, in epilepsy and some cases of tumor. Brain SPECT appears as an atraumatic test which is useful to establish a functional evaluation of the cerebral parenchyma, and which is a complement to arteriography, X-ray scan and regional cerebral blood flow measurement

  13. Brain Drain: A Child's Brain on Poverty. Poverty Fact Sheet

    Science.gov (United States)

    Damron, Neil

    2015-01-01

    "Brain Drain: A Child's Brain on Poverty," released in March 2015 and prepared by intern Neil Damron, explores the brain's basic anatomy and recent research findings suggesting that poverty affects the brain development of infants and young children and the potential lifelong effects of the changes. The sheet draws from a variety of…

  14. A Right Brain/Left Brain Model of Acting.

    Science.gov (United States)

    Bowlen, Clark

    Using current right brain/left brain research, this paper develops a model that explains acting's underlying quality--the actor is both himself and the character. Part 1 presents (1) the background of the right brain/left brain theory, (2) studies showing that propositional communication is a left hemisphere function while affective communication…

  15. Management of Brain Metastases.

    Science.gov (United States)

    Jeyapalan, Suriya A.; Batchelor, Tracy

    2004-07-01

    Advances in neurosurgery and the development of stereotactic radiosurgery have expanded treatment options available for patients with brain metastases. However, despite several randomized clinical trials and multiple uncontrolled studies, there is not a uniform consensus on the best treatment strategy for all patients with brain metastases. The heterogeneity of this patient population in terms of functional status, types of underlying cancers, status of systemic disease control, and number and location of brain metastases make such consensus difficult. Nevertheless, in certain situations, there is Class I evidence that supports one approach or another. The primary objectives in the management of this patient population include improved duration and quality of survival. Very few patients achieve long-term survival after the diagnosis of a brain metastasis.

  16. of brain tumours

    African Journals Online (AJOL)

    outline of the important clinical issues related to brain tumours and psychiatry. ... Left-sided, frontal tumours also seem to be associated with higher rates of depression, while those in the frontal lobe of the right .... Oxford: Blackwell Science,.

  17. Brain versus Machine Control.

    Directory of Open Access Journals (Sweden)

    Jose M Carmena

    2004-12-01

    Full Text Available Dr. Octopus, the villain of the movie "Spiderman 2", is a fusion of man and machine. Neuroscientist Jose Carmena examines the facts behind this fictional account of a brain- machine interface

  18. Brain Basics: Preventing Stroke

    Science.gov (United States)

    ... NINDS) are committed to reducing that burden through biomedical research. What is a Stroke? A stroke, or "brain ... Testimony Legislative Updates Impact NINDS Contributions to Approved Therapies ... Director, Division of Intramural Research

  19. Brain and Addiction

    Science.gov (United States)

    ... reward” circuit, which is part of the limbic system. Normally, the reward circuit responds to feelings of pleasure by releasing ... infographic, discover how drug use affects the brain's reward system. This publication is available for your use and ...

  20. Severe Traumatic Brain Injury

    Science.gov (United States)

    ... TBI Online Concussion Training Press Room Guide to Writing about TBI in News and Social Media Living with TBI HEADS UP to Brain Injury Awareness Get Email Updates To receive email updates about this topic, ...

  1. The neonatal brain

    International Nuclear Information System (INIS)

    Flodmark, O.

    1987-01-01

    The clinical examination of the CNS in the neonate is often difficult in cases of complex pathology. Diagnostic imaging of the neonatal brain has become extremely useful and in the last decade has developed in two main directions: CT and US. MR imaging has been used recently with varying success in the diagnosis of pathology in the neonatal brain. Despite technical difficulties, this imaging method is likely to become increasingly important in the neonate. The paper examines the normal neonatal brain anatomy as seen with the different modalities, followed by pathologic conditions. Attention is directed to the common pathology, in asphyxiated newborns, the patholphysiology of intraventicular hemorrhage and periventricular leukomalacia in the preterm neonate, and hypoxic-ischemic brain injury in the term neonate. Pitfalls, artifacts, and problems in image interpretation are illustrated. Finally, the subsequent appearance of neonatal pathology later in infancy and childhood is discussed

  2. Postnatal brain development

    DEFF Research Database (Denmark)

    Jernigan, Terry L; Baaré, William F C; Stiles, Joan

    2011-01-01

    After birth, there is striking biological and functional development of the brain's fiber tracts as well as remodeling of cortical and subcortical structures. Behavioral development in children involves a complex and dynamic set of genetically guided processes by which neural structures interact...... in children and adolescents, as well as studies that link these changes to behavioral differences. Finally, we discuss evidence for effects on the brain of several factors that may play a role in mediating these brain-behavior associations in children, including genetic variation, behavioral interventions...... constantly with the environment. This is a protracted process, beginning in the third week of gestation and continuing into early adulthood. Reviewed here are studies using structural imaging techniques, with a special focus on diffusion weighted imaging, describing age-related brain maturational changes...

  3. Postnatal brain development

    DEFF Research Database (Denmark)

    Jernigan, Terry L; Baaré, William F C; Stiles, Joan

    2011-01-01

    After birth, there is striking biological and functional development of the brain's fiber tracts as well as remodeling of cortical and subcortical structures. Behavioral development in children involves a complex and dynamic set of genetically guided processes by which neural structures interact...... constantly with the environment. This is a protracted process, beginning in the third week of gestation and continuing into early adulthood. Reviewed here are studies using structural imaging techniques, with a special focus on diffusion weighted imaging, describing age-related brain maturational changes...... in children and adolescents, as well as studies that link these changes to behavioral differences. Finally, we discuss evidence for effects on the brain of several factors that may play a role in mediating these brain-behavior associations in children, including genetic variation, behavioral interventions...

  4. Osmotherapy in brain edema

    DEFF Research Database (Denmark)

    Grände, Per-Olof; Romner, Bertil

    2012-01-01

    Despite the fact that it has been used since the 1960s in diseases associated with brain edema and has been investigated in >150 publications on head injury, very little has been published on the outcome of osmotherapy. We can only speculate whether osmotherapy improves outcome, has no effect......, osmotherapy can be negative for outcome, which may explain why we lack scientific support for its use. These drawbacks, and the fact that the most recent Cochrane meta-analyses of osmotherapy in brain edema and stroke could not find any beneficial effects on outcome, make routine use of osmotherapy in brain...... edema doubtful. Nevertheless, the use of osmotherapy as a temporary measure may be justified to acutely prevent brain stem compression until other measures, such as evacuation of space-occupying lesions or decompressive craniotomy, can be performed. This article is the Con part in a Pro-Con debate...

  5. Brains on video games.

    Science.gov (United States)

    Bavelier, Daphne; Green, C Shawn; Han, Doug Hyun; Renshaw, Perry F; Merzenich, Michael M; Gentile, Douglas A

    2011-11-18

    The popular press is replete with stories about the effects of video and computer games on the brain. Sensationalist headlines claiming that video games 'damage the brain' or 'boost brain power' do not do justice to the complexities and limitations of the studies involved, and create a confusing overall picture about the effects of gaming on the brain. Here, six experts in the field shed light on our current understanding of the positive and negative ways in which playing video games can affect cognition and behaviour, and explain how this knowledge can be harnessed for educational and rehabilitation purposes. As research in this area is still in its early days, the contributors of this Viewpoint also discuss several issues and challenges that should be addressed to move the field forward.

  6. Epigenetics and brain evolution.

    Science.gov (United States)

    Keverne, Eric B

    2011-04-01

    Fundamental aspects of mammalian brain evolution occurred in the context of viviparity and placentation brought about by the epigenetic regulation of imprinted genes. Since the fetal placenta hormonally primes the maternal brain, two genomes in one individual are transgenerationally co-adapted to ensure maternal care and nurturing. Advanced aspects of neocortical brain evolution has shown very few genetic changes between monkeys and humans. Although these lineages diverged at approximately the same time as the rat and mouse (20 million years ago), synonymous sequence divergence between the rat and mouse is double that when comparing monkey with human sequences. Paradoxically, encephalization of rat and mouse are remarkably similar, while comparison of the human and monkey shows the human cortex to be three times the size of the monkey. This suggests an element of genetic stability between the brains of monkey and man with a greater emphasis on epigenetics providing adaptable variability.

  7. Genetics and the Brain

    Science.gov (United States)

    ... Epigenetic regulation of gene expression in physiological and pathological brain processes. Physiol Rev , 2011 Apr; 91(2): ... term potentiation and spine size enlargement. J. Neuroscience , March 18, 2009. 29(11):3395–3403 [xviii] Tapper, ...

  8. Brain Training for Seniors

    Science.gov (United States)

    ... it or lose it” commonly refers to the importance of exercising your body and staying fit. Exercising ... physical exercise can make a difference. Just like physical activity, the earlier you start brain-training activity, the ...

  9. Analysis of Brain Recurrence

    Science.gov (United States)

    Frilot, Clifton; Kim, Paul Y.; Carrubba, Simona; McCarty, David E.; Chesson, Andrew L.; Marino, Andrew A.

    Analysis of Brain Recurrence (ABR) is a method for extracting physiologically significant information from the electroencephalogram (EEG), a non-stationary electrical output of the brain, the ultimate complex dynamical system. ABR permits quantification of temporal patterns in the EEG produced by the non-autonomous differential laws that govern brain metabolism. In the context of appropriate experimental and statistical designs, ABR is ideally suited to the task of interpreting the EEG. Present applications of ABR include discovery of a human magnetic sense, increased mechanistic understanding of neuronal membrane processes, diagnosis of degenerative neurological disease, detection of changes in brain metabolism caused by weak environmental electromagnetic fields, objective characterization of the quality of human sleep, and evaluation of sleep disorders. ABR has important beneficial implications for the development of clinical and experimental neuroscience.

  10. Negative brain scintigrams in brain tumors

    International Nuclear Information System (INIS)

    Dalke, K.G.

    1978-01-01

    With 53 histologically verified and 2 histologically not identified brain tumors, that showed a negative scintigram, it was tried to find reasons for the wrong and negative dropout of these scintigrams. The electroencephalograms and angiograms, that were made simultaneously were taken into consideration with respect to their propositional capability and were compared with the scintigram findings. For the formation of the negative brain scintigrams there could be found no unique cause or causal constellation. The scintigraphic tumor representation is likely based on a complex process. Therefore the reasons for the negativity of the brain scintigrams can be a manifold of causes. An important role plays the vascularisation of the tumor, but not in a sole way. As well the tumor localisation gains some importance; especially in the temporal lobe or in the deeper structures situated tumors can be negative in the scintigram. To hold down the rate of wrong-negative quote in the case of intracranial tumor search, one is advised to continue with an further exposure after 2 to 4 hours besides the usual exposures, unless a sequential scintigraphy was made from the beginning. (orig./MG) [de

  11. The multilingual brain

    OpenAIRE

    Engel de Abreu, Pascale

    2014-01-01

    The multilingual brain. Is a multilingual education beneficial for children? What are the optimal conditions under which a child can become perfectly multilingual? The given lecture will focus on the "cognitive advantages" of multilingualism and illustrate the impact that being multilingual has on the cognitive organisation of the brain. Practical questions regarding multilingual education will also be discussed. Ass et gutt e Kand méisproocheg ze erzéien? Wat sinn déi optimal Konditio...

  12. Insulin and brain aging

    OpenAIRE

    Baranowska-Bik, Agnieszka; Bik, Wojciech

    2017-01-01

    The world’s population is living much longer than in the past. It is crucial to find as many pathological factors that deteriorate the health condition and well-being of elderly people as possible. Loss of activity and functions over time is typical for elderly people. Aging affects brain function, metabolism and structure in different ways, and these effects have multiple etiologies. Cognitive impairment, impaired neurotransmitter activity and reduction of brain volume are observed in th...

  13. Pediatric brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Poussaint, Tina Y. [Department of Radiology, Boston, MA (United States); Panigrahy, Ashok [Children' s Hospital of Pittsburgh of University of Pittsburgh Medical Center, Department of Radiology, Pittsburgh, PA (United States); Huisman, Thierry A.G.M. [Charlotte R. Bloomberg Children' s Center, Johns Hopkins Hospital, Division of Pediatric Radiology and Pediatric Neuroradiology, Baltimore, MD (United States)

    2015-09-15

    Among all causes of death in children from solid tumors, pediatric brain tumors are the most common. This article includes an overview of a subset of infratentorial and supratentorial tumors with a focus on tumor imaging features and molecular advances and treatments of these tumors. Key to understanding the imaging features of brain tumors is a firm grasp of other disease processes that can mimic tumor on imaging. We also review imaging features of a common subset of tumor mimics. (orig.)

  14. Brain derived neurotrophic factor

    DEFF Research Database (Denmark)

    Mitchelmore, Cathy; Gede, Lene

    2014-01-01

    Brain Derived Neurotrophic Factor (BDNF) is a neurotrophin with important functions in neuronal development and neuroplasticity. Accumulating evidence suggests that alterations in BDNF expression levels underlie a variety of psychiatric and neurological disorders. Indeed, BDNF therapies are curre......Brain Derived Neurotrophic Factor (BDNF) is a neurotrophin with important functions in neuronal development and neuroplasticity. Accumulating evidence suggests that alterations in BDNF expression levels underlie a variety of psychiatric and neurological disorders. Indeed, BDNF therapies...

  15. Neuroethics and Brain Privacy

    DEFF Research Database (Denmark)

    Ryberg, Jesper

    2017-01-01

    An introduction is presented in which editor discusses various articles within the issue on topics including ethical challenges with importance of privacy for well-being, impact of brain-reading on mind privacy and neurotechnology.......An introduction is presented in which editor discusses various articles within the issue on topics including ethical challenges with importance of privacy for well-being, impact of brain-reading on mind privacy and neurotechnology....

  16. Protect Your Brain

    Centers for Disease Control (CDC) Podcasts

    Recent high-profile cases among professional athletes have called attention to the serious problem of traumatic brain injuries, or TBI, but the problem isn’t limited to playing fields. In 2009, at least three and a half million people in the U.S. sustained a TBI, either with or without other injuries. In this podcast, Dr. Lisa McGuire discusses the importance of early diagnosis and treatment of brain injuries.

  17. Dyslexia singular brain

    International Nuclear Information System (INIS)

    Habis, M.; Robichon, F.; Demonet, J.F.

    1996-01-01

    Of late ten years, neurologists are studying the brain of the dyslectics. The cerebral imagery (NMR imaging, positron computed tomography) has allowed to confirm the anatomical particularities discovered by some of them: asymmetry default of cerebral hemispheres, size abnormally large of the white substance mass which connect the two hemispheres. The functional imagery, when visualizing this singular brain at work, allows to understand why it labors to reading. (O.M.)

  18. Your Brain and Nervous System

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Your Brain & Nervous System KidsHealth / For Kids / Your Brain & Nervous ... The coolest wetsuit? Nope — he needs his cerebellum! Brain Stem Keeps You Breathing — and More Another brain ...

  19. Brain fat embolism

    International Nuclear Information System (INIS)

    Sugiura, Yoshihiro; Kawamura, Yasutaka; Suzuki, Hisato; Yanagimoto, Masahiro; Goto, Yukio

    1994-01-01

    Recently CT and MR imaging have demonstrated that cerebral edema is present in cases of fat embolism syndrome. To simulate this we have made a model of brain-fat embolism in rats under MR imaging. In 20 rats, we did intravenous injection of heparinized blood, 1.5 ml·kg -1 taken from femoral bone marrow cavity. Twenty four hours after the injection, we examined the MR images (1.5 tesla, spin-echo method) of brains and histologic findings of brains and lungs were obtained. In 5 of 20 rats, high signal intensity on T2-weighted images and low signal intensity on T1-weighted images were observed in the area of the unilateral cerebral cortex or hippocampus. These findings showed edema of the brains. They disappeared, however, one week later. Histologic examinations showed massive micro-fat emboli in capillaries of the deep cerebral cortex and substantia nigra, but no edematous findings of the brain were revealed in HE staining. In pulmonary arteries, we also found large fat emboli. We conclude that our model is a useful one for the study of brain fat embolism. (author)

  20. Topodynamics of metastable brains

    Science.gov (United States)

    Tozzi, Arturo; Peters, James F.; Fingelkurts, Andrew A.; Fingelkurts, Alexander A.; Marijuán, Pedro C.

    2017-07-01

    The brain displays both the anatomical features of a vast amount of interconnected topological mappings as well as the functional features of a nonlinear, metastable system at the edge of chaos, equipped with a phase space where mental random walks tend towards lower energetic basins. Nevertheless, with the exception of some advanced neuro-anatomic descriptions and present-day connectomic research, very few studies have been addressing the topological path of a brain embedded or embodied in its external and internal environment. Herein, by using new formal tools derived from algebraic topology, we provide an account of the metastable brain, based on the neuro-scientific model of Operational Architectonics of brain-mind functioning. We introduce a ;topodynamic; description that shows how the relationships among the countless intertwined spatio-temporal levels of brain functioning can be assessed in terms of projections and mappings that take place on abstract structures, equipped with different dimensions, curvatures and energetic constraints. Such a topodynamical approach, apart from providing a biologically plausible model of brain function that can be operationalized, is also able to tackle the issue of a long-standing dichotomy: it throws indeed a bridge between the subjective, immediate datum of the naïve complex of sensations and mentations and the objective, quantitative, data extracted from experimental neuro-scientific procedures. Importantly, it opens the door to a series of new predictions and future directions of advancement for neuroscientific research.

  1. mammalian brain system

    Directory of Open Access Journals (Sweden)

    Alan Kania

    2014-06-01

    Full Text Available Relaxin-3, a member of the relaxin peptide family, was discovered in 2001 as a homologue of relaxin – a well-known reproductive hormone. However, it is the brain which turned out to be a major expression site of this newly discovered peptide. Both its molecular structure and expression pattern were shown to be very conserved among vertebrates. Extensive research carried out since the discovery of relaxin-3 contributed to the significant progress in our knowledge regarding this neuropeptide. The endogenous relaxin-3 receptor (RXFP3 was identified and the anatomy of the yet uncharacterized mammalian brain system was described, with nucleus incertus as the main center of relaxin-3 expression. Not only its diffusive projections throughout the whole brain, which reach various brain structures such as the hippocampus, septum, intergeniculate leaflet or amygdala, but also functional studies of the relaxin-3/RXFP3 signaling system, allowed this brain network to be classified as one of the ascending nonspecific brain systems. Thus far, research depicts the connection of relaxin-3 with phenomena such as feeding behavior, spatial memory, sleep/wake cycle or modulation of pituitary gland hormone secretion. Responsiveness of relaxin-3 neurons to stress factors and the strong orexigenic effect exerted by this peptide suggest its participation in modulation of feeding by stress, in particular of the chronic type. The discovery of relaxin-3 opened a new research field which will contribute to our better understanding of the neurobiological basis of feeding disorders.

  2. Brain/MINDS: brain-mapping project in Japan

    Science.gov (United States)

    Okano, Hideyuki; Miyawaki, Atsushi; Kasai, Kiyoto

    2015-01-01

    There is an emerging interest in brain-mapping projects in countries across the world, including the USA, Europe, Australia and China. In 2014, Japan started a brain-mapping project called Brain Mapping by Integrated Neurotechnologies for Disease Studies (Brain/MINDS). Brain/MINDS aims to map the structure and function of neuronal circuits to ultimately understand the vast complexity of the human brain, and takes advantage of a unique non-human primate animal model, the common marmoset (Callithrix jacchus). In Brain/MINDS, the RIKEN Brain Science Institute acts as a central institute. The objectives of Brain/MINDS can be categorized into the following three major subject areas: (i) structure and functional mapping of a non-human primate brain (the marmoset brain); (ii) development of innovative neurotechnologies for brain mapping; and (iii) human brain mapping; and clinical research. Brain/MINDS researchers are highly motivated to identify the neuronal circuits responsible for the phenotype of neurological and psychiatric disorders, and to understand the development of these devastating disorders through the integration of these three subject areas. PMID:25823872

  3. Brain/MINDS: brain-mapping project in Japan.

    Science.gov (United States)

    Okano, Hideyuki; Miyawaki, Atsushi; Kasai, Kiyoto

    2015-05-19

    There is an emerging interest in brain-mapping projects in countries across the world, including the USA, Europe, Australia and China. In 2014, Japan started a brain-mapping project called Brain Mapping by Integrated Neurotechnologies for Disease Studies (Brain/MINDS). Brain/MINDS aims to map the structure and function of neuronal circuits to ultimately understand the vast complexity of the human brain, and takes advantage of a unique non-human primate animal model, the common marmoset (Callithrix jacchus). In Brain/MINDS, the RIKEN Brain Science Institute acts as a central institute. The objectives of Brain/MINDS can be categorized into the following three major subject areas: (i) structure and functional mapping of a non-human primate brain (the marmoset brain); (ii) development of innovative neurotechnologies for brain mapping; and (iii) human brain mapping; and clinical research. Brain/MINDS researchers are highly motivated to identify the neuronal circuits responsible for the phenotype of neurological and psychiatric disorders, and to understand the development of these devastating disorders through the integration of these three subject areas.

  4. Immunopathogenesis of brain abscess

    Directory of Open Access Journals (Sweden)

    Kielian Tammy

    2004-08-01

    Full Text Available Abstract Brain abscess represents a significant medical problem despite recent advances made in detection and therapy. Due to the emergence of multi-drug resistant strains and the ubiquitous nature of bacteria, the occurrence of brain abscess is likely to persist. Our laboratory has developed a mouse experimental brain abscess model allowing for the identification of key mediators in the CNS anti-bacterial immune response through the use of cytokine and chemokine knockout mice. Studies of primary microglia and astrocytes from neonatal mice have revealed that S. aureus, one of the main etiologic agents of brain abscess in humans, is a potent stimulus for proinflammatory mediator production. Recent evidence from our laboratory indicates that Toll-like receptor 2 plays a pivotal role in the recognition of S. aureus and its cell wall product peptidoglycan by glia, although other receptors also participate in the recognition event. This review will summarize the consequences of S. aureus on CNS glial activation and the resultant neuroinflammatory response in the experimental brain abscess model.

  5. Pediatric acquired brain injury.

    Science.gov (United States)

    Bodack, Marie I

    2010-10-01

    Although pediatric patients are sometimes included in studies about visual problems in patients with acquired brain injury (ABI), few studies deal solely with children. Unlike studies dealing with adult patients, in which mechanisms of brain injury are divided into cerebral vascular accident (CVA) and traumatic brain injury (TBI), studies on pediatric patients deal almost exclusively with traumatic brain injury, specifically caused by accidents. Here we report on the vision problems of 4 pediatric patients, ages 3 to 18 years, who were examined in the ophthalmology/optometry clinic at a children's hospital. All patients had an internally caused brain injury and after the initial insult manifested problems in at least one of the following areas: acuity, binocularity, motility (tracking or saccades), accommodation, visual fields, and visual perceptual skills. Pediatric patients can suffer from a variety of oculo-visual problems after the onset of head injury. These patients may or may not be symptomatic and can benefit from optometric intervention. Copyright © 2010 American Optometric Association. Published by Elsevier Inc. All rights reserved.

  6. Brain hypoxia imaging

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ho Chun [Chonnam National University Medical School, Gwangju (Korea, Republic of)

    2007-04-15

    The measurement of pathologically low levels of tissue pO{sub 2} is an important diagnostic goal for determining the prognosis of many clinically important diseases including cardiovascular insufficiency, stroke and cancer. The target tissues nowadays have mostly been tumors or the myocardium, with less attention centered on the brain. Radiolabelled nitroimidazole or derivatives may be useful in identifying the hypoxic cells in cerebrovascular disease or traumatic brain injury, and hypoxic-ischemic encephalopathy. In acute stroke, the target of therapy is the severely hypoxic but salvageable tissue. {sup 18}F-MISO PET and {sup 99m}Tc-EC-metronidazole SPECT in patients with acute ischemic stroke identified hypoxic tissues and ischemic penumbra, and predicted its outcome. A study using {sup 123}I-IAZA in patient with closed head injury detected the hypoxic tissues after head injury. Up till now these radiopharmaceuticals have drawbacks due to its relatively low concentration with hypoxic tissues associated with/without low blood-brain barrier permeability and the necessity to wait a long time to achieve acceptable target to background ratios for imaging in acute ischemic stroke. It is needed to develop new hypoxic marker exhibiting more rapid localization in the hypoxic region in the brain. And then, the hypoxic brain imaging with imidazoles or non-imidazoles may be very useful in detecting the hypoxic tissues, determining therapeutic strategies and developing therapeutic drugs in several neurological disease, especially, in acute ischemic stroke.

  7. Imaging brain plasticity after trauma

    Institute of Scientific and Technical Information of China (English)

    Zhifeng Kou; Armin Iraji

    2014-01-01

    The brain is highly plastic after stroke or epilepsy;however, there is a paucity of brain plasticity investigation after traumatic brain injury (TBI). This mini review summarizes the most recent evidence of brain plasticity in human TBI patients from the perspective of advanced magnetic resonance imaging. Similar to other forms of acquired brain injury, TBI patients also demonstrat-ed both structural reorganization as well as functional compensation by the recruitment of other brain regions. However, the large scale brain network alterations after TBI are still unknown, and the ifeld is still short of proper means on how to guide the choice of TBI rehabilitation or treat-ment plan to promote brain plasticity. The authors also point out the new direction of brain plas-ticity investigation.

  8. Scintigraphic evaluation of brain death

    International Nuclear Information System (INIS)

    Park, C. H.; Bai, M. S.; Cho, K. K.; Kim, S. J.; Yoon, S. N.; Cho, C. W.

    1997-01-01

    A law recognizing brain death is a life saving legal measure in patients suffering from badly diseased organs such as kidney, liver, heart, and lung. Such law is being discussed for legalization at the Korean National Assembly. There are various criteria used for brain death in western world and brain scintiscan is one of them. However, the scintiscan is not considered in establishing brain death in the draft of the law. The purpose of this report is to spread this technique in nuclear medicine society as well as in other medical societies. We evaluated 7 patients with clinical suspicion of brain death by various causes. The patient's age ranged from 5 to 39 years. We used 5-20mCi 99m Tc-HMPAO (d.1-hexamethyl propylene amine oxime) or ECD (Ethyl Cysteinate Dimer), lipophilic agents that cross BBB (blood brain barrier). A dynamic study followed by static or SPECT (single photon emission tomography) was performed. Interpretive criteria used for brain death were 1) no intracranial circulation 2) no brain uptake. The second criteria is heavily used. Five of 7 patients were scintigraphically brain dead and the remaining 2 had some brain uptake excluding the diagnosis of scintigraphic brain death. In conclusion, cerebral perfusion study using a lipophilic brain tracer offers a noninvasive, rapid, easy, accurate and reliable mean in the diagnosis of brain death. We believe that this modality should be included in the criteria of brain death in the draft of the proposed Korean law

  9. Brain abscess: Current management

    Directory of Open Access Journals (Sweden)

    Hernando Alvis-Miranda

    2013-01-01

    Full Text Available Brain abscess (BA is defined as a focal infection within the brain parenchyma, which starts as a localized area of cerebritis, which is subsequently converted into a collection of pus within a well-vascularized capsule. BA must be differentiated from parameningeal infections, including epidural abscess and subdural empyema. The BA is a challenge for the neurosurgeon because it is needed good clinical, pharmacological, and surgical skills for providing good clinical outcomes and prognosis to BA patients. Considered an infrequent brain infection, BA could be a devastator entity that easily left the patient into dead. The aim of this work is to review the current concepts regarding epidemiology, pathophysiology, etiology, clinical presentation, diagnosis, and management of BA.

  10. Tumours of the brain

    International Nuclear Information System (INIS)

    Bleehen, N.M.

    1986-01-01

    This volume is the last in a series of publications containing the edited texts of the clinical oncology symposia patronaged by the Royal College of Radiologists. The topics included essentially cover the pathology, imaging, diagnosis, and treatment of common and uncommon tumors of the brain. Only malignant tumors are discussed in any detail. A short introductory chapter summarized the pathology of brain tumors and the still-prevailing confusion of classification of gliomas. Two interesting chapters deal with immunologic techniques: one for characterizing tumors with immunocytochemical methods; the other, for localization and imaging by means of radiolabeled antibodies. Conventional radiologic methods of imaging, with emphasis on computed tomography, are covered in a comprehensive chapter summarizing what is known today of the accuracy of these methods in the detection, characterization, and grading of tumors of the brain. Two chapters are devoted to more recent developments in imaging, namely, magnetic resonance (MR) imaging and positron emission tomography

  11. Brain Network Modelling

    DEFF Research Database (Denmark)

    Andersen, Kasper Winther

    Three main topics are presented in this thesis. The first and largest topic concerns network modelling of functional Magnetic Resonance Imaging (fMRI) and Diffusion Weighted Imaging (DWI). In particular nonparametric Bayesian methods are used to model brain networks derived from resting state f...... for their ability to reproduce node clustering and predict unseen data. Comparing the models on whole brain networks, BCD and IRM showed better reproducibility and predictability than IDM, suggesting that resting state networks exhibit community structure. This also points to the importance of using models, which...... allow for complex interactions between all pairs of clusters. In addition, it is demonstrated how the IRM can be used for segmenting brain structures into functionally coherent clusters. A new nonparametric Bayesian network model is presented. The model builds upon the IRM and can be used to infer...

  12. Initial brain aging

    DEFF Research Database (Denmark)

    Thomsen, Kirsten; Yokota, Takashi; Hasan-Olive, Md Mahdi

    2018-01-01

    Brain aging is accompanied by declining mitochondrial respiration. We hypothesized that mitochondrial morphology and dynamics would reflect this decline. Using hippocampus and frontal cortex of a segmental progeroid mouse model lacking Cockayne syndrome protein B (CSB(m/m)) and C57Bl/6 (WT......) controls and comparing young (2-5 months) to middle-aged mice (13-14 months), we found that complex I-linked state 3 respiration (CI) was reduced at middle age in CSB(m/m) hippocampus, but not in CSB(m/m) cortex or WT brain. In hippocampus of both genotypes, mitochondrial size heterogeneity increased....... Mitochondrial DNA content was lower, and hypoxia-induced factor 1α mRNA was greater at both ages in CSB(m/m) compared to WT brain. Our findings show that decreased CI and increased mitochondrial size heterogeneity are highly associated and point to declining mitochondrial quality control as an initial event...

  13. Artificial Intelligence and brain.

    Science.gov (United States)

    Shapshak, Paul

    2018-01-01

    From the start, Kurt Godel observed that computer and brain paradigms were considered on a par by researchers and that researchers had misunderstood his theorems. He hailed with displeasure that the brain transcends computers. In this brief article, we point out that Artificial Intelligence (AI) comprises multitudes of human-made methodologies, systems, and languages, and implemented with computer technology. These advances enhance development in the electron and quantum realms. In the biological realm, animal neurons function, also utilizing electron flow, and are products of evolution. Mirror neurons are an important paradigm in neuroscience research. Moreover, the paradigm shift proposed here - 'hall of mirror neurons' - is a potentially further productive research tactic. These concepts further expand AI and brain research.

  14. Central nervous system: brain

    International Nuclear Information System (INIS)

    Mishkin, F.S.

    1975-01-01

    Present radiopharmaceuticals and detector systems have provided nuclear medicine physicians with tools capable of detecting a variety of brain abnormalities with little radiation exposure to pediatric patients. It is essential that the referring physician as well as the physician performing the procedure recognize both the limitations and virtues of these techniques. Appropriate selection of brain imaging procedures in each specific case must be the rule. Brain scintigraphy reliably solves certain problems, such as detecting or excluding intracranial tumors and identifying early cerebral inflammatory disease, cerebral ischemic disease, and a variety of congenital anomalies. Other situations, such as seizures without a focal neurologic deficit, acute meningitis, and hydrocephalus, are less often benefited by these studies. The role of these procedures in acute trauma and its sequelae is at the present time limited in pediatric practice. (auth)

  15. Brains, Genes and Primates

    Science.gov (United States)

    Belmonte, Juan Carlos Izpisua; Callaway, Edward M.; Churchland, Patricia; Caddick, Sarah J.; Feng, Guoping; Homanics, Gregg E.; Lee, Kuo-Fen; Leopold, David A.; Miller, Cory T.; Mitchell, Jude F.; Mitalipov, Shoukhrat; Moutri, Alysson R.; Movshon, J. Anthony; Okano, Hideyuki; Reynolds, John H.; Ringach, Dario; Sejnowski, Terrence J.; Silva, Afonso C.; Strick, Peter L.; Wu, Jun; Zhang, Feng

    2015-01-01

    One of the great strengths of the mouse model is the wide array of genetic tools that have been developed. Striking examples include methods for directed modification of the genome, and for regulated expression or inactivation of genes. Within neuroscience, it is now routine to express reporter genes, neuronal activity indicators and opsins in specific neuronal types in the mouse. However, there are considerable anatomical, physiological, cognitive and behavioral differences between the mouse and the human that, in some areas of inquiry, limit the degree to which insights derived from the mouse can be applied to understanding human neurobiology. Several recent advances have now brought into reach the goal of applying these tools to understanding the primate brain. Here we describe these advances, consider their potential to advance our understanding of the human brain and brain disorders, discuss bioethical considerations, and describe what will be needed to move forward. PMID:25950631

  16. [Why do we call the brain 'brain'?

    Science.gov (United States)

    Garcia-Molina, A; Ensenat, A

    2017-01-16

    Every day millions of professionals use a countless number of technical words to refer to the different structures inside the skull. But few of them would know how to explain their origin. In this study we take an in-depth look into the etymological origins of some of these neuroanatomical terms. The study takes an etymological tour of the central nervous system. It is in no way meant to be an exhaustive, detailed review of the terms currently in use, but instead a means to familiarise the reader with the linguistic past of words like brain, hippocampus, thalamus, claustrum, fornix, corpus callosum or limbic system. All of them come from either Greek or Latin, which were used for centuries as the lingua francas of science. The study also analyses the evolution of the word meninges, originally of Greco-Latin origin, although its current usages derive from Arabic. The neuroanatomical terms that are in use today do not come from words that associate a particular brain structure with its function, but instead from words that reflect the formal or conceptual similarity between a structure and a familiar or everyday entity (for example, an object or a part of the human body). In other cases, these words indicate the spatial location of the neuroanatomical structure with respect to a third, or they may be terms derived from characters in Greco-Latin mythology.

  17. Brain injury in sports.

    Science.gov (United States)

    Lloyd, John; Conidi, Frank

    2016-03-01

    Helmets are used for sports, military, and transportation to protect against impact forces and associated injuries. The common belief among end users is that the helmet protects the whole head, including the brain. However, current consensus among biomechanists and sports neurologists indicates that helmets do not provide significant protection against concussion and brain injuries. In this paper the authors present existing scientific evidence on the mechanisms underlying traumatic head and brain injuries, along with a biomechanical evaluation of 21 current and retired football helmets. The National Operating Committee on Standards for Athletic Equipment (NOCSAE) standard test apparatus was modified and validated for impact testing of protective headwear to include the measurement of both linear and angular kinematics. From a drop height of 2.0 m onto a flat steel anvil, each football helmet was impacted 5 times in the occipital area. Skull fracture risk was determined for each of the current varsity football helmets by calculating the percentage reduction in linear acceleration relative to a 140-g skull fracture threshold. Risk of subdural hematoma was determined by calculating the percentage reduction in angular acceleration relative to the bridging vein failure threshold, computed as a function of impact duration. Ranking the helmets according to their performance under these criteria, the authors determined that the Schutt Vengeance performed the best overall. The study findings demonstrated that not all football helmets provide equal or adequate protection against either focal head injuries or traumatic brain injuries. In fact, some of the most popular helmets on the field ranked among the worst. While protection is improving, none of the current or retired varsity football helmets can provide absolute protection against brain injuries, including concussions and subdural hematomas. To maximize protection against head and brain injuries for football players of

  18. [Patterns of brain ageing].

    Science.gov (United States)

    Fernández Viadero, Carlos; Verduga Vélez, Rosario; Crespo Santiago, Dámaso

    2017-06-01

    Neuroplasticity lends the brain a strong ability to adapt to changes in the environment that occur during ageing. Animal models have shown alterations in neurotransmission and imbalances in the expression of neural growth factor. Changes at the morphometric level are not constant. Volume loss is related to alterations in neuroplasticity and involvement of the cerebral neuropil. Although there are no conclusive data, physical exercise improves the molecular, biological, functional and behavioural-cognitive changes associated with brain ageing. The aged human brain has been described as showing weight and volume loss and increased ventricular size. However, neuroimaging shows significant variation and many healthy elderly individuals show no significant macroscopic changes. In most brain regions, the number of neurons remains stable throughout life. Neuroplasticity does not disappear with ageing, and changes in dendritic arborization and the density of spines and synapses are more closely related to brain activity than to age. At the molecular level, although the presence of altered Tau and β-amyloid proteins is used as a biomarker of neurodegenerative disease, postmortem studies show that these abnormal proteins are common in the brains of elderly people without dementia. Finally, due to the relationship between neurodegenerative diseases and metabolic alterations, this article analyses the influence of insulin-like growth factor and ageing, both in animal models and in humans, and the possible neuroprotective effect of insulin. Copyright © 2017 Sociedad Española de Geriatría y Gerontología. Publicado por Elsevier España, S.L.U. All rights reserved.

  19. Serotonin metabolism in rat brain

    International Nuclear Information System (INIS)

    Schutte, H.H.

    1976-01-01

    The metabolism of serotonin in rat brain was studied by measuring specific activities of tryptophan in plasma and of serotonin, 5-hydroxyindole acetic acid and tryptophan in the brain after intravenous injection of tritiated tryptophan. For a detailed analysis of the specific activities, a computer simulation technique was used. It was found that only a minor part of serotonin in rat brain is synthesized from tryptophan rapidly transported from the blood. It is suggested that the brain tryptophan originates from brain proteins. It was also found that the serotonin in rat brain is divided into more than one metabolic compartment

  20. Brain stem cavernous angioma

    International Nuclear Information System (INIS)

    Delcarpio-O'Donovan, R.; Melanson, D.; Tampieri, D.; Ethier, R.

    1988-01-01

    Twenty-two cases of cavernous angioma of the brain stem were definitely diagnosed by means of magnetic resonance (MR) imaging. In many cases, the diagnosis had remained elusive for several years. Clinically, some cases behaved like multiple sclerosis or brain stem tumor. Others, usually associated with bleeding, caused increased intracranial pressure or subarachnoid hemorrhage. The diagnostic limitations of computed tomography in the posterior fossa are well known. Angiography fails to reveal abnormalities, since this malformation has neither a feeding artery nor a draining vein. Diagnosticians' familiarity with the MR appearance of this lesion may save patients from invasive diagnostic studies and potentially risky treatment

  1. Brain, body and culture

    DEFF Research Database (Denmark)

    Geertz, Armin W.

    2010-01-01

    This essay sketches out a biocultural theory of religion which is based on an expanded view of cognition that is anchored in brain and body (embrained and embodied), deeply dependent on culture (enculturated) and extended and distributed beyond the borders of individual brains. Such an approach...... uniquely accommodates contemporary cultural and neurobiological sciences. Since the challenge that the study of religion faces, in my opinion, is at the interstices of these sciences, I have tried to develop a theory of religion which acknowledges the fact. My hope is that the theory can be of use...

  2. Contextualizing aquired brain damage

    DEFF Research Database (Denmark)

    Nielsen, Charlotte Marie Bisgaard

    2014-01-01

    Contextualizing aquired brain damage Traditional approaches study ’communicational problems’ often in a discourse of disabledness or deficitness. With an ontology of communcation as something unique and a presupposed uniqueness of each one of us, how could an integrational approach (Integrational...... for people with aquired brain injuries will be presented and comparatively discussed in a traditional versus an integrational perspective. Preliminary results and considerations on ”methods” and ”participation” from this study will be presented along with an overview of the project's empirical data....

  3. Brain Image Motion Correction

    DEFF Research Database (Denmark)

    Jensen, Rasmus Ramsbøl; Benjaminsen, Claus; Larsen, Rasmus

    2015-01-01

    The application of motion tracking is wide, including: industrial production lines, motion interaction in gaming, computer-aided surgery and motion correction in medical brain imaging. Several devices for motion tracking exist using a variety of different methodologies. In order to use such devices...... offset and tracking noise in medical brain imaging. The data are generated from a phantom mounted on a rotary stage and have been collected using a Siemens High Resolution Research Tomograph for positron emission tomography. During acquisition the phantom was tracked with our latest tracking prototype...

  4. Teaching Creativity for Right Brain and Left Brain Thinkers.

    Science.gov (United States)

    Geske, Joel

    Right brain and left brain dominant people process information differently and need different techniques to learn how to become more creative. Various exercises can help students take advantage of both sides of their brains. Students must feel comfortable and unthreatened to reach maximal creativity, and a positive personal relationship with…

  5. Left Brain/Right Brain Learning for Adult Education.

    Science.gov (United States)

    Garvin, Barbara

    1986-01-01

    Contrasts and compares the theory and practice of adult education as it relates to the issue of right brain/left brain learning. The author stresses the need for a whole-brain approach to teaching and suggests that adult educators, given their philosophical directions, are the perfect potential users of this integrated system. (Editor/CT)

  6. The Brain on Music

    Indian Academy of Sciences (India)

    effects of music training on auditory .... dala but is distributed over a network of regions that also in- clude the ... In addition to the emotional impact of music on the brain, these ... social cognition, contact, copathy, and social cohesion in a group.

  7. Sleep, Memory & Brain Rhythms.

    Science.gov (United States)

    Watson, Brendon O; Buzsáki, György

    2015-01-01

    Sleep occupies roughly one-third of our lives, yet the scientific community is still not entirely clear on its purpose or function. Existing data point most strongly to its role in memory and homeostasis: that sleep helps maintain basic brain functioning via a homeostatic mechanism that loosens connections between overworked synapses, and that sleep helps consolidate and re-form important memories. In this review, we will summarize these theories, but also focus on substantial new information regarding the relation of electrical brain rhythms to sleep. In particular, while REM sleep may contribute to the homeostatic weakening of overactive synapses, a prominent and transient oscillatory rhythm called "sharp-wave ripple" seems to allow for consolidation of behaviorally relevant memories across many structures of the brain. We propose that a theory of sleep involving the division of labor between two states of sleep-REM and non-REM, the latter of which has an abundance of ripple electrical activity-might allow for a fusion of the two main sleep theories. This theory then postulates that sleep performs a combination of consolidation and homeostasis that promotes optimal knowledge retention as well as optimal waking brain function.

  8. The Duchenne brain

    NARCIS (Netherlands)

    Doorenweerd, N.

    2017-01-01

    Duchenne muscular dystrophy (DMD) is characterized by progressive muscle weakness caused by DMD gene mutations leading to absence of the full-length dystrophin protein in muscle. Multiple dystrophin isoforms are expressed in brain, but little is known about their function. DMD is associated with

  9. From Ear to Brain

    Science.gov (United States)

    Kimura, Doreen

    2011-01-01

    In this paper Doreen Kimura gives a personal history of the "right-ear effect" in dichotic listening. The focus is on the early ground-breaking papers, describing how she did the first dichotic listening studies relating the effects to brain asymmetry. The paper also gives a description of the visual half-field technique for lateralized stimulus…

  10. Brain abscess in childhood

    African Journals Online (AJOL)

    Abstract The presentation, treatment and outcome of 98 children with brain abscesses at Red Cross War. Memorial Children's Hospital, Cape Town, is reviewed. Middle ear disease and trauma were the commonest sources ofinfection in 60% ofpatients. The usual presentation was that of meningitis and it is recommended ...

  11. Brain Aneurysm: Treatment Options

    Science.gov (United States)

    ... inoperable aneurysms. Decisions regarding management of an unruptured brain aneurysm are based on the careful comparison of the short- and ... so Tired? How Do I Deal With Depression? Learning Principles to Aid Recovery The Memory Book ... Aneurysm Foundation Support Community Research & Grants BAF Research ...

  12. Brain imaging and autism

    International Nuclear Information System (INIS)

    Zilbovicius, M.

    2006-01-01

    Autism is a neuro-developmental disorder with a range of clinical presentations, from mild to severe, referred to as autism spectrum disorders (ASD). The most common clinical ASD sign is social interaction impairment, which is associated with verbal and non-verbal communication deficits and stereotyped and obsessive behaviors. Thanks to recent brain imaging studies, scientists are getting a better idea of the neural circuits involved in ASD. Indeed, functional brain imaging, such as positron emission tomography (PET), single positron emission tomograph y (SPECT) and functional MRI (fMRI) have opened a new perspective to study normal and pathological brain functions. Three independent studies have found anatomical and rest functional temporal abnormalities. These anomalies are localized in the superior temporal sulcus bilaterally which are critical for perception of key social stimuli. In addition, functional studies have shown hypo-activation of most areas implicated in social perception (face and voice perception) and social cognition (theory of mind). These data suggest an abnormal functioning of the social brain network. The understanding of such crucial abnormal mechanism may drive the elaboration of new and more adequate social re-educative strategies in autism. (author)

  13. Brain Aneurysm: Recovery

    Science.gov (United States)

    ... people, but they are growing larger as medical technology continues to grow and early detection and treatment becomes more prevalent. Read More “I’ve met many people through The Brain Aneurysm Foundation. Each one with their own unique story. Of survival, of appreciation for what we still ...

  14. Aging Brain, Aging Mind.

    Science.gov (United States)

    Selkoe, Dennis J.

    1992-01-01

    Discusses the aging process related to physical changes of the human neural structure involved in learning, memory, and reasoning. Presents evidence that indicates such alterations do not necessarily signal the decline in cognitive function. Vignettes provide images of brain structures involved in learning, memory, and reasoning; hippocampal…

  15. Hemorrhagic brain metastases

    International Nuclear Information System (INIS)

    Takahashi, Motoichiro; Takekawa, S.D.; Suzuki, Kenzo

    1986-01-01

    Tumor hemorrhage on computed tomography (CT) was found in 14 patients with brain metastases (7 % of two hundred patients with brain metastases), from April 1979 to July 1983. Primary foci of these lesions were the lung (6 patients), breast (2), kidney (2), uterus (2), colon (1) and adrenal gland (1). ''Stroke'' syndrome was the initial presenting symptom in 3 patients; neurological focal sign or symptoms of increased intracranial pressure in the remaining patients. CT demonstrated peritumoral hemorrhage in all patients with solid mass, intratumoral hemorrhage in a few patients and also cerebral or ventricular hemorrhage, which was fatal complication, in 2 patients (colon and breast cancers). A cystic mass with fluid-blood level was noted in a patient with breast cancer. Several predisposing factors including chemotherapy, thrombocytopenia, radiotherapy or combination of these were recognized in 8 patients. Of these, chemotherapy was the most causative factor of tumor hemorrhage. Brain irradiation for hemorrhagic brain metastases was effective for prolongation of mean survival time of these patients as follows; 10 months in irradiated group, whereas 1.5 months in non-irradiated group. (author)

  16. The polyphonic brain

    DEFF Research Database (Denmark)

    Sturm, Irene; Treder, Matthias S.; Dähne, Sven

    Rapid changes in the stimulus envelope (indicating tone onsets) elicit an N1-P2 ERP response, as has been shown for clicks and sine waves, musical tones and for speech. Canonical Correlation Analysis with temporal embedding (tkCCA), a multivariate correlation-based method, allows to extract brain...

  17. Ben's Plastic Brain

    Science.gov (United States)

    Kaplan, Susan L.

    2010-01-01

    This article shares a story of Ben who as a result of his premature birth, suffered a brain hemorrhage resulting in cerebral palsy, which affected his left side (left hemiparesis) and caused learning disabilities. Despite these challenges, he graduated from college and currently works doing information management for a local biotech start-up…

  18. Paraneoplastic brain stem encephalitis.

    Science.gov (United States)

    Blaes, Franz

    2013-04-01

    Paraneoplastic brain stem encephalitis can occur as an isolated clinical syndrome or, more often, may be part of a more widespread encephalitis. Different antineuronal autoantibodies, such as anti-Hu, anti-Ri, and anti-Ma2 can be associated with the syndrome, and the most frequent tumors are lung and testicular cancer. Anti-Hu-associated brain stem encephalitis does not normally respond to immunotherapy; the syndrome may stabilize under tumor treatment. Brain stem encephalitis with anti-Ma2 often improves after immunotherapy and/or tumor therapy, whereas only a minority of anti-Ri positive patients respond to immunosuppressants or tumor treatment. The Opsoclonus-myoclonus syndrome (OMS) in children, almost exclusively associated with neuroblastoma, shows a good response to steroids, ACTH, and rituximab, some patients do respond to intravenous immunoglobulins or cyclophosphamide. In adults, OMS is mainly associated with small cell lung cancer or gynecological tumors and only a small part of the patients show improvement after immunotherapy. Earlier diagnosis and treatment seem to be one major problem to improve the prognosis of both, paraneoplastic brain stem encephalitis, and OMS.

  19. Brain Games for Babies.

    Science.gov (United States)

    Silberg, Jackie

    2001-01-01

    Presents games for caregivers to use with infants to enhance brain development. Includes games that develop trust and security, language skills, and fine motor skills, as well as games that are fun or stimulate vision. Includes videotape references for parents and caregivers. (KB)

  20. NEUROSPIN, sensing brain

    International Nuclear Information System (INIS)

    Ganier, Aude

    2007-01-01

    Research center, the NeuroSpin platform is to be equipped with unrivalled means of exploring the nervous system and cognitive process. Located at Saclay, it will soon gather together the world's best experts in neuro-sciences, for example in imaging and physics. An exceptional complex that does not just have the brain in mind. (authors)