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Sample records for dynein stalk head

  1. Sliding of microtubules by a team of dynein motors: Understanding the effect of spatial distribution of motor tails and mutual exclusion of motor heads on microtubules

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    Singh, Hanumant Pratap; Takshak, Anjneya; Mall, Utkarsh; Kunwar, Ambarish

    2016-06-01

    Molecular motors are natural nanomachines that use the free energy released from ATP hydrolysis to generate mechanical forces. Cytoplasmic dynein motors often work collectively as a team to drive important processes such as axonal growth, proplatelet formation and mitosis, as forces generated by single motors are insufficient. A large team of dynein motors is used to slide cytoskeletal microtubules with respect to one another during the process of proplatelet formation and axonal growth. These motors attach to a cargo microtubule via their tail domains, undergo the process of detachment and reattachment of their head domains on another track microtubule, while sliding the cargo microtubule along the track. Traditional continuum/mean-field approaches used in the past are not ideal for studying the sliding mechanism of microtubules, as they ignore spatial and temporal fluctuations due to different possible distributions of motor tails on cargo filament, as well as binding/unbinding of motors from their track. Therefore, these models cannot be used to address important questions such as how the distribution of motor tails on microtubules, or how the mutual exclusion of motor heads on microtubule tracks affects the sliding velocity of cargo microtubule. To answer these, here we use a computational stochastic model where we model each dynein motor explicitly. In our model, we use both random as well as uniform distributions of dynein motors on cargo microtubule, as well as mutual exclusion of motors on microtubule tracks. We find that sliding velocities are least affected by the distribution of motor tails on microtubules, whereas they are greatly affected by mutual exclusion of motor heads on microtubule tracks. We also find that sliding velocity depends on the length of cargo microtubule if mutual exclusion among motor heads is considered.

  2. Sex-biased gene expression during head development in a sexually dimorphic stalk-eyed fly.

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    Wilkinson, Gerald S; Johns, Philip M; Metheny, Jackie D; Baker, Richard H

    2013-01-01

    Stalk-eyed flies (family Diopsidae) are a model system for studying sexual selection due to the elongated and sexually dimorphic eye-stalks found in many species. These flies are of additional interest because their X chromosome is derived largely from an autosomal arm in other flies. To identify candidate genes required for development of dimorphic eyestalks and investigate how sex-biased expression arose on the novel X, we compared gene expression between males and females using oligonucleotide microarrays and RNA from developing eyestalk tissue or adult heads in the dimorphic diopsid, Teleopsis dalmanni. Microarray analysis revealed sex-biased expression for 26% of 3,748 genes expressed in eye-antennal imaginal discs and concordant sex-biased expression for 86 genes in adult heads. Overall, 415 female-biased and 482 male-biased genes were associated with dimorphic eyestalk development but not differential expression in the adult head. Functional analysis revealed that male-biased genes are disproportionately associated with growth and mitochondrial function while female-biased genes are associated with cell differentiation and patterning or are novel transcripts. With regard to chromosomal effects, dosage compensation occurs by elevated expression of X-linked genes in males. Genes with female-biased expression were more common on the X and less common on autosomes than expected, while male-biased genes exhibited no chromosomal pattern. Rates of protein evolution were lower for female-biased genes but higher for genes that moved on or off the novel X chromosome. These findings cannot be due to meiotic sex chromosome inactivation or by constraints associated with dosage compensation. Instead, they could be consistent with sexual conflict in which female-biased genes on the novel X act primarily to reduce eyespan in females while other genes increase eyespan in both sexes. Additional information on sex-biased gene expression in other tissues and related sexually

  3. Sex-biased gene expression during head development in a sexually dimorphic stalk-eyed fly.

    Directory of Open Access Journals (Sweden)

    Gerald S Wilkinson

    Full Text Available Stalk-eyed flies (family Diopsidae are a model system for studying sexual selection due to the elongated and sexually dimorphic eye-stalks found in many species. These flies are of additional interest because their X chromosome is derived largely from an autosomal arm in other flies. To identify candidate genes required for development of dimorphic eyestalks and investigate how sex-biased expression arose on the novel X, we compared gene expression between males and females using oligonucleotide microarrays and RNA from developing eyestalk tissue or adult heads in the dimorphic diopsid, Teleopsis dalmanni. Microarray analysis revealed sex-biased expression for 26% of 3,748 genes expressed in eye-antennal imaginal discs and concordant sex-biased expression for 86 genes in adult heads. Overall, 415 female-biased and 482 male-biased genes were associated with dimorphic eyestalk development but not differential expression in the adult head. Functional analysis revealed that male-biased genes are disproportionately associated with growth and mitochondrial function while female-biased genes are associated with cell differentiation and patterning or are novel transcripts. With regard to chromosomal effects, dosage compensation occurs by elevated expression of X-linked genes in males. Genes with female-biased expression were more common on the X and less common on autosomes than expected, while male-biased genes exhibited no chromosomal pattern. Rates of protein evolution were lower for female-biased genes but higher for genes that moved on or off the novel X chromosome. These findings cannot be due to meiotic sex chromosome inactivation or by constraints associated with dosage compensation. Instead, they could be consistent with sexual conflict in which female-biased genes on the novel X act primarily to reduce eyespan in females while other genes increase eyespan in both sexes. Additional information on sex-biased gene expression in other tissues and

  4. Dyneins across eukaryotes: a comparative genomic analysis.

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    Wickstead, Bill; Gull, Keith

    2007-12-01

    Dyneins are large minus-end-directed microtubule motors. Each dynein contains at least one dynein heavy chain (DHC) and a variable number of intermediate chains (IC), light intermediate chains (LIC) and light chains (LC). Here, we used genome sequence data from 24 diverse eukaryotes to assess the distribution of DHCs, ICs, LICs and LCs across Eukaryota. Phylogenetic inference identified nine DHC families (two cytoplasmic and seven axonemal) and six IC families (one cytoplasmic). We confirm that dyneins have been lost from higher plants and show that this is most likely because of a single loss of cytoplasmic dynein 1 from the ancestor of Rhodophyta and Viridiplantae, followed by lineage-specific losses of other families. Independent losses in Entamoeba mean that at least three extant eukaryotic lineages are entirely devoid of dyneins. Cytoplasmic dynein 2 is associated with intraflagellar transport (IFT), but in two chromalveolate organisms, we find an IFT footprint without the retrograde motor. The distribution of one family of outer-arm dyneins accounts for 2-headed or 3-headed outer-arm ultrastructures observed in different organisms. One diatom species builds motile axonemes without any inner-arm dyneins (IAD), and the unexpected conservation of IAD I1 in non-flagellate algae and LC8 (DYNLL1/2) in all lineages reveals a surprising fluidity to dynein function.

  5. Intraflagellar transport dynein is autoinhibited by trapping of its mechanical and track-binding elements.

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    Toropova, Katerina; Mladenov, Miroslav; Roberts, Anthony J

    2017-05-01

    Cilia are multifunctional organelles that are constructed using intraflagellar transport (IFT) of cargo to and from their tip. It is widely held that the retrograde IFT motor, dynein-2, must be controlled in order to reach the ciliary tip and then unleashed to power the return journey. However, the mechanism is unknown. Here, we systematically define the mechanochemistry of human dynein-2 motors as monomers, dimers, and multimotor assemblies with kinesin-II. Combining these data with insights from single-particle EM, we discover that dynein-2 dimers are intrinsically autoinhibited. Inhibition is mediated by trapping dynein-2's mechanical 'linker' and 'stalk' domains within a novel motor-motor interface. We find that linker-mediated inhibition enables efficient transport of dynein-2 by kinesin-II in vitro. These results suggest a conserved mechanism for autoregulation among dimeric dyneins, which is exploited as a switch for dynein-2's recycling activity during IFT.

  6. Model for bidirectional movement of cytoplasmic dynein

    CERN Document Server

    Sumathy, S

    2014-01-01

    Cytoplasmic dynein exhibits a directional processive movement on microtubule filaments and is known to move in steps of varying length based on the number of ATP molecules bound to it and the load that it carries. It is experimentally observed that dynein takes occasional backward steps and the frequency of such backward steps increases as the load approaches the stall force. Using a stochastic process model, we investigate the bidirectional movement of single head of a dynein motor. The probability for backward step is implemented based on Crook's fluctuation theorem of non-equilibrium statistical mechanics. We find that the movement of dynein motor is characterized with negative velocity implying backward motion beyond stall force. We observe that the motor moves backward for super stall forces by hydrolyzing the ATP exactly the same way as it does while moving forward for sub stall forces.

  7. Cytoplasmic dynein nomenclature

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    Pfister, K. Kevin; Fisher, Elizabeth M.C.; Gibbons, Ian R.; Hays, Thomas S.; Holzbaur, Erika L.F.; McIntosh, J. Richard; Porter, Mary E.; Schroer, Trina A.; Vaughan, Kevin T.; Witman, George B.; King, Stephen M.; Vallee, Richard B.

    2005-01-01

    A variety of names has been used in the literature for the subunits of cytoplasmic dynein complexes. Thus, there is a strong need for a more definitive consensus statement on nomenclature. This is especially important for mammalian cytoplasmic dyneins, many subunits of which are encoded by multiple genes. We propose names for the mammalian cytoplasmic dynein subunit genes and proteins that reflect the phylogenetic relationships of the genes and the published studies clarifying the functions of the polypeptides. This nomenclature recognizes the two distinct cytoplasmic dynein complexes and has the flexibility to accommodate the discovery of new subunits and isoforms. PMID:16260502

  8. Cytoplasmic dynein binding, run length, and velocity are guided by long-range electrostatic interactions.

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    Li, Lin; Alper, Joshua; Alexov, Emil

    2016-08-17

    Dyneins are important molecular motors involved in many essential biological processes, including cargo transport along microtubules, mitosis, and in cilia. Dynein motility involves the coupling of microtubule binding and unbinding to a change in the configuration of the linker domain induced by ATP hydrolysis, which occur some 25 nm apart. This leaves the accuracy of dynein stepping relatively inaccurate and susceptible to thermal noise. Using multi-scale modeling with a computational focusing technique, we demonstrate that the microtubule forms an electrostatic funnel that guides the dynein's microtubule binding domain (MTBD) as it finally docks to the precise, keyed binding location on the microtubule. Furthermore, we demonstrate that electrostatic component of the MTBD's binding free energy is linearly correlated with the velocity and run length of dynein, and we use this linearity to predict the effect of mutating each glutamic and aspartic acid located in MTBD domain to alanine. Lastly, we show that the binding of dynein to the microtubule is associated with conformational changes involving several helices, and we localize flexible hinge points within the stalk helices. Taken all together, we demonstrate that long range electrostatic interactions bring a level of precision to an otherwise noisy dynein stepping process.

  9. Analyses of Dynein Heavy Chain Mutations Reveal Complex Interactions Between Dynein Motor Domains and Cellular Dynein Functions

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    Sivagurunathan, Senthilkumar; Schnittker, Robert R.; Razafsky, David S.; Nandini, Swaran; Plamann, Michael D.; King, Stephen J.

    2012-01-01

    Cytoplasmic dynein transports cargoes for a variety of crucial cellular functions. However, since dynein is essential in most eukaryotic organisms, the in-depth study of the cellular function of dynein via genetic analysis of dynein mutations has not been practical. Here, we identify and characterize 34 different dynein heavy chain mutations using a genetic screen of the ascomycete fungus Neurospora crassa, in which dynein is nonessential. Interestingly, our studies show that these mutations segregate into five different classes based on the in vivo localization of the mutated dynein motors. Furthermore, we have determined that the different classes of dynein mutations alter vesicle trafficking, microtubule organization, and nuclear distribution in distinct ways and require dynactin to different extents. In addition, biochemical analyses of dynein from one mutant strain show a strong correlation between its in vitro biochemical properties and the aberrant intracellular function of that altered dynein. When the mutations were mapped to the published dynein crystal structure, we found that the three-dimensional structural locations of the heavy chain mutations were linked to particular classes of altered dynein functions observed in cells. Together, our data indicate that the five classes of dynein mutations represent the entrapment of dynein at five separate points in the dynein mechanochemical and transport cycles. We have developed N. crassa as a model system where we can dissect the complexities of dynein structure, function, and interaction with other proteins with genetic, biochemical, and cell biological studies. PMID:22649085

  10. Subunit organization in cytoplasmic dynein subcomplexes

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    King, Stephen J.; Bonilla, Myriam; Rodgers, Michael E.; Schroer, Trina A.

    2002-01-01

    Because cytoplasmic dynein plays numerous critical roles in eukaryotic cells, determining the subunit composition and the organization and functions of the subunits within dynein are important goals. This has been difficult partly because of accessory polypeptide heterogeneity of dynein populations. The motor domain containing heavy chains of cytoplasmic dynein are associated with multiple intermediate, light intermediate, and light chain accessory polypeptides. We examined the organization of these subunits within cytoplasmic dynein by separating the molecule into two distinct subcomplexes. These subcomplexes were competent to reassemble into a molecule with dynein-like properties. One subcomplex was composed of the dynein heavy and light intermediate chains whereas the other subcomplex was composed of the intermediate and light chains. The intermediate and light chain subcomplex could be further separated into two pools, only one of which contained dynein light chains. The two pools had distinct intermediate chain compositions, suggesting that intermediate chain isoforms have different light chain–binding properties. When the two intermediate chain pools were characterized by analytical velocity sedimentation, at least four molecular components were seen: intermediate chain monomers, intermediate chain dimers, intermediate chain monomers with bound light chains, and a mixture of intermediate chain dimers with assorted bound light chains. These data provide new insights into the compositional heterogeneity and assembly of the cytoplasmic dynein complex and suggest that individual dynein molecules have distinct molecular compositions in vivo. PMID:11967380

  11. Integrated Control of Axonemal Dynein AAA+ Motors

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    King, Stephen M.

    2012-01-01

    Axonemal dyneins are AAA+ enzymes that convert ATP hydrolysis to mechanical work. This leads to the sliding of doublet microtubules with respect to each other and ultimately the generation of ciliary/flagellar beating. However, in order for useful work to be generated, the action of individual dynein motors must be precisely controlled. In addition, cells modulate the motility of these organelles through a variety of second messenger systems and these signals too must be integrated by the dynein motors to yield an appropriate output. This review describes the current status of efforts to understand dynein control mechanisms and their connectivity focusing mainly on studies of the outer dynein arm from axonemes of the unicellular biflagellate green alga Chlamydomonas. PMID:22406539

  12. A Mouse Neurodegenerative Dynein Heavy Chain Mutation Alters Dynein Motility and Localization in Neurospora crassa

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    Sivagurunathan, Senthilkumar; Schnittker, Robert R.; Nandini, Swaran; Plamann, Michael D.; King, Stephen J.

    2013-01-01

    Cytoplasmic dynein is responsible for the transport and delivery of cargoes in organisms ranging from humans to fungi. Dysfunction of dynein motor machinery due to mutations in dynein or its activating complex dynactin can result in one of several neurological diseases in mammals. The mouse Legs at odd angles (Loa) mutation in the tail domain of the dynein heavy chain has been shown to lead to progressive neurodegeneration in mice. The mechanism by which the Loa mutation affects dynein function is just beginning to be understood. In this work, we generated the dynein tail mutation observed in Loa mice into the Neurospora crassa genome and utilized cell biological and complementing biochemical approaches to characterize how that tail mutation affected dynein function. We determined that the Loa mutation exhibits several subtle defects upon dynein function in N. crassa that were not seen in mice, including alterations in dynein localization, impaired velocity of vesicle transport, and in the biochemical properties of purified motors. Our work provides new information on the role of the tail domain on dynein function and points out areas of future research that will be of interest to pursue in mammalian systems. PMID:22991199

  13. Characterization and localization of dynein and myosins V and VI in the ovaries of queen bees.

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    Patricio, Karina; Calábria, Luciana Karen; Peixoto, Pablo Marco; Espindola, Foued Salmen; Da Cruz-Landim, Carminda

    2010-10-01

    The presence of myosin and dynein in the ovaries of both Apis mellifera and Scaptotrigona postica was investigated in extracts and in histological sections. In the ovary extracts, motor proteins, myosins V, VI and dynein were detected by Western blot. In histological sections, they were detected by immunocytochemistry, using a mouse monoclonal antibody against the intermediary chain of dynein and a rabbit polyclonal antibody against the myosin V head domain. The myosin VI tail domain was recognized by a pig polyclonal antibody. The results show that these molecular motors are expressed in the ovaries of both bee species with few differences in location and intensity, in regions where movement of substances is expected during oogenesis. The fact that antibodies against vertebrate proteins recognize proteins of bee species indicates that the specific epitopes are evolutionarily well preserved.

  14. Free flight maneuvers of stalk-eyed flies: do eye-stalks affect aerial turning behavior?

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    Ribak, Gal; Swallow, John G

    2007-10-01

    The eyes of stalk-eyed flies (Diopsidae) are positioned at the end of rigid peduncles projected laterally from the head. In dimorphic species the eye-stalks of males exceed the eye-stalks of females and can exceed body length. Eye-stalk length is sexually selected in males improving male reproductive success. We tested whether the long eye-stalks have a negative effect on free-flight and aerial turning behavior by analyzing the morphology and free-flight trajectories of male and female Cyrtodiopsis dalmanni. At flight posture the mass-moment-of-inertia for rotation about a vertical axis was 1.49-fold higher in males. Males also showed a 5% increase in wing length compared to females. During free-flight females made larger turns than males (54 +/- 31.4 vs. 49 +/- 36.2 degrees , t test, P span does result in an increase in the mechanical requirements for aerial turning but that male C. dalmanni are capable of compensating for the constraint of longer eye-stalks during the range of turns observed through wingbeat kinematics and increased wing size.

  15. Lis1 regulates dynein by sterically blocking its mechanochemical cycle.

    Science.gov (United States)

    Toropova, Katerina; Zou, Sirui; Roberts, Anthony J; Redwine, William B; Goodman, Brian S; Reck-Peterson, Samara L; Leschziner, Andres E

    2014-11-07

    Regulation of cytoplasmic dynein's motor activity is essential for diverse eukaryotic functions, including cell division, intracellular transport, and brain development. The dynein regulator Lis1 is known to keep dynein bound to microtubules; however, how this is accomplished mechanistically remains unknown. We have used three-dimensional electron microscopy, single-molecule imaging, biochemistry, and in vivo assays to help establish this mechanism. The three-dimensional structure of the dynein-Lis1 complex shows that binding of Lis1 to dynein's AAA+ ring sterically prevents dynein's main mechanical element, the 'linker', from completing its normal conformational cycle. Single-molecule experiments show that eliminating this block by shortening the linker to a point where it can physically bypass Lis1 renders single dynein motors insensitive to regulation by Lis1. Our data reveal that Lis1 keeps dynein in a persistent microtubule-bound state by directly blocking the progression of its mechanochemical cycle.

  16. Dynein at kinetochores: Making the connection.

    Science.gov (United States)

    McHugh, Toni; Welburn, Julie P I

    2017-04-03

    Dynein removes the checkpoint proteins from kinetochores once chromosomes are bioriented. In this issue, Gama et al. (2017. J. Cell Biol. https://doi.org/10.1083/jcb.201610108) and Mosalaganti et al. (2017. J. Cell Biol. https://doi.org/10.1083/jcb.201611060) reveal the molecular basis for how dynein and its adaptor protein Spindly are recruited to the ROD-Zw10-Zwilch complex in the fibrous corona of unattached kinetochores.

  17. Caulobacter and Asticcacaulis stalk bands as indicators of stalk age.

    OpenAIRE

    Poindexter, J S; Staley, J T

    1996-01-01

    The prosthecae (stalks) of dimorphic caulobacters of the genera Caulobacter and Asticcacaulis are distinguished among such appendages by the presence of disk-like components known as stalk bands. Whether bands are added to a cell's stalk(s) as a regular event coordinated with the cell's reproductive cycle has not been settled by previous studies. Analysis of the frequency of stalks with i, i + 1, i + 2, etc. bands 'among more than 7,000 stalks of Caulobacter crescentus revealed that in finite...

  18. Stalking: a neurobiological perspective.

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    Marazziti, Donatella; Falaschi, Valentina; Lombardi, Amedeo; Mungai, Francesco; Dell'Osso, Liliana

    2015-01-01

    Nowadays stalking is becoming a real social emergency, as it may often fuel severe aggressive behaviours. No exhaustive aetiological hypothesis is still available regarding this complex phenomenon. However, the detailed descriptions of some of its peculiar features allow to draw with cautions some general suggestions. Probably stalking may arise from the derangement of those neural networks subserving the so-called social brain and the pair bonding formation, in particular the processes of attachment/separation, attraction/romantic love/reward. In addition, it seems to be modulated by excessive functioning of the dopamine system coupled with decreased serotonin tone. It is believed that the investigation and deepening of its possible neurobiological substrates may be helpful in the prevention of the severe consequences of stalking.

  19. A Unified Taxonomy for Ciliary Dyneins

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    Hom, Erik F.Y.; Witman, George B.; Harris, Elizabeth H.; Dutcher, Susan K.; Kamiya, Ritsu; Mitchell, David R.; Pazour, Gregory J.; Porter, Mary E.; Sale, Winfield S.; Wirschell, Maureen; Yagi, Toshiki; King, Stephen M.

    2011-01-01

    The formation and function of eukaryotic cilia/flagella require the action of a large array of dynein microtubule motor complexes. Due to genetic, biochemical, and microscopic tractability, Chlamydomonas reinhardtii has become the premier model system in which to dissect the role of dyneins in flagellar assembly, motility, and signaling. Currently, fifty-four proteins have been described as components of various Chlamydomonas flagellar dyneins or as factors required for their assembly in the cytoplasm and/or transport into the flagellum; orthologues of nearly all these components are present in other ciliated organisms including humans. For historical reasons, the nomenclature of these diverse dynein components and their corresponding genes, mutant alleles and orthologues has become extraordinarily confusing. Here, we unify Chlamydomonas dynein gene nomenclature and establish a systematic classification scheme based on structural properties of the encoded proteins. Furthermore, we provide detailed tabulations of the various mutant alleles and protein aliases that have been used and explicitly define the correspondence with orthologous components in other model organisms and humans. PMID:21953912

  20. Cytoplasmic Dynein Promotes HIV-1 Uncoating

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    Paulina Pawlica

    2014-11-01

    Full Text Available Retroviral capsid (CA cores undergo uncoating during their retrograde transport (toward the nucleus, and/or after reaching the nuclear membrane. However, whether HIV-1 CA core uncoating is dependent upon its transport is not understood. There is some evidence that HIV-1 cores retrograde transport involves cytoplasmic dynein complexes translocating on microtubules. Here we investigate the role of dynein-dependent transport in HIV-1 uncoating. To interfere with dynein function, we depleted dynein heavy chain (DHC using RNA interference, and we over-expressed p50/dynamitin. In immunofluorescence microscopy experiments, DHC depletion caused an accumulation of CA foci in HIV-1 infected cells. Using a biochemical assay to monitor HIV-1 CA core disassembly in infected cells, we observed an increase in amounts of intact (pelletable CA cores upon DHC depletion or p50 over-expression. Results from these two complementary assays suggest that inhibiting dynein-mediated transport interferes with HIV-1 uncoating in infected cells, indicating the existence of a functional link between HIV-1 transport and uncoating.

  1. The ciliary inner dynein arm, I1 dynein, is assembled in the cytoplasm and transported by IFT before axonemal docking.

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    Viswanadha, Rasagnya; Hunter, Emily L; Yamamoto, Ryosuke; Wirschell, Maureen; Alford, Lea M; Dutcher, Susan K; Sale, Winfield S

    2014-10-01

    To determine mechanisms of assembly of ciliary dyneins, we focused on the Chlamydomonas inner dynein arm, I1 dynein, also known as dynein f. I1 dynein assembles in the cytoplasm as a 20S complex similar to the 20S I1 dynein complex isolated from the axoneme. The intermediate chain subunit, IC140 (IDA7), and heavy chains (IDA1, IDA2) are required for 20S I1 dynein preassembly in the cytoplasm. Unlike I1 dynein derived from the axoneme, the cytoplasmic 20S I1 complex will not rebind I1-deficient axonemes in vitro. To test the hypothesis that I1 dynein is transported to the distal tip of the cilia for assembly in the axoneme, we performed cytoplasmic complementation in dikaryons formed between wild-type and I1 dynein mutant cells. Rescue of I1 dynein assembly in mutant cilia occurred first at the distal tip and then proceeded toward the proximal axoneme. Notably, in contrast to other combinations, I1 dynein assembly was significantly delayed in dikaryons formed between ida7 and ida3. Furthermore, rescue of I1 dynein assembly required new protein synthesis in the ida7 × ida3 dikaryons. On the basis of the additional observations, we postulate that IDA3 is required for 20S I1 dynein transport. Cytoplasmic complementation in dikaryons using the conditional kinesin-2 mutant, fla10-1 revealed that transport of I1 dynein is dependent on kinesin-2 activity. Thus, I1 dynein complex assembly depends upon IFT for transport to the ciliary distal tip prior to docking in the axoneme.

  2. Caulobacter and Asticcacaulis stalk bands as indicators of stalk age.

    Science.gov (United States)

    Poindexter, J S; Staley, J T

    1996-07-01

    The prosthecae (stalks) of dimorphic caulobacters of the genera Caulobacter and Asticcacaulis are distinguished among such appendages by the presence of disk-like components known as stalk bands. Whether bands are added to a cell's stalk(s) as a regular event coordinated with the cell's reproductive cycle has not been settled by previous studies. Analysis of the frequency of stalks with i, i + 1, i + 2, etc. bands 'among more than 7,000 stalks of Caulobacter crescentus revealed that in finite (batch) cultures (in which all offspring accumulate), the proportion of stalks with i + 1 hands was regularly 50% of the proportion of stalks with i bands. This implied that the number of bands correlated with the number of reproductive cycles completed by a stalked cell. In chemostat-maintained perpetual cultures, the proportion was greater than 50% because stalked cells, with their shorter reproductive cycle times, contributed a larger proportion of offspring to the steady-state population than did their swarmer siblings. In Asticcacaulis biprosthecum cells, which bear twin prosthecae, the twins on a typical cell possessed the same number of bands. For both genera, stalk bands provide a unique morphological feature that could be employed in an assessment of age distribution and reproductive dynamics within natural populations of these caulobacters.

  3. Ciliobrevins as Tools for Studying Dynein Motor Function

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    Douglas eRoossien

    2015-07-01

    Full Text Available Dyneins are a small class of molecular motors that bind to microtubules and walk towards their minus ends. They are essential for the transport and distribution of organelles, signaling complexes and cytoskeletal elements. In addition dyneins generate forces on microtubule arrays that power the beating of cilia and flagella, cell division, migration and growth cone motility. Classical approaches to the study of dynein function in axons involve the depletion of dynein, expression of mutant/truncated forms of the motor, or interference with accessory subunits. By necessity, these approaches require prolonged time period for the expression or manipulation of cellular dynein levels. With the discovery of the ciliobrevins, a class of cell permeable small molecule inhibitors of dynein, it is now possible to acutely disrupt dynein both globally and locally. In this review, we briefly summarize recent work using ciliobrevins to inhibit dynein and discuss the insights ciliobrevins have provided about dynein function in various cell types with a focus on neurons. We temper this with a discussion of the need for studies that will elucidate the mechanism of action of ciliobrevin and as well as the need for experiments to further analyze the specificity of ciliobreviens for dynein. Although much remains to be learned about ciliobrevins, these small molecules are proving themselves to be valuable novel tools to assess the cellular functions of dynein.

  4. Regulation of Cytoplasmic Dynein ATPase by Lis1

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    Mesngon, Mariano T.; Tarricone, Cataldo; Hebbar, Sachin; Guillotte, Aimee M.; Schmitt, E. William; Lanier, Lorene; Musacchio, Andrea; King, Stephen J.; Smith, Deanna S.

    2015-01-01

    Mutations in Lis1 cause classical lissencephaly, a developmental brain abnormality characterized by defects in neuronal positioning. Over the last decade, a clear link has been forged between Lis1 and the microtubule motor cytoplasmic dynein. Substantial evidence indicates that Lis1 functions in a highly conserved pathway with dynein to regulate neuronal migration and other motile events. Yeast two-hybrid studies predict that Lis1 binds directly to dynein heavy chains (Sasaki et al., 2000; Tai et al., 2002), but the mechanistic significance of this interaction is not well understood. We now report that recombinant Lis1 binds to native brain dynein and significantly increases the microtubule-stimulated enzymatic activity of dynein in vitro. Lis1 does this without increasing the proportion of dynein that binds to microtubules, indicating that Lis1 influences enzymatic activity rather than microtubule association. Dynein stimulation in vitro is not a generic feature of microtubule-associated proteins, because tau did not stimulate dynein. To our knowledge, this is the first indication that Lis1 or any other factor directly modulates the enzymatic activity of cytoplasmic dynein. Lis1 must be able to homodimerize to stimulate dynein, because a C-terminal fragment (containing the dynein interaction site but missing the self-association domain) was unable to stimulate dynein. Binding and colocalization studies indicate that Lis1 does not interact with all dynein complexes found in the brain. We propose a model in which Lis1 stimulates the activity of a subset of motors, which could be particularly important during neuronal migration and long-distance axonal transport. PMID:16481446

  5. PAPERMAKING POTENTIAL OF CANOLA STALKS

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    Ali Akbar Enayati

    2000-02-01

    Full Text Available A fundamental study was carried out to explore the properties of canola stalks with regards to pulp and paper production. In this study the morphological properties, chemical composition, and soda pulping properties of canola stalks were investigated. The mean values of length, diameter, and cell wall thickness of canola stalks fibers were measured as 1.17 mm, 23.02 m, and 5.26 m, respectively. The morphological properties analysis indicated that despite the thicker cell wall, the morphological properties of canola stalks fibers were comparable to those of non-woods and hardwoods fibers. The holocelluloses, alpha-cellulose, lignin, and ash contents of canola stalks were determined to be 73.6, 42.0, 17.3, and 8.2 wt%, respectively. The hot water and dilute alkali extractives of canola stalks were determined as 18 and 46.1 wt%. In comparison to most other non-wood papermaking raw materials, soda pulping of canola stalks required higher chemical charge and cooking time. Soda pulping of canola stalks gave a low yield bleachable grade pulp. The strength properties of bleached canola stalks soda pulp appeared to be similar to those of common non-wood papermaking resources. The overall results showed that canola has a promising potential to be used in pulp and paper production.

  6. Campus Stalking: Theoretical Implications and Responses

    Science.gov (United States)

    Scott, Joel H.; Cooper, Dianne L.

    2011-01-01

    The problem of campus stalking requires uniting several departments to develop a response plan reflective of the comprehensive nature of campus stalking. This article highlights how research on stalking, stalking theories, and related environmental theories support the formation of a cross-functional team to develop a multifaceted response to this…

  7. Campus Stalking: Theoretical Implications and Responses

    Science.gov (United States)

    Scott, Joel H.; Cooper, Dianne L.

    2011-01-01

    The problem of campus stalking requires uniting several departments to develop a response plan reflective of the comprehensive nature of campus stalking. This article highlights how research on stalking, stalking theories, and related environmental theories support the formation of a cross-functional team to develop a multifaceted response to this…

  8. Structure of the microtubule-binding domain of flagellar dynein.

    Science.gov (United States)

    Kato, Yusuke S; Yagi, Toshiki; Harris, Sarah A; Ohki, Shin-ya; Yura, Kei; Shimizu, Youské; Honda, Shinya; Kamiya, Ritsu; Burgess, Stan A; Tanokura, Masaru

    2014-11-04

    Flagellar dyneins are essential microtubule motors in eukaryotes, as they drive the beating motions of cilia and flagella. Unlike myosin and kinesin motors, the track binding mechanism of dyneins and the regulation between the strong and weak binding states remain obscure. Here we report the solution structure of the microtubule-binding domain of flagellar dynein-c/DHC9 (dynein-c MTBD). The structure reveals a similar overall helix-rich fold to that of the MTBD of cytoplasmic dynein (cytoplasmic MTBD), but dynein-c MTBD has an additional flap, consisting of an antiparallel b sheet. The flap is positively charged and highly flexible. Despite the structural similarity to cytoplasmic MTBD, dynein-c MTBD shows only a small change in the microtubule- binding affinity depending on the registry change of coiled coil-sliding, whereby lacks the apparent strong binding state. The surface charge distribution of dynein-c MTBD also differs from that of cytoplasmic MTBD, which suggests a difference in the microtubule-binding mechanism.

  9. Stalking: Klinische und forensische Bedeutung

    Directory of Open Access Journals (Sweden)

    Dreßing H

    2008-01-01

    Full Text Available Stalking ist in der Bevölkerung von Industrienationen ein weit verbreitetes Phänomen. Die Lebenszeitprävalenz beträgt über 11 %. Hinter den relativ gleichförmig erscheinenden Stalkingverhaltensweisen lassen sich unterschiedliche Täter-Opfer-Beziehungen und Motivationsstrukturen nachweisen. In der vorliegenden Arbeit werden wesentliche Aspekte der Tätertypologie sowie der psychischen Auswirkungen auf die Opfer diskutiert, sowie sich daraus ableitende und bisher noch kaum wahrgenommene Aufgaben der klinischen und forensischen Psychiatrie benannt. Da die Versorgung der Stalking-Opfer dringend verbessert werden muss, wird exemplarisch das Mannheimer Modellprojekt Stopp Stalking (MMSS vorgestellt.

  10. BICD2, dynactin, and LIS1 cooperate in regulating dynein recruitment to cellular structures

    NARCIS (Netherlands)

    D. Splinter (Daniël); D.S. Razafsky (David); M.A. Schlager (Max); A. Serra-Marques (Andrea); I. Grigoriev (Ilya); J.A.A. Demmers (Jeroen); N. Keijzer (Nanda); K. Jiang (Kai); S. Poser; A. Hyman (Anthony); C.C. Hoogenraad (Casper); S.J. King (Stephen); A.S. Akhmanova (Anna)

    2012-01-01

    textabstractCytoplasmic dynein is the major microtubule minus-end-directed cellular motor. Most dynein activities require dynactin, but the mechanisms regulating cargo-dependent dynein-dynactin interaction are poorly understood. In this study, we focus on dynein-dynactin recruitment to cargo by the

  11. BICD2, dynactin, and LIS1 cooperate in regulating dynein recruitment to cellular structures

    NARCIS (Netherlands)

    D. Splinter (Daniël); D.S. Razafsky (David); M.A. Schlager (Max); A. Serra-Marques (Andrea); I. Grigoriev (Ilya); J.A.A. Demmers (Jeroen); N. Keijzer (Nanda); K. Jiang (Kai); S. Poser; A. Hyman (Anthony); C.C. Hoogenraad (Casper); S.J. King (Stephen); A.S. Akhmanova (Anna)

    2012-01-01

    textabstractCytoplasmic dynein is the major microtubule minus-end-directed cellular motor. Most dynein activities require dynactin, but the mechanisms regulating cargo-dependent dynein-dynactin interaction are poorly understood. In this study, we focus on dynein-dynactin recruitment to cargo by the

  12. Stalking the ultimate particle

    CERN Multimedia

    2003-01-01

    If you missed the ARTE programme entitled "L'Ultime Particule" broadcast in February, you have another chance to catch it in CERN's Main Auditorium on 13 March. "L'Ultime Particule" is a documentary by the French director Michel Andrieu that seeks to explain particle physics through a contemplative quest for the research physicists of matter of today and yesteryear. Invariably kitted out in a red parka and a soft hat, the programme's investigator scours the planet and the archives in search of the research physicists who are stalking the ultimate particle, the Higgs boson, in their quest to understand the structure of matter. Naturally enough, CERN is an important stage of his journey where Michel Andrieu and his team spent several days last year. Both from the physics and metaphysical points of view, "L'Ultime Particule" is worth seeing. The film's director, Michel Andrieu, will introduce his documentary and answer questions from the audience after the documentary has been shown. L'Ultime Particule by Mic...

  13. Dynein at the kinetochore: Timing, Interactions and Functions.

    Science.gov (United States)

    Bader, Jason R; Vaughan, Kevin T

    2010-05-01

    Kinetochores have been proposed to play multiple roles in mitotic chromosome alignment, including initial microtubule (MT) capture, monitoring MT attachments, prometaphase and anaphase chromosome movement and tension generation at metaphase. In addition, kinetochores are essential components of the spindle assembly checkpoint (SAC), and couple chromosome alignment with SAC silencing at metaphase. Although the molecular details of these activities remain under investigation, cytoplasmic dynein has been implicated in several aspects of MT and SAC regulation. Recent work clarifies the contribution of dynein to MT interactions and to events that drive anaphase onset. This review summarizes these studies and provides new models for dynein function. Copyright 2010 Elsevier Ltd. All rights reserved.

  14. Quantitative Analysis of Pac1/LIS1-mediated Dynein Targeting: Implications for Regulation of Dynein Activity in Budding Yeast

    OpenAIRE

    Markus, Steven M.; Plevock, Karen M.; St. Germain, Bryan J.; Punch, Jesse J.; Meaden, Christopher W.; Lee, Wei-Lih

    2011-01-01

    LIS1 is a critical regulator of dynein function during mitosis and organelle transport. Here, we investigated how Pac1, the budding yeast LIS1 homologue, regulates dynein targeting and activity during nuclear migration. We show that Pac1 and Dyn1 (dynein heavy chain) are dependent upon each other and upon Bik1 (budding yeast CLIP-170 homologue) for plus end localization, whereas Bik1 is independent of either. Dyn1, Pac1 and Bik1 interact in vivo at the plus ends, where an excess amount of Bik...

  15. Self-organization of dynein motors generates meiotic nuclear oscillations.

    Directory of Open Access Journals (Sweden)

    Sven K Vogel

    2009-04-01

    Full Text Available Meiotic nuclear oscillations in the fission yeast Schizosaccharomyces pombe are crucial for proper chromosome pairing and recombination. We report a mechanism of these oscillations on the basis of collective behavior of dynein motors linking the cell cortex and dynamic microtubules that extend from the spindle pole body in opposite directions. By combining quantitative live cell imaging and laser ablation with a theoretical description, we show that dynein dynamically redistributes in the cell in response to load forces, resulting in more dynein attached to the leading than to the trailing microtubules. The redistribution of motors introduces an asymmetry of motor forces pulling in opposite directions, leading to the generation of oscillations. Our work provides the first direct in vivo observation of self-organized dynamic dynein distributions, which, owing to the intrinsic motor properties, generate regular large-scale movements in the cell.

  16. Catch bond mechanism in Dynein motor driven collective transport

    CERN Document Server

    Nair, Anil; Mitra, Mithun K; Muhuri, Sudipto; Chaudhuri, Abhishek

    2016-01-01

    Recent experiments have demonstrated that dynein motor exhibits catch bonding behaviour, in which the unbinding rate of a single dynein decreases with increasing force, for a certain range of force. Motivated by these experiments, we propose a model for catch bonding in dynein using a threshold force bond deformation (TFBD) model wherein catch bonding sets in beyond a critical applied load force. We study the effect of catch bonding on unidirectional transport properties of cellular cargo carried by multiple dynein motors within the framework of this model. We find catch bonding can result in dramatic changes in the transport properties, which are in sharp contrast to kinesin driven unidirectional transport, where catch bonding is absent. We predict that, under certain conditions, the average velocity of the cellular cargo can actually increase as applied load is increased. We characterize the transport properties in terms of a velocity profile phase plot in the parameter space of the catch bond strength and ...

  17. Dlic1 deficiency impairs ciliogenesis of photoreceptors by destabilizing dynein

    Institute of Scientific and Technical Information of China (English)

    Shanshan Kong; Xinrong Du; Chao Peng; Yiming Wu; Huirong Li; Xi Jin; Ling Hou

    2013-01-01

    Cytoplasmic dynein 1 is fundamentally important for transporting a variety of essential cargoes along microtubules within eukaryotic cells.However,in mammals,few mutants are available for studying the effects of defects in dynein-controlled processes in the context of the whole organism.Here,we deleted mouse Dlic1 gene encoding DLIC1,a subunit of the dynein complex.Dlic1-/-mice are viable,but display severe photoreceptor degeneration.Ablation of Dlic1 results in ectopic accumulation of outer segment (OS) proteins,and impairs OS growth and ciliogenesis of photoreceptors by interfering with Rabll-vesicle trafficking and blocking efficient OS protein transport from Golgi to the basal body.Our studies show that Dlic1 deficiency partially blocks vesicle export from endoplasmic reticulum (ER),but seems not to affect vesicle transport from the ER to Golgi.Further mechanistic study reveals that lack of Dlic1 destabilizes dynein subunits and alters the normal subcellular distribution of dynein in photoreceptors,probably due to the impaired transport function of dynein.Our results demonstrate that Dlic1 plays important roles in ciliogenesis and protein transport to the OS,and is required for photoreceptor development and survival.The Dlic1-/-mice also provide a new mouse model to study human retinal degeneration.

  18. The development of cellular stalks in bacteria.

    Science.gov (United States)

    Schmidt, J M; Stanier, R Y

    1966-03-01

    Extensive stalk elongation in Caulobacter and Asticcacaulis can be obtained in a defined medium by limiting the concentration of phosphate. Caulobacter cells which were initiating stalk formation were labeled with tritiated glucose. After removal of exogenous tritiated material, the cells were subjected to phosphate limitation while stalk elongation occurred. The location of tritiated material in the elongated stalks as detected by radioautographic techniques allowed identification of the site of stalk development. The labeling pattern obtained was consistent with the hypothesis that the materials of the stalk are synthesized at the juncture of the stalk with the cell. Complementary labeling experiments with Caulobacter and Asticcacaulis confirmed this result. In spheroplasts of C. crescentus prepared by treatment with lysozyme, the stalks lost their normal rigid outline after several minutes of exposure to the enzyme, indicating that the rigid layer of the cell wall attacked by lysozyme is present in the stalk. In spheroplasts of growing cells induced with penicillin, the stalks did not appear to be affected, indicating that the stalk wall is a relatively inert, nongrowing structure. The morphogenetic implications of these findings are discussed.

  19. Analysis of the Dynein-Dynactin Interaction In Vitro and In Vivo

    Science.gov (United States)

    King, Stephen J.; Brown, Christa L.; Maier, Kerstin C.; Quintyne, Nicholas J.; Schroer, Trina A.

    2003-01-01

    Cytoplasmic dynein and dynactin are megadalton-sized multisubunit molecules that function together as a cytoskeletal motor. In the present study, we explore the mechanism of dynein-dynactin binding in vitro and then extend our findings to an in vivo context. Solution binding assays were used to define binding domains in the dynein intermediate chain (IC) and dynactin p150Glued subunit. Transient overexpression of a series of fragments of the dynein IC was used to determine the importance of this subunit for dynein function in mammalian tissue culture cells. Our results suggest that a functional dynein-dynactin interaction is required for proper microtubule organization and for the transport and localization of centrosomal components and endomembrane compartments. The dynein IC fragments have different effects on endomembrane localization, suggesting that different endomembranes may bind dynein via distinct mechanisms. PMID:14565986

  20. Dynein prevents erroneous kinetochore-microtubule attachments in mitosis.

    Science.gov (United States)

    Barisic, Marin; Maiato, Helder

    2015-01-01

    Equal distribution of the genetic material during cell division relies on efficient congression of chromosomes to the metaphase plate. Prior to their alignment, the Dynein motor recruited to kinetochores transports a fraction of laterally-attached chromosomes along microtubules toward the spindle poles. By doing that, Dynein not only contributes to chromosome movements, but also prevents premature stabilization of end-on kinetochore-microtubule attachments. This is achieved by 2 parallel mechanisms: 1) Dynein-mediated poleward movement of chromosomes counteracts opposite polar-ejection forces (PEFs) on chromosome arms by the microtubule plus-end-directed motors chromokinesins. Otherwise, they could stabilize erroneous syntelic kinetochore-microtubule attachments and lead to the random ejection of chromosomes away from the spindle poles; and 2) By transporting chromosomes to the spindle poles, Dynein brings the former to the zone of highest Aurora A kinase activity, further destabilizing kinetochore-microtubule attachments. Thus, Dynein plays an important role in keeping chromosome segregation error-free by preventing premature stabilization of kinetochore-microtubule attachments near the spindle poles.

  1. Schwann cell myelination requires Dynein function

    Directory of Open Access Journals (Sweden)

    Langworthy Melissa M

    2012-11-01

    Full Text Available Abstract Background Interaction of Schwann cells with axons triggers signal transduction that drives expression of Pou3f1 and Egr2 transcription factors, which in turn promote myelination. Signal transduction appears to be mediated, at least in part, by cyclic adenosine monophosphate (cAMP because elevation of cAMP levels can stimulate myelination in the absence of axon contact. The mechanisms by which the myelinating signal is conveyed remain unclear. Results By analyzing mutations that disrupt myelination in zebrafish, we learned that Dynein cytoplasmic 1 heavy chain 1 (Dync1h1, which functions as a motor for intracellular molecular trafficking, is required for peripheral myelination. In dync1h1 mutants, Schwann cell progenitors migrated to peripheral nerves but then failed to express Pou3f1 and Egr2 or make myelin membrane. Genetic mosaic experiments revealed that robust Myelin Basic Protein expression required Dync1h1 function within both Schwann cells and axons. Finally, treatment of dync1h1 mutants with a drug to elevate cAMP levels stimulated myelin gene expression. Conclusion Dync1h1 is required for retrograde transport in axons and mutations of Dync1h1 have been implicated in axon disease. Our data now provide evidence that Dync1h1 is also required for efficient myelination of peripheral axons by Schwann cells, perhaps by facilitating signal transduction necessary for myelination.

  2. Cell cycle regulation of dynein association with membranes modulates microtubule-based organelle transport.

    Science.gov (United States)

    Niclas, J; Allan, V J; Vale, R D

    1996-05-01

    Cytoplasmic dynein is a minus end-directed microtubule motor that performs distinct functions in interphase and mitosis. In interphase, dynein transports organelles along microtubules, whereas in metaphase this motor has been implicated in mitotic spindle formation and orientation as well as chromosome segregation. The manner in which dynein activity is regulated during the cell cycle, however, has not been resolved. In this study, we have examined the mechanism by which organelle transport is controlled by the cell cycle in extracts of Xenopus laevis eggs. Here, we show that photocleavage of the dynein heavy chain dramatically inhibits minus end-directed organelle transport and that purified dynein restores this motility, indicating that dynein is the predominant minus end-directed membrane motor in Xenopus egg extracts. By measuring the amount of dynein associated with isolated membranes, we find that cytoplasmic dynein and its activator dynactin detach from the membrane surface in metaphase extracts. The sevenfold decrease in membrane-associated dynein correlated well with the eightfold reduction in minus end-directed membrane transport observed in metaphase versus interphase extracts. Although dynein heavy or intermediate chain phosphorylation did not change in a cell cycle-dependent manner, the dynein light intermediate chain incorporated approximately 12-fold more radiolabeled phosphate in metaphase than in interphase extracts. These studies suggest that cell cycle-dependent phosphorylation of cytoplasmic dynein may regulate organelle transport by modulating the association of this motor with membranes.

  3. Phosphoregulation of an Inner Dynein Arm Complex in Chlamydomonas reinhardtii Is Altered in Phototactic Mutant Strains

    Science.gov (United States)

    King, Stephen J.; Dutcher, Susan K.

    1997-01-01

    To gain a further understanding of axonemal dynein regulation, mutant strains of Chlamydomonas reinhardtii that had defects in both phototactic behavior and flagellar motility were identified and characterized. ptm1, ptm2, and ptm3 mutant strains exhibited motility phenotypes that resembled those of known inner dynein arm region mutant strains, but did not have biochemical or genetic phenotypes characteristic of other inner dynein arm mutations. Three other mutant strains had defects in the f class of inner dynein arms. Dynein extracts from the pf9-4 strain were missing the entire f complex. Strains with mutations in pf9/ida1, ida2, or ida3 failed to assemble the f dynein complex and did not exhibit phototactic behavior. Fractionated dynein from mia1-1 and mia2-1 axonemes exhibited a novel f class inner dynein arm biochemical phenotype; the 138-kD f intermediate chain was present in altered phosphorylation forms. In vitro axonemal dynein activity was reduced by the mia1-1 and mia2-1 mutations. The addition of kinase inhibitor restored axonemal dynein activity concomitant with the dephosphorylation of the 138-kD f intermediate chain. Dynein extracts from uni1-1 axonemes, which specifically assemble only one of the two flagella, contained relatively high levels of the altered phosphorylation forms of the 138-kD intermediate chain. We suggest that the f dynein complex may be phosphoregulated asymmetrically between the two flagella to achieve phototactic turning. PMID:9008712

  4. Stalking: Notion, characteristics and social responses

    Directory of Open Access Journals (Sweden)

    Nikolić-Ristanović Vesna

    2007-01-01

    Full Text Available In the last two decades stalking phenomenon is recognized and actualized in the world in professional, scientific circles, in media and the everyday talk. Recently, stalking is identified as specific and complex problem studied separately from domestic violence, workplace abuse, sexual harassment, threats, following, homicide, voyeurism and the other phenomenon to which stalking may or not be related. This paper is aimed to determine the notion of stalking and its relationship with similar phenomena, to review the research about the prevalence and nature of stalking, as well as to review the measures for its prevention, supporting victims and prosecution of offenders. Finally, the paper intend to contribute toward initiation of research and legal reforms regarding stalking victimisation in Serbia.

  5. Genetic analysis of the cytoplasmic dynein subunit families.

    Directory of Open Access Journals (Sweden)

    K Kevin Pfister

    2006-01-01

    Full Text Available Cytoplasmic dyneins, the principal microtubule minus-end-directed motor proteins of the cell, are involved in many essential cellular processes. The major form of this enzyme is a complex of at least six protein subunits, and in mammals all but one of the subunits are encoded by at least two genes. Here we review current knowledge concerning the subunits, their interactions, and their functional roles as derived from biochemical and genetic analyses. We also carried out extensive database searches to look for new genes and to clarify anomalies in the databases. Our analysis documents evolutionary relationships among the dynein subunits of mammals and other model organisms, and sheds new light on the role of this diverse group of proteins, highlighting the existence of two cytoplasmic dynein complexes with distinct cellular roles.

  6. Identification of the t Complex–encoded Cytoplasmic Dynein Light Chain Tctex1 in Inner Arm I1 Supports the Involvement of Flagellar Dyneins in Meiotic Drive

    Science.gov (United States)

    Harrison, Alistair; Olds-Clarke, Patricia; King, Stephen M.

    1998-01-01

    The cytoplasmic dynein light chain Tctex1 is a candidate for one of the distorter products involved in the non-Mendelian transmission of mouse t haplotypes. It has been unclear, however, how the t-specific mutations in this protein, which is found associated with cytoplasmic dynein in many tissues, could result in a male germ cell–specific phenotype. Here, we demonstrate that Tctex1 is not only a cytoplasmic dynein component, but is also present both in mouse sperm and Chlamydomonas flagella. Genetic and biochemical dissection of the Chlamydomonas flagellum reveal that Tctex1 is a previously undescribed component of inner dynein arm I1. Combined with the recent identification of another putative t complex distorter, Tctex2, within the outer dynein arm, these results support the hypothesis that transmission ratio distortion (meiotic drive) of mouse t haplotypes involves dysfunction of both flagellar inner and outer dynein arms but does not require the cytoplasmic isozyme. PMID:9490726

  7. The Fear Factor: Exploring Predictors of Fear among Stalking Victims throughout the Stalking Encounter

    Science.gov (United States)

    Reyns, Bradford W.; Englebrecht, Christine M.

    2013-01-01

    The crime of stalking has received much research attention, yet there are still important questions to be explored surrounding this behavior. One such question relates to definitions of stalking, including the requirement that victims must express fear to qualify as victims of stalking. The current study addresses this issue by exploring the…

  8. The Fear Factor: Exploring Predictors of Fear among Stalking Victims throughout the Stalking Encounter

    Science.gov (United States)

    Reyns, Bradford W.; Englebrecht, Christine M.

    2013-01-01

    The crime of stalking has received much research attention, yet there are still important questions to be explored surrounding this behavior. One such question relates to definitions of stalking, including the requirement that victims must express fear to qualify as victims of stalking. The current study addresses this issue by exploring the…

  9. Structure and mutagenesis of the parainfluenza virus 5 hemagglutinin-neuraminidase stalk domain reveals a four-helix bundle and the role of the stalk in fusion promotion.

    Science.gov (United States)

    Bose, Sayantan; Welch, Brett D; Kors, Christopher A; Yuan, Ping; Jardetzky, Theodore S; Lamb, Robert A

    2011-12-01

    Paramyxovirus entry into cells requires the fusion protein (F) and a receptor binding protein (hemagglutinin-neuraminidase [HN], H, or G). The multifunctional HN protein of some paramyxoviruses, besides functioning as the receptor (sialic acid) binding protein (hemagglutinin activity) and the receptor-destroying protein (neuraminidase activity), enhances F activity, presumably by lowering the activation energy required for F to mediate fusion of viral and cellular membranes. Before or upon receptor binding by the HN globular head, F is believed to interact with the HN stalk. Unfortunately, until recently none of the receptor binding protein crystal structures have shown electron density for the stalk domain. Parainfluenza virus 5 (PIV5) HN exists as a noncovalent dimer-of-dimers on the surface of cells, linked by a single disulfide bond in the stalk. Here we present the crystal structure of the PIV5-HN stalk domain at a resolution of 2.65 Å, revealing a four-helix bundle (4HB) with an upper (N-terminal) straight region and a lower (C-terminal) supercoiled part. The hydrophobic core residues are a mix of an 11-mer repeat and a 3- to 4-heptad repeat. To functionally characterize the role of the HN stalk in F interactions and fusion, we designed mutants along the PIV5-HN stalk that are N-glycosylated to physically disrupt F-HN interactions. By extensive study of receptor binding, neuraminidase activity, oligomerization, and fusion-promoting functions of the mutant proteins, we found a correlation between the position of the N-glycosylation mutants on the stalk structure and their neuraminidase activities as well as their abilities to promote fusion.

  10. Structure and Mutagenesis of the Parainfluenza Virus 5 Hemagglutinin-Neuraminidase Stalk Domain Reveals a Four-Helix Bundle and the Role of the Stalk in Fusion Promotion

    Energy Technology Data Exchange (ETDEWEB)

    Bose, Sayantan; Welch, Brett D.; Kors, Christopher A.; Yuan, Ping; Jardetzky, Theodore S.; Lamb, Robert A. (NWU); (Stanford-MED)

    2014-10-02

    Paramyxovirus entry into cells requires the fusion protein (F) and a receptor binding protein (hemagglutinin-neuraminidase [HN], H, or G). The multifunctional HN protein of some paramyxoviruses, besides functioning as the receptor (sialic acid) binding protein (hemagglutinin activity) and the receptor-destroying protein (neuraminidase activity), enhances F activity, presumably by lowering the activation energy required for F to mediate fusion of viral and cellular membranes. Before or upon receptor binding by the HN globular head, F is believed to interact with the HN stalk. Unfortunately, until recently none of the receptor binding protein crystal structures have shown electron density for the stalk domain. Parainfluenza virus 5 (PIV5) HN exists as a noncovalent dimer-of-dimers on the surface of cells, linked by a single disulfide bond in the stalk. Here we present the crystal structure of the PIV5-HN stalk domain at a resolution of 2.65 {angstrom}, revealing a four-helix bundle (4HB) with an upper (N-terminal) straight region and a lower (C-terminal) supercoiled part. The hydrophobic core residues are a mix of an 11-mer repeat and a 3- to 4-heptad repeat. To functionally characterize the role of the HN stalk in F interactions and fusion, we designed mutants along the PIV5-HN stalk that are N-glycosylated to physically disrupt F-HN interactions. By extensive study of receptor binding, neuraminidase activity, oligomerization, and fusion-promoting functions of the mutant proteins, we found a correlation between the position of the N-glycosylation mutants on the stalk structure and their neuraminidase activities as well as their abilities to promote fusion.

  11. CCDC39 is required for assembly of inner dynein arms and the dynein regulatory complex and for normal ciliary motility in humans and dogs

    DEFF Research Database (Denmark)

    Merveille, Anne-Christine; Davis, Erica E; Becker-Heck, Anita

    2011-01-01

    cilia that are responsible for airway clearance, the flagella that propel sperm cells and the nodal monocilia that determine left-right asymmetry. Recessive mutations that cause PCD have been identified in genes encoding components of the outer dynein arms, radial spokes and cytoplasmic pre...... with axonemal disorganization and abnormal ciliary beating. Functional analyses indicated that CCDC39 localizes to ciliary axonemes and is essential for assembly of inner dynein arms and the dynein regulatory complex....

  12. Building complexity: an in vitro study of cytoplasmic dynein with in vivo implications.

    Science.gov (United States)

    Mallik, Roop; Petrov, Dmitri; Lex, S A; King, S J; Gross, S P

    2005-12-06

    Cytoplasmic dynein is the molecular motor responsible for most retrograde microtubule-based vesicular transport. In vitro single-molecule experiments suggest that dynein function is not as robust as that of kinesin-1 or myosin-V because dynein moves only a limited distance (approximately 800 nm) before detaching and can exert a modest (approximately 1 pN) force. However, dynein-driven cargos in vivo move robustly over many microns and exert forces of multiple pN. To determine how to go from limited single-molecule function to robust in vivo transport, we began to build complexity in a controlled manner by using in vitro experiments. We show that a single cytoplasmic dynein motor frequently transitions into an off-pathway unproductive state that impairs net transport. Addition of a second (and/or third) dynein motor, so that cargos are moved by two (or three) motors rather than one, is sufficient to recover several properties of in vivo motion; such properties include long cargo travels, robust motion, and increased forces. Part of this improvement appears to arise from selective suppression of the unproductive state of dynein rather than from a fundamental change in dynein's mechanochemical cycle. Multiple dyneins working together suppress shortcomings of a single motor and generate robust motion under in vitro conditions. There appears to be no need for additional cofactors (e.g., dynactin) for this improvement. Because cargos are often driven by multiple dyneins in vivo, our results show that changing the number of dynein motors could allow modulation of dynein function from the mediocre single-dynein limit to robust in vivo-like dynein-driven motion.

  13. Functional Architecture of the Outer Arm Dynein Conformational Switch*

    Science.gov (United States)

    King, Stephen M.; Patel-King, Ramila S.

    2012-01-01

    Dynein light chain 1 (LC1/DNAL1) is one of the most highly conserved components of ciliary axonemal outer arm dyneins, and it associates with both a heavy chain motor unit and tubulin located within the A-tubule of the axonemal outer doublet microtubules. In a variety of model systems, lack of LC1 or expression of mutant forms leads to profound defects in ciliary motility, including the failure of the hydrodynamic coupling needed for ciliary metachronal synchrony, random stalling during the power/recovery stroke transition, an aberrant response to imposed viscous load, and in some cases partial failure of motor assembly. These phenotypes have led to the proposal that LC1 acts as part of a mechanical switch to control motor function in response to alterations in axonemal curvature. Here we have used NMR chemical shift mapping to define the regions perturbed by a series of mutations in the C-terminal domain that yield a range of phenotypic effects on motility. In addition, we have identified the subdomain of LC1 involved in binding microtubules and characterized the consequences of an Asn → Ser alteration within the terminal leucine-rich repeat that in humans causes primary ciliary dyskinesia. Together, these data define a series of functional subdomains within LC1 and allow us to propose a structural model for the organization of the dynein heavy chain-LC1-microtubule ternary complex that is required for the coordinated activity of dynein motors in cilia. PMID:22157010

  14. Comparative pulping of sunflower stalks

    Directory of Open Access Journals (Sweden)

    Valerii Barbash

    2016-03-01

    Full Text Available The procedure of holocellulose content determination in non-wood plant raw materials was developed. The strength properties of pulp obtained from sunflower stalks by neutral-sulphite, soda, alkaline sulphite-anthraquinone-ethanol and peracetic methods of delignification were studied. Methodology of comparison of plant materials delignification methods using new lignin-carbohydrate diagram was proposed. It was shown, that the alkaline sulphite-anthraquinone-ethanol method of pulping is characterized by the highest delignification degree and is the most efficient among the studied methods

  15. Corn stalk as a bioenergy resource

    Science.gov (United States)

    Haney, Paul E., Jr.

    Waste corn stalk has the potential to help reduce the nation's dependence upon foreign sources of petroleum by becoming a major bioenergy resource. There are many sources of biomass that could also be utilized for this endeavor. It is estimated that over 100 million tons of agricultural waste are produced in the United States alone. This represents a significant source of energy. Through gasification, this waste could be used to generate power, fuels, and/or products. This dissertation shows that the gasification of corn stalk can produce char, heat, synthesis gases (CO and H2), and can also be used for work to dry moist biomass. Through the integration of drying, gasification, and carbon production, waste corn stalk can be used as a significant bioenergy resource. Novel concepts included in this dissertation include: (1) using corn stalk as a gasification fuel, (2) using corn stalk to generate activated carbon, (3) using activated carbon from corn stalk to adsorb organic pollutants, (4) using the gasification of corn stalk in a new process to dry moist biomass, (5) using the "partial" gasification of moist corn stalk in another new process to dry moist biomass in a single step. Each concept could be integrated with existing gasification technology to increase the efficient utilization of energy from biomass.

  16. Differential Light Chain Assembly Influences Outer Arm Dynein Motor Function

    Science.gov (United States)

    DiBella, Linda M.; Gorbatyuk, Oksana; Sakato, Miho; Wakabayashi, Ken-ichi; Patel-King, Ramila S.; Pazour, Gregory J.; Witman, George B.; King, Stephen M.

    2005-01-01

    Tctex1 and Tctex2 were originally described as potential distorters/sterility factors in the non-Mendelian transmission of t-haplotypes in mice. These proteins have since been identified as subunits of cytoplasmic and/or axonemal dyneins. Within the Chlamydomonas flagellum, Tctex1 is a subunit of inner arm I1. We have now identified a second Tctex1-related protein (here termed LC9) in Chlamydomonas. LC9 copurifies with outer arm dynein in sucrose density gradients and is missing only in those strains completely lacking this motor. Zero-length cross-linking of purified outer arm dynein indicates that LC9 interacts directly with both the IC1 and IC2 intermediate chains. Immunoblot analysis revealed that LC2, LC6, and LC9 are missing in an IC2 mutant strain (oda6-r88) that can assemble outer arms but exhibits significantly reduced flagellar beat frequency. This defect is unlikely to be due to lack of LC6, because an LC6 null mutant (oda13) exhibits only a minor swimming abnormality. Using an LC2 null mutant (oda12-1), we find that although some outer arm dynein components assemble in the absence of LC2, they are nonfunctional. In contrast, dyneins from oda6-r88, which also lack LC2, retain some activity. Furthermore, we observed a synthetic assembly defect in an oda6-r88 oda12-1 double mutant. These data suggest that LC2, LC6, and LC9 have different roles in outer arm assembly and are required for wild-type motor function in the Chlamydomonas flagellum. PMID:16195342

  17. Cell cycle-dependent microtubule-based dynamic transport of cytoplasmic dynein in mammalian cells.

    Directory of Open Access Journals (Sweden)

    Takuya Kobayashi

    Full Text Available BACKGROUND: Cytoplasmic dynein complex is a large multi-subunit microtubule (MT-associated molecular motor involved in various cellular functions including organelle positioning, vesicle transport and cell division. However, regulatory mechanism of the cell-cycle dependent distribution of dynein has not fully been understood. METHODOLOGY/PRINCIPAL FINDINGS: Here we report live-cell imaging of cytoplasmic dynein in HeLa cells, by expressing multifunctional green fluorescent protein (mfGFP-tagged 74-kDa intermediate chain (IC74. IC74-mfGFP was successfully incorporated into functional dynein complex. In interphase, dynein moved bi-directionally along with MTs, which might carry cargos such as transport vesicles. A substantial fraction of dynein moved toward cell periphery together with EB1, a member of MT plus end-tracking proteins (+TIPs, suggesting +TIPs-mediated transport of dynein. In late-interphase and prophase, dynein was localized at the centrosomes and the radial MT array. In prometaphase and metaphase, dynein was localized at spindle MTs where it frequently moved from spindle poles toward chromosomes or cell cortex. +TIPs may be involved in the transport of spindle dyneins. Possible kinetochore and cortical dyneins were also observed. CONCLUSIONS AND SIGNIFICANCE: These findings suggest that cytoplasmic dynein is transported to the site of action in preparation for the following cellular events, primarily by the MT-based transport. The MT-based transport may have greater advantage than simple diffusion of soluble dynein in rapid and efficient transport of the limited concentration of the protein.

  18. Stalking

    Science.gov (United States)

    ... Address Confidentiality Programs Resources For Law Enforcement For Prosecutors For Victim Service Providers Helpful Links Publications For ... News Releases Newsroom National Center in the News Speeches and Testimony Crime and Victimization in the News ...

  19. Bioethanol production from dried sweet sorghum stalk

    Energy Technology Data Exchange (ETDEWEB)

    Almodares, A.; Etemadifar, Z.; Ghoreishi, F.; Yosefi, F. [Biology Dept. Univ. of Isfahan, Isfahan (Iran, Islamic Republic of)], e-mail: aalmodares@yahoo.com

    2012-11-01

    Bioethanol as a renewable transportation fuel has a great potential for energy and clean environment. Among crops sweet sorghum is one of the best feedstock for ethanol production under hot and dry climatic conditions. Because it has higher tolerance to salt and drought comparing to sugarcane and corn that are currently used for bio-fuel production in the world. Generally mills are used to extract the juice from sweet sorghum stalks. Three roller mills extract around nearly 50 percent of the juice and more mills is needed to extract higher percentage of the juice. More over under cold weather the stalks become dry and juice is not extracted from the stalk, therefore reduce harvesting period. In this study stalks were harvested, leaves were stripped from the stalks and the stalks were chopped to nearly 4 mm length and sun dried. The dry stalks were grounded to 60 mesh powder by a mill. Fermentation medium consists of 15-35% (w/w) sweet sorghum powder, micronutrients and active yeast inoculum from 0.5-1% (w/w) by submerge fermentation method. The fermentation time and temperature were 48-72 hours and 30 deg, respectively. The results showed the highest amount of ethanol (14.5 % w/w sorghum) was produced with 10% sweet sorghum powder and 1% of yeast inoculum, three day fermentation at 30 deg.

  20. Interplay between kinesin-1 and cortical dynein during axonal outgrowth and microtubule organization in Drosophila neurons.

    Science.gov (United States)

    del Castillo, Urko; Winding, Michael; Lu, Wen; Gelfand, Vladimir I

    2015-12-28

    In this study, we investigated how microtubule motors organize microtubules in Drosophila neurons. We showed that, during the initial stages of axon outgrowth, microtubules display mixed polarity and minus-end-out microtubules push the tip of the axon, consistent with kinesin-1 driving outgrowth by sliding antiparallel microtubules. At later stages, the microtubule orientation in the axon switches from mixed to uniform polarity with plus-end-out. Dynein knockdown prevents this rearrangement and results in microtubules of mixed orientation in axons and accumulation of microtubule minus-ends at axon tips. Microtubule reorganization requires recruitment of dynein to the actin cortex, as actin depolymerization phenocopies dynein depletion, and direct recruitment of dynein to the membrane bypasses the actin requirement. Our results show that cortical dynein slides 'minus-end-out' microtubules from the axon, generating uniform microtubule arrays. We speculate that differences in microtubule orientation between axons and dendrites could be dictated by differential activity of cortical dynein.

  1. Research on mechanical properties of corn stalk

    Science.gov (United States)

    Zhang, Kaifei; He, Yujing; Zhang, Hongmei; Li, He

    2017-03-01

    Many domestic scholars have studied on straw utilization from lodging resistance, by breeding agricultural experts to optimization parameters, which selected by agricultural mechanical experts and efficient utilization after the harvest crush. Therefore, the study of the mechanical properties of corn stalks has great prospects. It can provide the basis for the design of agricultural machinery and comprehensive utilization of straw that study the relationship between the properties of the corn stalk and the mechanical properties. In this paper, the radial compression and bending mechanical properties of corn stalk was conducted by universal material testing machine, which contributes to the increase of corn crop and provides basis for the development of equipment.

  2. ALKALINE PULP OF CORN STALKS

    Institute of Scientific and Technical Information of China (English)

    M.SarwarJalaan; M.AN.Russell; S.A.N.Shamim; A.I.Mostafa; Md.AbdulQuaiyyum

    2004-01-01

    Pulping of corn stalks was studied in soda,soda-anthraquinone (AQ), kraft and kraft-AQprocesses. The time, temperature and alkaliconcentration were varied in soda process. In respectto kappa number and pulp yield, 1 hour cooking at1400C in 14% alkali were best conditions for cornstalks pulping. Pulp yield was increased by 5.5% andkappa number was reduced by 4.4 points with anaddition of 0.05% AQ in the soda liquor. Breakinglength was better in soda-AQ process than sodaprocess but tear strength was inferior. In the kraftprocess, pulp yield was increased with increasingsulphidity and decreasing active alkali. Theeffectiveness of AQ in the low and high sulphiditykraft process was studied. Results showed that AQwas more effective in low sulphidity than highsulphidity. Strength properties in kraft processeswere better than the soda and soda-AQ processes.

  3. Body Stalk Syndrome: A Curiosity

    Directory of Open Access Journals (Sweden)

    Anita Javalgi

    2014-07-01

    Full Text Available Limb body wall complex (LBWC /Body stalk syndrome anomaly refers to a rare complicated polymalformative fetal malformation syndrome of uncertain etiology firstly described by Van Allen et al in 1987. There are very few cases reported in literature and thus we report a rare case of LBWC. Twenty seven years female presented to labour room with 32 weeks of gestation with no prenatal care and delivered a low birth weight still born fetus weighing 1100gms. On fetal autopsy large abdominal wall defect was noted with difficulty in identifying abdomino-pelvic organs and ambiguous genitalia. Placenta weighed 250gms with attached short umbilical cord measuring 7cms, arising from periphery. A cyst noted attached to placental membrane measuring 9x5cms which on dissection retrieved partially maldeveloped organs. Post mortem radiological findings included Absence of right femur with short tibia and right fibula, Complex vestibral malformation, Craniosynostosis and Overcrowding of ribs.

  4. Dynein modifiers in C. elegans: light chains suppress conditional heavy chain mutants.

    Directory of Open Access Journals (Sweden)

    Sean M O'Rourke

    2007-08-01

    Full Text Available Cytoplasmic dynein is a microtubule-dependent motor protein that functions in mitotic cells during centrosome separation, metaphase chromosome congression, anaphase spindle elongation, and chromosome segregation. Dynein is also utilized during interphase for vesicle transport and organelle positioning. While numerous cellular processes require cytoplasmic dynein, the mechanisms that target and regulate this microtubule motor remain largely unknown. By screening a conditional Caenorhabditis elegans cytoplasmic dynein heavy chain mutant at a semipermissive temperature with a genome-wide RNA interference library to reduce gene functions, we have isolated and characterized twenty dynein-specific suppressor genes. When reduced in function, these genes suppress dynein mutants but not other conditionally mutant loci, and twelve of the 20 specific suppressors do not exhibit sterile or lethal phenotypes when their function is reduced in wild-type worms. Many of the suppressor proteins, including two dynein light chains, localize to subcellular sites that overlap with those reported by others for the dynein heavy chain. Furthermore, knocking down any one of four putative dynein accessory chains suppresses the conditional heavy chain mutants, suggesting that some accessory chains negatively regulate heavy chain function. We also identified 29 additional genes that, when reduced in function, suppress conditional mutations not only in dynein but also in loci required for unrelated essential processes. In conclusion, we have identified twenty genes that in many cases are not essential themselves but are conserved and when reduced in function can suppress conditionally lethal C. elegans cytoplasmic dynein heavy chain mutants. We conclude that conserved but nonessential genes contribute to dynein function during the essential process of mitosis.

  5. BICD2, dynactin, and LIS1 cooperate in regulating dynein recruitment to cellular structures

    Science.gov (United States)

    Splinter, Daniël; Razafsky, David S.; Schlager, Max A.; Serra-Marques, Andrea; Grigoriev, Ilya; Demmers, Jeroen; Keijzer, Nanda; Jiang, Kai; Poser, Ina; Hyman, Anthony A.; Hoogenraad, Casper C.; King, Stephen J.; Akhmanova, Anna

    2012-01-01

    Cytoplasmic dynein is the major microtubule minus-end–directed cellular motor. Most dynein activities require dynactin, but the mechanisms regulating cargo-dependent dynein–dynactin interaction are poorly understood. In this study, we focus on dynein–dynactin recruitment to cargo by the conserved motor adaptor Bicaudal D2 (BICD2). We show that dynein and dynactin depend on each other for BICD2-mediated targeting to cargo and that BICD2 N-terminus (BICD2-N) strongly promotes stable interaction between dynein and dynactin both in vitro and in vivo. Direct visualization of dynein in live cells indicates that by itself the triple BICD2-N–dynein–dynactin complex is unable to interact with either cargo or microtubules. However, tethering of BICD2-N to different membranes promotes their microtubule minus-end–directed motility. We further show that LIS1 is required for dynein-mediated transport induced by membrane tethering of BICD2-N and that LIS1 contributes to dynein accumulation at microtubule plus ends and BICD2-positive cellular structures. Our results demonstrate that dynein recruitment to cargo requires concerted action of multiple dynein cofactors. PMID:22956769

  6. Diverse Roles of Axonemal Dyneins in Drosophila Auditory Neuron Function and Mechanical Amplification in Hearing.

    Science.gov (United States)

    Karak, Somdatta; Jacobs, Julie S; Kittelmann, Maike; Spalthoff, Christian; Katana, Radoslaw; Sivan-Loukianova, Elena; Schon, Michael A; Kernan, Maurice J; Eberl, Daniel F; Göpfert, Martin C

    2015-11-26

    Much like vertebrate hair cells, the chordotonal sensory neurons that mediate hearing in Drosophila are motile and amplify the mechanical input of the ear. Because the neurons bear mechanosensory primary cilia whose microtubule axonemes display dynein arms, we hypothesized that their motility is powered by dyneins. Here, we describe two axonemal dynein proteins that are required for Drosophila auditory neuron function, localize to their primary cilia, and differently contribute to mechanical amplification in hearing. Promoter fusions revealed that the two axonemal dynein genes Dmdnah3 (=CG17150) and Dmdnai2 (=CG6053) are expressed in chordotonal neurons, including the auditory ones in the fly's ear. Null alleles of both dyneins equally abolished electrical auditory neuron responses, yet whereas mutations in Dmdnah3 facilitated mechanical amplification, amplification was abolished by mutations in Dmdnai2. Epistasis analysis revealed that Dmdnah3 acts downstream of Nan-Iav channels in controlling the amplificatory gain. Dmdnai2, in addition to being required for amplification, was essential for outer dynein arms in auditory neuron cilia. This establishes diverse roles of axonemal dyneins in Drosophila auditory neuron function and links auditory neuron motility to primary cilia and axonemal dyneins. Mutant defects in sperm competition suggest that both dyneins also function in sperm motility.

  7. Pretreatment of Corn Stalk by Steam Explosion

    Institute of Scientific and Technical Information of China (English)

    邵自强; 田永生; 谭惠民

    2003-01-01

    A steam explosion pretreatment, which is one of the best ways of pretreating plant stalk, is applied at various severities to corn stalk. It could effectively modify the super-molecular structure of corn stalk and defibrating corn stalk into individual components. The relationship between yield of reducing sugar and the operating conditions, including temperature, pressure of steam explosion pretreatment and acidity, is also established. Experimental results prove that the steam explosion substantially increases the yield of reducing sugar, and the optimal condition for steam explosion is as follows: the pressure is 2.0 MPa, the pressure-retaining time 300 s, the initial acid concentration 1% and the acid treatment time 24 h.

  8. Depression Can Stalk Families Through Generations

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_160354.html Depression Can Stalk Families Through Generations People whose parents, ... News) -- People whose parents and grandparents suffered from depression are at much higher risk of developing the ...

  9. Chlamydomonas axonemal dynein assembly locus ODA8 encodes a conserved flagellar protein needed for cytoplasmic maturation of outer dynein arm complexes.

    Science.gov (United States)

    Desai, Paurav B; Freshour, Judy R; Mitchell, David R

    2015-01-01

    The Chlamydomonas reinhardtii oda8 mutation blocks assembly of flagellar outer dynein arms (ODAs), and interacts genetically with ODA5 and ODA10, which encode axonemal proteins thought to aid dynein binding onto axonemal docking sites. We positionally cloned ODA8 and identified the gene product as the algal homolog of vertebrate LRRC56. Its flagellar localization depends on ODA5 and ODA10, consistent with genetic interaction studies, but phylogenomics suggests that LRRC56 homologs play a role in intraflagellar transport (IFT)-dependent assembly of outer row dynein arms, not axonemal docking. ODA8 distribution between cytoplasm and flagella is similar to that of IFT proteins and about half of flagellar ODA8 is in the soluble matrix fraction. Dynein extracted in vitro from wild type axonemes will rebind efficiently to oda8 mutant axonemes, without re-binding of ODA8, further supporting a role in dynein assembly or transport, not axonemal binding. Assays comparing preassembled ODA complexes from the cytoplasm of wild type and mutant strains show that dynein in oda8 mutant cytoplasm has not properly preassembled and cannot bind normally onto oda axonemes. We conclude that ODA8 plays an important role in formation and transport of mature dynein complexes during flagellar assembly.

  10. Adolescent stalking and risk of violence.

    Science.gov (United States)

    Smith-Darden, Joanne P; Reidy, Dennis E; Kernsmith, Poco D

    2016-10-01

    Stalking perpetration and the associated risk for violence among adolescents has generally been neglected. In the present study, 1236 youth completed surveys assessing empirically established stalking indicators, threats and aggression toward stalking victims, dating violence, and violent delinquency. Latent Profile Analysis identified 3 latent classes of boys: non-perpetrators (NP), hyper-intimate pursuit (HIP), and comprehensive stalking perpetrators (CSP) and, and 2 classes for girls: NP and HIP. Boys in the CSP class were the most violent youth on nearly all indices with boys in the HIP class demonstrating an intermediate level of violence compared to NP boys. Girls in the HIP class were more violent than NP girls on all indices. These findings suggest stalking in adolescence merits attention by violence prevention experts. In particular, juvenile stalking may signify youth at risk for multiple forms of violence perpetrated against multiple types of victims, not just the object of their infatuation. Copyright © 2016 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

  11. [Nurses' experiences of stalking: a narrative review].

    Science.gov (United States)

    Comparcini, Dania; Simonetti, Valentina; Lupo, Roberto; Cicolini, Giancarlo

    2015-01-01

    This narrative review aimed to synthetize the results of the main studies analysing nurses' experience of stalking in different clinical settings. We searched the electronic databases MEDLINE (through PubMed), CINAHL (through EBSCOhost) and the search engine "Google Scholar". Searches were limited to articles published in English and Italian, and published between 1999 and 2013. Stalking refers to a behavioural pattern characterized by persistent unwanted communications and contacts imposed to another person, which, consequently suffer from distress, fear, and anxiety. Several studies explored the risk of stalking in healthcare system, especially in doctors and psychiatrists. Some authors analysed nurses' experience of stalking with particular attention to mental health professionals as a group category with an increased risk of stalking by patients. Results of some studies carried out in different clinical settings (medical and surgical areas, and other healthcare settings) also revealed, even if in a minority, the presence of this phenomenon, showing the presence of staking's behaviours by patients and healthcare colleagues too. However, more researches with large sample size are needed to better understand the phenomenon of stalking in nurses working in different clinical areas.

  12. Breeding Report of Purple Flowering Stalk, Flowering Chinese Cabbage and White Flowering Stalk from 1985 to 2014%“三薹”育种研究报告(1985-2014)

    Institute of Scientific and Technical Information of China (English)

    晏儒来; 王先琳; 杨静; 陈利丹; 周妍萍

    2014-01-01

    自1985-2014年育成一批红菜薹、菜心雄性不育系及其保持系,并用不育系配成一批红菜薹、白菜薹及菜心等杂交种,育成菜心、白菜薹、红菜薹新品种共9个,极大丰富了这3种薹用不结球白菜的品种,现将其育种研究过程总结发表,希望对育种工作者有参考价值。%We have bred some male sterile lines and maintainer lines of purple flowering stalk and flowering Chinese cabbage from 1985 to 2014, and obtained some hybrids of purple flowering stalk, white flowering stalk and flowering Chinese cabbage by mating with the sterile lines, meanwhile, we bred nine new cultivars of flowering Chinese cabbage, white flowering stalk and purple flowering stalk, which has greatly enriched cultivars of non-heading Chinese cabbage for stalk. Here, we summarize research process of their breeding, in order to provide reference value for breeders.

  13. Innovative Prototype for Separate Harvesting of Cynara Cardunculus Achenes and Stalks

    Energy Technology Data Exchange (ETDEWEB)

    Pari, L.; Fedrizzi, M.; Pansini, L. (Consiglio per la Ricerca e la Sperimentazione in Agricoltura, Unita di Ricerca per l' Ingegneria Agraria, Monterotondo, RM (Italy))

    2008-10-15

    The CRA-ING took part to the Cynara cardunculus harvesting tests organized in Spain in 2007, where UPM has experimental cultivations in the Instituto Madrileno de Investigacion y Desarrollo Rural, Agrario y Alimentario (IMIDRA) de la Consejeria de Economia y Innovacion Tecnologica de la Comunidad de Madrid in El Encin, near Alcala De Henarez. The harvesting tests were carried out in week 33 (August 13th-17th); the cultivation was found part in good condition of maturity, part still not ready for harvesting. The test was carried out on the dried part of the crops. The tests aimed at evaluating a new mechanical equipment (head) working connected to a selfpropelled combine for separated harvesting of the different fractions obtainable by the cultivation assigned to different transformation: oil extraction from seeds and energy production from epigeous biomass combustion. During the tests carried out in 2006 in Portugal and Spain, it was observed how a combine harvester with a maize head was able to separate the seed with good accuracy. Likewise the difficulty of collecting the lignocellulosic fraction after its passage was highlighted. A combine with a wheat head could cut the stalk in an appropriate height range, but could not separate the head from the stalk. A sunflower head cut the capitula, but not the stalk. The project concept, supplied to a Firm that already builds heads for maize, wheat, sunflowers, soybean and so on, included the upper devices of a maize head and a classic wheat head (without the paddle wheel) in the lower part, to obtain capitula detachment and effective threshing and, at the same time, the stalk cut. Some modifications were specified to allow the cut of the stalk next to the ground and its successive tier in the space between the front wheels, where the discharge system of the threshing device would then provide to drop the remains of the capitula threshing. The basic concept of the machine, to separate and thresh the capitula and to drop

  14. Does the stalk contractility of Vorticella convallaria depend on the stalk length?

    Science.gov (United States)

    Chung, Eun-Gul; Ryu, Sangjin

    2015-11-01

    Vorticella convallaria is a sessile stalked ciliate living in water, and its stalk coils to move the cell body (zooid) towards its residence substrate at a maximum speed of ~ 50 mm/s. Our previous microfluidics study shows that the isometric tension of the V. convallaria stalk is linearly proportional to the stalk length. Based on this observation, we hypothesize that the contractility of V. convallaria during normal contraction is also dependent on the stalk length. To investigate our hypothesis, we measured the contraction speed of V. convallaria using high-speed videography and evaluated the contractile force and energetics of V. convallaria using fluid dynamics modeling. We appreciate support from UNL Layman Seed Grant and Nebraska EPSCoR First Award Grant.

  15. Time-Dependent Measure of a Nano-Scale Force-Pulse Driven by the Axonemal Dynein Motors in Individual Live Sperm Cells

    Energy Technology Data Exchange (ETDEWEB)

    Allen, M J; Rudd, R E; McElfresh, M W; Balhorn, R

    2009-04-23

    Nano-scale mechanical forces generated by motor proteins are crucial to normal cellular and organismal functioning. The ability to measure and exploit such forces would be important to developing motile biomimetic nanodevices powered by biological motors for Nanomedicine. Axonemal dynein motors positioned inside the sperm flagellum drive microtubule sliding giving rise to rhythmic beating of the flagellum. This force-generating action makes it possible for the sperm cell to move through viscous media. Here we report new nano-scale information on how the propulsive force is generated by the sperm flagellum and how this force varies over time. Single cell recordings reveal discrete {approx}50 ms pulses oscillating with amplitude 9.8 {+-} 2.6 nN independent of pulse frequency (3.5-19.5 Hz). The average work carried out by each cell is 4.6 x 10{sup -16} J per pulse, equivalent to the hydrolysis of {approx}5,500 ATP molecules. The mechanochemical coupling at each active dynein head is {approx}2.2 pN/ATP, and {approx}3.9 pN per dynein arm, in agreement with previously published values obtained using different methods.

  16. CCDC151 Mutations Cause Primary Ciliary Dyskinesia by Disruption of the Outer Dynein Arm Docking Complex Formation

    NARCIS (Netherlands)

    Hjeij, R.; Onoufriadis, A.; Watson, C.M.; Slagle, C.E.; Klena, N.T.; Dougherty, G.W.; Kurkowiak, M.; Loges, N.T.; Diggle, C.P.; Morante, N.F.; Gabriel, G.C.; Lemke, K.L.; Li, Y.; Pennekamp, P.; Menchen, T.; Konert, F.; Marthin, J.K.; Mans, D.A.; Letteboer, S.J.F.; Werner, C.; Burgoyne, T.; Westermann, C.; Rutman, A.; Carr, I.M.; O'Callaghan, C.; Moya, E.; Chung, E.M.; Consortium, U.K.; Sheridan, E.; Nielsen, K.G.; Roepman, R.; Bartscherer, K.; Burdine, R.D.; Lo, C.W.; Omran, H.; Mitchison, H.M.

    2014-01-01

    A diverse family of cytoskeletal dynein motors powers various cellular transport systems, including axonemal dyneins generating the force for ciliary and flagellar beating essential to movement of extracellular fluids and of cells through fluid. Multisubunit outer dynein arm (ODA) motor complexes, p

  17. Emergence of flagellar beating from the collective behavior of individual ATP-powered dyneins

    Science.gov (United States)

    Namdeo, S.; Onck, P. R.

    2016-10-01

    Flagella are hair-like projections from the surface of eukaryotic cells, and they play an important role in many cellular functions, such as cell-motility. The beating of flagella is enabled by their internal architecture, the axoneme, and is powered by a dense distribution of motor proteins, dyneins. The dyneins deliver the required mechanical work through the hydrolysis of ATP. Although the dynein-ATP cycle, the axoneme microstructure, and the flagellar-beating kinematics are well studied, their integration into a coherent picture of ATP-powered flagellar beating is still lacking. Here we show that a time-delayed negative-work-based switching mechanism is able to convert the individual sliding action of hundreds of dyneins into a regular overall beating pattern leading to propulsion. We developed a computational model based on a minimal representation of the axoneme consisting of two representative doublet microtubules connected by nexin links. The relative sliding of the microtubules is incorporated by modeling two groups of ATP-powered dyneins, each responsible for sliding in opposite directions. A time-delayed switching mechanism is postulated, which is key in converting the local individual sliding action of multiple dyneins into global beating. Our results demonstrate that an overall nonreciprocal beating pattern can emerge with time due to the spatial and temporal coordination of the individual dyneins. These findings provide insights in the fundamental working mechanism of axonemal dyneins and could possibly open new research directions in the field of flagellar motility.

  18. Bi-directional transport of the nucleus by dynein and kinesin-1.

    Science.gov (United States)

    Tanenbaum, Marvin E; Akhmanova, Anna; Medema, René H

    2011-01-01

    Proper transport and positioning of cell organelles often depends on the antagonistic activities of dynein and kinesin-1, two microtubule motors with opposite directionality.1 One of the largest known transport cargoes is the cell nucleus. Both dynein and kinesin-1 participate in positioning of the nucleus through binding to the nuclear envelope (NE).2-9 Surprisingly, both dynein and kinesin-1 can be recruited to the NE through multiple pathways, one involving SUN-KASH domain containing proteins and the other involving nuclear pore complexes (NPCs). Here, we discuss the molecular mechanisms of dynein and kinesin recruitment to the NE through NPCs, as well as the functional implications of dynein and kinesin-1 activity at the NE in mammalian cells. Finally, we discuss how motor activities at the NE might be controlled during the cell cycle.

  19. Broadly Neutralizing Hemagglutinin Stalk-Specific Antibodies Induce Potent Phagocytosis of Immune Complexes by Neutrophils in an Fc-Dependent Manner.

    Science.gov (United States)

    Mullarkey, Caitlin E; Bailey, Mark J; Golubeva, Diana A; Tan, Gene S; Nachbagauer, Raffael; He, Wenqian; Novakowski, Kyle E; Bowdish, Dawn M; Miller, Matthew S; Palese, Peter

    2016-10-04

    Broadly neutralizing antibodies that recognize the conserved hemagglutinin (HA) stalk have emerged as exciting new biotherapeutic tools to combat seasonal and pandemic influenza viruses. Our general understanding of the mechanisms by which stalk-specific antibodies achieve protection is rapidly evolving. It has recently been demonstrated that broadly neutralizing HA stalk-specific IgG antibodies require Fc-Fcγ receptor (FcγR) interactions for optimal protection in vivo Here we examine the neutrophil effector functions induced by stalk-specific antibodies. As the most abundant subset of blood leukocytes, neutrophils represent a critical innate effector cell population and serve an instrumental role in orchestrating downstream adaptive responses to influenza virus infection. Yet, the interplay of HA stalk-specific IgG, Fc-FcγR engagement, and neutrophils has remained largely uncharacterized. Using an in vitro assay to detect the production of reactive oxygen species (ROS), we show that human and mouse monoclonal HA stalk-specific IgG antibodies are able to induce the production of ROS by neutrophils, while HA head-specific antibodies do not. Furthermore, our results indicate that the production of ROS is dependent on Fc receptor (FcR) engagement and phagocytosis. We went on to assess the ability of monoclonal HA stalk-specific IgA antibodies to induce ROS. Consistent with our findings for monoclonal IgGs, only HA stalk-specific IgA antibodies elicited ROS production by neutrophils. This induction is dependent on the engagement of FcαR1. Taken together, our findings describe a novel FcR-dependent effector function induced by HA stalk-specific IgG and IgA antibodies, and importantly, our studies shed light on the mechanisms by which HA stalk-specific antibodies achieve protection.

  20. Broadly Neutralizing Hemagglutinin Stalk-Specific Antibodies Induce Potent Phagocytosis of Immune Complexes by Neutrophils in an Fc-Dependent Manner

    Directory of Open Access Journals (Sweden)

    Caitlin E. Mullarkey

    2016-10-01

    Full Text Available Broadly neutralizing antibodies that recognize the conserved hemagglutinin (HA stalk have emerged as exciting new biotherapeutic tools to combat seasonal and pandemic influenza viruses. Our general understanding of the mechanisms by which stalk-specific antibodies achieve protection is rapidly evolving. It has recently been demonstrated that broadly neutralizing HA stalk-specific IgG antibodies require Fc-Fcγ receptor (FcγR interactions for optimal protection in vivo. Here we examine the neutrophil effector functions induced by stalk-specific antibodies. As the most abundant subset of blood leukocytes, neutrophils represent a critical innate effector cell population and serve an instrumental role in orchestrating downstream adaptive responses to influenza virus infection. Yet, the interplay of HA stalk-specific IgG, Fc-FcγR engagement, and neutrophils has remained largely uncharacterized. Using an in vitro assay to detect the production of reactive oxygen species (ROS, we show that human and mouse monoclonal HA stalk-specific IgG antibodies are able to induce the production of ROS by neutrophils, while HA head-specific antibodies do not. Furthermore, our results indicate that the production of ROS is dependent on Fc receptor (FcR engagement and phagocytosis. We went on to assess the ability of monoclonal HA stalk-specific IgA antibodies to induce ROS. Consistent with our findings for monoclonal IgGs, only HA stalk-specific IgA antibodies elicited ROS production by neutrophils. This induction is dependent on the engagement of FcαR1. Taken together, our findings describe a novel FcR-dependent effector function induced by HA stalk-specific IgG and IgA antibodies, and importantly, our studies shed light on the mechanisms by which HA stalk-specific antibodies achieve protection.

  1. N-Acetyl-D-Glucosamine Kinase Interacts with Dynein-Lis1-NudE1 Complex and Regulates Cell Division.

    Science.gov (United States)

    Sharif, Syeda Ridita; Islam, Ariful; Moon, Il Soo

    2016-09-01

    N-acetyl-D-glucosamine kinase (GlcNAc kinase or NAGK) primarily catalyzes phosphoryl transfer to GlcNAc during amino sugar metabolism. Recently, it was shown NAGK interacts with dynein light chain roadblock type 1 (DYNLRB1) and upregulates axo-dendritic growth, which is an enzyme activity-independent, non-canonical structural role. The authors examined the distributions of NAGK and NAGK-dynein complexes during the cell cycle in HEK293T cells. NAGK was expressed throughout different stages of cell division and immunocytochemistry (ICC) showed NAGK was localized at nuclear envelope, spindle microtubules (MTs), and kinetochores (KTs). A proximity ligation assay (PLA) for NAGK and DYNLRB1 revealed NAGK-dynein complex on nuclear envelopes in prophase cells and on chromosomes in metaphase cells. NAGK-DYNLRB1 PLA followed by Lis1/NudE1 immunostaining showed NAGK-dynein complexes were colocalized with Lis1 and NudE1 signals, and PLA for NAGK-Lis1 showed similar signal patterns, suggesting a functional link between NAGK and dynein-Lis1 complex. Subsequently, NAGK-dynein complexes were found in KTs and on nuclear membranes where KTs were marked with CENP-B ICC and nuclear membrane with lamin ICC. Furthermore, knockdown of NAGK by small hairpin (sh) RNA was found to delay cell division. These results indicate that the NAGK-dynein interaction with the involvements of Lis1 and NudE1 plays an important role in prophase nuclear envelope breakdown (NEB) and metaphase MT-KT attachment during eukaryotic cell division.

  2. Corn stalk orientation effect on mechanical cutting

    Energy Technology Data Exchange (ETDEWEB)

    Igathinathane, C. [Mississippi State University (MSU); Womac, A.R. [University of Tennessee; Sokhansanj, Shahabaddine [ORNL

    2010-07-01

    Research efforts that increase the efficiency of size reduction of biomass can lead to a significant energy saving. This paper deals with the determination of the effect of sample orientation with respect to cutting element and quantify the possible cutting energy reduction, utilising dry corn stalks as the test material (15%e20% wet basis). To evaluate the mechanical cutting characteristics of corn stalks, a Warnere Bratzler device was modified by replacing its blunt edged cutting element with one having a 30_ single bevel sharp knife edge. Cutting force-deformation characteristics obtained with a universal testing machine were analysed to evaluate the orientation effects at perpendicular (90o), inclined (45o), and parallel (0o) orientations on internodes and nodes for cutting force, energy, ultimate stress, and specific energy of corn stalks. The corn stalks cutting force-displacement characteristics were found to differ with orientation, and internode and node material difference. Overall, the peak failure force, and the total cutting energy of internodes and nodes varied significantly (P < 0.05) with stalk cross-sectional area. The specific energy values (total energy per unit cut area) of dry corn stalk internodes ranged from 11.3 to 23.5 kN m_1, and nodes from 8.6 to 14.0 kN m_1. The parallel orientation (along grain) compared to perpendicular (across grain) produced a significant reduction of the cutting stress and the specific energy to one tenth or better for internodes, and to about one-fifth for nodes.

  3. Cargo transport by cytoplasmic Dynein can center embryonic centrosomes.

    Directory of Open Access Journals (Sweden)

    Rafael A Longoria

    Full Text Available To complete meiosis II in animal cells, the male DNA material needs to meet the female DNA material contained in the female pronucleus at the egg center, but it is not known how the male pronucleus, deposited by the sperm at the periphery of the cell, finds the cell center in large eggs. Pronucleus centering is an active process that appears to involve microtubules and molecular motors. For small and medium-sized cells, the force required to move the centrosome can arise from either microtubule pushing on the cortex, or cortically-attached dynein pulling on microtubules. However, in large cells, such as the fertilized Xenopus laevis embryo, where microtubules are too long to support pushing forces or they do not reach all boundaries before centrosome centering begins, a different force generating mechanism must exist. Here, we present a centrosome positioning model in which the cytosolic drag experienced by cargoes hauled by cytoplasmic dynein on the sperm aster microtubules can move the centrosome towards the cell's center. We find that small, fast cargoes (diameter ∼100 nm, cargo velocity ∼2 µm/s are sufficient to move the centrosome in the geometry of the Xenopus laevis embryo within the experimentally observed length and time scales.

  4. Using Dandelion Flower Stalks for Gravitropic Studies.

    Science.gov (United States)

    Clifford, Paul E.; Oxlade, Edwin L.

    1991-01-01

    Activities that use dandelions to show the phenomena of geotropism and autotropism are described. Directions for collecting the stalks and observing the gravitropic response are included. The topics of lag time and bending rates, autotropism, growth rate changes, presentation time, and gravity detection are discussed. (KR)

  5. Gravitropism in cut flower stalks of snapdragon

    NARCIS (Netherlands)

    Philosoph-Hadas, S.; Friedman, H.; Meir, S.; Berkovitz-SimanTov, R.; Rosenberger, I.; Halevy, A.H.; Kaufman, P.B.; Balk, P.; Woltering, E.J.

    2002-01-01

    The negative gravitropic response of cut flower stalks is a complex multistep process that requires the participation of various cellular components acting in succession or in parallel. The process was particularly characterized in snapdragon (Antirrhinum majus L.) spikes with regard to (1) gravity

  6. Gravitropism in cut flower stalks of snapdragon

    NARCIS (Netherlands)

    Philosoph-Hadas, S.; Friedman, H.; Meir, S.; Berkovitz-SimanTov, R.; Rosenberger, I.; Halevy, A.H.; Kaufman, P.B.; Balk, P.; Woltering, E.J.

    2002-01-01

    The negative gravitropic response of cut flower stalks is a complex multistep process that requires the participation of various cellular components acting in succession or in parallel. The process was particularly characterized in snapdragon (Antirrhinum majus L.) spikes with regard to (1) gravity

  7. How does Vorticella utilize its stalk contraction-relaxation cycle?

    Science.gov (United States)

    Zhou, Jiazhong; Admiraal, David; Ryu, Sangjin

    2015-03-01

    Vorticella is a sessile ciliate living in water, and it coils its slender stalk to pull the cell body (zooid) towards the substrate at a maximum speed of ~ 1 cm/s. After stalk contraction is completed, the stalk slowly relaxes to its extended state. Although this ultrafast stalk contraction has been studied in terms of cell motility, it is poorly understood how Vorticella utilizes its stalk contraction. Here we propose a hypothesis that Vorticella can augment transport of particles near the substrate relying on water flow induced by the stalk contraction-relaxation cycle. We investigated our hypothesis using a computational fluid dynamics (CFD) model which models Vorticella as a solid sphere moving normal to a solid surface in water. Having simulated water flow caused by Vorticella, we calculated motions of particles near Vorticella, and then quantified the transport effect of Vorticella's stalk contraction using microfluidic mixing indices. Supported by Laymann Seed grant from UNL.

  8. Recurring RNA structural motifs underlie the mechanics of L1 stalk movement

    Science.gov (United States)

    Mohan, Srividya; Noller, Harry F.

    2017-02-01

    The L1 stalk of the large ribosomal subunit undergoes large-scale movements coupled to the translocation of deacylated tRNA during protein synthesis. We use quantitative comparative structural analysis to localize the origins of L1 stalk movement and to understand its dynamic interactions with tRNA and other structural elements of the ribosome. Besides its stacking interactions with the tRNA elbow, stalk movement is directly linked to intersubunit rotation, rotation of the 30S head domain and contact of the acceptor arm of deacylated tRNA with helix 68 of 23S rRNA. Movement originates from pivoting at stacked non-canonical base pairs in a Family A three-way junction and bending in an internal G-U-rich zone. Use of these same motifs as hinge points to enable such dynamic events as rotation of the 30S subunit head domain and in flexing of the anticodon arm of tRNA suggests that they represent general strategies for movement of functional RNAs.

  9. Dynein light intermediate chains maintain spindle bipolarity by functioning in centriole cohesion.

    Science.gov (United States)

    Jones, Laura A; Villemant, Cécile; Starborg, Toby; Salter, Anna; Goddard, Georgina; Ruane, Peter; Woodman, Philip G; Papalopulu, Nancy; Woolner, Sarah; Allan, Victoria J

    2014-11-24

    Cytoplasmic dynein 1 (dynein) is a minus end-directed microtubule motor protein with many cellular functions, including during cell division. The role of the light intermediate chains (LICs; DYNC1LI1 and 2) within the complex is poorly understood. In this paper, we have used small interfering RNAs or morpholino oligonucleotides to deplete the LICs in human cell lines and Xenopus laevis early embryos to dissect the LICs' role in cell division. We show that although dynein lacking LICs drives microtubule gliding at normal rates, the LICs are required for the formation and maintenance of a bipolar spindle. Multipolar spindles with poles that contain single centrioles were formed in cells lacking LICs, indicating that they are needed for maintaining centrosome integrity. The formation of multipolar spindles via centrosome splitting after LIC depletion could be rescued by inhibiting Eg5. This suggests a novel role for the dynein complex, counteracted by Eg5, in the maintenance of centriole cohesion during mitosis.

  10. Intraflagellar transport dynein is autoinhibited by trapping of its mechanical and track-binding elements

    OpenAIRE

    Toropova, K.; Mladenov, M; Roberts, Anthony

    2017-01-01

    Cilia are multi-functional organelles that are constructed using intraflagellar transport (IFT) of cargo to and from their tip. It is widely held that the retrograde IFT motor, dynein-2, must be controlled in order to reach the ciliary tip and then unleashed to power the return journey. However, the mechanism is unknown. Here, we systematically define the mechanochemistry of human dynein-2 motors as monomers, dimers, and multi-motor assemblies with kinesin-II. Combining these data with insigh...

  11. Dynein, Lis1 and CLIP-170 counteract Eg5-dependent centrosome separation during bipolar spindle assembly.

    Science.gov (United States)

    Tanenbaum, Marvin E; Macůrek, Libor; Galjart, Niels; Medema, René H

    2008-12-17

    Bipolar spindle assembly critically depends on the microtubule plus-end-directed motor Eg5 that binds antiparallel microtubules and slides them in opposite directions. As such, Eg5 can produce the necessary outward force within the spindle that drives centrosome separation and inhibition of this antiparallel sliding activity results in the formation of monopolar spindles. Here, we show that upon depletion of the minus-end-directed motor dynein, or the dynein-binding protein Lis1, bipolar spindles can form in human cells with substantially less Eg5 activity, suggesting that dynein and Lis1 produce an inward force that counteracts the Eg5-dependent outward force. Interestingly, we also observe restoration of spindle bipolarity upon depletion of the microtubule plus-end-tracking protein CLIP-170. This function of CLIP-170 in spindle bipolarity seems to be mediated through its interaction with dynein, as loss of CLIP-115, a highly homologous protein that lacks the dynein-dynactin interaction domain, does not restore spindle bipolarity. Taken together, these results suggest that complexes of dynein, Lis1 and CLIP-170 crosslink and slide microtubules within the spindle, thereby producing an inward force that pulls centrosomes together.

  12. Cytoplasmic dynein crosslinks and slides anti-parallel microtubules using its two motor domains.

    Science.gov (United States)

    Tanenbaum, Marvin E; Vale, Ronald D; McKenney, Richard J

    2013-09-03

    Cytoplasmic dynein is the predominant minus-end-directed microtubule (MT) motor in most eukaryotic cells. In addition to transporting vesicular cargos, dynein helps to organize MTs within MT networks such as mitotic spindles. How dynein performs such non-canonical functions is unknown. Here we demonstrate that dynein crosslinks and slides anti-parallel MTs in vitro. Surprisingly, a minimal dimeric motor lacking a tail domain and associated subunits can cause MT sliding. Single molecule imaging reveals that motors pause and frequently reverse direction when encountering an anti-parallel MT overlap, suggesting that the two motor domains can bind both MTs simultaneously. In the mitotic spindle, inward microtubule sliding by dynein counteracts outward sliding generated by kinesin-5, and we show that a tailless, dimeric motor is sufficient to drive this activity in mammalian cells. Our results identify an unexpected mechanism for dynein-driven microtubule sliding, which differs from filament sliding mechanisms described for other motor proteins. DOI:http://dx.doi.org/10.7554/eLife.00943.001.

  13. Dynein and dynactin leverage their bivalent character to form a high-affinity interaction.

    Directory of Open Access Journals (Sweden)

    Amanda E Siglin

    Full Text Available Cytoplasmic dynein and dynactin participate in retrograde transport of organelles, checkpoint signaling and cell division. The principal subunits that mediate this interaction are the dynein intermediate chain (IC and the dynactin p150(Glued; however, the interface and mechanism that regulates this interaction remains poorly defined. Herein, we use multiple methods to show the N-terminus of mammalian dynein IC, residues 10-44, is sufficient for binding p150(Glued. Consistent with this mapping, monoclonal antibodies that antagonize the dynein-dynactin interaction also bind to this region of the IC. Furthermore, double and triple alanine point mutations spanning residues 6 to 19 in the yeast IC homolog, Pac11, produce significant defects in spindle positioning. Using the same methods we show residues 381 to 530 of p150(Glued form a minimal fragment that binds to the dynein IC. Sedimentation equilibrium experiments indicate that these individual fragments are predominantly monomeric, but admixtures of the IC and p150(Glued fragments produce a 2:2 complex. This tetrameric complex is sensitive to salt, temperature and pH, suggesting that the binding is dominated by electrostatic interactions. Finally, circular dichroism (CD experiments indicate that the N-terminus of the IC is disordered and becomes ordered upon binding p150(Glued. Taken together, the data indicate that the dynein-dynactin interaction proceeds through a disorder-to-order transition, leveraging its bivalent-bivalent character to form a high affinity, but readily reversible interaction.

  14. Briquetting of Charcoal from Sesame Stalk

    Directory of Open Access Journals (Sweden)

    Alula Gebresas

    2015-01-01

    Full Text Available Due to the easy availability of wood in Ethiopia, wood charcoal has been the main source fuel for cooking. This study has been started on sesame stalk biomass briquetting which can potentially solve the health problems and shortage of energy, which consequently can solve deforestation. The result of the data collection shows that, using 30% conversion efficiency of carbonizer, it was found that more than 150,000 tonnes of charcoal can be produced from the available sesame stalk in Humera, a place in north Ethiopia. The clay binders that are mixed with carbonized sesame stalk were found to have 69 liquid limits; thus, the optimum amount of clay that should be added as a binder is 15%, which results in better burning and heat holding capacity and better heating time. The developed briquetting machine has a capacity of producing 60 Kg/hr but the carbonization kiln can only carbonize 3.1 Kg in 2 : 40 hours; hence, it is a bottle neck for the briquette production. The hydrocarbon laboratory analysis showed that the calorific value of the charcoal produced with 15% clay content is 4647.75 Cal/gm and decreases as clay ratio increases and is found to be sufficient energy content for cooking.

  15. Sunflower stalks as adsorbents for color removal from textile wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Sun, G.; Xu, X. [Univ. of California, Davis, CA (United States). Div. of Textiles and Clothing

    1997-03-01

    Sunflower stalks as adsorbents for two basic dyes (Methylene Blue and Basic Red 9) and two direct dyes (Congo Red and Direct Blue 71) in aqueous solutions were studied with equilibrium isotherms and kinetic adsorptions. The maximum adsorptions of two basic dyes on sunflower stalks are very high, i.e., 205 and 317 mg/g for Methylene Blue and Basic Red 9, respectively. The two direct dyes have relatively lower adsorption on sunflower stalks. The adsorptive behaviors of sunflower stalk components are different. The pith, which is the soft and porous material in the center of stalks, has twice the adsorptive capacity of the skin. Particle sizes of sunflower stalks also affect the adsorption of dyes. The adsorption rates of two basic dyestuffs are much higher than that of the direct dyes. Within 30 min about 80% basic dyes were removed from the solutions.

  16. Pretreatment of Agave americana stalk for enzymatic saccharification.

    Science.gov (United States)

    Yang, Qiang; Pan, Xuejun

    2012-12-01

    Agave americana is one of commonly grown agave species but currently less valuable because its large flower stalk cannot be used for producing alcoholic beverage. In the present study, the stalk was pretreated with dilute acid (DA), sulfite (SPORL), and sodium hydroxide (NaOH) to preliminarily assess its potential as feedstock for bioethanol production. The changes of cell wall components during the pretreatments, enzymatic digestibility of the pretreated stalks, and the adsorption of cellulases on the substrates were investigated. Results indicated that the pretreatments significantly improved the enzymatic digestibility of the agave stalk. SPORL pretreatment gave higher substrate and sugar yields, while NaOH pretreated stalk had better digestibility under the investigated conditions. The better hydrolysability of NaOH-pretreated stalk was attributed to low lignin and hemicellulose content and high affinity to cellulases.

  17. Adenovirus Recruits Dynein by an Evolutionary Novel Mechanism Involving Direct Binding to pH-Primed Hexon

    Directory of Open Access Journals (Sweden)

    Julian Scherer

    2011-08-01

    Full Text Available Following receptor-mediated uptake into endocytic vesicles and escape from the endosome, adenovirus is transported by cytoplasmic dynein along microtubules to the perinuclear region of the cell. How motor proteins are recruited to viruses for their own use has begun to be investigated only recently. We review here the evidence for a role for dynein and other motor proteins in adenovirus infectivity. We also discuss the implications of recent studies on the mechanism of dynein recruitment to adenovirus for understanding the relationship between pathogenic and physiological cargo recruitment and for the evolutionary origins of dynein-mediated adenovirus transport.

  18. Inhibition of Vorticella microstoma stalk formation by wheat germ agglutinin.

    Science.gov (United States)

    Bramucci, Michael G; Nagarajan, Vasantha

    2004-01-01

    Fluorescently labeled conjugates of wheat germ agglutinin and concanavalin A stained the contractile stalk but not the cell body of Vorticella microstoma trophonts. Binding of the fluorescent conjugants did not noticeably alter the activity of the trophonts. However, unconjugated wheat germ agglutinin prevented free swimming telotrochs from adhering to a glass surface and deploying a contractile stalk during differentiation into trophonts. These observations indicated that the stalk, the material that binds the stalk to surfaces, and the precursors for these components have saccharide residues in common.

  19. Plant population and weeds influence stalk insects, soil moisture, and yield in rainfed sunflowers

    Institute of Scientific and Technical Information of China (English)

    JAWWAD A. QURESHI; PHILLIP W. STAHLMAN; J. P. MICHAUD

    2007-01-01

    Insect infestation, soil moisture, and yield were examined in populations of≈ 33 140 plants/ha (low) and ≈ 40 340 plants/ha (high) of an oilseed sunflower, Helianthus annuus L, cv. ' Triumph 660CL' with two levels of weediness. Less weedy plots resulted from the application of herbicide combination of S-metolachlor and sulfentrazone, whereas more weedy plots resulted from application of sulfentrazone alone. Among the 12 weed species recorded, neither plant numbers nor biomass differed between crop plant densities.Larvae of the stalk-boring insects Cylindrocopturus adspersus (Coleoptera: Curculionidae) and Mordellistena sp. (Coleoptera: Mordellidae) were less abundant in high density sunflowers, ostensibly due to reduced plant size. However, the same effect was not observed for Dectes texanus (Coleoptera: Cerambycidae) or Pelochrista womanana (Lepidoptera:Tortricidae), two other stalk-boring insects. Soil moisture was highest in low density and lowest in the high density sunflowers that were less weedy. Stalk circumference, head diameter, and seed weight were reduced for sunflower plants with short interplant distances (mean = 20 cm apart) compared to plants with long interplant distances (mean = 46 cm apart).These three variables were greater in less weedy plots compared with more weedy plots and positively correlated with interplant distance. Yields on a per-hectare basis paralleled those on a per-plant basis but were not different among treatments. The agronomic implications of planting density are discussed in the context of weed and insect management.

  20. CCDC39 is required for assembly of inner dynein arms and the dynein regulatory complex and for normal ciliary motility in humans and dogs

    Science.gov (United States)

    Merveille, Anne-Christine; Davis, Erica E; Becker-Heck, Anita; Legendre, Marie; Amirav, Israel; Bataille, Géraldine; Belmont, John; Beydon, Nicole; Billen, Frédéric; Clément, Annick; Clercx, Cécile; Coste, André; Crosbie, Rachelle; de Blic, Jacques; Deleuze, Stephane; Duquesnoy, Philippe; Escalier, Denise; Escudier, Estelle; Fliegauf, Manfred; Horvath, Judith; Hill, Kent; Jorissen, Mark; Just, Jocelyne; Kispert, Andreas; Lathrop, Mark; Loges, Niki Tomas; Marthin, June K; Momozawa, Yukihide; Montantin, Guy; Nielsen, Kim G; Olbrich, Heike; Papon, Jean-François; Rayet, Isabelle; Roger, Gilles; Schmidts, Miriam; Tenreiro, Henrique; Towbin, Jeffrey A; Zelenika, Diana; Zentgraf, Hanswalter; Georges, Michel; Lequarré, Anne-Sophie; Katsanis, Nicholas; Omran, Heymut; Amselem, Serge

    2012-01-01

    Primary ciliary dyskinesia (PCD) is an inherited disorder characterized by recurrent infections of the upper and lower respiratory tract, reduced fertility in males and situs inversus in about 50% of affected individuals (Kartagener syndrome). It is caused by motility defects in the respiratory cilia that are responsible for airway clearance, the flagella that propel sperm cells and the nodal monocilia that determine left-right asymmetry1. Recessive mutations that cause PCD have been identified in genes encoding components of the outer dynein arms, radial spokes and cytoplasmic pre-assembly factors of axonemal dyneins, but these mutations account for only about 50% of cases of PCD. We exploited the unique properties of dog populations to positionally clone a new PCD gene, CCDC39. We found that loss-of-function mutations in the human ortholog underlie a substantial fraction of PCD cases with axonemal disorganization and abnormal ciliary beating. Functional analyses indicated that CCDC39 localizes to ciliary axonemes and is essential for assembly of inner dynein arms and the dynein regulatory complex. PMID:21131972

  1. CCDC39 is required for assembly of inner dynein arms and the dynein regulatory complex and for normal ciliary motility in humans and dogs.

    Science.gov (United States)

    Merveille, Anne-Christine; Davis, Erica E; Becker-Heck, Anita; Legendre, Marie; Amirav, Israel; Bataille, Géraldine; Belmont, John; Beydon, Nicole; Billen, Frédéric; Clément, Annick; Clercx, Cécile; Coste, André; Crosbie, Rachelle; de Blic, Jacques; Deleuze, Stephane; Duquesnoy, Philippe; Escalier, Denise; Escudier, Estelle; Fliegauf, Manfred; Horvath, Judith; Hill, Kent; Jorissen, Mark; Just, Jocelyne; Kispert, Andreas; Lathrop, Mark; Loges, Niki Tomas; Marthin, June K; Momozawa, Yukihide; Montantin, Guy; Nielsen, Kim G; Olbrich, Heike; Papon, Jean-François; Rayet, Isabelle; Roger, Gilles; Schmidts, Miriam; Tenreiro, Henrique; Towbin, Jeffrey A; Zelenika, Diana; Zentgraf, Hanswalter; Georges, Michel; Lequarré, Anne-Sophie; Katsanis, Nicholas; Omran, Heymut; Amselem, Serge

    2011-01-01

    Primary ciliary dyskinesia (PCD) is an inherited disorder characterized by recurrent infections of the upper and lower respiratory tract, reduced fertility in males and situs inversus in about 50% of affected individuals (Kartagener syndrome). It is caused by motility defects in the respiratory cilia that are responsible for airway clearance, the flagella that propel sperm cells and the nodal monocilia that determine left-right asymmetry. Recessive mutations that cause PCD have been identified in genes encoding components of the outer dynein arms, radial spokes and cytoplasmic pre-assembly factors of axonemal dyneins, but these mutations account for only about 50% of cases of PCD. We exploited the unique properties of dog populations to positionally clone a new PCD gene, CCDC39. We found that loss-of-function mutations in the human ortholog underlie a substantial fraction of PCD cases with axonemal disorganization and abnormal ciliary beating. Functional analyses indicated that CCDC39 localizes to ciliary axonemes and is essential for assembly of inner dynein arms and the dynein regulatory complex.

  2. Kinetochore dynein generates a poleward pulling force to facilitate congression and full chromosome alignment

    Institute of Scientific and Technical Information of China (English)

    Yan Li; Wei Yu; Yun Liang; Xueliang Zhu

    2007-01-01

    For proper chromosome segregation, all kinetochores must achieve bipolar microtubule (MT) attachment and subsequently align at the spindle equator before anaphase onset. The MT minus end-directed motor dynein/dynactin binds kinetochores in prometaphase and has long been implicated in chromosome congression. Unfortunately, inactivation of dynein usually disturbs spindle organization, thus hampering evaluation of its kinetochore roles. Here we specifically eliminated kinetochore dynein/dynactin by RNAi-mediated depletion of ZW10, a protein essential for kinetochore localization of the motor. Time-lapse microscopy indicated markedly-reduced congression efficiency, though congressing chromosomes displayed similar velocities as in control cells. Moreover, cells frequently failed to achieve full chromosome alignment, despite their normal spindles. Confocal microcopy revealed that the misaligned kinetochores were monoori-ented or unattached and mostly lying outside the spindle, suggesting a difficulty to capture MTs from the opposite pole. Kinetochores on monoastral spindles were dispersed farther away from the pole and exhibited only mild oscillation. Furthermore, inactivating dynein by other means generated similar phenotypes. Therefore, kinetochore dynein produces on monooriented kinetochores a poleward pulling force, which may contribute to efficient bipolar attachment by facilitating their proper microtubule captures to promote congression as well as full chromosome alignment.

  3. DRC3 connects the N-DRC to dynein g to regulate flagellar waveform

    Science.gov (United States)

    Awata, Junya; Song, Kangkang; Lin, Jianfeng; King, Stephen M.; Sanderson, Michael J.; Nicastro, Daniela; Witman, George B.

    2015-01-01

    The nexin-dynein regulatory complex (N-DRC), which is a major hub for the control of flagellar motility, contains at least 11 different subunits. A major challenge is to determine the location and function of each of these subunits within the N-DRC. We characterized a Chlamydomonas mutant defective in the N-DRC subunit DRC3. Of the known N-DRC subunits, the drc3 mutant is missing only DRC3. Like other N-DRC mutants, the drc3 mutant has a defect in flagellar motility. However, in contrast to other mutations affecting the N-DRC, drc3 does not suppress flagellar paralysis caused by loss of radial spokes. Cryo–electron tomography revealed that the drc3 mutant lacks a portion of the N-DRC linker domain, including the L1 protrusion, part of the distal lobe, and the connection between these two structures, thus localizing DRC3 to this part of the N-DRC. This and additional considerations enable us to assign DRC3 to the L1 protrusion. Because the L1 protrusion is the only non-dynein structure in contact with the dynein g motor domain in wild-type axonemes and this is the only N-DRC–dynein connection missing in the drc3 mutant, we conclude that DRC3 interacts with dynein g to regulate flagellar waveform. PMID:26063732

  4. Tuning microtubule-based transport via filamentous MAPs: the problem of dynein

    Science.gov (United States)

    Vershinin, Michael; Xu, Jing; Razafsky, David S.; King, Stephen J.; Gross, Steven P.

    2010-01-01

    We recently proposed that regulating the single-to-multiple motor transition was a likely strategy for regulating kinesin-based transport in vivo. Here, we use an in vitro bead assay coupled with an optical trap to investigate how this proposed regulatory mechanism affects dynein-based transport. We show that tau’s regulation of kinesin function can proceed without interfering with dynein-based transport. Surprisingly, at extremely high tau levels—where kinesin cannot bind microtubules—dynein can still contact microtubules. The difference between tau’s effects on kinesin- and dynein-based motility suggests that tau can be used to tune relative amounts of plus-end and minus-end directed transport. As in the case of kinesin, we find that the 3RS isoform of tau is a more potent inhibitor of dynein binding to microtubules. We show that this isoform-specific effect is not due to steric interference of tau’s projection domains, but rather due to tau’s interactions with the motor at the microtubule surface. Nonetheless, we do observe a modest steric interference effect of tau away from the microtubule and discuss the potential implications of this for molecular motor structure. PMID:18373727

  5. Misfolded Gβ is recruited to cytoplasmic dynein by Nudel for efficient clearance

    Institute of Scientific and Technical Information of China (English)

    Yihan Wan; Zhenye Yang; Jing Guo; Qiangge Zhang; Liyong Zeng; Wei Song; Yue Xiao; Xueliang Zhu

    2012-01-01

    The Gβγ heterodimer is an important signal transducer.Gβ,however,is prone to misfolding due to its requirement for Gγ and chaperones for proper folding.How cells dispose of misfolded Gβ (mfGβ) is not clear.Here,we showed that mfGβ was able to be polyubiquitinated and subsequently degraded by the proteasome.It was sequestered in aggresomes after the inhibition of the proteasome activity with MG132.Sustained activation of Gβγ signaling further elevated cellular levels of the ubiquitinated Gβ.Moreover,Nudel,a regulator of cytoplasmic dynein,the microtubule minus end-directed motor,directly interacted with both the unubiquitinated and ubiquitinated mfGβ.Increasing the levels of both mfGβ and Nudel promoted the association of Gβ with both Nudel and dynein,resulting in robust aggresome formation in a dynein-dependent manner.Depletion of Nudel by RNAi reduced the dynein-associated mfGβ,impaired the MG132-induced aggresome formation,and markedly prolonged the half-life of nascent Gβ.Therefore,cytosolic mfGβ is recruited to dynein by Nudel and transported to the centrosome for rapid sequestration and degradation.Such a process not only eliminates mfGβ efficiently for the control of protein quality,but may also help to terminate the Gβγ signaling.

  6. Dynein mutations associated with hereditary motor neuropathies impair mitochondrial morphology and function with age.

    Science.gov (United States)

    Eschbach, Judith; Sinniger, Jérôme; Bouitbir, Jamal; Fergani, Anissa; Schlagowski, Anna-Isabel; Zoll, Joffrey; Geny, Bernard; René, Frédérique; Larmet, Yves; Marion, Vincent; Baloh, Robert H; Harms, Matthew B; Shy, Michael E; Messadeq, Nadia; Weydt, Patrick; Loeffler, Jean-Philippe; Ludolph, Albert C; Dupuis, Luc

    2013-10-01

    Mutations in the DYNC1H1 gene encoding for dynein heavy chain cause two closely related human motor neuropathies, dominant spinal muscular atrophy with lower extremity predominance (SMA-LED) and axonal Charcot-Marie-Tooth (CMT) disease, and lead to sensory neuropathy and striatal atrophy in mutant mice. Dynein is the molecular motor carrying mitochondria retrogradely on microtubules, yet the consequences of dynein mutations on mitochondrial physiology have not been explored. Here, we show that mouse fibroblasts bearing heterozygous or homozygous point mutation in Dync1h1, similar to human mutations, show profoundly abnormal mitochondrial morphology associated with the loss of mitofusin 1. Furthermore, heterozygous Dync1h1 mutant mice display progressive mitochondrial dysfunction in muscle and mitochondria progressively increase in size and invade sarcomeres. As a likely consequence of systemic mitochondrial dysfunction, Dync1h1 mutant mice develop hyperinsulinemia and hyperglycemia and progress to glucose intolerance with age. Similar defects in mitochondrial morphology and mitofusin levels are observed in fibroblasts from patients with SMA-LED. Last, we show that Dync1h1 mutant fibroblasts show impaired perinuclear clustering of mitochondria in response to mitochondrial uncoupling. Our results show that dynein function is required for the maintenance of mitochondrial morphology and function with aging and suggest that mitochondrial dysfunction contributes to dynein-dependent neurological diseases, such as SMA-LED.

  7. DRC3 connects the N-DRC to dynein g to regulate flagellar waveform.

    Science.gov (United States)

    Awata, Junya; Song, Kangkang; Lin, Jianfeng; King, Stephen M; Sanderson, Michael J; Nicastro, Daniela; Witman, George B

    2015-08-01

    The nexin-dynein regulatory complex (N-DRC), which is a major hub for the control of flagellar motility, contains at least 11 different subunits. A major challenge is to determine the location and function of each of these subunits within the N-DRC. We characterized a Chlamydomonas mutant defective in the N-DRC subunit DRC3. Of the known N-DRC subunits, the drc3 mutant is missing only DRC3. Like other N-DRC mutants, the drc3 mutant has a defect in flagellar motility. However, in contrast to other mutations affecting the N-DRC, drc3 does not suppress flagellar paralysis caused by loss of radial spokes. Cryo-electron tomography revealed that the drc3 mutant lacks a portion of the N-DRC linker domain, including the L1 protrusion, part of the distal lobe, and the connection between these two structures, thus localizing DRC3 to this part of the N-DRC. This and additional considerations enable us to assign DRC3 to the L1 protrusion. Because the L1 protrusion is the only non-dynein structure in contact with the dynein g motor domain in wild-type axonemes and this is the only N-DRC-dynein connection missing in the drc3 mutant, we conclude that DRC3 interacts with dynein g to regulate flagellar waveform.

  8. Cytoplasmic dynein and its regulatory proteins in Golgi pathology in nervous system disorders

    Directory of Open Access Journals (Sweden)

    Dick eJaarsma

    2015-10-01

    Full Text Available The Golgi apparatus is a dynamic organelle involved in processing and sorting of lipids and proteins. In neurons, the Golgi apparatus is important for the development of axons and dendrites and maintenance of their highly polarized morphology. The motor protein complex cytoplasmic dynein has an important role in Golgi apparatus positioning and function. Together with dynactin and other regulatory factors it drives microtubule minus-end directed motility of Golgi membranes. Inhibition of dynein results in fragmentation and dispersion of the Golgi ribbon in the neuronal cell body, resembling the Golgi abnormalities observed in some neurodegenerative disorders, in particular motor neuron diseases. Mutations in dynein and its regulatory factors, including the dynactin subunit p150Glued, BICD2 and Lis-1, are associated with several human nervous system disorders, including cortical malformation and motor neuropathy. Here we review the role of dynein and its regulatory factors in Golgi function and positioning, and the potential role of dynein malfunction in causing Golgi apparatus abnormalities in nervous system disorders.

  9. Three Members of the LC8/DYNLL Family Are Required for Outer Arm Dynein Motor Function

    Science.gov (United States)

    Tanner, Christopher A.; Rompolas, Panteleimon; Patel-King, Ramila S.; Gorbatyuk, Oksana; Wakabayashi, Ken-ichi; Pazour, Gregory J.

    2008-01-01

    The highly conserved LC8/DYNLL family proteins were originally identified in axonemal dyneins and subsequently found to function in multiple enzyme systems. Genomic analysis uncovered a third member (LC10) of this protein class in Chlamydomonas. The LC10 protein is extracted from flagellar axonemes with 0.6 M NaCl and cofractionates with the outer dynein arm in sucrose density gradients. Furthermore, LC10 is specifically missing only from axonemes of those strains that fail to assemble outer dynein arms. Previously, the oda12-1 insertional allele was shown to lack the Tctex2-related dynein light chain LC2. The LC10 gene is located ∼2 kb from that of LC2 and is also completely missing from this mutant but not from oda12-2, which lacks only the 3′ end of the LC2 gene. Although oda12-1 cells assemble outer arms that lack only LC2 and LC10, this strain exhibits a flagellar beat frequency that is consistently less than that observed for strains that fail to assemble the entire outer arm and docking complex (e.g., oda1). These results support a key regulatory role for the intermediate chain/light chain complex that is an integral and highly conserved feature of all oligomeric dynein motors. PMID:18579685

  10. 75 FR 81085 - National Stalking Awareness Month, 2011

    Science.gov (United States)

    2010-12-27

    ... President of the United States of America A Proclamation Stalking is a serious and pervasive crime that... consequences for victims, whose lives may be upended by fear. Some victims may be forced to take extreme.... Stalking can be a difficult crime to recognize. The majority of survivors do not report...

  11. Fusarium stalk blight and rot in sugar beet

    Science.gov (United States)

    Fusarium stalk blight of sugar beet can cause reductions or complete loss of seed production. The causal agent is Fusarium oxysporum. In addition, Fusarium solani has been demonstrated to cause a rot of sugar beet seed stalk, and other species have been reported associated with sugar beet fruit, but...

  12. Stalking als Straftatbestand : Neue Tendenzen in den EU-Mitgliedstaaten

    NARCIS (Netherlands)

    van der Aa, Suzanne; Bachman, Roland; Ortiz-Müller, Wolf

    2017-01-01

    Article 34 of the Council of Europe Convention on Preventing and Combating Violence against Women and Domestic Violence obliges signatory states to criminalize stalking. This article provides an inventory of criminal anti-stalking legislation in the 28 EU Member States in order to see whether they

  13. Kinesin-3 and dynein cooperate in long-range retrograde endosome motility along a nonuniform microtubule array

    NARCIS (Netherlands)

    Schuster, M.; Kilaru, S.; Fink, G.; Collemare, J.A.R.; Roger, Y.; Steinberg, G.

    2011-01-01

    The polarity of microtubules (MTs) determines the motors for intracellular motility, with kinesins moving to plus ends and dynein to minus ends. In elongated cells of Ustilago maydis, dynein is thought to move early endosomes (EEs) toward the septum (retrograde), whereas kinesin-3 transports them to

  14. Kinesin-3 and dynein cooperate in long-range retrograde endosome motility along a nonuniform microtubule array

    NARCIS (Netherlands)

    Schuster, M.; Kilaru, S.; Fink, G.; Collemare, J.A.R.; Roger, Y.; Steinberg, G.

    2011-01-01

    The polarity of microtubules (MTs) determines the motors for intracellular motility, with kinesins moving to plus ends and dynein to minus ends. In elongated cells of Ustilago maydis, dynein is thought to move early endosomes (EEs) toward the septum (retrograde), whereas kinesin-3 transports them to

  15. An analytical solution describing the propagation of positive injury signals in an axon: effect of dynein velocity distribution.

    Science.gov (United States)

    Kuznetsov, A V

    2013-01-01

    A model describing the propagation of positive injury signals from the lesion site in an axon towards the neuron soma is described. It is assumed that these signals are driven by dynein molecular motors. An analytical solution that accounts for the probability density function (pdf) of a dynein velocity distribution is obtained. Two examples of pdf of dynein velocity distributions that follow from the results published in Ross et al. (2006, Processive bidirectional motion of dynein-dynactin complexes in vitro. Nat Cell Biol. 8:562-570) and Deinhardt et al. (2006, Rab5 and Rab7 control endocytic sorting along the axonal retrograde transport pathway. Neuron 52:293-305) are considered. The effect of dynein velocity distribution on the rate of spreading of the signal wave is discussed. It is demonstrated that the obtained solution can be applied to the problem of how neurons measure the distance between the lesion site and the neuron soma.

  16. [Anaerobic co-digestion of corn stalk and vermicompost].

    Science.gov (United States)

    Chen, Guang-yin; Zheng, Zheng; Zou, Xing-xing; Fang, Cai-xia; Luo, Yan

    2010-02-01

    The characteristics of corn stalk digested alone at different total solid (TS) loading rates and co-digestion of various proportions of corn stalk and vermicompost were investigated by batch model at 35 degrees C +/- 1 degrees C. The organic loading rates (OLRs) studied were in the range of 1.2%-6.0% TS and increasing proportions of vermicompost from 20% to 80% TS. A maximum methane yield of corn stalk digested alone was 217.60 mL/g obtained at the TS loading rate of 4.8%. However, when the TS loading rate was 6.0%, the anaerobic system was acidified and the lowest pH value was 5.10 obtained on day 4 and the biogas productivity decreased. Furthermore, co-digestion of vermicompost and corn stalk in varying proportions were investigated at constant of 6.0% TS. Co-digestion with vermicompost improved the biodegradability of corn stalk and the methane yield was improved by 4.42%-58.61%, and led to higher pH values, higher volatile fatty acids (VFAs) concentration and lower alkalinity content compared with corn stalk digested alone. The maximum biogas yield and methane yield of 410.30 mL/g and 259. 35 mL/g were obtained for 40% vermicompost and 60% corn stalk respectively. Compared with corn stalk digested alone, co-digested with vermicompost didn' t affect methane content and the fermentation type, but promoted the destruction of crystalline of cellulose and the highest destruction rate was 29.36% for 40% vermicompost and 60% corn stalk. Therefore, adding vermicompost was beneficial for the decomposition and increasing the biotransformation rate of corn stalk.

  17. Tissue Specific Roles of Dynein Light Chain 1 in Regulating Germ Cell Apoptosis in Ceanorhabditis elegans

    DEFF Research Database (Denmark)

    Morthorst, Tine Hørning

    2015-01-01

    (dlc-1) in apoptosis are described. DLC-1 is a part of the motor complex dynein, which moves along microtubules inside the cell. DLC-1 has been demonstrated to have both dynein dependent and independent functions in mammalian cells, which is also apparent from the studies presented here. Specifically......, DLC-1 was found to play a cell-nonautonomous role in somatic tissue to negatively regulate the apoptotic response to ironizing radiation-induced apoptosis upstream of the KRIT1/CCM1 homolog KRI-1. Depletion of dlc-1 results in ectopic apoptosis in the germline, which is dependent on the BH3-only...... proteins EGL-1 and CED-13. These proteins are normally regulated by the p53 homolog CEP-1, however, DLC-1 regulates apoptosis independently of the function of CEP-1. Furthermore, the function of DLC-1 is independent of its association with dynein. The other apoptotic mechanism of DLC-1 regulates...

  18. Dynein Clusters into Lipid Microdomains on Phagosomes to Drive Rapid Transport toward Lysosomes

    Science.gov (United States)

    Rai, Ashim; Pathak, Divya; Thakur, Shreyasi; Singh, Shampa; Dubey, Alok Kumar; Mallik, Roop

    2016-01-01

    Summary Diverse cellular processes are driven by motor proteins that are recruited to and generate force on lipid membranes. Surprisingly little is known about how membranes control the force from motors and how this may impact specific cellular functions. Here, we show that dynein motors physically cluster into microdomains on the membrane of a phagosome as it matures inside cells. Such geometrical reorganization allows many dyneins within a cluster to generate cooperative force on a single microtubule. This results in rapid directed transport of the phagosome toward microtubule minus ends, likely promoting phagolysosome fusion and pathogen degradation. We show that lipophosphoglycan, the major molecule implicated in immune evasion of Leishmania donovani, inhibits phagosome motion by disrupting the clustering and therefore the cooperative force generation of dynein. These findings appear relevant to several pathogens that prevent phagosome-lysosome fusion by targeting lipid microdomains on phagosomes. PMID:26853472

  19. Detailed structural and biochemical characterization of the nexin-dynein regulatory complex

    OpenAIRE

    Oda, Toshiyuki; Yanagisawa, Haruaki; Kikkawa, Masahide

    2015-01-01

    The nexin-dynein regulatory complex (N-DRC) forms a cross-bridge between the outer doublet microtubules of the axoneme and regulates dynein motor activity in cilia/flagella. Although the molecular composition and the three-dimensional structure of N-DRC have been studied using mutant strains lacking N-DRC subunits, more accurate approaches are necessary to characterize the structure and function of N-DRC. In this study, we precisely localized DRC1, DRC2, and DRC4 using cryo–electron tomograph...

  20. Flow caused by the stalk contraction of Vorticella

    Science.gov (United States)

    Ryu, Sangjin; Chung, Eun-Gul; Admiraal, David

    2016-11-01

    Vorticella is a stalked protozoan, and its ultrafast stalk contraction moves the spherically-shrunken cell body (zooid) and thus causes surrounding water to flow. Because the fluid dynamics of this water flow is important for understanding the motility of Vorticella, we investigated the flow based on various fluid dynamics approaches. To find why Vorticella contracts its stalk, we propose a hypothesis that the protist utilizes the contraction-induced water flow to augment transport of food particles. This hypothesis was investigated using a computational fluid dynamics (CFD) model, which was validated with an experimental scale model of Vorticella. The CFD model enabled calculating the motion of particles around Vorticella and thus quantifying the transport effect of the stalk contraction. Also, we have developed a hydrodynamic drag model for easier estimation of Vorticella's contractility without using the CFD model. Because the contractile force of the stalk equals the drag on the moving zooid, the model enabled evaluating the contractile force and energetics of Vorticella based on its contraction speed. Analyses using the drag model show that the stalk contractility of Vorticella depends on the stalk length. This study was supported by UNL Layman Seed Grant and Nebraska EPSCoR First Award Grant.

  1. Chlamydomonas DYX1C1/PF23 is essential for axonemal assembly and proper morphology of inner dynein arms.

    Directory of Open Access Journals (Sweden)

    Ryosuke Yamamoto

    2017-09-01

    Full Text Available Cytoplasmic assembly of ciliary dyneins, a process known as preassembly, requires numerous non-dynein proteins, but the identities and functions of these proteins are not fully elucidated. Here, we show that the classical Chlamydomonas motility mutant pf23 is defective in the Chlamydomonas homolog of DYX1C1. The pf23 mutant has a 494 bp deletion in the DYX1C1 gene and expresses a shorter DYX1C1 protein in the cytoplasm. Structural analyses, using cryo-ET, reveal that pf23 axonemes lack most of the inner dynein arms. Spectral counting confirms that DYX1C1 is essential for the assembly of the majority of ciliary inner dynein arms (IDA as well as a fraction of the outer dynein arms (ODA. A C-terminal truncation of DYX1C1 shows a reduction in a subset of these ciliary IDAs. Sucrose gradients of cytoplasmic extracts show that preassembled ciliary dyneins are reduced compared to wild-type, which suggests an important role in dynein complex stability. The role of PF23/DYX1C1 remains unknown, but we suggest that DYX1C1 could provide a scaffold for macromolecular assembly.

  2. The LC7 Light Chains of Chlamydomonas Flagellar Dyneins Interact with Components Required for Both Motor Assembly and Regulation

    Science.gov (United States)

    DiBella, Linda M.; Sakato, Miho; Patel-King, Ramila S.; Pazour, Gregory J.; King, Stephen M.

    2004-01-01

    Members of the LC7/Roadblock family of light chains (LCs) have been found in both cytoplasmic and axonemal dyneins. LC7a was originally identified within Chlamydomonas outer arm dynein and associates with this motor's cargo-binding region. We describe here a novel member of this protein family, termed LC7b that is also present in the Chlamydomonas flagellum. Levels of LC7b are reduced ∼20% in axonemes isolated from strains lacking inner arm I1 and are ∼80% lower in the absence of the outer arms. When both dyneins are missing, LC7b levels are diminished to <10%. In oda9 axonemal extracts that completely lack outer arms, LC7b copurifies with inner arm I1, whereas in ida1 extracts that are devoid of I1 inner arms it associates with outer arm dynein. We also have observed that some LC7a is present in both isolated axonemes and purified 18S dynein from oda1, suggesting that it is also a component of both the outer arm and inner arm I1. Intriguingly, in axonemal extracts from the LC7a null mutant, oda15, which assembles ∼30% of its outer arms, LC7b fails to copurify with either dynein, suggesting that it interacts with LC7a. Furthermore, both the outer arm γ heavy chain and DC2 from the outer arm docking complex completely dissociate after salt extraction from oda15 axonemes. EDC cross-linking of purified dynein revealed that LC7b interacts with LC3, an outer dynein arm thioredoxin; DC2, an outer arm docking complex component; and also with the phosphoprotein IC138 from inner arm I1. These data suggest that LC7a stabilizes both the outer arms and inner arm I1 and that both LC7a and LC7b are involved in multiple intradynein interactions within both dyneins. PMID:15304520

  3. DYNC1H1 mutations associated with neurological diseases compromise processivity of dynein-dynactin-cargo adaptor complexes.

    Science.gov (United States)

    Hoang, Ha Thi; Schlager, Max A; Carter, Andrew P; Bullock, Simon L

    2017-02-28

    Mutations in the human DYNC1H1 gene are associated with neurological diseases. DYNC1H1 encodes the heavy chain of cytoplasmic dynein-1, a 1.4-MDa motor complex that traffics organelles, vesicles, and macromolecules toward microtubule minus ends. The effects of the DYNC1H1 mutations on dynein motility, and consequently their links to neuropathology, are not understood. Here, we address this issue using a recombinant expression system for human dynein coupled to single-molecule resolution in vitro motility assays. We functionally characterize 14 DYNC1H1 mutations identified in humans diagnosed with malformations in cortical development (MCD) or spinal muscular atrophy with lower extremity predominance (SMALED), as well as three mutations that cause motor and sensory defects in mice. Two of the human mutations, R1962C and H3822P, strongly interfere with dynein's core mechanochemical properties. The remaining mutations selectively compromise the processive mode of dynein movement that is activated by binding to the accessory complex dynactin and the cargo adaptor Bicaudal-D2 (BICD2). Mutations with the strongest effects on dynein motility in vitro are associated with MCD. The vast majority of mutations do not affect binding of dynein to dynactin and BICD2 and are therefore expected to result in linkage of cargos to dynein-dynactin complexes that have defective long-range motility. This observation offers an explanation for the dominant effects of DYNC1H1 mutations in vivo. Collectively, our results suggest that compromised processivity of cargo-motor assemblies contributes to human neurological disease and provide insight into the influence of different regions of the heavy chain on dynein motility.

  4. Steady dynein forces induce flutter instability and propagating waves in mathematical models of flagella.

    Science.gov (United States)

    Bayly, P V; Dutcher, S K

    2016-10-01

    Cilia and flagella are highly conserved organelles that beat rhythmically with propulsive, oscillatory waveforms. The mechanism that produces these autonomous oscillations remains a mystery. It is widely believed that dynein activity must be dynamically regulated (switched on and off, or modulated) on opposite sides of the axoneme to produce oscillations. A variety of regulation mechanisms have been proposed based on feedback from mechanical deformation to dynein force. In this paper, we show that a much simpler interaction between dynein and the passive components of the axoneme can produce coordinated, propulsive oscillations. Steady, distributed axial forces, acting in opposite directions on coupled beams in viscous fluid, lead to dynamic structural instability and oscillatory, wave-like motion. This 'flutter' instability is a dynamic analogue to the well-known static instability, buckling. Flutter also occurs in slender beams subjected to tangential axial loads, in aircraft wings exposed to steady air flow and in flexible pipes conveying fluid. By analysis of the flagellar equations of motion and simulation of structural models of flagella, we demonstrate that dynein does not need to switch direction or inactivate to produce autonomous, propulsive oscillations, but must simply pull steadily above a critical threshold force.

  5. WD60/FAP163 is a dynein intermediate chain required for retrograde intraflagellar transport in cilia.

    Science.gov (United States)

    Patel-King, Ramila S; Gilberti, Renée M; Hom, Erik F Y; King, Stephen M

    2013-09-01

    Retrograde intraflagellar transport (IFT) is required for assembly of cilia. We identify a Chlamydomonas flagellar protein (flagellar-associated protein 163 [FAP163]) as being closely related to the D1bIC(FAP133) intermediate chain (IC) of the dynein that powers this movement. Biochemical analysis revealed that FAP163 is present in the flagellar matrix and is actively trafficked by IFT. Furthermore, FAP163 copurified with D1bIC(FAP133) and the LC8 dynein light chain, indicating that it is an integral component of the retrograde IFT dynein. To assess the functional role of FAP163, we generated an RNA interference knockdown of the orthologous protein (WD60) in planaria. The Smed-wd60(RNAi) animals had a severe ciliary assembly defect that dramatically compromised whole-organism motility. Most cilia were present as short stubs that had accumulated large quantities of IFT particle-like material between the doublet microtubules and the membrane. The few remaining approximately full-length cilia had a chaotic beat with a frequency reduced from 24 to ∼10 Hz. Thus WD60/FAP163 is a dynein IC that is absolutely required for retrograde IFT and ciliary assembly.

  6. Mitochondria-driven assembly of a cortical anchor for mitochondria and dynein.

    Science.gov (United States)

    Kraft, Lauren M; Lackner, Laura L

    2017-10-02

    Interorganelle contacts facilitate communication between organelles and impact fundamental cellular functions. In this study, we examine the assembly of the MECA (mitochondria-endoplasmic reticulum [ER]-cortex anchor), which tethers mitochondria to the ER and plasma membrane. We find that the assembly of Num1, the core component of MECA, requires mitochondria. Once assembled, Num1 clusters persistently anchor mitochondria to the cell cortex. Num1 clusters also function to anchor dynein to the plasma membrane, where dynein captures and walks along astral microtubules to help orient the mitotic spindle. We find that dynein is anchored by Num1 clusters that have been assembled by mitochondria. When mitochondrial inheritance is inhibited, Num1 clusters are not assembled in the bud, and defects in dynein-mediated spindle positioning are observed. The mitochondria-dependent assembly of a dual-function cortical anchor provides a mechanism to integrate the positioning and inheritance of the two essential organelles and expands the function of organelle contact sites. © 2017 Kraft and Lackner.

  7. WD60/FAP163 is a dynein intermediate chain required for retrograde intraflagellar transport in cilia

    Science.gov (United States)

    Patel-King, Ramila S.; Gilberti, Renée M.; Hom, Erik F. Y.; King, Stephen M.

    2013-01-01

    Retrograde intraflagellar transport (IFT) is required for assembly of cilia. We identify a Chlamydomonas flagellar protein (flagellar-associated protein 163 [FAP163]) as being closely related to the D1bIC(FAP133) intermediate chain (IC) of the dynein that powers this movement. Biochemical analysis revealed that FAP163 is present in the flagellar matrix and is actively trafficked by IFT. Furthermore, FAP163 copurified with D1bIC(FAP133) and the LC8 dynein light chain, indicating that it is an integral component of the retrograde IFT dynein. To assess the functional role of FAP163, we generated an RNA interference knockdown of the orthologous protein (WD60) in planaria. The Smed-wd60(RNAi) animals had a severe ciliary assembly defect that dramatically compromised whole-organism motility. Most cilia were present as short stubs that had accumulated large quantities of IFT particle–like material between the doublet microtubules and the membrane. The few remaining approximately full-length cilia had a chaotic beat with a frequency reduced from 24 to ∼10 Hz. Thus WD60/FAP163 is a dynein IC that is absolutely required for retrograde IFT and ciliary assembly. PMID:23864713

  8. Understanding the Roles of Nudel/Lis1/Dynein Pathway in Cell Motility

    Institute of Scientific and Technical Information of China (English)

    Xie Lele; Zhu Xueliang

    2007-01-01

    @@ Under the support of multiple grants by NSFC, including General Program, Key Program, National Science Fund for Distinguished Young Scholars, and Fund for Creative Research Groups, the research group explored how the Nudel/Lis1/dynein pathway functions in cell motility.

  9. Exploitation of microtubule cytoskeleton and dynein during parvoviral traffic toward the nucleus.

    Science.gov (United States)

    Suikkanen, Sanna; Aaltonen, Tuula; Nevalainen, Marjukka; Välilehto, Outi; Lindholm, Laura; Vuento, Matti; Vihinen-Ranta, Maija

    2003-10-01

    Canine parvovirus (CPV), a model virus for the study of parvoviral entry, enters host cells by receptor-mediated endocytosis, escapes from endosomal vesicles to the cytosol, and then replicates in the nucleus. We examined the role of the microtubule (MT)-mediated cytoplasmic trafficking of viral particles toward the nucleus. Immunofluorescence and immunoelectron microscopy showed that capsids were transported through the cytoplasm into the nucleus after cytoplasmic microinjection but that in the presence of MT-depolymerizing agents, viral capsids were unable to reach the nucleus. The nuclear accumulation of capsids was also reduced by microinjection of an anti-dynein antibody. Moreover, electron microscopy and light microscopy experiments demonstrated that viral capsids associate with tubulin and dynein in vitro. Coprecipitation studies indicated that viral capsids interact with dynein. When the cytoplasmic transport process was studied in living cells by microinjecting fluorescently labeled capsids into the cytoplasm of cells containing fluorescent tubulin, capsids were found in close contact with MTs. These results suggest that intact MTs and the motor protein dynein are required for the cytoplasmic transport of CPV capsids and contribute to the accumulation of the capsid in the nucleus.

  10. Stress-Induced CDK5 Activation Disrupts Axonal Transport via Lis1/Ndel1/Dynein

    Directory of Open Access Journals (Sweden)

    Eva Klinman

    2015-07-01

    Full Text Available Axonal transport is essential for neuronal function, and defects in transport are associated with multiple neurodegenerative diseases. Aberrant cyclin-dependent kinase 5 (CDK5 activity, driven by the stress-induced activator p25, also is observed in these diseases. Here we show that elevated CDK5 activity increases the frequency of nonprocessive events for a range of organelles, including lysosomes, autophagosomes, mitochondria, and signaling endosomes. Transport disruption induced by aberrant CDK5 activation depends on the Lis1/Ndel1 complex, which directly regulates dynein activity. CDK5 phosphorylation of Ndel1 favors a high affinity Lis1/Ndel/dynein complex that blocks the ATP-dependent release of dynein from microtubules, inhibiting processive motility of dynein-driven cargo. Similar transport defects observed in neurons from a mouse model of amyotrophic lateral sclerosis are rescued by CDK5 inhibition. Together, these studies identify CDK5 as a Lis1/Ndel1-dependent regulator of transport in stressed neurons, and suggest that dysregulated CDK5 activity contributes to the transport deficits observed during neurodegeneration.

  11. Bicaudal d family adaptor proteins control the velocity of Dynein-based movements

    NARCIS (Netherlands)

    Schlager, M.A.; Serra-Marquez, A.; Grigoriev, Ilya; Gumy, Laura; Estevez da Silva, M.; Wulf, Phebe; Akhmanova, Anna; Hoogenraad, Casper

    2014-01-01

    Cargo transport along microtubules is driven by the collective function of microtubule plus- and minus-end-directed motors (kinesins and dyneins). How the velocity of cargo transport is driven by opposing teams of motors is still poorly understood. Here, we combined inducible recruitment of motors a

  12. CCDC103 mutations cause primary ciliary dyskinesia by disrupting assembly of ciliary dynein arms

    Science.gov (United States)

    Panizzi, Jennifer R.; Becker-Heck, Anita; Castleman, Victoria H.; Al-Mutairi, Dalal; Liu, Yan; Loges, Niki T.; Pathak, Narendra; Austin-Tse, Christina; Sheridan, Eamonn; Schmidts, Miriam; Olbrich, Heike; Werner, Claudius; Häffner, Karsten; Hellman, Nathan; Chodhari, Rahul; Gupta, Amar; Kramer-Zucker, Albrecht; Olale, Felix; Burdine, Rebecca D.; Schier, Alexander F.; O’Callaghan, Christopher; Chung, Eddie MK; Reinhardt, Richard; Mitchison, Hannah M.; King, Stephen M.; Omran, Heymut; Drummond, Iain A.

    2012-01-01

    Cilia are essential for fertilization, respiratory clearance, cerebrospinal fluid circulation, and to establish laterality1. Cilia motility defects cause Primary Ciliary Dyskinesia (PCD, MIM 242650), a disorder affecting 1:15-30,000 births. Cilia motility requires the assembly of multisubunit dynein arms that drive cilia bending2. Despite progress in understanding the genetic basis of PCD, mutations remain to be identified for several PCD linked loci3. Here we show that the zebrafish cilia paralysis mutant schmalhanstn222 (smh) mutant encodes the coiled-coil domain containing 103 protein (Ccdc103), a foxj1a regulated gene. Screening 146 unrelated PCD families identified patients in six families with reduced outer dynein arms, carrying mutations in CCDC103. Dynein arm assembly in smh mutant zebrafish was rescued by wild-type but not mutant human CCDC103. Chlamydomonas Ccdc103 functions as a tightly bound, axoneme-associated protein. The results identify Ccdc103 as a novel dynein arm attachment factor that when mutated causes Primary Ciliary Dyskinesia. PMID:22581229

  13. Cytoplasmic dynein and its regulatory proteins in Golgi pathology in nervous system disorders

    NARCIS (Netherlands)

    Jaarsma, Dick; Hoogenraad, Casper C

    2015-01-01

    The Golgi apparatus is a dynamic organelle involved in processing and sorting of lipids and proteins. In neurons, the Golgi apparatus is important for the development of axons and dendrites and maintenance of their highly complex polarized morphology. The motor protein complex cytoplasmic dynein has

  14. Emergence of flagellar beating from the collective behavior of individual ATP-powered dyneins

    NARCIS (Netherlands)

    Namdeo, S.; Onck, P. R.

    2016-01-01

    Flagella are hair-like projections from the surface of eukaryotic cells, and they play an important role in many cellular functions, such as cell-motility. The beating of flagella is enabled by their internal architecture, the axoneme, and is powered by a dense distribution of motor proteins, dynein

  15. LRRC6 mutation causes primary ciliary dyskinesia with dynein arm defects.

    Directory of Open Access Journals (Sweden)

    Amjad Horani

    Full Text Available Despite recent progress in defining the ciliome, the genetic basis for many cases of primary ciliary dyskinesia (PCD remains elusive. We evaluated five children from two unrelated, consanguineous Palestinian families who had PCD with typical clinical features, reduced nasal nitric oxide concentrations, and absent dynein arms. Linkage analyses revealed a single common homozygous region on chromosome 8 and one candidate was conserved in organisms with motile cilia. Sequencing revealed a single novel mutation in LRRC6 (Leucine-rich repeat containing protein 6 that fit the model of autosomal recessive genetic transmission, leading to a change of a highly conserved amino acid from aspartic acid to histidine (Asp146His. LRRC6 was localized to the cytoplasm and was up-regulated during ciliogenesis in human airway epithelial cells in a Foxj1-dependent fashion. Nasal epithelial cells isolated from affected individuals and shRNA-mediated silencing in human airway epithelial cells, showed reduced LRRC6 expression, absent dynein arms, and slowed cilia beat frequency. Dynein arm proteins were either absent or mislocalized to the cytoplasm in airway epithelial cells from a primary ciliary dyskinesia subject. These findings suggest that LRRC6 plays a role in dynein arm assembly or trafficking and when mutated leads to primary ciliary dyskinesia with laterality defects.

  16. An Outer Arm Dynein Conformational Switch Is Required for Metachronal Synchrony of Motile Cilia in Planaria

    Science.gov (United States)

    Rompolas, Panteleimon; Patel-King, Ramila S.

    2010-01-01

    Motile cilia mediate the flow of mucus and other fluids across the surface of specialized epithelia in metazoans. Efficient clearance of peri-ciliary fluids depends on the precise coordination of ciliary beating to produce metachronal waves. The role of individual dynein motors and the mechanical feedback mechanisms required for this process are not well understood. Here we used the ciliated epithelium of the planarian Schmidtea mediterranea to dissect the role of outer arm dynein motors in the metachronal synchrony of motile cilia. We demonstrate that animals that completely lack outer dynein arms display a significant decline in beat frequency and an inability of cilia to coordinate their oscillations and form metachronal waves. Furthermore, lack of a key mechanosensitive regulatory component (LC1) yields a similar phenotype even though outer arms still assemble in the axoneme. The lack of metachrony was not due simply to a decrease in ciliary beat frequency, as reducing this parameter by altering medium viscosity did not affect ciliary coordination. In addition, we did not observe a significant temporal variability in the beat cycle of impaired cilia. We propose that this conformational switch provides a mechanical feedback system within outer arm dynein that is necessary to entrain metachronal synchrony. PMID:20844081

  17. 77 FR 211 - National Stalking Awareness Month, 2012

    Science.gov (United States)

    2012-01-03

    ... fear through intimidation, explicit or implied threats, and nonconsensual communication--often by... danger. Among men and women alike, victims are most commonly stalked by current or former intimate...

  18. Xinjiang: Cotton Stalk Fiber Will Bring Profits to Farmers

    Institute of Scientific and Technical Information of China (English)

    Zheng Yan

    2007-01-01

    @@ On April 19,2007,Seminar on the Development and Application of Xinjiang Cotton Stalk Fiber,hosted by the Economic Operations Bureau of National Development and Reform Commission(NDRC),successfully opened in Xinjiang Hotel of Beijing.

  19. Enhanced ethanol production from stalk juice of sweet sorghum by ...

    African Journals Online (AJOL)

    user

    2012-03-15

    Mar 15, 2012 ... ethanol production by a Saccharomyces cerevisiae strain because of the high content of sugar. ... Key words: Ethanol, sweet sorghum, stalk juice, medium ..... production from Kinnow mandarin (Citrus reticulata) waste via a.

  20. Dynein and mast/orbit/CLASP have antagonistic roles in regulating kinetochore-microtubule plus-end dynamics.

    Science.gov (United States)

    Reis, Rita; Feijão, Tália; Gouveia, Susana; Pereira, António J; Matos, Irina; Sampaio, Paula; Maiato, Helder; Sunkel, Claudio E

    2009-07-15

    Establishment and maintenance of the mitotic spindle requires the balanced activity of microtubule-associated proteins and motors. In this study we have addressed how the microtubule plus-end tracking protein mast/orbit/CLASP and cytoplasmic dynein regulate this process in Drosophila melanogaster embryos and S2 cells. We show that mast accumulates at kinetochores early in mitosis, which is followed by a poleward streaming upon microtubule attachment. This leads to a reduction of mast levels at kinetochores during metaphase and anaphase that depends largely on the microtubule minus end-directed motor cytoplasmic dynein. Surprisingly, we also found that co-depletion of dynein rescues spindle bipolarity in mast-depleted cells, while restoring normal microtubule poleward flux. Our results suggest that mast and dynein have antagonistic roles in the local regulation of microtubule plus-end dynamics at kinetochores, which are important for the maintenance of spindle bipolarity and normal spindle length.

  1. Analysis of dynein intermediate chains, light intermediate chains and light chains in a cohort of hereditary peripheral neuropathies.

    Science.gov (United States)

    Tey, Shelisa; Ahmad-Annuar, Azlina; Drew, Alexander P; Shahrizaila, Nortina; Nicholson, Garth A; Kennerson, Marina L

    2014-10-01

    The cytoplasmic dynein heavy chain (DYNC1H1) gene has been increasingly associated with neurodegenerative disorders including axonal Charcot-Marie-Tooth disease (CMT2), intellectual disability and malformations of cortical development. In addition, evidence from mouse models (Loa, catabolite repressor-activator (Cra) and Sprawling (Swl)) has shown that mutations in Dync1h1 cause a range of neurodegenerative phenotypes with motor and sensory neuron involvement. In this current study, we examined the possible contribution of other cytoplasmic dynein subunits that bind to DYNC1H1 as a cause of inherited peripheral neuropathy. We focused on screening the cytoplasmic dynein intermediate, light intermediate and light chain genes in a cohort of families with inherited peripheral neuropathies. Nine genes were screened and ten variants were detected, but none was identified as pathogenic, indicating that cytoplasmic dynein intermediate, light intermediate and light chains are not a cause of neuropathy in our cohort.

  2. A stalk of grain and light

    Directory of Open Access Journals (Sweden)

    Erín Moure

    2010-11-01

    Full Text Available "Stalk of Grain and Light" is an excerpt from O Resplandor (Toronto: Anansi, forthcoming 2010, a book of poetry that explodes notions of authorship and translation. In it, the heteronymic character Elisa Sampedrín translates from Nichita Stãnescu, though she knows no Romanian, and the orthonymic character Erín Moure translates Paul Celan, using not Celan but English transcreations from the language of Celan by Oana Avasilichioaei which she appropriates and reorganizes to create the true translation of a poem by Paul Celan, which exists only in her mind. In this world where corporations copyright human cells, where academics and libraries appropriate works of writers, and where writing itself - moreso than visual art - is limited by expanded notions of plagiarism and ownership, of continuity of copyright for decades that prevents works from influencing art's future, Moure refutes the idea that writing is inspired out of nowhere. Here it is rooted to human interaction, to love and loss, to the art of others, and is dedicated to creating a world where the free irruption of thought is possible, and lineages are acknowledged.

  3. Dynein Light Intermediate Chain 2 Facilitates the Metaphase to Anaphase Transition by Inactivating the Spindle Assembly Checkpoint.

    Directory of Open Access Journals (Sweden)

    Sagar P Mahale

    Full Text Available The multi-functional molecular motor cytoplasmic dynein performs diverse essential roles during mitosis. The mechanistic importance of the dynein Light Intermediate Chain homologs, LIC1 and LIC2 is unappreciated, especially in the context of mitosis. LIC1 and LIC2 are believed to exist in distinct cytoplasmic dynein complexes as obligate subunits. LIC1 had earlier been reported to be required for metaphase to anaphase progression by inactivating the kinetochore-microtubule attachment-sensing arm of the spindle assembly checkpoint (SAC. However, the functional importance of LIC2 during mitosis remains elusive. Here we report prominent novel roles for the LIC2 subunit of cytoplasmic dynein in regulating the spindle assembly checkpoint. LIC2 depletion in mammalian cells led to prolonged metaphase arrest in the presence of an active SAC and also to stretched kinetochores, thus implicating it in SAC inactivation. Quantitative fluorescence microscopy of SAC components revealed accumulation of both attachment- and tension-sensing checkpoint proteins at metaphase kinetochores upon LIC2 depletion. These observations support a stronger and more diverse role in checkpoint inactivation for LIC2 in comparison to its close homolog LIC1. Our study uncovers a novel functional hierarchy during mitotic checkpoint inactivation between the closely related but homologous LIC subunits of cytoplasmic dynein. These subtle functional distinctions between dynein subpopulations could be exploited to study specific aspects of the spindle assembly checkpoint, which is a key mediator of fidelity in eukaryotic cell division.

  4. Inositol hexakisphosphate kinase 1 (IP6K1) activity is required for cytoplasmic dynein-driven transport

    Science.gov (United States)

    Chanduri, Manasa; Rai, Ashim; Malla, Aushaq Bashir; Wu, Mingxuan; Fiedler, Dorothea; Mallik, Roop; Bhandari, Rashna

    2016-01-01

    Inositol pyrophosphates, such as diphosphoinositol pentakisphosphate (IP7), are conserved eukaryotic signaling molecules that possess pyrophosphate and monophosphate moieties. Generated predominantly by inositol hexakisphosphate kinases (IP6Ks), inositol pyrophosphates can modulate protein function by posttranslational serine pyrophosphorylation. Here, we report inositol pyrophosphates as novel regulators of cytoplasmic dynein-driven vesicle transport. Mammalian cells lacking IP6K1 display defects in dynein-dependent trafficking pathways, including endosomal sorting, vesicle movement, and Golgi maintenance. Expression of catalytically active but not inactive IP6K1 reverses these defects, suggesting a role for inositol pyrophosphates in these processes. Endosomes derived from slime mold lacking inositol pyrophosphates also display reduced dynein-directed microtubule transport. We demonstrate that Ser51 in the dynein intermediate chain (IC) is a target for pyrophosphorylation by IP7, and this modification promotes the interaction of the IC N-terminus with the p150Glued subunit of dynactin. IC–p150Glued interaction is decreased, and IC recruitment to membranes is reduced in cells lacking IP6K1. Our study provides the first evidence for the involvement of IP6Ks in dynein function and proposes that inositol pyrophosphate-mediated pyrophosphorylation may act as a regulatory signal to enhance dynein-driven transport. PMID:27474409

  5. Transport and arrangement of the outer-dynein-arm docking complex in the flagella of Chlamydomonas mutants that lack outer dynein arms.

    Science.gov (United States)

    Wakabayashi, K; Takada, S; Witman, G B; Kamiya, R

    2001-04-01

    The outer dynein arms of Chlamydomonas flagella are attached to a precise site on the outer doublet microtubules and repeat at a regular interval of 24 nm. This binding is mediated by the outer dynein arm docking complex (ODA-DC), which is composed of three protein subunits. In this study, antibodies against the 83- and 62-kD subunits (DC83 and DC62) of the ODA-DC were used to analyze its state of association with outer arm components within the cytoplasm, and its localization in the axonemes of oda mutants. Immunoprecipitation indicates that DC83 and DC62 are preassembled within the cytoplasm, but that they are not associated with outer arm dynein. Both proteins are lost or greatly diminished in oda1 and oda3, mutants in the structural genes of DC62 and DC83, respectively, demonstrating that their association is necessary for their stable presence in the cytoplasm. Immunoelectron microscopy indicates that DC83 repeats at 24-nm intervals along the length of the doublet microtubules of oda6, which lacks outer arms; thus, outer arm periodicity may be determined by the ODA-DC. Flagellar regeneration and temporary dikaryon experiments indicate that the ODA-DC can be rapidly transported into the flagellum and assembled on the doublet microtubules independently of the outer arms and independently of flagellar growth. Unexpectedly, the intensity of ODA-DC labeling decreased toward the distal ends of axonemes of oda6 but not wild-type cells, suggesting that the outer arms reciprocally contribute to the assembly/stability of the ODA-DC.

  6. Female same gender stalking: a brief review of the literature and case report.

    Science.gov (United States)

    Carabellese, Felice; Candelli, Chiara; La Tegola, Donatella; Alfarano, Egle; Catanesi, Roberto

    2013-05-10

    The authors analyze a rare case of female same gender stalking that came to their observation as forensic psychiatry experts. Despite previously only heterosexual experiences, the woman, who was 30 in 2002, had three intimate same gender relationships in succession from 2002 to 2009: she broke off with each woman in order to take up with another. When she separated from the third woman she began violent persecutory behavior against her, in the form of harassment coming under the heading of stalking, and was reported to the authorities. In treatment with SSRI since 2003 for an anxiety disorder with panic episodes, she had been taking the drugs irregularly during the stalking period. At the end of the third relationship, after she had violently attacked her girlfriend she was advised by her family to present to a Hospital center in Northern Italy. There, she was diagnosed with a "Narcissistic Paranoid Personality Disorder", and it was hypothesized that the SSRI she was taking could have induced hypo/manic episodes and disinhibition in the woman, who had previously been heterosexual. At this hospital, mood stabilizers were prescribed. The defending lawyer therefore applied for a forensic psychiatry assessment, claiming that the persecutory behavior against the third girlfriend was induced by taking SSRI. In Italy the penal code specifies the recognition of abolished or diminished liability for crimes if a correlation between the mental disease and the crime can be demonstrated, if the disease was in course at the time of the crime, and if the motives behind the crime and the disease can be shown to be linked. In short, if the crime can be shown to be a symptom of the disease. But the forensic psychiatry assessment demonstrated that despite the presence of some factors of a psychopathological nature, the motives underlying the harassment were attributable to the woman's existential history and personality structure rather than to psychopathological causes. She was

  7. ENZYMATIC DIGESTIBILITY OF TOMATO, PEPPER, AND EGGPLANT STALKS MIXTURE

    Directory of Open Access Journals (Sweden)

    Yalçın Çöpür,

    2012-06-01

    Full Text Available Turkey annually produces 26 million tons of vegetables and is the third-biggest vegetable producer. After harvest, the waste of vegetable stalks lacking of economic value is burnt or left in the fields, causing environmental pollution. The aim of this study was to examine bioethanol production of a mixture of tomato, pepper, and eggplant stalks using an alternative chemical, sodium borohydrate (NaBH4 in a chemical pretreatment step. Both steam-exploded (SE and dry-milled (DM stalks were chemically pretreated and enzymatically hydrolyzed in this study. Results showed that SE stalks had better enzymatic digestibility compared to DM. NaOH treatment removed the highest amount of lignin (17.1%; SE, 2%, 90 min but also glucose (21.5%; SE, 2%, 90 min from the structure. On the other hand, NaBH4 removed the highest lignin in proportion to glucose for both SE and DM samples. Enzymatically hydrolyzed stalks gave the highest sugar yields of 30.1% (o.d.-dry matter for the SE sample when it was pretreated with 2% NaOH for 30 min.

  8. Cytoplasmic Dynein Is Required for the Spatial Organization of Protein Aggregates in Filamentous Fungi

    Directory of Open Access Journals (Sweden)

    Martin J. Egan

    2015-04-01

    Full Text Available Eukaryotes have evolved multiple strategies for maintaining cellular protein homeostasis. One such mechanism involves neutralization of deleterious protein aggregates via their defined spatial segregation. Here, using the molecular disaggregase Hsp104 as a marker for protein aggregation, we describe the spatial and temporal dynamics of protein aggregates in the filamentous fungus Aspergillus nidulans. Filamentous fungi, such as A. nidulans, are a diverse group of species of major health and economic importance and also serve as model systems for studying highly polarized eukaryotic cells. We find that microtubules promote the formation of Hsp104-positive aggregates, which coalesce into discrete subcellular structures in a process dependent on the microtubule-based motor cytoplasmic dynein. Finally, we find that impaired clearance of these inclusions negatively impacts retrograde trafficking of endosomes, a conventional dynein cargo, indicating that microtubule-based transport can be overwhelmed by chronic cellular stress.

  9. The p25 Subunit of the Dynactin Complex is Required for Dynein-Early Endosome Interaction

    Science.gov (United States)

    2011-01-01

    dynein–early endosome interaction in the filamen- tous fungus Aspergillus nidulans. In filamentous fungi , dynein and its regulators are important for...backbone of the dynactin complex, and its loss leads to a disruption of the whole complex. In Drosoph- ila and in filamentous fungi such as N. crassa...how the motor is targeted to these cargoes is still a topic under investigation. In filamentous fungi and higher eukaryotic cells such as neurons

  10. Drosophila Dynein intermediate chain gene, Dic61B, is required for spermatogenesis.

    Directory of Open Access Journals (Sweden)

    Roshan Fatima

    Full Text Available This study reports the identification and characterization of a novel gene, Dic61B, required for male fertility in Drosophila. Complementation mapping of a novel male sterile mutation, ms21, isolated in our lab revealed it to be allelic to CG7051 at 61B1 cytogenetic region, since two piggyBac insertion alleles, CG7051(c05439 and CG7051(f07138 failed to complement. CG7051 putatively encodes a Dynein intermediate chain. All three mutants, ms21, CG7051(c05439 and CG7051(f07138, exhibited absolute recessive male sterility with abnormally coiled sperm axonemes causing faulty sperm individualization as revealed by Phalloidin staining in Don Juan-GFP background. Sequencing of PCR amplicons uncovered two point mutations in ms21 allele and confirmed the piggyBac insertions in CG7051(c05439 and CG7051(f07138 alleles to be in 5'UTR and 4(th exon of CG7051 respectively, excision of which reverted the male sterility. In situ hybridization to polytene chromosomes demonstrated CG7051 to be a single copy gene. RT-PCR of testis RNA revealed defective splicing of the CG7051 transcripts in mutants. Interestingly, expression of cytoplasmic dynein intermediate chain, α, β, γ tubulins and α-spectrin was normal in mutants while ultra structural studies revealed defects in the assembly of sperm axonemes. Bioinformatics further highlighted the homology of CG7051 to axonemal dynein intermediate chain of various organisms, including DNAI1 of humans, mutations in which lead to male sterility due to immotile sperms. Based on these observations we conclude that CG7051 encodes a novel axonemal dynein intermediate chain essential for male fertility in Drosophila and rename it as Dic61B. This is the first axonemal Dic gene of Drosophila to be characterized at molecular level and shown to be required for spermatogenesis.

  11. Apparent role of dynein in glucose-6-phosphate dehydrogenase trafficking in neutrophils from pregnant women.

    Science.gov (United States)

    Huang, Ji-Biao; Espinoza, Jimmy; Romero, Roberto; Petty, Howard R

    2006-03-01

    To better understand the mechanisms of metabolic microcompartmentalization associated with neutrophil hexose monophosphate shunt activity during pregnancy, we have studied the intracellular trafficking of glucose-6-phosphate dehydrogenase (G6PDase). Microtubule motor proteins colocalize with G6PDase. Dynein inhibitors block G6PDase accumulation at the microtubule-organizing center in pregnancy cells. On this basis, we conclude that microtubule motor proteins participate in hexose monophosphate shunt enzyme transport within leukocytes.

  12. Nucleoporin translocated promoter region (Tpr) associates with dynein complex, preventing chromosome lagging formation during mitosis.

    Science.gov (United States)

    Nakano, Hiroshi; Funasaka, Tatsuyoshi; Hashizume, Chieko; Wong, Richard W

    2010-04-01

    Gain or loss of whole chromosomes is often observed in cancer cells and is thought to be due to aberrant chromosome segregation during mitosis. Proper chromosome segregation depends on a faithful interaction between spindle microtubules and kinetochores. Several components of the nuclear pore complex/nucleoporins play critical roles in orchestrating the rapid remodeling events that occur during mitosis. Our recent studies revealed that the nucleoporin, Rae1, plays critical roles in maintaining spindle bipolarity. Here, we show association of another nucleoporin, termed Tpr (translocated promoter region), with the molecular motors dynein and dynactin, which both orchestrate with the spindle checkpoints Mad1 and Mad2 during cell division. Overexpression of Tpr enhanced multinucleated cell formation. RNA interference-mediated knockdown of Tpr caused a severe lagging chromosome phenotype and disrupted spindle checkpoint proteins expression and localization. Next, we performed a series of rescue and dominant negative experiments to confirm that Tpr orchestrates proper chromosome segregation through interaction with dynein light chain. Our data indicate that Tpr functions as a spatial and temporal regulator of spindle checkpoints, ensuring the efficient recruitment of checkpoint proteins to the molecular motor dynein to promote proper anaphase formation.

  13. Detailed structural and biochemical characterization of the nexin-dynein regulatory complex.

    Science.gov (United States)

    Oda, Toshiyuki; Yanagisawa, Haruaki; Kikkawa, Masahide

    2015-01-15

    The nexin-dynein regulatory complex (N-DRC) forms a cross-bridge between the outer doublet microtubules of the axoneme and regulates dynein motor activity in cilia/flagella. Although the molecular composition and the three-dimensional structure of N-DRC have been studied using mutant strains lacking N-DRC subunits, more accurate approaches are necessary to characterize the structure and function of N-DRC. In this study, we precisely localized DRC1, DRC2, and DRC4 using cryo-electron tomography and structural labeling. All three N-DRC subunits had elongated conformations and spanned the length of N-DRC. Furthermore, we purified N-DRC and characterized its microtubule-binding properties. Purified N-DRC bound to the microtubule and partially inhibited microtubule sliding driven by the outer dynein arms (ODAs). Of interest, microtubule sliding was observed even in the presence of fourfold molar excess of N-DRC relative to ODA. These results provide insights into the role of N-DRC in generating the beating motions of cilia/flagella.

  14. Dynein regulates epithelial polarity and the apical localization of stardust A mRNA.

    Science.gov (United States)

    Horne-Badovinac, Sally; Bilder, David

    2008-01-01

    Intense investigation has identified an elaborate protein network controlling epithelial polarity. Although precise subcellular targeting of apical and basolateral determinants is required for epithelial architecture, little is known about how the individual determinant proteins become localized within the cell. Through a genetic screen for epithelial defects in the Drosophila follicle cells, we have found that the cytoplasmic Dynein motor is an essential regulator of apico-basal polarity. Our data suggest that Dynein acts through the cytoplasmic scaffolding protein Stardust (Sdt) to localize the transmembrane protein Crumbs, in part through the apical targeting of specific sdt mRNA isoforms. We have mapped the sdt mRNA localization signal to an alternatively spliced coding exon. Intriguingly, the presence or absence of this exon corresponds to a developmental switch in sdt mRNA localization in which apical transcripts are only found during early stages of epithelial development, while unlocalized transcripts predominate in mature epithelia. This work represents the first demonstration that Dynein is required for epithelial polarity and suggests that mRNA localization may have a functional role in the regulation of apico-basal organization. Moreover, we introduce a unique mechanism in which alternative splicing of a coding exon is used to control mRNA localization during development.

  15. Dynein regulates epithelial polarity and the apical localization of stardust A mRNA.

    Directory of Open Access Journals (Sweden)

    Sally Horne-Badovinac

    2008-01-01

    Full Text Available Intense investigation has identified an elaborate protein network controlling epithelial polarity. Although precise subcellular targeting of apical and basolateral determinants is required for epithelial architecture, little is known about how the individual determinant proteins become localized within the cell. Through a genetic screen for epithelial defects in the Drosophila follicle cells, we have found that the cytoplasmic Dynein motor is an essential regulator of apico-basal polarity. Our data suggest that Dynein acts through the cytoplasmic scaffolding protein Stardust (Sdt to localize the transmembrane protein Crumbs, in part through the apical targeting of specific sdt mRNA isoforms. We have mapped the sdt mRNA localization signal to an alternatively spliced coding exon. Intriguingly, the presence or absence of this exon corresponds to a developmental switch in sdt mRNA localization in which apical transcripts are only found during early stages of epithelial development, while unlocalized transcripts predominate in mature epithelia. This work represents the first demonstration that Dynein is required for epithelial polarity and suggests that mRNA localization may have a functional role in the regulation of apico-basal organization. Moreover, we introduce a unique mechanism in which alternative splicing of a coding exon is used to control mRNA localization during development.

  16. Effect of catch bonding on transport of cellular cargo by dynein motors

    Science.gov (United States)

    Nair, Anil; Chandel, Sameep; Mitra, Mithun K.; Muhuri, Sudipto; Chaudhuri, Abhishek

    2016-09-01

    Recent experiments have demonstrated that dynein motors exhibit catch bonding behavior, in which the unbinding rate of a single dynein decreases with increasing force, for a certain range of force. Motivated by these experiments, we study the effect of catch bonding on unidirectional transport properties of cellular cargo carried by multiple dynein motors. We introduce a threshold force bond deformation (TFBD) model, consistent with the experiments, wherein catch bonding sets in beyond a critical applied load force. We find catch bonding can result in dramatic changes in the transport properties, which are in sharp contrast to kinesin-driven unidirectional transport, where catch bonding is absent. We predict that under certain conditions, the average velocity of the cellular cargo can actually increase as applied load is increased. We characterize the transport properties in terms of a velocity profile plot in the parameter space of the catch bond strength and the stall force of the motor. This plot yields predictions that may be experimentally accessed by suitable modifications of motor transport and binding properties.

  17. Regulation of dynein-mediated autophagosomes trafficking by ASM in CASMCs.

    Science.gov (United States)

    Xu, Ming; Zhang, Qiufang; Li, Pin-Lan; Nguyen, Thaison; Li, Xiang; Zhang, Yang

    2016-01-01

    Acid sphingomyelinase (ASM; gene symbol Smpd1) has been shown to play a crucial role in autophagy maturation by controlling lysosomal fusion with autophagosomes in coronary arterial smooth muscle cells (CASMCs). However, the underlying molecular mechanism by which ASM controls autophagolysosomal fusion remains unknown. In primary cultured CASMCs, lysosomal Ca2+ induced by 7-ketocholesterol (7-Ket, an atherogenic stimulus and autophagy inducer) was markedly attenuated by ASM deficiency or TRPML1 gene silencing suggesting that ASM signaling is required for TRPML1 channel activity and subsequent lysosomal Ca(2+) release. In these CASMCs, ASM deficiency or TRPML1 gene silencing markedly inhibited 7-Ket-induced dynein activation. In addition, 7-Ket-induced autophagosome trafficking, an event associated with lysosomal Ca(2+) release and dynein activity, was significantly inhibited in ASM-deficient (Smpd1(-/-)) CASMCs compared to that in Smpd1(+/+) CASMCs. Finally, overexpression of TRPML1 proteins restored 7-Ket-induced lysosomal Ca(2+) release and autophagosome trafficking in Smpd1-/- CASMCs. Collectively, these results suggest that ASM plays a critical role in regulating lysosomal TRPML1-Ca(2+) signaling and subsequent dynein-mediated autophagosome trafficking, which leads its role in controlling autophagy maturation in CASMCs under atherogenic stimulation.

  18. An outer arm dynein light chain acts in a conformational switch for flagellar motility

    Science.gov (United States)

    Patel-King, Ramila S.

    2009-01-01

    A system distinct from the central pair–radial spoke complex was proposed to control outer arm dynein function in response to alterations in the mechanical state of the flagellum. In this study, we examine the role of a Chlamydomonas reinhardtii outer arm dynein light chain that associates with the motor domain of the γ heavy chain (HC). We demonstrate that expression of mutant forms of LC1 yield dominant-negative effects on swimming velocity, as the flagella continually beat out of phase and stall near or at the power/recovery stroke switchpoint. Furthermore, we observed that LC1 interacts directly with tubulin in a nucleotide-independent manner and tethers this motor unit to the A-tubule of the outer doublet microtubules within the axoneme. Therefore, this dynein HC is attached to the same microtubule by two sites: via both the N-terminal region and the motor domain. We propose that this γ HC–LC1–microtubule ternary complex functions as a conformational switch to control outer arm activity. PMID:19620633

  19. Floral stalk on date palm: a new discovery

    Directory of Open Access Journals (Sweden)

    P. Kumar

    2014-12-01

    Full Text Available Date palm (Phoenix dactylifera L. is harvested for its sweet fruit mainly in the middle east and other parts of the world. It has been cultivated for several thousand years and is known to be found in Mesopotamia as well. Besides the fruit, the various parts of the tree are employed for variety of uses. The stalks of the fruit, which connect the fruit to the spikelet, are very beautiful, colourful flower like structures, which have never been described earlier. These fruit stalks could be used for decorations in houses and would then add to more economic gain to the farmer. We observed these stalks and describe here this interesting finding hitherto unreported in the world literature.

  20. Contribution to the discussion on the criminalization of stalking

    Directory of Open Access Journals (Sweden)

    Miladinović-Stefanović Dušica

    2016-01-01

    Full Text Available The serious and complex nature of stalking, as a social phenomenon, is reflected in diverse forms of this illicit act, the severity of consequences caused by its commission, and the likelihood of being turned into violence. Whereas it may be observed from different perspectives, in this paper stalking is examined from the aspect of substantive criminal law. In the first part of this article, the author provides an overview of legal provisions on the crime of stalking as envisaged in selected European legislations. In the second part of the paper, the author re-examines the capacity of the existing Serbian criminal legislation to respond to this problem, especially through the envisaged criminal offence of endangering safety of another. In conclusion, the author discusses the inadequacy of the existing legislation and the need for further legislative intervention in this area.

  1. Predicting Overt and Cyber Stalking Perpetration by Male and Female College Students

    Science.gov (United States)

    Menard, Kim S.; Pincus, Aaron L.

    2012-01-01

    In this study, self-report student surveys on early childhood maltreatment, attachment styles, alcohol expectancies, and narcissistic personality traits are examined to determine their influence on stalking behavior. Two subtypes of stalking were measured using Spitzberg and Cupach's (2008) Obsessive Relational Intrusion: cyber stalking (one…

  2. Impacts of fungal stalk rot pathogens on physicochemical properties of sorghum grain

    Science.gov (United States)

    Stalk rot diseases are among the most ubiquitous and damaging fungal diseases of sorghum worldwide. Although reports of quantitative stalk rot yield losses are available, the impact of stalk rot on the physicochemical attributes of sorghum grain is currently unknown. This study was conducted to test...

  3. 40 CFR 180.1087 - Sesame stalks; exemption from the requirement of a tolerance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Sesame stalks; exemption from the... Exemptions From Tolerances § 180.1087 Sesame stalks; exemption from the requirement of a tolerance. An... sesame stalk in or on the following raw agricultural commodities: Almond; almond, hulls; cotton...

  4. A Microfluidic Flow-switching Device Powered by Vorticella Stalk

    Science.gov (United States)

    Nagai, M.; Tanizaki, K.; Hayasaka, Y.; Kawashima, T.; Shibata, T.

    2013-04-01

    Bioactuators are an attractive alternative for mechanical components of MEMS devices. We propose a flow-switching device active to calcium ion based on bioactuator of Vorticella. We develop a fundamental procedure for immobilization of Vorticella in a microfluidic chamber and control of contraction and extension of stalks. Cells were trapped in microfluidic chambers and allowed to adhere. After treatment of cells, stalks were contracted and extended by injecting solutions. Flow speed changed during the motion. Our developed method presents a strategy for application of bioactuator.

  5. Two unusual causes of pituitary stalk thickening in children without clinical features of diabetes insipidus

    Energy Technology Data Exchange (ETDEWEB)

    Andronikou, Savvas; Furlan, Gisella; Fieggen, Anthony G.; Wilmshurst, Jo [Department of Paediatric Neuroradiology, University of Cape Town, Klipfontein Road, 7700, Rondebosch, Cape Town (South Africa); Cross War Memorial Children' s Hospital, University of Cape Town, Klipfontein Road, 7700, Rondebosch, Cape Town (South Africa); School of Child and Adolescent Health, University of Cape Town, Klipfontein Road, 7700, Rondebosch, Cape Town (South Africa)

    2003-07-01

    Pituitary stalk thickening has a wide differential diagnosis, but almost all infundibular diseases present with diabetes insipidus (DI). We present a child with metastatic involvement of the pituitary stalk from a primary pontine tumour and a child with tuberculous infiltration of the pituitary stalk and associated meningeal inflammation. Neither child presented with DI. Even though both metastatic disease and tuberculous infiltration of the stalk have been reported in adults, these are the first reports with accompanying cross-sectional images of pituitary stalk involvement by these diseases in children. (orig.)

  6. 78 FR 1125 - National Stalking Awareness Month, 2013

    Science.gov (United States)

    2013-01-07

    ... President of the United States of America A Proclamation Each year, millions of Americans face the fear... to bring perpetrators to justice. Stalking is a pattern of unwanted contact that causes victims to fear for their safety or the safety of family members. It can include implied or explicit threats...

  7. Xinjiang:Cotton Stalk Fiber Will Bring Profits to Farmers

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    On April 19,2007,Seminar on the Development and Application of Xinjiang Cotton Stalk Fiber,hosted by the Economic Operations Bureau of National Development and Reform Commission (NDRC),successfully opened in Xinjiang Hotel of Beijing.The Seminar was attended by inspector Zhang

  8. Fatal attraction syndrome: stalking behavior and borderline personality.

    Science.gov (United States)

    Sansone, Randy A; Sansone, Lori A

    2010-05-01

    Stalking, which consists of chronic nuisance behaviors by an offender that result in deleterious emotional and/or physical effects on a victim, is experienced by a significant minority of individuals in the community. According to the United States Department of Justice, eight percent of women and two percent of men have been victimized at some time in their lives by stalkers. Stalking could be viewed as an illogical or irrational preoccupation with another individual. Because of the unusual and intense attachment dynamics in borderline personality disorder, this diagnosis is particularly suggestive among stalkers. In this edition of The Interface, we examine the possible association between stalking behavior and borderline personality disorder. Five studies report prevalence rates of borderline personality disorder among stalkers, with four reporting rates between 4 and 15 percent (i.e., a small minority). However, three of these studies represent forensic populations and one consists of patients who stalked their psychiatrists. In contrast, in the remaining sample of stalkers, where being charged with a crime was not an inclusion criterion, the prevalence of borderline personality disorder was considerably higher at 45 percent. These data suggest that in less forensically focused samples of stalkers, rates of borderline personality are likely to be substantially higher, but confirmatory data is lacking.

  9. Hyperprolactinemia associated to calcification of the pituitary stalk: case report

    Directory of Open Access Journals (Sweden)

    OLIVEIRA MIRIAM DA COSTA

    1998-01-01

    Full Text Available In this work, the authors report the case of a female patient with 24 years of age with hyperprolactinemia, who presented a pituitary stalk calcification as seen by CT scan. Once other possible etiologies were excluded, we concluded that the calcification was probably related to hyperprolactinemia caused by interruption of the input of dopamine to the pituitary gland.

  10. [Allelopathy of decomposing pepper stalk on pepper growth].

    Science.gov (United States)

    Hou, Yongxia; Zhou, Baoli; Wu, Xiaoling; Fu, Yawen; Wang, Yueying

    2006-04-01

    With decomposing pepper stalk as test material, this paper studied its allelopathy on the growth of pepper plants. The results showed that after 60 days of decomposition, the decomposed pepper stalk could decrease the plant height, stem diameter, dry weights of above-and underground biomass, leaf area, and chlorophyll content of pepper plants by 0.0374 - 0.0646, 0.0020 - 0.0097, 0.0050 - 0.0355 and 0.0916 - 0.3584, 0.0016 - 0.0251, and 0.0043 - 0.0242 respectively. These inhibitory effects were enhanced after 120 days of decomposition, but the difference with CK was not significant. The root vigor and its SOD, POD and CAT activities of pepper plants were decreased, while the MDA content and relative conductivity were increased with the increasing concentration of decomposed pepper stalk and with the prolong of treating time. The allelopathic effects of decomposed pepper stalk on the physiological indices of pepper root activity ranged from 0.0163 to 0.6507, which was significantly higher than that of plant growth index.

  11. Shift of the pituitary stalk in intrasellar pituitary adenomas

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Jusuke; Tokiguchi, Susumu; Nakamori, Akitoshi (Niigata Univ. (Japan). School of Medicine); Watanabe, Akira; Yokoyama, Motoharu

    1982-08-01

    Fifty-one patients from a group of 344 patients undergoing the evaluation of intrasellar or parasellar tumors were diagnosed on CT as having an intrasellar pituitary adenoma. Axial transverse sections were performed at -10/sup 0/ to Reid's basal line, using 1.5-mm-thick slices and sagittal and coronal reformation. Of these 51 patients, 17 showed a shift of the pituitary stalk. The area where a tumor was thought to be located within the sella turcica on preoperative CT became defective on CT after transsphenoidal surgery in all cases. Histological verification was obtained in all cases. Also, the shift of the pituitary stalk was normalized or markedly improved after surgery in all cases. In functioning tumors, all cases except two showed an endocrinologically normal state or a marked improvement after transsphenoidal surgery. On the basis of the above-mentioned facts, it was concluded that the shift of the pituitary stalk in intrasellar pituitary adenomas indicated the evidence of a mass and its location in the sella turcica. However, a shift of the pituitary stalk was also observed under other conditions, such as empty sella and tuberculum sellae meningioma, and so it is not a pathognomonic finding in intrasellar pituitary adenomas.

  12. Rapid continuous pyrolysis of cotton stalks for charcoal production

    Energy Technology Data Exchange (ETDEWEB)

    Mobarak, F.

    1983-10-01

    Charcoal of more than 80% carbon content was obtained from cotton stalks by using a rapid continuous pyrolysis process. The yield ranged from 17 to 37% depending on the pyrolysis temperature. When raising the temperature from 400 to 700 degrees C the carbon content of the charcoal initially increased, then remained constant while the yield decreased continually. The optimum pyrolysis temperature was found to be 600 degrees C. At this temperature a product having 86% carbon content on a moisture and ash free basis was obtained. The bulk density went through a minimum at a pyrolysis temperature of 600 degrees C. The increase observed at higher temperatures was attributed to the collapse of the cell wall structure. On the other hand, the adsorption activity decreased continually with increasing pyrolysis temperature. To some extent, charcoal properties depend on particle size of the raw material. Thus, the fine fraction had a higher ash content and a higher adsorption capacity than the coarse fraction. Compared to similar charcoal samples from other agricultural residues and wood the cotton stalk charcoal showed a remarkably high adsorption activity even without any additional activation. Gathering cotton stalks and their prompt conversion to charcoal by rapid continuous pyrolysis would eliminate worm dissemination and fire hazards resulting from storage of the stalks by the farmers.

  13. THE FINE STRUCTURE OF STALKED BACTERIA BELONGING TO THE FAMILY CAULOBACTERACEAE.

    Science.gov (United States)

    STOVEPOINDEXTER, J L; COHEN-BAZIRE, G

    1964-12-01

    The fine structure of a series of stalked bacteria belonging to the genera Caulobacter and Asticcacaulis has been examined in thin sections. The cell wall has the multilayered structure typical of many Gram-negative bacteria, and continues without interruption throughout the length of the stalk. The core of the stalk, continuous with the cytoplasmic region of the cell, is enclosed in an extension of the cell membrane, and contains a system of internal membranes: it is devoid of ribosomes and nucleoplasm. A membranous organelle occupies the juncture of stalk and cell, separating the ribosomal region from the core of the stalk. Typical mesosomes also occur in the cell, being particularly frequent at the plane of division. The secreted holdfast is located at the tip of the stalk in Caulobacter, and at the pole of the cell adjacent to the stalk in Asticcacaulis.

  14. Intimate partner stalking victimization and posttraumatic stress symptoms in post-abuse women.

    Science.gov (United States)

    Fleming, Kimberly N; Newton, Tamara L; Fernandez-Botran, Rafael; Miller, James J; Ellison Burns, Vicki

    2012-12-01

    This study aimed to further understanding of intimate partner stalking victimization in post-abuse women, with particular attention to the definition of stalking (with or without fear and threat) most predictive of posttraumatic stress (PTS) symptoms. In community midlife women with histories of divorce (N = 192), a history of stalking victimization accompanied by fear and threat was positively correlated with PTS symptom severity, after accounting for other partner abuse. The presence, compared with absence, of fear-and-threat stalking history doubled the odds of symptomatic levels of hyperarousal. Greater physical assault and injury chronicity differentiated fear-and-threat stalked women from other stalked women. Stalking contributed to a fuller understanding of PTS symptoms in women, showing particular relevance for hyperarousal.

  15. Effect of Potassium on Ultrastructure of Maize Stalk Pith and Young Root and Their Relation to Stalk Rot Resistance

    Institute of Scientific and Technical Information of China (English)

    LI Wen-juan; HE Ping; JIN Ji-yun

    2010-01-01

    To study the mechanism of potassium(K)application on improvement of maize resistance to stalk rot at cellular level,scanning electron microscope and transmission electron microscope were used to observe the effect of K on the ultrastructure of maize stalk pith tissue and young root tip cell influenced by K and pathogen.In K deficient treatment,parenchyma cells of stalk pith had abnormal structure,and the cell wall between upper and lower adjacent cell was damaged,resulting in the loss of connections between vascular cells and insufficient supporting capacity.However,an improved K nutrition helped to keep a quite tight arrangement of root cell with thick cell wall,and prevent the invasion of pathogen effectively.Moreover,K treated root cell had abundant golgi apparatus,which could excrete large amount of secretions to degrade mycelium.Papillary and highly electronic intensity dot were accumulated at the invading point to prevent the development of the mycelium.Improved K nutrition could increase the resistant ability of maize plant to stalk rot,through keeping cell structure stability,preventing the expansion of intracellular space to reduce the chances of pathogen invasions,and through reinforcing cell wall and formation of intercellular and intracellular material to restrict further development of pathogen in host cell.

  16. Distribution of tubulin, kinesin, and dynein in light- and dark-adapted octopus retinas.

    Science.gov (United States)

    Martinez, J M; Elfarissi, H; De Velasco, B; Ochoa, G H; Miller, A M; Clark, Y M; Matsumoto, B; Robles, L J

    2000-01-01

    Cephalopod retinas exhibit several responses to light and dark adaptation, including rhabdom size changes, photopigment movements, and pigment granule migration. Light- and dark-directed rearrangements of microfilament and microtubule cytoskeletal transport pathways could drive these changes. Recently, we localized actin-binding proteins in light-/dark-adapted octopus rhabdoms and suggested that actin cytoskeletal rearrangements bring about the formation and degradation of rhabdomere microvilli subsets. To determine if the microtubule cytoskeleton and associated motor proteins control the other light/dark changes, we used immunoblotting and immunocytochemical procedures to map the distribution of tubulin, kinesin, and dynein in dorsal and ventral halves of light- and dark-adapted octopus retinas. Immunoblots detected alpha- and beta-tubulin, dynein intermediate chain, and kinesin heavy chain in extracts of whole retinas. Epifluorescence and confocal microscopy showed that the tubulin proteins were distributed throughout the retina with more immunoreactivity in retinas exposed to light. Kinesin localization was heavy in the pigment layer of light- and dark-adapted ventral retinas but was less prominent in the dorsal region. Dynein distribution also varied in dorsal and ventral retinas with more immunoreactivity in light- and dark-adapted ventral retinas and confocal microscopy emphasized the granular nature of this labeling. We suggest that light may regulate the distribution of microtubule cytoskeletal proteins in the octopus retina and that position, dorsal versus ventral, also influences the distribution of motor proteins. The microtubule cytoskeleton is most likely involved in pigment granule migration in the light and dark and with the movement of transport vesicles from the photoreceptor inner segments to the rhabdoms.

  17. DRC3 connects the N-DRC to dynein g to regulate flagellar waveform

    OpenAIRE

    Awata, Junya; Song, Kangkang; Lin, Jianfeng; King, Stephen M.; Sanderson, Michael J.; Nicastro, Daniela; Witman, George B.

    2015-01-01

    The nexin-dynein regulatory complex (N-DRC), which is a major hub for the control of flagellar motility, contains at least 11 different subunits. A major challenge is to determine the location and function of each of these subunits within the N-DRC. We characterized a Chlamydomonas mutant defective in the N-DRC subunit DRC3. Of the known N-DRC subunits, the drc3 mutant is missing only DRC3. Like other N-DRC mutants, the drc3 mutant has a defect in flagellar motility. However, in contrast to o...

  18. Monte Carlo Simulation on Coordinated Movement of Kinesin and Dynein Motors

    Institute of Scientific and Technical Information of China (English)

    WANG Hong; DOU Shuo-Xing; WANG Peng-Ye

    2008-01-01

    Kinesin and dynein are two important classes of molecular motors which are responsible for active organelle trafficking and cell division.They call work together to carry a cargo,moving along the microtubule in a coordinated way.We use Monte Carlo method to simulate the dynamics of this coordinated movement.Based on four essential assumptions,our simulations reproduce some features of the recent in vivo experiments.The fast moving speed of the cargo js simulated and the speed distribution is presented.

  19. Ebola Virus VP35 Interaction with Dynein LC8 Regulates Viral RNA Synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Luthra, Priya; Jordan, David S.; Leung, Daisy W.; Amarasinghe, Gaya K.; Basler, Christopher F.; Lyles, D. S.

    2015-03-04

    Ebola virus VP35 inhibits alpha/beta interferon production and functions as a viral polymerase cofactor. Previously, the 8-kDa cytoplasmic dynein light chain (LC8) was demonstrated to interact with VP35, but the functional consequences were unclear. Here we demonstrate that the interaction is direct and of high affinity and that binding stabilizes the VP35 N-terminal oligomerization domain and enhances viral RNA synthesis. Mutational analysis demonstrates that VP35 interaction is required for the functional effects of LC8.

  20. Limb body wall complex or body stalk complex or cyllosomas: a case report

    Directory of Open Access Journals (Sweden)

    S. Saritha

    2013-04-01

    Full Text Available Limb body wall complex (LBWC is also called Body stalk complex and Cyllosomas. We present this rare congenital malformation complex highlighting the importance of early sonographic imaging findings in LBWC along with differentiation from other anterior abdominal wall defects. Limb body wall complex / Body stalk anomaly refers to a rare complicated polymalformative fetal malformation syndrome of uncertain etiology and results in head, heart, lung, diaphragm, kidney or gonadal abnormalities. LBWC was first described by Van Allen et al; in (1987. The two of the three following anomalies must be present to establish the diagnosis: 1. Exencephaly / Encephalocele with facial clefts, 2. Thoraco-Abdominoschisis / ventral body wall defects and 3. Limb defects. LBWC arises as a result of early amnion disruptions or error in embryonic development. If all components of the syndrome are present, the condition is lethal. LBWC is invariably fatal and incompatible with life. No case of postnatal survival is reported so far. Serum alpha-fetoprotein measurement and ultrasonography examination is the key to the prenatal diagnosis and followed by medical termination of pregnancy. It presents two distinct phenotypes described by Russo et al (1993 and later Cusi et al in (1996, according to the foetoplacental relationships: 1. Placento-cranial and 2.Placento-abdominal types. Among the 168 live births at S.V.S. Medical College & hospital Mahabubnagar (INDIA during the period of 2010-2011 we came across an aborted female fetus. It was weighing 1800gms, 30 weeks of gestation diagnosed by antenatal ultrasonography as ventral body wall defect. It was associated with ompholocele, severe scoliosis and limb defects. Its confirmation of the diagnosis of Limb body wall complex with Placento-abdominal type was done by postmortem fetography. [Int J Res Med Sci 2013; 1(2.000: 132-137

  1. [Effects of hot-NaOH pretreatment on Jerusalem artichoke stalk composition and subsequent enzymatic hydrolysis].

    Science.gov (United States)

    Wang, Qing; Qiu, Jingwen; Li, Yang; Shen, Fei

    2015-10-01

    In order to explore the possibility of Jerusalem artichoke stalk for bioenergy conversion, we analyzed the main composition of whole stalk, pitch, and core of the stalk. Meanwhile, these parts were pretreated with different NaOH concentrations at 121 degrees C. Afterwards, enzymatic hydrolysis was performed to evaluate the pretreatment efficiency. Jerusalem artichoke stalk was characterized by relatively high lignin content (32.0%) compared with traditional crop stalks. The total carbohydrate content was close to that of crop stalks, but with higher cellulose content (40.5%) and lower hemicellulose (19.6%) than those of traditional crop stalks. After pretreatment, the lignin content in the whole stalk, pitch, and core decreased by 13.1%-13.4%, 8.3%-13.5%, and 19.9%-27.2%, respectively, compared with the unpretreated substrates. The hemicellulose content in the whole stalk, pitch, and core decreased 87.8%-96.9%, 87.6%-95.0%, and 74.0%-90.2%, respectively. Correspondingly, the cellulose content in the pretreated whole stalk, pitch, and core increased by 56.5%-60.2%, 52.2%-55.4%, and 62.7%-73.2%, respectively. Moreover, increase of NaOH concentration for pretreatment could improve the enzymatic hydrolysis of the whole stalk and pitch by 2.3-2.6 folds and 10.3-18.5 folds, respectively. The hydrolysis of pretreated stalk core decreased significantly as 2.0 mol/L NaOH was employed, although the increased NaOH concentration can also improve its hydrolysis performance. Based on these results, hot-NaOH can be regarded as an option for Jerusalem artichoke stalk pretreatment. Increasing NaOH concentration was beneficial to hemicellulose and lignin removal, and consequently improved sugar conversion. However, the potential decrease of sugar conversion of the pretreated core by higher NaOH concentration suggested further optimization on the pretreatment conditions should be performed.

  2. Pituitary stalk lesion in a 13-year-old female.

    Science.gov (United States)

    Zilbermint, Mihail; Ramnitz, Mary S; Lodish, Maya B; Kanaka-Gantenbein, Christina; Kattamis, Antonis; Lyssikatos, Charalampos; Patronas, Nicholas J; Quezado, Martha M; Stratakis, Constantine A

    2014-03-01

    Germinomas presenting with a pituitary stalk lesion and panhypopituitarism are rare in children, and their definite diagnosis is challenging. An invasive diagnostic approach, such as a transsphenoidal biopsy, is often required prior to establishing a treatment regimen. A 13-year-old female presented with 1 year of secondary amenorrhea, fatigue, and progressive thirst with polyuria. Laboratory work-up revealed panhypopituitarism (central hypothyroidism, hypogonadotropic hypogonadism, adrenal insufficiency and central diabetes insipidus). α-Fetoprotein and β-human chorionic gonadotropin were not elevated in serum nor in cerebrospinal fluid. The magnetic resonance imaging (MRI) of the pituitary region showed an enhancing infundibular lesion, extending into the hypothalamus, and infiltrating the pituitary gland. A transsphenoidal biopsy of the infundibular lesion confirmed the diagnosis of germinoma (germ-cell tumor). After appropriate hormone replacement therapy, chemotherapy and low-dose radiation therapy, the patient achieved complete resolution of the pituitary stalk lesion on the MRI.

  3. Pituitary stalk lesion in a 13-year-old female

    Science.gov (United States)

    Zilbermint, Mihail; Ramnitz, Mary S.; Lodish, Maya B.; Kanaka-Gantenbein, Christina; Kattamis, Antonis; Lyssikatos, Charalampos; Patronas, Nicholas J.; Quezado, Martha M.

    2016-01-01

    Germinomas presenting with a pituitary stalk lesion and panhypopituitarism are rare in children, and their definite diagnosis is challenging. An invasive diagnostic approach, such as a transsphenoidal biopsy, is often required prior to establishing a treatment regimen. A 13-year-old female presented with 1 year of secondary amenorrhea, fatigue, and progressive thirst with polyuria. Laboratory work-up revealed panhypopituitarism (central hypothyroidism, hypogonadotropic hypogonadism, adrenal insufficiency and central diabetes insipidus). α-Fetoprotein and β-human chorionic gonadotropin were not elevated in serum nor in cerebrospinal fluid. The magnetic resonance imaging (MRI) of the pituitary region showed an enhancing infundibular lesion, extending into the hypothalamus, and infiltrating the pituitary gland. A transsphenoidal biopsy of the infundibular lesion confirmed the diagnosis of germinoma (germ-cell tumor). After appropriate hormone replacement therapy, chemotherapy and low-dose radiation therapy, the patient achieved complete resolution of the pituitary stalk lesion on the MRI. PMID:24129100

  4. Phenolic Compounds Analysis of Root, Stalk, and Leaves of Nettle

    Directory of Open Access Journals (Sweden)

    Semih Otles

    2012-01-01

    Full Text Available Types of nettles (Urtica dioica were collected from different regions to analyze phenolic compounds in this research. Nettles are specially grown in the coastal part. According to this kind of properties, nettle samples were collected from coastal part of (Mediterranean, Aegean, Black sea, and Marmara Turkey. Phenolic profile, total phenol compounds, and antioxidant activities of nettle samples were analyzed. Nettles were separated to the part of root, stalk, and leaves. Then, these parts of nettle were analyzed to understand the difference of phenolic compounds and amount of them. Nettle (root, stalk and leaves samples were analyzed by using High-Performance Liquid Chromatography with Diode-Array Detection (HPLC-DAD to qualitative and quantitative determination of the phenolic compounds. Total phenolic components were measured by using Folin-Ciocalteu method. The antioxidant activity was measured by using DPPH (2,2-diphenyl-1-picrylhydrazyl which is generally used for herbal samples and based on single electron transfer (SET.

  5. Fuel ethanol production from Jerusalem artichoke stalks using different yeasts

    Energy Technology Data Exchange (ETDEWEB)

    Margaritis, A.; Bajpai, P.; Bajpai, P.K.

    1983-01-01

    The inulin-type sugars present in the stalks of Jerusalem artichoke (Helianthus tuberosus) were extracted with hot water and were used as a substrate to produce fuel EtOH. Seven different yeasts were used to obtain batch kinetic data. The medium consisted of stalk extract from Jerusalem artichoke containing 7.3% total sugars, supplemented with 0.01% oleic acid, 0.01% corn steep liquor, and 0.05% Tween 80. All batch fermentations were carried out in a 1-L bioreactor at 35 degrees and pH 4.6, and the following parameters were measured as a function of time: total sugars, EtOH and biomass concentration, maximum specific growth rate, and biomass and EtOH yields. The best EtOH producer was Kluyveromyces marxianus UCD (FST) 55-82 which gave an EtOH-to-sugar yield 97% of the theoretical maximum value, with almost 100% sugar utilization.

  6. Role of kinesin-1 and cytoplasmic dynein in endoplasmic reticulum movement in VERO cells

    Science.gov (United States)

    Woźniak, Marcin J.; Bola, Becky; Brownhill, Kim; Yang, Yen-Ching; Levakova, Vesselina; Allan, Victoria J.

    2009-01-01

    Summary Generating the extended endoplasmic reticulum (ER) network depends on microtubules, which act as tracks for motor-driven ER tubule movement, generate the force to extend ER tubules by means of attachment to growing microtubule plus-ends and provide static attachment points. We have analysed ER dynamics in living VERO cells and find that most ER tubule extension is driven by microtubule motors. Surprisingly, we observe that ∼50% of rapid ER tubule movements occur in the direction of the centre of the cell, driven by cytoplasmic dynein. Inhibition of this movement leads to an accumulation of lamellar ER in the cell periphery. By expressing dominant-negative kinesin-1 constructs, we show that kinesin-1 drives ER tubule extension towards the cell periphery and that this motility is dependent on the KLC1B kinesin light chain splice form but not on KLC1D. Inhibition of kinesin-1 promotes a shift from tubular to lamellar morphology and slows down the recovery of the ER network after microtubule depolymerisation and regrowth. These observations reconcile previous conflicting studies of kinesin-1 function in ER motility in vivo. Furthermore, our data reveal that cytoplasmic dynein plays a role in ER motility in a mammalian cultured cell, demonstrating that ER motility is more complex than previously thought. PMID:19454478

  7. Impact-Free Measurement of Microtubule Rotations on Kinesin and Cytoplasmic-Dynein Coated Surfaces

    Science.gov (United States)

    Mitra, Aniruddha; Ruhnow, Felix; Nitzsche, Bert; Diez, Stefan

    2015-01-01

    Knowledge about the three-dimensional stepping of motor proteins on the surface of microtubules (MTs) as well as the torsional components in their power strokes can be inferred from longitudinal MT rotations in gliding motility assays. In previous studies, optical detection of these rotations relied on the tracking of rather large optical probes present on the outer MT surface. However, these probes may act as obstacles for motor stepping and may prevent the unhindered rotation of the gliding MTs. To overcome these limitations, we devised a novel, impact-free method to detect MT rotations based on fluorescent speckles within the MT structure in combination with fluorescence-interference contrast microscopy. We (i) confirmed the rotational pitches of MTs gliding on surfaces coated by kinesin-1 and kinesin-8 motors, (ii) demonstrated the superiority of our method over previous approaches on kinesin-8 coated surfaces at low ATP concentration, and (iii) identified MT rotations driven by mammalian cytoplasmic dynein, indicating that during collective motion cytoplasmic dynein side-steps with a bias in one direction. Our novel method is easy to implement on any state-of-the-art fluorescence microscope and allows for high-throughput experiments. PMID:26368807

  8. Bicaudal D2, dynein, and kinesin-1 associate with nuclear pore complexes and regulate centrosome and nuclear positioning during mitotic entry.

    Directory of Open Access Journals (Sweden)

    Daniël Splinter

    Full Text Available BICD2 is one of the two mammalian homologues of the Drosophila Bicaudal D, an evolutionarily conserved adaptor between microtubule motors and their cargo that was previously shown to link vesicles and mRNP complexes to the dynein motor. Here, we identified a G2-specific role for BICD2 in the relative positioning of the nucleus and centrosomes in dividing cells. By combining mass spectrometry, biochemical and cell biological approaches, we show that the nuclear pore complex (NPC component RanBP2 directly binds to BICD2 and recruits it to NPCs specifically in G2 phase of the cell cycle. BICD2, in turn, recruits dynein-dynactin to NPCs and as such is needed to keep centrosomes closely tethered to the nucleus prior to mitotic entry. When dynein function is suppressed by RNA interference-mediated depletion or antibody microinjection, centrosomes and nuclei are actively pushed apart in late G2 and we show that this is due to the action of kinesin-1. Surprisingly, depletion of BICD2 inhibits both dynein and kinesin-1-dependent movements of the nucleus and cytoplasmic NPCs, demonstrating that BICD2 is needed not only for the dynein function at the nuclear pores but also for the antagonistic activity of kinesin-1. Our study demonstrates that the nucleus is subject to opposing activities of dynein and kinesin-1 motors and that BICD2 contributes to nuclear and centrosomal positioning prior to mitotic entry through regulation of both dynein and kinesin-1.

  9. Ultrasonically assisted antioxidant extraction from grape stalks and olive leaves

    Science.gov (United States)

    Cárcel, Juan A.; García-Pérez, José V.; Mulet, Antonio; Rodríguez, Ligia; Riera, Enrique

    2010-01-01

    Grape stalks and olive leaves present high amount of phenolic compounds with antioxidant properties. The extraction of these compounds may be considered a way to increase in value both agro-food by-products. Ultrasound is widely applied in extraction due to its effects (cavitation, microstirring or sponge effect) over the process. The goal of this work was to address the application of ultrasound on the antioxidant extraction of olive leaves and grape stalk. For that purpose, the extraction of antioxidant compounds from grape stalks and olive leaves, previously dried at 100 °C, were carried out using a ethanolic solution (80 % v/v) at 60 °C. Extractions were carried out with (US; 30 kHz; 600W)) and agitation (AG) without ultrasound application. In the AG experiments, the solution was agitated with a stirrer. Samples were obtained at different extraction time (10, 30, 60, 120, 180, 240, 360, 480 and 1440 min) and their antioxidant capacity was measured using FRAP method. The Naik model was used to model the extraction kinetics, being identified the antioxidant capacity of extracts at the equilibrium (Y eq) and the initial velocity of extraction (Y eq/B). For grape stalks, the antioxidant capacity of extracts at the equilibrium (Y eq) and the initial velocity of extraction (Y eq/B) were higher in AG experiments than in US experiments. In the olive leaves extractions, the Y eq/B was of the same order for both treatments but Y eq was significantly higher for US experiments. The different influence of ultrasound for both by-products can be explained from their different geometry and structure.

  10. Stalked protozoa identification by image analysis and multivariable statistical techniques

    OpenAIRE

    Amaral, A.L.; Ginoris, Y. P.; Nicolau, Ana; M.A.Z. Coelho; Ferreira, E. C.

    2008-01-01

    Protozoa are considered good indicators of the treatment quality in activated sludge systems as they are sensitive to physical, chemical and operational processes. Therefore, it is possible to correlate the predominance of certain species or groups and several operational parameters of the plant. This work presents a semiautomatic image analysis procedure for the recognition of the stalked protozoa species most frequently found in wastewater treatment plants by determinin...

  11. Cathode Stalk Cooling System for the MK 1 Quarterwave Gun

    Science.gov (United States)

    2012-06-01

    of electrons can occur for strong fields, a π≥ . In this case, the electrons are shifted from the proper phase for gain to one for absorption ...better representing the pressure rise and decrease. The cooling system was then tested with a water chiller , which was easier to establish basic... chiller was set up in the evening, with the stalk temperatures at a room temperature of 293 K, and left on overnight to ensure a steady temperature

  12. Proteomic Analysis of Dynein-Interacting Proteins in Amyotrophic Lateral Sclerosis Synaptosomes Reveals Alterations in the RNA-Binding Protein Staufen1.

    Science.gov (United States)

    Gershoni-Emek, Noga; Mazza, Arnon; Chein, Michael; Gradus-Pery, Tal; Xiang, Xin; Li, Ka Wan; Sharan, Roded; Perlson, Eran

    2016-02-01

    Synapse disruption takes place in many neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS). However, the mechanistic understanding of this process is still limited. We set out to study a possible role for dynein in synapse integrity. Cytoplasmic dynein is a multisubunit intracellular molecule responsible for diverse cellular functions, including long-distance transport of vesicles, organelles, and signaling factors toward the cell center. A less well-characterized role dynein may play is the spatial clustering and anchoring of various factors including mRNAs in distinct cellular domains such as the neuronal synapse. Here, in order to gain insight into dynein functions in synapse integrity and disruption, we performed a screen for novel dynein interactors at the synapse. Dynein immunoprecipitation from synaptic fractions of the ALS model mSOD1(G93A) and wild-type controls, followed by mass spectrometry analysis on synaptic fractions of the ALS model mSOD1(G93A) and wild-type controls, was performed. Using advanced network analysis, we identified Staufen1, an RNA-binding protein required for the transport and localization of neuronal RNAs, as a major mediator of dynein interactions via its interaction with protein phosphatase 1-beta (PP1B). Both in vitro and in vivo validation assays demonstrate the interactions of Staufen1 and PP1B with dynein, and their colocalization with synaptic markers was altered as a result of two separate ALS-linked mutations: mSOD1(G93A) and TDP43(A315T). Taken together, we suggest a model in which dynein's interaction with Staufen1 regulates mRNA localization along the axon and the synapses, and alterations in this process may correlate with synapse disruption and ALS toxicity.

  13. Chemical composition of tomato (Solanum lycopersicum) stalk and suitability in the particleboard production.

    Science.gov (United States)

    Guuntekin, Ergun; Uner, Birol; Karakus, Beyhan

    2009-09-01

    This study examined chemical composition of tomato stalks and their possible feasibility in the production of particleboard. Three-layer experimental particleboards with density of 0.53, 0.63, and 0.73 g cm(-3) were manufactured from tomato stalks using certain ratios of urea formaldehyde (UF) and melamine urea formaldehyde (MUF) adhesives. Modulus of elasticity (MOE), modulus of rupture (MOR), internal bond strength (IB), thickness swelling (TS) properties of the boards were evaluated, and a statistical analysis was performed in order to examine possible feasibility of these stalks in commercial particleboard manufacturing. The experimental results have shown that production of general purpose particleboard used in dry conditions using tomato stalks is technically viable. The results of the study demonstrate that tomato stalks can be an alternative raw material source for particleboard industry. Use of agricultural waste such as tomato stalk can help solving waste management problems and contribute conservation of natural resources.

  14. Utilization of rorippa stalks (Rorippa austriaca in the production of medium density fiberboard

    Directory of Open Access Journals (Sweden)

    Ayhan Tozluoğlu

    2016-07-01

    Full Text Available The main objective of this study was to investigate the potential of rorippa stalks (Rorippa austriaca as a fiber-stalk mixture to produce fiberboards for general purposes. For panel production, the addition of stalks at various percentages to the wood fiber was the only variable. Panels produced utilizing rorippa stalks were compared to panels produced using 100% wood fiber. The chemical properties of rorippa stalks; holocellulose, α cellulose, lignin and ash content and alcohol-benzene, hot and cold water, and dilute alkali (1% NaOH solubilities, were also determined. Results indicated that panels could be produced utilizing up to 25% rorippa stalks without affecting the usability of the panels. It was not possible to meet the minimum IB strength standards when peanut husk was added to the mixture. Higher additions resulted in panels having lower elastic and rupture moduli than the minimum requirements according to TS-EN standards.

  15. Sensing the Mechanical State of the Axoneme and Integration of Ca2+ Signaling by Outer Arm Dynein

    Science.gov (United States)

    King, Stephen M.

    2010-01-01

    Axonemal dyneins have been demonstrated to monitor the mechanical state of the axoneme and must also alter activity in response to various signaling pathways. The central pair/radial spoke systems are clearly involved in controlling inner dynein arm function; however, the mechanisms by which the outer dynein arm transduces regulatory signals appear quite distinct at the molecular level. In Chlamydomonas, these regulatory components include thioredoxins involved in response to redox changes, molecules that tether the γ heavy chain motor unit to the A-tubule of the outer doublet and a Ca2+-binding protein that controls the structure of the γ heavy chain N-terminal domain. Together, these studies now suggest that the γ heavy chain acts as a key regulatory node for controlling outer arm function in response to alterations in curvature and ligand binding. Furthermore, they allow us to propose a testable molecular mechanism by which altered Ca2+ levels might lead to a change in ciliary waveform by controlling whether one heavy chain of outer arm dynein acts as a microtubule translocase or as an ATP-dependent brake that limits the amount of inter-doublet sliding. PMID:20186692

  16. Dynein light chain binding to a 3′-untranslated sequence mediates parathyroid hormone mRNA association with microtubules

    Science.gov (United States)

    Epstein, Eyal; Sela-Brown, Alin; Ringel, Israel; Kilav, Rachel; King, Stephen M.; Benashski, Sharon E.; Yisraeli, Joel K.; Silver, Justin; Naveh-Many, Tally

    2000-01-01

    The 3′-untranslated region (UTR) of mRNAs binds proteins that determine mRNA stability and localization. The 3′-UTR of parathyroid hormone (PTH) mRNA specifically binds cytoplasmic proteins. We screened an expression library for proteins that bind the PTH mRNA 3′-UTR, and the sequence of 1 clone was identical to that of the dynein light chain LC8, a component of the dynein complexes that translocate cytoplasmic components along microtubules. Recombinant LC8 binds PTH mRNA 3′-UTR, as shown by RNA electrophoretic mobility shift assay. We showed that PTH mRNA colocalizes with microtubules in the parathyroid gland, as well as with a purified microtubule preparation from calf brain, and that this association was mediated by LC8. To our knowledge, this is the first report of a dynein complex protein binding an mRNA. The dynein complex may be the motor that is responsible for transporting mRNAs to specific locations in the cytoplasm and for the consequent is asymmetric distribution of translated proteins in the cell. PMID:10683380

  17. Association of Lis1 with outer arm dynein is modulated in response to alterations in flagellar motility

    Science.gov (United States)

    Rompolas, Panteleimon; Patel-King, Ramila S.; King, Stephen M.

    2012-01-01

    The cytoplasmic dynein regulatory factor Lis1, which induces a persistent tight binding to microtubules and allows for transport of cargoes under high-load conditions, is also present in motile cilia/flagella. We observed that Lis1 levels in flagella of Chlamydomonas strains that exhibit defective motility due to mutation of various axonemal substructures were greatly enhanced compared with wild type; this increase was absolutely dependent on the presence within the flagellum of the outer arm dynein α heavy chain/light chain 5 thioredoxin unit. To assess whether cells might interpret defective motility as a “high-load environment,” we reduced the flagellar beat frequency of wild-type cells through enhanced viscous load and by reductive stress; both treatments resulted in increased levels of flagellar Lis1, which altered the intrinsic beat frequency of the trans flagellum. Differential extraction of Lis1 from wild-type and mutant axonemes suggests that the affinity of outer arm dynein for Lis1 is directly modulated. In cytoplasm, Lis1 localized to two punctate structures, one of which was located near the base of the flagella. These data reveal that the cell actively monitors motility and dynamically modulates flagellar levels of the dynein regulatory factor Lis1 in response to imposed alterations in beat parameters. PMID:22855525

  18. X-linked primary ciliary dyskinesia due to mutations in the cytoplasmic axonemal dynein assembly factor PIH1D3

    Science.gov (United States)

    Olcese, Chiara; Patel, Mitali P.; Shoemark, Amelia; Kiviluoto, Santeri; Legendre, Marie; Williams, Hywel J.; Vaughan, Cara K.; Hayward, Jane; Goldenberg, Alice; Emes, Richard D.; Munye, Mustafa M.; Dyer, Laura; Cahill, Thomas; Bevillard, Jeremy; Gehrig, Corinne; Guipponi, Michel; Chantot, Sandra; Duquesnoy, Philippe; Thomas, Lucie; Jeanson, Ludovic; Copin, Bruno; Tamalet, Aline; Thauvin-Robinet, Christel; Papon, Jean- François; Garin, Antoine; Pin, Isabelle; Vera, Gabriella; Aurora, Paul; Fassad, Mahmoud R.; Jenkins, Lucy; Boustred, Christopher; Cullup, Thomas; Dixon, Mellisa; Onoufriadis, Alexandros; Bush, Andrew; Chung, Eddie M. K.; Antonarakis, Stylianos E.; Loebinger, Michael R.; Wilson, Robert; Armengot, Miguel; Escudier, Estelle; Hogg, Claire; Al-Turki, Saeed; Anderson, Carl; Antony, Dinu; Barroso, Inês; Beales, Philip L.; Bentham, Jamie; Bhattacharya, Shoumo; Carss, Keren; Chatterjee, Krishna; Cirak, Sebahattin; Cosgrove, Catherine; Allan, Daly; Durbin, Richard; Fitzpatrick, David; Floyd, Jamie; Foley, A. Reghan; Franklin, Chris; Futema, Marta; Humphries, Steve E.; Hurles, Matt; McCarthy, Shane; Muddyman, Dawn; Muntoni, Francesco; Parker, Victoria; Payne, Felicity; Plagnol, Vincent; Raymond, Lucy; Savage, David B.; Scambler, Peter J.; Schmidts, Miriam; Semple, Robert; Serra, Eva; Stalker, Jim; van Kogelenberg, Margriet; Vijayarangakannan, Parthiban; Walter, Klaudia; Amselem, Serge; Sun, Zhaoxia; Bartoloni, Lucia; Blouin, Jean-Louis; Mitchison, Hannah M.

    2017-01-01

    By moving essential body fluids and molecules, motile cilia and flagella govern respiratory mucociliary clearance, laterality determination and the transport of gametes and cerebrospinal fluid. Primary ciliary dyskinesia (PCD) is an autosomal recessive disorder frequently caused by non-assembly of dynein arm motors into cilia and flagella axonemes. Before their import into cilia and flagella, multi-subunit axonemal dynein arms are thought to be stabilized and pre-assembled in the cytoplasm through a DNAAF2–DNAAF4–HSP90 complex akin to the HSP90 co-chaperone R2TP complex. Here, we demonstrate that large genomic deletions as well as point mutations involving PIH1D3 are responsible for an X-linked form of PCD causing disruption of early axonemal dynein assembly. We propose that PIH1D3, a protein that emerges as a new player of the cytoplasmic pre-assembly pathway, is part of a complementary conserved R2TP-like HSP90 co-chaperone complex, the loss of which affects assembly of a subset of inner arm dyneins. PMID:28176794

  19. Epidermal Growth Factor Stimulates Extracellular-Signal Regulated Kinase Phosphorylation of a Novel Site on Cytoplasmic Dynein Intermediate Chain 2

    Directory of Open Access Journals (Sweden)

    Andrew D. Catling

    2013-02-01

    Full Text Available Extracellular-signal regulated kinase (ERK signaling is required for a multitude of physiological and patho-physiological processes. However, the identities of the proteins that ERK phosphorylates to elicit these responses are incompletely known. Using an affinity purification methodology of general utility, here we identify cytoplasmic dynein intermediate chain 2 (DYNC1I-2, IC-2 as a novel substrate for ERK following epidermal growth factor receptor stimulation of fibroblasts. IC-2 is a subunit of cytoplasmic dynein, a minus-end directed motor protein necessary for transport of diverse cargos along microtubules. Emerging data support the hypothesis that post-translational modification regulates dynein but the signaling mechanisms used are currently unknown. We find that ERK phosphorylates IC-2 on a novel, highly conserved Serine residue proximal to the binding site for the p150Glued subunit of the cargo adapter dynactin. Surprisingly, neither constitutive phosphorylation nor a phosphomimetic substitution of this Serine influences binding of p150Glued to IC-2. These data suggest that ERK phosphorylation of IC-2 regulates dynein function through mechanisms other than its interaction with dynactin.

  20. Sequential activities of Dynein, Mud and Asp in centrosome-spindle coupling maintain centrosome number upon mitosis.

    Science.gov (United States)

    Bosveld, Floris; Ainslie, Anna; Bellaïche, Yohanns

    2017-09-01

    Centrosomes nucleate microtubules and are tightly coupled to the bipolar spindle to ensure genome integrity, cell division orientation and centrosome segregation. While the mechanisms of centrosome-dependent microtubule nucleation and bipolar spindle assembly have been the focus of numerous works, less is known on the mechanisms ensuring the centrosome-spindle coupling. The conserved NuMA protein (Mud in Drosophila) is best known for its role in spindle orientation. Here we analyzed the role of Mud and two of its interactors, Asp and Dynein, in the regulation of centrosome numbers in Drosophila epithelial cells. We found that Dynein and Mud mainly initiate centrosome-spindle coupling prior to nuclear envelope breakdown (NEB) by promoting correct centrosome positioning or separation, while Asp acts largely independently of Dynein and Mud to maintain centrosome-spindle coupling. Failure in the centrosome-spindle coupling leads to mis-segregation of the two centrosomes into one daughter cell resulting in cells with supernumerary centrosomes during subsequent divisions. Together, we propose that Dynein, Mud and Asp sequentially operate during the cell cycle to ensure efficient centrosome-spindle coupling in mitosis preventing centrosome mis-segregation to maintain centrosome number. © 2017. Published by The Company of Biologists Ltd.

  1. Mutations in ZMYND10, a gene essential for proper axonemal assembly of inner and outer dynein arms in humans and flies, cause primary ciliary dyskinesia

    DEFF Research Database (Denmark)

    Moore, Daniel J; Onoufriadis, Alexandros; Shoemark, Amelia

    2013-01-01

    Primary ciliary dyskinesia (PCD) is a ciliopathy characterized by airway disease, infertility, and laterality defects, often caused by dual loss of the inner dynein arms (IDAs) and outer dynein arms (ODAs), which power cilia and flagella beating. Using whole-exome and candidate-gene Sanger...... resequencing in PCD-affected families afflicted with combined IDA and ODA defects, we found that 6/38 (16%) carried biallelic mutations in the conserved zinc-finger gene BLU (ZMYND10). ZMYND10 mutations conferred dynein-arm loss seen at the ultrastructural and immunofluorescence level and complete cilia...

  2. Police and public perceptions of stalking: the role of prior victim-offender relationship.

    Science.gov (United States)

    Weller, Michelle; Hope, Lorraine; Sheridan, Lorraine

    2013-01-01

    One in every five women will experience stalking in their lifetime. Research suggests the lifetime prevalence rate ranges between 12% and 32% for among women and 4% and 17% among men. The majority of stalking victims have had some form of prior relationship with their stalker. The aim of the current study was to examine whether victim-offender relationship influences police officers' perception of a stalking event. Police officers (n = 132) and lay participants (n = 225) read one of three stalking scenarios where the nature of relationship between the victim and the stalker was manipulated to reflect an ex-intimate, work acquaintance, or stranger relationship. Results revealed that, for both samples, prior victim-offender relationship affected the extent to which the scenario was perceived to involve stalking behavior, with the stranger stalker scenario endorsed as most strongly constituting a case of stalking. Officer experience of stalking cases mitigated some prevalent stereotypical beliefs concerning stalking (e.g., victim responsibility). The findings suggest that further training is necessary to combat common misconceptions surrounding stalking. The importance of understanding how both lay and police responses are influenced by the perceived victim-offender relationship is discussed in relation to the development of public awareness campaigns and police officer training.

  3. A Constitutive Model for Uni-axial Compaction of Non-adhesive Corn Stalk Powder

    Institute of Scientific and Technical Information of China (English)

    Zhao Dong; Sun Yanling

    2004-01-01

    In order to study mechanical behaviors of corn stalk powder during the compaction, the yield criterion for corn stalk powder is proposed with a plasticity theory. From the stress-strain curves of uni-axial compaction test for corn stalk powder, the constitutive model, in which the equations are modified by experiments on corn stalk powder, is adopted to describe plastic behaviors of powder, and is discussed based on the incremental theory and deformation theory. The numerical results agree well with the experimental ones.

  4. A NudE/14-3-3 pathway coordinates Dynein and the Kinesin Khc73 to position the mitotic spindle

    OpenAIRE

    2013-01-01

    Mitotic spindle position is controlled by interactions of cortical molecular motors with astral microtubules. In animal cells, Partner of Inscuteable (Pins) acts at the cortex to coordinate the activity of Dynein and Kinesin-73 (Khc73; Kif13B in mammals) to orient the spindle. Though the two motors move in opposite directions, their synergistic activity is required for robust Pins-mediated spindle orientation. Here we identify a physical connection between Dynein and Khc73 that mediates coope...

  5. Role of recycling endosomes and lysosomes in dynein-dependent entry of canine parvovirus.

    Science.gov (United States)

    Suikkanen, Sanna; Sääjärvi, Katja; Hirsimäki, Jonna; Välilehto, Outi; Reunanen, Hilkka; Vihinen-Ranta, Maija; Vuento, Matti

    2002-05-01

    Canine parvovirus (CPV) is a nonenveloped virus with a 5-kb single-stranded DNA genome. Lysosomotropic agents and low temperature are known to prevent CPV infection, indicating that the virus enters its host cells by endocytosis and requires an acidic intracellular compartment for penetration into the cytoplasm. After escape from the endocytotic vesicles, CPV is transported to the nucleus for replication. In the present study the intracellular entry pathway of the canine parvovirus in NLFK (Nordisk Laboratory feline kidney) cells was studied. After clustering in clathrin-coated pits and being taken up in coated vesicles, CPV colocalized with coendocytosed transferrin in endosomes resembling recycling endosomes. Later, CPV was found to enter, via late endosomes, a perinuclear vesicular compartment, where it colocalized with lysosomal markers. There was no indication of CPV entry into the trans-Golgi or the endoplasmic reticulum. Similar results were obtained both with full and with empty capsids. The data thus suggest that CPV or its DNA was released from the lysosomal compartment to the cytoplasm to be then transported to the nucleus. Electron microscopy analysis revealed endosomal vesicles containing CPV to be associated with microtubules. In the presence of nocodazole, a microtubule-disrupting drug, CPV entry was blocked and the virus was found in peripheral vesicles. Thus, some step(s) of the entry process were dependent on microtubules. Microinjection of antibodies to dynein caused CPV to remain in pericellular vesicles. This suggests an important role for the motor protein dynein in transporting vesicles containing CPV along the microtubule network.

  6. Disruption of the murine dynein light chain gene Tcte3-3 results in asthenozoospermia.

    Science.gov (United States)

    Rashid, Sajid; Grzmil, Pawel; Drenckhahn, Joerg-Detlef; Meinhardt, Andreas; Adham, Ibrahim; Engel, Wolfgang; Neesen, Juergen

    2010-01-01

    To elucidate the role of the mouse gene Tcte3 (Tctex2), which encodes a putative light chain of the outer dynein arm of cilia and sperm flagella, we have inactivated this gene in mice using targeted disruption. Breeding of heterozygous males and females resulted in normal litter size; however, we were not able to detect homozygous Tcte3-deficent mice using standard genotype techniques. In fact, our results indicate the presence of at least three highly similar copies of the Tcte3 gene (Tcte3-1, Tcte3-2, and Tcte3-3) in the murine genome. Therefore, quantitative real-time PCR was established to differentiate between mice having one or two targeted Tcte3-3 alleles. By this approach, Tcte3-3(-/-) animals were identified, which were viable and revealed no obvious malformation. Interestingly, some homozygous Tcte3-3-deficient male mice bred with wild-type female produced no offspring while other Tcte3-3-deficient males revealed decreased sperm motility but were fertile. In infertile Tcte3-3(-/-) males, spermatogenesis was affected and sperm motility was reduced, too, resulting in decreased ability of Tcte3-3-deficient spermatozoa to move from the uterus into the oviduct. Impaired flagellar motility is not correlated with any gross defects in the axonemal structure, since outer dynein arms are detectable in sperm of Tcte3-3(-/-) males. However, in infertile males, deficient Tcte3-3 function is correlated with increased apoptosis during male germ cell development, resulting in a reduction of sperm number. Moreover, multiple malformations in developing haploid germ cells are present. Our results support a role of Tcte3-3 in generation of sperm motility as well as in male germ cell differentiation.

  7. 苎麻茎秆力学模型的试验分析%Experimental analysis on mechanical model of ramie stalk

    Institute of Scientific and Technical Information of China (English)

    沈成; 李显旺; 田昆鹏; 张彬; 黄继承; 陈巧敏

    2015-01-01

    decided according to the assumption of ramie geometrical shape and experimental equipment conditions, as well as the calculation formula of each elastic parameter. Thirdly, PC-controlled universal testing machine was applied to make mechanical test, such as tensile, compressive and bending, to ramie stalk from each direction (axial direction and radial direction) and to each part (xylem, phloem and the whole stalk), to acquire mechanical parameter data. The universal testing machine used in the experiment was WDW-10 PC-controlled electronic universal testing machine with test power range 5 kN, and the accuracy of its force sensor and displacement sensor were both maintained within ±0.1%. In tensile test, xylem, phloem and stalk samples were 20 groups of rectangle samples about 80 mm long, 6-7 mm wide, material thickness thick. Plate fixture was used, and the clamped position was covered by gauze for protection. Pre-tightening force when starting was less than 5 N, test loading rate was 5 mm/min. Then, axial tensile stress-strain curve of each sample group was obtained. In compressive test, xylem, phloem and stalk samples were 10 groups of rectangle samples about 10- 11 mm long, 5-6 mm wide, material thickness thick. Compressive test briquetting was used. Thus, radial comprehensive stress-strain curve of each sample group was obtained. In bending test, xylem and stalk samples were 10 groups of samples with the length of about 120 mm. The sample cross section was tube-shape, and external and inner diameter was decided by material conditions. Sample was placed between the support and pressure head of three-point bending test fixture. Span of the support was 80 mm, pre-tightening force when starting was less than 5 N, and test loading rate was 5 mm/min. Radial bending force-deformation curve was obtained. At last, all elastic parameters of ramie stalk mechanical model were obtained with analysis of test data. The radial compressive elasticity modulus were 9.73 MPa (stalk

  8. Sex Chromosome Meiotic Drive in Stalk-Eyed Flies

    OpenAIRE

    1997-01-01

    Meiotically driven sex chromosomes can quickly spread to fixation and cause population extinction unless balanced by selection or suppressed by genetic modifiers. We report results of genetic analyses that demonstrate that extreme female-biased sex ratios in two sister species of stalk-eyed flies, Cyrtodiopsis dalmanni and C. whitei, are due to a meiotic drive element on the X chromosome (X(d)). Relatively high frequencies of X(d) in C. dalmanni and C. whitei (13-17% and 29%, respectively) ca...

  9. The Oligomeric Outer Dynein Arm Assembly Factor CCDC103 Is Tightly Integrated within the Ciliary Axoneme and Exhibits Periodic Binding to Microtubules*

    Science.gov (United States)

    King, Stephen M.; Patel-King, Ramila S.

    2015-01-01

    CCDC103 is an ∼29-kDa protein consisting of a central RPAP3_C domain flanked by N- and C-terminal coiled coils. Defects in CCDC103 lead to primary ciliary dyskinesia caused by the loss of outer dynein arms. This protein is present along the entire length of the ciliary axoneme and does not require other dynein or docking complex components for its integration. Unlike other known dynein assembly factors within the axoneme, CCDC103 is not solubilized by 0.6 m NaCl and requires more chaotropic conditions, such as 0.5 m KI. Alternatively, it can be extracted using 0.3% sarkosyl. CCDC103 forms stable dimers and other oligomers in solution through interactions involving the central domain. The smallest particle observed by dynamic light scattering has a hydrodynamic diameter of ∼25 nm. Furthermore, CCDC103 binds microtubules directly, forming ∼9-nm diameter particles that exhibit a 12-nm spacing on the microtubule lattice, suggesting that there may be two CCDC103 units per outer arm dynein repeat. Although the outer dynein arm docking complex is necessary to form arrays of dyneins along microtubules, it is not sufficient to set up a single array in a precise location on each axonemal doublet. We propose that CCDC103 helps generate a high-affinity site on the doublets for outer arm assembly, either through direct interactions or indirectly, perhaps by modifying the underlying microtubule lattice. PMID:25572396

  10. Nigrostriatal dynein changes in A53T alpha-synuclein transgenic mice [v1; ref status: indexed, http://f1000r.es/2wb

    Directory of Open Access Journals (Sweden)

    Yan Liu

    2014-03-01

    Full Text Available The accumulation of misfolded a-synuclein is mechanistically linked to neurodegeneration in Parkinson’s disease (PD and other alpha-synucleinopathies. However, how alpha-synuclein causes neurodegeneration is unresolved. Several studies have supported the involvement of dynein, the major motor for retrograde axonal transport in alpha-synuclein-dependent neurodegeneration, especially in the nigrostriatal system. Therefore, we examined the nigrostriatal dyneins in transgenic mice that overexpress human A53T alpha-synuclein and recapitulate key features of a PD-like neuronal synucleinopathy. Age-matched nontransgenic littermates were used as controls. The results demonstrated that the protein level of dynein was decreased in the striatum, whereas it was elevated in the substantia nigra. Double immunostaining results revealed that the reduction in dynein level was associated with aggregation of A53T a-synuclein in the striatum. Furthermore, we performed a quantitative analysis of motor behaviors in A53T alpha-synuclein transgenic mice and controls using a modified open field test. We demonstrated that the protein level of dynein in the striatum was significantly correlated with the motor behaviors. Together, our data indicate that dynein changes in the nigrostriatal system of A53T alpha-synuclein transgenic mice may contribute to their severe movement disorder.

  11. Evaluation of elastic modulus and hardness of crop stalks cell walls by nano-indentation.

    Science.gov (United States)

    Wu, Yan; Wang, Siqun; Zhou, Dingguo; Xing, Cheng; Zhang, Yang; Cai, Zhiyong

    2010-04-01

    Agricultural biomaterials such as crop stalks are natural sources of cellulosic fiber and have great potential as reinforced materials in bio-composites. In order to evaluate their potential as materials for reinforcement, the nano-mechanical properties of crop-stalk cell walls, i.e. those of cotton (Gossypium herbaceu) stalk, soybean (Glycine max) stalk, cassava (Manihot esculent) stalk, rice (Oryza sativa L.) straw, and wheat (Triticum aestivum L.) straw, were investigated by means of nano-indentation and atomic force microscopy (AFM). The elastic modulus of wheat straw was found to be 20.8 GPa, which was higher than that of the other four crops. The highest hardness was observed in cotton stalk at 0.85 GPa. The elastic moduli of the crop stalks were lower than those of most of the hardwood species, but higher than that of some softwoods and of lyocell fiber. The mean value of the hardness of the five crop stalks' cell walls was higher than those of wood or lyocell fiber.

  12. Victims of stalking in India: A study of girl college students in Tirunelveli City

    Directory of Open Access Journals (Sweden)

    Jaishankar Karuppannan

    2007-01-01

    Full Text Available The word 'stalking' was not commonly known in India, until Priyadharshini Mattoo's case (1996 hit the headlines. Eve teasing, a colloquial word for gender harassment is popularly known and Tamil Nadu Prohibition of Eve-Teasing Act, 1998 on that was developed after the brutal killing of a girl named Sarika Shah in Chennai. Though, stalking is there in the past, it was not acknowledged with this terminology and it was always merged with Eve teasing. On the other hand, stalking is much graver than Eve teasing and it is an obsessive behaviour. After the Matoo's case, the Indian Criminal Justice System awoke and the National Commission for Women is ready with a draft Bill (Sexual Assault Prevention Bill to make the Indian Penal Code more effective against the menace of stalkers. Research studies related to stalking in India are sparse and there is a need to study this phenomenon in depth. This paper presents some results from a study of stalking victims among Girl College students at Tirunelveli City, Tamil Nadu, India. In-depth questionnaire data are drawn on to investigate the course and nature of prolonged stalking in 150 self-defined victims. Findings indicate a pattern of repeated intrusions, the stalking harassment methods, lack of reporting behaviour, and effects of stalking on the victims.

  13. Radiation-induced grafting of sweet sorghum stalk for copper(II) removal from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Jing; Hu, Jun [Laboratory of Environmental Technology, INET, Tsinghua University, Beijing 100084 (China); Wang, Jianlong, E-mail: wangjl@mail.tsinghua.edu.cn [Laboratory of Environmental Technology, INET, Tsinghua University, Beijing 100084 (China); Key Laboratory of Advanced Reactor Engineering and Safety, Ministry of Education, Tsinghua University, Beijing 100084 (China)

    2013-11-15

    Highlights: • Radiation-induced grafting was used to modify the stalk. • Cellulose, hemicellulose and lignin participated in grafting reaction. • Both the structure and composition of stalk had influence on grafting. • The sorption capacity of the grafted stalk increased about five times. -- Abstract: The influence of main components (cellulose, hemicellulose and lignin) of the sweet sorghum stalk on radiation-induced grafting reaction and adsorption of copper from aqueous solution was investigated. Sweet sorghum stalk was grafted with acrylic acid induced by γ-irradiation. The results showed that the grafted stalk contained 1.6 mmol/g carboxyl groups, and its maximal adsorption capacity was 13.32 mg/g. The cellulose, hemicellulose and lignin of the raw materials were confirmed to involve in grafting reaction through comparing the grafting yield and the structure of the grafted materials. Both the structure and the composition of the sweet sorghum stalk had influence on the grafting reaction and adsorption capacity. The adsorption capacity of the grafted sweet sorghum stalk increased about five times, and the adsorption isotherm of the grafted materials conformed to the Langmuir model. The main mechanism for copper adsorption involved in ion exchange.

  14. [Are journalists more frequently victims of stalking? Results of first empirical examinations].

    Science.gov (United States)

    Dressing, H; Martini, M; Witthöft, M; Bailer, J; Gass, P

    2007-12-01

    The lifetime prevalence of stalking is about 12% in the general population. The risk to become a stalking victim is increased for psychiatrists and psychologists. However, there are no studies with regard to other professions. The present study analyses the lifetime prevalence of stalking victimization for journalists, because some professional tasks may also put members of this professional group at a higher risk to become a stalking victim. 493 journalists answered an internet questionnaire. 12% of the journalists reported stalking victimization due to private or other non-professional reasons. This is nearly exactly the same lifetime prevalence that was found in a German community sample. However, 2.2% of the journalists reported stalking victimization that was related to their professional work. This is the first empirical study on this issue. Due to methodological problems no other studies have been published on this topic so far. The reported data of this study have to be interpreted cautiously, because the data are not based on a representative sample. However, comparisons with community-based epidemiological studies render our data a valid basis for starting a discussion of a so far neglected research issue. Our preliminary data suggest that journalists may be at higher risk to become a stalking victim because of their professional activities. Since stalking may cause severe psychological distress in the victims and, in some cases, puts them in severe risk of aggressive violence, preventive strategies should be considered.

  15. The effect of DL-5-hydroxytryptophan (5-HTP) on plasma prolactin in pituitary stalk sectioned rats.

    Science.gov (United States)

    Akabori, A; Araki, S; Tamada, T

    1981-08-01

    5-HTP (5 mg/100 g body weight), a precursor of serotonin, was administered intravenously to pituitary stalk sectioned rats. Plasma prolactin levels were initially increased 30 and 60 min after the injection of 5-HTP and thereafter decreased. Pituitary prolactin content was decreased 60 min after the stalk section as compared to those seen following sham operation. The treatment of 5-HTP induced a moderate increase in pituitary prolactin content in the stalk sectioned rats. In order to confirm the complete disconnection of pituitary stalk after the operation, 2.5 micrograms of dopamine hydrochloride was given into the lateral ventricle of stalk sectioned rats. Plasma prolactin did not change following the administration. Our results demonstrate that 5-HTP acts either directly at the pituitary level or via some mechanism yet to be determined.

  16. Evaluation of the mass transfer effect of the stalk contraction cycle of Vorticella

    Science.gov (United States)

    Zhou, Jiazhong; Admiraal, David; Ryu, Sangjin

    2014-03-01

    Vorticella is a protozoan with a contractile stalk that can contract pulling the cell body toward the substrate in less than 10 ms and return to the extended state in a few seconds. Although this stalk contraction is one of the fastest cellular motions, it is unknown why Vorticella contracts. Because the flow field induced by Vorticella shows different characteristics between contraction and relaxation, it has been suggested that Vorticella augments mass transfer near the substrate based on its stalk contraction-relaxation. We investigate this hypothesis using computational fluid dynamics (CFD) simulations and particle image velocimetry (PIV) experiments. In both approaches, Vorticella is modelled as a solid sphere that translates perpendicular to a solid surface in liquid based on the measured stalk length changes of Vorticella. Based on the computationally and experimentally simulated flow, we evaluate the mass transfer capability of Vorticella, for a possible application of the stalk contraction of Vorticella as a biomimetic model system for microfluidic mixers.

  17. The consequences of coping with stalking-results from the first qualitative study on stalking in Denmark

    DEFF Research Database (Denmark)

    Johansen, Katrine Bindesbøl Holm; Tjørnhøj-Thomsen, Tine

    2016-01-01

    indicate that rather than the stalkers' harassment itself; it is the unpredictability of the stalkers' potential actions that inform the victims' primary coping strategy-self-regulation. Self-regulation consists of various strategies victims employ to avoid the stalker. Our analysis shows that self-regulation...... and well-being. METHODS: Qualitative semi-structured interviews were conducted with 25 victims of stalking. Thematic content analysis was employed, and themes were primarily identified inductively and broad into dialogue with concepts, such as Foucault's panopticism. RESULTS: The results of the study...

  18. Hormonal regulation of the growth of leaves and inflorescence stalk in Muscari armeniacum Leichtl.

    Directory of Open Access Journals (Sweden)

    Marian Saniewski

    2016-04-01

    Full Text Available It is known that chilling of Muscari bulbs is necessary for the growth of the inflorescence stalk and flowering, but not for the growth of leaves. Gibberellic acid (GA accelerated stem growth and flowering in chilled Muscari bulbs. In the present experiment it was shown that in unchilled derooted Muscari bulbs the growth of leaves, but not the growth of the inflorescence stalk, was observed when bulbs were stored in water, GA at a concentration of 50 and 100 mg/L, benzyladenine (BA at a concentration of 25 and 50 mg/L, or a mixture of GA+BA (50+25 mg/L, but abscisic acid (ABA at a concentration of 10 mg/L greatly inhibited the growth of leaves. In chilled derooted Muscari bulbs the growth of leaves and inflorescence stalk was observed when bulbs were stored in water or GA, but BA and GA+BA treatments totally inhibited the growth of the inflorescence stalk without an effect on the growth of leaves. These results clearly showed that the growth of leaves and inflorescence stalk in Muscari bulbs are controlled by plant growth regulators in different ways. ABA totally inhibited the growth of leaves and inflorescence stalk in chilled derooted Muscari bulbs. It was shown that after the excision of the inflorescence bud in cultivated chilled Muscari bulbs, the inflorescence stalk died, but application of indole-3-acetic acid (IAA 0.5% in the place of the removed inflorescence bud induced the growth of the inflorescence stalk. IAA applied under the inflorescence bud inhibited the development of flowers (flower-bud blasting and induced the growth of the inflorescence stalk below the treatment site. These results are discussed with reference to hormonal regulation of stem (stalk growth in tulip, narcissus, hyacinth, and Hippeastrum.

  19. Flow Regulator Powered by the Stalk of Vorticella convarallia

    Science.gov (United States)

    Matsumoto, N.; Nagai, M.; Hayasaka, Y.; Oguri, M.; Kawashima, T.; Shibata, T.

    2012-03-01

    We propose flow regulation by the stalk of Vorticella convarallia. The motion of stalk can be controlled by introducing Ca2+ and chelator solutions alternatively. The fluid channel is narrowed by fully extended V. convarallia, which results in increasing fluidic resistance and reducing flow rate. The flow regulator consists of a microchannel and Vorticella. The microchannel has two layers. The top layer contains a fluid channel where Vorticella is stored to control the flow rate. The bottom layer includes a control channel which enables control of the fluid channel by an external compressed air supply. After cells were introduced to the device at 1.0×103 cells/μL, eight of 18 chambers contained more than a single cell. Four cells of Vorticella were cultured in one chamber at a maximum. The cells were alive for two days after the injection. We evaluated the change in mean flow rate through the fluidic channel. The flow rate without V. convarallia increased linearly from 5.5nL/min to 1.1μL/min with applied pressure from 4 to 18kPa. The switching time of solutions measured two seconds at 10 kPa. The response time for the device was estimated to be approximately four seconds after the partial removal of cell membrane.

  20. Protein-Protein Interactions between Intermediate Chains and the Docking Complex of Chlamydomonas Flagellar Outer Arm Dynein

    Science.gov (United States)

    Ide, Takahiro; Owa, Mikito; King, Stephen M.; Kamiya, Ritsu; Wakabayashi, Ken-ichi

    2013-01-01

    Outer arm dynein (OAD) is bound to specific loci on outer-doublet-microtubules by interactions at two sites: via intermediate chain 1 (IC1) and the outer dynein arm docking complex (ODA-DC). Studies using Chlamydomonas mutants have suggested that the individual sites have rather weak affinities for microtubules, and therefore strong OAD attachment to microtubules is achieved by their cooperation. To test this idea, we examined interactions between IC1, IC2 (another intermediate chain) and ODA-DC using recombinant proteins. Recombinant IC1 and IC2 were found to form a 1:1 complex, and this complex associated with ODA-DC in vitro. Binding of IC1 to mutant axonemes revealed that there are specific binding sites for IC1. From these data, we propose a novel model of OAD-outer doublet association. PMID:23747306

  1. Structure–function–folding relationships and native energy landscape of dynein light chain protein: nuclear magnetic resonance insights

    Indian Academy of Sciences (India)

    P M Krishna Mohan; Ramakrishna V Hosur

    2009-09-01

    The detailed characterization of the structure, dynamics and folding process of a protein is crucial for understanding the biological functions it performs. Modern biophysical and nuclear magnetic resonance (NMR) techniques have provided a way to obtain accurate structural and thermodynamic information on various species populated on the energy landscape of a given protein. In this context, we review here the structure–function–folding relationship of an important protein, namely, dynein light chain protein (DLC8). DLC8, the smallest subunit of the dynein motor complex, acts as a cargo adaptor. The protein exists as a dimer under physiological conditions and dissociates into a pure monomer below pH 4. Cargo binding occurs at the dimer interface. Dimer stability and relay of perturbations through the dimer interface are anticipated to be playing crucial roles in the variety of functions the protein performs. NMR investigations have provided great insights into these aspects of DLC8 in recent years.

  2. A Chlamydomonas Homologue of the Putative Murine t Complex Distorter Tctex-2 Is an Outer Arm Dynein Light Chain

    Science.gov (United States)

    Patel-King, Ramila S.; Benashski, Sharon E.; Harrison, Alistair; King, Stephen M.

    1997-01-01

    Molecular analysis of a 19,000-Mr protein from the Chlamydomonas flagellum reveals that it is homologous to the t complex–encoded protein Tctex-2, which is a candidate for one of the distorter products that cause the extreme transmission ratio distortion (meiotic drive) of the murine t complex. The 19,000-Mr protein is extracted from the axoneme with 0.6 M NaCl and comigrates with the outer dynein arm in sucrose density gradients. This protein also is specifically missing in axonemes prepared from a mutant that does not assemble the outer arm. These data raise the possibility that Tctex-2 is a sperm flagellar dynein component. Combined with the recent identification of Tctex-1 (another distorter candidate) as a light chain of cytoplasmic dynein, these results lead to a biochemical model for how differential defects in spermiogenesis that result in the phenomenon of meiotic drive might be generated in wild-type vs t-bearing sperm. PMID:9166408

  3. Partially Functional Outer-Arm Dynein in a Novel Chlamydomonas Mutant Expressing a Truncated γ Heavy Chain▿

    Science.gov (United States)

    Liu, Zhongmei; Takazaki, Hiroko; Nakazawa, Yuki; Sakato, Miho; Yagi, Toshiki; Yasunaga, Takuo; King, Stephen M.; Kamiya, Ritsu

    2008-01-01

    The outer dynein arm of Chlamydomonas flagella contains three heavy chains (α, β, and γ), each of which exhibits motor activity. How they assemble and cooperate is of considerable interest. Here we report the isolation of a novel mutant, oda2-t, whose γ heavy chain is truncated at about 30% of the sequence. While the previously isolated γ chain mutant oda2 lacks the entire outer arm, oda2-t retains outer arms that contain α and β heavy chains, suggesting that the N-terminal sequence (corresponding to the tail region) is necessary and sufficient for stable outer-arm assembly. Thin-section electron microscopy and image analysis localize the γ heavy chain to a basal region of the outer-arm image in the axonemal cross section. The motility of oda2-t is lower than that of the wild type and oda11 (lacking the α heavy chain) but higher than that of oda2 and oda4-s7 (lacking the motor domain of the β heavy chain). Thus, the outer-arm dynein lacking the γ heavy-chain motor domain is partially functional. The availability of mutants lacking individual heavy chains should greatly facilitate studies on the structure and function of the outer-arm dynein. PMID:18487347

  4. Formin-mediated actin polymerization cooperates with Mushroom body defect (Mud)-Dynein during Frizzled-Dishevelled spindle orientation.

    Science.gov (United States)

    Johnston, Christopher A; Manning, Laurina; Lu, Michelle S; Golub, Ognjen; Doe, Chris Q; Prehoda, Kenneth E

    2013-10-01

    To position the mitotic spindle, cytoskeletal components must be coordinated to generate cortical forces on astral microtubules. Although the dynein motor is common to many spindle orientation systems, 'accessory pathways' are often also required. In this work, we identified an accessory spindle orientation pathway in Drosophila that functions with Dynein during planar cell polarity, downstream of the Frizzled (Fz) effector Dishevelled (Dsh). Dsh contains a PDZ ligand and a Dynein-recruiting DEP domain that are both required for spindle orientation. The Dsh PDZ ligand recruits Canoe/Afadin and ultimately leads to Rho GTPase signaling mediated through RhoGEF2. The formin Diaphanous (Dia) functions as the Rho effector in this pathway, inducing F-actin enrichment at sites of cortical Dsh. Chimeric protein experiments show that the Dia-actin accessory pathway can be replaced by an independent kinesin (Khc73) accessory pathway for Dsh-mediated spindle orientation. Our results define two 'modular' spindle orientation pathways and show an essential role for actin regulation in Dsh-mediated spindle orientation.

  5. Mitotic chromosome biorientation in fission yeast is enhanced by dynein and a minus-end-directed, kinesin-like protein.

    Science.gov (United States)

    Grishchuk, Ekaterina L; Spiridonov, Ilia S; McIntosh, J Richard

    2007-06-01

    Chromosome biorientation, the attachment of sister kinetochores to sister spindle poles, is vitally important for accurate chromosome segregation. We have studied this process by following the congression of pole-proximal kinetochores and their subsequent anaphase segregation in fission yeast cells that carry deletions in any or all of this organism's minus end-directed, microtubule-dependent motors: two related kinesin 14s (Pkl1p and Klp2p) and dynein. None of these deletions abolished biorientation, but fewer chromosomes segregated normally without Pkl1p, and to a lesser degree without dynein, than in wild-type cells. In the absence of Pkl1p, which normally localizes to the spindle and its poles, the checkpoint that monitors chromosome biorientation was defective, leading to frequent precocious anaphase. Ultrastructural analysis of mutant mitotic spindles suggests that Pkl1p contributes to error-free biorientation by promoting normal spindle pole organization, whereas dynein helps to anchor a focused bundle of spindle microtubules at the pole.

  6. Dynein Heavy Chain, Encoded by Two Genes in Agaricomycetes, Is Required for Nuclear Migration in Schizophyllum commune.

    Science.gov (United States)

    Brunsch, Melanie; Schubert, Daniela; Gube, Matthias; Ring, Christiane; Hanisch, Lisa; Linde, Jörg; Krause, Katrin; Kothe, Erika

    2015-01-01

    The white-rot fungus Schizophyllum commune (Agaricomycetes) was used to study the cell biology of microtubular trafficking during mating interactions, when the two partners exchange nuclei, which are transported along microtubule tracks. For this transport activity, the motor protein dynein is required. In S. commune, the dynein heavy chain is encoded in two parts by two separate genes, dhc1 and dhc2. The N-terminal protein Dhc1 supplies the dimerization domain, while Dhc2 encodes the motor machinery and the microtubule binding domain. This split motor protein is unique to Basidiomycota, where three different sequence patterns suggest independent split events during evolution. To investigate the function of the dynein heavy chain, the gene dhc1 and the motor domain in dhc2 were deleted. Both resulting mutants were viable, but revealed phenotypes in hyphal growth morphology and mating behavior as well as in sexual development. Viability of strain Δdhc2 is due to the higher expression of kinesin-2 and kinesin-14, which was proven via RNA sequencing.

  7. Dynein Heavy Chain, Encoded by Two Genes in Agaricomycetes, Is Required for Nuclear Migration in Schizophyllum commune.

    Directory of Open Access Journals (Sweden)

    Melanie Brunsch

    Full Text Available The white-rot fungus Schizophyllum commune (Agaricomycetes was used to study the cell biology of microtubular trafficking during mating interactions, when the two partners exchange nuclei, which are transported along microtubule tracks. For this transport activity, the motor protein dynein is required. In S. commune, the dynein heavy chain is encoded in two parts by two separate genes, dhc1 and dhc2. The N-terminal protein Dhc1 supplies the dimerization domain, while Dhc2 encodes the motor machinery and the microtubule binding domain. This split motor protein is unique to Basidiomycota, where three different sequence patterns suggest independent split events during evolution. To investigate the function of the dynein heavy chain, the gene dhc1 and the motor domain in dhc2 were deleted. Both resulting mutants were viable, but revealed phenotypes in hyphal growth morphology and mating behavior as well as in sexual development. Viability of strain Δdhc2 is due to the higher expression of kinesin-2 and kinesin-14, which was proven via RNA sequencing.

  8. Changes in the Length of the Neuraminidase Stalk Region Impact H7N9 Virulence in Mice

    Science.gov (United States)

    Xiao, Haixia; Chen, Quanjiao; Wu, Yan; Fu, Lifeng; Quan, Chuansong; Wong, Gary; Liu, Jun; Haywood, Joel; Liu, Yingxia; Zhou, Boping; Yan, Jinghua; Liu, Wenjun

    2015-01-01

    The neuraminidase stalk of the newly emerged H7N9 influenza virus possesses a 5-amino-acid deletion. This study focuses on characterizing the biological functions of H7N9 with varied neuraminidase stalk lengths. Results indicate that the 5-amino-acid deletion had no impact on virus infectivity or replication in vitro or in vivo compared to that of a virus with a full-length stalk, but enhanced virulence in mice was observed for H7N9 encoding a 19- to 20-amino-acid deletion, suggesting that N9 stalk length impacts virulence in mammals, as N1 stalk length does. PMID:26656694

  9. Lifetime prevalence and impact of stalking: Epidemiological data from Eastern Austria

    Directory of Open Access Journals (Sweden)

    Stefan Stieger

    2008-12-01

    Full Text Available Background and Objectives: Community-based studies of stalking in European countries are scarce. The aim of the present study was to replicate the epidemiological study by Dressing and colleagues, which analyzed a sample drawn from a middle-sized German city (Dressing et al., 2005 by using a general population sample (urban as well as rural citizens from Eastern Austria. Methods: In a survey of 401 persons from Eastern Austria we tried to replicate the study on the lifetime and point prevalence of stalking in a German urban community. The survey included a stalking questionnaire and the WHO-5 well-being scale. Results: Nearly 11% of the respondents (n = 43, 37 women, 6 men reported having been stalked. Victims scored significantly lower on the WHO-5 well-being scale. We found no significant differences in stalking and well-being between rural and urban areas. Conclusions: Epidemiological data on stalking collected in an Austrian community closely resemble the data derived from a community-based sample in a middle-sized German city. We also inquired about the living environment of the participants (rural or urban, but found no difference between the two. Furthermore, the lifetime prevalence of being a stalking victim is associated with currently impaired psychological well-being as measured by the WHO-5 Well-being Index.

  10. Nitrate removal from groundwater in columns packed with reed and rice stalks.

    Science.gov (United States)

    Qian, Jiazhong; Wang, Zhiping; Jin, Song; Liu, Yong; Chen, Tianhu; Fallgren, Paul H

    2011-10-01

    Nitrate leaching contaminates groundwater. The objective of this study was to determine if reed and rice stalks could enhance denitrification and reduce nitrate leaching into groundwater. Artificial groundwater spiked with nitrate and field groundwater samples were tested in the columns in sand reactors packed with either reed or rice stalks. The maximum nitrate removal rates were determined to be 1.93 and 1.97 mg nitrate-N l(-1) h(-1), respectively, in the reed and rice stalk-packed columns. The maximum nitrate-nitrogen removal rate in reactors packed with reed stalk was 1.33 mg nitrate-N l(-1) h(-1) when experimented with natural groundwater. Chemical oxygen demand consumption was higher when rice stalk (176.1 mg l(-1)) was used as the substrate, compared to reed stalk (35.2 mg l(-1)) at the same substrate dosage. No nitrite accumulation was detected during the test. The results demonstrate that agricultural byproducts, such as reed and rice stalks, may be used as substrate amendments for enhanced denitrification in natural settings, such as lakeside lagoons, ditches or wetlands.

  11. Soil properties, nutrient dynamics, and soil enzyme activities associated with garlic stalk decomposition under various conditions.

    Directory of Open Access Journals (Sweden)

    Xu Han

    Full Text Available The garlic stalk is a byproduct of garlic production and normally abandoned or burned, both of which cause environmental pollution. It is therefore appropriate to determine the conditions of efficient decomposition, and equally appropriate to determine the impact of this decomposition on soil properties. In this study, the soil properties, enzyme activities and nutrient dynamics associated with the decomposition of garlic stalk at different temperatures, concentrations and durations were investigated. Stalk decomposition significantly increased the values of soil pH and electrical conductivity. In addition, total nitrogen and organic carbon concentration were significantly increased by decomposing stalks at 40°C, with a 5:100 ratio and for 10 or 60 days. The highest activities of sucrase, urease and alkaline phosphatase in soil were detected when stalk decomposition was performed at the lowest temperature (10°C, highest concentration (5:100, and shortest duration (10 or 20 days. The evidence presented here suggests that garlic stalk decomposition improves the quality of soil by altering the value of soil pH and electrical conductivity and by changing nutrient dynamics and soil enzyme activity, compared to the soil decomposition without garlic stalks.

  12. Soil properties, nutrient dynamics, and soil enzyme activities associated with garlic stalk decomposition under various conditions.

    Science.gov (United States)

    Han, Xu; Cheng, Zhihui; Meng, Huanwen

    2012-01-01

    The garlic stalk is a byproduct of garlic production and normally abandoned or burned, both of which cause environmental pollution. It is therefore appropriate to determine the conditions of efficient decomposition, and equally appropriate to determine the impact of this decomposition on soil properties. In this study, the soil properties, enzyme activities and nutrient dynamics associated with the decomposition of garlic stalk at different temperatures, concentrations and durations were investigated. Stalk decomposition significantly increased the values of soil pH and electrical conductivity. In addition, total nitrogen and organic carbon concentration were significantly increased by decomposing stalks at 40°C, with a 5:100 ratio and for 10 or 60 days. The highest activities of sucrase, urease and alkaline phosphatase in soil were detected when stalk decomposition was performed at the lowest temperature (10°C), highest concentration (5:100), and shortest duration (10 or 20 days). The evidence presented here suggests that garlic stalk decomposition improves the quality of soil by altering the value of soil pH and electrical conductivity and by changing nutrient dynamics and soil enzyme activity, compared to the soil decomposition without garlic stalks.

  13. Lithotrophic iron-oxidizing bacteria produce organic stalks to control mineral growth: implications for biosignature formation.

    Science.gov (United States)

    Chan, Clara S; Fakra, Sirine C; Emerson, David; Fleming, Emily J; Edwards, Katrina J

    2011-04-01

    Neutrophilic Fe-oxidizing bacteria (FeOB) are often identified by their distinctive morphologies, such as the extracellular twisted ribbon-like stalks formed by Gallionella ferruginea or Mariprofundus ferrooxydans. Similar filaments preserved in silica are often identified as FeOB fossils in rocks. Although it is assumed that twisted iron stalks are indicative of FeOB, the stalk's metabolic role has not been established. To this end, we studied the marine FeOB M. ferrooxydans by light, X-ray and electron microscopy. Using time-lapse light microscopy, we observed cells excreting stalks during growth (averaging 2.2  μm  h(-1)). Scanning transmission X-ray microscopy and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy show that stalks are Fe(III)-rich, whereas cells are low in Fe. Transmission electron microscopy reveals that stalks are composed of several fibrils, which contain few-nanometer-sized iron oxyhydroxide crystals. Lepidocrocite crystals that nucleated on the fibril surface are much larger (∼100  nm), suggesting that mineral growth within fibrils is retarded, relative to sites surrounding fibrils. C and N 1s NEXAFS spectroscopy and fluorescence probing show that stalks primarily contain carboxyl-rich polysaccharides. On the basis of these results, we suggest a physiological model for Fe oxidation in which cells excrete oxidized Fe bound to organic polymers. These organic molecules retard mineral growth, preventing cell encrustation. This model describes an essential role for stalk formation in FeOB growth. We suggest that stalk-like morphologies observed in modern and ancient samples may be correlated confidently with the Fe-oxidizing metabolism as a robust biosignature.

  14. Lithotrophic iron-oxidizing bacteria produce organic stalks to control mineral growth: implications for biosignature formation

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Clara S; Fakra, Sirine C; Emerson, David; Fleming, Emily J; Edwards, Katrina J

    2011-07-01

    Neutrophilic Fe-oxidizing bacteria (FeOB) are often identified by their distinctive morphologies, such as the extracellular twisted ribbon-like stalks formed by Gallionella ferruginea or Mariprofundus ferrooxydans. Similar filaments preserved in silica are often identified as FeOB fossils in rocks. Although it is assumed that twisted iron stalks are indicative of FeOB, the stalk's metabolic role has not been established. To this end, we studied the marine FeOB M. ferrooxydans by light, X-ray and electron microscopy. Using time-lapse light microscopy, we observed cells excreting stalks during growth (averaging 2.2 {micro}m h(-1)). Scanning transmission X-ray microscopy and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy show that stalks are Fe(III)-rich, whereas cells are low in Fe. Transmission electron microscopy reveals that stalks are composed of several fibrils, which contain few-nanometer-sized iron oxyhydroxide crystals. Lepidocrocite crystals that nucleated on the fibril surface are much larger ({approx}100 nm), suggesting that mineral growth within fibrils is retarded, relative to sites surrounding fibrils. C and N 1s NEXAFS spectroscopy and fluorescence probing show that stalks primarily contain carboxyl-rich polysaccharides. On the basis of these results, we suggest a physiological model for Fe oxidation in which cells excrete oxidized Fe bound to organic polymers. These organic molecules retard mineral growth, preventing cell encrustation. This model describes an essential role for stalk formation in FeOB growth. We suggest that stalk-like morphologies observed in modern and ancient samples may be correlated confidently with the Fe-oxidizing metabolism as a robust biosignature.

  15. Ethanol Production by Fermentation of Various Sweet-Stalk Sorghum Juices Using Various Yeast Strains

    OpenAIRE

    Donny Widianto; Akbar Arofatullah; Triwibowo Yuwono; Irfan Dwidya Prijambada

    2015-01-01

    The ethanol production by fermentation of sweet-stalk sorghum juice is affected by the juice composition and the capability of the yeast strain to ferment it. Eight yeast strains were tested on their growth and ethanol fermentation abilities in sweet-stalk sorghum juices extracted from three cultivars of sweet sorghum. The best specific growth rate of the yeast strains grown aerobically in the yeast extract peptone dextrose (YEPD) broth and the sweet-stalk sorghum juices of KCS105, FS501, and...

  16. Thermochemical characterization of pigeon pea stalk for its efficient utilization as an energy source

    Energy Technology Data Exchange (ETDEWEB)

    Katyal, S.K.; Iyer, P.V.R.

    2000-05-01

    Pigeon pea stalk is a widely available biomass species in India. In this article the potential use of pigeon pea stalk as a fuel source through thermochemical conversion methods such as combustion, gasification, and pyrolysis has been investigated through experimentation using a thermogravimetric analyzer and pilot-plant-scale equipment. It has been proposed that pigeon pea stalks can be effectively utilized in two ways. The first is to pyrolyze the material to produce value-added products such as char, tar, and fuel gas. The second alternative is to partially pyrolyze the material to remove tar-forming volatiles, followed by gasification of reactive char to generate producer gas.

  17. Stalked protozoa identification by image analysis and multivariable statistical techniques.

    Science.gov (United States)

    Amaral, A L; Ginoris, Y P; Nicolau, A; Coelho, M A Z; Ferreira, E C

    2008-06-01

    Protozoa are considered good indicators of the treatment quality in activated sludge systems as they are sensitive to physical, chemical and operational processes. Therefore, it is possible to correlate the predominance of certain species or groups and several operational parameters of the plant. This work presents a semiautomatic image analysis procedure for the recognition of the stalked protozoa species most frequently found in wastewater treatment plants by determining the geometrical, morphological and signature data and subsequent processing by discriminant analysis and neural network techniques. Geometrical descriptors were found to be responsible for the best identification ability and the identification of the crucial Opercularia and Vorticella microstoma microorganisms provided some degree of confidence to establish their presence in wastewater treatment plants.

  18. APPLICATION OF ALKALINE SULFITE PULPING ON CORN STALKS

    Directory of Open Access Journals (Sweden)

    Ahmad Jahan Latibari

    2011-02-01

    Full Text Available Alkaline sulfite pulping of corn stalks was investigated to produce supplementary pulp for corrugating board manufacture. Three pulping temperatures (125, 145, and 165°C and five active alkali charges (10, 12, 14, 16, and 18% were used. Cooking time at 30 minutes, Na2SO3/ NaOH ratio at 50:50, and liquor to residue ratio of 8:1 were kept constant. The highest total yield (61.9% was reached applying the treatment combination of 125°C and 10% active alkali, and the lowest total yield (42.5% was related to 165°C and 16% chemical. The influence of sodium sulfite/sodium hydroxide ratios was studied applying different ratios (30:70, 40:60, 50:50, 60:40, and 70:30 at constant time and temperature of 30 minutes and 145°C respectively and 14 and 16% active alkali. Pulping condition; 16% active alkali, 30 minutes time, 145°C pulping temperature and varying ratios of sodium sulfite/sodium hydroxide were selected for pulp strength evaluation. The results of handsheet evaluation indicated that 16% active alkali, 30 minutes pulping at 145ºC and sodium sulfite/sodium hydroxide ratio of 50:50 is the optimum pulping condition for corn stalks. Tear, tensile, and burst indices and breaking length of this pulp were measured as 10.53 mN.m2g-1, 62.4 N.mg-1, 3.80 kPa.m2g-1, and 6.07 km, respectively.

  19. Clarification properties of trash and stalk tissues from sugar cane.

    Science.gov (United States)

    Eggleston, Gillian; Grisham, Michael; Antoine, April

    2010-01-13

    The effect of the U.S. and worldwide change from burnt to unburnt (green) sugar cane harvesting on processing and the use of sugar cane leaves and tops as a biomass source has not been fully characterized. Sugar cane whole-stalks were harvested from the first ratoon (repeat) crop of five commercial, Louisiana sugar cane varieties (LCP 85-384, HoCP 96-540, L 97-128, L 99-226, and L 99-233). Replicated sample tissues of brown, dry leaves (BL), green leaves (GL), growing point region (GPR), and stalk (S) were separated. Composite juice from each tissue type was clarified following a hot lime clarification process operated by most U.S. factories. Only GPR and GL juices foamed on heating and followed the normal settling behavior of factory sugar cane juice, although GL was markedly slower than GPR. GPR juice aided settling. S juice tended to thin out rather than follow normal settling and exhibited the most unwanted upward motion of flocs. Most varietal variation in settling, mud, and clarified juice (CJ) characteristics occurred for GL. The quality rather than the quantity of impurities in the different tissues mostly affected the volume of mud produced: After 30 min of settling, mud volume per unit tissue juice degrees Brix (% dissolved solids) varied markedly among the tissues (S 1.09, BL 11.3, GPR 3.0, and GL 3.1 mL/degrees Brix). Heat transfer properties of tissue juices and CJs are described. Clarification was unable to remove all BL cellulosic particles. GL and BL increased color, turbidity, and suspended particles in CJs with BL worse than GL. This will make the future attainment of very high pol (VHP) raw sugar in the U.S. more difficult. Although optimization of factory unit processes will alleviate extra trash problems, economical strategies to reduce the amount of green and brown leaves processed need to be identified and implemented.

  20. Docking-complex-independent alignment of Chlamydomonas outer dynein arms with 24-nm periodicity in vitro.

    Science.gov (United States)

    Oda, Toshiyuki; Abe, Tatsuki; Yanagisawa, Haruaki; Kikkawa, Masahide

    2016-04-15

    The docking complex is a molecular complex necessary for assembly of outer dynein arms (ODAs) on the axonemal doublet microtubules (DMTs) in cilia and flagella. The docking complex is hypothesized to be a 24-nm molecular ruler because ODAs align along the DMTs with 24-nm periodicity. In this study, we rigorously tested this hypothesis using structural and genetic methods. We found that the ODAs can bind to DMTs and porcine microtubules with 24-nm periodicities even in the absence of the docking complexin vitro Using cryo-electron tomography and structural labeling, we observed that the docking complex took an unexpectedly flexible conformation and did not lie along the length of DMTs. In the absence of docking complex, ODAs were released from the DMT at relatively low ionic strength conditions, suggesting that the docking complex strengthens the electrostatic interactions between the ODA and DMT. Based on these results, we conclude that the docking complex serves as a flexible stabilizer of the ODA rather than as a molecular ruler.

  1. Transport of the outer dynein arm complex to cilia requires a cytoplasmic protein Lrrc6.

    Science.gov (United States)

    Inaba, Yasuko; Shinohara, Kyosuke; Botilde, Yanick; Nabeshima, Ryo; Takaoka, Katsuyoshi; Ajima, Rieko; Lamri, Lynda; Takeda, Hiroyuki; Saga, Yumiko; Nakamura, Tetsuya; Hamada, Hiroshi

    2016-07-01

    Lrrc6 encodes a cytoplasmic protein that is expressed specifically in cells with motile cilia including the node, trachea and testes of the mice. A mutation of Lrrc6 has been identified in human patients with primary ciliary dyskinesia (PCD). Mutant mice lacking Lrrc6 show typical PCD defects such as hydrocephalus and laterality defects. We found that in the absence of Lrrc6, the morphology of motile cilia remained normal, but their motility was completely lost. The 9 + 2 arrangement of microtubules remained normal in Lrrc6(-/-) mice, but the outer dynein arms (ODAs), the structures essential for the ciliary beating, were absent from the cilia. In the absence of Lrrc6, ODA proteins such as DNAH5, DNAH9 and IC2, which are assembled in the cytoplasm and transported to the ciliary axoneme, remained in the cytoplasm and were not transported to the ciliary axoneme. The IC2-IC1 interaction, which is the first step of ODA assembly, was normal in Lrrc6(-/-) mice testes. Our results suggest that ODA proteins may be transported from the cytoplasm to the cilia by an Lrrc6-dependent mechanism.

  2. Miro-1 links mitochondria and microtubule Dynein motors to control lymphocyte migration and polarity.

    Science.gov (United States)

    Morlino, Giulia; Barreiro, Olga; Baixauli, Francesc; Robles-Valero, Javier; González-Granado, José M; Villa-Bellosta, Ricardo; Cuenca, Jesús; Sánchez-Sorzano, Carlos O; Veiga, Esteban; Martín-Cófreces, Noa B; Sánchez-Madrid, Francisco

    2014-04-01

    The recruitment of leukocytes to sites of inflammation is crucial for a functional immune response. In the present work, we explored the role of mitochondria in lymphocyte adhesion, polarity, and migration. We show that during adhesion to the activated endothelium under physiological flow conditions, lymphocyte mitochondria redistribute to the adhesion zone together with the microtubule-organizing center (MTOC) in an integrin-dependent manner. Mitochondrial redistribution and efficient lymphocyte adhesion to the endothelium require the function of Miro-1, an adaptor molecule that couples mitochondria to microtubules. Our data demonstrate that Miro-1 associates with the dynein complex. Moreover, mitochondria accumulate around the MTOC in response to the chemokine CXCL12/SDF-1α; this redistribution is regulated by Miro-1. CXCL12-dependent cell polarization and migration are reduced in Miro-1-silenced cells, due to impaired myosin II activation at the cell uropod and diminished actin polymerization. These data point to a key role of Miro-1 in the control of lymphocyte adhesion and migration through the regulation of mitochondrial redistribution.

  3. Head Injuries

    Science.gov (United States)

    ... object that's stuck in the wound. previous continue Concussions Concussions — the temporary loss of normal brain function due ... also a type of internal head injury. Repeated concussions can permanently damage the brain. In many cases, ...

  4. Head Tilt

    Science.gov (United States)

    ... Healthy Living Healthy Living Healthy Living Nutrition Fitness Sports Oral Health Emotional Wellness Growing Healthy Sleep Safety & ... When this happens, the neck muscles go into spasm, causing the head to tilt to one side. ...

  5. Head Injuries

    Science.gov (United States)

    ... ATV) Safety Balance Disorders Knowing Your Child's Medical History First Aid: Falls First Aid: Head Injuries Preventing Children's Sports Injuries Getting Help: Know the Numbers Concussions Stay Safe: Baseball Concussions Concussions: Getting Better Sports and Concussions Dealing ...

  6. Head MRI

    Science.gov (United States)

    ... heart valves Heart defibrillator or pacemaker Inner ear (cochlear) implants Kidney disease or dialysis (you may not ... to: Abnormal blood vessels in the brain ( arteriovenous malformations of the head ) Tumor of the nerve that ...

  7. Secreted Cyclic Di-GMP Induces Stalk Cell Differentiation in the Eukaryote Dictyostelium discoideum.

    Science.gov (United States)

    Chen, Zhi-hui; Schaap, Pauline

    2016-01-01

    Cyclic di-GMP (c-di-GMP) is currently recognized as the most widely used intracellular signal molecule in prokaryotes, but roles in eukaryotes were only recently discovered. In the social amoeba Dictyostelium discoideum, c-di-GMP, produced by a prokaryote-type diguanylate cyclase, induces the differentiation of stalk cells, thereby enabling the formation of spore-bearing fruiting bodies. In this review, we summarize the currently known mechanisms that control the major life cycle transitions of Dictyostelium and focus particularly on the role of c-di-GMP in stalk formation. Stalk cell differentiation has characteristics of autophagic cell death, a process that also occurs in higher eukaryotes. We discuss the respective roles of c-di-GMP and of another signal molecule, differentiation-inducing factor 1, in autophagic cell death in vitro and in stalk formation in vivo.

  8. Chemical isolation and characterization of different cellulose nanofibers from cotton stalks

    Science.gov (United States)

    Recently, cellulose nanofibers (CNFs) have received wide attention in green nanomaterial technologies. Production of CNFs from agricultural residues has many economic and environmental advantages. In this study, four different CNFs were prepared from cotton stalks by different chemical treatments fo...

  9. Study of Nutrient Content Variation in Bulb And Stalk of Onions ...

    African Journals Online (AJOL)

    acer

    Keywords: Onion bulbs and stalks, proximate, nutrient elements, vitamins A and C; oxalate. INTRODUCTION ... In addition, onion is among the food plants to which moderate ..... by change of colour or taste and cost of fortified iron products, the ...

  10. Child maltreatment, personality pathology, and stalking victimization among male and female college students.

    Science.gov (United States)

    Ménard, Kim S; Pincus, Aaron L

    2014-01-01

    Self-report college student surveys on childhood maltreatment, and borderline and narcissistic personality features are examined to determine their influence on stalking victimization vulnerability. Stalking victimization was measured using Spitzberg and Cupach's (2008) Obsessive Relational Intrusion scale. Ordinary least squares (OLS) regression models were run separately for men (N = 677) and women (N = 1,017). Results indicated childhood sexual maltreatment and borderline traits were associated with stalking victimization among both men and women. These were the only significant relationships for men (R2 = .10). For women, stalking victimization was also associated with narcissistic grandiosity and vulnerability and with a child sexual abuse by borderline features interaction (R2 = .13), demonstrating women reporting prior sexual abuse and borderline personality pathology are especially vulnerable. Methodological and policy implications are discussed.

  11. Physical and Mechanical Characterization of Fiber Cell Wall in Castor (Ricinus communis L. Stalk

    Directory of Open Access Journals (Sweden)

    Xiaoping Li

    2014-02-01

    Full Text Available Castor (Ricinus communis L. stalk is a byproduct of the production of castor oil. As a natural material, castor stalk has great potential in the production of bio-composites as reinforcement materials. To provide more information about the castor stalk for using it better, the structure, microfibril angle (MFA, relative degree of crystallinity (%, and mechanical properties of castor fiber cell walls were investigated using X-ray diffraction (XRD and nanoindentation. The influence of chemical composition and MFA on the mechanical properties of fiber cell wall was studied as well. The cortex of castor stalks primarily contains long fibers, while the xylem of castor stalk, an excellent wood-type material, comprises most of the castor stalk (83.95% by weight; the pith of the stalk is composed of parenchyma cells. The average elastic modulus of fiber cell wall in lower, upper, and branch parts are 16.0 GPa, 18.6 GPa, and 13.2 GPa, respectively. The average hardness of fiber cell wall in lower, upper, and branch parts are 0.50 GPa, 0.54 GPa, and 0.43 GPa, respectively. As lignin content increases from 15.57% to 17.41% and MFA decreases from 21.3˚ to 15.4˚, the elastic modulus increases from 13.2 GPa to 18.6 GPa and the hardness increases from 0.43 GPa to 0.54 GPa. The mechanical properties, including the elastic modulus and the hardness of the fiber cell wall in the upper region of the castor stalk, are higher than those in the lower region, while the mechanical properties of the fiber cell wall in the branches are lower than those in either the upper or lower regions.

  12. Anaerobic Co-Digestion of Cattle Slurry with Maize Stalk at Mesophilic Temperature

    Directory of Open Access Journals (Sweden)

    A.O. Adebayo

    2016-07-01

    Full Text Available Anaerobic digestion from batch digester containing varying ratio of mixture of cow slurry and maize stalk was studied at mesophilic temperature (37oC. Cattle slurry and maize stalks were co-digested at ratios 3:1, 1:1 and 1:3 using the percentage volatile solid of each substrate. The experiment was carried out in a laboratory scale batch digester. The digester was fed with cattle slurry-maize stalks mixtures calculated for the selected ratios based on the volatile solid (VS concentration of the selected substrates. Co-digestion of cattle slurry with maize stalks at ratios 3:1, 1:1 and 3:1 at mesophilic temperature gave biogas yields of 0.426, 0.385 and 0.391m3 /kgoDM respectively while the methane yields were 0.297, 0.270 and 0.262m3CH4/kgoDM respectively. From the fresh mass of the substrate, biogas yields of 0.052, 0.059 and 0.090 m3 /kgFM were obtained for cattle slurry-maize stalks ratios of 3:1, 1:1 and 1:3 respectively while the methane yields from the fresh mass for the same ratios were 0.036, 0.043 and 0.060 CH4/kgFM respectively. Co-digestion of cattle slurry with maize stalks was found to have methane concentrations of 69.66, 70.24 and 66.98% at cattle slurry/maize stalks combinations of 3:1, 1:1 and 1:3 respectively. The highest biogas yields (oDM of 0.426 m3 /kgoDM was obtained at the mixing ratio of 3:1; therefore the mixing ratio of 3:1 is recommended as the optimal for the codigestion of cattle slurry with maize stalks at mesophilic temperature.

  13. Susceptibility of Maize to Stalk Rot Caused by Fusarium graminearum Deoxynivalenol and Zearalenone Mutants.

    Science.gov (United States)

    Quesada-Ocampo, L M; Al-Haddad, J; Scruggs, A C; Buell, C R; Trail, F

    2016-08-01

    Fusarium graminearum is a destructive pathogen of cereals that can cause stalk rot in maize. Stalk rot results in yield losses due to impaired grain filling, premature senescence, and lodging, which limits production and harvesting of ears. In addition, mycotoxins can make infected tissues unfit for silage. Our objectives were to evaluate the natural variation in stalk rot resistance among maize inbreds, to establish whether deoxynivalenol (DON)- and zearalenone (ZEA)-deficient strains are pathogenic on a panel of diverse inbreds, and to quantify the accumulation of DON in infected stalk tissue. Wild-type F. graminearum and mycotoxin mutants (DON and ZEA) were used to separately inoculate stalks of 9-week-old plants of 20 inbreds in the greenhouse. Plants were evaluated for lesion area at the inoculation point at 0, 2, 14, and 28 days postinoculation and tissues around lesions were sampled to determine the DON content. Regardless of their ability to produce DON or ZEA, all tested F. graminearum strains caused stalk rot; however, significant differences in disease levels were detected. Among the tested inbreds, Mp717 was resistant to all three F. graminearum strains while Mp317 and HP301 were only partially resistant. Accumulation of DON was significantly lower in infected stalks of the resistant and partially resistant inbreds than the susceptible inbreds. Analysis of the 20 inbreds using data from 17 simple-sequence repeats revealed population structure among the individuals; however, there was no association between genetic clustering and stalk rot resistance. These findings are an additional step toward breeding maize inbreds suitable for planting in fields infested with F. graminearum.

  14. Calcareous Sodic Soil Reclamation as Affected by Corn Stalk Application and Incubation:A Laboratory Study

    Institute of Scientific and Technical Information of China (English)

    LI Fa-Hu; R.KEREN

    2009-01-01

    A laboratory lysimeter experiment was conducted to investigate the effects of forage corn (Zea mays L.) stalk application on the CO2 concentration in soil air and calcareous sodic soil reclamation.The experimental treatments tested were soil exchangeable sodium percentage (ESP) levels of 1,11,and 19,added corn stalk contents of 0 to 36 g kg-1,and incubation durations of 30 and 60 days.The experimental results indicated that corn stalk application and incubation significantly increased CO2 partial pressure in soil profile and lowered pH value in soil solution,subsequently increased native CaCO3 mineral dissolution and electrolyte concentration of soil solution,and finally significantly contributed to reduction on soil sodicity level.The reclamation efficiency of calcareous sodic soils increased with the added corn stalk.When corn stalks were added at the rates of 22 and 34 g kg-1 into the soil with initial ESP of 19,its ESP value was decreased by 56% and 78%,respectively,after incubation of 60 days and the leaching of 6.5 pore volumes (about 48 L of percolation water) with distilled water.Therefore,crop stalk application and incubation could be used as a choice to reclaim moderate calcareous sodic soils or as a supplement of phytoremediation to improve reclamation efficiency.

  15. Study on Humic Acids of the Soil Applied with Corn Stalk by Spectroscopy Measurements

    Institute of Scientific and Technical Information of China (English)

    WU Jing-gui; WANG Ming-hui; JIANG Yi-mei; XU Yan

    2005-01-01

    Spectroscopy measurements (Fourier transform infrared differential spectroscopy, Carbon-13 nuclear magnetic resonance spectrometry, Matrix-assisted laser desorption/ionization-time of flight mass spectrometry) were performed to study the humic acids of the soil applied with corn stalk. The results showed that after incorporation of corn stalks into the soil, the soil humic acid (HA) changed significantly in different stages. During first 60 days, new HAs were formed by polymerization and seems to be similar to that of initial HAs from composting corn stalk, some little molecular organic matters also reacted with soil HAs and turned into parts of soil HAs. After 60 days of the corn stalk residue incorporation, new HAs were formed by polymerization of decomposed lignin molecules, some methylenes transformed into methyls and methoxyls since the 90th day. Application of corn stalk led to the increase of aliphatic components in soil HAs, the decrease in aromatic components of soil HAs and the suppression in oxidation degree of soil HAs. The average molecular weight of soil HAs also declined because of application of corn stalk.

  16. Extraction and Characterization of Fibres from the Stalk and Spikelets of Empty Fruit Bunch

    Directory of Open Access Journals (Sweden)

    Yakum Reneta Nafu

    2015-01-01

    Full Text Available Fibres from different parts of empty fruit bunch, which is a major solid waste from oil palm processing, were subjected to different pretreatments and characterised for variability in length and diameter, mechanical performance, and proximate and trace element composition. Morphology and surface composition of the fibres were determined using scanning electron microscopy with energy dispersive X-ray. The fibres were further treated with KOH-boric acid and characterized by Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. Fibre yield was higher for spikelet than stalk. Fibres from stalk were generally larger in diameter and showed significant differences in potassium and galacturonic acid content, strength, and rigidity. Scanning electron microscopy confirmed the widespread occurrence of silica bodies as well as significant differences in the microstructure of stalk and spikelet fibres. Stalk fibres showed a greater level of porosity than spikelet fibres in the section perpendicular to the major axis. The morphology of KOH-boric acid treated fibres suggested higher recalcitrance of spikelet fibres. The significant differences between fibres from stalk and spikelet suggest that EFB, used as feedstock for biobased industries, requires more systematic characterization and separation into stalk and spikelet, which may lead to a more judicious exploitation of this valuable waste.

  17. Enzymatic saccharification of high pressure assist-alkali pretreated cotton stalk and structural characterization.

    Science.gov (United States)

    Du, Shuang-kui; Su, Xia; Yang, Weihua; Wang, Yanqin; Kuang, Meng; Ma, Lei; Fang, Dan; Zhou, Dayun

    2016-04-20

    Cotton stalk is a potential biomass for bioethanol production, while the conversion of direct saccharification or biotransformation of cotton stalk is extremely low due to the recalcitrant nature of lignocellulose. To enhance the enzymatic conversion of cotton stalks, the enzymatic saccharification parameters of high pressure assist-alkali pretreatment (HPAP) cotton stalk were optimized in the present study. Results indicated that a maximum reducing sugar yield of 54.7g/100g dry biomass cellulose was achieved at a substrate concentration of 2%, 100rpm agitation, 0.6g/g enzyme loading, 40°C hydrolysis temperature, 50h saccharification time, and pH 5.0. Scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy were used to identify structural changes in native, pretreated biomass and hydrolyzed residues. Structural analysis revealed large part of amorphous cellulose and partial crystalline cellulose in the HPAP cotton stalk were hydrolyzed during enzymatic treatment. HPAP cotton stalk can be used as a potential feed stock for bioethanol production.

  18. Ethanol Production by Fermentation of Various Sweet-Stalk Sorghum Juices Using Various Yeast Strains

    Directory of Open Access Journals (Sweden)

    Donny Widianto

    2015-11-01

    Full Text Available The ethanol production by fermentation of sweet-stalk sorghum juice is affected by the juice composition and the capability of the yeast strain to ferment it. Eight yeast strains were tested on their growth and ethanol fermentation abilities in sweet-stalk sorghum juices extracted from three cultivars of sweet sorghum. The best specific growth rate of the yeast strains grown aerobically in the yeast extract peptone dextrose (YEPD broth and the sweet-stalk sorghum juices of KCS105, FS501, and FS902 cultivars, were achieved by OUT7903, OUT7913, OUT7903, and OUT7027 yeast strains, respectively. However, the best specific CO2 evolution rate of the yeast strain during fermentation of the juices was achieved by OUT7027 yeast strains. The highest ethanol concentration, ethanol yield, and sugar conversion efficiency (SCE were obtained by strain OUT7921 when it was employed to ferment sweet-stem sorghum juice of FS902 cultivar. It was also observed that the juice extracted from sweet-stalk sorghum of FS902 cultivar is the most suitable medium for all yeast strains to achieve their best fermentation abilities. Thus, it is likely that the growth and ethanol production ability of a yeast strain in sweet-stalk sorghum juice depend on the physiological responses of the yeasts to nutrientcomposition of the sorghum juice and the sorghum cultivar from which the juice was extracted.Key words : Sweet-stalk sorghum juice, ethanol, fermentation, yeast

  19. Preventing lodging in bioenergy crops: a biomechanical analysis of maize stalks suggests a new approach.

    Science.gov (United States)

    Von Forell, Greg; Robertson, Daniel; Lee, Shien Yang; Cook, Douglas D

    2015-07-01

    The hypothetical ideal for maize (Zea mays) bioenergy production would be a no-waste plant: high-yielding, with silage that is easily digestible for conversion to biofuel. However, increased digestibility is typically associated with low structural strength and a propensity for lodging. The solution to this dilemma may lie in our ability to optimize maize morphology using tools from structural engineering. To investigate how material (tissue) and geometric (morphological) factors influence stalk strength, detailed structural models of the maize stalk were created using finite-element software. Model geometry was obtained from high-resolution x-ray computed tomography (CT) scans, and scan intensity information was integrated into the models to infer inhomogeneous material properties. A sensitivity analysis was performed by systematically varying material properties over broad ranges, and by modifying stalk geometry. Computational models exhibited realistic stress and deformation patterns. In agreement with natural failure patterns, maximum stresses were predicted near the node. Maximum stresses were observed to be much more sensitive to changes in dimensions of the stalk cross section than they were to changes in material properties of stalk components. The average sensitivity to geometry was found to be more than 10-fold higher than the average sensitivity to material properties. These results suggest a new strategy for the breeding and development of bioenergy maize varieties in which tissue weaknesses are counterbalanced by relatively small increases (e.g. 5%) in stalk diameter that reduce structural stresses.

  20. Ca(2+)-induced tension development in the stalks of glycerinated Vorticella convallaria.

    Science.gov (United States)

    Moriyama, Y; Yasuda, K; Ishiwata, S; Asai, H

    1996-01-01

    We have developed a method of measuring the isometric tension in glycerinated stalks of Vorticella convallaria. Using this method, we measured tension vs. pCa relations in glycerinated V. convallaria stalks. The maximum isometric tension was 4 x 10(-8) N on average. The Hill's parameter, n, which is the number of calcium ions bound simultaneously and cooperatively to a contractile element (a force generating element), is approximately 3.2 when the Ca2+ concentration is increased and 2.5 when it is decreased. In order to estimate the efficiency of the energy conversion of Ca2+ binding to mechanical work, we measured the Ca(2+)-induced Carnot cycle in the Vorticella stalk. The energy efficiency was tentatively estimated to be about 7%. With this method, we have also succeeded in measuring the isometric tension of isolated spasmoneme, the rubber-like contractile fibrous organelle in the stalk. The maximum tension of spasmoneme was approximately one tenth that of the glycerinated stalk. We speculate that the isolated spasmoneme was only partially functional due to damage sustained when it was pulled out of the stalk.

  1. Effect of microbial pretreatment on enzymatic hydrolysis and fermentation of cotton stalks for ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Jian; Sharma-Shivappa, Ratna R.; Chinn, Mari [Department of Biological and Agricultural Engineering, Campus Box 7625, North Carolina State University, Raleigh, NC 27695-7625 (United States); Howell, Noura [North Carolina School of Science and Mathematics, Durham, NC 27715 (United States)

    2009-01-15

    The potential of microbial pretreatment of cotton stalks by Phanerochaete chrysosporium to degrade lignin and facilitate fuel ethanol production was investigated under two culture conditions: submerged cultivation (SmC) and solid state (SSC) cultivation. Although microbial pretreatments showed significant lignin degradation (LD) (19.38% and 35.53% for SmC and SSC, respectively), a study on hydrolysis and fermentation of the microbial-pretreated cotton stalks showed no increase in cellulose conversion (10.98% and 3.04% for SmC and SSC pretreated samples, respectively) compared to untreated cotton stalks (17.93%). Solid state cultivation demonstrated better selectivity of 0.82 than 0.70 with submerged pretreatment. Washing of pretreated cotton stalks did not significantly increase cellulose conversion. However, heating and washing remarkably improved (P<0.05) cellulose conversion to 14.94% and 17.81% for SmC and SSC 14 day pretreatment, respectively. Ethanol yields, up to 0.027 g ethanol g{sup -1} initial cotton stalks, were low for all untreated and pretreated samples mainly due to the low cellulose conversion. Although potential and some critical aspects of fungal pretreatment using P. chrysosporium have been explored in this study, additional investigation is still required especially to improve the selectivity for preferential LD and to optimize hydrolysis efficiency. The mechanism of catalytic binding of cellulolytic enzymes to cotton stalks as affected by the presence of fungal mycelia also warrants further study. (author)

  2. Two genes conferring resistance to Pythium stalk rot in maize inbred line Qi319.

    Science.gov (United States)

    Song, Feng-Jing; Xiao, Ming-Gang; Duan, Can-Xing; Li, Hong-Jie; Zhu, Zhen-Dong; Liu, Bao-Tao; Sun, Su-Li; Wu, Xiao-Fei; Wang, Xiao-Ming

    2015-08-01

    Stalk rots are destructive diseases in maize around the world, and are most often caused by the pathogen Pythium, Fusarium and other fungi. The most efficient management for controlling stalk rots is to breed resistant cultivars. Pythium stalk rot can cause serious yield loss on maize, and to find the resistance genes from the existing germplasm is the basis to develop Pythium-resistance hybrid lines. In this study, we investigated the genetic resistance to Pythium stalk rot in inbred line Qi319 using F2 and F2:3 population, and found that the resistance to Pythium inflatum in Qi319 was conferred by two independently inherited dominant genes, RpiQI319-1 and RpiQI319-2. Linkage analysis uncovered that the RpiQI319-1 co-segregated with markers bnlg1203, and bnlg2057 on chromosome 1, and that the RpiQI319-2 locus co-segregated with markers umc2069 and bnlg1716 on chromosome 10. The RpiQI319-1 locus was further mapped into a ~500-kb interval flanked by markers SSRZ33 and SSRZ47. These results will facilitate marker-assisted selection of Pythium stalk rot-resistant cultivars in maize breeding. To our knowledge, this is the first report on the resistance to P. inflatum in the inbred line Qi319, and is also the first description of two independently inherited dominant genes conferring the resistance of Pythium stalk rot in maize.

  3. Cyber stalking victimisation of women: Evaluating the effectiveness of current laws in India from restorative justice and therapeutic jurisprudential perspectives

    Directory of Open Access Journals (Sweden)

    Halder Debarati

    2015-01-01

    Full Text Available Victimisation of women through cyber stalking is one of the most serious crimes against women. Many countries including India have developed laws regulating cyber stalking. This article argues that since both, restorative justice (RJ and therapeutic jurisprudence (TJ are victim oriented, the issue of cyber stalking of women may be dealt with by RJ process and the laws in this regard must be analysed by the legal actors with a background in RJ and TJ philosophy. India had earlier taken up therapeutic punishment policy to enforce rights of the accused. But the modern principles of TJ have still not been considered in the RJ background in cyber stalking cases. This article therefore examines whether RJ and TJ principles can replace retributive principles for cyber stalking victimisation. It also examines the Indian cyber stalking law from RJ and TJ perspectives to assess its effectiveness for victims.

  4. Biodegradation of lignin and nicotine with white rot fungi for the delignification and detoxification of tobacco stalk

    OpenAIRE

    Su, Yulong; Xian, He; Shi, Sujuan; Zhang, Chengsheng; Manik, S. M. Nuruzzaman; Mao, Jingjing; Zhang, Ge; Liao, Weihong; Wang, Qian; Liu, Haobao

    2016-01-01

    Background Tobacco stalk is one kind of abundant crop residues in China. The high lignification of tobacco stalk increases its reusing cost and the existing of nicotine will cause serious pollution. The biodegradation of lignocellulosic biomass has been demonstrated to be an environmental and economical approach for the utilization of plant stalk. Meanwhile, many nicotine-degrading microorganisms were found in nature. However, microorganisms which could degraded both nicotine and lignin haven...

  5. Biodegradation of lignin and nicotine with white rot fungi for the delignification and detoxification of tobacco stalk

    OpenAIRE

    Su, Yulong; Xian, He; Shi, Sujuan; Zhang, Chengsheng; Manik, S. M. Nuruzzaman; Mao, Jingjing; Zhang, Ge; Liao, Weihong; Wang, Qian; Liu, Haobao

    2016-01-01

    Background Tobacco stalk is one kind of abundant crop residues in China. The high lignification of tobacco stalk increases its reusing cost and the existing of nicotine will cause serious pollution. The biodegradation of lignocellulosic biomass has been demonstrated to be an environmental and economical approach for the utilization of plant stalk. Meanwhile, many nicotine-degrading microorganisms were found in nature. However, microorganisms which could degraded both nicotine and lignin haven...

  6. Absorption of ethanol by steam-exploded corn stalk.

    Science.gov (United States)

    Fei, Chi; Hongzhang, Chen

    2009-02-01

    The aim of this work is to study the feasibility of using a low-cost biomass absorbent steam-exploded corn stalk (SECS) to absorb ethanol in its production by fermentation. Measurement of many the physical properties of SECS showed its specific surface area was about 214 m(2)/g and it had a good structure for absorption. Some influencing parameters of using SECS to absorb ethanol in water were studied. Second-order and parabolic diffusion equations excellently described the kinetics of absorption for ethanol. Its absorption isotherm was well described by an improved BET equation, indicating that it was a process of polymolecular layer absorption and had phenomena similar to capillary coacervation. Mesh size did not significantly affect absorptivity, but absorbency decreased with temperature. Absorptivity of SECS for ethanol was compared to that of other absorbents: at 30 degrees C and 5% initial ethanol, the absorptivity of SECS for ethanol at 5h was 92 mg/g. When inactivated through use, SECS can continue to be used as an substrate to produce more ethanol, thus avoiding pollution through discarding.

  7. ACID- AND BASE-CATALIZED HYDROLYSES OF CORN STALK

    Directory of Open Access Journals (Sweden)

    Cristina Sánchez

    2011-04-01

    Full Text Available Nowadays agricultural wastes represent an alternative source of renewable raw materials. Different processes can be applied to these alternative materials to separate their components and obtain chemical products with high added value, such as bioethanol, organic acids, monomers, and biopolymers. The main objective of this work is to study the extraction of hemicelluloses from corn stalks using different reagents [H2SO4, HNO3, HCL, CH3COOH, CF3COOH, Ca(OH2, NaOH]. The raw material was characterized and fractionated with autoclave hydrolysis processes (121 ºC, 1:20 solid/liquid ratio, 60 min, pH = 4 or 8. Monomeric sugars concentration, TDS, MO, MI, density, and final pH of the hydrolysate were determined. Hemicelluloses were precipitated and analyzed by different techniques (FTIR, TGA and GPC. The highest yield of hemicelluloses extraction was achieved by sulphuric acid (0.98 g/L total sugar content and the less effective reagent was Ca(OH2 (0.52 g/L total sugar content.

  8. Extraction and Hydrophobic Modification of Cotton Stalk Bark Fiber

    Directory of Open Access Journals (Sweden)

    Ya-Yu Li

    2016-01-01

    Full Text Available Cotton stalk bark fiber (CSBF was extracted at high temperature and under high pressure, under the condition of the alkali content of 11 wt%. Experimental results proved that the extraction yield of CSBF was 27.3 wt%, and the residual alkali concentration was 2.1 wt%. Then five kinds of modifiers including methyl methacrylate (MMA, MMA plus initiator, epoxy propane, copper ethanolamine, and silane coupling agent were chosen to modify the surface of CSBF. It was found by measuring water retention value (WRV that these five kinds of modifiers were all effective and the silane coupling agent was best modifier among all. The optimal modifying conditions of silane coupling agent were obtained: modifier concentration was 5%, the mixing temperature was 20°C, the mixing time was 1 h, and vacuum drying time was 1 h. Under the optimal condition, the WRV of the modified CSBF was 89%. It is expected that these modified CSBF may be a filler with strengthening effect in wood plastic composites (WPC fields.

  9. Perceptual advertisement by the prey of stalking or ambushing predators.

    Science.gov (United States)

    Broom, Mark; Ruxton, Graeme D

    2012-12-21

    There has been previous theoretical explorations of the stability of signals by prey that they have detected a stalking or ambush predator, where such perceptual advertisement dissuades the predator from attacking. Here we use a game theoretical model to extend the theory to consider some empirically-motivated complexities: (i) many perceptual advertisement signals appear to have the potential to vary in intensity, (ii) higher intensity signals are likely to be most costly to produce, and (iii) some high-cost signals (such as staring directly at the predator) can only be utilised if the prey is very confident of the existence of a nearby predator (that is, there are reserved or unfakable signals). We demonstrate that these complexities still allow for stable signalling. However, we do not find solutions where prey use a range of signal intensities to signal different degrees of confidence in the proximity of a predator; with prey simply adopting a binary response of not signalling or always signalling at the same fixed level. However this fixed level will not always be the cheapest possible signal, and we predict that prey that require more certainty about proximity of a predator will use higher-cost signals. The availability of reserved signals does not prohibit the stability of signalling based on lower-cost signals, but we also find circumstances where only the reserved signal is used. We discuss the potential to empirically test our model predictions, and to develop theory further to allow perceptual advertisement to be combined with other signalling functions.

  10. Light absorption of organic aerosol from pyrolysis of corn stalk

    Science.gov (United States)

    Li, Xinghua; Chen, Yanju; Bond, Tami C.

    2016-11-01

    Organic aerosol (OA) can absorb solar radiation in the low-visible and ultra-violet wavelengths thereby modifying radiative forcing. Agricultural waste burning emits a large quantity of organic carbon in many developing countries. In this work, we improved the extraction and analysis method developed by Chen and Bond, and extended the spectral range of OC absorption. We examined light absorbing properties of primary OA from pyrolysis of corn stalk, which is a major type of agricultural wastes. Light absorption of bulk liquid extracts of OA was measured using a UV-vis recording spectrophotometer. OA can be extracted by methanol at 95%, close to full extent, and shows polar character. Light absorption of organic aerosol has strong spectral dependence (Absorption Ångström exponent = 7.7) and is not negligible at ultra-violet and low-visible regions. Higher pyrolysis temperature produced OA with higher absorption. Imaginary refractive index of organic aerosol (kOA) is 0.041 at 400 nm wavelength and 0.005 at 550 nm wavelength, respectively.

  11. When professional kindness is misunderstood: boundaries and stalking issues: a case study for the home health clinician.

    Science.gov (United States)

    Holz, Cheryl L

    2009-01-01

    There is the potential for home health nurses and other home care clinicians to be subjected to intrusive and possibly stalking behavior by current and former clients. Most healthcare clinicians do not receive training on the risk of intrusive interactions or stalking, nor on strategies to manage this objectionable client behavior. This article informs nurses and other home health clinicians about the potential risk of stalking. Included is a true case vignette, the legal definition of stalking, incidence occurrence among clinicians, the basic profile and behaviors of a stalker, the victimology and psychological consequences, and implications for policy and procedures and prevention techniques.

  12. Experimental co-digestion of corn stalk and vermicompost to improve biogas production.

    Science.gov (United States)

    Chen, Guangyin; Zheng, Zheng; Yang, Shiguan; Fang, Caixia; Zou, Xingxing; Luo, Yan

    2010-10-01

    Anaerobic co-digestion of corn stalk and vermicompost (VC) as well as mono-digestion of corn stalk were investigated. Batch mono-digestion experiments were performed at 35+/-1 degrees C and initial total solid loading (TSL) ranged from 1.2% to 6.0%. Batch co-digestion experiments were performed at 35+/-1 degrees C and initial TSL of 6% with VC proportions ranged from 20% to 80% of total solid (TS). For mono-digestion of corn stalk, a maximum methane yield of 217.60+/-13.87 mL/g TS(added) was obtained at initial TSL of 4.8%, and acidification was found at initial TSL of 6.0% with the lowest pH value of 5.10 on day 4. Co-digestion improved the methane yields by 4.42-58.61% via enhancing volatile fatty acids (VFAs) concentration and pH value compared with mono-digestion of corn stalk. The maximum biogas yield of 410.30+/-11.01 mL/g TS(added) and methane yield of 259.35+/-13.85 mL/g TS(added) were obtained for 40% VC addition. Structure analysis by X-ray diffractometry (XRD) showed that the lowest crystallinity of 35.04 of digested corn stalk was obtained from co-digestion with 40% VC, which decreased 29.4% compared to 49.6 obtained from un-treated corn stalk. It is concluded that co-digestion with VC is beneficial for improving biodigestibility and methane yield from corn stalk.

  13. Head Start.

    Science.gov (United States)

    Greenman, Geri

    2000-01-01

    Discusses an art project in which students created drawings of mop heads. Explains that the approach of drawing was more important than the subject. States that the students used the chiaroscuro technique, used by Rembrandt and Caravaggio, in which light appears out of the darkness. (CMK)

  14. Nuclear envelope-associated dynein drives prophase centrosome separation and enables Eg5-independent bipolar spindle formation.

    Science.gov (United States)

    Raaijmakers, Jonne A; van Heesbeen, Roy G H P; Meaders, Johnathan L; Geers, Erica F; Fernandez-Garcia, Belen; Medema, René H; Tanenbaum, Marvin E

    2012-11-05

    The microtubule motor protein kinesin-5 (Eg5) provides an outward force on centrosomes, which drives bipolar spindle assembly. Acute inhibition of Eg5 blocks centrosome separation and causes mitotic arrest in human cells, making Eg5 an attractive target for anti-cancer therapy. Using in vitro directed evolution, we show that human cells treated with Eg5 inhibitors can rapidly acquire the ability to divide in the complete absence of Eg5 activity. We have used these Eg5-independent cells to study alternative mechanisms of centrosome separation. We uncovered a pathway involving nuclear envelope (NE)-associated dynein that drives centrosome separation in prophase. This NE-dynein pathway is essential for bipolar spindle assembly in the absence of Eg5, but also functions in the presence of full Eg5 activity, where it pulls individual centrosomes along the NE and acts in concert with Eg5-dependent outward pushing forces to coordinate prophase centrosome separation. Together, these results reveal how the forces are produced to drive prophase centrosome separation and identify a novel mechanism of resistance to kinesin-5 inhibitors.

  15. Phosphorylation of Nlp by Plk1 negatively regulates its dynein-dynactin-dependent targeting to the centrosome.

    Science.gov (United States)

    Casenghi, Martina; Barr, Francis A; Nigg, Erich A

    2005-11-01

    When cells enter mitosis the microtubule (MT) network undergoes a profound rearrangement, in part due to alterations in the MT nucleating and anchoring properties of the centrosome. Ninein and the ninein-like protein (Nlp) are centrosomal proteins involved in MT organisation in interphase cells. We show that the overexpression of these two proteins induces the fragmentation of the Golgi, and causes lysosomes to disperse toward the cell periphery. The ability of Nlp and ninein to perturb the cytoplasmic distribution of these organelles depends on their ability to interact with the dynein-dynactin motor complex. Our data also indicate that dynactin is required for the targeting of Nlp and ninein to the centrosome. Furthermore, phosphorylation of Nlp by the polo-like kinase 1 (Plk1) negatively regulates its association with dynactin. These findings uncover a mechanism through which Plk1 helps to coordinate changes in MT organisation with cell cycle progression, by controlling the dynein-dynactin-dependent transport of centrosomal proteins.

  16. Fast track, dynein-dependent nuclear targeting of human immunodeficiency virus Vpr protein; impaired trafficking in a clinical isolate

    Energy Technology Data Exchange (ETDEWEB)

    Caly, Leon [Department of Biochemistry and Molecular Biology, Monash University, Clayton, Vic. 3800 (Australia); Kassouf, Vicki T. [Centre for Virus Research, The Westmead Institute for Medical Research, The University of Sydney, Westmead, NSW 2145 (Australia); Moseley, Gregory W. [Department of Biochemistry and Molecular Biology, Monash University, Clayton, Vic. 3800 (Australia); Diefenbach, Russell J.; Cunningham, Anthony L. [Centre for Virus Research, The Westmead Institute for Medical Research, The University of Sydney, Westmead, NSW 2145 (Australia); Jans, David A., E-mail: david.jans@monash.edu [Department of Biochemistry and Molecular Biology, Monash University, Clayton, Vic. 3800 (Australia)

    2016-02-12

    Nuclear import of the accessory protein Vpr is central to infection by human immunodeficiency virus (HIV). We previously identified the Vpr F72L mutation in a HIV-infected, long-term non-progressor, showing that it resulted in reduced Vpr nuclear accumulation and altered cytoplasmic localisation. Here we demonstrate for the first time that the effects of nuclear accumulation of the F72L mutation are due to impairment of microtubule-dependent-enhancement of Vpr nuclear import. We use high resolution imaging approaches including fluorescence recovery after photobleaching and other approaches to document interaction between Vpr and the dynein light chain protein, DYNLT1, and impaired interaction of the F72L mutant with DYNLT1. The results implicate MTs/DYNLT1 as drivers of Vpr nuclear import and HIV infection, with important therapeutic implications. - Highlights: • HIV-1 Vpr utilizes the microtubule network to traffic towards the nucleus. • Mechanism relies on interaction between Vpr and dynein light chain protein DYNLT1. • Long-term non-progressor derived mutation (F72L) impairs this interaction. • Key residues in the vicinity of F72 contribute to interaction with DYNLT1.

  17. JAM-A regulates cortical dynein localization through Cdc42 to control planar spindle orientation during mitosis.

    Science.gov (United States)

    Tuncay, Hüseyin; Brinkmann, Benjamin F; Steinbacher, Tim; Schürmann, Annika; Gerke, Volker; Iden, Sandra; Ebnet, Klaus

    2015-08-26

    Planar spindle orientation in polarized epithelial cells depends on the precise localization of the dynein-dynactin motor protein complex at the lateral cortex. The contribution of cell adhesion molecules to the cortical localization of the dynein-dynactin complex is poorly understood. Here we find that junctional adhesion molecule-A (JAM-A) regulates the planar orientation of the mitotic spindle during epithelial morphogenesis. During mitosis, JAM-A triggers a transient activation of Cdc42 and PI(3)K, generates a gradient of PtdIns(3,4,5)P3 at the cortex and regulates the formation of the cortical actin cytoskeleton. In the absence of functional JAM-A, dynactin localization at the cortex is reduced, the mitotic spindle apparatus is misaligned and epithelial morphogenesis in three-dimensional culture is compromised. Our findings indicate that a PI(3)K- and cortical F-actin-dependent pathway of planar spindle orientation operates in polarized epithelial cells to regulate epithelial morphogenesis, and we identify JAM-A as a junctional regulator of this pathway.

  18. Dynein light chain DLC-1 promotes localization and function of the PUF protein FBF-2 in germline progenitor cells.

    Science.gov (United States)

    Wang, Xiaobo; Olson, Jenessa R; Rasoloson, Dominique; Ellenbecker, Mary; Bailey, Jessica; Voronina, Ekaterina

    2016-12-15

    PUF family translational repressors are conserved developmental regulators, but the molecular function provided by the regions flanking the PUF RNA-binding domain is unknown. In C. elegans, the PUF proteins FBF-1 and FBF-2 support germline progenitor maintenance by repressing production of meiotic proteins and use distinct mechanisms to repress their target mRNAs. We identify dynein light chain DLC-1 as an important regulator of FBF-2 function. DLC-1 directly binds to FBF-2 outside of the RNA-binding domain and promotes FBF-2 localization and function. By contrast, DLC-1 does not interact with FBF-1 and does not contribute to FBF-1 activity. Surprisingly, we find that the contribution of DLC-1 to FBF-2 activity is independent of the dynein motor. Our findings suggest that PUF protein localization and activity are mediated by sequences flanking the RNA-binding domain that bind specific molecular partners. Furthermore, these results identify a new role for DLC-1 in post-transcriptional regulation of gene expression.

  19. Enhancing the anaerobic digestion of corn stalks using composite microbial pretreatment.

    Science.gov (United States)

    Yuan, Xufeng; Li, Peipei; Wang, Hui; Wang, Xiaofen; Cheng, Xu; Cui, Zongjun

    2011-07-01

    A composite microbial system (XDC-2) was used to pretreat and hydrolyze corn stalk to enhance anaerobic digestion. The results of pretreatment indicated that sCOD concentrations of hydrolysate were highest (8,233 mg/l) at the fifth day. XDC-2 efficiently degraded the corn stalk by nearly 45%, decreasing the cellulose content by 22.7% and the hemicellulose content by 74.1%. Total levels of volatile products peaked on the fifth day. The six major compounds present were ethanol (0.29 g/l), acetic acid (0.55 g/l), 1,2-ethanediol (0.49 g/l), propionic acid (0.15 g/l), butyric acid (0.22 g/l), and glycerine (2.48 g/l). The results of anaerobic digestion showed that corn stalks treated by XDC-2 produced 68.3% more total biogas and 87.9% more total methane than untreated controls. The technical digestion time for the treated corn stalks was 35.7% shorter than without treatment. The composite microbial system pretreatment could be a cost-effective and environmentally friendly microbial method for efficient biological conversion of corn stalk into bioenergy.

  20. Two Escape Mechanisms of Influenza A Virus to a Broadly Neutralizing Stalk-Binding Antibody.

    Science.gov (United States)

    Chai, Ning; Swem, Lee R; Reichelt, Mike; Chen-Harris, Haiyin; Luis, Elizabeth; Park, Summer; Fouts, Ashley; Lupardus, Patrick; Wu, Thomas D; Li, Olga; McBride, Jacqueline; Lawrence, Michael; Xu, Min; Tan, Man-Wah

    2016-06-01

    Broadly neutralizing antibodies targeting the stalk region of influenza A virus (IAV) hemagglutinin (HA) are effective in blocking virus infection both in vitro and in vivo. The highly conserved epitopes recognized by these antibodies are critical for the membrane fusion function of HA and therefore less likely to be permissive for virus mutational escape. Here we report three resistant viruses of the A/Perth/16/2009 strain that were selected in the presence of a broadly neutralizing stalk-binding antibody. The three resistant viruses harbor three different mutations in the HA stalk: (1) Gln387Lys; (2) Asp391Tyr; (3) Asp391Gly. The Gln387Lys mutation completely abolishes binding of the antibody to the HA stalk epitope. The other two mutations, Asp391Tyr and Asp391Gly, do not affect antibody binding at neutral pH and only slightly reduce binding at low pH. Interestingly, they enhance the fusion ability of the HA, representing a novel mechanism that allows productive membrane fusion even in the presence of antibody and hence virus escape from antibody neutralization. Therefore, these mutations illustrate two different resistance mechanisms used by IAV to escape broadly neutralizing stalk-binding antibodies. Compared to the wild type virus, the resistant viruses release fewer progeny viral particles during replication and are more sensitive to Tamiflu, suggesting reduced viral fitness.

  1. Cultural Models Shaping Stalking From a Content Analysis of Italian Newspapers

    Directory of Open Access Journals (Sweden)

    Andrea Caputo

    2013-08-01

    Full Text Available The increasing spread of stalking in recent years has captured the community’s and media’s interest and highlighted complex legal, clinical and cultural issues. This phenomenon, far from being an individual problem, can be considered as a product of a growing culture that seems to reveal the crisis of current rules of social coexistence. This work aims at detecting the cultural repertoires that organise the stalking discourse, from an analysis of Italian newspaper articles, within a socio-constructivist paradigm. Emotional text analysis was conducted on a corpus of headlines and subheadings derived from 496 articles. These articles were published in major national newspapers and helped to identify four cultural repertoires (clusters that characterise the social representation of stalking: gender violence and women’s social independence (Cluster 1, psychological violence and control as illusion of intimacy (Cluster 2, anomic violence and intolerant individualism (Cluster 3, domestic violence and women’s marital obligation (Cluster 4. These repertoires are conceived along three latent dimensions which respectively refer to the cultural functions of stalking (Factor 1, representations of the victim (Factor 2, and gender inequalities (Factor 3. The paper offers a key to a social contextualisation of stalking in Italy, in order to re-think work practices within institutional agencies that deal with this phenomenon.

  2. Effect of Torrefaction on the Properties of Corn Stalk to Enhance Solid Fuel Qualities

    Directory of Open Access Journals (Sweden)

    Jeeban Poudel

    2014-08-01

    Full Text Available This study presents the effects of torrefaction on the basic characteristics of corn stalks. Corn stalks were torrefied in a horizontal tubular reactor at temperatures ranging from 150 °C to 400 °C, for torrefaction periods varying from 0 min to 50 min. The torrefied corn stalk products were characterized in terms of their elemental composition, energy yield, ash content, and volatile fraction. The gaseous products were also analyzed. Thermogravimetric analysis (TGA of the samples was carried out in order to obtain the apparent activation energy for the torrefaction of corn stalks. The weight loss data according to the degradation temperature were analyzed using three different methods. The energy and mass yield were found to decrease with an increase in the temperature, whereas the higher heating value (HHV increased. From this work, it was found that the compounds with oxygen were emitted at a temperature lower than that for hydrocarbon gases and the temperatures of 290–330 °C were the optimum torrefaction temperatures for corn stalks.

  3. Mass transfer effect of the stalk contraction-relaxation cycle of Vorticella convallaria

    Science.gov (United States)

    Zhou, Jiazhong; Admiraal, David; Ryu, Sangjin

    2014-11-01

    Vorticella convallaria is a genus of protozoa living in freshwater. Its stalk contracts and coil pulling the cell body towards the substrate at a remarkable speed, and then relaxes to its extended state much more slowly than the contraction. However, the reason for Vorticella's stalk contraction is still unknown. It is presumed that water flow induced by the stalk contraction-relaxation cycle may augment mass transfer near the substrate. We investigated this hypothesis using an experimental model with particle tracking velocimetry and a computational fluid dynamics model. In both approaches, Vorticella was modeled as a solid sphere translating perpendicular to a solid surface in water. After having been validated by the experimental model and verified by grid convergence index test, the computational model simulated water flow during the cycle based on the measured time course of stalk length changes of Vorticella. Based on the simulated flow field, we calculated trajectories of particles near the model Vorticella, and then evaluated the mass transfer effect of Vorticella's stalk contraction based on the particles' motion. We acknowlege support from Laymann Seed Grant of the University of Nebraska-Lincoln.

  4. A Kinetic Study of Marginal Soil Energy Plant Helianthus annuus Stalk Pyrolysis

    Directory of Open Access Journals (Sweden)

    Huaxiao Yan

    2013-01-01

    Full Text Available The pyrolytic characteristics and kinetics of new marginal soil energy plant Helianthus annuus stalk were investigated using thermogravimetric (TG method from 50 to 800°C in an inert argon atmosphere at different heating rates of 5, 10, 20, and 30°C min−1. The kinetic parameters of activation energy and pre-exponential factor were deduced by Popescu, Flynn-Wall-Ozawa (FWO, and Kissinger-Akahira-Sunose (KAS methods, respectively. The results showed that three stages appeared in the thermal degradation process. The primary devolatilization stage of H. annuus stalk can be described by the Avrami-Erofeev function (n=4. The average activation energy of H. annuus stalk was only 142.9 kJ mol−1. There were minor kinetic compensation effects between the pre-exponential factor and the activation energy. The results suggest that H. annuus stalk is suitable for pyrolysis, and more importantly, the experimental results and kinetic parameters provided useful information for the design of pyrolytic processing system using H. annuus stalk as feedstock.

  5. Analysis of cellulose content in stalks and leaves of large leaf tobacco

    Directory of Open Access Journals (Sweden)

    Kulić Gordana J.

    2011-01-01

    Full Text Available Tobacco stalks are an under-utilized material that remains after the harvest of leaves. Given the share of large leaf tobacco in total production in Serbia (more than 85% stalks could be easily available as well as payable raw material in the fabrication of cellulose. The aim of this study was to determine cellulose content in leaves and more importantly in stalks of large leaf tobacco and to provide necessary data to processors engaged in processing of biomass. Stalks and leaves of two types of tobacco, Burley and Virginia, reared in Srem, were used as experimental material samples. Two parallel methods were applied for determining cellulose content: method by Kürschner-Hanack and method by Updegraff. It can be concluded that both methods are applicable to tobacco, but the method by Kürschner-Hanack was found to be simpler, more convenient, faster and economically more cost-effective. Thus, it should be recommended for use. Results showed that stalks of large leaf tobacco contain on average 30.50% to 34.30% of cellulose. There was no statistically significant difference in the cellulose content between the two applied methods. Given the number of plants that lag behind in fields after harvesting leaves, 28,000 tons of cellulose could be used.

  6. Postharvest Quality and Physiological Behavior of Sweet Potato (Ipomoea batatas Lam.) Leaf Stalks Under Three Temperatures

    Institute of Scientific and Technical Information of China (English)

    PENG Yan; XU Yong-quan; DUAN Dao-fu; MAO Lin-chun

    2009-01-01

    Sweet potato (lpomoea batatas Lam.) leaf stalks were cut into 20 cm length, and stored at 20, 6, and 2℃. The respiration rate, ethylene production, ascorbic acid, free amino acid, total chlorophyll content, freshness, and shelf life were determined during storage to investigate the effect of storage temperatures on the quality and physiological responses in sweet potato leaf stalks. Wound responses were observed as high respiration rate and ethylene production immediately after cutting. Sweet potato leaf stalks were found to be sensitive to chilling injury manifested as browning and water-soaking on the surface at 2℃. In contrast, sweet potato leaf stalks were susceptible to senescence, exhibited by etiolating and yellowing, at 20℃. Loss in weight and chlorophyll was minimized under low temperatures. High temperatures also caused the accumulation of amino acids with a significant loss of ascorbic acid and chlorophyll. Sweet potato leaf stalks had a storage life of 16 days at 6℃, 8 days at 2℃, and 6 days at 20℃, respectively.

  7. Exploration of the pituitary stalk and gland by high-resolution computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, Y.; Fukami, T.; Takase, K.; Matsumoto, K.

    1984-11-01

    By means of high-resolution CT, pituitary stalks and glands were demonstrated in 189 normal subjects and in six patients with microadenomas. In the horizontal view and in reconstructed coronal and sagittal projections, the normal stalks and glands showed homogeneous enhancement with the contrast medium. On metrizamide CT, the stalks and glands were demonstrated in high-density areas as a ''defect''. The detection-rate of the stalks and glands was more than 93.6% in all dimensions on enhanced CT and 100% on metrizamide CT. On reconstructed sagittal projections, there was a tendency for the glands to decrease in size with advancing age. Under the age of 29, especially in females, most of the glands were demonstrated as an oval area that filled the sella turcica. After the age of 50, the gland frequently was flattened with enlargement of the CSF space within the sella turcica, giving an appearance reminiscent of the ''empty stella''. Of six patients with microadenomas, five presented the appearance of oval gland, and one showed visualization of CSF space in the anterosuperior portion of the stella turcica. On reconstructed coronal projections, the angle of inclination of stalks was 1.5+-1.2/sup 0/ in normal subjects and 9.3+-2.4/sup 0/ in patients with microadenomas.

  8. The special neuraminidase stalk-motif responsible for increased virulence and pathogenesis of H5N1 influenza A virus.

    Directory of Open Access Journals (Sweden)

    Hongbo Zhou

    Full Text Available The variation of highly pathogenic avian influenza H5N1 virus results in gradually increased virulence in poultry, and human cases continue to accumulate. The neuraminidase (NA stalk region of influenza virus varies considerably and may associate with its virulence. The NA stalk region of all N1 subtype influenza A viruses can be divided into six different stalk-motifs, H5N1/2004-like (NA-wt, WSN-like, H5N1/97-like, PR/8-like, H7N1/99-like and H5N1/96-like. The NA-wt is a special NA stalk-motif which was first observed in H5N1 influenza virus in 2000, with a 20-amino acid deletion in the 49(th to 68(th positions of the stalk region. Here we show that there is a gradual increase of the special NA stalk-motif in H5N1 isolates from 2000 to 2007, and notably, the special stalk-motif is observed in all 173 H5N1 human isolates from 2004 to 2007. The recombinant H5N1 virus with the special stalk-motif possesses the highest virulence and pathogenicity in chicken and mice, while the recombinant viruses with the other stalk-motifs display attenuated phenotype. This indicates that the special stalk-motif has contributed to the high virulence and pathogenicity of H5N1 isolates since 2000. The gradually increasing emergence of the special NA stalk-motif in H5N1 isolates, especially in human isolates, deserves attention by all.

  9. The lissencephaly protein Lis1 is present in motile mammalian cilia and requires outer arm dynein for targeting to Chlamydomonas flagella

    DEFF Research Database (Denmark)

    Pedersen, Lotte B; Rompolas, Panteleimon; Christensen, Søren T

    2007-01-01

    Lissencephaly is a developmental brain disorder characterized by a smooth cerebral surface, thickened cortex and misplaced neurons. Classical lissencephaly is caused by mutations in LIS1, which encodes a WD-repeat protein involved in cytoplasmic dynein regulation, mitosis and nuclear migration. S...

  10. Snapin Recruits Dynein to BDNF-TrkB Signaling Endosomes for Retrograde Axonal Transport and Is Essential for Dendrite Growth of Cortical Neurons

    Directory of Open Access Journals (Sweden)

    Bing Zhou

    2012-07-01

    Full Text Available Neurotrophin signaling is crucial for neuron growth. While the “signaling endosomes” hypothesis is one of the accepted models, the molecular machinery that drives retrograde axonal transport of TrkB signaling endosomes is largely unknown. In particular, mechanisms recruiting dynein to TrkB signaling endosomes have not been elucidated. Here, using snapin deficient mice and gene rescue experiments combined with compartmentalized cultures of live cortical neurons, we reveal that Snapin, as a dynein adaptor, mediates retrograde axonal transport of TrkB signaling endosomes. Such a role is essential for dendritic growth of cortical neurons. Deleting snapin or disrupting Snapin-dynein interaction abolishes TrkB retrograde transport, impairs BDNF-induced retrograde signaling from axonal terminals to the nucleus, and decreases dendritic growth. Such defects were rescued by reintroducing the snapin gene. Our study indicates that Snapin-dynein coupling is one of the primary mechanisms driving BDNF-TrkB retrograde transport, thus providing mechanistic insights into the regulation of neuronal growth and survival.

  11. Dynein associates with oskar mRNPs and is required for their efficient net plus-end localization in Drosophila oocytes.

    Directory of Open Access Journals (Sweden)

    Paulomi Sanghavi

    Full Text Available In order for eukaryotic cells to function properly, they must establish polarity. The Drosophila oocyte uses mRNA localization to establish polarity and hence provides a genetically tractable model in which to study this process. The spatial restriction of oskar mRNA and its subsequent protein product is necessary for embryonic patterning. The localization of oskar mRNA requires microtubules and microtubule-based motor proteins. Null mutants in Kinesin heavy chain (Khc, the motor subunit of the plus end-directed Kinesin-1, result in oskar mRNA delocalization. Although the majority of oskar particles are non-motile in khc nulls, a small fraction of particles display active motility. Thus, a motor other than Kinesin-1 could conceivably also participate in oskar mRNA localization. Here we show that Dynein heavy chain (Dhc, the motor subunit of the minus end-directed Dynein complex, extensively co-localizes with Khc and oskar mRNA. In addition, immunoprecipitation of the Dynein complex specifically co-precipitated oskar mRNA and Khc. Lastly, germline-specific depletion of Dhc resulted in oskar mRNA and Khc delocalization. Our results therefore suggest that efficient posterior localization of oskar mRNA requires the concerted activities of both Dynein and Kinesin-1.

  12. Muscle and nerve net organization in stalked jellyfish (Medusozoa: Staurozoa).

    Science.gov (United States)

    Westlake, Hannah E; Page, Louise R

    2017-01-01

    Staurozoan cnidarians display an unusual combination of polyp and medusa characteristics and their morphology may be informative about the evolutionary origin of medusae. We studied neuromuscular morphology of two staurozoans, Haliclystus 'sanjuanensis' and Manania handi, using whole mount immunohistochemistry with antibodies against FMRFamide and α-tubulin to label neurons and phalloidin to label muscles. All muscles appeared to lack striations. Longitudinal interradial muscles are probable homologues of stalk muscles in scyphopolyps, but in adult staurozoans they are elaborated to inwardly flex marginal lobes of the calyx during prey capture; these muscles are pennate in M. handi. Manubrial perradial muscles, like the manubrium itself, are an innovation shared with pelagic medusae and manubrial interradial muscles are shared with scyphozoan ephyra. Marginal muscles of M. handi displayed occasional synchronous contraction reminiscent of a medusa swim pulse, but contractions were not repetitive. The nerve net in both species showed regional variation in density and orientation of neurons. Some areas labeled predominantly by α-tubulin antibodies (exumbrellar epidermis), other areas labeled exclusively by FMRFamide antibodies (dense plexus of neurites surrounding the base of secondary tentacles, neuronal concentration at the base of transformed primary tentacles; gastrodermal nerve net), but most areas showed a mix of neurons labeled by these two antibodies and frequent co-labeling of neurons. Transformed primary tentacles had a concentration of FMRFamide-immunoreactive neurons at their base that was associated with a pigment spot in M. handi; this is consistent with their homology with rhopalia of medusae, which are also derived from primary tentacles. The muscular system of these staurozoans embodies characteristics of both scyphopolyps and pelagic medusae. However, their nerve net is more polyp-like, although marginal concentrations of the net associated with

  13. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Professions Site Index A-Z Computed Tomography (CT) - Head Computed tomography (CT) of the head uses special ... the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a CT ...

  14. Inhibition of microtubules and dynein rescues human immunodeficiency virus type 1 from owl monkey TRIMCyp-mediated restriction in a cellular context-specific fashion.

    Science.gov (United States)

    Pawlica, Paulina; Dufour, Caroline; Berthoux, Lionel

    2015-04-01

    IFN-induced restriction factors can significantly affect the replicative capacity of retroviruses in mammals. TRIM5α (tripartite motif protein 5, isoform α) is a restriction factor that acts at early stages of the virus life cycle by intercepting and destabilizing incoming retroviral cores. Sensitivity to TRIM5α maps to the N-terminal domain of the retroviral capsid proteins. In several New World and Old World monkey species, independent events of retrotransposon-mediated insertion of the cyclophilin A (CypA)-coding sequence in the trim5 gene have given rise to TRIMCyp (also called TRIM5-CypA), a hybrid protein that is active against some lentiviruses in a species-specific fashion. In particular, TRIMCyp from the owl monkey (omkTRIMCyp) very efficiently inhibits human immunodeficiency virus type 1 (HIV-1). Previously, we showed that disrupting the integrity of microtubules (MTs) and of cytoplasmic dynein complexes partially rescued replication of retroviruses, including HIV-1, from restriction mediated by TRIM5α. Here, we showed that efficient restriction of HIV-1 by omkTRIMCyp was similarly dependent on the MT network and on dynein complexes, but in a context-dependent fashion. When omkTRIMCyp was expressed in human HeLa cells, restriction was partially counteracted by pharmacological agents targeting MTs or by small interfering RNA-mediated inhibition of dynein. The same drugs (nocodazole and paclitaxel) also rescued HIV-1 from restriction in cat CRFK cells, although to a lesser extent. Strikingly, neither nocodazole, paclitaxel nor depletion of the dynein heavy chain had a significant effect on the restriction of HIV-1 in an owl monkey cell line. These results suggested the existence of cell-specific functional interactions between MTs/dynein and TRIMCyp. © 2015 The Authors.

  15. Effect of acid pretreatment on different parts of corn stalk for second generation ethanol production.

    Science.gov (United States)

    Li, Ping; Cai, Di; Luo, Zhangfeng; Qin, Peiyong; Chen, Changjing; Wang, Yong; Zhang, Changwei; Wang, Zheng; Tan, Tianwei

    2016-04-01

    In this study, the effects of different parts of corn stalk, including stem, leaf, flower, cob and husk on second generation ethanol production were evaluated. FTIR, XRD and SEM were performed to investigate the effect of dilute acid pretreatment. The bagasse obtained after pretreatment were further hydrolyzed by cellulase and used as the substrate for ethanol fermentation. As results, hemicelluloses fractions in different parts of corn stalk were dramatically removed and the solid fractions showed vivid compositions and crystallinities. Compared with other parts of corn stalk, the cob had higher sugar content and better enzymatic digestibility. The highest glucose yield of 94.2% and ethanol production of 24.0 g L(-1) were achieved when the cob was used as feedstock, while the glucose yield and the ethanol production were only 86.0% and 17.1 g L(-1) in the case of flower.

  16. Body stalk anomaly complicated by ectopia cordis in the first trimester.

    Science.gov (United States)

    Y, Shibata; K, Terada; M, Igarashi; S, Suzuki

    2014-05-01

    The most serious conditions seen in body stalk anomaly may be the cases which are complicated by ectopia cordis, which is characterized by the abnormal location of the heart outside the thorax. We encountered four cases of body stalk anomaly, which were complicated by ectopia cordis, which were diagnosed in the first trimesters of pregnancy. In three of these cases, ultrasound scans revealed foetuses with large anterior abdominal wall defects, with their hearts extending outside their thoracic cavities. Their mothers, along with their husbands opted for termination of their pregnancies. In 1 other case, an ultrasound scan revealed a dead foetus, with gastroschisis. Based on the current cases, we suggest that the diagnosis of ectopia cordis caused by body stalk anomaly can be made during the first trimester of pregnancy.

  17. The complete mitochondrial genome of the Antarctic stalked jellyfish, Haliclystus antarcticus Pfeffer, 1889 (Staurozoa: Stauromedusae

    Directory of Open Access Journals (Sweden)

    Hsing-Hui Li

    2016-06-01

    Full Text Available In present study, the complete mitogenome sequence of the Antarctic stalked jellyfish, Haliclystus antarcticus Pfeffer (Staurozoa: Stauromedusae has been sequenced by next-generation sequencing method. The assembled mitogenome comprises of 15,766 bp including 13 protein coding genes, 7 transfer RNAs, and 2 ribosomal RNA genes. The overall base of Antarctic stalked jellyfish constitutes of 26.5% for A, 19.6% for C, 19.8% for G, 34.1% for T and show 90% identity to Sessile Jelly, Haliclystus sanjuanensis, in the northeastern Pacific Ocean. The complete mitogenome of the Antarctic stalked jellyfish, contributes fundamental and significant DNA molecular data for further phylogeography and evolutionary analysis for seahorse phylogeny. The complete sequence was deposited in DBBJ/EMBL/GenBank under accession number KU947038.

  18. Chemical-free Extraction of Cotton Stalk Bark Fibers by Steam Flash Explosion

    Directory of Open Access Journals (Sweden)

    Xiuliang Hou

    2014-10-01

    Full Text Available Cotton stalk bark fibers (CSBF were extracted by steam flash explosion, completed within 0.09 s, and the extracted fibers were compared with those obtained by conventional alkaline treatment. Results indicate that the optimum steam pressure was 2.5 MPa when steaming time was set to 2 min for extracting CSBF. Under the optimized conditions, the obtained CSBF had a cellulose content of 72%, length of 48 mm, fineness of 45 dtex, crystallinity index of 68, moisture regain of 8%, water retention of 98%, and tensile strength of 2.4 cN/dtex, which were similar to results obtained by conventional alkaline treatment. Compared with bark of cotton stalks, CSBF had lower moisture regain and water retention, and higher onset decomposition temperature. The results show that moderate steam flash explosion is a chemical-free, quick, and effective method for exploring the industrial applications of bark of cotton stalks as natural cellulose fibers.

  19. The effect of viscosity on the contraction of the stalk of Vorticella Convallaria

    Science.gov (United States)

    Kantha, Deependra; van Winkle, David

    2006-03-01

    The contraction of the stalk of Vorticella Convallaria behaves as one of the most powerful single cell biological engines.Contractions in three different viscous mediums were recorded by a PhantomV5 camera (Vision Research) on a bright field microscope with 20X objective. The contractions were recorded as cines (image sequences) with the image resolution of 256 pixels X 128 pixels at 7000 pictures per second. The maximum variation in maximum velocity of one organism was 5.2 cm/s and the minimum variation for a different organism was 0.4 cm/s for the same viscous medium. It occurred at 2-3ms after the start of contraction. The force of contraction and the force constant were calculated as a function of the time to see the effect of viscosity on the contraction of the stalk. This experiment needs further investigation to see the net effect of viscosity on the contraction of the stalk.

  20. Two Adult Patients with Ectopic Neurohypophysis and Panhypopituitarism Due to Absent Pituitary Stalk

    Directory of Open Access Journals (Sweden)

    Fettah Acıbucu

    2014-12-01

    Full Text Available We report two cases of 27-year-old and 19-year-old female patients with ectopic neurohypophysis and panhypopituitarism due to absent pituitary stalk. They were admitted to the endocrinology clinic with short stature, growth retardation and primary amenorrhea. Basal hormones revealed secondary hypothyroidism, adrenal insufficiency, hypogonadism and growth hormone insufficiency. Peak cortisol response to the short synacthen test (SST was normal but was inadequate to insulin tolerance test. The other dynamic pituitary function tests showed panhypopituitarism. Magnetic resonance imaging of the pituitary gland revealed an ectopic posterior pituitary tissue and absent pituitary stalk. We administered hormone replacement therapy. As this disorder is usually encountered in the pediatric age group, we report here two adult patients with ectopic posterior pituitary tissue, absent pituitary stalk and panhypopituitarism.

  1. Sunflower stalks as adsorbents for the removal of metal ions from wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Sun, G.; Shi, W. [Univ. of California, Davis, CA (United States). Div. of Textiles and Clothing

    1998-04-01

    Sunflower stalks as adsorbents for the removal of metal ions such as copper, cadmium, zinc, and chromium ions in aqueous solutions were studied with equilibrium isotherms and kinetic adsorptions. The maximum adsorptions of four heavy metals are 29.3 mg/g (Cu{sup 2+}), 30.73 mg/g (Zn{sup 2+}), 42.18 mg/g (Cd{sup 2+}), and 25.07 mg/g (Cr{sup 3+}), respectively. Particle sizes of sunflower stalks affected the adsorption of metal ions; the finer size of particles showed better adsorption to the ions. Temperature also plays an interesting role in the adsorption of different metal ions. Copper, zinc, and cadmium exhibited lower adsorption on sunflower stalks at higher temperature, while chromium showed the opposite phenomenon. The adsorption rates of copper, cadmium, and chromium are quite rapid. Within 60 min of operation about 60--80% of these ions were removed from the solutions.

  2. Structure, composition and enzymatic hydrolysis of steam-exploded lespedeza stalks

    Institute of Scientific and Technical Information of China (English)

    Wang Kun; Wang Fang; Jiang Jian-xin; Zhu Li-wei; Fan Hong-zhuai

    2007-01-01

    Pretreatment of lespedeza stalks by steam explosion has been studied. The results indicate that steam-exploded pretreatment has strong effects on physical features, morphology, crystallinity, and composition of lespedeza stalks as shown by scanning electron microscopy (SEM), infrared (IR), and X-ray diffraction spectrometry methods. After steam explosion, the cellulose and lignin contents of lespedeza stalks varied only slightly, but the hemicellulose content had decreased from 29.34% to 7.48%. The cellulose obtained by steam-exploded pretreatment had a higher degree of crystallinity than that of the raw material. At the explosion condition of 2.25 MPa and 4 min, lignocellulose is easier to hydrolyze by enzyme than the original lignocellulose. The concentration of reduced sugar in the hydrolyzate liquid increased from 71.77 to 162.84 g·L-1.

  3. Simultaneous saccharification and fermentation of steam-pretreated lespedeza stalks for the production of ethanol

    Institute of Scientific and Technical Information of China (English)

    Jiang Jian-xin; Zhu Li-wei; Wang Kun; Wang Wei-gan

    2006-01-01

    Lespedeza stalks were subjected to steam pretreatment at 210℃ for some steaming time before simultaneous saccharification and fermentation (SSF). Cellulose-derived glucose was extensively utilized by yeast during SSF. The ethanol yields after steam pretreatment of the lespedeza stalks at 210℃ were 59.3%, 72.8% and 62.2% of the theoretically expected values when the steaming times were 2, 4 and 6 min, respectively. The highest yield from α-cellulose was 92.7% of the theoretical value. Steam explosion pretreatment of lespedeza stalks increased ethanol yields by a factor of 4.4, from 16.4% (untreated) to 72.8% (steam explosion pretreated).

  4. Wet Oxidation Pretreatment of Tobacco Stalks and Orange Waste for Bioethanol Production. Preliminary results

    DEFF Research Database (Denmark)

    Martin, Carlos; Fernandez, Teresa; Garcia, Ariel

    2009-01-01

    Wet oxidation (WO) was used as a pretreatment method prior to enzymatic hydrolysis of tobacco stalks and orange waste. The pretreatment, performed at 195 degrees C and an oxygen pressure of 1.2 MPa, for 15 min, in the presence of Na2CO3, increased the cellulose content of the materials and gave...... cellulose recoveries of approximately 90%. The pretreatment enhanced the susceptibility of cellulose to enzymatic hydrolysis. The highest enzymatic convertibility, that of 64.9%, was achieved for pretreated tobacco stalks. The ethanolic fermentation of the WO filtrates, using Saccharomyces cerevisiae......, was inhibited compared to the fermentation of a reference glucose solution. Inhibition was more intense for the filtrate of tobacco stalks than for that of orange waste. The inhibition degree of the volumetric productivity of ethanol was higher (79.1-86.8%) than that of the ethanol yield (7.1-9.5%)....

  5. Inheritance of resistance to anthracnose stalk rot (Colletotrichum graminicola in tropical maize inbred lines

    Directory of Open Access Journals (Sweden)

    Herberte Pereira da Silva

    2012-09-01

    Full Text Available Generation means was used to study the mode of inheritance of resistance to anthracnose stalk rot in tropical maize. Each population was comprised of six generations in two trials under a randomized block design. Inoculations were performed using a suspension of 10*5 conidia mL -1 applied into the stalk. Internal lesion length was directly measured by opening the stalk thirty days after inoculation. Results indicated contrasting modes of inheritance. In one population, dominant gene effects predominated. Besides, additive x dominant and additive x additive interactions were also found. Intermediate values of heritability indicated a complex resistance inheritance probably conditioned by several genes of small effects. An additive-dominant genetic model sufficed to explain the variation in the second population, where additive gene effects predominated. Few genes of major effects control disease resistance in this cross. Heterosis widely differed between populations, which can be attributed to the genetic background of the parental resistant lines.

  6. Gibberella stalk rot (Fusarium graminearum) resistance of maize inbreds and their F1 hybrids and their potential for use in resistance breeding programs

    OpenAIRE

    Santiago Carabelos, Rogelio; Reid, Lana M.; Zhu, X.(Central China Normal University, Wuhan, China); Butrón Gómez, Ana María; Malvar Pintos, Rosa Ana

    2010-01-01

    Fusarium graminearum Schwabe is one of the predominant fungal species responsible for stalk rot of maize in Canada and many other countries. Adapted sources of resistance to this disease are scarce but recently a few have been identified. To evaluate the usefulness of these sources in a breeding programme to improve stalk rot resistance, a complete diallel cross of five inbreds of varying susceptibility to stalk rot was conducted. Artificial inoculations of stalks were accomplished by injecti...

  7. Ecological and physiological aspects of aestivation-diapause in the larvae of twe pyralid stalk borers of maize in Kenya

    NARCIS (Netherlands)

    Scheltes, P.

    1978-01-01

    Stalk borers are highly destructive to a large number of important graminaceous crops all over the world. Some examples of economically important stalk borers and a general description of their life-cycle are mentioned in chapter 1. In the same chapter difficulties in controlling the insects are des

  8. Necessity of the stalk region for immunoglobulin E interaction with CD23.

    Science.gov (United States)

    Chen, Bing-Hung; Ma, Check; Caven, Timothy H; Chan-Li, Yee; Beavil, Andrew; Beavil, Rebecca; Gould, Hannah; Conrad, Daniel H

    2002-11-01

    Previously, a soluble mouse CD23 chimera, composed of an N-terminal trimeric isoleucine zipper motif (lz) followed by the entire extracellular region (amino acids 48-331) of CD23 (lz-CD2348-331), was prepared and exhibited strong binding to rodent immunoglobulin E (IgE). In the current study, we report the construction of a similar human chimeric protein (lz-huCD2345-321), as well as a series of murine chimeric lz-CD23 mutants with incremental portions of stalk deleted, to further investigate the role of the stalk region in mediating the CD23-IgE interaction. All chimeric proteins were designed such that the predicted heptad structure of the stalk was retained. IgE binding, as determined by the capacity to inhibit 125I-IgE from binding to FcepsilonRI-bearing RBL-2H3 cells, and by surface plasmon-resonance analysis using an IgE-coated sensor chip, was unchanged from the original lz chimera and the binding parameters were similar to those of cell-surface CD23. The minimal murine chimera that retained IgE-binding activity was lz-CD23139-331, which still contains 35 amino acids of the stalk region. When the lz motif was linked to CD23 amino acid 157 (or higher), significant IgE-binding capacity was lost. With human lz-CD23, as with mouse, deletion of the stalk greatly reduced IgE-binding ability. In summary, the data support the concept that at least a portion of the stalk region of CD23 plays a crucial role in maintaining high-affinity/avidity interaction with IgE. The lz-CD23 constructs represent a possible alternative for both blocking the IgE/FcepsilonRI interaction and inhibiting IgE production by B lymphocytes.

  9. Characterisation of a DNA sequence element that directs Dictyostelium stalk cell-specific gene expression.

    Science.gov (United States)

    Ceccarelli, A; Zhukovskaya, N; Kawata, T; Bozzaro, S; Williams, J

    2000-12-01

    The ecmB gene of Dictyostelium is expressed at culmination both in the prestalk cells that enter the stalk tube and in ancillary stalk cell structures such as the basal disc. Stalk tube-specific expression is regulated by sequence elements within the cap-site proximal part of the promoter, the stalk tube (ST) promoter region. Dd-STATa, a member of the STAT transcription factor family, binds to elements present in the ST promoter-region and represses transcription prior to entry into the stalk tube. We have characterised an activatory DNA sequence element, that lies distal to the repressor elements and that is both necessary and sufficient for expression within the stalk tube. We have mapped this activator to a 28 nucleotide region (the 28-mer) within which we have identified a GA-containing sequence element that is required for efficient gene transcription. The Dd-STATa protein binds to the 28-mer in an in vitro binding assay, and binding is dependent upon the GA-containing sequence. However, the ecmB gene is expressed in a Dd-STATa null mutant, therefore Dd-STATa cannot be responsible for activating the 28-mer in vivo. Instead, we identified a distinct 28-mer binding activity in nuclear extracts from the Dd-STATa null mutant, the activity of this GA binding activity being largely masked in wild type extracts by the high affinity binding of the Dd-STATa protein. We suggest, that in addition to the long range repression exerted by binding to the two known repressor sites, Dd-STATa inhibits transcription by direct competition with this putative activator for binding to the GA sequence.

  10. Stalk rot resistance in Maksimir 3 synthetic maize population after four cycles of recurrent selection

    Directory of Open Access Journals (Sweden)

    Bukan Miroslav

    2013-01-01

    Full Text Available Fusarium stalk rot (FSR and anthracnose stalk rot (ASR, caused by Fusarium spp. and Colletotrichum graminicola (Ces. G.W. Wils. respectively, are the two most important stalk diseases in maize which increase the incidence of stalk lodging and reduce grain yield. The aim of the present study was to (1 evaluate the effect of four cycles of recurrent selection in the Maksimir 3 Synthetic (M3S maize population on ASR and FSR resistance and (2 to investigate the correlation among the different disease rating methods. The experiment included six M3S cycle populations per se and their test-crosses with a single cross hybrid. ASR resistance was estimated on artificially inoculated plant rows using three ratings (the number of infected internodes, the number of internodes rotten more than 75% and evaluation of outer stalk discoloration whereas FSR resistance was estimated in artificially inoculated rows as well as in naturally inoculated rows by rating severity of disease symptoms on longitudinally cut stalks using the standard resistance scale. The results of the present study showed that four cycles of selection in the M3S maize population, conducted primarily for grain yield improvement, did not significantly affect its resistance to both ASR and FSR. Among the disease ratings a moderate positive correlation was found only between two ASR resistance ratings (the number of infected internodes and the number of internodes rotted more than 75% in both population per se (r=0.49** and population test-crosses (r=0.56**.

  11. [Multiaxial classification of stalking. Guidelines for the assessment of criminal liability and prognosis].

    Science.gov (United States)

    Dressing, H; Kühner, C; Gass, P

    2007-07-01

    Stalking is a widespread phenomenon describing a pattern of intrusive and threatening behaviour that leads to the victim's perception of being harassed and of him or her being rendered fearful. Physical assault and even homicide may occur in the context of stalking. Anglo-Saxon studies have revealed a lifetime prevalence of being a victim of stalking ranging from 4-7% in men and 12-17% in women. Recently, these rates have been confirmed by the first community based study carried out in Germany. As a stalker can have a number of victims during his or her lifetime, the prevalence of stalkers may be less than this, although at present data for this are lacking. Although the phenomenology of stalking appears to be rather homogenous, fairly distinct stalker typologies and perpetrator-victim relationships have to be considered. Requests for psychiatric and forensic assessment of stalkers are increasing. According to the German penal code, psychiatrists must provide expert opinion on criminal responsibility and the placement of stalkers. So far, all typologies of stalkers refer to the Anglo-Saxon cultural background and do not consider the special needs of German forensic psychiatry. In particular, the psychopathological dimension is widely neglected in common typologies. The present paper proposes a multiaxial typology of stalking that considers the psychopathological dimension, the relationship between stalker and victim and motivational aspects. Consequences for the forensic psychiatric assessment according to section 20, 21 StGB are outlined. It should be pointed out that stalking is not a new diagnostic category, but only involves, at a descriptive level, deviation from a normal behavioural pattern. The central components of the forensic psychiatric assessment remain the known diagnostic categories, the effects of which on behaviour can be analysed.

  12. Stalk region of beta-chain enhances the coreceptor function of CD8.

    Science.gov (United States)

    Wong, Jenny S; Wang, Xiaosong; Witte, Torsten; Nie, Linghu; Carvou, Nicolas; Kern, Petra; Chang, Hsiu-Ching

    2003-07-15

    CD8 glycoproteins are expressed as either alphaalpha homodimers or alphabeta heterodimers on the surface of T cells. CD8alphabeta is a more efficient coreceptor than the CD8alphaalpha for peptide Ag recognition by TCR. Each CD8 subunit is composed of four structural domains, namely, Ig-like domain, stalk region, transmembrane region, and cytoplasmic domain. In an attempt to understand why CD8alphabeta is a better coreceptor than CD8alphaalpha, we engineered, expressed, and functionally tested a chimeric CD8alpha protein whose stalk region is replaced with that of CD8beta. We found that the beta stalk region enhances the coreceptor function of chimeric CD8alphaalpha to a level similar to that of CD8alphabeta. Surprisingly, the beta stalk region also restored functional activity to an inactive CD8alpha variant, carrying an Ala mutation at Arg(8) (R8A), to a level similar to that of wild-type CD8alphabeta. Using the R8A variant of CD8alpha, a panel of anti-CD8alpha Abs, and three MHC class I (MHCI) variants differing in key residues known to be involved in CD8alpha interaction, we show that the introduction of the CD8beta stalk leads to a different topology of the CD8alpha-MHCI complex without altering the overall structure of the Ig-like domain of CD8alpha or causing the MHCI to employ different residues to interact with the CD8alpha Ig domain. Our results show that the stalk region of CD8beta is capable of fine-tuning the coreceptor function of CD8 proteins as a coreceptor, possibly due to its distinct protein structure, smaller physical size and the unique glycan adducts associated with this region.

  13. Using feature objects aided strategy to evaluate the biomethane production of food waste and corn stalk anaerobic co-digestion.

    Science.gov (United States)

    Zhou, Qi; Yuan, Hairong; Liu, Yanping; Zou, Dexun; Zhu, Baoning; Chufo, Wachemo A; Jaffar, Muhammad; Li, Xiujin

    2015-03-01

    Feature objects aided strategy was used to predict and evaluate the biomethane production of food waste and corn stalk anaerobic co-digestion. The kinetics of co-digestion and mono-digestion of food waste and/or corn stalk was also analyzed. The results indicated that the compositions of food waste and corn stalk were significantly different. The anaerobic digestion of three feature objects at different mixing ratios showed the different biomethane yields and kinetic constants. Food waste and corn stalk co-digestion enhanced the digestion rate and achieved 22.48% and 41.55% higher biomethane production than those of food waste and corn stalk mono-digestion, respectively.

  14. Biogas production from mixtures of cattle slurry and pressed sugar cane stalk, with and without urea

    Energy Technology Data Exchange (ETDEWEB)

    Pound, B.; Done, F.; Preston, T.R.

    1981-01-01

    An integrated crop/livestock/energy system being investigated involves feeding cows with diets containing sugar cane and sugar cane juice and using slurry for biogas production and then as a fertilizer. In a laboratory scale trial 82-liter glass bottles were used as anaerobic digesters to compare biogas production from mixtures of cattle slurry with pressed sugar cane stalk. Addition of cane stalk decreased initial gas production and increased pH. Adding urea increased the pH and substantially reduced the length of the lag phase of cumulative biogas production curves. (Refs. 14).

  15. Study on the Possibility of Using Vine Stalk Waste ( Vitis Vinifera) for Producing Gypsum Particleboards

    Science.gov (United States)

    Rangavar, H.; Khosro, S. Kh.; Payan, M. H.; Soltani, A.

    2014-09-01

    The objective of this study was the production of gypsum particleboards with vine stalk waste and the investigation of some physical and mechanical properties of the boards. For this purpose, boards were made from gypsum, oven-dried mass of vine stalk waste, and the white portland cement in various ratios. The thickness swelling and water absorption after 2 and 24 hours of immersion in water, the modulus of rupture, the modulus of elasticity, and the internal bond strength of the boards were determined according to the European Norms standard. The results show that, by selecting proper ratios between the constituents, particleboards with good physicomechanical properties can be produced.

  16. Wet Oxidation Pretreatment of Tobacco Stalks and Orange Waste for Bioethanol Production. Preliminary results

    DEFF Research Database (Denmark)

    Martin, Carlos; Fernandez, Teresa; Garcia, Ariel

    2009-01-01

    Wet oxidation (WO) was used as a pretreatment method prior to enzymatic hydrolysis of tobacco stalks and orange waste. The pretreatment, performed at 195 degrees C and an oxygen pressure of 1.2 MPa, for 15 min, in the presence of Na2CO3, increased the cellulose content of the materials and gave...... cellulose recoveries of approximately 90%. The pretreatment enhanced the susceptibility of cellulose to enzymatic hydrolysis. The highest enzymatic convertibility, that of 64.9%, was achieved for pretreated tobacco stalks. The ethanolic fermentation of the WO filtrates, using Saccharomyces cerevisiae...

  17. Cytoskeletal architecture of isolated mitotic spindle with special reference to microtubule-associated proteins and cytoplasmic dynein.

    Science.gov (United States)

    Hirokawa, N; Takemura, R; Hisanaga, S

    1985-11-01

    We have studied cytoskeletal architectures of isolated mitotic apparatus from sea urchin eggs using quick-freeze, deep-etch electron microscopy. This method revealed the existence of an extensive three-dimensional network of straight and branching crossbridges between spindle microtubules. The surface of the spindle microtubules was almost entirely covered with hexagonally packed, small, round button-like structures which were very uniform in shape and size (approximately 8 nm in diameter), and these microtubule buttons frequently provided bases for crossbridges between adjacent microtubules. These structures were removed from the surface of microtubules by high salt (0.6 M NaCl) extraction. Microtubule-associated proteins (MAPs) and microtubules isolated from mitotic spindles which were mainly composed of a large amount of 75-kD protein and some high molecular mass (250 kD, 245 kD) proteins were polymerized in vitro and examined by quick-freeze, deep-etch electron microscopy. The surfaces of microtubules were entirely covered with the same hexagonally packed round buttons, the arrangement of which is intimately related to that of tubulin dimers. Short crossbridges and some longer crossbridges were also observed. High salt treatment (0.6 M NaCl) extracted both 75-kD protein and high molecular weight proteins and removed microtubule buttons and most of crossbridges from the surface of microtubules. Considering the relatively high amount of 75-kD protein among MAPs isolated from mitotic spindles, it is concluded that these microtubule buttons probably consist of 75-kD MAP and that some of the crossbridges in vivo could belong to MAPs. Another kind of granule, larger in size (11-26 nm in diameter), was also on occasion associated with the surface of microtubules of mitotic spindles. A fine sidearm sometimes connected the larger granule to adjacent microtubules. Localization of cytoplasmic dynein ATPase in the mitotic spindle was investigated by electron microscopic

  18. Head Position and Internally Headed Relative Clauses.

    Science.gov (United States)

    Basilico, David

    1996-01-01

    Examines "Head Movement" in internally headed relative clauses (IHRCs). The article shows that in some cases, head movement to an external position need not take place and demonstrates that this movement of the head to a sentence-internal position results from the quantificational nature of IHRCs and Diesing's mapping hypothesis (1990, 1992). (56…

  19. Solution structure of the dimerization domain of the eukaryotic stalk P1/P2 complex reveals the structural organization of eukaryotic stalk complex.

    Science.gov (United States)

    Lee, Ka-Ming; Yu, Conny Wing-Heng; Chiu, Teddy Yu-Hin; Sze, Kong-Hung; Shaw, Pang-Chui; Wong, Kam-Bo

    2012-04-01

    The lateral ribosomal stalk is responsible for the kingdom-specific binding of translation factors and activation of GTP hydrolysis during protein synthesis. The eukaryotic stalk is composed of three acidic ribosomal proteins P0, P1 and P2. P0 binds two copies of P1/P2 hetero-dimers to form a pentameric P-complex. The structure of the eukaryotic stalk is currently not known. To provide a better understanding on the structural organization of eukaryotic stalk, we have determined the solution structure of the N-terminal dimerization domain (NTD) of P1/P2 hetero-dimer. Helix-1, -2 and -4 from each of the NTD-P1 and NTD-P2 form the dimeric interface that buries 2200 A(2) of solvent accessible surface area. In contrast to the symmetric P2 homo-dimer, P1/P2 hetero-dimer is asymmetric. Three conserved hydrophobic residues on the surface of NTD-P1 are replaced by charged residues in NTD-P2. Moreover, NTD-P1 has an extra turn in helix-1, which forms extensive intermolecular interactions with helix-1 and -4 of NTD-P2. Truncation of this extra turn of P1 abolished the formation of P1/P2 hetero-dimer. Systematic truncation studies suggest that P0 contains two spine-helices that each binds one copy of P1/P2 hetero-dimer. Modeling studies suggest that a large hydrophobic cavity, which can accommodate the loop between the spine-helices of P0, can be found on NTD-P1 but not on NTD-P2 when the helix-4 adopts an 'open' conformation. Based on the asymmetric properties of NTD-P1/NTD-P2, a structural model of the eukaryotic P-complex with P2/P1:P1/P2 topology is proposed.

  20. Microtubules and Lis-1/NudE/dynein regulate invasive cell-on-cell migration in Drosophila.

    Directory of Open Access Journals (Sweden)

    Nachen Yang

    Full Text Available The environment through which cells migrate in vivo differs considerably from the in vitro environment where cell migration is often studied. In vivo many cells migrate in crowded and complex 3-dimensional tissues and may use other cells as the substratum on which they move. This includes neurons, glia and their progenitors in the brain. Here we use a Drosophila model of invasive, collective migration in a cellular environment to investigate the roles of microtubules and microtubule regulators in this type of cell movement. Border cells are of epithelial origin and have no visible microtubule organizing center (MTOC. Interestingly, microtubule plus-end growth was biased away from the leading edge. General perturbation of the microtubule cytoskeleton and analysis by live imaging showed that microtubules in both the migrating cells and the substrate cells affect movement. Also, whole-tissue and cell autonomous deletion of the microtubule regulator Stathmin had distinct effects. A screen of 67 genes encoding microtubule interacting proteins uncovered cell autonomous requirements for Lis-1, NudE and Dynein in border cell migration. Net cluster migration was decreased, with initiation of migration and formation of dominant front cell protrusion being most dramatically affected. Organization of cells within the cluster and localization of cell-cell adhesion molecules were also abnormal. Given the established role of Lis-1 in migrating neurons, this could indicate a general role of Lis-1/NudE, Dynein and microtubules, in cell-on-cell migration. Spatial regulation of cell-cell adhesion may be a common theme, consistent with observing both cell autonomous and non-autonomous requirements in both systems.

  1. Integrated proteomics identified novel activation of dynein IC2-GR-COX-1 signaling in neurofibromatosis type I (NF1) disease model cells.

    Science.gov (United States)

    Hirayama, Mio; Kobayashi, Daiki; Mizuguchi, Souhei; Morikawa, Takashi; Nagayama, Megumi; Midorikawa, Uichi; Wilson, Masayo M; Nambu, Akiko N; Yoshizawa, Akiyasu C; Kawano, Shin; Araki, Norie

    2013-05-01

    Neurofibromatosis type 1 (NF1) tumor suppressor gene product, neurofibromin, functions in part as a Ras-GAP, and though its loss is implicated in the neuronal abnormality of NF1 patients, its precise cellular function remains unclear. To study the molecular mechanism of NF1 pathogenesis, we prepared NF1 gene knockdown (KD) PC12 cells, as a NF1 disease model, and analyzed their molecular (gene and protein) expression profiles with a unique integrated proteomics approach, comprising iTRAQ, 2D-DIGE, and DNA microarrays, using an integrated protein and gene expression analysis chart (iPEACH). In NF1-KD PC12 cells showing abnormal neuronal differentiation after NGF treatment, of 3198 molecules quantitatively identified and listed in iPEACH, 97 molecules continuously up- or down-regulated over time were extracted. Pathway and network analysis further revealed overrepresentation of calcium signaling and transcriptional regulation by glucocorticoid receptor (GR) in the up-regulated protein set, whereas nerve system development was overrepresented in the down-regulated protein set. The novel up-regulated network we discovered, "dynein IC2-GR-COX-1 signaling," was then examined in NF1-KD cells. Validation studies confirmed that NF1 knockdown induces altered splicing and phosphorylation patterns of dynein IC2 isomers, up-regulation and accumulation of nuclear GR, and increased COX-1 expression in NGF-treated cells. Moreover, the neurite retraction phenotype observed in NF1-KD cells was significantly recovered by knockdown of the dynein IC2-C isoform and COX-1. In addition, dynein IC2 siRNA significantly inhibited nuclear translocation and accumulation of GR and up-regulation of COX-1 expression. These results suggest that dynein IC2 up-regulates GR nuclear translocation and accumulation, and subsequently causes increased COX-1 expression, in this NF1 disease model. Our integrated proteomics strategy, which combines multiple approaches, demonstrates that NF1-related neural

  2. Phomopsis subordinaria and associated stalk disease in natural-populations of Plantago lanceolata

    NARCIS (Netherlands)

    De Nooij, M.P.; Van der Aa, H.A.

    1987-01-01

    Natural populations of Plantago lanceolata L. can be infected by the fungus Phomopsis subordinaria (Desm.) Trav., which causes a stalk disease. Inoculation experiments revealed that the fungus needs a wound to enter the plant tissue. Symptoms of the disease in the field and from inoculation

  3. A rare cause of hyperprolactinemia: persistent trigeminal artery with stalk-section effect

    Energy Technology Data Exchange (ETDEWEB)

    Ekinci, G.; Baltacioglu, F.; Cimsit, C.; Akpinar, I.; Erzen, C. [Dept. of Radiology, Marmara University, Altunizade Istanbul (Turkey); Kilic, T.; Pamir, N. [Dept. of Neurosurgery, Faculty of Medicine, Marmara University, Altunizade Istanbul (Turkey)

    2001-04-01

    The primitive trigeminal, otic, hypoglossal, and proatlantal intersegmental arteries are fetal anastomoses between the carotid and vertebrobasilar systems. Persistent trigeminal artery (PTA) is the most frequent embryonic communication between the vertebrobasilar and carotid systems in adults. We report a case of PTA compressing the left side of the pituitary gland and stalk, in a patient with elevated blood prolactin level. (orig.)

  4. Response of sweet sorghum lines to stalk pathogens fusarium thapsinum and macrophomina phaseolina

    Science.gov (United States)

    Sweet sorghum [Sorghum bicolor (L.) Moench] has potential for bioenergy. It is adapted to a variety of U.S. locations and the extracted juice can be directly fermented into ethanol. However, little research on fungal stalk rots has been reported, even though these diseases pose serious constraints f...

  5. Status of maize stalk rot complex in western belts of Nepal and its integrated management

    Directory of Open Access Journals (Sweden)

    Subash Subedi

    2016-12-01

    Full Text Available Maize stalk rot complex is becoming a serious threat for maize growing areas of Nepal. A field monitoring for maize stalk rot complex was done during crop season (August, 2016 covering 10 farmers field each of Surkhet, Banke, Dang, Chitwan and Nawalparasi districts. Maize crop showed highly susceptible reaction to the disease at western belts of Dang and susceptible reaction was marked in Chitwan and Nawalparasi districts while the disease effect was mild at Banke and Surkhet district. Most of the plant diseases managed successfully through the application of bio-control agents, host resistance, chemicals and other different cultural control methods. The result of field experiment conducted at Dang showed that all the treatments had significant (P≤0.05 effect on percent disease index (PDI and crop yield over farmers practice to control maize stalk rot. The higher percent disease control (52.36% and yield increase (40.29% were recorded from the plot sprayed with streptocyclin @ 2 g L-1 and insecticide (cypermethrin + chloropyrifos @ 2.5 ml L-1 of water during knee height and subsequent spray after 15 days interval as compared to farmers practice. Out of 30 genotypes, Rampur composit, Arun 2, Rampur 34, RamS03F08, TLBRS07F16 and Rampur 24 were found resistant against stalk rot complex with higher yield at Rampur Chitwan.

  6. Material and microbial changes during corn stalk silage and their effects on methane fermentation.

    Science.gov (United States)

    Zhao, Yubin; Yu, Jiadong; Liu, Jingjing; Yang, HongYan; Gao, Lijuan; Yuan, XuFeng; Cui, Zong-Jun; Wang, Xiaofen

    2016-12-01

    Silage efficiency is crucial for corn stalk storage in methane production. This study investigated characteristics of dynamic changes in materials and microbes during the silage process of corn stalks from the initial to stable state. We conducted laboratory-scale study of different silage corn stalks, and optimized silage time (0, 2, 5, 10, 20, and 30days) for methane production and the endogenous microbial community. The volatile fatty acid concentration increased to 3.00g/L on Day 10 from 0.42g/L on Day 0, and the pH remained below 4.20 from 5.80. The lactic acid concentration (44%) on Day 10 lowered the pH and inhibited the methane yield, which gradually decreased from 229mL/g TS at the initial state (Day 0, 2) to 207mL/g TS at the stable state (Day 10, 20, 30). Methanosaeta was the predominant archaea in both fresh and silage stalks; however, richness decreased from 14.11% to 4.75%. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Mechanical properties and microstructural analysis of Al–Si–Mg/carbonized maize stalk waste particulate composites

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    J.E. Oghenevweta

    2016-07-01

    Full Text Available The mechanical properties and morphological analysis of Al–Si–Mg/carbonized maize stalk particulate composites was investigated. The compositions of the composite include a matrix of Al–Si–Mg and the carbonized maize stalk particulates as reinforcement ranging from 2% to 10% at an interval of 2%. Properties such as mechanical behaviour of the composites were examined and these include tensile strength, tensile modulus, hardness value, impact energy, percentage elongation and percentage reduction in area. Besides, the microstructures of the developed Al–Si–Mg/carbonized maize stalk particulate composites were investigated. The results of the microstructures of the composite show a uniform dispersion of the reinforcement along the grain boundaries of the alloy. The tensile strength and hardness values increase to 85.60 N/mm2 and 24HRB at 8 and 10 wt% of carbonized maize stalk respectively, but there is a slight decrease in the impact energy values, values of percentage elongation and percentage reduction in area as the reinforcement increases. From these results of investigation, we concluded that the carbonized reinforcing maize particulates can be used to enhance the properties of Al–Si–Mg alloy for engineering applications.

  8. Epibiosis in decapod crustaceans by stalked barnacle Octolasmis lowei (Cirripedia: Poecilasmatidae

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    Glauco B. de O. Machado

    2013-06-01

    Full Text Available Stalked barnacles Octolasmis lowei Darwin, 1851 are frequently found attached to decapod crustaceans. Their epibiotic association depends on many factors, which are mainly related to characteristics of the host's biology. This study evaluated the infestation and distribution of stalked barnacles in the branchial chambers of crabs, and analyzed the data with respect to the host's sex, maturity stage, molt cycle and size. The crab species Arenaeus cribrarius Lamarck, 1818, Callinectes danae Smith, 1869, Callinectes ornatus Ordway, 1863, Hepatus pudibundus Herbst, 1785, Libinia ferreirae Brito Capello, 1871, and Persephona punctata Linnaeus, 1758 were sampled and found to be infested by O. lowei. No juvenile crabs were infested. The prevalence of infestation by O. lowei was significantly different among C. danae, C. ornatus, and H. pudibundus males and females. All infested hosts were in the intermolt period. The mean size of infested crabs was larger than that observed for non-infested individuals. Internally, stalked barnacles were concentrated on the central gills or walls and floor of branchial chambers, suggesting that these gills provide more favorable conditions for the settlement and development of these epibionts. These results highlight the relationship between epibiont infestation and host biology, as well as the role of decapod crustaceans as a suitable substrate for the development of stalked barnacle O. lowei.

  9. Continuous ethanol production using yeast immobilized on sugar-cane stalks

    Energy Technology Data Exchange (ETDEWEB)

    Vasconcelos, J.N. de [Alagoas Univ., Maceio, AL (Brazil). Dept. de Engenharia Quimica]. E-mail: jnunes@ctec.ufal.br; Lopes, C.E. [Pernambuco Univ., Recife, PE (Brazil). Dept. de Antibioticos; Franca, F.P. de [Universidade Federal, Rio de Janeiro, RJ (Brazil). Escola de Quimica. Dept. de Engenharia Bioquimica

    2004-09-01

    Sugar-cane stalks, 2.0 cm long, were used as a support for yeast immobilization envisaging ethanol production. The assays were conducted in 38.5 L fermenters containing a bed of stalks with 50% porosity. The operational stability of the immobilized yeast, the efficiency and stability of the process, as well as the best dilution rate were evaluated. Molasses from demerara sugar production was used in the medium formulation. It was diluted to obtain 111.75 {+-} 1.51 g/L without any further treatment. Sulfuric acid was used to adjust the pH value to around 4.2. Every two days Kamoran HJ (10 ppm) or with a mixture containing penicillin (10 ppm) and tetracycline (10 ppm), was added to the medium. Ethanol yield and efficiency were 29.64 g/L.h and 86.40%, respectively, and the total reducing sugars conversion was 74.61% at a dilution rate of 0.83 h{sup -1}. The yeast-stalk system was shown to be stable for over a 60 day period at extremely variable dilution rates ranging from 0.05 h{sup -1} to 3.00 h{sup -1}. The concentration of immobilized cell reached around 109 cells/gram of dry sugar-cane stalk when the fermenter was operating at the highest dilution rate (3.00 h{sup -1}). (author)

  10. The role of barren stalk1 in the architecture of maize.

    Science.gov (United States)

    Gallavotti, Andrea; Zhao, Qiong; Kyozuka, Junko; Meeley, Robert B; Ritter, Matthew K; Doebley, John F; Pè, M Enrico; Schmidt, Robert J

    2004-12-02

    The architecture of higher plants is established through the activity of lateral meristems--small groups of stem cells formed during vegetative and reproductive development. Lateral meristems generate branches and inflorescence structures, which define the overall form of a plant, and are largely responsible for the evolution of different plant architectures. Here, we report the isolation of the barren stalk1 gene, which encodes a non-canonical basic helix-loop-helix protein required for the initiation of all aerial lateral meristems in maize. barren stalk1 represents one of the earliest genes involved in the patterning of maize inflorescences, and, together with the teosinte branched1 gene, it regulates vegetative lateral meristem development. The architecture of maize has been a major target of selection for early agriculturalists and modern farmers, because it influences harvesting, breeding strategies and mechanization. By sampling nucleotide diversity in the barren stalk1 region, we show that two haplotypes entered the maize gene pool from its wild progenitor, teosinte, and that only one was incorporated throughout modern inbreds, suggesting that barren stalk1 was selected for agronomic purposes.

  11. Improving biological control of stalk borers in sugarcane by applying silicon as a soil amendment

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    Nikpay Amin

    2016-12-01

    Full Text Available The sugarcane stalk borers, Sesamia spp. (Lepidoptera: Noctuidae are the most destructive sugarcane insect pests in Iran. The efficiency of Telenomus busseolae Gahan (Hymenoptera: Scelionidae used alone or in combination with silicon fertilization was investigated for controlling the sugarcane stalk borers under field conditions. The treatments were: a combination of silicon plus multiple releases of 2,500 T. busseolae, and multiple releases of 5,000, 2,500 and 1,250 T. busseolae alone. Plots receiving no soil amendment or parasites were included as the controls. Three weeks after the first application of each treatment, 100 shoots were selected randomly from each plot and the percentage of dead heart was determined. Then, three months after the first application of parasites, the percentage of stalks damaged, the percentage of internodes bored, and the level of parasitism were determined. Finally, at harvest the percentage of stalks damaged, the percentage of internodes bored, and sugarcane quality characteristics were determined. Results indicated that the efficiency of parasitism increased when combined with an application of silicon fertilizer. The release of 2,500 T. busseolae followed by an application of silicon fertilizer decreased dead hearts to 4%, while 12% dead hearts was observed in the control plots. For the combination treatment, the percentages of stalk damage were 1.5% and 17.2%, at 3 weeks and 3 months after time release, respectively. However, the percentages of stalk damage were 35.2% and 51% when no treatment was applied. Cane quality was significantly higher with the application of silicon fertilizer plus the release of 2,500 T. busseolae, followed by releasing 5,000 Hymenoptera. The level of parasitism was also greater when parasites were released in combination with an application of silicon. We conclude that biological control by egg parasitoids can be enhanced with concurrent applications of silicon fertilizer as a soil

  12. The impact of frequency of behavior and type of contact on judgments involving a criminal stalking case.

    Science.gov (United States)

    Magyarics, Casey L; Lynch, Kellie R; Golding, Jonathan M; Lippert, Anne

    2015-12-01

    We investigated mock juror perceptions of the frequency of behavior and type of contact in an ex-intimate stalking case. We used a mock-juror methodology, in which 204 community members (129 women) read a stalking trial summary, rendered a verdict, and evaluated the intent of the defendant to cause the victim fear and distress, as well as the victim's experience with these emotions. The trial varied as to whether there were 5 or 30 stalking incidents and whether the stalking involved personal contact or stalking via text message. Results showed that females were more likely to render a guilty verdict when the victim had been stalked 30 times rather than 5 times while males were equally likely to render a guilty verdict regardless of the frequency. Mock jurors were significantly more likely to render guilty verdicts in the personal contact condition than in the text message condition. Females' perceptions of the victim's fear and distress mediated the frequency of incidents x gender interaction. The victim's fear and the defendant's intentions mediated the main effect of type of contact on verdict. Cognitive network analyses showed that victim fear and the defendant's intent to cause fear were central to participant verdict decision making. We discuss these results in terms of the implications, specifically that victim fear should be a primary focus in stalking legislation. (c) 2015 APA, all rights reserved).

  13. [Effects of cotton stalk biochar on microbial community structure and function of continuous cropping cotton rhizosphere soil in Xinjiang, China].

    Science.gov (United States)

    Gu, Mei-ying; Tang, Guang-mu; Liu, Hong-liang; Li, Zhi-qiang; Liu, Xiao-wei; Xu, Wan-li

    2016-01-01

    In this study, field trials were conducted to examine the effects of cotton stalk biochar on microbial population, function and structural diversity of microorganisms in rhizosphere soil of continuous cotton cropping field in Xinjiang by plate count, Biolog and DGGE methods. The experiment was a factorial design with four treatments: 1) normal fertilization with cotton stalk removed (NPK); 2) normal fertilization with cotton stalk powdered and returned to field (NPKS); 3) normal fertilization plus cotton stalk biochar at 22.50 t · hm⁻² (NPKB₁); and 4) normal fertilization plus cotton stalk biochar at 45.00 t · hm⁻² (NPKB₂). The results showed that cotton stalk biochar application obviously increased the numbers of bacteria and actinomycetes in the rhizospheric soil. Compared with NPK treatment, the number of fungi was significantly increased in the NPKB₁treatment, but not in the NPKB₂ treatment. However, the number of fungi was generally lower in the biochar amended (NPKB₁, NPKB₂) than in the cotton stalk applied plots (NPKS). Application of cotton stalk biochar increased values of AWCD, and significantly improved microbial richness index, suggesting that the microbial ability of utilizing carbohydrates, amino acids and carboxylic acids, especially phenolic acids was enhanced. The number of DGGE bands of NPKB₂ treatment was the greatest, with some species of Gemmatimonadetes, Acidobacteria, Proteobacteria and Actinobacteria being enriched. UPGMC Cluster analysis pointed out that bacterial communities in the rhizospheric soil of NPKB₂ treatment were different from those in the NPK, NPKS and NPKB₁treatments, which belonged to the same cluster. These results indicated that application of cotton stalk biochar could significantly increase microbial diversity and change soil bacterial community structure in the cotton rhizosphere soil, thus improving the health of soil ecosystem.

  14. Biochemical and molecular dynamic simulation analysis of a weak coiled coil association between kinesin-II stalks.

    Directory of Open Access Journals (Sweden)

    Harinath Doodhi

    Full Text Available DEFINITION: Kinesin-2 refers to the family of motor proteins represented by conserved, heterotrimeric kinesin-II and homodimeric Osm3/Kif17 class of motors. BACKGROUND: Kinesin-II, a microtubule-based anterograde motor, is composed of three different conserved subunits, named KLP64D, KLP68D and DmKAP in Drosophila. Although previous reports indicated that coiled coil interaction between the middle segments of two dissimilar motor subunits established the heterodimer, the molecular basis of the association is still unknown. METHODOLOGY/PRINCIPAL FINDINGS: Here, we present a detailed heterodimeric association model of the KLP64D/68D stalk supported by extensive experimental analysis and molecular dynamic simulations. We find that KLP64D stalk is unstable, but forms a weak coiled coil heteroduplex with the KLP68D stalk when coexpressed in bacteria. Local instabilities, relative affinities between the C-terminal stalk segments, and dynamic long-range interactions along the stalks specify the heterodimerization. Thermal unfolding studies and independent simulations further suggest that interactions between the C-terminal stalk fragments are comparatively stable, whereas the N-terminal stalk reversibly unfolds at ambient temperature. CONCLUSIONS/SIGNIFICANCE: Results obtained in this study suggest that coiled coil interaction between the C-terminal stalks of kinesin-II motor subunits is held together through a few hydrophobic and charged interactions. The N-terminal stalk segments are flexible and could uncoil reversibly during a motor walk. This supports the requirement for a flexible coiled coil association between the motor subunits, and its role in motor function needs to be elucidated.

  15. Structure of the Newcastle disease virus hemagglutinin-neuraminidase (HN) ectodomain reveals a four-helix bundle stalk

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Ping; Swanson, Kurt A.; Leser, George P.; Paterson, Reay G.; Lamb, Robert A.; Jardetzky, Theodore S. (Stanford-MED); (NWU)

    2014-10-02

    The paramyxovirus hemagglutinin-neuraminidase (HN) protein plays multiple roles in viral entry and egress, including binding to sialic acid receptors, activating the fusion (F) protein to activate membrane fusion and viral entry, and cleaving sialic acid from carbohydrate chains. HN is an oligomeric integral membrane protein consisting of an N-terminal transmembrane domain, a stalk region, and an enzymatically active neuraminidase (NA) domain. Structures of the HN NA domains have been solved previously; however, the structure of the stalk region has remained elusive. The stalk region contains specificity determinants for F interactions and activation, underlying the requirement for homotypic F and HN interactions in viral entry. Mutations of the Newcastle disease virus HN stalk region have been shown to affect both F activation and NA activities, but a structural basis for understanding these dual affects on HN functions has been lacking. Here, we report the structure of the Newcastle disease virus HN ectodomain, revealing dimers of NA domain dimers flanking the N-terminal stalk domain. The stalk forms a parallel tetrameric coiled-coil bundle (4HB) that allows classification of extensive mutational data, providing insight into the functional roles of the stalk region. Mutations that affect both F activation and NA activities map predominantly to the 4HB hydrophobic core, whereas mutations that affect only F-protein activation map primarily to the 4HB surface. Two of four NA domains interact with the 4HB stalk, and residues at this interface in both the stalk and NA domain have been implicated in HN function.

  16. Co-digestion of Sorghum Stalk and Sludge for Biogas Production

    Directory of Open Access Journals (Sweden)

    Muhammad Romli

    2015-12-01

    Full Text Available The recycling of residual agricultural biomass using anaerobic digestion allows for the recovery of biomass carbon and nutrients as sources of energy and fertilizer. The obstacles that are encountered in this process include the lignocellulosic structure of biomass tissue and its high carbon-to-nitrogen (C:N ratio. This study evaluates the co-digestion system of pretreated sorghum stalks and wastewater sludge. The stalks were pretreated by partial bio-oxidation to improve their bacterial accessibility. The digesters were fed a mixture of stalk and sludge at ratios of 100:0, 80:20, 60:40, and 40:60 (total solids [TS] basis. The digesters were run in batches at 35-36 °C, with an initial TS of 15%. The digesters’ performance was evaluated in terms of biogas production rate and yield. The digesters that were run with feed ratios of 80:20 and 60:40 showed shorter lag phase, higher biogas generation rates, and higher biogas yields compared to those run with feed ratios of 100:0 and 40:60. The highest specific biogas production (of 122 L/kg TS was achieved by the digesters run at ratios of 80:20 and 60:40. The digesters run only with stalks (ratio 100:0 resulted in specific gas production of 67 L/kg TS, whereas those fed on a feed ratio of 40:60 generated only 13 L/kg TS. We conclude that the co-digestion of sorghum stalks and wastewater sludge at a proper ratio improves biogas production.

  17. Is HEADS in our heads?

    DEFF Research Database (Denmark)

    Boisen, Kirsten A; Hertz, Pernille Grarup; Blix, Charlotte

    2016-01-01

    BACKGROUND: Outpatient clinic visits are a window of opportunity to address health risk behaviors and promote a healthier lifestyle among young people. The HEADS (Home, Education, Eating, Activities, Drugs [i.e. substance use including tobacco, alcohol, and illegal drugs], Sexuality [including...... care professionals participated. We found only small reported differences between staff and young patients regarding whether home, education, and activity were addressed. However, staff reported twice the rate of addressing smoking, alcohol, illegal drugs, sexuality, and contraception compared to young...... patients. Young patients reported that smoking, alcohol, illegal drugs, sexuality, and contraception were addressed significantly more at adult clinics in comparison to pediatric clinics. After controlling for age, gender and duration of illness, according to young patients, adjusted odds ratios...

  18. Dynactin Is an Indispensable Helper for Dynein's Function in Intracellular Motility%Dynactin辅助dynein进行细胞内物质运输的研究进展

    Institute of Scientific and Technical Information of China (English)

    王圣柳; 孙飞

    2012-01-01

    Cytoplasmic dynein is a microtubule motor protein which is responsible for the majority of minus end microtubule-based intracellular motility. The cargoes of dynein include not only mRNA and protein, but also cell organelle and vesicle. Dynactin, a huge complex with Mw of 1.2 Mda, is necessary for dynein's function. The subunits composition and an overall structure model of the dynactin has been revealed based on biochemistry and immuno-electron microscopy. Since the initial discovery, it has become clear that dynactin links dynein to cargo and increases dynein processivity. Although how dynactin ineracts with dynein and how dynactin act as an adapter between dynein and cargoes remain unclear, a lot of achievements have been made in the last decade. We will review these progresses and share a perspective future in this field.%胞质动力蛋白(cytoplasmic dynein)是沿微管向负极运动的马达蛋白,参与细胞内多种物质的运输,运输的货物(cargo)小至信使RNA和蛋白质,大至细胞器和囊泡.动力蛋白只有与动力激活蛋白(dynactin)结合在一起时才有活性.动力激活蛋白是一个分子量为1.2 MDa的多亚基复合物,利用分子生物学和免疫电子显微镜技术,研究者已阐明了其亚基的组成信息,并得到了一个初步的结构模型.10年来,随着对各亚基功能研究的不断深入,研究者发现动力激活蛋白不仅可以增强动力蛋白在微管上的运动持续性,而且还可帮助其结合细胞内的其他成分.然而,动力激活蛋白与动力蛋白之间如何相互调节功能,动力激活蛋白作为接头蛋白如何控制货物在动力蛋白上的结合与解离,这两个核心问题尚未解决.本文就动力激活蛋白的亚基组成及其辅助动力蛋白发挥功能等研究成果进行总结,并对以后的研究趋势进行展望.

  19. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... of the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a ... of page What are some common uses of the procedure? CT scanning of the head is typically ...

  20. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... of the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a ... of page What are some common uses of the procedure? CT scanning of the head is typically ...

  1. Dynein Light Chain LC8 Is Required for RNA Polymerase I-Mediated Transcription in Trypanosoma brucei, Facilitating Assembly and Promoter Binding of Class I Transcription Factor A.

    Science.gov (United States)

    Kirkham, Justin K; Park, Sung Hee; Nguyen, Tu N; Lee, Ju Huck; Günzl, Arthur

    2016-01-01

    Dynein light chain LC8 is highly conserved among eukaryotes and has both dynein-dependent and dynein-independent functions. Interestingly, LC8 was identified as a subunit of the class I transcription factor A (CITFA), which is essential for transcription by RNA polymerase I (Pol I) in the parasite Trypanosoma brucei. Given that LC8 has never been identified with a basal transcription factor and that T. brucei relies on RNA Pol I for expressing the variant surface glycoprotein (VSG), the key protein in antigenic variation, we investigated the CITFA-specific role of LC8. Depletion of LC8 from mammalian-infective bloodstream trypanosomes affected cell cycle progression, reduced the abundances of rRNA and VSG mRNA, and resulted in rapid cell death. Sedimentation analysis, coimmunoprecipitation of recombinant proteins, and bioinformatic analysis revealed an LC8 binding site near the N terminus of the subunit CITFA2. Mutation of this site prevented the formation of a CITFA2-LC8 heterotetramer and, in vivo, was lethal, affecting assembly of a functional CITFA complex. Gel shift assays and UV cross-linking experiments identified CITFA2 as a promoter-binding CITFA subunit. Accordingly, silencing of LC8 or CITFA2 resulted in a loss of CITFA from RNA Pol I promoters. Hence, we discovered an LC8 interaction that, unprecedentedly, has a basal function in transcription.

  2. LC2, the Chlamydomonas Homologue of the t Complex-encoded Protein Tctex2, Is Essential for Outer Dynein Arm Assembly

    Science.gov (United States)

    Pazour, Gregory J.; Koutoulis, Anthony; Benashski, Sharon E.; Dickert, Bethany L.; Sheng, Hong; Patel-King, Ramila S.; King, Stephen M.; Witman, George B.

    1999-01-01

    Tctex2 is thought to be one of the distorter genes of the mouse t haplotype. This complex greatly biases the segregation of the chromosome that carries it such that in heterozygous +/t males, the t haplotype is transmitted to >95% of the offspring, a phenomenon known as transmission ratio distortion. The LC2 outer dynein arm light chain of Chlamydomonas reinhardtii is a homologue of the mouse protein Tctex2. We have identified Chlamydomonas insertional mutants with deletions in the gene encoding LC2 and demonstrate that the LC2 gene is the same as the ODA12 gene, the product of which had not been identified previously. Complete deletion of the LC2/ODA12 gene causes loss of all outer arms and a slow jerky swimming phenotype. Transformation of the deletion mutant with the cloned LC2/ODA12 gene restores the outer arms and rescues the motility phenotype. Therefore, LC2 is required for outer arm assembly. The fact that LC2 is an essential subunit of flagellar outer dynein arms allows us to propose a detailed mechanism whereby transmission ratio distortion is explained by the differential binding of mutant (t haplotype encoded) and wild-type dyneins to the axonemal microtubules of t-bearing or wild-type sperm, with resulting differences in their motility. PMID:10512883

  3. Transcription factor NF-kappaB is transported to the nucleus via cytoplasmic dynein/dynactin motor complex in hippocampal neurons.

    Directory of Open Access Journals (Sweden)

    Ilja Mikenberg

    Full Text Available BACKGROUND: Long-term changes in synaptic plasticity require gene transcription, indicating that signals generated at the synapse must be transported to the nucleus. Synaptic activation of hippocampal neurons is known to trigger retrograde transport of transcription factor NF-kappaB. Transcription factors of the NF-kappaB family are widely expressed in the nervous system and regulate expression of several genes involved in neuroplasticity, cell survival, learning and memory. PRINCIPAL FINDINGS: In this study, we examine the role of the dynein/dynactin motor complex in the cellular mechanism targeting and transporting activated NF-kappaB to the nucleus in response to synaptic stimulation. We demonstrate that overexpression of dynamitin, which is known to dissociate dynein from microtubules, and treatment with microtubule-disrupting drugs inhibits nuclear accumulation of NF-kappaB p65 and reduces NF-kappaB-dependent transcription activity. In this line, we show that p65 is associated with components of the dynein/dynactin complex in vivo and in vitro and that the nuclear localization sequence (NLS within NF-kappaB p65 is essential for this binding. CONCLUSION: This study shows the molecular mechanism for the retrograde transport of activated NF-kappaB from distant synaptic sites towards the nucleus.

  4. Head Impact Laboratory (HIL)

    Data.gov (United States)

    Federal Laboratory Consortium — The HIL uses testing devices to evaluate vehicle interior energy attenuating (EA) technologies for mitigating head injuries resulting from head impacts during mine/...

  5. Direct observation of the binding state of the kinesin head to the microtubule.

    Science.gov (United States)

    Guydosh, Nicholas R; Block, Steven M

    2009-09-03

    The dimeric motor protein kinesin-1 converts chemical energy from ATP hydrolysis into mechanical work used to transport cargo along microtubules. Cargo attached to the kinesin stalk moves processively in 8-nm increments as its twin motor domains (heads) carry out an asymmetric, 'hand-over-hand' walk. The extent of individual head interactions with the microtubule during stepping, however, remains controversial. A major experimental limitation has been the lack of a means to monitor the attachment of an individual head to the microtubule during movement, necessitating indirect approaches. Here we report the development of a single-molecule assay that can directly report head binding in a walking kinesin molecule, and show that only a single head is bound to the microtubule between steps at low ATP concentrations. A bead was linked to one of the two kinesin heads by means of a short DNA tether and used to apply rapidly alternating hindering and assisting loads with an optical trap. The time-dependent difference between forwards and backwards displacements of the bead alternated between two discrete values during stepping, corresponding to those intervals when the linked head adopted a bound or an unbound state. The linked head could only rebind the microtubule once ATP had become bound to its partner head.

  6. Heading and head injuries in soccer.

    Science.gov (United States)

    Kirkendall, D T; Jordan, S E; Garrett, W E

    2001-01-01

    In the world of sports, soccer is unique because of the purposeful use of the unprotected head for controlling and advancing the ball. This skill obviously places the player at risk of head injury and the game does carry some risk. Head injury can be a result of contact of the head with another head (or other body parts), ground, goal post, other unknown objects or even the ball. Such impacts can lead to contusions, fractures, eye injuries, concussions or even, in rare cases, death. Coaches, players, parents and physicians are rightly concerned about the risk of head injury in soccer. Current research shows that selected soccer players have some degree of cognitive dysfunction. It is important to determine the reasons behind such deficits. Purposeful heading has been blamed, but a closer look at the studies that focus on heading has revealed methodological concerns that question the validity of blaming purposeful heading of the ball. The player's history and age (did they play when the ball was leather and could absorb significant amounts of water), alcohol intake, drug intake, learning disabilities, concussion definition and control group use/composition are all factors that cloud the ability to blame purposeful heading. What does seem clear is that a player's history of concussive episodes is a more likely explanation for cognitive deficits. While it is likely that the subconcussive impact of purposeful heading is a doubtful factor in the noted deficits, it is unknown whether multiple subconcussive impacts might have some lingering effects. In addition, it is unknown whether the noted deficits have any affect on daily life. Proper instruction in the technique is critical because if the ball contacts an unprepared head (as in accidental head-ball contacts), the potential for serious injury is possible. To further our understanding of the relationship of heading, head injury and cognitive deficits, we need to: learn more about the actual impact of a ball on the

  7. Antagonistic and Biocontrol Potential of Trichoderma asperellum ZJSX5003 Against the Maize Stalk Rot Pathogen Fusarium graminearum

    National Research Council Canada - National Science Library

    Li, Yaqian; Sun, Ruiyan; Yu, Jia; Saravanakumar, Kandasamy; Chen, Jie

    2016-01-01

    ...) the causal agent of corn stalk rot of maize were in vitro for their antagonistic properties followed by statistical model of principal compound analysis to identify the beneficial antagonist T. asperellum strain...

  8. Hypothalamic-pituitary vascularization in pituitary stalk transection syndrome: is the pituitary stalk really transected? The role of gadolinium-DTPA with spin-echo T1 imaging and turbo-FLASH technique

    Energy Technology Data Exchange (ETDEWEB)

    Genovese, E. [Dept. of Radiology, IRCCS Policlinico S. Matteo, Pavia (Italy); Maghnie, M. [Dept. of Pediatrics, Univ. of Pavia (Italy); Beluffi, G. [Dept. of Radiodiagnosis, Section of Pediatric Radiology, IRCCS Policlinico S. Matteo, Pavia (Italy); Villa, A. [Dept. of Radiology, IRCCS Policlinico S. Matteo, Pavia (Italy); Sammarchi, L. [Dept. of Radiology, IRCCS Policlinico S. Matteo, Pavia (Italy); Severi, F. [Dept. of Pediatrics, Univ. of Pavia (Italy); Campani, R. [Dept. of Radiology, IRCCS Policlinico S. Matteo, Pavia (Italy)

    1997-01-01

    We examined 14 patients, aged 10-25 years, with idiopathic hypopituitarism. All presented an ectopic posterior pituitary at the median eminence with a hypoplastic anterior pituitary on magnetic resonance imaging (MRI). Eight patients had isolated growth hormone deficit (IGHD) and six had multiple hormone deficits (MPHD). Unenhanced MRI showed the pituitary stalk, which was extremely thin, in only three patients, while T1-weighted images obtained after intravenous injection of gadopentetate dimeglumine (Gd-DTPA) showed a thin pituitary stalk in seven patients (six with IGHD and one with MPHD), demonstrating a preserved vascular component of the stalk. MRI with Gd-DTPA was more sensitive than unenhanced MRI in detecting the pituitary stalk in patients with hypopituitarism with an ectopic posterior pituitary: the stalk was demonstrated in 50 % of the cases (seven patients), versus 21.4 % (three patients) by unenhanced MRI. The dynamic study of the hypothalamo-hypophyseal axis performed with turbo-FLASH sequences after bolus injection of Gd-DTPA showed the residual anterior pituitary to have arterial enhancement times, which suggests that an arterial system compensates for the absent or diminished blood supply from the portal system, independent of stalk detection. (orig.). With 5 figs., 1 tab.

  9. Measurement of the heat of smoldering combustion in straws and stalks by means of simultaneous thermal analysis

    Energy Technology Data Exchange (ETDEWEB)

    He, Fang; Yi, Weiming; Zha, Jianwen [School of Light Industry and Agricultural Engineering, Shandong University of Technology, Zibo, Shandong 255049 (China)

    2009-01-15

    In order to investigate reaction heat of agro-stalks smoldering, wheat straw, corn stalk, cotton stalk, millet straw, sorghum stalk and sweet potato rattan powder were smoldered and pyrolyzed in a simultaneous thermal analyzer (STA). The samples were placed in a platinum crucible (5 mm x 5 mm) with a lid (with a 1 mm hole) on a high-accuracy differential scanning calorimetry-heat capacity (DSC-cp) holder in the furnace of an STA and heated from 303 to 1073 K at a heating rate of 10 K min{sup -1}. Sweeping gas with a flow rate of 25 ml min{sup -1} was air and nitrogen during smoldering and pyrolysis, respectively. Results showed that the heat emission characteristic of the smoldering process differed remarkably from the pyrolysis process. Based on the analysis of the DSC curves, oxidative polymer degradation heat and char oxidation heat were obtained from experimental data. It showed that the oxidative polymer degradation heat of the agro-stalks is more than 6.92 MJ kg{sup -1} consumed matter, higher than that of cellulose paper. And char oxidation heat is around 23 MJ kg{sup -1} consumed matter, similar to that of cellulose paper, but higher than that of cigarette. Total net heat emission of smoldering in STA was also obtained. These data can be used as reference data in analyzing smoldering of agro-stalks under similar conditions. (author)

  10. An Adenovirus-Vectored Influenza Vaccine Induces Durable Cross-Protective Hemagglutinin Stalk Antibody Responses in Mice

    Directory of Open Access Journals (Sweden)

    Eun Hye Kim

    2017-08-01

    Full Text Available Currently licensed vaccines against the influenza A virus (IAV need to be updated annually to match the constantly evolving antigenicity of the influenza virus glycoproteins, hemagglutinin (HA, and neuramidiase (NA. Attempts to develop universal vaccines that provide broad protection have resulted in some success. Herein, we have shown that a replication-deficient adenovirus expressing H5/M2e induced significant humoral immunity against the conserved HA stalk. Compared to the humoral responses induced by an inactivated influenza vaccine, the humoral responses induced by the adenovirus-vectored vaccine against the conserved stalk domain mediated cross-protection against heterosubtypic influenza viruses. Importantly, virus inactivation by formaldehyde significantly reduced the binding of monoclonal antibodies (mAbs to the conserved nucleoprotein (NP, M2e, and HA stalk. These results suggest that inactivation by formaldehyde significantly alters the antigenicity of the HA stalk, and suggest that the conformation of the intact HA stalk provided by vector-based vaccines is important for induction of HA stalk-binding Abs. Our study provides insight into the mechanism by which a vector-based vaccine induces broad protection by stimulation of cross-protective Abs targeting conserved domains of viral proteins. The findings support further strategies to develop a vectored vaccine as a universal influenza vaccine for the control of influenza epidemics and unpredicted pandemics.

  11. An Adenovirus-Vectored Influenza Vaccine Induces Durable Cross-Protective Hemagglutinin Stalk Antibody Responses in Mice.

    Science.gov (United States)

    Kim, Eun Hye; Han, Gye-Yeong; Nguyen, Huan

    2017-08-21

    Currently licensed vaccines against the influenza A virus (IAV) need to be updated annually to match the constantly evolving antigenicity of the influenza virus glycoproteins, hemagglutinin (HA), and neuramidiase (NA). Attempts to develop universal vaccines that provide broad protection have resulted in some success. Herein, we have shown that a replication-deficient adenovirus expressing H5/M2e induced significant humoral immunity against the conserved HA stalk. Compared to the humoral responses induced by an inactivated influenza vaccine, the humoral responses induced by the adenovirus-vectored vaccine against the conserved stalk domain mediated cross-protection against heterosubtypic influenza viruses. Importantly, virus inactivation by formaldehyde significantly reduced the binding of monoclonal antibodies (mAbs) to the conserved nucleoprotein (NP), M2e, and HA stalk. These results suggest that inactivation by formaldehyde significantly alters the antigenicity of the HA stalk, and suggest that the conformation of the intact HA stalk provided by vector-based vaccines is important for induction of HA stalk-binding Abs. Our study provides insight into the mechanism by which a vector-based vaccine induces broad protection by stimulation of cross-protective Abs targeting conserved domains of viral proteins. The findings support further strategies to develop a vectored vaccine as a universal influenza vaccine for the control of influenza epidemics and unpredicted pandemics.

  12. Recycling agriculture wastes of ramie stalk as bioadsorbents for Cd(2+) removal: a kinetic and thermodynamic study.

    Science.gov (United States)

    Xu, S; Gong, X F; Zou, H L; Liu, C Y; Chen, C L; Zeng, X X

    2016-01-01

    In this study, we exhibit the recycling of agriculture wastes of ramie stalk as bioadsorbents for Cd(2+) removal. Based on our experimental results, it is realized that Cd(2+) adsorption to ramie stalk is highly pH sensitive, indicating the adsorption is driven by surface complexation reaction. The high adsorption capacity of ramie stalk toward Cd(2+) (qm = 10.33 mg g(-1), 0.09 mol-Cd g(-1)), which corresponds to around 21.95% of active adsorption sites available of ramie stalk, is believed to be closely related to its high cellulose and lignin content. The inhomogeneous surface of ramie stalk due to the high cellulose and lignin content also accounts for the observation that the adsorption kinetic is described well by the pseudo second order kinetic model. Results from thermodynamic studies suggest that the adsorption process is endothermic and spontaneous. All these properties demonstrate the potential of ramie stalk as a low cost bioadsorbent for the application of heavy metal removal.

  13. Biochar influences the microbial community structure during tomato stalk composting with chicken manure.

    Science.gov (United States)

    Wei, Liu; Shutao, Wang; Jin, Zhang; Tong, Xu

    2014-02-01

    A batch composting study was performed to evaluate effects of biochar addition on dynamics of microbial community and changes of key physic-chemical properties during composting of tomato stalk and chicken manure. As a comparison, two amendments of peat bog and zeolite were selected. The results indicated that biochar addition for composting showed a shorter time to enter thermophilic phase (3 d) and a higher temperature (56°C) and longer duration of thermophilic phase compared to that of peat bog addition, zeolite addition and raw composts. The highest C/N ratio and volatile fatty acids' concentration with biochar addition were obtained. Biochar addition also showed more influence on bacterial community changes than that of peat bog and zeolite. Thus, biochar addition could significantly affect physic-chemical process and microbial community diversity on tomato stalk and chicken manure composting. This study provides valuable information for improving composting and a better understanding of biodegradation processes.

  14. The parallels between undue influence, domestic violence, stalking, and sexual assault.

    Science.gov (United States)

    Brandl, Bonnie; Heisler, Candace J; Stiegel, Lori A

    2005-01-01

    The dynamics of undue influence (UI) have many similarities with domestic violence, stalking, and grooming behavior used by some sexual predators. This article will help practitioners-particularly law enforcement investigators and prosecutors-better recognize UI as a pattern of behaviors, not an isolated incident. Understanding the dynamics of UI will enhance professionals' appreciation of the responses of victims and the manipulative nature of exploiters. Strategies that have been used effectively with domestic violence, stalking, and some sexual abuse cases may provide remedies for victims of UI and criminal justice options for holding perpetrators accountable. Enhanced awareness of these dynamics should lead to improved investigations, more effective strategies when interviewing and working with victims, and more successful prosecutions of perpetrators who use UI to financially exploit an older person.

  15. Continuous acetone-butanol-ethanol production by corn stalk immobilized cells.

    Science.gov (United States)

    Zhang, Yuedong; Ma, Yujiu; Yang, Fangxiao; Zhang, Chunhui

    2009-08-01

    Corn stalk was used as a support to immobilize Clostridia beijerinckii ATCC 55025 in the fermentation process of acetone, butanol, and ethanol production. The effect of the dilution rate on solvent production was examined in a steady-state 20-day continuous flow operation. The maximum total solvent concentration of 8.99 g l(-1) was obtained at a dilution rate of 0.2 h(-1). Increasing the dilution rate between 0.2 and 1.0 h(-1) resulted in an increased solvent productivity, and the highest solvent productivity was obtained at 5.06 g l(-1) h(-1) with a dilution rate of 1 h(-1). The maximum solvent yield from glucose of 0.32 g g(-1) was observed at 0.25 h(-1). The cell adsorption and morphology change during the growth on corn stalk support were examined by the SEM.

  16. Direct bioconversion of raw corn stalk to hydrogen by a new strain Clostridium sp. FS3.

    Science.gov (United States)

    Song, Zhao-Xia; Li, Xiao-Hu; Li, Wei-Wei; Bai, Yan-Xia; Fan, Yao-Ting; Hou, Hong-Wei

    2014-04-01

    A new strain FS3 which could achieve an efficient bioconversion of raw corn stalk to hydrogen had been isolated from anaerobic acclimated sludge, and identified as Clostridium butyricum on the basis of a series of physiological and biochemical experiments and 16S rDNA gene sequence. The strain could utilize various carbon sources to produce hydrogen. On the basis of single-factor experiments, the response surface methodology (RSM) was performed to optimize the media for hydrogen production. The maximum hydrogen yield of 92.9ml/g was observed under the optimal conditions: 20g/l raw corn stalk, 1.76g/l NH4HCO3, 0.91g/l KH2PO4 and 10.4ml/l nutrient solution. This finding opens a new avenue for direct conversion of raw cellulosic biomass to bio-hydrogen.

  17. Recycled aqueous ammonia expansion (RAAE) pretreatment to improve enzymatic digestibility of corn stalks.

    Science.gov (United States)

    Zhang, Chao; Pang, Feng; Li, Bing; Xue, Shulin; Kang, Yong

    2013-06-01

    A novel lignocellulose pretreatment method using aqueous ammonia for biofuel production was proposed in this study, which named recycled aqueous ammonia expansion (RAAE). Effects of temperature, pretreatment time, water to dry corn stalks loading and flow rate of aqueous ammonia on substrate enzymatic digestibility and sugar yield were investigated. Pretreatment temperature and time are important factors that affect RAAE process. Recirculation process could improve biomass digestibility and sugar yield compared with batch experiment. After RAAE pretreatment, about 70% of the lignin was removed, while more than 90% of the cellulose was preserved in the solids, the substrate crystallinity also increased because of the removal of amorphous portion. The maximum glucan enzymatic digestibility of pretreated biomass was 85.70%, which was obtained at 85°C, 11 min, 80% water to dry corn stalks loading and 1.5L/min aqueous ammonia flow rate. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Size reduction of high- and low-moisture corn stalks by linear knife grid system

    Energy Technology Data Exchange (ETDEWEB)

    Womac, A.R. [University of Tennessee; Igathinathane, C. [Mississippi State University (MSU); Sokhansanj, Shahabaddine [ORNL; Narayan, S. [First American Scientific Co.

    2009-04-01

    High- and low-moisture corn stalks were tested using a linear knife grid size reduction device developed for first-stage size reduction. The device was used in conjunction with a universal test machine that quantified shearing stress and energy characteristics for forcing a bed of corn stalks through a grid of sharp knives. No published engineering performance data for corn stover with similar devices are available to optimize performance; however, commercial knife grid systems exist for forage size reduction. From the force displacement data, mean and maximum ultimate shear stresses, cumulative and peak mass-based cutting energies for corn stalks, and mean new surface area-based cutting energies were determined from 4 5 refill runs at two moisture contents (78.8% and 11.3% wet basis), three knife grid spacings (25.4, 50.8, and 101.6 mm), and three bed depths (50.8, 101.6, and 152.4 mm). In general, the results indicated that peak failure load, ultimate shear stress, and cutting energy values varied directly with bed depth and inversely with knife grid spacing. Mean separation analysis established that high- and low-moisture conditions and bed depths 101.6 mm did not differ significantly (P < 0.05) for ultimate stress and cutting energy values, but knife grid spacing were significantly different. Linear knife grid cutting energy requirements for both moisture conditions of corn stalks were much smaller than reported cutting energy requirements. Ultimate shear stress and cutting energy results of this research should aid the engineering design of commercial scale linear knife gird size reduction equipment for various biomass feedstocks.

  19. Synthesis of Bio-Ethanol from Corn Stalk by Fermentation Process

    Directory of Open Access Journals (Sweden)

    Y. C. Wong

    2014-06-01

    Full Text Available Ethanol synthesis from corn stalk through fermentation process was studied. The ethanol produced was studied by various enzymatic treatment temperature and different feedstock loading in term of weight. The result shows that the highest concentration of ethanol contained in the sample was 48.90% at enzymatic temperature of 50°C. The temperature for optimum enzyme treatment have been identified as 50°C followed by 30, 40 and 60°C respectively.

  20. Relationship between potassium chloride suppression of corn stalk rot and soil microorganism characteristics

    Institute of Scientific and Technical Information of China (English)

    LIU Xiaoyan; JIN Jiyun; HE Ping; LIU Hailong; LI Wenjuan

    2007-01-01

    Observations from a site-fixed field trial of 12 years in Jilin Province show that potassium chloride (KC1)application has a significant positive influence on corn stalk rot incidence.Incubation experiments were conducted to study the effects of KC1 and soil extracts on the growth of Fusarium graminearum,the most common stalk rot fungi in this area,and the population changes in rhizosphere fungi,bacteria and actinomyces at different growth stages of corn.The results show that KC1 addition to the potato dextrose agar (PDA) medium could not directly suppress Fusarium graminearum development.Soil extracts from soil samples taken from the field plots with and without KC1 application affected Fusarium graminearum development,with soil extracts with KC1 treatments suppressing Fusarium graminearum development more significantly,compared with that from the KC1-free treatment.These results indicate that soil extracts play a role in the interaction between corn and Fusarium graminearum.Long-term KC1 application may increase the populations of rhizosphere fungi and actinomyces in the early growth stages,while there is no significant difference in the number of bacteria in rhizosphere among the treatments.Also,the populations of rhizosphere fungi are negatively correlated with the incidence of stalk rot in the early growth stages of corn.The sensitive infection stages of pathogen to corn consist of the stages when there is significant difference in the populations of rhizosphere fungi and actinomyces.The change of microorganism populations (especially fungi) in soil may be associated with the incidence decrease and is one of the mechanisms of KC1 suppressing corn stalk rot.

  1. [Obscene telephone calls--relations to paraphilias, paraphilia related disorders and stalking].

    Science.gov (United States)

    Briken, Peer; Hill, Andreas; Nika, Evangelia; Berner, Wolfgang

    2005-09-01

    Little is known about the aetiology, course and therapy of obscene telephone calls as a paraphilic behaviour. Overlaps to other paraphilias like voyeurism, paraphilia related disorders and the concept of stalking are reported in the literature. In case reports we describe the paraphilic development and course with a focus on the relationship to the victim. We discuss this on the background of different concepts regarding risk assessment and therapy.

  2. [Preservation of the pituitary stalk and the gland in transsphenoidal microsurgery for pituitary adenomas].

    Science.gov (United States)

    Li, Haoyu; Yuan, Xianrui; Liao, Yiwei; Xie, Yuanyang; Zhang, Chi; Li, Juan; Su, Jun; Wang, Xiangyu; Chen, Xiaoyu; Liu, Qing

    2014-02-01

    To improve the surgical outcome of pituitary adenomas by identifying and preserving the pituitary stalk and the gland during surgery. From October 2010 to September 2012, the author from the Department of Neurosurgery of Xiangya Hospital, Central South University operated on 51 patients with pituitary adenoma. During the operations, we carefully identified the normal adenohypophysis, pituitary stalk, neurohypophysis and the abnormal tissues either by direct observation or by medical images, aiming to excise the tumor thoroughly, protect the pituitary function and reduce the postoperative complications. Totally 37 patients (72.5%, 37/51) had total resection of the tumor, 12 (23.5%, 12/51) had subtotal tumor resection and the other 2 had major removal. The gland and the pituitary stalk were well identified and reserved. Detection of hormone content proved that the operation had little effect on the free triiodothyronine (FT3) and adrenocorticotropic hormone (ACTH), while for free tetraiodothyronine (FT4) and thyroid stimulating hormone (TSH) and postoperative followup significant alleviation was found. There was no significant fluctuation for the testosterone in the men preoperatively and postoperatively (all the above results were obtained without hormone replacement therapy). The main postoperative complications were as follows: temporary diabetes insipidus in 5 patients (9.8%, 5/51); electrolyte disorder (the appearance of hyponatremia) in 17 (33.3%, 17/51); and cerebrospinal fluid rhinorrhea and postoperative intracranial infection in 1 (2%, 1/51). No one died during the perioperation period. Microscopic transsphenoidal surgery is effective for pituitary adenomas including tumors violating the cavernous sinus. Accurate identification of the pituitary stalk, the gland and the abnormal tissue during the microscopic transsphenoidal operation plays a critical role in preserving the pituitary function and promoting postoperative rehabilitation.

  3. Separation and identification of flavonoids from fistular onion stalk (Allium fisturosum L. var. Caespitosum Makio).

    Science.gov (United States)

    Fu, Qinqin; Liu, Jingyou; Zhang, Changgong; Zhou, Yinbo; Zhang, Geng; Ma, Dan; Yang, Xinzhou

    2010-04-01

    The chemical constituents of fistular onion stalk obtained by supercritical CO(2) extraction were separated and purified by silica gel and sephadex LH-20 gel column chromatography and the preparative TLC method and four flavonoids were obtained. On the basis of the spectral data, they were structurally identified as (+)-catechin, (-)-epicatechin, astragalin, and 3-O-beta-D(2-O-beta-D-glucopyranosyl)-glucopyranosides of kaempferol.

  4. LOFT reactor vessel 290/sup 0/ downcomer stalk instrument penetration flange stress analysis

    Energy Technology Data Exchange (ETDEWEB)

    Finicle, D.P.

    1978-06-06

    The LOFT Reactor Vessel 290/sup 0/ Downcomer Stalk Instrument Penetration Flange Stress Analysis has been completed using normal operational and blowdown loading. A linear elastic analysis was completed using simplified hand analysis techniques. The analysis was in accordance with the 1977 ASME Boiler and Pressure Vessel Code, Section III, for a Class 1 component. Loading included internal pressure, bolt preload, and thermal gradients due to normal operating and blowdown.

  5. Corn stalk as matrix in decomposting toilet for treating urine and feces

    Science.gov (United States)

    Sintawardani, N.; Nilawati, D.; Astuti, J. T.

    2017-03-01

    Bio-Toilet technology (BT) which is appropriate for the habits of Indonesian people has been studied and developed. BT is a dry toilet technology commonly uses ligno-cellulosic waste materials as matrix to facilitate the growth of natural microbes. In aerobic condition, microbes degrade feces and urine. Mineral as the leftover of feces and urine, such as nitrogen (N), phosphorus (P), and potassium (K) remain in the rest of matrix waste. After certain period. matrix can be harvested and used as soil conditioner. BT uses much less water, mobile, and very useful to be applied in areas where water availability is limited. BT type with different capacities, user amounts and mixing systems has been developed using sawdust for matrix. Since corn stalk is categorized as useless and priceless waste, its application in BT is challenging. Performance of BT with corn stalk as matrix to degrade feces and urine of carnivore imitating the human waste was observed. BT M-15 manual mixing type with paddle was filled with chopped corn stalk as much as 45% of total volume. This BT was designed for 15 person as users per day if 80% reactor volume was filled with ligno-cellulosic matrix. It is assumed that 150 g of feces are discharged once per person/day and 1000 mL of urine 6-8 times per day. Start up process was made in the beginning to initialize the needed microbes in the reactor (matrix). The discharge of feces and urine were increased slowly and gradually the users were increased from 1 to 4 users per day. Performance of BT was indicated by the change in the pile that showed by moisture content, temperature and pH. C/N ratio in matrix decreased significantly from 43 to 17. This result showed that the corn stalk could be used as matrix in BT.

  6. Size reduction of high- and low-moisture corn stalks by linear knife grid system

    Energy Technology Data Exchange (ETDEWEB)

    Igathinathane, C. [Agricultural and Biological Engineering Department, 130 Creelman Street, Mississippi State University, Mississippi State, Mississippi 39762 (United States); Womac, A.R. [Department of Biosystems Engineering and Soil Science, 2506 E. J. Chapman Drive, The University of Tennessee, Knoxville, Tennessee 37996 (United States); Sokhansanj, S. [Oak Ridge National Laboratory, Environmental Sciences Division, Oak Ridge, P. O. Box 2008, Tennessee 37831 (United States); Narayan, S. [First American Scientific Company, 100 Park Royal South West Vancouver, British Columbia, V7T 1A2 (Canada)

    2009-04-15

    High- and low-moisture corn stalks were tested using a linear knife grid size reduction device developed for first-stage size reduction. The device was used in conjunction with a universal test machine that quantified shearing stress and energy characteristics for forcing a bed of corn stalks through a grid of sharp knives. No published engineering performance data for corn stover with similar devices are available to optimize performance; however, commercial knife grid systems exist for forage size reduction. From the force-displacement data, mean and maximum ultimate shear stresses, cumulative and peak mass-based cutting energies for corn stalks, and mean new surface area-based cutting energies were determined from 4-5 refill runs at two moisture contents (78.8% and 11.3% wet basis), three knife grid spacings (25.4, 50.8, and 101.6 mm), and three bed depths (50.8, 101.6, and 152.4 mm). In general, the results indicated that peak failure load, ultimate shear stress, and cutting energy values varied directly with bed depth and inversely with knife grid spacing. Mean separation analysis established that high- and low-moisture conditions and bed depths {>=} 101.6 mm did not differ significantly (P < 0.05) for ultimate stress and cutting energy values, but knife grid spacing were significantly different. Linear knife grid cutting energy requirements for both moisture conditions of corn stalks were much smaller than reported cutting energy requirements. Ultimate shear stress and cutting energy results of this research should aid the engineering design of commercial scale linear knife gird size reduction equipment for various biomass feedstocks. (author)

  7. Preparation of nitrogen-doped cotton stalk microporous activated carbon fiber electrodes with different surface area from hexamethylenetetramine-modified cotton stalk for electrochemical degradation of methylene blue

    Science.gov (United States)

    Li, Kunquan; Rong, Zhang; Li, Ye; Li, Cheng; Zheng, Zheng

    Cotton-stalk activated carbon fibers (CSCFs) with controllable micropore area and nitrogen content were prepared as an efficient electrode from hexamethylenetetramine-modified cotton stalk by steam/ammonia activation. The influence of microporous area, nitrogen content, voltage and initial concentration on the electrical degradation efficiency of methylene blue (MB) was evaluated by using CSCFs as anode. Results showed that the CSCF electrodes exhibited excellent MB electrochemical degradation ability including decolorization and COD removal. Increasing micropore surface area and nitrogen content of CSCF anode leaded to a corresponding increase in MB removal. The prepared CSCF-800-15-N, which has highest N content but lowest microporous area, attained the best degradation effect with 97% MB decolorization ratio for 5 mg/L MB at 12 V in 4 h, implying the doped nitrogen played a prominent role in improving the electrochemical degradation ability. The electrical degradation reaction was well described by first-order kinetics model. Overall, the aforesaid findings suggested that the nitrogen-doped CSCFs were potential electrode materials, and their electrical degradation abilities could be effectively enhanced by controlling the nitrogen content and micropore surface area.

  8. Effects of different pretreatment strategies on corn stalk acidogenic fermentation using a microbial consortium.

    Science.gov (United States)

    Guo, Peng; Mochidzuki, Kazuhiro; Cheng, Wei; Zhou, Ming; Gao, Hong; Zheng, Dan; Wang, Xiaofen; Cui, Zongjun

    2011-08-01

    The effects of sulfuric acid, acetic acid, aqueous ammonia, sodium hydroxide, and steam explosion pretreatments of corn stalk on organic acid production by a microbial consortium, MC1, were determined. Steam explosion resulted in a substrate that was most favorable for microbial growth and organic acid productions. The total amounts of organic acids produced by MC1 on steam exploded, sodium hydroxide, sulfuric acid, acetic acid, and aqueous ammonia pretreated corn stalk were 2.99, 2.74, 1.96, 1.45, and 2.21g/l, respectively after 3days of fermentation at 50°C. The most prominent organic products during fermentation of steam-exploded corn stalks were formic (0.86g/l), acetic (0.59g/l), propanoic (0.27g/l), butanoic (0.62g/l), and lactic acid (0.64g/l) after 3days of fermentation; ethanol (0.18g/l), ethanediol (0.68g/l), and glycerin (3.06g/l) were also produced. These compounds would be suitable substrates for conversion to methane by anaerobic digestion.

  9. Effect of EDTA on divalent metal adsorption onto grape stalk and exhausted coffee wastes.

    Science.gov (United States)

    Escudero, Carlos; Gabaldón, Carmen; Marzal, Paula; Villaescusa, Isabel

    2008-04-01

    In the present work, two industrial vegetable wastes, grape stalk, coming from a wine producer, and exhausted coffee, coming from a soluble coffee manufacturer, have been investigated for the removal of Cu(II) and Ni(II) from aqueous solutions in presence and in absence of the strongly complexing agent EDTA. Effects of pH and metal-EDTA molar ratio, kinetics as a function of sorbent concentration, and sorption equilibrium for both metals onto both sorbents were evaluated in batch experiments. Metal uptake was dependent of pH, reaching a maximum from pH around 5.5. EDTA was found to dramatically reduce metal adsorption, reaching total uptake inhibition for both metals onto both sorbents at equimolar metal:ligand concentrations. Kinetic results were successfully modelled by means of the pseudo second order model. Langmuir and Freundlich models were used to describe the sorption equilibrium data. Grape stalk showed the best performance for Cu(II) and Ni(II) removal in presence and in absence of EDTA, despite exhausted coffee appears as less sensitive to the presence of complexing agent. The performance of Cu(II) and Ni(II) sorption onto grape stalk in a continuous flow process was evaluated. In solutions containing EDTA, an initial metal concentration in the outlet flow corresponding to the complexed metal fraction was observed from the beginning of the process. A high metal recovery yield (>97%) was achieved by feeding the metal-loaded column with 0.05 M HCl.

  10. High pressure assist-alkali pretreatment of cotton stalk and physiochemical characterization of biomass.

    Science.gov (United States)

    Du, Shuang-kui; Zhu, Xinna; Wang, Hua; Zhou, Dayun; Yang, Weihua; Xu, Hongxia

    2013-11-01

    Ground cotton stalks were pretreated with sodium hydroxide (NaOH) at concentrations of 1-4% (w/v), pressures of 30-130 kPa, durations of 15-75 min, and liquid/solid ratios of 10:1-30:1. Modeling of the high pressure assist-alkali pretreatment (HPAP) of cotton stalk was attempted. The levels of NaOH concentration, pressure, and duration were optimized using a Box-Behnken design to enhance the cellulose content of treated solid residue. The optimum pretreatment conditions were as follows: liquid/solid ratio, 20:1; pressure, 130 kPa; NaOH concentration, 3.0%; duration, 40 min. During the conditions, cellulose content of pretreated cotton stalk residue was 64.07%. The maximum cellulose conversion of 45.82% and reducing sugar yield of 0.293 g/g upon hydrolysis were obtained. Significant differences were observed in biomass composition and physiochemical characteristics between native and alkali-treated biomass. High NaOH concentration and pressure were conducive to lignin dissolution and resulted in increased cellulose content and conversion.

  11. Use of grape stalk, a waste of the viticulture industry, to obtain activated carbon.

    Science.gov (United States)

    Deiana, A C; Sardella, M F; Silva, H; Amaya, A; Tancredi, N

    2009-12-15

    Grape stalk is an organic waste produced in great amounts in the industrialization processes of grape. This work presents the results of studies carried out to use this waste as raw material to prepare activated carbon through the physical and chemical route. The physicochemical characterization of this material suggests the presence of unusually high levels of ashes. Metal content was determined and high levels of potassium, sodium, iron, calcium and magnesium in carbonized and raw grape stalk were exhibited. This characteristic made difficult physical activation at high temperatures. A leaching step was included before the activation with steam, and adsorbents with surface areas between 700 and 900 m(2)/g were obtained. Physical activation was also performed at lower temperatures using carbonized grape stalk without leaching, leading to the development of some grade of porosity, with an area of 412 m(2)/g. These results would indicate the catalytic effect of the minerals present in this raw material. Chemical activation using phosphoric acid as activating agent seemed to be a very efficient method as final products with BET areas between 1000 and 1500 m(2)/g were obtained.

  12. Genetic variability among sorghum accessions for seed starch and stalk total sugar content

    Directory of Open Access Journals (Sweden)

    Abe Shegro Gerrano

    2014-12-01

    Full Text Available Sorghum (Sorghum bicolor (L. Moench is a staple food grain in many semi-arid and tropical areas of the world, notably in sub-Saharan Africa because of its adaptation to harsh environments. Among important biochemical components for sorghum for processors are the levels of starch (amylose and amylopectin and total sugar contents. The aim of this study was to determine the genetic variation for total starch in the seed, its components and total sugar in the stalks of the sorghum accessions from Ethiopia and South Africa. Samples of 22 sorghum accessions were evaluated. Significant variations were observed in total starch (31.01 to 64.88 %, amylose (14.05 to 18.91 %, the amylose/amylopectin ratio (0.31 to 0.73 and total stalk sugar content (9.36 to 16.84 %. Multivariate analysis showed a wide genetic variation within and among germplasm accessions which could be used in the selection of parental lines for the improvement of traits of interest through breeding. The variation found among the sorghum accessions shows that an improved total starch and starch components and stalk sugar contents can be achieved through crossing these selected genotypes.

  13. Adjuvants and immunization strategies to induce influenza virus hemagglutinin stalk antibodies.

    Directory of Open Access Journals (Sweden)

    Peter H Goff

    Full Text Available The global population remains vulnerable in the face of the next pandemic influenza virus outbreak, and reformulated vaccinations are administered annually to manage seasonal epidemics. Therefore, development of a new generation of vaccines is needed to generate broad and persistent immunity to influenza viruses. Here, we describe three adjuvants that enhance the induction of stalk-directed antibodies against heterologous and heterosubtypic influenza viruses when administered with chimeric HA proteins. Addavax, an MF59-like nanoemulsion, poly(I:C, and an RNA hairpin derived from Sendai virus (SeV Cantell were efficacious intramuscularly. The SeV RNA and poly(I:C also proved to be effective respiratory mucosal adjuvants. Although the quantity and quality of antibodies induced by the adjuvants varied, immunized mice demonstrated comparable levels of protection against challenge with influenza A viruses on the basis of HA stalk reactivity. Finally, we present that intranasally, but not intramuscularly, administered chimeric HA proteins induce mucosal IgA antibodies directed at the HA stalk.

  14. Durability characteristics of cement-bonded particleboards manufac-tured from maize stalk residue

    Institute of Scientific and Technical Information of China (English)

    Ajaye Babatunde

    2011-01-01

    Cement-bonded particleboards of 6 mm in thickness were manufactured using maize stalk (Zea mays) particles of uniform sizes at three levels of board density and additive concentrations respectively.The bending strength and dimensional properties were assessed. Increase in board density and additive concentration caused increase in Modulus of rupture (MOR), Modulus of elasticity (MOE), and decrease in Thickness swelling (TS) and Water absorption (WA). The MOR, MOE and TS of the boards were significantly affected by board density except for WA,but additive concentration affected ail the boards' properties examined at p ≥ 0.05. Strong and dimensional stable cement-bonded boards could be manufactured from maize stalk particles with Portland cement as the binder after hot water treatment. Although the dimensional stability and mechanical strength properties of the boards were affected by the board density and additive concentration, the study revealed that cement-bonded particleboards could be manufactured from maize stalk (Zea mays) particles. However, the increase in board density and additive concentration could cause the increase in MOR and MOE, and cause the decrease in TS and WA of boards.

  15. Removal of methylene blue from aqueous solution using cotton stalk, cotton waste and cotton dust

    Energy Technology Data Exchange (ETDEWEB)

    Ertas, Murat [Department of Forest Industrial Engineering, Faculty of Forestry, Kahramanmaras Sutcu Imam University, 46060 Kahramanmaras (Turkey); Acemioglu, Bilal, E-mail: acemioglu@kilis.edu.tr [Department of Chemistry, Faculty of Science and Arts, Kilis 7 Aralik University, 79000 Kilis (Turkey); Alma, M. Hakki [Department of Forest Industrial Engineering, Faculty of Forestry, Kahramanmaras Sutcu Imam University, 46060 Kahramanmaras (Turkey); Usta, Mustafa [Department of Forest Industrial Engineering, Faculty of Forestry, Karadeniz Technical University, 61080 Trabzon (Turkey)

    2010-11-15

    In this study, cotton stalk (CS), cotton waste (CW) and cotton dust (CD) was used as sorbents to remove methylene blue (MB) from aqueous solution by batch sorption technique. Effects of initial dye concentration, solution pH, solution temperature and sorbent dose on sorption were studied. It was seen that the removal of methylene blue increased with increasing initial dye concentration (from 25 to 100 mg/l), solution pH (from 5 to 10), solution temperature (from 20 to 50 deg. C) and sorbent dose (from 0.25 to 1.50 g/50 ml). The maximum dye removal was reached at 90 min. Sorption isotherms were analyzed by Langmuir and Freundlich models at different temperatures of 20, 30, 40 and 50 deg. C, and the results were discussed in detail. Moreover, the thermodynamics of sorption were also studied. It was found that the values of standard free energy ({Delta}G{sup o}) were positive for cotton stalk and negative for cotton waste and cotton dust. The values of standard enthalpy ({Delta}H{sup o}) and entropy ({Delta}S{sup o}) were found to be positive, and the obtained results were interpreted in detail. The results of this study showed that cotton stalk, cotton waste and cotton dust could be employed as effective and low-cost materials for the removal of dyes from aqueous solution.

  16. Cellulose-hydrogen production from corn stalk biomass by anaerobic fermentation

    Institute of Scientific and Technical Information of China (English)

    XING Yan; MA HongCui; FAN YaoTing; HOU HongWei; CHEN JingRun

    2009-01-01

    Cellulose-hydrogen production from corn stalk by lesser panda manure was carried out in batch testa and a 5 L scale-up continuously stirred anaerobic bioreactor (CSABR),respectively.The bio-pretreat-ment of corn stalk was found most effective at 25℃ using microbe additive of 7.5 g/kg,in which the yields of soluble saccharides (SS) and lactic acid were 212 mg/g-TS and 21 mg/g-TS,respectively.The maximum cumulative H2 yield (176 ml/g-TS) and H2 production rate (14.5 ml/g-TS h-1) were obtained at pH 5.5,36℃ by treating a substrate of 15 g/L.The hydrogen content in biogas was 57.2% and there was no significant methane gas observed.During the optimal period of H2 production,the ORP values stayed in the lower level ranging from -445 mV to -455 mV.The results show that the bio-pretreatment of the raw materials played a vital role in the effective conversion of corn stalk into cellulose-hydrogen by mixed culture.

  17. Identification of sources of resistance to anthracnose stalk rot in maize

    Directory of Open Access Journals (Sweden)

    Alessandro Nicoli

    Full Text Available ABSTRACT: Adoption of resistant cultivars is the primary measure used to control anthracnose stalk rot. The goal of this study was to identify maize-resistant genotypes to anthracnose stalk rot, which are similar to the hybrid 2B710. Experiments were performed at Embrapa Maize and Sorghum experimental fields in Brazil. The first experimental trial evaluated 234 maize lines as well as two commercials hybrids, BRS1010 (susceptible and 2B710 (resistant. Artificial inoculations were performed with a strain at the blister (R2 phase, and evaluation of disease severity was performed after 30 days. The second experimental trial evaluated 48 maize lines and hybrids, inoculated with two Colletotrichum graminicola strains. In the first trial, eight resistance groups were formed, and the last lines were more resistant, as was the hybrid 2B710, with values between 11.50% and 23.0% of severity. In the second trial, there was an interaction between the two factors, lines and isolates, and the lines often showed the same reaction features as those obtained in the first trial. However, the disease severity was higher for most lines, even when using other isolates. These lines with effective levels of resistance could be used in future studies of inheritance, in programs to develop hybrids, and to identify molecular markers associated with resistance to anthracnose stalk rot in maize.

  18. Dynein light chain 1 induces assembly of large Bim complexes on mitochondria that stabilize Mcl-1 and regulate apoptosis.

    Science.gov (United States)

    Singh, Prafull Kumar; Roukounakis, Aristomenis; Frank, Daniel O; Kirschnek, Susanne; Das, Kushal Kumar; Neumann, Simon; Madl, Josef; Römer, Winfried; Zorzin, Carina; Borner, Christoph; Haimovici, Aladin; Garcia-Saez, Ana; Weber, Arnim; Häcker, Georg

    2017-09-01

    The Bcl-2 family protein Bim triggers mitochondrial apoptosis. Bim is expressed in nonapoptotic cells at the mitochondrial outer membrane, where it is activated by largely unknown mechanisms. We found that Bim is regulated by formation of large protein complexes containing dynein light chain 1 (DLC1). Bim rapidly inserted into cardiolipin-containing membranes in vitro and recruited DLC1 to the membrane. Bim binding to DLC1 induced the formation of large Bim complexes on lipid vesicles, on isolated mitochondria, and in intact cells. Native gel electrophoresis and gel filtration showed Bim-containing mitochondrial complexes of several hundred kilodaltons in all cells tested. Bim unable to form complexes was consistently more active than complexed Bim, which correlated with its substantially reduced binding to anti-apoptotic Bcl-2 proteins. At endogenous levels, Bim surprisingly bound only anti-apoptotic Mcl-1 but not Bcl-2 or Bcl-XL, recruiting only Mcl-1 into large complexes. Targeting of DLC1 by RNAi in human cell lines induced disassembly of Bim-Mcl-1 complexes and the proteasomal degradation of Mcl-1 and sensitized the cells to the Bcl-2/Bcl-XL inhibitor ABT-737. Regulation of apoptosis at mitochondria thus extends beyond the interaction of monomers of proapoptotic and anti-apoptotic Bcl-2 family members but involves more complex structures of proteins at the mitochondrial outer membrane, and targeting complexes may be a novel therapeutic strategy. © 2017 Singh et al.; Published by Cold Spring Harbor Laboratory Press.

  19. Cooperative binding of the outer arm-docking complex underlies the regular arrangement of outer arm dynein in the axoneme

    Science.gov (United States)

    Owa, Mikito; Furuta, Akane; Usukura, Jiro; Arisaka, Fumio; King, Stephen M.; Witman, George B.; Kamiya, Ritsu; Wakabayashi, Ken-ichi

    2014-01-01

    Outer arm dynein (OAD) in cilia and flagella is bound to the outer doublet microtubules every 24 nm. Periodic binding of OADs at specific sites is important for efficient cilia/flagella beating; however, the molecular mechanism that specifies OAD arrangement remains elusive. Studies using the green alga Chlamydomonas reinhardtii have shown that the OAD-docking complex (ODA-DC), a heterotrimeric complex present at the OAD base, functions as the OAD docking site on the doublet. We find that the ODA–DC has an ellipsoidal shape ∼24 nm in length. In mutant axonemes that lack OAD but retain the ODA-DC, ODA-DC molecules are aligned in an end-to-end manner along the outer doublets. When flagella of a mutant lacking ODA-DCs are supplied with ODA-DCs upon gamete fusion, ODA-DC molecules first bind to the mutant axonemes in the proximal region, and the occupied region gradually extends toward the tip, followed by binding of OADs. This and other results indicate that a cooperative association of the ODA-DC underlies its function as the OAD-docking site and is the determinant of the 24-nm periodicity. PMID:24979786

  20. Axonemal dynein intermediate-chain gene (DNAI1) mutations result in situs inversus and primary ciliary dyskinesia (Kartagener syndrome).

    Science.gov (United States)

    Guichard, C; Harricane, M C; Lafitte, J J; Godard, P; Zaegel, M; Tack, V; Lalau, G; Bouvagnet, P

    2001-04-01

    Kartagener syndrome (KS) is a trilogy of symptoms (nasal polyps, bronchiectasis, and situs inversus totalis) that is associated with ultrastructural anomalies of cilia of epithelial cells covering the upper and lower respiratory tracts and spermatozoa flagellae. The axonemal dynein intermediate-chain gene 1 (DNAI1), which has been demonstrated to be responsible for a case of primary ciliary dyskinesia (PCD) without situs inversus, was screened for mutation in a series of 34 patients with KS. We identified compound heterozygous DNAI1 gene defects in three independent patients and in two of their siblings who presented with PCD and situs solitus (i.e., normal position of inner organs). Strikingly, these five patients share one mutant allele (splice defect), which is identical to one of the mutant DNAI1 alleles found in the patient with PCD, reported elsewhere. Finally, this study demonstrates a link between ciliary function and situs determination, since compound mutation heterozygosity in DNAI1 results in PCD with situs solitus or situs inversus (KS).

  1. Mitosin/CENP-F is a conserved kinetochore protein subjected to cytoplasmic dynein-mediated poleward transport

    Institute of Scientific and Technical Information of China (English)

    ZHEN YE YANG; JING GUO; NING LI; MIN QIAN; SHENG NIAN WANG; XUE LIANG ZHU

    2003-01-01

    Mitosin/CENP-F is a human nuclear protein transiently associated with the outer kinetochore plate in M phase and is involved in M phase progression. LEK1 and CMF1, which are its murine and chicken orthologs, however, are implicated in muscle differentiation and reportedly not distributed at kinetochores.We therefore conducted several assays to clarify this issue. The typical centromere staining patterns were observed in mitotic cells from both human primary culture and murine, canine, and mink cell lines. A C-terminal portion of LEK1 also conferred centromere localization. Our analysis further suggests conserved kinetochore localization of mammalian mitosin orthologs. Moreover, mitosin was associated preferentially with kinetochores of unaligned chromosomes. It was also constantly transported from kinetochores to spindle poles by cytoplasmic dynein. These properties resemble those of other kinetochore proteins important for the spindle checkpoint, thus implying a role of mitosin in this checkpoint. Therefore, mitosin family may serve as multifunctional proteins involved in both mitosis and differentiation.

  2. Biodegradation of lignin and nicotine with white rot fungi for the delignification and detoxification of tobacco stalk.

    Science.gov (United States)

    Su, Yulong; Xian, He; Shi, Sujuan; Zhang, Chengsheng; Manik, S M Nuruzzaman; Mao, Jingjing; Zhang, Ge; Liao, Weihong; Wang, Qian; Liu, Haobao

    2016-11-21

    Tobacco stalk is one kind of abundant crop residues in China. The high lignification of tobacco stalk increases its reusing cost and the existing of nicotine will cause serious pollution. The biodegradation of lignocellulosic biomass has been demonstrated to be an environmental and economical approach for the utilization of plant stalk. Meanwhile, many nicotine-degrading microorganisms were found in nature. However, microorganisms which could degraded both nicotine and lignin haven't been reported. Therefore, it's imperative to find some suitable microorganisms to break down lignin and simultaneously remove nicotine in tobacco stalk. The nicotine in tobacco stalk could be degraded effectively by Trametes versicolor, Trametes hirsute and Phanerochaete chrysosporium. The nicotine content in tobacco stalk was lowered to below 500 mg/kg (a safe concentration to environment) after 10 days of fermentation with Phanerochaete chrysosporium and Trametes versicolor, and 15 days with Trametes hirsute. The degradation rate of lignin in the fermented tobacco stalk was 37.70, 51.56 and 53.75% with Trametes versicolor, Trametes hirsute and Phanerochaete chrysosporium, respectively. Meanwhile, 24.28% hemicellulose was degraded by Phanerochaete chrysosporium and 28.19% cellulose was removed by Trametes hirsute. Through the enzyme activity analysis, the main and highest ligninolytic enzymes produced by Phanerochaete chrysosporium, Trametes hirsute and Trametes versicolor were lignin peroxidase (88.62 U · L(-1)), manganese peroxidase (100.95 U · L(-1)) and laccase (745.65 U · L(-1)). Meanwhile, relatively high and stable cellulase activity was also detected during the fermentation with Phanerochaete chrysosporium, and the highest endoglucanase, exoglucanase and filter paper enzyme activities were 0.38 U · mL(-1), 0.45 U · mL(-1) and 0.35U · mL(-1), respectively. Moreover, the products in the fermentation of tobacco stalk with P. chrysosporium were

  3. Effect of spent cotton stalks on color removal and chemical oxygen demand lowering in olive oil mill wastewater by white rot fungi.

    Science.gov (United States)

    Kahraman, S; Yeşilada, O

    1999-01-01

    Wastewater from olive oil mill was decolorized (and its chemical oxygen demand reduced in static cultivation) using the fungi Coriolus versicolor, Funalia trogii, Phanerochaete chrysosporium and Pleurotus sajor-caju. The effect of cotton stalk on decolorizing and COD removing capability was demonstrated. P. chrysosporium (in 20% medium with cotton stalk) reduced the COD by 48% and color by 58%, F. trogii (in 30% medium with cotton stalk)) by 51 and 55%, respectively.

  4. Rapid Communication. Monitoring the occurrence of bacteria in stored cabbage heads

    Directory of Open Access Journals (Sweden)

    Eichmeier Aleš

    2016-08-01

    Full Text Available Twenty-six cabbage heads stored under typical conditions in a storage hall in Moravia, Czech Republic, were tested for the presence of bacteria by the method of isolation from three different parts of the cabbage heads. Isolations were carried out from stalks, inner and superficial leaves. Two samplings were done; in November 2015 and February 2016. Bacterial cultures were sequenced in the part of 16S rRNA region; bacteria were identified according to the sequences obtained. The most prevalent bacteria were of the genus Pseudomonas. Genera: Klebsiella, Erwinia, Pantoea, Bacillus were also identified. The results provided an interesting insight into the bacterial spectrum in stored cabbage heads and their dynamics during storage. The nucleotide sequences which were found were saved in GenBank/NCBI under accession numbers KX160104-KX160145.

  5. Role of CD97stalk and CD55 as molecular markers for prognosis and therapy of gastric carcinoma patients

    Institute of Scientific and Technical Information of China (English)

    LIU Yong; CHEN Li; PENG Shu-you; CHEN Zhou-xun; HOANG-VU C

    2005-01-01

    Objectives: To explore the mechanism of development and aggressiveness in gastric carcinomas by investigating the expression and role of CD97 and its cellular ligand CD55 in gastric carcinomas. Methods: Tumor and corresponding normal mucosal tissue, collected from 39 gastric carcinoma patients, were examined by immunohistochemistry and RT-PCR for the expression of CD97 and CD55. Results: CD97stalk was strongly stained on scattered tumor cells or small tumor cell clusters at the invasion front of gastric carcinomas. The expression of CD97stalk was frequently observed in tumors of stage Ⅰ and T1 gastric carcinoma patients. The expression of CD97stalk between Stage Ⅰ and Stage Ⅱ, Ⅲ, Ⅳ specimens showed significant difference (P<0.05), between T1 and T2, T3, T4 specimens also showed significant difference (P<0.05). Specimens with tumor invasion depth limited in mucosa of T 1 specimens showed higher positive CD55 expression than specimens with the same tumor invasion depth in T2, T3, T4 specimens, the expression of CD55 between T1 and T2, T3, T4 specimens was significantly different (P<0.05).There was strong correlation between the distribution patterns of CD97stalk and CD55 on tumor tissues (r=0.73, P<0.05). Signet ring cell carcinomas frequently contained strong CD97stalk and CD55-staining. Conclusions: Our results suggest that CD97stalk is probably involved in the growth, invasion and aggressiveness of gastric carcinomas by binding its cellular ligand CD55. CD97stalk and CD55 could be useful as molecular markers for prognosis and therapy of gastric carcinoma patients.

  6. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... limitations of CT Scanning of the Head? What is CT Scanning of the Head? Computed tomography, more ... the body being studied. top of page How is the procedure performed? The technologist begins by positioning ...

  7. Coarse-grained molecular dynamics study of membrane fusion: Curvature effects on free energy barriers along the stalk mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Kawamoto, Shuhei; Shinoda, Wataru, E-mail: w.shinoda@apchem.nagoya-u.ac.jp [Department of Applied Chemistry, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603 (Japan); Klein, Michael L. [Institute for Computational Molecular Science, Temple University, SERC Building 1925 North 12th Street, Philadelphia, Pennsylvania 19122 (United States)

    2015-12-28

    The effects of membrane curvature on the free energy barrier for membrane fusion have been investigated using coarse-grained molecular dynamics (CG-MD) simulations, assuming that fusion takes place through a stalk intermediate. Free energy barriers were estimated for stalk formation as well as for fusion pore formation using the guiding potential method. Specifically, the three different geometries of two apposed membranes were considered: vesicle–vesicle, vesicle–planar, and planar–planar membranes. The free energy barriers for the resulting fusion were found to depend importantly on the fusing membrane geometries; the lowest barrier was obtained for vesicular membranes. Further, lipid sorting was observed in fusion of the mixed membranes of dimyristoyl phosphatidylcholine and dioleoyl phosphatidylethanolamine (DOPE). Specifically, DOPE molecules were found to assemble around the stalk to support the highly negative curved membrane surface. A consistent result for lipid sorting was observed when a simple continuum model (CM) was used, where the Helfrich energy and mixing entropy of the lipids were taken into account. However, the CM predicts a much higher free energy barrier than found using CG-MD. This discrepancy originates from the conformational changes of lipids, which were not considered in the CM. The results of the CG-MD simulations reveal that a large conformational change in the lipid takes place around the stalk region, which results in a reduction of free energy barriers along the stalk mechanism of membrane fusion.

  8. Effect of Piper betel leaf stalk extract on protein metabolism in reproductive tissues of male albino rats

    Institute of Scientific and Technical Information of China (English)

    Vengaiah V; Govardhan Naik A; Changamma C

    2015-01-01

    Objective: To know the impact of Piper betel leaf stalk (P. betel) extract on Protein and energy metabolism and its role in male albino rats. Methods: Healthy adult (3-4 months old) male Wistar strain albino rats were administered with betel leaf stalk extract, at the dose of 50 mg/kg/day through oral gavages for 15 days. Twenty four hours after the last dose, the animals were autopsied. In order to assess antifertility effect in testis, epididymis, seminal vesicle and prostate gland, estimation of total, soluble and structural proteins, free amino acids and DNA, RNA were undertaken. Results: The accumulation in proteins indicates the anti-androgenic effect of extract. The reduction in free amino acids will affect the sertoli cell function, results in the damage of spermatogenesis. The significant elevation in testicular DNA content (hyperplasia) was observed. In the present study, P. betel leaf stalk extract decreases the concentration of RNA, in testes, seminal vesicle and prostate gland except in epididymis where it was elevated. It indicates the alterations in rate of protein synthesis and growth rate of tissues due to the administration of P. betel leaf stalk extraction. However, the RNA: DNA ratio was reduced except in prostate. Conclusions: P. betel leaf stalk extract exert its anti androgenic effect by alterations in rate of protein synthesis and cellular hypertrophy occur in prostate.

  9. 玉米秆热解的最概然机理%Maximum probability mechanisms of pyrolysis of corn stalk

    Institute of Scientific and Technical Information of China (English)

    李小民; 林其钊

    2012-01-01

    The mechanisms of pyrolysis of corn stalk were investigated by means of both model method and model-free method, and following the idea of dual extrapolation method at the same time. Firstly, a thermogravimetry experiment was performed to investigate the process of pyrolysis of corn stalk, in nitrogen gas and at various heating rates. Secondly, an analysis, combining model method and model-free method, was utilized to understand the mechanisms of pyrolysis of corn stalk. The several mechanisms were screened by means of the Popescu method. Then, the kinetic parameters are obtained by the integral formula proposed by Tang and the iso-conversion methods respectively. Moreover, the aforementioned results are all extrapolated following the idea of dual extrapolation method. It is found from the comparison that 2 mechanisms are both probable to satisfy pyrolysis of corn stalk. Furthermore, a preliminary comparison was carried out between the results from the two models and the experimental data. According to the comparison, combined the status of pyrolysis research of biomass, it was concluded that the mechanisms for corn stalk follow reaction of 2. 5-order. And it was obtained that the activation energy, 97. 72 kJ · mol-1 , and the frequency factor, 3661231 s-1. Finally, an analysis was conducted concerning the discrepancy between the calculation and the experiment.

  10. Coarse-grained molecular dynamics study of membrane fusion: Curvature effects on free energy barriers along the stalk mechanism.

    Science.gov (United States)

    Kawamoto, Shuhei; Klein, Michael L; Shinoda, Wataru

    2015-12-28

    The effects of membrane curvature on the free energy barrier for membrane fusion have been investigated using coarse-grained molecular dynamics (CG-MD) simulations, assuming that fusion takes place through a stalk intermediate. Free energy barriers were estimated for stalk formation as well as for fusion pore formation using the guiding potential method. Specifically, the three different geometries of two apposed membranes were considered: vesicle-vesicle, vesicle-planar, and planar-planar membranes. The free energy barriers for the resulting fusion were found to depend importantly on the fusing membrane geometries; the lowest barrier was obtained for vesicular membranes. Further, lipid sorting was observed in fusion of the mixed membranes of dimyristoyl phosphatidylcholine and dioleoyl phosphatidylethanolamine (DOPE). Specifically, DOPE molecules were found to assemble around the stalk to support the highly negative curved membrane surface. A consistent result for lipid sorting was observed when a simple continuum model (CM) was used, where the Helfrich energy and mixing entropy of the lipids were taken into account. However, the CM predicts a much higher free energy barrier than found using CG-MD. This discrepancy originates from the conformational changes of lipids, which were not considered in the CM. The results of the CG-MD simulations reveal that a large conformational change in the lipid takes place around the stalk region, which results in a reduction of free energy barriers along the stalk mechanism of membrane fusion.

  11. LC8 dynein light chain (DYNLL1) binds to the C-terminal domain of ATM-interacting protein (ATMIN/ASCIZ) and regulates its subcellular localization

    Energy Technology Data Exchange (ETDEWEB)

    Rapali, Peter [Dept. Biochemistry, Eoetvoes Lorand University, Budapest (Hungary); Garcia-Mayoral, Maria Flor [Dept. Biological Physical Chemistry, IQFR, CSIC, Madrid (Spain); Martinez-Moreno, Monica [Dept. Biochemistry and Molecular Biology I, Universidad Complutense, Madrid (Spain); Tarnok, Krisztian; Schlett, Katalin [Dept. Physiology and Neurobiology, Eoetvoes Lorand University, Budapest (Hungary); Albar, Juan Pablo [Proteomics Facility, CNB, CSIC, Madrid (Spain); Bruix, Marta [Dept. Biological Physical Chemistry, IQFR, CSIC, Madrid (Spain); Nyitray, Laszlo, E-mail: nyitray@elte.hu [Dept. Biochemistry, Eoetvoes Lorand University, Budapest (Hungary); Rodriguez-Crespo, Ignacio, E-mail: nacho@bbm1.ucm.es [Dept. Biochemistry and Molecular Biology I, Universidad Complutense, Madrid (Spain)

    2011-10-28

    Highlights: Black-Right-Pointing-Pointer We have screened a human library with dynein light chain DYNLL1 (DLC8) as bait. Black-Right-Pointing-Pointer Dynein light chain DYNLL1 binds to ATM-kinase interacting protein (ATMIN). Black-Right-Pointing-Pointer ATMIN has 17 SQ/TQ motifs, a motif frequently found in DYNLL1-binding partners. Black-Right-Pointing-Pointer The two proteins interact in vitro, with ATMIN displaying at least five binding sites. Black-Right-Pointing-Pointer The interaction of ATMIN and DYNNL1 in transfected cells can also be observed. -- Abstract: LC8 dynein light chain (now termed DYNLL1 and DYNLL2 in mammals), a dimeric 89 amino acid protein, is a component of the dynein multi-protein complex. However a substantial amount of DYNLL1 is not associated to microtubules and it can thus interact with dozens of cellular and viral proteins that display well-defined, short linear motifs. Using DYNLL1 as bait in a yeast two-hybrid screen of a human heart library we identified ATMIN, an ATM kinase-interacting protein, as a DYNLL1-binding partner. Interestingly, ATMIN displays at least 18 SQ/TQ motifs in its sequence and DYNLL1 is known to bind to proteins with KXTQT motifs. Using pepscan and yeast two-hybrid techniques we show that DYNLL1 binds to multiple SQ/TQ motifs present in the carboxy-terminal domain of ATMIN. Recombinant expression and purification of the DYNLL1-binding region of ATMIN allowed us to obtain a polypeptide with an apparent molecular mass in gel filtration close to 400 kDa that could bind to DYNLL1 in vitro. The NMR data-driven modelled complexes of DYNLL1 with two selected ATMIN peptides revealed a similar mode of binding to that observed between DYNLL1 and other peptide targets. Remarkably, co-expression of mCherry-DYNLL1 and GFP-ATMIN mutually affected intracellular protein localization. In GFP-ATMIN expressing-cells DNA damage induced efficiently nuclear foci formation, which was partly impeded by the presence of mCherry-DYNLL1

  12. Expression and genomic analysis of midasin, a novel and highly conserved AAA protein distantly related to dynein

    Directory of Open Access Journals (Sweden)

    Gibbons I R

    2002-07-01

    Full Text Available Abstract Background The largest open reading frame in the Saccharomyces genome encodes midasin (MDN1p, YLR106p, an AAA ATPase of 560 kDa that is essential for cell viability. Orthologs of midasin have been identified in the genome projects for Drosophila, Arabidopsis, and Schizosaccharomyces pombe. Results Midasin is present as a single-copy gene encoding a well-conserved protein of ~600 kDa in all eukaryotes for which data are available. In humans, the gene maps to 6q15 and encodes a predicted protein of 5596 residues (632 kDa. Sequence alignments of midasin from humans, yeast, Giardia and Encephalitozoon indicate that its domain structure comprises an N-terminal domain (35 kDa, followed by an AAA domain containing six tandem AAA protomers (~30 kDa each, a linker domain (260 kDa, an acidic domain (~70 kDa containing 35–40% aspartate and glutamate, and a carboxy-terminal M-domain (30 kDa that possesses MIDAS sequence motifs and is homologous to the I-domain of integrins. Expression of hemagglutamin-tagged midasin in yeast demonstrates a polypeptide of the anticipated size that is localized principally in the nucleus. Conclusions The highly conserved structure of midasin in eukaryotes, taken in conjunction with its nuclear localization in yeast, suggests that midasin may function as a nuclear chaperone and be involved in the assembly/disassembly of macromolecular complexes in the nucleus. The AAA domain of midasin is evolutionarily related to that of dynein, but it appears to lack a microtubule-binding site.

  13. Identification of dynein light chain road block-1 as a novel interaction partner with the human reduced folate carrier.

    Science.gov (United States)

    Ashokkumar, Balasubramaniem; Nabokina, Svetlana M; Ma, Thomas Y; Said, Hamid M

    2009-09-01

    The reduced folate carrier (RFC) is a major folate transport system in mammalian cells. RFC is highly expressed in the intestine and believed to play a role in folate absorption. Studies from our laboratory and others have characterized different aspects of the intestinal folate absorption process, but little is known about possible existence of accessory protein(s) that interacts with RFC and influences its physiology and/or cell biology. We investigated this issue by employing a bacterial two-hybrid system to screen a BacterioMatch II human intestinal cDNA library using the large intracellular loop between transmembrane domains 6 and 7 of the human RFC (hRFC) as bait. Our screening has resulted in the identification of dynein light chain road block-1 (DYNLRB1) as an interacting partner with hRFC. Existence of a direct protein-protein interaction between hRFC and DYNLRB1 was confirmed by in vitro pull-down assay and in vivo mammalian two-hybrid luciferase assay and coimmunoprecipitation analysis. Furthermore, confocal imaging of live human intestinal epithelial HuTu-80 cells demonstrated colocalization of DYNLRB1 with hRFC. Coexpression of DYNLRB1 with hRFC led to a significant (P < 0.05) increase in folate uptake. On the other hand, inhibiting the endogenous DYNLRB1 with gene-specific small interfering RNA or pharmacologically with a specific inhibitor (vanadate) led to a significant (P < 0.05) decrease in folate uptake. This study demonstrates for the first time the identification of DYNLRB1 as an interacting protein partner with hRFC. Furthermore, DYNLRB1 appears to influence the function and cell biology of hRFC.

  14. RAPD and mitochondrial DNA analysis of the soybean stalk weevil, Sternechus subsignatus (Coleoptera: Curculionidae).

    Science.gov (United States)

    Sosa-Gomez, D R; Coronel, N; Binneck, E; Zucchi, M I; Rosado-Neto, G

    2008-10-01

    Sternechus subsignatus Boheman (Curculionidae: Sternechini) is one of the primary Curculionidae species that reduces soybean yield in Brazil. Initially, outbreaks were reported in southern Brazil in 1973; but, more recent, outbreaks were reported in Bahia (summer 1997-1998) and Maranhão (summer 2003-2004), two states in northeastern Brazil. A putative related species, S. pinguis (Fabricius), was first detected in Salta Province, Argentina. The objective of this study was to evaluate intraspecific molecular polymorphisms of geographically distinct Sternechus populations. Randomly amplified polymorphic DNA (RAPD) profiles and partial mitochondrial cytochrome B (CytB) gene sequences were used to determine whether individual soybean stalk weevils were one of two different species and to infer pest invasion pattern. Putative S. pinguis and S. subsignatus populations were collected in San Agustin (Cruz Alta, Tucumán Province, Argentina) and different sampling sites in the Brazilian states of Paraná, Bahia and Maranhão. Polymorphic bands were obtained by RAPD and analyzed by Dice coefficients. Populations from southern Brazil were more closely related genetically to an Argentinean group than the populations sampled in northeastern Brazil. The Londrina Co., Brazil population displayed the highest intra-population genetic similarity. Most of the soybean stalk weevils collected from San Agustin, Tucumán, Argentina were divergent from those collected in Brazil. Sequencing and parsimony analysis of CytB did not differentiate specimens collected in Argentina and Brazil. Thus, our data show that soybean stalk weevil outbreaks and population increases in northeastern Brazil involved local genotypes.

  15. Pituitary stalk interruption syndrome in Chinese people: clinical characteristic analysis of 55 cases.

    Directory of Open Access Journals (Sweden)

    Qinghua Guo

    Full Text Available OBJECTIVE: Pituitary stalk interruption syndrome (PSIS is characterized by the absence of pituitary stalk, pituitary hypoplasia, and ectopic posterior pituitary. Due to the rarity of PSIS, clinical data are limited, especially in Chinese people. Herein, we analyzed the clinical characteristics of patients diagnosed with PSIS from our center over 10 years. PATIENTS AND METHODS: We retrospectively analyzed the clinical manifestations and laboratory and MRI findings in 55 patients with PSIS. RESULTS: Of the 55 patients with PSIS, 48 (87.3% were male. The average age was 19.7±6.7 years and there was no familial case. A history of breech delivery was documented in 40 of 45 patients (88.9% and 19 of 55 patients (34.5% had a history of dystocia. Short stature was found in 47 of 55 patients (85.5% and bone age delayed 7.26±5.37 years. Secondary sex characteristics were poor or undeveloped in most patients. The prevalence of deficiencies in growth hormone, gonadotropins, corticotropin, and thyrotropin were 100%, 95.8%, 81.8%, 76.3%, respectively. Hyperprolactinemia was found in 36.4% of patients. Three or more pituitary hormone deficiencies were found in 92.7% of the patients. All patients had normal posterior pituitary function and absent pituitary stalk on imaging. The average height of anterior pituitary was 28 mm, documented anterior pituitary hypoplasia. Midline abnormalities were presented in 9.1% of patients. CONCLUSIONS: The clinical features of our Chinese PSIS patients seem to be different from other reported patients in regarding to the higher degree of hypopituitarism and lower prevalence of midline defects. In addition, our patients were older at the time of case detection and the bone age was markedly delayed. We also had no cases of familial PSIS.

  16. Ribosomal Stalk Protein Silencing Partially Corrects the ΔF508-CFTR Functional Expression Defect.

    Science.gov (United States)

    Veit, Guido; Oliver, Kathryn; Apaja, Pirjo M; Perdomo, Doranda; Bidaud-Meynard, Aurélien; Lin, Sheng-Ting; Guo, Jingyu; Icyuz, Mert; Sorscher, Eric J; Hartman Iv, John L; Lukacs, Gergely L

    2016-05-01

    The most common cystic fibrosis (CF) causing mutation, deletion of phenylalanine 508 (ΔF508 or Phe508del), results in functional expression defect of the CF transmembrane conductance regulator (CFTR) at the apical plasma membrane (PM) of secretory epithelia, which is attributed to the degradation of the misfolded channel at the endoplasmic reticulum (ER). Deletion of phenylalanine 670 (ΔF670) in the yeast oligomycin resistance 1 gene (YOR1, an ABC transporter) of Saccharomyces cerevisiae phenocopies the ΔF508-CFTR folding and trafficking defects. Genome-wide phenotypic (phenomic) analysis of the Yor1-ΔF670 biogenesis identified several modifier genes of mRNA processing and translation, which conferred oligomycin resistance to yeast. Silencing of orthologues of these candidate genes enhanced the ΔF508-CFTR functional expression at the apical PM in human CF bronchial epithelia. Although knockdown of RPL12, a component of the ribosomal stalk, attenuated the translational elongation rate, it increased the folding efficiency as well as the conformational stability of the ΔF508-CFTR, manifesting in 3-fold augmented PM density and function of the mutant. Combination of RPL12 knockdown with the corrector drug, VX-809 (lumacaftor) restored the mutant function to ~50% of the wild-type channel in primary CFTRΔF508/ΔF508 human bronchial epithelia. These results and the observation that silencing of other ribosomal stalk proteins partially rescue the loss-of-function phenotype of ΔF508-CFTR suggest that the ribosomal stalk modulates the folding efficiency of the mutant and is a potential therapeutic target for correction of the ΔF508-CFTR folding defect.

  17. Refining bioethanol from stalk juice of sweet sorghum by immobilized yeast fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ronghou; Shen, Fei [Biomass Energy Engineering Research Centre, School of Agriculture and Biology, Shanghai JiaoTong University, 2678 Qixin Road, Minhang District, Shanghai 201101 (China); Li, Jinxia [College of Engineering, Shenyang Agricultural University, 120 Dongling Road, Shenyang 110161 (China)

    2008-05-15

    The relationship between total soluble sugar content and Brix in stalk juice of sweet sorghum was determined through one-dimensional linear regression. Meanwhile, bioethanol fermentation experiments were conducted in shaking flasks and 10 l fluidized bed bioreactor with stalk juice of Yuantian No. 1 sweet sorghum cultivar when immobilized yeast was applied. The experimental results in the shaking flasks showed that the order of influence on improving ethanol yield was (NH{sub 4}){sub 2}SO{sub 4}>MgSO{sub 4}>K{sub 2}HPO{sub 4}, and the optimum inorganic salts supplement dose was determined as follows: K{sub 2}HPO{sub 4} 0%, (NH{sub 4}){sub 2}SO{sub 4} 0.2%, MgSO{sub 4} 0.05%. When the optimum inorganic salts supplement dose was used in fermentation in 10 l fluidized bed reactor, the fermentation time and ethanol content were 5 h and 6.2% (v/v), respectively, and ethanol yield was 91.61%, which was increased by 9.73% than blank. In addition, the results showed that the fermentation time was about 6-8 times shorter in fluidized bed bioreactor with immobilized yeast than that of conventional fermentation technology. As a result, it can be concluded that the determined optimum inorganic salts supplement dose could be used as a guide for commercial ethanol production. The fluidized bed bioreactor with immobilized yeast technology has a great potential for ethanol fermentation of stalk juice of sweet sorghum. (author)

  18. Ribosomal Stalk Protein Silencing Partially Corrects the ΔF508-CFTR Functional Expression Defect.

    Directory of Open Access Journals (Sweden)

    Guido Veit

    2016-05-01

    Full Text Available The most common cystic fibrosis (CF causing mutation, deletion of phenylalanine 508 (ΔF508 or Phe508del, results in functional expression defect of the CF transmembrane conductance regulator (CFTR at the apical plasma membrane (PM of secretory epithelia, which is attributed to the degradation of the misfolded channel at the endoplasmic reticulum (ER. Deletion of phenylalanine 670 (ΔF670 in the yeast oligomycin resistance 1 gene (YOR1, an ABC transporter of Saccharomyces cerevisiae phenocopies the ΔF508-CFTR folding and trafficking defects. Genome-wide phenotypic (phenomic analysis of the Yor1-ΔF670 biogenesis identified several modifier genes of mRNA processing and translation, which conferred oligomycin resistance to yeast. Silencing of orthologues of these candidate genes enhanced the ΔF508-CFTR functional expression at the apical PM in human CF bronchial epithelia. Although knockdown of RPL12, a component of the ribosomal stalk, attenuated the translational elongation rate, it increased the folding efficiency as well as the conformational stability of the ΔF508-CFTR, manifesting in 3-fold augmented PM density and function of the mutant. Combination of RPL12 knockdown with the corrector drug, VX-809 (lumacaftor restored the mutant function to ~50% of the wild-type channel in primary CFTRΔF508/ΔF508 human bronchial epithelia. These results and the observation that silencing of other ribosomal stalk proteins partially rescue the loss-of-function phenotype of ΔF508-CFTR suggest that the ribosomal stalk modulates the folding efficiency of the mutant and is a potential therapeutic target for correction of the ΔF508-CFTR folding defect.

  19. 玉米秸秆及纤维素高值化应用的研究进展%Research progress on the high-valuable applications of corn stalks and corn stalks cellulose

    Institute of Scientific and Technical Information of China (English)

    王犇; 潘高峰; 黄科林

    2014-01-01

    文章从玉米产业废弃物玉米秸秆的应用出发,对玉米秸秆从传统方面进行总结,对玉米秸秆纤维素从降解、再生和制备吸附材料三个角度进行高值化应用的综述。%Starting From the applications of corn industry waste corn stalks, This paper summarizes from corn stover traditionally, then the high-value applications of corn stalk cellulose was reviewed from degradation, regeneration and the preparation of the adsorbent material.

  20. Diversity of microorganisms in decaying maize stalks revealed by a molecular method.

    Science.gov (United States)

    Yang, Ming-Xia; Zhang, Han-Bo

    2007-08-01

    Microbial diversity in decaying maize stalk was characterized by constructing and analyzing rRNA gene clone library. Total 47 OTUs were obtained from 82 bacterial clones, including Proteobacteria (64.6%), Actinobacteria (30.5%), Bacteroidetes (2.4%) and Firmicutes (2.4%). Most proteobacterial clones were members of Rhizobium, Pseudomonas and Stenotrophomonas. Eighty-four percent of Actinobacteria was related to Microbacterium. Only 14 OTUs were identified from 124 fungal clones, including Ascomycota (88%) and Basidiomycota (12%). Sixty percent of Ascomycota were members of Eupenicillium and Paecilomyces but all Basidiomycota were close to Kurtzmanomyces nectairei.

  1. Contraction behaviors of Vorticella sp. stalk investigated using high-speed video camera. I: Nucleation and growth model.

    Science.gov (United States)

    Kamiguri, Junko; Tsuchiya, Noriko; Hidema, Ruri; Tachibana, Masatoshi; Yatabe, Zenji; Shoji, Masahiko; Hashimoto, Chihiro; Pansu, Robert Bernard; Ushiki, Hideharu

    2012-01-01

    The contraction process of living Vorticella sp. has been investigated by image processing using a high-speed video camera. In order to express the temporal change in the stalk length resulting from the contraction, a damped spring model and a nucleation and growth model are applied. A double exponential is deduced from a conventional damped spring model, while a stretched exponential is newly proposed from a nucleation and growth model. The stretched exponential function is more suitable for the curve fitting and suggests a more particular contraction mechanism in which the contraction of the stalk begins near the cell body and spreads downwards along the stalk. The index value of the stretched exponential is evaluated in the range from 1 to 2 in accordance with the model in which the contraction undergoes through nucleation and growth in a one-dimensional space.

  2. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head uses ... of the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive medical ...

  3. High-resolution heavily T2-weighted magnetic resonance imaging for evaluation of the pituitary stalk in children with ectopic neurohypophysis

    Energy Technology Data Exchange (ETDEWEB)

    Sanharawi, Imane El; Tzarouchi, Loukia [Hopital Robert Debre, APHP, Service de Radiologie Pediatrique, Paris (France); Cardoen, Liesbeth [Hopital Robert Debre, APHP, Service de Radiologie Pediatrique, Paris (France); Universite Paris Diderot, Paris (France); Martinerie, Laetitia; Leger, Juliane; Carel, Jean-Claude [Universite Paris Diderot, Paris (France); Inserm U1141, DHU PROTECT, Paris (France); Hopital Robert Debre, APHP, Service d' Endocrinologie Pediatrique, Paris (France); Elmaleh-Berges, Monique [Hopital Robert Debre, APHP, Service de Radiologie Pediatrique, Paris (France); Inserm U1141, DHU PROTECT, Paris (France); Alison, Marianne [Hopital Robert Debre, APHP, Service de Radiologie Pediatrique, Paris (France); Universite Paris Diderot, Paris (France); Inserm U1141, DHU PROTECT, Paris (France)

    2017-05-15

    In anterior pituitary deficiency, patients with non visible pituitary stalk have more often multiple deficiencies and persistent deficiency than patients with visible pituitary stalk. To compare the diagnostic value of a high-resolution heavily T2-weighted sequence to 1.5-mm-thick unenhanced and contrast-enhanced sagittal T1-weighted sequences to assess the presence of the pituitary stalk in children with ectopic posterior pituitary gland. We retrospectively evaluated the MRI data of 14 children diagnosed with ectopic posterior pituitary gland between 2010 and 2014. We evaluated the presence of a pituitary stalk using a sagittal high-resolution heavily T2-weighted sequence and a 1.5-mm sagittal T1-weighted turbo spin-echo sequence before and after contrast medium administration. A pituitary stalk was present on at least one of the sequences in 10 of the 14 children (71%). T2-weighted sequence depicted the pituitary stalk in all 10 children, whereas the 1.5-mm-thick T1-weighted sequence depicted 2/10 (20%) before contrast injection and 8/10 (80%) after contrast injection (P=0.007). Compared with 1.5-mm-thick contrast-enhanced T1-weighted sequences, high-resolution heavily T2-weighted sequence demonstrates better sensitivity in detecting the pituitary stalk in children with ectopic posterior pituitary gland, suggesting that contrast injection is unnecessary to assess the presence of a pituitary stalk in this setting. (orig.)

  4. Evidence of the Most Stretchable Egg Sac Silk Stalk, of the European Spider of the Year Meta menardi

    Science.gov (United States)

    Lepore, Emiliano; Marchioro, Andrea; Isaia, Marco; Buehler, Markus J.; Pugno, Nicola M.

    2012-01-01

    Spider silks display generally strong mechanical properties, even if differences between species and within the same species can be observed. While many different types of silks have been tested, the mechanical properties of stalks of silk taken from the egg sac of the cave spider Meta menardi have not yet been analyzed. Meta menardi has recently been chosen as the “European spider of the year 2012”, from the European Society of Arachnology. Here we report a study where silk stalks were collected directly from several caves in the north-west of Italy. Field emission scanning electron microscope (FESEM) images showed that stalks are made up of a large number of threads, each of them with diameter of 6.03±0.58 µm. The stalks were strained at the constant rate of 2 mm/min, using a tensile testing machine. The observed maximum stress, strain and toughness modulus, defined as the area under the stress-strain curve, are 0.64 GPa, 751% and 130.7 MJ/m3, respectively. To the best of our knowledge, such an observed huge elongation has never been reported for egg sac silk stalks and suggests a huge unrolling microscopic mechanism of the macroscopic stalk that, as a continuation of the protective egg sac, is expected to be composed by fibres very densely and randomly packed. The Weibull statistics was used to analyze the results from mechanical testing, and an average value of Weibull modulus (m) is deduced to be in the range of 1.5–1.8 with a Weibull scale parameter (σ0) in the range of 0.33–0.41 GPa, showing a high coefficient of correlation (R2 = 0.97). PMID:22347380

  5. Evidence of the most stretchable egg sac silk stalk, of the European spider of the year Meta menardi.

    Directory of Open Access Journals (Sweden)

    Emiliano Lepore

    Full Text Available Spider silks display generally strong mechanical properties, even if differences between species and within the same species can be observed. While many different types of silks have been tested, the mechanical properties of stalks of silk taken from the egg sac of the cave spider Meta menardi have not yet been analyzed. Meta menardi has recently been chosen as the "European spider of the year 2012", from the European Society of Arachnology. Here we report a study where silk stalks were collected directly from several caves in the north-west of Italy. Field emission scanning electron microscope (FESEM images showed that stalks are made up of a large number of threads, each of them with diameter of 6.03 ± 0.58 µm. The stalks were strained at the constant rate of 2 mm/min, using a tensile testing machine. The observed maximum stress, strain and toughness modulus, defined as the area under the stress-strain curve, are 0.64 GPa, 751% and 130.7 MJ/m(3, respectively. To the best of our knowledge, such an observed huge elongation has never been reported for egg sac silk stalks and suggests a huge unrolling microscopic mechanism of the macroscopic stalk that, as a continuation of the protective egg sac, is expected to be composed by fibres very densely and randomly packed. The Weibull statistics was used to analyze the results from mechanical testing, and an average value of Weibull modulus (m is deduced to be in the range of 1.5-1.8 with a Weibull scale parameter (σ(0 in the range of 0.33-0.41 GPa, showing a high coefficient of correlation (R(2 = 0.97.

  6. Steam explosion distinctively enhances biomass enzymatic saccharification of cotton stalks by largely reducing cellulose polymerization degree in G. barbadense and G. hirsutum.

    Science.gov (United States)

    Huang, Yu; Wei, Xiaoyang; Zhou, Shiguang; Liu, Mingyong; Tu, Yuanyuan; Li, Ao; Chen, Peng; Wang, Yanting; Zhang, Xuewen; Tai, Hongzhong; Peng, Liangcai; Xia, Tao

    2015-04-01

    In this study, steam explosion pretreatment was performed in cotton stalks, leading to 5-6 folds enhancements on biomass enzymatic saccharification distinctive in Gossypium barbadense and Gossypium hirsutum species. Sequential 1% H2SO4 pretreatment could further increase biomass digestibility of the steam-exploded stalks, and also cause the highest sugar-ethanol conversion rates probably by releasing less inhibitor to yeast fermentation. By comparison, extremely high concentration alkali (16% NaOH) pretreatment with raw stalks resulted in the highest hexoses yields, but it had the lowest sugar-ethanol conversion rates. Characterization of wall polymer features indicated that biomass saccharification was enhanced with steam explosion by largely reducing cellulose DP and extracting hemicelluloses. It also showed that cellulose crystallinity and arabinose substitution degree of xylans were the major factors on biomass digestibility in cotton stalks. Hence, this study has provided the insights into cell wall modification and biomass process technology in cotton stalks and beyond.

  7. Late steps in cytoplasmic maturation of assembly-competent axonemal outer arm dynein in Chlamydomonas require interaction of ODA5 and ODA10 in a complex.

    Science.gov (United States)

    Dean, Anudariya B; Mitchell, David R

    2015-10-15

    Axonemal dyneins are multisubunit enzymes that must be preassembled in the cytoplasm, transported into cilia by intraflagellar transport, and bound to specific sites on doublet microtubules, where their activity facilitates microtubule sliding-based motility. Outer dynein arms (ODAs) require assembly factors to assist their preassembly, transport, and attachment to cargo (specific doublet A-tubule sites). In Chlamydomonas, three assembly factors--ODA5, ODA8, and ODA10--show genetic interactions and have been proposed to interact in a complex, but we recently showed that flagellar ODA8 does not copurify with ODA5 or ODA10. Here we show that ODA5 and ODA10 depend on each other for stability and coexist in a complex in both cytoplasmic and flagellar extracts. Immunofluorescence and immuno-electron microscopy reveal that ODA10 in flagella localizes strictly to a proximal region of doublet number 1, which completely lacks ODAs in Chlamydomonas. Studies of the in vitro binding of ODAs to axonemal doublets reveal a role for the ODA5/ODA10 assembly complex in cytoplasmic maturation of ODAs into a form that can bind to doublet microtubules.

  8. The subcellular distribution of the human ribosomal "stalk" components: P1, P2 and P0 proteins

    DEFF Research Database (Denmark)

    Tchórzewski, Marek; Krokowski, Dawid; Rzeski, Wojciech;

    2003-01-01

    The ribosomal "stalk" structure is a distinct lateral protuberance located on the large ribosomal subunit in prokaryotic, as well as in eukaryotic cells. In eukaryotes, this ribosomal structure is composed of the acidic ribosomal P proteins, forming two hetero-dimers (P1/P2) attached......-proteins that are not actively transported into the nucleus; moreover, this might imply that the "stalk" constituents are assembled onto the ribosomal particle at the very last step of ribosomal maturation, which takes part in the cell cytoplasm....

  9. Optimization of corn-stalk skin flake-wood shaving composite technology

    Institute of Scientific and Technical Information of China (English)

    Haixiang Lu; Xianquan Zhang; Bo Yu

    2015-01-01

    We focused on the optimization of corn-stalk skin flake-wood shaving composite technology. We studied the effects of material-mixture ratio, glue content, hot-pressing temperature, and hot-pressing time on the appear-ance, physical, and mechanical properties of the composite by the orthogonal experiment method. Our findings yielded highly significant results in all three cases:the effects of the material-mixture ratio on 2 h of thickness swelling (2hTS) and the modulus of rupture (MOR);the effects of glue con-tent on 2hTS, internal bond strength, and modulus of elas-ticity (MOE);and the effects of hot-pressing temperature on MOR and MOE. Product optimization is achieved when the ratio of corn stalk skin flake to wood shaving is 3:7, the glue content is 12%, the hot-pressing temperature is 150 ?C, and the hot-pressing time is 4.5 min.

  10. Secretome analysis of Pleurotus eryngii reveals enzymatic composition for ramie stalk degradation.

    Science.gov (United States)

    Xie, Chunliang; Luo, Wei; Li, Zhimin; Yan, Li; Zhu, Zuohua; Wang, Jing; Hu, Zhenxiu; Peng, Yuande

    2016-01-01

    Pleurotus eryngii (P. eryngii) can secrete large amount of hydrolytic and oxidative enzymes to degrade lignocellulosic biomass. In spite of several researches on the individual lignolytic enzymes, a direct deconstruction of lignocellulose by enzyme mixture is not yet possible. Identifying more high-performance enzymes or enzyme complexes will lead to efficient in vitro lignocelluloses degradation. In this report, secretomic analysis was used to search for the new or interesting enzymes for lignocellulose degradation. Besides, the utilization ability of P. eryngii to ramie stalk substrate was evaluated from the degradation of cellulose, hemicellulose, and lignin in medium and six extracellular enzymes activities during different growth stages were discussed. The results showed that a high biological efficiency of 71% was obtained; cellulose, hemicelluloses, and lignin decomposition rates of P. eryngii were 29.2, 26.0, and 51.2%, respectively. Enzyme activity showed that carboxymethyl cellulase, xylanase, laccase, and peroxidase activity peaks appeared at the primordial initiation stage. In addition, we profiled a global view of the secretome of P. eryngii cultivated in ramie stalk media to understand the mechanism behind lignocellulosic biomass hydrolysis. Eighty-seven nonredundant proteins were identified and a diverse group of enzymes, including cellulases, hemicellulases, pectinase, ligninase, protease, peptidases, and phosphatase implicated in lignocellulose degradation were found. In conclusion, the information in this report will be helpful to better understand the lignocelluloses degradation mechanisms of P. eryngii.

  11. Ethanol production from the enzymatic hydrolysis of non-detoxified steam-exploded corn stalk.

    Science.gov (United States)

    Yang, Xiushan; Zhang, Sijin; Zuo, Zhuang; Men, Xun; Tian, Shen

    2011-09-01

    To reduce water consumption and equipment investment, and simplify the technological process, a Pichia stipitis-adapted strain with improved tolerance against inhibitors and ethanol was used in ethanol production. The steam-exploded corn stalk was directly enzymatically hydrolyzed without detoxification, and then the enzymatic hydrolysate was used as the fermentation substrate. Results from laboratory experiments in shake flasks and fermentation tanks indicated that, after fermentation for 48 h, ethanol concentration reached to 43.42 g/L; the ethanol yield was 0.47 g(p)/g(s), which was 92.16% of the theoretical ethanol yield. The results of the present research demonstrated that the application of this strain avoided detoxification of the steam-pretreated material through washing, thus simplifying the technological process. In addition, the application of the adapted strain reduced water consumption and lowered the equipment investment of ethanol production from corn stalk, which are important factors in further promotion of the development of ethanol production from straw.

  12. Ethanol production from concentrated food waste hydrolysates with yeast cells immobilized on corn stalk.

    Science.gov (United States)

    Yan, Shoubao; Chen, Xiangsong; Wu, Jingyong; Wang, Pingchao

    2012-05-01

    The aim of the present study was to examine ethanol production from concentrated food waste hydrolysates using whole cells of S. cerevisiae immobilized on corn stalks. In order to improve cell immobilization efficiency, biological modification of the carrier was carried out by cellulase hydrolysis. The results show that proper modification of the carrier with cellulase hydrolysis was suitable for cell immobilization. The mechanism proposed, cellulase hydrolysis, not only increased the immobilized cell concentration, but also disrupted the sleek surface to become rough and porous, which enhanced ethanol production. In batch fermentation with an initial reducing sugar concentration of 202.64 ± 1.86 g/l, an optimal ethanol concentration of 87.91 ± 1.98 g/l was obtained using a modified corn stalk-immobilized cell system. The ethanol concentration produced by the immobilized cells was 6.9% higher than that produced by the free cells. Ethanol production in the 14th cycle repeated batch fermentation demonstrated the enhanced stability of the immobilized yeast cells. Under continuous fermentation in an immobilized cell reactor, the maximum ethanol concentration of 84.85 g/l, and the highest ethanol yield of 0.43 g/g (of reducing sugar) were achieved at hydraulic retention time (HRT) of 3.10 h, whereas the maximum volumetric ethanol productivity of 43.54 g/l/h was observed at a HRT of 1.55 h.

  13. An environment-friendly thermal insulation material from cotton stalk fibers

    Energy Technology Data Exchange (ETDEWEB)

    Xiao-yan Zhou; Fei Zheng; Hua-guan Li; Cheng-long Lu [College of Wood Science and Technology, Nanjing Forestry University, No. 159 Longpan Road, Nanjing 210037 (China)

    2010-07-15

    A new environment-friendly thermal insulation material - binderless cotton stalk fiberboard (BCSF) made from cotton stalk fibers with no chemical additives was developed using high frequency hot-pressing. The goal of this paper was to investigate the effect of board density, fiber moisture content (MC) and pressing time on thermal conductivity and mechanical properties of BCSF. The results showed that the board with a density of 150-450 kg/m{sup 3} had the thermal conductivity values ranging from 0.0585 to 0.0815 W/m K, which was close to that of the expanded perlite and vermiculite within the same density range. The thermal conductivity values had a strong linear correlation with the board density. The internal bonding strength (IBS) of boards was good at the relatively low-density level, which can be significantly improved with increasing the fiber MC and prolonging pressing time. The same trend was observed for modulus of rapture (MOR) and modulus of elasticity (MOE) of the boards. As an environment-friendly and renewable material, the BCSF is particularly suitable for ceiling and wall applications to save energy. (author)

  14. Stalk and sucrose yield in response to nitrogen fertilization of sugarcane under reduced tillage

    Directory of Open Access Journals (Sweden)

    Caio Fortes

    2013-01-01

    Full Text Available The objective of this work was to evaluate the agroindustrial production of sugarcane (millable stalks and sucrose yield after successive nitrogen fertilizations of plant cane and ratoons in a reduced tillage system. The experiment was carried out at Jaboticabal, SP, Brazil, on a Rhodic Eutrustox soil, during four consecutive crop cycles (March 2005 to July 2009. Plant cane treatments consisted of N-urea levels (control, 40, 80, and 120 kg ha-1 N + 120 kg ha-1 P2O5 and K2O in furrow application. In the first and second ratoons, the plant cane plots were subdivided in N-ammonium nitrate treatments (control, 50, 100, and 150 kg ha-1 N + 150 kg ha-1 K2O as top dressing over rows. In the third ratoon, N fertilization was leveled to 100 kg ha-1 in all plots, including controls, to detect residual effects of previous fertilizations on the last crop's cycle. Sugarcane ratoon was mechanically harvested. A weighing truck was used to evaluate stalk yield (TCH, and samples were collected in the field for analysis of sugar content (TSH. Increasing N doses and meteorological conditions promote significant responses in TCH and TSH in cane plant and ratoons, in the average and accumulated yield of the consecutive crop cycles.

  15. Grape stalks as substrate for white rot fungi, lignocellulolytic enzyme production and dye decolorization.

    Science.gov (United States)

    Levin, Laura; Diorio, Luis; Grassi, Emanuel; Forchiassin, Flavia

    2012-01-01

    The aim of this work was to evaluate the potential of grape stalks, an agroindustrial waste, for growth and lignocellulolytic enzyme production via solid-state fermentation, using the following three white rot fungi: Trametes trogii, Stereum hirsutum and Coriolus antarcticus. The decolorization of several dyes by the above mentioned cultures was also investigated. Similar values of dry weight loss of the substrate were measured after 60 days (33-43 %). C. antarcticus produced the highest laccase and Mn-peroxidase activities (33.0 and 1.6 U/g dry solid). The maximum endoglucanase production was measured in S. hirsutum cultures (10.4 U/g), while the endoxylanase peak corresponded to T. trogii (14.6 U/g). The C. antarcticus/grape stalk system seems potentially competitive in bioremediation of textile processing effluents, attaining percentages of decolorization of 93, 86, 82, 82, 77, and 58% for indigo carmine, malachite green, azure B, remazol brilliant blue R, crystal violet and xylidine, respectively, in 5 h.

  16. [Phenolic foam prepared by lignin from a steam-explosion derived biorefinery of corn stalk].

    Science.gov (United States)

    Wang, Guanhua; Chen, Hongzhang

    2014-06-01

    To increase the integral economic effectiveness, biorefineries of lignocellulosic materials should not only utilize carbohydrates hydrolyzed from cellulose and hemicellulose but also use lignin. We used steam-exploded corn stalk as raw materials and optimized the temperature and alkali concentration in the lignin extraction process to obtain lignin liquor with higher yield and purity. Then the concentrated lignin liquor was used directly to substitute phenol for phenolic foam preparation and the performances of phenolic foam were characterized by microscopic structure analysis, FTIR, compression strength and thermal conductivity detection. The results indicated that, when steam-exploded corn stalk was extracted at 120 degrees C for 2 h by 1% NaOH with a solid to liquid ratio of 1:10, the extraction yield of lignin was 79.67%. The phenolic foam prepared from the concentrated lignin liquor showed higher apparent density and compression strength with the increasing substitution rate of lignin liquor. However, there were not significant differences of thermal conductivity and flame retardant properties by the addition of lignin, which meant that the phenolic foam substituted by lignin liquor was approved for commercial application. This study, which uses alkali-extracted lignin liquor directly for phenolic foam preparation, provides a relatively simple way for utilization of lignin and finally increases the overall commercial operability ofa lignocellulosic biorefinery derived by steam explosion.

  17. Mass transfer during osmotic dehydration of celery stalks in a batch osmo-reactor

    Science.gov (United States)

    Sareban, M.; Abbasi Souraki, B.

    2017-03-01

    In this study, dehydration behavior of bulk of celery stalks, during osmotic drying in a limited volume of salt solution, was investigated. Experiments were carried out in the three initial solution concentrations of 10, 18 and 25 % (w/w) and at the three temperatures of 35, 45 and 55 °C. The volume ratio of the fruit to the solution was considered 1:3. A two-parameter model was used for prediction of kinetics of mass transfer and values of equilibrium moisture loss and solid gain. Moisture and salt effective diffusivities in celery stalks were estimated by fitting the experimental data of moisture loss and solute gain to the analytical solution of Fick's second law of diffusion. The analytical model was solved by defining a partition factor, K, assuming that the concentration of solute just within the surface of the material is K times that in the solution. Results showed that moisture and salt effective diffusivities and equilibrium values of moisture loss and solute gain increased with increasing the temperature and solution concentration. Results showed a good agreement between the two parameter model (with mean relative error of 4.016 % for moisture loss and 5.977 % for solid gain), analytical solution of Fick's second law (with mean relative error of 8.924 % for moisture loss and 9.164 % for solid gain) and experimental data.

  18. Rhamnolipid Biosurfactant against Fusarium verticillioides to Control Stalk and Ear Rot Disease of Maize.

    Science.gov (United States)

    Borah, Siddhartha N; Goswami, Debahuti; Sarma, Hridip K; Cameotra, Swaranjit S; Deka, Suresh

    2016-01-01

    Antifungal activity of rhamnolipids (RLs) has been widely studied against many plant pathogenic fungi, but not against Fusarium verticillioides, a major pathogen of maize (Zea mays L.). F. verticillioides causes stalk and ear rot of maize or asymptomatically colonizes the plant and ears resulting in moderate to heavy crop loss throughout the world. F. verticillioides produces fumonisin mycotoxins, reported carcinogens, which makes the contaminated ears unsuitable for consumption. In this study, the RL produced using glucose as sole carbon source was characterized by FTIR and LCMS analyses and its antifungal activity against F. verticillioides was evaluated in vitro on maize stalks and seeds. Further, the effect of RL on the mycelia of F. verticillioides was investigated by scanning electron microscopy which revealed visible damage to the mycelial structure as compared to control samples. In planta, treatment of maize seeds with a RL concentration of 50 mg l(-1) resulted in improved biomass and fruiting compared to those of healthy control plants and complete suppression of characteristic disease symptoms and colonization of maize by F. verticillioides. The study highlights the potential of RLs to be used for an effective biocontrol strategy against colonization of maize plant by F. verticillioides.

  19. Chemical modification of glycerinated stalks shows tyrosine residues essential for spasmoneme contraction of Vorticella sp.

    Science.gov (United States)

    Fang, Jie; Zhang, Bei; Chen, Ning; Asai, Hiroshi

    2004-05-01

    Chemical modification of glycerinated stalks of Vorticella with TNM is used to investigate the role of tyrosine residues in the Ca(2+)-induced contraction of the spasmoneme. Tetranitromethane (TNM) is often employed as a specific reagent for the nitration of tyrosine residues in a protein at neutral and slightly alkaline pHs although TNM can also oxidize cysteine residues in the acidic and neutral pH range. Prior incubation with Ca(2+) of stalks to be treated with TNM can protect the spasmoneme from irreversible denaturation. On the other hand, TNM treatment in the absence of free Ca(2+) causes an irreversible denaturation of the spasmoneme. It was revealed by us that an isolated Ca(2+)-binding protein called spasmin could not bind with Ca(2+) after TNM treatment, even if the treatment was performed in the presence of Ca(2+). In an additional experiment, we confirmed that the chemical modification of cysteine residues in the spasmoneme with N-7-dimethyl-amino-4methyl- coumarinyl- maleimide (DACM) has no effect on the contractibility. These results suggest that tyrosine residues in spasmin are essential for spasmoneme contraction and are protected from TNM in the presence of Ca(2+) when spasmin binds with its receptor protein in the spasmoneme.

  20. Occult Langerhans Cell Histiocytosis Presenting with Papillary Thyroid Carcinoma, a Thickened Pituitary Stalk and Diabetes Insipidus

    Science.gov (United States)

    2016-01-01

    Etiologies of a thickened stalk include inflammatory, neoplastic, and idiopathic origins, and the underlying diagnosis may remain occult. We report a patient with a thickened pituitary stalk (TPS) and papillary thyroid carcinoma (PTC) whose diagnosis remained obscure until a skin lesion appeared. The patient presented with PTC, status postthyroidectomy, and I131 therapy. PTC molecular testing revealed BRAF mutant (V600E, GTC>GAG). She had a 5-year history of polyuria/polydipsia. Overnight dehydration study confirmed diabetes insipidus (DI). MRI revealed TPS with loss of the posterior pituitary bright spot. Evaluation showed hypogonadotropic hypogonadism and low IGF-1. Chest X-ray and ACE levels were normal. Radiographs to evaluate for extrapituitary sites of Langerhans Cell Histiocytosis (LCH) were unremarkable. Germinoma studies were negative: normal serum and CSF beta-hCG, alpha-fetoprotein, and CEA. Three years later, the patient developed vulvar labial lesions followed by inguinal region skin lesions, biopsy of which revealed LCH. Reanalysis of thyroid pathology was consistent with concurrent LCH, PTC, and Hashimoto's thyroiditis within the thyroid. This case illustrates that one must be vigilant for extrapituitary manifestations of systemic diseases to diagnose the etiology of TPS. An activating mutation of the protooncogene BRAF is a potential unifying etiology of both PTC and LCH. PMID:27656301

  1. Colonization of Fiber Cells by Colletotrichum graminicola in Wounded Maize Stalks.

    Science.gov (United States)

    Venard, C; Vaillancourt, L

    2007-04-01

    ABSTRACT Colonization of wounded maize stalks by a wild-type strain of Colletotrichum graminicola was compared with colonization by a C. graminicola mutant that is avirulent on maize leaves, and by a wild-type strain of C. sublineolum that is normally a pathogen of sorghum but not maize. Local infection by all strains at the wound site resulted in formation of primary lesions consisting of disintegrated parenchyma cells beneath an intact rind and epidermis. However, subsequent rapid longitudinal expansion of the primary lesion occurred only in infections with the wild-type C. graminicola strain, and proceeded specifically through the fiber cells associated with the vascular bundles and the rind. Hyphae emerged from the fiber cells to produce discontinuous secondary lesions. There was no evidence that C. graminicola is a vascular wilt pathogen. Resistance of wounded cv. Jubilee maize stalks to the mutant strain of C. graminicola and to C. sublineolum was associated with restriction of colonization and spread of the pathogen through the fibers, as well as with the limitation of localized destruction of parenchyma cells at the wound site.

  2. Ethanol production from concentrated food waste hydrolysates with yeast cells immobilized on corn stalk

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Shoubao [Huainan Normal Univ., Anhui (China). School of Life Science; Chen, Xiangsong; Wu, Jingyong; Wang, Pingchao [Chinese Academy of Sciences, Hefei (China). Key Lab. of Ion Beam Bio-engineering of Inst. of Plasma Physics

    2012-05-15

    The aim of the present study was to examine ethanol production from concentrated food waste hydrolysates using whole cells of S. cerevisiae immobilized on corn stalks. In order to improve cell immobilization efficiency, biological modification of the carrier was carried out by cellulase hydrolysis. The results show that proper modification of the carrier with cellulase hydrolysis was suitable for cell immobilization. The mechanism proposed, cellulase hydrolysis, not only increased the immobilized cell concentration, but also disrupted the sleek surface to become rough and porous, which enhanced ethanol production. In batch fermentation with an initial reducing sugar concentration of 202.64 {+-} 1.86 g/l, an optimal ethanol concentration of 87.91 {+-} 1.98 g/l was obtained using a modified corn stalk-immobilized cell system. The ethanol concentration produced by the immobilized cells was 6.9% higher than that produced by the free cells. Ethanol production in the 14th cycle repeated batch fermentation demonstrated the enhanced stability of the immobilized yeast cells. Under continuous fermentation in an immobilized cell reactor, the maximum ethanol concentration of 84.85 g/l, and the highest ethanol yield of 0.43 g/g (of reducing sugar) were achieved at hydraulic retention time (HRT) of 3.10 h, whereas the maximum volumetric ethanol productivity of 43.54 g/l/h was observed at a HRT of 1.55 h. (orig.)

  3. Rhamnolipid Biosurfactant against Fusarium verticillioides to Control Stalk and Ear Rot Disease of Maize

    Directory of Open Access Journals (Sweden)

    Siddhartha Narayan Borah

    2016-09-01

    Full Text Available Antifungal activity of rhamnolipids (RLs has been widely studied against many plant pathogenic fungi, but not against Fusarium verticillioides, a major pathogen of maize (Zea mays L.. F. verticillioides causes stalk and ear rot of maize or asymptomatically colonizes the plant and ears resulting in moderate to heavy crop loss throughout the world. F. verticillioides produces fumonisin mycotoxins, reported carcinogens, which makes the contaminated ears unsuitable for consumption. In this study, the RL produced using glucose as sole carbon source was characterized by FTIR and LCMS analyses and its antifungal activity against F. verticillioides was evaluated in vitro on maize stalks and seeds. Further, the effect of RL on the mycelia of F. verticillioides was investigated by scanning electron microscopy which revealed visible damage to the mycelial structure as compared to control samples. In planta, treatment of maize seeds with a RL concentration of 50 mg l-1 resulted in improved biomass and fruiting compared to those of healthy control plants and complete suppression of characteristic disease symptoms and colonization of maize by F. verticillioides. The study highlights the potential of RLs to be used for an effective biocontrol strategy against colonization of maize plant by F. verticillioides.

  4. Isolation and Structural Characterization of Lignin from Cotton Stalk Treated in an Ammonia Hydrothermal System

    Science.gov (United States)

    Kang, Sumin; Xiao, Lingping; Meng, Lingyan; Zhang, Xueming; Sun, Runcang

    2012-01-01

    To investigate the potential for the utilization of cotton stalk, ammonia hydrothermal treatment was applied to fractionate the samples into aqueous ammonia-soluble and ammonia-insoluble portions. The ammonia-soluble portion was purified to yield lignin fractions. The lignin fractions obtained were characterized by wet chemistry (carbohydrate analysis) and spectroscopy methods (FT-IR, 13C and 1H-13C HSQC NMR spectroscopy) as well as gel permeation chromatography (GPC). The results showed that the cotton stalk lignin fractions were almost absent of neutral sugars (0.43%–1.29%) and had relatively low average molecular weights (1255–1746 g/mol). The lignin fractions belonged to typical G-S lignin, which was composed predominately of G-type units (59%) and noticeable amounts of S-type units (40%) together with a small amount of H-type units (~1%). Furthermore, the ammonia-extractable lignin fractions were mainly composed of β-O-4′ inter-unit linkages (75.6%), and small quantities of β-β′ (12.2%), together with lower amounts of β-5′ carbon-carbon linkages (7.4%) and p-hydroxycinnamyl alcohol end groups. PMID:23203120

  5. Characterization of vine shoots, cotton stalks, Leucaena leucocephala and Chamaecytisus proliferus, and of their ethyleneglycol pulps.

    Science.gov (United States)

    Jiménez, Luis; Pérez, Antonio; de la Torre, María Jesús; Moral, Ana; Serrano, Luis

    2007-12-01

    We characterized vine shoots, cotton stalks, Leucaena leucocephala and Chamaecytisus proliferus as pulping raw materials and found C. proliferus and cotton stalks to be the best for the intended purpose on the grounds of their increased contents in holocellulose (79.73% and 72.86%) and alpha-cellulose (45.37% and 58.48%), and their decreased contents in ethanol-benzene extractables (2.64% and 1.42%), hot water solubles (2.79% and 3.33%) and 1% soda solubles (16.67% and 20.34%). These properties resulted in increased pulp yields and hence in efficient use of these two types of raw material. The previous raw materials were pulped by using an ethyleneglycol concentration of 65% at 180 degrees C for 75min, followed by beating at 1500 revolutions in a PFI refiner. The paper sheets obtained were characterized and those from C. proliferus found to be the best overall as they exhibited an increased breaking length (4644m), stretch (2.87%), burst index (2.46kN/g) tear index (0.33mNm(2)/g) and brightness (49.92% ISO); in addition C. proliferus pulp was obtained with a high-yield (62.88%). On the other hand, vine shoots provided the poorest results among the studied raw materials.

  6. Rhamnolipid Biosurfactant against Fusarium verticillioides to Control Stalk and Ear Rot Disease of Maize

    Science.gov (United States)

    Borah, Siddhartha N.; Goswami, Debahuti; Sarma, Hridip K.; Cameotra, Swaranjit S.; Deka, Suresh

    2016-01-01

    Antifungal activity of rhamnolipids (RLs) has been widely studied against many plant pathogenic fungi, but not against Fusarium verticillioides, a major pathogen of maize (Zea mays L.). F. verticillioides causes stalk and ear rot of maize or asymptomatically colonizes the plant and ears resulting in moderate to heavy crop loss throughout the world. F. verticillioides produces fumonisin mycotoxins, reported carcinogens, which makes the contaminated ears unsuitable for consumption. In this study, the RL produced using glucose as sole carbon source was characterized by FTIR and LCMS analyses and its antifungal activity against F. verticillioides was evaluated in vitro on maize stalks and seeds. Further, the effect of RL on the mycelia of F. verticillioides was investigated by scanning electron microscopy which revealed visible damage to the mycelial structure as compared to control samples. In planta, treatment of maize seeds with a RL concentration of 50 mg l-1 resulted in improved biomass and fruiting compared to those of healthy control plants and complete suppression of characteristic disease symptoms and colonization of maize by F. verticillioides. The study highlights the potential of RLs to be used for an effective biocontrol strategy against colonization of maize plant by F. verticillioides. PMID:27708638

  7. Evolution of genital asymmetry, exaggerated eye stalks, and extreme palpal elongation in Panjange spiders (Araneae: Pholcidae

    Directory of Open Access Journals (Sweden)

    Bernhard Huber

    2015-12-01

    Full Text Available We describe several new species of the previously monotypic Panjange lanthana species group from the Philippines and document their extraordinary morphology. Some species show strong male genital asymmetry, a phenomenon that seems to be exceedingly rare in spiders. Males of most species have eye stalks, and in two species these eye stalks are among the longest ever recorded in spiders. Some species show a tendency for male genital (pedipalp elongation, and one species has the longest and thinnest palps ever recorded in Pholcidae. A cladistic analysis is performed including all described and several undescribed species of Panjange (except for one “problem species”, supporting the lanthana group and its close relationship with members of the possibly paraphyletic cavicola group. The following eight new species are described: Panjange malagos Huber sp. nov.; Pa. casaroro Huber sp. nov.; Pa. camiguin Huber sp. nov.; Pa. hamiguitan Huber sp. nov.; Pa. isarog Huber sp. nov.; Pa. dinagat Huber sp. nov.; Pa. marilog Huber sp. nov.; Pa. bukidnon Huber sp. nov.

  8. Experimental Study of Reciprocating Friction between Rape Stalk and Bionic Nonsmooth Surface Units

    Directory of Open Access Journals (Sweden)

    Zheng Ma

    2015-01-01

    Full Text Available Background. China is the largest producer of rape oilseed in the world; however, the mechanization level of rape harvest is relatively low, because rape materials easily adhere to the cleaning screens of combine harvesters, resulting in significant cleaning losses. Previous studies have shown that bionic nonsmooth surface cleaning screens restrain the adhesion of rape materials, but the underlying mechanisms remain unclear. Objective. The reciprocating friction between rape stalk and bionic nonsmooth metal surface was examined. Methods. The short-time Fourier transform method was used to discriminate the stable phase of friction signals and the stick-lag distance was defined to analyze the stable reciprocating friction in a phase diagram. Results. The reciprocating friction between rape stalk and metal surface is a typical stick-slip friction, and the bionic nonsmooth metal surfaces with concave or convex units reduced friction force with increasing reciprocating frequency. The results also showed that the stick-lag distance of convex surface increased with reciprocating frequency, which indicated that convex surface reduces friction force more efficiently. Conclusions. We suggest that bionic nonsmooth surface cleaning screens, especially with convex units, restrain the adhesion of rape materials more efficiently compared to the smooth surface cleaning screens.

  9. Experimental Study of Reciprocating Friction between Rape Stalk and Bionic Nonsmooth Surface Units.

    Science.gov (United States)

    Ma, Zheng; Li, Yaoming; Xu, Lizhang

    2015-01-01

    Background. China is the largest producer of rape oilseed in the world; however, the mechanization level of rape harvest is relatively low, because rape materials easily adhere to the cleaning screens of combine harvesters, resulting in significant cleaning losses. Previous studies have shown that bionic nonsmooth surface cleaning screens restrain the adhesion of rape materials, but the underlying mechanisms remain unclear. Objective. The reciprocating friction between rape stalk and bionic nonsmooth metal surface was examined. Methods. The short-time Fourier transform method was used to discriminate the stable phase of friction signals and the stick-lag distance was defined to analyze the stable reciprocating friction in a phase diagram. Results. The reciprocating friction between rape stalk and metal surface is a typical stick-slip friction, and the bionic nonsmooth metal surfaces with concave or convex units reduced friction force with increasing reciprocating frequency. The results also showed that the stick-lag distance of convex surface increased with reciprocating frequency, which indicated that convex surface reduces friction force more efficiently. Conclusions. We suggest that bionic nonsmooth surface cleaning screens, especially with convex units, restrain the adhesion of rape materials more efficiently compared to the smooth surface cleaning screens.

  10. Two-stage alkaline-enzymatic pretreatments to enhance biohydrogen production from sunflower stalks.

    Science.gov (United States)

    Monlau, Florian; Trably, Eric; Barakat, Abdellatif; Hamelin, Jérôme; Steyer, Jean-Philippe; Carrere, Hélène

    2013-01-01

    Because of their rich composition in carbohydrates, lignocellulosic residues represent an interesting source of biomass to produce biohydrogen by dark fermentation. Nevertheless, pretreatments should be applied to enhance the solubilization of holocelluloses and increase their further conversion into biohydrogen. The aim of this study was to investigate the effect of thermo-alkaline pretreatment alone and combined with enzymatic hydrolysis to enhance biohydrogen production from sunflower stalks. A low increase of hydrogen potentials from 2.3 ± 0.9 to 4.4 ± 2.6 and 20.6 ± 5.6 mL of H2 g(-1) of volatile solids (VS) was observed with raw sunflower stalks and after thermo-alkaline pretreatment at 55 °C, 24 h, and 4% NaOH and 170 °C, 1 h, and 4% NaOH, respectively. Enzymatic pretreatment alone showed an enhancement of the biohydrogen yields to 30.4 mL of H2 g(-1) of initial VS, whereas it led to 49 and 59.5 mL of H2 g(-1) of initial VS when combined with alkaline pretreatment at 55 and 170 °C, respectively. Interestingly, a diauxic effect was observed with sequential consumption of sugars by the mixed cultures during dark fermentation. Glucose was first consumed, and once glucose was completely exhausted, xylose was used by the microorganisms, mainly related to Clostridium species.

  11. Mass transfer during osmotic dehydration of celery stalks in a batch osmo-reactor

    Science.gov (United States)

    Sareban, M.; Abbasi Souraki, B.

    2016-07-01

    In this study, dehydration behavior of bulk of celery stalks, during osmotic drying in a limited volume of salt solution, was investigated. Experiments were carried out in the three initial solution concentrations of 10, 18 and 25 % (w/w) and at the three temperatures of 35, 45 and 55 °C. The volume ratio of the fruit to the solution was considered 1:3. A two-parameter model was used for prediction of kinetics of mass transfer and values of equilibrium moisture loss and solid gain. Moisture and salt effective diffusivities in celery stalks were estimated by fitting the experimental data of moisture loss and solute gain to the analytical solution of Fick's second law of diffusion. The analytical model was solved by defining a partition factor, K, assuming that the concentration of solute just within the surface of the material is K times that in the solution. Results showed that moisture and salt effective diffusivities and equilibrium values of moisture loss and solute gain increased with increasing the temperature and solution concentration. Results showed a good agreement between the two parameter model (with mean relative error of 4.016 % for moisture loss and 5.977 % for solid gain), analytical solution of Fick's second law (with mean relative error of 8.924 % for moisture loss and 9.164 % for solid gain) and experimental data.

  12. Head and Neck

    DEFF Research Database (Denmark)

    Højgaard, Liselotte; Berthelsen, Anne Kiil; Loft, Annika

    2014-01-01

    Positron emission tomography (PET)/computed tomography with FDG of the head and neck region is mainly used for the diagnosis of head and neck cancer, for staging, treatment evaluation, relapse, and planning of surgery and radio therapy. This article is a practical guide of imaging techniques......, including a detailed protocol for FDG PET in head and neck imaging, physiologic findings, and pitfalls in selected case stories....

  13. Prediction of postoperative diabetes insipidus using morphological hyperintensity patterns in the pituitary stalk on magnetic resonance imaging after transsphenoidal surgery for sellar tumors.

    Science.gov (United States)

    Hayashi, Yasuhiko; Kita, Daisuke; Watanabe, Takuya; Fukui, Issei; Sasagawa, Yasuo; Oishi, Masahiro; Tachibana, Osamu; Ueda, Fumiaki; Nakada, Mitsutoshi

    2016-12-01

    Diabetes insipidus (DI) remains a complication of transsphenoidal surgery (TSS) for sellar and parasellar tumors. Antidiuretic hormone (ADH) appears as hyper intensity (HI) in the pituitary stalk and the posterior lobe of the pituitary gland on T1-weighted magnetic resonance (MR) imaging. Its disappearance from the posterior lobe occurs with DI, indicating a lack of ADH. The appearance of HI in the pituitary stalk indicates disturbances in ADH transport. This retrospective study included 172 patients undergoing TSS for sellar tumors at our institute from 2006 to 2014. Sequential T1-weighted MR images without enhancement were evaluated for HI in the pituitary stalk and the posterior lobe to assess the localization of ADH before and at intervals after TSS. DI was assessed pre- and postoperatively. HI in the pituitary stalk showed the following morphology: (1) ovoid in the distal end of the pituitary stalk (group A), (2) linear in the distal part of the pituitary stalk (group B), (3) linear in the whole pituitary stalk (group C). Preoperative DI occurred in 6 patients (3.5 %) with no HI observed in the posterior lobe. Postoperative DI was transient in 82 patients (47.7 %), and permanent in 11 (6.4 %). One week after surgery, HI was absent in the posterior lobe in 74 patients (43.0 %), and present in the pituitary stalk in 99 patients (57.6 %); both were significantly correlated with postoperative DI (p < 0.001). The absence of HI in the posterior lobe (A, 48.9 %; B, 68.3 %; C, 92.3 %), persistence of DI (A, 3.7 days; B, 45.9 days; C, 20.5 months), and duration until HI recovery in the posterior lobe (A, 3.6 months; B, 6.8 months; C, 22.9 months) were greatest in group C, followed by group B, and then group A. Fourteen group A patients did not have postoperative DI despite having HI in the pituitary stalk and the posterior lobe. Four group C patients developed permanent DI with persistence HI in the pituitary stalk. HI in the pituitary stalk and its

  14. Effect of cotton stalk pattern and screening size on properties of cotton stalk/recycled plastic composite panels%棉秆形态对棉秆/回收塑料复合板性能的影响

    Institute of Scientific and Technical Information of China (English)

    蔺焘; 郭文静; 高黎; 常亮; 王正

    2011-01-01

    Cotton stalk particles and cotton stalk fibers were compounded with recycled polyethylene separately and 2 kinds of cotton stalk/plastic composite panels were formed using hot pressing. The effects of different cotton stalk shapes and screening of cotton stalk on the properties of the composite panels were evaluated. The results showed that: (1) The physical and mechanical properties of the composite panels made of screened fibers or particles were better than those of the unscreened fibers or particles. (2) The physical and mechanical properties of the composite panels made of cotton stalk particles were better than those of cotton stalk fibers. (3) The properties of the composite panels covered with poplar veneers on the surface, such as MOR was 42.2 Mpa, MOE was 6 010 Mpa, 24 h TS was 8.11% , IB was 1.19 Mpa, could meet the demanded Values of the particleboard for load-bearing boards for use in humid conditions according to National Standards GB/T 4897.7 -2003.%采用2种不同工艺形态(搓丝纤维态和刨花态)的棉秆与聚乙烯塑料复合,制备棉秆/回收塑料复合板材,研究了棉秆形态和筛分值对复合板材物理力学性能的影响.结果表明:(1)筛分过的棉秆搓丝和刨花制备复合板材的各项物理力学性能均优于未筛分的棉秆搓丝与刨花制备出的复合板材;(2)棉秆刨花制备复合板材的各项物理力学性能均优于棉秆搓丝制备出的复合板材;(3)基材表面覆单板之后复合板材的MOR达到42.2 MPa,MOE达到6 010 MPa,24hTS为8.11%,IB为1.19 MPa,均满足刨花板国家标准GB/T 4897.7 - 2003——在潮湿状态下使用的增强结构用板的性能指标.

  15. Selection and adaptation to high plant density in the Iowa Stiff Stalk synthetic maize (Zea mays L.) population

    Science.gov (United States)

    The plant density at which Zea mays L. hybrids achieve maximum grain yield has increased throughout the hybrid era while grain yield on a per plant basis has increased little. Changes in plant traits including grain yield, moisture, test weight, and stalk and root lodging have been well characterize...

  16. Production of charcoal briquettes from cotton stalk in malawi: methodology for feasibility studies using experiences in Sudan

    NARCIS (Netherlands)

    Onaji, P.B.; Siemons, R.V.

    1993-01-01

    The feasibility of charcoal production from cotton stalks in Malawi was studied based on experience from Sudan. The country relies considerably on biomass fuels. Of the total energy consumption in Malawi of 2.376 MTOE in 1989, 92% was met by biomass (fuelwood: 83.6% and charcoal: 8.3% Petroleum fuel

  17. Occurrence and Control of Corn Stalk Rot%玉米茎腐病的发生与防治

    Institute of Scientific and Technical Information of China (English)

    李英; 钟文

    2015-01-01

    根据侵染源的不同,玉米茎腐病分为真菌性茎腐病和细菌性茎腐病。在分别介绍了这2种病害的病原特征、侵染循环、发生规律、危害症状后,指出生产上应采取农业防治、物理防治和化学防治相结合的综合防治措施。为有效识别与防治玉米茎腐病,提高玉米的产量和品质提供了理论依据。%According to different infec-tion source, corn stalk rot could be di-vided into fungal stalk rot and bacterial stalk rot.After introducing the pathogenic characteristics, infection cycle, occur-rence regulation and damage symptom of these two diseases respectively, the com-prehensive prevention measures were put forward, including agricultural control, physical control and chemical control. The study provided theoretical basis for effectively recognizing and controlling corn stalk rot,and improving yield and quality of corn.

  18. 24 CFR 5.2005 - Protection of victims of domestic violence, dating violence, and stalking in public and Section 8...

    Science.gov (United States)

    2010-04-01

    ... criminal acts of physical violence against family members or others, without evicting, removing... violence, dating violence, and stalking in public and Section 8 housing. 5.2005 Section 5.2005 Housing and... PROGRAM REQUIREMENTS; WAIVERS Protection for Victims of Domestic Violence in Public and Section 8...

  19. Flower stalk segments of Arabidopsis thaliana ecotype Columbia lack the capacity to grow in response to exogenously applied auxin.

    Science.gov (United States)

    Soga, K; Wakabayashi, K; Hoson, T; Kamisaka, S

    2000-12-01

    Exogenously applied IAA stimulated cell elongation of segments excised from flower stalks of Arabidopsis thaliana ecotype Landsberg erecta (Ler) by increasing the cell wall extensibility, but it did not affect that of ecotype Columbia (Col). Treatment with a low pH buffer solution (pH 4.0) or fusicoccin (FC), a reagent activating H(+)-ATPases, significantly increased the cell wall extensibility and promoted elongation growth of flower stalk segments of both ecotypes, indicating that the flower stalk segments of Col possess the capacity to grow under acidic pH conditions. IAA promoted the proton excretion in segments of Ler but not of Col. On the other hand, FC increased the proton excretion in segments of Col as much as that of Ler. These results suggest that IAA activates the plasma membrane H(+)-ATPases in the segments of Ler but not those of Col, while FC activates them in both ecotypes. Flower stalks of Col may lack the mechanisms of activation by IAA of the plasma membrane H(+)-ATPases.

  20. Effects of ornamentation and phylogeny on the evolution of wing shape in stalk-eyed flies (Diopsidae).

    Science.gov (United States)

    Husak, J F; Ribak, G; Baker, R H; Rivera, G; Wilkinson, G S; Swallow, J G

    2013-06-01

    Exaggerated male ornaments are predicted to be costly to their bearers, but these negative effects may be offset by the correlated evolution of compensatory traits. However, when locomotor systems, such as wings in flying species, evolve to decrease such costs, it remains unclear whether functional changes across related species are achieved via the same morphological route or via alternate changes that have similar function. We conducted a comparative analysis of wing shape in relation to eye-stalk elongation across 24 species of stalk-eyed flies, using geometric morphometrics to determine how species with increased eye span, a sexually selected trait, have modified wing morphology as a compensatory mechanism. Using traditional and phylogenetically informed multivariate analyses of shape in combination with phenotypic trajectory analysis, we found a strong phylogenetic signal in wing shape. However, dimorphic species possessed shifted wing veins with the result of lengthening and narrowing wings compared to monomorphic species. Dimorphic species also had changes that seem unrelated to wing size, but instead may govern wing flexion. Nevertheless, the lack of a uniform, compensatory pattern suggests that stalk-eyed flies used alternative modifications in wing structure to increase wing area and aspect ratio, thus taking divergent morphological routes to compensate for exaggerated eye stalks.

  1. SNP discovery and QTL mapping of Sclerotinia basal stalk rot resistance in sunflower using genotyping-by-sequencing (GBS)

    Science.gov (United States)

    Basal stalk rot (BSR) caused by the ascomycete fungus Sclerotinia sclerotiorum (Lib.) de Bary is a serious disease of sunflower (Helianthus annuus L.) in the cool and humid production areas of the world. Quantitative trait loci (QTL) for BSR resistance were identified in a sunflower recombinant inbr...

  2. Modeling of kinetics of Cr(VI) sorption onto grape stalk waste in a stirred batch reactor.

    Science.gov (United States)

    Escudero, Carlos; Fiol, Nuria; Poch, Jordi; Villaescusa, Isabel

    2009-10-15

    Recently, Cr(VI) removal by grape stalks has been postulated to follow two mechanisms, adsorption and reduction to trivalent chromium. Nevertheless, the rate at which both processes take place and the possible simultaneity of both processes has not been investigated. In this work, kinetics of Cr(VI) sorption onto grape stalk waste has been studied. Experiments were carried out at different temperatures but at a constant pH (3+/-0.1) in a stirred batch reactor. Results showed that three steps take place in the process of Cr(VI) sorption onto grape stalk waste: Cr(VI) sorption, Cr(VI) reduction to Cr(III) and the adsorption of the formed Cr(III). Taking into account the evidences above mentioned, a model has been developed to predict Cr(VI) sorption on grape stalks on the basis of (i) irreversible reduction of Cr(VI) to Cr(III) reaction, whose reaction rate is assumed to be proportional to the Cr(VI) concentration in solution and (ii) adsorption and desorption of Cr(VI) and formed Cr(III) assuming that all the processes follow Langmuir type kinetics. The proposed model fits successfully the kinetic data obtained at different temperatures and describes the kinetics profile of total, hexavalent and trivalent chromium. The proposed model would be helpful for researchers in the field of Cr(VI) biosorption to design and predict the performance of sorption processes.

  3. Nutritional Value of the Maize Stalk Borer and American Bollworm as Unconventional Protein Sources

    Directory of Open Access Journals (Sweden)

    Abdel E. Ghaly

    2010-01-01

    Full Text Available Problem statement: The maize stalk borer and American bollworm were grown in an artificial media to evaluate their potential as human food sources. Approach: Both cultures were started from moths and the life cycle and culture structures were evaluated. Results: The larvae of both insects reached maximum weight and maximum length at the same time. The growth rate of the youngest larvae was found to be the highest and the increase in the body weight during the growth period appeared to be linear. The larvae of these insects started to decrease in weight after they reached the maximum size. For efficient systems for the commercial production of the maize stalk borer and the American bollworm, the larvae should be harvested when they are 39 and 21 days old, respectively. The protein contents were 38.0 and 33.0% and the fat contents were 14.5 and 14.4% for the dried larvae of the American bollworm and maize stalk borer, respectively. The larvae of both insects contained the essential amino acids and minerals. Only 10% mortality was observed with older larvae of both species. A system where eggs are separated from adults and hatched in separate chambers would alleviate the possible danger of losing the population due to microbial infection. The high moisture content of the larvae (60.4-61.0% could cause handling and storage problems. Drying and grinding the larvae would reduce them to easily manageable forms and would improve their marketability as novel food. Conclusion: The results obtained from this study show the potential of using insects as a protein source for human consumption to alleviate protein deficiency in many parts of the world, especially in Latin America, Africa and Asia. Further research is required to evaluate their growth characteristics on low substrates. Future research should also evaluate environmental parameters such as temperature, relative humidity and heat and CO2 production on food consumption and protein yield per gram

  4. Computational Screening of Tip and Stalk Cell Behavior Proposes a Role for Apelin Signaling in Sprout Progression

    Science.gov (United States)

    Palm, Margriet M.; Dallinga, Marchien G.; Klaassen, Ingeborg; Schlingemann, Reinier O.

    2016-01-01

    Angiogenesis involves the formation of new blood vessels by sprouting or splitting of existing blood vessels. During sprouting, a highly motile type of endothelial cell, called the tip cell, migrates from the blood vessels followed by stalk cells, an endothelial cell type that forms the body of the sprout. To get more insight into how tip cells contribute to angiogenesis, we extended an existing computational model of vascular network formation based on the cellular Potts model with tip and stalk differentiation, without making a priori assumptions about the differences between tip cells and stalk cells. To predict potential differences, we looked for parameter values that make tip cells (a) move to the sprout tip, and (b) change the morphology of the angiogenic networks. The screening predicted that if tip cells respond less effectively to an endothelial chemoattractant than stalk cells, they move to the tips of the sprouts, which impacts the morphology of the networks. A comparison of this model prediction with genes expressed differentially in tip and stalk cells revealed that the endothelial chemoattractant Apelin and its receptor APJ may match the model prediction. To test the model prediction we inhibited Apelin signaling in our model and in an in vitro model of angiogenic sprouting, and found that in both cases inhibition of Apelin or of its receptor APJ reduces sprouting. Based on the prediction of the computational model, we propose that the differential expression of Apelin and APJ yields a “self-generated” gradient mechanisms that accelerates the extension of the sprout. PMID:27828952

  5. Head Injuries in Children

    Science.gov (United States)

    Pennington, Nicole

    2010-01-01

    School nurses play a crucial role in injury prevention and initial treatment when injuries occur at school. The role of school nurses includes being knowledgeable about the management of head injuries, including assessment and initial treatment. The school nurse must be familiar with the outcomes of a head injury and know when further evaluation…

  6. Stalking : El nuevo delito de acecho del art. 172 ter del Código Penal. Aproximación al cyberstalking

    OpenAIRE

    Lorenzo Barcenilla, Silvia

    2015-01-01

    En el presente trabajo se analiza el tratamiento en el ordenamiento penal español de las conductas de stalking, también denominado acecho o acoso predatorio. Se realiza en primer lugar una definición del concepto y de sus características, con una breve referencia a las diferencias con otras modalidades de acoso. A continuación se analiza una concreta forma de stalking, denominada cyberstalking, por presentar particularidades respecto al stalking tradicional y constituir un fenómeno creciente ...

  7. Evidence that the Dictyostelium Dd-STATa protein is a repressor that regulates commitment to stalk cell differentiation and is also required for efficient chemotaxis.

    Science.gov (United States)

    Mohanty, S; Jermyn, K A; Early, A; Kawata, T; Aubry, L; Ceccarelli, A; Schaap, P; Williams, J G; Firtel, R A

    1999-08-01

    Dd-STATa is a structural and functional homologue of the metazoan STAT (Signal Transducer and Activator of Transcription) proteins. We show that Dd-STATa null cells exhibit several distinct developmental phenotypes. The aggregation of Dd-STATa null cells is delayed and they chemotax slowly to a cyclic AMP source, suggesting a role for Dd-STATa in these early processes. In Dd-STATa null strains, slug-like structures are formed but they have an aberrant pattern of gene expression. In such slugs, ecmB/lacZ, a marker that is normally specific for cells on the stalk cell differentiation pathway, is expressed throughout the prestalk region. Stalk cell differentiation in Dictyostelium has been proposed to be under negative control, mediated by repressor elements present in the promoters of stalk cell-specific genes. Dd-STATa binds these repressor elements in vitro and the ectopic expression of ecmB/lacZ in the null strain provides in vivo evidence that Dd-STATa is the repressor protein that regulates commitment to stalk cell differentiation. Dd-STATa null cells display aberrant behavior in a monolayer assay wherein stalk cell differentiation is induced using the stalk cell morphogen DIF. The ecmB gene, a general marker for stalk cell differentiation, is greatly overinduced by DIF in Dd-STATa null cells. Also, Dd-STATa null cells are hypersensitive to DIF for expression of ST/lacZ, a marker for the earliest stages in the differentiation of one of the stalk cell sub-types. We suggest that both these manifestations of DIF hypersensitivity in the null strain result from the balance between activation and repression of the promoter elements being tipped in favor of activation when the repressor is absent. Paradoxically, although Dd-STATa null cells are hypersensitive to the inducing effects of DIF and readily form stalk cells in monolayer assay, the Dd-STATa null cells show little or no terminal stalk cell differentiation within the slug. Dd-STATa null slugs remain

  8. Pyrolysis of agricultural residues. Part II. Yield and chemical composition of tars and oils produced from cotton stalks, and assessment of lignin structure

    Energy Technology Data Exchange (ETDEWEB)

    Fahmy, Y.; Mobarak, F.; Schweers, W.

    1982-01-01

    The pyrolysis of cotton stalks at 400-600 degrees resulted in the production of char and tar in highest yield, and the increase of temperature within this range decreased the yield of tar and phenolic compounds in the tar but increased the ratio of neutrals to acids in the tar. On decreasing the particle size of stalks, the total yield of tar remained almost constant regardless of pyrolysis temperature but that of phenols increased while that of neutrals and acids decreased. The distribution of syringol and guaiacol in phenolic products indicated that lignin in stalks belongs to the guaiacyl-syringyl type.

  9. Comparative Study on the Pyrolysis Behaviors of Corn Stalk and Pine Sawdust Using TG-MS

    Institute of Scientific and Technical Information of China (English)

    赵云鹏; 丁曼; 窦有权; 樊星; 王月伦; 魏贤勇

    2014-01-01

    The pyrolysis behaviors of corn stalk (CS) and pine sawdust (PS) were investigated with thermogravim-etry-mass spectroscopy (TG-MS). The peak temperature of PS was higher and the main decomposition region shifted to higher temperature compared with CS, which implied that the hemicellulose and cellulose of PS were more ther-mally stable than those of CS. However, the hemicellulose and cellulose of PS were more easily decomposed into gaseous products than those of CS during pyrolysis. The pyrolysis process of biomass can be described by a two-step independent first-order kinetic model. This fundamental study provides a basic insight into the biomass pyrolysis, which is beneficial for understanding the pyrolysis mechanism of biomass and developing an advanced thermal proc-ess for effective utilization of biomass.

  10. Chemical modification of amino acid residues in glycerinated Vorticella stalk and Ca(2+)-induced contractility.

    Science.gov (United States)

    Kono, R; Ochiai, T; Asai, H

    1997-01-01

    The glycerinated stalk of the peritrich ciliate Vorticella, was treated with various reagents to chemically modify the amino acid residues. The influences of these modifcations on spasmoneme contractility were investigated. First, it was confirmed that the spasmoneme contraction is not inhibited by alteration of SH groups. It was also demonstrated that chemical modification of methionine and tryptophan residues abolishes spasmoneme contractility. The reagents used for chemical modification were N-bromosuccinimide (NBS), chloramine T, and 2-hydroxy-5-nitrobenzyl bromide (HNBB), which abolished spasmoneme contractility at concentrations of 40-50 microM, 200-300 microM, and 4 mM, respectively. These results suggest that, along with Ca2+ binding proteins, there are other as yet to be identified proteins involved in contractility.

  11. Microbial pretreatment of cotton stalks by Phanerochaete chrysosporium for bioethanol production

    Science.gov (United States)

    Shi, Jian

    Lignocellulosic biomass has been recognized as a widespread, potentially low cost renewable source of mixed sugars for fermentation to fuel ethanol. Pretreatment, as the first step towards conversion of lignocellulose to ethanol, remains one of the main barriers to technical and commercial success of the processing technology. Existing pretreatment methods have largely been developed on the basis of physiochemical technologies which are considered relatively expensive and usually involve adverse environmental impacts. In this study, an environmentally benign alternative, microbial pretreatment using Phanerochaete chrysosporium, was explored to degrade lignin in cotton stalks and facilitate their conversion into ethanol. Two submerged liquid pretreatment techniques (SmC), shallow stationary and agitated cultivation, at three inorganic salt concentrations (no salts, modified salts without Mn2+, modified salts with Mn2+) were compared by evaluating their pretreatment efficiencies. Shallow stationary cultivation with no salt was superior to other pretreatment conditions and gave 20.7% lignin degradation along with 76.3% solids recovery and 29.0% carbohydrate availability over a 14 day period. The influence of substrate moisture content (65%, 75% and 80% M.C. wet-basis), inorganic salt concentration (no salts, modified salts without Mn2+ , modified salts with Mn2+) and culture time (0-14 days) on pretreatment effectiveness in solid state (SSC) systems was also examined. It was shown that solid state cultivation at 75% M.C. without salts was the most preferable pretreatment resulting in 27.6% lignin degradation, 71.1% solids recovery and 41.6% carbohydrate availability over a period of 14 days. A study on hydrolysis and fermentation of cotton stalks treated microbially using the most promising SmC (shallow stationary, no salts) and SSC (75% moisture content, no salts) methods resulted in no increase in cellulose conversion with direct enzyme application (10.98% and 3

  12. A biorefinery-based approach for the production of ethanol from enzymatically hydrolysed cotton stalks.

    Science.gov (United States)

    Christopher, Meera; Mathew, Anil K; Kiran Kumar, M; Pandey, Ashok; Sukumaran, Rajeev K

    2017-10-01

    Cotton post-harvest residue/cotton stalk (CS) - a major agro-residue in south asian countries was evaluated as a feed stock for bioethanol production. The common thermochemical pretreatment strategies based on dilute acid and alkali and different combinations of biomass hydrolyzing enzymes were evaluated for saccharification of CS biomass. A hydrolytic efficiency of 80% was achieved for alkali treated biomass using cellulase supplemented with beta glucosidase. Recycling of undigested/residual biomass and/or enzyme supported same final sugar concentration as for fresh hydrolytic experiments. Fermentation was carried out using a novel, inhibitor-resistant strain of Saccharomyces cerevisiae where 76% of theoretical maximum efficiency was attained. Material balances were derived for the entire process from biomass pre-processing to hydrolysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Removal of insecticide carbofuran from aqueous solutions by banana stalks activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Salman, J.M. [School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Hameed, B.H., E-mail: chbassim@eng.usm.my [School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia)

    2010-04-15

    In this work, activated carbon was prepared from banana stalks (BSAC) waste to remove the insecticide carbofuran from aqueous solutions. The effects of contact time, initial carbofuran concentration, solution pH and temperature (30, 40 and 50 deg. C) were investigated. Adsorption isotherm, kinetics and thermodynamics of carbofuran on BSAC were studied. Equilibrium data were fitted to the Langmuir, Freundlich and Temkin isotherm models and the data best represented by the Langmuir isotherm. Thermodynamic parameters such as standard enthalpy ({Delta}H{sup o}), standard entropy ({Delta}S{sup o}) and standard free energy ({Delta}G{sup o}) were evaluated. Regeneration efficiency of spent BSAC was studied using ethanol as a solvent. The efficiency was found to be in the range of 96.97-97.35%. The results indicated that the BSAC has good regeneration and reusability characteristics and can be used as alternative to present commercial activated carbon.

  14. Removal of insecticide carbofuran from aqueous solutions by banana stalks activated carbon.

    Science.gov (United States)

    Salman, J M; Hameed, B H

    2010-04-15

    In this work, activated carbon was prepared from banana stalks (BSAC) waste to remove the insecticide carbofuran from aqueous solutions. The effects of contact time, initial carbofuran concentration, solution pH and temperature (30, 40 and 50 degrees C) were investigated. Adsorption isotherm, kinetics and thermodynamics of carbofuran on BSAC were studied. Equilibrium data were fitted to the Langmuir, Freundlich and Temkin isotherm models and the data best represented by the Langmuir isotherm. Thermodynamic parameters such as standard enthalpy (DeltaH(o)), standard entropy (DeltaS(o)) and standard free energy (DeltaG(o)) were evaluated. Regeneration efficiency of spent BSAC was studied using ethanol as a solvent. The efficiency was found to be in the range of 96.97-97.35%. The results indicated that the BSAC has good regeneration and reusability characteristics and can be used as alternative to present commercial activated carbon.

  15. Evaluation of Dried Sweet Sorghum Stalks as Raw Material for Methane Production

    Science.gov (United States)

    Matsakas, Leonidas; Rova, Ulrika; Christakopoulos, Paul

    2014-01-01

    The potential of utilizing dried sweet sorghum stalks as raw material for anaerobic digestion has been evaluated. Two different treatments were tested, a mild thermal and an enzymatic, alone or in combination. Thermal pretreatment was found to decrease the methane yields, whereas one-step enzymatic treatment resulted in a significant increase of 15.1% comparing to the untreated sweet sorghum. Subsequently, in order to increase the total methane production, the combined effect of enzyme load and I/S on methane yields from sweet sorghum was evaluated by employing response surface methodology. The obtained model showed that the maximum methane yield that could be achieved is 296 mL CH4/g VS at I/S ratio of 0.35 with the addition of 11.12 FPU/g sweet sorghum. PMID:25210715

  16. Study on loading coefficient in steam explosion process of corn stalk.

    Science.gov (United States)

    Sui, Wenjie; Chen, Hongzhang

    2015-03-01

    The object of this work was to evaluate the effect of loading coefficient on steam explosion process and efficacy of corn stalk. Loading coefficient's relation with loading pattern and material property was first revealed, then its effect on transfer process and pretreatment efficacy of steam explosion was assessed by established models and enzymatic hydrolysis tests, respectively, in order to propose its optimization strategy for improving the process economy. Results showed that loading coefficient was mainly determined by loading pattern, moisture content and chip size. Both compact loading pattern and low moisture content improved the energy efficiency of steam explosion pretreatment and overall sugar yield of pretreated materials, indicating that they are desirable to improve the process economy. Pretreatment of small chip size showed opposite effects in pretreatment energy efficiency and enzymatic hydrolysis performance, thus its optimization should be balanced in investigated aspects according to further techno-economical evaluation.

  17. Identification and some properties of anthocyanin isolated from Zuiki, stalk of Colocasia esculenta.

    Science.gov (United States)

    Terasawa, Naoko; Saotome, Ayako; Tachimura, Yuki; Mochizuki, Ayumi; Ono, Hiroshi; Takenaka, Makiko; Murata, Masatsune

    2007-05-16

    Zuiki, a stalk of taro (Colocasia esculenta), is a traditional vegetable in Japan. Raw zuiki is often boiled and vinegared to eat. The surface color of zuiki is reddish. Here, we isolated a red pigment from zuiki and identified it as cyanidin 3-rutinoside using instrumental analyses. The color of zuiki disappeared by boiling, but the zuiki turned red again in an acetic acid solution. It seems that the cyanidin 3-rutinoside that exists on the surface of zuiki elutes in boiling water and then, the pigment that seeps out from the inside of the zuiki is exposed to an acid solution, and its surface turns red again. The radical scavenging activity of purified zuiki anthocyanin was 114 mg equivalent to BHT/g. About half of the anthocyanin in fresh zuiki was washed out by boiling, and the radical scavenging activity of zuiki was definitely reduced.

  18. Degradation of corn stalk by the composite microbial system of MC1

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The composite microbial system of MC1 was used to degrade corn stalk in order to determine properties of the degraded products as well as bacterial composition of MC1. Results indicated that the pH of the fermentation broth was typical of lignocellulose degradatioin by MC1, decreasing in the early phase and increasing in later stages of the degradation. The microbial biomass peaked on the day 3 after degradation. The MC1 effeciently degraded the corn stalk by nearly 70% during which its cellulose content decreased by 71.2%, hemicellulose by 76.5% and lignin by 24.6%. The content of water-soluble carbohydrates (WSC) in the fermentation broth increased progressively during the first three days, and decreased thereafter, suggesting an accumulation of WSC in the early phase of the degradation process. Total levels of various volatile products peaked in the third day after degradation , and 7 types of volatile products were detected in the fermentation broth. These were ethanol, acetic acid, 1,2-ethanediol, propanoic acid, butanoic acid, 3-methyl-butanoic acid and glycerine. Six major compounds were quantitatively analysed and the contents of each compound were ethanol (0.584 g/L), acetic acid (0.735 g/L), 1,2-ethanediol (0.772 g/L), propanoic acid (0.026 g/L), butanoic acid (0.018 g/L) and glycerine (4.203 g/L). Characterization of bacterial cells collected from the culture solution, based on 16S rDNA PCR-DGGE analysis of DNAs, showed that the composition of bacterial community in MC1 coincided basically with observations from previous studies. This indicated that the structure of MC1 is very stable during degradation of different lignocellulose materials.

  19. Identification of interacting hot spots in the beta3 integrin stalk using comprehensive interface design.

    Science.gov (United States)

    Donald, Jason E; Zhu, Hua; Litvinov, Rustem I; DeGrado, William F; Bennett, Joel S

    2010-12-03

    Protein-protein interfaces are usually large and complementary surfaces, but specific side chains, representing energetic "hot spots," often contribute disproportionately to binding free energy. We used a computational method, comprehensive interface design, to identify hot spots in the interface between the stalk regions of the β3 and the complementary αIIb and αv integrin subunits. Using the Rosetta alanine-scanning and design algorithms to predict destabilizing, stabilizing, and neutral mutations in the β3 region extending from residues Lys(532) through Gly(690), we predicted eight alanine mutations that would destabilize the αIIbβ3 interface as well as nine predicted to destabilize the αvβ3 interface, by at least 0.3 kcal/mol. The mutations were widely and unevenly distributed, with four between residues 552 and 563 and five between 590 and 610, but none between 565 and 589, and 611 and 655. Further, mutations destabilizing the αvβ3 and αIIbβ3 interfaces were not identical. The predictions were then tested by introducing selected mutations into the full-length integrins expressed in Chinese hamster ovary cells. Five mutations predicted to destabilize αIIb and β3 caused fibrinogen binding to αIIbβ3, whereas three of four predicted to be neutral or stabilizing did not. Conversely, a mutation predicted to destabilize αvβ3, but not αIIbβ3 (D552A), caused osteopontin binding to αvβ3, but not fibrinogen binding to αIIbβ3. These results indicate that stability of the distal stalk interface is involved in constraining integrins in stable, inactive conformations. Further, they demonstrate the ability of comprehensive interface design to identify functionally significant integrin mutations.

  20. Genome-Wide Association Study on Resistance to Stalk Rot Diseases in Grain Sorghum.

    Science.gov (United States)

    Adeyanju, Adedayo; Little, Christopher; Yu, Jianming; Tesso, Tesfaye

    2015-04-16

    Stalk rots are important biotic constraints to sorghum production worldwide. Several pathogens may be associated with the disease, but Macrophomina phaseolina and Fusarium thapsinum are recognized as the major causal organisms. The diseases become more aggressive when drought and high-temperature stress occur during grain filling. Progress in genetic improvement efforts has been slow due to lack of effective phenotyping protocol and the strong environmental effect on disease incidence and severity. Deployment of modern molecular tools is expected to accelerate efforts to develop resistant hybrids. This study was aimed at identifying genomic regions associated with resistance to both causal organisms. A sorghum diversity panel consisting of 300 genotypes assembled from different parts of the world was evaluated for response to infection by both pathogens. Community resources of 79,132 single nucleotide polymorphic (SNP) markers developed on the panel were used in association studies using a multi-locus mixed model to map loci associated with stalk rot resistance. Adequate genetic variation was observed for resistance to both pathogens. Structure analysis grouped the genotypes into five subpopulations primarily based on the racial category of the genotypes. Fourteen loci and a set of candidate genes appear to be involved in connected functions controlling plant defense response. However, each associated SNP had relatively small effect on the traits, accounting for 19-30% of phenotypic variation. Linkage disequilibrium analyses suggest that significant SNPs are genetically independent. Estimation of frequencies of associated alleles revealed that durra and caudatum subpopulations were enriched for resistant alleles, but the results suggest complex molecular mechanisms underlying resistance to both pathogens. Copyright © 2015 Adeyanju et al.

  1. A new stalked filter-feeder from the middle Cambrian Burgess Shale, British Columbia, Canada.

    Directory of Open Access Journals (Sweden)

    Lorna J O'Brien

    Full Text Available Burgess Shale-type deposits provide invaluable insights into the early evolution of body plans and the ecological structure of Cambrian communities, but a number of species, continue to defy phylogenetic interpretations. Here we extend this list to include a new soft-bodied animal, Siphusauctum gregarium n. gen. and n. sp., from the Tulip Beds (Campsite Cliff Shale Member, Burgess Shale Formation of Mount Stephen (Yoho National Park, British Columbia. With 1,133 specimens collected, S. gregarium is clearly the most abundant animal from this locality.This stalked animal (reaching at least 20 cm in length, has a large ovoid calyx connected to a narrow bilayered stem and a small flattened or bulb-like holdfast. The calyx is enclosed by a flexible sheath with six small openings at the base, and a central terminal anus near the top encircled by indistinct openings. A prominent organ, represented by six radially symmetrical segments with comb-like elements, surrounds an internal body cavity with a large stomach, conical median gut and straight intestine. Siphusauctum gregarium was probably an active filter-feeder, with water passing through the calyx openings, capturing food particles with its comb-like elements. It often occurs in large assemblages on single bedding planes suggesting a gregarious lifestyle, with the animal living in high tier clusters. These were probably buried en masse more or less in-situ by rapid mud flow events.Siphusauctum gregarium resembles Dinomischus, another Cambrian enigmatic stalked animal. Principal points of comparison include a long stem with a calyx containing a visceral mass and bract-like elements, and a similar lifestyle albeit occupying different tiering levels. The presence in both animals of a digestive tract with a potential stomach and anus suggest a grade of organization within bilaterians, but relationships with extant phyla are not straightforward. Thus, the broader affinities of S. gregarium remain

  2. A new stalked filter-feeder from the middle Cambrian Burgess Shale, British Columbia, Canada.

    Science.gov (United States)

    O'Brien, Lorna J; Caron, Jean-Bernard

    2012-01-01

    Burgess Shale-type deposits provide invaluable insights into the early evolution of body plans and the ecological structure of Cambrian communities, but a number of species, continue to defy phylogenetic interpretations. Here we extend this list to include a new soft-bodied animal, Siphusauctum gregarium n. gen. and n. sp., from the Tulip Beds (Campsite Cliff Shale Member, Burgess Shale Formation) of Mount Stephen (Yoho National Park, British Columbia). With 1,133 specimens collected, S. gregarium is clearly the most abundant animal from this locality.This stalked animal (reaching at least 20 cm in length), has a large ovoid calyx connected to a narrow bilayered stem and a small flattened or bulb-like holdfast. The calyx is enclosed by a flexible sheath with six small openings at the base, and a central terminal anus near the top encircled by indistinct openings. A prominent organ, represented by six radially symmetrical segments with comb-like elements, surrounds an internal body cavity with a large stomach, conical median gut and straight intestine. Siphusauctum gregarium was probably an active filter-feeder, with water passing through the calyx openings, capturing food particles with its comb-like elements. It often occurs in large assemblages on single bedding planes suggesting a gregarious lifestyle, with the animal living in high tier clusters. These were probably buried en masse more or less in-situ by rapid mud flow events.Siphusauctum gregarium resembles Dinomischus, another Cambrian enigmatic stalked animal. Principal points of comparison include a long stem with a calyx containing a visceral mass and bract-like elements, and a similar lifestyle albeit occupying different tiering levels. The presence in both animals of a digestive tract with a potential stomach and anus suggest a grade of organization within bilaterians, but relationships with extant phyla are not straightforward. Thus, the broader affinities of S. gregarium remain largely unconstrained.

  3. Phosphatidylserine-Dependent Catalysis of Stalk and Pore Formation by Synaptobrevin JMR-TMD Peptide.

    Science.gov (United States)

    Tarafdar, Pradip K; Chakraborty, Hirak; Bruno, Michael J; Lentz, Barry R

    2015-11-03

    Although the importance of a SNARE complex in neurotransmitter release is widely accepted, there exist different views on how the complex promotes fusion. One hypothesis is that the SNARE complex's ability to bring membranes into contact is sufficient for fusion, another points to possible roles of juxtamembrane regions (JMRs) and transmembrane domains (TMDs) in catalyzing lipid rearrangement, and another notes the complex's presumed ability to bend membranes near the point of contact. Here, we performed experiments with highly curved vesicles brought into contact using low concentrations of polyethylene glycol (PEG) to investigate the influence of the synaptobrevin (SB) TMD with an attached JMR (SB-JMR-TMD) on the rates of stalk and pore formation during vesicle fusion. SB-JMR-TMD enhanced the rates of stalk and fusion pore (FP) formation in a sharply sigmoidal fashion. We observed an optimal influence at an average of three peptides per vesicle, but only with phosphatidylserine (PS)-containing vesicles. Approximately three SB-JMR-TMDs per vesicle optimally ordered the bilayer interior and excluded water in a similar sigmoidal fashion. The catalytic influences of hexadecane and SB-JMR-TMD on fusion kinetics showed little in common, suggesting different mechanisms. Both kinetic and membrane structure measurements support the hypotheses that SB-JMR-TMD 1) catalyzes initial intermediate formation as a result of its basic JMR disrupting ordered interbilayer water and permitting closer interbilayer approach, and 2) catalyzes pore formation by forming a membrane-spanning complex that increases curvature stress at the circumference of the hemifused diaphragm of the prepore intermediate state. Copyright © 2015 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  4. Adhesive proteins of stalked and acorn barnacles display homology with low sequence similarities.

    Directory of Open Access Journals (Sweden)

    Jaimie-Leigh Jonker

    Full Text Available Barnacle adhesion underwater is an important phenomenon to understand for the prevention of biofouling and potential biotechnological innovations, yet so far, identifying what makes barnacle glue proteins 'sticky' has proved elusive. Examination of a broad range of species within the barnacles may be instructive to identify conserved adhesive domains. We add to extensive information from the acorn barnacles (order Sessilia by providing the first protein analysis of a stalked barnacle adhesive, Lepas anatifera (order Lepadiformes. It was possible to separate the L. anatifera adhesive into at least 10 protein bands using SDS-PAGE. Intense bands were present at approximately 30, 70, 90 and 110 kilodaltons (kDa. Mass spectrometry for protein identification was followed by de novo sequencing which detected 52 peptides of 7-16 amino acids in length. None of the peptides matched published or unpublished transcriptome sequences, but some amino acid sequence similarity was apparent between L. anatifera and closely-related Dosima fascicularis. Antibodies against two acorn barnacle proteins (ab-cp-52k and ab-cp-68k showed cross-reactivity in the adhesive glands of L. anatifera. We also analysed the similarity of adhesive proteins across several barnacle taxa, including Pollicipes pollicipes (a stalked barnacle in the order Scalpelliformes. Sequence alignment of published expressed sequence tags clearly indicated that P. pollicipes possesses homologues for the 19 kDa and 100 kDa proteins in acorn barnacles. Homology aside, sequence similarity in amino acid and gene sequences tended to decline as taxonomic distance increased, with minimum similarities of 18-26%, depending on the gene. The results indicate that some adhesive proteins (e.g. 100 kDa are more conserved within barnacles than others (20 kDa.

  5. Biological Control of Fusarium Stalk Rot of Maize Using Bacillus spp

    Directory of Open Access Journals (Sweden)

    Joon-Hee Han

    2015-12-01

    Full Text Available Maize (Zea mays L. is an economically important crop in worldwide. While the consumption of the maize is steadily increasing, the yield is decreasing due to continuous mono-cultivation and infection of soil-borne fungal pathogens such as Fusarium species. Recently, stalk rot disease in maize, caused by F. subglutinans and F. temperatum has been reported in Korea. In this study, we isolated bacterial isolates in rhizosphere soil of maize and subsequently tested for antagonistic activities against F. subglutinans and F. temperatum. A total of 1,357 bacterial strains were isolated from rhizosphere. Among them three bacterial isolates (GC02, GC07, GC08 were selected, based on antagonistic effects against Fusarium species. The isolates GC02 and GC07 were most efficient in inhibiting the mycelium growth of the pathogens. The three isolates GC02, GC07 and GC08 were identified as Bacillus methylotrophicus, B. amyloliquefaciens and B. thuringiensis using 16S rRNA sequence analysis, respectively. GC02 and GC07 bacterial suspensions were able to suppress over 80% conidial germination of the pathogens. GC02, GC07 and GC08 were capable of producing large quantities of protease enzymes, whereas the isolates GC07 and GC08 produced cellulase enzymes. The isolates GC02 and GC07 were more efficient in phosphate solubilization and siderophore production than GC08. Analysis of disease suppression revealed that GC07 was most effective in suppressing the disease development of stalk rot. It was also found that B. methylotrophicus GC02 and B. amyloliquefaciens GC07 have an ability to inhibit the growth of other plant pathogenic fungi. This study indicated B. methylotrophicus GC02 and B. amyloliquefaciens GC07 has potential for being used for the development of a biological control agent.

  6. Structure of the head of the Bartonella adhesin BadA.

    Directory of Open Access Journals (Sweden)

    Pawel Szczesny

    Full Text Available Trimeric autotransporter adhesins (TAAs are a major class of proteins by which pathogenic proteobacteria adhere to their hosts. Prominent examples include Yersinia YadA, Haemophilus Hia and Hsf, Moraxella UspA1 and A2, and Neisseria NadA. TAAs also occur in symbiotic and environmental species and presumably represent a general solution to the problem of adhesion in proteobacteria. The general structure of TAAs follows a head-stalk-anchor architecture, where the heads are the primary mediators of attachment and autoagglutination. In the major adhesin of Bartonella henselae, BadA, the head consists of three domains, the N-terminal of which shows strong sequence similarity to the head of Yersinia YadA. The two other domains were not recognizably similar to any protein of known structure. We therefore determined their crystal structure to a resolution of 1.1 A. Both domains are beta-prisms, the N-terminal one formed by interleaved, five-stranded beta-meanders parallel to the trimer axis and the C-terminal one by five-stranded beta-meanders orthogonal to the axis. Despite the absence of statistically significant sequence similarity, the two domains are structurally similar to domains from Haemophilus Hia, albeit in permuted order. Thus, the BadA head appears to be a chimera of domains seen in two other TAAs, YadA and Hia, highlighting the combinatorial evolutionary strategy taken by pathogens.

  7. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... MRI of the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive ... of page What are some common uses of the procedure? MR imaging of the head is performed ...

  8. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... MRI of the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive ... of page What are some common uses of the procedure? MR imaging of the head is performed ...

  9. Ulnar head replacement.

    Science.gov (United States)

    Herbert, Timothy J; van Schoonhoven, Joerg

    2007-03-01

    Recent years have seen an increasing awareness of the anatomical and biomechanical significance of the distal radioulnar joint (DRUJ). With this has come a more critical approach to surgical management of DRUJ disorders and a realization that all forms of "excision arthroplasty" can only restore forearm rotation at the expense of forearm stability. This, in turn, has led to renewed interest in prosthetic replacement of the ulnar head, a procedure that had previously fallen into disrepute because of material failures with early implants, in particular, the Swanson silicone ulnar head replacement. In response to these early failures, a new prosthesis was developed in the early 1990s, using materials designed to withstand the loads across the DRUJ associated with normal functional use of the upper limb. Released onto the market in 1995 (Herbert ulnar head prosthesis), clinical experience during the last 10 years has shown that this prosthesis is able to restore forearm function after ulnar head excision and that the materials (ceramic head and noncemented titanium stem), even with normal use of the limb, are showing no signs of failure in the medium to long term. As experience with the use of an ulnar head prosthesis grows, so does its acceptance as a viable and attractive alternative to more traditional operations, such as the Darrach and Sauve-Kapandji procedures. This article discusses the current indications and contraindications for ulnar head replacement and details the surgical procedure, rehabilitation, and likely outcomes.

  10. Maneuvering impact boring head

    Science.gov (United States)

    Zollinger, W. Thor; Reutzel, Edward W.

    1998-01-01

    An impact boring head may comprise a main body having an internal cavity with a front end and a rear end. A striker having a head end and a tail end is slidably mounted in the internal cavity of the main body so that the striker can be reciprocated between a forward position and an aft position in response to hydraulic pressure. A compressible gas contained in the internal cavity between the head end of the striker and the front end of the internal cavity returns the striker to the aft position upon removal of the hydraulic pressure.

  11. Effect of different parts (leaf, stem and stalk) and seasons (summer and winter) on the chemical compositions and antioxidant activity of Moringa oleifera.

    Science.gov (United States)

    Shih, Ming-Chih; Chang, Cheng-Ming; Kang, Sue-Ming; Tsai, Min-Lang

    2011-01-01

    Moringa oleifera, Lam. (Moringaceae) is grown world-wide in the tropics and sub-tropics of Asia and Africa and contains abundant various nutrients. This study describes the effect of different parts (leaf, stem and stalk) and seasons (summer and winter) on the chemical compositions and antioxidant activity of M. oleifera grown in Taiwan. The results showed that the winter samples of Moringa had higher ash (except the stalk part), calcium and phenolic compounds (except the leaf part) and stronger antioxidative activity than summer samples. The methanolic extract of Moringa showed strong scavenging effect of DPPH radicals and reducing power. The trend of antioxidative activity as a function of the part of Moringa was: leaf > stem > stalk for samples from both seasons investigated. The Moringa extract showed strong hydrogen peroxide scavenging activity and high Superoxide Dismutase (SOD) activity except the stalk part.

  12. Effect of Different Parts (Leaf, Stem and Stalk and Seasons (Summer and Winter on the Chemical Compositions and Antioxidant Activity of Moringa oleifera

    Directory of Open Access Journals (Sweden)

    Cheng-Ming Chang

    2011-09-01

    Full Text Available Moringa oleifera, Lam. (Moringaceae is grown world-wide in the tropics and sub-tropics of Asia and Africa and contains abundant various nutrients. This study describes the effect of different parts (leaf, stem and stalk and seasons (summer and winter on the chemical compositions and antioxidant activity of M. oleifera grown in Taiwan. The results showed that the winter samples of Moringa had higher ash (except the stalk part, calcium and phenolic compounds (except the leaf part and stronger antioxidative activity than summer samples. The methanolic extract of Moringa showed strong scavenging effect of DPPH radicals and reducing power. The trend of antioxidative activity as a function of the part of Moringa was: leaf > stem > stalk for samples from both seasons investigated. The Moringa extract showed strong hydrogen peroxide scavenging activity and high Superoxide Dismutase (SOD activity except the stalk part.

  13. Early Head Start Evaluation

    Data.gov (United States)

    U.S. Department of Health & Human Services — Longitudinal information from an evaluation where children were randomly assigned to Early Head Start or community services as usual;direct assessments and...

  14. Computed Tomography (CT) -- Head

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    Full Text Available ... you! Do you have a personal story about radiology? Share your patient story here Images × Image Gallery ... Pregnancy Head and Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to ...

  15. Head and face reconstruction

    Science.gov (United States)

    ... work together. Head and neck surgeons also perform craniofacial reconstruction operations. The surgery is done while you are deep asleep and pain-free (under general anesthesia ). The surgery may take ...

  16. Computed Tomography (CT) -- Head

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    Full Text Available ... headaches, dizziness, and other symptoms of aneurysm, bleeding, stroke and brain tumors. It also helps your doctor ... scanning provides more detailed information on head injuries, stroke , brain tumors and other brain diseases than regular ...

  17. Computed Tomography (CT) -- Head

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    Full Text Available ... a stroke, especially with a new technique called Perfusion CT. brain tumors. enlarged brain cavities (ventricles) in ... X-Ray and CT Exams Blood Clots CT Perfusion of the Head CT Angiography (CTA) Stroke Brain ...

  18. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... traditional x-rays, particularly of soft tissues and blood vessels. CT scanning provides more detailed information on head injuries, stroke , brain tumors and other brain diseases than ...

  19. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... special x-ray equipment to help assess head injuries, severe headaches, dizziness, and other symptoms of aneurysm, ... cancer. In emergency cases, it can reveal internal injuries and bleeding quickly enough to help save lives. ...

  20. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... headaches, dizziness, and other symptoms of aneurysm, bleeding, stroke and brain tumors. It also helps your doctor ... scanning provides more detailed information on head injuries, stroke , brain tumors and other brain diseases than regular ...

  1. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... images of internal organs, bones, soft tissue and blood vessels provide greater detail than traditional x-rays, particularly of soft tissues and blood vessels. CT scanning provides more detailed information on head ...

  2. Head CT scan

    Science.gov (United States)

    Brain CT; Cranial CT; CT scan - skull; CT scan - head; CT scan - orbits; CT scan - sinuses; Computed tomography - cranial; CAT scan - brain ... hold your breath for short periods. A complete scan usually take only 30 seconds to a few ...

  3. Head Start Impact Study

    Data.gov (United States)

    U.S. Department of Health & Human Services — Nationally representative, longitudinal information from an evaluation where children were randomly assigned to Head Start or community services as usual;direct...

  4. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... special x-ray equipment to help assess head injuries, severe headaches, dizziness, and other symptoms of aneurysm, ... cancer. In emergency cases, it can reveal internal injuries and bleeding quickly enough to help save lives. ...

  5. Head and neck teratomas

    OpenAIRE

    Shah, Ajaz; Latoo, Suhail; Ahmed, Irshad; Malik, Altaf H

    2009-01-01

    Teratomas are complex lesions composed of diverse tissues from all 3 germinal cell layers and may exhibit variable levels of maturity. Head and neck teratomas are most commonly cervical with the oropharynx (epignathus) being the second commonest location. In this article, clinical presentation, behaviour and associated significance of head and neck teratomas have been highlightened. Because of their obscure origin, bizarre microscopic appearance, unpredictable behaviour and often dramatic cli...

  6. Effect of Different Parts (Leaf, Stem and Stalk) and Seasons (Summer and Winter) on the Chemical Compositions and Antioxidant Activity of Moringa oleifera

    OpenAIRE

    Cheng-Ming Chang; Min-Lang Tsai; Sue-Ming Kang; Ming-Chih Shih

    2011-01-01

    Moringa oleifera, Lam. (Moringaceae) is grown world-wide in the tropics and sub-tropics of Asia and Africa and contains abundant various nutrients. This study describes the effect of different parts (leaf, stem and stalk) and seasons (summer and winter) on the chemical compositions and antioxidant activity of M. oleifera grown in Taiwan. The results showed that the winter samples of Moringa had higher ash (except the stalk part), calcium and phenolic compounds (except the leaf part) and stron...

  7. Seasonal Variation of the Effect of Extremely Diluted Agitated Gibberellic Acid (10e-30) on Wheat Stalk Growth: A Multiresearcher Study

    OpenAIRE

    Peter Christian Endler; Wolfgang Matzer; Christian Reich; Thomas Reischl; Anna Maria Hartmann; Karin Thieves; Andrea Pfleger; Jürgen Hofäcker; Harald Lothaller; Waltraud Scherer-Pongratz

    2011-01-01

    The influence of a homeopathic high dilution of gibberellic acid on wheat growth was studied at different seasons of the year. Seedlings were allowed to develop under standardized conditions for 7 days; plants were harvested and stalk lengths were measured. The data obtained confirm previous findings, that ultrahigh diluted potentized gibberellic acid affects stalk growth. Furthermore, the outcome of the study suggests that experiments utilizing the bioassay presented should best be performed...

  8. Protective effects of egg stalk of Paratrioza sinica (Hemiptera: Psyllidae) at various angles and spacing against three predaceous coccinellids, Harmonia axyridis, Coccinella septempunctata and Hippodamia variegata (Coleoptera: Coccinellidae).

    Science.gov (United States)

    Wu, Pengxiang; Ma, Baoxu; Yan, Shuo; Xu, Jing; He, Jia; Zhang, Rong; Zhang, Runzhi

    2017-08-26

    Paratrioza sinica, is a major pest of wolfberries. Coccinellids could effectively control various developmental stages of P. sinica damage except the stalked egg. To analyze the protective role of egg stalks against predaceous coccinellids, Harmonia axyridis, Coccinella septempunctata and Hippodamia variegata, we studied the functional responses and effects of two potential factors: the angle between egg stalk and leaf plane, and the spacing between egg stalks. The searching rate, handling time and theoretical maximum egg consumption of H. variegata was optimal among 3 ladybug species. The egg consumption by coccinellids were maximum and minimum at 0° and 90°, respectively. Average reduction rates from 0° to 90° of egg consumed by larvae of coccinellids and H. variegata were significantly lower compared to adults and other 2 species, respectively. Optimal spacing of egg consumption varied with different predator species and their developmental stages, which were nearly close to the body lengths of predators. Egg stalk was served as a physical protection against the predators. Selective advantage of egg stalk is a facilitator in protection against predators during evolution, which needs more attention. Reasonable selection of predator and irrigation strategy may exhibit positive control performance. This article is protected by copyright. All rights reserved.

  9. Eggs of Mallada desjardinsi (Neuroptera: Chrysopidae) are protected by ants: the role of egg stalks in ant-tended aphid colonies.

    Science.gov (United States)

    Hayashi, Masayuki; Nomura, Masashi

    2014-08-01

    In ant-aphid mutualisms, ants usually attack and exclude enemies of aphids. However, larvae of the green lacewing Mallada desjardinsi (Navas) prey on ant-tended aphids without being excluded by ants; these larvae protect themselves from ants by carrying aphid carcasses on their backs. Eggs of M. desjardinsi laid at the tips of stalks have also been observed in ant-tended aphid colonies in the field. Here, we examined whether the egg stalks of M. desjardinsi protect the eggs from ants and predators. When exposed to ants, almost all eggs with intact stalks were untouched, whereas 50-80% of eggs in which stalks had been severed at their bases were destroyed by ants. In contrast, most eggs were preyed upon by larvae of the lacewing Chrysoperla nipponensis (Okamoto), an intraguild predator of M. desjardinsi, regardless of whether their stalks had been severed. These findings suggest that egg stalks provide protection from ants but not from C. nipponensis larvae. To test whether M. desjardinsi eggs are protected from predators by aphid-tending ants, we introduced C. nipponensis larvae onto plants colonized by ant-tended aphids. A significantly greater number of eggs survived in the presence of ants because aphid-tending ants excluded larvae of C. nipponensis. This finding indicates that M. desjardinsi eggs are indirectly protected from predators by ants in ant-tended aphid colonies.

  10. The production of glucose from corn stalk using hydrothermal process with pre-treatment ultrasound assisted alkaline

    Science.gov (United States)

    Yolanda, Dora; Prasutiyo, Indry; Trisanti, P. N.; Sumarno

    2015-12-01

    The production of glucose from corn stalk by using subcritical hydrothermal technology is studied in this work. Ultrasound-assisted alkaline delignification methods are used as pre-treatment. The corn stalk powder were pretreated with ultrasound-assisted alkaline (NaOH 2% w/w, solid to liquid ratio 1:22 w/v) at room temperature and 30 minutes. After pre-treatment, solid residue and liquid fractions are separated by filtration. Pretreated solids are further submitted to hydrothermal process for glucose production. Hydrothermal process was carried out at 100 Bar and 120°C in various times. The solid product was characterized by SEM and XRD. And liquid product was analysis using DNS method to determine percentage of glucose. From XRD analysis showed that crystallinity of material was lower than delignification product.

  11. Catalytic conversion of xylose and corn stalk into furfural over carbon solid acid catalyst in γ-valerolactone.

    Science.gov (United States)

    Zhang, Tingwei; Li, Wenzhi; Xu, Zhiping; Liu, Qiyu; Ma, Qiaozhi; Jameel, Hasan; Chang, Hou-min; Ma, Longlong

    2016-06-01

    A novel carbon solid acid catalyst was synthesized by the sulfonation of carbonaceous material which was prepared by carbonization of sucrose using 4-BDS as a sulfonating agent. TEM, N2 adsorption-desorption, elemental analysis, XPS and FT-IR were used to characterize the catalyst. Then, the catalyst was applied for the conversion of xylose and corn stalk into furfural in GVL. The influence of the reaction time, temperature and dosage of catalyst on xylose dehydration were also investigated. The Brønsted acid catalyst exhibited high activity in the dehydration of xylose, with a high furfural yield of 78.5% at 170°C in 30min. What's more, a 60.6% furfural yield from corn stalk was achieved in 100min at 200°C. The recyclability of the sulfonated carbon catalyst was perfect, and it could be reused for 5times without the loss of furfural yields.

  12. Antagonistic and Biocontrol Potential of Trichoderma asperellum ZJSX5003 Against the Maize Stalk Rot Pathogen Fusarium graminearum.

    Science.gov (United States)

    Li, Yaqian; Sun, Ruiyan; Yu, Jia; Saravanakumar, Kandasamy; Chen, Jie

    2016-09-01

    The efficacy of seven strains of Trichoderma asperellum collected from the fields in Southern China was assessed against Fusarium graminearum (FG) the causal agent of corn stalk rot of maize were in vitro for their antagonistic properties followed by statistical model of principal compound analysis to identify the beneficial antagonist T. asperellum strain. The key factors of antagonist activity were attributed to a total of 13 factors including cell wall degrading enzymes (chitnase, protease and β-glucanases), secondary metabolites and peptaibols and these were analyzed from eight strains of Trichoderma. A linear regression model demonstrated that interaction of enzymes and secondary metabolites of T. asperellum strain ZJSX5003 enhanced the antagonist activity against FG. Further, this strain displayed a disease reduction of 71 % in maize plants inoculated with FG compared to negative control. Pointing out that the T. asperellum strain ZJSX5003 is a potential source for the development of a biocontrol agent against corn stalk rot.

  13. The structural characterization of corn stalks hemicelluloses during active oxygen cooking as a pretreatment for biomass conversion

    Directory of Open Access Journals (Sweden)

    Jian-Bin Shi

    2012-11-01

    Full Text Available The structural characteristics of corn stalks hemicelluloses during the active oxygen cooking process as a pretreatment of biomass conversion were investigated in this work. The hemicelluloses obtained from the corn stalks, pulp, and yellow liquor were evaluated by high-performance anion-exchange chromatography (HPAEC, Fourier transform infrared spectroscopy (FT-IR, gel permeation chromatography (GPC, and 1H-13C 2D hetero-nuclear single quantum coherence (HSQC spectroscopy. Based on the sugar and GPC analysis, FT-IR, and NMR spectroscopy, it could be concluded that the hemicelluloses were composed of backbones of (1→4-β-D-xylopyranose substituted α-L-arabinofuranose and 4-O-methyl-α-D-glucuronic acid. During the cooking process, the hemicelluloses with more side chains were removed from raw material. The backbones were significantly damaged as well. Additionally, the ester linkages in the raw material were completely broken after the cooking.

  14. EFFECT OF INHIBITORS ON ENZYMATIC HYDROLYSIS AND SIMULTANEOUS SACCHARIFICATION FERMENTATION FOR LACTIC ACID PRODUCTION FROM STEAM EXPLOSION PRETREATED LESPEDEZA STALKS

    Directory of Open Access Journals (Sweden)

    Yue Feng,

    2012-06-01

    Full Text Available The effects on both cellulose conversion rate and lactic acid yield were studied by adding inhibitors, including formic acid, acetic acid, furfural, and vanillin into the hydrolysate of steam-pretreated Lespedeza stalks. The results suggest that formic acid has a significant influence on the enzyme activity and poisoned bacterial cells, resulting in the reduction of cellulose conversion rate and lactic acid yield by 21% and 16.4%, respectively. Acetic acid showed a strong inhibition on simultaneous saccharification fermentation (SSF process, but little effect on enzymatic hydrolysis. Hydrolysis and SSF were less affected by furfural and vanillin compared with weak acids. The lactic acid yield of Lespedeza stalks rinsed with water increased from 64.0% to 89.4%, and the time to reach the maximum concentration was shortened from 96 hours to 48 hours when compared with the unwashed materials.

  15. The Orphan Receptor Tie1 Controls Angiogenesis and Vascular Remodeling by Differentially Regulating Tie2 in Tip and Stalk Cells.

    Science.gov (United States)

    Savant, Soniya; La Porta, Silvia; Budnik, Annika; Busch, Katrin; Hu, Junhao; Tisch, Nathalie; Korn, Claudia; Valls, Aida Freire; Benest, Andrew V; Terhardt, Dorothee; Qu, Xianghu; Adams, Ralf H; Baldwin, H Scott; Ruiz de Almodóvar, Carmen; Rodewald, Hans-Reimer; Augustin, Hellmut G

    2015-09-22

    Tie1 is a mechanistically poorly characterized endothelial cell (EC)-specific orphan receptor. Yet, Tie1 deletion is embryonic lethal and Tie1 has been implicated in critical vascular pathologies, including atherosclerosis and tumor angiogenesis. Here, we show that Tie1 does not function independently but exerts context-dependent effects on the related receptor Tie2. Tie1 was identified as an EC activation marker that is expressed during angiogenesis by a subset of angiogenic tip and remodeling stalk cells and downregulated in the adult quiescent vasculature. Functionally, Tie1 expression by angiogenic EC contributes to shaping the tip cell phenotype by negatively regulating Tie2 surface presentation. In contrast, Tie1 acts in remodeling stalk cells cooperatively to sustain Tie2 signaling. Collectively, our data support an interactive model of Tie1 and Tie2 function, in which dynamically regulated Tie1 versus Tie2 expression determines the net positive or negative effect of Tie1 on Tie2 signaling.

  16. INFLUENCE OF STEAM PRESSURE ON THE PHYSICO-CHEMICAL PROPERTIES OF DEGRADED HEMICELLULOSES OBTAINED FROM STEAM-EXPLODED LESPEDEZA STALKS

    Directory of Open Access Journals (Sweden)

    Kun Wang

    2010-06-01

    Full Text Available Steam explosion pretreatment was used to release hemicelluloses from the stalks of Lespedeza crytobotrya, a potential woody biomass crop. Hemicelluloses from Lespedeza crytobotrya subjected to five different pretreatment severities were extracted with 60% aqueous ethanol solution containing 1% NaOH, characterized by component analysis, gel permeation chromatography (GPC, FT-IR, NMR spectroscopy, and thermal analysis, and compared with hemicelluloses obtained from untreated stalks. It was found that the hemicellulosic fractions mainly consisted of arabinoxylans and β-glucans or xyloglucans. Steam explosion pretreatment yielded noticeable degradation and debranching reactions, illustrated by a linear decrease of molecular weight and Ara/Xyl ratio with increasing severity. For further high-value utilization of the hemicellulosic polymers, steam explosion at 20 or 22.5 kg/m2 for 4 min is promising because of improved extraction efficiency and avoidance of over-drastic degradation of the polymers.

  17. Antagonism of Gluconacetobacter diazotrophicus (a sugarcane endosymbiont) against Xanthomonas albilineans (pathogen) studied in alginate-immobilized sugarcane stalk tissues.

    Science.gov (United States)

    Blanco, Yolanda; Blanch, María; Piñón, Dolores; Legaz, María-Estrella; Vicente, Carlos

    2005-04-01

    Xanthomonas albilineans, a pathogenic bacterium that produces leaf scald disease of sugarcane, secretes a xanthan-like gum that invades both xylem and phloem of the host. Xanthan production has been verified after experimental infection of stalk segments of healthy plants. Moreover, Gluconacetobacter diazotrophicus is a nitrogen-fixing endosymbiont of sugarcane plants that antagonizes with X. albilineans by impeding the production of the bacterial gum. The physiological basis of this antagonism has been studied using tissues of sugarcane stalks previously inoculated with the endosymbiont, then immobilized in calcium alginate and maintained in a culture medium for Gluconacetobacter. Under these conditions, bacteria infecting immobilized tissues are able to secrete to the medium a lysozyme-like bacteriocin that inhibits the growth of X. albilineans.

  18. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head ... limitations of MRI of the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is ...

  19. Missouri: Early Head Start Initiative

    Science.gov (United States)

    Center for Law and Social Policy, Inc. (CLASP), 2012

    2012-01-01

    Missouri's Early Head Start/Child Care Partnership Project expands access to Early Head Start (EHS) services for children birth to age 3 by developing partnerships between federal Head Start, EHS contractors, and child care providers. Head Start and EHS contractors that participate in the initiative provide services through community child care…

  20. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head uses a powerful ... the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive medical test that ...