Proteomic identification of putative microRNA394 target genes in Arabidopsis thaliana identifies MLP family members critical for normal development

Expression of the F-Box protein Leaf Curling Responsiveness (LCR) is regulated by microRNA, miR394, and alterations to this interplay in Arabidopsis thaliana produce defects in leaf polarity and shoot apical meristem (SAM) organisation. Although the miR394-LCR node has been documented in Arabidopsis, the identification of proteins targeted by LCR F-box itself has proven problematic. Here, a proteomic analysis of shoot apices from plants with altered LCR levels identified a member of the Major Latex Protein (MLP) family gene as a potential LCR F-box target. Bioinformatic and molecular analyses also suggested that other MLP family members are likely to be targets for this post-translational regulation. Direct interaction between LCR F-Box and MLP423 was validated. Additional MLP members had reduction in protein accumulation, in varying degrees, mediated by LCR F-Box. Transgenic Arabidopsis lines, in which MLP28 expression was reduced through an artificial miRNA technology, displayed severe developmental defects, including changes in leaf patterning and morphology, shoot apex defects, and eventual premature death. These phenotypic characteristics resemble those of Arabidopsis plants modified to over-express LCR. Taken together, the results demonstrate that MLPs are driven to degradation by LCR, and indicate that MLP gene family is target of miR394-LCR regulatory node, representing potential targets for directly post-translational regulation mediated by LCR F-Box. In addition, MLP28 family member is associated with the LCR regulation that is critical for normal Arabidopsis development.

Higher order vortex gyrotropic modes in circular ferromagnetic nanodots

Magnetic vortex that consists of an in-plane curling magnetization configuration and a needle-like core region with out-of-plane magnetization is known to be the ground state of geometrically confined submicron soft magnetic elements. Here magnetodynamics of relatively thick (50-100 nm) circular Ni80Fe20 dots were probed by broadband ferromagnetic resonance in the absence of external magnetic field. Spin excitation modes related to the thickness dependent vortex core gyrotropic dynamics were detected experimentally in the gigahertz frequency range. Both analytical theory and micromagnetic simulations revealed that these exchange dominated modes are flexure oscillations of the vortex core string with n = 0,1,2 nodes along the dot thickness. The intensity of the mode with n = 1 depends significantly on both dot thickness and diameter and in some cases is higher than the one of the uniform mode with n = 0. This opens promising perspectives in the area of spin transfer torque oscillators.

OsRMC基因调控水稻根生长发育的机理研究

实验室前期工作证明OsRAA1在玉米泛素启动子驱动下组成型表达，可以抑制水稻初生根的生长，促进不定根的形成，形成不同程度螺旋状的初生根，根的向地性反应减缓，这些表型和野生型水稻用生长素处理的表型类似，而且OsRAA1基因的转录受生长素诱导，这些结果表明OsRAA1可能参与了生长素的信号转导途径。但这些表型产生的机理还不是很清楚。在水稻中，茉莉酸在根发育过程中的作用多为生理实验的报道;拟南芥中的研究表明生长素信号转导和茉莉酸信号转导可能都受26S蛋白酶体的调控。由此我们推测茉莉酸在根的发育过程中可能也起着同样的促进作用。本论文在超表达OsRAA1水稻基础上旨在克隆新基因，并对新基因功能进行研究，以探讨茉莉酸在水稻根发育过程中的分子机理，并对生长素和茉莉酸信号转导的关系进行探讨。 　　首先运用双向电泳技术结合质谱分析技术，在超表达OsRAA1水稻背景下发现了受体激酶家族DUF26的一个成员明显下调，我们命名为OsRMC（Oryza sativa Root Meander and Curling，AAL87185），Western杂交进一步证明了这个结果。 　　OsRMC位于4号染色体，信息学分析表明只有一个拷贝，没有内含子，ORF阅读框为777bp，编码的蛋白分子量为27.9 kDa，等电点（pI）为5.01。对该蛋白进行同源性比较发现，其含有2个C-X8-C-X2-C基序（Cys-rich repeat, CRR）即半胱氨酸富集区，其中第四个半胱氨酸残基不保守，该基序会形成二硫键，编码两个未知功能的DUF26（Domain Unknown Function 26）结构域。OsRMC由一个信号肽和两个CRR区组成，但没有跨膜区和激酶区。RT-PCR显示OsRMC可能是组成型表达的基因;亚细胞实验表明OsRMC是膜定位的蛋白。Western blot显示OsRMC受茉莉酸诱导表达，受生长素的抑制。 　　RNAiOsRMC转基因水稻在暗处培养时，抑制了初生根的生长，使侧根数目减少，但促进了不定根的生长和数目的增加;第二叶鞘变短，这些表型和前人报道的外源茉莉酸处理野生型的表型一致。转基因对生长素信号转导和合成没有影响，但初生根和第二叶鞘对外源茉莉酸更加敏感，说明RNAiOsRMC转基因水稻可能增强了茉莉酸信号转导途径。分析转基因水稻的茉莉酸信号转导途径部分相关基因的表达变化，根中受茉莉酸信号转导特异诱导的病原相关基因RSOsPR10的表达明显增多，而JAmyb和OsNDPK1的表达没有变化，证实转基因增强了茉莉酸信号转导其中的一个路径;进一步分析茉莉酸合成途径12-OXO-PDA（12-氧代-顺，顺-10，15-植物二烯酸）还原酶基因OsOPR的表达发现与野生型没有明显差别，说明转基因可能没有影响体内的茉莉酸合成途径。RNAiOsRMC转基因水稻的初生根比野生型的更容易发生弯曲，实验表明培养过程中茉莉酸和背触反应（negative thigmotropism）共同作用使转基因的初生根更容易发生卷曲，而光信号会增强卷曲程度。但RNAiOsRMC转基因水稻并没有影响根的向地性，暗示RNAiOsRMC转基因可能增强了根的回旋运动或（和）背触反应，从而促进了根的弯曲和卷曲。这些结果证明OsRMC参与的茉莉酸信号转导过程在水稻根的发育、弯曲和卷曲过程中起着重要的促进作用。通过对超表达OsRAA1和RNAiOsRMC转基因水稻的分析，说明水稻中存在着生长素信号转导促进茉莉酸信号转导的途径。 　　综合以上实验结果认为，OsRAA1调控了受体激酶家族DUF26的一个成员OsRMC，使其表达量降低，该过程增强了茉莉酸信号转导途径;确认了受体激酶家族DUF26的基因具有重要的生物学功能，证实了OsRMC调控的茉莉酸信号转导在水稻根系发育、根弯曲和卷曲过程中具有重要的促进作用;证明水稻中存在着生长素信号转导促进茉莉酸信号转导的途径，为完善各种植物激素调控水稻根系发育的网络提供了新的实验证据。 　　 　　

Modelling the mechanical response of the Reed-mouthpiece-lip system of a clarinet. Part I. A one-dimensional distributed model

The motion of a clarinet reed that is clamped to a mouthpiece and supported by a lip is simulated in the time-domain using finite difference methods. The reed is modelled as a bar with non-uniform cross section, and is described using a one-dimensional, fourth-order partial differential equation. The interactions with the mouthpiece Jay and the player's lip are taken into account by incorporating conditional contact forces in the bar equation. The model is completed by clamped-free boundary conditions for the reed. An implicit finite difference method is used for discretising the system, and values for the physical parameters are chosen both from laboratory measurements and by accurate tuning of the numerical simulations. The accuracy of the numerical system is assessed through analysis of frequency warping effects and of resonance estimation. Finally, the mechanical properties of the system are studied by analysing its response to external driving forces. In particular, the effects of reed curling are investigated.

Coaches

A seated Ed Davis points out to (form left to right) Dr. Gunther Doeker, Fencing Coach; Mr. Les Korchok, Basketball Coach; Prof. A. G. Lowenberger, Director of Physical Education and Recreation; Mr. Tony Biernacki, Rowing Coach; Dr. E. Mirynech, Faculty Advisor; and Dr. Cam Lewis, Curling Coach when Brock will open its 1967-68 Ontario Intercollegiate hockey season.

Managing Volunteers in Canadian Community Sport Organizations

This study examined the use of human resource management (HRM) practices with volunteers in Canadian Community Sport Organizations (CSOs). Using the Volunteer Management Inventory (VMI; Cuskelly, Taylor, Hoye & Darcy, 2006), 219 leaders of associations in basketball, curling, ice hockey, skating, skiing, swimming, and volleyball participated in this study and identified current trends in HRM practices and perceived issues in the retention of volunteers. Data collected was analyzed using mean and descriptive statistics, T-tests, ANOVAs, and regression analyses. Results indicate that there is a varying use of HRM practices amongst the organizations, and also a significant correlation between the use of HRM practices and the retention of volunteers, particularly board members. Implications and future research directions are discussed regarding how HRM practices and principles may be applied to CSOs.

Proline Accumulation and Salt Tolerance in Rice

The morphological and biochemical response of calli and seedlings of different rice cultivars were compared under acid saline conditions. Calli of both tolerant and sensitive varieties showed severe stress symptoms like browning and necrosis, but the onset of stress symptoms was delayed in Pokkali. Seedlings of Pokkali showed minimal stress symptoms in lower salinities, and curling and senescence of older leaves in higher salinities although plants revived on amelioration of stress. Seedlings of the other varieties showed severe stress symptoms even at low salinities and plant death at higher salinities. Salt stress induced accumulation of the putative osmoprotectant proline in calli and seedlings of all varieties. Proline accumulation was higher in sensitive varieties than in Pokkali. These results indicate that proline accumulation is not directly correlated with salt tolerance in rice.

Comparación: injerto libre o cierre primario más lente de contacto, en resección de tumores de conjuntiva limbar

INTRODUCCION: Existe controversia en cuanto a la técnica quirúrgica para el manejo de tumores del limbo conjuntival. El uso de cierre primario con uso de lente de contacto puede ofrecer una mejor cicatrización y tener ventajas adicionales sobre la técnica tradicional con el uso de plastia. OBJETIVOS: Comparar los resultados en cuanto a grado de dolor, picadas, prurito, porcentaje de epitelización y cicatrización, comodidad del paciente, grado de quemosis y tiempo de retorno a actividades diarias en ambas técnicas quirúrgicas. MATERIALES Y METODOS: Experimento clínico controlado aleatorizado en dos grupos: Al primer grupo se le realizó cirugía de resección de la lesión más plastia. Al segundo grupo se le practicó la resección de la lesión cierre primario y lente de contacto. El seguimiento se realizó al primer y cuarto día, y cada semana durante el primer mes de postoperatorio. Se utilizó el SPSS 20.0 ® para análisis estadístico de datos y se utilizó estadística no paramétrica. RESULTADOS: Se conto con 10 pacientes por grupo. El dolor y porcentaje de cicatrización al primer día postoperatorio fueron mayores en el grupo usando lente de contacto (p=0.048). Al cuarto día postquirúrgico se encontró un mayor porcentaje de cicatrización en el grupo usando lente de contacto. (p=0.075). CONCLUSIONES: El cierre por afrontamiento con uso de lente de contacto mostró dolor y picadas mayores al primer y cuarto día postoperatorio. Pero la epitelización y cicatrización fueron tempranas con un retorno corto a actividades cotidianas.

Contrasting responses to drought stress in herbaceous perennial legumes

Background and aims Medicago sativa L. is widely grown in southern Australia, but is poorly adapted to dry, hot summers. This study aimed to identify perennial herbaceous legumes with greater resistance to drought stress and explore their adaptive strategies. Methods Ten herbaceous perennial legume species/accessions were grown in deep pots in a sandy, low-phosphorus field soil in a glasshouse. Drought stress was imposed by ceasing to water. A companion M. sativa plant in each pot minimised differences in leaf area and water consumption among species. Plants were harvested when stomatal conductance of stressed plants decreased to around 10% of well watered plants. Results A range of responses to drought stress were identified, including: reduced shoot growth; leaf curling; thicker pubescence on leaves and stems; an increased root:shoot ratio; an increase, decrease or no change in root distribution with depth; reductions in specific leaf area or leaf water potential; and osmotic adjustment. The suite of changes differed substantially among species and, less so, among accessions. Conclusions The inter- and intra-specific variability of responses to drought-stress in the plants examined suggests a wide range of strategies are available in perennial legumes to cope with drying conditions, and these could be harnessed in breeding/selection programs.

New features of Cuban endemic Pinguicula filifolia (Lentibulariaceae) and considerations on its habitat and ecology

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Sintomas de deficiências de macronutrientes em pimentão

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Avaliação da influência de variáveis na produção de batentes de painel EGP de Pinus taeda

Pós-graduação em Engenharia Mecânica - FEG

Evolutionary tendencies in flowers of Marantaceae with special reference to the style movement mechanism

One of the quickest plant movements ever known is made by the ´explosive´ style in Marantaceae in the service of secondary pollen presentation – herewith showing a striking apomorphy to the sister Cannaceae that might be of high evolutionary consequence. Though known already since the beginning of the 19th century the underlying mechanism of the movement has hitherto not been clarified. The present study reports about the biomechanics of the style-staminode complex and the hydraulic principles of the movement. For the first time it is shown by experiment that in Maranta noctiflora through longitudinal growth of the maturing style in the ´straitjacket´ of the hooded staminode both the hold of the style prior to its release and its tensioning for the movement are brought about. The longer the style grows in relation to the enclosing hooded staminode the more does its capacity for curling up for pollen transfer increase. Hereby I distinguish between the ´basic tension´ that a growing style builds up anyway, even when the hooded staminode is removed beforehand, and the ´induced tension´ which comes about only under the pressure of a ´too short´ hooded staminode and which enables the movement. The results of these investigations are discussed in view of previous interpretations ranging from possible biomechanical to electrophysiological mechanisms. To understand furthermore by which means the style gives way to the strong bending movement without suffering outwardly visible damage I examined its anatomical structure in several genera for its mechanical and hydraulic properties and for the determination of the entire curvature after release. The actual bending part contains tubulate cells whose walls are extraordinarily porous and large longitudinal intercellular spaces. SEM indicates the starting points of cell-wall loosening in primary walls and lysis of middle lamellae - probably through an intense pectinase activity in the maturing style. Fluorescence pictures of macerated and living style-tissue confirm cell-wall perforations that do apparently connect neighbouring cells, which leads to an extremely permeable parenchyma. The ´water-body´ can be shifted from central to dorsal cell layers to support the bending. The geometrical form of the curvature is determined by the vascular bundles. I conclude that the style in Marantaceae contains no ´antagonistic´ motile tissues as in Mimosa or Dionaea. Instead, through self-maceration it develops to a ´hydraulic tissue´ which carries out an irreversible movement through a sudden reshaping. To ascertain the evolutionary consequence of this apomorphic pollination mechanism the diversity and systematic value of hooded staminodes are examined. For this hooded staminodes of 24 genera are sorted according to a minimalistic selection of shape characters and eight morphological types are abstracted from the resulting groups. These types are mapped onto an already available maximally parsimonious tree comprising five major clades. An amazing correspondence is found between the morphological types and the clades; several sister-relationships are confirmed and in cases of uncertain position possible evolutionary pathways, such as convergence, dispersal or re-migration, are discussed, as well as the great evolutionary tendencies for the entire family in which – at least as regards the shape of hooded staminodes – there is obviously a tendency from complicated to strongly simplified forms. It suggests itself that such simplifying derivations may very likely have taken place as adaptations to pollinating animals about which at present too little is known. The value of morphological characters in relation to modern phylogenetic analysis is discussed and conditions for the selection of morphological characters valuable for a systematic grouping are proposed. Altogether, in view of the evolutionary success of Marantaceae compared with Cannaceae the movement mechanism of the style-staminode complex can safely be considered a key innovation within the order Zingiberales.

Ermittlung optimaler Bauteilorientierung zur Verbesserung der Prozessplanung in der CAD/RP-Kette

Ein wesentlicher Einflussfaktor auf die Bauteilqualität und Prozessgüte bei der generativen Herstellung von Prototypen ist die Orientierung der Bauteile. So kann eine optimierte Ausrichtung den Treppenstufeneffekt (Staircasing) sowie den Curling-Effekt minimieren und somit die Oberflächenqualität bzw. die Bauteilgenauigkeit erhöhen oder die Berücksichtigung von Formtoleranzen (z.B. Rundheit) ermöglichen. Des Weiteren können verschiedene Bauteilausrichtungen unterschiedliche Ausführungen von Stützkonstruktionen bewirken und die Bauteilstabilität beeinflussen. Diese und ähnliche Wechselwirkungen gilt es bei der Auswahl einer geeigneten Bauteilorientierung für RP-Anwendungen zu berücksichtigen. Dieser Vortrag stellt ein generisches System vor, welches unter Berücksichtigung der genannten Einflussfaktoren sowie weiterer Effekte eine rechnergestützte Optimierung der Bauteilorientierung durchführt. Neben der weiterhin notwendigen Erfahrung der Anwender zur endgültigen Festlegung der fallabhängigen Bauteilausrichtung liefert das System Vorschläge auf Basis einer intensiven Geometrieanalyse, die eine entsprechende Datenaufbereitung im Rahmen der Prozessplanung unterstützen.

Traité pratique des maladies du testicule, du cordon spermatique et du scrotum /

Mode of access: Internet.