13,889 research outputs found

    Directional selection effects on patterns of phenotypic (co)variation in wild populations.

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    Phenotypic (co)variation is a prerequisite for evolutionary change, and understanding how (co)variation evolves is of crucial importance to the biological sciences. Theoretical models predict that under directional selection, phenotypic (co)variation should evolve in step with the underlying adaptive landscape, increasing the degree of correlation among co-selected traits as well as the amount of genetic variance in the direction of selection. Whether either of these outcomes occurs in natural populations is an open question and thus an important gap in evolutionary theory. Here, we documented changes in the phenotypic (co)variation structure in two separate natural populations in each of two chipmunk species (Tamias alpinus and T. speciosus) undergoing directional selection. In populations where selection was strongest (those of T. alpinus), we observed changes, at least for one population, in phenotypic (co)variation that matched theoretical expectations, namely an increase of both phenotypic integration and (co)variance in the direction of selection and a re-alignment of the major axis of variation with the selection gradient

    Activation of type II calcium/calmodulin-dependent protein kinase by Ca^(2+)/calmodulin is inhibited by autophosphorylation of threonine within the calmodulin-binding domain

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    It is now well established that autophosphorylation of a threonine residue located next to each calmodulin-binding domain in the subunits of type II Ca^(2+)/calmodulin-dependent protein kinase causes the kinase to remain active, although at a reduced rate, after Ca^(2+) is removed from the reaction. This autophosphorylated form of the kinase is still sensitive to Ca2+/calmodulin, which is required for a maximum catalytic rate. After removal of Ca^(2+), new sites are autophosphorylated by the partially active kinase. Autophosphorylation of these sites abolishes sensitivity of the kinase to Ca^(2+)/calmodulin (Hashimoto, Y., Schworer, C. M., Colbran, R. J., and Soderling, T. R. (1987) J. Biol. Chem. 262, 8051-8055). We have identified two pairs of homologous residues, Thr^(305) and Ser^(314) in the alpha subunit and Thr^(306) and Ser^(315) in the beta subunit, that are autophosphorylated only after removal of Ca^(2+) from an autophosphorylation reaction. The sites were identified by direct sequencing of labeled tryptic phosphopeptides isolated by reverse-phase high pressure liquid chromatography. Thr^(305-306) is rapidly dephosphorylated by purified protein phosphatases 1 and 2A, whereas Ser^(314-315) is resistant to dephosphorylation. We have shown by selective dephosphorylation that the presence of phosphate on Thr^(305-306) blocks sensitivity of the kinase to Ca^(2+)/calmodulin. In contrast, the presence of phosphate on Ser^(314-315) is associated with an increase in the Kact for Ca^(2+)/calmodulin of only about 2-fold, producing a relatively small decrease in sensitivity to Ca^(2+)/calmodulin

    Omission of Realty in Probate Administration

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    Evolution of Legislation on Proof of Title to Land

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    Possessory titles are recognized by the courts when they protect a first trespassing squatter against acts of a subsequent trespasser. They are given priority over the claims of the conventional title holder when the latter has lost his right to judicial assistance by reason of acts which raise an estoppel or for failure to act within a period of time which the courts or the legislature have fixed as a limitation of action. In these cases the holder of the possessory title may by court action secure a documentary title in the form of a judgment which confirms a title acquired by estoppel or by adverse possession

    PREPARATION OF A MODEL PROBATE CODE

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    At the 1940 meeting of the American Bar Association held in Philadelphia, the Section of Real Property, Probate and Trust Law included in its program a discussion of the proposal of a Model Probate Code. The section had previously had committees to consider the subjects of uniformity in probate codes and improvement in probate practice, and its programs had included not only reports of these committees but addresses outlining the increasing importance of probate law and the need for statutes which would create adequate standards of practice and administration. During the year 1940 the Journal of the American Judicature Society had carried a series of articles by Professor Thomas E. Atkinson on probate courts and procedure which was concluded in the February issue under the heading Wanted-A Model Probate Code. After pointing out a few of the archaic and inconsistent provisions of the codes of some states, Professor Atkinson called attention to the fact that in recent years several states had enacted new probate codes, all of them undoubted improvements over their previous codes. The drafting was done by committees, councils or commissions and the new acts indicate the borrowing of provisions from other states. However, as pointed out by the author, it is important for such draftsmen to consult and fully consider the statutes of all the other states so as to select the best ideas and the most appropriate phraseology. He raised the question, is the remedy a uniform probate act; and if so, under whose auspices should it be prepared? He concluded that such an act would be an improvement upon the best of existing probate codes and called attention to various organizations which have been interested in the improvement of statutes, The National Conference of Commissioners on Uniform Laws, The American Judicature Society, The American Law Institute, The National Conference of Judicial Councils and the Committees on Improvement in Probate Practice and on Uniformity in Probate Codes, of the Section of Real Property, Probate and Trust Law of the American Bar Association

    Education Bills in the 1962 General Assembly

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    Momentum and scalar transport within a vegetation canopy following atmospheric stability and seasonal canopy changes: the CHATS experiment

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    Momentum and scalar (heat and water vapor) transfer between a walnut canopy and the overlying atmosphere are investigated for two seasonal periods (before and after leaf-out), and for five thermal stability regimes (free and forced convection, near-neutral condition, transition to stable, and stable). Quadrant and octant analyses of momentum and scalar fluxes followed by space-time autocorrelations of observations from the Canopy Horizontal Array Turbulence Study's (CHATS) thirty meter tower help characterize the motions exchanging momentum, heat, and moisture between the canopy layers and aloft. <br><br> During sufficiently windy conditions, i.e. in forced convection, near-neutral and transition to stable regimes, momentum and scalars are generally transported by sweep and ejection motions associated with the well-known canopy-top "shear-driven" coherent eddy structures. During extreme stability conditions (both unstable and stable), the role of these "shear-driven" structures in transporting scalars decreases, inducing notable dissimilarity between momentum and scalar transport. <br><br> In unstable conditions, "shear-driven" coherent structures are progressively replaced by "buo-yantly-driven" structures, known as thermal plumes; which appear very efficient at transporting scalars, especially upward thermal plumes above the canopy. Within the canopy, downward thermal plumes become more efficient at transporting scalars than upward thermal plumes if scalar sources are located in the upper canopy. We explain these features by suggesting that: (i) downward plumes within the canopy correspond to large downward plumes coming from above, and (ii) upward plumes within the canopy are local small plumes induced by canopy heat sources where passive scalars are first injected if there sources are at the same location as heat sources. Above the canopy, these small upward thermal plumes aggregate to form larger scale upward thermal plumes. Furthermore, scalar quantities carried by downward plumes are not modified when penetrating the canopy and crossing upper scalar sources. Consequently, scalars appear to be preferentially injected into upward thermal plumes as opposed to in downward thermal plumes. <br><br> In stable conditions, intermittent downward and upward motions probably related to elevated shear layers are responsible for canopy-top heat and water vapor transport through the initiation of turbulent instabilities, but this transport remains small. During the foliated period, lower-canopy heat and water vapor transport occurs through thermal plumes associated with a subcanopy unstable layer

    On the shot-noise limit of a thermal current

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    The noise power spectral density of a thermal current between two macroscopic dielectric bodies held at different temperatures and connected only at a quantum point contact is calculated. Assuming the thermal energy is carried only by phonons, we model the quantum point contact as a mechanical link, having a harmonic spring potential. In the weak coupling, or weak-link limit, we find the thermal current analog of the well-known electronic shot-noise expression.Comment: 4 pages, 1 figur

    Beyond Sovereignty

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