Martian sub-surface ionising radiation: biosignature and geology

The surface of Mars, unshielded by thick atmosphere or global magnetic field, is exposed to high levels of cosmic radiation. This ionising radiation field is deleterious to the survival of dormant cells or spores and the persistence of molecular biomarkers in the subsurface, and so its characterisation is of prime astrobiological interest. Here, we present modelling results of the absorbed radiation dose as a function of depth through the Martian subsurface, suitable for calculation of biomarker persistence. A second major implementation of this dose accumulation rate data is in application of the optically stimulated luminescence technique for dating Martian sediments. We present calculations of the dose-depth profile in the Martian subsurface for various scenarios: variations of surface composition (dry regolith, ice, layered permafrost), solar minimum and maximum conditions, locations of different elevation (Olympus Mons, Hellas basin, datum altitude), and increasing atmospheric thickness over geological history. We also model the changing composition of the subsurface radiation field with depth compared between Martian locations with different shielding material, determine the relative dose contributions from primaries of different energies, and discuss particle deflection by the crustal magnetic fields.

Plant ion channels: gene families, physiology, and functional genomics analyses

Distinct potassium, anion, and calcium channels in the plasma membrane and vacuolar membrane of plant cells have been identified and characterized by patch clamping. Primarily owing to advances in Arabidopsis genetics and genomics, and yeast functional complementation, many of the corresponding genes have been identified. Recent advances in our understanding of ion channel genes that mediate signal transduction and ion transport are discussed here. Some plant ion channels, for example, ALMT and SLAC anion channel subunits, are unique. The majority of plant ion channel families exhibit homology to animal genes; such families include both hyperpolarization- and depolarization-activated Shaker-type potassium channels, CLC chloride transporters/channels, cyclic nucleotide-gated channels, and ionotropic glutamate receptor homologs. These plant ion channels offer unique opportunities to analyze the structural mechanisms and functions of ion channels. Here we review gene families of selected plant ion channel classes and discuss unique structure-function aspects and their physiological roles in plant cell signaling and transport.

Three Decades of Social Work in France: from Security within the Welfare State to a State of «Disembedded Modernity»

This article gives an overview of trends in policy on the functions and role of social work in French society over the past twenty years. The author suggests several reasons for the current feeling of crisis of professional identity among professionals and the complexities of the political demands made on social work. These are analysed as a consequence of the specific French context of decentralisation of the State and of the multitude of approaches to organisation and to professional training programs. On a broader level, it seems that French social work reflects many characteristics of “modernity” being concerned with difficulties in defining a clear identity, lack of a clear territorial and institutional base (or “disembeddedness” to borrow Giddens term) and difficulties in finding a clear voice to make its values heard in an increasingly politicised arena of public debate.

AtPTR1, a plasma membrane peptide transporter expressed during seed germination and in vascular tissue of Arabidopsis

For the efficient translocation of organic nitrogen, small peptides of two to three amino acids are posited as an important alternative to amino acids. A new transporter mediating the uptake of di- and tripeptides was isolated from Arabidopsis thaliana by heterologous complementation of a peptide transport-deficient Saccharomyces cerevisiae mutant. AtPTR1 mediated growth of S. cerevisiae cells on different di- and tripeptides and caused sensitivity to the phytotoxin phaseolotoxin. The spectrum of substrates recognized by AtPTR1 was determined in Xenopus laevis oocytes injected with AtPTR1 cRNA under voltage clamp conditions. AtPTR1 not only recognized a broad spectrum of di- and tripeptides, but also substrates lacking a peptide bond. However, amino acids, omega-amino fatty acids or peptides with more than three amino acid residues did not interact with AtPTR1. At pH 5.5 AtPTR1 had an apparent lower affinity (K-0.5 = 416 mum) for Ala-Asp compared with Ala-Ala (K-0.5 = 54 mum) and Ala-Lys (K-0.5 = 112 mum). Transient expression of AtPTR1/GFP fusion proteins in tobacco protoplasts showed that AtPTR1 is localized at the plasma membrane. In addition, transgenic plants expressing the beta-glucuronidase (uidA) gene under control of the AtPTR1 promoter demonstrated expression in the vascular tissue throughout the plant, indicative of a role in long-distance transport of di- and tripeptides.

Testimony, 1733

Young's testimony regarding an altercation he witnessed between Israel Chittenden, Benjamin House, John Hyland, and John Lindsey in or near the town of Scituate in September 1732. Heard before justice of the peace John Cushing in September 1732, and before John Winslow in Plymouth County Court of Assize, April 28, 1733. Signed by both.

Captain Mulford's list of writings left in his hands for the publick, ca. 1708

List includes "Our originall deed with the Indians and counterbond" and "Governor Lovelace's confirmation...." One of the listed items, "The testimony of Robert Hudson, Benjamin Smith and John Shaw," is included in HU ALP4671.

Warrants from the governor and chief justice of New York, 1703-1704

Copies of warrants and writs concerning public unrest caused by an attempt to survey lands on Long Island in 1702.

Warrant to attach goods of Abel Taylor, 1783

A warrant to seize nine pounds, the equal in property, or the body of Abel Taylor of Stow, to answer charges of debt brought by Nathan Smith of Weston.

Letter: to Francis Nicholson, [17--]

Letter, undated, from committee of eight members of the Church of England in Boston, John Barnes, Thomas Greaves, Anthony Blount, John Gibbins, George Cradock, Thomas Selbey and two others, appealing to Nicholson to help support the founding and building of Christ Church.

View's of all the cathedrall churches of England and Wales &c neatly engrav'd = Vues de toutes les englises cathederalles d'Angleterre et de Galle &c. proprement gravée.

Comprises title leaf, and 29 views etched by J. Harris. Last plate has additional legend: H. Beighton delin. 1715.

Scottish national melodies /

Mode of access: Internet.

Reports and pleadings of cases in assise, for offices, nusances, lands and tenaments; shewing the manner of proceeding in assises of novel disseinsin ... with observations on every case ... To which are added, writs of assise, & c.

Spine title: Lilly's reports.

Condition and resources of Southern Dakota : prospective trade and travel of the Dakota Southern Railroad /

Cover title.