The benefits of parenting: Government financial support for families with children since 1975

This commentary describes the changes to the structure of child-contingent support through the tax and benefit system since 1975. It also presents new results, which were produced to quantify explicitly the amount of government support for families with children, using representative samples of families from over the past three decades. With these data, it is possible to examine whether child-contingent support has become more or less progressive, or more or less slanted towards large families, lone-parents families or families with young children

Modification of silicon carbide fibers for use in SiC/Ti composites

The degradation of silicon carbide fibers during exposure to conditions typical of composite fabrication was investigated. The tensile strength of pristine fibers and fibers sputtered with thin metal coatings were determined before and after treatment at 870 C for one hour in vacuum. Each fiber strength distribution was related by an analytical procedure to a projected composite ultimate tensile strength (PC UTS). The results indicate that a thin aluminum diffusion barrier can yield a 150 percent increase in PC UTS over the baseline SiC/Ti system

The Effect of Temperature on the Benthic Stages of Cyanea (Cnidaria: Scyphozoa), and Their Seasonal Distribution in the Niantic River Estuary, Connecticut

There are three benthic stages in the life history of Cyanea: the polyp stage and two kinds of cysts; one kind is produced by the polyp (podocysts), and the other by the planula larvae (planulocysts); both types of cysts develop into additional polyps. Physical and biological factors affecting these benthic stages and their processes influence the success of the ecologically important medusa stage which is produced by asexual budding (strobilation) by the polyp. Experimentally, a transfer from low to high temperature was most favorable for podocyst formation by polyps, and the transfer from high to low temperature led to both the excystment of podocysts and the strobilation of polyps. In the benthos of the Niantic River, planulocysts and podocysts appear during the warmest time of the year having formed during a period of increasing temperature throughout spring. Both types of cyst excyst when temperature decreases beginning in late summer and continuing into early winter. During this period of declining temperature, polyps strobilate forming ephyrae, the young medusae. The relationship between seasonal temperature change and processes of the benthic stages in the field agrees with laboratory results; thus, change in temperature is at least minimally sufficient to account for the regular annual appearance of the medusa. Such a life history requires a longevous ephyral stage resistant to low temperatures and this seems to be the case. Indirect evidence is presented showing that the encysted stages may serve as a defense against predators and competitors for space which are active during the summer

Ion engine thrust vector study

Probability of thrust vector misalignment in ion thrustor arra

Monotonic Prefix Consistency in Distributed Systems

We study the issue of data consistency in distributed systems. Specifically, we consider a distributed system that replicates its data at multiple sites, which is prone to partitions, and which is assumed to be available (in the sense that queries are always eventually answered). In such a setting, strong consistency, where all replicas of the system apply synchronously every operation, is not possible to implement. However, many weaker consistency criteria that allow a greater number of behaviors than strong consistency, are implementable in available distributed systems. We focus on determining the strongest consistency criterion that can be implemented in a convergent and available distributed system that tolerates partitions. We focus on objects where the set of operations can be split into updates and queries. We show that no criterion stronger than Monotonic Prefix Consistency (MPC) can be implemented.Comment: Submitted pape

The Herbertsmithite Hamiltonian: μ\muSR measurements on single crystals

We present transverse field muon spin rotation/relaxation measurements on single crystals of the spin-1/2 kagome antiferromagnet Herbertsmithite. We find that the spins are more easily polarized when the field is perpendicular to the kagome plane. We demonstrate that the difference in magnetization between the different directions cannot be accounted for by Dzyaloshinksii-Moriya type interactions alone, and that anisotropic axial interaction is present.Comment: 8 pages, 3 figures, accepted to JPCM special issue on geometrically frustrated magnetis

A late Pleistocene long pollen record from Lake Urmia, NW Iran

A palynological study based on two 100-m long cores from Lake Urmia in northwestern Iran provides a vegetation record spanning 200 ka, the longest pollen record for the continental interior of the Near East. During both penultimate and last glaciations, a steppe of Artemisia and Poaceae dominated the upland vegetation with a high proportion of Chenopodiaceae in both upland and lowland saline ecosystems. While Juniperus and deciduous Quercus trees were extremely rare and restricted to some refugia, Hippophaë rhamnoides constituted an important phanerophyte, particularly during the upper last glacial sediments. A pronounced expansion in Ephedra shrub-steppe occurred at the end of the penultimate late-glacial period but was followed by extreme aridity that favoured an Artemisia steppe. Very high lake levels, registered by both pollen and sedimentary markers, occurred during the middle of the last glaciation and upper part of the penultimate glaciation. The late-glacial to early Holocene transition is represented by a succession of Hippophaë, Ephedra, Betula, Pistacia and finally Juniperus and Quercus. The last interglacial period (Eemian), slightly warmer and moister than the Holocene, was followed by two interstadial phases similar in pattern to those recorded in the marine isotope record and southern European pollen sequences

Virtual light-by-light scattering and the g factor of a bound electron

The contribution of the light-by-light diagram to the g factor of electron and muon bound in Coulomb field is obtained. For electron in a ground state, our results are in good agreement with the results of other authors obtained numerically for large Z. For relatively small Z our results have essentially higher accuracy as compared to the previous ones. For muonic atoms, the contribution is obtained for the first time with the high accuracy in whole region of Z.Comment: 10 pages, 3 figures, RevTe