Extreme oxygen isotope ratios in the early Solar System

The origins of the building blocks of the Solar System can be studied using the isotopic composition of early planetary and meteoritic material. Oxygen isotopes in planetary materials show variations at the per cent level that are not related to the mass of the isotopes; rather, they result from the mixture of components having different nucleosynthetic or chemical origins. Isotopic variations reaching orders of magnitude in minute meteoritic grains are usually attributed to stellar nucleosynthesis before the birth of the Solar System, whereby different grains were contributed by different stars. Here we report the discovery of abundant silica-rich grains embedded in meteoritic organic matter, having the most extreme 18O/16O and 17O/16O ratios observed (both approximately 10(-1)) together with a solar silicon isotopic composition. Both O and Si isotopes indicate a single nucleosynthetic process. These compositions can be accounted for by one of two processes: a single exotic evolved star seeding the young Solar System, or irradiation of the circumsolar gas by high energy particles accelerated during an active phase of the young Sun. We favour the latter interpretation, because the observed compositions are usually not expected from nucleosynthetic processes in evolved stars, whereas they are predicted by the selective trapping of irradiation products.     

Zoeal stages of Hiplyra variegata (Rüppell, 1830) (Crustacea: Brachyura: Leucosiidae) reared in the laboratory and collected from plankton at Al-Kharrar creek,central Red Sea

The zoeal stages of Hiplyra variegata are described and illustrated for the first time. Zoea I was obtained from an ovigerous female, and the zoea II and zoea III stages were captured in the plankton (their identity was confirmed by rearing some of them from earlier stages). Comparisons are made with the only other species of the genus of which larvae are known, i.e. H. platycheir. The presence of a lateral spine on the carapace of zoea I is one of the most important characters that can be used for easy recognition of H. variegata. It is important to note that the third zoea of H. variegata has four small spines at each posterolateral margin of the carapace, in contrast to three spines in other species.     

Nesomyrmex micheleae,a new ant species (Hymenoptera: Formicidae) from the Dhofar Governorate,Oman, with a synoptic list,distribution map and key to the Arabian Nesomyrmex

ABSTRACT

A new species of the myrmicine ant genus Nesomyrmex Wheeler, 1910, N. micheleae Sharaf sp. nov., is described and illustrated from Oman based on the worker caste. The new species is a member of the N. angulatus species group and can be diagnosed by the golden yellow gaster that contrasts with the dark brown body; the irregular longitudinal rugulose sculpture on the cephalic surface; and the finely punctate mesonotum and propodeal dorsum. A synoptic species list, an updated key and a distribution map to the Arabian Nesomyrmex species are presented. Continued ant species discoveries are central to large-scale diversity patterns, conservation biology and macroecology.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:FBCEACA7-E543-4B10-AB9D-D63319DCB31F http://www.zoobank.org/urn:lsid:zoobank.org:act:1D2EC498-3B2E-43CD-A3C0-1C6C237471E2     

Skyrmions in a ferromagnetic Bose-Einstein condensate.

Multi-component Bose-Einstein condensates provide opportunities to explore experimentally the wealth of physics associated with the spin degrees of freedom. The ground-state properties and line-like vortex excitations of these quantum systems have been studied theoretically. In principle, nontrivial spin textures consisting of point-like topological excitations, or skyrmions, could exist in a multi-component Bose-Einstein condensate, owing to the superfluid nature of the gas. Although skyrmion excitations are already known in the context of nuclear physics and the quantum-Hall effect, creating these excitations in an atomic condensate would offer an opportunity to study their physical behaviour in much greater detail, while also enabling an ab initio comparison between theory and experiment. Here we investigate theoretically the stability of skyrmions in a fictitious spin-1/2 condensate of 87Rb atoms. We find that skyrmions can exist in such a gas only as a metastable state, but with a lifetime comparable to (or even longer than) the typical lifetime of the condensate itself.     

Effect of consumption of green and black tea on the level of various enzymes in rats

Summary Drinking of both green and black tea as the only liquid ingested resulted in significant decreases in the activity of transketolase in whole blood of rats both before and after the in vitro addition, of thiamin diphosphate. Liver transketolase activity was decreased only by green tea. Mucosal transketolase activity was not affected by either type of tea. The activity of lactate dehydrogenase (LDH) was not affected by either type of tea, while whole blood LDH was decreased by both green and black tea. Neither tea had any affect on mucosal alkaline phosphatase, but thiamin diphosphatase activity was decreased by both teas. An increase in liver total thiamin resulted from the drinking of both types of tea.     

内蒙古白音诺铅锌矿床富锰单斜辉石与矿化的关系

内蒙古白音诺铅锌矿床是我国北方一个典型矽卡岩矿床，具有大而富的特点，矿区矽卡岩广泛发育，富锰单斜辉石矽卡岩与矿化的关系最为密切。单斜辉石主要为两期形成。早期富Ｍｇ，贫Ｆｅ，Ｍｎ的透辉石形成于较高的温度、ｆＯ２和ＰＨ条件下；晚期富Ｆｅ，Ｍｎ的锰钙铁辉石形成于较低的温底、ｆＯ２和ＰＨ条件下，后者与铅锌矿化具有密切的时空关第。成矿流体自矿区南西向北东方向流运过程中物理化学条件的改变，是造成矽卡岩矿物及矿     

Revision of the digger wasps of the Ampulicidae and Heterogynaidae (Hymenoptera) of Saudi Arabia,with the description of a new species of the enigmatic genus Heterogyna Nagy

The apoid wasps of the families Ampulicidae and Heterogynaidae of Saudi Arabia are revised. In Ampulicidae, four species in three genera are reported, of which three species are recorded for the first time from Saudi Arabia (Al-Baha, Asir and Riyadh regions): Ampulex assimilis Kohl, Dolichurus arabicus Ohl and Trirogma caerulea Westwood. Additionally, the family Heterogynaidae is reported for the first time from Saudi Arabia (Asir and Riyadh regions), and a new species, Heterogyna saudita sp. nov., is described, diagnosed and illustrated. An illustrated key to the species of Heterogyna from the Arabian Peninsula is provided.

www.zoobank.org/urn:lsid:zoobank.org:pub:C23C70A7-AA1C-47C0-951A-D164E7B20001     

Loss-of-function variant in DNASE1L3 causes a familial form of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a complex autoimmune disease that causes substantial morbidity. As is typical for many other multifactorial disorders, much of the heritability of SLE remains unknown. We identified a rare autosomal recessive form of SLE, in which autozygome analysis revealed a null mutation in the DNASE1L3 gene. The DNASE1L3-related SLE we describe was always pediatric in onset and correlated with a high frequency of lupus nephritis. Our findings confirm the critical role of impaired clearance of degraded DNA in SLE pathogenesis.     

Mutations in ORC1, encoding the largest subunit of the origin recognition complex, cause microcephalic primordial dwarfism resembling Meier-Gorlin syndrome

Studies into disorders of extreme growth failure (for example, Seckel syndrome and Majewski osteodysplastic primordial dwarfism type II) have implicated fundamental cellular processes of DNA damage response signaling and centrosome function in the regulation of human growth. Here we report that mutations in ORC1, encoding a subunit of the origin recognition complex, cause microcephalic primordial dwarfism resembling Meier-Gorlin syndrome. We establish that these mutations disrupt known ORC1 functions including pre-replicative complex formation and origin activation. ORC1 deficiency perturbs S-phase entry and S-phase progression. Additionally, we show that Orc1 depletion in zebrafish is sufficient to markedly reduce body size during rapid embryonic growth. Our data suggest a model in which ORC1 mutations impair replication licensing, slowing cell cycle progression and consequently impeding growth during development, particularly at times of rapid proliferation. These findings establish a novel mechanism for the pathogenesis of microcephalic dwarfism and show a surprising but important developmental impact of impaired origin licensing.