Radiochemical Determination of Rare Earth Elements in Proton-Irradiated Lead–Bismuth Eutectic

Various types of proton-irradiated lead–bismuth eutectic (LBE) samples from the MEGAPIE prototype spallation target were analyzed concerning their content of 148Gd, 173Lu, and 146Pm by use of α- and γ-spectrometry. A radiochemical separation procedure was developed to isolate the lanthanide fraction and to prepare thin samples for α-ray measurement. The results prove a substantial depletion of these three elements in bulk samples, whereas accumulation on the LBE/steel-interfaces was observed. The amount of material accumulated on surfaces was roughly estimated by relating the values measured on the sample surfaces to the total surface of the inner target walls. The amount of 148Gd, 173Lu, and 146Pm was then quantified by summing up the contributions from every sample type. The results show a reasonable agreement with theoretical predictions. The obtained results are of utmost importance for the evaluation of the performance of high-power spallation targets, especially concerning the residual nuclide production, the physicochemical behavior of the produced radionuclides during operation, and in terms of an intermediate or final disposal.

Are there signs of change in gendered language use in children's early reading material?

In this study we investigate the relative frequencies of female and male terms in early reading material for children using the Children’s Printed Word Database as a resource. As roles of females and males have changed over time it is of interest to see if there has been a corresponding change in representations of females and males in children’s books. We carried out analyses regarding different words related to gender. Except for nouns referring to relatives, we found in all word groups a preponderance of male terms. The imbalance of male and female pronouns is equivalent to that reported by Carroll, Davies, and Richman (1971) in a frequency count of printed words in children’s book in the USA conducted some 40 years ago. The results are discussed in terms of gender inequality in reading materials and the development of social mores and stereotypical ideas.

Trace Elements in the Statoliths of Jumbo Flying Squid Off the Exclusive Economic Zones of Chile and Peru

Ontogenetic variation in 4 trace element ((88)Sr, (137)Ba, (24)Mg, (23)Na) concentrations and their ratios to Ca were measured in statoliths of the jumbo flying squid Dosidicus gigas off the Exclusive Economic Zone of Chilean and Peruvian waters using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The element compositions of statoliths showed no significant differences between females and males. All of the elements in different growth zones showed significant variations, except for Mg. Sr:Ca and Mg:Ca were good indicators for distinguishing squid from autumn and winter spawning seasons. Sr:Ca and Ba:Ca distribution patterns in statoliths confirmed that paralarvae and juvenile squid inhabit surface waters, while subadult squid migrate into deeper waters. An increasing Sr: Ca ratio of subadult squid could be explained by declining temperature gradients from northern to southern sampling locations, although no significant Sr: Ca differences were observed (p > 0.05). Mg:Ca ratios decreased progressively from the nucleus to the peripheral zone, which might be correlated with statolith growth rates. Na:Ca ratios slightly declined from paralarvae to the subadult phase. Quantitative relationships between statolith trace elements and environmental conditions under different growth stages are needed to improve our understanding of life history of D. gigas.

Assessment of English Language Learners Seeking a Graduate Degree in Speech Language Pathology

A shortage of bilingual/bicultural speech language pathologists may reflect a problem with recruitment and retention of bilingual/bicultural students. The purpose of the present study was to survey graduate training programs in speech language pathology to determine typical policies and practices concerning students who apply and are admitted as ELLs. With a growing number of ELL children needing services from a bilingual SLP, it seems that little is being done to address the issue. The problem may be with the reluctance of programs to not only accept ELL students, but there also seems to be a disinclination for any sort of training program to be established for these ELL students. Clinic directors were asked to complete a survey about ELLs seeking clinical training in speech language pathology. In particular, we were interested in obtaining information about whether clinical training programs a) provided opportunities for ELL to participate in clinic, b) assessed the English skills of these students, and c) provided remediation if these students English skills were judged to be less than proficient.

Evolution of cis-regulatory elements in a repetitive sequence adjacent to a sea urchin aboral ectoderm -specific gene

The creation, preservation, and degeneration of cis-regulatory elements controlling developmental gene expression are fundamental genome-level evolutionary processes about which little is known. In this study, critical differences in cis-regulatory elements controlling the expression of the sea urchin aboral ectoderm-specific spec genes were identified and explored. In genomes of species within the Strongylocentrotidae family, multiple copies of a repetitive sequence element termed RSR were present, but RSRs were not detected in genomes of species outside Strongylocentrotidae. RSRs are invariably associated with spec genes, and in Strongylocentrotus purpuratus, the spec2a RSR functioned as a transcriptional enhancer displaying greater activity than RSRs from the spec1 or spec2c paralogs. Single base-pair differences at two cis-regulatory elements within the spec2a RSR greatly increased the binding affinities of four transcription factors: SpCCAAT-binding factor at one element and SpOtx, SpGoosecoid, and SpGATA-E at another. The cis-regulatory elements to which SpCCAAT-binding factor, SpOtx, SpGoosecoid, and SpGATA-E bound were recent evolutionary acquisitions that could act either to activate or repress transcription, depending on the cell type. These elements were found in the spec2a RSR ortholog in Strongylocentrotus pallidus but not in the RSR orthologs of Strongylocentrotus droebachiensis or Hemicentrotus pulcherrimus. These results indicate that spec genes exhibit a dynamic pattern of cis-regulatory element evolution while stabilizing selection preserves their aboral ectoderm expression domain. ^

Geochemical investigations of elements in sediment core CRP-1 from the Ross Sea, Antarctica

Geochemical data are presented for samples from strata, mainly of Miocene age, in the Cape Roberts-1 core (western McMurdo Sound, Antarctica) to assess the sediment provenance. Bulk (major and trace element) chemistry together with bulk mineralogy of fine-grained sandstones, siltstones, mudstones, and diamictites indicate that chemical alteration of source materials, fractionation due to sedimentary sorting, and diagenetic effects were not significant in the Cape Roberts sediment history. Relevant geochemical parameters are consistent with the Cape Roberts sediments being derived mainly from the crystalline basement and the Beacon Supergroup. On the basis of element distributions, an additional contribution from the Ferrar Dolerite and, mainly above about 60 m, influxes of detritus derived from basanitic to intermediate members of the McMurdo Volcanic Group are recognised.

Average contents of chemical elements in different types of hydrothermal manifestations within 16°38'N hydrothermal field, MAR

An additional ore field in the central part of the MARhas been discovered. Together with previously discovered Logachev (14°45'N) and Ashadze (12°58'N) ore fields, the new ore field constitutes a cluster with preliminarily estimated total ore reserve of >10 Mt, which is comparable with large continental massive sulfide deposits.