bluuebunny/crossref_metadata_2025 huggingface dataset:
THE GENERAL EXACT SOLUTION FOR RELATIVISTIC SPHERICAL SHELLS
Authors: KIJOWSKI J. , MAGLI G. , MALAFARINA D.
Published: December 2009

The general exact solution to the Einstein matter field equations describing spherically symmetric shells satisfying an equation of state in closed form is discussed under general assumptions of physical reasonableness. The solutions split into two classes: one describes the behavior of "ordinary" matter satisfying the weak energy condition, while the other describes "exotic" matter for which this condition can be violated. In both cases all those solutions which are already known are recovered as particular cases.
CAPTURE OF DARK MATTER BY THE SOLAR SYSTEM
Authors: KHRIPLOVICH I. B. , SHEPELYANSKY D. L.
Published: December 2009

We study the capture of galactic dark matter by the solar system. The effect is due to the gravitational three-body interaction between the sun, one of the planets, and a dark matter particle. The analytical estimate for the capture cross-section is derived and the upper and lower bounds for the total mass of the captured dark matter particles are found. The estimates for their density are less reliable. The most optimistic of them gives an enhancement of dark matter density by about three orders of magnitudes compared to its value in our galaxy. However, even this optimistic value remains below the best present observational upper limits by about two orders of magnitude.
THE SIMULTANEOUS APPROXIMATION OF QUASI-HERMITE INTERPOLATION ON THE WEIGHTED MEAN NORM
Authors: XU GUIQIAO , CUI RAN , WANG XIN
Published: December 2009

We research the simultaneous approximation problem of the quasi-Hermite interpolation that based on the zeros of Chebyshev polynomials under weighted Lp-norm where our estimation is sharp.
A REMARK ON JACOBI POLYNOMIAL ESTIMATES
Authors: ZHANG XIRONG
Published: December 2009

In this paper, an estimate of Jacobi polynomials with complex indices is proved. It improves a corresponding result of Ref. 2.
INFERENCE OF GENE REGULATORY NETWORKS USING BOOLEAN-NETWORK INFERENCE METHODS
Authors: HICKMAN GRAHAM J. , HODGMAN T. CHARLIE
Published: December 2009

The modeling of genetic networks especially from microarray and related data has become an important aspect of the biosciences. This review takes a fresh look at a specific family of models used for constructing genetic networks, the so-called Boolean networks. The review outlines the various different types of Boolean network developed to date, from the original Random Boolean Network to the current Probabilistic Boolean Network. In addition, some of the different inference methods available to infer these genetic networks are also examined. Where possible, particular attention is paid to input requirements as well as the efficiency, advantages and drawbacks of each method. Though the Boolean network model is one of many models available for network inference today, it is well established and remains a topic of considerable interest in the field of genetic network inference. Hybrids of Boolean networks with other approaches may well be the way forward in inferring the most informative networks.
Finding flows in software development
Authors: Feng Yu
Published: December 2009

Nowadays, many developers lose their passions for software development. Flow is a theory to describe experience associated with optimal performance. In this article, I analyzed essential components of flow and their meanings for software developers. I also made recommendations on the fields of study where flow can be made.
Exploiting web resources for teaching/learning best software design tips
Authors: Pandey R. K.
Published: December 2009

Teaching software design principles using conventional class room methodologies has its own limitations and as such is less effective. Software design being the most crucial phase of the Software Development Life Cycle (SDLC) requires considerable practical experience on the part of the teacher. The approach presented in this paper may help the computer science/software engineering students learn the advanced level software design tips through Internet based resources. Such type of approaches to teaching/learning software engineering principles through Free/Open Source (F/OSS) resources have been quite successfully used and reported in the literature. The approach presented in this paper is somewhat similar and may be of great help to the persons having background in JAVA and .NET technologies and involved in the design/development of JAVA/.NET based components/applications. The approach has a number of advantages over the approaches used by others and is quite effective.
A semantic-based framework for multimedia management and interoperability
Authors: Tsinaraki Chrisa , Christodoulakis Stavros
Published: December 2009

Interoperable, semantic-based audiovisual content services are necessary in the open Internet environment, where the volume of the available audiovisual information is growing rapidly. Such services can be built on top of structured, semantic-based audiovisual content descriptions. This thesis focuses on the representation and management of the audiovisual content semantics. The representation and management of the audiovisual content semantics are based on the dominant standards for audiovisual content description and ontology representation which are, respectively, the MPEG-7 and the OWL. In particular, the following components have been developed for the representation and management of the audiovisual content semantics:

• An MPEG-7 based model that allows: (a) The representation of the audiovisual content semantics; and (b) The representation of domain ontologies that extend the generalpurpose MPEG-7 semantics with domain knowledge and may be utilized in the audiovisual content description.

• An ontological infrastructure, which allows the representation and management of the audiovisual content semantics. This ontological infrastructure represents the MPEG-7 semantics and allows their extension with application-specific and domain-specific knowledge.

• A mapping model that allows interoperability support between MPEG-7 and OWL. This model maps the MPEG-7 constructs to OWL constructs and allows the transformation of OWL domain ontologies and OWL/RDF audiovisual content descriptions into MPEG-7 descriptions.
Don't ask me
Authors: Hsieh Gary
Published: December 2009

Searching for information online has become an integral part of our everyday lives. However, sometimes we don't know the specific search terms to use, while other times, the specific information we're seeking hasn't been recorded online yet.
A Life of Adventure in Immunobiology
Authors: Cooper Max D.
Published: December 2009

This article outlines my early start in medicine, a late start in immunology research, and my efforts to integrate the two activities. I first describe some of the background information, excitement, and implications of the recognition of T and B cells as separate but functionally intertwined arms of the adaptive immune system. The article continues with a brief account of my colleagues' and my efforts to use the model of hematopoietic stem cell differentiation along T and B cell lines to gain a better understanding of immunodeficiency diseases and lymphoid malignancies. It concludes with the discovery of a more ancient adaptive immune system in which T-like and B-like cells in jawless vertebrates use variable lymphocyte receptors constructed with leucine-rich-repeat sequences to recognize antigens.
Functional Anatomy of T Cell Activation and Synapse Formation
Authors: Fooksman David R. , Vardhana Santosh , Vasiliver-Shamis Gaia , Liese Jan , Blair David A. , Waite Janelle , Sacristán Catarina , Victora Gabriel D. , Zanin-Zhorov Alexandra , Dustin Michael L.
Published: December 2009

T cell activation and function require a structured engagement of antigen-presenting cells. These cell contacts are characterized by two distinct dynamics in vivo: transient contacts resulting from promigratory junctions called immunological kinapses or prolonged contacts from stable junctions called immunological synapses. Kinapses operate in the steady state to allow referencing to self-peptide-MHC (pMHC) and searching for pathogen-derived pMHC. Synapses are induced by T cell receptor (TCR) interactions with agonist pMHC under specific conditions and correlate with robust immune responses that generate effector and memory T cells. High-resolution imaging has revealed that the synapse is highly coordinated, integrating cell adhesion, TCR recognition of pMHC complexes, and an array of activating and inhibitory ligands to promote or prevent T cell signaling. In this review, we examine the molecular components, geometry, and timing underlying kinapses and synapses. We integrate recent molecular and physiological data to provide a synthesis and suggest ways forward.
Crystal structure of NaAlF4, a new aristotype
Authors: Le Bail A.
Published: December 2009

A model for the long awaited crystal structure of metastable NaAlF4 is established from the powder diffraction pattern of a partly disproportionated sample. Orthorhombic, Cmcm, a=3.6121(3), b=14.952(1), c=5.2692(4) Å, Z=4, V=284.58(4) Å3. Sodium atoms are in NaF6 trigonal prisms interconnected by edges in compact layers. AlF6 octahedra are both cis- and trans-corner connected forming a layer structure similar to that observed in the NaNbO2F2 (P21/c) and BaZnF4 (Cmc21) structure types. NaAlF4 is ideally simple and symmetrical, isostructural with BiReO4 (Cmcm), representing the aristotype of the NaMIIIF4 and BaMIIF4 series.
New powder diffraction data of some derivatives of N-(hydroxyalkyl)-4-chlorophenoxyacetamide—Potential pesticides
Authors: Olszewska E. , Tarasiuk B. , Pikus S.
Published: December 2009

Five new derivatives of N-(ω-hydroxyalkyl)-4-chlorophenoxyacetamide [namely, 2-(4-chlorophenoxy)-N-(2-hydroxyethyl) acetamide, 2-(4-chlorophenoxy)-N-(3-hydroxypropyl) acetamide, 2-(4-chlorophenoxy)-N-[1-(hydroxymethyl) propyl] acetamide, 2-(4-chlorophenoxy)-N-(2-hydroxy-1,1-dimethylethyl) acetamide, and 2-(4-chlorophenoxy)-N-{2-[(2-hydroxyethyl) amino] ethyl} acetamide] and one 2-(4-chlorophenoxy) acetohydrazide have been characterized by X-ray powder diffraction. These organic compounds are potential pesticides. New diffraction data including experimental and calculated 2θ peaks positions, values of d, experimental relative peak intensities, and Miller indices as well as unit-cell parameters are reported.
Tensorial Model for Photolithography Aerial Image Simulation
Authors: Fossati Caroline , Bourennane Salah , Sabatier Romuald , Di Giacomo Antonio
Published: December 2009

In this paper, we propose to adapt the multilinear algebra tools to the tensor of Transmission Cross-Coefficients (TCC) values for aerial image simulation in order to keep the data
tensor as a whole entity. This new approach implicitly extends the singular value decomposition (SVD) to tensors, that is, Higher Order SVD or TUCKER3 tensor
decomposition which is used to obtain lower rank- tensor approximation (LRTA ). This model
requires an Alternating Least Square (ALS) process known as TUCKALS3 algorithm. The needed number of kernels is estimated
using two adapted criteria, well known in signal processing and information theory. For runtime improvement, we use the fixed
point algorithm to calculate only the needed eigenvectors. This new approach leads to a fast and accurate algorithm to compute
aerial images.
Sentinel Node Detection in Head and Neck Malignancies: Innovations in Radioguided Surgery
Authors: Vermeeren L. , Klop W. M. C. , van den Brekel M. W. M. , Balm A. J. M. , Nieweg O. E. , Valdés Olmos R. A.
Published: December 2009

Sentinel node mapping is becoming a routine procedure for staging of various malignancies, because it can determine lymph node status more precisely. Due to anatomical problems, localizing sentinel nodes in the head and neck region on the basis of conventional images can be difficult. New diagnostic tools can provide better visualization of sentinel nodes. In an attempt to keep up with possible scientific progress, this article reviews new and innovative tools for sentinel node localization in this specific area. The overview comprises a short introduction of the sentinel node procedure as well as indications in the head and neck region. Then the results of SPECT/CT for sentinel node detection are described. Finally, a portable gamma camera to enable intraoperative real-time imaging with improved sentinel node detection is described.
EGR4 Is a Master Gene Responsible for Fertility in Cryptorchidism
Authors: Hadziselimovic F. , Hadziselimovic N.O. , Demougin P. , Krey G. , Hoecht B. , Oakeley E.J.
Published: December 2009

The purpose of early medical or surgical treatment of boys with undescended testes is to prevent the development of infertility. However, early and successful surgery cannot prevent infertility in cryptorchid boys who lack type A dark (Ad) spermatogonia. The aim of this study was to compare the gene expression pattern of patients with completed transformation of gonocytes into Ad spermatogonia, associated with low infertility risk, with patients that had failed to undergo this process and had a high infertility risk. Genes expressed in the 16 cryptorchid testes were estimated using Affymetrix whole-genome microarray and compared to the expression profiles from four contralateral gonads of boys with unilateral testicular agenesis. Whole-genome expression profiling showed that boys in the high infertility risk group according to testicular histology, showed decreased or lack of expression of most of the genes essential for hypothalamo-pituitary-testicular axis function relative to low or intermediate risk group as well as controls. In particular, EGR4, which is involved in regulating the secretion of luteinizing hormone, was virtually not expressed. Thus, we found multiple differences in gene expression between the high and low infertility risk groups, confirming the importance of an intact hypothalamo-pituitary testicular axis and EGR4 in fertility development.
Profiles of Gonadal Gene Expression in the Developing Bovine Embryo
Authors: Ross D.G.F. , Bowles J. , Hope M. , Lehnert S. , Koopman P.
Published: December 2009

Our current understanding of the molecular basis of sex determination and gonadal development in humans is mostly an extrapolation of knowledge gained from studies in the mouse. However, the timing of gene expression in the mouse is unusual among mammals, and it is therefore important that data from other models are also available to help elucidate this pivotal process in human development. Here we describe the sequence of molecular and morphological events marking testis differentiation in bovine embryos. The genital ridges first appeared at CRL 12 (day 32). SRY expression began at CRL 18 (day 37) and peaked at CRL 20 (day 39), leading to a cascade of regulatory, signaling, and steroidogenic gene expression at later stages, detected by quantitative real-time RT-PCR and immunohistochemistry. Testis cords were distinguishable at CRL 27 (day 42). We conclude that the timing of gene expression observed in developing human embryos is much more similar to bovine development than it is to the mouse. Therefore, Bos taurus may represent a useful model in which to study gene expression during sex determination, relevant to human development.
Insulin Receptor and IGF1R Are Not Required for Oocyte Growth, Differentiation, and Maturation in Mice
Authors: Pitetti J.L. , Torre D. , Conne B. , Papaioannou M.D. , Cederroth C.R. , Xuan S. , Kahn R. , Parada L.F. , Vassalli J.D. , Efstratiadis A. , Nef S.
Published: December 2009

In mammals, insulin and insulin-like growth factors (IGFs: IGF1 and IGF2) act through 2 structurally related receptors, the insulin receptor (INSR) and the type 1 IGF receptor (IGF1R), both of which are expressed in developing oocytes. IGF1 plays an important role in female reproduction, and female Igf1 knockout mice fail to ovulate and are infertile. On the other hand, little is known about the in vivo role of the insulin signaling pathway in oocytes during follicular development, although exposure to insulin or IGF1 in vitro improves oocyte maturation. To further address the significance of insulin/IGF signaling, we used conditional mutant mice and ablated the function of the genes encoding INSR, IGF1R, or both receptors specifically in developing mouse oocytes. Our genetic evidence showed unexpectedly that the female reproductive functions are not affected when Insr, Igf1r or both Insr;Igf1r are ablated in oocytes, as the female mice are fertile and exhibit normal estrous cyclicity, oocyte development and maturation, parturition frequency, and litter size. In view of these novel observations indicating that the insulin/IGF signaling is not essential in oocytes, the IGF1-dependent female fertility is re-evaluated and discussed.
Abnormal Spermatid Formation in the Presence of the Parasitic B24 Chromosome in the Grasshopper Eyprepocnemis plorans
Authors: Teruel M. , Cabrero J. , Perfectti F. , Alché J.D. , Camacho J.P.M.
Published: December 2009

Morphology and size of spermatids were analysed in the grasshopper Eyprepocnemis plorans by means of light and electron microscopy. At light microscopy, normal and abnormal (macro- and micro-) spermatids differed in size and number of centriolar adjuncts (CAs): 1 CA in normal spermatids and 2 or more CAs, depending on ploidy level, in macrospermatids. Males carrying the additional B24 chromosome showed significantly more macro- and microspermatids than 0B males. The frequency of macro- and microspermatids showed an odd-even pattern in respect to the number of B chromosomes, with a higher frequency of abnormal spermatids associated with odd B numbers. Transmission electron microscopy showed that macrospermatids carried more than one axoneme, depending on ploidy level: 2 for diploid, 3 for triploid, and 4 for tetraploid spermatids. In 0B males, the most frequent abnormal spermatids were diploid, whereas in 1B males they were the tetraploid spermatids and, to a lesser extent, triploid ones. This suggests that most macrospermatids derived from cytokinesis failure and nucleus restitution. The implications of aberrant spermatids on B chromosome transmission and male fertility are discussed.
Over-Expression of Müllerian Inhibiting Substance mRNA in the Turner Syndrome Ovary
Authors: Modi D. , Sane S. , Bhartiya D.
Published: December 2009

Turner Syndrome (TS) is a disorder of human females associated with complete or partial loss of one of the X chromosomes, varying degrees of multiple congenital malformations and gonadal dysgenesis. However, the reason for the premature loss of germ cells in the TS ovaries is currently unknown. To understand the molecular basis of the gonadal dysgenesis the mRNA expression of Müllerian Inhibiting Substance (MIS) was examined in human fetal and adult TS ovaries and compared with normal ovaries by in situ hybridization. The expression of MIS was found to be increased in the granulosa cells of the TS ovaries as compared to that in normal ovaries, and these granulosa cells were organized to form testicular tubule like structures. MIS was also found to be ectopically expressed in the oocytes of the developing TS gonads. The stromal cells of the streak gonads of adult TS women abundantly expressed MIS. We speculate that the absence of a second X chromosome leads to over-expression of MIS that may be co-responsible for failure of ovarian differentiation in TS. MIS may be a potential negative regulator of ovarian development in humans.
Population Drinking and Fatal Injuries in Eastern Europe: A Time-Series Analysis of Six Countries
Authors: Landberg Jonas
Published: December 2009

Aims: To estimate to what extent injury mortality rates in 6 Eastern European countries are affected by changes in population drinking during the post-war period. Data and Methods: The analysis included injury mortality rates and per capita alcohol consumption in Russia, Belarus, Poland, Hungary, Bulgaria and the former Czechoslovakia. Total population and gender-specific models were estimated using auto regressive integrated moving average time-series modelling. Results: The estimates for the total population were generally positive and significant. For Russia and Belarus, a 1-litre increase in per capita consumption was associated with an increase in injury mortality of 7.5 and 5.5 per 100,000 inhabitants, respectively. The estimates for the remaining countries ranged between 1.4 and 2.0. The gender-specific estimates displayed national variations similar to the total population estimates although the estimates for males were higher than for females in all countries. Conclusions: The results suggest that changes in per capita consumption have a significant impact on injury mortality in these countries, but the strength of the association tends to be stronger in countries where intoxication-oriented drinking is more common.
Morphologic Patterns of Human Endometrial Epithelium in Women with Uterine Myomata Treated with Leuprorelin Acetate
Authors: Palmara Vittorio , Triolo Onofrio , Benedetto Vincenzo , Lo Re Carmela , Sturlese Emanuele , Retto Giovanni , Santoro Giuseppe
Published: December 2009

Aim: We studied morphologic modifications of the endometrium induced by leuprorelin acetate, a gonadotropin-releasing hormone agonist, in women with uterine myomata. Methods: Transmission and scanning electron microscopy observations were performed after 2 or 6 cycles of therapy (every 28 days). Results: A near-normal endometrium was observed after 2 months of therapy, while treatment with 6 cycles of leuprorelin acetate induced a uniform morphologic regression of the uterine mucosa. Conclusions: The study demonstrates that leuprorelin acetate induces a unique and time-dependent regression of the endometrial mucous membrane.
Non-Diabetic Chronic Kidney Disease Influences Retinal Microvasculature
Authors: Baumann Marcus , Schwarz Sonja , Kotliar Konstantin , von Eynatten Maximilian , Schmidt Trucksaess Arno , Burkhardt Klaus , Lutz Jens , Heemann Uwe , Lanzl Ines
Published: December 2009

Background: Chronic kidney disease (CKD) is characterized by increased cerebrovascular risk. Retinal vessel analysis (RVA) is an accepted measure of the retinal microvasculature, mirrors hypertension and cardiovascular morbidity. Epidemiological studies demonstrate narrower retinal arterioles with declining renal function. The effect of CKD on the retinal microcirculation remains uncertain. Methods: RVA was performed in 34 non-diabetic CKD patients and 33 age-matched volunteers with normal renal function. Retinal photographs were digitized, vascular lumen diameters measured and the ratio of retinal arteriolar and venular lumen diameters (AVR) calculated. Office blood pressure (BP) was measured and cardiovascular risk factors assessed. Results: AVR was lower in CKD patients as compared to age-matched volunteers (0.77 ± 0.05 vs. 0.86 ± 0.06; p < 0.05). In particular, retinal arterioles were narrower in CKD patients as compared to volunteers (169.6 ± 20.4 vs. 189.5 ± 14.2 µm; p < 0.01). In CKD, estimated glomerular filtration rate, BP and renin-angiotensin system blocker independently predicted AVR. Moreover, retinal arteriolar diameter independently predicted renal function (β = 0.33; p < 0.05). Conclusion: CKD narrowed retinal arterioles suggesting an extended effect of CKD on the cerebral microvasculature. This study shows that in CKD patients, renal function, BP status and renin-angiotensin system blockade independently predict AVR as a marker for microvascular damage and that retinal microvasculature can predict renal function.
Numerical Investigation of Spectral Evolution of Wind Waves. Part I: Wind-Input Source Function
Authors: Tsagareli K. N. , Babanin A. V. , Walker D. J. , Young I. R.
Published: December 2009

This paper is dedicated to the investigation and calibration of the parameterized form for the wind-input source term Sin proposed earlier on the basis of field observations at Lake George, Australia. The main objective of this study was to obtain spectral forms for the wind-input source function Sin, which incorporates the novel observation-based features and at the same time satisfies the important physical constraint that the total integrated wind input must agree with independently observed magnitudes of the wind stress. Within this approach, a new methodology, a dynamic self-adjusting routine, was developed for correction of the wind-input source function Sin. This correction involves a frequency-dependent adjustment to the growth rate γ( f ), based on extrapolations from field data. The model results also show that light winds require higher-rate adjustments of the wind input than strong winds.
The Effects of Receptive and Productive Learning of Word Pairs on Vocabulary Knowledge
Authors: Webb Stuart
Published: December 2009

■ English as a foreign language students in Japan learned target words in word pairs receptively and productively. Five aspects of vocabulary knowledge — orthography, association, syntax, grammatical functions, and meaning and form — were each measured by receptive and productive tests. The study uses an innovative methodology in that each target word was tested in ten different ways. The results showed that the direction of learning had a significant effect on the type and amount of knowledge gained. Productive learning led to larger gains in both receptive and productive knowledge of orthography, and productive knowledge of meaning, syntax, and grammatical functions. In contrast, receptive learning led to larger gains in receptive knowledge of meaning. The findings suggest that if only one method is used, productive learning of word pairs might be more effective. The effects of each learning task on the different aspects of vocabulary knowledge are discussed in detail.
Emergent comprehension: Understanding comprehension development among young literacy learners
Authors: McMunn Dooley Caitlin , Matthews Mona W.
Published: December 2009

This article hones what is meant by ‘emergent comprehension’. The authors define emergent comprehension as the period when young children, prior to conventional reading, engage in meaningful experiences that stimulate the development and use of meaning-making strategies with potential to affect later reading comprehension. The construct ‘emergent comprehension’ reflects the theoretical line the authors drew from meaning making, viewed primarily via theories of child development, to reading comprehension as conceived by the RAND model, a commonly accepted conception of comprehension. A vignette from a three year longitudinal study of very young children’s literacy learning, illustrates the authors’ conceptions. The vignette, one of more than 100 collected in the first year of the study, is interpreted via the three dimensions of the RAND model as well as relevant research and theories from the child development literature. This new model contributes to a life-long theory of reading development (Alexander, 2006) as well as theories of emergent literacy (Clay, 1966).
Redesigning and transforming: A case study of the role of semiotic import in early composing processes
Authors: Ranker Jason
Published: December 2009

In this article, I explore the role of semiotic import (Van Leeuwen, 2005) in the composing processes of three bilingual students (six to seven years old) emerging as writers of English. Using social semiotic (Van Leeuwen, 2005) and design (New London Group, 2000) frameworks, I trace a qualitative ‘micro-history’ of how the students imported multimodal composing resources from multiple, previous writing contexts during a focal writing event (part of a larger study of multimodality and semiosis and additional language literacies). By comparing the writing practices with how they were used during previous events, I demonstrate how the students transformed, or redesigned, these practices as they imported them. This study has implications for how curricular contexts can support student redesign processes as part of written composition, providing examples of how to conceptualize the pedagogical importance of semiotic import and transformation in early composition classrooms.
Social contexts of development: Parent-child interactions during reading and play
Authors: Vandermaas-Peeler Maureen , Nelson Jackie , Bumpass Charity , Sassine Bianca
Published: December 2009

The study purpose was to describe parent—child engagement and parental guidance of children’s participation in literacy-related activities at home. Of the 37 families who participated in a home-based multimethod assessment of storybook reading and play activities, 13 were considered low income. The children’s mean age was 60 months. Parents read two storybooks with their child and engaged in a 15-minute play session with toys related to the stories. Results indicated that the overall amount of guidance provided did not differ due to income level of the families. Certain findings indicated that middle income parents provided greater support for early literacy learning, in that they engaged in more teaching during reading, made more connections between the book and the play episode, and reported reading to their children daily. However, regardless of income or education, parents provided high levels of support to sustain the children’s interest and engagement in both activities, using social connections such as humor and personal references. The extent to which both teaching-oriented guidance and socio-emotional involvement in early home-based literacy activities may be linked to enjoyment, motivation and success in subsequent school-based literacy experiences warrants further investigation among economically diverse families.
Triclinic titanite from the Heftetjern granitic pegmatite, Tørdal, southern Norway
Authors: Lussier A. J. , Cooper M. A. , Hawthorne F. C. , Kristiansen R.
Published: December 2009

Two crystals from a sample of titanite from the Heftetjern granitic pegmatite, Tørdal, southern Norway, were extracted for structure analysis and shown to have triclinic symmetry. Unit-cell parameters are as follows:a= 7.0696(4) Å,b= 8.7167(5) Å,c= 6.5695(3) Å, α = 89.7372(11)°, β = 113.7607(10)°, γ = 90.2929(13)°,V= 370.52(6) Å3for one crystal anda= 7.0612(5) Å,b= 8.7102(6) Å,c= 6.5628(4) Å, α = 89.7804(16)°, β = 113.7713(13)°, γ = 90.2502(16)°,V= 369.39(7) Å3for the other. The interaxial angles α and γ deviate from the value of 90° required for monoclinic symmetry by ~200–250 standard deviations. The single-crystal X-ray intensities were averaged in both monoclinic and triclinic Laue symmetries, givingR(merge) values of ~14% and ~1.3% respectively. For both crystals, more than 50 reflections withI> 3σIviolated the criterion for the presence of thea-glide required for monoclinicA2/asymmetry. Both crystals were refined in the space groupAwithZ= 4, and finalR1indices are 4.4% and 4.7% (wR2= 8.4 and 8.9%) respectively. The composition of one crystal was determined by electron microprobe analysis: Ca[Ti0.623Ta0.105Nb0.018Al0.137Fe0.0463+Sn0.0834+]Σ=1.012(SiO4)O. The characteristic corner-sharing [MO5] chains of identical octahedra observed in monoclinic titanite become chains of alternating M(1) and M(2) octahedra of different size, with the stronger X-ray scattering constituents concentrated at the M(2) site. Short-range bond-valence considerations suggest that theMcations will order as Al—O—Ta in adjacent octahedra, and when present in sufficient amounts, will couple along the chain to break long-range monoclinic symmetry.
Description and crystal structure of nyholmite, a new mineral related to hureaulite, from Broken Hill, New South Wales, Australia
Authors: Elliott P. , Turner P. , Jensen P. , Kolitsch U. , Pring A.
Published: December 2009

Nyholmite, Cd3Zn2(AsO3OH)2(AsO4)2·4H2O, from the Block 14 Opencut, Broken Hill, New South Wales, Australia, is a new Cd-Zn arsenate species, isostructural with the minerals of the hureaulite group. The mineral occurs in a quartz-garnet-arsenopyrite matrix as white globules, tufted aggregates of fibrous crystals and radiating hemispheres of thin, colourless, bladed crystals. Associated minerals are goldquarryite, lavendulan-sampleite, scorodite-strengite and gypsum. Individual crystals are up to 0.2 mm in length and 0.05 mm across. The mineral is transparent to translucent with a vitreous lustre. It is brittle with an uneven fracture and a white streak. The Mohs hardness is 3–3.5 and the calculated density is 4.23 g cm–3 for the empirical formula. Electron microprobe analyses yielded CdO 34.58, ZnO 9.72, MnO 3.59, CuO 3.39, Al2O3 0.20, CaO 0.16, PbO 0.37, As2O5 34.55, P2O5 6.29 totalling 92.85 wt.%. The empirical formula, based on 20 oxygen atoms, is Ca0.03Pb0.02 Cd2.80Al0.04Zn1.24-Cu0.44Mn0.53[(AsO4)3.13(PO4)0.92]Σ4.05H1.91·3.79H2O. Nyholmite is monoclinic, C2/c, a = 18.062(4) Å, b = 9.341(2) Å, c = 9.844(2) Å, β = 96.17(3)°, V = 1651.2(6) Å3 (single-crystal data, at 123 K). The six strongest lines in the X-ray powder diffraction pattern are [d(Å),I,(hkl)]: 8.985,30,(200); 8.283,85,(110); 6.169,25,(111); 4.878,25,(002); 3.234,100,(2, 420); 3.079,65,(222, 511); 2.976’45’(113). The crystal structure was solved by Patterson methods and refined using 2045 observed reflections to R1(F) = 3.73%. The structure is characterized by a kinked, five-membered chain of edge-sharing Mφ6 (φ = unspecified anion) octahedra, or pentamer, that extends in the a direction. The pentamers link by sharing corners to form a sheet in the (001) plane. Pentamers are also linked, via corner-sharing, by (As,P)O4 groups forming thick slabs in the (001) plane. The slabs link in the c direction by cornersharing between octahedra and tetrahedra to form a dense heteropolyhedral framework. Moderate to weak hydrogen-bonding provides additional linkage between the slabs.
The magnetite ore districts of the southern Aosta Valley (Western Alps, Italy): a mineralogical study of metasomatized chromite ore
Authors: Rossetti P. , Gatta G. D. , Diella V. , Carbonin S. , Della Giusta A. , Ferrario A.
Published: December 2009

In the southern Aosta Valley (Italian Western Alps), several massive magnetite bodies occur within serpentinized ultramafic rocks belonging to the Mesozoic meta-ophiolite nappe. The ultramafic rocks consist of lherzolite with minor dunite bodies and show a high pressure metamorphic overprint. The results of a multi-methodological study, based on optical microscopy, electron microprobe analysis and single-crystal X-ray diffraction, are reported here in order to give new insights into (1) the mineralogy and crystal chemistry of spinels and silicates and (2) the genesis of the massive magnetite bodies. Chromium-rich relict cores inside the magnetite grains suggest a derivation from primary chromite concentrations. The major-element behaviour shows the presence of two chromite types: a Cr2O3-rich (Al2O3-poor) type and a Cr2O3-poor (Al2O3-rich) type. Magnetite ore deposits probably represent the product of transformation from a chromite proto-ore which formed in ultramafic rocks pertaining to an ophiolite suite. The transformation of chromite to magnetite occurred during multiple stages: the pre- metamorphic setting of the ultramafics and the petrographic evidence suggest that metasomatism started before the onset of the alpine metamorphism and was active during the early alpine, eclogite- facies metamorphic overprint related to a subduction process under high fluid activity.
From structure topology to chemical composition. X. Titanium silicates: the crystal structure and crystal chemistry of nechelyustovite, a group III Ti-disilicate mineral
Authors: Cámaraite F. , Sokolova E.
Published: December 2009

The crystal structure of nechelyustovite, ideally Na4Ba2Mn1.5☐2.5Ti5Nb(Si2O7)4O4(OH)3F(H2O)6, a 5.447(1) Å, b 7.157(1) Å, c 47.259(9) Å, α 95.759(4)°, β 92.136(4)°, γ 89.978(4)°, V 1831.7(4) Å3, space group P, Z = 2, Dcalc. 3.041 g cm–3, from Lovozero alkaline massif, Kola Peninsula, Russia, has been solved and refined to R1 = 13.9% on the basis of 1745 unique reflections (Fo > 15σF). Electron microprobe analysis yielded the empirical formula (H20)6.01, Z = 2, calculated on the basis of 42 (O + F) a.p.f.u., H2O and OH are calculated from structure refinement (H2O = 6 p.f.u.; F + OH = 4 p.f.u.). The crystal structure of nechelyustovite is a combination of a TS (titanium silicate) block and an I (intermediate) block. The TS block consists of HOH sheets (H-heteropolyhedral, O-octahedral). The TS block exhibits linkage and stereochemistry typical for Group III (Ti = 3 a.p.f.u.) of Ti-disilicate minerals: two H sheets connect to the O sheet such that two (Si2O7) groups link to the trans edges of a Ti octahedron of the O sheet. There are two distinct TS blocks of the same topology, TS1 and TS2, that differ in the cations of the O sheet, [(Na1.5Mn1☐0.5)Ti] and [(Na2Mn0.5☐0.5)Ti] (4 a.p.f.u.) respectively. The TS1 and TS2 blocks have two different H sheets, H1,2 and H3,4, where (Si2O7) groups link to [5]- and [6]-coordinated (Ti,Nb) polyhedra respectively. There are three peripheral sites, AP(1—3), occupied mainly by Ba (less Sr and K) at 96, 86 and 26% and one peripheral site AP(4) occupied by Na at 50%. There are two I blocks: the I1 block is a layer of Ba atoms; the I2 block consists of H2O groups and AP(3) atoms. TS blocks alternate with I blocks or link through hydrogen bonds (as in epistolite). There is a sequence of four TS blocks and three I blocks per the c cell parameter: TS2 — I1 — TS1 — I2 — TS1 — I1 — TS2.
Compositional variation in the chevkinite group: new data from igneous and metamorphic rocks
Authors: Macdonald R. , Belkin H. E. , Wall F. , Baginski B.
Published: December 2009

Electron microprobe analyses are presented of chevkinite-group minerals from Canada, USA, Guatemala, Norway, Scotland, Italy and India. The host rocks are metacarbonates, alkaline and subalkaline granitoids, quartz-bearing pegmatites, carbonatite and an inferred K-rich tuff. The analyses extend slightly the range of compositions in the chevkinite group, e.g. the most MgO-rich phases yet recorded, and we report two further examples where La is the dominant cation in theAsite. Patchily- zoned crystals from Virginia and Guatemala contain both perrierite and chevkinite compositions. The new and published analyses are used to review compositional variation in minerals of the perrierite subgroup, which can form in a wide range of host rock compositions and over a substantial pressure- temperature range. The dominant substitutions in the various cation sites and a generalized substitution scheme are described.
Fluoro-aluminoleakeite, NaNa2(Mg2Al2Li)Si8O22F2, a new mineral of the amphibole group from Norra Kärr, Sweden: description and crystal structure
Authors: Oberti R. , Cámaraite F. , Hawthorne F. C. , Ball N. A.
Published: December 2009

Fluoro-aluminoleakeite, ideally , is a new mineral of the amphibole group from Norra Kärr, Sweden (IMA-CNMMNC 2009-012). It occurs in a proterozoic alkaline intrusion that mainly comprises a fine-grained schistose agpaitic nepheline-syenite (grennaite). Fluoro- aluminoleakeite occurs as isolated prismatic crystals 0.10–2 mm long in a syenitic matrix. Crystals are light greenish-blue with a greenish-blue streak. It is brittle, has a Mohs hardness of 6 and a splintery fracture; it is non-fluorescent with perfect {110} cleavage, no observable parting, and has a calculated density of 3.14 g cm–3. In plane-polarized light, it is pleochroic, X = pale green, Y = dark green, Z = pale green; X ^ a = 62.9° (in β obtuse), Y || b. Fluoro-aluminoleakeite is biaxial negative, α = 1.632(1), β = 1.638(1), γ = 1.643(1); 2Vobs. = 98.0(4)°, 2Vcalc. = 95.5°.M

Fluoro-aluminoleakeite is monoclinic, space group C2/m, a = 9.7043(5) Å, b = 17.7341(8) Å, c = 5.2833(3) Å, β = 104.067(4)°, V = 882.0(2) Å3, Z = 2. The eight strongest X-ray diffraction lines in the powder-diffraction pattern are [d in Å, (I), (hkl)]: 2.687, (100), (31, 151); 4.435, (80), (021, 040); 3.377, (80), (131); 2.527, (60), (02); 8.342, (50), (110); 3.096, (40), (310); 2.259, (40), (71, 12) and 2.557, (30), (002, 061). Analysis, by a combination of electron microprobe and crystal-structure refinement, gives SiO2 58.61, Al2O3 7.06, TiO2 0.32, FeO 3.27, Fe2O3 6.05, MgO 8.61, MnO 0.73, ZnO 0.43, CaO 0.05, Na2O 9.90, K2O 2.43, Li2O 1.62, F 3.37, H2Ocalc. 0.50, sum 101.08 wt.%. The formula unit, calculated on the basis of 24 (O,OH,F,Cl) p.f.u. with (OH) + F = 2 a.p.f.u., is A(Na0.65 O22W(F1.47OH0.53)Σ=2.00. Crystal-structure analysis shows CLi to be completely ordered at the M(3) site, and provided reliable site populations. Fluoro-aluminoleakeite is related to the end-member leakeite, , by the substitutions CFe3+ → CAl and WF → W(OH).
The crystal structure of Ga-rich plumbogummite from Tsumeb, Namibia
Authors: Mills S. J. , Kampf A. R. , Raudsepp M. , Christy A. G.
Published: December 2009

Ga-rich plumbogummite, (Pb0.87,Ca0.13)Σ1.00H(Al1.95,Ga1.05)Σ3.00(PO4)2(OH)6, from Tsumeb, Namibia, has rhombohedral symmetry, space group Rm, with the cell parameters a = 7.0752(19) Å, c = 16.818(4) Å and V = 729.1(3) Å3. The crystal structure has been refined to R1 = 2.05%. Ga-rich plumbogummite has an alunite-type structure comprised of a rhombohedral stacking of (001) composite layers of corner-shared (Al,Ga)O6 octahedra and PO4 tetrahedra, with Pb atoms occupying icosahedrally coordinated sites between the layers. The Pb and H positions are discussed. Ga-rich plumbogummite is nonpleochroic, uniaxial (+), with indices of refraction, ε = 1.742(3) and ω = 1.722(3), determined in white light. The five strongest powder-diffraction lines [d in Å, (I/I°), (hkl)] are: 2.995, (100), (113); 5.766, (95), (101); 2.236, (43), (107, 122); 3.539, (38), (110); 1.919 (32), (303, 033).
Cámaraite, Ba3NaTi4(Fe2+,Mn)8(Si2O7)4O4(OH,F)7. I. A new Ti-silicate mineral from the Verkhnee Espe Deposit, Akjailyautas Mountains, Kazakhstan
Authors: Sokolova E. , Abdu Y. , Hawthorne F. C. , Stepanov A. V. , Bekenova G. K. , Kotel’nikov P. E.
Published: December 2009

Cámaraite, ideally Ba3NaTi4(Fe2+,Mn)8(Si2O7)4O4(OH,F)7, is a new mineral from the Verkhnee Espe deposit, Akjailyautas Mountains, Kazakhstan. It occurs as intergrowths with bafertisite and jinshajiangite in separate platy crystals up to 8 mm × 15 mm × 2 mm in size, or as star-shaped aggregates of crystals with different orientations. Individual crystals are orange-red to brownish-red, and are platy on {001}. Cámaraite is translucent and has a pale-yellow streak, a vitreous lustre, and does not fluoresce under cathode or ultraviolet light. Cleavage is {001} perfect, no parting was observed, and Mohs hardness is <5; the mineral is brittle. The calculated density is 4.018 g cm-3. In transmitted light, camaraite is strongly pleochroic, X = light brown, Y = reddish-brown, Z = yellow- brown, with Z < X < Y. Cámaraite is biaxial +ve and 2Vmeas. = 93(1)°. All refractive indices are greater than 1.80. Cámaraite is triclinic, space group C, a = 10.678(4) Å, b = 13.744(8) Å, c = 21.40(2) Å, α = 99.28(8)°, β = 92.38(5)°, γ = 90.00(6)°, V = 3096(3) Å3, Z = 4, a:b:c = 0.7761:1:1.5565. The seven strongest lines in the X-ray powder-diffraction pattern are as follows: [d (Å), (I), (hkl)]: 2.63, (100), (401); 2.79, (90), (3, 41, 26, 225); 1.721, (70), (11, 49, 02); 3.39, (50), (24, 223); 3.18, (50), (5, 24); 2.101, (50), (2, 40); 1.578, (50), (1, 2, 61, 40). Chemical analysis by electron microprobe gave: Nb2O5 1.57, SiO2 25.25, TiO2 15.69, ZrO2 0.33, Al2O3 0.13, Fe2O3 2.77, FeO 16.54, MnO 9.46, ZnO 0.12, MgO 0.21, CaO 0.56, BaO 21.11, Na2O 1.41, K2O 0.84, H2O 1.84, F 3.11, less O:F 1.31, total 99.63 wt.%, where the valence state of Fe was determined by Mössbauer spectroscopy [Fe3+/(Fe2+ + Fe3+) = 0.13(8)] and the H2O content was derived by crystal-structure determination. The resulting empirical formula on the basis of 39 anions is Ca0.05)Σ7.78Si7.97O35.89H3.88F3.11. Cámaraite is a Group-II TS-block mineral in the structure hierarchy of Sokolova (2006). The mineral is named camaraite after Fernando Cámaraite (born 1967) of Melilla, Spain, in recognition of his contribution to the fields of mineralogy and crystallography. The new mineral and mineral name have been approved by the Commission on New Minerals, Nomenclature and Classification, International Mineralogical Association (IMA 2009-11).
Cámaraite, Ba3NaTi4(Fe2+,Mn)8(Si2O7)4O4(OH,F)7. II. The crystal structure and crystal chemistry of a new group-II Ti-disilicate mineral
Authors: Cámara F. , Sokolova E. , Nieto F.
Published: December 2009

Cámaraite — ideally Ba3NaTi4Fe82+(Si2O7)4O4(OH)4F3 — is triclinic, space group C, a = 10.6965(7) Å, b = 13.7861(9) Å, c = 21.478(2) Å, α = 99.345(1)°, β = 92.315(2)°, γ = 89.993(2)°, V = 3122.6(4) Å3, Z = 4, Dcalc. = 4.018 g cm–3, from the Verkhnee Espe alkaline deposit, Akjailyautas Mountains, Kazakhstan, has been solved and refined to R1 5.87% on the basis of 6682 unique reflections (Fo >4σF). The crystal structure of cámaraite can be described as a combination of a TS block and an intermediate (I) block. The TS (titanium silicate) block consists of HOH sheets (H-heteropolyhedral, O-octahedral), and is characterized by a minimal cell based on translation vectors t1 and t2, with t1 ~5.5 and t2 ~7 Å and t1 ^ t2 close to 90°. We describe the crystal structure of cámaraite using a double minimal cell, with 2t1 and 2t2 translations. In the O sheet, there are eight [6]-coordinated MO sites occupied mainly by Fe2+ and Mn, with minor Fe3+, Mg, Zr, Ca and Zn with  = 2.185 Å. Eight MO sites give, ideally Fe82+ p.f.u. In the H sheet, there are four [6]-coordinated MH sites occupied almost solely by Ti (Ti = 4 a.p.f.u.), with <MH–ϕ= = 1.963 Å, and eight [4]-coordinated Si sites occupied solely by Si, with  = 1.621 Å. The topology of the TS block is as in Group II of the Ti-disilicates (Ti = 2 a.p.f.u. per minimal cell) in the structure hierarchy of Sokolova (2006). There are six peripheral (P) sites, four [8–12]-coordinated Ba-dominant AP sites, giving ideally 3 Ba p.f.u., and two [10]-coordinated Na-dominant BP sites, giving ideally 1 Na p.f.u. There are two I blocks: the I1 block is a layer of Ba atoms (two AP sites); the I2 block is a layer of Ba (two AP sites) and Na atoms (two BP sites). Along c, there are two types of linkage of TS blocks: (1) TS blocks link via AP cations which constitute the I1 block, and (2) TS blocks link via common vertices of MH octahedra (as in astrophyllite-group minerals) and AP and BP cations which constitute the I2 block. Cámaraite is the only mineral of Group II with two types of linkage of TS blocks and two types of I blocks in its structure. The relation of cámaraite to the Group-II minerals is discussed.