bluuebunny/crossref_metadata_2025 huggingface dataset:
Workers’ Learning Needs Regarding Mental Health in Aboriginal, Same-Sex Attracted and Culturally and Linguistically Diverse Young People
Authors: Hillin Anthony , McAlpine Rob , Montague Ros , Markham Ros
Published: November 2007

Objective: Some groups of young people experience elevated rates of mental disorders and low rates of uptake of mental health services. Because an association between staff competence and uptake of services has been demonstrated a key objective of this paper is to identify relevant staff learning needs.

Method: A learning needs analysis was undertaken of adolescent mental health workers employed in the health and education sectors in NSW, Australia, to explore their learning needs regarding Aboriginal, same-sex attracted and culturally and linguistically diverse young people.

Results: Significant differences were found between learning needs in relation to location but no significant differences were found in relation to agency or experience. Participants ranked their learning needs as high and their knowledge and skills in working with depression and related disorders in these young people as low.

Conclusion: This article highlights issues that may be of interest to clinicians and their managers regarding training, policy and service delivery.
Should Mental Health Issues be Addressed in Primary Care, and can it be Done? Views of Rural General Practitioners in Queensland
Authors: Sturk Heidi , Kavanagh David , Gallois Cindy , King David , Turpin Merrill , King Robert , Bartlett Helen
Published: November 2007

Objective: The aim of this paper was to examine self-efficacy and perceived appropriateness among rural general practitioners (GPs) in regards to screening and intervention for physical, lifestyle and mental health issues.

Method: Fifty GPs from 25 practices in eight rural Queensland towns completed a written survey designed for the study.

Results: General practitioners rated opportunistic screening or assessment for smoking and for detection of relapse of mental disorders as the most appropriate, with even cardiovascular and diabetes risk falling behind these. Self-efficacy was highest for medical disorders for smoking assessment. It was significantly lower for alcohol, mental health issues, and addressing risks of physical disorder in people with mental disorders.

Conclusions: High appropriateness ratings suggest that current strategies to boost self-efficacy of GPs in addressing mental health issues are timely.
Solastalgia: The Distress Caused by Environmental Change
Authors: Albrecht Glenn , Sartore Gina-Maree , Connor Linda , Higginbotham Nick , Freeman Sonia , Kelly Brian , Stain Helen , Tonna Anne , Pollard Georgia
Published: November 2007

Objective: Solastalgia is a new concept developed to give greater meaning and clarity to environmentally induced distress. As opposed to nostalgia – the melancholia or homesickness experienced by individuals when separated from a loved home – solastalgia is the distress that is produced by environmental change impacting on people while they are directly connected to their home environment. The paper will focus on two contexts where collaborative research teams have found solastalgia to be evident: the experiences of persistent drought in rural NSW and the impact of large-scale open-cut coal mining on individuals in the Upper Hunter Valley of NSW. In both cases, people exposed to environmental change experienced negative affect that is exacerbated by a sense of powerlessness or lack of control over the unfolding change process.

Methods: Qualitative (interviews and focus groups) and quantitative (community-based surveys) research has been conducted on the lived experience of drought and mining, and the findings relevant to solastalgia are presented.

Results: The authors are exploring the potential uses and applications of the concept of solastalgia for understanding the psychological impact of the increasing incidence of environmental change worldwide.

Conclusions: Worldwide, there is an increase in ecosystem distress syndromes matched by a corresponding increase in human distress syndromes. The specific role played by global-scale environmental challenges to ‘sense of place’ and identity will be explored in the future development of the concept of solastalgia.
Modeling Community-Based, Self-Help Mental Health Rehabilitation Reform
Authors: Lloyd Robbie
Published: November 2007

Objectives: The research used supported collaborative inquiry in participative action research to record the effectiveness of peer support and narrative therapy, in an indigenous-informed community of belonging, or open urban tribe. There were three objectives: (i) to identify the active attributes of consciousness among those living with intellectual disability and/or mental illness, which can be acknowledged, nurtured and developed to strengthen their balanced self-awareness, and assist them in taking more responsibility for their lives; (ii) to identify how these aspects of self awareness can be used to inform improved individual and group empowerment and improved rehabilitation practice, in communities of inter-subjective relationship and belonging, and; (iii) by exploring collaborative engagement with ‘the system’ which serves these two groups, to identify how they can more effectively be empowered to manage the planning, policies, programs and service delivery which largely determine their quality of life. The research also seeks to clarify how this person-valuing approach can be applied, in a self-help, peer-supported, community-based rehabilitation system.

Findings: People living with mental illness and/or intellectual disability experience improved quality of life and self-determining sense of self when they are included in mixed open urban tribes, or communities of belonging. The predominant way this comes about is through the diverse shared metaphors of being which the participants provide for each other, through their energy of life and testimonies of experience which give each other encouragement and stimulation, generating motivation and strengthened intention for life. It is not the cognitive or social ability to perform particular skills in individual or group exchange that determines the impact of this open urban tribal model; it is more the spirit and essence of the people, and their way of exchanging loving interaction and generous caring, listening and feedback that enhances participants’ quality of life experience. Successful psychosocial rehabilitation depends on people's motivation for recovery, growth and development, and this happens best in communities of belonging, not in isolated ‘group homes’ or patronizing ‘professional’ service delivery that pathologizes its recipients. Improvement in mental health and supported living services will accelerate and create cheaper bottom line costs, with the provision of equitably facilitated, self-help, peer-supported, open urban tribe models of mutual support and motivation for ongoing life development.
Poetry and Self Recovery
Authors: Clark Trevor
Published: November 2007

Objective: The author, a mental health consumer, describes key elements of ‘self-directed recovery’ central to which was the writing of poetry. Examples of poetry through the recovery journey are presented and provide a means to identify other resources to this end.

Conclusions: The periodic reflection of poetry as a recovery tool, coupled with the support of family and peers and other recovery realizations such as self talk, can make the recuperation from mental illness less debilitating and something to embrace.
SNARE-catalyzed Fusion Events Are Regulated by Syntaxin1A–Lipid Interactions
Authors: Lam Alice D. , Tryoen-Toth Petra , Tsai Bill , Vitale Nicolas , Stuenkel Edward L.
Published: November 2007

Membrane fusion is a process that intimately involves both proteins and lipids. Although the SNARE proteins, which ultimately overcome the energy barrier for fusion, have been extensively studied, regulation of the energy barrier itself, determined by specific membrane lipids, has been largely overlooked. Our findings reveal a novel function for SNARE proteins in reducing the energy barrier for fusion, by directly binding and sequestering fusogenic lipids to sites of fusion. We demonstrate a specific interaction between Syntaxin1A and the fusogenic lipid phosphatidic acid, in addition to multiple polyphosphoinositide lipids, and define a polybasic juxtamembrane region within Syntaxin1A as its lipid-binding domain. In PC-12 cells, Syntaxin1A mutations that progressively reduced lipid binding resulted in a progressive reduction in evoked secretion. Moreover, amperometric analysis of fusion events driven by a lipid-binding–deficient Syntaxin1A mutant (5RK/A) demonstrated alterations in fusion pore dynamics, suggestive of an energetic defect in secretion. Overexpression of the phosphatidic acid–generating enzyme, phospholipase D1, completely rescued the secretory defect seen with the 5RK/A mutant. Moreover, knockdown of phospholipase D1 activity drastically reduced control secretion, while leaving 5RK/A-mediated secretion relatively unaffected. Altogether, these data suggest that Syntaxin1A–lipid interactions are a critical determinant of the energetics of SNARE-catalyzed fusion events.
Distinct Functions for Arf Guanine Nucleotide Exchange Factors at the Golgi Complex: GBF1 and BIGs Are Required for Assembly and Maintenance of the Golgi Stack andtrans-Golgi Network, Respectively
Authors: Manolea Florin , Claude Alejandro , Chun Justin , Rosas Javier , Melançon Paul
Published: November 2007

We examined the relative function of the two classes of guanine nucleotide exchange factors (GEFs) for ADP-ribosylation factors that regulate recruitment of coat proteins on the Golgi complex. Complementary overexpression and RNA-based knockdown approaches established that GBF1 regulates COPI recruitment on cis-Golgi compartments, whereas BIGs appear specialized for adaptor proteins on the trans-Golgi. Knockdown of GBF1 and/or COPI did not prevent export of VSVGtsO45 from the endoplasmic reticulum (ER), but caused its accumulation into peripheral vesiculotubular clusters. In contrast, knockdown of BIG1 and BIG2 caused loss of clathrin adaptor proteins and redistribution of several TGN markers, but had no impact on COPI and several Golgi markers. Surprisingly, brefeldin A–inhibited guanine nucleotide exchange factors (BIGs) knockdown prevented neither traffic of VSVGtsO45 to the plasma membrane nor assembly of a polarized Golgi stack. Our observations indicate that COPII is the only coat required for sorting and export from the ER exit sites, whereas GBF1 but not BIGs, is required for COPI recruitment, Golgi subcompartmentalization, and cargo progression to the cell surface.
Apical Sterol-rich Membranes Are Essential for Localizing Cell End Markers That Determine Growth Directionality in the Filamentous FungusAspergillus nidulans
Authors: Takeshita Norio , Higashitsuji Yuhei , Konzack Sven , Fischer Reinhard
Published: November 2007

In filamentous fungi, hyphal extension depends on the continuous delivery of vesicles to the growing tip. Here, we describe the identification of two cell end marker proteins, TeaA and TeaR, in Aspergillus nidulans, corresponding to Tea1 and Mod5 in Schizosaccharomyces pombe. Deletion of teaA or teaR caused zig-zag-growing and meandering hyphae, respectively. The Kelch-repeat protein TeaA, the putatively prenylated TeaR protein, and the formin SepA were highly concentrated in the Spitzenkörper, a vesicle transit station at the tip, and localized along the tip membrane. TeaA localization at tips depended on microtubules, and TeaA was required for microtuble convergence in the hyphal apex. The CENP-E family kinesin KipA was necessary for proper localization of TeaA and TeaR, but not for their transportation. TeaA and TeaR localization were interdependent. TeaA interacted in vivo with TeaR, and TeaA colocalized with SepA. Sterol-rich membrane domains localized at the tip in teaA and teaR mutants like in wild type, and filipin treatment caused mislocalization of both proteins. This suggests that sterol-rich membrane domains determine cell end factor destinations and thereby polarized growth.
Distinct Dgrip84 Isoforms Correlate with Distinct γ-Tubulins inDrosophila
Authors: Wiese Christiane
Published: November 2007

γ-Tubulin is an indispensable component of the animal centrosome and is required for proper microtubule organization. Within the cell, γ-tubulin exists in a multiprotein complex containing between two (some yeasts) and six or more (metazoa) additional highly conserved proteins named gamma ring proteins (Grips) or gamma complex proteins (GCPs). γ-Tubulin containing complexes isolated from Xenopus eggs or Drosophila embryos appear ring-shaped and have therefore been named the γ-tubulin ring complex (γTuRC). Curiously, many organisms (including humans) have two distinct γ-tubulin genes. In Drosophila, where the two γ-tubulin isotypes have been studied most extensively, the γ-tubulin genes are developmentally regulated: the “maternal” γ-tubulin isotype (named γTub37CD according to its location on the genetic map) is expressed in the ovary and is deposited in the egg, where it is thought to orchestrate the meiotic and early embryonic cleavages. The second γ-tubulin isotype (γTub23C) is ubiquitously expressed and persists in most of the cells of the adult fly. In those rare cases where both γ-tubulins coexist in the same cell, they show distinct subcellular distributions and cell-cycle-dependent changes: γTub37CD mainly localizes to the centrosome, where its levels vary only slightly with the cell cycle. In contrast, the level of γTub23C at the centrosome increases at the beginning of mitosis, and γTub23C also associates with spindle pole microtubules. Here, we show that γTub23C forms discrete complexes that closely resemble the complexes formed by γTub37CD. Surprisingly, however, γTub23C associates with a distinct, longer splice variant of Dgrip84. This may reflect a role for Dgrip84 in regulating the activity and/or the location of the γ-tubulin complexes formed with γTub37CD and γTub23C.
Adducin Promotes Micrometer-Scale Organization of β2-Spectrin in Lateral Membranes of Bronchial Epithelial Cells
Authors: Abdi Khadar M. , Bennett Vann
Published: November 2007

Adducin promotes assembly of spectrin–actin complexes, and is a target for regulation by calmodulin, protein kinase C, and rho kinase. We demonstrate here that adducin is required to stabilize preformed lateral membranes of human bronchial epithelial (HBE) cells through interaction with β2-spectrin. We use a Tet-on regulated inducible small interfering RNA (siRNA) system to deplete α-adducin from confluent HBE cells. Depletion of α-adducin resulted in increased detergent solubility of spectrin after normal membrane biogenesis during mitosis. Conversely, depletion of β2-spectrin resulted in loss of adducin from the lateral membrane. siRNA–resistant α-adducin prevented loss of lateral membrane, but only if α-adducin retained the MARCKS domain that mediates spectrin–actin interactions. Phospho-mimetic versions of adducin with S/D substitutions at protein kinase C phosphorylation sites in the MARCKS domain were not active in rescue. We find that adducin modulates long-range organization of the lateral membrane based on several criteria. First, the lateral membrane of adducin-depleted cells exhibited reduced height, increased curvature, and expansion into the basal surface. Moreover, E-cadherin-GFP, which normally is restricted in lateral mobility, rapidly diffuses over distances up to 10 μm. We conclude that adducin acting through spectrin provides a novel mechanism to regulate global properties of the lateral membrane of bronchial epithelial cells.
N‐Butanol Extract from Melilotus suaveolens Ledeb Affects Pro‐ and Anti‐Inflammatory Cytokines and Mediators
Authors: Zhao Lei , Tao Jun-Yan , Zhang Shu-Ling , Jin Feng , Pang Ran , Dong Ji-Hua
Published: November 2007

Melilotus suaveolens Ledeb is a traditional medicinal plant for treating inflammation‐related disease. This explores the inner anti‐inflammatory mechanism of n‐butanol extract from M. suaveolens Ledeb. Inflammatory cellular model was established by lipopolysaccharide intervention on RAW264.7 cell line. Levels of secreted cytokines TNF‐α, IL‐1β, IL‐6, NO and IL‐10 in supernatant, mRNA expression of TNF‐α, COX‐2, iNOS and HO‐1, protein expression of COX‐2 and HO‐1, activation of NF‐κB and ingredients in the extract were assayed by ELISA, real time quantitative PCR, western blot, immunocytochemical test and HPLC fingerprint test, respectively. As a result, the extract could not only markedly reduce the production of pro‐inflammatory mediators to different extents by blocking NF‐κB activation but also promote the release of anti‐inflammatory mediator HO‐1 significantly. Each 1 g extract contained 0.023531 mg coumarin and another two high polar ingredients, probably saponins. It can be concluded that the extract has similar effects on antagonizing pro‐inflammatory mediators and cytokines like Dexamethasone, and has effects on promoting the production of anti‐inflammatory mediators.
Nuclear accumulation of cyclin D1 during S phase inhibits Cul4-dependent Cdt1 proteolysis and triggers p53-dependent DNA rereplication
Authors: Aggarwal Priya , Lessie Matthew D. , Lin Douglas I. , Pontano Laura , Gladden Andrew B. , Nuskey Beth , Goradia Ami , Wasik Mariusz A. , Klein-Szanto Andres J.P. , Rustgi Anil K. , Bassing Craig H. , Diehl J. Alan
Published: November 2007

Deregulation of cyclin D1 occurs in numerous human cancers through mutations, alternative splicing, and gene amplification. Although cancer-derived cyclin D1 mutants are potent oncogenes in vitro and in vivo, the mechanisms whereby they contribute to neoplasia are poorly understood. We now provide evidence derived from both mouse models and human cancer-derived cells revealing that nuclear accumulation of catalytically active mutant cyclin D1/CDK4 complexes triggers DNA rereplication, resulting from Cdt1 stabilization, which in turn triggers the DNA damage checkpoint and p53-dependent apoptosis. Loss of p53 through mutations or targeted deletion results in increased genomic instability and neoplastic growth. Collectively, the data presented reveal mechanistic insights into how uncoupling of critical cell cycle regulatory events will perturb DNA replication fidelity, thereby contributing to neoplastic transformation.
Autophagy: process and function
Authors: Mizushima Noboru
Published: November 2007

Autophagy is an intracellular degradation system that delivers cytoplasmic constituents to the lysosome. Despite its simplicity, recent progress has demonstrated that autophagy plays a wide variety of physiological and pathophysiological roles, which are sometimes complex. Autophagy consists of several sequential steps—sequestration, transport to lysosomes, degradation, and utilization of degradation products—and each step may exert different function. In this review, the process of autophagy is summarized, and the role of autophagy is discussed in a process-based manner.
RECQL5/Recql5 helicase regulates homologous recombination and suppresses tumor formation via disruption of Rad51 presynaptic filaments
Authors: Hu Yiduo , Raynard Steven , Sehorn Michael G. , Lu Xincheng , Bussen Wendy , Zheng Lu , Stark Jeremy M. , Barnes Ellen L. , Chi Peter , Janscak Pavel , Jasin Maria , Vogel Hannes , Sung Patrick , Luo Guangbin
Published: November 2007

Members of the RecQ helicase family play critical roles in genome maintenance. There are five RecQ homologs in mammals, and defects in three of these (BLM, WRN, and RECQL4) give rise to cancer predisposition syndromes in humans. RECQL and RECQL5 have not been associated with a human disease. Here we show that deletion of Recql5 in mice results in cancer susceptibility. Recql5-deficient cells exhibit elevated frequencies of spontaneous DNA double-strand breaks and homologous recombination (HR) as scored using a reporter that harbors a direct repeat, and are prone to gross chromosomal rearrangements in response to replication stress. To understand how RECQL5 regulates HR, we use purified proteins to demonstrate that human RECQL5 binds the Rad51 recombinase and inhibits Rad51-mediated D-loop formation. By biochemical means and electron microscopy, we show that RECQL5 displaces Rad51 from single-stranded DNA (ssDNA) in a reaction that requires ATP hydrolysis and RPA. Together, our results identify RECQL5 as an important tumor suppressor that may act by preventing inappropriate HR events via Rad51 presynaptic filament disruption.
Structure of calcium aluminate decahydrate (CaAl2O4·10D2O) from neutron and X-ray powder diffraction data
Authors: Christensen Axel Nørlund , Lebech Bente , Sheptyakov Denis , Hanson Jonathan C.
Published: November 2007

Calcium aluminate decahydrate is hexagonal with the space group P63/m and Z = 6. The compound has been named CaAl2O4·10H2O (CAH10) for decades and is known as the product obtained by hydration of CaAl2O4 (CA) in the temperature region 273–288 K – one of the main components in high-alumina cements. The lattice constants depend on the water content. Several sample preparations were used in this investigation: one CAH10, three CAD10 and one CA(D/H)10, where the latter is a zero-matrix sample showing no coherent scattering contribution from the D/H atoms in a neutron diffraction powder pattern. The crystal structure including the positions of the H/D atoms was determined from analyses of four neutron diffraction powder patterns by means of the ab initio crystal structure determination program FOX and the FULLPROF crystal structure refinement program. Additionally, eight X-ray powder diffraction patterns (Cu Kα1 and synchrotron X-rays) were used to establish phase purity. The analyses of these combined neutron and X-ray diffraction data clearly show that the previously published positions of the O atoms in the water molecules are in error. Thermogravimetric analysis of the CAD10 sample preparation used for the neutron diffraction studies gave the composition CaAl2(OD)8(D2O)2·2.42D2O. Neutron and X-ray powder diffraction data gave the structural formula CaAl2(OX)8(X
2O)2·γX
2O (X = D, H and D/H), where the γ values are sample dependent and lie between 2.3 and 3.3.
Supramolecular structures in N-isonicotinoyl arylaldehydehydrazones: multiple hydrogen-bonding modes in series of geometric isomers
Authors: Wardell Solange M. S. V. , de Souza Marcus V. N. , Wardell James L. , Low John N. , Glidewell Christopher
Published: November 2007

Sixteen N-isonicotinoyl arylaldehydehydrazones, NC5H4CONHN=CHC6H4
R, have been studied and the structures of 14 of them have been determined, including the unsubstituted parent compound with R = H, and the complete sets of 2-, 3- and 4-substituted geometric isomers for R = F, Br and OMe, and two of the three isomers for R = Cl and OEt. The 2-chloro and 3-chloro derivatives are isostructural with the corresponding bromo isomers, and all compounds contain trans amide groups apart from the isostructural pair where R = 2-Cl and 2-Br, which contain cis amide groups. The structures exhibit a wide range of direction-specific intermolecular interactions, including eight types of hydrogen bonds, N—H...N, N—H...O, O—H...O, O—H...N, C—H...N, C—H...O, C—H...π(arene) and C—H...π(pyridyl), as well as π...π stacking interactions. The structures exhibit a very broad range of combinations of these interactions: the resulting hydrogen-bonded supramolecular structures range from one-dimensional when R = 2-F, 2-OMe or 2-OEt, via two-dimensional when R = 4-F, 3-Cl, 3-Br, 4-OMe or 3-OEt, to three-dimensional when R = H, 3-F, 2-Cl, 2-Br, 4-Br or 3-OMe. Minor changes in either the identity of the substituent or its location can lead to substantial changes in the pattern of supramolecular aggregation, posing significant problems of predictability. The new structures are compared with the recently published structures of the isomeric series having R = NO2, with several monosubstituted analogues containing 2-pyridyl or 3-pyridyl units rather than 4-pyridyl, and with a number of examples having two or three substituents in the aryl ring: some 30 structures in all are discussed.
Compressed hydrogen-bond effects in the pressure-frozen chloroacetic acid
Authors: Gajda Roman , Katrusiak Andrzej
Published: November 2007

The competing effects of squeezed OH...O bonds, destabilizing the H-atom position, and of displaced hydrogen donor and acceptor groups, favouring the ordered H-atom sites, have been tuned by pressure in the pressure-frozen dichloroacetic acid. Its structure has been determined at 0.1, 0.7, 0.9 and 1.4 GPa: in this pressure range the crystals are stable in the monoclinic space group P21/n. The molecules are O—H...O hydrogen bonded into dimers, which in turn interact via a unique pattern of halogen...halogen contacts. Between 0.1 and 1.4 GPa the OH...O bond is squeezed from 2.674 (13) to 2.632 (9) Å. Within the pressure range investigated the hydrogen bonds are squeezed and the shear displacement of the molecules compensate, and the H atoms remain ordered.
Neutron diffraction investigation of the temperature dependence of crystal structure and thermal motions of red HgI2
Authors: Schwarzenbach Dieter , Birkedal Henrik , Hostettler Marc , Fischer Peter
Published: November 2007

The structure of, and anisotropic thermal motions in, the red semiconductor tetrahedral layer structure of HgI2 have been studied with neutron powder diffraction as a function of temperature from 10 to 293 K. Average thermal displacement parameters U
eq of the two atoms are comparable in size at 10 K, but U
eq(Hg) increases considerably faster with temperature than U
eq(I), the Hg—I bond being highly non-rigid. The anisotropic displacement tensor
U
(I) is strongly anisotropic with one term about twice as large as the others, while
U
(Hg) is nearly isotropic. All displacement tensor elements, except U
22(I), increase faster with temperature than harmonic quantum oscillator curves indicating a softening of the isolated-atom potentials at large amplitudes. A lattice dynamical model provides arguments that the anisotropic thermal motions of I are dominated by a soft mode with a wavevector at the [½ ½ 0] boundary of the Brillouin zone consisting essentially of coupled librations of the HgI4 tetrahedra, and by translations of the entire layer. The large vibration amplitudes of Hg suggest weak Hg–I force constants compared with the I–I force constants, allowing Hg to move quite freely inside the tetrahedra. The libration mode induces dynamic deformations of the Hg—I bond with twice its frequency. This provides a mechanism for the anharmonicity and may explain the lightening of the color from red to orange upon cooling at ca 80 K.
Isobaric and isochoric freezing of CH2BrCl and isostructural relations between CH2Cl2, CH2Br2 and CH2BrCl
Authors: Podsiadło Marcin , Katrusiak Andrzej
Published: November 2007

Bromochloromethane, CH2BrCl, has been temperature-frozen and in situ pressure-frozen and the structure determined by X-ray diffraction at low temperatures of 170 and 100 K at ambient pressure (0.10 MPa), and at high pressures of 1.04 and 1.72 GPa at room temperature (295 K). CH2BrCl exhibits a remarkable polymorphism: at low temperature it crystallizes in the monoclinic space group C2/c (phase I), isostructural to the crystals of CH2Br2. The pressure-frozen crystal of CH2BrCl is orthorhombic, space group Pbcn, and is isostructural to the crystal of CH2Cl2. In both phases I and II the Br and Cl atoms are substitutionally disordered. The freezing temperatures and pressures of simple dihalomethanes have been correlated to their molecular weight and halogen... ˙˙halogen distances. Calculated electrostatic potential surfaces have been related to the different crystal packing of dihalomethanes investigated.
Experimental and theoretical characterization of the Zn—Zn bond in [Zn2(η5-C5Me5)2]
Authors: Van der Maelen Juan F. , Gutiérrez-Puebla Enrique , Monge Ángeles , García-Granda Santiago , Resa Irene , Carmona Ernesto , Fernández-Díaz María Teresa , McIntyre Garry J. , Pattison Philip , Weber Hans-Peter
Published: November 2007

The existence and characterization of a bond between the Zn atoms in the recently synthesized complex [Zn2(η5-C5Me5)2], as well as between Zn and ligand C atoms is firmly based on neutron diffraction and low-temperature X-ray synchrotron diffraction experiments. The multipolar analysis of the experimental electron density and its topological analysis by means of the `Atoms in Molecules' (AIM) approach reveals details of the Zn—Zn bond, such as its open-shell intermediate character (the results are consistent with a typical metal–metal single bond), as well as many other topological properties of the compound. Experimental results are also compared with theoretical ab initio calculations of the DFT (density functional theory) and MP2 (Møller-Plesset perturbation theory) electron densities, giving a coherent view of the bonding in the complex. For instance, charges calculated from the AIM approach applied to the atomic basin of each Zn atom are, on average, +0.72 e from both the experimental and the theoretical electron density, showing a moderate charge transfer from the metal, confirmed by the calculated topological indexes.
Structural stability and formability of ABO3-type perovskite compounds
Authors: Zhang Huan , Li Na , Li Keyan , Xue Dongfeng
Published: November 2007

On the basis of the bond-valence model (BVM) and structure-map technology, the structural stability and formability of ABO3-type perovskite compounds were investigated in 376 ABO3-type compounds. A new criterion of structural stability for ABO3-type perovskite compounds has been established by the bond-valence calculated tolerance factors, which are in the range 0.822−1.139. All global instability indices for ABO3-type perovskite compounds are found to be less than 1.2 v.u. (valence units) and increase with a decrease in oxidation state of the B cations (i.e. structural stability in the formation of an ideal cubic perovskite follows the order A
+
B
5+O3-type > A
2+
B
4+O3-type > A
3+
B
3+O3-type). Three new two-dimensional structure maps were constructed based on the ideal A—O and B—O bond distances derived from the BVM. These maps indicate the likelihood of particular perovskite compounds being formed. The present work enables novel perovskite and perovskite-related compounds to be explored by screening all the possible elemental combinations in future crystal engineering.
Structure determination of Mg3(OH)5Cl·4H2O (F5 phase) from laboratory powder diffraction data and its impact on the analysis of problematic magnesia floors
Authors: Sugimoto Kunihisa , Dinnebier Robert E. , Schlecht Thomas
Published: November 2007

The crystal structure with the idealized formula Mg3(OH)5Cl·4H2O, the so-called F5 phase according to 5Mg(OH)2·MgCl2·8H2O in the system MgCl2–MgO–H2O, has been solved ab initio from high-quality laboratory powder diffraction data at room temperature. The F5 phase is structurally related to 3Mg(OH)2·MgCl2·8H2O (F3 form). The F5 phase consists of infinite triple chains with one Mg(OH)6 and two Mg(OH)4(OH2)2 octahedra as building units intercalated by chlorides, which are partly substituted by disordered hydroxides in the real structure. The F5 phase is of technological importance as the most important binder phase in Sorel cements. Knowledge of the crystal structure enables the full quantitative phase analysis of magnesia cements for the first time, which turns out to be very helpful in the search for possible causes of broken or bleached magnesia floors. Two real-life examples are given.
Equilibrium langbeinite-related phosphates Cs1 + x
Ln
x
Zr2 − x
(PO4)3 (Ln = Sm–Lu) in the melted systems Cs2O–P2O5–LnF3–ZrF4
Authors: Ogorodnyk Ivan V. , Baumer Vyacheslav N. , Zatovsky Igor V. , Slobodyanik Nikolay S. , Shishkin Oleg V. , Domasevitch Konstantin V.
Published: November 2007

Nine novel phosphates, based upon a combination of caesium, zirconium and lanthanide ions, were obtained from fluoride-containing fluxes using high-temperature crystallization. The structures of Cs1.80Eu0.80Zr1.20(PO4)3 (CsEuZrP), Cs1.79Gd0.79Zr1.21(PO4)3 (CsGdZrP), Cs1.87Tb0.87Zr1.13(PO4)3 (CsTbZrP), Cs1.67Dy0.67Zr1.33(PO4)3 (CsDyZrP), Cs1.75Ho0.75Zr1.25(PO4)3 (CsHoZrP), Cs1.78Er0.78Zr1.22(PO4)3 (CsErZrP), Cs1.70Tm0.70Zr1.30(PO4)3 (CsTmZrP), Cs1.52Yb0.52Zr1.48(PO4)3 (CsYbZrP) and Cs1.63Lu0.63Zr1.37(PO4)3 (CsLuZrP) were solved using single-crystal X-ray diffraction. All compounds are isostructural to the mineral langbeinite (cubic system, space group P213). Their framework structures originate from the cross-linking of metal octahedra [MO6] (M = Zr, Ln) by phosphate tetrahedra. Cs+ cations are located in the closed cavities of the framework and preferentially occupy one of the two available sites. The principles of crystallization of the equilibrium langbeinite-related phosphates in the fluxes of the system Cs2O–P2O5–LnF3–ZrF4 (Ln = La–Nd, Sm–Lu) are discussed based on their crystal structures.
Temperature dependence of the AV3O7 (A = Ca, Sr) structure
Authors: Prinz Sebastian , Sparta Karine M. , Roth Georg
Published: November 2007

The V4+ (spin ½) oxovanadates AV3O7 (A = Ca, Sr) were synthesized and studied by means of single-crystal X-ray diffraction. The room-temperature structures of both compounds are orthorhombic and their respective space groups are Pnma and Pmmn. The previously assumed structure of SrV3O7 has been revised and the temperature dependence of both crystal structures in the temperature ranges 297–100 K and 315–100 K, respectively, is discussed for the first time.
Rietveld refinement of a wrong crystal structure
Authors: Buchsbaum Christian , Schmidt Martin U.
Published: November 2007

Rietveld refinements are generally used to confirm crystal structures solved from powder diffraction data. If the Rietveld refinement converges with low R values and with a smooth difference curve, and the structure looks chemically sensible, the resulting structure is generally considered to be close to the correct crystal structure. Here we present a counter example: The Rietveld refinement of the X-ray powder pattern of γ-quinacridone with the crystal structure of β-quinacridone gives quite a smooth difference curve; the resulting crystal structure looks reasonable in terms of molecular conformation, molecular packing and intermolecular hydrogen bonds. However, neither the lattice parameters, the molecular packing nor the conformation of the molecules show any similarity with the actual structure, which was determined from single-crystal data. This example shows that a successful Rietveld refinement is not always final proof of the correctness of a crystal structure; in special cases the resulting crystal structure may still be wrong.
Probabilistic model-based methodology for the conformational study of cyclic systems: application to copper complexes double-bridged by phosphate and related ligands
Authors: Kessler M. , Pérez J. , Bueso M. C. , García L. , Pérez E. , Serrano J. L. , Carrascosa R.
Published: November 2007

A methodology for the conformational study of cyclic systems through the statistical analysis of torsion angles is presented. It relies on a combination of different methods based on a probabilistic model which takes into account the topological symmetry of the structures. This methodology is applied to copper complexes double-bridged by phosphate and related ligands. Structures from the Cambridge Structural Database (CSD) are analyzed and the chair, boat-chair and boat conformations are identified as the most frequent conformations. The output of the methodology also provides information about distortions from the ideal conformations, the most frequent being: chair ↔ twist-chair, chair ↔ twist-boat-chair and boat ↔ twist-boat. Molecular mechanics calculations identify these distortions as energetically accessible pathways.
Reticular merohedral twinning within the La9Sb5O5 structure family: structure of Pr9Sb5O5, Sm9Sb5O5 and Dy9Sb5O5
Authors: Nuss Jürgen , Jansen Martin
Published: November 2007

The novel antimonide oxides Pr9Sb5O5, Sm9Sb5O5 and Dy9Sb5O5 were synthesized from the respective RESb, the rare-earth metals (RE = Pr, Sm, Dy), and RE
2O3 (RE = Sm, Dy) or Pr4O7, respectively, in sealed tantalum ampoules at 1920 K. Those compounds, which are sensitive against air and moisture, form black cube-like crystals with metallic lustre. They crystallize in the La9Sb5O5 type of structure, which represents a fivefold superstructure of the KCoO2 structure: O10K5Co5 \^= La9□Sb5O5. The investigated crystals of the Sm and Dy compounds were twinned using the reticular merohedral law, with the twin symmetry 4/mm′m′, and the (310) and (120) mirror planes as twinning symmetry elements. The twin index is [j] = 5.
Monitoring structural transformations in crystals. 11. Yang photocyclizations – one type of reaction, but diversity of structural changes
Authors: Turowska-Tyrk Ilona , Bąkowicz Julia , Scheffer John R.
Published: November 2007

Structural changes proceeding in a crystal during the Yang photocyclization of the salt 6,6-diethyl-5-oxo-5,6,7,8-tetrahydronaphthalene-2-carboxylate with (1S)-1-(4-methylphenyl)ethylamine were monitored by means of X-ray structure analysis. The course of the photoreaction was evaluated on the basis of the geometrical parameters for the pure reactant crystal. Variations in the cell constants, the product content, the geometry of the reaction centre, the orientation of molecular fragments and the geometry of hydrogen bonds were described and analyzed. It was found that the cell volume increased until 56% product content and decreased thereafter. The distance between the directly reacting C atoms was constant, ∼ 3.0 Å, until ∼ 75% reaction progress. Analysis of the distance between atoms that would participate in the formation of the second (unobserved) enantiomorph excluded the formation of such an isomer. Molecular fragments varied their orientation during the photoreaction, and the largest change was observed for the carboxylate group despite its participation in strong hydrogen bonds. The geometry of the hydrogen bonds changed during the photoreaction. The largest change was 0.17 Å for the D...A distance and 13° for the D—H...A angle. A comparison of the intra- and intermolecular parameters for the studied salt with data for other compounds undergoing the Yang photocyclization in crystals revealed a diversity of structural changes brought about by this type of photochemical reaction.
An unexpected co-crystal with a variable degree of order: 1:1 rac-1,2-cyclohexanediol/triphenylphosphine oxide
Authors: Siegler Maxime A. , Fu Yigang , Simpson Greg H. , King Daniel P. , Parkin Sean , Brock Carolyn Pratt
Published: November 2007

A 1:1 co-crystal of rac-trans-1,2-C6H10(OH)2 and (C6H5)3PO has been found that is unusual because there are no strong interactions between the two kinds of molecules, which are segregated into layers. Furthermore, neither pure rac-1,2-cyclohexanediol (CHD) nor pure triphenylphosphine oxide (TPPO) has any obvious packing problem that would make the formation of inclusion complexes likely. The TPPO layers are very much like those found in two of the four known polymorphs of pure TPPO. The hydrogen-bonded ribbons of CHD are similar to those found in other vic-diol crystals. The co-crystals are triclinic (space group P\overline 1), but the deviations from monoclinic symmetry (space group C2/c) are small. The magnitudes of those deviations depend on the solvent from which the crystal is grown; the deviations are largest for crystals grown from acetone, smallest for crystals grown from toluene, and intermediate for crystals grown from ethanol. The deviations arise from incomplete enantiomeric disorder of the R,R and S,S diols; this disorder is not required by symmetry in either space group, but occupancy factors are nearly 0.50 when the structure is refined as monoclinic. When the structure is refined as triclinic the deviations of the occupancy factors from 0.50 mirror the deviations from monoclinic symmetry because information about the partial R,R/S,S ordering is transmitted from one diol layer to the next through the very pseudosymmetric TPPO layer. Analyses suggest individual CHD layers are at least mostly ordered. The degree of order seems to be established at the time the crystal is grown and is unlikely to change with heating or cooling. Thermal data suggest the existence of the co-crystal is a consequence of kinetic rather than thermodynamic factors.
The effects of exposure and microbes on hatchability of eggs in open‐cup and cavity nests
Authors: Godard Renee D. , Morgan Wilson C. , Frick Jessica W. , Siegel Paul B. , Bowers Bonnie B.
Published: November 2007

Many avian species initiate incubation before clutch completion, resulting in an asynchronous hatch of their eggs. Several studies suggest that early laid eggs in birds that exhibit synchronous hatching may be more vulnerable to the negative impacts of ambient temperatures and/or trans‐shell infection by microbes. However, nearly all of these studies have exposed fertile eggs to environmental conditions in artificial cavity nests, and thus, the effects of exposure of eggs to environmental conditions in open‐cup nests remains largely unknown. Therefore, we directly compared hatchability and rates of trans‐shell infection in fertile domestic chicken eggs that were exposed for 1–5 days in either open‐cup or cavity nests. Eggs in open‐cup nests had significantly higher rates of trans‐shell infection and lower hatchability than those in cavity nests. These differences may result from different environmental conditions in open‐cup nests, as well as in rates of microbial colonization of eggs. Cavity nests maintained slightly higher temperatures than did open‐cup nests in the same location; thus, eggs in cavity nests were exposed for a longer period of time to temperatures ≥27°C, the temperature at which antibacterial enzymatic activity is initiated in the albumen. Moreover, microbial growth on eggs was much higher in open‐cup nests even when eggs in these nests were cleaned daily with alcohol. It may be that the increased exposure to rain events in open‐cup nests may facilitate microbial growth and egg infection. Thus, our data suggest that open‐cup nesters may face constraints on reproduction different from those that cavity nesters face, and therefore may make choices regarding incubation that reflect these challenges.
Regression to the mean in substance use disorder treatment research
Authors: Finney John W.
Published: November 2007

Aims  Regression to the mean (RTM) refers to the tendency for a group of cases that differ from the population mean to move (regress) towards the mean, on average, when re‐assessed, if scores at the two points are less than perfectly correlated. This paper considers factors that affect the magnitude of RTM and how RTM may impact findings from primary studies and reviews of substance use disorder (SUD) treatment.

Design and methods  The paper is guided largely by A Primer on Regression Artifacts by Campbell and Kenny. It reviews potential RTM effects in three areas of SUD treatment research. One is the extent to which within‐group improvement in comparative treatment trials, including ‘placebo effects’, is a function of RTM. The second is the vulnerability of treatment evaluations employing non‐equivalent control group designs to RTM and biased estimates of treatment effects when matching, or statistical equating is used to adjust for pre‐existing group differences. The final issue is the impact of RTM in syntheses of research findings on SUD treatments. In particular, the tendency for later studies of a particular intervention to have smaller treatment effect sizes relative to earlier studies is considered as an RTM phenomenon.

Findings  RTM is a pervasive, but often unrecognized phenomenon that can bias findings in SUD treatment studies and in systematic reviews of that research.

Conclusion  SUD treatment researchers should be aware of RTM, take any available steps to reduce it, and try to diagnose whether it is still affecting research findings.
Economic comparison of forage production from annual crops, perennial pasture and native grassland in the alpine region of the Qinghai‐Tibetan Plateau, China
Authors: Dong S. K. , Kang M. Y. , Yun X. J. , Long R. J. , Hu Z. Z.
Published: November 2007

Economic costs and benefits for different grassland production systems were analysed. Comparisons included one native grassland (alpine meadow dominated by sedges) system, four perennial monocultures of smooth bromegrass (Bromus inermis Leyss, SB), Siberian wild ryegrass (Elymus sibricus Linn., SW), drooping wild ryegrass (Elymus nutans Griseb, DW) and crested wheatgrass (Agropyron cristatum Gaertn., CW), three mixtures of these grasses (SB + DW, SB + SW + CW and SB + SW + DW + CW), and two annual monocultures of forage oats (FO) and annual ryegrass (Lolium annual, AR) in the alpine grasslands of Qinghai‐Tibet, China. Perennial grass monocultures of SW and DW and perennial grass mixtures of SB + SW + DW + CW and SB + SW + CW had higher forage yields, total revenues, output:input ratios and net profits than native grassland. These grasses and mixtures can be used to reseed native grassland and improve degraded grassland in the alpine region of the Qinghai‐Tibetan Plateau. Perennial grass mixtures can replace FO for more sustainable agricultural production systems as they are comparable in economic value and superior in ecological value to FO.
Effect of a stay‐green locus on the dry‐matter yield, nitrogen yield and shoot density of perennial ryegrass
Authors: Wilkins P. W. , Lovatt J. A. , Hayes R. C.
Published: November 2007

A rare stay‐green allele transferred from meadow fescue (Festuca pratensis L.) to perennial ryegrass (Lolium perenne L.) has improved both the colour of turf and the nutritive value of herbage. In this study its effect on shoot density and forage yield was assessed. Equivalent populations of perennial ryegrass were constructed with and without the stay‐green allele, following eight generations of backcrossing to perennial ryegrass. The stay‐green population, the normal population and the cv. AberStar were compared over two harvest years (2005 and 2006) in a field experiment with six application rates of N fertilizer (100, 200, 300, 400, 500 and 600 kg ha−1 annually). There were no significant interactions between level of N fertilizer and population in any of the traits measured. The mean annual dry‐matter (DM) yield over all populations and fertilizer levels was 6·45 t ha−1 lower in the second harvest year. Mean annual DM yields over all fertilizer levels of the normal population were higher than, or equal to, AberStar while those of the stay‐green population were significantly (proportionately 0·10–0·13) lower than the normal population. In 2005, the mean total yield of N in the herbage of the stay‐green population was 0·09 lower than that of the normal population and the mean concentration of N over all harvests was 1·5 g kg−1 DM higher. The shoot density of the stay‐green population after the last harvest in November 2006 was 0·18 lower than that of the normal population (3689 and 4478 shoots m−2 respectively).