bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterizing crystalline polymorph transitions in HfO2 by extended x-ray absorption fine-structure spectroscopy
Authors: Lysaght Patrick S. , Woicik Joseph C. , Alper Sahiner M. , Lee Byoung-Hun , Jammy Raj
Published: September 2007

Atomic layer deposited HfO2 films on Si(100) substrates have been measured by extended x-ray absorption fine-structure (EXAFS), pre- and postanneal processing. Analysis of the second coordination shell indicates an increase in atomic order with increasing film thickness for each anneal temperature and with increasing anneal temperature for each film thickness. Fourier transformed EXAFS spectra fit with HfO2 reference phases have identified orthorhombic to tetragonal to monoclinic transformations. Evidence for greater retention of the higher permittivity metastable tetragonal phase corresponding to thinner HfO2 films is consistent with a surface energy effect giving rise to the critical grain size phenomenon.
Identification of sediment sources to Lake Wivenhoe, south-east Queensland, Australia
Authors: Douglas G. , Palmer M. , Caitcheon G. , Orr P.
Published: September 2007

Effective management of sediment fluxes in aquatic systems involves, in part, the identification of catchment sediment sources. Lake Wivenhoe (LW), the largest water storage in south-east Queensland, serves two important roles: it supplies 80% of the drinking water to the region and acts as a major flood mitigation feature for the city of Brisbane. Highly developed subcatchments in LW have resulted in declining waterway health, with sediment movement from the catchment to LW of major concern. Although there is considerable hydrological information, only limited data exist on sediment and nutrient fluxes. A detailed lake sediment (128 samples) and reconnaissance catchment soil sampling program (89 samples) was undertaken. Geochemical, Nd–Sr isotopic and statistical analyses were used to identify major sources of sediment to LW. A purpose-built Bayesian mixing model was then used to quantitatively estimate the proportion of sediment from major catchment sources. Approximately 36% of the LW catchment delivers the majority of sediment; enrichment factors for the three major sediment sources (dam to catchment ratio) range from ~2 to 5. The Esk Formation is the major sediment source comprising ~10% of catchment area but contributing 50% of the sediment and 33% of the total phosphorus delivered to LW.
Categorisation of soils based on potassium reserves and production systems: implications in K management
Authors: Srinivasarao Ch. , Vittal K. P. R. , Tiwari K. N. , Gajbhiye P. N. , Kundu Sumanta
Published: September 2007

Crop fertilisation with potassium in rainfed agriculture in India is not practised, merely on the assumption that Indian soils are rich in potassium and crops do not need external K supply. However, under continuous cropping in rainfed regions, huge crop K removals are reported, up to 150–200 kg/ha annually, depending upon amount and distribution of rainfall and biomass production. Thus, most of the crops essentially deplete soil K reserves. The present study evaluates the soil K reserves under diverse rainfed production systems and categorises rainfed soils based on different soil K fractions. Depth-wise sampling was done from 21 locations across different soil types under 8 production systems, and various fractions of soil K were determined. Total K was highest in Inceptisols (1.60–2.28%), followed by Aridisols (1.45–1.84%), Vertisols and Vertic sub-groups (0.24–1.72%), and Alfisols and Oxisols (0.30–1.86%), showing a wide variation within each group. Nonexchangeable K reserves were found in a proportionate manner to total K in most of the soil profile. Unlike nonexchangeable K reserves, Vertisols had higher exchangeable K than Inceptisols and Alfisols/Oxisols. Nonexchageable K showed significant positive correlation with total K in Inceptisols and Vertisols, whereas it was non-significant in Alfisols/Oxisosls. However, significant positive correlations were recorded with exchangeable K and nonexchangeable K in all soil types, indicating the dynamic equilibrium between 2 soil K fractions. Nonexchangeable K reserves were included along with exchangeable K in categorising soils into 9 groups for evolving better strategies to manage soil K fertility in rainfed agriculture in India. Finger millet and groundnut crops at Bangalore and Anantapur regions (category I) need immediate attention on K nutrition, as these soils are low in both exchangeable and nonexchangeable K. Similarly, crops grown on soils of S.K. Nagar, Ballowal-Saunkri, and Rakh-Dhiansar, with low exchangeable K and medium nonexchangeable K, would need K fertilisation as these crops (maize and pearlmillet) are K-exhaustive (category II). Pearl millet and upland rice in category III and cotton in category IV need K additions at critical stages. Upland rice in category V needs a maintenance dose of K. In category VI, cereal crops may not need K additions immediately as they have medium exchangeable K and high nonexchangeable K. Long-term sorghum cropping may need K supply after few years (category VII). Soils in category VIII are adequate in nonexchangeable K and medium exchangeable K and the crops, groundnut, cotton, sorghum, and soybean, may not need external K immediately. For soils in category IX, K fertilisation is not required to the crops (sorghum and soybean) as these soils have high exchangeable and nonexchangeable K.
Medicago ciliaris growing in Tunisian soils is preferentially nodulated by Sinorhizobium medicae
Authors: Zribi K. , Badri Y. , Saidi S. , van Berkum P. , Aouani M. E.
Published: September 2007

Variation in growth of Medicago ciliaris was recorded across soils from 5 different regions in Tunisia that represented different soil types and climatic zones. In 4 of these soils (Mateur, Enfidha, Rhayet, and Soliman) this variation appeared to be related to the nodule number on the roots of the plants. With the exception of one isolate the rhizobia isolated from these nodules had 16S rRNA PCR-RFLP fingerprint patterns that were characteristic of Sinorhizobium medicae. Plant growth in the fifth soil (Jelma) was the poorest; plants had few nodules that yielded exclusively rhizobia with 16S rRNA fingerprint patterns characteristic of S. meliloti. In subsequent plant tests, S. medicae isolates formed effective nitrogen fixation symbioses with M. ciliaris, while S. meliloti formed small, white, ineffective nodules. Therefore, plant growth in Jelma soil was poor because only S. meliloti are present and this species is ineffective with M. ciliaris. In a co-inoculation experiment with M. ciliaris, S. medicae was more competitive for nodulation than S. meliloti, perhaps explaining why the majority of the isolates from Enfidha and Rhayet were S. medicae, since S. meliloti is present in these soils. However, it is not clear how the host influences rhizobia for nodulation by S. medicae in preference to S. meliloti when present.
Synthesis of crystals with a programmable kinetic barrier to nucleation
Authors: Schulman Rebecca , Winfree Erik
Published: September 2007

A central goal of chemistry is to fabricate supramolecular structures of defined function and composition. In biology, control of supramolecular synthesis is often achieved through precise control over nucleation and growth processes: A seed molecule initiates growth of a structure, but this growth is kinetically inhibited in the seed's absence. Here we show how such control can be systematically designed into self-assembling structures made of DNA tiles. These structures, “zig-zag ribbons,” are designed to have a fixed width but can grow arbitrarily long. Under slightly supersaturated conditions, theory predicts that elongation is always favorable but that nucleation rates decrease exponentially with increasing width. We confirm experimentally that although ribbons of different widths have similar thermodynamics, nucleation rates decrease for wider ribbons. It is therefore possible to program the nucleation rate by choosing a ribbon width. The presence of a seed molecule, a stabilized version of the presumed critical nucleus, removes the kinetic barrier to nucleation of a ribbon. Thus, we demonstrate the ability to grow supramolecular structures from rationally designed seeds, while suppressing spurious nucleation. Control over DNA tile nucleation allows for proper initiation of algorithmic crystal growth, which could lead to the high-yield synthesis of micrometer-scale structures with complex programmed features. More generally, this work shows how a self-assembly subroutine can be initiated.
Going beyond panaceas
Authors: Ostrom Elinor , Janssen Marco A. , Anderies John M.
Published: September 2007

In the context of governance of human–environment interactions, a panacea refers to a blueprint for a single type of governance system (e.g., government ownership, privatization, community property) that is applied to all environmental problems. The aim of this special feature is to provide theoretical analysis and empirical evidence to caution against the tendency, when confronted with pervasive uncertainty, to believe that scholars can generate simple models of linked social–ecological systems and deduce general solutions to the overuse of resources. Practitioners and scholars who fall into panacea traps falsely assume that all problems of resource governance can be represented by a small set of simple models, because they falsely perceive that the preferences and perceptions of most resource users are the same. Readers of this special feature will become acquainted with many cases in which panaceas fail. The articles provide an excellent overview of why they fail. Furthermore, the articles in this special feature address how scholars and public officials can increase the prospects for future sustainable resource use by facilitating a diagnostic approach in selecting appropriate starting points for governance and monitoring, as well as by learning from the outcomes of new policies and adapting in light of effective feedback.
Panaceas and diversification of environmental policy
Authors: Brock William A. , Carpenter Stephen R.
Published: September 2007

We consider panacea formation in the framework of adaptive learning and decision for social–ecological systems (SESs). Institutions for managing such systems must address multiple timescales of ecological change, as well as features of the social community in which the ecosystem policy problem is embedded. Response of the SES to each candidate institution must be modeled and treated as a stochastic process with unknown parameters to be estimated. A fundamental challenge is to design institutions that are not vulnerable to capture by subsets of the community that self-organize to direct the institution against the overall social interest. In a world of episodic structural change, such as SESs, adaptive learning can lock in to a single institution, model, or parameter estimate. Policy diversification, leading to escape from panacea traps, can come from monitoring indicators of episodic change on slow timescales, minimax regret decision making, active experimentation to accelerate model identification, mechanisms for broadening the set of models or institutions under consideration, and processes for discovery of new institutions and technologies for ecosystem management. It is difficult to take all of these factors into account, but the discipline that comes with the attempt to model the coupled social–ecological dynamics forces policy makers to confront all conceivable responses. This process helps induce the modesty needed to avoid panacea traps while supporting systematic effort to improve resource management in the public interest.
The precursors of governance in the Maine lobster fishery
Authors: Wilson James , Yan Liying , Wilson Carl
Published: September 2007

Collective action is more likely to occur and to be effective when it is consistent with the self-interest of the affected individuals. The Maine lobster fishery is an instructive example of biological and technological circumstances combining with individual self-interest to create conditions favorable to collective action. The model describes the way social structure emerges from the adaptive behavior of competing fishers. Fishers compete in two ways: in a scramble to find the lobsters first and by directly interfering in other fishers' ability to compete, i.e., by cutting their traps. Both forms of competition lead fishers to interact frequently and to self-organize into relatively small groups. They learn to restrain their competitive behavior toward their neighbors but do not extend that same restraint to nonneighbors. Groups work within well defined boundaries, contact one another frequently, actively exchange information about the resource, and, most importantly, depend on continuing mutual restraint for their economic well-being. These self-organizing, competitive processes lay the foundation for successful collective action, i.e., mutual agreements that create the additional restraint required for conservation. The modeling approach we use is a combined multiagent and classifier systems simulation. The model allows us to simulate the dynamic adaptation (learning) of multiple individuals interacting in a complex, changing environment and, consequently, provides a way to analyze the fine-scale processes that emerge as the broad social–ecological patterns of the fishery. Patterns generated by the model are compared with patterns observed in a large dataset collected by 44 Maine fishers.
Distinct requirements for Gab1 in Met and EGF receptor signaling
in vivo
Authors: Schaeper Ute , Vogel Regina , Chmielowiec Jolanta , Huelsken Joerg , Rosario Marta , Birchmeier Walter
Published: September 2007

Gab1 is a multiadaptor protein that has been shown to be required for multiple processes in embryonic development and oncogenic transformation. Gab1 functions by amplifying signal transduction downstream of various receptor tyrosine kinases through recruitment of multiple signaling effectors, including phosphatidylinositol 3-kinase and Shp2. Until now, the functional significance of individual interactions
in vivo
was not known. Here we have generated knockin mice that carry point mutations in either the P13K or Shp2 binding sites of Gab1. We show that different effector interactions with Gab1 play distinct biological roles downstream of Gab1 during the development of different organs. Recruitment of phosphatidylinositol 3-kinase by Gab1 is essential for EGF receptor-mediated embryonic eyelid closure and keratinocyte migration, and the Gab1–Shp2 interaction is crucial for Met receptor-directed placental development and muscle progenitor cell migration to the limbs. Furthermore, we investigate the dual association of Gab1 with the Met receptor. By analyzing knockin mice with mutations in the Grb2 or Met binding site of Gab1, we show that the requirements for Gab1 recruitment to Met varies in different biological contexts. Either the direct or the indirect interaction of Gab1 with Met is sufficient for Met-dependent muscle precursor cell migration, whereas both modes of interaction are required and neither is sufficient for placenta development, liver growth, and palatal shelf closure. These data demonstrate that Gab1 induces different biological responses through the recruitment of distinct effectors and that different modes of recruitment for Gab1 are required in different organs.
Panaceas, uncertainty, and the robust control framework in sustainability science
Authors: Anderies John M. , Rodriguez Armando A. , Janssen Marco A. , Cifdaloz Oguzhan
Published: September 2007

A critical challenge faced by sustainability science is to develop strategies to cope with highly uncertain social and ecological dynamics. This article explores the use of the robust control framework toward this end. After briefly outlining the robust control framework, we apply it to the traditional Gordon–Schaefer fishery model to explore fundamental performance–robustness and robustness–vulnerability trade-offs in natural resource management. We find that the classic optimal control policy can be very sensitive to parametric uncertainty. By exploring a large class of alternative strategies, we show that there are no panaceas: even mild robustness properties are difficult to achieve, and increasing robustness to some parameters (e.g., biological parameters) results in decreased robustness with respect to others (e.g., economic parameters). On the basis of this example, we extract some broader themes for better management of resources under uncertainty and for sustainability science in general. Specifically, we focus attention on the importance of a continual learning process and the use of robust control to inform this process.
Identification of human-induced changes in atmospheric moisture content
Authors: Santer B. D. , Mears C. , Wentz F. J. , Taylor K. E. , Gleckler P. J. , Wigley T. M. L. , Barnett T. P. , Boyle J. S. , Brüggemann W. , Gillett N. P. , Klein S. A. , Meehl G. A. , Nozawa T. , Pierce D. W. , Stott P. A. , Washington W. M. , Wehner M. F.
Published: September 2007

Data from the satellite-based Special Sensor Microwave Imager (SSM/I) show that the total atmospheric moisture content over oceans has increased by 0.41 kg/m
2
per decade since 1988. Results from current climate models indicate that water vapor increases of this magnitude cannot be explained by climate noise alone. In a formal detection and attribution analysis using the pooled results from 22 different climate models, the simulated “fingerprint” pattern of anthropogenically caused changes in water vapor is identifiable with high statistical confidence in the SSM/I data. Experiments in which forcing factors are varied individually suggest that this fingerprint “match” is primarily due to human-caused increases in greenhouse gases and not to solar forcing or recovery from the eruption of Mount Pinatubo. Our findings provide preliminary evidence of an emerging anthropogenic signal in the moisture content of earth's atmosphere.
The oxysterol binding protein Kes1p regulates Golgi apparatus phosphatidylinositol-4-phosphate function
Authors: Fairn Gregory D. , Curwin Amy J. , Stefan Christopher J. , McMaster Christopher R.
Published: September 2007

The
Saccharomyces cerevisiae
phosphatidylcholine/phosphatidylinositol transfer protein Sec14p is required for Golgi apparatus-derived vesicular transport through coordinate regulation of phospholipid metabolism. Sec14p is normally essential. The essential requirement for
SEC14
can be bypassed by inactivation of (
i
) the CDP–choline pathway for phosphatidylcholine synthesis or (
ii
)
KES1
, which encodes an oxysterol binding protein. A unique screen was used to determine genome-wide genetic interactions for the essential gene
SEC14
and to assess whether the two modes of “
sec14
bypass” were similar or distinct. The results indicate that inactivation of the CDP–choline pathway allows cells with inactivated
SEC14
to live through a mechanism distinct from that of inactivation of
KES1
. We go on to demonstrate an important biological function of Kes1p. Kes1p regulates Golgi apparatus-derived vesicular transport by inhibiting the function of Pik1p-generated Golgi apparatus phosphatidylinositol-4-phosphate (PI-4P). Kes1p affects both the availability and level of Golgi apparatus PI-4P. A set of potential PI-4P-responsive proteins that include the Rab GTPase Ypt31p and its GTP exchange factor are described.
Electrostatic interactions in phospholipid membranes revealed by coherent 2D IR spectroscopy
Authors: Volkov V. V. , Chelli R. , Zhuang W. , Nuti F. , Takaoka Y. , Papini A. M. , Mukamel S. , Righini R.
Published: September 2007

The inter- and intramolecular interactions of the carbonyl moieties at the polar interface of a phospholipid membrane are probed by using nonlinear femtosecond infrared spectroscopy. Two-dimensional IR correlation spectra separate homogeneous and inhomogeneous broadenings and show a distinct cross-peak pattern controlled by electrostatic interactions. The inter- and intramolecular electrostatic interactions determine the inhomogeneous character of the optical response. Using molecular dynamics simulation and the nonlinear exciton equations approach, we extract from the spectra short-range structural correlations between carbonyls at the interface.
Shannon's monotonicity problem for free and classical entropy
Authors: Shlyakhtenko Dimitri , Schultz Hanne
Published: September 2007

We give a short unified proof of the following theorem, valid in the context of both classical probability theory and Voiculescu's free probability theory: let (
X

j

(1)
, …,
X

j

(
n
)

) be independent (resp., freely independent)
n
-tuples of random variables. Let
Z

N

(
p
)

=
N
−1/2
(
X
1

(
p
)

+ … +
X

N

(
p
)

) be their central limit sums. Then the entropy (resp., free entropy) of the
n
-tuple (
Z

N

(1)
, …,
Z

N

(
n
)

) is a monotone function of
N
. The classical case (for
n
= 1) is a celebrated result of Artstein, Ball, Barthe, and Naor, and our proof is an adaptation and simplification of their argument.
Properties of GluR3 receptors tagged with GFP at the amino or carboxyl terminus
Authors: Limon Agenor , Reyes-Ruiz Jorge Mauricio , Eusebi Fabrizio , Miledi Ricardo
Published: September 2007

Anatomical visualization of neurotransmitter receptor localization is facilitated by tagging receptors, but this process can alter their functional properties. We have evaluated the distribution and properties of WT glutamate receptor 3 (GluR3) α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors (WT GluR3) and two receptors in which GFP was tagged to the amino terminus (GFP-GluR3) or to the carboxyl terminus (GluR3-GFP). Although the fluorescence inXenopusoocytes was stronger in the vegetal hemisphere because of localization of internal structures (probable sites of production, storage or recycling of receptors), the insertion of receptors into the plasma membrane was polarized to the animal hemisphere. The fluorescence intensity of oocytes injected with GluR3-GFP RNA was approximately double that of oocytes injected with GFP-GluR3 RNA. Accordingly, GluR3-GFP oocytes generated larger kainate-induced currents than GFP-GluR3 oocytes, with similar EC50values. Currents elicited by glutamate, or AMPA coapplied with cyclothiazide, were also larger in GluR3-GFP oocytes. The glutamate- to kainate-current amplitude ratios differed, with GluR3-GFP being activated more efficiently by glutamate than the WT or GFP-GluR3 receptors. This pattern correlates with the slower decay of glutamate-induced currents generated by GluR3-GFP receptors. These changes were not observed when GFP was tagged to the amino terminus, and these receptors behaved like the WT. The antagonistic effects of 6-nitro-7-sulfamoylbenzo[f]quinoxaline-2,3-dione (NBQX) and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) were not altered in any of the tagged receptors. We conclude that GFP is a useful and convenient tag for visualizing these proteins. However, the effects of different sites of tag insertion on receptor characteristics must be taken into account in assessing the roles played by these receptor proteins.
Improvement of water use efficiency in rice by expression of
HARDY
, an
Arabidopsis
drought and salt tolerance gene
Authors: Karaba Aarati , Dixit Shital , Greco Raffaella , Aharoni Asaph , Trijatmiko Kurniawan R. , Marsch-Martinez Nayelli , Krishnan Arjun , Nataraja Karaba N. , Udayakumar Makarla , Pereira Andy
Published: September 2007

Freshwater is a limited and dwindling global resource; therefore, efficient water use is required for food crops that have high water demands, such as rice, or for the production of sustainable energy biomass. We show here that expression of the
Arabidopsis HARDY
(
HRD
) gene in rice improves water use efficiency, the ratio of biomass produced to the water used, by enhancing photosynthetic assimilation and reducing transpiration. These drought-tolerant, low-water-consuming rice plants exhibit increased shoot biomass under well irrigated conditions and an adaptive increase in root biomass under drought stress. The
HRD
gene, an AP2/ERF-like transcription factor, identified by a gain-of-function
Arabidopsis
mutant
hrd-D
having roots with enhanced strength, branching, and cortical cells, exhibits drought resistance and salt tolerance, accompanied by an enhancement in the expression of abiotic stress associated genes.
HRD
overexpression in
Arabidopsis
produces thicker leaves with more chloroplast-bearing mesophyll cells, and in rice, there is an increase in leaf biomass and bundle sheath cells that probably contributes to the enhanced photosynthesis assimilation and efficiency. The results exemplify application of a gene identified from the model plant
Arabidopsis
for the improvement of water use efficiency coincident with drought resistance in the crop plant rice.
Sustained antigen presentation can promote an immunogenic T cell response, like dendritic cell activation
Authors: Obst Reinhard , van Santen Hisse-Martien , Melamed Rachel , Kamphorst Alice O. , Benoist Christophe , Mathis Diane
Published: September 2007

Activation of dendritic cells (DCs) enhances their ability to prime naïve T cells. How activation renders them immunogenic rather than tolerogenic is unclear. Here, we show, using temporally regulated expression of a transgene-encoded neoself antigen in DCs, that either prolonged antigen presentation or DC activation could elicit full expansion, effector cytokine production, and memory-cell differentiation. Microarray analysis of gene expression in T cells showed that all changes linked to DC activation through CD40 could be reproduced by persistent antigen delivery, suggesting that stabilization of antigen presentation is an important consequence of DC activationin vivo. In this system, DC activation by CD40 engagement indeed extended their ability to present antigen to CD4+T cellsin vivo, although different results were obtained with antigen delivered to DCs by means of endocytosis from the cell surface. These results suggest that antigen persistence may be an important discriminator of immunogenic and tolerogenic antigen exposure.
Structural plasticity in Ig superfamily domain 4 of ICAM-1 mediates cell surface dimerization
Authors: Chen Xuehui , Kim Thomas Doohun , Carman Christopher V. , Mi Li-Zhi , Song Gang , Springer Timothy A.
Published: September 2007

The Ig superfamily (IgSF) intercellular adhesion molecule-1 (ICAM-1) equilibrates between monomeric and dimeric forms on the cell surface, and dimerization enhances cell adhesion. A crystal structure of ICAM-1 IgSF domains (D) 3–5 revealed a unique dimerization interface in which D4s of two protomers fuse through edge β-strands to form a single super β-sandwich domain. Here, we describe a crystal structure at 2.7-Å resolution of monomeric ICAM-1 D3–D5, stabilized by the monomer-specific Fab CA7. CA7 binds to D5 in a region that is buried in the dimeric interface and is distal from the dimerization site in D4. In monomeric ICAM-1 D3–D5, a 16-residue loop in D4 that is disordered in the dimeric structure could clearly be traced as a BC loop, a short C strand, and a CE meander with a cis-Pro followed by a solvent-exposed, flexible four-residue region. Deletions of 6 or 10 residues showed that the C-strand is essential for monomer stability, whereas a distinct six-residue deletion showed little contribution of the CE meander. Mutation of two inward-pointing Leu residues in edge β-strand E to Lys increased monomer stability, confirming the hypothesis that inward-pointing charged side chains on edge β-strands are an important design feature to prevent β-supersheet formation. Overall, the studies reveal that monomer–dimer transition is associated with a surprisingly large, physiologically relevant, IgSF domain rearrangement.
Fragile X mental retardation protein deficiency leads to excessive mGluR5-dependent internalization of AMPA receptors
Authors: Nakamoto Mika , Nalavadi Vijayalaxmi , Epstein Michael P. , Narayanan Usha , Bassell Gary J. , Warren Stephen T.
Published: September 2007

Fragile X syndrome (FXS), a common inherited form of mental retardation, is caused by the functional absence of the fragile X mental retardation protein (FMRP), an RNA-binding protein that regulates the translation of specific mRNAs at synapses. Altered synaptic plasticity has been described in a mouse FXS model. However, the mechanism by which the loss of FMRP alters synaptic function, and subsequently causes the mental impairment, is unknown. Here, in cultured hippocampal neurons, we used siRNAs againstFmr1to demonstrate that a reduction of FMRP in dendrites leads to an increase in internalization of the α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor (AMPAR) subunit, GluR1, in dendrites. This abnormal AMPAR trafficking was caused by spontaneous action potential-driven network activity without synaptic stimulation by an exogenous agonist and was rescued by 2-methyl-6-phenylethynyl-pyridine (MPEP), an mGluR5-specific inverse agonist. Because AMPAR internalization depends on local protein synthesis after mGluR5 stimulation, FMRP, a negative regulator of translation, may be viewed as a counterbalancing signal, wherein the absence of FMRP leads to an apparent excess of mGluR5 signaling in dendrites. Because AMPAR trafficking is a driving process for synaptic plasticity underlying learning and memory, our data suggest that hypersensitive AMPAR internalization in response to excess mGluR signaling may represent a principal cellular defect in FXS, which may be corrected by using mGluR antagonists.
Control of Emi2 activity and stability through Mos-mediated recruitment of PP2A
Authors: Wu Judy Qiju , Hansen David V. , Guo Yanxiang , Wang Michael Zhuo , Tang Wanli , Freel Christopher D. , Tung Jeffrey J. , Jackson Peter K. , Kornbluth Sally
Published: September 2007

Before fertilization, vertebrate eggs are arrested in meiosis II by cytostatic factor (CSF), which holds the anaphase-promoting complex (APC) in an inactive state. It was recently reported that Mos, an integral component of CSF, acts in part by promoting the Rsk-mediated phosphorylation of the APC inhibitor Emi2/Erp1. We report here that Rsk phosphorylation of Emi2 promotes its interaction with the protein phosphatase PP2A. Emi2 residues adjacent to the Rsk phosphorylation site were important for PP2A binding. An Emi2 mutant that retained Rsk phosphorylation but lacked PP2A binding could not be modulated by Mos. PP2A bound to Emi2 acted on two distinct clusters of sites phosphorylated by Cdc2, one responsible for modulating its stability during CSF arrest and one that controls binding to the APC. These findings provide a molecular mechanism for Mos action in promoting CSF arrest and also define an unusual mechanism, whereby protein phosphorylation recruits a phosphatase for dephosphorylation of distinct sites phosphorylated by another kinase.
Assessing the restorative value of the environment: A study on the elderly in comparison with young adults and adolescents
Authors: Berto Rita
Published: September 2007

Nature is not only appreciated for its aesthetic characteristics, but is also a useful resource for people. It plays an important role in the process of attention restoration and recovery from stress. Young adults and adolescents assess natural environments as being more restorative than built environments. This study sought to test whether natural environments are more restorative than built environments for the elderly as well. The study is made up of two phases: (1) an empirical study with the elderly, (2) a comparison of data from the elderly with two earlier studies of adolescents and young adults. To achieve this aim a group of 50 elderly people (age range: 62–93 years) was asked to rate the restorative value of 10 pictures of environments ranging from natural to built, covering 5 environmental categories: housing, industrial zone, city streets, hills, and lakes. Each picture was assessed using the Perceived Restorativeness Scale. Participants were from three living situations: elderly living in a place for old people located in a green area (N = 18), elderly living in a place for old people located in an urban area (N = 20), and elderly living in their own homes (N = 12). Results showed that all three groups of the elderly evaluated the natural environments as more restorative than the built environments. The elderly data were then compared with the data from a sample of adolescents (N = 60, age range: 11–14 years) and of young adults (N = 100, age range: 18–29 years). All three groups rated natural environments as more restorative than built environments. The evaluation of preference and familiarity, however, differed between age groups, with adolescence being less familiar with and less in favour of natural environments than young adults and the elderly. Restorativeness and preference were correlated among all age groups, while familiarity and restorativeness were correlated only among the elderly.
Taiwanese and American mothers' goals and values for their children's futures
Authors: Suizzo Marie‐Anne , Cheng Chi‐Chia
Published: September 2007

Cross‐cultural research on parents' socialization goals and practices with young children has increasingly shown that parents promote aspects of both independence and interdependence in their children. However, few studies have examined parents' long‐term goals for their children's futures, which may be equally or more influential than short‐term socialization goals on children's development. This study compared long‐term goals and values for young children in a sample of 201 mothers from two industrialized countries: Taiwan and the United States. Six dimensions of long‐term goals and values were measured: agency and self‐direction, power and achievement, intimacy and enjoyment, conformity and tradition, family relatedness, and benevolence and universalism. Controlling for maternal education, there were no group differences in the importance attached to agency, benevolence, and family relatedness: Both groups attached highest importance to agency and benevolence, and considered family relatedness much less important. Differences were found in importance attached to intimacy, conformity, and power: Although both groups highly valued intimacy, European American mothers valued intimacy more than Taiwanese mothers; and Taiwanese mothers attached greater importance to conformity and power. All dimensions were positively correlated across groups, and only three correlations differed in their magnitude between the groups: Agency and conformity, agency and intimacy, and conformity and universalism, all of which were more strongly associated among Taiwanese than among European American mothers. Among Taiwanese mothers, maternal education was positively related to agency, intimacy, conformity, benevolence, and power. Among European American mothers, more educated mothers attached less importance to conformity than less educated mothers. This study demonstrates that Taiwanese and European American mothers' long‐term goals for their children include aspects of both independence and interdependence, and extends findings of prior research focusing only on short‐term goals. These findings suggest that parents' goals may differ depending on the child's age (short‐term or long‐term), and underscore the importance of examining social context when comparing parents' goals across cultures.
Charismatic leadership and organizational outcomes: The mediating role of employees' work‐group identification
Authors: Cicero Lavinia , Pierro Antonio
Published: September 2007

This research examines the degree of employees' identification with the work‐group as a function of charismatic leadership (e.g., Conger & Kanungo, 1998) and the mediating role of work‐group identification (Van Knippenberg & Van Shie, 2000) in the relationship between charismatic style and different work outcomes. Thus, the general aim was to analyse leadership and work outcomes as they are associated to social identification processes, referring both to recent developments of charismatic leadership models and to the recent developments of the social identity analysis applied to the workplace (see Abrams & Hogg, 2001). Two field surveys were conducted using 200 Italian public and private sector employees (two different working organizations). Two questionnaires were designed in order to collect data. They included different measures of charismatic leadership derived by the literature (e.g., the Conger‐Kanungo Charismatic Leadership Questionnaire; Conger & Kanungo, 1994, 1998, for Study 2), a scale to assess the degree of identification with the work‐group (Van Knippenberg & Van Shie, 2000), and some scales to measure the different outcomes considered (e.g., Brown and Leigh's effort measure, 1996; Mobley's turnover intention measure, 1977). As predicted, results of Study 1 revealed that charismatic leadership was positively related to work‐group identification, and employees' work effort was positively related to work‐group identification. Work‐group identification also mediates relationship between charismatic leadership and work effort. Results of Study 2 replicated the positive association between charismatic leadership and employees' work‐group identification; work‐group identification is also associated with their job involvement, job satisfaction, performance, and turnover intention. The same mediating role of work‐group identification between charismatic leadership and the criteria mentioned above was found. Underlying mechanisms as well as implications are discussed.
Depressed mood: The role of negative thoughts, self‐consciousness, and sex role stereotypes
Authors: Panayiotou Georgia , Papageorgiou Myroula
Published: September 2007

Research typically finds that depression is twice as common among women as among men. This may relate to differences in socialization that result in different emotions, cognitions, and coping reactions. Sex‐role stereotypes, employment and marital status, and differential social pressures may also be significant in making women more vulnerable to the development of depression. Women may have less decision‐making power, face more adverse life events, and have limited access to resources, which may lead to feelings of helplessness and low self‐esteem. Low self‐esteem and negative cognitions about the self in turn may be proximal factors predictive of negative mood. Additionally, women may be more prone to ruminative self‐focus rather than active coping, a significant risk factor for depression. This study examined individual predictors of depressed mood for each sex, including coping, self‐esteem, negative thoughts, self‐consciousness (rumination), as well as social factors such as the endorsement of sex‐role stereotypes and decision‐making power in the family. Results indicated that social factors were not related to depressed mood in either sex, but were related to coping styles and self‐esteem. Depressed mood was associated with individual characteristics, such as avoidant coping styles, social anxiety for women, and ruminative self‐focus for men. Regression analysis showed that coping through denial and negative thoughts explained depressed mood, and the latter was particularly true for men. These results point to the significance of examining both individual and social factors when attempting to understand depression in men and women.
Nothing But the Truth
Authors: Golestan Hengameh
Published: September 2007

The celebrated Iranian photojournalist Kaveh Golestan was killed when he stepped on a landmine while on assignment in Iraq, in April 2003. His widow, the photographer Hengameh Golestan, here introduces an essay and selection of photographs from the forthcoming book Kaveh Golestan 1950—2003: Recording the Truth in Iran, edited by Malu Halasa and Hengameh Golestan, to be published by Hatje Cantz and the Prince Claus Fund Library in October.
Alcohol Abuse in Sickle Cell Disease: The Pisces Project
Authors: Levenson James L. , McClish Donna K. , Dahman Bassam A. , Penberthy Lynne T. , Bovbjerg Viktor E. , Aisiku Imoigele P. , Roseff Susan D. , Smith Wally R.
Published: September 2007

Alcohol abuse is common in patients with chronic painful medical disorders, but it has not been studied in sickle cell disease (SCD). In a prospective cohort study of SCD adults, 31.4% were identified as abusing alcohol. There were no significant differences between alcohol abusers and nonabusers on demographics, biological variables, depression, anxiety, measures of crisis and noncrisis pain, or opioid use, but abusers reported more pain relief from opioids than nonabusers did. Alcohol abusers had fewer unscheduled clinic visits, emergency room visits, hospital days, and any health care utilization for SCD, but this was only significant for emergency room visits. Quality of life was similar between both groups, except that alcohol abusers unexpectedly had better overall physical summary scores. Alcohol abusers were more likely to report coping by ignoring pain, diverting attention, and using particular self‐statements.
Child Neglect and Oral Health Problems in Offspring of Substance‐Abusing Fathers
Authors: Mezzich Ada C. , Bretz Walter A. , Day Bang‐Shiuh , Corby Patricia M. , Kirisci Levent , Swaney Michelle , Cornelius Jack R. , Weyant Robert J.
Published: September 2007

This study examined (1) orodental (OD) problems in 10–19‐year‐old children of substance use disorder (SUD) (n = 127) and non‐SUD fathers (n = 111) and (2) the moderating effect of child's substance use (SU) involvement in the associations of paternal SUD and neglectful parenting with OD problems in the offspring. The results showed that periodontal problems differentiated between groups and the interactions between child's SU involvement and paternal SUD and neglectful parenting were respectively associated with hard=soft tissue lesions and carious lesions in the offspring, indicating that SU involvement increases risk for OD due to paternal SUD and neglectful parenting.
Gender Similarities and Differences in Antisocial Behavioral Syndromes among Injection Drug Users
Authors: Mikulich‐Gilbertson Susan K. , Salomonsen‐Sautel Stacy , Sakai Joseph T. , Booth Robert E.
Published: September 2007

Studies report that more female substance users meet the adult antisocial behavioral (AASB) criteria of antisocial personality disorder (ASPD) without having conduct disorder. We assessed gender and antisocial syndrome (ASPD vs. AASB) effects jointly on multiple outcomes in injection drug users. More males had ASPD (40%) and more females had AASB (67%). After adjusting for gender, the ASPD group was consistently more severe, indicating discriminative validity for the diagnosis. However, the AASB group reported substantial pathology, signifying AASB as an important sub‐threshold antisocial syndrome. Antisocial behavior might be described as a distribution, with AASB and ASPD defined by increasingly extreme points.
Does Social Class Predict Substance Problems in Young Adults with ADHD?
Authors: Monuteaux Michael C. , Wilens Timothy E. , Biederman Joseph
Published: September 2007

The relationship between social class and substance use problems is unclear. We aimed to clarify this association in a sample of young adult males with and without attention‐deficit/hyperactivity disorder (ADHD). We included 69 ADHD and 78 control subjects. Substance use problems were measured with the Drug Use Screening Inventory–Revised (DUSI). Among ADHD subjects, we found a U‐shaped association, with elevated risk for substance‐related problems at both ends of the SES spectrum. No significant association was found in controls. These findings indicate that substance use risk in ADHD subjects is especially vulnerable to social class.
Treatment of Cannabis Use Disorders: A Review of the Literature
Authors: Nordstrom Benjamin R. , Levin Frances R.
Published: September 2007

Cannabis is the most widely used illicit drug in the United States. Despite the fact that there are large numbers of people with cannabis dependence, relatively little attention has been paid to the treatment of this condition. This article seeks to critically review the existing literature about the various psychosocial and pharmacologic treatments of cannabis dependence. We begin with a discussion of the early treatment literature which draws primarily from anecdotal experience and open, uncontrolled trials and proceed through two recent, large, randomized controlled trials of psychotherapies for the treatment of cannabis dependence. We conclude that while a number of psychotherapies have been found to be effective in treating this disorder, with the exception of adding vouchers to reinforce negative urine toxicology screens, no form of psychotherapy has been found to be more effective than any other. In addition, we review the only two clinical pharmacotherapy trials for cannabis dependence as well as the pre‐clinical laboratory pharmacotherapy trials in cannabis dependent individuals. We also review pertinent dual‐diagnosis pharmacotherapy trials and discuss potential future directions in treatment research for the pharmacotherapy of cannabis dependence.
Internet Gambling Is Common in College Students and Associated with Poor Mental Health
Authors: Petry Nancy M. , Weinstock Jeremiah
Published: September 2007

This study evaluated prevalence of Internet gambling and its association with pathological gambling and mental health status in college students. The South Oaks Gambling Screen and General Health Questionnaire were administered to 1356 undergraduates, and 23% reported ever gambling on the Internet, with 6.3% reporting Internet gambling weekly. Almost two‐thirds (61.6%) of regular Internet gamblers were pathological gamblers, compared with 23.9% of infrequent Internet gamblers and 5.0% of non‐Internet gamblers. Internet gambling frequency was significantly associated with poor mental health, after controlling for demographics and pathological gambling. These data call for prevention and treatment efforts of Internet gambling in students.
Comorbid Psychiatric Diagnoses and Their Association with Cocaine‐Induced Psychosis in Cocaine‐Dependent Subjects
Authors: Tang Yi‐Lang , Kranzler Henry R. , Gelernter Joel , Farrer Lindsay A. , Cubells Joseph F.
Published: September 2007

Comorbidity between drug abuse and mental illness is very common, but the association of such comorbidity with specific responses to drugs of abuse remains obscure. The current study examined the relationship between the presence of non‐psychotic Axis I psychiatric diagnoses and the frequency and severity of cocaine‐induced psychosis. We interviewed 243 unrelated cocaine‐dependent adults [37% European American (EA), 52.3% African American (AA); 58.8% male] using the Semi‐Structured Assessment for Drug Dependence and Alcoholism (SSADDA) to establish DSM‐IV diagnoses, and two instruments for the identification of cocaine‐induced paranoia, the Cocaine Experience Questionnaire (CEQ) and the Scale for Assessment of Positive Symptoms for Cocaine‐Induced Psychosis (SAPS‐CIP). Comorbid substance use and psychiatric disorders were common in this cocaine‐dependent sample. Ninety percent of subjects met criteria for substance use disorders other than cocaine dependence; common non‐substance‐use disorders included antisocial personality disorder (ASPD), adult ASPD, major depression, and attention deficit‐hyperactivity disorder (ADHD). Comorbid opioid dependence was more common in EA subjects than in AA participants. After correction for multiple comparisons, a lifetime diagnosis of ADHD was associated with the categorical presence of CIP (p = 0.007), as well as significantly more severe CIP symptoms. Comorbid substance use and psychiatric disorders are very common among individuals with cocaine dependence. Comorbid ADHD increases the odds of an individual endorsing CIP, suggesting some common basis for these phenomena.