bluuebunny/crossref_metadata_2025 huggingface dataset:
Physicochemical characterization of Sepia officinalis ink and the effects of storage conditions on the coagulation process
Authors: Neifar A. , Ben Rebah F. , Gargouri A. , Abdelmouleh A.
Published: September 2008

Sepia officinalis produces a dark ink constituted of a suspension of melanin granules in a viscous colourless medium showing a large variability in composition. The examination of the spectra obtained by scanning electron microscopy of crude and the melanin-free ink showed slight variation in elemental composition related to the elimination of melanin substance after centrifugation. Ink elemental content varied also depending on the period of sampling. Temperature, light and oxygen can be considered as coagulation factors. Temperature around ambient temperature (e.g. 30°C) gave strong coagulation, while lower temperature (2–4°C), lack of oxygen and darkness greatly inhibited the ink coagulation process. Moreover, we showed that hydrogen peroxide activated the ink coagulation process and the coagulation rate depends on the amount of H2O2 added. Heat treatment (100°C for 5 minutes) of ink inhibited the coagulation. Interestingly, the addition of an adequate volume of fresh melanin-free ink to the heated sample activated significantly the coagulation process.
Cognitive Therapy for Anxiety Disorders: Current Status and Future Challenges
Authors: McManus Freda , Grey Nick , Shafran Roz
Published: September 2008

This paper reviews recent theoretical, conceptual and practice developments in cognitive-behaviour therapy (CBT) for anxiety disorders. The empirical status of CBT for anxiety disorders is reviewed and recent advances in the field are outlined. Challenges for the future development of CBT for the anxiety disorders are examined in relation to the efficacy, effectiveness and cost-effectiveness of the approach. It is concluded that the major challenge currently facing CBT for anxiety disorders in the UK is how to meet the increased demand for provision whilst maintaining high levels of efficacy and effectiveness. It is suggested that the creation of an evidence base for the dissemination of CBT needs to become a priority for empirical investigation in order effectively to expand the provision of CBT for anxiety disorders.
Getting a GRASP on CASP: properties and role of the cytohesin‐associated scaffolding protein in immunity
Authors: MacNeil Adam J , Pohajdak Bill
Published: September 2008

Cytohesin‐associated scaffolding protein (CASP) is a novel human adaptor protein that participates in the assembly and recruitment of protein complexes associated with intracellular trafficking and signaling. Owing to its exclusive expression in cells of hematopoietic origin, CASP has attracted attention from many groups of researchers as a potential key contributor to molecular mechanisms governing cells of the immune system. The functional characterization of CASP has involved a wide range of experimental approaches and provided broad and interesting insights that, collectively, distinguish CASP as an important contributor for a fully functioning and rapidly responsive immune system. Protein interaction studies have demonstrated that CASP interacts with members of the ADP ribosylation factor (ARF)‐activating cytohesin family and with a unique PDZ domain‐containing member of the sorting nexin family of endocytic trafficking proteins. Physiological knockout studies, however, have revealed that CASP may not be an essential protein in immunity under normal conditions, but rather a streamlining protein that greatly ameliorates the efficiency of the immune system under circumstances of significant stress. Interestingly, an evolutionarily related neuronal protein, called GRP1‐associated scaffolding protein, may further participate in CASP‐related functions in immune cells, conferring a level of redundancy in associated molecular pathways. In this review, we summarize and critically review the current literature, bringing together common themes from a variety of studies that, when considered together, provide new insights into the nature and significance of CASP function in the broad context of immunity.
Customers' Perceptions of Ski Resorts' Images: Implications for Resorts' Positioning Strategies
Authors: Frochot Isabelle , Kreziak Dominique
Published: September 2008

Image is a core element in a communication strategy especially in regards to destination branding and positioning strategy. The present study aims at investigating to which extent French ski resorts can develop different positioning strategies, based on tourists' perceptions of a set of pictures taken from brochures and representing the resorts in which they are staying. The results indicate that, regardless of their characteristics, resorts share a core of common and recurring images that represent the ethos of skiing holidays. A second set of images can then be used to ascertain different communication strategies and position the resort on different markets.
n
-
In
Ga
N
∕
p
-
Ga
N
single heterostructure light emitting diode with p-side down
Authors: Reed M. L. , Readinger E. D. , Shen H. , Wraback M. , Syrkin A. , Usikov A. , Kovalenkov O. V. , Dmitriev V. A.
Published: September 2008

The effects of negative polarization charge at the n-InGaN∕p-GaN interface on the performance of hydride vapor phase-epitaxy deposited single heterostructure n-InGaN∕p-GaN LEDs with p-side down are investigated. The strong peak emission wavelength blueshift and concomitant superlinear increase in light output as the injection current increases below 25A∕cm2 are characteristic of radiative tunneling. We show that the combination of two-dimensional hole gas formation on the n-InGaN side of the heterointerface and enhancement of the electron barrier to transport across this interface results in only ∼10% efficiency droop up to 500A∕cm2 without implementation of an AlGaN electron-blocking layer or a second heterointerface.
The Biasing of Figure – Ground Assignment by Shading Cues for Objects and Faces in Prosopagnosia
Authors: Hefter Rebecca , Jerskey Beth A , Barton Jason J S
Published: September 2008

Prosopagnosia is defined by impaired recognition of the identity of specific faces. Whether the perception of faces at the categorical level (recognizing that a face is a face) is also impaired to a lesser degree is unclear. We examined whether prosopagnosia is associated with impaired detection of facial contours in a bistable display, by testing a series of five prosopagnosic patients on a variation of Rubin's vase illusion, in which shading was introduced to bias perception towards either the face or the vase. We also included a control bistable display in which a disc or an aperture were the two possible percepts.

With the control disc/aperture test, prosopagnosic patients did not generate a normal sigmoid function, but a U-shaped function, indicating that they perceived the shading but had difficulty in using the shading to make the appropriate figure – ground assignment. While controls still generated a sigmoid function for the vase/face test, prosopagnosic patients showed a severe impairment in using shading to make consistent perceptual assignments. We conclude that prosopagnosic patients have difficulty in using shading to segment figures from background correctly, particularly with complex stimuli like faces. This suggests that a subtler defect in face categorization accompanies their severe defect in face identification, consistent with predictions of computational models and recent data from functional imaging.
Bioelectrocatalytic hydrogels from electron-conducting metallopolypeptides coassembled with bifunctional enzymatic building blocks
Authors: Wheeldon Ian R. , Gallaway Joshua W. , Barton Scott Calabrese , Banta Scott
Published: September 2008

Here, we present two bifunctional protein building blocks that coassemble to form a bioelectrocatalytic hydrogel that catalyzes the reduction of dioxygen to water. One building block, a metallopolypeptide based on a previously designed triblock polypeptide, is electron-conducting. A second building block is a chimera of artificial α-helical leucine zipper and random coil domains fused to a polyphenol oxidase, small laccase (SLAC). The metallopolypeptide has a helix–random-helix secondary structure and forms a hydrogel via tetrameric coiled coils. The helical and random domains are identical to those fused to the polyphenol oxidase. Electron-conducting functionality is derived from the divalent attachment of an osmium bis-bipyrdine complex to histidine residues within the peptide. Attachment of the osmium moiety is demonstrated by mass spectroscopy (MS-MALDI-TOF) and cyclic voltammetry. The structure and function of the α-helical domains are confirmed by circular dichroism spectroscopy and by rheological measurements. The metallopolypeptide shows the ability to make electrical contact to a solid-state electrode and to the redox centers of modified SLAC. Neat samples of the modified SLAC form hydrogels, indicating that the fused α-helical domain functions as a physical cross-linker. The fusion does not disrupt dimer formation, a necessity for catalytic activity. Mixtures of the two building blocks coassemble to form a continuous supramolecular hydrogel that, when polarized, generates a catalytic current in the presence of oxygen. The specific application of the system is a biofuel cell cathode, but this protein-engineering approach to advanced functional hydrogel design is general and broadly applicable to biocatalytic, biosensing, and tissue-engineering applications.
Irreversible chemical steps control intersubunit dynamics during translation
Authors: Marshall R. Andrew , Dorywalska Magdalena , Puglisi Joseph D.
Published: September 2008

The ribosome, a two-subunit macromolecular machine, deciphers the genetic code and catalyzes peptide bond formation. Dynamic rotational movement between ribosomal subunits is likely required for efficient and accurate protein synthesis, but direct observation of intersubunit dynamics has been obscured by the repetitive, multistep nature of translation. Here, we report a collection of single-molecule fluorescence resonance energy transfer assays that reveal a ribosomal intersubunit conformational cycle in real time during initiation and the first round of elongation. After subunit joining and delivery of correct aminoacyl-tRNA to the ribosome, peptide bond formation results in a rapid conformational change, consistent with the counterclockwise rotation of the 30S subunit with respect to the 50S subunit implied by prior structural and biochemical studies. Subsequent binding of elongation factor G and GTP hydrolysis results in a clockwise rotation of the 30S subunit relative to the 50S subunit, preparing the ribosome for the next round of tRNA selection and peptide bond formation. The ribosome thus harnesses the free energy of irreversible peptidyl transfer and GTP hydrolysis to surmount activation barriers to large-scale conformational changes during translation. Intersubunit rotation is likely a requirement for the concerted movement of tRNA and mRNA substrates during translocation.
RETRACTED: Selection of cyclic peptide aptamers to HCV IRES RNA using mRNA display
Authors: Litovchick Alexander , Szostak Jack W.
Published: September 2008

The hepatitis C virus (HCV) is a positive strand RNA flavivirus that is a major causative agent of serious liver disease, making new treatment modalities an urgent priority. Because HCV translation initiation occurs by a mechanism that is fundamentally distinct from that of host mRNAs, it is an attractive target for drug discovery. The translation of HCV mRNA is initiated from an internal ribosomal entry site (IRES), independent of cap and poly(A) recognition and bypassing eIF4F complex formation. We used mRNA display selection technology combined with a simple and robust cyclization procedure to screen a peptide library of >10
13
different sequences and isolate cyclic peptides that bind with high affinity and specificity to HCV IRES RNA. The best peptide binds the IRES with subnanomolar affinity, and a specificity of at least 100-fold relative to binding to several other RNAs of similar length. The peptide specifically inhibits HCV IRES-initiated translation
in vitro
with no detectable effect on normal cap-dependent translation initiation. An 8-aa cyclic peptide retains most of the activity of the full-length 27-aa bicyclic peptide. These peptides may be useful tools for the study of HCV translation and may have potential for further development as an anti-HCV drug.
Caulobacter
requires a dedicated mechanism to initiate chromosome segregation
Authors: Toro Esteban , Hong Sun-Hae , McAdams Harley H. , Shapiro Lucy
Published: September 2008

Chromosome segregation in bacteria is rapid and directed, but the mechanisms responsible for this movement are still unclear. We show that
Caulobacter crescentus
makes use of and requires a dedicated mechanism to initiate chromosome segregation.
Caulobacter
has a single circular chromosome whose origin of replication is positioned at one cell pole. Upon initiation of replication, an 8-kb region of the chromosome containing both the origin and
parS
moves rapidly to the opposite pole. This movement requires the highly conserved
ParABS
locus that is essential in
Caulobacter.
We use chromosomal inversions and
in vivo
time-lapse imaging to show that
parS
is the
Caulobacter
site of force exertion, independent of its position in the chromosome. When
parS
is moved farther from the origin, the cell waits for
parS
to be replicated before segregation can begin. Also, a mutation in the ATPase domain of ParA halts segregation without affecting replication initiation. Chromosome segregation in
Caulobacter
cannot occur unless a dedicated
parS
guiding mechanism initiates movement.
The microRNA miR-8 is a conserved negative regulator of Wnt signaling
Authors: Kennell Jennifer A. , Gerin Isabelle , MacDougald Ormond A. , Cadigan Ken M.
Published: September 2008

Wnt signaling plays many important roles in animal development. This evolutionarily conserved signaling pathway is highly regulated at all levels. To identify regulators of the Wnt/Wingless (Wg) pathway, we performed a genetic screen in
Drosophila.
We identified the microRNA miR-8 as an inhibitor of Wg signaling. Expression of miR-8 potently antagonizes Wg signaling
in vivo
, in part by directly targeting
wntless
, a gene required for Wg secretion. In addition, miR-8 inhibits the pathway downstream of the Wg signal by repressing TCF protein levels. Another positive regulator of the pathway,
CG32767
, is also targeted by miR-8. Our data suggest that miR-8 potently antagonizes the Wg pathway at multiple levels, from secretion of the ligand to transcription of target genes. In addition, mammalian homologues of miR-8 promote adipogenesis of marrow stromal cells by inhibiting Wnt signaling. These findings indicate that miR-8 family members play an evolutionarily conserved role in regulating the Wnt signaling pathway.
International migration beyond gravity: A statistical model for use in population projections
Authors: Cohen Joel E. , Roig Marta , Reuman Daniel C. , GoGwilt Cai
Published: September 2008

International migration will play an increasing role in the demographic future of most nations if fertility continues to decline globally. We developed an algorithm to project future numbers of international migrants from any country or region to any other. The proposed generalized linear model (GLM) used geographic and demographic independent variables only (the population and area of origins and destinations of migrants, the distance between origin and destination, the calendar year, and indicator variables to quantify nonrandom characteristics of individual countries). The dependent variable, yearly numbers of migrants, was quantified by 43653 reports from 11 countries of migration from 228 origins and to 195 destinations during 1960–2004. The final GLM based on all data was selected by the Bayesian information criterion. The number of migrants per year from origin to destination was proportional to (population of origin)0.86(area of origin)−0.21(population of destination)0.36(distance)−0.97, multiplied by functions of year and country-specific indicator variables. The number of emigrants from an origin depended on both its population and its population density. For a variable initial year and a fixed terminal year 2004, the parameter estimates appeared stable. MultipleR2, the fraction of variation in log numbers of migrants accounted for by the starting model, improved gradually with recentness of the data:R2= 0.57 for data from 1960 to 2004,R2= 0.59 for 1985–2004,R2= 0.61 for 1995–2004, andR2= 0.64 for 2000–2004. The migration estimates generated by the model may be embedded in deterministic or stochastic population projections.
Odessa and Lvov or Odesa and Lviv: How Important is a Letter? Reflections on the “Other” in Two Ukrainian Cities
Authors: Polese Abel , Wylegala Anna
Published: September 2008

Independence forced Ukraine to face a set of statehood and nationhood challenges. State and institution building progressed quickly and effectively. In 1996 the country adopted a constitution and based its institution building on pre-existing ones. Having been a Soviet Republic, Ukraine's institutions were shaped well before 1991—if we exclude the Ministry of Foreign Affairs and the diplomatic corps. The country also diligently quelled Crimean separatism by granting a high level of autonomy to the region, with Kiev retaining control of financial matters.
The International Baccalaureate in England and Wales: the alternative paths for the future
Authors: Bunnell Tristan
Published: September 2008

The year 2007 was a significant one for the International Baccalaureate (IB) in England and Wales. Several milestones were reached, and the number of schools offering the curriculum reached one hundred. This article charts the growth and development in England and Wales of this continuum of international education and shows how the Diploma Programme, in particular, has reached a fundamental crossroads. On the one hand, the IB looks set for further growth and has the ability to be an influential and respected catalyst for the movement towards international education in curriculum development. On the other hand, the IB is emerging as an elite programme of study alongside other ‘baccalaureate’ curricula and in competition to A level, and other ‘Diploma’ developments. The ability of the IB to be a divisive force is explored.
Curriculum and assessment for the knowledge society: interrogating experiences in the Republic of Ireland and Queensland, Australia
Authors: Looney Anne , Klenowski Val
Published: September 2008

The ‘knowledge society’ has become a central discourse within educational reform. This article posits that the impact of the knowledge society discourse on curriculum and assessment has led to the emergence of what the authors term a new‐form/re‐form curriculum, and it asks whether what is transacting in contemporary movements in curriculum is less the reform of curriculum and more the emergence of a new‐form/re‐form curriculum. What is emerging is well beyond the discussions of outcomes and curriculum alignment that characterised much curriculum reform effort in the late 1990s. In this new‐form/re‐form curriculum ‘content’ is displaced by ‘skills’ and ‘knowledge acquisition’ by ‘learning’. Curriculum coverage is replaced by learner engagement. In this context, assessment also begins to take on new‐form/re‐form. Assessment now engages and promotes learning as process rather than as product. Two cases – the Republic of Ireland and Queensland, Australia – are analysed and compared to illustrate this shift in the conceptualisation of curriculum and assessment. Consideration is given to the possibility that this new‐form/re‐form curriculum represents a settlement in the contestation associated with learning outcomes and their perceived technical rationality and market focus. The paper concludes that the new‐form/re‐form curriculum is emerging in locations as diverse as Ireland and Queensland.
Conceptions of learning and pedagogy: developing trainee teachers' epistemological understandings
Authors: Fisher Annie , Rush Linda
Published: September 2008

This work has a particular focus on exposing important connections between trainee teachers' personal beliefs about knowledge (epistemological beliefs) and their conceptions of learning. These, the authors argue, are central to the assumptions which underpin their pedagogy when working with children in school. The link between these constructs emerged as key issues during a collaborative research project between five practitioners across two universities which explored the use of a ‘learning to learn’ (L2L) approach with a particular emphasis on postgraduate ITT courses. This seems particularly pertinent to expanding the capacity to learn of trainees, yet, to date, it has received little attention within research on L2L, given its more immediate focus within the school setting. The authors believe, however, that the climate is now ripe for research focusing on the context of lifelong learning, in particular teacher trainee learning in ITT. They argue that a focus on the role of epistemology in helping to shape teaching approaches is likely to be a key element in developing students with a capacity to reflect critically on practice.
Adolescent methamphetamine use and sexual risk behaviour in secondary school students in Cape Town, South Africa
Authors: PLÜDDEMANN ANDREAS , FLISHER ALAN J. , MATHEWS CATHERINE , CARNEY TARA , LOMBARD CARL
Published: September 2008

This study investigated involvement in substance use and sexual activities among adolescents in Cape Town, and specifically the associations between methampethamine use and sexual risk behaviours. Data were collected from 15 randomly selected and 15 matched schools in Cape Town via quantitative questionnaires. Students used hand‐held computers (PDAs) to answer the questions. A total of 4605 grade 9 students were sampled. Male and female students were almost equally likely to have used methamphetamine at least once (13% versus 12%). Students who had used methamphetamine in the past 30 days were significantly more likely to have had vaginal, anal or oral sex than students who had never used it, to have been pregnant/been responsible for a pregnancy and to have been diagnosed with a sexually transmitted infection. Logistic regression analysis indicated significant associations between methamphetamine use in the past 12 months and engaging in vaginal and anal sex. Drug abuse and sexually transmitted infections (STI) prevention services should incorporate the link between drugs and STI into their prevention and education strategies, especially those aimed at school‐going adolescents.
Delta-like 4 is indispensable in thymic environment specific for T cell development
Authors: Hozumi Katsuto , Mailhos Carolina , Negishi Naoko , Hirano Ken-ichi , Yahata Takashi , Ando Kiyoshi , Zuklys Saulius , Holländer Georg A. , Shima David T. , Habu Sonoko
Published: September 2008

The thymic microenvironment is required for T cell development in vivo. However, in vitro studies have shown that when hematopoietic progenitors acquire Notch signaling via Delta-like (Dll)1 or Dll4, they differentiate into the T cell lineage in the absence of a thymic microenvironment. It is not clear, however, whether the thymus supports T cell development specifically by providing Notch signaling. To address this issue, we generated mice with a loxP-flanked allele of Dll4 and induced gene deletion specifically in thymic epithelial cells (TECs). In the thymus of mutant mice, the expression of Dll4 was abrogated on the epithelium, and the proportion of hematopoietic cells bearing the intracellular fragment of Notch1 (ICN1) was markedly decreased. Corresponding to this, CD4 CD8 double-positive or single-positive T cells were not detected in the thymus. Further analysis showed that the double-negative cell fraction was lacking T cell progenitors. The enforced expression of ICN1 in hematopoietic progenitors restored thymic T cell differentiation, even when the TECs were deficient in Dll4. These results indicate that the thymus-specific environment for determining T cell fate indispensably requires Dll4 expression to induce Notch signaling in the thymic immigrant cells.
The IκBα/NF‐κB complex has two hot spots, one at either end of the interface
Authors: Bergqvist Simon , Ghosh Gourisankar , Komives Elizabeth A.
Published: September 2008

IκBα binds to and inhibits the transcriptional activity of NF‐κB family members via its ankyrin repeat (AR) domain. The binding affinity of IκBα with NF‐κB(p50/p65) heterodimers and NF‐κB(p65/65) homodimers is in the picomolar range, and in the cell, this results in long half‐lives of the complexes. Direct binding experiments have been performed using surface plasmon resonance (SPR) and isothermal titration calorimetry (ITC) on a series of truncations and mutations in order to understand what regions of the interface are most important for the tight binding affinity of this complex. We previously showed that interactions between residues 305 and 321 of NF‐κB(p65) with the first AR of IκBα are critical for the binding energy. Interactions in this region are responsible for more than 7 kcal/mol of the binding energy. Here we show equally drastic consequences for the binding energy occur upon truncation of even a few residues at the C terminus of IκBα. Thus, the interface actually has two hot spots, one at either end of the elongated and large surface of interaction. These results suggest a “squeeze” mechanism that leads to the extremely high affinity of the IκBα•NF‐κB complex through stabilization of the ankyrin repeat domain.
Positive interactions among plant species for pollinator service: assessing the ‘magnet species’ concept with invasive species
Authors: Molina‐Montenegro Marco A. , Badano Ernesto I. , Cavieres Lohengrin A.
Published: September 2008

Plants with poorly attractive flowers or with little floral rewards may have inadequate pollinator service, which in turn reduces seed output. However, pollinator service of less attractive species could be enhanced when they are associated with species with highly attractive flowers (so called ‘magnet‐species’). Although several studies have reported the magnet species effect, few of them have evaluated whether this positive interaction result in an enhancement of the seed output for the beneficiary species. Here, we compared pollinator visitation rates and seed output of the invasive annual species Carduus pycnocephalus when grow associated with shrubs of the invasive Lupinus arboreus and when grow alone, and hypothesized that L. arboreus acts as a magnet species for C. pycnocephalus. Results showed that C. pycnocephalus individuals associated with L. arboreus had higher pollinator visitation rates and higher seed output than individuals growing alone. The higher visitation rates of C. pycnocephalus associated to L. arboreus were maintained after accounting for flower density, which consistently supports our hypothesis on the magnet species effect of L. arboreus. Given that both species are invasives, the facilitated pollination and reproduction of C. pycnocephalus by L. arboreus could promote its naturalization in the community, suggesting a synergistic invasional process contributing to an ‘invasional meltdown’. The magnet effect of Lupinus on Carduus found in this study seems to be one the first examples of indirect facilitative interactions via increased pollination among invasive species.
‘Form variation’ of the O12 antigen is critical for persistence of Salmonella Typhimurium in the murine intestine
Authors: Bogomolnaya Lydia M. , Santiviago Carlos A. , Yang Hee‐Jeong , Baumler Andreas J. , Andrews‐Polymenis Helene L.
Published: September 2008

Salmonella enterica subspecies I serotypes are responsible for the vast majority of salmonellosis in mammals and birds, yet only a few factors specific to this group that allow them to persist in this niche have been identified. We show that STM0557, a S. enterica subspecies I‐specific gene encoding an inner membrane protein, is critical for faecal shedding and intestinal persistence of S. enterica serotype Typhimurium ATCC14028 in Salmonella‐resistant mice, but mutations in this gene do not diminish short‐term intestinal colonization or invasion of cultured epithelial cells. STM0557 and two neighbouring genes, located on a pathogenicity island termed SPI‐16, resemble genes of the gtrA,B, gtr(type) cluster in seroconverting bacteriophages. In general, the gtr genes encode proteins responsible for serotype conversion of the infected bacterium by addition glucose residues to repeating O‐antigen subunits of lipopolysaccharide (LPS). In lysogenized Shigella, such modifications have been previously shown to be constitutively expressed and to facilitate invasion of host cells. We show that serotype Typhimurium gtr orthologues, STM0557–0559, are responsible for ‘form variation’ or glucosylation of the O12 antigen galactose (4 position) to generate the 12‐2 variant. Form variation in Typhimurium is not constitutive, but occurred upon exposure and during intracellular growth of serotype Typhimurium in J774 macrophages. Our data suggest that the 12‐2 antigen is a S. enterica subspecies I‐specific LPS modification that enhances long‐term intestinal colonization, and is in contrast to the role of O‐antigen variation described for Shigella.
Plasma amitriptyline level after acute administration, and driving performance in healthy volunteers
Authors: Iwamoto Kunihiro , Kawamura Yukiko , Takahashi Masahiro , Uchiyama Yuji , Ebe Kazutoshi , Yoshida Keizo , Iidaka Tetsuya , Noda Yukihiro , Ozaki Norio
Published: September 2008

Aims:  Amitriptyline triggers the impairment of cognitive and motor functions and has been confirmed to have harmful effects on driving performance. Although interindividual differences in plasma concentration may cause variations in driving performance, the relationship between plasma amitriptyline concentration and its effect on driving performance has not been completely elucidated. Thus, the aim of the present study was to assess the influence of individual pharmacokinetic differences on driving performance and cognitive functions.

Methods:  In this double‐blinded study, 17 healthy male volunteers were given an acute, single, 25‐mg dose of amitriptyline. The subjects were assigned three driving simulator tasks, three cognitive tasks, and the questionnaire of the Stanford Sleepiness Scale at the baseline and at 4 h after dosing. The plasma amitriptyline concentrations were measured on high‐performance liquid chromatography.

Results:  A significant positive correlation was observed between the plasma amitriptyline concentration and road‐tracking performance (r = 0.543, P < 0.05). There was no significant correlation between the plasma amitriptyline concentration and other driving performance, cognitive functions, and subjective somnolence.

Conclusions:  Amitriptyline produces a concentration‐related impairment on road‐tracking performance. Therapeutic monitoring of amitriptyline would be useful for predicting the difficulties involved while driving.
Cognitive functions in bipolar affective disorder and schizophrenia: Comparison
Authors: Pradhan Basant K. , Chakrabarti Subho , Nehra Ritu , Mankotia Anupama
Published: September 2008

Aims:  Earlier comparisons of cognitive impairment among patients with bipolar disorder and schizophrenia have found a largely similar profile of deficits, but results have varied between studies. This prompted the current attempt at another such comparison.

Methods:  Executive functions, memory, IQ, attention–concentration and perceptuomotor function were assessed in 48 bipolar disorder patients with operationally defined euthymia, and compared with 32 schizophrenia patients in remission, and 23 normal controls. Comparisons were re‐attempted after controlling for years of schooling and residual affective symptoms.

Results:  Uncontrolled comparisons indicated that, compared to controls, both bipolar disorder and schizophrenia patients were significantly impaired on different tests of executive function, memory, IQ and perceptuomotor functions. Controlling for years of schooling and residual affective symptoms, however, served to remove most of the differences between patients and controls, apart from some aspects of executive function in schizophrenia and memory impairment in both schizophrenia and bipolar disorder. Patients with schizophrenia consistently performed worse than patients with bipolar disorder, but none of the differences between schizophrenia and bipolar disorder were significant.

Conclusions:  Patients with bipolar disorder exhibit cognitive difficulties that are very similar to schizophrenia in terms of their profile, although patients with schizophrenia may have more severe and widespread impairments. The resemblance in cognitive profiles has important implications for the etiology and treatment of both disorders.
Childhood emotional abuse, dissociation, and suicidality among patients with drug dependency in Turkey
Authors: Tamar‐Gurol Defne , Sar Vedat , Karadag Figen , Evren Cuneyt , Karagoz Mustafa
Published: September 2008

Aim: The aim of the present study was to determine the prevalence and correlates of dissociative disorders among patients with drug dependency.

Methods: The Dissociative Experiences Scale (DES) was used to screen 104 consecutive patients at an addiction treatment center. Thirty‐seven patients who had scores ≥30 were compared with 21 patients who scored <10 on the DES. Both groups were then evaluated using the Dissociative Disorders Interview Schedule and the Structured Clinical Interview for Dissociative Disorders (SCID‐D). The interviewers were blind to the DES scores.

Results: Twenty‐seven patients (26.0%) had a dissociative disorder according to the SCID‐D. Dissociative patients were younger than the non‐dissociative group. History of suicide attempt and/or childhood emotional abuse was significant predictors of a dissociative disorder. The majority (59.3%) of dissociative drug users reported that dissociative experiences had existed prior to substance use. More patients in the dissociative disorder than in the non‐dissociative group stopped their treatment prematurely.

Conclusion: A considerable proportion of drug users have a dissociative disorder, which may also interfere with treatment process. The relatively young age of this subgroup of patients and frequent reports of childhood emotional abuse underline potential preventive benefits of early intervention among adolescents with developmental trauma history and dissociative psychopathology.
Subsurface microbiology and biogeochemistry of a deep, cold‐water carbonate mound from the Porcupine Seabight (IODP Expedition 307)
Authors: Webster Gordon , Blazejak Anna , Cragg Barry A. , Schippers Axel , Sass Henrik , Rinna Joachim , Tang Xiaohong , Mathes Falko , Ferdelman Timothy G. , Fry John C. , Weightman Andrew J. , Parkes R. John
Published: September 2008

The Porcupine Seabight Challenger Mound is the first carbonate mound to be drilled (∼270 m) and analyzed in detail microbiologically and biogeochemically. Two mound sites and a non‐mound Reference site were analyzed with a range of molecular techniques [catalyzed reporter deposition‐fluorescence in situ hybridization (CARD‐FISH), quantitative PCR (16S rRNA and functional genes, dsrA and mcrA), and 16S rRNA gene PCR‐DGGE] to assess prokaryotic diversity, and this was compared with the distribution of total and culturable cell counts, radiotracer activity measurements and geochemistry. There was a significant and active prokaryotic community both within and beneath the carbonate mound. Although total cell numbers at certain depths were lower than the global average for other subseafloor sediments and prokaryotic activities were relatively low (iron and sulfate reduction, acetate oxidation, methanogenesis) they were significantly enhanced compared with the Reference site. In addition, there was some stimulation of prokaryotic activity in the deepest sediments (Miocene, > 10 Ma) including potential for anaerobic oxidation of methane activity below the mound base. Both Bacteria and Archaea were present, with neither dominant, and these were related to sequences commonly found in other subseafloor sediments. With an estimate of some 1600 mounds in the Porcupine Basin alone, carbonate mounds may represent a significant prokaryotic subseafloor habitat.
Relative contributions of archaea and bacteria to aerobic ammonia oxidation in the environment
Authors: Prosser James I. , Nicol Graeme W.
Published: September 2008

Traditionally, organisms responsible for major biogeochemical cycling processes have been determined by physiological characterization of environmental isolates in laboratory culture. Molecular techniques have, however, confirmed the widespread occurrence of abundant bacterial and archaeal groups with no cultivated representative, making it difficult to determine their ecosystem function. Until recently, ammonia oxidation, the first step in the globally important process of nitrification, was thought to be performed almost exclusively by bacteria. Metagenome studies, followed by laboratory isolation, then demonstrated the potential for significant ammonia oxidation by mesophilic crenarchaea, whose ecosystem function was previously unknown. Re‐assessment of the role of bacteria in ammonia oxidation is now required and this article reviews the current evidence for the relative importance of bacteria and archaea. Much of this evidence is based on metagenomic analysis and molecular techniques for estimation of gene and gene transcript abundance, changes in ammonia oxidizer community structure during active nitrification and phylogeny of natural communities. These studies have been complemented by physiological characterization of a laboratory isolate and by incorporation of labelled substrates. Data from these studies provide increasingly convincing evidence for the importance of archaeal ammonia oxidizers in the global nitrogen cycle. They also highlight the need to re‐assess the importance of ammonia‐oxidizing bacteria, the requirement and limitations of molecular techniques in linking specific microbial groups to ecosystem function and the limitations of reliance on laboratory cultures.
TIME‐VARYING UNCERTAINTY AND THE CREDIT CHANNEL
Authors: Dorofeenko Victor , Lee Gabriel S. , Salyer Kevin D.
Published: September 2008

We extend the Carlstrom and Fuerst (American Economic Review, 1997, 87, pp. 893–910) agency cost model of business cycles by including time‐varying uncertainty in the technology shocks that affect capital production. We first demonstrate that standard linearization methods can be used to solve the model yet second moments enter the economy's equilibrium policy functions. We then demonstrate that an increase in uncertainty causes, ceteris paribus, a fall in investment supply. We also show that persistence of uncertainty affects both quantitatively and qualitatively the behaviour of the economy.
‘SPRACHKULTUR’ IN LAY AND ACADEMIC DISCOURSE IN MODERN GERMANY1
Authors: Davies Winifred V.
Published: September 2008

The term ‘Sprachkultur’ is common in German‐language academic and lay discourse, but what exactly does it mean? Is it used in the same way by trained and lay linguists? This article defines the term and traces its history, before going on to compare and contrast its use by both groups. Data taken from lay‐linguistic works are analysed and two recurring motifs (i. the link between morality and linguistic usage and ii. accuracy/clarity) are discussed to see what light they throw on conceptions of language and language use. The concluding section sums up the similarities and differences between lay and academic linguists. The latter tend to concentrate on ‘Sprachgebrauchskultur’ whereas the former are prepared to criticise the language system as well. The stress laid by lay linguists on accuracy and the link between morality and linguistic choices reflects a ‘telementational’ view of language which has major shortcomings, and appears to be rooted in a world‐view that equates diversity with cultural and ideological fragmentation rather than seeing it as enriching. However, the study of pronouncements by trained linguists shows that their work, too, reflects ideological assumptions about the nature of standard and other varieties of German.
SETTING THE STANDARD: USAGE LABELS IN ADVANCED MONOLINGUAL LEARNERS' DICTIONARIES OF GERMAN
Authors: Kirkness Alan
Published: September 2008

Using lexical items from Martin Durrell's classification of register variation as a sample, the study investigates how the current advanced monolingual learners' dictionaries of German as an additional language treat such variation and indicate to their users what they consider to be standard usage: how do they set the standard? Abbreviated usage labels as conventionally found in dictionaries for first‐language users are the primary indications, and the dictionaries seldom go beyond such labels. German Standard German is the norm. At its core are unmarked or unlabelled items, while its range extends to include less formal items from everyday use, especially spoken, which are typically labelled umg. or gespr., and more formal items, more particularly found in written usage, which are labelled geh. or geschr. Non‐standard items, if entered as headwords, may be labelled derb or vulgär, veraltet or lit. No one dictionary stands out from the others as setting the standard in terms of treating register variation, and it must be questioned whether learners of German as an additional language would not be better served by more detailed, discursive information on different contexts of use and stylistic levels.
Corporate Governance Structure and the Valuation of Australian Firms: Is There Value in Ticking the Boxes?
Authors: Henry Darren
Published: September 2008

Abstract:  This paper provides an investigation of the valuation and agency consequences of corporate governance policy. This is achieved by examining variation in voluntary adoption by Australian listed firms, during the period from 1992 to 2002, of corporate governance frameworks representative of the governance code of practice introduced by the Australian Stock Exchange in 2003. The findings indicate benefits for firms from overall corporate governance structuring, but not in isolation, in line with the requirements now in place, and a significant role played by institutional and external shareholders as alternative agency mechanisms. Corporate governance structure is found to be important, however, the likely impact of disclosure of governance practice or compliance on valuation is less clear.
Invasion, Disturbance, and Competition: Modeling the Fate of Coastal Plant Populations
Authors: PATHIKONDA SHARMILA , ACKLEH AZMY S. , HASENSTEIN KARL H. , MOPPER SUSAN
Published: September 2008

Abstract:  Wetland habitats are besieged by biotic and abiotic disturbances such as invasive species, hurricanes, habitat fragmentation, and salinization. Predicting how these factors will alter local population dynamics and community structure is a monumental challenge. By examining ecologically similar congeners, such as Iris hexagona and I. pseudacorus (which reproduce clonally and sexually and tolerate a wide range of environmental conditions), one can identify life‐history traits that are most influential to population growth and viability. We combined empirical data and stage‐structured matrix models to investigate the demographic responses of native (I. hexagona) and invasive (I. pseudacorus) plant populations to hurricanes and salinity stress in freshwater and brackish wetlands. In our models I. hexagona and I. pseudacorus responded differently to salinity stress, and species coexistence was rare. In 82% of computer simulations of freshwater marsh, invasive iris populations excluded the native species within 50 years, whereas native populations excluded the invasive species in 99% of the simulations in brackish marsh. The occurrence of hurricanes allowed the species to coexist, and species persistence was determined by the length of time it took the ecosystem to recover. Rapid recovery (2 years) favored the invasive species, whereas gradual recovery (30 years) favored the native species. Little is known about the effects of hurricanes on competitive interactions between native and invasive plant species in marsh ecosystems. Our models contribute new insight into the relationship between environmental disturbance and invasion and demonstrate how influential abiotic factors such as climate change will be in determining interspecific interactions.
Plant Diversity Hotspots in the Atlantic Coastal Forests of Brazil
Authors: MURRAY‐SMITH CHARLOTTE , BRUMMITT NEIL A. , OLIVEIRA‐FILHO ARY T. , BACHMAN STEVEN , MOAT JUSTIN , LUGHADHA EIMEAR M. NIC , LUCAS EVE J.
Published: September 2008

Abstract: Plant‐diversity hotspots on a global scale are well established, but smaller local hotspots within these must be identified for effective conservation of plants at the global and local scales. We used the distributions of endemic and endemic‐threatened species of Myrtaceae to indicate areas of plant diversity and conservation importance within the Atlantic coastal forests (Mata Atlântica) of Brazil. We applied 3 simple, inexpensive geographic information system (GIS) techniques to a herbarium specimen database: predictive species‐distribution modeling (Maxent); complementarity analysis (DIVA‐GIS); and mapping of herbarium specimen collection locations. We also considered collecting intensity, which is an inherent limitation of use of natural history records for biodiversity studies. Two separate areas of endemism were evident: the Serra do Mar mountain range from Paraná to Rio de Janeiro and the coastal forests of northern Espírito Santo and southern Bahia. We identified 12 areas of approximately 35 km2each as priority areas for conservation. These areas had the highest species richness and were highly threatened by urban and agricultural expansion. Observed species occurrences, species occurrences predicted from the model, and results of our complementarity analysis were congruent in identifying those areas with the most endemic species. These areas were then prioritized for conservation importance by comparing ecological data for each.
Breaking through the Crisis in Marine Conservation and Management: Insights from the Philosophies of Ed Ricketts
Authors: SAGARIN RAPHAEL D. , CROWDER LARRY B.
Published: September 2008

Abstract:  Over the last decade, 2 major U.S. commissions on ocean policy and a wide range of independent sources have argued that ocean ecosystems are in a period of crisis and that current policies are inadequate to prevent further ecological damage. These sources have advocated ecosystem‐based management as an approach to address conservation issues in the oceans, but managers remain uncertain as to how to implement ecosystem‐based approaches in the real world. We argue that the philosophies of Edward F. Ricketts, a mid‐20th‐century marine ecologist, offer a framework and clear guidance for taking an ecosystem approach to marine conservation. Ricketts' philosophies, which were grounded in basic observations of natural history, espoused building a holistic picture of the natural world, including the influence of humans, through repeated observation. This approach, when applied to conservation, grounds management in what is observable in nature, encourages early action in the face of uncertainty, and supports an adaptive approach to management as new information becomes available. Ricketts' philosophy of “breaking through,” which focuses on getting beyond crisis and conflict through honest debate of different parties' needs (rather than forcing compromise of differing positions), emphasizes the social dimension of natural resource management. New observational technologies, long‐term ecological data sets, and especially advances in the social sciences made available since Ricketts' time greatly enhance the utility of Ricketts' philosophy of marine conservation.