bluuebunny/crossref_metadata_2025 huggingface dataset:
Positive regulation of plasmacytoid dendritic cell function via Ly49Q recognition of class I MHC
Authors: Tai Lee-Hwa , Goulet Marie-Line , Belanger Simon , Toyama-Sorimachi Noriko , Fodil-Cornu Nassima , Vidal Silvia M. , Troke Angela D. , McVicar Daniel W. , Makrigiannis Andrew P.
Published: December 2008

Plasmacytoid dendritic cells (pDCs) are an important source of type I interferon (IFN) during initial immune responses to viral infections. In mice, pDCs are uniquely characterized by high-level expression of Ly49Q, a C-type lectin-like receptor specific for class I major histocompatibility complex (MHC) molecules. Despite having a cytoplasmic immunoreceptor tyrosine-based inhibitory motif, Ly49Q was found to enhance pDC function in vitro, as pDC cytokine production in response to the Toll-like receptor (TLR) 9 agonist CpG-oligonucleotide (ODN) could be blocked using soluble monoclonal antibody (mAb) to Ly49Q or H-2Kb. Conversely, CpG-ODN–dependent IFN-α production by pDCs was greatly augmented upon receptor cross-linking using immobilized anti-Ly49Q mAb or recombinant H-2Kb ligand. Accordingly, Ly49Q-deficient pDCs displayed a severely reduced capacity to produce cytokines in response to TLR7 and TLR9 stimulation both in vitro and in vivo. Finally, TLR9-dependent antiviral responses were compromised in Ly49Q-null mice infected with mouse cytomegalovirus. Thus, class I MHC recognition by Ly49Q on pDCs is necessary for optimal activation of innate immune responses in vivo.
Prostaglandin E2 regulates B cell proliferation through a candidate tumor suppressor, Ptger4
Authors: Murn Jernej , Alibert Olivier , Wu Ning , Tendil Simon , Gidrol Xavier
Published: December 2008

B cell receptor (BCR) signaling contributes to the pathogenesis of B cell malignancies, and most B cell lymphomas depend on BCR signals for survival. Identification of genes that restrain BCR-mediated proliferation is therefore an important goal toward improving the therapy of B cell lymphoma. Here, we identify Ptger4 as a negative feedback regulator of proliferation in response to BCR signals and show that its encoded EP4 receptor is a principal molecule conveying the growth-suppressive effect of prostaglandin E2 (PGE2). Stable knockdown of Ptger4 in B cell lymphoma markedly accelerated tumor spread in mice, whereas Ptger4 overexpression yielded significant protection. Mechanistically, we show that the intrinsic activity of Ptger4 and PGE2–EP4 signaling target a similar set of activating genes, and find Ptger4 to be significantly down-regulated in human B cell lymphoma. We postulate that Ptger4 functions in B cells as a candidate tumor suppressor whose activity is regulated by PGE2 in the microenvironment. These findings suggest that targeting EP4 receptor for prostaglandin may present a novel strategy for treatment of B cell malignancies.
Interleukin (IL)-1 promotes allogeneic T cell intimal infiltration and IL-17 production in a model of human artery rejection
Authors: Rao Deepak A. , Eid Raymond E. , Qin Lingfeng , Yi Tai , Kirkiles-Smith Nancy C. , Tellides George , Pober Jordan S.
Published: December 2008

Interleukin (IL) 1α produced by human endothelial cells (ECs), in response to tumor necrosis factor (TNF) or to co-culture with allogeneic T cells in a TNF-dependent manner, can augment the release of cytokines from alloreactive memory T cells in vitro. In a human–mouse chimeric model of artery allograft rejection, ECs lining the transplanted human arteries express IL-1α, and blocking IL-1 reduces the extent of human T cell infiltration into the artery intima and selectively inhibits IL-17 production by infiltrating T cells. In human skin grafts implanted on immunodeficient mice, administration of IL-17 is sufficient to induce mild inflammation. In cultured cells, IL-17 acts preferentially on vascular smooth muscle cells rather than ECs to enhance production of proinflammatory mediators, including IL-6, CXCL8, and CCL20. Neutralization of IL-17 does not reduce T cell infiltration into allogeneic human artery grafts, but markedly reduces IL-6, CXCL8, and CCL20 expression and selectively inhibits CCR6+ T cell accumulation in rejecting arteries. We conclude that graft-derived IL-1 can promote T cell intimal recruitment and IL-17 production during human artery allograft rejection, and suggest that targeting IL-1 in the perioperative transplant period may modulate host alloreactivity.
Involvement of Artemis in nonhomologous end-joining during immunoglobulin class switch recombination
Authors: Du Likun , van der Burg Mirjam , Popov Sergey W. , Kotnis Ashwin , van Dongen Jacques J.M. , Gennery Andrew R. , Pan-Hammarström Qiang
Published: December 2008

DNA double-strand breaks (DSBs) introduced in the switch (S) regions are intermediates during immunoglobulin class switch recombination (CSR). These breaks are subsequently recognized, processed, and joined, leading to recombination of the two S regions. Nonhomologous end-joining (NHEJ) is believed to be the principle mechanism involved in DSB repair during CSR. One important component in NHEJ, Artemis, has however been considered to be dispensable for efficient CSR. In this study, we have characterized the S recombinational junctions from Artemis-deficient human B cells. Sμ–Sα junctions could be amplified from all patients tested and were characterized by a complete lack of “direct” end-joining and a remarkable shift in the use of an alternative, microhomology-based end-joining pathway. Sμ–Sγ junctions could only be amplified from one patient who carries “hypomorphic” mutations. Although these Sμ–Sγ junctions appear to be normal, a significant increase of an unusual type of sequential switching from immunoglobulin (Ig)M, through one IgG subclass, to a different IgG subclass was observed, and the Sγ–Sγ junctions showed long microhomologies. Thus, when the function of Artemis is impaired, varying modes of CSR junction resolution may be used for different S regions. Our findings strongly link Artemis to the predominant NHEJ pathway during CSR.
RS rearrangement frequency as a marker of receptor editing in lupus and type 1 diabetes
Authors: Panigrahi Anil K. , Goodman Noah G. , Eisenberg Robert A. , Rickels Michael R. , Naji Ali , Luning Prak Eline T.
Published: December 2008

Continued antibody gene rearrangement, termed receptor editing, is an important mechanism of central B cell tolerance that may be defective in some autoimmune individuals. We describe a quantitative assay for recombining sequence (RS) rearrangement that we use to estimate levels of antibody light chain receptor editing in various B cell populations. RS rearrangement is a recombination of a noncoding gene segment in the κ antibody light chain locus. RS rearrangement levels are highest in the most highly edited B cells, and are inappropriately low in autoimmune mouse models of systemic lupus erythematosus (SLE) and type 1 diabetes (T1D), including those without overt disease. Low RS rearrangement levels are also observed in human subjects with SLE or T1D.
Causes of early-onset type 1 diabetes: toward data-driven environmental approaches
Authors: Bougnères Pierre , Valleron Alain-Jacques
Published: December 2008

A new study reveals distinctive metabolic changes that precede the development of type 1 diabetes (T1D), tossing a stone into the quiet waters of T1D immunology and genetics. The causes of these metabolic changes and their relationship to autoimmunity and β cell destruction are not yet known, but the identification of a metabolic phenotype linked to susceptibility to type I diabetes may help pave the way to a new era of investigation of T1D causality.
The Standard Model as a Philosophical Challenge
Authors: MacKinnon Edward
Published: December 2008

There are two opposing traditions in contemporary quantum field theory (QFT). Mainstream Lagrangian QFT led to and supports the standard model of particle interactions. Algebraic QFT seeks to provide a rigorous consistent mathematical foundation for field theory, but cannot accommodate the local gauge interactions of the standard model. Interested philosophers face a choice. They can accept algebraic QFT on the grounds of mathematical consistency and general accord with the semantic conception of theory interpretation. This suggests a rejection of particle ontology. Or they can accept the standard model on the grounds of its established success. This alternative, which I defend, suggests revising philosophical accounts of scientific theory and finding some way of accommodating particles.
Quantum Computation and Pseudotelepathic Games
Authors: Bub Jeffrey
Published: December 2008

A quantum algorithm succeeds not because the superposition principle allows ‘the computation of all values of a function at once’ via ‘quantum parallelism’, but rather because the structure of a quantum state space allows new sorts of correlations associated with entanglement, with new possibilities for information-processing transformations between correlations, that are not possible in a classical state space. I illustrate this with an elementary example of a problem for which a quantum algorithm is more efficient than any classical algorithm. I also introduce the notion of ‘pseudotelepathic’ games and show how the difference between classical and quantum correlations plays a similar role here for games that can be won by quantum players exploiting entanglement, but not by classical players whose only allowed common resource consists of shared strings of random numbers (common causes of the players’ correlated responses in a game).
ATOM: a powerful gene-based association test by combining optimally weighted markers
Authors: Li Mingyao , Wang Kai , Grant Struan F. A. , Hakonarson Hakon , Li Chun
Published: December 2008

Background: Large-scale candidate-gene and genome-wide association studies genotype multiple SNPs within or surrounding a gene, including both tag and functional SNPs. The immense amount of data generated in these studies poses new challenges to analysis. One particularly challenging yet important question is how to best use all genetic information to test whether a gene or a region is associated with the trait of interest.

Methods: Here we propose a powerful gene-based Association Test by combining Optimally Weighted Markers (ATOM) within a genomic region. Due to variation in linkage disequilibrium, different markers often associate with the trait of interest at different levels. To appropriately apportion their contributions, we assign a weight to each marker that is proportional to the amount of information it captures about the trait locus. We analytically derive the optimal weights for both quantitative and binary traits, and describe a procedure for estimating the weights from a reference database such as the HapMap. Compared with existing approaches, our method has several distinct advantages, including (i) the ability to borrow information from an external database to increase power, (ii) the theoretical derivation of optimal marker weights and (iii) the scalability to simultaneous analysis of all SNPs in candidate genes and pathways.

Results: Through extensive simulations and analysis of the FTO gene in our ongoing genome-wide association study on childhood obesity, we demonstrate that ATOM increases the power to detect genetic association as compared with several commonly used multi-marker association tests.

Contact:  mingyao@mail.med.upenn.edu; chun.li@vanderbilt.edu

Supplementary information:  Supplementary data are available at Bioinformatics online.
Empirical versus Theoretical Claims about Extreme Counterfactuals: A Response
Authors: King Gary , Zeng Langche
Published: December 2008

In response to the data-based measures of model dependence proposed in King and Zeng (2006), Sambanis and Michaelides (2008) propose alternative measures that rely upon assumptions untestable in observational data. If these assumptions are correct, then their measures are appropriate and ours, based solely on the empirical data, may be too conservative. If instead, and as is usually the case, the researcher is not certain of the precise functional form of the data generating process, the distribution from which the data are drawn, and the applicability of these modeling assumptions to new counterfactuals, then the data-based measures proposed in King and Zeng (2006) are much preferred. After all, the point of model dependence checks is to verify empirically, rather than to stipulate by assumption, the effects of modeling assumptions on counterfactual inferences.
Discretion Rather than Rules: Choice of Instruments to Control Bureaucratic Policy Making
Authors: Gailmard Sean
Published: December 2008

In this paper I investigate the trade-off a legislature faces in the choice of instruments to ensure accountability by bureaucrats with private information. The legislature can either design a state-contingent incentive scheme or “menu law” to elicit the bureau's information or it can simply limit the set of choices open to the bureaucrat and let it choose as it wishes (an action restriction). I show that the optimal action restriction is simply a connected interval of the policy space. However, this class of instruments is not optimal without some sort of limitation on the set of levers of control available to the legislature. I then analyze one such limitation salient in politics, the legislative principal's inability to commit to honor a schedule of (state contingent) policy choices and transfer payments for a menu law. In this case the optimal action restriction outperforms (in terms of the legislature's welfare) the best available menu law.
Induction of autoimmune cholangitis in non-obese diabetic (NOD).1101 mice following a chemical xenobiotic immunization
Authors: Wakabayashi K , Yoshida K , Leung P S C , Moritoki Y , Yang G-X , Tsuneyama K , Lian Z-X , Hibi T , Ansari A A , Wicker L S , Ridgway W M , Coppel R L , Mackay I R , Gershwin M E
Published: December 2008

Our laboratory has suggested that loss of tolerance to pyruvate dehydrogenase (PDC-E2) leads to an anti-mitochondrial antibody response and autoimmune cholangitis, similar to human primary biliary cirrhosis (PBC). We have suggested that this loss of tolerance can be induced either via chemical xenobiotic immunization or exposure to select bacteria. Our work has also highlighted the importance of genetic susceptibility. Using the non-obese diabetic (NOD) congenic strain 1101 (hereafter referred to as NOD.1101 mice), which has chromosome 3 regions from B6 introgressed onto a NOD background, we exposed animals to 2-octynoic acid (2OA) coupled to bovine serum albumin (BSA). 2OA has been demonstrated previously by a quantitative structural activity relationship to react as well as or better than lipoic acid to anti-mitochondrial antibodies. We demonstrate herein that NOD.1101 mice immunized with 2OA-BSA, but not with BSA alone, develop high titre anti-mitochondrial antibodies and histological features, including portal infiltrates enriched in CD8+ cells and liver granulomas, similar to human PBC. We believe this model will allow the rigorous dissection of early immunogenetic cause of biliary damage.
Effect of the preliminary hydration on gastric emptying time for water in healthy volunteers
Authors: UMENAI T. , ARAI N. , CHIHARA E.
Published: December 2008

Background: International guidelines allow healthy patients to drink clear liquid up to 2 h before general anesthesia. Recently, MRI measurements have been used for tracking gastric volume in humans. Hence, we used MRI to examine the gastric emptying rate of water in healthy volunteers with or without prior water loading.

Methods: Fifteen healthy volunteers were enrolled. The participants had MRI examinations on separate days under two different protocols: The preliminary hydration protocol (group H) and the water restriction protocol (group R). After the intake of water, MR imaging was performed every 10 min for 60 min. The gastric content was outlined as area of interest (AOI), and the AOI area of each slice was summated to calculate the volume of gastric contents.

Results: The 50% reduction time of gastric volume in group R and group H was 18±9 and 16±8 min (mean±SD), respectively. There were no significant changes between the two groups.

Conclusion: The gastric emptying time for water evaluated with MRI was not affected by preliminary hydration, which shows the safety of repeated oral hydrations in the pre‐operative period.
Persistent pain after groin hernia surgery: a qualitative analysis of pain and its consequences for quality of life
Authors: KALLIOMÄKI M.‐L. , SANDBLOM G. , GUNNARSSON U. , GORDH T.
Published: December 2008

Background: Despite a high prevalence of persistent groin pain after hernia repair, the specific nature of the pain and its clinical manifestation are poorly known. The aim of this study was to determine the type of post‐herniorrhaphy pain and its influence on daily life.

Methods: In order to assess long‐term pain qualitatively and to explore how it affects quality of life, 100 individuals with persisting pain, identified in a cohort study of patients operated for groin hernia, were neurologically examined, along with 100 pain‐free controls matched for age, gender and type of operation. The patients were asked to answer the SF‐36 questionnaire, the hospital anxiety and depression scale, the Swedish Scales of Personality (SSP) and a standardised questionnaire for assessing everyday life coping. The patients were approached approximately 4.9 years after surgery.

Results: Twenty‐two patients from the pain group had become pain free by the time of examination, whereas 76 patients still had pain, of whom 47 (68%) suffered from neuropathic pain and 11 from nociceptive pain. The remaining patients suffered from mixed pain, neuropathic and nociceptive, or were found to have another reason for pain. All dimensions of SF‐36 were poorer for the pain group than the control group.

Conclusion: Persistent post‐herniorrhaphy pain is mainly neuropathic and has a substantial impact on health‐related quality of life.
Urea derivatives on the move: cytokinin‐like activity and adventitious rooting enhancement depend on chemical structure
Authors: Ricci A. , Bertoletti C.
Published: December 2008

Urea derivatives are synthetic compounds, some of which have proved to be positive regulators of cell division and differentiation.N‐phenyl‐N′‐(2‐chloro‐4‐pyridyl)urea (forchlorofenuron, CPPU) andN‐phenyl‐N′‐(1,2,3‐thiadiazol‐5‐yl)urea (thidiazuron, TDZ), well known urea cytokinin representatives, are extensively used inin vitroplant morphogenesis studies, as they show cytokinin‐like activity often exceeding that of adenine compounds. In recent years, renewed interest in structure–activity relationship studies allowed identification of new urea cytokinins and other urea derivatives that specifically enhance adventitious root formation. In this review, we report the research history of urea derivatives, new insights into their biological activity, and recent progress on their mode of action.
The Source of Enhanced Cognitive Control in Bilinguals
Authors: Emmorey Karen , Luk Gigi , Pyers Jennie E. , Bialystok Ellen
Published: December 2008

Bilinguals often outperform monolinguals on nonverbal tasks that require resolving conflict from competing alternatives. The regular need to select a target language is argued to enhance executive control. We investigated whether this enhancement stems from a general effect of bilingualism (the representation of two languages) or from a modality constraint that forces language selection. Bimodal bilinguals can, but do not always, sign and speak at the same time. Their two languages involve distinct motor and perceptual systems, leading to weaker demands on language control. We compared the performance of 15 monolinguals, 15 bimodal bilinguals, and 15 unimodal bilinguals on a set of flanker tasks. There were no group differences in accuracy, but unimodal bilinguals were faster than the other groups; bimodal bilinguals did not differ from monolinguals. These results trace the bilingual advantage in cognitive control to the unimodal bilingual's experience controlling two languages in the same modality.
The Cognitive Benefits of Interacting With Nature
Authors: Berman Marc G. , Jonides John , Kaplan Stephen
Published: December 2008

We compare the restorative effects on cognitive functioning of interactions with natural versus urban environments. Attention restoration theory (ART) provides an analysis of the kinds of environments that lead to improvements in directed-attention abilities. Nature, which is filled with intriguing stimuli, modestly grabs attention in a bottom-up fashion, allowing top-down directed-attention abilities a chance to replenish. Unlike natural environments, urban environments are filled with stimulation that captures attention dramatically and additionally requires directed attention (e.g., to avoid being hit by a car), making them less restorative. We present two experiments that show that walking in nature or viewing pictures of nature can improve directed-attention abilities as measured with a backwards digit-span task and the Attention Network Task, thus validating attention restoration theory.
Differential Processing of Consonants and Vowels in Lexical Access Through Reading
Authors: New Boris , Araújo Verónica , Nazzi Thierry
Published: December 2008

Do consonants and vowels have the same importance during reading? Recently, it has been proposed that consonants play a more important role than vowels for language acquisition and adult speech processing. This proposal has started receiving developmental support from studies showing that infants are better at processing specific consonantal than vocalic information while learning new words. This proposal also received support from adult speech processing. In our study, we directly investigated the relative contributions of consonants and vowels to lexical access while reading by using a visual masked-priming lexical decision task. Test items were presented following four different primes: identity (e.g., for the word joli, joli), unrelated ( vabu), consonant-related ( jalu), and vowel-related ( vobi). Priming was found for the identity and consonant-related conditions, but not for the vowel-related condition. These results establish the privileged role of consonants during lexical access while reading.
Looking to the Future to Appreciate the Present
Authors: Kurtz Jaime L.
Published: December 2008

Both psychological research and conventional wisdom suggest that it can be difficult to attend to and derive enjoyment from the pleasant things in life. The present study examined whether focusing on the imminent ending of a positive life experience can lead to increased enjoyment. A temporal distance manipulation was used to make college graduation seem more or less close at hand. Twice a week over the course of 2 weeks, college students were told to write about their college life, with graduation being framed as either very close or very far off. As predicted, thinking about graduation as being close led to a significant increase in college-related behaviors and subjective well-being over the course of the study. The present research provides support for the counterintuitive hypothesis that thinking about an experience's ending can enhance one's present enjoyment of it.
Twelve-Month-Old Infants Benefit From Prior Experience in Statistical Learning
Authors: Lany Jill , Gómez Rebecca L.
Published: December 2008

A decade of research suggests that infants readily detect patterns in their environment, but it is unclear how such learning changes with experience. We tested how prior experience influences sensitivity to statistical regularities in an artificial language. Although 12-month-old infants learn adjacent relationships between word categories, they do not track nonadjacent relationships until 15 months. We asked whether 12-month-old infants could generalize experience with adjacent dependencies to nonadjacent ones. Infants were familiarized to an artificial language either containing or lacking adjacent dependencies between word categories and were subsequently habituated to novel nonadjacent dependencies. Prior experience with adjacent dependencies resulted in enhanced learning of the nonadjacent dependencies. Female infants showed better discrimination than males did, which is consistent with earlier reported sex differences in verbal memory capacity. The findings suggest that prior experience can bootstrap infants' learning of difficult language structure and that learning mechanisms are powerfully affected by experience.
An Attentional Mechanism for Selecting Appropriate Actions Afforded by Graspable Objects
Authors: Loach Daniel , Frischen Alexandra , Bruce Neil , Tsotsos John K.
Published: December 2008

An object may afford a number of different actions. In this article, we show that an attentional mechanism inhibits competing motor programs that could elicit erroneous actions. Participants made a speeded key press to categorize the second of two successively presented door handles that were rotated at varying orientations relative to one another. Their responding hand was compatible or incompatible with the graspable part of the door handles (rightward or leftward facing). Compatible responses were faster than incompatible responses if the two handles shared an identical orientation, but they were slower if the two handles were aligned at slightly dissimilar orientations. Such suppressive surround effects are hallmarks of attentional processing in the visual domain, but they have never been observed behaviorally in the motor domain. This finding delineates a common mechanism involved in two of the most important functions of the brain: processing sensory data and preparing actions based on that information.
Construal Level and Procrastination
Authors: McCrea Sean M. , Liberman Nira , Trope Yaacov , Sherman Steven J.
Published: December 2008

According to construal-level theory, events that are distant in time tend to be represented more abstractly than are events that are close in time. This mental association between level of abstractness and temporal distance is proposed to be a bidirectional relationship, such that level of representation of an event should also have effects on the time when the activity is performed. In the present studies, participants were asked to respond to a questionnaire via e-mail within 3 weeks. The questionnaire was designed to induce either an abstract or a concrete construal. Using a variety of manipulations of construal level, the studies supported the predictions of construal-level theory. Individuals were less likely to procrastinate performing the task when the questionnaire induced a more concrete construal. Furthermore, this effect did not depend on the attractiveness, importance, or perceived difficulty of the task.
Power, Distress, and Compassion
Authors: van Kleef Gerben A. , Oveis Christopher , van der Löwe Ilmo , LuoKogan Aleksandr , Goetz Jennifer , Keltner Dacher
Published: December 2008

Responses to individuals who suffer are a foundation of cooperative communities. On the basis of the approach/inhibition theory of power (Keltner, Gruenfeld, & Anderson, 2003), we hypothesized that elevated social power is associated with diminished reciprocal emotional responses to another person's suffering (feeling distress at another person's distress) and with diminished complementary emotion (e.g., compassion). In face-to-face conversations, participants disclosed experiences that had caused them suffering. As predicted, participants with a higher sense of power experienced less distress and less compassion and exhibited greater autonomic emotion regulation when confronted with another participant's suffering. Additional analyses revealed that these findings could not be attributed to power-related differences in baseline emotion or decoding accuracy, but were likely shaped by power-related differences in the motivation to affiliate. Implications for theorizing about power and the social functions of emotions are discussed.
We Infer Rather Than Perceive the Moment We Decided to Act
Authors: Banks William P. , Isham Eve A.
Published: December 2008

A seminal experiment found that the reported time of a decision to perform a simple action was at least 300 ms after the onset of brain activity that normally preceded the action. In Experiment 1, we presented deceptive feedback (an auditory beep) 5 to 60 ms after the action to signify a movement time later than the actual movement. The reported time of decision moved forward in time linearly with the delay in feedback, and came after the muscular initiation of the response at all but the 5-ms delay. In Experiment 2, participants viewed their hand with and without a 120-ms video delay, and gave a time of decision 44 ms later with than without the delay. We conclude that participants' report of their decision time is largely inferred from the apparent time of response. The perception of a hypothetical brain event prior to the response could have, at most, a small influence.
Effects of Aging on Functional Connectivity of the Amygdala for Subsequent Memory of Negative Pictures
Authors: St. Jacques Peggy L. , Dolcos Florin , Cabeza Roberto
Published: December 2008

Aging is associated with preserved enhancement of emotional memory, as well as with age-related reductions in memory for negative stimuli, but the neural networks underlying such alterations are not clear. We used a subsequent-memory paradigm to identify brain activity predicting enhanced emotional memory in young and older adults. Activity in the amygdala predicted enhanced emotional memory, with subsequent-memory activity greater for negative stimuli than for neutral stimuli, across age groups, a finding consistent with an overall enhancement of emotional memory. However, older adults recruited greater activity in anterior regions and less activity in posterior regions in general for negative stimuli that were subsequently remembered. Functional connectivity of the amygdala with the rest of the brain was consistent with age-related reductions in memory for negative stimuli: Older adults showed decreased functional connectivity between the amygdala and the hippocampus, but increased functional connectivity between the amygdala and dorsolateral prefrontal cortices. These findings suggest that age-related differences in the enhancement of emotional memory might reflect decreased connectivity between the amygdala and typical subsequent-memory regions, as well as the engagement of regulatory processes that inhibit emotional responses.
Fibromyalgia Comorbidity in Primary Headaches
Authors: de Tommaso M , Sardaro M , Serpino C , Costantini F , Vecchio F , Prudenzano M Pia , Lamberti P , Livrea P
Published: December 2008

Fibromyalgia syndrome (FMS) is a chronic pain condition of unknown aetiology characterized by diffuse pain and tenderness at tender points. The aim of the study was to assess the prevalence and clinical features of FMS in the different forms of primary headaches, in a tertiary headache centre. Primary headache patients ( n = 217) were selected and submitted to the Total Tenderness Score, anxiety and depression scales, Migraine Disability Assessment, allodynia questionnaire, Short Form 36 Health Survey and the Medical Outcomes Study-Sleep Scale. In patients with FMS, the Multidimensional Assessment of Fatigue, the Pain Visual Analog Scale, the Manual Tender Point Survey and the Fibromyalgia Impact Questionnaire were employed. FMS was present in 36.4% of patients and prevailed significantly in tension-type headache and in patients with higher headache frequency. Headache frequency, pericranial muscle tenderness, anxiety and sleep inadequacy were especially associated with FMS comorbidity. In the FMS patients, fatigue and pain at tender points were significantly correlated with headache frequency. FMS seems increasingly prevalent with increased headache frequency, for the facilitation of central sensitization phenomena favoured by anxiety and sleep disturbances.
Advantages of Volunteer‐Based Biodiversity Monitoring in Europe
Authors: SCHMELLER DIRK S. , HENRY PIERRE‐YVES , JULLIARD ROMAIN , GRUBER BERND , CLOBERT JEAN , DZIOCK FRANK , LENGYEL SZABOLCS , NOWICKI PIOTR , DÉRI ESZTER , BUDRYS EDUARDAS , KULL TIIU , TALI KADRI , BAUCH BIANCA , SETTELE JOSEF , VAN SWAAY CHRIS , KOBLER ANDREJ , BABIJ VALERIJA , PAPASTERGIADOU EVA , HENLE KLAUS
Published: December 2008

Abstract:  Without robust and unbiased systems for monitoring, changes in natural systems will remain enigmatic for policy makers, leaving them without a clear idea of the consequences of any environmental policies they might adopt. Generally, biodiversity‐monitoring activities are not integrated or evaluated across any large geographic region. The EuMon project conducted the first large‐scale evaluation of monitoring practices in Europe through an on‐line questionnaire and is reporting on the results of this survey. In September 2007 the EuMon project had documented 395 monitoring schemes for species, which represents a total annual cost of about €4 million, involving more than 46,000 persons devoting over 148,000 person‐days/year to biodiversity‐monitoring activities. Here we focused on the analysis of variations of monitoring practices across a set of taxonomic groups (birds, amphibians and reptiles, mammals, butterflies, plants, and other insects) and across 5 European countries (France, Germany, Hungary, Lithuania, and Poland). Our results suggest that the overall sampling effort of a scheme is linked with the proportion of volunteers involved in that scheme. Because precision is a function of the number of monitored sites and the number of sites is maximized by volunteer involvement, our results do not support the common belief that volunteer‐based schemes are too noisy to be informative. Just the opposite, we believe volunteer‐based schemes provide relatively reliable data, with state‐of‐the‐art survey designs or data‐analysis methods, and consequently can yield unbiased results. Quality of data collected by volunteers is more likely determined by survey design, analytical methodology, and communication skills within the schemes rather than by volunteer involvement per se.
Effects of Land Use on Threatened Species
Authors: LENZEN MANFRED , LANE AMANDA , WIDMER‐COOPER ASAPH , WILLIAMS MOIRA
Published: December 2008

Abstract: There is widespread agreement that biodiversity loss must be reduced, yet to alleviate threats to plant and animal species, the forces driving these losses need to be better understood. We searched for explanatory variables for threatened‐species data at the country level through land‐use information instead of previously used socioeconomic and demographic variables. To explain the number of threatened species in one country, we used information on land‐use patterns in all neighboring countries and on the extent of the country's sea border. We carried out multiple regressions of the numbers of threatened species as a function of land‐use patterns, and we tested various specifications of this function, including spatial autocorrelation. Most cross‐border land‐use patterns had a significant influence on the number of threatened species, and land‐use patterns explained the number of threatened species better than less proximate socioeconomic variables. More specifically, our overall results showed a highly adverse influence of plantations and permanent cropland, a weaker negative influence of permanent pasture, and, for the most part, a beneficial influence of nonarable lands and natural forest. Surprisingly, built‐up land also showed a conserving influence on threatened species. The adverse influences extended to distances between about 250 km (plants) and 2000 km (birds and mammals) away from where the species threat was recorded, depending on the species. Our results highlight that legislation affecting biodiversity should look beyond national boundaries.
Vagus nerve stimulation for refractory epilepsy in children: More to VNS than seizure frequency reduction
Authors: Shahwan Amre , Bailey Catherine , Maxiner Wirginia , Harvey A. Simon
Published: December 2008

Purpose:  Vagus nerve stimulation (VNS) is used increasingly as adjunctive therapy for refractory epilepsy. Studies of VNS in children report mainly seizure frequency reduction as a measure of efficacy and clinical details are often scanty. We report our experience with VNS in children with refractory epilepsy and emphasize the positive effects of VNS in terms of seizure severity.

Methods:  We reviewed 26 consecutive children who had VNS with a minimum follow‐up period of 18 months. We examined their clinical characteristics, seizure types, seizure frequency, epilepsy syndrome diagnosis, and response to VNS in terms of seizure frequency and seizure severity.

Results:  Fifty‐four percent of patients responded to VNS with ≥50% seizure frequency reduction. Patients with Lennox‐Gastaut syndrome (LGS) and tonic seizures had a higher responder rate; 78% (seven of nine patients) (p < 0.01). Status epilepticus (SE) episodes were reduced or ceased in the four patients with recurrent SE. Seizure severity, duration, and recovery time decreased in all responders. Increased alertness was reported in all responders and three nonresponders.

Conclusion:  Decreased seizure severity, recovery time, abolition of daytime drop attacks, and reduced hospitalization due to SE improved patients’ lives over and above the benefit from seizure frequency reduction.
Effect of pH on the Preparation of α‐Calcium Sulfate Hemihydrate from FGD Gypsum with the Hydrothermal Method
Authors: Guan Baohong , Shen Zhuoxian , Wu Zhongbiao , Yang Liuchun , Ma Xianfa
Published: December 2008

pH is one of the most important parameters that determine the crystallization process, but it is always neglected in the preparation of α‐calcium sulfate hemihydrate (α‐HH) from calcium sulfate dihydrate (DH) with the hydrothermal method. Flue gas desulfurization (FGD) gypsum, which is mainly composed of DH, was used as raw material to obtain α‐HH through dehydration in a Ca–Mg–K–Cl‐solution medium at 95°C under atmospheric pressure. The initial pH values of the suspensions were adjusted from 1.2 to 8.0 to explore the influence of pH on the dehydration process and the product characteristics. The results showed that α‐HH crystal was the only dehydration product with the pH ranging from 1.2 to 8.0. With the increase of initial pH, the dehydration rate decreased and the formed α‐HH crystal had a larger particle size. The length/width ratio decreased markedly from 4.8 to 2.9 as the initial pH increased from 1.2 to 7.3. pH had a profound influence on the dehydration of DH and the morphology of α‐HH via its effect on the supersaturation and perhaps also the precipitation of Ca(OH)2 in an alkaline environment.
Temperature‐Dependent Electrical Properties of 0.94Bi0.5Na0.5TiO3–0.06BaTiO3 Ceramics
Authors: Zhang Shan‐Tao , Kounga Alain B. , Aulbach Emil , Deng Yu
Published: December 2008

Temperature‐dependent electrical properties of lead‐free 0.94Bi0.5Na0.5TiO3–0.06BaTiO3 (BNT–BT) ceramics were investigated. Below 100°C, this rhombohedral–tetragonal morphotropic phase‐boundary composition shows dominant ferroelectric order with typical ferroelectric polarization–electric field (P(E)) loop and butterfly bipolar strain–electric (S(E)) curve. Antiferroelectric order tends to prevail when temperature reaches about 100°C, characterized by a pinched P(E) loop and altered bipolar S(E) butterfly. Near the ferroelectric–antiferroelectric transition temperature, the composition shows a giant bipolar and unipolar strain of 0.40% and 0.42%, respectively. The highest value of maximum strain divided by the applied field (i.e., Smax/Emax) reaches 700 pm/V at 100°C. With a further increase of temperature to 200°C, a slight decrease of the strain is observed. Especially, it is found that the hysteresis of the unipolar S(E) curve decreases with increasing temperature. These results may be helpful for further understanding and thus designing new BNT‐based lead‐free piezoelectric systems.
Crack Healing of Machining Cracks Introduced by Wheel Grinding and Resultant High‐Temperature Mechanical Properties in a Si3N4/SiC Composite
Authors: Jung Young‐Soon , Nakao Wataru , Takahashi Koji , Ando Kotoji , Saito Shinji
Published: December 2008

The crack‐healing behavior of machining cracks in a Si3N4/SiC composite containing Y2O3 and Al2O3 as a sintering additive was investigated. The machining cracks were introduced by a wheel grinding process, which is the most common method for finishing ceramic components. A semicircular groove was made at the center of small bending specimens by the machining. The machined specimens were healed at various temperatures and times in air. The optimized crack‐healing condition of the machined specimen was found to be a temperature of 1300°C and a time of 1 h. The specimens healed by this condition exhibited almost the same strength as the smooth specimens that underwent the healing process. Moreover, the bending strength and fatigue limit of the machined and healed specimens were systematically investigated at temperatures ranging from room temperature to 1300°C. The heat‐resistance temperature has been determined to be approximately 1000°C. Also, the specimens exhibited high static and cyclic fatigue limits at temperatures of 800° and 1000°C. These results demonstrate that crack healing could be an effective method for improving the structural integrity and reducing the manufacturing costs of a Si3N4/SiC composite ceramic.
Characterization of Pore Space of Cement‐Based Materials by Combined Mercury and Wood's Metal Intrusion
Authors: Kaufmann Josef
Published: December 2008

Analysis of the pore space is crucial for a profound understanding of the transport and mechanical properties of porous materials. Mercury intrusion porosimetry (MIP) is an easy and widely applied method to determine the pore size distribution of mesoporous materials, but a principal problem makes data interpretation difficult. Large ink‐bottle pores may be accessed by the intruding mercury through smaller, so‐called neck pores only. This leads to significant under estimaion of pore sizes and to hysteresis effects between intrusion and extrusion in materials with a broad pore size distribution such as cement‐based materials. More accurate pore space information is obtained when ink‐bottle pores in the measurement are excluded from analysis. This may be achieved by repeated intrusion cycles or by impregnating the ink‐bottle pore space with Wood's metal. The combination of Wood's metal impregnation (WMI) and mercury intrusion in mortars and cement pastes as presented allows a characterization of the pore space independent of accessibility considerations. Different special pore types are defined, analyzed, and quantified. In a cement paste, 50% of all pores are found to be ink‐bottle type, of which 60% are accessible through neck entrances larger than 20 nm in diameter. A further 30% of all pores are nonink‐bottle type but are connected to the surface through such ink‐bottle pores only. Furthermore, hysteresis and contact angle alternation effects between intrusion and extrusion were studied. A contact angle shift of 26° between intrusion and extrusion is proposed.
Spark Plasma Sintering of Sol–Gel Derived Amorphous ZrW2O8 Nanopowder
Authors: Kanamori Kenji , Kineri Tohru , Fukuda Ryohei , Nishio Keishi , Hashimoto Masashi , Mae Hideo
Published: December 2008

Dense ZrW2O8 was prepared by spark plasma sintering (SPS), using amorphous ZrW2O8 nanopowder as a raw material, at 873 K for 10 min. We investigated the effects of SPS conditions, such as sintering temperature, heating rate, and the discharge power that is expressed as the product of pulsed direct current and voltage, on the densification process of ZrW2O8. The relative density and microstructure of ZrW2O8 prepared by SPS were compared with those of ZrW2O8 prepared by hot pressing (HP). The relative density of ZrW2O8 prepared by HP at 873 K for 1 h was 63.1%. On the contrary, the relative density of ZrW2O8 prepared by SPS at 873 K for 10 min at a heating rate of 50 K/min was 98.6%. These results show that the discharge pressure that is proportional to discharge power enhances the densification and grain growth of ZrW2O8 in the SPS process.
Porous Silicon Carbide Ceramics Produced by a Carbon Foam Derived from Mixtures of Mesophase Pitch and Si Particles
Authors: Zhang Zhijin , Wang Fuchi , Yu Xiaodong , Wang Yangwei , Yan Yinghui , Li Kai , Luan Zhiqiang
Published: December 2008

Carbon foam templates were prepared from a mixture of mesophase pitch (MP) and Si particles, followed by foaming and carbonization. Subsequent molten Si infiltrated into the carbon foam at 1500°C for 4 h in an inert atmosphere resulted in the formation of porous SiC ceramics. Micrographs were investigated by a scanning electron microscope (SEM), and phase identification of porous SiC ceramics was performed by X‐ray diffraction (XRD). The flexural strength and bulk density of porous SiC ceramics were also measured and calculated. The results revealed that the flexural strength of porous SiC ceramics increases with increasing Si content and decreasing porosity. The addition of Si in MP results in an increased densification of porous SiC struts. With 50 wt% Si, porous SiC ceramics with a high flexural strength of 23.9 MPa and a porosity of 55% were obtained.
Fabrication and Properties of Porous SiC Sheets from Clutch Lining Wastes
Authors: Shimada Shiro , Murata Maito , Narisawa Masaki
Published: December 2008

During the production of friction sheets with their pack assemblies used in clutch for automatic transmission of motorcars, useless sheet fragments are formed and have to be disposed of, amounting to several tens of tons per a month. These wastes are composed of cellulose, diatomaceous earth, synthetic fibers, and carbon powder/fibers, impregnated with phenol resin as the bonding medium. When two types of these sheets are heated in an inert atmosphere at 600°C, they become porous and contain excess carbon formed by decomposition of the resin. The reaction of these porous sheets with a source of silicon such as tetra‐ethoxy‐silane or SiO at 1500°–1600°C results in the formation of porous silicon carbide (SiC) (∼80% porosity). If the porous sheets are impregnated with phenol resin and again reacted with SiO gas at 1500°–1600°C in Ar, SiC sheets with reduced porosity (<70%) are obtained. The surfaces and cross sections of the SiC sheets were observed by scanning electron microscopy, and their pore size distribution in the samples heated at 1600° and 1900°C in Ar was determined by mercury porosimetry. The oxidation and corrosion properties of the SiC sheets with 60% and 80% porosities were determined at 1200°C in Ar/O2 in the absence and presence of NaCl vapor.
Molecular Dynamics Simulations of the Structure and Properties of Low Silica Yttrium Aluminosilicate Glasses
Authors: Du Jincheng
Published: December 2008

Yttrium aluminosilicate glasses are of technological importance in photonics, nuclear waste disposal, and as a delivery vehicle for radiation therapy. Their structures are also of great interest in glass science to elucidate the principles of glass formation and structures. We provide classical molecular dynamics simulation results of a series of yttrium aluminosilicate glasses with low silica concentration. Detailed structure analyses including coordination number, pair and bond angle distributions, Si–O and Al–O network structures, and primitive ring statistics are reported. It is found that the average aluminum coordination number decreases from 4.7 to 4.2 with increasing silica content from 5 to 20 mol%, while maintaining alumina at 55 mol%. Four‐coordinated aluminum ions increase from 40% to 84% in the series and the fraction of edge‐sharing alumino‐oxygen polyhedra decreases, indicating an increased network former role of aluminum ions with increasing silica content. Physical properties such as elastic constant, bulk modulus, Young's modulus, and Possion's ratio were calculated. The results show a decrease of bulk, Young's, and shear moduli with increasing silica and decreasing yttria contents that is in good agreement with experimental data.