bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electronic Properties of Vanadium‐Doped TiO2
Authors: Islam Mazharul M. , Bredow Thomas , Gerson Andrea 
Published: October 2011

AbstractThe electronic properties of vanadium‐doped rutile TiO2 are investigated theoretically with a Hartree–Fock/DFT hybrid approach. The most common oxidation states (V2+, V3+, V4+, and V5+) in different spin states are investigated and their relative stability is calculated. The most stable spin states are quartet, quintet, doublet, and singlet for V2+, V3+, V4+, and V5+ doping, respectively. By comparing the formation energy with respect to the parent oxides and gas‐phase oxygen (ΔE), we conclude that V4+ (ΔE=145.3 kJ mol−1) is the most likely oxidation state for vanadium doping with the possibility of V5+ doping (ΔE=283.5 kJ mol−1). The energetic and electronic properties are converged with dopant concentrations in the range of 0.9 to 3.2 %, which is within the experimentally accessible range. The investigation of electronic properties shows that V4+ doping creates both occupied and unoccupied vanadium states in the band gap and V5+ doping creates unoccupied states at the bottom of the conduction band. In both cases there is a significant reduction of the band gap by 0.65 to 0.75 eV compared to that of undoped rutile TiO2.
Strong spatial genetic structure in five tropical Piper species: should the Baker–Fedorov hypothesis be revived for tropical shrubs?
Authors: Lasso E. , Dalling J. W. , Bermingham E. 
Published: October 2011

AbstractFifty years ago, Baker and Fedorov proposed that the high species diversity of tropical forests could arise from the combined effects of inbreeding and genetic drift leading to population differentiation and eventually to sympatric speciation. Decades of research, however have failed to support the Baker–Fedorov hypothesis (BFH), and it has now been discarded in favor of a paradigm where most trees are self‐incompatible or strongly outcrossing, and where long‐distance pollen dispersal prevents population drift. Here, we propose that several hyper‐diverse genera of tropical herbs and shrubs, including Piper (>1,000 species), may provide an exception. Species in this genus often have aggregated, high‐density populations with self‐compatible breeding systems; characteristics which the BFH would predict lead to high local genetic differentiation. We test this prediction for five Piper species on Barro Colorado Island, Panama, using Amplified Fragment Length Polymorphism (AFLP) markers. All species showed strong genetic structure at both fine‐ and large‐spatial scales. Over short distances (200–750 m) populations showed significant genetic differentiation (Fst 0.11–0.46, P < 0.05), with values of spatial genetic structure that exceed those reported for other tropical tree species (Sp = 0.03–0.136). This genetic structure probably results from the combined effects of limited seed and pollen dispersal, clonal spread, and selfing. These processes are likely to have facilitated the diversification of populations in response to local natural selection or genetic drift and may explain the remarkable diversity of this rich genus.
Total Synthesis of (+)‐Hyacinthacine A1, (+)‐7a‐epi‐Hyacinthacine A1, (6R)‐6‐Hydroxyhyacinthacine A1 and (6S)‐6‐Hydroxy‐7a‐epi‐hyacinthacine A1
Authors: D'Adamio Giampiero , Goti Andrea , Parmeggiani Camilla , Moreno‐Clavijo Elena , Robina Inmaculada , Cardona Francesca 
Published: October 2011

AbstractThe total synthesis of natural (+)‐hyacinthacine A1 (6), (+)‐7a‐epi‐hyacinthacine A1 (7) and their 6‐hydroxy analogues 21 and 16 was achieved using a nitrone cycloaddition strategy with D‐ribose‐derived cyclic nitrone 8 as the dipole and tert‐butyl acrylate as the dipolarophile. After separation of the adducts, reductive cleavage of the N–O bond followed by lactam reduction and deprotection afforded the two non‐natural hydroxy analogues in excellent yields. The synthesis of (+)‐hyacinthacine A1 (6) and of (+)‐7a‐epi‐hyacinthacine A1 (7), which required deoxygenation at C(6), was accomplished by DIBAL‐H reduction of mesylate derivatives of the pyrrolizidinols 20 and 15, respectively. Evaluation of the synthesized compounds against a panel of 12 commercially available glycosidases showed that hyacinthacine A1 (6) and its (6R)‐hydroxy analogue 21 are good inhibitors of amyloglucosidase; the non‐natural compound 21 is also a strong inhibitor of β‐glucosidase, while 6 showed only moderate inhibition. The non‐natural (+)‐7a‐epi‐hyacinthacine A1 (7) is a moderate inhibitor of amyloglucosidase and α‐L‐fucosidase; the presence of the (6S)‐hydroxy group in 16 led to diminished activity.
Metarelational models: Configurations of social relationships
Authors: Fiske Alan Page 
Published: October 2011

AbstractBeyond cognizing persons and social relationships, people also think about combinations of relationships: metarelational models (MeRMs). If relationships are words, then MeRMs are syntax; if relationships are atoms, MeRMs are chemical compounds. MeRMs are the motivated, emotionally experienced, morally directive models for generating, understanding, coordinating, planning, evaluating, modulating, sanctioning, and redressing configurations of social relationships. Previous research and theory on triads and balance, networks, cross‐cutting ties, and kinship systems has explored the causal connections among social relationships, but MeRM theory posits something more: shared, culturally informed MeRMs that people use to jointly construct meaningful coordinated action. The social interactions of nonhuman animals and pre‐verbal infants indicate that they use MeRMs, supporting the contention that core innate cognition includes the basic structures of MeRMs. There are six elementary kinds of MeRMs, and recursive linking of relational models (RMs) generates indefinitely more. MeRMs shape individual psychology, relationships, groups, institutions, and cultures. Copyright © 2011 John Wiley & Sons, Ltd.
Finding fossils in new ways: An artificial neural network approach to predicting the location of productive fossil localities
Authors: Anemone Robert , Emerson Charles , Conroy Glenn 
Published: October 2011

AbstractChance and serendipity have long played a role in the location of productive fossil localities by vertebrate paleontologists and paleoanthropologists. We offer an alternative approach, informed by methods borrowed from the geographic information sciences and using recent advances in computer science, to more efficiently predict where fossil localities might be found. Our model uses an artificial neural network (ANN) that is trained to recognize the spectral characteristics of known productive localities and other land cover classes, such as forest, wetlands, and scrubland, within a study area based on the analysis of remotely sensed (RS) imagery. Using these spectral signatures, the model then classifies other pixels throughout the study area. The results of the neural network classification can be examined and further manipulated within a geographic information systems (GIS) software package. While we have developed and tested this model on fossil mammal localities in deposits of Paleocene and Eocene age in the Great Divide Basin of southwestern Wyoming, a similar analytical approach can be easily applied to fossil‐bearing sedimentary deposits of any age in any part of the world. We suggest that new analytical tools and methods of the geographic sciences, including remote sensing and geographic information systems, are poised to greatly enrich paleoanthropological investigations, and that these new methods should be embraced by field workers in the search for, and geospatial analysis of, fossil primates and hominins. © 2011 Wiley‐Liss, Inc.
Copy number defects of G1‐Cell cycle genes in neuroblastoma are frequent and correlate with high expression of E2F target genes and a poor prognosis
Authors: Molenaar Jan J. , Koster Jan , Ebus Marli E. , van Sluis Peter , Westerhout Ellen M. , de Preter Katleen , Gisselsson David , Øra Ingrid , Speleman Frank , Caron Huib N. , Versteeg Rogier 
Published: October 2011

AbstractThe tightly controlled network of cell cycle genes consists of a core of cyclin dependent kinases (CDKs) that are activated by periodically expressed cyclins. The activity of the cyclin‐CDK complexes is regulated by cyclin dependent kinase inhibitors (CDKIs) and multiple signal transduction routes that converge on the cell cycle. Neuroblastoma are pediatric tumors that belong to the group of small round blue cell tumors, characterized by a fast proliferation. Here, we present high throughput analyses of cell cycle regulating genes in neuroblastoma. We analyzed a series of 82 neuroblastomas by comparative genomic hybridization arrays, single nucleotide polymorphism arrays, and Affymetrix expression arrays and analyzed the datasets in parallel with the R2 bioinformatic tool (http://r2.amc.nl). About 30% of the tumors had genomic amplifications, gains, or losses with shortest regions of overlap that suggested implication of a series of G1 cell cycle regulating genes. CCND1 (cyclin D1) and CDK4 were amplified or gained and the chromosomal regions containing the CDKN2 (INK4) group of CDKIs were frequently deleted. Cluster analysis showed that tumors with genomic aberrations in G1 regulating genes over‐expressed E2F target genes, which regulate S and G2/M phase progression. These tumors have a poor prognosis. Our findings suggest that pharmacological inhibition of cell cycle genes might bear therapeutic promises for patients with high risk neuroblastoma. © 2011 Wiley Periodicals, Inc.
Gap junctions mediate intercellular spread of sodium between hippocampal astrocytes in situ
Authors: Langer Julia , Stephan Jonathan , Theis Martin , Rose Christine R. 
Published: October 2011

AbstractActivation of glutamatergic synapses results in long‐lasting sodium transients in astrocytes mediated mainly by sodium‐dependent glutamate uptake. Sodium elevations activate Na+/K+‐ATPase and glucose uptake by astrocytes, representing key signals for coupling glial metabolism to neuronal activity. Here, we analyzed the spread of sodium signals between astrocytes in hippocampal slice preparations. Stimulation of a single astrocyte resulted in an immediate sodium elevation that spread to neighboring astrocytes within a distance of ∼ 100 μm. Amplitude, slope, and propagation speed of sodium elevations in downstream cells decayed monotonically with increasing distance, indicative of a diffusion process. In contrast to sodium, calcium increases elicited by electrical stimulation were restricted to the stimulated cell and a few neighboring astrocytes. Pharmacological inhibition of mGluR1/5 slightly dampened the spread of sodium, whereas inhibition of glutamate uptake or purinergic receptors had no effect. Spread of sodium to neighboring cells was disturbed on pharmacological inhibition of gap junctions, reduced in animals at P4 and virtually omitted in Cx30/Cx43 double‐deficient mice. In contrast to results obtained earlier in cultured astrocytes, our data thus indicate that calcium signaling and metabotropic glutamate receptors are supportive of, but not prerequisites for, the spread of sodium between hippocampal astrocytes in situ, whereas expression of Cx30 and Cx43 is essential. Cx30/Cx43‐mediated sodium diffusion between astrocytes could represent a signal indicating increased metabolic needs, independent of concomitant calcium signaling. Spread of sodium might also serve a homeostatic function by supporting the re‐establishment of steep sodium gradients and by lowering the metabolic burden imposed on single cells. © 2011 Wiley Periodicals, Inc.
Three polymorphisms of the eNOS gene and plasma levels of metabolites of nitric oxide in depressed Japanese patients: a preliminary report
Authors: Ikenouchi‐Sugita Atsuko , Yoshimura Reiji , Kishi Taro , Umene‐Nakano Wakako , Hori Hikaru , Hayashi Kenji , Katsuki Asuka , Ueda Nobuhisa , Iwata Nakao , Nakamura Jun 
Published: October 2011

BackgroundDepression is a risk factor for coronary heart disease. Nitric oxide (NO) plays an important role in both coronary heart disease and depression.MethodsFifty‐one inpatients and outpatients who met the Diagnostic and Statistical Manual of Mental Disorders—Fourth Edition criteria for major depressive disorder (MDD) in the university hospital of the University of Occupational and Environmental Health and 58 age‐matched and sex‐matched healthy controls enrolled in this study. We investigated the association between the three polymorphisms of the endothelial nitric oxide synthase (eNOS) gene (single‐nucleotide polymorphism (SNP); rs2070744, rs1799983, variable number tandem repeat (VNTR) in intron 4) and scores on the Hamilton Rating Scale for Depression, plasma metabolites of NO (NOx) or ankle brachial index in patients with MDD and healthy controls.ResultsWe did not find significant differences in the genotype distributions between patients with MDD and healthy volunteers. No associations were observed between any of the polymorphisms of the eNOS gene and the Hamilton Rating Scale for Depression or ankle brachial index in patients with MDD. However, plasma NOx level was significantly associated with a polymorphism of the eNOS gene (rs207044 and variable number tandem repeat in intron 4).ConclusionThese results suggest that the direct association was not observed between the polymorphisms of the eNOS gene and the pathogenesis of depression. Copyright © 2011 John Wiley & Sons, Ltd.
Systemic and local human papillomavirus 16‐specific T‐cell immunity in patients with head and neck cancer
Authors: Heusinkveld M. , Goedemans R. , Briet R.J.P. , Gelderblom H. , Nortier J.W.R. , Gorter A. , Smit V.T.H.B.M. , Langeveld A.P.M. , Jansen J.C. , van der Burg S.H. 
Published: October 2011

AbstractSquamous cell carcinomas of the head and neck (HNSCC), in particular those of the oropharynx, can be caused by human papilloma virus Type 16 (HPV16). Whereas these HPV‐induced oropharyngeal carcinomas may express the HPV16 E6 and E7 oncoproteins and are associated with better survival, the nonvirally induced HNSCC are associated with overexpression of p53. In this study we assessed the presence of systemic and local T cells reactive against these oncoproteins in HNSCC. An exploratory study on the presence, type and function of HPV16‐ and/or p53‐specific T cells in the blood, tumor and/or metastatic lymph node as measured by several immune assays was performed in an unselected group of 50 patients with HNSCC. Tumor tissue was tested for HPV DNA and the overexpression of p53 protein. Almost all HPV16+ tumors were located in the oropharynx. Circulating HPV16‐ and p53‐specific T cells were found in 17/47 and 7/45 tested patients. T cells were isolated from tumor cultures and/or lymph nodes of 20 patients. HPV16‐specific T cells were detected in six of eight HPV+ tumors, but in none of the 12 HPV‐tumors. Tumor‐infiltrating p53‐specific T cells were not detected. In depth analysis of the HPV16‐specific T‐cell response revealed that this response comprised a broad repertoire of CD4+ T‐helper Type 1 and 2 cells, CD4+ regulatory T cells and CD8+ T cells reactive to HPV16. The local presence of HPV16‐specific T‐cell immunity in HPV16‐induced HNSCC implicates a role in the antitumor response and support the development of immunotherapy for HNSCC.
Acinetobacter baylyi ADP1: Transforming the choice of model organism
Authors: Elliott Kathryn T. , Neidle Ellen L. 
Published: October 2011

AbstractFor more than 25 years, Acinetobacter baylyi ADP1 has been used in molecular biology studies that address a broad range of questions. Recently, the rapid accumulation of data from DNA sequencing, gene expression, protein structure, and other high‐throughput methodology has increased the ability to tackle complex topics using sophisticated approaches to metabolic and genetic engineering. While the genetic malleability of ADP1 makes it an ideal organism for such investigations, A. baylyi ADP1 has yet to become a common choice for bacterial studies. This review describes examples of ADP1‐based studies that exploit its highly efficient system for natural transformation and chromosomal incorporation of exogenous DNA. These studies focus on a wide array of problems, including gene duplication and amplification, horizontal gene transfer, bioreporters, and metabolic reconstruction. Interesting results in these diverse areas highlight the utility of using A. baylyi in laboratory and industrial settings. © 2011 IUBMB IUBMB Life, 63(12): 1075–1080, 2011
Oxygen and nitric oxide rebinding kinetics in nonsymbiotic hemoglobin AHb1 from Arabidopsis thaliana
Authors: Abbruzzetti Stefania , Faggiano Serena , Spyrakis Francesca , Bruno Stefano , Mozzarelli Andrea , Astegno Alessandra , Dominici Paola , Viappiani Cristiano 
Published: October 2011

AbstractType 1 nonsymbiotic hemoglobin from Arabidopsis thaliana (AHb1) shows a partial bis‐histidyl hexacoordination but can reversibly bind diatomic ligands. The physiological function is still unclear, but the high oxygen affinity rules out a function related to O2 sensing, carrying, or storing. To gain insight into its possible functional roles, we have investigated its O2 and NO rebinding kinetics after laser flash photolysis. The rate constants of the rebinding from the primary docking site for both O2 and NO are higher than CO, with lower photolysis yields. Moreover, the amplitude of the geminate phase increases and, as for CO, the numerical analysis of the experimental curves suggests the existence of an internal pathway leading, with high rate, to an additional docking site. However, the accessibility to this site seems to be strongly ligand‐dependent, being lower for O2 and higher for NO. © 2011 IUBMB IUBMB Life, 63(12): 1094–1100, 2011
Contributions of Rad9 to tumorigenesis
Authors: Broustas Constantinos G. , Lieberman Howard B. 
Published: October 2011

AbstractRad9 plays a crucial role in maintaining genomic stability by regulating cell cycle checkpoints, DNA repair, telomere stability, and apoptosis. Rad9 controls these processes mainly as part of the heterotrimeric 9‐1‐1 (Rad9‐Hus1‐Rad1) complex. However, in recent years it has been demonstrated that Rad9 can also act independently of the 9‐1‐1 complex as a transcriptional factor, participate in immunoglobulin class switch recombination, and show 3′‐5′ exonuclease activity. Aberrant Rad9 expression has been associated with prostate, breast, lung, skin, thyroid, and gastric cancers. High expression of Rad9 is causally related to, at least, human prostate cancer growth. On the other hand, deletion of Mrad9, the mouse homolog, is responsible for increased skin cancer incidence. These results reveal that Rad9 can act as an oncogene or tumor suppressor. Which of the many functions of Rad9 are causally related to initiation and progression of tumorigenesis and the mechanistic details by which Rad9 induces or suppresses tumorigenesis are presently not known, but are crucial for the development of targeted therapeutic interventions. J. Cell. Biochem. 113: 742–751, 2012. © 2011 Wiley Periodicals, Inc.
Sonographic findings of fibrous pseudotumor of the tunica vaginalis
Authors: Mo Yang Dal , Cheol Kim Hyun , Jig Lim Sung 
Published: October 2011

AbstractWe report the sonographic findings in a case of fibrous pseudotumor of the tunica vaginalis. Scrotal gray‐scale sonography revealed a well‐margined, hypoechoic mass with an onion ring appearance and central calcifications in the left scrotum. Color Doppler sonography showed no blood flow within the mass. The pathological examination revealed a fibrous pseudotumor with a paucicellular and fibroblastic proliferation of cells within a hyalinized collagenous stroma. © 2011 Wiley Periodicals, Inc. J Clin Ultrasound, 2011;
AGRICULTURE AND ARTISANAL GOLD MINING IN SIERRA LEONE: ALTERNATIVES OR COMPLEMENTS?
Authors: Cartier Laurent E. , Bürge Michael 
Published: October 2011

AbstractThis article explores a number of the productivity and marketing difficulties that are hindering the establishment of sustainable livelihoods in small‐scale agriculture in Sierra Leone. The emergence of the artisanal gold mining and trading sector in the central part of the country and synergies between farming and mining cycles are discussed. It is argued that small‐scale agriculture and artisanal mining are not livelihood alternatives but are instead livelihood complements. The potentially catalysing role of gold income in reinvigorating non‐mining activities is critically examined. Recent findings that explain the differing profitability of farming and mining are presented. Finally, a policy outlook is offered on how these fragile dynamics could be harnessed to promote sustainable livelihoods in rural Sierra Leone. Copyright © 2011 John Wiley & Sons, Ltd.
POVERTY AND LIVELIHOOD DIVERSIFICATION: EXPLORING THE LINKAGES BETWEEN SMALLHOLDER FARMING AND ARTISANAL MINING IN RURAL GHANA
Authors: Okoh Godfried , Hilson Gavin 
Published: October 2011

AbstractThis article draws attention to the importance of promoting and regularizing artisanal and small‐scale mining (ASM)—low‐tech, labour‐intensive mineral extraction and processing activity—in sub‐Saharan Africa, focusing on the case of Ghana. An estimated one million people are employed directly in the sector in the country, the majority operating illegally (without a license or on unlicensed lands) and in very precarious conditions. The difficulty with reprimanding these people is that many have moved into ASM out of necessity, ‘branching out’ from smallholder farming, which in many areas of Ghana has become an unviable enterprise over the past two decades. A case study of the Brong‐Ahafo Region, the location of Ghana's most recent gold discoveries, is used to illustrate the growing interconnectedness between the two activities and the imperativeness of recognizing these dynamics in policy. Copyright © 2011 John Wiley & Sons, Ltd.
‘CAN I GO?’—EXITING THE ARTISANAL MINING SECTOR IN THE DEMOCRATIC REPUBLIC OF CONGO
Authors: Perks Rachel 
Published: October 2011

AbstractThe analysis of exit options out of artisanal mining provides a useful entry point for discussing recent efforts made in many African countries' poverty alleviation strategies to promote smallholder farming. This article critically analyses exit options and their applicability to wider rural development policy and planning in the context of the Democratic Republic of Congo. Although smallholder rural agriculture is perceived to be an appropriate exit strategy by supporting agencies, it may, in fact, not be suitable for a variety of reasons. These include, but are not limited to, land access and tenure, economic remuneration, security and relevant skills. The article examines whether trade and small businesses may be more suitable alternatives, given that these exit options build on present artisanal miners' skills, knowledge and social networks. As agencies consider support towards exit options for artisanal miners, within a broader rural development framework, an analysis of not only the technical nature of alternative opportunities is critical; equally, an analysis of the socio‐political constraints to exit is necessary. In effect, a ‘critical re‐think’ of the region's rural development strategy is imperative. Copyright © 2011 John Wiley & Sons, Ltd.