bluuebunny/crossref_metadata_2025 huggingface dataset:
Biofuels and the Lessons of Easter Island
Authors: Chaves Antonio R.
Published: July 2009

The return to land-based biofuels ignores the lessons of the past that led to the collapse of civilizations such as that of Easter Island. Even the more efficient ethanol feedstocks such as sugar cane and switchgrass can greatly worsen the environmental damage associated with agriculture because they would require enormous amounts of land to meet US demand for transportation fuel. Too often, style wins over substance because most citizens do not know the basics of well-to-wheel analysis. Therefore, the incorporation of energy literacy into the high school curricula should play a significant role in any comprehensive plan for addressing the energy crisis.
Alveolar Macrophages Transport Pathogens to Lung Draining Lymph Nodes
Authors: Kirby Alun C. , Coles Mark C. , Kaye Paul M.
Published: July 2009

The first step in inducing pulmonary adaptive immunity to allergens and airborne pathogens is Ag acquisition and transport to the lung draining lymph nodes (dLN). Dendritic cells (DC) sample the airways, and active transfer of Ag to the lung dLN is considered an exclusive property of migratory DC. However, alveolar macrophages (AM) are the first phagocytes to contact inhaled particulate matter. Although having well-defined immunoregulatory capabilities, AM are generally considered as restricted to the alveoli. We show that murine AM constitutively migrate from lung to dLN and that following exposure to Streptococcus pneumoniae, AM rapidly transport bacteria to this site. Thus AM, and not DC, appear responsible for the earliest delivery of these bacteria to secondary lymphoid tissue. The identification of this novel transport pathway has important consequences for our understanding of lung immunity and suggests more widespread roles for macrophages in the transport of Ags to lymphoid organs than previously appreciated.
Plant communities of the Soutpansberg Arid Northern Bushveld
Authors: Mostert Theo H.C. , Bredenkamp George J. , Mostert Rachel E.
Published: July 2009

The Soutpansberg Arid Northern Bushveld is one of eight major vegetation types (MVT) described for the Soutpansberg-Blouberg region. The plant communities of this MVT are described in detail. Main ecological drivers of the vegetation structure and species composition of these communities are discussed and some conservation recommendations are made. Phytosociological data from a subset of 72 Braun-Blanquet sample plots collected in the Soutpansberg Arid Northern Bushveld were classified using Two-way Indicator Species Analysis (TWINSPAN) and ordinated using a Detrended Correspondence Analysis (DECORANA). The resulting classification was further refined with table-sorting procedures based on the Braun-Blanquet floristic-sociological approach to vegetation classification using the computer software MEGATAB and JUICE. Eight plant communities were identified and described as Commiphora tenuipetiolata-Adansonia digitata short open woodland, Ledebouria ovatifolia-Commiphora mollis short bushland, Phyllanthus reticulatus-Acacia nigrescens short bushland, Tinnea rhodesiana-Combretum apiculatum short bushland, Dichrostachys cinerea subsp. africana-Spirostachys africana low thickets, Themeda triandra-Pterocarpus rotundifolius short closed grassland on steep basaltic slopes, Cyperus albostriatus-Syzygium cordatum sandveld wetlands, and Sesamothamnus lugardii-Catophractes alexandri tall sparse shrubland. These plant communities are event-driven ecosystems, predominantly infl uenced by frequent droughts, exposure to desiccation and unpredictable rainfall events. The complex topography of the Soutpansberg further contributes to the aridity of these ecosystems. The classifi cation and ordination analyses show similar groupings in the vegetation of the Soutpansberg Arid Mountain Bushveld. This confi rms the usefulness of complimentary analysis, using both classifi cation and ordination methods on a single data set in order to examine patterns and to search for group structure.Conservation implications: The results from this study will alter existing regional vegetation maps profoundly. The described plant communities of these arid event-driven ecosystems should be used as benchmark examples of the region’s primary vegetation. Conservation and management planning should be based on these vegetation units.
Sense of coherence and employees’ perceptions of helping and restraining factors in an organisation
Authors: Muller Yolande , Rothmann Sebastiaan
Published: July 2009

The objectives of this study were to assess the construct validity and reliability of the 13-item version of the Orientation to Life Questionnaire (OLQ)  and to investigate whether employees with a strong sense of coherence perceived helping and restraining factors in their organisation differently to those with a weak sense of coherence. A cross-sectional survey design was used. The total population (N = 2 678) of employees in a financial institution in Gauteng participated in the study. The OLQ was administered and it showed acceptable reliability and construct validity. Individuals with high scores (n = 300) and those with low scores (n = 300) on sense of coherence differed regarding their perceptions of helping and restraining factors in their work and organisation.
Habits of the heart: Life history and the developmental neuroendocrinology of emotion
Authors: Worthman Carol M.
Published: July 2009

The centrality of emotion in cognition and social intelligence as well as its impact on health has intensified investigation into the causes and consequences of individual variation in emotion regulation. Central processing of experience directly informs regulation of endocrine axes, essentially forming a neuro‐endocrine continuum integrating information intake, processing, and physiological and behavioral response. Two major elements of life history—resource allocation and niche partitioning—are served by linking cognitive‐affective with physiologic and behavioral processes. Scarce cognitive resources (attention, memory, and time) are allocated under guidance from affective co‐processing. Affective‐cognitive processing, in turn, regulates physiologic activity through neuro‐endocrine outflow and thereby orchestrates energetic resource allocation and trade‐offs, both acutely and through time. Reciprocally, peripheral activity (e.g., immunologic, metabolic, or energetic markers) influences affective‐cognitive processing. By guiding attention, memory, and behavior, affective‐cognitive processing also informs individual stances toward, patterns of activity in, and relationships with the world. As such, it mediates processes of niche partitioning that adaptively exploit social and material resources. Developmental behavioral neurobiology has identified multiple factors that influence the ontogeny of emotion regulation to form affective and behavioral styles. Evidence is reviewed documenting roles for genetic, epigenetic, and experiential factors in the development of emotion regulation, social cognition, and behavior with important implications for understanding mechanisms that underlie life history construction and the sources of differential health. Overall, this dynamic arena for research promises to link the biological bases of life history theory with the psychobehavioral phenomena that figure so centrally in quotidian experience and adaptation, particularly, for humans. Am. J. Hum. Biol. 2009. © 2009 Wiley‐Liss, Inc.
Quantifying calcium intake in school age children: Development and validation of the Calcium Counts!© food frequency questionnaire
Authors: Zemel Babette S. , Carey Lisa B. , Paulhamus Donna R. , Stallings Virginia A. , Ittenbach Richard F.
Published: July 2009

Quantifying dietary behavior is difficult and can be intrusive. Calcium, an essential mineral for skeletal development during childhood, is difficult to assess. Few studies have examined the use of food frequency questionnaires (FFQs) for assessing calcium intake in school‐age children. This study evaluated the validity and reliability of the Calcium Counts!© FFQ (CCFFQ) for estimating calcium intake in school children in the US. Healthy children, aged 7–10 years (n = 139) completed the CCFFQ and 7‐day weighed food records. A subset of subjects completed a second CCFFQ within 3.6 months. Concurrent validity was determined using Pearson correlations between the CCFFQ and food record estimates of calcium intake, and the relationship between quintiles for the two measures. Predictive validity was determined using generalized linear regression models to explore the effects of age, race, and gender. Inter‐ and intra‐individual variability in calcium intake was high (>300 mg/day). Calcium intake was ∼300 mg/day higher by CCFFQ compared to food records. Concurrent validity was moderate (r = 0.61) for the entire cohort and higher for selected subgroups. Predictive validity estimates yielded significant relationships between CCFFQ and food record estimates of calcium intake alone and in the presence of such potential effect modifiers as age group, race, and gender. Test–retest reliability was high (r = 0.74). Although calcium intake estimated by the CCFFQ was greater than that measured by food records, the CCFFQ provides valid and reliable estimates of calcium intake in children. The CCFFQ is especially well‐suited as a tool to identify children with low calcium intakes. Am. J. Hum. Biol. 2010. © 2009 Wiley‐Liss, Inc.
Power generation from coal and biomass based on integrated gasification combined cycle concept with pre‐ and post‐combustion carbon capture methods
Authors: Cormos Calin‐Cristian , Cormos Ana‐Maria , Agachi Serban
Published: July 2009

Gasification technology is a process in which solid fuel is partially oxidised by oxygen and steam/water to produce a combustible gas called syngas (mainly a mixture of hydrogen and carbon monoxide). Syngas can be used either for power generation or processed to obtain various chemicals (hydrogen, ammonia, methanol, etc.). This article evaluates the possibilities of solid fuel decarbonisation by capturing carbon dioxide resulted form thermo‐chemical conversion of solid fuel using gasification. Evaluation is focused on power generation technology using syngas produced by solid fuel gasification (so‐called integrated gasification combined cycle—IGCC). Case studies analysed in the article are using a mixture of coal and biomass (sawdust) to produce around 400 MW electricity simultaneously with capturing about 90% of the feedstock carbon. Various carbon dioxide capture options (post‐ and pre‐combustion) are compared with situation of no carbon capture in terms of plant configurations, energy penalty, CO2 emissions, etc. Plant options are modelled using ChemCAD, and simulation results are used to assess the plant performances. Plant flexibility and future improvements are also discussed. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Temperature dependence of heterogeneous uptake of N2O5 by ammonium sulfate aerosol
Authors: Griffiths Paul T. , Anthony Cox R.
Published: July 2009

We present laboratory measurements of the dependence of the uptake coefficient γ on temperature for removal of the NOx reservoir N2O5 by sub‐micron aerosols containing ammonium sulfate and ammonium hydrogen sulfate. Uptake coefficients were measured over the range 263–303 K at 50% RH, which varied in the range 0.005–0.036. A simple negative dependence of uptake on temperature is observed for ammonium sulfate over this range, while the form of the temperature dependence of uptake by ammonium hydrogen sulfate is more complex. The results consolidate those of an earlier less definitive study of the temperature effect on N2O5 uptake. Copyright © 2009 Royal Meteorological Society
COMU: A Safer and More Effective Replacement for Benzotriazole‐Based Uronium Coupling Reagents
Authors: El‐Faham Ayman , Funosas Ramon Subirós , Prohens Rafel , Albericio Fernando
Published: July 2009

We describe a new family of uronium‐type coupling reagents that differ in their iminium moieties and leaving groups. The presence of the morpholino group in conjunction with an oxime derivative—especially ethyl 2‐cyano‐2‐(hydroxyimino)acetate (Oxyma)—had a marked influence on the solubilities, stabilities, and reactivities of the reagents. Finally, the new uronium salt derived from Oxyma (COMU) performed extremely well in the presence of only 1 equiv of base, thereby confirming the effect of the hydrogen bond acceptor in the reaction. COMU also showed a less hazardous safety profile than the benzotriazole‐based HDMA and HDMB, which exhibited unpredictable autocatalytic decompositions. Furthermore, the Oxyma moiety contained in COMU suggests a lower risk of explosion than in the case of the benzotriazole derivatives.
Homo‐ and Heterodinuclear Helicates of Lanthanide(III), Zinc(II) and Aluminium(III) Based on 8‐Hydroxyquinoline Ligands
Authors: Albrecht Markus , Osetska Olga , Bünzli Jean‐Claude G. , Gumy Frédéric , Fröhlich Roland
Published: July 2009

Homonuclear helicates with rare‐earth‐metal(III) ions or heteronuclear derivatives with rare‐earth‐metal and aluminium or zinc centres are obtained in alkali‐metal‐templated self‐assembly processes from isobutenylidene‐bridged homoditopic bis(2‐carbamido‐8‐hydroxyquinoline)‐derived ligands 1H2 and 2H2 or heteroditopic (8‐hydroxyquinoline)(2‐carbamido‐8‐hydroxyquinoline)‐derived ligands 3H2 and 4H2. Diamagnetic coordination compounds possess a high stability in organic solvents such as CDCl3, [D4]MeOH or [D6]DMSO and can be well characterised by 1H NMR spectroscopy by using methylene protons and the protons of the vinylic units of the ligand as stereochemical or symmetry probes, respectively. Some of the homonuclear complexes could be crystallised and were characterised by using X‐ray diffraction studies. The complexes adopt a triple‐stranded helical structure with a central templating cation encapsulated in their interior. An unusual orientation of the double bond of one spacer towards this cation is observed. The homo‐ and heterodinuclear helicates with ytterbium(III), neodymium(III) or erbium(III) of ligands 2 and 4 were of special interest owing to their near‐infrared (NIR) emitting properties, which were investigated depending on the lanthanide and on the encapsulated alkali‐metal cation.
Development of a CE‐MS method to analyze components of the potential biomarker vascular endothelial growth factor 165
Authors: Puerta Angel , Bergquist Jonas
Published: July 2009

The vascular endothelial growth factor 165 (VEGF165) is the predominant form of the complex VEGF‐A family. Its angiogenic effect is involved in many physiological and pathological events. For this reason, its roles as a potential biomarker and as a therapeutic drug have been considered. Nevertheless, very little is known about the existence of different forms of VEGF165 arising from glycosylation and potentially from other PTMs. This aspect is important because different forms may differ in biological activity (therapeutic drug application) and the pattern of the different forms can vary with pathological changes (biomarker application). In this work a CE‐MS method to separate up to seven peaks containing, at least, 19 isoforms of intact VEGF165 is described. Comparison between human VEGF165 expressed in a glycosylating system, i.e. insect cells, and in a non‐glycosylating system, i.e. E. coli cells, has been carried out. The method developed provides structural information (mass fingerprint) about the different forms of VEGF165 and after the deconvolution and the analysis of the MS spectra, PTMs pattern of VEGF165 including glycosylation and loss of amino acids at the N‐ and C‐terminus was identified. Glycans involved in PTMs promoting different glycoforms observed in the CE‐MS fingerprint were confirmed by MALDI‐MS after deglycosylation with peptide N‐glycosidase F. This approach is a starting point to study the role of VEGF165 as a potential biomarker and to perform quality control of the drug during manufacturing. To our knowledge this is the first time that a CE‐MS method for the analysis of VEGF165 has been developed.
Expression of caspase and apoptotic signal pathway induced by sulfur dioxide
Authors: Bai Juli , Meng Ziqiang
Published: July 2009

Sulfur dioxide (SO2) is a common air pollutant that is released in low concentrations into the atmosphere and in higher concentrations in some work places. In the present study, male Wistar rats were housed in exposure chambers and treated with 14.00 ± 1.01, 28.00 ± 1.77, and 56.00 ± 3.44 mg/m3 SO2 for 7 days (6 hr/day), while control rats were exposed to filtered air under the same conditions. The mRNA and protein levels of caspase‐3, caspase‐8, and caspase‐9 were analyzed using a real‐time reverse transcription‐polymerase chain reaction (real‐time RT‐PCR) assay and an immunohistochemistry method. Activities of caspases were detected using colorimetric and fluorescent assays. Chromatin degradation and cell morphological changes were investigated by TUNEL assay and H&E staining in livers and lungs, respectively. The results showed that mRNA levels, protein levels and activities of caspase‐3, caspase‐8, and caspase‐9 were increased in a dose‐dependent manner in livers and lungs of rats after SO2 inhalation. In addition, livers were infiltrated with lymphocytes, congestion and inflammation occurred in lungs, and eosinophil cells and apoptotic cells increased in both livers and lungs after SO2 inhalation. These results suggest that SO2 exposure increases the expression and activity of both initiator and and effector caspases, and may induce apoptosis in liver and lung of rats through both death receptor and mitochondrial pathways. Environ. Mol. Mutagen. 2010. © 2009 Wiley‐Liss, Inc.
Structural equation models for meta‐analysis in environmental risk assessment
Authors: Budtz‐Jørgensen Esben , Debes Frodi , Weihe Pal , Grandjean Philippe
Published: July 2009

The potential of structural equation models for combining information from different studies in environmental epidemiology is explored. For illustration, we synthesize data from two birth cohorts assessing the effects of prenatal exposure to methylmercury (MeHg) on childhood cognitive performance. One cohort was the largest by far, but a smaller cohort included superior assessment of the PCB exposure which has been considered an important confounder when estimating the mercury effect. The data were analyzed by specification of a structural equation model for each cohort. Information was then pooled based on a joint likelihood function with key parameters constrained to be equal in the different models. Modeling assumptions were chosen to obtain a meaningful biological interpretation of the joint effect parameters. Measurement errors in mercury variables were taken into account by viewing observed variables as indicators of latent variables. Adjustments for measurement error were also included for confounder variables. In particular, this example illustrates how to properly utilize that one study provided superior information about a confounder. A final more advanced model pooled information across different outcomes to gain power and to avoid multiple testing problems. In this model, the mercury effect remained statistically significant, while the effect of PCB was less certain. Copyright © 2009 John Wiley & Sons, Ltd.
Coherence in consciousness: Paralimbic gamma synchrony of self‐reference links conscious experiences
Authors: Lou Hans C. , Gross Joachim , Biermann‐Ruben Katja , Kjaer Troels W. , Schnitzler Alfons
Published: July 2009

A coherent and meaningful percept of the world is essential for human nature. Consequently, much speculation has focused on how this is achieved in the brain. It is thought that all conscious experiences have reference to the self. Self‐reference may either be minimal or extended, i.e., autonoetic. In minimal self‐reference subjective experiences are self‐aware in the weak sense that there is something it feels like for the subject to experience something. In autonoetic consciousness, consciousness emerges, by definition, by retrieval of memories of personally experienced events (episodic memory). It has been shown with transcranial magnetic stimulation (TMS) that a medial paralimbic circuitry is critical for self‐reference. This circuitry includes anterior cingulate/medial prefrontal and posterior cingulate/medial parietal cortices, connected directly and via thalamus. We here hypothesized that interaction in the circuitry may bind conscious experiences with widely different degrees of self‐reference through synchrony of high frequency oscillations as a common neural event. This hypothesis was confirmed with magneto‐encephalography (MEG). The observed coupling between the neural events in conscious experience may explain the sense of unity of consciousness and the severe symptoms associated with paralimbic dysfunction. Hum Brain Mapp, 2010. © 2009 Wiley‐Liss, Inc.
Test–retest reproducibility of the default‐mode network in healthy individuals
Authors: Meindl Thomas , Teipel Stefan , Elmouden Rachid , Mueller Sophia , Koch Walter , Dietrich Olaf , Coates Ute , Reiser Maximilian , Glaser Christian
Published: July 2009

Independent component analysis (ICA) of functional magnetic resonance imaging (fMRI) time‐series reveals distinct coactivation patterns in the resting brain representing spatially coherent spontaneous fluctuations of the fMRI signal. Among these patterns, the so‐called default‐mode network (DMN) has been attributed to the ongoing mental activity of the brain during wakeful resting state. Studies suggest that many neuropsychiatric diseases disconnect brain areas belonging to the DMN. The potential use of the DMN as functional imaging marker for individuals at risk for these diseases, however, requires that the components of the DMN are reproducible over time in healthy individuals. In this study, we assessed the reproducibility of the DMN components within and between imaging sessions in 18 healthy young subjects (mean age, 27.5 years) who were scanned three times with two resting state scans during each session at 3.0T field strength. Statistical analysis of fMRI time‐series was done using ICA implemented with BrainVoyager QX. At all three sessions the essential components of the DMN could be identified in each individual. Spatial extent of DMN activity and size of overlap within and between sessions were most reproducible for the anterior and posterior cingulate gyrus. The degree of reproducibility of the DMN agrees with the degree of reproducibility found with motor paradigms. We conclude that DMN coactivation patterns are reproducible in healthy young subjects. Therefore, these data can serve as basis to further explore the effects of aging and neuropsychiatric diseases on the DMN of the brain. Hum Brain Mapp, 2010. © 2009 Wiley‐Liss, Inc.
The strength of the Fas ligand signal determines whether hepatocytes act as type 1 or type 2 cells in murine livers #
Authors: Schüngel Sven , Buitrago-Molina Laura Elisa , Nalapareddy Padmavathi devi , Lebofsky Margitta , Manns Michael P. , Jaeschke Hartmut , Gross Atan , Vogel Arndt
Published: July 2009

The BH3-interacting domain death agonist Bid has been shown to be critical for Fas-induced hepatocellular apoptosis. Furthermore, some studies have suggested that phosphorylation of Bid may determine its apoptotic function and may act as a switch to nonapoptotic functions. The aim of this study was to evaluate the role of Bid and phosphorylated Bid for Fas ligand (FasL)-induced apoptosis in murine livers. The monoclonal antibody Jo2 and a hexameric form of sFasL (MegaFasL) were used to induce apoptosis in wild-type, Bid-deficient (Bid
−/−), Bid transgenic mice expressing a nonphosphorable form of Bid and Fas receptor-deficient lpr mice. Apoptosis sensitivity was determined in healthy mice and in mice following bile duct ligation, partial hepatectomy, or suramin pretreatment. As previously reported, loss of Bid protects mice against Jo2-induced liver failure. Remarkably however, Bid
−/− mice are highly sensitive to MegaFasL-induced apoptosis. MegaFasL-treated Bid
−/− mice showed a typical type I cell signaling behavior with activation of caspase-3 without Bax translocation to the mitochondria and no cytochrome C/Smac release into the cytosol. In contrast to previous in vitro findings, phosphorylation of Bid does not affect the sensitivity of hepatocytes to Fas receptor-mediated apoptosis in vivo. Conclusion: Our data suggest that Bid mainly amplifies a weak death receptor signal in quiescent and nonquiescent hepatocytes rendering the liver more sensitive to FasL-induced apoptosis. Thus, depending on the efficacy of Fas receptor activation, hepatocytes and nonparenchymal cells can either behave as type I or type II cells. (Hepatology 2009.)
Radiofrequency ablation of hepatocellular carcinoma: Long-term results and prognostic factors in 235 Western patients with cirrhosis #
Authors: N'Kontchou Gisèle , Mahamoudi Amel , Aout Mounir , Ganne-Carrié Nathalie , Grando Véronique , Coderc Emmanuelle , Vicaut Eric , Trinchet Jean Claude , Sellier Nicolas , Beaugrand Michel , Seror Olivier
Published: July 2009

For the treatment of small hepatocellular carcinoma (HCC), radiofrequency ablation (RFA) is in some centers considered a first-line therapeutic option. However, such a strategy is still under debate with regard to tumor and patient characteristics. In this single-center study we assessed the 5-year survival and prognosis factors in 235 consecutive patients with cirrhosis (Child-Pugh A/B: 205/30) who received RFA as first-line treatment for up to three HCC ≤5 cm (307 tumors; mean diameter: 29 ± 10 mm; 53 multinodular forms). Among these patients, 67 satisfied the criteria for resection according to the Barcelona Clinic Liver Cancer. Complete ablation was obtained in 222 patients (94%). Overall, 337 RFA sessions were performed including iterative RFA for recurrence. Major complications occurred in three patients (0.9%), including one treatment-related death. After 27 ± 20 months of mean follow-up, local or distant, or both, tumor recurrence occurred in 16, 88, and 11 patients, respectively. Twenty-nine patients underwent transplantation and were removed from the study at this point. Overall 5-year, recurrence-free, and tumor-free (including results of iterative RFA) survival rates were, respectively, 40%, 17%, and 32%. The overall 5-year survival rate was 76% for operable patients. Factors associated with overall survival were prothrombin activity (hazard ratio [HR] = 0.97, 0.96–0.98; P < 0.0001) and serum levels of α-fetoprotein (AFP) (HR = 1.02, 1.02–1.02; P < 0.0001), and factors associated with tumor recurrence were multinodular forms (HR = 2.34; 1.52–3.6; P = 0.0001) and serum AFP levels (HR = 1.015, 1.014–1.016; P = 0.015). Tumor size was associated with local recurrence but not with overall and tumor-free survival. Conclusion: RFA is a safe and effective first-line treatment of HCC up to 5 cm in diameter, especially for patients with a single tumor, a low serum AFP level, and well-preserved liver function. (Hepatology 2009.)
The niche of stellate cells within rat liver #
Authors: Sawitza Iris , Kordes Claus , Reister Sven , Häussinger Dieter
Published: July 2009

It is well-accepted that hepatic stellate cells (HSCs) can develop into myofibroblast-like cells that synthesize extracellular matrix proteins and contribute to liver fibrosis. Recently, molecular markers of stem/progenitor cells were discovered in HSCs of rats. Moreover, the cells displayed the capacity to differentiate and to participate in liver regeneration. In addition, stellate cells possess signaling pathways important for maintenance of stemness and cell differentiation such as hedgehog and β-catenin–dependent Wnt signaling. All these properties are congruently found in stem/progenitor cells. Stem cells require a special microenvironment, the so-called stem cell niche, to maintain their characteristics. Thus, we investigated if the space of Disse, where stellate cells reside in the liver innervated by the sympathetic nervous system and surrounded by sinusoidal endothelial cells and parenchymal cells, exhibits similarities with known stem cell niches. The present study describes the niche of stellate cells within the liver of rats that is composed of sinusoidal endothelial cells, which release stromal cell–derived factor-1 to attract stellate cells via the cysteine-X-cysteine receptor 4, basal lamina proteins (laminin and collagen type IV), and parenchymal cells, which synthesize β-catenin–dependent Wnt ligands and Jagged1. Conclusion: The space of Disse shows analogies to typical stem cell niches comprising of basal lamina components, sympathetic innervation, and adjacent cells that constitute a milieu by paracrine factors and direct physical interactions to retain HSCs at this site and to influence their cellular fate. The space of Disse serves as a niche of stellate cells, which is a novel function of this unique organ structure. (Hepatology 2009.)
Inhibition of phosphatidylinositol 3-kinase signaling in hepatic stellate cells blocks the progression of hepatic fibrosis #
Authors: Son Gakuhei , Hines Ian N. , Lindquist Jeff , Schrum Laura W. , Rippe Richard A.
Published: July 2009

The hepatic stellate cell (HSC) is the primary cell type in the liver responsible for excess collagen deposition during fibrosis. Following a fibrogenic stimulus the cell changes from a quiescent vitamin A–storing cell to an activated cell type associated with increased extracellular matrix synthesis and increased cell proliferation. The phosphatidylinositol 3-kinase (PI3K) signaling pathway has been shown to regulate several aspects of HSC activation in vitro, including collagen synthesis and cell proliferation. Using a targeted approach to inhibit PI3K signaling specifically in HSCs, we investigated the role of PI3K in HSCs using a rodent model of hepatic fibrosis. An adenovirus expressing a dominant negative form of PI3K under control of the smooth muscle α-actin (αSMA) promoter was generated (Ad-SMAdnPI3K). Transducing HSCs with Ad-SMAdnPI3K resulted in decreased proliferation, migration, collagen expression, and several additional profibrogenic genes, while also promoting cell death. Inhibition of PI3K signaling was also associated with reduced activation of Akt, p70 S6 kinase, and extracellular regulated kinase signaling as well as reduced cyclin D1 expression. Administering Ad-SMAdnPI3K to mice following bile duct ligation resulted in reduced HSC activation and decreased extracellular matrix deposition, including collagen expression. A reduction in profibrogenic mediators, including transforming growth factor beta, tissue inhibitor of metalloproteinase 1, and connective tissue growth factor was also noted. However, liver damage, assessed by alanine aminotransferase levels, was not reduced. Conclusion: Inhibition of PI3K signaling in HSCs during active fibrogenesis inhibits extracellular matrix deposition, including synthesis of type I collagen, and reduces expression of profibrogenic factors. These data suggest that targeting PI3K signaling in HSCs may represent an effective therapeutic target for hepatic fibrosis. (Hepatology 2009.)
Vitamin D mediates its action in human colon carcinoma cells in a calcium‐sensing receptor‐dependent manner: downregulates malignant cell behavior and the expression of thymidylate synthase and survivin and promotes cellular sensitivity to 5‐FU
Authors: Liu Guangming , Hu Xin , Chakrabarty Subhas
Published: July 2009

Vitamin D (VD) protects against colon carcinogenesis by mechanisms not fully understood. We had earlier reported on the similarity in the biologic action of VD and that of the calcium‐sensing receptor (CaSR) in human colon carcinoma cells. At the molecular level, the CaSR gene contains 2 VD response elements and VD stimulates the expression of CaSR. In this study, we investigated on the relationship between VD action and CaSR function. We determined and compared the action of VD in human colon carcinoma cells (CBS, Moser, Caco‐2 and HCT116) and their CaSR knocked‐down counterparts. VD inhibited cellular proliferation, cellular invasion, and anchorage‐independent growth and stimulated the expression of p21/Waf1 but not in CaSR knocked‐down cells. These results demonstrate, for the first time, that the known tumor‐suppressive function of VD requires functional CaSR and knocking down CaSR expression abrogated this function of VD. We recently reported that activation of CaSR in human colon carcinoma cells downregulated the expression of thymidylate synthase (TS) and survivin and promoted a significant increase in sensitivity to cytotoxic drugs. We now demonstrate, for the first time, that VD suppressed the expression of TS and survivin, TS and survivin gene transcriptional activities and promoted a cytotoxic response to 5‐FU in a CaSR‐dependent manner. Ectopic expression of wild‐type CaSR in colon carcinoma cells also inhibited the expression of TS and survivin and enhanced cellular sensitivity to 5‐FU. VD, however, could no longer enhance cellular sensitivity to 5‐FU in cells overexpressing CaSR.
Tip‐enhanced Raman scattering studies of histidine on novel silver substrates
Authors: Deckert‐Gaudig Tanja , Deckert Volker
Published: July 2009

Tip‐enhanced Raman scattering (TERS) experiments of histidine immobilized on an atomically flat silver surface are presented. The substrate consists of silver nanoplates with a diameter of a few micrometers and a height about 20 nm. At such heights, the plates are still transparent to visible wavelengths, which is important for optimal illumination and detection. The Raman spectroscopic results strongly support a homogeneous adsorption of chemically different states of histidine on the silver surface. In addition, the influence of the silver surface and the TERS tip on the spectra of histidine is discussed with respect to the multiple coordination centers in the molecule. Copyright © 2009 John Wiley & Sons, Ltd.
Determination of purine alkaloids and catechins in different parts of Camellia assamica var. kucha by HPLC‐DAD/ESI‐MS/MS
Authors: Lu Jia‐Li , Wang Dong‐Mei , Shi Xiang‐Gang , Yang De‐Po , Zheng Xin‐Qiang , Ye Chuang‐Xing
Published: July 2009

BACKGROUND: Kucha (Camellia assamica var. kucha) is a novel wild tea resource grown in China and a tea plant containing a sizable amount of theacrine (1,3,7,9‐tetramethyluric acid). High‐performance liquid chromatography (HPLC) analysis of purine alkaloids and catechins in young leaves of Kucha has been reported previously. However, the compositions of purine alkaloids and catechins in other parts of the plant remain unknown, and more information about the chemical constituents of Kucha is also necessary for further research and development of this new tea resource.

RESULTS: Using HPLC with diode array detection coupled with electrospray ionisation tandem mass spectrometry (HPLC‐DAD/ESI‐MS/MS), three purine alkaloids, seven catechins and four non‐catechin phenolic compounds were identified or tentatively identified in Kucha. Purine alkaloids and catechins in leaves at different developmental stages, flowers, stems, pericarps and seeds of the plant were also quantified for the first time by the HPLC method, which was fully validated. Recoveries of the quantified compounds ranged from 96.67 to 104.33%.

CONCLUSION: The results showed that the total contents of purine alkaloids and catechins were highest in young leaves of Kucha. Theacrine was detected in all parts of the plant and found to be most abundant in pericarps. Copyright © 2009 Society of Chemical Industry
Post‐treatment of Ganoderma lucidum reduced liver fibrosis induced by thioacetamide in mice
Authors: Wu Yueh‐Wern , Fang Hsun‐Lang , Lin Wen‐Chuan
Published: July 2009

The present study was aimed at assessing the effects of Ganoderma lucidum extract (GLE) on an established liver fibrosis model with reference to the previously reported hepatoprotective effect of GLE against CCl4‐induced fibrosis in rats. Repeated administration of thioacetamide (TAA) for 12 weeks to mice induced liver fibrosis. Treatment with GLE after the induction of liver fibrosis decreased the hepatic hydroxyproline content and improved liver histology. RT‐qPCR analysis showed that GLE treatment reduced the mRNA expression of collagen (α1)(I), smooth muscle α‐actin, tissue inhibitor of metalloproteinase 1 and metalloproteinase‐13. In addition, the TAA‐induced decrease in total collagenase activity was reversed by GLE treatment. In conclusion, oral administration of GLE reversed TAA‐induced liver fibrosis, the mechanism of which might be related to the enhancement of collagenase activity. Copyright © 2009 John Wiley & Sons, Ltd.
Experience with an extensible workspace for analysis of low‐level usage data
Authors: Thomas Richard C. , Karahasanović Amela
Published: July 2009

Analysis of low‐level usage data collected in empirical studies of user interaction is well known as a demanding task. Existing techniques for data collection and analysis are either application specific or data‐driven. This paper presents a workspace for data cleaning, transformation and analysis of low‐level usage data that we have developed and reports our experience with it. By its five‐level architecture, the workspace makes a distinction between more general data that typically can be used in initial data analysis and the data answering a specific research question. The workspace was used in four studies and in total 6.5M user actions were collected from 238 participants. The collected data have been proven to be useful for: (i) validating solution times, (ii) validating process conformances, (iii) exploratory studies on program comprehension for understanding use of classes and documents and (iv) testing hypotheses on keystroke latencies. We have found workspace creation to be demanding in time. Particularly demanding were determining the context of actions and dealing with deficiencies. However, once these processes were understood, it was easy to reuse the workspace for different experiments and to extend it to answer new research questions. Based on our experience, we give a set of guidelines that might help in setting up studies, collecting and preparing data. We recommend that designers of data collection instruments add context to each action. Furthermore, we recommend rapid iterations starting early in the process of data preparation and analysis, and covering both general and specific data. Copyright © 2009 John Wiley & Sons, Ltd.
Regulatory roles of transforming growth factor beta family members in folliculogenesis
Authors: Myers Michelle , Pangas Stephanie A.
Published: July 2009

Bidirectional signaling between the oocyte and surrounding somatic cells is absolutely essential for successful germ cell development in mammals. Oocytes secrete proteins that are necessary for granulosa cells growth and differentiation, whilst granulosa cells regulate oocyte development and integrate ovarian function with the rest of the body by orchestrating gonadal steroidogenesis. The importance of communication between the oocyte and granulosa cells is highlighted by genetic deletion of members of the transforming growth factor beta (TGFβ) family and their downstream signaling components. Such knockout models have uncovered an interesting spectrum of reproductive phenotypes that have greatly advanced our knowledge of ovarian function and dysfunction. The current review focuses on some of the more recent transgenic mouse models that elucidate the intraovarian TGFβ signaling vital for oocyte and granulosa cell development. Copyright © 2009 John Wiley & Sons, Inc.

This article is categorized under:

Developmental Biology > Lineages
Volar Marginal Articular Fractures with Loss of Articular Apposition
Authors: Souer J. Sebastiaan , Davis James S. , Marent Marta , Ring David
Published: July 2009

Five patients with a volar marginal articular fracture with dislocation (complete loss of apposition of the articular surfaces) were treated with open reduction and internal plate fixation. This is an unusual type of volar shearing fracture and represents the volar type of radiocarpal fracture–dislocation. The results of treatment were comparable to other volar shearing type fractures.
Activation of translation via reduction by thioredoxin–thioredoxin reductase in Saccharomyces cerevisiae
Authors: Jun Kyung Ok , Song Chin-Hee , Kim Young-Bum , An Jinseok , Oh Jae Hyeun , Choi Sang Ki
Published: July 2009

Previously we reported that in vitro translation activity in extracts of Saccharomyces cerevisiae was stimulated by dithiothreitol (DTT) and further increased by the addition of thioredoxin (TRX1) [Choi, S.K. (2007) Thioredoxin‐mediated regulation of protein synthesis by redox in Saccharomyces cerevisiae. Kor. J. Microbiol. Biotechnol. 35, 36–40]. To identify the pathway affecting translation, we cloned and purified thioredoxin reductase 1 (TRR1), thioredoxin reductase 2 (TRR2), glutaredoxin 1 (GRX1) and glutaredoxin reductase 1 (GLR1) as fusion proteins. Thioredoxin‐mediated activation of translation was more effectively stimulated by NADPH or NADH than by DTT. Moreover, addition of TRR1 led to a further increase of translation in the presence of thioredoxin plus NADPH. These findings indicate that redox control via the thioredoxin–thioredoxin reductase system plays an important role in the regulation of translation.
Near‐Earth initiation of a terrestrial substorm
Authors: Rae I. Jonathan , Mann Ian R. , Angelopoulos Vassilis , Murphy Kyle R. , Milling David K. , Kale Andy , Frey Harald U. , Rostoker Gordon , Russell Christopher T. , Watt Clare E. J. , Engebretson Mark J. , Moldwin Mark B. , Mende Stephen B. , Singer Howard J. , Donovan Eric F.
Published: July 2009

Despite the characterization of the auroral substorm more than 40 years ago, controversy still surrounds the processes triggering substorm onset initiation. That stretching of the Earth's magnetotail following the addition of new nightside magnetic flux from dayside reconnection powers the substorm is well understood; the trigger for explosive energy release at substorm expansion phase onset is not. Using ground‐based data sets with unprecedented combined spatial and temporal coverage, we report the discovery of new localized and contemporaneous magnetic wave and small azimuthal scale auroral signature of substorm onset. These local auroral arc undulations and magnetic field signatures rapidly evolve on second time scales for several minutes in advance of the release of the auroral surge. We also present evidence from a conjugate geosynchronous satellite of the concurrent magnetic onset in space as the onset of magnetic pulsations in the ionosphere, to within technique error. Throughout this time period, the more poleward arcs that correspond to the auroral oval which maps to the central plasma sheet remain undisturbed. There is good evidence that flows from the midtail crossing the plasma sheet can generate north‐south auroral structures, yet no such auroral forms are seen in this event. Our observations present a severe challenge to the standard hypothesis that magnetic reconnection in stretched magnetotail fields triggers onset, indicating substorm expansion phase initiation occurs on field lines that are close to the Earth, as bounded by observations at geosynchronous orbit and in the conjugate ionosphere.
Heating and cooling of the thermosphere by internal gravity waves
Authors: Yiğit Erdal , Medvedev Alexander S.
Published: July 2009

For the first time, estimates of heating and cooling in the upper thermosphere due to dissipating and breaking gravity waves (GWs) of tropospheric origin have been obtained with a comprehensive general circulation model (GCM). A GW parameterization specifically designed for thermospheric heights has been implemented in the CMAT2 GCM covering altitudes from the tropopause to the F2 region, and simulations for the June solstice have been performed. They reveal that the net thermal effect of GWs above the turbopause is cooling. The largest (up to −170 K d−1 in a zonally and temporally averaged sense) cooling takes place in the high latitudes of both hemispheres near 210 km. The instantaneous values of heating and cooling rates are highly variable, and reach up to 500 and −3000 K d−1 in the F2 region, respectively. Inclusion of the GW thermal effects reduces the simulated model temperatures by up to 200 K over the summer pole and by 100 to 170 K at other latitudes near 210 km.
The Political Ecology of a Ramsar Site Conservation Failure: The Case of Burdur Lake, Turkey
Authors: Adaman Fikret , Hakyemez Serra , Özkaynak Begüm
Published: July 2009

The Burdur Lake basin in Turkey's Mediterranean region has been facing severe environmental damage in the form of increased pollution and a decrease in water volume, despite its Ramsar status as a major wintering site for the endangered white-headed duck ( Oxyura leucocephala). In fact, after the basin was granted Ramsar status it was made the subject of a ‘hard-park’ conservation policy. This in practice disenfranchised and alienated local people but did not lead to the effective preservation of the basin. We aim to shed light on the political ecology of the ongoing degradation, which has layers at local, national, and international levels, by using both quantitative and qualitative methods (consisting of in-depth interviews, focus groups, and face-to-face, randomly selected interviews with 625 people). We specifically explore the possible reasons why local people by and large did not—despite their high level of environmental concern about the site—demand conservation policies or voluntarily take action to preserve their site. Acknowledging that the sources of the problem are multilayered in nature, thus requiring a multilevel solution, we then propose a governance modality tailored for the case at hand. Since many of the problems that Burdur Lake faces are not unique, it is hoped that the conducted analysis will be relevant to other similar sites.
A Novel Robot-Assisted Technique for Excision of a Posterior Mediastinal Thyroid Goiter
Authors: Podgaetz Eitan , Gharagozloo Farid , Najam Farzad , Sadeghi Nader , Margolis Marc , Tempesta Barbara J.
Published: July 2009

Objective

Intrathoracic thyroid goiter is an uncommon condition. Most goiters are found in the superior and anterior mediastinum, which can be removed either through a cervical approach or through a combined cervicotomy and sternotomy approach. Extension of the goiter into the posterior mediastinum is even less common. Transcervival approach to thyroid goiters in the posterior mediastinum can be difficult, necessitating a thoracotomy, with its associated morbidity.

Methods

A 69-year-old patient underwent robotic assisted minimally invasive procedure, with the daVinci surgical robotic system to excise a thyroid goiter that extended into the posterior mediastinum. The blood supply of the mediastinal portion of the goiter originated from the right internal thoracic artery. The thoracic and mediastinal portion of the goiter was approached with robot-assisted minimally invasive surgical techniques. Small incisions were used to gain access to the posterior mediastinum via the right pleural cavity, obviating the need for thoracotomy. Using precise movements of the robotic arm, the mediastinal part of the goiter was dissected off vital structures, from within the posterior mediastinum. Total thyroidectomy was then completed using the cervical approach.

Results

The patient tolerated the procedure well, with minimal intraoperative blood loss. The patient was discharged home after a short hospital stay.

Conclusions

Robotic surgical techniques for removal of a substernal goiter and other thyroid masses with mediastinal extension, in combination with cervical incision, are effective. Robotic-assisted techniques can complement video-assisted thoracic surgical techniques and broaden the indications for minimally invasive surgery.