bluuebunny/crossref_metadata_2025 huggingface dataset:
Telocytes in human skin – are they involved in skin regeneration?
Authors: Ceafalan Laura , Gherghiceanu Mihaela , Popescu L. M. , Simionescu Olga
Published: April 2012

Telocytes (TCs), a particular interstitial cell type, have been recently described in a wide variety of mammalian organs (www.telocytes.com). The TCs are identified morphologically by a small cell body and extremely long (tens to hundreds of μm), thin prolongations (less than 100 nm in diameter, below the resolving power of light microscopy) called telopodes. Here, we demonstrated with electron microscopy and immunofluorescence that TCs were present in human dermis. In particular, TCs were found in the reticular dermis, around blood vessels, in the perifollicular sheath, outside the glassy membrane and surrounding sebaceous glands, arrector pili muscles and both the secretory and excretory portions of eccrine sweat glands. Immunofluorescence screening and laser scanning confocal microscopy showed two subpopulations of dermal TCs; one expressed c‐kit/CD117 and the other was positive for CD34. Both subpopulations were also positive for vimentin. The TCs were connected to each other by homocellular junctions, and they formed an interstitial 3D network. We also found TCs adjoined to stem cells in the bulge region of hair follicles. Moreover, TCs established atypical heterocellular junctions with stem cells (clusters of undifferentiated cells). Given the frequency of allergic skin pathologies, we would like to emphasize the finding that close, planar junctions were frequently observed between TCs and mast cells. In conclusion, based on TC distribution and intercellular connections, our results suggested that TCs might be involved in skin homeostasis, skin remodelling, skin regeneration and skin repair.
Refining definitions of periodontal disease and caries for prediction models of incident tooth loss
Authors: Houshmand Mohammad , Holtfreter Birte , Berg Marie Henrike , Schwahn Christian , Meisel Peter , Biffar Reiner , Kindler Stefan , Kocher Thomas
Published: April 2012

Aim

To assess the suitability of different definitions of caries and periodontitis for inclusion in tooth loss prediction models.

Materials and Methods

The Study of Health in Pomerania (SHIP) is a population‐based cohort study conducted in 1997–2001 (SHIP‐0) and 2002–2006 (SHIP‐1). This sample comprised 2,780 subjects aged 20–81 years with complete information on dental and periodontal status [DMFS status, clinical attachment loss (CAL) and probing depth (PD)]. Analyses on five‐year tooth loss were limited to half‐mouth data.

Results

The predictive value of tested definitions was markedly age‐ and gender‐dependent: in 20–39‐aged men, the number of decayed or filled surfaces best predicted the number of lost teeth, whereas in young women CAL≥4 mm performed best. In older subjects, periodontal definitions were superior to caries definitions: mean CAL performed best in 40–59‐year olds, whereas AL‐ or PD‐related definitions predicted best in 60–81‐year olds. On tooth level, mean CAL was the superior definition to assess 5‐year incident tooth loss in all strata except for young men.

Conclusions

Caries parameters best predicted incident tooth loss in men aged 20–39 years; in the intermediate and oldest age group and in young women, mean AL was most informative. Therefore, prediction models need to be developed for different age and gender groups.
Neutrophil superoxide production in the presence of cigarette smoke extract, nicotine and cotinine
Authors: Matthews John B. , Chen Fa‐Ming , Milward Michael R. , Ling Martin R. , Chapple Iain L. C.
Published: April 2012

Aim

To determine the effect of cigarette smoke extract, nicotine and cotinine on lucigenin‐detectable neutrophil superoxide production.

Materials & Methods

Neutrophils from periodontally healthy individuals were treated with aqueous smoke extract, nicotine and cotinine, prior to stimulation or at the same time as stimulation with Fusobacterium nucleatum, IgG‐opsonized Staphylococcus aureus and Escherichia coli Lipopolysaccharide (LPS). Superoxide generation was determined by lucigenin chemiluminescence.

Results

Smoke extract induced superoxide release from neutrophils (p <0.0001) in a dose‐dependent manner. By contrast, superoxide generation by neutrophils in response to pathologically relevant stimuli was inhibited by pre‐treatment with smoke extract (p <0.01). This inhibition did not require the continued presence of the extract. A similar reduction in stimulated superoxide production by smoke extract was detected when neutrophils were simultaneously exposed to the extract and stimuli. Nicotine and cotinine (0–10 μg/ml) had no effect on superoxide release from unstimulated or stimulated neutrophils.

Conclusions

Stable water‐soluble components of cigarette smoke directly induce superoxide generation by otherwise unstimulated neutrophils, but reduce superoxide responses of cells to pathologically relevant stimuli. These data suggest potential neutrophil‐mediated mechanisms by which smoking may initiate and maintain oxidative stress at periodontally healthy sites and participate in disease progression, by reducing innate immune responses.
Prognostic value of the periodontal risk assessment in patients with aggressive periodontitis
Authors: Meyer‐Bäumer Amelie , Pritsch Maria , Cosgarea Raluca , El Sayed Nihad , Kim Ti‐Sun , Eickholz Peter , Pretzl Bernadette
Published: April 2012

Objectives

Aim of the study was to evaluate the predictive value of the modified periodontal risk assessment (PRA) in patients with aggressive periodontitis (AgP) for the first time.

Material and Methods

A total of 86 Patients with AgP were re‐examined 5–17 years after active periodontal treatment. Risk profile according to the modified PRA was assigned and regularity of maintenance monitored. Tooth loss, bone loss and recurrence of periodontitis were analysed in association with gender, diagnosis, compliance and risk profile using uni‐ and multivariate parametric regression and Cox proportional hazards models.

Results

A total of 14 patients showed a localized AgP, 60 a high‐risk‐profile and 19 were compliant with the proposed maintenance‐interval. Of 2202 teeth 98 were lost. Multivariate analysis could not assign a statistically significant impact to risk‐profile. By excluding Interleukin‐1 composite genotype from the modified PRA a significant influence (p = 0.003, HR 2.74) was detected. The impact of compliance was shown to be nearly significant (p = 0.059, HR 2.0). In patients with generalized AgP a tendency for increased tooth loss was found.

Conclusion

The prognostic value of the modified PRA could not be confirmed in patients with AgP. However, exclusion of Interleukin‐1 composite genotype led to a model with significant influence on tooth loss.
Salinity influences the distribution of marine snakes: implications for evolutionary transitions to marine life
Authors: Brischoux François , Tingley Reid , Shine Richard , Lillywhite Harvey B.
Published: April 2012

Secondary transitions from terrestrial to marine life provide remarkable examples of evolutionary change. Although the maintenance of osmotic balance poses a major challenge to secondarily marine vertebrates, its potential role during evolutionary transitions has not been assessed. In the current study, we investigate the role of oceanic salinity as a proximate physiological challenge for snakes during the phylogenetic transition from the land to the sea. Large‐scale biogeographical analyses using the four extant lineages of marine snakes suggest that salinity constrains their current distribution, especially in groups thought to resemble early transitional forms between the land and the sea. Analyses at the species‐level suggest that a more efficient salt‐secreting gland allows a species to exploit more saline, and hence larger, oceanic areas. Salinity also emerged as the strongest predictor of sea snake richness. Snake species richness was negatively correlated with mean annual salinity, but positively correlated with monthly variation in salinity. We infer that all four independent transitions from terrestrial to marine life in snakes may have occurred in the Indonesian Basin, where salinity is low and seasonally variable. More generally, osmoregulatory challenges may have influenced the evolutionary history and ecological traits of other secondarily marine vertebrates (turtles, birds and mammals) and may affect the impact of climate change on marine vertebrates.
microRNA‐21 is upregulated in malignant melanoma and influences apoptosis of melanocytic cells
Authors: Satzger Imke , Mattern Anika , Kuettler Uta , Weinspach Dirk , Niebuhr Margarete , Kapp Alexander , Gutzmer Ralf
Published: April 2012

Overexpression of microRNA‐21 (miR‐21) has been observed in various cancer types, but little is known about the role of miR‐21 in melanoma. In this study, we demonstrate that levels of miR‐21 are significantly increased in primary melanoma tissues as compared to benign nevi and in human melanoma cell lines as compared to melanocytic cell preparations. We show that downregulation of miR‐21 in melanoma cell lines with high endogenous miR‐21 expression induced apoptosis, whereas proliferation was not significantly altered. Upregulation of miR‐21 in melanocytes resulted in increased proliferation and decreased apoptosis. However, in the MEWO melanoma cells with low endogenous miR‐21 expression, upregulation of miR‐21 had no functional effects. These findings indicate a potential pathogenetic role of miR‐21 upregulation in a subgroup of melanomas.
Drought‐mediated stem and below‐ground bud dynamics in restored grasslands
Authors: Carter Daniel L. , VanderWeide Benjamin L. , Blair John M.
Published: April 2012

Question

Does the below‐ground bud bank mediate response to drought in restored grasslands?

Location

Platte River Valley region of south‐central Nebraska, USA.

Methods

We imposed severe drought for one growing season using rainfall manipulation structures and measured the response of above‐ and below‐ground plant communities (ramet and below‐ground bud densities) with respect to non‐drought controls during the drought year and a recovery year.

Results

Drought reduced below‐ground bud bank density and above‐ground stem density. However, bud bank density recovered, and bud production was higher on previously droughted subplots relative to controls in the year following drought. The response of below‐ground bud and above‐ground stem density to drought differed according to functional identity (C3 grass, C4 grass, and forb), with forbs least resistant to, but having the greatest recovery from, drought.

Conclusions

While overall density in restored grasslands was resilient, drought effects on below‐ground bud banks may have longer‐term impacts on plant community structure. Reduced density above‐ or below‐ground during the growing season following drought may allow for the persistence of species relatively more reliant on recruitment from seed banks in favourable micro‐sites.
Adenosine A2A receptor activation and hyaluronan fragment inhibition reduce inflammation in mouse articular chondrocytes stimulated with interleukin‐1β
Authors: Campo Giuseppe M. , Avenoso Angela , D’Ascola Angela , Scuruchi Michele , Prestipino Vera , Nastasi Giancarlo , Calatroni Alberto , Campo Salvatore
Published: April 2012

Small hyaluronan (HA) fragments produced from native HA during inflammation contribute greatly to cell injury in many pathologies. HA oligosaccharides increase proinflammatory cytokine levels by activating both CD44 and toll‐like receptor (TLR)‐4. Stimulation of CD44 and TLR‐4 then activates nuclear factor‐κB, which induces the production of proinflammatory cytokines. The adenosine 2A receptor (A2AR) is also involved in several inflammation pathologies, and the nucleoside adenosine acts as a potent endogenous inhibitor of inflammation in various tissues by interacting with this receptor. The aim of this study was to investigate the effects of an HA‐blocking peptide that inhibits the proinflammatory action of HA oligosaccharides produced during inflammation, together with a specific A2AR agonist in a model of normal mouse articular chondrocytes stimulated with interleukin (IL)‐1β. IL‐1β stimulation significantly increased mRNA expression and the related protein production of TLR‐4, TLR‐2, CD44 and A2AR in articular chondrocytes. The induced nuclear factor‐κB activation was also associated with increased levels of inflammatory cytokines, including tumor necrosis factor‐α and IL‐6, and other inflammatory mediators, such as matrix metalloprotease‐13 and inducible nitric oxide synthase. Treatment of chondrocytes with the HA‐blocking peptide Pep‐1 and/or a specific A2AR agonist (CGS‐21680) significantly reduced all of the inflammatory parameters upregulated by IL‐1β. These results suggest that the inflammatory response may be reduced either by blocking oligosaccharides from HA degradation or by A2AR stimulation.
Do Ranger Stations Deter Poaching Activity in National Parks in Thailand?
Authors: Jenks Kate E. , Howard JoGayle , Leimgruber Peter
Published: April 2012

As protected areas become more accessible via transportation networks, fragmentation, and encroachment from the borders, carnivores in these areas frequently decline. To counter these pressures, patrolling and active wildlife enforcement are widely accepted as fundamental conservation strategies. Using the case example of Khao Yai National Park (KYNP) and data from a camera trap survey, we modeled and evaluated the effectiveness of ranger stations in reducing human access and illegal activities, and in increasing prey and predator presence. This type of data and analysis is needed to monitor and evaluate enforcement effectiveness and develop adaptive management strategies. At KYNP, we used camera‐trapping data as a proxy to evaluate whether or not a positive impact of ranger stations on wildlife distribution could outweigh edge effects from human disturbance. We assessed factors affecting the distribution of poachers and wildlife using Maxent. Our analysis was based on 217 camera trap locations (6260 trap nights) and suggests that ungulates and poachers persist nearby ranger stations. Rangers should increase patrolling efforts of border areas; however, increasing wildlife patrolling in inaccessible areas with mobile range units may be more effective than establishing more ranger stations along park boundaries.
Ruft Blausäure eine Adrenalinausschüttung hervor?1
Authors: Møller Knud O. , Reykjavik Kristin Stefansson
Published: April 2012

Subkutane Injektion, von 1–2 mg/kg Natriumzyanid ruft im Laufe von wenigen Minuten bei Kaninchen eine ausgesprochene, etwa 2 bis 3 Stunden dauernde Hyperglykämie hervor; bei epinephrektomierten Tieren bewirkt Natriumzyanid keine Veränderung der Blutzuckerkonzentration.
Über die Hemmung der Blutgerinnung durch basische Körper und deren Beziehung zu organischen gerinnungshemmenden Säuren1
Authors: Herrmann Heinz
Published: April 2012

1. Es wird gezeigt, daß auch basische Substanzen gerinnungshemmend wirken können. Von den untersuchten Basen erwies sich Janusgrün am wirksamsten. Dieser Farbstoff gleicht in seiner Wirkung dem Heparinpräparat von Kahlbaum.

2. Saure und basische gerinnungshemmende Körper verhalten sich auch im Gerinnungsversuch antagonistisch.

3. Die gerinnungshemmenden Säuren zeichnen sich durch ein besonders starkes Fällungsvermögen von basischen Farbstoffen aus.
Der Stoffwechsel bakterienfreier Tiere. IV. Die Zusammensetzung der Meerschweinchenmilch1
Authors: Neymark Marit
Published: April 2012

In Meerschweinchenmilch ist der Gehalt an Eiweißstoffen, Fett, Zucker und Mineralbestandteilen bestimmt worden. Bei einem Vergleich zwischen den bei diesen Analysen gefundenen Werten und den von Abderhalden (1899) veröffentlichten Werten findet man in unseren Bestimmungen einen bedeutend höheren Gehalt an Kasein und Albumin. Abderhalden gibt den Totaleiweißgehalt als Summe von Kasein und Albumin an. In den vorliegenden Analysen ist im Mittel ein Globulingehalt von einem halben Prozent erhalten worden. Der Fettgehalt ist etwas niedriger und der Zuckergehalt etwas höher als in Abderhaldens Analysen. Der totale Aschegehalt, sowie der Calciumgehalt ist etwas höher, während der Phosphorgehalt exakt mit Abderhaldens übereinstimmt.

Die Untersuchung wurde mit Unterstützung von der Rockefeller Foundation ausgeführt.
Findet sich bei der Mehrzahl der Individuen ein photochromatisches Intervall für langwelliges “rotes” Licht?1
Authors: Brenning Runar , Cöster Arne
Published: April 2012

Mit Göthlins Liminospektroskop, welches monochromatisches Licht von einwandfreier Reinheit erzeugt, wurden die Licht‐und Farbenschwellen bei 62 Studenten der Medizin teils nach 1 stündiger Dunkeladaptation in vollständiger Dunkelheit, teils nach 5 Minuten langer Adaptation für eine Lichtstärke von 10 Lux bestimmt. Von diesen 62 Reagenten gaben 59 an, daß beim Betrachten von Licht der Wellenlängen 680, 740 bzw. 800 mμ die Empfindung schon an der Lichtschwelle rotfarbig war. Die 3 übrigen Reagenten gaben ein farbloses Intervall für Licht der genannten Wellenlängen an. Von diesen drei hatte einer einen protanomalen, ein anderer einen deuteranomalen Farbensinn; der dritte wies einen leichten Grad von Farbensinnschwäche auf, ohne jedoch ein anomaler Trichromat zu sein.
Zur Methodik der Bestimmung der Blutmenge in den peripheren Blutgefäßen1
Authors: Sjöstrand Torgny
Published: April 2012

Bestimmungen der Gefrierzeit von Mäusen im Gewicht von 5 bis 7 Gramm beim Eintauchen in flüssige Luft zeigen, daß hierbei die verschiedenen Gewebe je nach ihrer Lage zur Körperoberfläche in 1–10 Sekunden fixiert werden. Bis die Gefrierung auch das Herz erreicht, wird die Herzfrequenz nur in geringem Grade verändert und die Tiere weisen Zeichen eines sehr schnellen Todes auf. Durch Fixierung der gefrorenen Kadaver (ohne vorheriges Auftauen) in Formalin bei — 8 bis — 9 Grad und nachfolgende Behandlung in früher angegebener Weise wird es möglich, die roten Blutkörperchen mit Orthotolidin‐Wasserstoffsuperoxyd zu färben und Bestimmungen der Blutmenge auszuführen.

Ein Vergleich zwischen den auf diese Weise getöteten Tieren und solchen, die, wie bei früheren Untersuchungen durch Zerquetschung des Halsmarks getötet worden waren, zeigt im großen ganzen übereinstimmende Blutmengen in Leber, Niere, Nebenniere, Darm und Skelettmuskulatur. Tiere, die vor der Gefrierung mit Pernocton eingeschläfert und laparotomiert worden waren, wiesen eine größere Blutmenge in den peripheren Blutgefäßen von Leber, Niere und Darm auf, wie dies schon frühere Untersuchungen zeigten.
The Etiology‐Filling Pattern‐Pulmonary Artery Pressure Score: A Simple Tool for Risk Stratification of Patients with Systolic Heart Failure
Authors: Vallebona Alessandro , Gigli Guido , Orlandi Sandro , Orlandi Davide , Gigli Lorenzo , Reggiardo Giorgio
Published: April 2012

©2012 Wiley Periodicals, Inc.

Heart failure (HF) is a leading cause of morbidity and mortality. The detection of patients at high risk for death is a major challenge in HF management. The authors compared the prognostic value of 23 clinical Doppler echocardiography and cardiopulmonary exercise indexes in a stable, moderately symptomatic, systolic HF outpatient population receiving optimal medical therapy. The end point was the incidence of overall mortality. Between January 2002 and December 2008, a total of 146 patients with left ventricular (LV) ejection fraction 0.31±0.8 and New York Heart Association functional class II or III were enrolled. The prognostic power of single variables was assessed using chi‐square test for categoric variables and t test for continuous variables. Variables associated with the prespecified end point were included as predictors in a binary logistic regression multivariate model. At multivariate analysis, “restrictive” LV filling pattern (P=.004), ischemic etiology (P=.022), pulmonary artery systolic pressure (PASP) ≥50 mm Hg (P=.027), and peak oxygen uptake (VO2) <15.9 mL/kg/min (P=.046) resulted independent predictors of the outcome. A simple risk score was then obtained using these significant independent variables, excluding peak VO2 because of only borderline significance. Patients with ischemic etiology, restrictive LV filling pattern, and PASP ≥50 mm Hg have a very high risk of death (odds ratio, 33.77; 95% confidence interval, 5.74–198.8; P<.001, compared with patients with no risk factors). In this high‐risk group, evaluation of peak VO2 could be superfluous. A very simple clinical echocardiographic model based on etiology‐LV filling and pulmonary pressure is a powerful tool for risk stratification of systolic HF in ambulatory patients.
Accuracy and reliability of microbubble ultrasound measurements for the non‐invasive assessment of hepatic fibrosis in chronic hepatitis C
Authors: Cobbold Jeremy F. L. , Patel Dhupal , Fitzpatrick Julie A. , Patel Nayna , Crossey Mary M. E. , AbdAlla Mohamed Saad , Goldin Robert D. , Vennart William , Thomas Howard C. , Taylor‐Robinson Simon D.
Published: April 2012

Aim:  Contrast‐enhanced ultrasound can be used to assess liver disease severity non‐invasively by observing intra‐ and extrahepatic hemodynamic changes. Transit times are calculated to include intra‐ and extrahepatic components (hepatic vein transit time, HVTT) or the intrahepatic component (hepatic transit time, HTT), but these have not been compared directly. We aimed to compare diagnostic accuracy of HVTT and HTT in gauging the severity of chronic hepatitis C (CHC) and to assess inter‐ and intra‐observer reliability.

Methods:  Recorded ultrasound scans performed on 75 patients with biopsy‐staged CHC, using the microbubble contrast agent Sonovue were analyzed.

Results:  Diagnostic accuracy of HTT and HVTT for diagnosis of cirrhosis was 0.78 and 0.71 (P = 0.24). Diagnostic accuracy of HTT and HVTT for diagnosis of fibrosis stage >2 was 0.76 and 0.72 (P = 0.23). Negative predictive value for cirrhosis using this cut‐off was high for both techniques (HVTT, 88%; HTT, 92%), suggesting utility for exclusion of cirrhosis. Inter‐observer reliability for HTT and HVTT were 0.92 and 0.94, respectively. Intra‐observer reliability for HTT and HVTT were 0.98 and 0.99.

Conclusion:  In this cohort, reliability exceeded 90% while diagnostic accuracy was in keeping with previous studies of microbubble transit time analysis. Despite higher numerical diagnostic accuracy for HTT, no significant difference was demonstrated between the techniques, suggesting that both methods can be used reliably.
Toll‐like receptor 4 mediates intrauterine growth restriction after systemic Campylobacter rectus infection in mice
Authors: Arce R.M. , Caron K.M. , Barros S.P. , Offenbacher S.
Published: April 2012

Campylobacter rectus is associated with fetal exposure and low birthweight in humans. C. rectus also invades placental tissues and induces fetal intrauterine growth restriction (IUGR) in mice, along with overexpression of Toll‐like receptors (TLR4), suggesting that TLR4 may mediate placental immunity and IUGR in mice. To test this hypothesis we examined the effect of in vitro TLR4 neutralization on trophoblastic proinflammatory activity and studied the IUGR phenotype in a congenic TLR4‐mutant mouse strain after in vivo C. rectus infection. Human trophoblasts were pretreated with TLR4 neutralizing antibodies and infected with C. rectus; proinflammatory cytokine production was assessed by cytokine multiplex assays. Neutralizing TLR4 antibodies significantly impaired the production of proinflammatory cytokines in trophoblastic cells after infection in a dose‐dependent manner. We used a subcutaneous chamber model to provide a C. rectus challenge in BALB/cAnPt (TLR4Lps‐d) and wild‐type (WT) females. Females were mated with WT or TLR4Lps‐d males once/week; pregnant mice were infected at (E)7.5 and sacrificed at (E)16.5 to establish IUGR phenotypes. Maternal C. rectus infection significantly decreased fetal weight/length in infected WT when compared with sham WT controls (P < 0.05, analysis of variance). However, infected TLR4Lps‐d−/− mice did not show statistically significant differences in fetal weight and length when compared with WT controls (P > 0.05). Furthermore, heterozygous TLR4Lps‐d+/− fetuses showed IUGR phenotype rescue. We conclude that TLR4 is an important mediator of trophoblastic proinflammatory responses and TLR4‐deficient fetuses do not develop IUGR phenotypes after C. rectus infection, suggesting that placental cytokine activation is likely to be mediated by TLR4 during low birthweight/preterm birth pathogenesis.
Theoretical and legal issues related to choice blindness for voices
Authors: Sauerland Melanie , Sagana Anna , Otgaar Henry
Published: April 2012

Purpose. To examine whether choice blindness occurs for auditory stimuli, namely voices.

Methods. One hundred participants listened to three pairs of voices and had to decide each time which one they found more sympathetic or sounded more criminal. After they made a choice, participants were presented with the chosen voice again and had to match it to a face. However, during the second trial, participants were actually presented with the voice they had previously not chosen.

Results. Only 19% of the participants detected this change concurrently, an additional 10% detected it retrospectively. This indicates that choice blindness transfers to auditory stimuli. Whether participants had previously evaluated sympathy or criminality of the voices had no effect on choice blindness.

Conclusions. The study shows that choice blindness is a robust phenomenon that can also be elicited when auditory stimuli are employed. Implications for earwitness testimony and expert witnesses in the context of forensic speech analysis are discussed.
Near-Field Radiative Heat Exchange Analysis of a Spacecraft Waste Heat Converter Design
Authors: Carrillo Laurie Y. , Bayazitoglu Yildiz
Published: April 2012

This paper presents a new design to convert spacecraft waste heat to electrical energy. The proposed device utilizes near-field radiative heat transfer incorporated with pyroelectric materials. To generate electricity, the pyroelectric materials are cyclically heated using spacecraft waste heat and cooled by the thermal environment of deep space (∼2.7 K). Near-field plane-to-plane radiative heat exchange within the device is calculated using a modified sphere-to-plane asymptotic approximation. This method is superimposed on multiple spheres to approximate a plane-to-plane environment. Silica and lithium fluoride coatings are considered in this study to maximize the near-field heat exchange. The efficiency of the device is 17% and 32% when compared to the Carnot cycle efficiency and the Curzon-Ahlborn efficiency, respectively. Initial results indicate that the device is promising but requires further development before it is manufactured for operational use. Suggestions for possible future developments to enhance the design are presented.
Irradiation Effect of Gamma Ray on Electrical Characteristics of Perfluorosulfonic Acid Polymer Membrane
Authors: Forozani Ghasem , Shamshiri Pezhman , Sheikh Nasrin
Published: April 2012

Perfluorosulfonic acid polymer membranes, such as Nafion®, Aciplex®, and Flemion®, are attracting great attention as electrolyte membranes for fuel cells because they have high proton conductivity. In this paper, the effect of γ rays on the electrical properties of perfluorosulfonic acid membranes by applying a variable voltage and measuring the current and dimension of the sample have been investigated. In order to understand the irradiation effects on conductivity changes, we have used optical absorption measurement in the wavelength of 190 ∼ 500 nm. The results show that the electrical conductivity has been increased by increasing the absorption dose, and intensity of the absorption bands have increased by increasing the absorption dose. The electrical conductivities of the irradiated membranes at room temperature are enhanced about one order of magnitude higher than the conductivities of an unirradiated membrane. Moreover, an optical absorption measurement shows that the structures of the membranes are modified by γ radiation. Intensity absorption bands associated to fluorocarbon and peroxy radicals and C=O groups increased with increasing the dose. The change in electrical conductivity seems to be related to the high production of peroxy radicals in the irradiated membrane.
Binding of styrene on silicon (111)-7 × 7 surfaces as a model molecular electronics system
Authors: Weiland Conan R. , Yang Liu , Doren Douglas J. , Menning Carl A. , Skliar Dimitri , Willis Brian G. , Chen Jingguang G. , Opila Robert L.
Published: April 2012

Styrene on Si(111)-7 × 7 surfaces was investigated as a model molecular electronics system to study the effects of conjugation to the semiconductor surface. Scanning tunneling microscopy imaging, combined with theoretical images show that styrene molecules bind in a [4 + 2] cycloaddition mode, binding at the terminal C of the vinyl substituent and a C on the phenyl ring. These single molecule results are consistent with those of ensembles of molecules as obtained by high resolution electron energy loss spectroscopy. For styrene on Si(111)-7 × 7, the aromaticity of the phenyl ring is broken and the conjugated π-system does not extend to the silicon surface, potentially hindering conduction between molecule and surface. However, styrene does retain a conjugated π-system after binding, as is evident in the π-π* shakeup transition in the C 1s x-ray photoelectron spectra as well as UV photoemission spectra. This suggests that styrene-type molecules, when bonded to Si surfaces, do not maintain ready conduction between molecule and surface.
Fabrication and characterization of thin film ZnO Schottky contacts based UV photodetectors: A comparative study
Authors: Ali Ghusoon M. , Chakrabarti Parthasarathi
Published: April 2012

The authors report on characterization of Pd/ZnO thin film Schottky contacts based UV photodetector fabricated by two methods. The ZnO film was grown on p-type Si ⟨100⟩ substrate by using vacuum thermal evaporation and sol-gel methods. With applied voltage in the range from −2 to +2 V we estimated the photocurrent, contrast ratio, responsivity, and quantum efficiency of the photodetectors for an incident optical power of 0.1 mW at 365 nm ultraviolet wavelength. The current–voltage characteristics were studied and the parameters such as ideality factor, leakage current, and barrier height of the Schottky contacts were extracted from the measured data. The surface morphology and the structural properties of the thin film were studied by atomic force microscope and scanning electron microscope. The bandgap of ZnO is evaluated from the absorbance spectra of ZnO thin film obtained by using double beam spectrophotometer. For the investigation of the surface chemical bonding, x-ray photoelectron spectroscopy measurements were also performed. The study revealed that sol-gel derived devices exhibit better photoresponse as compared to those using thin film deposited by vacuum deposition technique.
Incompatibility of standard III–V compound semiconductor processing techniques with terbium-doped InGaAs of high terbium concentration
Authors: Ramu Ashok T. , Clinger Laura E. , Dongmo Pernell B. , Imamura Jeffrey T. , Zide Joshua M. O. , Bowers John E.
Published: April 2012

Terbium-doped InGaAs with a high terbium concentration shows promise as a high-efficiency thermoelectric material, with the thermal conductivity dropping to 1.27 W/m K at a TbAs concentration of 1.55% by number of atoms. However, large discrepancies are noted in Hall effect measurements on terbium-doped InGaAs grown by molecular beam epitaxy on InP substrate following standard III–V wet chemical processing techniques, when compared to samples with no processing beyond deposition of indium contacts. These discrepancies preclude systematic exposition of temperature- and composition-dependent thermoelectric figures of merit. The discrepancy is seen to be correlated with the terbium concentration and the thickness of the active material. The steps in the process sequence are examined under controlled conditions. Although the exact cause for the discrepancy has not been found, some of the obvious reasons have been ruled out. It is therefore surmised that (1) chemical reaction with photoresist, (2) ultraviolet irradiation during photolithography, or (3) reaction with photoresist developing solutions and HF are the factors responsible for the changes in Hall voltage. Evidence is presented for the creation of surface states that corrupt Hall effect measurements on the bulk semiconductor.
Generation of a novel phase‐space‐based cylindrical dose kernel for IMRT optimization
Authors: Zhong Hualiang , Chetty Indrin J.
Published: April 2012

Purpose:

Improving dose calculation accuracy is crucial in intensity‐modulated radiation therapy (IMRT). We have developed a method for generating a phase‐space‐based dose kernel for IMRT planning of lung cancer patients.

Methods:

Particle transport in the linear accelerator treatment head of a 21EX, 6 MV photon beam (Varian Medical Systems, Palo Alto, CA) was simulated using the EGSnrc/BEAMnrc code system. The phase space information was recorded under the secondary jaws. Each particle in the phase space file was associated with a beamlet whose index was calculated and saved in the particle's LATCH variable. The DOSXYZnrc code was modified to accumulate the energy deposited by each particle based on its beamlet index. Furthermore, the central axis of each beamlet was calculated from the orientation of all the particles in this beamlet. A cylinder was then defined around the central axis so that only the energy deposited within the cylinder was counted. A look‐up table was established for each cylinder during the tallying process. The efficiency and accuracy of the cylindrical beamlet energy deposition approach was evaluated using a treatment plan developed on a simulated lung phantom.

Results:

Profile and percentage depth doses computed in a water phantom for an open, square field size were within 1.5% of measurements. Dose optimized with the cylindrical dose kernel was found to be within 0.6% of that computed with the nontruncated 3D kernel. The cylindrical truncation reduced optimization time by approximately 80%.

Conclusions:

A method for generating a phase‐space‐based dose kernel, using a truncated cylinder for scoring dose, in beamlet‐based optimization of lung treatment planning was developed and found to be in good agreement with the standard, nontruncated scoring approach. Compared to previous techniques, our method significantly reduces computational time and memory requirements, which may be useful for Monte‐Carlo‐based 4D IMRT or IMAT treatment planning.
Why do people volunteer for community first responder groups?
Authors: Timmons Stephen , Vernon-Evans Alix
Published: April 2012

Background

There is a growing number of community first responder (CFR) groups in the UK who provide emergency care in their local communities.

Objective

To understand why people volunteer for, and continue to be active in CFR groups.

Design

Qualitative study, using focus groups of CFRs. Five focus groups were conducted, with a total of 35 participants.

Results

Ideas of altruism and a sense of community were found to be important to volunteers, though motives were complex and individual. Many volunteers had some sort of prior experience relevant to the CFR role, either as health professionals or first-aiders.

Conclusion

Though volunteers' motives had some commonalities with the limited literature, there were issues that were unique to the CFR context. The flexibility and autonomy of CFR volunteering was particularly attractive to volunteers. It remains to be seen how sustainable the CFR model is.
Repeat vaccinations
Authors: Williams David
Published: April 2012

An owner presents her one‐year‐old dog for its repeat vaccinations. She is a lecturer in immunology at the local university and asks you why her dog needs to be vaccinated again. The whole idea of an immune response is that it has a long‐lasting memory, she says. As an example, she points out that children do not need to be vaccinated yearly against measles, mumps or rubella. She suggests that yearly vaccinations are only recommended to provide veterinary surgeons with a regular income stream and that she considers this to be unethical. How should you respond?
Clinical audit: application in small animal practice
Authors: Dunn Frances , Dunn James
Published: April 2012

In an article in the March issue of In Practice, James Dunn outlined a stepwise process for conducting clinical audits in first‐opinion small animal practice. In this article, he and Frances Dunn describe how this process might be applied to a specific aspect of small animal practice, using the prescription of fluoroquinolones as an example.
Medical support for cattle and small ruminant surgical patients
Authors: Hallowell Gayle , Potter Timothy , Aldridge Brian
Published: April 2012

While the initial assessment of cattle and small ruminants presented for surgery is similar to that in other species, it can be more challenging because farm animals are often sicker than they appear to be. This article outlines how to identify and manage potential medical problems in large animal surgical patients, including practical fluid therapy, analgesia, sedation, anaesthesia and rational antimicrobial use.
Influence of genetics and inbreeding on disease
Authors: Woolliams John
Published: April 2012

Genetic influences on disease are far more common in epidemiology than those expressed through the phenomenon of inbreeding. However, it is useful to explore the associations between inbreeding and the occurrence of disease before considering the wider role of genetics, as the influence of inbreeding is most overtly seen in simple Mendelian diseases. In such cases, a single locus is responsible for disease manifestation, while in more complex diseases, genetic influences are commonly associated with a number of loci. While this article examines the role of genetics in cattle diseases, with a particular emphasis on inbreeding, all the principles discussed can be extended directly to other livestock, horses and companion animals.
Anti-VEGF/VEGFR Therapy for Cancer: Reassessing the Target
Authors: Sitohy Basel , Nagy Janice A. , Dvorak Harold F.
Published: April 2012

Judah Folkman recognized that new blood vessel formation is important for tumor growth and proposed antiangiogenesis as a novel approach to cancer therapy. Discovery of vascular permeability factor VEGF-A as the primary tumor angiogenesis factor prompted the development of a number of drugs that targeted it or its receptors. These agents have often been successful in halting tumor angiogenesis and in regressing rapidly growing mouse tumors. However, results in human cancer have been less impressive. A number of reasons have been offered for the lack of greater success, and, here, we call attention to the heterogeneity of the tumor vasculature as an important issue. Human and mouse tumors are supplied by at least 6 well-defined blood vessel types that arise by both angiogenesis and arterio-venogenesis. All 6 types can be generated in mouse tissues by an adenoviral vector expressing VEGF-A164. Once formed, 4 of the 6 types lose their VEGF-A dependency, and so their responsiveness to anti-VEGF/VEGF receptor therapy. If therapies directed against the vasculature are to have a greater impact on human cancer, targets other than VEGF and its receptors will need to be identified on these resistant tumor vessels. Cancer Res; 72(8); 1909–14. ©2012 AACR.
Nodal Expression and Detection in Cancer: Experience and Challenges
Authors: Strizzi Luigi , Hardy Katharine M. , Kirschmann Dawn A. , Ahrlund-Richter Lars , Hendrix Mary J.C.
Published: April 2012

Nodal is a TGF-β–related embryonic morphogen that is expressed in multiple human cancers. Detection of Nodal expression in these tissues can be challenging if issues related to Nodal transcription and protein processing are not considered. Here, we discuss certain characteristics related to Nodal expression and function and how these can facilitate acquisition and interpretation of expression data, contributing to our understanding of the potential role of Nodal in human cancer. We also discuss how Nodal could be exploited clinically as a novel biomarker for cancer progression and therapeutic target. Cancer Res; 72(8); 1915–20. ©2012 AACR.
Irrigation in the Medieval Islamic Fayyum: Local Control in a Large-Scale Hydraulic System
Authors: Rapoport Yossef , Shahar Ido
Published: April 2012

Abstract

Because of the unique set of sources available, the Fayyum in Middle Egypt offers a unique case study of large-scale irrigation from antiquity to the Islamic period. A close reading of a cadastral survey of the province from 641/1243-4 shows that the distinctive aspect of the Islamic period was the local control of water supply and management. Drawing on the engineering experience of the villagers, water allocation and management in the gravity-fed canals of the Fayyum were in the hands ofiqṭāʿholders and tribal groups along the main canals, a pattern similar to that which pertained in mediaeval al-Andalus.
Prostitution, Islamic Law and Ottoman Societies
Authors: Baldwin James E.
Published: April 2012

Abstract

This article examines the treatment of prostitution in several genres of Ottoman legal writing—manuals and commentaries of Islamic jurisprudence,fatwās(legal opinions) andḳānūnnāmes(Sultanic legislation)—and looks at how prostitution was dealt with in practice by the empire’s sharīʿa courts and by its provincial executive authorities. The article uses prostitution as a case study to investigate the relationships between the different genres of legal writing and between normative law and legal practice. It also throws light on various manifestations of prostitution in the Ottoman provinces of Egypt and Syria between the mid-sixteenth and mid-eighteenth centuries.
Charmed Circle: Stonehenge, Contemporary Paganism, and Alternative Archaeology
Authors: Cusack Carole M.
Published: April 2012

Abstract

The impressive stone circle Stonehenge is understood by academic archaeologists to be a site of ritual significance to the prehistoric inhabitants of Wiltshire. It is constructed on cosmological principles based on a solar alignment, reflecting “a distinctive idea of time, which revolved around the cyclical movements of sun, moon, and stars across the heavens, as indicators of the passing seasons” (Fagan 1998:160). This article sketches mainstream archaeological interpretations of Stonehenge, then contrasts them with the popular narrative of its Druidic origin and purpose, which emerged in the seventeenth century. Modern Druids have negotiated the right to perform rituals at Stonehenge with English Heritage, the custodial body with responsibility for the monument, and Druidry has been recognised as a religion in the United Kingdom in 2010 (Beckford 2010). Modern Druidry, an “invented tradition,” conflicts with academic archaeology in its claims regarding Stonehenge (Chippindale 1986:38–58). Postmodern archaeological theories, which privilege “popular folk archaeology” (Holtorf 2005b:11), are more open to vernacular interpretations of artifacts and sites. These perspectives are broadly compatible with the deregulated religio-spiritual marketplace of the twenty-first century, which is characterized by a plethora of new religions and a pluralistic model of religious truth.1
Excavating Tradition: Alternative Archaeologies as Legitimation Strategies
Authors: Lewis James R.
Published: April 2012

Abstract

For the most part, religiously-motivated actors become interested in archaeological findings when these findings appear to support their religious assumptions, though a small but notable minority seek clues to the ideologies and practices of their presumptive religious ancestors in the archaeological record. This involvement in archaeology can vary tremendously in depth, from trained LDS archaeologists seeking support forThe Book of Mormonat Mesoamerican excavation sites, to casual references about Atlantis by ordinary participants in New Age spiritual groups. In many cases, religious appeals to the authority of archaeology to support a specific issue become inextricably bound up with appeals to the authority of tradition, in part because archaeology is brought to bear on past events that are already a part of a given tradition’s sacred narratives.
Traces of the Gods: Ancient Astronauts as a Vision of Our Future
Authors: Richter Jonas
Published: April 2012

Abstract

Ancient astronaut speculation (also called paleo-SETI), often labeled pseudoscience or modern myth, still awaits in-depth research. Focusing on Erich von Däniken and reconstructing his views on god and cosmology from scattered statements throughout his books, this article analyzes his attitudes toward science and religion as well as his concepts of god and creation. In this regard, his pantheistic combination of the big bang theory with a model of god as supercomputer is of special interest. Analogous to interpretatio Romana, Däniken utilizes what I call an interpretatio technologica, explaining myths by converting them into technological language. Building on the works of Pierre Teilhard de Chardin and Jean E. Charon, the Swiss writer also develops the vision of a cosmic tendency towards increasing knowledge and information. A short comparison with Raël demonstrates that similar ancient astronaut myths can lead to different applications or worldviews.
Towards a Reassessment of British Aristotelianism
Authors: Sgarbi Marco
Published: April 2012

Abstract

The aim of the paper is to reassess the role of British Aristotelianism within the history of early modern logic between the sixteenth and seventeenth centuries, as a crucial moment of cultural transition from the model of humanistic rhetoric and dialectic to that of facultative logic, that is, a logic which concerns the study of the cognitive powers of the mind. The paper shows that there is a special connection between Paduan Aristotelianism and British empiricism, through the mediation of British Aristotelianism. British Aristotelians took the ideas of the Paduan Aristotelian tradition and carried them to an extreme, gradually removing them from the original Aristotelian context in which they were grounded and developing what would later become the fundamental ideas of British empiricism.
Re-examining Local Governance in Eritrea: The Redrawing of Administration Regions
Authors: Bereketeab Redie
Published: April 2012

Abstract

The post-independence government of Eritrea introduced Proclamation 86/1996 to redraw the administrative structure of the newly independent territory. The principle behind the redrawing was pronounced to be to serve decentralised governance system where considerable power is devolved to the regions. According to this principle the regions were provided with legislative, executive and judiciary bodies of local governance. Further the regions were also to be divided into sub-regions and village/area units with provisions of legislative, executive and judiciary organs that would enhance the local governing system where the local communities are provided both legally and practically the autonomy to run their political, economic, social and cultural life with less central interference. In practice however the governance system that was introduced following independence proved to be highly centralised. This became glaringly obvious following the outbreak of the second war (1998-2000) between Eritrea and Ethiopia. The paper critically re-examines local governance in Eritrea. It examines the various stages of redrawing of the regions over the historical trajectory of the making of Eritrea until the redrawing following independence. It examines the corresponding power structures and local governance systems. It also examines the modality of the redrawing and the political intentionality behind it. Through text interpretation and analysis the paper examines the connection between local governance and decentralisation. The paper draws the conclusion that the legal mechanism put in place and the discretionary power arrangement between the executive and legislative bodies could not provide ample space for local governance.