bluuebunny/crossref_metadata_2025 huggingface dataset:
Dying to be responsible: adolescence, autonomy and responsibility
Authors: Lyons Barry
Published: May 2010

The United Nations Standard Minimum Rules for the Administration of Juvenile Justice state that there should be ‘a close relationship between the notion of responsibility for delinquent or criminal behaviour and other social rights and responsibilities’. If healthcare autonomy, or the ‘right to be responsible for making decisions about our own medical welfare’, is accepted as one of these social rights then, in England, the age gap between criminal responsibility and healthcare right is considerable. It has been suggested that this age difference might be explained in terms of the attribution of responsibility; in essence that there is a difference in the timing and nature of the responsibility being ascribed. The aim of this paper is to examine the concept of responsibility, particularly as it relates to adolescent decisions concerning death; the refusal of life-saving treatment, on the one hand, and the commission of homicidal acts, on the other. It would appear that there is considerable overlap in the types of responsibility alluded to in both situations, most particularly in the notions of capacity responsibility and prospective responsibility. If this is so, then having a wide gap between the two ages of responsibility would seem to lack a secure jurisprudential basis.
The role of fluctuating resource supply in a habitat maintained by the competition‐colonization trade‐off
Authors: Chakraborty Amit , Li Bai‐Lian
Published: May 2010

An exotic species can be a superior colonizer but inferior resource competitor relative to native species. Such species can spatially coexist for an extended period of time in a community maintained via competition‐colonization (CC) trade‐offs. Whether fluctuations in resource supply allow such exotic species to successfully invade and displace the native species or hold the coexistence is not previously explored, and it is the focus of this study. In this article, we model propagule‐limited spatial competition explicitly linked with resource‐competition within the framework of the classic CC‐model, while time‐dependent fluctuations in resource supply are considered in a sinusoidal function. The model predicts that if the amplitude of the fluctuations is greater than the average resource supply rate, there exist a range of values of fluctuation frequency that can allow the exotic species to successfully invade the habitat and to reduce the extent of native species. On the other hand, if the fluctuation amplitude is less than the average resource supply rate, such exotic species can coexist with the native species, independent of fluctuation frequencies. In addition, we found that at a constant resource supply rate, the exotic species can stably coexist with the native species at competitive equilibrium.
Comprehending ecological and economic sustainability
Authors: Makarieva Anastassia M. , Gorshkov Victor G. , Li Bai‐Lian
Published: May 2010

The global environmental imperative demands urgent actions on ecological stabilization, yet the global scale of such actions is persistently insufficient. This calls for investigating why the world economy appears to be so fearful of any potential environmental expenditure. Using the formalism of Lyapunov potential function it is shown that the stability principles for biomass in the ecosystem and for employment in economics are mathematically similar. The ecosystem has a stable and unstable stationary state with high (forest) and low (grasslands) biomass, respectively. In economics, there is a stable stationary state with high employment in mass production of conventional goods sold at low cost price, and an unstable stationary state with lower employment in production of novel products of technological progress sold at higher prices. An additional stable state is described for economics with very low employment in production of life essentials, such as energy and raw materials that are sold at greatly inflated prices. In this state the civilization pays 10% of global GDP for energy produced by a negligible minority of the working population (currently ∼0.2%) and sold at prices exceeding the cost price by 40 times, a state when any extra expenditures of whatever nature appear intolerable. The reason lies in the fundamental shortcoming of economic theory, which allows for economic ownership over energy sources. This is shown to be equivalent to equating measurable variables of different dimensions (stores and fluxes), which leads to effective violation of the laws of energy and matter conservation in modern economics.
Soil fertility controls the size‐specific distribution of eukaryotes
Authors: Mulder Christian
Published: May 2010

The large range of body‐mass values of soil organisms provides a tool to assess the organization of soil ecological communities. Relationships between log‐transformed body massMand log‐transformed numerical abundanceNof all eukaryotes occurring under organic pastures, mature grasslands, and seminatural heathlands in the Netherlands were investigated. The observed allometry of (M,N) assemblages of below‐ground communities strongly reflects the availability of primary macronutrients and essential micronutrients. This log‐linear model describes the continuous variation in the allometric slope of animals and fungi along an increasing soil fertility gradient. The aggregate contribution of small invertebrates (M< 1 μg) to the entire faunal community is highest under nutrient deficiency and causes shifts in the mass–abundance relationships. The phosphorus concentration in the soil explains 72% of these shifts but the nitrogen concentration explains only 36%, with copper and zinc as intermediate predictors (59% and 49%, respectively). Empirical evidence supports common responses of invertebrates to the rates of resource supply and, possibly, to the above‐ground primary production of ecosystems.
Effects of biodiversity and plant community composition on productivity in semiarid grasslands of Hulunbeir, Inner Mongolia, China
Authors: Zheng Xiao‐Xuan , Liu Guo‐Hua , Fu Bo‐Jie , Jin Tian‐Tian , Liu Zhan‐Feng
Published: May 2010

Many recent studies have focused on the relationship between biodiversity and ecosystem functioning, such as investigations into the productivity of experimental plant communities. One of the central issues affecting the functioning of ecosystems is the diversity of resident species richness and the composition of the plant community. However, one challenge to experimental studies is that results from artificial ecosystems may have little value for predicting loss of diversity and function degradation in natural ecosystems. Thus, recent studies have focused more on investigations of natural ecosystems; these studies have found that species diversity and ecosystem productivity usually correlate with various abiotic factors including environmental effects, such as soil nutrition and precipitation, as well as anthropic activities, such as grazing and agricultural yield. In this study, we aimed to test the validity of biotic factors reported in experimental studies to be major factors affecting the productivity of ecosystems, and then to determine whether the relationship between biodiversity and ecosystem function is confounded by environmental factors. We investigated the effects of plant biodiversity and community composition on ecosystem function (productivity) in semiarid grassland in Inner Mongolia, China that contained three vegetation types: arid steppe, steppe, and meadow steppe. Our results show that both diversity and community composition significantly affect productivity and are better predictors of productivity than environmental factors, such as soil conditions. Our findings are consistent with the assumptions of niche complementarity. This study suggests that both biodiversity and community composition are important biotic factors in the functioning of ecosystems located in semiarid grasslands. In addition, environmental parameters, such as soil conditions influence productivity indirectly by affecting both biotic factors at the same time.
A Model for Inactivation of Microbes Suspended in the Atmosphere by Solar Ultraviolet Radiation
Authors: Ben‐David Avishai , Sagripanti Jose‐Luis
Published: May 2010

Solar ultraviolet (UV) light within 280–320 nm (UVB) is the primary cause for virus inactivation in the atmosphere. Only the effect of the direct component has been previously evaluated. We developed a simple regression model to estimate the inactivation of a virus due to direct (unscattered), diffuse (scattered) and total (direct + diffuse) components of solar UV (daily integrated irradiances). The model predicts the maximum number of radiation‐days a virus will survive at a given altitude above the ground in rural and urban environments under clear skies. We explored the effect of several environmental variables: visibility, altitude and ground reflectivity. We found that the effect of diffuse radiation on virus inactivation was larger than the direct component. The diffuse irradiance increased with ground albedo (mainly due to reflection of the direct attenuated solar off the ground) and decreased with increased visibility (proportional to aerosol loading in the atmosphere). The diffuse component increased with altitude, but the ratio of diffuse to the total decreased with increased altitude, highlighting the importance of the diffuse component of UV near the ground. Our model may help public health studies in predicting and understanding the effect of environmental parameters on the survival of germs.
Spectrum‐specific Damage and Solar Ultraviolet Radiation Avoidance in the Two‐spotted Spider Mite
Authors: Sakai Yuta , Osakabe Masahiro
Published: May 2010

The spatial distribution of the two‐spotted spider mite Tetranychus urticae Koch is biased toward the lower surfaces of leaves as compared with the upper leaf surfaces on their host plants. Because of the deleterious effects of solar ultraviolet (UV) irradiation, we hypothesized T. urticae remains on lower leaf surfaces as an adaptation to avoid solar UV radiation (UVR). We examined the effects of solar UVR components on females and tested whether spatial distribution was associated with solar UVR avoidance. Attenuation of solar UVR using UV opaque film increased fecundity and reduced the movement of females from the upper to the lower leaf surfaces. In contrast, diverting solar UVR to the lower leaf surface using a light reflection sheet caused the mites to move from the lower to the upper leaf surfaces; however, attenuated UV reflection did not, suggesting that they occupy the lower leaf surface to avoid solar UVR. In monochromatic UVR tests, no eggs hatched when placed under 280–300 nm radiation, whereas almost all eggs hatched at 320–360 nm. Adult females, however, did not avoid wavelengths of 280 and 300 nm, but avoided 320–340 nm. We conclude that T. urticae exploit UVA information to avoid ambient UVB radiation.
The Effect of Tryptophan on UV‐induced DNA Photodamage
Authors: Oladepo Sulayman A. , Loppnow Glen R.
Published: May 2010

Trp–DNA adducts resulting from UV irradiation of pyrimidine bases and nucleotides in the presence of tryptophan (Trp) have been the subject of previous research. However, the relative yield of the adducts compared with the UV screening effect of Trp has not been previously considered. To determine whether Trp–DNA adduct formation or absorption “screening” by Trp is the predominant process when DNA solutions are irradiated with UV light in the presence of Trp, we irradiated Trp‐containing DNA oligonucleotide solutions with UVC light and incubated aliquots of those solutions with molecular beacons (MBs) to detect the damage. We observed a rapid decay of fluorescence of the MBs for pure DNA solutions, thereby indicating damage. However, in the presence of Trp, the fluorescence decay is prolonged, with time constants that increase exponentially with Trp concentration. The results are discussed in terms of a beneficial in vivo cellular protection rather than harmful adduct formation and suggest a net sacrificial absorption of UV light by Trp which actually protects the DNA from UV damage.
Relationships between migration rates and landscape resistance assessed using individual‐based simulations
Authors: LANDGUTH E. L. , CUSHMAN S. A. , MURPHY M.A. , LUIKART G.
Published: May 2010

Linking landscape effects on gene flow to processes such as dispersal and mating is essential to provide a conceptual foundation for landscape genetics. It is particularly important to determine how classical population genetic models relate to recent individual‐based landscape genetic models when assessing individual movement and its influence on population genetic structure. We used classical Wright–Fisher models and spatially explicit, individual‐based, landscape genetic models to simulate gene flow via dispersal and mating in a series of landscapes representing two patches of habitat separated by a barrier. We developed a mathematical formula that predicts the relationship between barrier strength (i.e., permeability) and the migration rate (m) across the barrier, thereby linking spatially explicit landscape genetics to classical population genetics theory. We then assessed the reliability of the function by obtaining population genetics parameters (m, FST) using simulations for both spatially explicit and Wright–Fisher simulation models for a range of gene flow rates. Next, we show that relaxing some of the assumptions of the Wright–Fisher model can substantially change population substructure (i.e., FST). For example, isolation by distance among individuals on each side of a barrier maintains an FST of ∼0.20 regardless of migration rate across the barrier, whereas panmixia on each side of the barrier results in an FST that changes with m as predicted by classical population genetics theory. We suggest that individual‐based, spatially explicit modelling provides a general framework to investigate how interactions between movement and landscape resistance drive population genetic patterns and connectivity across complex landscapes.
Development of a species‐specific AFLP‐based SCAR marker for authentication of black muntjac (Muntiacus crinifrons)
Authors: LIANG WENMING , YU JIAN , LI JIN , WU HAILONG , WU XIAO‐BING
Published: May 2010

Black muntjac is a rare and endangered deer endemic to eastern China. Due to the economic and pharmaceutical value of the meat, antlers and skin, the species has chronically suffered from poaching though it is regarded as the state key protected animal. To provide an effective molecular method for authentication of tissue specimen (such as meat, skin etc.) of the species, we developed a Sequence Characterized Amplified Region (SCAR) derived from a species specific Amplification Fragment Length Polymorphism (AFLP) marker. Initially, a 707‐bp species specific DNA fragment of the animal was detected by a pair of AFLP primers (Ep7/Mp8). Subsequently, a species‐specific primer pair (P‐F/P1‐R) was designed based on the specific AFLP fragment sequence, obtaining a 298‐bp SCAR for the species. Finally, the reliability of the SCAR primers was verified by two separate PCRs using the designed SCAR primers and a cyt b universal primer pair. As expected, all black muntjac samples presented two bands but the others failed to produce the SCAR by merely showing one band. Our results indicated that the SCAR primers developed in this study may provide a useful tool for forensic authentication of black muntjac samples though further testing with larger sample sizes is warranted.
Toxicity testing of the VEGF inhibitors bevacizumab, ranibizumab and pegaptanib in rats both with and without prior retinal ganglion cell damage
Authors: Thaler Sebastian , Fiedorowicz Michal , Choragiewicz Tomasz J. , Bolz Sylvia , Tura Ayseguel , Henke‐Fahle Sigrid , Yoeruek Efdal , Zrenner Eberhart , Bartz‐Schmidt Karl‐Ulrich , Ziemssen Focke , Schuettauf Frank
Published: May 2010

Purpose:  To evaluate the effects of intravitreally introduced vascular endothelial growth factor (VEGF) inhibitors in rat eyes with healthy retinal ganglion cells (RGC) and into others with N‐methyl‐D‐aspartate (NMDA)‐induced RGC damage.

Methods:  Bevacizumab, ranibizumab and pegaptanib were intravitreally injected each at two different concentrations. Respective vehicles of the three substances served as controls. In a different group, additionally a rat anti‐VEGF antibody was injected after NMDA treatment. Retrogradely labelled RGC were counted on retinal wholemounts 1 week or 2 months after intravitreal introduction of the VEGF inhibitors. Electron microscopy (EM) was performed on normal rat eyes 2 months after introduction of the VEGF inhibitors.

Results:  RGC counts in healthy rat eyes were essentially unchanged from those of the control animals after the administration of both low and high concentrations of bevacizumab, ranibizumab or pegaptanib. Compared to the other two substances, however, high doses of pegaptanib and its respective vehicle significantly decreased RGC after 1 week and led to a marked increase of mitochondrial swelling in EM. In eyes with NMDA‐induced RGC damage, no changes of RGC numbers were detected after rat anti‐VEGF antibody or bevacizumab, ranibizumab and pegaptanib at both tested concentrations.

Conclusions:  Even at higher doses, bevacizumab and ranibizumab showed no toxic effects on RGC in vivo in either untreated rats or in the NMDA‐induced RGC damage model. Also a rat anti‐VEGF antibody showed no adverse effects after NMDA. Anti‐VEGF therapy therefore appears safe even for eyes with additional excitotoxic RGC damage. Potential harm from the pegaptanib carrier solution at very high local concentrations cannot be excluded.
The first description and confirmation of the Vista Alegre impact structure in the Paraná flood basalts of southern Brazil
Authors: CRÓSTA Alvaro P. , KOEBERL Christian , FURUIE Rafael A. , KAZZUO‐VIEIRA Cesar
Published: May 2010

Abstract– The Vista Alegre structure, centered at 25°57′S and 52°41′W, has been recently proposed as a meteorite impact structure. The 9.5 km‐diameter structure is located in the Paraná state of southern Brazil, within the Paraná Basin, which contains one of the largest and most extensive flood basalt provinces on Earth. The Paraná flood basalts belong to the Serra Geral Formation and are temporally related to the opening of the South Atlantic Ocean, having been dated at about 133–132 Ma. Tholeiitic basalts dominate the western portion of Paraná state, with some minor rhyodacites. Morphologically, Vista Alegre has a prominent circular outline, in the form of an incomplete ring of escarpments, and an inner depression. The presence of a central uplift is not obvious, but it is inferred by the occurrence of deformed sandstone blocks near the center of the structure. These sandstones are possibly related to the Triassic Pirambóia Formation and/or to the Cretaceous Botucatu Formation. These units are normally at stratigraphic depths of about 700–800 m below the present surface in this portion of the Paraná Basin. The structure appears to be in an advanced erosion stage and its interior is occupied by a soil cover several meters thick, extensively used for agriculture. As a result there are limited outcrops in the interior of the structure, all of polymict breccias, some of them melt‐bearing. We report the extensive occurrence of shatter cones, in the form of fine‐grained rock clasts within the polymict breccias. The shatter cone‐bearing breccias occur at different locations within the structure, separated by several kilometers. The nested shatter cones range in size from about 0.5 to 20 cm for individual cones, and up to half a meter for complete assemblages. The shatter cones formed in fine‐grained Parana flood basalt and might be the first examples of shatter cones in such a rock type. In addition, planar deformation features (PDFs) were found in quartz grains within sedimentary rock clasts of the polymict breccia. These findings confirm the impact origin of the Vista Alegre structure.
Reflectance spectra of iron meteorites: Implications for spectral identification of their parent bodies
Authors: CLOUTIS Edward A. , HARDERSEN Paul S. , BISH David L. , BAILEY Daniel T. , GAFFEY Michael J. , CRAIG Michael A.
Published: May 2010

Abstract– The 0.35–2.5 μm reflectance spectra of iron meteorite powders and slabs have been studied as a function of composition, surface texture (for slabs), grain size (for powders), and viewing geometry (for powders). Powder spectra are invariably red‐sloped over this wavelength interval and have a narrow range of visible albedos (approximately 10–15% at 0.56 μm). Metal (Fe:Ni) compositional variations have no systematic effect on the powder spectra, increasing grain size results in more red‐sloped spectra, and changes in viewing geometry have variable effects on overall reflectance and spectral slope. Roughened metal slab spectra have a wider, and higher, range of visible albedos than powders (22–74% at 0.56 μm), and are also red‐sloped. Smoother slabs exhibit greater differences from iron meteorite powder spectra, exhibiting wider variations in overall reflectance, spectral slopes, and spectral shapes. No unique spectral parameters exist that allow for powder and slab spectra to be fully separated in all cases. Spectral differences between slabs and powders can be used to constrain possible surface properties, and causes of rotational spectral variations, of M‐asteroids. The magnitude of spectral variations between M‐asteroids and rotational and spectral variability does not necessarily imply a dramatic change in surface properties, as the differences in albedo and/or spectral slope can be accommodated by modest changes in grain size (for powders), small changes in surface roughness (for slabs), or variations in viewing geometry. Since metal powders exhibit much less spectral variability than slabs, M‐asteroid spectral variability requires larger changes in either powder properties or viewing geometry than for slabs for a given degree of spectral variation.
Obama's “Smart‐Power” Strategy, One Year On: The Case of the Middle East
Authors: Zweiri Mahjoob , Awwad Rula
Published: May 2010

A year ago, President Obama was cheered into the White House. His election represented hope for many, not just in the United States, but around the world. Charged with such force and charisma, unprecedented in U.S. Presidential history, he promised the much needed change that America and the world are waiting for. Obama's election was more of a rebirth that represented hope, “Yes We Can,” to regain the credibility of the United States lost during the last decade.
The Use of EMDR in Treatment of Traumatized Iraqi Children
Authors: Wadaa Najla N. , Zaharim Norzarina Mohd , Alqashan Humoud F.
Published: May 2010

The purpose of this article is to determine the prevalence of post‐traumatic stress disorder (PTSD) among Iraqi children and the effectiveness of eye movement desensitization and reprocessing (EMDR) treatment in traumatized Iraqi children. The participants in the present study were Iraqi children, ages 7–12; mean age = 10.17 years. There were 29 boys and 31 girls who immigrated to Malaysia during the recent war in Iraq. Those children were assessed for PTSD. Following the assessment, 37 children were assigned to two groups: 12 to the experimental group and 25 to the control group. The 12 children in the experimental group were treated with EMDR and were compared with the 25 children in the control group. This was done in order to determine the effectiveness of EMDR in reducing PTSD symptoms among traumatized children. UCLA PTSD DSM‐IV (Revision 1) was used to determine the prevalence of PTSD among Iraqi children. The results suggested that EMDR was effective in reducing PTSD symptoms.
The Arab Opposition Molehill
Authors: Singh Ranjit
Published: May 2010

Arab Islamic oppositions have proven largely ineffectual in molding regime outcomes since the liberalizations of the 1980s and 1990s, although many continue to overestimate their potential for propelling reform. This article argues that a keen sense of the past is necessary when evaluating whether or not an opposition matters for political reform.Section Iintroduces noted scholar Juan Linz's notion of “semi‐opposition”—limited and “semi‐free” opposition groups that may sustain authoritarian regimes as much as repression. Using interviews and English and Arabic sources,Section IIdemonstrates historical correspondences between semi‐opposition and the Jordanian and Egyptian Muslim Brotherhood (MB) organizations concerning origins and support, ideology and approach to politics, regime tolerance and political environment, and political behavior.Section IIIdevelops Linz's hypothesis on the links between semi‐opposition and authoritarian persistence by examining how the MB marginalizes and raises the costs of dissent for other opposition groups and actors. The MB is briefly contrasted with the Algerian Front Islamique du Salut (FIS) opposition party of 1989–1992 inSection IV. Decidedly not a semi‐opposition, the FIS proved far more transformative than either the Jordanian or Egyptian MB, inducing centrifugal politics and the collapse of the Front de Libération Nationale (FLN) state that governed Algeria from 1962.
The War on Terror from the Perspective of Indonesia and Saudi Arabia
Authors: Alghanim Abdullah A. , Salhi Ribhi I.
Published: May 2010

This article examines the perspective of two major Islamic nations—Saudi Arabia and Indonesia—toward the United States' War on terror and how this war shaped and influenced the behavior of the two Islamic governments toward domestic challenges and their partnership with the United States, as they have declared their support of the United States. Indeed the war against terror has developed several security concerns for both Saudi Arabia and Indonesia. However, each state has followed different methods to fight Islamic radical movements as well as a different framework of partnership with the United States on its war against terrorism.
Defects in ryanodine receptor function are associated with systolic dysfunction in rats subjected to volume overload
Authors: Juric Danijel , Yao Xinghai , Thandapilly Sijo , Louis Xavier , Cantor Elliott , Chaze Brian , Wojciechowski Peter , Vasanji Zainisha , Yang Tonghua , Wigle Jeffrey , Netticadan Thomas
Published: May 2010

Cardiac hypertrophy is the compensatory enlargement of the heart aimed at reducing stress induced by either pressure overload or volume overload (VO); however, sustained hypertrophy leads to cardiac dysfunction. We hypothesize that cardiac dysfunction which develops due to VO will be associated with abnormalities in sarcoplasmic reticulum (SR) function. Volume overload was induced in rats by aortocaval shunt surgery (‘VO rats’). Echocardiographic measurements were used to compare cardiac structure and function in control and VO rats. The SR was isolated from left ventricular tissue. Sarcoplasmic reticulum Ca2+ uptake and SR Ca2+ release were examined by the filtration method. The expression levels of SR proteins were assessed by Western immunoblotting. Rats subjected to VO developed eccentric hypertrophy. Diastolic function in VO rats was improved at all time points and was associated with elevated SR Ca2+ uptake at 16 and 28 weeks. Sarcoendoplasmic reticulum ATPase 2a protein level was increased at 16 weeks but normalized at 28 weeks; Amounts of phospholamban protein were unaltered, but Serine16 phospholamban and Threonine17 phospholamban were reduced at 28 weeks. Systolic function was impaired in the VO rats at 16 and 28 weeks and was associated with reduced Ca2+ release at the 28 week time point. The ryanodine receptor 2 (RyR2) protein level was reduced at 28 weeks; RyR2 phosphorylation status and the amount of FK‐binding protein 12.6 were increased at 28 weeks. On the basis of the results, we conclude that the progression of hypertrophy due to VO in rats is accompanied by the impairment of systolic function, which in turn is associated with defects in RyR2 expression and function.
Peroxisome proliferation activation receptor α modulation of Ca2+‐regulated exocytosis via arachidonic acid in guinea‐pig antral mucous cells
Authors: Sawabe Yukinori , Shimamoto Chikao , Sakai Akiko , Kuwabara Hiroko , Saad Adel H. , Nakano Takashi , Takitani Kimitaka , Tamai Hiroshi , Mori Hiroshi , Marunaka Yoshinori , Nakahari Takashi
Published: May 2010

Indomethacin (IDM, 10 μm), not aspirin (ASA; 10 μm), enhanced the Ca2+‐regulated exocytosis stimulated by 1 μm acetylcholine (ACh) in guinea‐pig antral mucous cells. Indomethacin inhibits prostaglandin G/H (PGG/H) and 15R‐hydroperoxy‐eicosatetraenoic acid (15R‐HPETE) production from arachidonic acid (AA), while ASA inhibits PGG/H production but accelerates 15R‐HPETE production. This suggests that IDM accumulates AA. Arachidonic acid (2 μm) enhanced Ca2+‐regulated exocytosis in antral mucous cells to a similar extent to IDM. Moreover, a stable analogue of AA, arachidonyltrifluoromethyl ketone (AACOCF3), also enhanced Ca2+‐regulated exocytosis, indicating that AA, not products from AA, enhances Ca2+‐regulated exocytosis. We hypothesized that AA activates peroxisome proliferation activation receptor α (PPARα), because AA is a natural ligand for PPARα. A PPARα agonist (WY14643; 1 μm) enhanced Ca2+‐regulated exocytosis, and a PPARα blocker (MK886; 50 μm) abolished the enhancement of Ca2+‐regulated exocytosis induced by AA, IDM, AACOCF3 and WY14643. Western blotting and immunohistochemical examinations demonstrated that PPARα exists in antral mucous cells. Moreover, MK886 decreased the frequency of Ca2+‐regulated exocytosis activated by 1 μm ACh or 2 μm thapsigargin alone by 25–30%. Thus, ACh stimulates AA accumulation via an [Ca2+]i increase, which activates PPARα, leading to enhancement of Ca2+‐regulated exocytosis in antral mucous cells. A novel autocrine mechanism mediated via PPARα enhances Ca2+‐regulated exocytosis in guinea‐pig antral mucous cells.
Active Control of Flow Separation in a Radial Blower
Authors: Greenblatt David , Arzuan Guy
Published: May 2010

An experimental investigation was undertaken as a proof-of-concept study for active separation control in a radial blower. Acoustic perturbations were introduced into the impeller housing of a small radial blower with fully stalled blades. Increases in the plenum pressure of 35% were achieved and, based on tuft-based flow visualization, it was concluded that the pressure increases were brought about due to excitation and deflection of the leading-edge separated shear layer. Within the parameter range considered here, the optimum dimensionless control frequencies were found to be O(0.5), irrespective of the blade orientation or number of blades. Moreover, the maximum pressure rise was achieved with an investment of only 2% of the fan input power. Backward bladed impeller blades exhibited slightly larger increases in pressure coefficients when compared with their forward bladed counterparts. The dependence of blower performance on reduced frequency was remarkably similar to that seen on flat plate airfoils at similar Reynolds numbers under periodic excitation.
Influence of the Slant Angle of 3D Bluff Bodies on Longitudinal Vortex Formation
Authors: Gilliéron Patrick , Leroy Annie , Aubrun Sandrine , Audier Pierre
Published: May 2010

This paper presents the experimental results and analytical arguments concerning simplified geometries of the rear window and windscreen of automotive vehicles in order to contribute to a better understanding of the swirling structure formation and vortex bursting processes. Static pressure distributions and skin friction line visualizations on both sides of the edge where the swirling structure is generated on the rear window of an Ahmed body are presented for different slant angles. Results show the influence of the slant angle on the swirling structure formation and further show that the vortex bursting process can be promoted by small rear window angles. These results are then extrapolated with the help of analytical demonstrations to the windscreen configuration to demonstrate that large windscreen slopes would have the same disintegration effect.
A Serendipitous Application of Supercavitation Theory to the Water-Running Basilisk Lizard
Authors: White Eric R. , Miller Timothy F.
Published: May 2010

The classic study of the water entry of a body has applications ranging from hydroballistics to behavior of basilisk lizards. The availability of Russian supercavitation theory in recent years has allowed for an even greater understanding, and was used to develop a model to predict the dynamic size, shape, and pressure of a naturally or artificially produced underwater cavity. This model combines supercavitation theory, rigid body dynamics, and hydrodynamic theory into a comprehensive model capable of determining the motional behavior of underwater objects. This model was used as the basis for modeling the vertical water entry of solid objects into a free water surface. Results from simulation of water entry of various-sized thin disks compared favorably with published experimental data from the technical literature. Additional simulated data support a disk radius dependence on a relative object depth at cavity closure that was not previously recognized. Cavity closure times are also presented.
Mitigation of Damage to Solid Surfaces From the Collapse of Cavitation Bubble Clouds
Authors: Chitnis Parag V. , Manzi Nicholas J. , Cleveland Robin O. , Roy Ronald A. , Holt R. Glynn
Published: May 2010

The collapse of transient bubble clouds near a solid surface was investigated to test a scheme for mitigation of cavitation-induced damage. The target was a porous ceramic disk through which air could be forced. Transient cavitation bubbles were created using a shock-wave lithotripter focused on the surface of the disk. The dynamics of bubble clouds near the ceramic disks were studied for two boundary conditions: no back pressure resulting in surface free of bubbles and 10 psi (0.7 atm) of back pressure, resulting in a surface with a sparse (30% of area) bubble layer. Images of the cavitation near the surface were obtained from a high-speed camera. Additionally, a passive cavitation detector (3.5 MHz focused acoustic transducer) was aligned with the surface. Both the images and the acoustic measurements indicated that bubble clouds near a ceramic face without a bubble layer collapsed onto the boundary, subsequently leading to surface erosion. When a sparse bubble layer was introduced, bubble clouds collapsed away from the surface, thus mitigating cavitation damage. The erosion damage to the ceramic disks after 300 shock waves was quantified using micro-CT imaging. Pitting up to 1 mm deep was measured for the bubble-free surface, and the damage to the bubble surface was too small to be detected.
Particle Trajectory Study in Submerged Flows With Baffles Using ν2¯−f and k−ε Turbulence Models
Authors: Mehdizadeh A. , Firoozabadi B. , Sherif S. A.
Published: May 2010

In this paper, the structure of a wall jet deflected by a baffle along with the trajectory of particles has been studied. This baffle is used to produce a stable deflected surface jet, thereby deflecting the high-velocity supercritical stream away from the bed to the surface. An elliptic relaxation turbulence model (ν2¯−f model) has been used to simulate this submerged flow. In recent years, the ν2¯−f turbulence model has become increasingly popular due to its ability to account for near-wall damping without use of damping functions. In addition, it has been proven that the ν2¯−f model is superior to other Reynolds-averaged Navier-Stokes (RANS) methods in many flows where complex flow features are present. In this study, we compare the results of the ν2¯−f model with available experimental data. Since erosion and deposition are coupled, the study of this problem should consider both of these phenomena using a proper approach. In addition to erosion over the bed, the trajectory of the particles is examined using a Lagrangian–Eulerian approach, the distribution of deposited particles over the bed is predicted for a two-phase test case based on a series of numerical simulations. Results show that the maximum erosion happens in a place in which no particle can be deposited, which causes the bed to deform very rapidly in that region. This should help prevent or reduce erosion over the bed. On the other hand, the study will help predict the trajectory of particles and the deposition rates at any section of the channel, and should thus provide useful information to control the erosion and deposition on the channel bed.
Investigation of the Flow Field in a Rectangular Vessel Equipped With a Side-Entering Agitator
Authors: Gómez C. , Bennington C. P. J. , Taghipour F.
Published: May 2010

The hydrodynamics of stirred vessels with side-entering impellers, which are used in numerous process industries including petroleum, foods, and pulp and paper manufacturing, have received limited attention. In the present work, the flow in a reduced size rectangular tank equipped with a side-entering axial flow impeller, scaled down from the industrial agitation of low consistency pulp fiber suspensions, was investigated using particle image velocimetry (PIV) and computational fluid dynamics (CFD), in the laminar regime (18≤Re≤120). Tuning of the PIV measuring parameters for an optimum capture of valid velocity vectors within a representative portion of the vessel is described. A detailed description of the construction and refinement of the grid and quantification of the discretization error in the CFD results is also presented. The simulation predictions were extensively evaluated by comparing the measured planar flow patterns and velocity fields at various locations in the mixing vessel. Very good agreement was found between PIV measurements and computed velocities confirming the efficiency of CFD in the analysis of mixing systems. The prediction of global mixing parameters was also evaluated. The computed impeller torque and impeller power number agreed very well with experimental measurements over the range of Re studied.
Fluid Force Moment on the Backshroud of a Francis Turbine Runner in Precession Motion
Authors: Song Bingwei , Horiguchi Hironori , Nishiyama Yumeto , Hata Shinichiro , Ma Zhenyue , Tsujimoto Yoshinobu
Published: May 2010

The fundamental characteristics of rotordynamic fluid force moment on the backshroud of a Francis turbine runner in precession motion were studied using model tests and computations based on a bulk flow model. The runner is modeled by a disk positioned close to a casing with a small axial clearance. An inward leakage flow is produced by an external pump in the model test. The effects of the leakage flow rate, the preswirl velocity at the inlet of the clearance, and the axial clearance on the fluid force moment were examined. It was found that the fluid force moment encourages the precession motion at small forward precession angular velocity ratios and the region encouraging the precession motion is affected by the preswirl velocity. Through the comparisons of the fluid force moment with and without the rotation of the disk, it was found that the normal moment without the disk rotation did not have the effect to encourage the precession motion. Thus, the swirl flow due to disk rotation was found to be responsible for the encouragement of the precession motion.
On the Derivation of Pressure Field Distribution at the Entrance of a Rectangular Capillary
Authors: Waghmare Prashant R. , Mitra Sushanta K.
Published: May 2010

In capillary flow, integral momentum approach is used to derive the governing equation, which requires an expression for the pressure field at the inlet of the capillary. Generally, the pressure field for circular capillary is deduced with hemispherical control volume. This expression has been extended for other noncircular capillaries with an equivalent radius approximation. In case of high aspect ratio channels, the semicylindrical control volume needs to be considered. In the present study, the correct expression for the entrance pressure field for high aspect ratio capillaries is derived with such appropriate control volume.
MiR-33 Contributes to the Regulation of Cholesterol Homeostasis
Authors: Rayner Katey J. , Suárez Yajaira , Dávalos Alberto , Parathath Saj , Fitzgerald Michael L. , Tamehiro Norimasa , Fisher Edward A. , Moore Kathryn J. , Fernández-Hernando Carlos
Published: May 2010

miR-33 in Cholesterol Control

With the well-established link between serum cholesterol levels and cardiovascular disease and the availability of effective cholesterol-lowering drugs, cholesterol screening has rapidly become a routine part of health care. Yet, much remains to be learned about how cholesterol levels are regulated at the cellular level (see the Perspective by

Brown
et al.

). Now,

Najafi-Shoushtari
et al.

(p.
1566
, published online 13 May) and

Rayner
et al.

(p.
1570
, published online 13 May) have discovered a new molecular player in cholesterol control—a small noncoding RNA that, intriguingly, is embedded within the genes coding for sterol regulatory element-binding proteins (SREBPs), transcription factors already known to regulate cholesterol levels. This microRNA, called miR-33, represses expression of the adenosine triphosphate–binding cassette transporter A1, a protein that regulates synthesis of high-density lipoprotein (HDL, or “good” cholesterol) and that helps to remove “bad” cholesterol from the blood. Reducing the levels of miR-33 in mice boosted serum HDL levels, suggesting that manipulation of this regulatory circuit might be therapeutically useful.
The Cyclic AMP (cAMP)-cAMP Receptor Protein Signaling System Mediates Resistance of
Vibrio cholerae
O1 Strains to Multiple Environmental Bacteriophages
Authors: Zahid M. Shamim Hasan , Waise T. M. Zaved , Kamruzzaman M. , Ghosh Amar N. , Nair G. Balakrish , Mekalanos John J. , Faruque Shah M.
Published: May 2010

Toxigenic
Vibrio cholerae
, the causative agent of the epidemic diarrheal disease cholera, interacts with diverse environmental bacteriophages. These interactions promote genetic diversity or cause selective enrichment of phage-resistant bacterial clones. To identify bacterial genes involved in mediating the phage-resistant phenotype, we screened a transposon insertion library of
V. cholerae
O1 El Tor biotype strain C6706 to identify mutants showing altered susceptibility to a panel of phages isolated from surface waters in Bangladesh. Mutants with insertion in
cyaA
or
crp
genes encoding adenylate cyclase or cyclic AMP (cAMP) receptor protein (CRP), respectively, were susceptible to a phage designated JSF9 to which the parent strain was completely resistant. Application of the
cyaA
mutant as an indicator strain in environmental phage monitoring enhanced phage detection, and we identified 3 additional phages to which the parent strain was resistant. Incorporation of the
cyaA
or
crp
mutations into other
V. cholerae
O1 strains caused similar alterations in their phage susceptibility patterns, and the susceptibility correlated with the ability of the bacteria to adsorb these phages. Our results suggest that cAMP-CRP-mediated downregulation of phage adsorption may contribute to a mechanism for the
V. cholerae
O1 strains to survive predation by multiple environmental phages. Furthermore, the
cyaA
or
crp
mutant strains may be used as suitable indicators in monitoring cholera phages in the water.
Novel Carbohydrate-Binding Module Identified in a Ruminal Metagenomic Endoglucanase
Authors: Duan Cheng-Jie , Liu Jun-Liang , Wu Xi , Tang Ji-Liang , Feng Jia-Xun
Published: May 2010

Endoglucanase C5614-1 comprises a catalytic module (CM) and an X module (XM). The XM showed no significant homology with known carbohydrate-binding modules (CBMs). Recombinant full-length endoglucanase could bind Avicel, whereas the CM could not. The XM could bind various polysaccharides. The results demonstrated that the XM was a new CBM.
Presence of
Coxiella burnetii
DNA in the Environment of the United States, 2006 to 2008
Authors: Kersh Gilbert J. , Wolfe Teresa M. , Fitzpatrick Kelly A. , Candee Amanda J. , Oliver Lindsay D. , Patterson Nicole E. , Self Joshua S. , Priestley Rachael A. , Loftis Amanda D. , Massung Robert F.
Published: May 2010

Coxiella burnetii
is an obligate intracellular bacterium that causes the zoonotic disease Q fever. Because
C. burnetii
is highly infectious, can survive under a variety of environmental conditions, and has been weaponized in the past, it is classified as a select agent and is considered a potential bioweapon. The agent is known to be present in domestic livestock and in wild animal populations, but the background levels of
C. burnetii
in the environment have not been reported. To better understand the amount of
C. burnetii
present in the environment of the United States, more than 1,600 environmental samples were collected from six geographically diverse parts of the United States in the years 2006 to 2008. DNA was purified from these samples, and the presence of
C. burnetii
DNA was evaluated by quantitative PCR of the IS
1111
repetitive element. Overall, 23.8% of the samples were positive for C.
burnetii
DNA. The prevalence in the different states ranged from 6 to 44%.
C. burnetii
DNA was detected in locations with livestock and also in locations with primarily human activity (post offices, stores, schools, etc.). This study demonstrates that
C. burnetii
is fairly common in the environment in the United States, and any analysis of
C. burnetii
after a suspected intentional release should be interpreted in light of these background levels. It also suggests that human exposure to
C. burnetii
may be more common than what is suggested by the number of reported cases of Q fever.
Production of Indole froml-Tryptophan and Effects of These Compounds on Biofilm Formation byFusobacterium nucleatumATCC 25586
Authors: Sasaki-Imamura Takako , Yano Akira , Yoshida Yasuo
Published: May 2010

Thel-tryptophan degradation product indole is a purported extracellular signaling molecule that influences biofilm formation in various bacteria. Here we analyzed the mechanisms of indole production inFusobacterium nucleatumand the effects of tryptophan and indole onF. nucleatumplanktonic and biofilm cells. The amino acid sequence deduced from thefn1943gene inF. nucleatumATCC 25586 was 28% identical to that deduced fromtnaAinEscherichia coli, which encodes tryptophanase catalyzing the β-elimination ofl-tryptophan to produce indole. Thefn1943gene was cotranscribed with the downstream genefn1944, which is a homolog oftnaBencoding low-affinity tryptophan permease. The transcript started at position −68 or −153 from the first nucleotide of thefn1943translation initiation codon. Real-time quantitative PCR showed that much moreF. nucleatum fn1943transcripts were obtained from log-phase cells than from stationary-phase cells. Indole production by the purified recombinant protein encoded byfn1943was examined using high-performance liquid chromatography. TheKmandkcatof the enzyme were 0.26 ± 0.03 mM and 0.74 ± 0.04 s−1, respectively.F. nucleatumbiofilm formation and the biofilm supernatant concentration of indole increased dose dependently with increasing tryptophan concentrations. Exogenous indole also increasedF. nucleatumbiofilm formation in a dose-dependent manner. Even at very high concentrations, tryptophan did not affectfn1943expression, whereas similar indole concentrations decreased expression. Thus, exogenous tryptophan and indole were suggested to increaseF. nucleatumbiofilms.
Animal-to-Animal Variation in Fecal Microbial Diversity among Beef Cattle
Authors: Durso Lisa M. , Harhay Gregory P. , Smith Timothy P. L. , Bono James L. , DeSantis Todd Z. , Harhay Dayna M. , Andersen Gary L. , Keen James E. , Laegreid William W. , Clawson Michael L.
Published: May 2010

The intestinal microbiota of beef cattle are important for animal health, food safety, and methane emissions. This full-length sequencing survey of 11,171 16S rRNA genes reveals animal-to-animal variation in communities that cannot be attributed to breed, gender, diet, age, or weather. Beef communities differ from those of dairy. Core bovine taxa are identified.