bluuebunny/crossref_metadata_2025 huggingface dataset:
Modelling future changes to the stratospheric source gas injection of biogenic bromocarbons
Authors: Hossaini R. , Chipperfield M. P. , Dhomse S. , Ordóñez C. , Saiz‐Lopez A. , Abraham N. L. , Archibald A. , Braesicke P. , Telford P. , Warwick N. , Yang X. , Pyle J.
Published: October 2012

Simulations with a chemistry‐climate model (CCM) show a future increase in the stratospheric source gas injection (SGI) of biogenic very short‐lived substances (VSLS). For 2000, the modelled SGI of bromine from VSLS is ∼1.7 parts per trillion (pptv) and largest over the tropical West Pacific. For 2100, this increases to ∼2.0 and ∼2.7 pptv when the model is forced with Intergovernmental Panel on Climate Change (IPCC) representative concentration pathways (RCPs) 4.5 and 8.5. The increase is largely due to stronger tropical deep convection transporting more CHBr3 to the lower stratosphere. For CH2Br2, CHBr2Cl, CH2BrCl and CHBrCl2, changes to primary oxidant OH determines their SGI contribution. Under RCP 4.5 (moderate warming), OH increases in a warmer, more humid troposphere. Under RCP 8.5 (extreme warming) OH decreases significantly due to a large methane increase, allowing greater SGI of bromine from these VSLS. Potentially enhanced VSLS emissions in the future would further increase these estimates.
Modeling wood dynamics, jam formation, and sediment storage in a gravel‐bed stream
Authors: Eaton B. C. , Hassan M. A. , Davidson S. L.
Published: October 2012

In small and intermediate sized streams, the interaction between wood and bed material transport often determines the nature of the physical habitat, which in turn influences the health of the stream's ecosystem. We present a stochastic model that can be used to simulate the effects on physical habitat of forest fires, climate change, and other environmental disturbances that alter wood recruitment. The model predicts large wood (LW) loads in a stream as well as the volume of sediment stored by the wood; while it is parameterized to describe gravel bed streams similar to a well‐studied field prototype, Fishtrap Creek, British Columbia, it can be calibrated to other systems as well. In the model, LW pieces are produced and modified over time as a result of random tree‐fall, LW breakage, LW movement, and piece interaction to form LW jams. Each LW piece traps a portion of the annual bed material transport entering the reach and releases the stored sediment when the LW piece is entrained and moved. The equations governing sediment storage are based on a set of flume experiments also scaled to the field prototype. The model predicts wood loads ranging from 70 m3/ha to more than 300 m3/ha, with a mean value of 178 m3/ha: both the range and the mean value are consistent with field data from streams with similar riparian forest types and climate. The model also predicts an LW jam spacing that is consistent with field data. Furthermore, our modeling results demonstrate that the high spatial and temporal variability in sediment storage, sediment transport, and channel morphology associated with LW‐dominated streams occurs only when LW pieces interact and form jams. Model runs that do not include jam formation are much less variable. These results suggest that river restoration efforts using engineered LW pieces that are fixed in place and not permitted to interact will be less successful at restoring the geomorphic processes responsible for producing diverse, productive physical habitats than efforts using LW pieces that are free to move, interact, and form LW jams.
Trans-Golgi proteins participate in the control of lipid droplet and chylomicron formation
Authors: Hesse Deike , Jaschke Alexander , Chung Bomee , Schürmann Annette
Published: October 2012

LDs (lipid droplets) carrying TAG (triacylglycerol) and cholesteryl esters are emerging as dynamic cellular organelles that are generated in nearly every cell. They play a key role in lipid and membrane homoeostasis. Abnormal LD dynamics are associated with the pathophysiology of many metabolic diseases, such as obesity, diabetes, atherosclerosis, fatty liver and even cancer. Chylomicrons, stable droplets also consisting of TAG and cholesterol are generated in the intestinal epithelium to transport exogenous (dietary) lipids after meals from the small intestine to tissues for degradation. Defective chylomicron formation is responsible for inherited lipoprotein deficiencies, including abetalipoproteinaemia, hypobetalipoproteinaemia and chylomicron retention disease. These are disorders sharing characteristics such as fat malabsorption, low levels of circulating lipids and fat-soluble vitamins, failure to thrive in early childhood, ataxic neuropathy and visual impairment. Thus understanding the molecular mechanisms governing the dynamics of LDs and chylomicrons, namely, their biogenesis, growth, maintenance and degradation, will not only clarify their molecular role, but might also provide additional indications to treatment of metabolic diseases. In this review, we highlight the role of two small GTPases [ARFRP1 (ADP-ribosylation factor related protein 1) and ARL1 (ADP-ribosylation factor-like 1)] and their downstream targets acting on the trans-Golgi (Golgins and Rab proteins) on LD and chylomicron formation.
Cytogenetic characterization reveals differences in nuclear organization of cystic cells among Brazilian species of Triatoma (Heteroptera, Reduviidae)
Authors: Bardella Vanessa Bellini , de Souza Rosana Silistino , San Martin Juca Abramo Barrera , Andrade Célia Guadalupe Tardeli de Jesus , Vanzela André Luís Laforga , de Azeredo‐Oliveira Maria Tercília Vilela
Published: October 2012

Cytogenetic studies in triatomines have described the occurrence of holokinetic chromosomes, heterochromatin distribution and the location of rDNA (ribosomal DNA) sites, but few aspects of nuclear organization in this group have been discussed. We have focused on ultrastructural and cytogenetic features and differences in cystic cells of seminiferous tubules between five species of Triatoma. Cystic cells showed evidence of polyploidy events and heterochromatic blocks appeared predominantly in the central region of the nuclei. Cytogenetic analyses showed that there was variation in chromocenter number between species, and that the central regions were AT‐rich [DAPI+ (4′,6‐diamidino‐2‐phenylindole+)], whereas the periphery was CG‐rich (CMA+). Another characteristic was the distribution of 45S rDNA, which differed according to the chromosomal location of this sequence. In all we have compared aspects of nuclear organization, polyploidy, heterochromatin, rDNA site distribution and methylation levels, as well as the relationships between five species of Triatoma from a cystic cell perspective.
Optimal mixing and optimal stirring for fixed energy, fixed power, or fixed palenstrophy flows
Authors: Lunasin Evelyn , Lin Zhi , Novikov Alexei , Mazzucato Anna , Doering Charles R.
Published: October 2012

We consider passive scalar mixing by a prescribed divergence-free velocity vector field in a periodic box and address the following question: Starting from a given initial inhomogeneous distribution of passive tracers, and given a certain energy budget, power budget, or finite palenstrophy budget, what incompressible flow field best mixes the scalar quantity? We focus on the optimal stirring strategy recently proposed by Lin et al. [“Optimal stirring strategies for passive scalar mixing,” J. Fluid Mech. 675, 465 (2011)]10.1017/S0022112011000292 that determines the flow field that instantaneously maximizes the depletion of the H−1 mix-norm. In this work, we bridge some of the gap between the best available a priori analysis and simulation results. After recalling some previous analysis, we present an explicit example demonstrating finite-time perfect mixing with a finite energy constraint on the stirring flow. On the other hand, using a recent result by Wirosoetisno et al. [“Long time stability of a classical efficient scheme for two dimensional Navier-Stokes equations,” SIAM J. Numer. Anal. 50(1), 126–150 (2012)]10.1137/110834901 we establish that the H−1 mix-norm decays at most exponentially in time if the two-dimensional incompressible flow is constrained to have constant palenstrophy. Finite-time perfect mixing is thus ruled out when too much cost is incurred by small scale structures in the stirring. Direct numerical simulations in two dimensions suggest the impossibility of finite-time perfect mixing for flows with fixed power constraint and we conjecture an exponential lower bound on the H−1 mix-norm in this case. We also discuss some related problems from other areas of analysis that are similarly suggestive of an exponential lower bound for the H−1 mix-norm.
Thermochemical analysis and kinetics aspects for a chemical model for camphene ozonolysis
Authors: Oliveira R. C. de M. , Bauerfeldt G. F.
Published: October 2012

In this work, a chemical model for the camphene ozonolysis, leading to carbonyl final products, is proposed and discussed on the basis of the thermochemical properties and kinetic data obtained at density functional theory levels of calculation. The mechanism is initiated by the electrophilic attack of ozone to the double bond in camphene leading to a 1,2,3-trioxolane intermediate, which decomposes to peroxy radicals and carbonyl compounds in a total of 10 elementary reactions. The thermodynamic properties (enthalpy and entropies differences) are calculated at 298 K. For the thermochemical evaluation, theoretical calculations are performed with the B3LYP, MPW1PW91, and mPW1K density functionals and the basis sets 6-31G(d), 6-31G(2d,2p), 6-31+G(d,p), and 6-31+G(2d,2p). Eventually, single point calculations adopting the 6-311++G(2d,2p) basis set are performed in order to improve the electronic energies. The enthalpy profiles suggest highly exothermic reactions for the individual steps, with a global enthalpy difference of −179.18 kcal mol−1, determined at the B3LYP/6-31+G(2d,2p) level. The Gibbs free energy differences for each step, at 298 K, calculated at the B3LYP/6-311++G(2d,2p)//B3LYP/6-31+G(2d,2p) level, are used to estimate the composition of a final product mixture under equilibrium conditions as 58% of camphenilone and 42% of 6,6-dimethyl-ɛ-caprolactone-2,5-methylene. For the reaction kinetics, the bimolecular O3 + camphene step is assumed to be rate determining in the global mechanism. A saddle point for the ozone addition to the double bond is located and rate constants are determined on the basis of the transition state theory. This saddle point is well represented by a loosely bound structure and corrections for the basis set superposition error (BSSE) are calculated, either by considering the effect over the geometry optimization procedure (here referred as CP1 procedure), or the effect of the BSSE over the electronic energy of a previously optimized geometry, included a posteriori (here referred as CP2). The rate constants, calculated at 298 K from the data obtained at the mPW1K/6-31+G(d,p), CP1/B3LYP//6-31+G(2d,2p), and CP2/B3LYP//6-31+G(2d,2p) levels (3.62 × 10−18, 1.12 × 10−18, and 1.39 × 10−18 cm3 molecule−1 s−1), are found in good agreement with the available experimental data at the same temperature, 0.9 × 10−18 cm3 molecule−1 s−1 [R. Atkinson, S. M. Aschmann, and J. Arey, Atmos. Environ. 24, 2647 (1990)10.1016/0960-1686(90)90144-C]. The importance of the BSSE corrections for the final rate constants must be pointed out. Furthermore, this work will contribute to a better understanding of the chemistry of monoterpenes in the atmosphere, as well as the implications for the phenomena of pollution.
Ion-acoustic solitary waves and their multi-dimensional instability in a magnetized degenerate plasma
Authors: Haider M. M. , Mamun A. A.
Published: October 2012

A rigorous theoretical investigation has been made on Zakharov-Kuznetsov (ZK) equation of ion-acoustic (IA) solitary waves (SWs) and their multi-dimensional instability in a magnetized degenerate plasma which consists of inertialess electrons, inertial ions, negatively, and positively charged stationary heavy ions. The ZK equation is derived by the reductive perturbation method, and multi-dimensional instability of these solitary structures is also studied by the small-k (long wave-length plane wave) perturbation expansion technique. The effects of the external magnetic field are found to significantly modify the basic properties of small but finite-amplitude IA SWs. The external magnetic field and the propagation directions of both the nonlinear waves and their perturbation modes are found to play a very important role in changing the instability criterion and the growth rate of the unstable IA SWs. The basic features (viz., amplitude, width, instability, etc.) and the underlying physics of the IA SWs, which are relevant to space and laboratory plasma situations, are briefly discussed.
Oxygen vacancy filament formation in TiO2: A kinetic Monte Carlo study
Authors: Li Duo , Li Maozhi , Zahid Ferdows , Wang Jian , Guo Hong
Published: October 2012

We report a kinetic Monte Carlo (kMC) investigation of an atomistic model for 3-dimensional structural configurations of TiO2 memristor, focusing on the oxygen vacancy migration and interaction under an external voltage bias. kMC allows the access of experimental time scales so that the formation of well defined vacancy filaments in thin TiO2 films can be simulated. The results show that the electric field drives vacancy migration; and vacancy hopping-induced localized electric field plays a key role for the filament evolution. Using the kMC structure of the filaments at different stages of the formation process, electronic density of states (DOS) are calculated by density functional theory. Filament induced gap states are found which gives rise to a transition from insulating behavior to conducting behavior during the filament formation process. By varying kMC simulations parameters, relations between vacancy diffusion, filament formation, and DOS in the TiO2 thin film are elucidated.
The collision effect between dust grains and ions to the dust ion acoustic waves in a dusty plasma
Authors: Yang Xue , Wang Cang-Long , Liu Cong-Bo , Zhang Jian-Rong , Shi Yu-Ren , Duan Wen-Shan , Yang Lei
Published: October 2012

Damping solitary wave in dusty plasma is studied by considering the collision effect between dust grains and ions. It can be described by a KdV type equation in which a damping term of φ2 exist. It is found that both the amplitude and propagation velocity of the solitary wave decrease with time exponentially. Our results are compared with another KdV type equation with the damping term of φ. It is noted that the damping rate of the KdV type equation with the damping term of φ2 is larger than that with the term of φ. It is found that the damping rate is proportional to the collision frequency between dust grains and ions.
Wave breaking phenomenon of lower-hybrid oscillations induced by a background inhomogeneous magnetic field
Authors: Maity Chandan , Chakrabarti Nikhil , Sengupta Sudip
Published: October 2012

In a fluid description, we study space-time evolution of lower hybrid modes in a cold quasi-neutral homogeneous plasma in presence of a background inhomogeneous magnetic field. Within a linear analysis, a dispersion relation with inhomogeneous magnetic field shows “phase mixing” of such oscillations. A manifestation of “phase mixing” is shown in “mode coupling.” By using Lagrangian variables, an exact solution is presented in parametric form of this nonlinear time dependent problem. It is demonstrated that initially excited lower hybrid modes always break via phase mixing phenomenon in presence of an inhomogeneous magnetic field. Breaking of such oscillations is revealed by the appearance of spikes in the plasma density profile.
Electromechanical instabilities of thermoplastics: Theory and in situ observation
Authors: Wang Qiming , Niu Xiaofan , Pei Qibing , Dickey Michael D. , Zhao Xuanhe
Published: October 2012

Thermoplastics under voltages are used in diverse applications ranging from insulating cables to organic capacitors. Electromechanical instabilities have been proposed as a mechanism that causes electrical breakdown of thermoplastics. However, existing experiments cannot provide direct observations of the instability process, and existing theories for the instabilities generally assume thermoplastics are mechanically unconstrained. Here, we report in situ observations of electromechanical instabilities in various thermoplastics. A theory is formulated for electromechanical instabilities of thermoplastics under different mechanical constraints. We find that the instabilities generally occur in thermoplastics when temperature is above their glass transition temperatures and electric field reaches a critical value. The critical electric field for the instabilities scales with square root of yield stress of the thermoplastic and depends on its Young's modulus and hardening property.
Hybrid organic/GaN photonic crystal light-emitting diode
Authors: Herrnsdorf J. , Guilhabert B. , McKendry J. J. D. , Gong Z. , Massoubre D. , Zhang S. , Watson S. , Kelly A. E. , Gu E. , Laurand N. , Dawson M. D.
Published: October 2012

Periodically nano-patterned organic films incorporating color converting light-emitting polymers have been integrated onto InGaN/GaN light-emitting diodes (LEDs). Polarized and strongly modified hybrid LED emission is observed due to the photonic crystal effect of the nano-pattern. Emission characteristics are appropriate for various applications, and fast modulation capability with an optical −3 dB bandwidth of 168 MHz is demonstrated.
Temporal characterization of a picosecond extreme ultraviolet laser pumped in grazing incidence
Authors: Meng L. , Bourgaux A.-C. , Bastiani-Ceccotti S. , Guilbaud O. , Pittman M. , Kazamias S. , Cassou K. , Daboussi S. , Ros D. , Klisnick A.
Published: October 2012

We report an experimental study of the temporal duration of a transient pumping extreme ultraviolet (XUV) laser emitted at 18.9 nm, using an ultrafast x-ray streak camera. We have investigated the shot-to-shot reproducibility of the pulse duration, as well as its behaviour as a function of several pumping parameters. Our results show that the pulse duration increases slowly with the pump pulse duration, in agreement with previous observations performed in a different geometry. The angle of the pump laser relative to the target surface also affects the XUV laser duration in a measurable way.
Minimum domain size and stability in carbon nanotube-ferroelectric devices
Authors: Blaser C. , Paruch P.
Published: October 2012

Ferroelectric domain switching in c-axis-oriented epitaxial Pb(Zr0.2Ti0.8)O3 thin films was studied using different field geometries and compared to numerical simulations and theoretical predictions. With carbon nanotubes as electrodes, continuous nanodomains as small as 9 nm in radius in a 270 nm thick film could be switched, remaining stable for over 20 months. Defect pinning of domain walls appears to play a key role in stabilizing such domains, below the predicted thermodynamic size limit.
Apertureless near-field microscopy using a knife blade as a scanning probe at millimeter wavelengths
Authors: Nozokido Tatsuo , Ishino Manabu , Tokuriki Masakazu , Kamikawa Hiroyuki , Bae Jongsuck
Published: October 2012

We report on the use of a knife blade as a scanning probe for apertureless near-field microscopy at millimeter wavelengths. Since the knife blade probe is a wider version of the metal tip probe commonly used in this technique, and therefore the interaction area between the probe tip and the sample is larger, an improvement in the intensity of the measured near-field signal is expected. The knife blade probe can also work as a part of a resonator in the illumination optics used in this microscopy format to enhance the strength of the near field that interacts with the sample, resulting in a further improvement in the signal intensity. A scanning method and an image reconstruction algorithm based on computerized tomography are adopted to obtain 2-D near-field images. Experiments performed at 60 GHz using a knife blade with a tip radius of 6 μm (∼λ/1000) show that the signal intensity is enhanced by ∼20 dB compared with an equivalent metal tip probe, and that an image resolution approaching the tip radius of the knife blade is achieved.
Living Together but Apart: Material Geographies of Everyday Sustainability in Extended Family Households
Authors: Klocker Natascha , Gibson Chris , Borger Erin
Published: October 2012

In the Industrialized West, ageing populations and cultural diversity—combined with rising property prices and extensive years spent in education—have been recognized as diverse factors driving increases in extended family living. At the same time, there is growing awareness that household size is inversely related to per capita resource consumption patterns, and that urgent problems of environmental sustainability are negotiated, on a day-to-day basis (and often unconsciously), at the household level. This paper explores the sustainability implications of everyday decisions to fashion, consume, and share resources around the home, through the lens of extended family households. Through interviews with extended family households in Australia, we explore the potential for these living arrangements to reduce resource use, and thus improve sustainability outcomes. In these households, a desire to care for and support family members in hard times (rather than an overt sustainability agenda) has promoted particular modes of extended family living, including unique forms of sharing and pooling material goods. But cultural values of privacy, space, and independence—and the sanctity of the nuclear family—have led to duplication (and even multiplication) of household spaces, appliances, and resources, under one roof. The potential environmental and economic benefits of resource sharing within larger households are thus mediated by deep cultural values and exigencies of everyday life.
Auto-Disabilities: The Case of Shared Space Environments
Authors: Imrie Rob
Published: October 2012

Many urban environments are being redesigned around a relatively new approach to street design termed shared space. Shared space is a traffic engineering concept that eliminates physical barriers separating motor vehicles, pedestrians, and other road users to encourage a sharing of street space. Such sharing is seen as a means to calm traffic and to create convivial urban spaces. The evidence shows that local authorities in the UK and overseas are enthusiastic about shared space for its potential to enhance the urban realm. Vulnerable street users, such as vision-impaired people, do not share this enthusiasm. They perceive shared space as likely to bring them into increasing contact with motor vehicles, and as compromising their safety and well-being. Shared spaces are, potentially, what I refer to as auto-disabling environments. Referring to data from the UK, I develop the proposition that shared space can be characterised as ‘disembodied urban design’ that fails to capture the complexity of corporeal form and the manifold interactions of bodies-in-space. The disembodied understanding of the interactions between bodies, space, and movement, propagated by shared space design, (re)produces both existential insecurity and ontological uncertainty amongst certain categories of users, such as vision-impaired people. Shared space can be understood as a manifestation of disabling design in the built environment, and as a reaffirmation of disabled people's relative invisibility in relation to the crafting of designed spaces.
Trihalomethane formation potential of aquatic and terrestrial fulvic and humic acids: examining correlation between specific trihalomethane formation potential and specific ultraviolet absorbance
Authors: Abouleish Mohamed Y. Z. , Wells Martha J. M.
Published: October 2012

Environmental context When surface water is disinfected to produce potable drinking water, toxic by-products are generated by reaction with naturally occurring organic matter. The production of trihalomethane disinfection by-products was investigated for different types of well-characterised organic matter from various geographic locations. Increased understanding of the character of organic matter dissolved in water is needed for improving the ability to provide safe water and protect public health. Abstract Trihalomethanes (THMs) – a class of disinfection by-products (DBPs) including chloroform – are produced when natural water is chlorinated. Many THMs are believed to result from the reaction of chlorine with the aromatic structures in humic substances, which can be represented by ultraviolet absorbance at 254 nm (UVA). However, in the literature, plots of the specific, or carbon-normalised, UVA (SUVA) compared with the specific, or carbon-normalised, trihalomethane formation potential, THMFP (STHMFP) are poorly correlated. Therefore, well characterised samples of organic matter were obtained from the International Humic Substances Society (IHSS) to study the effect of type (fulvic acid, FA; humic acid, HA), origin (aquatic, terrestrial), geographical source (Nordic, Suwannee River, peat, soil) and pH (6, 9) on the formation of trihalomethanes. In this research, parameters expressed on a weight-average moles-of-humic substance basis were compared with those on a mass-of-carbon basis. Using factorial analysis, SUVA was statistically described by the main effect type (P = 0.0044), whereas STHMFP was statistically described by the main effects type (P = 0.0078) and origin (P = 0.0210). Separate relationships between SUVA and STHMFP normalised to moles of humic substance were defined for aquatic substances (R2 = 0.9948) and for terrestrial substances (R2 = 0.9512). The occurrence of aquatically derived fulvic-like humic acid (Suwannee River humic acid) and aquatically derived terrestrial-like humic acid (Nordic humic acid) were observed. Some aquatic substances were capable of generating levels of THMs per mole of humic substance that were greater than or equal to the most reactive terrestrial humic acid.
β-Nerve growth factor is a major component of alpaca seminal plasma and induces ovulation in female alpacas
Authors: Kershaw-Young C. M. , Druart X. , Vaughan J. , Maxwell W. M. C.
Published: October 2012

Ovulation in camelids is induced by an unidentified protein in the seminal plasma of the male termed ‘ovulation-inducing factor’. This protein has been reported to be a 14-kDa protein under reducing conditions, which, when purified from seminal plasma, induces ovulation in llamas. The identification of this protein and investigation of its potential to induce ovulation in camelids may aid the development of protocols for the induction of ovulation. In the present study, alpaca seminal plasma proteins were separated using one-dimensional sodium dodecyl sulfate–polyacrylamide gel electrophoresis and the most abundant protein of 14 kDa was identified as β-nerve growth factor (β-NGF) by liquid chromatography mass spectrometry. Female alpacas (n = 5 per group) were given intramuscular injections of: (1) 1 mL of 0.9% saline; (2) 4 µg buserelin, a gonadotrophin-releasing hormone agonist; (3) 2 mL alpaca seminal plasma; or (4) 1 mg human β-NGF. Ovulation was detected by transrectal ultrasonography 8 days after treatment and confirmed by plasma progesterone concentrations. Ovulation occurred in 0%, 80%, 80% and 80% of animals treated with saline, buserelin, seminal plasma and β-NGF, respectively. Treatment type did not affect the diameter of the corpus luteum, but plasma progesterone concentrations were lower in saline-treated animals than in the other treatment groups owing to the lack of a corpus luteum. The present study is the first to identify the ovulation-inducing factor protein in alpacas. β-NGF successfully induces ovulation in alpacas and this finding may lead to new methods for the induction of ovulation in camelids.
Court-based participatory research: collaborating with the justice system to enhance sexual health services for vulnerable women in the United States
Authors: Roth Alexis , Fortenberry J. Dennis , Van Der Pol Barbara , Rosenberger Joshua , Dodge Brian , Arno Janet , Waters Janine , Certo David , Reece Michael
Published: October 2012

Background
Although jail screening programs have an important role in the diagnosis and treatment of sexually transmissible infections (STI) and HIV among incarcerated individuals, many arrestees are not screened before release. Justice-involved women are at particularly high risk for these conditions because of individual risk behaviour as well as other network-level risk factors. Court-based programs could provide a critical bridge between these women, STI risk counselling and health services. This formative study explored the features of a program that would encourage STI testing among court-involved women. Further, we describe how community-based participatory research principles were adapted for use in a court setting and the resulting justice–public health partnership. Methods: Using semistructured interviews and focus group discussions, we explored issues related to health-seeking behaviours, perceived gaps in services for high-risk women and the components of a court-based screening program. Results: Six focus groups were conducted with women with a history of commercial sex work and staff from the court, as well as local organisations providing HIV and social support services for high-risk women. Community-based participatory research (CBPR) principles facilitated development of relevant research questions and equitable processes, and assisted partners to consider individual and sociostructural sources of health disparities. Discussion: Although not every principle was applicable in a court setting, the CBPR framework was helpful for building cohesion and support for the project. We provide a description of how CBPR principles were operationalised, describe the key lessons learned and discuss the implications for CBPR projects in a community court.
Estimating the costs of climate change adaptation in the agricultural sector.
Authors: Wreford A. , Renwick A.
Published: October 2012

With the increasing recognition of the importance of adaptation in addressing climate change, an understanding of the costs and benefits of potential adaptations is necessary. To date, few detailed studies provide comprehensive economic estimates of adaptation, given the uncertainties and complexities involved. Those that consider adaptation can be loosely grouped into top-down global estimates and bottom-up estimates. The different approaches provide estimates that are useful for different purposes. In this paper, we introduce the concept of adaptation and the role it can play in reducing climate change damage, before reviewing the available literature on both approaches in the agricultural sector and highlighting the advantages and disadvantages of both. We then discuss possible reasons for the dearth of estimates and suggest ways forward.
The positive contribution of invertebrates to sustainable agriculture and food security.
Authors: Cock M. J. W. , Biesmeijer J. C. , Cannon R. J. C. , Gerard P. J. , Gillespie D. , Jiménez J. J. , Lavelle P. M. , Raina S. K.
Published: October 2012

This study focuses on three main groups of organisms: soil invertebrates, biological control agents (BCAs) and pollinators. These groups play key roles in agricultural systems, and have the potential to be used, moved or manipulated for the benefit of agriculture. Soil invertebrates are a key component of agricultural landscapes. They participate in essential soil processes that maintain healthy productive soils in the face of changing environmental conditions. Reducing the diversity of a community of soil invertebrates reduces its beneficial functions and services, with drastic ecological effects such as long-term deterioration of soil fertility and agricultural productive capacity. The introduction of a keystone species may have detrimental or beneficial effects depending on the context. The interaction between soil invertebrates and soil micro-organisms is critical: the activities of soil invertebrates regulate microbial activity in soils, and micro-organisms enter into intimate relationships with soil invertebrates to help them degrade highly complex compounds such as cellulose. Different groups of invertebrates provide biological control of crop pests. In many situations, they form the basis of, and tools for, the integrated pest management (IPM) approach. Given that the losses caused by pre- and post-harvest pests can be very substantial, the potential benefits of using invertebrates as BCAs are vast, but as yet only partially tapped. The potential for soil invertebrates to assist in this function is still largely unknown. Pollination services by animals, especially by insects, are among the most widespread and important processes that structure ecological communities in both natural and agricultural landscapes. An estimated 60-90% of the world's flowering plants - including a range of economically important species - depend on insects for pollination. Crop pollination used to be (and often still is) provided by wild pollinators spilling over from natural and semi-natural habitats close to crop fields. This service has generally been free and therefore has received little attention in agricultural management. If wild pollinators are lacking or additional pollination is required, as is the case in many intensive agricultural production systems, farmers in some developed countries can buy or rent managed honeybees or sometimes other species (e.g. bumblebees, alfalfa leafcutter bees and alkali bees). Both options - i.e. use of wild species and managed bees - have recently come under pressure, a development that is sometimes referred to as the 'pollination crisis'. Of the interactions and overlaps between these key groups, that between soil invertebrates and BCAs is the most important, and further research is needed to evaluate the scope and impact of manipulation of the soil ecosystem to conserve or encourage beneficial BCAs.
Major bacterial diseases in aquaculture and their vaccine development.
Authors: Pridgeon J. W. , Klesius P. H.
Published: October 2012

Aquaculture is emerging as the fastest growing food-producing industry in the world because of the increasing demand for food fish consumption. However, the intensive culture of food fish has led to outbreaks of various bacterial diseases, resulting in annual economic losses to the aquaculture industry estimated at billions of dollars worldwide. Feeding infected fish with antibiotic-medicated food is a general practice but has led to antibiotic resistance development in bacterial pathogen, resulting in a higher dose requirement for effective control, a matter of increasing public concern. Therefore, alternatives to antibiotics that give similar or enhanced protection to aquatic animals are urgently needed. Various vaccines have been developed recently to combat bacterial diseases in aquaculture. The purpose of this review is to summarize the major bacterial pathogens in aquaculture and the development of vaccines as alternatives to antibiotics to protect aquatic animals from these bacterial diseases.
NOT QUITE ‘SUI GENERIS’ ENOUGH
Authors: Diez Thomas
Published: October 2012

The debate about the role of the EU in international politics is dominated by the characterisation of the EU as a normative power. In this article, I argue that there are fundamental tensions between the core values that the EU is supposed to embody and articulate in this context. In a first step, I introduce democracy and justice as two exemplary values associated with European integration and introduce the argument about the tensions between these values, which I largely take from the so-called English School of International Relations. This then serves as a basis for exploring these tensions in relation to two illustrative cases: EU-Turkey relations and the control of the external EU (or, to be more precise, Schengen) border. I conclude that the EU's often-invoked character as a ‘post-modern’ political system may well apply to its internal configuration, but much less so to its external relations. It thus cannot escape the normative tensions inherent to a territorially configured international society.
Efficacy of Improved Hydrogen Peroxide against Important Healthcare-Associated Pathogens
Authors: Rutala William A. , Gergen Maria F. , Weber David J.
Published: October 2012

This study was designed to test in vitro efficacy of 2 improved hydrogen peroxide (HP) products against 3 standard HP products and 1 quaternary ammonium compound. Improved HP is significantly superior to standard HP at the same concentration and can be used for disinfection of environmental surfaces or noncritical patient care items.
A Clinical History of Methicillin-Resistant Staphylococcus aureus Is a Poor Predictor of Preoperative Colonization Status and Postoperative Infections
Authors: Strymish Judith , Branch-Elliman Westyn , Itani Kamal M. F. , Williams Sandra , Gupta Kalpana
Published: October 2012

Objective.

In the absence of established methicillin-resistant Staphylococcus aureus (MRSA) screening programs, many centers use a history of a positive culture or a nasal screen as a surrogate for preoperative MRSA colonization status. We aimed to evaluate the test characteristics of these surrogates.

Design.

Retrospective cohort study.

Participants.

Veterans Affairs Boston Healthcare System surgical patients with a preoperative nasal MRSA polymerase chain reaction (PCR) screen.

Methods.

We assessed the performance of a history of a MRSA-positive culture or a positive nasal MRSA PCR screen during the year prior to surgery for predicting the preoperative nasal PCR screen result. The associations between MRSA history and postoperative outcomes, including MRSA cultures and infections, were also evaluated.

Results.

Among 4,238 patients, a positive MRSA culture history had a sensitivity of 19.7% (95% confidence interval [CI], 15.4%–24.8%) and positive predictive value of 57.3% for the preoperative nasal MRSA status. The specificity of MRSA culture history was 99% (95% CI, 98.5%–99.2%). Prior-year nasal MRSA screen results had similar test characteristics. A history of a MRSA-positive culture was associated with an increased risk of postoperative MRSA-positive cultures (risk ratio [RR], 3.54 [95% CI, 1.70–7.37], P< .001) but not of infections (RR, 1.71 [95% CI, 0.58–5.01]), after adjustment for preoperative nasal MRSA status, vancomycin surgical prophylaxis, surgical scrub, and age.

Conclusions.

A history of a MRSA-positive culture and a positive nasal PCR screen are poor surrogate markers of preoperative colonization status, missing at least 70% of MRSA-colonized patients. Prior-year history is also not independently associated with MRSA-related postoperative infections. Strong consideration should be given to preoperative MRSA screening in patients at high risk for surgical complications.
Equal Efficacy of Glucoprotamin and an Aldehyde Product for Environmental Disinfection in a Hematologic Transplant Unit: A Prospective Crossover Trial
Authors: Meinke Ruth , Meyer Bernhard , Frei Reno , Passweg Jakob , Widmer Andreas F.
Published: October 2012

Background.

The inanimate hospital environment has emerged as an important reservoir of nosocomial pathogens. In particular, multidrug-resistant pathogens, such as methicillin-resistant Staphylococcus aureus, Acinetobacter species, and Clostridium difficile, play a major role in the transmission of hospital-acquired infections. In Europe, aldehydes, chlorine, and quaternary ammonium compounds have been commonly used for environmental disinfection. Glucoprotamin, a newer active compound for disinfectants, has been clinically tested for disinfection of instruments but not for environmental disinfection.

Objective.

This study evaluated the antimicrobial effectiveness of a glucoprotamin-containing product (Incidin) compared with that of an aldehyde-containing product (Deconex), the current standard at our institution.

Methods.

This prospective crossover study was conducted in our access-restricted hematologic transplant unit. A total of 3,086 samples from the environment were processed and examined for overall bacterial burden as well as selectively for S. aureus, C. difficile, and gram-negative bacteria.

Results.

There was no significant difference in residual bacteria after disinfection between the 2 products in terms of overall burden and selected pathogens. Enterococci were the predominant pathogens recovered from surfaces, but no vancomycin-resistant enterococci were recovered. Similarly, C. difficile could not be found in the patients' environment, even in rooms, despite the use of selective media.

Conclusion.

The aldehyde-containing product (Deconex) and the glucoprotamin-containing product (Incidin) demonstrated similar efficacy against environmental contamination in a hematologic transplant unit with the application of selective media for C. difficile, S. aureus, and gram-negative bacteria in addition to standard medium.
Bed Bugs in Healthcare Settings
Authors: Munoz-Price L. Silvia , Safdar Nasia , Beier John C. , Doggett Stephen L.
Published: October 2012

Infestations caused by bed bugs have resurfaced during the past decade across all continents. Even though bed bugs primarily cause skin manifestations in humans, a major stigma is placed upon people or institutions found to carry them. It is important for healthcare facilities to be prepared for this pest by implementing policies, carefully selecting materials used for hospital furniture, and educating providers on early identification and control.
Intraoperative Cardiac Arrests in Adults Undergoing Noncardiac Surgery
Authors: Goswami Sumeet , Brady Joanne E. , Jordan Desmond A. , Li Guohua
Published: October 2012

Background

Intraoperative cardiac arrest (ICA) is a rare but potentially catastrophic event. There is a paucity of recent epidemiological data on the incidence and risk factors for ICA. The objective of this study was to assess the incidence, risk factors, and survival outcome of ICAs in adults undergoing noncardiac surgery.

Methods

The authors analyzed prospectively collected data for all noncardiac cases in the American College of Surgeons National Surgical Quality Improvement Program database from the years 2005 to 2007 (n = 362,767).

Results

The incidence of ICA was 7.22 per 10,000 surgeries. After adjustment for American Society of Anesthesiologists physical status and other covariates, the odds of ICA increased progressively with the amount of transfusion (adjusted odds ratios = 2.51, 7.59, 11.40, and 29.68 for those receiving 1-3, 4-6, 7-9, and ≥ 10 units of erythrocytes, respectively). Other significant risk factors for ICA were emergency surgery (adjusted odds ratio = 2.04, 95% CI = 1.45-2.86) and being functionally dependent presurgery (adjusted odds ratio = 2.33, 95% CI = 1.69-3.22). Of the 262 patients with ICA, 116 (44.3%) died within 24 h, and 164 (62.6%) died within 30 days.

Conclusions

Intraoperative blood loss as indicated by the amount of transfusion was the most important predictor of ICA. The urgency of surgery and the preoperative composite indicators of health such as American Society of Anesthesiologists status and functional status were other important risk factors. The high case fatality suggests that primary prevention might be the key to reducing mortality from ICA.
Comparison between Respiratory Variations in Pulse Oximetry Plethysmographic Waveform Amplitude and Arterial Pulse Pressure during Major Abdominal Surgery
Authors: Hengy Baptiste , Gazon Mathieu , Schmitt Zoe , Benyoub Karima , Bonnet Aurélie , Viale Jean Paul , Aubrun Frederic
Published: October 2012

Background

To assess preload dependence, the variation of the plethysmographic waveform of pulse oximetry (ΔPOP) has been proposed as a surrogate of the pulse pressure variation (ΔPP). The aim of the study was to assess the ability of the pulse oximeter-derived plethysmographic analysis to accurately trend ΔPP in patients undergoing major abdominal surgery by using standard monitors.

Methods

A continuous recording of arterial and plethysmographic waveform was performed in 43 patients undergoing abdominal surgery. ΔPP and ΔPOP were calculated on validated respiratory cycles.

Results

For analysis, 92,467 respiratory cycles were kept (73.5% of cycles recorded in 40 patients). The mean of intrapatient coefficients of correlation was low (r = 0.22). The Bland and Altman analysis showed a systematic bias of 5.21; the ΔPOP being greater than the ΔPP, this bias increased with the mean value of the two indices and the limits of agreement were wide (upper 21.7% and lower -11.3%). Considering a ΔPP threshold at 12% to classify respiratory cycles as responders and nonresponders, the corresponding best cutoff value of ΔPOP was 13.6 ± 4.3%. Using these threshold values, the observed classification agreement was moderate (κ = 0.50 ± 0.09).

Conclusions

The wide limits of agreement between ΔPP and ΔPOP and the weak correlation between both values cast doubt regarding the ability of ΔPOP to substitute ΔPP to follow trend in preload dependence and classify respiratory cycles as responders or nonresponders using standard monitor during anesthesia for major abdominal surgery.
Hypnotic Hypersensitivity to Volatile Anesthetics and Dexmedetomidine in Dopamine β-Hydroxylase Knockout Mice
Authors: Hu Frances Y. , Hanna George M. , Han Wei , Mardini Feras , Thomas Steven A. , Wyner Abraham J. , Kelz Max B.
Published: October 2012

Background

Multiple lines of evidence suggest that the adrenergic system can modulate sensitivity to anesthetic-induced immobility and anesthetic-induced hypnosis as well. However, several considerations prevent the conclusion that the endogenous adrenergic ligands norepinephrine and epinephrine alter anesthetic sensitivity.

Methods

Using dopamine β-hydroxylase knockout (Dbh) mice genetically engineered to lack the adrenergic ligands and their siblings with normal adrenergic levels, we test the contribution of the adrenergic ligands upon volatile anesthetic induction and emergence. Moreover, we investigate the effects of intravenous dexmedetomidine in adrenergic-deficient mice and their siblings using both righting reflex and processed electroencephalographic measures of anesthetic hypnosis.

Results

We demonstrate that the loss of norepinephrine and epinephrine and not other neuromodulators co-packaged in adrenergic neurons is sufficient to cause hypersensitivity to induction of volatile anesthesia. However, the most profound effect of adrenergic deficiency is retarding emergence from anesthesia, which takes two to three times as long in Dbh mice for sevoflurane, isoflurane, and halothane. Having shown that Dbh mice are hypersensitive to volatile anesthetics, we further demonstrate that their hypnotic hypersensitivity persists at multiple doses of dexmedetomidine. Dbh mice exhibit up to 67% shorter latencies to loss of righting reflex and up to 545% longer durations of dexmedetomidine-induced general anesthesia. Central rescue of adrenergic signaling restores control-like dexmedetomidine sensitivity. A novel continuous electroencephalographic analysis illustrates that the longer duration of dexmedetomidine-induced hypnosis is not due to a motor confound, but occurs because of impaired anesthetic emergence.

Conclusions

Adrenergic signaling is essential for normal emergence from general anesthesia. Dexmedetomidine-induced general anesthesia does not depend on inhibition of adrenergic neurotransmission.