bluuebunny/crossref_metadata_2025 huggingface dataset:
Leaf microbiota in an agroecosystem: spatiotemporal variation in bacterial community composition on field-grown lettuce
Authors: Rastogi Gurdeep , Sbodio Adrian , Tech Jan J , Suslow Trevor V , Coaker Gitta L , Leveau Johan H J
Published: April 2012

The presence, size and importance of bacterial communities on plant leaf surfaces are widely appreciated. However, information is scarce regarding their composition and how it changes along geographical and seasonal scales. We collected 106 samples of field-grown Romaine lettuce from commercial production regions in California and Arizona during the 2009–2010 crop cycle. Total bacterial populations averaged between 105 and 106 per gram of tissue, whereas counts of culturable bacteria were on average one (summer season) or two (winter season) orders of magnitude lower. Pyrosequencing of 16S rRNA gene amplicons from 88 samples revealed that Proteobacteria, Firmicutes, Bacteroidetes and Actinobacteria were the most abundantly represented phyla. At the genus level, Pseudomonas, Bacillus, Massilia, Arthrobacter and Pantoea were the most consistently found across samples, suggesting that they form the bacterial ‘core’ phyllosphere microbiota on lettuce. The foliar presence of Xanthomonas campestris pv. vitians, which is the causal agent of bacterial leaf spot of lettuce, correlated positively with the relative representation of bacteria from the genus Alkanindiges, but negatively with Bacillus, Erwinia and Pantoea. Summer samples showed an overrepresentation of Enterobacteriaceae sequences and culturable coliforms compared with winter samples. The distance between fields or the timing of a dust storm, but not Romaine cultivar, explained differences in bacterial community composition between several of the fields sampled. As one of the largest surveys of leaf surface microbiology, this study offers new insights into the extent and underlying causes of variability in bacterial community composition on plant leaves as a function of time, space and environment.
Optimizing the crystal environment through extended x-ray absorption fine structure to increase the luminescent lifetimes of Er3+ doped Y2O3 nanoparticles
Authors: Dorman James A. , Choi Ju H. , Kuzmanich Gregory , Bargar John R. , Chang Jane P.
Published: April 2012

To predict and optimize luminescence efficiency of rare-earth ion doped (RE) nanophosphors, a relationship between the RE-concentration and the luminescent parameters is often obtained by Judd-Ofelt analysis, where the quality factor (χ=Ω4/Ω6) depends on the Er interactions with other RE elements in the second nearest neighboring shell. In this work, a detailed analysis of the local bonding environment by extended x-ray absorption fine structure (EXAFS) analyses is shown as effective as the Judd-Ofelt analysis to quantify the Er↔RE interaction in the second nearest neighboring shell (ρN=IREr↔RE2/IREr↔RE1). As the physical basis of ρN is consistent to that of χ, the EXAFS analysis becomes a viable alternative to replace Judd-Ofelt analysis to predict the optimum dopant concentration. This approach was corroborated based on analysis of Er3+:Y2O3 and core-shell Er3+:Y2O3|Y2O3 (5 nm shell) nanoparticles (NPs), with Er3+ concentrations up to 20 mol %. The ρN ratio from EXAFS analysis was shown to strongly correlate to the lifetimes extracted from the Judd-Ofelt analysis, both predicting the optimal dopant concentrations to be at 5 mol % and 2 mol % for the Er3+:Y2O3 and core-shell NPs, respectively. This confirms that EXAFS analysis can be used as a more time efficient method to achieve the same outcome typically obtained by Judd-Ofelt analysis, enabling the optimization of the luminescent lifetimes of RE doped nano-phosphors.
Towards constructing multi-bit binary adder based on Belousov-Zhabotinsky reaction
Authors: Zhang Guo-Mao , Wong Ieong , Chou Meng-Ta , Zhao Xin
Published: April 2012

It has been proposed that the spatial excitable media can perform a wide range of computational operations, from image processing, to path planning, to logical and arithmetic computations. The realizations in the field of chemical logical and arithmetic computations are mainly concerned with single simple logical functions in experiments. In this study, based on Belousov-Zhabotinsky reaction, we performed simulations toward the realization of a more complex operation, the binary adder. Combining with some of the existing functional structures that have been verified experimentally, we designed a planar geometrical binary adder chemical device. Through numerical simulations, we first demonstrated that the device can implement the function of a single-bit full binary adder. Then we show that the binary adder units can be further extended in plane, and coupled together to realize a two-bit, or even multi-bit binary adder. The realization of chemical adders can guide the constructions of other sophisticated arithmetic functions, ultimately leading to the implementation of chemical computer and other intelligent systems.
Interaction of a bi-molecular liquid crystal film with functionalized nanoparticles
Authors: Taylor Jefferson W. , Kurihara Lynn K. , Martínez-Miranda L. J.
Published: April 2012

We investigate the properties of a bi-molecular film of liquid crystal close to a magnetic nanoparticle terminated with a variety of functionalization compounds using atomic force microscopy. Studies in bulk liquid crystals have shown that the functionalization compound influences how the liquid crystal reorients. The results of this investigation are compared to the results of work done on phospholipids in close contact with uncovered silica nanoparticles. Our studies of the liquid crystal in contact with the nanoparticles show that its behavior is dependent on the functionalization compound.
Co/Ni multilayers with perpendicular anisotropy for spintronic device applications
Authors: You L. , Sousa R. C. , Bandiera S. , Rodmacq B. , Dieny B.
Published: April 2012

This letter presents a study of perpendicular anisotropy in Co/Ni multilayers, which could constitute a thick polarizer in spin torque oscillators or a magnetic electrode in magnetic tunnel junctions (MTJ) with perpendicular anisotropy. Perfectly square perpendicular loops are observed for as-deposited Co/Ni multilayers with various sublayer thicknesses and bilayer repetition numbers using a Pt buffer layer. An anisotropy energy of 1.0 × 106 erg·cm−3 is obtained for 9 nm thick Co/Ni multilayers. For Co/Ni multilayers deposited on MgO, no perpendicular magnetization component is observed in the as-deposited state, but it develops (even in 2.1 nm Co/Ni multilayers) after annealing at 250 °C.
Oscillatory transverse instability of interfacial waves in horizontally oscillating flows
Authors: Jalikop Shreyas V. , Juel Anne
Published: April 2012

We present the results of an experimental investigation into the stability of steep interfacial waves in two immiscible liquid layers subject to horizontal oscillations. Two-dimensional waves, which arise beyond a critical forcing speed Vc (product of forcing frequency and amplitude), can in turn lose stability to oscillatory transverse amplitude modulations with a near sub-harmonic response at a critical value of the forcing speed, Vcs > Vc. We characterize the resulting transverse waves and study the effect of viscosity on the onset of this secondary instability. Our experiments show that Vcs increases with the ratio of the viscosities of the two liquids, N ⩾ 1, which is in contrast to the decreasing trend of Vc. The thresholds converge with decreasing N but appear to remain distinct even as N → 1. However, our results suggest a change of behavior for N ⩽ 39, which also coincides with the first observations of interface breakup.
Gas-phase calorimetry of protonated water clusters
Authors: Schmidt M. , von Issendorff B.
Published: April 2012

Protonated water clusters with 60 to 79 molecules have been studied by nanocalorimetry. The technique is based on multi-collision excitations of the accelerated clusters with helium. The caloric curves indicate transitions that resemble those of water clusters charged by an excess electron, but the transition temperatures of the protonated clusters are higher.
Hydrodynamic model for electron-hole plasma in graphene
Authors: Svintsov D. , Vyurkov V. , Yurchenko S. , Otsuji T. , Ryzhii V.
Published: April 2012

We propose a hydrodynamic model describing steady-state and dynamic electron and hole transport properties of graphene structures which accounts for the features of the electron and hole spectra. It is intended for electron-hole plasma in graphene characterized by high rate of inter-carrier scattering compared to external scattering (on phonons and impurities), i.e., for intrinsic or optically pumped (bipolar plasma), and gated graphene (virtually monopolar plasma). We demonstrate that the effect of strong interaction of electrons and holes on their transport can be treated as a viscous friction between the electron and hole components. We apply the developed model for the calculations of the graphene dc conductivity; in particular, the effect of mutual drag of electrons and holes is described. The spectra and damping of collective excitations in graphene in the bipolar and monopolar limits are found. It is shown that at high gate voltages and, hence, at high electron and low hole densities (or vice-versa), the excitations are associated with the self-consistent electric field and the hydrodynamic pressure (plasma waves). In intrinsic and optically pumped graphene, the waves constitute quasineutral perturbations of the electron and hole densities (electron-hole sound waves) with the velocity being dependent only on the fundamental graphene constants.
On the energy conversion efficiency in magnetic hyperthermia applications: A new perspective to analyze the departure from the linear regime
Authors: Landi G. T. , Bakuzis A. F.
Published: April 2012

The success of magnetic hyperthermia cancer treatments rely strongly on the magnetic properties of the nanoparticles and their intricate dependence on the externally applied field. This is particularly more so as the response departs from the low field linear regime. In this paper we introduce a new parameter, referred to as the efficiency in converting electromagnetic energy into thermal energy, which is shown to be remarkably useful in the analysis of the system response, especially when the power loss is investigated as a function of the applied field amplitude. Using numerical simulations of dynamic hysteresis, through the stochastic Landau-Lifshitz model, we map in detail the efficiency as a function of all relevant parameters of the system and compare the results with simple—yet powerful—predictions based on heuristic arguments about the relaxation time.
Colloidal crystallization in the quasi-two-dimensional induced by electrolyte gradients
Authors: Reinmüller A. , Oğuz E. C. , Messina R. , Löwen H. , Schöpe H. J. , Palberg T.
Published: April 2012

We investigated driven crystal formation events in thin layers of sedimented colloidal particles under low salt conditions. Using optical microscopy, we observe particles in a thermodynamically stable colloidal fluid to move radially converging towards cation exchange resin fragments acting as seed particles. When the local particle concentration has become sufficiently large, subsequently crystallization occurs. Brownian dynamics simulations of a 2D system of purely repulsive point-like particles exposed to an attractive potential, yield strikingly similar scenarios, and kinetics of accumulation and micro-structure formation. This offers the possibility of flexibly designing and manufacturing thin colloidal crystals at controlled positions and thus to obtain specific micro-structures not accessible by conventional approaches. We further demonstrate that particle motion is correlated with the existence of a gradient in electrolyte concentration due to the release of electrolyte by the seeds.
An accurate study of the dynamics of the C+OH reaction on the second excited 14A″ potential energy surface
Authors: Zanchet A. , González-Lezana T. , Roncero O. , Jorfi M. , Honvault P. , Hankel M.
Published: April 2012

The dynamics of the C(3P)+OH(X2Π) → CO(a3Π)+H(2S) on its second excited potential energy surface, 14A″, have been investigated in detail by means of an accurate quantum mechanical (QM) time-dependent wave packet (TDWP) approach. Reaction probabilities for values of the total angular momentum J up to 50 are calculated and integral cross sections for a collision energy range which extends up to 0.1 eV are shown. The comparison with quasi-classical trajectory (QCT) and statistical methods reveals the important role played by the double well structure existing in the potential energy surface. The TDWP differential cross sections exhibit a forward-backward symmetry which could be interpreted as indicative of a complex-forming mechanism governing the dynamics of the process. The QM statistical method employed in this study, however, is not capable to reproduce the main features of the possible insertion nature in the reactive collision. The ability to stop individual trajectories selectively at specific locations inside the potential energy surface makes the QCT version of the statistical approach a better option to understand the overall dynamics of the process.
A new model of chemical bonding in ionic melts
Authors: Chaban Vitaly V. , Pereverzev Yuriy V. , Prezhdo Oleg V.
Published: April 2012

We developed a new physical model to predict macroscopic properties of inorganic molten systems using a realistic description of inter-atomic interactions. Unlike the conventional approach, which tends to overestimate viscosity by several times, our systems consist of a set of ions with an admixture of neutral atoms. The neutral atom subsystem is a consequence of the covalent/ionic state reduction, occurring in the liquid phase. Comparison of the calculated macroscopic properties (shear viscosity and self-diffusion constants) with the experiment demonstrates good performance of our model. The presented approach is inspired by a significant degree of covalent interaction between the alkali and chlorine atoms, predicted by the coupled cluster theory.
Frequency control in the process of a multicell superconducting cavity production
Authors: Shemelin Valery , Carriere Paul
Published: April 2012

Modifications in the geometry of a superconducting RF cavity due to various processing procedures are presented in a convenient matrix formulation. Specifically, the effect of chemical etching, cooling down, and preloading are characterized, while the corresponding frequency shifts are calculated with a reliable software. This matrix method was used in the fabrication of the first cornell energy recovery linac (ERL) 7-cell cavity. Cavity fabrication can be broken down into three main stages: deep-drawing cups, welding the cups in pairs to obtain “dumbbells” and end groups, and, finally, welding the obtained components into a completed cavity. Frequency measurements and precise machining were implemented after the second stage. A custom RF fixture and data acquisition system were designed and validated for this purpose. The system comprised of a mechanical press with RF contacts, a network analyzer, a load cell and custom LABVIEW and MATLAB scripts. To extract the individual frequencies of the cups from these measurements, the established algorithm of calculations was analysed and corrected. Corrections for the ambient environment were also incorporated into the measurement protocol. Using the procedure presented, the frequency deviation of the completed 1.3 GHz 7-cell cavity was 360 kHz, corresponding to an average error about 75 μm in length for every cell.
An oscillator circuit to produce a radio-frequency discharge and application to metastable helium saturated absorption spectroscopy
Authors: Moron F. , Hoendervanger A. L. , Bonneau M. , Bouton Q. , Aspect A. , Boiron D. , Clément D. , Westbrook C. I.
Published: April 2012

We present a rf gas discharge apparatus which provides an atomic frequency reference for laser manipulation of metastable helium. We discuss the biasing and operation of a Colpitts oscillator in which the discharge coil is part of the oscillator circuit. Radiofrequency radiation is reduced by placing the entire oscillator in a metal enclosure.
Realization of high-quality HfO2 on In0.53Ga0.47As by in-situ atomic-layer-deposition
Authors: Lin T. D. , Chang Y. H. , Lin C. A. , Huang M. L. , Lee W. C. , Kwo J. , Hong M.
Published: April 2012

High κ dielectric of HfAlO/HfO2 was an in-situ atomic-layer-deposited directly on molecular beam epitaxy grown In0.53Ga0.47As surface without using pre-treatments or interfacial passivation layers, where HfAlO (HfO2:Al2O3 ∼ 4:1) with high re-crystallization temperature was employed as the top oxide layer. The HfAlO (∼4.5 nm)/HfO2 (0.8 nm)/In0.53Ga0.47As metal oxide semiconductor capacitors have exhibited an oxide/In0.53Ga0.47As interface free of arsenic-related defective bonding, thermodynamic stability at 800 °C, and low leakage current densities of <10−7 A/cm2 at ±1 MV/cm. The interfacial trap density (Dit) spectra in absence of mid-gap peaks were obtained by temperature-dependent capacitance and conductance with Dit’s of 2–3 × 1012 eV−1 cm−2 below and 6–12 × 1011 eV−1 cm−2 above the mid-gap of In0.53Ga0.47As, respectively. An equivalent oxide thickness of less than 1 nm has been achieved by reducing the HfAlO thickness to ∼2.7 nm with the same initial HfO2 thickness of ∼0.8 nm.
Impact of the Ga/In ratio on the N incorporation into (In,Ga)(As,N) quantum dots
Authors: Gargallo-Caballero R. , Guzmán A. , Ulloa J. M. , Hierro A. , Hopkinson M. , Luna E. , Trampert A.
Published: April 2012

In this work, we demonstrate the dependence of the nitrogen incorporation on the Ga/In content into (In,Ga)(As,N) quantum dots (QDs) grown on GaAs (100) by radio-frequency plasma assisted molecular beam epitaxy (MBE). Morphological analysis by atomic force microscopy and cross-sectional transmission electron microscopy, together with an estimation of the transition thickness, monitored in situ during the growth, predict a maximum in the N incorporation for 30% Ga content. This result is confirmed by photoluminescence measurements of the as-grown and post-growth annealed samples. We attribute this behavior to a trade off between two mechanisms depending on the Ga/In content: one related to the stability of the Ga-N bond, and the other related to the surface strain and/or In segregation.
In-situ neutron diffraction study of Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 single crystals under uniaxial mechanical stress
Authors: Li Qian , Liu Yun , Luzin Vladimir , Studer Andrew J. , Wan Yuhui , Li Zhengrong , Norén Lasse , Withers Ray L. , Xu Zhuo
Published: April 2012

In this paper, we report the phase transition behavior of ternary relaxor ferroelectric single crystals of 0.25Pb(In1/2Nb1/2)O3-0.44Pb(Mg1/3Nb2/3)O3-0.31PbTiO3 subject to a uniaxial mechanical stress up to 400 MPa. The resultant in situ neutron diffraction data are interpreted in terms of the polarization rotation theory and provide direct structural evidence for the stress-induced polarization rotation pathway deduced from studies of macroscopic physical properties under stress. It is suggested that an intermediate, metastable orthorhombic phase is induced above a critical pressure of ∼75 MPa. This critical stress level appears to be unaffected by sample poling although the ground states (at zero stress) for the poled and unpoled crystals are different. The critical stress level, however, does decrease with increasing temperature. The elastic behavior of the intermediate phases is also studied based on a calculation of the associated lattice strains.
Defect level distributions and atomic relaxations induced by charge trapping in amorphous silica
Authors: Anderson Nathan L. , Pramod Vedula Ravi , Schultz Peter A. , Ginhoven R. M. Van , Strachan Alejandro
Published: April 2012

We compute the distribution of electronic levels of native defects in amorphous silica from total energy differences of charge-state density functional theory calculations over an ensemble of atomic structures. The predicted distributions reproduce results from trap spectroscopy by charge injection experiments, validating the calculations. Furthermore, our study characterizes the experimentally inaccessible contributions of individual defect types to the overall distribution. Computed electron and hole trapping levels provide insight into the positive charge buildup in bulk silica observed in negative-bias-temperature-instability, an important degradation mechanism of metal-oxide-semiconductor devices.
Near-infrared sensitization of solid-state dye-sensitized solar cells with a squaraine dye
Authors: Dualeh Amalie , Delcamp Jared H. , Nazeeruddin Mohammad K. , Grätzel Michael
Published: April 2012

Here, we report the use of a squaraine-based dye, JD10, as a near-infrared sensitizer for solid-state dye-sensitized solar cells (ssDSCs). Using spiro-MeOTAD as a hole-transport material, JD10 gave the highest reported power conversion efficiencies (PCE), 3.16% for squaraine-based ssDSCs. The photocurrent was further enhanced by co-sensitization with the organic D-π-A dye D35, increasing the light harvested leading to a PCE to 4.42%.
Substrate-assisted nucleation of ultra-thin dielectric layers on graphene by atomic layer deposition
Authors: Dlubak B. , Kidambi P. R. , Weatherup R. S. , Hofmann S. , Robertson J.
Published: April 2012

We report on a large improvement in the wetting of Al2O3 thin films grown by un-seeded atomic layer deposition on monolayer graphene, without creating point defects. This enhanced wetting is achieved by greatly increasing the nucleation density through the use of polar traps induced on the graphene surface by an underlying metallic substrate. The resulting Al2O3/graphene stack is then transferred to SiO2 by standard methods.
Capping effect of GaAsSb and InGaAsSb on the structural and optical properties of type II GaSb/GaAs quantum dots
Authors: He Jun , Bao Feng , Zhang Jinping
Published: April 2012

We systematically study the influence of group V intermixing on the structural and optical properties of type II GaSb/GaAs quantum dots (QDs) capped by selected capping layers. Compared to GaSb QDs capped directly by a GaAs layer, we observe a strong enhancement of photoluminescence (PL) intensity and a significant red-shift of the photoluminescence peak energy to 1.35 μm at 300 K by the introduction of a GaAsSb capping layer. In addition, Z-contrast cross sectional transmission electron microscopy shows Sb segregation and group V mixing is greatly suppressed by GaAsSb or InGaAsSb capping layers. The new capping layers offers the possibility of controlling optical properties of type II GaSb/GaAs quantum dots and this opens up new means for achieving high efficient GaSb/GaAs quantum dot solar cell.
Enhanced piezoelectricity and nature of electric-field induced structural phase transformation in textured lead-free piezoelectric Na0.5Bi0.5TiO3-BaTiO3 ceramics
Authors: Maurya Deepam , Pramanick Abhijit , An Ke , Priya Shashank
Published: April 2012

This letter provides a comparative description of the properties of textured and randomly oriented poly-crystalline lead-free piezoelectric 0.93(Na0.5Bi0.5TiO3)-0.07BaTiO3 (NBT-BT) ceramics. A high longitudinal piezoelectric constant of (d33) ∼ 322 pC/N was obtained in (001)PC textured NBT-7BT ceramics, which is almost ∼2× times the d33 coefficient reported for randomly oriented ceramics of the same composition. In situ neutron diffraction experiments revealed that characteristically different structural responses are induced in textured and randomly oriented NBT-BT ceramics upon application of electric fields (E), which are likely related to the varying coherence lengths of polar nanoregions and internal stresses induced by domain switching.
Effect of Gaussian doping on the performance of a n+-p thin film polycrystalline solar cell under illumination
Authors: Kolsi S. , Ben Amar M. , Samet H. , Ouali A.
Published: April 2012

A two-dimensional (2D) analytical model based on the Green’s function method is applied to an n+-p thin film polycrystalline solar cell that allows us to calculate the conversion efficiency. This model considers the effective Gaussian doping profile in the p region in order to improve cell efficiency. The dependence of mobility and lifetime on grain doping is also investigated. This model is implemented through a simulation program in order to optimize conversion efficiency while varying thickness and doping profile in the base region of the cell. Compared with back surface field (BSF) technology, our proposed structure shows a 31% improvement in conversion efficiency for a polycrystalline solar cell. For a monocrystalline solar cell, the BSF technology becomes more efficient.
What is “theory of mind”? Concepts, cognitive processes and individual differences
Authors: Apperly Ian A.
Published: April 2012

Research on “theory of mind” has traditionally focused on a narrow participant group (preschool children) using a narrow range of experimental tasks (most notably, false-belief tasks). Recent work has greatly expanded the age range of human participants tested to include human infants, older children, and adults, has devised new tasks, and has adopted methods from cognitive psychology and neuroscience. However, theoretical work has not kept pace with these changes, with the result that studies using one kind of method or participant group often inherit assumptions about the nature of theory of mind from other research, with little regard for whether these assumptions are appropriate. I argue that three distinct approaches to thinking about theory of mind are already implicit in research practice, and that future work, whether with infants, children, or adults, will benefit from articulating these approaches more clearly and following their different implications for what theory of mind is and how it should be studied.
Semi-implicit Krylov deferred correction methods for differential algebraic equations
Authors: Bu Sunyoung , Huang Jingfang , Minion Michael
Published: April 2012

In the recently developed Krylov deferred correction (KDC) methods for differential algebraic equation initial value problems (Huang, Jia, Minion, 2007), a Picard-type collocation formulation is preconditioned using low-order time integration schemes based on spectral deferred correction (SDC), and the resulting system is solved efficiently using Newton-Krylov methods. KDC methods have the advantage that methods with arbitrarily high order of accuracy can be easily constructed which have similar computational complexity as lower order methods. In this paper, we investigate semi-implicit KDC (SI-KDC) methods in which the stiff component of the preconditioner is treated implicitly and the non-stiff parts explicitly. For certain types of problems, such a semi-implicit treatment can significantly reduce the computational cost of the preconditioner compared to fully implicit KDC (FI-KDC) methods. Preliminary analysis and numerical experiments show that the convergence of Newton-Krylov iterations in the SI-KDC methods is similar to that in FI-KDC, and hence the SI-KDC methods offer a reduction in overall computational cost for such problems.
Cell survival, DNA damage, and oncogenic transformation after a transient and reversible apoptotic response
Authors: Tang Ho Lam , Tang Ho Man , Mak Keng Hou , Hu Shaomin , Wang Shan Shan , Wong Kit Man , Wong Chung Sing Timothy , Wu Hoi Yan , Law Hiu Tung , Liu Kan , Talbot C. Conover , Lau Wan Keung , Montell Denise J. , Fung Ming Chiu
Published: April 2012

Apoptosis serves as a protective mechanism by eliminating damaged cells through programmed cell death. After apoptotic cells pass critical checkpoints, including mitochondrial fragmentation, executioner caspase activation, and DNA damage, it is assumed that cell death inevitably follows. However, this assumption has not been tested directly. Here we report an unexpected reversal of late-stage apoptosis in primary liver and heart cells, macrophages, NIH 3T3 fibroblasts, cervical cancer HeLa cells, and brain cells. After exposure to an inducer of apoptosis, cells exhibited multiple morphological and biochemical hallmarks of late-stage apoptosis, including mitochondrial fragmentation, caspase-3 activation, and DNA damage. Surprisingly, the vast majority of dying cells arrested the apoptotic process and recovered when the inducer was washed away. Of importance, some cells acquired permanent genetic changes and underwent oncogenic transformation at a higher frequency than controls. Global gene expression analysis identified a molecular signature of the reversal process. We propose that reversal of apoptosis is an unanticipated mechanism to rescue cells from crisis and propose to name this mechanism “anastasis” (Greek for “rising to life”). Whereas carcinogenesis represents a harmful side effect, potential benefits of anastasis could include preservation of cells that are difficult to replace and stress-induced genetic diversity.
Expertise from experience: mental health recovery and wellness
Authors: Swarbrick Margaret
Published: April 2012

Persons who were formerly recipients of services (service users) have become architects in the design, delivery, and evaluation of services. This chapter will examine the evolution of the user-led self-help movement, and its impacts on transforming community mental health practice to promote mental health recovery and wellness as a vision and outcome.
Measuring the needs of people with mental illness
Authors: Slade Mike , Glover Gyles , Tansella Michele
Published: April 2012

The importance of needs assessment has been one of the most consistent themes to emerge from the evolution of community mental health services. The term ‘need’ has become especially influential in European mental health practice. In the United Kingdom, for example, national policy has emphasized the importance of needs assessment underpinning the planning, development, and evaluation of mental health services (Department of Health, 1999). However, the concept of ‘need’ is used in different, and sometimes contradictory, ways. At the individual level, all mental health and social care should be provided on the basis of need. At the population level, funding allocation is intended to match the needs of the population, so that whether or not overall resources are adequate, efficiency and equity are achieved. The aim of this chapter is to define needs assessment, to consider different approaches to assessing needs at the individual and at the population levels, and to discuss how needs assessments can be applied in real-world settings in planning and delivering clinical care.
Mental health, ethnicity, and cultural diversity: evidence and challenges
Authors: Morgan Craig
Published: April 2012

Migration is the primary driving force behind increasing ethnic and cultural diversity in many societies around the world. The movement of people across (and within) national boundaries, be it in search of economic prosperity or fleeing war and persecution, has been a central feature of modern history and has accelerated in recent years (Castles and Miller, 2009). Estimates by the United Nations (UN) suggest the total number of migrants (i.e. persons who have lived outside their country of birth for 12 months or more) is around 190 to 200 million or 3 % of the world’s population (UNDESA, 2004). These estimates do not include settled minority ethnic populations where, increasingly, the majority were born in the countries to which their parents or grandparents migrated. In the United Kingdom (UK), for example, minority ethnic groups now form 12 % of the population, with this rising to over 50 % in some areas of London (e.g. Newham) (Office for National Statistics). In the most recent edition of their textbook, Castles and Miller (2009) identify a number of trends in migration that are likely to have important ongoing political, economic, and social consequences. These include: the globalization of migration (i.e. the tendency for more countries to be affected by migration, both inward and outward); the acceleration of migration (i.e. the continued rise in absolute numbers of migrants in most regions of the world); and the differentiation of migration (i.e. the increased diversity of types and origins of migrants moving to single countries). These trends are already evident in, for example, many European countries, including Britain which has migrants from over 40 countries (Institute for Public Policy Research), and the United States (US) where estimates suggest that by 2050 minority ethnic and racial groups will comprise over 50 % of the population (U.S. Census Bureau, 2004). What these processes point to is an inexorable rise in ethnic and cultural diversity in many countries. This has major implications for the development and delivery of public services and, in particular, poses an ongoing challenge for mental health policy and service provision. It is these challenges that are the focus of this chapter. Three specific aspects are critically reviewed, with examples drawn mainly from the US and the UK: 1) the extent of, and variations in, mental health needs in migrant and minority ethnic groups; 2) access to and use of mental health services among these groups; and 3) proposals for ensuring mental health services are more responsive to the needs of ethnically and culturally diverse populations. To begin with, some definitions are necessary.
Organizing the range of community mental health services
Authors: Thornicroft Graham , Tansella Michele , Drake Robert E.
Published: April 2012

In discussing the organization of the full range of community mental health services in this chapter, we shall first consider some important pre-conditions, namely the scale of needs in any given population, the degree of coverage of these needs by existing services, the quantity and quality of available resources, and how far the attitudes of staff and the population at large promote or hinder a service primarily focused upon the needs of service users. We go on to describe a ‘balanced care’ model, which includes both hospital-based and community-based care, and its application in low-, medium-, and high-resource settings. We then summarize our own experience in developing community care to draw out the key lessons learned, including the need to include a wide range of stakeholder groups. Finally we discuss the key barriers that can impede the implementation of the balanced care model, and methods to overcome these forms of resistance.
Illness self-management programmes
Authors: Mueser Kim T. , Gingerich Susan
Published: April 2012

In recent years there has been a growth in programmes aimed at teaching illness self-management skills to individuals with a major mental illness. This trend reflects a broader trend in modern medicine towards adopting a more collaborative approach that includes the patient and family members in the management of chronic medical disorders. Education about psychiatric disorders and teaching of illness self-management strategies is now a common practice in the mental health field, and a growing number of programmes have been developed with standard curriculum and teaching methods designed to achieve this. While the goal of these programmes is to improve illness self-management through better adherence to treatment recommendations and improved skills for coping with persistent symptoms and impairments, the management of psychiatric disorders in these programmes is generally viewed as a collaborative process that involves the client, treatment team, and family members or friends.

We begin this chapter with a review of factors that led to the development and growth of illness self-management programmes. We then discuss the goals of illness self-management programmes, followed by a review of different approaches to teaching illness self-management. We then address research supporting illness self-management, and briefly describe several programmes. We conclude with a brief summary of illness self-management for people with serious psychiatric disorders.
Shaping national mental health policy
Authors: Whiteford Harvey
Published: April 2012

From the perspective of those at the service delivery coalface, national mental health policy often seems a remote activity unrelated to their daily responsibilities. The concept of national policy can be vague and how it is formed opaque. The time taken from the beginnings of policy formulation to adoption and implementation can seem extraordinarily long. When national policy does become relevant it is often because it is driving change that the clinician or service manager finds confronting and difficult. It is therefore easy to be cynical about government policy, but most of us still want and expect explicit national mental health policy, the implementation of which drives improved services for people with mental illness and their families. For the creation of good policy, those working outside of government bureaucracies need to better understand, and be able to exert influence on, the policy-making process.

The aim of this chapter is to describe the policy development cycle and the factors that shape national mental health policy. A good understanding of these should enhance the capacity of service providers and others to influence the content and effectiveness of mental health policy. At the outset it is important to provide a caveat. This chapter is most relevant to countries that operate a democratic system of government. While many of the concepts discussed in the chapter will apply to policy development in any country with an organized system of government, the assumptions that underpin the policy cycle described in the chapter are most applicable in a democratically governed society.
Producing guidelines, protocols, and toolkits
Authors: Moore Troy A. , Miller Alexander L. , Kuipers Elizabeth
Published: April 2012

Over the past several decades, multiple factors have resulted in the development of guidelines, treatment protocols, and implementation toolkits in all branches of medicine, including psychiatry.

First, a number of studies showed that some accepted practices could not be shown to be effective when tested in randomized controlled trials (RCTs: Coffman et al., 1987; Gaebel, 1995; Gaebel et al., 2002; Kinon et al., 1998). The lack of practice effectiveness in randomized studies is often attributed to the interventions not being well defined (Michie et al., 2009).

Second, community surveys showed that many evidence-based practices were either not used, or not used properly (i.e. not used with fidelity to the key details of implementation of the practice) (Buchanan et al., 2002; Cradock et al., 2001; Howard et al., 2009; Young et al., 1998). Fidelity refers to the degree to which a particular programme follows a programme model, which is a well-defined set of interventions and procedures that helps individuals achieve some desired goal (Bond et al., 2000).

Third, studies of incorporation of evidence-based practices into everyday practice showed long delays (Codyre et al., 2008; Rosen et al., 2007; Ruggeri et al., 2008). Meanwhile, evaluation of the impact of continuing medical education programmes demonstrated their ineffectiveness in changing physician practices (Davis et al., 1995). Thus, it became clear that to affect actual medical practices, it would be necessary to put together detailed sets of recommendations, and the means to operationalize them.
Heart failure syndromes
Authors: Clark Andrew L.
Published: April 2012

Heart failure (HF) is a protean condition, presenting acutely tohospital in most cases, but presenting with a more insidious courseto primary care physicians in many cases. Patients may only bediagnosed as having a primary cardiac problem after being seen byrespiratory physicians or even, on occasion, after gastrointestinalworkup for hepatomegaly (with or without jaundice) or weightloss. Nevertheless, there are common presenting clinical syndromesin patients with HF which should prompt different initialtreatment strategies.
The classical causes of heart failure
Authors: Gardner Roy S. , Jackson Colette E.
Published: April 2012

Heart failure (HF) is the complex clinical syndrome that may resultfrom a broad spectrum of structural or functional cardiac and non-cardiacdiseases, often causing the classical triad ofsymptoms: breathlessness, fatigue, and fluid retention. It is not a singledisease entity, but rather a process that may potentially complicatemost forms of cardiac pathology, particularly in their final stages.
The genetics of heart failure
Authors: Limongelli Giuseppe , Elliott Perry M.
Published: April 2012

Heart failure (HF), defined in its broadest sense as a syndromecharacterized by symptoms and signs of ventricular dysfunction inthe presence of structural and or functional abnormalities of heartfunction, affects millions of people worldwide; in addition, a substantialnumber of individuals have asymptomatic abnormalitiesof heart function that predispose them to symptomatic HF in laterlife. Coronary artery disease and hypertension are by far the most common causes of HF, but a substantial minority of cases arecaused by a heterogeneous group of heart muscle diseases, the cardiomyopathies.These disorders differ in several important respectsfrom other causes of HF in that they are often familial and presentthroughout life. With recent advances in the understanding of themolecular genetics of cardiomyopathies, cardiologists are havingto adapt diagnostic and treatment protocols in order to optimizemanagement of individual patients and their families. In thischapter we review the clinical presentation and pathophysiology ofthe most common monogenic cardiomyopathies and the cardiovascularmanifestations of mutations in the genes controlling therespiratory chain (mitochondrial diseases).
Adult congenital heart disease
Authors: Swan L.
Published: April 2012

Over the last 20 years, the face of congenital heart disease has changed beyond all recognition. Early death in childhood has been replaced by late death in adulthood. With increasing longevity, long-term sequelae of congenital disease corrected in early life are being recognized. In a sizeable proportion the consequences include ventricular dysfunction and heart failure (HF). The inclusion of congenital heart disease as an important aetiology of adult HF is a demonstration of changing demographics. Indeed, there are now more adults with congenital heart lesions than children. It is estimated that there are 185 000 adults with significant congenital heart disease in the United Kingdom. Many of the longterm consequences of congenital heart disease were not appreciated in the early era of paediatric cardiac surgery. Many patients (such as those with repaired coarctation of the aorta) were discharged, resulting in only a minority of the patients now being under specialist cardiology follow-up. When an adult patient presents with HF, it is important to exclude a pre-existing congenital aetiology.

It is difficult to define HF in adults with congenital heart disease. Early definitions (‘A clinical syndrome caused by an abnormality of the heart and recognized by a characteristic pattern of haemodynamic, renal, neural and hormonal responses’, Poole-Wilson,1985) could encompass every congenital cardiac lesion. Even the modern European Society of Cardiology definition (‘Symptoms of HF at rest or exercise and objective evidence of cardiac dysfunction ± response to treatment’, ESC Task Force 2005) captures a very wide and divergent range of congenital lesions. For the purpose of this chapter we will concentrate on disorders where ventricular function is the predominant lesion.
Infective and infiltrative causes of heart failure
Authors: Gardner Roy S. , Clark Andrew L.
Published: April 2012

Heart failure (HF) can result from any form of cardiac injury. Infective and infiltrative causes are rare, but important to identify,as many are potentially reversible.
Iatrogenic heart failure
Authors: Denvir Martin
Published: April 2012

Heart failure (HF) can result from adverse or unwanted effects oftreatment for unrelated conditions. Iatrogenic literally means anillness or condition generated by the physician (from the Greekiatros, a physician, and genic meaning ‘induced by’). In the acutesetting, the physician can induce HF — in a patient without anyclinically overt cardiac disease — by the inadvertent use of high volumes of fluid, or drugs known to depress cardiac function; or duringcardiac surgery when the left ventricle experiences injury (eitherdirectly or indirectly) while on cardiopulmonary bypass. ChronicHF, on the other hand, is more common in patients treated forlymphoma, breast cancer, or more rarely lung cancer. In this clinicalsetting, the patient may present many months or years after theinitial injury to the heart resulting from chemotherapeutic agentsand/or radiotherapy. This chapter outlines the main causes of HFinduced by the physician in the acute setting, and focuses on theepidemiology, presentation, and treatment of chronic HF syndromesresulting from treatment of childhood and adult cancers.
Intracellular calcium handling in heart failure
Authors: Smith Godfrey L. , Myles Rachel C.
Published: April 2012

Heart failure (HF) is a heterogeneous clinical syndrome which may be characterized by a variety of phenotypic changes, many of which have been linked to abnormalities in the intracellular calcium(Ca2+) signal. These range from mechanical dysfunction, usually characterized by reduced systolic contractile function, to electrophysiological dysfunction including QT interval prolongation, an increased incidence of ventricular premature beats (VPBs) and arrhythmic sudden cardiac death (SCD). In ventricular myocardial cells, intracellular Ca2+ ion fluxes govern the translation of the depolarizing signal into mechanical contraction, a process termed excitation–contraction (E-C) coupling. Abnormalities of intracellular Ca2+ handling are thought to underlie both mechanical and electrophysiological dysfunction in failing myocardium. This chapter summarizes the events involved in normal E-C coupling and describes the changes observed in HF, with particular focus on the changes reported in remodelled ventricular myocardium. Changes in intracellular Ca2+ signalling in other cardiac cell types, such as atrial cardiomyocytes and Purkinje fibre cells, may also be crucial to the final HF phenotype, but less is known about pathological changes in these tissues, and therefore these will only be mentioned briefly.
Cardiac natriuretic peptides and heart failure
Authors: McDonagh Theresa A.
Published: April 2012

The natriuretic peptide (NP) family, to date, consists of four structurallysimilar hormones, A, B, C, and D, each sharing a 17 aminoacid disulphide ring structure. They are counter-regulatoryhormones in heart failure (HF) and have a major role in controllingcardiovascular homeostasis via their key effector functions:natriuresis, diuresis, and vasodilatation.
Vasopressin
Authors: Szwejkowski Benjamin R. , Rekhraj Sushma , Struthers Allan
Published: April 2012

Arginine vasopressin (AVP; also known as antidiuretic hormone, ADH) is a polypeptide hormone synthesized by the neurosecretory cells of the supraoptic nucleus located within the hypothalamus.Vasopressin is packaged into secretory vesicles and transported by fast axons through the pituitary stalk to the posterior pituitary gland. The posterior pituitary gland acts as a supporting structure for the axonal nerve endings which lie on the surfaces of capillaries and it is here that vasopressin is secreted directly into the bloodstream. Oxytocin is also released by nerves in the posterior pituitary gland, but synthesized within a different nucleus of the hypothalamus called the paraventricular nucleus. Vasopressin contains nine amino acids and is similar in structure to oxytocin except that in vasopressin the isoleucine and leucine of oxytocin are replaced by phenylalanine and arginine.