bluuebunny/crossref_metadata_2025 huggingface dataset:
Network extreme eigenvalue: From mutimodal to scale-free networks
Authors: Chung N. N. , Chew L. Y. , Lai C. H.
Published: March 2012

The extreme eigenvalues of adjacency matrices are important indicators on the influence of topological structures to the collective dynamical behavior of complex networks. Recent findings on the ensemble averageability of the extreme eigenvalue have further authenticated its applicability to the study of network dynamics. However, the ensemble average of extreme eigenvalue has only been solved analytically up to the second order correction. Here, we determine the ensemble average of the extreme eigenvalue and characterize its deviation across the ensemble through the discrete form of random scale-free network. Remarkably, the analytical approximation derived from the discrete form shows significant improvement over previous results, which implies a more accurate prediction of the epidemic threshold. In addition, we show that bimodal networks, which are more robust against both random and targeted removal of nodes, are more vulnerable to the spreading of diseases.
Modified electrical transport probe design for standard magnetometer
Authors: Assaf B. A. , Cardinal T. , Wei P. , Katmis F. , Moodera J. S. , Heiman D.
Published: March 2012

Making electrical transport measurements on a material is often a time consuming process that involves testing a large number of samples. It is thus inconvenient to wire up and rewire samples onto a sample probe. We therefore present a method of modifying Quantum Design's MPMS SQUID magnetometer transport probe that simplifies the process of sample mounting. One of the difficulties to overcome is the small diameter of the sample space. A small socket is designed and mounted on the probe so that various samples mounted on individual headers can be readily exchanged in the socket. We also present some test results on the topological insulator Bi2Te2Se using the modified probe.
Simultaneous structure and elastic wave velocity measurement of SiO2 glass at high pressures and high temperatures in a Paris-Edinburgh cell
Authors: Kono Yoshio , Park Changyong , Sakamaki Tatsuya , Kenny-Benson Curtis , Shen Guoyin , Wang Yanbin
Published: March 2012

An integration of multi-angle energy-dispersive x-ray diffraction and ultrasonic elastic wave velocity measurements in a Paris-Edinburgh cell enabled us to simultaneously investigate the structures and elastic wave velocities of amorphous materials at high pressure and high temperature conditions. We report the first simultaneous structure and elastic wave velocity measurement for SiO2 glass at pressures up to 6.8 GPa at around 500°C. The first sharp diffraction peak (FSDP) in the structure factor S(Q) evidently shifted to higher Q with increasing pressure, reflecting the shrinking of intermediate-range order, while the Si-O bond distance was almost unchanged up to 6.8 GPa. In correlation with the shift of FSDP position, compressional wave velocity (Vp) and Poisson's ratio increased markedly with increasing pressure. In contrast, shear wave velocity (Vs) changed only at pressures below 4 GPa, and then remained unchanged at ∼4.0–6.8 GPa. These observations indicate a strong correlation between the intermediate range order variations and Vp or Poisson's ratio, but a complicated behavior for Vs. The result demonstrates a new capability of simultaneous measurement of structures and elastic wave velocities at high pressure and high temperature conditions to provide direct link between microscopic structure and macroscopic elastic properties of amorphous materials.
Absolute absorption cross sections of ligand-free colloidal germanium nanocrystals
Authors: Holman Zachary C. , Kortshagen Uwe R.
Published: March 2012

Extinction spectra of colloidal germanium nanocrystals suspended in benzonitrile without the use of ligands were measured, and absolute absorption cross sections are reported. Comparison to cross sections calculated using the Mie solution to Maxwell’s equations reveals that, as the mean nanocrystal size is reduced from 11 to 4 nm, the absorption features below 3.5 eV blueshift because of quantum confinement effects. The shifts are not, however, sufficiently large for the nanocrystal cores to produce the blue photoluminescence commonly observed from germanium nanocrystals. At energies greater than 3.5 eV the Mie and measured cross sections overlap, indicating a bulk-like band structure.
Al2O3/InAs metal-oxide-semiconductor capacitors on (100) and (111)B substrates
Authors: Wu Jun , Lind E. , Timm R. , Hjort Martin , Mikkelsen A. , Wernersson L.-E.
Published: March 2012

The influence of InAs orientations and high-k oxide deposition conditions on the electrical and structural quality of Au/W/Al2O3/InAs metal-oxide-semiconductor capacitors was investigated using capacitance-voltage (C-V) and x-ray photoemission spectroscopy techniques. The results suggest that the interface traps around the conduction band edge are correlated to the As-oxide amount, while less to those of As-As bonds and In-oxides. The quality of the deposited Al oxide determines the border trap density, hence the capacitance frequency dispersion. The comparison of different processing conditions is discussed, favoring a 350 °C high-k oxide deposition on (111)B substrates followed by an annealing procedure at 400 °C.
Magnetism mechanism in ZnO and ZnO doped with nonmagnetic elements X (X = Li, Mg, and Al): A first-principles study
Authors: Wang Q. J. , Wang J. B. , Zhong X. L. , Tan Q. H. , Hu Z. , Zhou Y. C.
Published: March 2012

First-principles calculations are performed to study the magnetism mechanism in undoped ZnO and ZnO doped with nonmagnetic elements X (X = Li, Mg, and Al). In undoped ZnO, it is found that the Zn vacancy is spin-polarized with a magnetic moment of 1.54 μB. The ferromagnetic coupling between two Zn vacancies is favorable in energy and a band coupling model is used to explain the magnetic coupling. In ZnO doped with nonmagnetic elements X, the magnetism is also attributed to the presence of Zn vacancies. The introduction of X reduces the formation energy of Zn vacancy and stabilizes it to some extent.
Positive-negative turbulence-free ghost imaging
Authors: Meyers Ronald E. , Deacon Keith S. , Shih Yanhua
Published: March 2012

This experiment observed turbulence-free positive and negative thermal light ghost images from independently recorded event histories of a “bucket” photo-detector and a charged coupled device (CCD) array. The positive (negative) ghost image is computed from the “bucket” detector counts which are above (below) its mean, and the ghost image is not degraded by the turbulence. How do the “bucket” photon counts yield a positive or negative ghost image with a distant CCD array? This letter provides a quantum interference model which effectively explains the phenomenon.
Temperature-dependent electron transport in highly ordered Co/Al2O3 core-shell nanocrystal memory synthesized with di-block co-polymers
Authors: Zhou Huimei , Dorman James A. , Perng Ya-Chuan , Chang Jane P. , Liu Jianlin
Published: March 2012

Di-block copolymer synthesized Co/Al2O3 core-shell nanocrystal (NC) capacitors were fabricated in order to study the temperature-dependent electron transport. The capacitance-voltage memory window is shown to increase proportionally with the substrate temperature, saturating at 3.5 V, at 175 °C. At elevated operating temperatures, the tunneling of electrons increases, resulting in large flatband voltage shift. Furthermore, the electron leakage of the NCs at high temperature is faster than the leakage at room temperature due to thermally assisted tunneling. The activation energy is determined by exponentially fitting the thermally dependent retention performance, which was then used to model the occupied energy levels and further elucidate the electron transport within the NC memory.
Thermal boundary resistance at silicon-silica interfaces by molecular dynamics simulations
Authors: Lampin E. , Nguyen Q.-H. , Francioso P. A. , Cleri F.
Published: March 2012

We use molecular dynamics simulations to study the heat transfer at the interface between crystalline Si and amorphous silica. In order to quantify the thermal boundary resistance, we compare the results of two simulation methods: one in which we apply a stationary thermal gradient across the interface, trying to extract the thermal resistance from the temperature jump; the other based on the exponential approach to thermal equilibrium, by monitoring the relaxation times of the heat flux exchanged across the interface. We compare crystalline Si/amorphous Si vs. crystalline Si/amorphous silica interfaces to assess the relative importance of structural disordering vs. chemistry difference.
Voltage impulse induced bistable magnetization switching in multiferroic heterostructures
Authors: Nan T. X. , Zhou Z. Y. , Lou J. , Liu M. , Yang X. , Gao Y. , Rand S. , Sun N. X.
Published: March 2012

We report on voltage impulse induced reversible bistable magnetization switching in FeGaB/lead zirconate titanate (PZT) multiferroic heterostructures at room temperature. This was realized through strain-mediated magnetoelectric coupling between ferroelectric PZT and ferromagnetic FeGaB layer. Two reversible and stable voltage-impulse induced mechanical strain states were obtained in the PZT by applying an electric field impulse with its amplitude smaller than the electric coercive field, which led to reversible voltage impulse induced bistable magnetization switching. These voltage impulse induced bistable magnetization switching in multiferroic heterostructures provides a promising approach to power efficient bistable magnetization switching that is crucial for information storage.
Polarization-induced remote interfacial charge scattering in Al2O3/AlGaN/GaN double heterojunction high electron mobility transistors
Authors: Ji Dong , Liu Bing , Lu Yanwu , Liu Guipeng , Zhu Qinsheng , Wang Zhanguo
Published: March 2012

This study investigated on polarization-induced remote interfacial charge scattering, a scattering mechanism caused by the interfacial polarization charge, for Al2O3/AlGaN/GaN double heterojunction high electron mobility transistors (HEMTs). Results show that remote interfacial charge scattering plays a critical role in the mobility of two-dimensional electron gas (2DEG) in thin barrier HEMTs. The electronic mobility limited by remote charge scattering is found to be a function of the fixed charge density induced by the Al2O3 layer, 2DEG density, and barrier thickness. Results of this study can be used in designing structures to generate higher electron mobility in Al2O3/AlGaN/GaN double heterojunction HEMTs.
Growth of oriented Au nanostructures: Role of oxide at the interface
Authors: Rath A. , Dash J. K. , Juluri R. R. , Rosenauer A. , Schoewalter Marcos , Satyam P. V.
Published: March 2012

We report on the formation of oriented gold nanostructures on Si(100) substrate by annealing procedures in low vacuum (≈10−2 mbar) and at high temperature (≈975 °C). Various thicknesses of gold films have been deposited with SiOx (using high vacuum thermal evaporation) and without SiOx (using molecular beam epitaxy) at the interface on Si(100). Electron microscopy measurements were performed to determine the morphology, orientation of the structures and the nature of oxide layer. Interfacial oxide layer, low vacuum and high temperature annealing conditions are found to be necessary to grow oriented gold structures. These gold structures can be transferred by simple scratching method.
Electronic tuning of La2/3Sr1/3MnO3 thin films via heteroepitaxy
Authors: Wong Franklin J. , Zhu Shaobo , Iwata-Harms Jodi M. , Suzuki Yuri
Published: March 2012

Epitaxial La2/3Sr1/3MnO3 films grown on LaAlO3 substrates of various orientations exhibit a range of magnetoresistive properties, demonstrating the utility of strain as an electronic tuning parameter for manganites. Large magnetoresistance over a broad range of temperatures—highest (−64% at 50 kOe) at the lowest temperatures measured—is observed in a coherently strained La2/3Sr1/3MnO3 film on a (001) LaAlO3 substrate. In addition to higher magnetoresistance, its reduced magnetization and conductance suggest the stabilization of a more insulating ground state and the possibility of strain-induced phase coexistence. Similar field-dependent magnetotransport features at low temperatures, distinct from those exhibited by bulk manganites, are also seen in a partially strained film on a (110) LaAlO3 substrate, but bulk-like magnetoresistive behavior is observed in a relaxed La2/3Sr1/3MnO3 film on a (111) LaAlO3 substrate.
The theory of modulated hormone therapy for the treatment of breast cancer in pre- and post-menopausal women
Authors: Wiley Teresa S. , Haraldsen Jason T.
Published: March 2012

We present a theory that questions the standard of care for pre- and post-menopausal women with breast cancer. Through the use of modulated hormones to mimic the natural multiphasic fluctuations of estrogen and progesterone cycles of healthy young women, it can be expected that patients will not only exhibit increased quality of life such as better sleep, well-being, and libido, but also memory improvement and less joint pain. Additionally, this regimen may engage genetic pathways that protect women in youth from breast cancers. We present a mathematical basis for the coupling of the hormone cycles through the use of Gaussian curves that provides the foundation of a new format of hormone replacement in women.
Anharmonic vibrations of the dicarbon antisite defect in 4H-SiC
Authors: Yan F. , Devaty R. P. , Choyke W. J. , Gali A. , Kimoto T. , Ohshima T. , Pensl G.
Published: March 2012

Dicarbon antisite defects were created by either electron irradiation or ion implantation into 4H-SiC. The no-phonon lines from the dicarbon antisite defect center were observed with their phonon replicas. The stretch frequencies of the defect were observed up to the fifth harmonic. The Morse potential model accounts for the anharmonicity quite well and gives a very good prediction of the vibration energies up to the fifth harmonic with an error of less than 1%. First principles calculations show that the model of a dicarbon antisite defect along with its four nearest neighboring carbon atoms can explain the observed anharmonicity.
Modeling electric charge distribution on insulator under electron bombardment: Case of rectangular surface implantation
Authors: Ghorbel Nouha , Kallel Ali , Damamme Gilles
Published: March 2012

Despite progress in the study of dielectric properties and the formation of secondary electrons images and especially in the understanding of their mirror curve shape, since the first models for mirror equation were developed, an exact quantitative prediction of the mirror curve for most materials has remained an unsolved problem. In this paper, recent development in the characterization of charge trapping ability of insulators using the scanning electron microscope mirror method (SEMMM) is reviewed. All this work has resulted in unprecedented insights into the early stage of dielectric study and it is also relevant for a deeper understanding of this anomalous effect (mirror effect) as well as for discussion of the factors affecting it. So the dependency of elliptic mirror and the anisotropic effect in the trapping phenomena of charge is highlighted.
Hexagonal boron nitride intercalated multi-layer graphene: a possible ultimate solution to ultra-scaled interconnect technology
Authors: Li Yong-Jun , Sun Qing-Qing , Chen Lin , Zhou Peng , Wang Peng-Fei , Ding Shi-Jin , Zhang David Wei
Published: March 2012

We proposed intercalation of hexagonal boron nitride (hBN) in multilayer graphene to improve its performance in ultra-scaled interconnects for integrated circuit. The effect of intercalated hBN layer in bilayer graphene is investigated using non-equilibrium Green's functions. We find the hBN intercalated bilayer graphene exhibit enhanced transport properties compared with pristine bilayer ones, and the improvement is attributed to suppression of interlayer scattering and good planar bonding condition of inbetween hBN layer. Based on these results, we proposed a via structure that not only benefits from suppressed interlayer scattering between multilayer graphene, but also sustains the unique electrical properties of graphene when many graphene layers are stacking together. The ideal current density across the structure can be as high as 4.6×109 A/cm2 at 1V, which is very promising for the future high-performance interconnect.
Graded-host phosphorescent light-emitting diodes with high efficiency and reduced roll-off
Authors: Liu S. W. , Sun X. W. , Demir Hilmi Volkan
Published: March 2012

We demonstrated graded-host phosphorescent organic light-emitting diodes with high efficiency and reduced efficiency roll-off. The emissive layer of the graded host device consists of both electron and hole transport type hosts, 1,3,5-tris(N-phenylbenzimidazole-2-yl)benzene (TPBI) and 4,4′,4′′-tris(N-carbazolyl)triphenylamine, respectively, with graded composition, and the phosphorescent red emitter bis(2-phenylquinoline) (acetylacetonate) iridium(III), which was uniformly doped into the graded host matrix. The graded host device shows improved quantum efficiency and power efficiency with significantly reduced efficiency roll-off as compared to the unipolar-host and double layer heterojunction host devices.
A comparison of vertical and horizontal camera trap orientations for detection of potoroos and bandicoots
Authors: Smith Justine K. , Coulson Graeme
Published: March 2012

Camera traps are increasingly used to monitor wildlife that is otherwise difficult to study. Traditionally, camera traps are set aimed horizontally towards a scent lure, capturing images of animals as they move past. A vertical camera orientation is also being used, whereby the camera lens and sensor face vertically down towards the scent lure, capturing images from above. We aimed to compare detection of southern brown bandicoots and long-nosed potoroos by camera traps set horizontally, to those set vertically. We also considered the number of false triggers and ease of species identification. Over 21 nights, we monitored 18 camera stations, each consisting of one PixController Inc. DigitalEye™ 7.2 camera aimed horizontally and one vertically, towards the same scent lure. We used PRESENCE (Version 3.0 (Beta)) to estimate detection probabilities for the two species, comparing a null model to a model with camera orientation as a covariate affecting probability of detection. Detection probabilities for both species was 2–5 times higher by vertical than by horizontal cameras, with no significant difference in false triggers. Vertical cameras also increased ease of species identification. Vertical camera orientation is shown to be superior in our study system, providing a valid alternative method.
Towards the Development of a Direct Electrochemical Biodetector of Avidin Based on the Poly(chloro amino-β-styryl terthiophene)-Coated Glassy Carbon Electrode
Authors: Mehenni Hakim , Dao Lê H.
Published: March 2012

In this study, a simple and direct biodetector was proposed, which was based on biotin immobilized onto a conducting polymer-coated electrode, for the detection of avidin, a highly stable glycoprotein found in egg-whites. Biotin was immobilized onto the electrode by covalent coupling to the primary amine group on the poly 3′-(3-chloro-4-amino-β-styryl)-(2,2′ : 5′,2″-terthiophene) (PCAST), and the biotin–avidin interaction was monitored by cyclic voltammetry. Incubation of the PCAST/biotin-modified-coated electrode with avidin in a phosphate buffered saline solution caused a significant change to its cyclic voltammogram, which was explained by the binding of avidin by biotin, and resulted in restricted ion transfer to and from the conducting polymer. This change was then utilized to detect avidin at 4 × 10–6 mol L–1.
p75 neurotrophin receptor regulates glucose homeostasis and insulin sensitivity
Authors: Baeza-Raja Bernat , Li Pingping , Le Moan Natacha , Sachs Benjamin D. , Schachtrup Christian , Davalos Dimitrios , Vagena Eirini , Bridges Dave , Kim Choel , Saltiel Alan R. , Olefsky Jerrold M. , Akassoglou Katerina
Published: March 2012

Insulin resistance is a key factor in the etiology of type 2 diabetes. Insulin-stimulated glucose uptake is mediated by the glucose transporter 4 (GLUT4), which is expressed mainly in skeletal muscle and adipose tissue. Insulin-stimulated translocation of GLUT4 from its intracellular compartment to the plasma membrane is regulated by small guanosine triphosphate hydrolases (GTPases) and is essential for the maintenance of normal glucose homeostasis. Here we show that the p75 neurotrophin receptor (p75
NTR
) is a regulator of glucose uptake and insulin resistance. p75
NTR
knockout mice show increased insulin sensitivity on normal chow diet, independent of changes in body weight. Euglycemic-hyperinsulinemic clamp studies demonstrate that deletion of the p75
NTR
gene increases the insulin-stimulated glucose disposal rate and suppression of hepatic glucose production. Genetic depletion or shRNA knockdown of p75
NTR
in adipocytes or myoblasts increases insulin-stimulated glucose uptake and GLUT4 translocation. Conversely, overexpression of p75
NTR
in adipocytes decreases insulin-stimulated glucose transport. In adipocytes, p75
NTR
forms a complex with the Rab5 family GTPases Rab5 and Rab31 that regulate GLUT4 trafficking. Rab5 and Rab31 directly interact with p75
NTR
primarily via helix 4 of the p75
NTR
death domain. Adipocytes from p75
NTR
knockout mice show increased Rab5 and decreased Rab31 activities, and dominant negative Rab5 rescues the increase in glucose uptake seen in p75
NTR
knockout adipocytes. Our results identify p75
NTR
as a unique player in glucose metabolism and suggest that signaling from p75
NTR
to Rab5 family GTPases may represent a unique therapeutic target for insulin resistance and diabetes.
Dendritic connectivity controls biodiversity patterns in experimental metacommunities
Authors: Carrara Francesco , Altermatt Florian , Rodriguez-Iturbe Ignacio , Rinaldo Andrea
Published: March 2012

Biological communities often occur in spatially structured habitats where connectivity directly affects dispersal and metacommunity processes. Recent theoretical work suggests that dispersal constrained by the connectivity of specific habitat structures, such as dendrites like river networks, can explain observed features of biodiversity, but direct evidence is still lacking. We experimentally show that connectivity per se shapes diversity patterns in microcosm metacommunities at different levels. Local dispersal in isotropic lattice landscapes homogenizes local species richness and leads to pronounced spatial persistence. On the contrary, dispersal along dendritic landscapes leads to higher variability in local diversity and among-community composition. Although headwaters exhibit relatively lower species richness, they are crucial for the maintenance of regional biodiversity. Our results establish that spatially constrained dendritic connectivity is a key factor for community composition and population persistence.
Active encoding of decisions about stimulus absence in primate prefrontal cortex neurons
Authors: Merten Katharina , Nieder Andreas
Published: March 2012

Judging the presence or absence of a stimulus is likely the most basic perceptual decision. A fundamental difference of detection tasks in contrast to discrimination tasks is that only the stimulus presence decision can be inferred from sensory evidence, whereas the alternative decision about stimulus absence lacks sensory evidence by definition. Detection decisions have been studied in an intentional, action-based framework, in which decisions were regarded as intentions to pursue particular actions. These studies have found that only stimulus-present decisions are actively encoded by neurons, whereas the decision about the absence of a stimulus does not affect default neuronal responses. We tested whether this processing mechanism also holds for abstract detection decisions that are dissociated from motor preparation. We recorded single-neuron activity from the prefrontal cortex (PFC) of monkeys performing a visual detection task that forced a report-independent decision. We not only found neurons that actively encoded the subjective decision of monkeys about the presence of a stimulus, but also cells responding actively for the decision about the absence of stimuli. These results suggest that abstract detection decisions are processed in a different way compared with the previously reported action-based decisions. In a report-independent framework, neuronal networks seem to generate a second set of neurons actively encoding the absence of sensory stimulation, thus translating decisions into abstract categories. This mechanism may allow the brain to “buffer” a decision in a nonmovement-related framework.
Anthropology of microbes
Authors: Benezra Amber , DeStefano Joseph , Gordon Jeffrey I.
Published: March 2012

We describe the need to further integrate the fields of human microbial ecology and anthropology and outline some of the potential goals and benefits of this collaborative work.
Invasive plant impacts on soil properties, nutrient cycling, and microbial communities.
Authors: Grant T. A., III , Paschke M. W.
Published: March 2012

This chapter reviews the processes and interactions by which exotic plant species alter the physical, chemical, and microbial characteristics of soil and provide a basis for applying these concepts to innovative soil management strategies that can reduce dominance of invasive plants and conserve diverse, functioning natural ecosystems. The impacts of invasive species on soil and selection of methods to manage soil processes for invasive species control are discussed.
What are alternative systems for poultry?
Authors: Fröhlich E. K. F. , Niebuhr K. , Schrader L. , Oester H.
Published: March 2012

By the late 1960s, poultry production had developed from a small-scale rural enterprise to an economically important branch of agriculture. Flock sizes increased and production systems, for hygienic and economic reasons, became more intensive. Rearing and housing of laying hens took place in conventional cages. At the same time, public concern for intensively housed birds began to increase, particularly following publications such as Animal Machines written by Ruth Harrison in 1964. New animal protection laws came into force and agriculture was forced to adapt to the welfare concerns of consumers. Alternative systems for housing laying hens that provided greater freedom of movement and facilities for natural behaviour including the use of the third dimension (perching, nesting) were developed. Production systems for meat birds were introduced that, in addition to higher space allowances, specified maximum rates of growth and feed ingredients. Time alone will show which type of system for poultry egg or meat production will survive the evolving social and economic pressures on producers and consumers.
The impact of legislation and assurance schemes on alternative systems for poultry welfare.
Authors: Pritchard D. G.
Published: March 2012

Whereas a wide range of policy instruments - legal, economic, education and publicity - are available to effect changes in production systems, legislation and market-led assurance schemes have been the main forces used to protect and enhance the welfare of farm animals. The Conventions of the Council of Europe (COE) and their Recommendations focused on the provisions of resources and duty of care to meet the needs of animals. They are part of the aquis of the European Union (EU) and are incorporated into some national legislations as well as being used as the basis for private standards. The European single market harmonized welfare and health rules, methods of production and labelling for hen's eggs and chicken meat, so allowing consumers to buy foods with known provenance. The EU responded with a legal framework from 'farm to fork' to secure food safety, animal health and welfare. Farmers, food processors and large retailers sought to provide evidence of the quality of their products by private assurance schemes not only to meet new obligations for due diligence but also to gain commercial advantage. These schemes often merely reflected minimum legal standards but some also focused on improved health, welfare or environmental provisions. Membership of assurance schemes is associated with better compliance with legal standards in Great Britain. The EU WELFAREQUALITY project concluded that assurance schemes usually had impact only at a niche market level. The EU ban on conventional cages for hens in 2012 has had the greatest political and economic impact on poultry in Europe. Some countries banned enriched cages ahead of the deadline, despite scientific evidence that supported continued use of enriched cages. New EU legislation to improve the quality of care of intensively kept meat chickens was novel in limiting stocking densities by measuring welfare outcomes at abattoirs. The COE Recommendations on geese, turkeys, ducks and Muscovies have been implemented by national rules and private codes of practice which are often used to support assurance schemes. Major impacts have been on traditional systems through the ban on live plucking of feathers from geese and on gavage and individual cages for the production of foie gras.
Housing and management of layer breeders in rearing and production.
Authors: Thiele H. H.
Published: March 2012

Housing and management of layer breeders has to be done in an optimal way otherwise farmers waste their genetic potential and high economic value. A good start secured by optimal brooding conditions, excellent feed quality and appropriate management in the early life of chicks is a prerequisite. The development of sufficient eating capacities during the later rearing period and a fine-tuned light stimulation ensures a good start into the production phase. Furthermore they have to be adjusted to the different housing systems for layer breeders and via a fitting vaccination schedule prepared to react to the different disease challenges in their production environment. Once in production, the nutrient requirements of the birds have to be secured by a phased feeding programme. Good hatching egg quality can be achieved when avoiding floor eggs and by appropriate egg handling.
Nutritional challenges of alternative production systems.
Authors: MacLeod M. G. , Bentley J. S.
Published: March 2012

Many of the nutritional challenges posed by alternative systems can be addressed by application of existing scientific knowledge. However, regulations applied to alternative systems may limit the nutritionist's freedom of action, particularly with regard to the ingredients which can be used to formulate diets. Practical comments on meeting the nutrition-related stipulations of the various regulations are included in the present chapter. It is possible to formulate diets without animal protein, potentially genetically modified organisms (e.g. soybean and maize products) and synthetic amino acids, but it is difficult to attain nutritional optima. On the positive side, in free range systems, the bird's nutritional inputs may be enhanced by access to forage plants and animals. Also, there is clearly greater scope for the bird to be provided with food in ways that give greater opportunities for a repertoire of feeding behaviour, such as feedstuff choice. Some alternative systems may increase the bird's energy requirements because of increased expenditure of energy on physical activity and on thermoregulation in a cooler environment. Since there is so much scope for variation in environmental factors in alternative systems, nutritional decisions may have to be made on an iterative basis, meaning that cooperation between the producer and the nutritionist may be the key to success. This is particularly true where there are strict regulatory limitations on rate of growth or final body weight. There is a tendency for alternative systems to have a greater ecological impact than conventional systems, largely because of the lower efficiency of nutrient utilization. This chapter comments on nutritional methods of helping to reduce environmental impact.
Genotype-environment interaction: breeding layers with different requirements for varying housing systems.
Authors: Icken W. , Schmutz M. , Preisinger R.
Published: March 2012

In addition to conventional selection criteria like egg production, feed conversion and egg quality, traits related to animal welfare have become more important in Europe and North America. To improve these traits and simultaneously capture performance data in non-cage environments hen-specifically, the Weihenstephan funnel nest box (FNB) was developed. The FNB captures egg production and egg quality data individually as well as nesting behaviour traits. A comparison of performance parameters from full siblings, tested in single bird cages and the FNB, leads back to potential genotype-environment interactions that will determine which testing system should be mainly used in the future for continuous improvement of egg production and egg quality. Low genetic correlations between full siblings, tested in varying housing systems, were estimated for egg number during the main laying periods. Otherwise, high genetic correlations and therefore no potential genotype-environment interactions could be assumed for the traits egg weight and egg number at the beginning of production. An additional breeding tool which has the potential to improve selection traits, regardless of the housing system, is genome-wide selection. Therefore, phenotypic performance recording must first be established for new traits before markers can be applied. Due to all these assumed effects, for a comprehensive performance testing with an evaluation of birds, consequent selection and reproduction of the best layers, layer breeding companies should implement hen-specific tests in non-cage systems in their breeding programmes.
4-(4-Nitrophenyl)morpholine
Authors: Wang Li-Jiao , Li Wei-Wei , Yang Sheng-Yong , Yang Li
Published: March 2012

Aromatic π–π stacking interactions stabilize the crystal structure of the title compound, C10H12N2O3, the perpendicular distance between parallel planes being 3.7721 (8) Å. The morpholine ring adopts a chair comformation.
Diaquabis(benzoato-κO)bis[4,4,5,5-tetramethyl-2-(pyridin-4-yl-κN)imidazoline-1-oxyl 3-oxide]cobalt(II)
Authors: Wang Kun-Miao , Zhou Jie , Qian Fen-Hua , Liu Jing
Published: March 2012

The title compound, [Co(C7H5O2)2(C12H16N3O2)2(H2O)2], was obtained from a conventional solvent evaporation method. The complex molecule is centrosymmetric, so pairs of equivalent ligands lietransto each other in a slightly distorted octahedral CoN2O4geometry. The CoIIion is coordinated by the pyridine N atoms from NITpPy ligands [NITpPy is 4,4,5,5-tetramethyl-2-(pyridin-4-yl)imidazoline-1-oxyl 3-oxide), water O atoms and two monodentate benzoate O atoms. The complex molecules are connected by O—H...O hydrogen bonds between water molecules and benzoate ligands, forming chains parallel to [100]. π–π stacking interactions between the benzoate ligands with centroid–centroid distances of 3.752 (2) Å connect the chains into layers parallel to (10-1).
4,4′-[(5-Carboxy-1,3-phenylene)bis(oxy)]dibenzoic acid
Authors: Du Chao , Wu Wei , Tian Ge
Published: March 2012

In the title compound, C21H14O8, the central benzene ring makes dihedral angles of 77.8 (6) and 75.9 (5)° with the outer benzene rings. In the crystal, molecules are linked by O—H...O hydrogen bonds involving carboxyl groups, forming one-dimensional ladders. Two-dimensional layers are formed by interpenetration of these one-dimensional ladders.
trans-Bis[(2-bromophenyl)diphenylphosphane-κP]carbonylchloridorhodium(I)
Authors: Malan Frederick P. , Malgas-Enus Rehana , Meijboom Reinout
Published: March 2012

The title compound,trans-[RhCl(C18H14BrP)2(CO)], has a slightly disordered square-planar geometry with the Rh ionIsituated on an inversion the centre and carbonyl–chloride disorder observed as a result of the crystallographic inversion symmetry. Selected geometric parameters include: Rh—P = 2.3430 (8) Å, Rh—Cl = 2.434 (3) Å, Rh—C = 1.722 (8) Å, P—Rh—P = 180.00 (3)°, P—Rh—Cl = 95.40 (7)°, 84.60 (7)° and Rh—C—O = 177.9 (8)°.
trans-Dichloridobis(triphenylphosphane-κP)palladium(II) benzene hemisolvate
Authors: Meyer-Wegner Frank , Lerner Hans-Wolfram , Sinke Tanja , Bolte Michael
Published: March 2012

The title complex, [PdCl2(C18H15P)2]·0.5C6H6, has the PdIIion in a square-planar coordination mode (r.m.s. deviation for Pd, P and Cl atoms = 0.024 Å) with the PPh3and Cl ligands mutuallytrans. The benzene solvent molecule is located about a crystallographic inversion centre. The title complex is isostructural withtrans-dichloridobis(triphenylphosphane)palladium(II) 1,4-dichlorobenzene sesquisolvate [Kitanoet al.(1983).Acta Cryst.C39, 1015–1017].
1-(4-Bromophenylsulfinyl)-2-methylnaphtho[2,1-b]furan
Authors: Choi Hong Dae , Seo Pil Ja , Lee Uk
Published: March 2012

In the title compound, C19H13BrO2S, the 4-bromophenyl ring makes a dihedral angle of 83.75 (4)° with the mean plane of the naphthofuran fragment [r.m.s. deviation = 0.024 (2) Å]. In the crystal, molecules are linkedviapairs of C—H...O hydrogen bonds, forming inversion dimers. These dimers are connected by weak π–π interactions between the central naphthofuran benzene rings of neighbouring molecules [centroid–centroid distance = 3.483 (2) Å, interplanar distance = 3.416 (2) Å and slippage = 0.680 (2) Å].
1-(5-Benzylsulfanyl-2,2-dimethyl-2,3-dihydro-1,3,4-thiadiazol-3-yl)-2,2-dimethylpropan-1-one
Authors: Yusof Mohd Sukeri Mohd , Mutalib Fatimah Abdul , Arshad Suhana , Razak Ibrahim Abdul
Published: March 2012

In the title compound, C16H22N2OS2, the S atom of the thiadiazole ring and the attached methyl groups are disordered over two orientations with a refined site-occupancy ratio of 0.641 (11):0.359 (11). The thiadiazole ring is in a twist conformation in both disorder components. The mean plane through the thiadiazole ring makes dihedral angles of 77.39 (8) (major component) and 67.45 (11)° (minor component) with the benzene ring. Intramolecular C—H...N interactions generate twoS(6) ring motifs. In the crystal, molecules are linked by C—H...O hydrogen bonds into zigzag chains parallel to thebaxis.
Bis(2-{[(9H-fluoren-2-yl)methylidene]amino}phenolato-κ2N,O)zinc methanol disolvate
Authors: Kim Young-Inn , Yun Sung-Jae , Hwang Inn-Hye , Kim Dae-Young , Kang Sung Kwon
Published: March 2012

In the title compound, [Zn(C20H14NO)2]·2CH3OH, the ZnIIatom lies on a crystallographic twofold rotation axis and is coordinated by two O atoms and two N atoms from two bidentate 2-{[(9H-fluoren-2-yl)methylidene]amino}phenolate ligands within a distorted tetrahedral geometry. The dihedral angle between the two chelate rings is 82.92 (5)°. In the coordinated ligand, the phenol ring is twisted at 30.22 (9)° from the mean plane of the fluorene ring. In the crystal, O—H...O hydrogen bonds link the complex molecules to the methanol solvent molecules.
Poly[hydrazin-1-ium [diaquabis(μ4-pyridazine-3,6-dicarboxylato)trilithate] monohydrate]
Authors: Starosta Wojciech , Leciejewicz Janusz
Published: March 2012

The structure of the title compound, {(N2H5)[Li3(C6H2N2O4)2(H2O)2]·H2O}n, is composed of molecular dimers, each built up of two symmetry-related LiIions with distorted trigonal–bipyramidal coordinations bridged by two deprotonated ligand moleculesviatheirN,O-bonding sites. Doubly solvated LiIions with a distorted tetrahedral geometry link adjacent dimers, forming a polymer generated by bridging bidentate carboxylato O atoms to LiIions in adjacent dimers, forming anionic layers parallel to theacplane with monoprotonated hydrazinium cations and crystal water molecules positioned between them. The layers are held together by an extended system of hydrogen bonds in which the hydrazinium cations and coordinated and crystal water molecules act as donors and carboxylate O atoms act as acceptors.
7-Chloro-4-[(E)-2-(2,5-dimethoxybenzylidene)hydrazin-1-yl]quinoline
Authors: Souza Marcus V. N. de , Ferreira Marcelle de Lima , Wardell Solange M. S. V. , Tiekink Edward R. T. , Wardell James L.
Published: March 2012

In the nearly planar title compound (r.m.s. deviation for the 24 non-H atoms = 0.064 Å), C18H16ClN3O2, the conformation about the N=C bond isE. Supramolecular chains propagated by glide symmetry along [001] are found in the crystal packing. These are sustained by N—H...N hydrogen bonds with the quinoline N atom being the acceptor. The chains are connected into a three-dimensional architecture by π–π interactions involving all three aromatic rings [centroid–centroid distances = 3.5650 (9)–3.6264 (9) Å].
Benzene-1,3,5-tricarbonyl trichloride
Authors: Fan Xin , Wang Yanrong , Jin Chengzhi , Jin Longfei
Published: March 2012

In the title molecule, C9H3Cl3O3, there are three short interactions involving the benzene H atoms and the chloroformyl Cl atoms. In the crystal, molecules stack along theaaxis with no significant non-bonded interactions.
2-[4-(2-Hydroxypropan-2-yl)-1H-1,2,3-triazol-1-yl]phenol
Authors: Zhang Li-Li , Yu Kai , Liu Ling-Ling , Guo Dian-Shun
Published: March 2012

In the title compound, C11H13N3O2, the 1,2,3-triazole ring and the phenol ring form a dihedral angle of 55.46 (5)°. In the crystal, inversion-related molecules associate through pairs of hydroxy–phenol O—H...O hydrogen bonds, giving centrosymmetric cyclic dimers [graph setR22(18)]. These dimers are linked into infinite chains along [001], giving an overall two-dimensional network structure parallel to thebcplane through hydroxy O—H...N and triazole C—H...N hydrogen bonds.
4-[(E)-2-(2,4-Dichlorobenzylidene)hydrazin-1-yl]quinolin-1-ium chloride monohydrate
Authors: Wardell Solange M. S. V. , Tiekink Edward R. T. , Wardell James L. , Ferreira Marcelle de Lima , Souza Marcus V. N. de
Published: March 2012

In the title hydrated salt, C16H12Cl2N3+·Cl−·H2O, there is a small twist in the cation as seen in the torsion angle linking the benzene ring to the rest of the molecule [171.96 (17)°]. In the crystal, the quinolinium H atom forms a hydrogen bond to the lattice water molecule, which also forms hydrogen bonds to two Cl−anions. Each Cl−ion also accepts a hydrogen bond from the hydrazine H atom. The three-dimensional architecture is also stabilized by π–π interactions between centrosymmetrically related quinoline residues [centroid–centroid distance = 3.5574 (11) Å].
Di-μ-benzoato-κ3O,O′:O;κ3O:O,O′-bis[aqua(nitrato-κO)(1,10-phenanthroline-κ2N,N′)lead(II)]
Authors: Cheng Yuanzheng , Yan Fang , Shi Weiwei , Zhang Liping
Published: March 2012

The title compound, [Pb2(C7H5O2)2(NO3)2(C12H8N2)2(H2O)2], crystallizes as a dinuclear centrosymmetric dimer containing two PbIIatoms bridged by two benzoate ligands. Each PbIIatom is seven-coordinated by a water molecule, a nitrate anion, a 1,10-phenanthroline (phen) ligand and two benzoate anions. The crystal packing is stabilized by O—H...O hydrogen bonds and by π–π stacking between neighboring phen ligands, with a centroid–centroid distance of 3.557 (3) Å.
catena-Poly[[bis(pyridine-3-carboxylic acid-κN)mercury(II)]-di-μ-chlorido]
Authors: Shirvan Sadif A. , Haydari Dezfuli Sara
Published: March 2012

In the title compound, [HgCl2(C6H5NO2)2]n, the HgIIcation is located on an inversion center and is six-coordinated in a distorted octahedral geometry by two N atoms from two pyridine-3-carboxylic acid molecules and four bridging Cl−anions. The bridging function of the Cl−anions leads to polymeric chains running along theaaxis. One Hg—Cl bond is much longer than the other. In the crystal, O—H...O and weak C—H...Cl hydrogen bonds are observed.
Bis{μ-2-[3-carboxylatomethyl-4-(phenylsulfanyl)phenyl]propanoato-κ4O,O′:O′′,O′′′}bis[(2,2′-bipyridine-κ2N,N′)cadmium]
Authors: Li Long , Ding Yu-Qiu , Diao Kai-Sheng
Published: March 2012

In the title complex, [Cd2(C17H14O4S)2(C10H8N2)2], which was hydrothermally synthesized, the CdIIcation is hexacoordinated in a distorted octahedral geometry by two N atoms from a 2,2′-bipyridine ligand and by four O atoms from two different 2-[3-carboxylatomethyl-4-(phenylsulfanyl)phenyl]propanoate ligands, forming a cyclic dimetallic complex.
{5,5′-Dimethoxy-2,2′-[2,2-dimethylpropane-1,3-diylbis(nitrilomethanylylidene)]diphenolato}palladium(II)
Authors: Che Soh Siti Kamilah , Shamsuddin Mustaffa , Rosli Mohd Mustaqim , Fun Hoong-Kun
Published: March 2012

In the title compound, [Pd(C21H24N2O4)], the complete molecule is generated by crystallographic mirror symmetry with the Pd and three C atoms lying on the mirror plane. The Pd—O and Pd—N distances are 1.9932 (6) and 2.0029 (7) Å, respectively. The dihedral angle between two benzene rings of the ligand is 79.21 (4)°. In the crystal, C—H...O hydrogen bonds link the molecules into layers parallel to theabplane. These planes are further connected by C—H...O interactions, forming a three-dimensional network.
2,11-Dibromo-5,8-dibutyl[4]helicene
Authors: Isobe Hiroyuki , Matsuno Taisuke , Hitosugi Shunpei , Nakanishi Waka
Published: March 2012

A racemic mixture of the title compound, C26H26Br2, a brominated [4]helicene, crystallizes, forming columns of stacked molecules. There are two crystallographically unique molecules in the asymmetric unit, both with the same helical handedness. As is typical with helicene congeners, the unique molecules show short interatomic contacts between H atoms at the fjord region, with H...H distances of 1.87 and 1.94 Å. Molecules with the same helical handedness segregate in the crystal packing, forming homochiral columns. The stacked molecules are piled in a column with alternate orientations. The shortest C...C distance in the stacked molecules is 3.306 (4) Å.
2-Vinylpyridine–tris(pentafluorophenyl)borane hexane monosolvate
Authors: Klahn Marcus , Spannenberg Anke , Rosenthal Uwe
Published: March 2012

The title compound, C7H7N·B(C6F5)3·C6H14, was obtained by the stoichiometric reaction of 2-vinylpyridine and tris(pentafluorophenyl)borane in toluene. The formed adduct exhibits a restricted rotation along the B—N bond resulting in an asymmetry, which can be also observed in the19F NMR spectra. The B—N distance is equivalent to the distances found for 2-methylpyridine and 2-ethylpyridine B(C6F5)3adducts. For the final refinement, the contributions of disordered solvent molecules were removed from the diffraction data with SQUEEZE inPLATON[van der Sluis & Spek (1990).Acta Cryst.A46, 194–201; Spek (2009).Acta Cryst.D65, 148–155].
3-Methyl-1-benzofuran-2-carbohydrazide
Authors: Abdel-Aziz Hatem A. , Ghabbour Hazem A. , Chantrapromma Suchada , Fun Hoong-Kun
Published: March 2012

In the asymmetric unit of the title benzofuran derivative, C10H10N2O2, there are three crystallograpically independent molecules, which are slightly twisted; the dihedral angle between the benzofuran ring system and the plane of the carbohydrazide unit is 8.64 (11)° in one molecule, whereas the dihedral angles are 9.58 (11) and 6.89 (10)° in the other two molecules. In the crystal, the three independent molecules are linked to each other through N—H...N hydrogen bonds, forming a trimer. The trimers are further linked by weak N—H...O and C—H...O hydrogen bonds into a three-dimensional network. π–π interactions with centroid–centroid distances in the range 3.4928 (11)–3.8561 (10) Å are also observed.
6-Methylideneandrost-4-ene-3,17-dione
Authors: Andrade L. C. R. , Almeida M. J. M. de , Fernandes Roleira F. M. , Varela C. L. , Tavares da Silva E. J.
Published: March 2012

In the title compound, C20H26O2, which is the 6-methylene derivative of androstenedione and a synthetic percursor of exemestane, the steroidAring approximates to a sofa (or envelope) conformation, with the methylene group adjacent to the link to theBring lying out of the plane of the other atoms. TheBandCrings have slightly flattened chair conformations and theDring is an envelope, with the CH group forming the flap. In the crystal, molecules are linked by two distinct C—H...O hydrogen bonds, involving acidic H atoms close to C=C and C=O double bonds.