bluuebunny/crossref_metadata_2025 huggingface dataset:
Admittance of Au/1,4-benzenedithiol/Au single-molecule junctions
Authors: Yamauchi Kazumasa , Kurokawa Shu , Sakai Akira
Published: December 2012

Employing the admittance formula for double-barrier junctions [Fu and Dudley, Phys. Rev. Lett. 70, 65 (1993)], we have estimated an ac susceptance (imaginary part of admittance) of Au/1,4-benzenedithiol/Au single-molecule junctions from their current-voltage characteristics. In the MHz regime, we find that the junction susceptance shows a very small (∼0.1 aF) capacitive component that can be entirely masked by a larger electrode capacitance. Direct ac signal transmission measurements up to 1 GHz reveal no molecular signals and confirm the smallness of the molecular capacitance in the MHz regime.
Molecular barcode and morphological analyses reveal the taxonomic and biogeographical status of the striped-legged hermit crab species Clibanarius sclopetarius (Herbst, 1796) and Clibanarius vittatus (Bosc, 1802) (Decapoda : Diogenidae)
Authors: Negri Mariana , Pileggi Leonardo G. , Mantelatto Fernando L.
Published: December 2012

The taxonomic status of the species Clibanarius sclopetarius (Herbst, 1796) and Clibanarius vittatus (Bosc, 1802), which have sympatric biogeographical distributions restricted to the western Atlantic Ocean, is based only on differences in the colour pattern of the walking legs of adults. Their morphological similarity led to the suggestion that they be synonymised. In order to investigate this hypothesis, we included species of Clibanarius Dana, 1892 in a molecular phylogenetic analysis of partial sequences of the mitochondrial 16S rDNA gene and the COI barcode region. In addition, we combined the molecular results with morphological observations obtained from several samples of these two species. The genetic divergences of the 16S rDNA and COI sequences between C. sclopetarius and C. vittatus ranged from 4.5 to 5.9% and 9.4 to 11.9%, which did not justify their synonymisation. Differences in the telson morphology, chela ornamentation, and coloration of the eyestalks and antennal peduncle provided support for the separation of the two species. Another interesting result was a considerable genetic difference found between populations of C. vittatus from Brazil and the Gulf of Mexico, which may indicate the existence of two homonymous species.
DNA barcoding in Nautilus pompilius (Mollusca : Cephalopoda): evolutionary divergence of an ancient species in modern times
Authors: Williams Rachel C. , Newman Stephen J. , Sinclair William
Published: December 2012

DNA barcoding studies to elucidate the evolutionary and dispersal history of the current populations of Nautilus pompilius allow us to develop a greater understanding of their biology, their movement and the systematic relationships between different groups. Phylogenetic analyses were conducted on Australian N. pompilius, and COI sequences were generated for 98 discrete accessions. Sequences from samples collected across the distribution were sourced from GenBank and included in the analyses. Maximum likelihood revealed three distinct clades for N. pompilius: (1) populations sourced from west Australia, Indonesia and the Philippines; (2) populations collected from east Australia and Papua New Guinea; (3) western Pacific accessions from Vanuatu, American Samoa and Fiji, supporting previous findings on the evolutionary divergence of N. pompilius. A minimum spanning tree revealed 49 discrete haplotypes for the 128 accessions, from a total of 16 discrete sampling locations. Population similarity reflects oceanic topographic features, with divergence between populations across the N. pompilius range mirroring geographical separation. This illustrates the success of DNA barcoding as a tool to identify geographic origin, and looks to the future role of such technology in population genetics and evolutionary biology.
Difficulties barcoding in the dark: the case of crustacean stygofauna from eastern Australia
Authors: Asmyhr Maria G. , Cooper Steven J. B.
Published: December 2012

The eastern Australian aquifers remain mostly unexplored; however, recent surveys suggest that there could be substantial levels of subterranean biodiversity hidden in these aquifers. Groundwater fauna (stygofauna) is often characterised by short-range endemism. Furthermore, high levels of cryptic species, and lack of formal taxonomic descriptions and taxonomic expertise for many of the groups demand innovative approaches for assessing subterranean biodiversity. Here we evaluate the potential of using DNA barcoding as a rapid biodiversity assessment tool for the subterranean groundwater fauna of New South Wales, Australia. We experienced low amplification success using universal and more taxon-specific primers for PCR amplification of the barcoding gene (COI) in a range of crustacean stygofauna. Sequence comparisons of the most commonly used COI universal primers in selected crustacean taxa revealed high levels of variability. Our results suggest that successful amplification of the COI region from crustacean stygofauna is not straightforward using the standard ‘universal’ primers. We propose that the development of a multiprimer (taxon specific) and multigene approach for DNA barcode analyses, using next-generation sequencing methodologies, will help to overcome many of the technical problems reported here and provide a basis for using DNA barcoding for rapid biodiversity assessments of subterranean aquatic ecosystems.
HIV-1 Tat recruits transcription elongation factors dispersed along a flexible AFF4 scaffold
Authors: Chou Seemay , Upton Heather , Bao Katherine , Schulze-Gahmen Ursula , Samelson Avi J. , He Nanhai , Nowak Anna , Lu Huasong , Krogan Nevan J. , Zhou Qiang , Alber Tom
Published: December 2012

The HIV-1 Tat protein stimulates viral gene expression by recruiting human transcription elongation complexes containing P-TEFb, AFF4, ELL2, and ENL or AF9 to the viral promoter, but the molecular organization of these complexes remains unknown. To establish the overall architecture of the HIV-1 Tat elongation complex, we mapped the binding sites that mediate complex assembly in vitro and in vivo. The AFF4 protein emerges as the central scaffold that recruits other factors through direct interactions with short hydrophobic regions along its structurally disordered axis. Direct binding partners CycT1, ELL2, and ENL or AF9 act as bridging components that link this complex to two major elongation factors, P-TEFb and the PAF complex. The unique scaffolding properties of AFF4 allow dynamic and flexible assembly of multiple elongation factors and connect the components not only to each other but also to a larger network of transcriptional regulators.
EUROPEAN MARKET MAKING AND POLICY DUPLICATION
Authors: Frankel Christian
Published: December 2012

This paper argues that private regulation has been essential to the making of the common European market. The distinction between negative and positive integration, usually used to understand the making of the common European market, only gives us part of the picture, as it focuses on public authorities and the regulation issued by them, and tends to ignore private authorities. A focus on private regulation is suggested to enlarge the focus on positive and negative integration, and this is used in an analysis of EU's removal of barriers to trade from 1958 to 2000. The paper shows that private regulation in the form of technical standardisation has become essential to European market making.
Intersection numbers for normal functions
Authors: Clemens C.
Published: December 2012

The purpose of this note is to simplify and generalize a formula of M. Green and P. Griffiths for the intersection number of two normal functions in complex algebraic geometry.
Une généralisation d’une construction de Richelot
Authors: Mestre Jean-François
Published: December 2012

We give a generalization of a construction of Richelot, which permits us to obtain a family of dimension

g
+
1

g+1

of pairs of hyperelliptic curves of genus

g
g

with

2
…
2

⏞

g

\overbrace {2\ldots 2}^g

-isogenous Jacobians.
Effect of High Night Temperature During Grain Filling on Amyloplast Development and Grain Quality in Japonica Rice
Authors: Song Xiaoyan , Du Yanxiu , Song Xingnian , Zhao Quanzhi
Published: December 2012

High‐quality japonica rices Yujing 6 and Fangxin 4 were cultured under ambient night temperature (ANT, 19.7°C) and high night temperature (HNT, 26.7°C) in a greenhouse for the analysis of amyloplast development and grain quality during the grain‐filling stage. Results indicated that the HNT treatment had distinct effects on the grain‐filling rate of Yujing 6 and Fangxin 4 1–10 days after anthesis. HNT increased the rate of grain filling by 9.89–40.45% and decreased the accumulation of grain‐filling matter, resulting in inferior appearance and poor milling qualities (e.g., brown rice rate, milled rice rate, head rice rate, imperfect rice rate, chalky rice rate, and chalkiness degree). Results from a rapid viscosity analyzer showed that the HNT treatment decreased the paste viscosity, depending on the rice cultivar. Differential scanning calorimetry results indicated that the gelatinization temperatures of HNT such as onset temperature, peak temperature, and final temperature were all significantly higher than those of ANT. However, HNT had no distinct effects on the X‐ray diffraction pattern of rice starch.
The AvrB_AvrC Domain of AvrXccC ofXanthomonas campestrispv.campestrisIs Required to Elicit Plant Defense Responses and Manipulate ABA Homeostasis
Authors: Ho Yi-Ping , Tan Choon Meng , Li Meng-Ying , Lin Hong , Deng Wen-Ling , Yang Jun-Yi
Published: December 2012

Plant disease induced by Xanthomonas campestris pv. campestris depends on type III effectors but the molecular basis is poorly understood. Here, AvrXccC8004was characterized, and it was found that the AvrB_AvrC domain was essential and sufficient to elicit defense responses in an Arabidopsis-resistant ecotype (Col-0). An upregulation of genes in responding to the AvrB_AvrC domain of AvrXccC8004was shown in a profile of host gene expression. The molecular changes were correlated with morphological changes observed in phenotypic and ultrastructural characterizations. Interestingly, the abscisic acid (ABA)-signaling pathway was also a prominent target for the AvrB_AvrC domain of AvrXccC8004. The highly elicited NCED5, encoding a key enzyme of ABA biosynthesis, was increased in parallel with ABA levels in AvrXccC8004transgenic plants. Consistently, the X. campestris pv. campestris 8004 ΔavrXccC mutant was severely impaired in the ability to manipulate the accumulation of ABA and induction of ABA-related genes in challenged leaves. Moreover, exogenous application of ABA also enhanced the susceptibility of Arabidopsis to the X. campestris pv. campestris strains. These results indicate that the AvrB_AvrC domain of AvrXccC8004alone has the activity to manipulate ABA homeostasis, which plays an important role in regulating the interactions of X. campestris pv. campestris and Arabidopsis.
Random T-DNA Mutagenesis Identifies a Cu/Zn Superoxide Dismutase Gene as a Virulence Factor of Sclerotinia sclerotiorum
Authors: Xu Liangsheng , Chen Weidong
Published: December 2012

Agrobacterium-mediated transformation (AMT) was used to identify potential virulence factors in Sclerotinia sclerotiorum. Screening AMT transformants identified two mutants showing significantly reduced virulence. The mutants showed growth rate, sclerotial formation, and oxalate production similar to that of the wild type. The mutation was due to a single T-DNA insertion at 212 bp downstream of the Cu/Zn superoxide dismutase (SOD) gene (SsSOD1, SS1G_00699). Expression levels of SsSOD1 were significantly increased under oxidative stresses or during plant infection in the wild-type strain but could not be detected in the mutant. SsSOD1 functionally complemented the Cu/Zn SOD gene in a Δsod1 Saccharomyces cerevisiae mutant. The SOD mutant had increased sensitivity to heavy metal toxicity and oxidative stress in culture and reduced ability to detoxify superoxide in infected leaves. The mutant also had reduced expression levels of other known pathogenicity genes such as endo-polygalacturanases sspg1 and sspg3. The functions of SsSOD1 were further confirmed by SsSOD1-deletion mutation. Like the AMT insertion mutant, the SsSOD1-deletion mutant exhibited normal growth rate, sclerotial formation, oxalate production, increased sensitivity to metal and oxidative stress, and reduced virulence. These results suggest that SsSOD1, while not being required for saprophytic growth and completion of the life cycle, plays critical roles in detoxification of reactive oxygen species during host–pathogen interactions and is an important virulence factor of Sclerotinia sclerotiorum.
Evidence for Acquisition of Copper Resistance Genes from Different Sources in Citrus-Associated Xanthomonads
Authors: Behlau Franklin , Hong Jason C. , Jones Jeffrey B. , Graham James H.
Published: December 2012

We determined that multiple and independent introductions of copper resistance genes have taken place for strains of Xanthomonas citri subsp. citri from Argentina and strains of X. alfalfae subsp. citrumelonis from Florida. This study compared the partial nucleotide sequences of principal copper resistance genes copL, copA, and copB from X. citri subsp. citri and X. alfalfae subsp. citrumelonis to strains of other Xanthomonas spp. resistant to copper that were isolated from 12 different countries or territories. The survey confirmed that the copLAB gene cluster is present in many species of Xanthomonas from different parts of the world. Alignment of partial nucleotide sequences of copper resistance genes among the copper-resistant (CuR) strains of Xanthomonas detected homology of ≥92, ≥96, and ≥91% for copL, copA, and copB, respectively. Grouping of strains based on branching patterns of phylogenetic trees was similar for copL and copA but differed for copB. When the three genes were concatenated and analyzed using various phylogenetic methods, it appeared that the plasmid had been horizontally transferred and various populations were mutating based on selection pressure unique to geographic regions. Although high homology of the genes among the strains indicated that the copper resistance in xanthomonads has a common origin, the slight differences in nucleotide sequences within groups of strains indicated that CuR genes have been independently exchanged among species of Xanthomonas throughout the world.
Finger pad friction and its role in grip and touch
Authors: Adams Michael J. , Johnson Simon A. , Lefèvre Philippe , Lévesque Vincent , Hayward Vincent , André Thibaut , Thonnard Jean-Louis
Published: December 2012

Many aspects of both grip function and tactile perception depend on complex frictional interactions occurring in the contact zone of the finger pad, which is the subject of the current review. While it is well established that friction plays a crucial role in grip function, its exact contribution for discriminatory touch involving the sliding of a finger pad is more elusive. For texture discrimination, it is clear that vibrotaction plays an important role in the discriminatory mechanisms. Among other factors, friction impacts the nature of the vibrations generated by the relative movement of the fingertip skin against a probed object. Friction also has a major influence on the perceived tactile pleasantness of a surface. The contact mechanics of a finger pad is governed by the fingerprint ridges and the sweat that is exuded from pores located on these ridges. Counterintuitively, the coefficient of friction can increase by an order of magnitude in a period of tens of seconds when in contact with an impermeably smooth surface, such as glass. In contrast, the value will decrease for a porous surface, such as paper. The increase in friction is attributed to an occlusion mechanism and can be described by first-order kinetics. Surprisingly, the sensitivity of the coefficient of friction to the normal load and sliding velocity is comparatively of second order, yet these dependencies provide the main basis of theoretical models which, to-date, largely ignore the time evolution of the frictional dynamics. One well-known effect on taction is the possibility of inducing stick–slip if the friction decreases with increasing sliding velocity. Moreover, the initial slip of a finger pad occurs by the propagation of an annulus of failure from the perimeter of the contact zone and this phenomenon could be important in tactile perception and grip function.
Glide performance and aerodynamics of non-equilibrium glides in northern flying squirrels (Glaucomys sabrinus)
Authors: Bahlman Joseph W. , Swartz Sharon M. , Riskin Daniel K. , Breuer Kenneth S.
Published: December 2012

Gliding is an efficient form of travel found in every major group of terrestrial vertebrates. Gliding is often modelled in equilibrium, where aerodynamic forces exactly balance body weight resulting in constant velocity. Although the equilibrium model is relevant for long-distance gliding, such as soaring by birds, it may not be realistic for shorter distances between trees. To understand the aerodynamics of inter-tree gliding, we used direct observation and mathematical modelling. We used videography (60–125 fps) to track and reconstruct the three-dimensional trajectories of northern flying squirrels (Glaucomys sabrinus) in nature. From their trajectories, we calculated velocities, aerodynamic forces and force coefficients. We determined that flying squirrels do not glide at equilibrium, and instead demonstrate continuously changing velocities, forces and force coefficients, and generate more lift than needed to balance body weight. We compared observed glide performance with mathematical simulations that use constant force coefficients, a characteristic of equilibrium glides. Simulations with varying force coefficients, such as those of live squirrels, demonstrated better whole-glide performance compared with the theoretical equilibrium state. Using results from both the observed glides and the simulation, we describe the mechanics and execution of inter-tree glides, and then discuss how gliding behaviour may relate to the evolution of flapping flight.
Dynamical modelling of haematopoiesis: an integrated view over the system in homeostasis and under perturbation
Authors: Manesso Erica , Teles José , Bryder David , Peterson Carsten
Published: December 2012

A very high number of different types of blood cells must be generated daily through a process called haematopoiesis in order to meet the physiological requirements of the organism. All blood cells originate from a population of relatively few haematopoietic stem cells residing in the bone marrow, which give rise to specific progenitors through different lineages. Steady-state dynamics are governed by cell division and commitment rates as well as by population sizes, while feedback components guarantee the restoration of steady-state conditions. In this study, all parameters governing these processes were estimated in a computational model to describe the haematopoietic hierarchy in adult mice. The model consisted of ordinary differential equations and included negative feedback regulation. A combination of literature data, a novel divide et impera approach for steady-state calculations and stochastic optimization allowed one to reduce possible configurations of the system. The model was able to recapitulate the fundamental steady-state features of haematopoiesis and simulate the re-establishment of steady-state conditions after haemorrhage and bone marrow transplantation. This computational approach to the haematopoietic system is novel and provides insight into the dynamics and the nature of possible solutions, with potential applications in both fundamental and clinical research.
Keynes, Newton and the Royal Society: the events of 1942 and 1943
Authors: Kuehn Daniel
Published: December 2012

Most discussions of John Maynard Keynes's activities in connection with Newton are restricted to the sale in 1936 at Sotheby's of Newton's Portsmouth Papers and to Keynes's 1946 essay ‘Newton, the Man’. This paper provides a history of Keynes's Newton-related work in the interim, highlighting especially the events of 1942 and 1943, which were particularly relevant to the Royal Society's role in the domestic and international promotion of Newton's legacy. During this period, Keynes lectured twice on Newton, leaving notes that would later be read by his brother Geoffrey in the famous commemoration of the Newton tercentenary in 1946. In 1943 Keynes assisted the Royal Society in its recognition of the Soviet celebrations and in the acquisition and preservation of more of the Newton library. In each instance Keynes took the opportunity to promote his interpretation of Newton as ‘the last of the magicians’: a scientist who had one foot in the pre-modern world and whose approach to understanding the world was as much intuitive as it was methodical.
Pairing context determines condition-dependence of song rate in a monogamous passerine bird
Authors: David Morgan , Auclair Yannick , Dall Sasha R. X. , Cézilly Frank
Published: December 2012

Condition-dependence of male ornaments is thought to provide honest signals on which females can base their sexual choice for genetic quality. Recent studies show that condition-dependence patterns can vary within populations. Although long-term association is thought to promote honest signalling, no study has explored the influence of pairing context on the condition-dependence of male ornaments. In this study, we assessed the influence of natural variation in body condition on song rate in zebra finches (Taeniopygia guttata) in three different situations: during short and long encounters with an unfamiliar female, and within heterosexual mated pairs. We found consistent individual differences in male directed and undirected song rate. Moreover, body condition had a positive effect on song rate in paired males. However, male song rate was not influenced by body condition during short or long encounters with unfamiliar females. Song rate appears to be an unreliable signal of condition to prospective females as even poor-condition birds can cheat and sing at a high rate. By contrast, paired females can reliably use song rate to assess their mate's body condition, and possibly the genetic quality. We propose that species' characteristics, such as mating system, should be systematically taken into account to generate relevant hypotheses about the evolution of condition-dependent male ornaments.
Crystal Structure of Rice Importin-α and Structural Basis of Its Interaction with Plant-Specific Nuclear Localization Signals
Authors: Chang Chiung-Wen , Couñago Rafael Lemos Miguez , Williams Simon J. , Bodén Mikael , Kobe Boštjan
Published: December 2012

In the classical nucleocytoplasmic import pathway, nuclear localization signals (NLSs) in cargo proteins are recognized by the import receptor importin-α. Importin-α has two separate NLS binding sites (the major and the minor site), both of which recognize positively charged amino acid clusters in NLSs. Little is known about the molecular basis of the unique features of the classical nuclear import pathway in plants. We determined the crystal structure of rice (Oryza sativa) importin-α1a at 2-Å resolution. The structure reveals that the autoinhibitory mechanism mediated by the importin-β binding domain of importin-α operates in plants, with NLS-mimicking sequences binding to both minor and major NLS binding sites. Consistent with yeast and mammalian proteins, rice importin-α binds the prototypical NLS from simian virus 40 large T-antigen preferentially at the major NLS binding site. We show that two NLSs, previously described as plant specific, bind to and are functional with plant, mammalian, and yeast importin-α proteins but interact with rice importin-α more strongly. The crystal structures of their complexes with rice importin-α show that they bind to the minor NLS binding site. By contrast, the crystal structures of their complexes with mouse (Mus musculus) importin-α show preferential binding to the major NLS binding site. Our results reveal the molecular basis of a number of features of the classical nuclear transport pathway specific to plants.
Differential equations and expansions for quaternionic modular forms in the discriminant 6 case
Authors: Baba Srinath , Granath Håkan
Published: December 2012

We study the differential structure of the ring of modular forms for the unit group of the quaternion algebra over ℚ of discriminant 6. Using these results we give an explicit formula for Taylor expansions of the modular forms at the elliptic points. Using appropriate normalizations we show that the Taylor coefficients at the elliptic points of the generators of the ring of modular forms are all rational and 6-integral. This gives a rational structure on the ring of modular forms. We give a recursive formula for computing the Taylor coefficients of modular forms at elliptic points and, as an application, give an algorithm for computing modular polynomials.
To Share or Not To Share: That Is Not the Question
Authors: Ohno-Machado Lucila
Published: December 2012

Sharing clinical and biomedical data could accelerate translational research.
Multimodal Actions of Neural Stem Cells in a Mouse Model of ALS: A Meta-Analysis
Authors: Teng Yang D. , Benn Susanna C. , Kalkanis Steven N. , Shefner Jeremy M. , Onario Renna C. , Cheng Bin , Lachyankar Mahesh B. , Marconi Michael , Li Jianxue , Yu Dou , Han Inbo , Maragakis Nicholas J. , Lládo Jeronia , Erkmen Kadir , Redmond D. Eugene , Sidman Richard L. , Przedborski Serge , Rothstein Jeffrey D. , Brown Robert H. , Snyder Evan Y.
Published: December 2012

A meta-analysis reports the beneficial effects of transplanting mouse or human neural stem cells into the spinal cord of the SOD1
G93A
mouse, a model of ALS.
Stress Structures the Brain
Authors: Singh Manpreet K.
Published: December 2012

Stress experienced as an infant can alter blood cortisol concentrations and brain development, leading to emotion dysregulation in adolescence.
The Teratoma Factory
Authors: Tanhehco Yvette
Published: December 2012

iPSC-generated teratomas can be sources of hematopoietic stem cells, antibodies, and cytokines.
Acute hepatic failure following intravenous amiodarone
Authors: Grecian Robert , Ainslie Mark
Published: December 2012

A 73-year-old gentleman presented to the hospital after an episode of loss of consciousness. He had a defibrillator in situ, which on interrogation was found to have fired for an episode of ventricular fibrillation. As an inpatient he developed frequent episodes of self-terminating ventricular tachycardia, treated initially with oral amiodarone. A 24 h amiodarone infusion was started on day 3 of admission, following which the patient developed hyperventilation. Investigations revealed that this was secondary to acute hepatic and renal failure, requiring haemofiltration on the intensive care unit. Cessation of amiodarone was associated with normalisation of liver function over 48 h. The patient had normal blood and jugular venous pressures throughout days 1–4 of admission. We discuss the role of amiodarone as the predominant factor in the deterioration of this patient's liver function, versus the differential diagnosis of ischaemia-induced hepatotoxicity, citing recent research regarding this subject.
Primary pituitary abscess in an adolescent boy: a rare occurrence
Authors: Hazra Samik , Acharyya Saugata , Acharyya Kakoli
Published: December 2012

Primary pituitary abscess is a rare clinical condition at a young age. It is characterised by atypical clinical features which makes the diagnosis difficult. Correct diagnosis and therapy are mandatory due to the potentially lethal outcome. We report the case of a 14–year-old healthy boy. The onset was acute with fever, gait imbalance, slurring of speech and amnesia. MRI brain revealed a hyperintense lesion in T2-weighted image (T2WI) in sellar and suprasellar region, which was hypointense in T1WI. After administration of contrast, there was peripheral rim enhancement suggesting pituitary abscess. The diagnosis was confirmed following evacuation of purulent material, during surgery, through a trans-sphenoidal approach. Postoperatively, the boy needed prolonged intensive care support. He was discharged on day 42 after surgery. Follow-up at 3 months revealed complete motor recovery. He required hormone replacement and was intermittently showing features suggestive of frontal lobe syndrome.
Rapid progression of coronary atherosclerosis after cardiac resynchronisation therapy: cause or coincidence?
Authors: Zaidi Abbas , Barry James , Chase Alexander
Published: December 2012

An 85-year-old man with a diagnosis of idiopathic dilated cardiomyopathy presented with worsening breathlessness and reduced functional capacity. Previous angiography had demonstrated only mild, single-vessel coronary atherosclerosis. Owing to the occurrence of severe symptoms despite optimal medical therapy, cardiac resynchronisation therapy (CRT) was performed by means of biventricular pacemaker implantation. The patient was readmitted, 6 months later, with an acute ST-segment myocardial infarction. Urgent coronary angiography demonstrated severe multivessel atherosclerotic coronary artery disease, in the absence of any alteration in basal drug therapy or modifiable cardiovascular risk factor profile. Percutaneous coronary intervention was performed with good result. We postulate a potential causal association between CRT and accelerated coronary atherosclerosis, with alterations in blood flow dynamics and coagulation properties as potential mechanisms. There are no previous reports of this phenomenon in the published literature.
Bronchoscopic and histological changes over time following acute ferrous sulphate tablet aspiration
Authors: Maw Matthew , Chiu Robert , Lim Albert Yick Hou
Published: December 2012

An 84-year-old woman accidentally aspirated an iron tablet. She was successfully treated with early endobronchial removal of the iron tablet remnants, oral corticosteroids and antibiotics. We describe the bronchoscopic and histological changes over time following acute iron tablet aspiration and highlight the importance of early intervention to avoid complications.
Trimethoprim/sulfamethoxazole induced multiorgan dysfunction
Authors: Lee Joshua Seung Oh , Owshalimpur David , Schofield Christina
Published: December 2012

A 22-year-old African-American man with AIDS who had recently started on trimethoprim/sulfamethoxazole daily for pneumocystis jirovecii pneumonia prophylaxis presented with an altered mental state, malaise and nausea was found to have hepatitis, pancreatitis, rhabdomyolitis, acute kidney injury and haemolytic anaemia. Cessation of Bactrim and supportive care with volume expansion resolved his clinical symptoms and laboratory abnormalities.
Management of a xeroderma pigmentosum case with oral findings in a dental setup
Authors: Banda Vanaja Reddy , Banda Naveen Reddy , Reddy Ramesh , Banda Praveen
Published: December 2012

Xeroderma pigmentosum (XP) is heterogeneous group of disorder transmitted as autosomal recessive trait. It is characterised by photosensitivity, freckled pigmentation and premature skin ageing and malignant tumour development. The manifestations are due to a cellular hypersensitivity to ultraviolet light resulting from a defect in DNA repair. Multiple cutaneous neoplasms develop at a young age in persons with XP. Two important causes of mortality are metastatic malignant melanoma and squamous cell carcinoma (SCC). We report a case of XP in a 22 year-old male patient who developed SCC of lower lip with in a short period of 1 month.
Coexistence of mitral regurgitation and pulmonary regurgitation in an adult with surgically corrected tetralogy of Fallot
Authors: Mytas Dimitrios Z , Kanakis Meletios A , Kosma Lamprini K , Mitropoulos Fotios A
Published: December 2012

In patients with corrected tetralogy of Fallot (TOF), progressive right ventricular volume overload from longstanding regurgitation of the pulmonary valve, results in severe late complications. The presence of additional major clinical conditions may aggravate the clinical status in these patients. We describe the case of a patient with coexistence of mitral and pulmonary regurgitation in the setting of corrected TOF who underwent successful surgical treatment.
Acute functional deterioration in a child with cerebral palsy
Authors: Smyth Elizabeth , Kaliaperumal Chandrasekaran , Leonard Jane , Caird John
Published: December 2012

We describe a case of acute functional deterioration in a 13-year-old girl with severe spastic diplegia (GMFCS III) and a new diagnosis of diffuse intrinsic pontine glioma (DIPG). She presented with acute deterioration in mobility and motor function over 1 month, which was associated with dysarthria, dysphagia and behavioural change. Her mother had noticed subtle functional deterioration over the 2 months prior to this. Her physiotherapist who was concerned about her acute functional deterioration referred her for emergency review. Neurological imaging revealed a diffuse pontine lesion consistent with DIPG. She was subsequently referred to oncology. She deteriorated further, clinically, over the next few days and following discussion with the team; her family opted for palliative treatment, given the poor prognosis associated with DIPG.
Effects of agricultural intensification and temperature on immune response to phytohemagglutinin in Tree Swallows (Tachycineta bicolor)
Authors: Pigeon G. , Baeta R. , Bélisle M. , Garant D. , Pelletier F.
Published: December 2012

Lower immune response usually translates into lower fitness. Environmental quality can play a key role in shaping immune responses in the wild, as it influences both resource availability and costly maintenance functions. The aim of this study is to evaluate the effect of habitat quality on proinflammatory response to phytohemagglutinin (PHA) in Tree Swallows (Tachycineta bicolor (Vieillot, 1808)) under contrasting agricultural practices. Specifically, we tested the hypothesis that lower quality habitat (intensive agricultural practices and low temperature) negatively impairs immune responses. To do so, we compared the response to PHA of adult female and nestling Tree Swallows nesting in intensive vs. nonintensive agricultural landscapes over 3 years (2008–2010). In accordance with our predictions, we found that habitat quality affected adult female responses to PHA. The response of adult females was significantly higher in nonintensive agricultural areas than in intensive ones. The level of agricultural intensity, however, had no influence on the response to PHA of nestlings. Our results suggest that female adults can buffer the negative impact of a low-quality habitat on their nestlings. Furthermore, our results suggest that under limiting conditions, individuals may have to trade between immunity and other functions such as parental effort.
Competition theory — science and application in mixed forest stands: review of experimental and modelling methods and suggestions for future research
Authors: Larocque Guy R. , Luckai Nancy , Adhikary Shailendra N. , Groot Arthur , Bell F. Wayne , Sharma Mahadev
Published: December 2012

Competition in forest stands has long been of interest to researchers. However, much of the knowledge originates from empirical studies that examined the effects of competition. For instance, many studies were focused on the effects of the presence of herbaceous species on the development of tree seedlings or the decrease in individual tree growth with increases in stand density. Several models that incorporate competitive effects have been developed to predict tree and stand growth, but with simplified representations of competitive interactions. While these studies provided guidance useful for forest management, they contributed only partially to furthering our understanding of competitive mechanisms. Also, most competition studies were conducted in single-species stands. As competitive interactions occurring in mixed stands are characterized by a higher degree of complexity than those in single-species stands, a better understanding of these mechanisms can contribute to developing optimal management scenarios. The dynamics of forest stands with at least two species may be affected not only by competition, but also by facilitation or complementarity mechanisms. Thus, knowledge of the mechanisms may provide insight into the relative importance of intra- versus inter-specific competition and whether competition is symmetric or asymmetric. Special attention to the implementation of field experimental designs is warranted for mixed stands. While traditional spacing trials are appropriate for single-species stands, the examination of competitive interactions in mixed stands requires more complex experimental designs to examine the relative importance of species combinations. Forest productivity models allow resource managers to test different management scenarios, but again most of these models were developed for single-species stands. As competitive interactions are more complex in mixed stands, models developed to predict their dynamics will need to include more mechanistic representations of competition.
GaN BASED 3D CORE-SHELL LEDS
Authors: WANG XUE , LI SHUNFENG , FÜNDLING SÖNKE , WEI JIANDONG , ERENBURG MILENA , LEDIG JOHANNES , WEHMANN HERGO H. , WAAG ANDREAS , BERGBAUER WERNER , MANDL MARTIN , STRASSBURG MARTIN , STEEGMÜLLER ULRICH
Published: December 2012

As a promising novel route towards highly efficient optoelectronic devices, GaN based 3D core-shell light emitting diodes (LEDs) have attracted increased attention in recent years. In comparison to conventional 2D thin film LED, the 3D LED systems using a core-shell geometry with high aspect ratio are a breakthrough in technology with lots of advantages. In this paper, we review our developed growth strategies of these LED systems on Si and sapphire substrates. A catalyst free selective area growth of GaN 3D core-shell LED systems was realized using patterned substrates by metal organic vapor phase deposition in a convenient continuous-flux growth mode. We have recently suggested that the surface polarity plays a crucial role for the morphology of GaN 3D structure growth. In order to analyze the surface polarity of 3D submicron or micron structures, Kelvin probe force microscopy and selective etching techniques have been developed. During the growth of GaN submicron rods and micron columns on patterned SiOx /sapphire templates, mixed polarity effects could be detected. A new "truncated pyramid + column" growth method was developed to effectively avoid the formation of mixed polarity and realize single N-polar GaN 3D devices. Transmission electron microscopy and spatially and spectrally resolved cathodoluminescence measurements evidently prove the core-shell structure of 3D LED systems.
PROGRESS IN SIC MATERIALS/DEVICES AND THEIR COMPETITION
Authors: SCHRODER DIETER K.
Published: December 2012

Power semiconductor devices are important for numerous applications with power conversion being an important one. Wide energy gap semiconductors SiC and GaN have properties that make them attractive for such applications. Among these properties are high thermal conductivity, high breakdown electric field, wide energy gap, low intrinsic carrier concentration, high thermal stability, high saturation velocity and chemical inertness. These lead to low on-resistance, high breakdown voltage, high frequencies, small volume, and small passive inductors and capacitors. These desirable properties are offset by the higher material costs and higher defect densities. Although wide energy gap devices have been in development for many years, only recently have they become available commercially. Their main competition is silicon power devices with breakdown voltages up to 8000 V and very high surge current capacity. However, silicon power devices are approaching their material limits and wide energy gap devices are beginning to have an impact in the power electronics space. SiC has the advantage of substrates with diameters approaching 150 mm and the ability to grow thermal SiO2 . GaN has the heterojunction advantage, but no viable substrate technology. In fact, a large portion of SiC production is used for GaN substrates. GaN material development has also benefited significantly from the development of optical devices, e.g., light-emitting diodes and lasers.
ORDERED GAN/INGAN NANORODS ARRAYS GROWN BY MOLECULAR BEAM EPITAXY FOR PHOSPHOR-FREE WHITE LIGHT EMISSION
Authors: ALBERT S. , BENGOECHEA-ENCABO A. , SANCHEZ-GARCÍA M.A. , BARBAGINI F. , CALLEJA E. , LUNA E. , TRAMPERT A. , JAHN U. , LEFEBVRE P. , LÓPEZ L.L. , ESTRADÉ S. , REBLED J.M. , PEIRÓ F. , NATAF G. , DE MIERRY P. , ZUÑIGA-PÉREZ J.
Published: December 2012

The basics of the self-assembled growth of GaN nanorods on Si(111) are reviewed. Morphology differences and optical properties are compared to those of GaN layers grown directly on Si(111) . The effects of the growth temperature on the In incorporation in self-assembled InGaN nanorods grown on Si(111) is described. In addition, the inclusion of InGaN quantum disk structures into self-assembled GaN nanorods show clear confinement effects as a function of the quantum disk thickness. In order to overcome the properties dispersion and the intrinsic inhomogeneous nature of the self-assembled growth, the selective area growth of GaN nanorods on both, c-plane and a-plane GaN on sapphire templates, is addressed, with special emphasis on optical quality and morphology differences. The analysis of the optical emission from a single InGaN quantum disk is shown for both polar and non-polar nanorod orientations.
THEORETICAL INVESTIGATION OF INTRABAND, INFRARED ABSORBANCE IN INORGANIC/ORGANIC NANOCOMPOSITE THIN FILMS WITH VARYING COLLOIDAL QUANTUM DOT SURFACE LIGAND MATERIALS
Authors: LANTZ KEVIN R. , STIFF-ROBERTS ADRIENNE D.
Published: December 2012

Hybrid nanocomposite thin films, composed of inorganic colloidal quantum dots (CQDs) embedded in a matrix of organic conjugated polymer, have shown promise as a method for room-temperature infrared detection due to the three-dimensional confinement of the CQD and significantly lower dark currents compared to inorganic detectors. However, in order to improve device performance, the excited charges must be efficiently promoted out of the CQD, which is surrounded by an insulating surface ligand. These short, organic molecules, which are required to prevent agglomeration of CQDs in solution, have been shown to inhibit charge transfer into and out of the CQD. In this work, the transfer matrix method is utilized to calculate the quantized energy levels and wavefunctions in the conduction band of the CdSe CQD for a variety of surface ligand materials. These results are used to calculate the absorption coefficient for a size distribution of CQDs and are compared with measured Fourier Transform Infrared absorbance spectra. Finally, the effect of the ligand on the calculated absorption coefficient will be used to optimize the design for an infrared photoconductor.
MINIMAL MODEL PROGRAM WITH SCALING AND ADJUNCTION THEORY
Authors: ANDREATTA MARCO
Published: December 2012

Let (X, L) be a quasi-polarized pair, i.e. X is a normal complex projective variety and L is a nef and big line bundle on it. We study, up to birational equivalence, the positivity (nefness) of the adjoint bundles KX + rL for high rational numbers r. For this we run a Minimal Model Program with scaling relative to the divisor KX + rL. We give then some applications, namely the classification up to birational equivalence of quasi-polarized pairs with sectional genus 0, 1 and of embedded projective varieties X ⊂ ℙN with degree smaller than 2 codim ℙN(X) + 2.
MULTISCALE MODELING FOR AMORPHOUS MATERIALS — MAPPING ATOMISTIC DISPLACEMENTS TO MACROSCOPIC DEFORMATION
Authors: SU ZHOU CHENG , TAY TONG-EARN , CHEN YU , TAN VINCENT B. C.
Published: December 2012

A method to relate the displacements of atoms within a representative volume element (RVE) of amorphous material to the deformation of the RVE is presented. The displacement relationship is expressed as a mapping matrix, T, which operates on the displacements of representative points in the RVE to return the atom displacements within it. While the mapping operation has the same mathematical form as an interpolation operation, the T matrix is not an interpolant. It is derived taking into account atom displacements in amorphous materials which cannot be simplified as a continuous, much less homogenous, field. It is shown that the computational domain of a material can be partitioned into nonintersecting sub-domains comprising representative cells — pseudo-amorphous cells (PAC) — and sub-domains of atoms for concurrent multiscale simulations of amorphous materials through the T matrix. Multiscale simulations of nanoindentation on a polymer substrate using the T matrix show good agreement with pure molecular mechanics simulations. When homogenization techniques commonly used for crystalline materials were employed for the same simulations, they gave much less accurate predictions.
EFFECTS OF INTERFACE ENERGY ON MULTIPLE SCATTERING OF PLANE COMPRESSIONAL WAVES BY TWO CYLINDRICAL FIBERS
Authors: OU Z. Y. , LEE D. W.
Published: December 2012

The multiple scattering of plane compressional waves by two cylindrical fibers with interface effects is investigated. Based on surface elasticity theory, the wave fields in a nanoscale solid medium can be obtained by applying the eigenfunction expansion method and the Graf's addition theorem. Our results indicate that surface energy significantly affects the diffraction of elastic waves, as the radii of the fibers approach nanometers. The dynamic stress concentration factors at the interfaces between the fibers and the matrix under incident plane compressional waves at different frequencies are examined to determine the effects of surface energy, properties of inhomogeneous materials, and the interaction between fibers in multiple scattering phenomena. These results are helpful in understanding the dynamic mechanical properties of nanocomposites, and the proposed method for investigating the multiple scattering of plane compressional waves can be extended to the case of fiber-reinforced composites.
THE COMPLEX VARIABLE ELEMENT-FREE GALERKIN (CVEFG) METHOD FOR TWO-DIMENSIONAL ELASTODYNAMICS PROBLEMS
Authors: CHENG YUMIN , WANG JIANFEI , LI RONGXIN
Published: December 2012

The complex variable moving least-squares (CVMLS) approximation is discussed in this paper, and the mathematical and physical meaning of the complex functional in the CVMLS approximation is presented. With the CVMLS approximation, the trial function of a two-dimensional problem is formed with a one-dimensional basis function. Then combining the CVMLS approximation and the Galerkin weak form, we investigate the complex variable element-free Galerkin (CVEFG) method for two-dimensional elastodynamics problems. The penalty method is used to apply the essential boundary conditions, and the implicit time integration method, which is the Newmark method, is used for time history analysis. Then the corresponding formulae of the CVEFG method for two-dimensional elastodynamics problems are obtained. For the purposes of demonstration, some selected numerical examples are solved using the CVEFG method. Compared with the EFG method, the CVEFG method has greater precision.