bluuebunny/crossref_metadata_2025 huggingface dataset:
Elastic properties and electronic structures of MgCe intermetallic compounds from first‐principles calculations
Authors: Yang Fang , Wang Ji‐Wei , Ke Jiang‐Ling , Pan Zheng‐Gui , Tang Bi‐Yu
Published: May 2011

First‐principles calculations have been carried out to investigate the elastic properties and electronic structures of the main binary MgCe phases MgCe, Mg2Ce, and Mg3Ce. The optimized equilibrium lattice constants are in agreement with the available experimental values, and the structural stability of MgCe, Mg2Ce, and Mg3Ce is studied from the calculated heat of formation and cohesive energy. The elastic constants Cij of these phases are calculated; then the bulk modulus, shear modulus, Young's modulus, Cauchy pressure, and the ratio of bulk to shear modulus B/G are further investigated. The obtained results indicate that Mg2Ce has the best ductility and plasticity, while Mg3Ce is the hardest and the most brittle among the three MgCe phases. The density of states (DOSs) and charge density distribution of the MgCe phases are also calculated to reveal the underlying mechanism for the structural stability and elastic properties of these MgCe phases.
Microspheres manipulation system by patterned AlGaN/GaN 2DEG electrodes
Authors: Fu Junxue , Chen Kevin J
Published: May 2011

A manipulation system utilizing the properties of two‐dimensional electron gas (2DEG) at the interface of AlGaN/GaN and dielectrophoresis (DEP) was investigated in this study. At an applied frequency ranging from 100 kHz to 1 MHz and a potential of 20 vpeak to peak, the positive and negative DEP of the microspheres were reported for the first time by the Fluorine ion patterned and parylene covered 2DEG. In addition, by simply switching the applied frequency between 100 kHz and 500 kHz, the microspheres could come onto or get off from 2DEG region of AlGaN/GaN surface. Thus, a promising sensing scheme was proposed by combining the manipulation with sensing properties of 2DEG. This manipulation system based on 2DEG will bring much benefit to sensor applications. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Blue LEDs – way to overcome efficiency droop
Authors: Zakheim Dmitry A. , Pavluchenko Alexey S. , Bauman Dmitry A.
Published: May 2011

In this paper we report on fabrication of high power InGaN based blue light emitting diodes (LEDs) with substantially suppressed efficiency droop. The key feature of proposed device is the utilization of short‐period superlattice in the active region of LED heterostructure. In this superlattice the GaN barriers between quantum wells (QWs) are transparent for tunnelling, thus enabling carrier delocalization in growth direction. This, in turn, leads to the reduction of carrier concentration at given pumping comparing to the standard LED heterostructure, where, usually, only one QW contributes to light emission. The reduction of carrier concentration results in substantial suppression of third order non‐radiative processes, such as Auger recombination, responsible for the efficiency droop at high pumping. As a result, the LED external efficiency at operating current 350 mA differs from its maximum value only by 7%. Also, fabricated LEDs demonstrate very good stability of spectral position of the emission line, the observed blue shift of electroluminescence being less than 1 nm at pumping up to 1000 mA. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mechanisms of impurity incorporation during MOVPE growth of m‐plane GaN layers on LiAlO2
Authors: Mauder Christof , Reuters Benjamin , Behmenburg Hannes , De Souza Roger A. , Woitok Joachim F. , Chou Mitch M. C. , Heuken Michael , Kalisch Holger , Jansen Rolf H.
Published: May 2011

We study the oxygen incorporation during growth of m‐plane GaN films on LiAlO2 substrates by metal organic vapour phase epitaxy (MOVPE). A broad peak at ∼550 nm in photoluminescence spectra is probably caused by oxygen impurities. Secondary ion mass spectroscopy (SIMS) confirms this finding and reveals a concentration in the order of 1019 cm‐3 which is consistent to the measured n‐type doping level. A general slow decrease of the oxygen concentration in growth direction is observed. A c‐plane GaN film grown on sapphire co‐loaded together with a piece of LiAlO2 shows a slightly increased doping concentration compared to a c‐plane GaN reference. However, the achieved concentration of ∼1017 cm‐3 is much lower compared to m‐plane GaN films. Growth of GaN on a backside‐coated GaN/LiAlO2 template does neither suppress the impurity incorporation. This implies that oxygen incorporation via the gas phase is not the dominant factor. The SIMS oxygen profile of this GaN film on the template shows a strong peak at the position of growth interruption indicating the formation of a surface oxide. We assume that the m‐plane GaN surface has a large affinity for oxygen at the deposition temperature which leads to the high oxygen impurity level. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Threshold voltage control by gate electrode in Ga–Sn–Zn–O thin‐film transistors for logic inverter application
Authors: Lee Hee Sung , Park Chan Ho , Lee Kwang H. , Kim Dong‐Ho , Kim Hye‐Ri , Lee Gun‐Hwan , Im Seongil
Published: May 2011

We report on the fabrication of Ga–Sn–Zn–O thin‐film transistors (GTZO‐TFTs) and their inverter application. For the most stable and highly‐performing GTZO‐TFT, an optimal oxygen pressure condition was extracted out during co‐sputter deposition of Ga‐doped ZnO and SnO2. Using the oxygen pressure condition, we fabricated top‐gate GTZO‐TFTs for a logic inverter, which has two serially‐connected top‐gate TFTs with different gate electrodes: conducting NiOx and Al. Since the electrodes have very different work functions controlling the threshold voltages of TFTs, our inverter demonstrated a nice operation at less than 5 V with a high voltage gain of over 25. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Successful pain relief in non‐responders to spinal cord stimulation: The combined use of ketamine and spinal cord stimulation
Authors: Truin M. , Janssen S.P.M. , van Kleef M. , Joosten E.A.J.
Published: May 2011

Although spinal cord stimulation (SCS) is an established therapy for chronic neuropathic pain, still 30% of patients do not respond adequately to trial stimulation. These so called “non‐responders” do not receive a permanent implantation for pain relief.

The induction and maintenance of central sensitization plays a pivotal role in (chronic) neuropathic pain and is thought to be the resultant of the activation of the N‐methyl‐d‐aspartate (NMDA) receptor in the dorsal horn. Blocking the NMDA receptor through the use of the non‐competitive blocker ketamine has shown to attenuate neuropathic pain, although the undesirable side effects limit its use. The present study was performed to examine whether the combination of SCS with an individually determined sub‐effective dose of intrathecal (i.t.) ketamine could convert non‐responders into responders in rats with chronic neuropathic pain. Rats received a partial ligation of the sciatic nerve for the induction of neuropathic pain. Animals with tactile hypersensitivity to von Frey monofilaments (n = 15) received 30 min of SCS. Non‐responders to SCS (n = 8) received their individually determined sub‐effective i.t. dose of ketamine followed by 30 min of SCS. No side effects of the sub‐effective dose of ketamine could be noted. The combined treatment of SCS and sub‐effective dose of i.t. ketamine in non‐responders resulted in a significant reduction of the withdrawal threshold in all previous non‐responders to SCS, thereby converting them into responders to SCS.
The influence of the gas phase on liquid imbibition in capillary tubes
Authors: HULTMARK MARCUS , ARISTOFF JEFFREY M. , STONE HOWARD A.
Published: May 2011

The imbibition of liquid into a capillary tube is studied both theoretically and experimentally for sufficiently long tubes where viscous resistance from the gas phase ahead of the moving front is significant. At early times, and as the length of the tube is increased, we observe a systematic deviation from classical theory that cannot be attributed to the inertia of the liquid nor entrance effects. Instead, this behaviour is rationalized by considering the viscous resistance from the gas as it is displaced by the liquid. An explicit analytical solution for a one-dimensional description of the flow is given that accounts for viscous resistance from the displaced fluid. Excellent agreement between experiment and theory is obtained.
Boniface and the Irish Heresy of Clemens
Authors: Meeder Sven
Published: May 2011

One of the few Irishmen active on the Continent in the eighth century of whom we have some information was a priest (or bishop) named Clemens. Together with the Gaul Aldebert, this peregrinus was the subject of an extensive correspondence between Boniface and the pope, which eventually led to the condemnation of both men at the Roman Council of 745. The accusations brought against Clemens by Boniface display parallels with known Irish teachings and practices, as well as other allegations leveled against individual traveling Irishmen and the Irish in general. This article closely examines the context of Boniface's charges and introduces an additional source to the framing of his arguments. It argues that the allegations must be viewed in the context of both contemporary practices and debates in Irish church and society, and the portrayal of these Irish peculiarities in texts written in and spread throughout the mid-eighth-century Continent and Anglo-Saxon England.
That All May Be One? Church Unity and the German National Idea, 1866–1883
Authors: Landry Stan M.
Published: May 2011

Despite the political unification of the German Empire in 1871, the longstanding confessional divide between German Catholics and Protestants persisted through the early Wilhelmine era. Because confessional identity and difference were pivotal to how Germans imagined a nation, the meaning of German national identity remained contested. But the formation of German national identity during this period was not neutral—confessional alterity and antagonism was used to imagine confessionally exclusive notions of German national identity. The establishment of a “kleindeutsch” German Empire under Prussian-Protestant hegemony, the anti-Catholic policies of the Kulturkampf, and the 1883 Luther anniversaries all conflated Protestantism with German national identity and facilitated the marginalization of German Catholics from early Wilhelmine society, culture, and politics. While scholars have recognized this “confessionalization of the German national idea” they have so far neglected how proponents of church unity imagined German national unity and identity. This paper examines how Ut Omnes Unum—an ecumenical group of German Catholics and Protestants—challenged the conflation of Protestantism and German national identity and instead proposed an inter-confessional notion of German national identity that was inclusive of both Catholics and Protestants.
Musings and Reflections
Authors: Hillerbrand Hans
Published: May 2011

Our fellow historian Peter Brown reports that according to a memoir written, sometime around 1900 by a contemporary of Benedetto Croce, the eminent Italian philosopher, Croce challenged a colleague to a duel over an issue of metaphysics. What a startling report that makes you eager to turn the page—as in a John Gresham volume—in order to find out what happened. But nothing more is said in the book, compelling the conclusion that for the author, this was routine, unimportant, and even normal for professors to challenge each other to deadly duels. He must have thought that no explanation was necessary. And so a single sentence stands alone, tantalizing, unexplained—for contemporaries commonplace; for posterity altogether startling. What a splendid introduction to how to see the past offered us by Peter Brown!
Editing at Duke
Authors: Heitzenrater Richard P.
Published: May 2011

My first subscription to Church History was in 1965, which came about the same way many people first began receiving the journal in those days—Ray Petry, our medievalist in graduate school at Duke University, recommended that anyone who was interested join the ASCH in order to receive the journal.
Leaving Providence Behind
Authors: Porterfield Amanda
Published: May 2011

The first issue of the journal Church History appeared in 1932—seventy-nine years ago—the year William Warren Sweet was president of the American Society of Church History. It was a time of considerable pain and social stress in many parts of the world. Perhaps in response to this turmoil, the inaugural issue conveyed a deep-seated optimism about the future. A bracing faith in the providential course of history characterized the three essays in that first issue and the authors conveyed that faith with erudition, narrative flair, and sweeping knowledge of Christian history. Few authors today exert such broad command of events in the larger history of Christianity, or display such facility with a wide range of primary documents, and few write with such ebullience. Such may be the price of leaving behind a world where providence is clearly in sight.
Decreased regional cerebral blood flow in medial prefrontal cortex during trauma-unrelated stressful imagery in Vietnam veterans with post-traumatic stress disorder
Authors: Gold A. L. , Shin L. M. , Orr S. P. , Carson M. A. , Rauch S. L. , Macklin M. L. , Lasko N. B. , Metzger L. J. , Dougherty D. D. , Alpert N. M. , Fischman A. J. , Pitman R. K.
Published: May 2011

Background

Neuroimaging research has demonstrated medial prefrontal cortex (mPFC) hyporesponsivity and amygdala hyperresponsivity to trauma-related or emotional stimuli in post-traumatic stress disorder (PTSD). Relatively few studies have examined brain responses to the recollection of stressful, but trauma-unrelated, personal events in PTSD. In the current study, we sought to determine whether regional cerebral blood flow (rCBF) abnormalities in mPFC and amygdala in PTSD could be observed during the recollection of trauma-unrelated stressful personal events.

Method

Participants were 35 right-handed male combat veterans (MCVs) and female nurse veterans (FNVs) who served in Vietnam: 17 (seven male, 10 female) with current military-related PTSD and 18 (nine male, nine female) with no current or lifetime PTSD. We used positron emission tomography (PET) and script-driven imagery to study rCBF during the recollection of trauma-unrelated stressfulversusneutral and traumatic events.

Results

Voxelwise tests revealed significant between-group differences for the trauma-unrelated stressfulversusneutral comparison in mPFC, specifically in the anterior cingulate cortex (ACC). Functional region of interest (ROI) analyses demonstrated that this interaction in mPFC represented greater rCBF decreases in the PTSD group during trauma-unrelated stressful imagery relative to neutral imagery compared to the non-PTSD group. No differential amygdala activation was observed between groups or in either group separately.

Conclusions

Veterans with PTSD, compared to those without PTSD, exhibited decreased rCBF in mPFC during mental imagery of trauma-unrelated stressful personal experiences. Functional neuroanatomical models of PTSD must account for diminished mPFC responses that extend to emotional stimuli, including stressful personal experiences that are not directly related to PTSD.
Is obsessive–compulsive disorder an anxiety disorder, and what, if any, are spectrum conditions? A family study perspective
Authors: Bienvenu O. J. , Samuels J. F. , Wuyek L. A. , Liang K.-Y. , Wang Y. , Grados M. A. , Cullen B. A. , Riddle M. A. , Greenberg B. D. , Rasmussen S. A. , Fyer A. J. , Pinto A. , Rauch S. L. , Pauls D. L. , McCracken J. T. , Piacentini J. , Murphy D. L. , Knowles J. A. , Nestadt G.
Published: May 2011

Background

Experts have proposed removing obsessive–compulsive disorder (OCD) from the anxiety disorders section and grouping it with putatively related conditions in DSM-5. The current study uses co-morbidity and familiality data to inform these issues.

Method

Case family data from the OCD Collaborative Genetics Study (382 OCD-affected probands and 974 of their first-degree relatives) were compared with control family data from the Johns Hopkins OCD Family Study (73 non-OCD-affected probands and 233 of their first-degree relatives).

Results

Anxiety disorders (especially agoraphobia and generalized anxiety disorder), cluster C personality disorders (especially obsessive–compulsive and avoidant), tic disorders, somatoform disorders (hypochondriasis and body dysmorphic disorder), grooming disorders (especially trichotillomania and pathological skin picking) and mood disorders (especially unipolar depressive disorders) were more common in case than control probands; however, the prevalences of eating disorders (anorexia and bulimia nervosa), other impulse-control disorders (pathological gambling, pyromania, kleptomania) and substance dependence (alcohol or drug) did not differ between the groups. The same general pattern was evident in relatives of case versus control probands. Results in relatives did not differ markedly when adjusted for demographic variables and proband diagnosis of the same disorder, though the strength of associations was lower when adjusted for OCD in relatives. Nevertheless, several anxiety, depressive and putative OCD-related conditions remained significantly more common in case than control relatives when adjusting for all of these variables simultaneously.

Conclusions

On the basis of co-morbidity and familiality, OCD appears related both to anxiety disorders and to some conditions currently classified in other sections of DSM-IV.
Omnidirectional locomotion and traction control of the wheel-driven, wall-climbing robot, Cromsci
Authors: Schmidt D. , Hillenbrand C. , Berns K.
Published: May 2011

Safe and cost-efficient inspection of large concrete buildings is a great challenge for mobile robots. This paper presents the locomotion system of the climbing robot, Cromsci, which uses three steerable standard wheels and negative pressure adhesion. We will introduce criteria to avoid robot slip and tilt, and methods to enhance stability. One elementary part is the close-loop-controlled adhesion system with seven individual negative pressure chambers to balance out tilt or dynamic effects caused by leaky pressure chambers. The second part is the locomotion control using a special traction control mechanism to enhance robot navigation, which will also be presented here.
Garlic in health and disease
Authors: Rana S. V. , Pal R. , Vaiphei K. , Sharma Sanjeev K. , Ola R. P.
Published: May 2011

The present article reviews the historical and popular uses of garlic, its antioxidant, haematological, antimicrobial, hepatoprotective and antineoplastic properties and its potential toxicity (from sulfoxide). Garlic has been suggested to affect several cardiovascular risk factors. It has also been shown that garlic and its organic allyl sulfur components are effective inhibitors of the cancer process. Since garlic and its constituents can suppress carcinogen formation, bioactivation and tumour proliferation, it is imperative that biomarkers be established to identify which individuals might benefit most. Garlic powder, aged garlic and garlic oil have demonstrated antiplatelet and anticoagulant effects by interfering with cyclo-oxygenase-mediated thromboxane synthesis. Garlic has also been found to have synergistic effects againstHelicobacter pyloriwith a proton pump inhibitor. The active compound allicin may affect atherosclerosis not only by acting as an antioxidant, but also by other mechanisms, such as lipoprotein modification and inhibition of LDL uptake and degradation by macrophages. Freshly prepared garlic homogenate protects against isoniazid+rifampicin-induced liver injury in experimental animal models. Several mechanisms are likely to account for this protection.
Good Language-Switchers are Good Task-Switchers: Evidence from Spanish–English and Mandarin–English Bilinguals
Authors: Prior Anat , Gollan Tamar H.
Published: May 2011

Bilingual advantages in executive control tasks are well documented, but it is not yet clear what degree or type of bilingualism leads to these advantages. To investigate this issue, we compared the performance of two bilingual groups and monolingual speakers in task-switching and language-switching paradigms. Spanish–English bilinguals, who reported switching between languages frequently in daily life, exhibited smaller task-switching costs than monolinguals after controlling for between-group differences in speed and parent education level. By contrast, Mandarin–English bilinguals, who reported switching languages less frequently than Spanish–English bilinguals, did not exhibit a task-switching advantage relative to monolinguals. Comparing the two bilingual groups in language-switching, Spanish–English bilinguals exhibited smaller costs than Mandarin–English bilinguals, even after matching for fluency in the non-dominant language. These results demonstrate an explicit link between language-switching and bilingual advantages in task-switching, while also illustrating some limitations on bilingual advantages. (JINS, 2011, 17, 682–691)
The image: print and pixel
Authors: Treib Marc
Published: May 2011

There is little question that we live in an age of images, in a mediated environment in which the image is ever-present – with its effects nevertheless still growing [1]. This essay – as an introduction to the four papers that follow – examines aspects of the complex questions surrounding the image and those that accompany the shift from print to pixel.
Recollecting Landscapes: landscape photography as a didactic tool
Authors: Notteboom Bruno
Published: May 2011

Recollecting Landscapes is a rephotographic survey project which documents a century of landscape transformation in Belgium. It is based on the successive photography of sixty sites at three moments in time between 1904 and 2004 [1, 2]. This paper takes the project as a starting point to investigate the subject of the image and its presentation. This means that the text develops some thoughts on how the images in the project are displayed and read, rather than on the content they display.
Hydrodynamic simulations of the core helium flash – CORRIGENDUM
Authors: Mocák Miroslav , Müller Ewald , Weiss Achim , Kifonidis Konstantinos
Published: May 2011

It is regretted that the originally published paper (Mocák, Müller, Weiss & Kifonidis, 2008) was not the authors' final amended version. We apologise for this oversight and reproduce the entire corrected paper here on-line only, with revised figure captions.
Automated bench test for UHF RFID tags measurement in operational environment
Authors: Pouzin Audrey , Vuong Tan-Phu , Tedjini Smaïl , Perdereau Jacques
Published: May 2011

This paper synthesizes protocol measurements for Ultra High Frequency (UHF) radiofrequency identification (RFID) tags’ performance. We introduce the main parameters allowing the evaluation of an inlay tag performances. We characterize all devices implemented on the test bench. We explain the different programs and all methods used for the software automation. Finally, we studied the variation of the measured parameters as a function of power, frequency, or tag orientation, both in free space and in disturbed environment through our automated test bench
Characteristics of neutral calcium and Ca+ near the mesopause, and their relationship with sporadic ion/electron layers at Arecibo
Authors: Raizada Shikha , Tepley Craig A. , Aponte Nestor , Cabassa Edvier
Published: May 2011

We present the first simultaneous observations of mesospheric neutral calcium, its ion, and electron density over Arecibo obtained on adjacent nights in December 2009. A good correlation is seen between Sporadic‐E and ion layers while the neutrals have different characteristics. The measurements reveal that average abundances in electron densities and ions to be at a maximum on 9 December with values ∼4.8 × 109 electrons cm−2 and 3.4 × 107 ions cm−2, while those of the neutrals to be low, of the order of 9.7 × 106 atoms cm−2. The neutral abundance maximizes with values of 1.8 × 107 atoms cm−2 on 10 December, when both ions and electrons display weak layers with abundances almost 3 times lower than on the previous night. A significant correlation between the ions and neutrals indicates that sudden enhancements are caused by advection while a poor correlation is related to chemistry. This study reveals that the ion‐neutral coupling is most efficient between 92 and 95 km. Also, the ion‐to‐neutral ratio is dependent on the strength of the ions or Sporadic‐E and can exceed 3.0 during such events. We present evidence of neutralization of the ionized layers occurring on scales of a few tens of minutes for the first time. This agrees fairly well with the lifetimes of Ca+ against neutralization as predicted by recent ion‐neutral reactions.
Electromagnetic waves on ion gyro‐radii scales across the magnetopause
Authors: Yao Y. , Chaston C. C. , Glassmeier K.‐H. , Angelopoulos V.
Published: May 2011

This report presents the first study of the global distribution and properties of kinetic scale electromagnetic waves on the Earth's magnetopause. From a statistical study using THEMIS fields observations over a frequency range from 0.01–2 Hz, we find waves on scales of the order of ion gyro‐radii at all magnetic local times surveyed (4–20 MLT). The spectral energy densities (ε) within these waves across the magnetopause are larger on the dawn (4–12 MLT) than duskside (12–20 MLT) irrespective of the direction of the magnetosheath magnetic field BZ_sheath component. Furthermore, these observations reveal that ε is magnetic shear dependent with large enhancements for shear angle >60°. The similarity between dawn‐dusk asymmetry in ε we observe and reported distribution of magnetosheath ions in the magnetosphere suggest that gyro‐radii scale magnetic field structures/waves may facilitate a significant fraction of cross magnetopause plasma transport.
Maturation of flaviviruses starts from one or more icosahedrally independent nucleation centres
Authors: Plevka Pavel , Battisti Anthony J , Junjhon Jiraphan , Winkler Dennis C , Holdaway Heather A , Keelapang Poonsook , Sittisombut Nopporn , Kuhn Richard J , Steven Alasdair C , Rossmann Michael G
Published: May 2011

Flaviviruses assemble as fusion‐incompetent immature particles and subsequently undergo conformational change leading to release of infectious virions. Flavivirus infections also produce combined ‘mosaic’ particles. Here, using cryo‐electron tomography, we report that mosaic particles of dengue virus type 2 had glycoproteins organized into two regions of mature and immature structure. Furthermore, particles of a maturation‐deficient mutant had their glycoproteins organized into two regions of immature structure with mismatching icosahedral symmetries. It is therefore apparent that the maturation‐related reorganization of the flavivirus glycoproteins is not synchronized across the whole virion, but is initiated from one or more nucleation centres. Similar deviation from icosahedral symmetry might be relevant to the asymmetrical mode of genome packaging and cell entry of other viruses.
A blizzard of stem cells in Santa Fe
Authors: Youssef Khalil Kass , Blanpain Cédric
Published: May 2011

The Keystone Symposium, ‘Stem Cells in Development, Tissue Homeostasis and Disease’ gathered together an impressive panel of speakers to discuss various aspects of stem‐cell biology from early development to adult homeostasis, as well as the implications of stem cells for human diseases.
Evaluation of resistance in wheat against Rhopalosiphumpadi (L.) (Homoptera:Aphididae) Under laboratory Conditions
Authors: Akhtar Naheed , Moin Noreen , Jilani Ghulam , Mohsin Ata , Yasmin Shaheena , Afzala Afzala , Goraya Munir , Baig Atif
Published: May 2011

Aims and introduction All over the world aphids are pests of economic importance, affecting all varieties of plants like cereal crops, vegetables, ornamental plants and fruits. Aphids damage plants either directly or indirectly. Aphids are one of the major agricultural pests. There are only a few plants that are not susceptible to infestation by this destructive pest. They cause direct damage by sucking the sap of leaves, blocking photosynthesis which results in leaf distortion, gall production, discoloration, stunting, leaf curling, wilting, twisting and premature leaf falls. They are directly involved in transmission of plant viruses and indirectly by depositing honey dew that reduces photosynthetic activity and induces sooty mold production and premature leaf senescence.Methodology Hosts were wheat and maize. There was twenty varieties of National Uniform Wheat Yield Trials (NUWYT) Normal (N) of year 2004-05, and twelve varieties of (NUWYT) Rain Fed (R.F) of year 2004-05 while there were twenty-two varieties of maize of year 2005-06. All these varieties were evaluated against bird cherry oat aphid R. padi L pest. Evaluation for resistance was done by seedling bulk test and by comparing the results of components of resistance like antibiosis, antixenosis and tolerance tests. These experiments were performed under controlled environmental conditions. Experiments were of randomized complete design and replicated. The data obtained was statistically analyzed of variance (ANOVA) and the mean values were compared by Duncan’s new multiple range test (DMRT) at 5 percent level of significance (Steel and Torrie, 1980).

Results

Among the tested germplasm (one variety and 11 lines of wheat), the V-5 line was found resistant and the NRL-2017 line was found susceptible to Rhopalosiphum padi. The results of the Antixenosis Test indicated that two wheat lines, V-5 and PR-83 were least preferred and three lines viz., NRL-2017, V-00055 and V-00BT004 were highly preferred by the test insect. The results of the Antibiosis Test showed that PR-83 line was least fecund whereas NR-241 and V-00055 lines were highly fecund. The results of the Tolerance Test indicated that four varieties, PR-83, V-5, SN-128 and NR-241 were highly tolerant, while only one line, V-00BT004 was least tolerant.

Conclusion

To avoid harmful effects of this insect pest, only resistant, least preferred, least fecund and highly tolerant lines must be used in wheat breeding programs.
Non-linear Regression Approaches in ABC
Authors: Blum Michael
Published: May 2011

In this talk, we consider different methods of parameter inference for ABC. Derivations of the asymptotic bias and variance of the standard ABC estimators indicates that ABC may achieve poor performance when the dimension of the summary statistics is large. The linear adjustment introduced by Beaumont et al. (2002) is found to achieve better performance when there is a nearly homoscedastic relationship between the summary statistics and the parameter of interest. To provide a more flexible adjustment method, we propose two innovations. The new method fits 1/a heteroscedatic rather than a homoscedastic regression model and consider 2/non linear instead of linear regression. The new algorithm is compared to the state-of-the-art approximate Bayesian methods and typically provides narrower credibility intervals.
OAT2 catalyses efflux of glutamate and uptake of orotic acid
Authors: Fork Christian , Bauer Tim , Golz Stefan , Geerts Andreas , Weiland Jessica , Del Turco Domenico , Schömig Edgar , Gründemann Dirk
Published: May 2011

OAT (organic anion transporter) 2 [human gene symbol SLC22A7 (SLC is solute carrier)] is a member of the SLC22 family of transport proteins. In the rat, the principal site of expression of OAT2 is the sinusoidal membrane domain of hepatocytes. The particular physiological function of OAT2 in liver has been unresolved so far. In the present paper, we have used the strategy of LC (liquid chromatography)–MS difference shading to search for specific and cross-species substrates of OAT2. Heterologous expression of human and rat OAT2 in HEK (human embryonic kidney)-293 cells stimulated accumulation of the zwitterion trigonelline; subsequently, orotic acid was identified as an excellent and specific substrate of OAT2 from the rat (clearance=106 μl·min−1·mg of protein−1) and human (46 μl·min−1·mg of protein−1). The force driving uptake of orotic acid was identified as glutamate antiport. Efficient transport of glutamate by OAT2 was directly demonstrated by uptake of [3H]glutamate. However, because of high intracellular glutamate, OAT2 operates as glutamate efflux transporter. Thus expression of OAT2 markedly increased the release of glutamate (measured by LC-MS) from cells, even without extracellular exchange substrate. Orotic acid strongly trans-stimulated efflux of glutamate. We thus propose that OAT2 physiologically functions as glutamate efflux transporter. OAT2 mRNA was detected, after laser capture microdissection of rat liver slices, equally in periportal and pericentral regions; previous reports of hepatic release of glutamate into blood can now be explained by OAT2 activity. A specific OAT2 inhibitor could, by lowering plasma glutamate and thus promoting brain-to-blood efflux of glutamate, alleviate glutamate exotoxicity in acute brain conditions.
The role of amino acid transporters in inherited and acquired diseases
Authors: Bröer Stefan , Palacín Manuel
Published: May 2011

Amino acids are essential building blocks of all mammalian cells. In addition to their role in protein synthesis, amino acids play an important role as energy fuels, precursors for a variety of metabolites and as signalling molecules. Disorders associated with the malfunction of amino acid transporters reflect the variety of roles that they fulfil in human physiology. Mutations of brain amino acid transporters affect neuronal excitability. Mutations of renal and intestinal amino acid transporters affect whole-body homoeostasis, resulting in malabsorption and renal problems. Amino acid transporters that are integral parts of metabolic pathways reduce the function of these pathways. Finally, amino acid uptake is essential for cell growth, thereby explaining their role in tumour progression. The present review summarizes the involvement of amino acid transporters in these roles as illustrated by diseases resulting from transporter malfunction.
The Hippo pathway and apico–basal cell polarity
Authors: Genevet Alice , Tapon Nicolas
Published: May 2011

The establishment and maintenance of apico–basal cell polarity is a pre-requisite for the formation of a functioning epithelial tissue. Many lines of evidence suggest that cell polarity perturbations favour cancer formation, even though the mechanistic basis for this link remains unclear. Studies in Drosophila have uncovered complex interactions between the conserved Hpo (Hippo) tumour suppressor pathway and apico–basal polarity determinants. The Hpo pathway is a crucial growth regulatory network whose inactivation in Drosophila epithelial tissues induces massive overproliferation. Its core consists of a phosphorylation cascade (comprising the kinases Hpo and Warts) that mediates the inactivation of the pro-growth transcriptional co-activator Yki [Yorkie; YAP (Yes-associated protein) in mammals]. Several apically located proteins, such as Merlin, Expanded or Kibra, have been identified as upstream regulators of the Hpo pathway, leading to the notion that an apical multi-molecular complex modulates core kinase activity and promotes Yki/YAP inactivation. In the present review, we explore the links between apico–basal polarity and Hpo signalling. We focus on the regulation of Yki/YAP by apical proteins, but also on how the Hpo pathway might in turn influence apical domain size as part of a regulatory feedback loop.
Dimerization of TOC receptor GTPases and its implementation for the control of protein import into chloroplasts
Authors: Aronsson Henrik , Jarvis Paul
Published: May 2011

Pre-protein import into chloroplasts is facilitated by multiprotein translocon complexes in the envelope membranes. Major components of the TOC (translocon at the outer envelope membrane of chloroplasts) complex are the receptor proteins Toc33 and Toc159. These two receptors are related GTPases, and they are predicted to engage in homodimerization and/or heterodimerization. Although such dimerization has been studied extensively, its exact function in vivo remains elusive. In this issue of the Biochemical Journal, Oreb et al. present evidence that homodimerization of Toc33 prevents nucleotide exchange, thereby locking the receptor in the GDP-loaded state and preventing further activity. Pre-protein arrival is proposed to release this lock, through disruption of the dimer and subsequent nucleotide exchange. The Toc33-bound pre-protein is then able to progress to downstream steps in the translocation mechanism, with GTP hydrolysis defining another important control point as well as preparing the receptor for the next pre-protein client. These new results are discussed in the context of previous findings pertaining to TOC receptor dimerization and function.
A New Device for Alveolar Bone Transportation
Authors: Vega Omar , Pérez Daniel , Páramo Viviana , Falcön Jocelyn
Published: May 2011

We present a retrospective review of a new technique for the transportation of alveolar bone using a Hyrax device modified by the principal author (O.A.V.). There were seven patients (five males and two females), including five patients with cleft palate and lip diagnosis, one patient with a high-speed gunshot wound, and one patient with facial trauma sequel due to mandibular fracture. They were all treated with an alveolar bone transportation technique (ABT) through the use of the modified Hyrax device (VEGAX). Before surgery, distraction osteogenesis of the bifocal type was performed on four patients, and the trifocal type was performed on the other three patients. However, in one case, direct dental anchorage was not used, only orthodontic appliances. In all the cases, new bone formation and gingival tissue around the defect were obtained, posterior to the alveolar distraction process; no complications were observed in any patient. In one case, two teeth involved in the disk of the ABT were extracted, due to a previous condition of periodontal disease. The alveolar bone transport with the VEGAX device is an accessible technique for almost every patient with alveolar defects due to diverse causes. In all the presented cases, predictability and success were demonstrated.
Future chlamydia screening preferences of men attending a sexually transmissible infection clinic
Authors: Roth Alexis , Van Der Pol Barbara , Dodge Brian , Fortenberry J. Dennis , Zimet Gregory
Published: May 2011

Background
Despite years of public health efforts, Chlamydia trachomatis remains a highly prevalent disease suggesting that current control strategies are not sufficient. Asymptomatic men with chlamydial infections are under-identified and probably play an important role in sustaining the epidemic. Novel methods of actively screening asymptomatic men are needed to reduce the prevalence of chlamydia. This formative study explored the features of a sexually transmissible infection (STI) control program that would encourage annual testing among men. Methods: Using semi-structured interviews and focus group discussions, we explored issues related to health seeking behaviours and preferences for STI screening among men recruited from a public health STI clinic. Results: All 29 participants acknowledged the expertise of clinic staff and most men preferred speaking with a provider over using electronic informational resources. The clinic was the preferred venue for future screening, followed by self-collected home sampling with clinic drop-off. Men expressed a preference for receiving results via the telephone rather than electronic options, and preferred personalised reminders for future STI screening. Conclusions: In this sample, there was high interest in utilising the expertise of STI clinic personnel and less in non-clinical options. While this may be due to recruiting from an STI clinic, the data serves as a reminder that service provision must be responsive to the needs of potential users. Our findings suggest that future non-clinic based screening strategies may require an initial educational component to address concerns about confidentiality and sample quality in order to be acceptable.
Sexual history taking and sexually transmissible infection screening practices among men who have sex with men: a survey of Victorian general practitioners
Authors: Barber Bridget , Hellard Margaret , Jenkinson Rebecca , Spelman Tim , Stoove Mark
Published: May 2011

Background HIV notifications among men who have sex with men (MSM) in Victoria, Australia, have increased recently. Early HIV diagnosis is a prevention strategy that requires general practitioners (GP) to recognise at-risk individuals and perform screening. Sexual history taking is part of this process. Methods: A cross-sectional survey of 354 Victorian GP to investigate attitudes and practices regarding sexual history taking and screening for HIV in MSM. Results: In total, 185 (53%, 95% CI: 47–58%) GPs reported being ‘very likely’ to take a sexual history from MSM presenting for a routine check-up; however 161 (46%, 95% CI: 40–51%) would not do so during the initial consultation. Barriers to sexual history taking included time constraints (28%, 95% CI: 24–36%), feeling inadequately trained (25%, 95% CI: 21–30%), discomfort discussing sex (24%, 95% CI: 20–29%) and fear of patient embarrassment (24%, 95% CI: 20–29%). Factors associated with a reduced likelihood included being male, time constraints, fear of patient embarrassment, and moral or religious views. Most GP (63%, 95% CI: 58–68%) reported they would offer HIV screening 3–6 monthly for MSM with casual partners; 54 (16%, 95% CI: 12–20%) would offer screening only on request. Being unlikely to take a sexual history and fear of patient embarrassment were associated with a decreased likelihood of offering an HIV test. Conclusion: GP often fail to take a sexual history from MSM, limiting opportunities to offer HIV screening. Strategies are required to increase GPs’ awareness of sexual health as a priority for MSM.
Risk factors for HIV seroconversion in men who have sex with men in Victoria, Australia: results from a sentinel surveillance system
Authors: Guy Rebecca J. , Spelman Tim , Stoove Mark , El-Hayek Carol , Goller Jane , Fairley Christopher K. , Leslie David , Tee BK , Roth Norman , Grulich Andrew E. , Hellard Margaret E.
Published: May 2011

Objectives HIV diagnosis rates in men who have sex with men (MSM) began increasing in Australia 10 years ago, and there has been a major resurgence of syphilis. We determined predictors of HIV positivity and seroconversion among MSM in Victoria, Australia. Methods: We conducted a retrospective longitudinal analysis of data from MSM who underwent HIV testing between April 2006 and June 2009 at three primary care clinics. Logistic regression was used to determine predictors of HIV positivity and seroconversion. Results: During the study period, 7857 MSM tested for HIV. Overall HIV positivity was 1.86% (95% confidence interval (CI): 1.6–2.2). There were 3272 repeat testers followed for 4837 person-years (PY); 60 seroconverted and HIV incidence was 1.24 (95% CI: 0.96–1.60) per 100 PY. Independent predictors of HIV seroconversion were: an infectious syphilis diagnosis within the last 2 years (adjusted hazard ratio (AHR) = 2.5, 95% CI: 1.1–5.7), reporting six or more anal sex partners in the past 6 months (AHR = 3.3, 95% CI: 1.8–6.3), reporting an HIV-positive current regular partner (AHR = 3.4, 95% CI: 1.1–10.6) and reporting inconsistent condom use with casual partners in the past 6 months (AHR = 4.4, 95% CI: 1.7–11.5). Conclusion: Our results call for HIV prevention to target high-risk MSM, including men with a recent syphilis diagnosis or a high numbers of partners, men who have unprotected anal sex with casual partners and men in serodiscordant relationships. The HIV incidence estimate will provide a baseline to enable public health officials to measure the effectiveness of future strategies.
Increased risks of early sexual initiators: time makes a difference
Authors: Baumann Philippe , Bélanger Richard E. , Akre Christina , Suris Joan-Carles
Published: May 2011

Background
Years since onset of sexual intercourse (YSSI) is a rarely used variable when studying adolescents’ sexual outcomes. The aim of this study is to evaluate the influence of YSSI on the adverse sexual outcomes of early sexual initiators. Methods: Data were drawn from the 2002 Swiss Multicenter Adolescent Survey on Health database, a nationally representative cross-sectional survey including 7429 adolescents in post-mandatory school aged 16–20 years. Only adolescents reporting sexual intercourse (SI) were included (n = 4388; 45% females) and categorised by age of onset of SI (early initiators, age <16: n = 1469, 44% females; and late initiators, age ≥16: n = 2919, 46% females). Analyses were done separately by gender. Groups were compared for personal characteristics at the bivariate level. We analysed three sexual outcomes (≥four sexual partners, pregnancy and condom non-use at last SI), controlling for all significant personal variables with two logistic regressions using first age, then YSSI as one of the confounding variables. Results are given as adjusted odds ratios (AOR) using late initiators as the reference category. Results: After adjusting for YSSI instead of age, negative sexual outcomes among early initiators were no longer significant, except for multiple sexual partners among females, although at a much lower level. Early initiators were less likely to report condom non-use at last SI when adjusting for YSSI (females: AOR = 0.59 [0.44–0.79], P < 0.001; males: AOR = 0.71 [0.50–1.00], P = 0.053). Conclusion: YSSI is an important explanatory variable when studying adolescents’ sexuality and needs to be included in future research on adolescents’ sexual health.
Increasing HIV diagnoses in Australia among men who have sex with men correlated with the growing number not taking antiretroviral therapy
Authors: Murray John M. , Prestage Garrett , Grierson Jeffrey , Middleton Melanie , McDonald Ann
Published: May 2011

Background Australia has experienced rising notifications of HIV diagnoses despite widely available combination antiretroviral therapy (CART). New HIV diagnoses have also been younger than the average age of those living with HIV. We investigated the degree to which several risk factors could explain this rise in notifications and the younger age profile. Methods: Numbers and ages of men who have sex with men (MSM) living with HIV in Australia from 1983 to 2007 were calculated from notifications of HIV diagnoses and deaths. We compared the trend over time as well as the average ages of MSM newly diagnosed with HIV infection from 1998 to 2007 with those for: notifications of gonorrhoea and syphilis, total MSM living with HIV infection, and the component not on CART. Results: The percentage of younger MSM not taking CART has increased since 1998 (aged <30 years P < 0.001; 30–39 years P = 0.004). The trend of new HIV diagnoses was most significantly correlated with the total number of MSM living with HIV infection and the sector not taking CART (P < 0.0001). Based on similarity of average ages, MSM living with HIV infection and not taking CART was the best predictor of the increasing trend in new HIV diagnoses (99.9999% probability, Akaike information criterion). Conclusions: Our analyses suggest MSM living with HIV infection and not taking CART could be the source of the increase in HIV infections. Consequently, greater CART enrolment should decrease HIV incidence, especially in younger MSM.