bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal reaction and stability of NiFe/Cu thin films investigated by atom probe tomography
Authors: Ene C. B. , Schmitz G. , Kirchheim R. , Hütten A.
Published: January 2007

NiFe/Cu multilayer stacks of 2 nm single layer thickness were deposited onto needle‐shaped W tips by ion beam sputtering and analysed by atom probe tomography (TAP) after appropriate heat treatments. After annealing at 250 °C for 30 min, no significant structural or chemical transformation of the initial layer system is detected, although such a heat treatment appreciably reduces the magneto resistivity. A slight decrease of the concentration slope at the interfaces is attributed to a very short‐range interdiffusion. Clear grain boundary diffusion is observed after annealing at 400 °C for 30 min. Further annealing at 500 °C for 20 min and 40 min still preserves the layered structure with a homogeneous solution of Ni inside the Cu layers of up to 25 at.% Ni. Copyright © 2007 John Wiley & Sons, Ltd.
The process of software maintenance: a comparison of object‐oriented and third‐generation development languages
Authors: Eierman Michael A. , Dishaw Mark T.
Published: January 2007

We suggest that there is a lack of empirical evidence for claims that object‐oriented software has an advantage in terms of software maintenance. We use a model of software maintenance that suggests that the maintenance task and programming language have an impact on the maintenance process and, in turn, use the maintenance process to explore the impact of the programming language on the maintenance process. A field study design, using students, examined the perceived difference in process employed by students using an object‐oriented language and those using a third‐generation language. We found a difference in the perceived process used by the two groups of students. Students using the object‐oriented language perceived that they performed more planning and diagnosis activities during the maintenance process and students using a third‐generation language perceived that they performed more knowledge building activities. Copyright © 2007 John Wiley & Sons, Ltd.
Review of content‐aware resource allocation schemes for video streaming over wireless networks
Authors: Pahalawatta Peshala V. , Katsaggelos Aggelos K.
Published: January 2007

As wireless technology evolves towards its fourth generation (4G) of development, the prospect of offering multimedia services such as on‐demand video streaming and video conferencing to wireless mobile clients becomes increasingly more viable. The eventual success of such applications depends on the efficient management of the limited system resources while taking into account the time‐varying wireless channel conditions as well as the varying multimedia source content. In this paper, we review some of the recent advances in cross‐layer design schemes, which aim at providing significant gains in performance for video streaming systems through content‐aware resource allocation. Advances in both, real‐time video streaming, where the video is encoded and transmitted in real‐time, as well as, on‐demand video streaming, where the video is pre‐encoded in a media server, are considered. Copyright © 2007 John Wiley & Sons, Ltd.
A time‐based adaptive retry strategy for video streaming in 802.11 WLANs
Authors: Lu Mei‐Hsuan , Steenkiste Peter , Chen Tsuhan
Published: January 2007

Video streaming over time‐varying, error‐prone wireless LANs (WLANs) poses many challenges. One problem is that WLANs are designed without awareness of the characteristics of application data, which causes performance degradation in a noisy or congested environment. In this paper, we propose a time‐based adaptive retry (TAR) mechanism for MPEG‐like video streaming over 802.11 wireless networks. TAR dynamically determines whether to send or discard a packet based on itsretransmission deadlineinstead of adopting a static retry limit uniformly over all the packets. Our approach can adapt the retry limit for each individual packet, thus providing indirect unequal error protection over different types of video frames. Analytical and simulation results show that TAR significantly improves video quality and saves channel bandwidth. We also describe a preliminary software‐based implementation of TAR and use it to demonstrate the practicality of the proposed approach. Copyright © 2007 John Wiley & Sons, Ltd.
Self-organization of stack-up block copolymers into polymeric supramolecules
Authors: Yuan Yong J. , Choi Ka-Wai , Wong Herbert
Published: January 2007

Polyethylene oxide –b– polypropylene oxide -b- polyethylene oxide (EO106PO70EO106) block copolymer self-organizes into polymeric supramolecules, characterized by NMR as phase transition from the isotropic stack-up block structure to the ordered cubic polymeric supramolecular structure. Its dependence on both temperature and copolymer concentration is clearly shown by the changes in line shape and chemical shift of the PO70blockβ,γ resonances.
Uniqueness of the critical mass blow up solution for the four dimensional gravitational Vlasov–Poisson system
Authors: Lemou Mohammed , Méhats Florian , Raphaël Pierre
Published: January 2007

We study the gravitational Vlasov–Poisson system

\partial _{t}f + v \cdot \mathrm{∇}_{x}f−E \cdot \mathrm{∇}_{v}f = 0

,

E(x) = \mathrm{∇}\phi (x)

,

\mathrm{\Delta }\phi (x) = \int f(x,v)\:\mathrm{d}v

, in dimension

N = 4

where the problem is

L^{1}

critical. We proved in [M. Lemou, F. Méhats, P. Raphael, On the orbital stability of the ground states and the singularity formation for the gravitational Vlasov Poisson system, preprint] a sharp criterion for the global existence of weak solutions based on the variational characterization of the polytropic steady states solutions. From the existence of a pseudo-conformal symmetry, this criterion is sharp and there exist critical mass blow up solutions. We prove in this paper the uniqueness of the critical mass blow up solution. This gives in particular a first dynamical classification of the polytropic stationary solutions. The proof is an adaptation of a similar result by Frank Merle [F. Merle, Determination of blow-up solutions with minimal mass for nonlinear Schrödinger equations with critical power, Duke Math. J. 69 (2) (1993) 427–454] for the

L^{2}

critical nonlinear Schrödinger equation.

Nous considérons le système de Vlasov–Poisson

\partial _{t}f + v \cdot \mathrm{∇}_{x}f−E \cdot \mathrm{∇}_{v}f = 0

,

E(x) = \mathrm{∇}\phi (x)

,

\mathrm{\Delta }\phi (x) = \int f(x,v)\:\mathrm{d}v

, en dimension

N = 4

où le problème est

L^{1}

critique. En se basant sur une caractérisation variationnelle des solutions stationnaires polytropiques, nous avons établi dans [M. Lemou, F. Méhats, P. Raphael, On the orbital stability of the ground states and the singularity formation for the gravitational Vlasov Poisson system, preprint] un critère optimal garantissant l'existence globale de solutions faibles pour ce système. L'optimalité de ce critère est une conséquence directe de l'existence d'une symétrie pseudo-conforme qui permet d'exhiber des solutions explosives de masse critique. Nous démontrons ici l'unicité de la solution explosive de masse critique. La preuve est une adaptation d'un résultat similaire de Frank Merle [F. Merle, Determination of blow-up solutions with minimal mass for nonlinear Schrödinger equations with critical power, Duke Math. J. 69 (2) (1993) 427–454] pour l'équation de Schrödinger non linéaire

L^{2}

critique.
Atypical manifestations of feline inflammatory polyps in three cats
Authors: MacPhail Catriona M. , Innocenti Christi M. , Kudnig Simon T. , Veir Julia K. , Lappin Michael R.
Published: January 2007

Inflammatory polyps of the feline middle ear and nasopharynx are non-neoplastic masses that are presumed to originate from the epithelial lining of the tympanic bulla or Eustachian tube. The exact origin and cause are unknown, however, it is thought that inflammatory polyps arise as a result of a prolonged inflammatory process. It is unclear whether this inflammation initiates or potentiates the development and growth of inflammatory polyps. Cats with inflammatory polyps typically present with either signs of otitis externa and otitis media or with signs consistent with upper airway obstruction. Traditional diagnostics involve imaging of the tympanic bulla either with skull radiographs or computed topography (CT). Treatment consists of traction and avulsion of the polyp with or without ventral bulla osteotomy (VBO) to remove the epithelial lining of the tympanic bulla. The three cases described here are unusual manifestations or presentations of feline inflammatory polyps that address the following issues: (1) concurrent otic and nasopharyngeal polyps, (2) potential association with chronic viral infection, (3) polyp development in the contralateral middle ear, (4) CT appearance of the skull following VBO, and (5) development of secondary pulmonary hypertension.
Optimization of the sampling strategy for establishing a gene bank: storing PrP alleles following a scrapie eradication plan as a case study
Authors: Fernández J. , Roughsedge T. , Woolliams J. A. , Villanueva B.
Published: January 2007

Gene banks are usually used for storing general genetic variability of endangered living populations but can be also used for storing alleles of a particular locus that are being eradicated through artificial selection programmes. In such scenarios gene banks would allow future re-introduction of one or more of the alleles being eradicated (and the associated diversity) into living populations. Frequencies within the bank for the locus of interest should have pre-determined target values. In this study, an algorithm is derived to obtain the optimal contributions of all candidate donors to achieve the target frequencies of the removed alleles in the bank while maintaining at the same time genetic variability in other loci unlinked to those targeted in the eradication programme. The efficiency of the algorithm is tested using the case of gene banks storing prion protein alleles currently disfavoured in scrapie eradication programmes (i.e., the AHQ, ARH, ARQ and VRQ alleles). Results showed that the algorithm was able to find the combinations of candidate contributions fulfilling different objectives regarding target frequencies and restrictions on coancestry. The most important factors influencing the optimal contributions were the allelic frequencies and the levels of diversity (coancestry) of the living population. Heterozygotes were favoured over homozygous individuals as, for a given number of animals contributing to the bank, the use of heterozygotes leads to lower levels of coancestry. Notwithstanding, almost all donors were sampled when restrictions on the global genetic diversity to be stored were severe.
Prediction of the percentage lean of pig carcasses with a small or a large number of instrumental carcass measurements – an illustration with HGP and Vision
Authors: Engel B. , Lambooij E. , Buist W. G. , Reimert H. , Mateman G.
Published: January 2007

In this paper we report on the results of a recent dissection experiment in The Netherlands where prediction formulae for the percentage lean meat in pig carcasses with the Hennessy Grading Probe (HGP) and a vision system (from now on referred to as Vision) were determined. Predictions with the HGP were based on one fat and one muscle depth measurement only, while predictions with Vision were based on as many as 115 direct and derived measurements. The data from this dissection experiment were used to illustrate the statistical calculations involved in relation to the number of carcass measurements. Prediction with instruments that gather a large number of measurements per carcass is not covered by the present European Community (EC) regulations. Therefore the calculations were conducted according to new regulations for statistical methodology in pig carcass grading that are expected to be adopted by the EC in the near future. The calculations included consideration of 3 subpopulations (females, entire males and castrated males). The Vision data were also used to show that ordinary regression after selection of a subset of carcass measurements severely under estimates the accuracy of prediction: instruments and associated prediction formulae are seemingly much more accurate than they truly are. When standard regression methods are used for instruments that gather a large number of measurements, there is a considerable risk that measurement instruments will be selected for the wrong reasons. Accuracy of approved instruments may not even comply with the EC-regulations, with poor consequences for harmonization within the EC.
Influence of energy intake on protein and lipid deposition in Creole and Large White growing pigs in a humid tropical climate
Authors: Renaudeau D. , Bocage B. , Noblet J.
Published: January 2007

Twenty-four castrated males were used to study the effect of breed (Large Whitev. Creole (LWv. CR)) and feeding level (0·70, 0·80, 0·90, and 1·00 ad libitum) on growth performance and protein deposition (PD) and lipid deposition (LD) between 30 and 60 kg in growing pigs under tropical climatic conditions; the CR pigs are raised in the Caribbean area and can be qualified as fat and slow growing pigs. Daily protein and amino acids supplies were calculated to be non-limiting for protein gain. Total PD and LD were measured according to the comparative slaughter technique. Digestibility coefficients of energy and nutrients were estimated over a 10-day period at 45 kg live weight. Neither the breed nor the feeding level influenced the apparent digestibility coefficients of dietary nutrients; only energy digestibility was increased at reduced feeding levels (P<0·05). Average daily gain increased linearly with the increase of metabolizable energy (ME) intake and the slope of the relationship was lower in CR than in LW pigs (30·4v. 36·6 g per additional MJ ME). The food conversion ratio was not affected by feeding level but it was significantly higher in CR than in LW pigs (2·88v. 2·36 kg /kg;P<0·001). Daily PD increased with ME intake according to a linear relationship in both breeds and the slope was significantly affected by breed (3·1v. 4·2 g/MJ ME in CR and LW pigs, respectively;P<0·001). In contrast, the increase of LD and total energy retained with ME were higher in CR than in LW pigs (8·4v. 6·4 g/MJ and 0·40v. 0·36 MJ/ MJ ME, respectively;P<0·001).
Effects of plane of nutrition during the first month of pregnancy on conception rate, foetal development and lamb output of mature and adolescent ewes
Authors: Annett R. W. , Carson A. F.
Published: January 2007

Embryo transfer studies have demonstrated that high plane feeding in early pregnancy is detrimental to the successful establishment of pregnancy in adolescent but not mature ewes. To further examine this relationship with ewes that conceive naturally and to investigate its effects on foetal development, 102 Greyface and Texel×Greyface ewes (body condition score (BCS) 3·8) and 114 Texel×Greyface adolescent ewes (BCS 3·3) were allocated to one of three treatments following a synchronized mating. From day 1 to 31 of pregnancy, animals were offered grass nuts (10·2 MJ metabolizable energy (ME) per kg dry matter (DM); 163 g crude protein per kg DM) at one of three levels to supply approximately 2·0 (H); 1·0 (M) and 0·6 (L) of their predicted ME requirements for maintenance. Increasing the post-mating plane of nutrition resulted in significant increases in ewe live weight (P<0·001) and BCS (P<0·001) during the treatment period. When diets were standardized for all animals during mid pregnancy (days 31 to 105), L ewes gained more live weight (P<0·05) and BCS (P<0·001) than H ewes. Early pregnancy nutrition had no effect on the conception rate of mature ewes; however adolescent ewes on the H and M treatments had lower conception rates (P<0·05) than those offered the L diet (0·59, 0·61 and 0·82 respectively). As a result, L adolescent ewes tended to have a higher mean total lamb birth weight per ewe mated (P=0·09) although lamb output at weaning was not influenced by plane of nutrition. Lambs born from adolescent mothers had lower lamb birth weights (P<0·001) and a shorter mean head length, crown-rump length and thoracic girth (P<0·001). Foetuses from H ewes had longer hind legs than those from L ewes on day 83 of gestation (P<0·05) and at term (P<0·05). The results of this study suggest that allowing adolescent but not mature ewes to lose live weight and body condition can increase the proportion of productive ewes following a natural service.
The influence of apple- and red-wine pomace rich diet on mRNA expression of inflammatory and apoptotic markers in different piglet organs
Authors: Sehm J. , Lindermayer H. , Meyer H. H. D. , Pfaffl M. W.
Published: January 2007

Flavan-3-ols are a class of flavonoids that are widely distributed in fruits and beverages including red wine and apples. Consumption of flavanoid-rich food has been shown to exhibit anti-microbial, anti-oxidative, anti-inflammatory, and immune-modulating effects. To test the nutritional effects of flavanols on mRNA gene-expression of inflammatory and apoptotic marker genes, piglets were given two flavanoids-rich feeding regimens: a low flavanoid standard diet (SD) was compared with diets enriched with 3·5% apple pomace (APD) or 3·5% red-wine pomace (RWPD). The influence on mRNA expression levels was investigated in different immunological active tissues and in the gastro-intestinal tract (GIT). The investigation took place from 1 week prior weaning to 19 days post weaning in 78 piglets. The expression of expressed marker genes was determinate by one-step quantitative real-time (qRT-PCR): TNFα, NFκB as pro-inflammatory; IL10, as anti-inflammatory; caspase 3 as apoptosis; cyclin D1 as cell cycle marker; and nucleosome component histon H3 as reference gene.

The feeding regimens result in tissue individual regulation of mRNA gene expression in all investigated organs. It was discovered that there were significant differences between the applied diets and significant changes during feeding time curse. Both pomace treatments caused a significant up-regulation of all investigated genes in liver. The effect on mesenterial lymph nodes and spleen was not prominent. In the GIT, the treatment groups showed a inhibitory effects on gene expression mainly in stomach and jejunum (NFκB, cyclin D1 and caspase 3). In colon the trend of caspase 3 was positive with the greatest change in the RWPD group.

In jejunum and stomach the cell cycle turn over was reduced, whereas in liver the cell turn over was highly accelerate. The influence on inflammatory marker gene expression is mainly relevant in stomach. It is presume that both flavanoid rich feeding regimens have the potential to modulate the mRNA expressions of inflammatory, proliferation and apoptotic marker genes in the GIT and piglet organs.
Fast scalar decay in a shear flow: modes and pseudomodes
Authors: VANNESTE J. , BYATT-SMITH J. G.
Published: January 2007

The decay of a passive scalar in a sinusoidal shear flow translating in the cross-stream direction at a constant speeduis studied in the limit of small diffusivity κ. The decay rate, obtained by solving an eigenvalue problem, is found to tend to a non-zero constant as κ→0 whenuis of order κ1/2. This result, establishing that fast decay is possible in shear flows, is fragile however: because of the existence of pseudomodes, the addition of a small noise leads to decay rates that decrease to zero with κ as κ2/5.
Parkinson's disease
Authors: Macphee Graeme JA , Stewart David A
Published: January 2007

Parkinson's disease (PD) is a progressive neurodegenerative disease characterized typically by motor features of tremor, rigidity and bradykinesia due to depletion of dopaminergic nigrostriatal neurons. PD is increasingly recognized as a non-motor disorder since symptoms such as dementia, depression and falls emerge with disease progression to become dominant in the clinical picture. PD results in a significant decline in quality of life for both patients and family and contributes to significant economic and institutional costs on family and society. PD is uncommon before the age of 40 but affects approximately 1% of patients over the age of 60, with a rising incidence and prevalence thereafter to around 2% in the population over 80 years of age.
Oblique rifting along the central and southern Kermadec Arc front (30°–36°S), SW Pacific
Authors: Campbell M. Ellen , Rowland Julie V. , Wright Ian C. , Smith Ian E. M.
Published: January 2007

We present a series of eleven structural maps of the central Kermadec arc front between 30°S and 35°50S interpreted from multibeam bathymetric data. These maps show the structural morphology of eighteen submarine arc volcanoes proximal to the Havre backarc, providing a critical window into the tectonomagmatic processes that operate at divergent arcs transitional to seafloor spreading. Each arc volcano, unaffected by subaerial processes, shows the structural imprint of oblique backarc rifting, providing an exceptional opportunity to evaluate tectonic influences on edifice construction and destruction. Mapped seafloor structures include faults, volcanic ridges, aligned vents and cones, cones aligned with faults, elongate calderas, and structurally controlled sector collapse. In addition to the structural maps, we present the results of quantitative analyses of fault orientation and growth behaviors. We demonstrate that >50% of identified faults strike NE‐SW between 030° and 060°, with a modal value of 047°, evidence in support of an extension axis dextrally oblique to the NNE trend of the rift. Further to this, minimum and maximum values for the extension axis are calculated as 137° and 150°, perpendicular to the modal strikes for all identified faults and for faults within the most oblique surveyed backarc rift domain, respectively. These values confirm moderate obliquity of opening along the Havre rift, with the SHT opening slightly less obliquely than the NHT, consistent with accommodation of a lesser partitioned component of dextral Pacific‐Australian plate convergence.
Selective melanocortin MC4receptor agonists reverse haemorrhagic shock and prevent multiple organ damage
Authors: Giuliani D , Mioni C , Bazzani C , Zaffe D , Botticelli A R , Capolongo S , Sabba A , Galantucci M , Iannone A , Grieco P , Novellino E , Colombo G , Tomasi A , Catania A , Guarini S
Published: January 2007

Background and purpose:

In circulatory shock, melanocortins have life‐saving effects likely to be mediated by MC4receptors. To gain direct insight into the role of melanocortin MC4receptors in haemorrhagic shock, we investigated the effects of two novel selective MC4receptor agonists.

Experimental approach:

Severe haemorrhagic shock was produced in rats under general anaesthesia. Rats were then treated with either the non‐selective agonist [Nle4, D‐Phe7]α‐melanocyte‐stimulating hormone (NDP‐α‐MSH) or with the selective MC4agonists RO27‐3225 and PG‐931. Cardiovascular and respiratory functions were continuously monitored for 2 h; survival rate was recorded up to 24 h. Free radicals in blood were measured using electron spin resonance spectrometry; tissue damage was evaluated histologically 25 min or 24 h after treatment.

Key results:

All shocked rats treated with saline died within 30‐35 min. Treatment with NDP‐α‐MSH, RO27‐3225 and PG‐931 produced a dose‐dependent (13‐108 nmol kg‐1i.v.) restoration of cardiovascular and respiratory functions, and improved survival. The three melanocortin agonists also markedly reduced circulating free radicals relative to saline‐treated shocked rats. All these effects were prevented by i.p. pretreatment with the selective MC4receptor antagonist HS024. Moreover, treatment with RO27‐3225 prevented morphological and immunocytochemical changes in heart, lung, liver, and kidney, at both early (25 min) and late (24 h) intervals.

Conclusions and Implications:

Stimulation of MC4receptors reversed haemorrhagic shock, reduced multiple organ damage and improved survival. Our findings suggest that selective MC4receptor agonists could have a protective role against multiple organ failure following circulatory shock.

British Journal of Pharmacology(2007)150, 595–603. doi:10.1038/sj.bjp.0707115
The psychoactive plant cannabinoid, Δ9‐tetrahydrocannabinol, is antagonized by Δ8‐ and Δ9‐tetrahydrocannabivarin in micein vivo
Authors: Pertwee R G , Thomas A , Stevenson L A , Ross R A , Varvel S A , Lichtman A H , Martin B R , Razdan R K
Published: January 2007

Background and purpose:

To follow upin vitroevidence that Δ9‐tetrahydrocannabivarin extracted from cannabis (eΔ9‐THCV) is a CB1receptor antagonist by establishing whether synthetic Δ9‐tetrahydrocannabivarin (O‐4394) and Δ8‐tetrahydrocannabivarin (O‐4395) behave as CB1antagonistsin vivo.

Experimental approach:

O‐4394 and O‐4395 were compared with eΔ9‐THCV as displacers of [3H]‐CP55940 from specific CB1binding sites on mouse brain membranes and as antagonists of CP55940 in [35S]GTPγS binding assays performed with mouse brain membranes and ofR‐(+)‐WIN55212 in mouse isolated vasa deferentia. Their ability to antagonizein vivoeffects of 3 or 10 mg kg−1(i.v.) Δ9‐tetrahydrocannabinol in mice was then investigated.

Key results:

O‐4394 and O‐4395 exhibited similar potencies to eΔ9‐THCV as displacers of [3H]‐CP55940 (Ki=46.6 and 64.4 nM, respectively) and as antagonists of CP55940 in the [35S]GTPγS binding assay (apparentKB=82.1 and 125.9 nM, respectively) andR‐(+)‐WIN55212 in the vas deferens (apparentKB=4.8 and 3.9 nM respectively). At i.v. doses of 0.1, 0.3, 1.0 and/or 3 mg kg−1O‐4394 and O‐4395 attenuated Δ9‐tetrahydrocannabinol‐induced anti‐nociception (tail‐flick test) and hypothermia (rectal temperature). O‐4395 but not O‐4394 also antagonized Δ9‐tetrahydrocannabinol‐induced ring immobility. By themselves, O‐4395 and O‐4394 induced ring immobility at 3 or 10 mg kg−1(i.v.) and antinociception at doses above 10 mg kg−1(i.v.). O‐4395 also induced hypothermia at 3 mg kg−1(i.v.) and above.

Conclusions and implications:

O‐4394 and O‐4395 exhibit similarin vitropotencies to eΔ9‐THCV as CB1receptor ligands and as antagonists of cannabinoid receptor agonists and can antagonize Δ9‐tetrahydrocannabinolin vivo.

British Journal of Pharmacology(2007)150, 586–594. doi:10.1038/sj.bjp.0707124
Cannabidiol displays unexpectedly high potency as an antagonist of CB1and CB2receptor agonistsin vitro
Authors: Thomas A , Baillie G L , Phillips A M , Razdan R K , Ross R A , Pertwee R G
Published: January 2007

Background and purpose:

A nonpsychoactive constituent of the cannabis plant, cannabidiol has been demonstrated to have low affinity for both cannabinoid CB1and CB2receptors. We have shown previously that cannabidiol can enhance electrically evoked contractions of the mouse vas deferens, suggestive of inverse agonism. We have also shown that cannabidiol can antagonize cannabinoid receptor agonists in this tissue with a greater potency than we would expect from its poor affinity for cannabinoid receptors. This study aimed to investigate whether these properties of cannabidiol extend to CB1receptors expressed in mouse brain and to human CB2receptors that have been transfected into CHO cells.

Experimental approach:

The [35S]GTPγS binding assay was used to determine both the efficacy of cannabidiol and the ability of cannabidiol to antagonize cannabinoid receptor agonists (CP55940 andR‐(+)‐WIN55212) at the mouse CB1and the human CB2receptor.

Key results:

This paper reports firstly that cannabidiol displays inverse agonism at the human CB2receptor. Secondly, we demonstrate that cannabidiol is a high potency antagonist of cannabinoid receptor agonists in mouse brain and in membranes from CHO cells transfected with human CB2receptors.

Conclusions and implications:

This study has provided the first evidence that cannabidiol can display CB2receptor inverse agonism, an action that appears to be responsible for its antagonism of CP55940 at the human CB2receptor. The ability of cannabidiol to behave as a CB2receptor inverse agonist may contribute to its documented anti‐inflammatory properties.

British Journal of Pharmacology(2007)150, 613–623. doi:10.1038/sj.bjp.0707133
Endothelium‐dependent metabolism by endocannabinoid hydrolases and cyclooxygenases limits vasorelaxation to anandamide and 2‐arachidonoylglycerol
Authors: Ho W‐Sv , Randall M D
Published: January 2007

Background and purpose:

The endocannabinoids, N‐arachidonoylethanolamide (anandamide) and 2‐arachidonoylglycerol (2‐AG) are rapidly degraded by fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MGL). Whilst these lipid mediators are known to modulate vascular tone, the extent to which they are inactivated via local metabolism in the vasculature remains unclear.

Experimental approach:

In rat isolated small mesenteric arteries, the regulatory role of FAAH, MGL and cyclooxygenase (COX) in relaxant responses to anandamide and 2‐AG was evaluated by using inhibitors of these enzymes. Relaxations to non‐hydrolysable analogues of endocannabinoids and arachidonic acid were also examined.

Key results:

Relaxation to anandamide but not 2‐AG was potentiated by the selective FAAH inhibitor, URB597 (1 μM). In contrast, MAFP (10 μM; an inhibitor of FAAH and MGL) enhanced responses to both anandamide and 2‐AG. Inhibition of COX‐1 by indomethacin (10 μM) potentiated relaxations to 2‐AG, whereas inhibition of COX‐2 by nimesulide (10 μM) potentiated anandamide‐induced relaxation. With the exception of MAFP, effects of FAAH and COX inhibitors were dependent on the endothelium. Relaxation to methanandamide and noladin ether, the non‐hydrolysable analogues of anandamide and 2‐AG respectively, were insensitive to the enzyme inhibitors.

Conclusion and implications:

This study shows that local activity of FAAH, MGL and COX, which is present largely in the endothelium, limits the vasodilator action of endocannabinoids in rat small mesenteric arteries. Despite the differential roles played by these enzymes on relaxation to anandamide versus 2‐AG, our results suggest that inhibitors of these enzymes enhance the vascular impact of endocannabinoids.

British Journal of Pharmacology (2007) 150, 641–651. doi:10.1038/sj.bjp.0707141
Stable, mode-matched, medium-finesse optical cavity incorporating a microcantilever mirror: Optical characterization and laser cooling
Authors: Harris J. G. E. , Zwickl B. M. , Jayich A. M.
Published: January 2007

A stable optical resonator has been built using a 30-μm-wide, metal-coated microcantilever as one mirror. The second mirror was a 12.7-mm-diameter concave dielectric mirror. By positioning the two mirrors 75mm apart in a near-hemispherical configuration, a Fabry-Pérot cavity with a finesse equal to 55 was achieved. The finesse was limited by the optical loss in the cantilever’s metal coating; diffraction losses from the small mirror were negligible. The cavity achieved passive laser cooling of the cantilever’s Brownian motion.
Experimental investigation of double layers in expanding plasmas
Authors: Plihon N. , Chabert P. , Corr C. S.
Published: January 2007

Double layers (DLs) have been observed in a plasma reactor composed of a source chamber attached to a larger expanding chamber. Positive ion beams generated across the DL were characterized in the low plasma potential region using retarding field energy analyzers. In electropositive gases, DLs were formed at very low pressures (between 0.1 and 1mTorr) with the plasma expansion forced by a strongly diverging magnetic field. The DL remains static, robust to changes in boundary conditions, and its position is related to the magnetic field lines. The voltage drop across the DL increases with decreasing pressure; i.e., with increasing electron temperature (around 20V at 0.17mTorr). DLs were also observed in electronegative gases without a magnetic field over a greater range of pressure (0.5 to 10mTorr). The actual profile of the electronegative DL is very sensitive to external parameters and intrusive elements, and they propagate at high negative ion fraction. Electrostatic probes measurements and laser-induced photodetachment show discontinuities in all plasma parameters (electron density, electron temperature, negative ion fraction) at the DL position. The voltage drop across the electronegative DL is about 8V, is independent of the gas pressure and therefore of the electron temperature.
Influence of bond flexibility on the vapor-liquid phase equilibria of water
Authors: Raabe Gabriele , Sadus Richard J.
Published: January 2007

The authors performed Gibbs ensemble simulations on the vapor-liquid equilibrium of water to investigate the influence of incorporating intramolecular degrees of freedom in the simple point charge (SPC) water model. Results for vapor pressures, saturation densities, heats of vaporization, and the critical point for two different flexible models are compared with data for the corresponding rigid SPC and SPC/E models. They found that the introduction of internal vibrations, and also their parametrization, has an observable effect on the prediction of the vapor-liquid coexistence curve. The flexible SPC/Fw model, although optimized to describe bulk diffusion and dielectric constants at ambient conditions, gives the best prediction of saturation densities and the critical point of the examined models.
Thin film patterning by surface-plasmon-induced thermocapillarity
Authors: Röntzsch Lars , Heinig Karl-Heinz , Schuller Jon A. , Brongersma Mark L.
Published: January 2007

It is reported that standing surface-plasmon-polariton (SPP) waves can cause regular thickness undulations of thin polymethyl methacrylate (PMMA) films above a metallic substrate. Ripples, rings, and hillock arrays with long-range order were found. Numerical calculations reveal that periodic in-plane temperature profiles are generated in the PMMA due to the nonradiative damping of SPP interference patterns. Computer simulations on the temperature-gradient-driven mass transport confirm that thermocapillarity is the dominating mechanism of the observed surface patterning.
Bending strength and flexibility of ZnO nanowires
Authors: Chen C. Q. , Zhu J.
Published: January 2007

The fracture strain, strength, and flexibility of ZnO nanowires (NWs) with a large range of diameters (85–542nm) are investigated at a quantitative level. Large strains up to 4%–7% have been obtained before the final elastic fracture, corresponding to fracture strengths close to the theoretical strength. The flexibility of a NW is discussed quantitatively in terms of the diameter and fracture strain. The fundamental mechanisms responsible for the observed exceptional properties are discussed.
Magnetotransport through two dimensional electron gas in a tubular geometry
Authors: Shaji Nakul , Qin Hua , Blick Robert H. , Klein Levente J. , Deneke Christoph , Schmidt Oliver G.
Published: January 2007

The authors report on topology dependent electron transport in tubular shaped two dimensional electron gas. These micron sized tubes are realized in strained InGaAs quantum wells as a first step towards investigating geometric potentials in low dimensional quantum systems. They investigate the topology induced change in magnetoresistance of the electronic system in a perpendicular magnetic field. At low magnetic field, an increased zero field magnetoresistance followed by a negative magnetoresistance is observed. They ascribe this effect to an increase in electron scattering along the curved regions. At high magnetic fields they observe a linear increase in resistance of the curved region as compared to planar regions.
Nanoparticle generation in ultrafast pulsed laser ablation of nickel
Authors: Liu Bing , Hu Zhendong , Che Yong , Chen Yanbin , Pan Xiaoqing
Published: January 2007

The process of particle generation during ultrafast pulsed laser ablation of nickel is investigated. Two types of particles with different sizes depending on the laser fluence are found, indicating different particle generation mechanisms. By limiting the laser fluence below a threshold of strong plasma formation, the large dropletlike particles can be eliminated. In addition, by supplying different background gases, various crystalline structures are obtained for the particles, including Ni∕NiO core/shell spheres and NiO cubes. This study provides evidence that ultrafast laser ablation can be a room temperature physical method for generating nanocrystals with a narrow particle size distribution.
Specialized Adaptation to Displaced Vision
Authors: Mikaelian H H , Malatesta V
Published: January 2007

Two conditions of exposure to prism rearrangement were used to explore specificity of visuo—motor adaptation. In one condition subjects viewed, in sequential alternation of one minute periods, the movements of one arm through base right prisms and those of the other arm through base left prisms for a total of 20 min. In the second condition subjects viewed the movements of only one arm for one minute periods followed by closing the eyes for the next, alternating between viewing arm movements and closing the eyes for a total of 20 min. The magnitude of postexposure sensorimotor changes following the alternating limb-exposure condition was equivalent and opposite in direction in each limb. Unilateral exposure generated commensurate sensorimotor changes in responses entailing the exposed arm. These results show that prism-mediated visual reafference from arm movements acts to recalibrate target-directed orientations of that arm only, and does not interact, or interfere with, recalibration of directed orientations of the other limbs.
Stimulus Intensity and Spatiality in Tactile Temporal Numerosity Discrimination
Authors: Lechelt E C
Published: January 2007

The role of signal intensity in tactile temporal numerosity discrimination was investigated for limited conditions of signal number and presentation rate. Trains of 5 to 18 mechanical ‘taps’ were presented at rates of 6, 8, 10, 12, or 15 s−1 to the ball of the left middle finger at either 75 or 125 V (15 or 20 dB SL, respectively). Trains of signals of greater intensity were counted reliably more accurately. Results from this spatially static arrangement are compared to those obtained under conditions of spatial variation where signals of identical intensity were delivered to multiple loci instead of to a single locus. It is concluded that the absolute judgment of the number of tactile signals in a train is a very labile process and highly dependent upon, and specific to, the physical characteristics—temporal, spatial, and intensive—of the stimulus complex.
Illusory Contours: Curious Cases of Simultaneous Brightness Contrast?
Authors: Frisby John P , Clatworthy Jeremy L
Published: January 2007

It is suggested that simultaneous brightness contrast mediated by lateral inhibition plays an important role in generating many illusory contours. These contours might reflect a further way in which lateral inhibition serves to clarify and sharpen the neural encoding of retinal images.
Component Analysis of Orientation Illusions
Authors: Wenderoth Peter , Beh Helen
Published: January 2007

Orientation illusions occur when the inducing figure is a line or grating (the tilt illusion) or a square outline frame (the rod-and-frame illusion). In the range of inducing figure tilts between vertical and horizontal, the tilt illusion describes one cycle of positive (direct) and negative (indirect) effects but the rod-and-frame illusion describes two such cycles. In two experiments, angular functions of illusions were measured with the six possible inducing figures which result when two of the four sides of a square inducing frame are deleted. As expected, the parallel-sided frame amputations induced angular functions similar to the tilt illusion and these functions differed from those induced by the orthogonal-sided amputations. In agreement with previous findings on the nonadditivity of tilt illusions, the sum of angular functions induced by frame amputations, which together form a complete frame, were not always equivalent to the angular function induced by a complete frame, and there were asymmetries in the data for which neither of two simple hypotheses could adequately account. The discussion focuses upon properties of inducing figures which psychophysical hypotheses might need to consider in order to account for the shapes of angular functions of orientation illusions and, in particular, a distinction is drawn between the global orientation of the inducing figure and the orientations of its (local) component features. It is suggested that it might be fruitful if the tilt illusion and the rod-and-frame illusion were conceived of as illusions resulting from inducing figures composed of all or part of n gratings of spatial frequency fn intersecting at angles of 180°/ n.
Linear Acceleration Modifies the Perceived Velocity of a Moving Visual Scene
Authors: Pavard Bernard , Berthoz Alain
Published: January 2007

In the present work, we have shown the effect of a vestibular stimulation on the velocity perception of a moving scene. The intensity of this effect is related to the amplitude of the cart acceleration, image velocity, spatial frequency of the visual stimulus, and the angle between the directions of cart and image movement. A simple model has been developed to determine whether the perception of visual movement is due to the geometric projection of the vestibular evaluation on the visual vector, or the inverse.
Sex Differences in Choice Behaviour: The Object-Person Dimension
Authors: McGuinness Diane , Symonds John
Published: January 2007

When viewing two conflicting stimuli in a stereoscope, males reported seeing objects significantly more often than human figures. The opposite effect was observed in females.
Pandemonium and Visual Search
Authors: Henderson Leslie
Published: January 2007

Pandemonium-like models have played a central role in theories of perceptual recognition. One model is examined which asserts that information is sorted unidirectionally through a hierarchy of increasingly abstract levels only to a depth required by the logical demands of the task and read off from the appropriate level to control response decisions. The support originally claimed for the model in terms of its application to visual search performance is questioned. It is suggested that the pervasiveness of such models is not due to their competition with alternative theories but rather to methatheoretic considerations.
Effects of Red Light and Loud Noise on the Rate at Which Monkeys Sample the Sensory Environment
Authors: Humphrey Nicholas K , Keeble Graham R
Published: January 2007

Monkeys, given the opportunity to move between two featureless chambers, ‘sample’ first one, then the other in a way which reflects a Poisson decision process. The rate of sampling is higher in red light than in blue and in loud noise than in quietness. We suggest that monkeys ‘tune’ their sampling rate to the a priori probability of change in the environment.
On Reexamining Fortes' Data: Some Implications of Drawings Made by Children Who Have Never Drawn before
Authors: Deregowski Jan B
Published: January 2007

Spontaneous drawings made by Tale subjects who had never drawn before, obtained by Fortes in the 1930s, are compared with those made by subjects coming from the same population who had learned to draw under Western influence. The disparity of styles of these drawings, it is argued, shows that it would be erroneous to suggest that a universal ‘grammar of drawing’ can be derived by examination of drawings obtained from Western populations only. Such rare data from remote cultures offer therefore important safeguards against ethnocentricity in psychological theorising.
Central and Peripheral Object Distances as Determinants of the Effective Visual Field in Early Infancy
Authors: de Schonen Scania , McKenzie Beryl , Maury Liliane , Bresson Francois
Published: January 2007

While visually fixating on a central, coloured object, thirty-six infants aged between two and five months were presented with a peripheral target to the right or to the left of midline. Both objects were presented at two distances: either 30 or 90 cm from the infant. The extent of the effective visual field was measured by the presence and the latency of saccadic shifts of gaze from the fixation object toward the target object placed at varying degrees of eccentricity. The effective visual field expanded between two and four months. Near peripheral targets were detected at greater angles of eccentricity than those more distant, but this effect was modified both by age and by the distance of central fixation. For two- and three-month infants the effective visual field was most reduced when the central fixation object was placed at 30 cm and the target object at 90 cm. The ability to respond to peripheral objects more distant than the fixation object develops after three months.
The Perception of Relative Motion by Young Infants
Authors: Lasky Robert E , Gogel Walter C
Published: January 2007

The perception of relations between stimuli is considered to be essential for perceptual grouping. The present study investigated the ability of five-month-old infants to perceive the relative motions between simultaneously moving dots. Two of the dots moved horizontally back and forth in parallel trajectories, and a third dot moved vertically up and down between the other two. As a consequence of the relative motions, adults perceived the vertically moving dot to be moving an average of 32° clockwise or counterclockwise from the vertical depending on the phase of motion between the vertical and horizontal dots. An habituation paradigm was used to determine whether infants also perceive these relative motions. A control group of infants was presented a display with the same phase of motion between the vertical and horizontally moving dots for twelve trials. The experimentals were presented with the same display as the controls during the first ten trials, but on the last two trials the phase of motion was reversed. Fixation of the display continued to decline during the last two trials for the control, but not for the experimental group. A second study in which the phase of motions could be varied in two simultaneously presented three-dot displays supports the results of the first study. By five months of age, infants seem to be sensitive to relative-motion cues, and presumably have the ability to group moving stimuli perceptually.
An Additional Dimension to Grating Perception
Authors: Tyler Christopher W
Published: January 2007

Visual acuity ( A) for a two-dimensional multiplicative sinusoidal contrast grid (sinusoidal chessboard) was measured as a function of spatial frequency (ω) of modulation in one of the dimensions. The reduction in acuity as frequency was increased was well described by the equation: A = −2 πkω + c, where k and c are constants. At suprathreshold contrasts, the frequency of modulation appeared to be doubled relative to the underlying modulation frequency. This doubling is not related to the frequency of the harmonic components of the chessboard, but suggests the existence of a perceptual mechanism sensitive to areas of sinusoidal modulation which are seen at twice the frequency of the variation in contrast.
Auditory Texture Perception
Authors: Lederman Susan J
Published: January 2007

A set of three studies was designed to investigate the role of touch-produced sounds in the perception of surface texture. Subjects were capable of judging roughness on the basis of sounds alone. Auditory judgments were similar, but not identical to corresponding haptic touch judgments. When both sources of information were available, subjects tended to use the tactile cues. The nature of the auditory stimulus for roughness is considered.