bluuebunny/crossref_metadata_2025 huggingface dataset:
Saturation of nonlinear optical absorption of metal-nanoparticle composites
Authors: Plaksin Oleg , Takeda Yoshihiko , Amekura Hiroshi , Kishimoto Naoki , Plaksin Sergey
Published: June 2008

Metal-nanoparticle composites consisting of copper and gold nanoparticles embedded in insulators (Cu:SiO2, Au:SiO2, and Cu:Al2O3) have been fabricated by metal-ion implantation. Nonlinear optical (NLO) absorption of the nanocomposites has been examined by the Z-scan method with a tunable femtosecond laser. We have measured (a) NLO absorption spectra near the surface-plasmon resonance and (b) laser-intensity dependence of NLO absorption, α(I). The results are compared to the data reported on NLO response for various laser pulse durations. By analyzing the laser-intensity dependence of Z-scan signals, the saturation intensity of light, IS, the coefficient of NLO absorption, β, and the radius of the beam waist, w0, are derived. This approach takes into account the saturation of optical absorption, whereas the conventional approach using the linear approximation α(I)≈α0+βI cannot do it. The analysis shows that transient optical absorption, |α(I)−α0|, decreases with shortening the laser pulse duration. The decrease in transient optical absorption is explained in terms of small contributions from slow components of the NLO response.
Dose dependent x-ray luminescence in MgF2:Eu2+, Mn2+ phosphors
Authors: Chen Wei , Westcott Sarah L. , Wang Shaopeng , Liu Yuanfang
Published: June 2008

In MgF2:Mn2+, Eu2+ phosphors, the x-ray excited luminescence from Eu2+ is decreased while the emission from Mn2+ is increased in intensity with the increase of x-ray dose. In MgF2:Mn2+, the luminescence is also increased, and in MgF2:Eu2+, the emission of Eu2+ is also decreased in intensity with the increase of x-ray dose. However, the intensity changes with x-ray dose in the singly doped MgF2:Mn2+ and MgF2:Eu2+ phosphors are much less than those in the doubly doped MgF2:Mn2+, Eu2+ phosphors. The increase of Mn2+ emission in intensity is likely due to the breakdown of the forbidden transition by the defects created by x-ray irradiation. No conversion of Eu2+ ions to Eu3+ ions was observed in MgF2:Eu2+ phosphors during x-ray irradiation. The decrease of Eu2+ emission in intensity in MgF2:Mn2+, Eu2+ must be closely related to the interaction and the energy transfer to Mn2+ ions. The phenomenon observed is potentially interesting for the practical applications for radiation detection, as utilizing the ratio of the two emissions from Mn2+ and Eu2+ for radiation detection is more sensitive and more reliable than using emission intensity change only.
Pulsed laser dewetting of patterned thin metal films: A means of directed assembly
Authors: Rack Philip D. , Guan Yingfeng , Fowlkes Jason D. , Melechko Anatoli V. , Simpson Michael L.
Published: June 2008

Thin nickel films were patterned into various shapes and treated with a series of laser pulses. The edges and vertices of the patterned shapes act as programable instabilities, which enable directed assembly via dewetting when the laser energy density is above the melting threshold. The pattern formations were monitored as a function of laser pulse and the retraction process was attributed liquid dewetting and a subsequent resolidification. The calculated retraction velocity (83m∕s) and liquid lifetime (12.3ns) were consistent with the measured nickel retraction distances. The vertices of the shapes had an initially larger retraction velocity which was attributed to an additional in-plane curvature.
Functional integration across a gradient of corticostriatal channels controls UP state transitions in the dorsal striatum
Authors: Kasanetz Fernando , Riquelme Luis A. , Della-Maggiore Valeria , O'Donnell Patricio , Murer M. Gustavo
Published: June 2008

Coordinated near-threshold depolarized states in cortical and striatal neurons may contribute to form functionally segregated channels of information processing. Recent anatomical studies have identified pathways that could support spiraling interactions across corticostriatal channels, but a functional outcome of such spiraling remains to be identified. Here, we examined whether plateau depolarizations (UP states) in striatal neurons relate better to active epochs in local field potentials recorded from closely related cortical areas than to those recorded in less-related cortical areas. Our results show that, in anesthetized rats, the coordination between cortical areas and striatal regions obeys a mediolateral gradient and keeps track of slow wave trajectory across the neocortex. Moreover, activity in one cortical area induced phase advances in UP state onset and phase delays in UP state termination in nonmatching striatal regions, reflecting the existence of functional connections that could encode large-scale interactions between corticostriatal channels as subthreshold influences on striatal projection neurons.
Label-free and dynamic detection of biomolecular interactions for high-throughput microarray applications
Authors: Özkumur Emre , Needham James W. , Bergstein David A. , Gonzalez Rodrigo , Cabodi Mario , Gershoni Jonathan M. , Goldberg Bennett B. , Ünlü M. Selim
Published: June 2008

Direct monitoring of primary molecular-binding interactions without the need for secondary reactants would markedly simplify and expand applications of high-throughput label-free detection methods. A simple interferometric technique is presented that monitors the optical phase difference resulting from accumulated biomolecular mass. As an example, 50 spots for each of four proteins consisting of BSA, human serum albumin, rabbit IgG, and protein G were dynamically monitored as they captured corresponding antibodies. Dynamic measurements were made at 26 pg/mm
2
SD per spot and with a detectable concentration of 19 ng/ml. The presented method is particularly relevant for protein microarray analysis because it is label-free, simple, sensitive, and easily scales to high-throughput.
Eyeblink conditioning in 12-day-old rats using pontine stimulation as the conditioned stimulus
Authors: Campolattaro Matthew M. , Freeman John H.
Published: June 2008

A fundamental issue in developmental science is whether ontogenetic changes in memory are caused by the development of cellular plasticity mechanisms within the brain's memory systems or maturation of sensory inputs to the memory systems. Here, we provide evidence that the development of eyeblink conditioning, a form of associative learning that depends on the cerebellum, is driven by the development of sensory inputs rather than the development of neuronal plasticity mechanisms. We find that rats as young as 12 days old show associative eyeblink conditioning when pontine stimulation is used in place of an external (e.g., a tone) conditioned stimulus. Eyeblink-conditioned responses established with pontine stimulation in 12-day-old rats were reversibly abolished by an infusion of muscimol into the cerebellar interpositus nucleus. The findings suggest that cerebellar neurons are capable of supporting associative learning-specific plasticity
in vivo
in very immature animals if given sufficient afferent stimulation.
The coactivators CBP/p300 and the histone chaperone NAP1 promote transcription-independent nucleosome eviction at the HTLV-1 promoter
Authors: Sharma Neelam , Nyborg Jennifer K.
Published: June 2008

The human T cell leukemia virus type 1 (HTLV-1) is the causative agent of adult T cell leukemia/lymphoma. The multifunctional virally encoded oncoprotein Tax is responsible for malignant transformation and potent activation of HTLV-1 transcription. Tax, in complex with phosphorylated cAMP response element binding protein (pCREB), strongly recruits the cellular coactivators CREB binding protein (CBP)/p300 to the viral promoter concomitant with transcriptional activation. Although the mechanism of activator/coactivator-mediated transcriptional activation is poorly understood, the recruitment of CBP/p300 by regulatory factors appears to function, in part, by promoting changes in chromatin architecture that are permissive to transcriptional activation. Here, we show that CBP/p300 recruitment promotes histone acetylation and eviction of the histone octamer from the chromatin-assembled HTLV-1 promoter template
in vitro
. Nucleosome disassembly is strictly acetyl-CoA dependent and is not linked to ATP utilization. We find that the histone chaperone, nucleosome assembly protein 1 (NAP1), cooperates with CBP/p300 in eviction of the acetylated histones from the chromatin template. These findings reveal a unique mechanism in which the DNA-bound Tax/pCREB complex recruits CBP/p300, and together with NAP1, the coactivators cooperate to dramatically reduce nucleosome occupancy at the viral promoter in an acetylation-dependent and transcription-independent fashion.
Cultural route to the emergence of linguistic categories
Authors: Puglisi Andrea , Baronchelli Andrea , Loreto Vittorio
Published: June 2008

Categories provide a coarse-grained description of the world. A fundamental question is whether categories simply mirror an underlying structure of nature or instead come from the complex interactions of human beings among themselves and with the environment. Here, we address this question by modeling a population of individuals who co-evolve their own system of symbols and meanings by playing elementary language games. The central result is the emergence of a hierarchical category structure made of two distinct levels: a basic layer, responsible for fine discrimination of the environment, and a shared linguistic layer that groups together perceptions to guarantee communicative success. Remarkably, the number of linguistic categories turns out to be finite and small, as observed in natural languages.
Barrierless evolution of structure during the submillisecond refolding reaction of a small protein
Authors: Sinha Kalyan K. , Udgaonkar Jayant B.
Published: June 2008

To determine whether a protein folding reaction can occur in the absence of a dominant barrier is crucial for understanding its complexity. Here direct ultrafast kinetic measurements have been used to study the initial submillisecond (sub-ms) folding reaction of the small protein barstar. The cooperativity of the initial folding reaction has been explored by using two probes: fluorescence resonance energy transfer, through which the contraction of two intramolecular distances is measured, and the binding of 8-anilino-1-naphthalene sulfonic acid, through which the formation of hydrophobic clusters is monitored. A fast chain contraction is shown to precede the formation of hydrophobic clusters, indicating that the sub-ms folding reaction is not cooperative. The observed rate constant of the sub-ms folding reaction monitored by 8-anilino-1-naphthalene sulfonic acid fluorescence has been found to be the same in stabilizing conditions (low urea concentrations), in which specific structure is formed, and in marginally stabilizing conditions (higher urea concentrations), where virtually no structure is formed in the product of the sub-ms folding reaction. The observation that the folding rate is independent of the folding conditions suggests that the initial folding reaction occurs in the absence of a dominant free energy barrier. These results provide kinetic evidence that the formation of specific structure need not be slowed down by any significant free energy barrier during the course of a very fast protein folding reaction.
Experimental evidence for negative selection in the evolution of a
Yersinia pestis
pseudogene
Authors: Sun Yi-Cheng , Hinnebusch B. Joseph , Darby Creg
Published: June 2008

Yersinia pestis
, the agent of bubonic plague, evolved from the enteric pathogen
Yersinia pseudotuberculosis
within the past 20,000 years. Because ancestor and descendant both exist, it is possible to infer steps in molecular evolution by direct experimental approaches. The
Y. pestis
life cycle includes establishment of a biofilm within its vector, the flea. Although
Y. pseudotuberculosis
makes biofilms in other environments, it fails to do so in the insect. We show that
rcsA
, a negative regulator of biofilms that is functional in
Y. pseudotuberculosis
, is a pseudogene in
Y. pestis
. Replacement of the pseudogene with the functional
Y. pseudotuberculosis rcsA
allele strongly represses biofilm formation and essentially abolishes flea biofilms. The conversion of
rcsA
to a pseudogene during
Y. pestis
evolution, therefore, was a case of negative selection rather than neutral genetic drift.
Plexin signaling selectively regulates the stereotyped pruning of corticospinal axons from visual cortex
Authors: Low Lawrence K. , Liu Xiao-Bo , Faulkner Regina L. , Coble Jeffrey , Cheng Hwai-Jong
Published: June 2008

Neurons in the developing CNS tend to send out long axon collaterals to multiple target areas. For these neurons to attain specific connections, some of their axon collaterals are subsequently pruned—a process called stereotyped axon pruning. One of the most striking examples of stereotyped pruning in the CNS is the pruning of corticospinal tract (CST) axons. The long CST collaterals from layer V neurons of the visual and motor cortices are differentially pruned during development. Here we demonstrate that select plexins and neuropilins, which serve as coreceptors for semaphorins, are expressed in visual cortical neurons at the time when CST axon collaterals are stereotypically pruned. By analyzing mutant mice, we find that the pruning of visual, but not motor, CST axon collaterals depends on plexin-A3, plexin-A4, and neuropilin-2. Expression pattern study suggests that Sema3F is a candidate local cue for the pruning of visual CST axons. Using electron microscopic analysis, we also show that visual CST axon collaterals form synaptic contacts in the spinal cord before pruning and that the unpruned collaterals in adult mutant mice are unmyelinated and maintain their synaptic contacts. Our results indicate that the stereotyped pruning of the visual and motor CST axon collaterals is differentially regulated and that this specificity arises from the differential expression of plexin receptors in the cortex.
Roger John Blin–Stoyle. 24 December 1924 — 31 January 2007
Authors: Elliott J. P.
Published: June 2008

Roger Blin–Stoyle was primarily a theoretical physicist who worked in the borderland between theories of the structure of atomicnuclei and theories of the interactions and relationships between the elementary particles from which nuclei are built. He made world–class contributions. But he was also driven by a desire to improve the communication of science in general and physics in particular, at all levels.This led him to accept an offer to become the founding Dean of Science at Sussex, the first of the ‘new' universities, and later tochair a number of national bodies including a committee responsible for reviewing the science curriculum in schools. Less well known was his accomplishment as a pianist and organist.
Universal growth law for knot energy of Faddeev type in general dimensions
Authors: Lin Fanghua , Yang Yisong
Published: June 2008

The presence of a fractional-exponent growth law relating knot energy and knot topology is known to be an essential characteristic for the existence of ‘ideal’ knots. In this paper, we show that the energy infimum
E

N

stratified at the Hopf charge
N
of the knot energy of the Faddeev type induced from the Hopf fibration

(
n
≥1) in general dimensions obeys the sharp fractional-exponent growth law

, where the exponent
p
is universally rendered as

, which is independent of the detailed fine structure of the knot energy but determined completely by the dimensions of the domain and range spaces of the field configuration maps.
Analysis of the Golgi Apparatus in Arabidopsis Seed Coat Cells during Polarized Secretion of Pectin-Rich Mucilage
Authors: Young Robin E. , McFarlane Heather E. , Hahn Michael G. , Western Tamara L. , Haughn George W. , Samuels A. Lacey
Published: June 2008

Differentiation of the Arabidopsis thaliana seed coat cells includes a secretory phase where large amounts of pectinaceous mucilage are deposited to a specific domain of the cell wall. During this phase, Golgi stacks had cisternae with swollen margins and trans-Golgi networks consisting of interconnected vesicular clusters. The proportion of Golgi stacks producing mucilage was determined by immunogold labeling and transmission electron microscopy using an antimucilage antibody, CCRC-M36. The large percentage of stacks found to contain mucilage supports a model where all Golgi stacks produce mucilage synchronously, rather than having a subset of specialist Golgi producing pectin product. Initiation of mucilage biosynthesis was also correlated with an increase in the number of Golgi stacks per cell. Interestingly, though the morphology of individual Golgi stacks was dependent on the volume of mucilage produced, the number was not, suggesting that proliferation of Golgi stacks is developmentally programmed. Mapping the position of mucilage-producing Golgi stacks within developing seed coat cells and live-cell imaging of cells labeled with a trans-Golgi marker showed that stacks were randomly distributed throughout the cytoplasm rather than clustered at the site of secretion. These data indicate that the destination of cargo has little effect on the location of the Golgi stack within the cell.
Temporal constraints on basin inversion provided by 3D seismic and well data: a case study from the South Viking Graben, offshore Norway
Authors: Jackson C. A‐L. , Larsen E.
Published: June 2008

Three‐dimensional (3D) seismic, well and biostratigraphic data are integrated to determine the timing of inversion on the hangingwall of the South Viking Graben, offshore Norway. Within the study area two, NW–SE to NE–SW trending normal faults are developed which were active during a Late Jurassic rift event. In the hangingwall of these faults asymmetric, 2–5 km wide anticlines are developed which trend parallel to the adjacent faults and are interpreted as growth folds formed in response to compressional shortening (inversion) of the syn‐rift basin‐fill. Marked thickness variations are observed in Late Jurassic and Early Cretaceous growth strata with respect to the inversion‐related folds, with seismic data indicating onlap and thinning of these units across the folds. In addition, well data suggests that not only are erosional surfaces only locally developed towards the crests of the folds, but these surfaces may also truncate underlying flooding surfaces towards the fold crests. Taken together, these observations indicate that inversion and growth of inversion‐related structures initiated in the late Early Volgian and continued until the Late Albian. Furthermore, it is demonstrated that individual folds amplified and propagated laterally through time, and that fold growth was not synchronous across the study area. This study demonstrates that the temporal evolution of structures associated with the inversion of sedimentary basins can be accurately determined through the integration of 3D seismic, well and biostratigraphic data. Furthermore, this study has local implications for constraining the timing of inversion within the South Viking Graben during the Late Mesozoic.
Effects of climate change on environmental factors in respiratory allergic diseases
Authors: D'Amato G. , Cecchi L.
Published: June 2008

A body of evidence suggests that major changes involving the atmosphere and the climate, including global warming induced by human activity, have an impact on the biosphere and the human environment. Studies on the effects of climate change on respiratory allergy are still lacking and current knowledge is provided by epidemiological and experimental studies on the relationship between asthma and environmental factors, such as meteorological variables, airborne allergens and air pollution. However, there is also considerable evidence that subjects affected by asthma are at an increased risk of developing obstructive airway exacerbations with exposure to gaseous and particulate components of air pollution. It is not easy to evaluate the impact of climate change and air pollution on the prevalence of asthma in general and on the timing of asthma exacerbations. However, the global rise in asthma prevalence and severity suggests that air pollution and climate changes could be contributing. Pollen allergy is frequently used to study the interrelationship between air pollution, rhinitis and bronchial asthma. Epidemiological studies have demonstrated that urbanization, high levels of vehicle emissions and westernized lifestyle are correlated to an increase in the frequency of pollen‐induced respiratory allergy, prevalent in people who live in urban areas compared with those who live in rural areas. Meteorological factors (temperature, wind speed, humidity, etc.) along with their climatological regimes (warm or cold anomalies and dry or wet periods, etc.), can affect both biological and chemical components of this interaction. In addition, by inducing airway inflammation, air pollution overcomes the mucosal barrier priming allergen‐induced responses. In conclusion, climate change might induce negative effects on respiratory allergic diseases. In particular, the increased length and severity of the pollen season, the higher occurrence of heavy precipitation events and the increasing frequency of urban air pollution episodes suggest that environmental risk factors will have a stronger effect in the following decades.
Sustaining ecosystem services in ancient limestone grassland: importance of major component plants and community composition
Authors: Phoenix Gareth K. , Johnson David , Grime J. Philip , Booth Rosemary E.
Published: June 2008

Limestone grasslands are among the most floristically rich ecosystems in northern Europe and have recently been shown to sustain ecosystem functioning under conditions of heavy nitrogen (N) deposition. Here we report a long‐term mesocosm experiment, designed to measure the importance of major component plants and community composition in providing ecosystem services (in particular preventing leaching of inorganic N).

A number of important steps were taken in the experimental design to increase conformity of the experimental communities to real limestone pasture, including using natural soils, plant cuttings of limestone grassland provenance and simulated management. Furthermore, communities were allowed to establish for 8 years before measurements were made.

Leaching ofandwere found to differ by up to a considerable two orders of magnitude according to functional group composition, with sedges and forbs leaching the most. Grass communities and communities containing all three functional groups (grasses, sedges and forbs) leached similarly low amounts ofand.

Levels of soilandfollowed a similar pattern of inter‐community differences to leaching, while vegetation biomass and vegetation N stocks were very similar between communities consisting of only grasses, only sedges and the most species rich community (4 grasses + 4 sedges + 4 forbs).

Perennial grasses appeared to play the key role in inorganic N retention, with communities consisting of these plants having equally low leaching as more species rich communities. Indeed, most ecosystem services were performed comparatively well by grass communities as by the most species rich community.

No overall effects on provision of services resulted from mixing functional groups or increasing the number of species representing each functional group.

Synthesis. This work shows that more than order‐of‐magnitude differences in provision of ecosystem services can occur between species that coexist naturally in ancient limestone pasture. However, despite these large differences, because of the key role played by grasses, expected shifts in community composition anticipated as a result of N pollution may not impair the capacity of these systems to provide ecosystems services.
Trade‐offs between direct and indirect defences of lima bean (Phaseolus lunatus)
Authors: Ballhorn Daniel J. , Kautz Stefanie , Lion Ulrich , Heil Martin
Published: June 2008

Plant defence theory predicts trade‐offs among defence traits as a result of resource limitation or pleiotropic effects. Although theoretically widely accepted, empirical demonstrations of such trade‐offs are surprisingly scarce and mechanistic explanations are usually lacking.

We quantified cyanogenesis (the release of hydrogen cyanide (HCN)) as a direct defence and the emission of volatile organic compounds (VOCs) as an indirect defence against herbivores. To elucidate whether the trade‐offs occur at the genetic or phenotypic level we investigated cultivated and wild‐type accessions of lima bean (Fabaceae: Phaseolus lunatus L.) and compared different leaf developmental stages. Genetic relationships among the accessions were studied using amplified fragment length polymorphism (AFLP) analysis.

Cyanogenesis and the release of VOCs differed significantly among the accessions and were negatively correlated: high cyanogenic accessions released low amounts of VOCs and vice versa. The same remained true for the ontogenetic stages, since primary leaves of all accessions hardly ever produced HCN at all, yet regularly showed high release rates of VOCs.

Low and high cyanogenic accessions of lima bean formed distinct clades in an AFLP‐based dendrogram, while wild‐types and cultivars did not separate. The first pattern indicates that the underlying defensive syndromes are genetically conserved, while the latter is likely to be caused by a multiple origin of cultivated lima beans or an extensive gene flow among cultivated and wild plants.

Synthesis. Trade‐offs between cynogenesis and VOC release were obvious both between accessions and at the ontogenetic level, and thus cannot be explained by pleiotropy. We contend that allocation restrictions and/or adaptations to different enemy pressures are most likely to explain why lima bean can invest into cyanogenesis or VOCs, but not both.
Deficiency in l‐serine deaminase results in abnormal growth and cell division of Escherichia coli K‐12
Authors: Zhang Xiao , Newman Elaine
Published: June 2008

The loss of the ability to deaminate l‐serine severely impairs growth and cell division in Escherichia coli K‐12. A strain from which the three genes (sdaA, sdaB, tdcG) coding for this organism's three l‐serine deaminases had been deleted grows well in glucose minimal medium but, on subculture into minimal medium with glucose and casamino acids, it makes very large, abnormally shaped cells, many of which lyse. When inoculated into Luria‐Bertani (LB) broth with or without glucose, it makes very long filaments. Provision of S‐adenosylmethionine restores cell division in LB broth with glucose, and repairs much of the difficulty in growth in medium with casamino acids. We suggest that replication of E. coli is regulated by methylation, that an unusually high intracellular l‐serine concentration, in the presence of other amino acids, starves the cell for S‐adenosylmethionine and that it is the absence of S‐adenosylmethionine and/or of C1‐tetrahydrofolate derivatives that prevents normal cell division.
Synthetic growth phenotypes of Escherichia coli lacking ppGpp and transketolase A (tktA) are due to ppGpp‐mediated transcriptional regulation of tktB
Authors: Harinarayanan Rajendran , Murphy Helen , Cashel Michael
Published: June 2008

Many physiological adjustments to nutrient changes involve ppGpp. Recent attempts to deduce ppGpp regulatory effects using proteomics or gene profiling can rigorously identify proteins or transcripts, but the functional significance is often unclear. Using a random screen for synthetic lethals we found a ppGpp‐dependent functional pathway that operates through transketolase B (TktB), and which is ‘buffered’ in wildtype strain by the presence of an isozyme, transketolase A (TktA). Transketolase activity is required in cells to make erythrose‐4‐phosphate, a precursor of aromatic amino acids and vitamins. By studying tktB‐dependent nutritional requirements as well as measuring activities using PtalA‐tktB′‐lacZ transcriptional reporter fusion, we show positive transcriptional regulation of the talA‐tktB operon by ppGpp. Our results show the existence of RpoS‐dependent and RpoS‐independent modes of positive regulation by ppGpp. Both routes of activation are magnified by elevating ppGpp levels with a spoT mutation (spoT‐R39A) defective in hydrolase but not synthetase activity or with the stringent suppressor mutations rpoB‐A532Δ or rpoB‐T563P in the absence of ppGpp.
Different effect of Toxoplasma gondii infection on adhesion capacity of fibroblasts and monocytes
Authors: PFAFF A. W , GEORGES S. , CANDOLFI E.
Published: June 2008

This study investigated the effect of infection with the apicomplexan parasite Toxoplasma gondii, in combination with the concomitant cytokine environment (IFN‐γ/TNF‐α), on adhesion of THP‐1 monocytic cells to MRC‐5 fibroblasts. Surprisingly, infection of THP‐1 cells decreased their adhesion to the MRC‐5 cell monolayer. This decrease was compensated by IFN‐γ/TNF‐α stimulation. In contrast, infection of MRC‐5 cells significantly increased adhesion, which was synergistically augmented by cytokine stimulation. Levels of ICAM‐1 (CD54) on MRC‐5 cells, as well as LFA‐1 (CD11a) on THP‐1 cells, were not changed by infection, neither in resting, nor in cytokine stimulated cells. These results show that T. gondii infection alters adhesion properties and reactivity to cytokine stimulation in a cell‐specific way.
Osteomyelitis of the rib caused by Aspergillus flavus following cardiac surgery
Authors: Verghese Susan , Chellamma Thabitha , Cherian K. M.
Published: June 2008

Deep sternal wound infections are a rare but severe complication of coronary artery bypass graft (CABG) surgery, with an estimated prevalence of 1%–4%. We report a case of osteomyelitis of the rib and chest wall abscess caused by Aspergillus flavus in a CABG patient, which was treated successfully with voriconazole.
Candida dubliniensis: first identification in Sfax hospital, Tunisia
Authors: Khlif M. , Sellami H. , Sellami A. , Chelly H. , Makni F. , Bouaziz M. , Ayadi A.
Published: June 2008

Candida dubliniensis, a newly described fungal pathogen associated mainly to immunocompromised host’s infection, is phenotypically closely related to C. albicans. In this study, we report for the first time, isolation and identification, in Tunisia, of 14 isolates of C. dubliniensis from 12 human immunodeficiency virus‐negative patients hospitalised in the intensive care unit (ICU) at Habib Bourguiba Sfax Hospital. Our study was firstly based on the failure to grow at 45 °C. This presumptive identification was completed by other tests: chlamydospore production, culture on Candiselect4 (Bio‐Rad) and the commercial test Bichro‐Dubli fumouze®, which specifically identify C. dubliniensis. The confirmation of the discrimination between both species was performed by PCR, targeting the hyphal wall protein (HWP1) gene. The recovery of C. dublinensis by routine laboratory diagnosis is recommended for elucidating the epidemiology of this novel pathogen.
Endosonographic features of gastric ectopic pancreases distinguishable from mesenchymal tumors
Authors: Kim Jie‐Hyun , Lim Joon Seok , Lee Yong Chan , Hyung Woo Jin , Lee Jei Hee , Kim Myeong‐Jin , Chung Jae Bock
Published: June 2008

Background and Aims:  Gastric ectopic pancreas is the second common submucosal lesion in the stomach, and differs from mesenchymal tumors with respect to clinical approach and prognosis. The purpose of our study was to evaluate the endoscopic ultrasound (EUS) findings for differentiating between gastric ectopic pancreases and mesenchymal tumors.

Methods:  All patients (n = 71) were diagnosed pathologically as having gastric ectopic pancreas (n = 18) or mesenchymal tumors (n = 53) between 2002 and 2006. The EUS images of the patients were retrospectively reviewed by two observers who were unaware of the pathological results, regarding location, size, growth pattern, layer of origin, presence or absence of layer disruption, margin, and internal echo pattern. These EUS imaging findings were compared for ectopic pancreases and mesenchymal tumors.

Results:  Compared with mesenchymal tumors, ectopic pancreases showed a significant difference in the lesion location, growth pattern, layer of origin, presence of layer disruption, margin, and internal echo (P < 0.05). The longest/shortest diameter ratio was also larger in ectopic pancreases (p < 0.05). There was no statistical difference in the lesion size and presence of focal anechoic portion.

Conclusion:  Careful assessment of the EUS findings may be a useful aid in the differentiation of ectopic pancreases from mesenchymal tumors in the stomach.
Comparative cross‐over study of sildenafil and apomorphine for treating erectile dysfunction
Authors: Afif‐Abdo João , Teloken Claudio , Damião Ronaldo , Koff Walter , Wroclawski Eric , Yamasaki Rui , Torres Luiz Otávio , Sabaneeff Jorge , Faria Geraldo , Pompeo Antonio Carlos , Cortado Pedro , Glina Sidney
Published: June 2008

OBJECTIVE

To compare the effectiveness, safety and tolerability of sildenafil and apomorphine in Brazilian patients with erectile dysfunction (ED) of various causes.

PATIENTS AND METHODS

In all, 108 patients (mean age 55 years, sd 11) and documented ED for ≥6 months were included in 12 centres in Brazil. The patients were initially followed for 2 weeks and then randomized to initial treatment with apomorphine or sildenafil, taken before sexual intercourse, no more than once a day. The initial dose (2 mg apomorphine and 50 mg sildenafil) could be adjusted (to 3 mg apomorphine, or to 25 or 100 mg for sildenafil) depending on the effectiveness and tolerability during the first 4 weeks of treatment. The patients were re‐evaluated after 8 weeks on treatment and, after a wash‐out period of 2 weeks (no treatment), received the other study drug (other than that received in the first phase), and then had the same procedures as in the first phase.

RESULTS

In all, 97 patients were evaluated for therapeutic effectiveness, the overall effectiveness being assessed using two questions; sildenafil had a significantly higher proportion of affirmative answers for both (P < 0.001). Likewise, the estimates for the mean (sd) proportion of successful sexual intercourse, of 83.3 (4.7)% vs 40.3 (4.7)% and the total ED Inventory of Treatment Satisfaction score, of 86.7 (2.9) vs 56.9 (2.9) (P < 0.001) were higher for sildenafil. At the end of the study, 93.8% of the patients randomized to initial therapy with apomorphine declared a preference for sildenafil, and 81.3% of those initially treated with sildenafil declared a preference for that drug. The two drugs were well tolerated, and the main adverse events for apomorphine were nausea, vomiting, headache, taste perversion and dizziness; for sildenafil they were headache, flushing or vasodilatation, abdominal pain or dyspepsia and nasal congestion.

CONCLUSIONS

Sildenafil is more effective than apomorphine for treating ED, in the domains of erectile function, satisfaction with sexual intercourse and overall satisfaction, and was the drug preferred by most of the patients.
Towards molecular breeding of reproductive traits in cereal crops
Authors: Dwivedi Sangam , Perotti Enrico , Ortiz Rodomiro
Published: June 2008

The transition from vegetative to reproductive phase, floweringper se, floral organ development, panicle structure and morphology, meiosis, pollination and fertilization, cytoplasmic male sterility (CMS) and fertility restoration, and grain development are the main reproductive traits. Unlocking their genetic insights will enable plant breeders to manipulate these traits in cereal germplasm enhancement. Multiple genes or quantitative trait loci (QTLs) affecting flowering (phase transition, photoperiod and vernalization, floweringper se), panicle morphology and grain development have been cloned, and gene expression research has provided new information about the nature of complex genetic networks involved in the expression of these traits. Molecular biology is also facilitating the identification of diverse CMS sources in hybrid breeding. FewRf(fertility restorer) genes have been cloned in maize, rice and sorghum. DNA markers are now used to assess the genetic purity of hybrids and their parental lines, and to pyramidRfortms(thermosensitive male sterility) genes in rice. Transgene(s) can be used to createde novoCMS trait in cereals. The understanding of reproductive biology facilitated by functional genomics will allow a better manipulation of genes by crop breeders and their potential use across species through genetic transformation.
Asymmetry and Gradient Asymmetry Functions: Density‐Based Skewness and Kurtosis
Authors: CRITCHLEY FRANK , JONES M. C.
Published: June 2008

Abstract. Functional measures of skewness and kurtosis, called asymmetry and gradient asymmetry functions, are described for continuous univariate unimodal distributions. They are defined and interpreted directly in terms of the density function and its derivative. Asymmetry is defined by comparing distances from points of equal density to the mode. Gradient asymmetry is defined, in novel fashion, as asymmetry of an appropriate function of the density derivative. Properties and illustrations of asymmetry and gradient asymmetry functions are presented. Estimation of them is considered and illustrated with an example. Scalar summary skewness and kurtosis measures associated with asymmetry and gradient asymmetry functions are discussed.
Uniform in Bandwidth Estimation of Integral Functionals of the Density Function
Authors: GINÉ EVARIST , MASON DAVID M.
Published: June 2008

Abstract.  We apply recent results on local U‐statistics to obtain uniform in bandwidth consistency and central limit theorems for some commonly used estimators of integral functionals of density functions.
LOW‐INCOME HOUSING IN INDIAN CITIES: SOME CONSIDERATIONS FOR POLICY
Authors: Bawa Zainab , Shah Parth J.
Published: June 2008

Across cities in India, migrant groups, squatters and the urban poor residing in slums have played a crucial role in developing low‐income housing. This form of housing is closely connected to the economic activity of the poor, which in turn contributes to the wider urban economy. It also enables the poor to consolidate their position in the city and make claims on the city administration for infrastructure. However, such housing has been bracketed as ‘informal’ and lacks legitimacy. Policies concerning low‐income housing must address this issue while enabling the poor to further their economic and entrepreneurial initiatives.
AN ETHICAL ASSESSMENT OF THE USE OF ECONOMIC SANCTIONS AS A TOOL OF FOREIGN POLICY
Authors: Rarick Charles A. , Duchatelet Martine
Published: June 2008

This paper is the third in a series of articles that examines the shortcomings of economic sanctions. Drawing on Mill's utilitarianism, Kant's categorical imperative and Rawls's theory of justice, the conceptual frameworks of consequentialism, deontology and contractualism are used to demonstrate the unethical nature of this increasingly popular instrument of foreign policy.
BUYING LOCAL IS NOT NECESSARILY GREEN
Authors: Lilico Andrew
Published: June 2008

Environmentalists are urging consumers to stop buying imports that needed to be transported long distances. However, the domestic production of the same goods would typically involve a much greater use of resources and therefore be counter‐productive.
HIGH COTTON: WHY THE USA SHOULD NOT PROVIDE SUBSIDIES TO COTTON FARMERS
Authors: Helling Madeline , Beaulier Scott , Hall Joshua
Published: June 2008

Trade theorists agree that barriers to trade are declining. Still more progress could be made if trade barriers and government interventions were eliminated. One area in which government interference can and should be vastly reduced is that of agricultural production in general and US cotton production in particular.
FRIEDRICH HAYEK: THE COMPLETE ECONOMIST
Authors: Steele G. R.
Published: June 2008

By the width of his perspective, Hayek presents a challenge. Those who face up to that challenge are changed by the experience. The inevitable conclusion is that mainstream economics is defective by both its self‐indulgent over‐quantification and its persistence in presuming to formulate meaningful relationships between aggregates and averages.
‘I just sit there’: shyness as an emotional and behavioural problem in school
Authors: Lund Ingrid
Published: June 2008

Shyness is not unlike many psychological constructs in that it connotes a rich cluster of behaviours, cognitions, feelings and bodily reactions. But when adolescents’ shyness creates keen sensitivity to cues of being rejected, preventing them from speaking up for their rights and expressing their own opinions, thereby encouraging self‐consciousness and excessive preoccupation with their emotions, it becomes a problem for both these adolescents and their surroundings. This paper presents 10 adolescents’ experiences of being shy in a school context to such a degree that it is regarded as being a behavioural and emotional problem. In light of elements from an existential‐phenomenological understanding, challenges and remedial measures for these adolescents as well as their peers and teachers are discussed. Finally, focus will be placed on how teachers can promote good relationships and working environments and in this manner prevent shyness from becoming a behavioural and emotional problem in school.
Umbilical cord plasma homocysteine concentrations at delivery in pregnancies complicated by pre‐eclampsia
Authors: NAPOLITANO Peter G. , WAKEFIELD Charles L. , ELLIOTT Dawn E. , DOHERTY Dorota A. , MAGANN Everett F.
Published: June 2008

Aim: To determine whether homocysteine concentrations in umbilical cord plasma of neonates born to mothers with pre‐eclampsia are elevated compared to concentrations in neonates born to normotensive women.

Method: Maternal blood from eight women with pre‐eclampsia and ten women without pre‐eclampsia was collected on admission for labour. Cord blood was collected from these same pregnancies at delivery. Plasma was extracted and stored at −70°C. Samples were batch‐analysed for homocysteine.

Result: Maternal plasma homocysteine levels were observed to be significantly higher in the pregnancies complicated by pre‐eclampsia compared to the control pregnancies (P = 0.043) with median levels of 5.4 µmol/L (interquartile range (IQR) 4.6–7.9; range 3.6–16.7) versus 4.1 µmol/L (IQR 3.4–5.1, range 3.1–6.7). Homocysteine concentrations in umbilical cord plasma in pregnancies complicated by pre‐eclampsia were also significantly higher compared to those in normotensive pregnancies (P = 0.016) with median concentration levels of 5.3 µmol/L (IQR 4.8–7.2, range 2.5–16.6) versus 3.8 µmol/L (IQR 2.8–4.4, range 0.8–1.6).

Conclusion: Both maternal and umbilical cord plasma homocysteine concentrations were elevated in pregnancies complicated by pre‐eclampsia compared to normotensive controls.
Symptoms of female pelvic organ prolapse: Correlation with organ descent in women with single compartment prolapse
Authors: BLAIN Gemma , DIETZ Hans Peter
Published: June 2008

Background: Female pelvic organ prolapse is a common condition that often leads to surgical intervention to alleviate symptoms. The relationship between symptoms of prolapse and pelvic organ descent however, remains unclear.

Aim: To determine the correlation between the symptom of a vaginal lump and objective measures of female pelvic organ descent.

Methods: Women seen at a tertiary urogynaecological unit were assessed using an interview, clinical examination, multichannel urodynamics and ultrasound imaging for symptoms of urinary dysfunction and pelvic organ prolapse. Receiver‐operating characteristic curves were developed to determine the correlation between a vaginal lump and pelvic organ prolapse on ultrasound and clinical assessment. In order to reduce the confounding effect of prolapse in other than the reference compartment, we included only patients with a prolapse that showed one compartment clearly dominant.

Results: A total of 1022 women were evaluated, of which 299 (29%) reported the symptom of a vaginal lump. The area under the curve for cystocele on ultrasound and clinical examination was 0.86 and 0.89, respectively. For rectocele, the areas were 0.81 for ultrasound and 0.89 for examination. The low number of women with an isolated uterine prolapse or enterocele limits the significance of the results for those two groups.

Conclusion:  The symptom of a vaginal lump correlates strongly with the degree of female pelvic organ prolapse as ascertained on clinical examination and ultrasound imaging. Ultrasound and clinical examination perform very well as tests for predicting symptomatic prolapse, provided that the confounding effect of other compartments is accounted for.
Alcohol and pregnancy: The pivotal role of the obstetrician
Authors: ELLIOTT Elizabeth J. , BOWER Carol
Published: June 2008

New draft alcohol guidelines for Australia state that, for pregnant women and women planning pregnancy, ‘no drinking is the safest option’. One of the best known adverse effects of alcohol exposure on the fetus is the fetal alcohol syndrome. Others include alcohol‐related birth defects, alcohol‐related neurodevelopmental disorders and increased risks of miscarriage, stillbirth, intrauterine growth restriction, preterm birth and low birthweight. Over half of Australian women consume alcohol during pregnancy. Obstetricians have a pivotal role in advising women of the effects of alcohol on the fetus and reducing fetal exposure.
The urethral motion profile: A novel method to evaluate urethral support and mobility
Authors: SHEK Ka Lai , DIETZ Hans Peter
Published: June 2008

Background: Urethral hypermobility is one of the theories developed to explain stress urinary incontinence. Traumatic damage to urethral supports during vaginal childbirth may be an important contributor.

Aims: To establish a methodology to study urethral mobility, to determine the urethral motion profile in a cohort of young nulliparous women, and to determine changes in urethral mobility after childbirth.

Methods: Ultrasound volume datasets of 44 nulligravidae and the 4D antepartum and post‐partum datasets of 73 nulliparous women were assessed using post‐processing software. Volumes were acquired translabially, at rest and on Valsalva, after voiding while supine. We marked six equidistant points from bladder neck to external urethral meatus and determined the position of these points relative to the inferoposterior symphyseal margin. Mobility vector distances for these points were determined by the formula √{(Vy − Ry)2+ (Vx − Rx)2} (V = Valsalva; R = rest). Reproducibility was determined in a test–retest series of 21 patients. Changes in urethral mobility after delivery were determined by comparing antepartum and post‐partum mobility vectors.

Results: The method was highly reproducible, with an intraclass correlation coefficient of 0.80 (confidence interval 0.73–0.86) for mobility vectors. The distal urethra was consistently found to be less mobile than the proximal part (P < 0.001). After childbirth, urethal mobility was significantly increased in five out of six segments. There was a trend towards more marked changes in mobility after vaginal operative delivery.

Conclusions: Urethral mobility can be studied using 3D/4D translabial ultrasound. There is an increase in urethral mobility after childbirth, especially after instrumental delivery, suggesting an alteration in urethral support. This increase in mobility seems to affect the entire urethra.