bluuebunny/crossref_metadata_2025 huggingface dataset:
AiiA, an enzyme that inactivates the acylhomoserine lactone quorum-sensing signal and attenuates the virulence of
Erwinia carotovora
Authors: Dong Yi-Hu , Xu Jin-Ling , Li Xian-Zhen , Zhang Lian-Hui
Published: July 2012

N
-acylhomoserine lactones, known as autoinducers (AIs), are widely conserved signal molecules present in quorum-sensing systems of many Gram-negative bacteria. AIs are involved in the regulation of diverse biological functions, including expression of pathogenic genes in the plant pathogens
Pseudomonas solanacearum
, several
Erwinia
species, and the human pathogen
Pseudomonas aeruginosa
. A bacterial isolate,
Bacillus
sp. 240B1, is capable of enzymatic inactivation of AIs. The gene (
aiiA
) for AI inactivation from
Bacillus
sp. 240B1 has been cloned and shown to encode a protein of 250 amino acids. Sequence alignment indicates that AiiA contains a “HXHXDH” zinc-binding motif that is conserved in several groups of metallohydrolases. Site-directed mutagenesis showed that conserved aspartate and most histidine residues are required for AiiA activity. Expression of
aiiA
in transformed
Erwinia carotovora
strain SCG1 significantly reduces the release of AI, decreases extracellular pectolytic enzyme activities, and attenuates pathogenicity on potato, eggplant, Chinese cabbage, carrot, celery, cauliflower, and tobacco. Our results indicate that the AI-inactivation approach represents a promising strategy for prevention of diseases in which virulence is regulated by AIs.
Reelin secretion from glutamatergic neurons in culture is independent from neurotransmitter regulation
Authors: Lacor Pascale N. , Grayson Dennis R. , Auta James , Sugaya Ikuko , Costa Erminio , Guidotti Alessandro
Published: July 2012

Reelin (Reln) is a glycoprotein that in postnatal and adult mammalian brain is believed to be secreted from telencephalic GABAergic interneurons and cerebellar glutamatergic granule neurons into the extracellular matrix. To address the question of whether Reln neurosecretion occurs via a regulated or a constitutive process, we exposed postnatal rat cerebellar granule neurons (CGNs) maintained in culture for 7–9 days to: (
i
) 100 μM
N-
methyl-
d
-aspartate (NMDA) in a Mg
+2
-free medium to stimulate NMDA-selective glutamate receptors and Ca
2+
-dependent neurotransmitter release, (
ii
) 50 mM KCl to depolarize the cells and elicit Ca
2+
-dependent exocytosis, (
iii
) 10–100 μM nicotine to activate excocytosis by nicotinic receptors present in these cells, (
iv
) 10 μM 1,2,3,4-tetrahydro-6-nitro-2,3-dioxo-benzo[f]quinoxaline-7-sulfonamide in combination with 10 μM dizocilpine to block α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid- and NMDA-preferring glutamate receptors activated by endogenously released glutamate, or (
v
) EGTA (5 mM) to virtually eliminate extracellular Ca
2+
and block Ca
2+
-dependent exocytosis. Although, CGNs express and secrete Reln (measured by quantitative immunoblotting), none of the above-mentioned conditions that control regulated exocytosis alters the stores or the rate of Reln release. In contrast, application of either: (
i
) a Reln antisense oligonucleotide (5′-GCAATGTGCAGGGAAATG-3′) (10 μM) that reduces Reln biosynthesis or (
ii
) brefeldin A (5 × 10
−5
M), an inhibitor of the traffic of proteins between the endoplasmic reticulum and the Golgi network, sharply curtail the rate of Reln secretion. Because, in subcellular fractionation studies, we have shown that Reln is not contained in synaptic vesicles, these data suggest that Reln secretion from CGNs does not require Ca
2+
-dependent exocytosis, but probably is related to a Reln pool stored in Golgi secretory vesicles mediating a constitutive secretory pathway.
A resource model of the neural basis of executive working memory
Authors: Bunge Silvia A. , Klingberg Torkel , Jacobsen Richard B. , Gabrieli John D. E.
Published: July 2012

Working memory (WM) refers to the temporary storage and processing of goal-relevant information. WM is thought to include domain-specific short-term memory stores and executive processes, such as coordination, that operate on the contents of WM. To examine the neural substrates of coordination, we acquired functional magnetic resonance imaging data while subjects performed a WM span test designed specifically to measure executive WM. Subjects performed two tasks (sentence reading and short-term memory for five words) either separately or concurrently. Dual-task performance activated frontal-lobe areas to a greater extent than performance of either task in isolation, but no new area was activated beyond those activated by either component task. These findings support a resource theory of WM executive processes in the frontal lobes.
Human neuronal threonine-for-leucine-248 α7 mutant nicotinic acetylcholine receptors are highly Ca
2+
permeable
Authors: Fucile S. , Palma E. , Mileo A. M. , Miledi R. , Eusebi F.
Published: July 2012

A cDNA coding for the human neuronal nicotinic α7 receptor subunit with Leu-248 mutated to threonine was expressed in
Xenopus
oocytes. When activated by acetylcholine (AcCho), the receptors expressed generated currents that had low desensitization, linear current–voltage relation, and high apparent affinity for both AcCho and nicotine. These characteristics are similar to those already described for the chick threonine-for-leucine-247 α7 nicotinic AcCho receptor (nAcChoR) mutant (L247Tα7). These properties were all substantially maintained when the human L248Tα7 mutant was transiently expressed in human Bosc 23 cells. Simultaneous whole-cell clamp and fluorescence measurements with the Ca
2+
indicator dye Fura-2 showed that nicotine induced a Ca
2+
influx in standard 2 mM Ca
2+
solution. The average fractional Ca
2+
current flowing through L248Tα7 nAcChoRs was 6.7%, which is larger than that flowing through muscle αβɛδ nAcChoRs (4.1%). The relative Ca
2+
permeability, determined in oocytes in the absence of Cl
−
, was measured from the shift in reversal potential caused by increasing the external Ca
2+
concentration from 1 to 10 mM. The human wild-type α7 nAcChoR was found to be more permeable than the L248Tα7 mutant to Ca
2+
. Our findings indicate that the Ca
2+
permeability of the
homomeric
α7 nAcChoR is larger than that of the
heteromeric
neuronal nicotinic receptors studied to date and is possibly similar to that of the
N
-methyl-
d
-aspartate subtype of brain glutamate receptors.
Distribution of mRNA for vanilloid receptor subtype 1 (VR1), and VR1-like immunoreactivity, in the central nervous system of the rat and human
Authors: Mezey Éva , Tóth Zsuzsanna E. , Cortright Daniel N. , Arzubi Michelle K. , Krause James E. , Elde Robert , Guo Athena , Blumberg Peter M. , Szallasi Arpad
Published: July 2012

The cloned vanilloid receptor VR1 has attracted recent attention as a molecular integrator of painful stimuli on primary sensory neurons. The existence of vanilloid-sensitive neurons in the brain is, however, controversial. In this study, we have used an antibody and a complementary RNA probe to explore the distribution of neurons that express VR1 in rat and in certain areas of human brain. In the rat, we observed VR1-expressing neurons throughout the whole neuroaxis, including all cortical areas (in layers 3 and 5), several members of the limbic system (e.g., hippocampus, central amygdala, and both medial and lateral habenula), striatum, hypothalamus, centromedian and paraventricular thalamic nuclei, substantia nigra, reticular formation, locus coeruleus, cerebellum, and inferior olive. VR1-immunopositive cells also were found in the third and fifth layers of human parietal cortex. Reverse transcription–PCR performed with rat VR1-specific primers verified the expression of VR1 mRNA in cortex, hippocampus, and hypothalamus. In the central nervous system, neonatal capsaicin treatment depleted VR1 mRNA from the spinal nucleus of the trigeminal nerve, but not from other areas such as the inferior olive. The finding that VR1 is expressed not only in primary sensory neurons but also in several brain nuclei is of great importance in that it places VRs in a much broader perspective than pain perception. VRs in the brain (and putative endogenous vanilloids) may be involved in the control of emotions, learning, and satiety, just to name a few exciting possibilities.
Antagonists of alcohol inhibition of cell adhesion
Authors: Wilkemeyer Michael F. , Sebastian Anita B. , Smith Sherri A. , Charness Michael E.
Published: July 2012

Increasing evidence suggests that alcohols act within specific binding pockets of selective neural proteins; however, antagonists at these sites have not been identified. 1-Alcohols from methanol through 1-butanol inhibit with increasing potency the cell–cell adhesion mediated by the immunoglobulin cell adhesion molecule L1. An abrupt cutoff exists after 1-butanol, with 1-pentanol and higher 1-alcohols showing no effect. Here, we demonstrate surprisingly strict structural requirements for alcohol inhibition of cell–cell adhesion in L1-transfected NIH 3T3 fibroblasts and in NG108–15 neuroblastoma × glioma hybrid cells treated with BMP-7, an inducer of L1 and neural cell adhesion molecule. The target site discriminates the tertiary structure of straight-chain and branched-chain alcohols and appears to comprise both a hydrophobic binding site and an adjacent hydrophilic allosteric site. Modifications to the 2- and 3-carbon positions of 1-butanol increased potency, whereas modifications that restrict movement about the 4-carbon abolished activity. The effects of ethanol and 1-butanol on cell–cell adhesion were antagonized by 1-pentanol (IC
50
= 715 μM) and 1-octanol (IC
50
= 3.6 μM). Antagonism by 1-octanol was complete, reversible, and noncompetitive. 1-Octanol also antagonized ethanol inhibition of BMP-7 morphogenesis in NG108–15 cells. 1-Octanol and related compounds may prove useful in dissecting the role of altered cell adhesion in ethanol-induced injury of the nervous system.
Molecular cloning and characterization of a distinct human phosphodiesterase gene family: PDE11A
Authors: Fawcett Lindsay , Baxendale Rhona , Stacey Peter , McGrouther Collette , Harrow Ian , Soderling Scott , Hetman Joanna , Beavo Joseph A. , Phillips Stephen C.
Published: July 2012

We report here the cloning, expression, and characterization of human PDE11A1, a member of a distinct cyclic nucleotide phosphodiesterase (PDE) family. PDE11A exhibits ≤50% amino acid identity with the catalytic domains of all other PDEs, being most similar to PDE5, and has distinct biochemical properties. The human PDE11A1 cDNA isolated contains a complete open reading frame encoding a 490-amino acid enzyme with a predicted molecular mass of 55,786 Da. At the N terminus PDE11A1 has a single GAF domain homologous to that found in other signaling molecules, including PDE2, PDE5, PDE6, and PDE10, which constitutes a potential allosteric binding site for cGMP or another small ligand. Tissue distribution studies indicate that PDE11A mRNA occurs at highest levels in skeletal muscle, prostate, kidney, liver, pituitary, and salivary glands and testis. PDE11A is expressed as at least three major transcripts of ≈10.5, ≈8.5, and ≈6.0 kb, thus suggesting the existence of multiple subtypes. This possibility is further supported by the detection of three distinct proteins of ≈78, ≈65, and ≈56 kDa by Western blotting of human tissues for PDE11A isoforms. Recombinant human PDE11A1 hydrolyzes both cGMP and cAMP with
K
m
values of 0.52 μM and 1.04 μM, respectively, and similar
V
max
values. Therefore, PDE11A represents a dual-substrate PDE that may regulate both cGMP and cAMP under physiological conditions. PDE11A is sensitive to the nonselective PDE inhibitor 3-isobutyl-1-methylxanthine (IBMX) as well as zaprinast and dipyridamole, inhibitors that are generally considered relatively specific for the cGMP-selective PDEs, with IC
50
values of 49.8 μM, 12.0 μM, and 0.37 μM, respectively.
TheSlocus glycoprotein and theSreceptor kinase are sufficient for self-pollen rejection inBrassica
Authors: Cui Yuhai , Bi Yong-Mei , Brugière Norbert , Arnoldo MaryAnne , Rothstein Steven J.
Published: July 2012

Self-incompatibility (SI) is one of several mechanisms that have evolved to prevent inbreeding in plants. SI inBrassicais controlled by the polymorphicSlocus complex. TwoSlocus-encoded proteins are coordinately expressed in the stigma epidermis: the cell wall-localizedSlocus glycoprotein (SLG) and the plasma membrane-anchoredSreceptor kinase (SRK). These proteins are thought to recognize a pollen factor that leads to the rejection of self-pollen. Evidence has accumulated that indicates that both proteins are necessary for the ability of the stigma to inhibit self-pollen. However, it has not been possible to prove this necessity definitively or to demonstrate that these genes are sufficient for this phenotype, because previous attempts to transfer this phenotype via transformation have not been successful. In this study, two overlappingSlocus genomic clones, which cover ≈55 kilobases of DNA and contain theSLG,SRK, and an anther-expressed gene in the region common to the two, were introduced into a self-compatibleBrassica napusline. The resulting transgenic plants were shown to carry the female part of the SI phenotype, rejecting pollen in a haplotype-specific manner. However, the pollen SI phenotype was not found in any of the transgenic plants. These data show that the SLG and SRK are sufficient for the female side but not the male side of the SI phenotype inBrassicaand that there must be an independent pollenSfactor encoded outside the cloned region.
The
Arabidopsis
SOS2 protein kinase physically interacts with and is activated by the calcium-binding protein SOS3
Authors: Halfter Ursula , Ishitani Manabu , Zhu Jian-Kang
Published: July 2012

The
Arabidopsis thaliana SOS2
and
SOS3
genes are required for intracellular Na
+
and K
+
homeostasis and plant tolerance to high Na
+
and low K
+
environments. SOS3 is an EF hand type calcium-binding protein having sequence similarities with animal neuronal calcium sensors and the yeast calcineurin B. SOS2 is a serine/threonine protein kinase in the SNF1/AMPK family. We report here that SOS3 physically interacts with and activates SOS2 protein kinase. Genetically,
sos2sos3
double mutant analysis indicates that
SOS2
and
SOS3
function in the same pathway. Biochemically, SOS2 interacts with SOS3 in the yeast two-hybrid system and
in vitro
binding assays. The interaction is mediated by the C-terminal regulatory domain of SOS2. SOS3 activates SOS2 protein kinase activity in a Ca
2+
-dependent manner. Therefore, SOS3 and SOS2 define a novel regulatory pathway important for the control of intracellular ion homeostasis and salt tolerance in plants.
A comparison of naïve and sophisticated subject behavior with game theoretic predictions
Authors: McCabe Kevin A. , Smith Vernon L.
Published: July 2012

We use an extensive form two-person game as the basis for two experiments designed to compare the behavior of two groups of subjects with each other and with the subgame perfect theoretical prediction in an anonymous interaction protocol. The two subject groups are undergraduates and advanced graduate students, the latter having studied economics and game theory. There is no difference in their choice behavior, and both groups depart substantially from game theoretic predictions. We also compare a subsample of the same graduate students with a typical undergraduate sample in an asset trading environment in which inexperienced undergraduates invariably produce substantial departures from the rational expectations prediction. In this way, we examine how robust are the results across two distinct anonymous interactive environments. In the constant sum trading game, the graduate students closely track the predictions of rational theory. Our interpretation is that the graduate student subjects' departure from subgame perfection to achieve cooperative outcomes in the two-person bargaining game is a consequence of a deliberate strategy and is not the result of error or inadequate learning.
INTRA-EU MIGRATION FROM SLOVAKIA
Authors: Bahna Miloslav
Published: July 2012

This paper focuses on migration from Slovakia in the context of migration from the 10 countries which became European Union members in May 2004. While on the aggregate level these migration flows confirm the basic assumptions of the neoclassic migration theory, this study tests if insights from the new economics of labour migration (NELM) and migrant network theory are confirmed by those movements. Contrary to Mexico–US migration, such theory evaluation is rather rare in European migration research which is probably caused by the requirement of detailed and reliable datasets. We try to overcome this inconvenience by using Labour Force Survey data. Those data include the necessary information about the households of migrants that can be used to test for predicted interactions. We show on post 2004 labour migration from Slovakia that foreign employment of a household member creates remittance flows and, as expected by the NELM theory, improves the income situation of the household. However, remittances are produced only if the migrating household members are in the position of parents. This finding has consequences for remittance estimations as most of the post accession migration are single young migrants. The existence of intra- and trans-generational migrant networks is also confirmed by our multivariate analysis. While both types of network effects are gender specific, the gender factor seems to be stronger in the case of trans-generational networks. Besides the strong and significant influence of networks that increase the odds of migration to a destination where migrant family members are present, we found preliminary evidence of a ‘culture of migration’ in the households of migrants.
Portuguese adults' physical activity during different periods of the year
Authors: Bento Teresa Cunha , Romero Félix , Leitão José Carlos , Mota Maria Paula
Published: July 2012

This study aims to describe the daily physical activity (PA) of a sample of adults over the course of 1 year and to examine if there are any changes in achieving PA recommendations when assessed at different periods of the year. Participants, 257 women (age: 58.99±18.93 years, BMI: 26.75±4.57 kg m−2) and 178 men (age: 49.22±20.39 years, BMI: 26.81±3.51 kg m−2), wore an accelerometer 4–7 days. Periods of data collection were defined as T1 (September to December), T2 (January to April) and T3 (May to July). From T1 and T2, men from 20 to 39 years significantly increased values of daily average ct.min−1 (U=506, p=0.012), due to an increase in moderate‐to‐vigorous PA by 15.96 min (U=455, p=0.003). Achievement of the two PA recommendations varied throughout the year and among the gender/age groups. Results from this study showed that women generally maintain their level of PA throughout the year, whereas men show some variation, and that there are periods of the year when individuals are more likely to be involved in PA, or perform lower‐intensity activities, especially older age groups. Also, recommendations of minimum PA are not accomplished in a constant way throughout the year. PA interventions should be conducted while being mindful of the time of year in which they will take place in order to help maintain a consistent PA level throughout the year to ensure health benefits from PA.
Sharp Adams-type inequalities in ℝⁿ
Authors: Ruf Bernhard , Sani Federica
Published: July 2012

Adams’ inequality for bounded domains

Ω
⊂

R

4

\Omega \subset \mathbb {R}^4

states that the supremum of

∫

Ω

e

32

π
2

u
2

d
x

\int _{\Omega } e^{32 \pi ^2 u^2} \, dx

over all functions

u
∈

W
0

2
,

2

(
Ω
)

u \in W_0^{2, \, 2}(\Omega )

with

‖
Δ
u

‖
2

≤
1

\| \Delta u\|_2 \leq 1

is bounded by a constant depending on

Ω
\Omega

only. This bound becomes infinite for unbounded domains and in particular for

R

4

\mathbb {R}^4

.

We prove that if

‖
Δ
u

‖
2

\|\Delta u\|_2

is replaced by a suitable norm, namely

‖
u
‖
:=
‖
−
Δ
u
+
u

‖
2

\| u \|:=\|- \Delta u + u\|_2

, then the supremum of

∫

Ω

(

e

32

π
2

u
2

−
1
)

d
x

\int _{\Omega } (e^{32 \pi ^2 u^2} -1) \, dx

over all functions

u
∈

W
0

2
,

2

(
Ω
)

u \in W_0^{2, \, 2}(\Omega )

with

‖
u
‖
≤
1

\|u\| \leq 1

is bounded by a constant independent of the domain

Ω
\Omega

.

Furthermore, we generalize this result to any

W
0

m
,

n
m

(
Ω
)

W_0^{m, \, \frac n m}(\Omega )

with

Ω
⊆

R

n

\Omega \subseteq \mathbb {R}^{n}

and

m
m

an even integer less than

n
n

.
Some spectral applications of McMullen’s Hausdorff dimension algorithm
Authors: Gittins K. , Peyerimhoff N. , Stoiciu M. , Wirosoetisno D.
Published: July 2012

Using McMullen’s Hausdorff dimension algorithm, we study numerically the dimension of the limit set of groups generated by reflections along three geodesics on the hyperbolic plane. Varying these geodesics, we found four minima in the two-dimensional parameter space, leading to a rigorous result why this must be so. Extending the algorithm to compute the limit measure and its moments, we study orthogonal polynomials on the unit circle associated with this measure. Several numerical observations on certain coefficients related to these moments and on the zeros of the polynomials are discussed.
Bacterial GRAS domain proteins throw new light on gibberellic acid response mechanisms
Authors: Zhang Dapeng , Iyer Lakshminarayan M. , Aravind L.
Published: July 2012

Summary: Gibberellic acids (GAs) are key plant hormones, regulating various aspects of growth and development, which have been at the center of the ‘green revolution’. GRAS family proteins, the primary players in GA signaling pathways, remain poorly understood. Using sequence-profile searches, structural comparisons and phylogenetic analysis, we establish that the GRAS family first emerged in bacteria and belongs to the Rossmann fold methyltransferase superfamily. All bacterial and a subset of plant GRAS proteins are likely to function as small-molecule methylases. The remaining plant versions have lost one or more AdoMet (SAM)-binding residues while preserving their substrate-binding residues. We predict that GRAS proteins might either modify or bind small molecules such as GAs or their derivatives.

Contact:  aravind@ncbi.nlm.nih.gov

Supplementary Information:  Supplementary Material for this article is available at Bioinformatics online.
A quantitative comparison of the diets of sympatric pelagic sharks in gulf and shelf ecosystems off southern Australia
Authors: Rogers Paul J. , Huveneers Charlie , Page Brad , Hamer Derek J. , Goldsworthy Simon D. , Mitchell James G. , Seuront Laurent
Published: July 2012

Rogers, P. J., Huveneers, C., Page, B., Hamer, D. J., Goldsworthy, S. D., Mitchell, J. G., and Seuront, L. 2012. A quantitative comparison of the diets of sympatric pelagic sharks in gulf and shelf ecosystems off southern Australia. – ICES Journal of Marine Science, 69: . Predator–prey dynamics represent an important determinant in the functioning of marine ecosystems. This study provides the first quantitative investigation of the diets of sympatric pelagic shark species in gulf and shelf waters off southern Australia. Stomachs of 417 sharks collected from fishery catches between 2007 and 2011 were examined, including 250 bronze whalers, 52 shortfin makos, 49 dusky sharks, 39 smooth hammerheads, and 27 common threshers. Dusky sharks had the highest dietary diversity of the five species examined. We found overlap in the consumption of cephalopods, small pelagic teleosts, crustaceans, and benthic teleosts in bronze whalers, dusky sharks, and smooth hammerheads, and preliminary evidence of specialization in the highly migratory species, the common thresher and the shortfin mako. Findings were discussed and compared with previous studies in other temperate marine ecosystems. This study will significantly improve the understanding of the ecological roles of these top predators in the gulf and shelf habitats off southern Australia, and enhance the ecosystem models being developed for this unique bioregion.
Spatial contagion drives colonization and recruitment of frogflies on clutches of red-eyed treefrogs
Authors: Hughey Myra C. , McCoy Michael W. , Vonesh James R. , Warkentin Karen M.
Published: July 2012

Spatial contagion occurs when the perceived suitability of neighbouring habitat patches is not independent. As a result, organisms may colonize less-preferred patches near preferred patches and avoid preferred patches near non-preferred patches. Spatial contagion may thus alter colonization dynamics as well as the type and frequency of post-colonization interactions. Studies have only recently documented the phenomenon of spatial contagion and begun to examine its consequences for local recruitment. Here, we test for spatial contagion in the colonization of arboreal egg clutches of red-eyed treefrogs by a frogfly and examine the consequences of contagion for fly recruitment. In laboratory choice experiments, flies oviposit almost exclusively on clutches containing dead frog eggs. In nature, however, flies often colonize intact clutches without dead eggs. Consistent with predictions of contagion-induced oviposition, we found that flies more frequently colonize intact clutches near damaged clutches and rarely colonize intact clutches near other intact clutches. Moreover, contagion appears to benefit flies. Flies survived equally well and suffered less parasitism on clutches lacking dead eggs. This study demonstrates how reward contagion can influence colonization dynamics and suggests that colonization patterns caused by contagion may have important population- and community-level consequences.
Variation in carotenoid–protein interaction in bird feathers produces novel plumage coloration
Authors: Mendes-Pinto Maria M. , LaFountain Amy M. , Stoddard Mary Caswell , Prum Richard O. , Frank Harry A. , Robert Bruno
Published: July 2012

Light absorption by carotenoids is known to vary substantially with the shape or conformation of the pigment molecule induced by the molecular environment, but the role of interactions between carotenoid pigments and the proteins to which they are bound, and the resulting impact on organismal coloration, remain unclear. Here, we present a spectroscopic investigation of feathers from the brilliant red scarlet ibis (Eudocimus ruber,Threskiornithidae), the orange-red summer tanager (Piranga rubra,Cardinalidae) and the violet-purple feathers of the white-browed purpletuft (Iodopleura isabellae,Tityridae). Despite their striking differences in colour, all three of these feathers contain canthaxanthin (β,β-carotene-4,4′-dione) as their primary pigment. Reflectance and resonance Raman (rR) spectroscopy were used to investigate the induced molecular structural changes and carotenoid–protein interactions responsible for the different coloration in these plumage samples. The results demonstrate a significant variation between species in the peak frequency of the strong ethylenic vibration (ν1) peak in the rR spectra, the most significant of which is found inI. isabellaefeathers and is correlated with a red-shift in canthaxanthin absorption that results in violet reflectance. Neither polarizability of the protein environment nor planarization of the molecule upon binding can entirely account for the full extent of the colour shift. Therefore, we suggest that head-to-tail molecular alignment (i.e. J-aggregation) of the protein-bound carotenoid molecules is an additional factor.
Tool durability maps for friction stir welding of an aluminium alloy
Authors: DebRoy T. , De A. , Bhadeshia H. K. D. H. , Manvatkar V. D. , Arora A.
Published: July 2012

Friction stir welding is not used for hard alloys because of premature tool failure. A scheme is created that exploits the physical three-dimensional heat and mass flow models, and implements them into a fast calculation algorithm, which, when combined with damage accumulation models, enables the plotting of tool durability maps that define the domains of satisfactory tool life. It is shown that fatigue is an unlikely mechanism for tool failure, particularly for the welding of thin plates. Plate thickness, welding speed, tool rotational speed, shoulder, and pin diameters and pin length all affect the stresses and temperatures experienced by the tool. The large number of these variables makes the experimental determination of their effects on stresses and temperatures intractable and the use of a well-tested, efficient friction stir welding model a realistic undertaking. An artificial neural network that is trained and tested with results from a phenomenological model is used to generate tool durability maps that show the ratio of the shear strength of the tool material to the maximum shear stress on the tool pin for various combinations of welding variables. These maps show how the thicker plates and faster welding speeds adversely affect tool durability and how that can be optimized.
Maternal effects in disease resistance: poor maternal environment increases offspring resistance to an insect virus
Authors: Boots Mike , Roberts Katherine E.
Published: July 2012

Maternal effects can be adaptive and because of their intrinsic time delays may have important effects on population dynamics. In vertebrates, and increasingly invertebrates, it is well established that offspring defence is in part determined by maternal parasite exposure. It has also been suggested that there may be indirect maternal effects on immunity mediated by other components of the maternal environment, including density and resource availability. Here, we examine the effect maternal resource availability has on the immunity of offspring in an insect—virus system. We use five different maternal resource levels and examine immunity in the offspring both directly, by challenge with a virus, and by measuring a major component of the immune system, across three offspring environments. Both the direct infection assay and the measure of immunocompetence show clearly that offspring from mothers in poor environments are more resistant to parasites. This may result from life-history optimization of mothers in poor environments, or because the poor environment acts as a cue for higher disease risk in the next generation. This emphasizes the importance of maternal effects on disease resistance, mediated through indirect environmental factors that will have important implications to both the ecological and evolutionary dynamics of host–parasite interactions.
Abdicating power for control: a precision timing strategy to modulate function of flight power muscles
Authors: Sponberg S. , Daniel T. L.
Published: July 2012

Muscles driving rhythmic locomotion typically show strong dependence of power on the timing or phase of activation. This is particularly true in insects' main flight muscles, canonical examples of muscles thought to have a dedicated power function. However, in the moth (Manduca sexta), these muscles normally activate at a phase where the instantaneous slope of the power–phase curve is steep and well below maximum power. We provide four lines of evidence demonstrating that, contrary to the current paradigm, the moth's nervous system establishes significant control authority in these muscles through precise timing modulation: (i) left–right pairs of flight muscles normally fire precisely, within 0.5–0.6 ms of each other; (ii) during a yawing optomotor response, left—right muscle timing differences shift throughout a wider 8 ms timing window, enabling at least a 50 per cent left–right power differential; (iii) timing differences correlate with turning torque; and (iv) the downstroke power muscles alone causally account for 47 per cent of turning torque. To establish (iv), we altered muscle activation during intact behaviour by stimulating individual muscle potentials to impose left—right timing differences. Because many organisms also have muscles operating with high power–phase gains (Δpower/Δphase), this motor control strategy may be ubiquitous in locomotor systems.
Variability in solar radiation and temperature explains observed patterns and trends in tree growth rates across four tropical forests
Authors: Dong Shirley Xiaobi , Davies Stuart J. , Ashton Peter S. , Bunyavejchewin Sarayudh , Supardi M. N. Nur , Kassim Abd Rahman , Tan Sylvester , Moorcroft Paul R.
Published: July 2012

The response of tropical forests to global climate variability and change remains poorly understood. Results from long-term studies of permanent forest plots have reported different, and in some cases opposing trends in tropical forest dynamics. In this study, we examined changes in tree growth rates at four long-term permanent tropical forest research plots in relation to variation in solar radiation, temperature and precipitation. Temporal variation in the stand-level growth rates measured at five-year intervals was found to be positively correlated with variation in incoming solar radiation and negatively related to temporal variation in night-time temperatures. Taken alone, neither solar radiation variability nor the effects of night-time temperatures can account for the observed temporal variation in tree growth rates across sites, but when considered together, these two climate variables account for most of the observed temporal variability in tree growth rates. Further analysis indicates that the stand-level response is primarily driven by the responses of smaller-sized trees (less than 20 cm in diameter). The combined temperature and radiation responses identified in this study provide a potential explanation for the conflicting patterns in tree growth rates found in previous studies.
Roles of Four Arabidopsis U-Box E3 Ubiquitin Ligases in Negative Regulation of Abscisic Acid-Mediated Drought Stress Responses
Authors: Seo Dong Hye , Ryu Moon Young , Jammes Fabien , Hwang Jae Hwan , Turek Michelle , Kang Bin Goo , Kwak June M. , Kim Woo Taek
Published: July 2012

AtPUB18 and AtPUB19 are homologous U-box E3 ubiquitin ligases in Arabidopsis (Arabidopsis thaliana). AtPUB19 is a negative regulator of abscisic acid (ABA)-mediated drought responses, whereas the role of AtPUB18 in drought responses is unknown. Here, loss-of-function and overexpression tests identified AtPUB18 as a negative regulator in ABA-mediated stomatal closure and water stress responses. The atpub18-2atpub19-3 double mutant line displayed more sensitivity to ABA and enhanced drought tolerance than each single mutant plant; therefore, AtPUB18 and AtPUB19 are agonistic. Stomatal closure of the atpub18-2atpub19-3 mutant was hypersensitive to hydrogen peroxide (H2O2) but not to calcium, suggesting that AtPUB18 and AtPUB19 exert negative effects on the ABA signaling pathway downstream of H2O2 and upstream of calcium. AtPUB22 and AtPUB23 are other U-box E3 negative regulators of drought responses. Although atpub22atpub23 was more tolerant to drought stress relative to wild-type plants, its ABA-mediated stomatal movements were highly similar to those of wild-type plants. The atpub18-2atpub19-3atpub22atpub23 quadruple mutant exhibited enhanced tolerance to drought stress as compared with each atpub18-2atpub19-3 and atpub22atpub23 double mutant progeny; however, its stomatal behavior was almost identical to the atpub18-2atpub19-3 double mutant in the presence of ABA, H2O2, and calcium. Overexpression of AtPUB18 and AtPUB19 in atpub22atpub23 effectively hindered ABA-dependent stomatal closure, but overexpression of AtPUB22 and AtPUB23 in atpub18-2atpub19-3 did not inhibit ABA-enhanced stomatal closure, highlighting their ABA-independent roles. Overall, these results suggest that AtPUB18 has a linked function with AtPUB19, but is independent from AtPUB22 and AtPUB23, in negative regulation of ABA-mediated drought stress responses.
High‐throughput sequence analysis of small RNAs in grapevine (Vitis viniferaL.) affected by grapevine leafroll disease
Authors: Alabi Olufemi J. , Zheng Yun , Jagadeeswaran Guru , Sunkar Ramanjulu , Naidu Rayapati A.
Published: July 2012

Grapevine leafroll disease (GLRD) is one of the most economically important virus diseases of grapevine (Vitis spp.) worldwide. In this study, we used high‐throughput sequencing of cDNA libraries made from small RNAs (sRNAs) to compare profiles of sRNA populations recovered from own‐rooted Merlot grapevines with and without GLRD symptoms. The data revealed the presence of sRNAs specific to Grapevine leafroll‐associated virus 3, Hop stunt viroid (HpSVd), Grapevine yellow speckle viroid 1 (GYSVd‐1) and Grapevine yellow speckle viroid 2 (GYSVd‐2) in symptomatic grapevines and sRNAs specific only to HpSVd, GYSVd‐1 and GYSVd‐2 in nonsymptomatic grapevines. In addition to 135 previously identified conserved microRNAs in grapevine (Vvi‐miRs), we identified 10 novel and several candidate Vvi‐miRs in both symptomatic and nonsymptomatic grapevine leaves based on the cloning of miRNA star sequences. Quantitative real‐time reverse transcriptase‐polymerase chain reaction (RT‐PCR) of selected conserved Vvi‐miRs indicated that individual members of an miRNA family are differentially expressed in symptomatic and nonsymptomatic leaves. The high‐resolution mapping of sRNAs specific to an ampelovirus and three viroids in mixed infections, the identification of novel Vvi‐miRs and the modulation of certain conserved Vvi‐miRs offers resources for the further elucidation of compatible host–pathogen interactions and for the provision of ecologically relevant information to better understand host–pathogen–environment interactions in a perennial fruit crop.
Evaluation of North American isolates of Soybean mosaic virus for gain of virulence on Rsv‐genotype soybeans with special emphasis on resistance‐breaking determinants on Rsv4
Authors: Khatabi B. , Fajolu O. L. , Wen R.‐H. , Hajimorad M. R.
Published: July 2012

Resistance to Soybean mosaic virus (SMV) in soybean is conferred by three dominant genes: Rsv1, Rsv3 and Rsv4. Over the years, scientists in the USA have utilized a set of standard pathotypes, SMV‐G1 to SMV‐G7, to study interaction with Rsv‐genotype soybeans. However, these pathotypes were isolated from a collection of imported soybean germplasm over 30 years ago. In this study, 35 SMV field isolates collected in recent years from 11 states were evaluated for gain of virulence on soybean genotypes containing individual Rsv genes. All isolates were avirulent on L78‐379 (Rsv1), whereas 19 were virulent on L29 (Rsv3). On PI88788 (Rsv4), 14 of 15 isolates tested were virulent; however, only one was capable of systemically infecting all of the inoculated V94‐5152 (Rsv4). Nevertheless, virulent variants from 11 other field isolates were rapidly selected on initial inoculation onto V94‐5152 (Rsv4). The P3 cistrons of the original isolates and their variants on Rsv4‐genotype soybeans were sequenced. Analysis showed that virulence on PI88788 (Rsv4) was not associated, in general, with selection of any new amino acid, whereas Q1033K and G1054R substitutions were consistently selected on V94‐5152 (Rsv4). The role of Q1033K and G1054R substitutions, individually or in combination, in virulence on V94‐5152 (Rsv4) was confirmed on reconstruction in the P3 cistron of avirulent SMV‐N, followed by biolistic inoculation. Collectively, our data demonstrate that SMV has evolved virulence towards Rsv3 and Rsv4, but not Rsv1, in the USA. Furthermore, they confirm that SMV virulence determinants on V94‐5152 (Rsv4) reside on P3.
Effect of surgery under general anaesthesia on antipyrine clearance.
Authors: Pessayre D , Allemand H , Benoist C , Afifi F , Francois M , Benhamou JP
Published: July 2012

1 The effect of surgery under general anaesthesia on drug metabolism was investigated in man. The activity of hepatic drug‐metabolizing enzymes was evaluated by measurement of antipyrine clearance, before surgery and 3 days after surgery, in eighteen patients. 2 In those patients in whom the operation lasted 2 h or less, the postoperative clearance of antipyrine was significantly (P less than 0.05) increased by 48%; in those patients in whom the operation lasted 2–4 h, it was non‐significantly decreased by 36%; in those patients in whom the operation lasted more than 4 h, it was significantly decreased by 47% (P less than 0.01). 3 It is concluded (a) that short operations are followed by increased activity of hepatic drug‐metabolizing enzymes, whereas (b) protracted operations are followed by decreased activity. It is suggested (a) that the former effect may be a consequence of enzyme induction by drugs used for premedication and anaesthesia, whereas (b) the latter effect may be the result of major surgical trauma.
Studies of uptake of the bretylium analogue, iodobenzyltrimethylammonium iodide, by non‐primate, monkey and human hearts.
Authors: Carr EA , Carroll M , Counsell RE , Tyson JW
Published: July 2012

Uptake of (+/‐)‐[3H]‐noradrenaline, [14C]‐bretylium and [125I]‐o‐ iodobenzyltrimethylammonium iodide (RIBA) by rat heart was studied by the Langendorff technique. All three compounds showed significant uptake. 2 Corticosterone and 17‐beta‐oestradiol inhibited the uptake of all three compounds by rat heart, a finding consistent with extraneuronal uptake (uptake2). 3 [131I]‐RIBA was injected intravenously into pigs and monkeys (M. speciosus). Myocardial samples taken from pigs killed 1 and 2 h after injection showed significant uptake. No significant uptake was found in myocardial samples of monkeys killed 10 min, 2 h and 24 h, respectively, after injection. 4 Four normal human volunteers received [125I]‐RIBA intravenously and the image of the precordial area was followed by means of scintillation camera for the first 4 h after injection. In two of the subjects, the scintigrams were repeated at 22 and 23 h after injection, respectively. No evidence of myocardial uptake was observed. 5 These results suggest the possibility that man and at least one other primate species may differ from lower species with regard to uptake.
The effect of intravenous disopyramide phosphate on recurrent paroxysmal tachycardias.
Authors: Camm J , Ward D , Spurrell RA
Published: July 2012

1 Reccurent paroxysmal atrial, atrioventricular and ventricular tachycardias in 50 patients without acute coronary insufficiency, heart failure or metabolic abnormlity were treated with disopyramide phosphate in a dose of 2 mg/kg body weight infused over 5 min. 2 Conversion to sinus rhythm within 10 min of the completed infusion occurred in 10 of 14 (71%) patients with paroxysmal ‘lone’ atrial fibrillation, 3 of 7 (43%) patients with paroxysmal atrial flutter, 6 of 9 (67%) patients with paroxysmal atrial tachycardia, 5 of 9 (56%) patients with paroxysmal atrioventricular tachycardia associated with the Wolff‐Parkinson‐White syndrome and 8 of 11 (73%) patients with paroxysmal ventricular tachycardia. 3 Side effects: significant systemic hypotension in 3, high grade AV block in 1, an increased ventricular response producing symptoms in 4, post conversion asystole in 1 land sinus bradycardia in 2. 4 The anti‐arrhythmic effect and arrhythmogenic side effects may be related to both the direct membrane stabilizing effect and the anticholinergic effect of disopyramide.
Sequestration of chlordecone in the porous structure of an andosol and effects of added organic matter: an alternative to decontamination
Authors: Woignier T. , Fernandes P. , Jannoyer‐Lesueur M. , Soler A.
Published: July 2012

The context of this study is the pollution of soils and water by a persistent organo‐chlorinated insecticide, chlordecone, in a tropical environment. The application of chlordecone to control the banana black weevil has led to continuing diffuse pollution of soils, and to its being a source of contamination for cultivated plants, as well as for terrestrial and marine ecosystems. Chlordecone is toxic and stable and is considered to be a persistent organic pesticide. Consequently, the amounts of chlordecone that could migrate through the environment and contaminate agricultural products need to be controlled. We measured the impact of two composts (5% weight) on chlordecone sequestration in andosols. To this end, we first characterized the transfer of chlordecone from soil to water, and then its transfer from soil to plants. After 3 months of maturation, soil‐water and soil‐plant transfers were reduced by a factor of from 3 to 10. We also showed that adding compost to contaminated soils increases chlordecone sequestration because it leads to changes in soil microstructure in the form of pore collapse and closure of the fractal structure of the allophane content.
Tai Chi exercise and auricular acupressure for people with rheumatoid arthritis: an evaluation study
Authors: Lee Hea‐Young , Hale Claire A , Hemingway Beverley , Woolridge Michael W
Published: July 2012

Aims and objectives.  (i) To assess the effectiveness of Tai Chi exercise in people with rheumatoid arthritis (RA). (ii) To ascertain if Tai Chi and auricular acupressure have a potentiation effect in controlling pain. (iii) To evaluate the acceptability and enjoyment of the classes.

Background.  Tai Chi has been suggested as a suitable exercise for people with arthritis and specific programmes have been developed. Auricular acupressure is a therapeutic method by which points on the ear are stimulated to treat various disorders.

Design.  A pragmatic non‐randomised before/after study to compare the effects of the interventions.

Methods.  People with RA (n = 21) were recruited and allocated into two groups. Both groups followed a Tai Chi exercise programme, twice a week for 12 weeks, but one group (n = 14) had, in addition, the auricular acupressure. Physical symptoms and function, pain, quality of life and self‐efficacy were measured in both groups before and after the programme. Acceptability and enjoyment were assessed at the end.

Results.  At 12 weeks, both groups had achieved statistically significant improvements in balance, grip strength, pinch strength, 50 foot walk time self reported joint pain, swollen joint count, tender joint count and in self efficacy in relation to pain control. All participants stated that they enjoyed the classes. There was no evidence to suggest that the auricular acupressure enhanced the effects of the Tai Chi intervention.

Conclusion.  The classes appeared to be mentally as well as physically helpful to participants.

Relevance to clinical practice.  People with a chronic debilitating disease such as RA should be encouraged to undertake gentle strengthening exercise such as Tai Chi because of its potential for physical and psychological improvements.
Knowledge of blood transfusion among nurses
Authors: Hijji Belal , Parahoo Kader , Hussein Mohammad Moshaddeque , Barr Owen
Published: July 2012

Aims and objectives.  To measure nurses’ knowledge of blood transfusion in the United Arab Emirates.

Background.  Blood transfusion is a fundamental aspect of nursing practice and nurses’ knowledge of it is essential for safe practice. Yet little is known about their blood transfusion practice and the knowledge that underpins it. The few studies that have investigated this topic previously have shown deficiencies in both knowledge and practice. To date, no such study has been carried out in the Middle East.

Designs.  A descriptive, cross‐sectional study.

Methods.  A random sample of 248 nurses from two general hospitals in the Emirate of Abu Dhabi. The response rate was 94AE3%. A knowledge questionnaire comprising six sections and 49 items was developed for this study. Data were analysed using descriptive and inferential statistics.

Results.  The overall knowledge scores of nurses were generally low ranging from 27–56 of a possible score of 70. Data analysis revealed knowledge deficits in several key aspects of blood transfusion. There were statistically significant relationship between nurses’ knowledge and the work setting, the country where they trained and type of qualifications.

Conclusion.  This survey highlighted knowledge deficits which could be detrimental to patient safety. These results have implications for nursing education, policy and practice.

Relevance to clinical practice.  Nurses have the responsibility to update their knowledge of and skills in carrying out blood transfusion. The tool developed in this study may be useful for educators and managers to identify gaps in knowledge and inform decisions to address them.