bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of the gene encoding alkylglycerol monooxygenase defines a third class of tetrahydrobiopterin-dependent enzymes
Authors: Watschinger Katrin , Keller Markus A. , Golderer Georg , Hermann Martin , Maglione Manuel , Sarg Bettina , Lindner Herbert H. , Hermetter Albin , Werner-Felmayer Gabriele , Konrat Robert , Hulo Nicolas , Werner Ernst R.
Published: July 2010

Alkylglycerol monooxygenase (glyceryl-ether monooxygenase, EC 1.14.16.5) is the only enzyme known to cleave the O-alkyl bond of ether lipids which are essential components of brain membranes, protect the eye from cataract, interfere or mediate signalling processes, and are required for spermatogenesis. Along with phenylalanine hydroxylase, tyrosine hydroxylase, tryptophan hydroxylase, and nitric oxide synthase, alkylglycerol monooxygenase is one of five known enzymatic reactions which depend on tetrahydrobiopterin. Although first described in 1964, no sequence had been assigned to this enzyme so far since it lost activity upon protein purification attempts. A functional library screen using pools of plasmids of a rat liver expression library transfected to CHO cells was also unsuccessful. We therefore selected human candidate genes by bioinformatic approaches and by proteomic analysis of partially purified enzyme and tested alkylglycerol monooxygenase activity in CHO cells transfected with expression plasmids. Transmembrane protein 195, a predicted membrane protein with unassigned function which occurs in bilateral animals, was found to encode for tetrahydrobiopterin-dependent alkylglycerol monooxygenase. This sequence assignment was confirmed by injection of transmembrane protein 195 cRNA intoXenopus laevisoocytes. Transmembrane protein 195 shows no sequence homology to aromatic amino acid hydroxylases or nitric oxide synthases, but contains the fatty acid hydroxylase motif. This motif is found in enzymes which contain a diiron center and which carry out hydroxylations of lipids at aliphatic carbon atoms like alkylglycerol monooxygenase. This sequence assignment suggests that alkylglycerol monooxygenase forms a distinct third group among tetrahydrobiopterin-dependent enzymes.
Behavioral performance follows the time course of neural facilitation and suppression during cued shifts of feature-selective attention
Authors: Andersen S. K. , Müller M. M.
Published: July 2010

A central question in the field of attention is whether visual processing is a strictly limited resource, which must be allocated by selective attention. If this were the case, attentional enhancement of one stimulus should invariably lead to suppression of unattended distracter stimuli. Here we examine voluntary cued shifts of feature-selective attention to either one of two superimposed red or blue random dot kinematograms (RDKs) to test whether such a reciprocal relationship between enhancement of an attended and suppression of an unattended stimulus can be observed. The steady-state visual evoked potential (SSVEP), an oscillatory brain response elicited by the flickering RDKs, was measured in human EEG. Supporting limited resources, we observed both an enhancement of the attended and a suppression of the unattended RDK, but this observed reciprocity did not occur concurrently: enhancement of the attended RDK started at 220 ms after cue onset and preceded suppression of the unattended RDK by about 130 ms. Furthermore, we found that behavior was significantly correlated with the SSVEP time course of a measure of selectivity (attended minus unattended) but not with a measure of total activity (attended plus unattended). The significant deviations from a temporally synchronized reciprocity between enhancement and suppression suggest that the enhancement of the attended stimulus may cause the suppression of the unattended stimulus in the present experiment.
Low-dose, simple, and fast grating-based X-ray phase-contrast imaging
Authors: Zhu Peiping , Zhang Kai , Wang Zhili , Liu Yijin , Liu Xiaosong , Wu Ziyu , McDonald Samuel A. , Marone Federica , Stampanoni Marco
Published: July 2010

Phase sensitive X-ray imaging methods can provide substantially increased contrast over conventional absorption-based imaging and therefore new and otherwise inaccessible information. The use of gratings as optical elements in hard X-ray phase imaging overcomes some of the problems that have impaired the wider use of phase contrast in X-ray radiography and tomography. So far, to separate the phase information from other contributions detected with a grating interferometer, a phase-stepping approach has been considered, which implies the acquisition of multiple radiographic projections. Here we present an innovative, highly sensitive X-ray tomographic phase-contrast imaging approach based on grating interferometry, which extracts the phase-contrast signal without the need of phase stepping. Compared to the existing phase-stepping approach, the main advantages of this new method dubbed “reverse projection” are not only the significantly reduced delivered dose, without the degradation of the image quality, but also the much higher efficiency. The new technique sets the prerequisites for future fast and low-dose phase-contrast imaging methods, fundamental for imaging biological specimens and in vivo studies.
Systematic determination of order parameters for chain dynamics using diffusion maps
Authors: Ferguson Andrew L. , Panagiotopoulos Athanassios Z. , Debenedetti Pablo G. , Kevrekidis Ioannis G.
Published: July 2010

We employ the diffusion map approach as a nonlinear dimensionality reduction technique to extract a dynamically relevant, low-dimensional description ofn-alkane chains in the ideal-gas phase and in aqueous solution. In the case ofC8we find the dynamics to be governed by torsional motions. ForC16andC24we extract three global order parameters with which we characterize the fundamental dynamics, and determine that the low free-energy pathway of globular collapse proceeds by a “kink and slide” mechanism, whereby a bend near the end of the linear chain migrates toward the middle to form a hairpin and, ultimately, a coiled helix. The low-dimensional representation is subtly perturbed in the solvated phase relative to the ideal gas, and its geometric structure is conserved betweenC16andC24. The methodology is directly extensible to biomolecular self-assembly processes, such as protein folding.
Osteoinductive ceramics as a synthetic alternative to autologous bone grafting
Authors: Yuan Huipin , Fernandes Hugo , Habibovic Pamela , de Boer Jan , Barradas Ana M. C. , de Ruiter Ad , Walsh William R. , van Blitterswijk Clemens A. , de Bruijn Joost D.
Published: July 2010

Biomaterials can be endowed with biologically instructive properties by changing basic parameters such as elasticity and surface texture. However, translation from in vitro proof of concept to clinical application is largely missing. Porous calcium phosphate ceramics are used to treat small bone defects but in general do not induce stem cell differentiation, which is essential for regenerating large bone defects. Here, we prepared calcium phosphate ceramics with varying physicochemical and structural characteristics. Microporosity correlated to their propensity to stimulate osteogenic differentiation of stem cells in vitro and bone induction in vivo. Implantation in a large bone defect in sheep unequivocally demonstrated that osteoinductive ceramics are equally efficient in bone repair as autologous bone grafts. Our results provide proof of concept for the clinical application of “smart” biomaterials.
Combining metabolic and protein engineering of a terpenoid biosynthetic pathway for overproduction and selectivity control
Authors: Leonard Effendi , Ajikumar Parayil Kumaran , Thayer Kelly , Xiao Wen-Hai , Mo Jeffrey D. , Tidor Bruce , Stephanopoulos Gregory , Prather Kristala L. J.
Published: July 2010

A common strategy of metabolic engineering is to increase the endogenous supply of precursor metabolites to improve pathway productivity. The ability to further enhance heterologous production of a desired compound may be limited by the inherent capacity of the imported pathway to accommodate high precursor supply. Here, we present engineered diterpenoid biosynthesis as a case where insufficient downstream pathway capacity limits high-level levopimaradiene production in
Escherichia coli
. To increase levopimaradiene synthesis, we amplified the flux toward isopentenyl diphosphate and dimethylallyl diphosphate precursors and reprogrammed the rate-limiting downstream pathway by generating combinatorial mutations in geranylgeranyl diphosphate synthase and levopimaradiene synthase. The mutant library contained pathway variants that not only increased diterpenoid production but also tuned the selectivity toward levopimaradiene. The most productive pathway, combining precursor flux amplification and mutant synthases, conferred approximately 2,600-fold increase in levopimaradiene levels. A maximum titer of approximately 700 mg/L was subsequently obtained by cultivation in a bench-scale bioreactor. The present study highlights the importance of engineering proteins along with pathways as a key strategy in achieving microbial biosynthesis and overproduction of pharmaceutical and chemical products.
Vespertilionid bats control the width of their biosonar sound beam dynamically during prey pursuit
Authors: Jakobsen Lasse , Surlykke Annemarie
Published: July 2010

Animals using sound for communication emit directional signals, focusing most acoustic energy in one direction. Echolocating bats are listening for soft echoes from insects. Therefore, a directional biosonar sound beam greatly increases detection probability in the forward direction and decreases off-axis echoes. However, high directionality has context-specific disadvantages: at close range the detection space will be vastly reduced, making a broad beam favorable. Hence, a flexible system would be very advantageous. We investigated whether bats can dynamically change directionality of their biosonar during aerial pursuit of insects. We trained five
Myotis daubentonii
and one
Eptesicus serotinus
to capture tethered mealworms and recorded their echolocation signals with a multimicrophone array. The results show that the bats broaden the echolocation beam drastically in the terminal phase of prey pursuit.
M. daubentonii
increased the half-amplitude angle from approximately 40° to approximately 90° horizontally and from approximately 45° to more than 90° vertically. The increase in beam width is achieved by lowering the frequency by roughly one octave from approximately 55 kHz to approximately 27.5 kHz. The
E. serotinus
showed beam broadening remarkably similar to that of
M. daubentonii
. Our results demonstrate dynamic control of beam width in both species. Hence, we propose directionality as an explanation for the frequency decrease observed in the buzz of aerial hawking vespertilionid bats. We predict that future studies will reveal dynamic control of beam width in a broad range of acoustically communicating animals.
Catalyst-free synthesis of transparent, mesoporous diamond monoliths from periodic mesoporous carbon CMK-8
Authors: Zhang Li , Mohanty Paritosh , Coombs Neil , Fei Yingwei , Mao Ho-Kwang , Landskron Kai
Published: July 2010

We report on the synthesis of optically transparent, mesoporous, monolithic diamond from periodic mesoporous carbon CMK-8 at a pressure of 21 GPa. The phase transformation is already complete at a mild synthesis temperature of 1,300 °C without the need of a catalyst. Surprisingly, the diamond is obtained as a mesoporous material despite the extreme pressure. X-ray diffraction, SEM, transmission electron microscopy, selected area electron diffraction, high-resolution transmission electron microscopy, and Z-contrast experiments suggest that the mesoporous diamond is composed of interconnected diamond nanocrystals having diameters around 5–10 nm. The Brunauer Emmett Teller surface area was determined to be 33 m
2
 g
-1
according Kr sorption data. The mesostructure is diminished yet still detectable when the diamond is produced from CMK-8 at 1,600 °C and 21 GPa. The temperature dependence of the porosity indicates that the mesoporous diamond exists metastable and withstands transformation into a dense form at a significant rate due to its high kinetic inertness at the mild synthesis temperature. The findings point toward ultrahard porous materials with potential as mechanically highly stable membranes.
Recovery of functional and structural age-related changes in the rat primary auditory cortex with operant training
Authors: de Villers-Sidani Etienne , Alzghoul Loai , Zhou Xiaoming , Simpson Kimberly L. , Lin Rick C. S. , Merzenich Michael M.
Published: July 2010

Cognitive decline is a virtually universal aspect of the aging process. However, its neurophysiological basis remains poorly understood. We describe here more than 20 age-related cortical processing deficits in the primary auditory cortex of aging versus young rats that appear to be strongly contributed to by altered cortical inhibition. Consistent with these changes, we recorded in old rats a decrease in parvalbumin-labeled inhibitory cortical neurons. Furthermore, old rats were slower to master a simple behavior, with learning progressions marked by more false-positive responses. We then examined the effect of intensive auditory training on the primary auditory cortex in these aged rats by using an oddball discrimination task. Following training, we found a nearly complete reversal of the majority of previously observed functional and structural cortical impairments. These findings suggest that age-related cognitive decline is a tightly regulated plastic process, and demonstrate that most of these age-related changes are, by their fundamental nature, reversible.
Therapeutic potential of a synthetic lethal interaction between the
MYC
proto-oncogene and inhibition of aurora-B kinase
Authors: Yang Dun , Liu Hong , Goga Andrei , Kim Suwon , Yuneva Mariia , Bishop J. Michael
Published: July 2010

The Myc protein and proteins that participate in mitosis represent attractive targets for cancer therapy. However, their potential is presently compromised by the threat of side effects and by a lack of pharmacological inhibitors of Myc. Here we report that a circumscribed exposure to the aurora kinase inhibitor, VX-680, selectively kills cells that overexpress Myc. This synthetic lethal interaction is attributable to inhibition of aurora-B kinase, with consequent disabling of the chromosomal passenger protein complex (CPPC) and ensuing DNA replication in the absence of cell division; executed by sequential apoptosis and autophagy; not reliant on the tumor suppressor protein p53; and effective against mouse models for B-cell and T-cell lymphomas initiated by transgenes of
MYC
. Our findings cast light on how inhibitors of aurora-B kinase may kill tumor cells, implicate Myc in the induction of a lethal form of autophagy, indicate that expression of Myc be a useful biomarker for sensitivity of tumor cells to inhibition of the CPPC, dramatize the virtue of bimodal killing by a single therapeutic agent, and suggest a therapeutic strategy for killing tumor cells that overexpress Myc while sparing normal cells.
Rediscovery of the nucleolinus, a dynamic RNA-rich organelle associated with the nucleolus, spindle, and centrosomes
Authors: Alliegro Mary Anne , Henry Jonathan J. , Alliegro Mark C.
Published: July 2010

The nucleolinus is an RNA-rich compartment, closely apposed to or embedded within the nucleolus. Discovered over 150 y ago, fewer than two dozen articles have been published on the nucleolinus, probably because complex histochemical stains are required for its visualization in the great majority of cells. The nucleolinus has been reported in invertebrate oocytes, mammalian and amphibian epithelial cells, neurons, and several transformed cell lines. A prominent nucleolinus, clearly visible with transmitted light microscopes at 10× magnification, is present in each oocyte of the surf clam,
Spisula solidissima
. We observed a consistent relationship between the nucleolinus and the developing meiotic apparatus following
Spisula
oocyte activation. Through sonication and sucrose gradient fractionation of purified oocyte nuclei, we isolated nucleolini, extracted their RNA, and prepared an in situ riboprobe (NLi-1), which is associated specifically with the nucleolinus, confirming its unique composition. Other in situ observations revealed a NLi-1 and nucleolinar association with the developing spindle and centrosomes. Laser microsurgery that targeted the nucleolinus resulted in failed meiotic cell division in parthenogenetically activated oocytes and failed mitosis in fertilized oocytes. Although the nucleolinus may be a forgotten organelle, its demonstrated role in spindle formation suggests it deserves renewed attention.
Role of calpain-mediated p53 truncation in semaphorin 3A-induced axonal growth regulation
Authors: Qin Qingyu , Liao Guanghong , Baudry Michel , Bi Xiaoning
Published: July 2010

Neurite outgrowth represents a critical stage in the correct development of neuronal circuitries, and is dependent on the complex regulation of actin filament and microtubule dynamics by intrinsic as well as extrinsic signals. Previous studies have implicated the tumor suppressor factor, p53, in the regulation of axonal outgrowth through a nontranscriptional effect involving local regulation of the Rho kinase signaling pathway that controls these dynamics. In the present study, we first showed that semaphorin 3A-induced growth cone collapse in cultured hippocampal neurons was associated with the partial truncation of phosphorylated p53, and that both effects were prevented by calpain inhibition with either m-calpain–specific siRNA or inhibitors. We further determined that semaphorin 3A-mediated calpain activation and growth cone collapse were associated with m-calpain phosphorylation and prevented by inhibition of MAPK, ERK, or p38. In vitro studies confirmed that p53 and especially phosphorylated p53 were partially truncated by calpain. Thus, our results indicate that semaphorin 3A-mediated growth cone collapse is mediated in part by m-calpain activation, possibly through MAPK-mediated phosphorylation, and the resulting truncation of phosphorylated p53, leading to Rho kinase activation and cytoskeletal reorganization. They provide a pathway by which extrinsic signals regulate axonal growth through activation of m-calpain and p53 truncation.
Epigenetic centromere specification directs aurora B accumulation but is insufficient to efficiently correct mitotic errors
Authors: Bassett Emily A. , Wood Stacey , Salimian Kevan J. , Ajith Sandya , Foltz Daniel R. , Black Ben E.
Published: July 2010

The nearly ubiquitous presence of repetitive centromere DNA sequences across eukaryotic species is in paradoxical contrast to their apparent functional dispensability. Centromeric chromatin is spatially delineated into the kinetochore-forming array of centromere protein A (CENP-A)–containing nucleosomes and the inner centromeric heterochromatin that lacks CENP-A but recruits the aurora B kinase that is necessary for correcting erroneous attachments to the mitotic spindle. We found that the self-perpetuating network of CENPs at the foundation of the kinetochore is intact at a human neocentromere lacking repetitive α-satellite DNA. However, aurora B is inappropriately silenced as a consequence of the altered geometry of the neocentromere, thereby compromising the error correction mechanism. This suggests a model wherein the neocentromere represents a primordial inheritance locus that requires subsequent generation of a robust inner centromere compartment to enhance fidelity of chromosome transmission.
A guide to super-resolution fluorescence microscopy
Authors: Schermelleh Lothar , Heintzmann Rainer , Leonhardt Heinrich
Published: July 2010

For centuries, cell biology has been based on light microscopy and at the same time been limited by its optical resolution. However, several new technologies have been developed recently that bypass this limit. These new super-resolution technologies are either based on tailored illumination, nonlinear fluorophore responses, or the precise localization of single molecules. Overall, these new approaches have created unprecedented new possibilities to investigate the structure and function of cells.
An Analysis of the Pricing of Traits in the U.S. Corn Seed Market
Authors: Shi Guanming , Chavas Jean-paul , Stiegert Kyle
Published: July 2010

We investigate the pricing of traits in the U.S. corn seed market under imperfect competition. In a multiproduct context, we examine how substitution/complementarity relationships among products can affect pricing. This is used to motivate generalizations of the Herfindahl‐Hirschman index capturing cross‐market effects of imperfect competition on pricing. The model is applied to pricing of U.S. conventional and biotech seeds from 2000 to 2007. We reject the standard component pricing in biotech traits in favor of subadditive bundle pricing. The econometric estimates show how changes in market structure (as measured by both own‐ and cross‐Herfindahl indexes) affect U.S. corn seed prices.
Comprehensive analysis of karyotypic mosaicism between trophectoderm and inner cell mass
Authors: Johnson D.S. , Cinnioglu C. , Ross R. , Filby A. , Gemelos G. , Hill M. , Ryan A. , Smotrich D. , Rabinowitz M. , Murray M.J.
Published: July 2010

Aneuploidy has been well-documented in blastocyst embryos, but prior studies have been limited in scale and/or lack mechanistic data. We previously reported preclinical validation of microarray 24-chromosome preimplantation genetic screening in a 24-h protocol. The method diagnoses chromosome copy number, structural chromosome aberrations, parental source of aneuploidy and distinguishes certain meiotic from mitotic errors. In this study, our objective was to examine aneuploidy in human blastocysts and determine correspondence of karyotypes between trophectoderm (TE) and inner cell mass (ICM). We disaggregated 51 blastocysts from 17 couples into ICM and one or two TE fractions. The average maternal age was 31. Next, we ran 24-chromosome microarray molecular karyotyping on all of the samples, and then performed a retrospective analysis of the data. The average per-chromosome confidence was 99.95%. Approximately 80% of blastocysts were euploid. The majority of aneuploid embryos were simple aneuploid, i.e. one or two whole-chromosome imbalances. Structural chromosome aberrations, which are common in cleavage stage embryos, occurred in only three blastocysts (5.8%). All TE biopsies derived from the same embryos were concordant. Forty-nine of 51 (96.1%) ICM samples were concordant with TE biopsies derived from the same embryos. Discordance between TE and ICM occurred only in the two embryos with structural chromosome aberration. We conclude that TE karyotype is an excellent predictor of ICM karyotype. Discordance between TE and ICM occurred only in embryos with structural chromosome aberrations.
High-throughput cardiac science on the Grid
Authors: Abramson David , Bernabeu Miguel O. , Bethwaite Blair , Burrage Kevin , Corrias Alberto , Enticott Colin , Garic Slavisa , Gavaghan David , Peachey Tom , Pitt-Francis J. , Pueyo E. , Rodriguez Blanca , Sher Anna , Tan Jefferson
Published: July 2010

Cardiac electrophysiology is a mature discipline, with the first model of a cardiac cell action potential having been developed in 1962. Current models range from single ion channels, through very complex models of individual cardiac cells, to geometrically and anatomically detailed models of the electrical activity in whole ventricles. A critical issue for model developers is how to choose parameters that allow the model to faithfully reproduce observed physiological effects without over-fitting. In this paper, we discuss the use of a parametric modelling toolkit, called N
imrod
, that makes it possible both to explore model behaviour as parameters are changed and also to tune parameters by optimizing model output. Importantly, N
imrod
leverages computers on the Grid, accelerating experiments by using available high-performance platforms. We illustrate the use of N
imrod
with two case studies, one at the cardiac tissue level and one at the cellular level.
CaMsrB2, Pepper Methionine Sulfoxide Reductase B2, Is a Novel Defense Regulator against Oxidative Stress and Pathogen Attack
Authors: Oh Sang-Keun , Baek Kwang-Hyun , Seong Eun Soo , Joung Young Hee , Choi Gyung-Ja , Park Jeong Mee , Cho Hye Sun , Kim Eun Ah , Lee Sangku , Choi Doil
Published: July 2010

Reactive oxygen species (ROS) are inevitably generated in aerobic organisms as by-products of normal metabolism or as the result of defense and development. ROS readily oxidize methionine (Met) residues in proteins/peptides to form Met-R-sulfoxide or Met-S-sulfoxide, causing inactivation or malfunction of the proteins. A pepper (Capsicum annuum) methionine sulfoxide reductase B2 gene (CaMsrB2) was isolated, and its roles in plant defense were studied. CaMsrB2 was down-regulated upon inoculation with either incompatible or compatible pathogens. The down-regulation, however, was restored to the original expression levels only in a compatible interaction. Gain-of-function studies using tomato (Solanum lycopersicum) plants transformed with CaMsrB2 resulted in enhanced resistance to Phytophthora capsici and Phytophthora infestans. Inversely, loss-of-function studies of CaMsrB2 using virus-induced gene silencing in pepper plants (cv Early Calwonder-30R) resulted in accelerated cell death from an incompatible bacterial pathogen, Xanthomonas axonopodis pv vesicatoria (Xav) race 1, and enhanced susceptibility to a compatible bacterial pathogen, virulent X. axonopodis pv vesicatoria race 3. Measurement of ROS levels in CaMsrB2-silenced pepper plants revealed that suppression of CaMsrB2 increased the production of ROS, which in turn resulted in the acceleration of cell death via accumulation of ROS. In contrast, the CaMsrB2-transgenic tomato plants showed reduced production of hydrogen peroxide. Taken together, our results suggest that the plant MsrBs have novel functions in active defense against pathogens via the regulation of cell redox status.
Identification and characterization of a Vibrio mimicus gene encoding the heme/hemoglobin receptor
Authors: Tanabe Tomotaka , Funahashi Tatsuya , Moon Yong‐Hwa , Tamai Eiji , Yamamoto Shigeo
Published: July 2010

The present authors have previously reported that Vibrio mimicus expresses 77‐kDa and 80‐kDa outer membrane proteins in response to iron‐limited conditions, and that the 77‐kDa protein serves as the receptor for ferriaerobactin. In this study, it was found that V. mimicus can use heme and hemoglobin as iron sources. FURTA was then applied to V. mimicus 7PT to obtain candidate gene fragments involved in utilization of heme and hemoglobin. One FURTA‐positive clone was shown to contain a partial gene, whose predicted amino acid sequence correlated with the N‐terminal amino acid sequence determined for the 80‐kDa outer membrane protein and also shared homology with heme/hemoglobin receptors of Gram‐negative bacteria. Based on this information, the entire gene (named mhuA), and a gene upstream of mhuA (named mhuB) encoding a LysR family of transcriptional activator, were cloned and analyzed. RNA analysis indicated that mhuA and mhuB are each transcribed from individual Fur‐regulated promoters. Moreover, RNA analysis of an mhuB deletion mutant and a promoter reporter assay coupled with β‐galactosidase suggested that MhuB could function as an activator for mhuA transcription. Finally, the role of MhuA as the heme/hemoglobin receptor was confirmed by construction of an mhuA deletion mutant and its complemented strain followed by growth assay.
Not all ants are equal: obligate acacia ants provide different levels of protection against mega‐herbivores
Authors: Martins Dino J.
Published: July 2010

In obligate ant–plant mutualisms, the asymmetric engagement of a single plant species with multiple ant species provides the opportunity for partners to vary in their behaviour. Variation in behaviour has implications for the interactions with third‐party species such as herbivores. This study assessed the effect of obligate ant‐mutualists (Crematogaster mimosae, Crematogaster nigriceps and Tetraponera penzigi) inhabiting the African ant‐acacia (Acacia drepanolobium) on three mega‐herbivore browsers: the Maasai giraffe (Giraffa camelopardalis tippelskirchi), the reticulated giraffe (Giraffa c. reticulata) and the black rhino (Diceros bicornis). Giraffes are abundant and wide‐ranging herbivores of the acacias, whereas black rhinos are localized and perennial herbivores of the acacias. Multiyear field studies comparing the ants’ aggressive behaviour and browsing by mega‐herbivores suggested differences between the tending abilities of the primary ant species inhabiting A. drepanolobium. Trees occupied by the aggressive ant species C. mimosae had significantly less browsing by giraffes and black rhino than trees occupied by other ant species. The results of this study provide evidence that ant‐mutualists on African acacias can serve as deterrents to mega‐herbivores and that different ant species vary in their tending abilities.
ORIGINAL ARTICLE: Optimal timing for the administration of intranasal dexmedetomidine for premedication in children
Authors: Yuen V. M. , Hui Theresa W. , Irwin M. G. , Yao T.‐J. , Wong G. L. , Yuen M. K.
Published: July 2010

Previous studies have shown that 1 μg.kg−1 intranasal dexmedetomidine produces significant sedation in children aged between 2 and 12 years. This investigation was designed to evaluate the onset time. One hundred children aged 1–12 years of ASA physical status 1–2 undergoing elective surgery were randomly allocated to five groups. Patients in groups A to D received intranasal dexmedetomidine 1 μg.kg−1. Patients in Group E received intranasal placebo (0.9% saline). Children from groups A, B, C, D and E had intravenous cannulation attempted at 30, 45, 60, 75 and 45 min respectively after intranasal drug or placebo administration. Vital signs, behaviour and sedation status of the children were assessed regularly until induction of anaesthesia. More children from groups A to D achieved satisfactory sedation at the time of cannulation when compared to group E (p < 0.001). The proportion of children who achieved satisfactory sedation was not significantly different among groups A to D. Overall 62% of the children who received intranasal dexmedetomidine had satisfactory sedation at the time of cannulation. The median (95% CI) time for onset of sedation was 25 (25–30) min. The median (95% CI) duration of sedation was 85 (55–100) min.
Can you shrinkwrap a cow? Protections available for the intellectual property of the animal breeding industry
Authors: Ogden E. R. , Weigel K.
Published: July 2010

There are currently four main intellectual property protection statutory schemes available: copyright, trade secret, trademark and patent. Each of these protects a different aspect of intellectual property, which leaves gaps of protection when an innovation does not fit squarely within the boundaries of the statutes. Contracts allow the industry to tailor the protection desired. One very common approach is to license the product via contract. Licences allow intellectual property owners to retain ownership and give permission to others to use the product. Although there are several types of licences, the most common is the field of use licence, which limits the licensee's use of the product. This often leads to price discrimination where various levels of restriction are offered at corresponding prices. The more rights retained by the owner, the more restricted the buyer is and the lower the purchase price allowing customers to choose the level of restriction they are willing to accept. Therefore, the different uses and needs of various customers can be accounted for and reflected in the price. The animal breeding industry is currently struggling to protect their innovations falling into these statutory gaps. The protection for animal breeding industry innovations is most likely through contract law rather than traditional intellectual property law. By taking advantage of the unique nature of contracts, industry will be able to tailor protection and pricing to best suit the variety of customers and uses for the products sold.
Genes affecting coat colour and pattern in domestic dogs: a review
Authors: Schmutz S. M. , Berryere T. G.
Published: July 2010

Tremendous progress has been made in identifying genes involved in pigmentation in dogs in the past few years. Comparative genomics has both aided and benefited from these findings. Seven genes that cause specific coat colours and/or patterns in dogs have been identified: melanocortin 1 receptor, tyrosinase related protein 1, agouti signal peptide, melanophilin, SILV (formerly PMEL17), microphthalmia‐associated transcription factor and beta‐defensin 103. Although not all alleles have been yet identified at each locus, DNA tests are available for many. The identification of these alleles has provided information on interactions in this complex set of genes involved in both pigmentation and neurological development. The review also discusses pleiotropic effects of some coat colour genes as they relate to disease. The alleles found in various breeds have shed light on some potential breed development histories and phylogenetic relationships. The information is of value to dog breeders who have selected for and against specific colours since breed standards and dog showing began in the late 1800s. Because coat colour is such a visible trait, this information will also be a valuable teaching resource.
The emotional labour of caring about looked‐after children
Authors: Leeson Caroline
Published: July 2010

Quality relationships form the backbone of social work with children and their families. They are particularly relevant in the close, intimate work with looked‐after children who have identified how important it is to them that their relationship with their social worker is positive, warm and meaningful. It is accepted that in order to achieve and maintain successful and meaningful relationships, practitioners need to engage at an emotional as well as a professional level. All too often this requires a trade‐off between organizational efficiency and the emotional work of caring for looked‐after children. Therefore, it would appear the role of corporate parent is increasingly difficult, involving complex decisions about how practitioners might best spend their time, where their loyalties lie and the quality and direction of the final output. Using data from a series of interviews with practitioners, this paper explores the difficulties of maintaining active emotional engagement with children using the sociological concept of emotional labour.
Use of HR‐NMR to classify propolis obtained using different harvesting methods
Authors: Papotti Giulia , Bertelli Davide , Plessi Maria , Rossi Maria Cecilia
Published: July 2010

Propolis has various biological activities closely related to the composition which varies according to environmental factors and also to the method of production. This study was aimed at determining whether or not HR‐NMR and multivariate statistical analysis were able to classify propolis according to the method used to harvest it. Sixty propolis samples were analysed in all. The ethanolic propolis extracts were initially analysed for quantification of the main bioactive substances, balsams and waxes. The 1H NMR and heteronuclear multiple bond correlation spectra were then acquired. Spectral data were analysed by the application of multivariate statistical techniques (Factor Analysis and General Discriminant Analysis). The best results were obtained using the 1H NMR which furnishes a sufficiently effective model by analysing the spectral region between 4.50 and 13.00 ppm (predictive capacity: 96.7%).
Influence of pH, NaCl and pre‐incubation on utilisation of surimi wash water in generation of antioxidative material by using the Maillard reaction
Authors: Thongraung Chakree , Kangsanan Sureeporn
Published: July 2010

Maillard reaction products (MRPs) were generated from reaction mixtures of surimi wash water (SWW) with glucose or fructose (5%w/v) heated at 95 °C for 2–12 h. The effects of pH, NaCl and pre‐incubation of SWW on the Maillard reaction and antioxidant capacity of MRPs were investigated. The antioxidative capacity of MRPs was determined by measuring free DPPH° radical scavenging activity and reducing power. The highest colour intensity (OD420) as well as antioxidative capacity was noted in the reaction mixture containing fructose at pH 9.0. The addition of NaCl (0.5–2.5%w/v) caused reduction in browning intensity but enhanced antioxidative capacity of the MRPs. Pre‐incubation of SWW at 45 °C for 4 h decreased soluble protein but increased the Maillard reaction and antioxidative capacity of MRPs. A positive effect of salt or pre‐incubation of SWW on the antioxidative capacity of MRPs was not associated with the soluble protein content in the reaction mixture.
Psychrophilic and psychrotrophic clostridia: sporulation and germination processes and their role in the spoilage of chilled, vacuum‐packaged beef, lamb and venison
Authors: Adam Katharine H. , Flint Steve H. , Brightwell Gale
Published: July 2010

Spoilage of beef, lamb and venison by psychrophilic and psychrotrophic clostridial species renders meat unacceptable resulting in financial losses and reduced consumer confidence. A number of clostridial strains, including Clostridium algidicarnis, Clostridium algidixylanolyticum, Clostridium estertheticum, Clostridium frigidicarnis and Clostridium gasigenes, have been implicated in red meat spoilage. Unlike other spoilers, these clostridia are able to grow in anaerobic conditions and at chilled temperatures (some at −1.5 °C the optimal storage temperature for chilled red meat). The spoilage they cause is characterised by softening of the meat, production of large amounts of drip (exudates), offensive odours and in the case of C. estertheticum and C. gasigenes production of gas. Spoilage occurs following the introduction of clostridial spores into vacuum packages during processing. Germination of spores is necessary for the growth of vegetative cells, which cause spoilage. Current mitigation strategies focus on good management practice within meat processing plants. However, this is not always sufficient to prevent spoilage. This review summarises the issues associated with meat spoilage because of psychrotolerant clostridia and discusses areas that require further study.
The capability of rosemary extract in preventing oxidation of fish lipid
Authors: Ozogul Yesim , Ayas Deniz , Yazgan Hatice , Ozogul Fatih , Boga Esmeray K. , Ozyurt Gulsun
Published: July 2010

The effects of rosemary extract at different levels (%1, R1, and %2, R2) on the quality of vacuum‐packed sardine in terms of sensory, biochemical (thiobarbituric acid, total volatile basic nitrogen, peroxide value and free fatty acids) and microbiological analyses (total viable counts) were investigated. Fish were filleted and divided into three groups. First group was used as the control (C) without rosemary extract, second group was treated with 1% rosemary extracts (10 g L−1) for 2 min (R1), and the third was treated with 2% rosemary extracts (20 g L−1) for 2 min (R2). Thirty fillets per litre were used. After that, all groups were vacuum‐packed in polyethylene bags. The samples were stored in the refrigerator condition (4 ± 1 °C) over the storage period of 20 days. The results showed that the use of rosemary extract improved the sensory quality of both raw and cooked sardine, most preferably sardine treated with 1% of rosemary. Biochemical analysis showed that the use of 2% of rosemary extract were found to be most effective (P < 0.05) in controlling the rate of lipid oxidation.
Kinetics of ascorbic acid degradation and colour change in ground cashew apples treated at high temperatures (100–180 °C)
Authors: Lima Janice R. , Elizondo Nadiarid J. , Bohuon Philippe
Published: July 2010

Ascorbic acid (AA) degradation and colour changes, measured by the lightness index (L*), were determined in cashew apples (at low dissolved O2 concentrations) heated at high temperature (100–180 °C) in a hermetically sealed cell. A nonisothermal method was developed to estimate thermal degradation kinetics. The results showed that reaction kinetics during heat treatments were well represented by first‐order reactions. The temperature dependence of the kinetic constants was described by an Arrhenius type equation. The activation energy (Ea) for AA degradation and lightness index were 94 ± 3 and 98 ± 3 kJ mol−1, respectively. The reaction rate constant at 140 °C for AA degradation (64 × 10−5 ± 3 × 10−5 s−1) was twice that for the lightness index change (33 × 10−5 ± 2 × 10−5 s−1). Results allow generating temperature profiles of heat processes that would help preserve the AA of cashew apples as well as control the colour formation during high‐temperature processes.
A phylogenetic approach to disentangling the role of competition and habitat filtering in community assembly of Neotropical forest birds
Authors: Gómez Juan Pablo , Bravo Gustavo A. , Brumfield Robb T. , Tello José G. , Cadena Carlos Daniel
Published: July 2010

1. Methods that assess patterns of phylogenetic relatedness, as well as character distribution and evolution, allow one to infer the ecological processes involved in community assembly. Assuming niche conservatism, assemblages should shift from phylogenetic clustering to evenness with decreasing geographic scale because the relative importance of mechanisms that shape assemblages is hypothesized to be scale‐dependent. Whereas habitat filtering is more likely to act at regional scales because of increased habitat heterogeneity that allows sorting of ecologically similar species in contrasting environments, competition is more likely to act at local scales because low habitat heterogeneity provides few opportunities for niche partitioning.

2. We used species lists to assess assemblage composition, data on ecologically‐relevant traits, and a molecular phylogeny, to examine the phylogenetic structure of antbird (Thamnophilidae) assemblages at three different geographical scales: regional (ecoregions), intermediate (100‐ha plots) and local (mixed‐flocks). In addition, we used patterns of phylogenetic beta diversity and beta diversity to separate the factors that structure antbird assemblages at regional scales.

3. Contrary to previous findings, we found a shift from phylogenetic evenness to clustering with decreasing geographical scale. We argue that this does not reject the hypothesis that habitat filtering is the predominant force in regional community assembly, because analyses of trait evolution and structure indicated a lack of niche conservatism in antbirds.

4. In some cases, phylogenetic evenness at regional scales can be an effect of historical biogeographic processes instead of niche‐based processes. However, regional patterns of beta diversity and phylogenetic beta diversity suggested that phylogenetic structure in our study cannot be explained by the history of speciation and dispersal of antbirds, further supporting the habitat‐filtering hypothesis.

5. Our analyses suggested that competitive interactions might not play an important role locally, which would provide a plausible explanation for the high alpha diversity of antbirds in Amazonia.

6. Finally, we emphasize the importance of including trait information in studies of phylogenetic community structure to adequately assess the mechanisms that determine species co‐existence.
The influence of dispersal on macroecological patterns of Lesser Antillean birds
Authors: Dexter Kyle Graham
Published: July 2010

Aim  Dispersal is often assumed to be a major force in shaping macroecological patterns, but this is rarely tested. Here I describe macroecological patterns for two groups of Lesser Antillean birds and then use population genetic data to assess if differences in dispersal ability could be responsible for the groups’ contrasting patterns. Importantly, the population genetic data are derived independently from any data used to generate the macroecological patterns.

Location  The Lesser Antilles, Caribbean.

Methods  I used data from the literature to construct species–area curves and evaluate the decline in species compositional similarity with geographic distance (hereafter distance–decay) for two sets of bird communities in the Lesser Antilles, those found in rain forest and those in dry forest. I then used mitochondrial DNA sequences from island populations to assess the dispersal ability of rain forest and dry forest species.

Results  Rain forest species show steeper species–area curves and greater distance–decay in community similarity than dry forest species, patterns that could be explained by rain forest species having more limited dispersal ability. Both conventional analyses of M, the number of migrants per generation between populations, and alternative analyses of DA, the genetic distance between populations, suggest that rain forest species disperse between islands less frequently than dry forest species.

Main conclusions  Differences in dispersal ability are a plausible explanation for the contrasting macroecological patterns of rain forest and dry forest species. Additionally, historical factors, such as the taxon cycle and Pleistocene climate fluctuations, may have played a role in shaping the distribution patterns of Lesser Antillean birds.
A DNA‐promoted amyloid proteinopathy in Escherichia coli
Authors: Fernández‐Tresguerres M. Elena , Moreno‐Díaz de la Espina Susana , Gasset‐Rosa Fátima , Giraldo Rafael
Published: July 2010

Protein amyloids arise from the conformational conversion and assembly of a soluble protein into fibrilar aggregates with a crossed β‐sheet backbone. Amyloid aggregates are able to replicate by acting as a template for the structural transformation and accretion of further protein molecules. In physicochemical terms, amyloids arguably constitute the simplest self‐replicative macromolecular assemblies. Similarly to the mammalian proteins PrP and α‐synuclein, the winged‐helix dimerization (WH1) domain of the bacterial, plasmid‐encoded protein RepA can assemble into amyloid fibres upon binding to DNA in vitro. Here we report that a hyper‐amyloidogenic functional variant (A31V) of RepA, fused to a red fluorescent protein, causes an amyloid proteinopathy in Escherichia coli with the following features: (i) in the presence of multiple copies of the specific DNA sequence opsp, WH1(A31V) accumulates as cytoplasmatic inclusions segregated from the nucleoid; (ii) such aggregates are amyloid in nature; (iii) bacteria carrying the amyloid inclusions age, exhibiting a fivefold expanded generation time; (iv) before cytokinesis, small inclusions are assembled de novo and transferred to the daughter cells, in which transmission failures cure amyloidosis; and (v) in the absence of inducer DNA, purified cellular WH1(A31V) inclusions seed amyloid fibre growth in vitro from the soluble protein. RepA‐WH1 is a suitable bacterial model system for amyloid proteinopathies.