bluuebunny/crossref_metadata_2025 huggingface dataset:
The Influence of Feature Conjunction on Object Inversion and Conversion Effects
Authors: Bushmakin Maxim A , James Thomas W
Published: February 2014

The face inversion effect is considered by some as a marker of holistic or configural processing. In an effort to understand the relations between object orientation and the use of configuration for recognition, we explored the extent to which the combination of information across discrete, spatially separated object features contributed to the impact of transforming the orientation of faces and other objects. Subjects performed a matching task on four different sets of faces and novel objects. For two of the sets (diagnostic), the match could be made based on information contained in a single feature. For the remaining two sets (conjunction and disjunction), the information useful for successful matching was divided between two spatially separated features (at the top and at the bottom of the object). For OR disjunctions the top and bottom features provided redundant information such that subjects could rely on either the top or the bottom feature, whereas for AND conjunctions the top and bottom features provided unique information such that subjects needed to use both the top and the bottom features. Experiment 1 assessed the cost of inversion on these stimulus sets with the typical inversion task, where both study and test stimuli were presented in the same orientation. Consistent with previous work, significant inversion effects were found for all of the face sets, but none of the novel object sets. Experiment 2 assessed the cost of ‘conversion’—that is, the effect of transforming the orientation of the stimulus between study and test. Consistent with previous work, significant conversion effects were found for all face sets; however, a significant conversion effect was also found for the AND novel set. That only the AND novel set was significant suggests that conversion effects are reliant on combination of information across features, which is compromised when the stimulus configuration is altered between study and test. The results suggest that configural processes, like those purportedly used for face recognition, may be domain-general processes that can also be recruited strategically with other types of objects.
How Does Vibration Reduce Pain?
Authors: Hollins Mark , McDermott Kyle , Harper Daniel
Published: February 2014

Cutaneous vibration is able to reduce both clinical and experimental pain, an effect called vibratory analgesia. The traditional explanation for this phenomenon is that it is mediated by lateral inhibition at the segmental (spinal cord) level, in pain-coding cells with center-surround receptive fields. We evaluated this hypothesis by testing for two signs of lateral inhibition—namely (1) an effect of the distance between the noxious and vibratory stimuli and (2) an inhibition-induced shift in the perceived location of the noxious stimulus. The experiment involved continuous ratings of the pain from pressure applied to the back of a finger, alone and in the presence of vibration delivered to sites on the palm of the hand both near to and far from the site of painful stimulation. Neither prediction of the segmental hypothesis was supported. There was also little evidence to support the view (widely held by subjects) that distraction is the primary mechanism of vibratory analgesia. The results are more consistent with a recently proposed theory of interactions between two cortical areas that are primarily involved in coding pain and touch, respectively (Vierck, Whitsel, Favorov, Brown, & Tommerdahl, 2013 Pain, 154, 334–344).
A lipid-mediated conformational switch modulates the thermosensing activity of DesK
Authors: Inda María Eugenia , Vandenbranden Michel , Fernández Ariel , de Mendoza Diego , Ruysschaert Jean-Marie , Cybulski Larisa Estefanía
Published: February 2014

Significance

Environmental temperature variations affect most biological processes and reactions, and cells must adapt accordingly. One such example is the fine-tuned regulation of membrane fluidity and its impact on a large array of cell physiological processes. How do cells “sense” membrane fluidity? Here, we discovered that the bacterial histidine-kinase, DesK, transmits temperature information through lipid-mediated conformational changes of a region of the protein that links its membrane sensor domain with its catalytic domain and activates the expression of a desaturase, which allows membrane fluidity to be recovered at this lower temperature. Because many thermosensors and other types of sensors contain similar linker domains, the mechanism we describe here could prove a general theme.
Recovering the Elliott invariant from the Cuntz semigroup
Authors: Antoine Ramon , Dadarlat Marius , Perera Francesc , Santiago Luis
Published: February 2014

Let

A
A

be a simple, separable C

∗

^*

-algebra of stable rank one. We prove that the Cuntz semigroup of

C

(

T

,
A
)

\mathrm {C}(\mathbb {T},A)

is determined by its Murray-von Neumann semigroup of projections and a certain semigroup of lower semicontinuous functions (with values in the Cuntz semigroup of

A
A

). This result has two consequences. First, specializing to the case that

A
A

is simple, finite, separable and

Z

\mathcal Z

-stable, this yields a description of the Cuntz semigroup of

C

(

T

,
A
)

\mathrm {C}(\mathbb {T},A)

in terms of the Elliott invariant of

A
A

. Second, suitably interpreted, it shows that the Elliott functor and the functor defined by the Cuntz semigroup of the tensor product with the algebra of continuous functions on the circle are naturally equivalent.
A search for primes 𝑝 such that the Euler number 𝐸_{𝑝-3} is divisible by 𝑝
Authors: Meštrović Romeo
Published: February 2014

Let

p
>
3

p>3

be a prime. Euler numbers

E

p
−
3

E_{p-3}

first appeared in H. S. Vandiver’s work (1940) in connection with the first case of Fermat’s Last Theorem. Vandiver proved that if

x
p

+

y
p

=

z
p

x^p+y^p=z^p

has a solution for integers

x
,
y
,
z

x,y,z

with

gcd
(
x
y
z
,
p
)
=
1

\gcd (xyz,p)=1

, then it must be that

E

p
−
3

≡
0

(
mod

p
)

E_{p-3}\equiv 0\,(\bmod \,p)

. Numerous combinatorial congruences recently obtained by Z.-W. Sun and Z.-H. Sun involve the Euler numbers

E

p
−
3

E_{p-3}

. This gives a new significance to the primes

p
p

for which

E

p
−
3

≡
0

(
mod

p
)

E_{p-3}\equiv 0\,(\bmod \,p)

.

For the computation of residues of Euler numbers

E

p
−
3

E_{p-3}

modulo a prime

p
p

, we use a congruence which runs significantly faster than other known congruences involving

E

p
−
3

E_{p-3}

. Applying this, congruence, via a computation in Mathematica 8, shows that there are only three primes less than

10
7

10^7

that satisfy the condition

E

p
−
3

≡
0

(
mod

p
)

E_{p-3}\equiv 0\,(\bmod \,p)

(these primes are 149, 241 and 2946901). By using related computational results and statistical considerations similar to those used for Wieferich, Fibonacci-Wieferich and Wolstenholme primes, we conjecture that there are infinitely many primes

p
p

such that

E

p
−
3

≡
0

(
mod

p
)

E_{p-3}\equiv 0\,(\bmod \,p)

.
The Neurospora crassa exocyst complex tethers Spitzenkörper vesicles to the apical plasma membrane during polarized growth
Authors: Riquelme Meritxell , Bredeweg Erin L. , Callejas-Negrete Olga , Roberson Robert W. , Ludwig Sarah , Beltrán-Aguilar Alejandro , Seiler Stephan , Novick Peter , Freitag Michael
Published: February 2014

Fungal hyphae are among the most highly polarized cells. Hyphal polarized growth is supported by tip-directed transport of secretory vesicles, which accumulate temporarily in a stratified manner in an apical vesicle cluster, the Spitzenkörper. The exocyst complex is required for tethering of secretory vesicles to the apical plasma membrane. We determined that the presence of an octameric exocyst complex is required for the formation of a functional Spitzenkörper and maintenance of regular hyphal growth in Neurospora crassa. Two distinct localization patterns of exocyst subunits at the hyphal tip suggest the dynamic formation of two assemblies. The EXO-70/EXO-84 subunits are found at the peripheral part of the Spitzenkörper, which partially coincides with the outer macrovesicular layer, whereas exocyst components SEC-5, -6, -8, and -15 form a delimited crescent at the apical plasma membrane. Localization of SEC-6 and EXO-70 to the plasma membrane and the Spitzenkörper, respectively, depends on actin and microtubule cytoskeletons. The apical region of exocyst-mediated vesicle fusion, elucidated by the plasma membrane–associated exocyst subunits, indicates the presence of an exocytotic gradient with a tip-high maximum that dissipates gradually toward the subapex, confirming the earlier predictions of the vesicle supply center model for hyphal morphogenesis.
The role of spartin and its novel ubiquitin binding region in DALIS occurrence
Authors: Karlsson Amelia B. , Washington Jacqueline , Dimitrova Valentina , Hooper Christopher , Shekhtman Alexander , Bakowska Joanna C.
Published: February 2014

Troyer syndrome is an autosomal recessive hereditary spastic paraplegia (HSP) caused by frameshift mutations in the SPG20 gene that results in a lack of expression of the truncated protein. Spartin is a multifunctional protein, yet only two conserved domains—a microtubule-interacting and trafficking domain and a plant-related senescence domain involved in cytokinesis and mitochondrial physiology, respectively—have been defined. We have shown that overexpressed spartin binds to the Ile44 hydrophobic pocket of ubiquitin, suggesting spartin might contain a ubiquitin-binding domain. In the present study, we demonstrate that spartin contributes to the formation of dendritic aggresome-like induced structures (DALIS) through a unique ubiquitin-binding region (UBR). Using short hairpin RNA, we knocked down spartin in RAW264.7 cells and found that DALIS frequency decreased; conversely, overexpression of spartin increased the percentage of cells containing DALIS. Using nuclear magnetic resonance spectroscopy, we characterized spartin's UBR and defined the UBR's amino acids that are key for ubiquitin binding. We also found that spartin, via the UBR, binds Lys-63–linked ubiquitin chains but does not bind Lys-48–linked ubiquitin chains. Finally, we demonstrate that spartin's role in DALIS formation depends on key residues within its UBR.
A benchmark for comparison of cell tracking algorithms
Authors: Maška Martin , Ulman Vladimír , Svoboda David , Matula Pavel , Matula Petr , Ederra Cristina , Urbiola Ainhoa , España Tomás , Venkatesan Subramanian , Balak Deepak M.W. , Karas Pavel , Bolcková Tereza , Štreitová Markéta , Carthel Craig , Coraluppi Stefano , Harder Nathalie , Rohr Karl , Magnusson Klas E. G. , Jaldén Joakim , Blau Helen M. , Dzyubachyk Oleh , Křížek Pavel , Hagen Guy M. , Pastor-Escuredo David , Jimenez-Carretero Daniel , Ledesma-Carbayo Maria J. , Muñoz-Barrutia Arrate , Meijering Erik , Kozubek Michal , Ortiz-de-Solorzano Carlos
Published: February 2014

Motivation: Automatic tracking of cells in multidimensional time-lapse fluorescence microscopy is an important task in many biomedical applications. A novel framework for objective evaluation of cell tracking algorithms has been established under the auspices of the IEEE International Symposium on Biomedical Imaging 2013 Cell Tracking Challenge. In this article, we present the logistics, datasets, methods and results of the challenge and lay down the principles for future uses of this benchmark.

Results: The main contributions of the challenge include the creation of a comprehensive video dataset repository and the definition of objective measures for comparison and ranking of the algorithms. With this benchmark, six algorithms covering a variety of segmentation and tracking paradigms have been compared and ranked based on their performance on both synthetic and real datasets. Given the diversity of the datasets, we do not declare a single winner of the challenge. Instead, we present and discuss the results for each individual dataset separately.

Availability and implementation: The challenge Web site (http://www.codesolorzano.com/celltrackingchallenge) provides access to the training and competition datasets, along with the ground truth of the training videos. It also provides access to Windows and Linux executable files of the evaluation software and most of the algorithms that competed in the challenge.

Contact:  codesolorzano@unav.es

Supplementary information:  Supplementary data are available at Bioinformatics online.
On the formation of warped gas discs in galaxies
Authors: Haan S. , Braun R.
Published: February 2014

We consider the most commonly occurring circumstances which apply to galaxies, namely membership in galaxy groups of about 1013 h−1 M⊙ total mass, and estimate the accompanying physical conditions of intergalactic medium (IGM) density and the relative galaxy–IGM space velocity. We then investigate the dynamical consequences of such a typical galaxy–IGM interaction on a rotating gaseous disc within the galaxy potential. We find that the rotating outer disc is systematically distorted into a characteristic ‘warp’ morphology, of the type that has been well-documented in the majority of well-studied nearby systems. The distortion is established rapidly, within 2 rotation periods, and is long-lived, surviving for at least 10. A second consequence of the interaction is the formation of a one-arm retrograde spiral wave pattern that propagates in the disc. We suggest that the ubiquity of the warp phenomenon might be used to reconstruct both the IGM density profile and individual member orbits within galaxy groups.
Lifelong Learning: Introduction
Authors: London Manuel
Published: February 2014

This chapter examines the scope of the field of lifelong learning, covering definitions, environmental pressures, principal theories of development and learning, and environmental resources and structures that support lifelong learning. Lifelong learning is a dynamic process that varies depending on individual skills and motivation for self-regulated, generative learning and on life events that impose challenges that sometimes demand incremental/adaptive change and other times require frame-breaking change and transformational learning. The chapter previews the major sections of this handbook, which cover theoretical perspectives, research on learning throughout life, methods to promote learning, goals for learning (i.e., what is learned), the importance of cultural and international perspectives, and emerging issues and learning challenges.
Carl Schmitt’s Political Theory of Dictatorship
Authors: Kelly Duncan
Published: February 2014

This chapter reconstructs the intellectual-historical background to Carl Schmitt’s well-known analysis of the problem of dictatorship and the powers of the Reichspräsident under the Weimar Constitution. The analysis focuses both on Schmitt’s wartime propaganda work, concerning a distinction between the state of siege and dictatorship, as well as on his more general analysis of modern German liberalism. It demonstrates why Schmitt attempted to produce a critical history of the history of modern political thought with the concept of dictatorship at its heart and how he came to distinguish between commissarial and sovereign forms of dictatorship to attack liberalism and liberal democracy. The chapter also focuses on the conceptual reworking of the relationship between legitimacy and dictatorship that Schmitt produced by interweaving the political thought of the Abbé Sieyès and the French Revolution into his basic rejection of contemporary liberal and socialist forms of politics.
Optimization of Headspace Solid-Phase Microextraction Conditions for the Identification of Phytophthora cinnamomi Rands
Authors: Qiu Rui , Qu Dong , Hardy Giles E. St. J. , Trengove Robert , Agarwal Manjree , Ren Yonglin
Published: February 2014

A robust technique was developed to identify Phytophthora cinnamomi using headspace solid-phase microextraction (HS-SPME) combined with gas chromatography (GC) coupled to a flame ionization detector (FID) for analyzing volatile organic compounds (VOCs). Six fiber types were evaluated and results indicated that the three-phase fiber 50/30 μm divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) had the highest extraction efficiency for both polar and nonpolar GC columns. The maximum extraction efficiency (equilibrium absorption) was achieved 16 h after fiber exposure in the HS. Absorbed compounds on the fiber were completely desorbed in the GC injector after 5 min at 250°C. Compared with the nonpolar column, the polar column showed optimum separation of VOCs released from P. cinnamomi. Under the optimized HS-SPME and GC/FID conditions, lower detection limits for the four external standards was found to be between 1.57 to 27.36 ng/liter. Relative standard deviations <9.010% showed that the method is precise and reliable. The method also showed good linearity for the concentration range that was analyzed using four standards, with regression coefficients between 0.989 and 0.995, and the sensitivity of the method was 104 times greater than that of the conventional HS method. In this study, the VOC profiles of six Phytophthora spp. and one Pythium sp. were characterized by the optimized HS-SPME-GC method. The combination of the VOCs creates a unique pattern for each pathogen; the chromatograms of different isolates of P. cinnamomi were the same and the specific VOC pattern of P. cinnamomi remained consistently independent of the growth medium used. The chromatograms and morphological studies showed that P. cinnamomi released specific VOCs at different stages of colony development. Using the optimized HS-SPME GC method, identification of P. cinnamomi from 15 in vivo diseased soil samples was as high as 100%. Results from this study demonstrate the feasibility of this method for identifying P. cinnamomi and the potential use of this method for physiological studies on P. cinnamomi.
Enhanced Excitability of Primary Sensory Neurons and Altered Gene Expression of Neuronal Ion Channels in Dorsal Root Ganglion in Paclitaxel-induced Peripheral Neuropathy
Authors: Zhang Haijun , Dougherty Patrick M.
Published: February 2014

Background:

The mechanism of chemotherapy-induced peripheral neuropathy after paclitaxel treatment is not well understood. Given the poor penetration of paclitaxel into central nervous system, peripheral nervous system is most at risk.

Methods:

Intrinsic membrane properties of dorsal root ganglion neurons were studied by intracellular recordings. Multiple-gene real-time polymerase chain reaction array was used to investigate gene expression of dorsal root ganglion neuronal ion channels.

Results:

Paclitaxel increased the incidence of spontaneous activity from 4.8 to 27.1% in large-sized and from 0 to 33.3% in medium-sized neurons. Paclitaxel decreased the rheobase (nA) from 1.6 ± 0.1 to 0.8 ± 0.1 in large-sized, from 1.5 ± 0.2 to 0.6 ± 0.1 in medium-sized, and from 1.6 ± 0.2 to 1.0 ± 0.1 in small-sized neurons. After paclitaxel treatment, other characteristics of membrane properties in each group remained the same except that Aδ neurons showed shorter action potential fall time (ms) (1.0 ± 0.2, n = 10 vs. 1.8 ± 0.3, n = 9, paclitaxel vs. vehicle). Meanwhile, real-time polymerase chain reaction array revealed an alteration in expression of some neuronal ion channel genes including up-regulation of hyperpolarization-activated cyclic nucleotide-gated channel 1 (fold change 1.76 ± 0.06) and Nav1.7 (1.26 ± 0.02) and down-regulation of Kir channels (Kir1.1, 0.73 ± 0.05, Kir3.4, 0.66 ± 0.06) in paclitaxel-treated animals.

Conclusion:

The increased neuronal excitability and the changes in gene expression of some neuronal ion channels in dorsal root ganglion may provide insight into the molecular and cellular basis of paclitaxel-induced neuropathy, which may lead to novel therapeutic strategies.
Transfer of Gluconacetobacter kakiaceti, Gluconacetobacter medellinensis and Gluconacetobacter maltaceti to the genus Komagataeibacter as Komagataeibacter kakiaceti comb. nov., Komagataeibacter medellinensis comb. nov. and Komagataeibacter maltaceti comb. nov.
Authors: Yamada Yuzo
Published: February 2014

Gluconacetobacter kakiaceti

,

Gluconacetobacter medellinensis

and

Gluconacetobacter maltaceti

are transferred to the genus

Komagataeibacter

as Komagataeibacter kakiaceti comb. nov. (type strain, G5-1T = JCM 25156T = NRIC 0798T = LMG 26206T), Komagataeibacter medellinensis comb. nov. (type strain, LMG 1693T = NBRC 3288T = Kondo 51T) and Komagataeibacter
maltaceti comb. nov. (type strain, LMG 1529T = NBRC 14815T = NCIMB 8752T).
Draconibacterium orientale gen. nov., sp. nov., isolated from two distinct marine environments, and proposal of Draconibacteriaceae fam. nov.
Authors: Du Zong-Jun , Wang Ying , Dunlap Christopher , Rooney Alejandro P. , Chen Guan-Jun
Published: February 2014

The taxonomic characteristics of two bacterial strains, FH5T and SS4, isolated from enrichment cultures obtained from two distinct marine environments, were determined. These bacteria were Gram-stain-negative, facultatively anaerobic rods. Growth occurred at 20–40 °C (optimum, 28–32 °C), pH 5.5–9.0 (optimum, pH 7.0–7.5) and in the presence of 1–7 % NaCl (optimum, 2–4 %). The major cellular fatty acids were anteiso-C15 : 0 and iso-C15 : 0. Menaquinone 7 (MK-7) was the sole respiratory quinone. The major polar lipids were phosphatidylethanolamine, an unkown phospholipid and an unknown lipid. The DNA G+C contents of strains FH5T and SS4 were both determined to be 42.0 mol%. The results of DNA–DNA hybridization studies indicated that the FH5T and SS4 genomes share greater than 95 % relatedness. The strains formed a distinct phyletic line within the class

Bacteroidia

, with less than 89.4 % sequence similarity to their closest relatives with validly published names. On the basis of physiological and biochemical characteristics, 16S rRNA gene sequences and chemical properties, a novel genus and species, Draconibacterium orientale gen. nov., sp. nov., within the class

Bacteroidia

, are proposed, with strain FH5T ( = DSM 25947T = CICC 10585T) as the type strain. In addition, a new family, Draconibacteriaceae fam. nov., is proposed to accommodate Draconibacterium gen. nov.
The asparagine residue in the FRNK box of potyviral helper-component protease is critical for its small RNA binding and subcellular localization
Authors: Sahana Nandita , Kaur Harpreet , Jain R. K. , Palukaitis Peter , Canto Tomas , Praveen Shelly
Published: February 2014

The multifunctional potyviral helper-component protease (HcPro) contains variable regions with some functionally conserved domains, such as the FRNK box. Natural variants occur at the FRNK box, a conserved central domain, known for its role in RNA binding and RNAi suppression activities, although no dominant natural variants for the N182 residue are known to occur. Here, a mutant at HcProN182L was developed to investigate its role in natural populations. Using in vitro studies, we found an increase in the small RNA (sRNA) binding potential of HcProN182L without affecting its protein–protein interaction properties, suggesting that the presence of N182 is critical to maintain threshold levels of sRNAs, but does not interfere in the self-interaction of HcPro. Furthermore, we found that expression of HcProN182L in Nicotiana benthamiana affected plant growth. Transient expression of HcProN182L induced reporter gene expression in 16c GFP transgenic plants more than HcPro did, suggesting that replacement of asparagine in the FRNK box favours RNA silencing suppression. HcPro was found to be distributed in the nucleus and cytoplasm, whereas HcProN182L was observed only in cytoplasmic inclusion bodies in N. benthamiana leaves, when fused to a GFP tag and expressed by agro-infiltration, suggesting mutation favours oligomerization of HcPro. These findings suggest that amino acid N182 of the conserved FRNK box may regulate RNA silencing mechanisms, and is required for maintenance of the subcellular localization of the protein for its multi-functionality. Hence, the N182 residue of the FRNK box seems to be indispensable for potyvirus infection during evolution.
Cell specific eQTL analysis without sorting cells
Authors: Westra Harm-Jan , Arends Danny , Esko Tõnu , Peters Marjolein J. , Schurmann Claudia , Schramm Katharina , Kettunen Johannes , Yaghootkar Hanieh , Fairfax Benjamin P. , Andiappan Anand Kumar , Li Yang , Fu Jingyuan , Karjalainen Juha , Platteel Mathieu , Visschedijk Marijn , Weersma Rinse , Kasela Silva , Milani Lili , Tserel Liina , Peterson Pärt , Reinmaa Eva , Hofman Albert , Uitterlinden André G. , Rivadeneira Fernando , Homuth Georg , Petersmann Astrid , Lorbeer Roberto , Prokisch Holger , Meitinger Thomas , Herder Christian , Roden Michael , Grallert Harald , Ripatti Samuli , Perola Markus , Wood Andrew R. , Melzer David , Ferrucci Luigi , Singleton Andrew B. , Hernandez Dena G. , Knight Julian C. , Melchiotti Rossella , Lee Bernett , Poidinger Michael , Zolezzi Francesca , Larbi Anis , Wang De Yun , van den Berg Leonard H. , Veldink Jan H. , Rotzschke Olaf , Makino Seiko , Frayling Timouthy M. , Salomaa Veikko , Strauch Konstantin , Völker Uwe , van Meurs Joyce B. J. , Metspalu Andres , Wijmenga Cisca , Jansen Ritsert C. , Franke Lude
Published: February 2014

Expression quantitative trait locus (eQTL) mapping on tissue, organ or whole organism data can detect associations that are generic across cell types. We describe a new method to focus upon specific cell types without first needing to sort cells. We applied the method to whole blood data from 5,683 samples and demonstrate that SNPs associated with Crohn's disease preferentially affect gene expression within neutrophils.
The R-spondin/Lgr5/Rnf43 module: regulator of Wnt signal strength
Authors: de Lau Wim , Peng Weng Chuan , Gros Piet , Clevers Hans
Published: February 2014

Lgr5 was originally discovered as a common Wnt target gene in adult intestinal crypts and colon cancer. It was subsequently identified as an exquisite marker of multiple Wnt-driven adult stem cell types. Lgr5 and its homologs, Lgr4 and Lgr6, constitute the receptors for R-spondins, potent Wnt signal enhancers and stem cell growth factors. The Lgr5/R-spondin complex acts by neutralizing Rnf43 and Znrf3, two transmembrane E3 ligases that remove Wnt receptors from the stem cell surface. Rnf43/Znrf3 are themselves encoded by Wnt target genes and constitute a negative Wnt feedback loop. Thus, adult stem cells are controlled by an intricate interplay of potent Wnt agonists, antagonists, and anti-antagonists.
Intertissue Signal Transfer of Abscisic Acid from Vascular Cells to Guard Cells
Authors: Kuromori Takashi , Sugimoto Eriko , Shinozaki Kazuo
Published: February 2014

Abscisic acid (ABA) is a phytohormone that responds to environmental stresses, such as water deficiency. Recent studies have shown that ABA biosynthetic enzymes are expressed in the vascular area under both nonstressed and water-stressed growth conditions. However, specific cells in the vasculature involved in ABA biosynthesis have not been identified. Here, we detected the expression of two genes encoding ABA biosynthetic enzymes, ABSCISIC ACID DEFICIENT2 and ABSCISIC ALDEHYDE OXIDASE3, in phloem companion cells in vascular tissues. Furthermore, we identified an ATP-binding cassette transporter, Arabidopsis thaliana ABCG25 (AtABCG25), expressed in the same cells. Additionally, AtABCG25-expressing Spodoptera frugiperda9 culture cells showed an ABA efflux function. Finally, we observed that enhancement of ABA biosynthesis in phloem companion cells induced guard cell responses, even under normal growth conditions. These results show that ABA is synthesized in specific cells and can be transported to target cells in different tissues.
Uptake of Water via Branches Helps Timberline Conifers Refill Embolized Xylem in Late Winter
Authors: Mayr Stefan , Schmid Peter , Laur Joan , Rosner Sabine , Charra-Vaskou Katline , Dämon Birgit , Hacke Uwe G.
Published: February 2014

Xylem embolism is a limiting factor for woody species worldwide. Conifers at the alpine timberline are exposed to drought and freeze-thaw stress during winter, which induce potentially lethal embolism. Previous studies indicated that timberline trees survive by xylem refilling. In this study on Picea abies, refilling was monitored during winter and spring seasons and analyzed in the laboratory and in situ experiments, based on hydraulic, anatomical, and histochemical methods. Refilling started in late winter, when the soil was frozen and soil water not available for the trees. Xylem embolism caused up to 86.2% ± 3.1% loss of conductivity and was correlated with the ratio of closed pits. Refilling of xylem as well as recovery in shoot conductance started in February and corresponded with starch accumulation in secondary phloem and in the mesophyll of needles, where we also observed increasing aquaporin densities in the phloem and endodermis. This indicates that active, cellular processes play a role for refilling even under winter conditions. As demonstrated by our experiments, water for refilling was thereby taken up via the branches, likely by foliar water uptake. Our results suggest that refilling is based on water shifts to embolized tracheids via intact xylem, phloem, and parenchyma, whereby aquaporins reduce resistances along the symplastic pathway and aspirated pits facilitate isolation of refilling tracheids. Refilling must be taken into account as a key process in plant hydraulics and in estimating future effects of climate change on forests and alpine tree ecosystems.
Crystal structure and conformational flexibility of the unligated FK506-binding protein FKBP12.6
Authors: Chen Hui , Mustafi Sourajit M. , LeMaster David M. , Li Zhong , Héroux Annie , Li Hongmin , Hernández Griselda
Published: February 2014

The primary known physiological function of FKBP12.6 involves its role in regulating the RyR2 isoform of ryanodine receptor Ca2+ channels in cardiac muscle, pancreatic β islets and the central nervous system. With only a single previously reported X-ray structure of FKBP12.6, bound to the immunosuppressant rapamycin, structural inferences for this protein have been drawn from the more extensive studies of the homologous FKBP12. X-ray structures at 1.70 and 1.90 Å resolution from P21 and P3121 crystal forms are reported for an unligated cysteine-free variant of FKBP12.6 which exhibit a notable diversity of conformations. In one monomer from the P3121 crystal form, the aromatic ring of Phe59 at the base of the active site is rotated perpendicular to its typical orientation, generating a steric conflict for the immunosuppressant-binding mode. The peptide unit linking Gly89 and Val90 at the tip of the protein-recognition `80s loop' is flipped in the P21 crystal form. Unlike the >30 reported FKBP12 structures, the backbone conformation of this loop closely follows that of the first FKBP domain of FKBP51. The NMR resonances for 21 backbone amides of FKBP12.6 are doubled, corresponding to a slow conformational transition centered near the tip of the 80s loop, as recently reported for 31 amides of FKBP12. The comparative absence of doubling for residues along the opposite face of the active-site pocket in FKBP12.6 may in part reflect attenuated structural coupling owing to increased conformational plasticity around the Phe59 ring.
Diaquabis[N-(2-fluorobenzyl)-N-nitrosohydroxylaminato-κ2O,O′]nickel(II)
Authors: Kovalchukova Olga , Bostanabad Ali Sheikh , Stash Adam , Strashnova Svetlana , Zyuzin Igor
Published: February 2014

In the centrosymmetric title compound, [Ni(C7H6FN2O2)2(H2O)2], the NiIIcation is in a slightly distorted octahedral environment and is surrounded by four O atoms from the N—O groups of the organic ligands [Ni—O = 2.0179 (13) and 2.0283 (12) Å], and two water molecules [Ni—O = 2.0967 (14) Å]. TheN-(2-fluorobenzyl)-N-nitrosohydroxylaminate monoanions act as bidentate chelating ligands. In the crystal, the Ni cations in the columns are shifted in such a way that the coordinated water molecules are involved in the formation of hydrogen bonds with the O atoms of the organic species of neighbouring molecules. Thus, a two-dimensional network parallel to (100) is built up by hydrogen-bonded molecules.
Methyl 4-(4-hydroxyphenyl)-6-methyl-2-sulfanylidene-1,2,3,4-tetrahydropyrimidine-5-carboxylate
Authors: Fathima Nikhath , Nagarajaiah H. , Begum Noor Shahina
Published: February 2014

In the title molecule, C13H14N2O3S, the dihydropyrimidine ring is in a flattened sofa conformation, with the methine C atom forming the flap. The dihedral angle between the mean plane of the five essentially planar atoms of the dihydropyrimidine ring [maximum deviation = 0.056 (4) Å] and the benzene ring is 89.4 (2)°. The O atom of the carbonyl group is in atransconformation with respect to the C=C bond of the dihydropyrimidine ring. In the crystal, N—H...O and O—H...S hydrogen bonds connect molecules, forming a two-dimensional network parallel to (001).
Categorization of fabric design using multi-class least-square support vector machine
Authors: Ghosh A. , Guha T. , Bhar R.
Published: February 2014

Purpose

– The purpose of this paper is to give an approach for categorization of diverse textile designs using their textural features as extracted from their gray images by means of multi-class least-square support vector machines (LS-SVM).

Design/methodology/approach

– In this work, the authors endeavor to devise a pattern recognition system based on LS-SVM which performs a multi-class categorization of three basic woven designs namely plain, twill and sateen after analyzing their features.

Findings

– The result establishes that LS-SVM is able to classify the fabric design with a reasonable degree of accuracy and it outperforms the standard SVM.

Originality/value

– The algorithmic simplicity of LS-SVM resulting from replacement of inequality constraints by equality ones and ability of handling noisy data by accommodating an error variable in its algorithm make it eminently suitable for textile pattern recognition. This paper offers a maiden application of LS-SVM in textile pattern recognition.
Effects of reciprocating motion parameters on lubricating properties of tripod sliding universal joints
Authors: Wang X.F. , Hu R.F. , Wang K.S. , Cui H.R.
Published: February 2014

Purpose

– This paper aims to clarify the effects of the reciprocating motion parameters on the lubricating performance of the tripod sliding universal joint (TSUJ). These parameters mainly include the frequency and amplitude of the reciprocating motion. This work will explain how the film thickness and pressure as well as the temperature vary with the frequency and amplitude of the reciprocating motion in order to improve the lubricating performance of the TSUJ and extend its working life.

Design/methodology/approach

– Based on the simplified geometrical model derived from the main mating surfaces, the effects of the frequency and amplitude on the pressure and film thickness as well as the temperature are theoretically investigated. In this work, multi-level method, multilevel multi-integration method and sequential line sweeping method were applied to solving Reynolds equation, the elastic deformation of the bounding surfaces and temperature, respectively.

Findings

– The overall film thickness increases with the increase of the amplitude or frequency. The consumed time of the rippled film passing through the contact zone hardly depends on the amplitude or frequency. The variation of the film or temperature lags behind the variation of the entrainment velocity. Increasing amplitude or frequency increases the temperature. The effect of the amplitude or frequency on the pressure focuses mainly on the second pressure peak.

Originality/value

– TSUJ is a new-type tripod joint and the obtained results are of great value for its design and application.
Comparison of static performance characteristics of different configurations of slot-entry hybrid journal bearing operating with non-Newtonian lubricants
Authors: Chander Garg Hem , Kumar Vijay
Published: February 2014

Purpose

– The slot-entry hybrid journal bearings have been successfully used in various engineering applications because of their good performance over wide range of speed and load, besides their relative simplicity in manufacturing. Most of the research work pertaining to non-recessed journal bearing assumes standard symmetric and asymmetric configurations. However, many more configurations are possible by changing the position of slot which may improve the performance of the slot-entry journal bearing. In the present work study of static performance characteristics of slot-entry journal bearing of different configuration has been carried out. The paper aims to discuss these issues.

Design/methodology/approach

– FEM has been used to solve the Reynolds equation governing the flow of lubricant in the bearing clearance space along with the restrictor flow equation. The non-Newtonian lubricant has been assumed to follow the cubic shear stress law. The performance characteristics of slot-entry hybrid journal bearings are computed by developing a computer program.

Findings

– The simulated results of bearing characteristics parameters in terms of minimum fluid-film thickness and bearing flow have been presented for the wide range of various values of non-linearity factor and external load. It is found that there is an increase in the oil requirement for slot-entry hybrid journal bearing with the specified operating and geometric parameters, when the viscosity of the lubricant decreases due to the non-Newtonian behavior of the lubricant. The effect of the decrease in the viscosity of the lubricant due to non-Newtonian behavior of the lubricant diminishes the attitude angle. The computed performance characteristics are helpful for the bearing designer while choosing a particular configuration of bearing.

Research limitations/implications

– The performance characteristics have been computed by considering the non-Newtonian lubricants. The thermal effects have been ignored in the analysis so as to obviate the mathematical complexity.

Originality/value

– Get idea from already published manuscripts.
Impact of preferential trade agreements (PTAs) on firms’ degree of internationalization
Authors: Hafeez Siddiqui Sulaman , Zafarullah Muhammad , Ijaz Latif Muhammad , Shabir Ghulam
Published: February 2014

Purpose

– The purpose of this paper is to postulate the impact of preferential trade agreements (PTAs) on internationalization strategies of member countries’ firms. The study also aims to triangulate the proposed model using empirical data from PTA partner economies.

Design/methodology/approach

– The mixed methods research design is used for the purpose of inquiry as suggested by Creswell. The inductive reasoning based on critical literature review and grounded theory methodology is used to postulate the model. Explanatory strength of the model is triangulated using empirical longitudinal trade data of Pakistan with her bilateral PTA partners, i.e. Malaysia, Mauritius, Iran, Sri Lanka and China. Internationalization indices are adapted following the Ietto-Gillies and London (2009) and Petri (1994) to measure the intensity and geographical diversification dimensions of internationalization. Country-level trade statistics are used as a proxy of firm-level data to explain the international expansion of home firms resulting from PTAs.

Findings

– Empirical results confirm a strong and long-term impact of PTAs on the intensity and extensity dimensions of internationalization over post-agreement period in Pakistan and member economies. Gravity index depicts greater concentration of Pakistan's trade in FTA markets and thereby confirms the influence of PTAs on international market selection. Analysis at sectoral level depicts a contraction in services trade whereas expansion in the manufacturing firms’ export growth to member economies.

Originality/value

– The paper extends the theory of internationalization by identifying PTAs as exogenous variable influencing internationalization strategies of member countries’ firms in a developing South Asian context. Coupled with findings from empirical data, the study identifies PTAs as a new strategic trade policy tool available to policy makers for promoting and influencing the home firms’ internationalization strategies.
Successful implementation of responsible business practice
Authors: Brookes Maureen , Altinay Levent , Ringham Kate
Published: February 2014

Purpose

– The main aim of this paper is to introduce the articles of this issue.

Design/methodology/approach

– A critical content analysis of the papers selected for the issue was undertaken.

Findings

– The final articles for this issue examine a range of responsible business practices within hospitality and tourism businesses in diverse country settings. In addition, each article is followed by a commentary from an industry representative who reflects on the key message and/or value of the article for industry practice.

Research limitations/implications

– Although only one article examined the role of education specifically, collectively the articles in this special theme edition point to the critical role of education in implementing responsible business practices in the near future, as well as for ensuring the sustainability of these practices in the years to come. Additionally, these articles highlight the need for greater cooperation between different hospitality and tourism stakeholders in the development and implementation of responsible business practices.

Originality/value

– The current theme issue explores emerging issues in the implementation of responsible business practice in the context of hospitality and tourism industries in different country contexts.
Gradual Change in International Organisations: Agency Theory and Historical Institutionalism
Authors: Hanrieder Tine
Published: February 2014

This research note discusses limitations of principal-agent (PA) analysis in explaining gradual change in international organisations (IOs). It suggests that historical institutionalism (HI) can fill important gaps left by the PA approach and identifies scope conditions for both approaches. For this purpose, a distinction is made between two sources of state power that PA usually treats as synergistic – namely the formal control of IO decisions and material power resources. While PA analysis is best applicable where reform coalitions of like-minded member states control both formal and material resources, in many contexts there exist frictions between material and formal power in IOs. In these constellations recent HI-inspired works on gradual modes of change such as ‘layering’ and ‘drift’ are of particular relevance. This research avenue is illustrated with empirical examples from a variety of international organisations.
Delivery by caesarean section and childhood cancer: a nationwide follow‐up study in three countries
Authors: Momen NC , Olsen J , Gissler M , Cnattingius S , Li J
Published: February 2014

Objective

To investigate the association between delivery by caesarean section and risk of childhood cancer.

Design

A population‐based, follow‐up study using register data from three countries.

Setting

Denmark, Sweden and Finland.

Population

Children born in Denmark (1973–2007), Sweden (1973–2006) and Finland (randomly selected sample of 90%, 1987–2007; n = 7 029 843).

Methods

Exposure was delivery by caesarean section and the outcome was childhood cancer diagnosis. Follow‐up started from birth and ended at the first of the following dates: cancer diagnosis, death, emigration, day before 15th birthday or end of follow‐up. Cox regression was used to obtain hazard ratios.

Main outcome measures

Childhood cancer diagnosis.

Results

A total of 882 907 (12.6%) children were delivered by caesarean section. Of these, 30.3% were elective (n = 267 603), 35.9% unplanned (n = 316 536) and 33.8% had no information on planning (n = 298 768). Altogether, 11 181 children received a cancer diagnosis. No evidence of an increased risk of childhood cancer was found for children born by caesarean section (hazard ratio, 1.05; 95% confidence interval, 0.99, 1.11). No association was found for any major type of childhood cancer, or when split by the type of caesarean section (elective/unplanned).

Conclusion

The evidence does not suggest that caesarean section is a risk factor for the overall risk of childhood cancer and possibly not for subtypes of childhood cancer either.
Comparison of Two Methods of Estimating Reader Variability in QT Interval Measurements in Thorough QT/QTc Studies
Authors: Salvi Vaibhav , Karnad Dilip R. , Kerkar Vaibhav , Panicker Gopi Krishna , Natekar Mili , Kothari Snehal
Published: February 2014

Background

Two methods of estimating reader variability (RV) in QT measurements between 12 readers were compared.

Methods

Using data from 500 electrocardiograms (ECGs) analyzed twice by 12 readers, we bootstrapped 1000 datasets each for both methods. In grouped analysis design (GAD), the same 40 ECGs were read twice by all readers. In pairwise analysis design (PAD), 40 ECGs analyzed by each reader in a clinical trial were reanalyzed by the same reader (intra‐RV) and also by another reader (inter‐RV); thus, variability between each pair of readers was estimated using different ECGs.

Results

Inter‐RV (mean [95% CI]) between pairs of readers by GAD and PAD was 3.9 ms (2.1–5.5 ms) and 4.1 ms (2.6–5.4 ms), respectively, using ANOVA, 0 ms (–0.0 to 0.4 ms), and 0 ms (–0.7 to 0.6 ms), respectively, by actual difference between readers and 7.7 ms (6.2–9.8 ms) and 7.7 ms (6.6–9.1 ms), respectively, by absolute difference between readers. Intra‐RV too was comparable.

Conclusions

RV estimates by the grouped‐ and pairwise analysis designs are comparable.
Anti‐arthritis effects of (E)‐2,4‐bis(p‐hydroxyphenyl)‐2‐butenal are mediated by inhibition of the STAT3 pathway
Authors: Ban Jung Ok , Kim Dae Hwan , Lee Hee Pom , Hwang Chul Ju , Shim Jung‐Hyun , Kim Dae Joong , Kim Tae Myoung , Jeong Heon‐Sang , Nah Seong Su , Chen Hanyong , Dong Zigang , Ham Young Wan , Kim Youngsoo , Han Sang‐Bae , Hong Jin Tae
Published: February 2014

Background and Purpose

Products of Maillard reactions between aminoacids and reducing sugars are known to have anti‐inflammatory properties. Here we have assessed the anti‐arthritis effects of (E)‐2,4‐bis(p‐hydroxyphenyl)‐2‐butenal and its possible mechanisms of action.

Experimental Approach

We used cultures of LPS‐activated macrophages (RAW264.7 cells) and human synoviocytes from patients with rheumatoid arthritis for in vitro assays and the collagen‐induced arthritis model in mice. NO generation, iNOS and COX2 expression, and NF‐κB/IKK and STAT3 activities were measured in vitro and in joint tissues of arthritic mice, along with clinical scores and histopathological assessments. Binding of (E)‐2,4‐bis(p‐hydroxyphenyl)‐2‐butenal to STAT3 was evaluated by a pull‐down assay and its binding site was predicted using molecular docking studies with Autodock VINA.

Key Results

(E)‐2,4‐bis(p‐hydroxyphenyl)‐2‐butenal (2.5–10 μg·mL−1) inhibited LPS‐inducedNO generation, iNOS and COX2 expression, and NF‐κB/IKK and STAT3 activities in macrophage and human synoviocytes. This compound also suppressedcollagen‐induced arthritic responses in mice by inhibiting expression of iNOS and COX2, and NF‐κB/IKK and STAT3 activities; it also reduced bone destruction and fibrosis in joint tissues. A pull‐down assay showed that (E)‐2,4‐bis(p‐hydroxyphenyl)‐2‐butenal interfered with binding of ATP to STAT3. Docking studies suggested that (E)‐2,4‐bis(p‐hydroxyphenyl)‐2‐butenal bound to the DNA‐binding interface of STAT3 possibly inhibiting ATP binding to STAT3 in an allosteric manner.

Conclusions and Implications

(E)‐2,4‐bis(p‐hydroxyphenyl)‐2‐butenal exerted anti‐inflammatory and anti‐arthritic effects through inhibition of the NF‐κB/STAT3 pathway by direct binding to STAT3. This compound could be a useful agent for the treatment of arthritic disease.