bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhanced polarization of (11–22) semi-polar InGaN nanorod array structure
Authors: Athanasiou M. , Smith R. M. , Hou Y. , Zhang Y. , Gong Y. , Wang T.
Published: October 2015

By means of a cost effective nanosphere lithography technique, an InGaN/GaN multiple quantum well structure grown on (11–22) semipolar GaN has been fabricated into two dimensional nanorod arrays which form a photonic crystal (PhC) structure. Such a PhC structure demonstrates not only significantly increased emission intensity, but also an enhanced polarization ratio of the emission. This is due to an effective inhibition of the emission in slab modes and then redistribution to the vertical direction, thus minimizing the light scattering processes that lead to randomizing of the optical polarization. The PhC structure is designed based on a standard finite-difference-time-domain simulation, and then optically confirmed by detailed time-resolved photoluminescence measurements. The results presented pave the way for the fabrication of semipolar InGaN/GaN based emitters with both high efficiency and highly polarized emission.
Rapid retraction of microvolume aqueous plugs traveling in a wettable capillary
Authors: Kim Jinho , O'Neill John D. , Vunjak-Novakovic Gordana
Published: October 2015

We report a transport behavior—specifically, rapid retraction movement—of small (∼μL) deionized water plugs traveling in series within a small wettable tubular geometry. In this study, two water plugs separated by a certain distance in a dry cylindrical glass capillary were moved by positive pressure airflow applied at the tube inlet. As the plugs travel, a thin aqueous film is generated between the plugs as a result of the leading plug's aqueous deposition onto the inner surface of the tube. The leading plug continuously loses volume by film deposition onto the surface and eventually ruptures. Then, the lagging plug quickly travels the distance initially separating the two plugs (plug retraction). Our studies show that the rapid retraction of the lagging plug is caused by surface tension in addition to the positive pressure applied. Furthermore, the plug retraction speed is strongly affected by tube radius and the distance between the plugs.
Nanoplasmonic heating and sensing to reveal the dynamics of thermoresponsive polymer brushes
Authors: Winkler P. , Belitsch M. , Tischler A. , Häfele V. , Ditlbacher H. , Krenn J. R. , Hohenau A. , Nguyen M. , Félidj N. , Mangeney C.
Published: October 2015

Understanding of the phase transition dynamics of substrate tethered brushes of thermoresponsive poly(N-isopropylacrylamide) (pNIPAM) is important for their application as, e.g., cell substrates with spatially selective cell affinity or drug delivery systems. But characterization of the brushes phase transition time is hampered by the low amount of involved pNIPAM. Here, by the simultaneous use of time resolved nanoplasmonic heating and sensing, we are able to measure a transition time of 160±20 μs for a 30 nm thick substrate tethered brush. The plasmon-induced temperature jump can be quantitatively deduced from the measured data. Nanoplasmonic platforms as applied here could serve as local and fast probes for a variety of dynamic processes in stimuli responsive molecules or polymers.
High frequency electromagnetic detection by nonlinear conduction modulation in graphene nanowire diodes
Authors: Winters M. , Thorsell M. , Strupiński W. , Rorsman N.
Published: October 2015

We present graphene nanowires implemented as dispersion free self switched microwave diode detectors. The microwave properties of the detectors are investigated using vector corrected large signal measurements in order to determine the detector responsivity and noise equivalent power (NEP) as a function of frequency, input power, and device geometry. We identify two distinct conductance nonlinearities which generate detector responsivity: an edge effect nonlinearity near zero bias due to lateral gating of the nanowire structures, and a velocity saturation nonlinearity which generates current compression at high power levels. The scaling study shows that detector responsivity obeys an exponential scaling law with respect to nanowire width, and a peak responsivity (NEP) of 250 V/W (50 pW/Hz) is observed in detectors of the smallest width. The results are promising as the devices exhibit responsivities which are comparable to state of the art self switched detectors in semiconductor technologies.
Influence of axial self-magnetic field component on arcing behavior of spiral-shaped contacts
Authors: Feng Dingyu , Xiu Shixin , Wang Yi , Liu Gang , Zhang Yali , Bi Dongli
Published: October 2015

The transverse magnetic field (TMF) contact design is commonly used in vacuum interrupters. When arcing occurs between the TMF contacts, the contact structure can create a self-induced magnetic field that drives the arc to move and rotate on the contact, and thus local overheating and severe erosion can be avoided. However, TMF contacts could also create an axial self-magnetic component, and the influence of this component on the arc behavior has not been considered to date. In this paper, five different types of Cu-Cr spiral-shaped TMF contacts with three different structures are investigated in a demountable vacuum chamber that contains a high-speed charge-coupled device video camera. It was found that the contact structure greatly influenced the arc behavior, especially in terms of arc rotation and the effective contact area, while contacts with the same slot structure but different diameters showed similar arc behavior and arc motion. The magnetic field distribution and the Lorentz force of each of the three different contact structures are simulated, and the axial self-magnetic field was first taken into consideration for investigation of the TMF contact design. It was found that contact designs that have higher axial self-magnetic field components tend to have arc columns with larger diameters and show poorer arc motion and rotation performance in the experiments.
Influence of thermal boundary conditions on the current-driven resistive transition in VO2 microbridges
Authors: Manca Nicola , Kanki Teruo , Tanaka Hidekazu , Marré Daniele , Pellegrino Luca
Published: October 2015

We investigate the resistive switching behaviour of VO2 microbridges under current bias as a function of temperature and thermal coupling with the heat bath. Upon increasing the electrical current bias, the formation of the metallic phase can progress smoothly or through sharp jumps. The magnitude and threshold current values of these sharp resistance drops show random behaviour and are dramatically influenced by thermal dissipation conditions. Our results also evidence how the propagation of the metallic phase induced by electrical current in VO2, and thus the shape of the resulting high-conductivity path, are not predictable. We discuss the origin of the switching events through a simple electro-thermal model based on the domain structure of VO2 films that can be useful to improve the stability and controllability of future VO2-based devices.
An ultra-wideband dielectric material characterization method using grounded coplanar waveguide and genetic algorithm optimization
Authors: Hadjloum Massinissa , El Gibari Mohammed , Li Hongwu , Daryoush Afshin S.
Published: October 2015

An ultra-wideband complex permittivity extraction method is reported here using numerical fitting of scattering parameters to measured results. A grounded coplanar waveguide transmission line is realized on an unknown dielectric material, whose dielectric constant and loss tangent are extracted by the best fitting of the simulated magnitude, |S21|, and phase, ϕ21, of forward scattering parameter using an electromagnetic full-wave simulator (high frequency structure simulator) to the measured results. The genetic algorithm is employed for optimum rapid extraction, where errors between the numerically simulated and measured S21 (|S21| and ϕ21) are minimized in an iterative manner. As long as the convergence criterion is not satisfied, modifications to dielectric properties are made with this genetic algorithm implemented in Matlab. Feasibility of this extraction technique is validated on benzocyclobutane polymer from 10 MHz to 40 GHz.
Highly sensitive phototransistor based on GaSe nanosheets
Authors: Huang Hai , Wang Peng , Gao Yanqing , Wang Xudong , Lin Tie , Wang Jianlu , Liao Lei , Sun Jinglan , Meng Xiangjian , Huang Zhiming , Chen Xiaoshuang , Chu Junhao
Published: October 2015

Phototransistors based on two dimensional semiconductors have drawn increasing attention in recent years. GaSe is a typical semiconductor with a layered structure. In this work, the ultrathin GaSe nanosheets were exfoliated from commercially available crystals using a micromechanical cleavage technique. Then, the nanosheets were used to fabricate field effect transistors (FETs) on Si/SiO2 substrates with interdigitated electrodes. The electrical and optoelectronic properties of the FET were characterized. The phototransistor based on a GaSe nanosheet had a high photoresponsivity (∼2200 mA/W) and a high Iphoto/Idark (photoresponse current over dark current) ratio of almost 103.
High surface mobility and fast surface enhanced crystallization of metallic glass
Authors: Cao C. R. , Lu Y. M. , Bai H. Y. , Wang W. H.
Published: October 2015

The surface viscosity and self-diffusion of a Pd-based metallic glass were measured using annealing-induced decay of its surface submicron gratings. Strong surface dynamics and surface diffusion with the value of more than 105 times faster than bulk diffusion are found at temperatures below glass transition. The high surface dynamic induces a fast crystallization below glass transition temperature at the free surface which is more than 100 times faster than that in bulk.
A tunable microplasma gradient-index lens for millimeter waves
Authors: Venkattraman Ayyaswamy
Published: October 2015

This work presents proof of concept of a novel application of field emission assisted (FEA) microplasmas that exploits the relatively high plasma number densities encountered in these devices. We hypothesize that the number density gradients and the resulting gradient in the microplasma relative permittivity/refractive index can be utilized as a tunable diverging lens with on/off ability to defocus waves in the Terahertz regime. Electron number density profiles obtained from one-dimensional particle-in-cell with Monte Carlo collisions simulations for a typical FEA microplasma are used to determine the relative permittivity and conductivity profiles. Frequency domain wave propagation simulations using these profiles show that sub-mm waves can be controlled using the microplasma lens with the degree of defocusing depending on the wavelength. In spite of the non-zero conductivity, the medium is not significantly lossy at the frequencies considered.
In search of photosensitising compounds in the annual forage legume Biserrula pelecinus L.
Authors: Swinny E. , Revell C. K. , Campbell N. , Spadek E. , Russo C.
Published: October 2015

Biserrula is an annual pasture legume endemic to the Mediterranean basin and has been recently domesticated for use in Mediterranean environments in southern Australia. Over the past 10 years the species has been associated with isolated cases of what appears to be a primary photosensitisation in sheep that graze green pastures in winter and spring. Whole-top samples of biserrula pasture were taken from a range of farmers’ paddocks over 2 years (including paddocks where photosensitisation had been observed) and methanolic extracts were screened by high-performance liquid chromatography and liquid chromatography coupled to mass spectrometry for known primary photosensitising compounds belonging to the classes furanocoumarins and dianthrones. None of these were detected. Pyrrolizidine alkaloids were also not detected and this supports the view that a secondary photosensitisation is not involved. Chlorophyll profiles were relatively unchanged between samples and this suggested that chlorophyll metabolites are unlikely to be responsible for a primary photosensitisation. A series of luteolin and apigenin mono- and diglycosides were identified in the extracts, but these are not regarded as photosensitising compounds. Further work is required to establish the photosensitising agent(s) in biserrula.
Isolation and characterisation of 16 polymorphic microsatellite loci for bight redfish, Centroberyx gerrardi (Actinopterygii : Berycidae), and cross-amplification in two other Centroberyx species
Authors: Bertram Andrea , Dias P. Joana , Lukehurst Sherralee , Kennington W. Jason , Fairclough David , Norriss Jeffrey , Jackson Gary
Published: October 2015

Bight redfish, Centroberyx gerrardi, is a demersal teleost endemic to continental shelf and upper slope waters of southern Australia. Throughout most of its range, C. gerrardi is targeted by a number of separately managed commercial and recreational fisheries across several jurisdictions. However, it is currently unknown whether stock assessments and management for this shared resource are being conducted at appropriate spatial scales, thereby requiring knowledge of population structure and connectivity. To investigate population structure and connectivity, we developed 16 new polymorphic microsatellite markers using 454 shotgun sequencing. Two to 15 alleles per locus were detected. There was no evidence of linkage disequilibrium between pairs of loci and all loci except one were in Hardy–Weinberg equilibrium. Cross-amplification trials in the congeneric C. australis and C. lineatus revealed that 11 and 16 loci are potentially useful, respectively. However, deviations from Hardy–Weinberg equilibrium and linkage disequilibrium between pairs of loci were detected at several of the 16 markers for C. australis, and therefore the number of markers useful for population genetic analyses with C. lineatus is likely considerably lower than 11.
Cable bacteria generate a firewall against euxinia in seasonally hypoxic basins
Authors: Seitaj Dorina , Schauer Regina , Sulu-Gambari Fatimah , Hidalgo-Martinez Silvia , Malkin Sairah Y. , Burdorf Laurine D. W. , Slomp Caroline P. , Meysman Filip J. R.
Published: October 2015

Significance

Seasonal hypoxia is increasing in coastal areas worldwide, as more nutrients are delivered to the coastal ocean and water temperatures are rising due to climate change. Hypoxia reaches a particularly harmful stage when sulfide, which is highly toxic for marine life, is released to the bottom water. Here, we document a natural microbial mechanism that counteracts the release of free sulfide, thus preventing the most adverse stage of seasonal hypoxia. Electricity-generating cable bacteria produce a large pool of oxidized sedimentary iron minerals, which efficiently bind free sulfide. As cable bacteria are likely abundant in many seasonally hypoxic basins worldwide, their “firewall” mechanism may be widespread.
The drawing effect: Evidence for reliable and robust memory benefits in free recall
Authors: Wammes Jeffrey D. , Meade Melissa E. , Fernandes Myra A.
Published: October 2015

In 7 free-recall experiments, the benefit of creating drawings of to-be-remembered information relative to writing was examined as a mnemonic strategy. In Experiments 1 and 2, participants were presented with a list of words and were asked to either draw or write out each. Drawn words were better recalled than written. Experiments 3–5 showed that the memory boost provided by drawing could not be explained by elaborative encoding (deep level of processing, LoP), visual imagery, or picture superiority, respectively. In Experiment 6, we explored potential limitations of the drawing effect, by reducing encoding time and increasing list length. Drawing, relative to writing, still benefited memory despite these constraints. In Experiment 7, the drawing effect was significant even when encoding trial types were compared in pure lists between participants, inconsistent with a distinctiveness account. Together these experiments indicate that drawing enhances memory relative to writing, across settings, instructions, and alternate encoding strategies, both within- and between-participants, and that a deep LoP, visual imagery, or picture superiority, alone or collectively, are not sufficient to explain the observed effect. We propose that drawing improves memory by encouraging a seamless integration of semantic, visual, and motor aspects of a memory trace.
Dissociating Biases towards the Self and Positive Emotion
Authors: Stolte Moritz , Humphreys Glyn , Yankouskaya Alla , Sui Jie
Published: October 2015

We examined whether self-biases in perceptual matching reflect the positive valence of self-related stimuli. Participants associated geometric shapes with either personal labels (e.g., you, friend, stranger) or faces with different emotional expressions (e.g., happy, neutral, sad). They then judged whether shape–label or shape–face pairs were as originally shown or re-paired. Match times were faster to self-associated stimuli and to stimuli associated with the most positive valence. In addition, both the self-bias and the positive emotion bias were reliable across individuals in different test sessions. In contrast there was no sign of a correlation between the self-bias and the emotion-bias effects. We argue that self-bias and the bias to stimuli linked to positive emotion are separate and may reflect different underlying processes.
Charge-trap flash memory using zirconium-nitride-based memristor switches
Authors: Kim Hee-Dong , Kim Kyeong Heon , An Ho-Myoung , Kim Tae Geun
Published: October 2015

Charge-trap flash (CTF) memory using a zirconium nitride (ZrN)-based memristor switch (MRS) is demonstrated for next-generation nonvolatile memory. This device consists of a metal/MRS/nitride/oxide/silicon (M/MRS/N/O/S) structure so that electrical transport via the ZrN-based MRS layer can be utilized. Compared to previous oxide materials used as conduction paths, the proposed CTF device with a ZrN-based MRS exhibits a faster program/erase switching speed (20 ns/7 ns), along with comparable endurance and retention properties.
Ice quivers with potential associated with triangulations and Cohen-Macaulay modules over orders
Authors: Demonet Laurent , Luo Xueyu
Published: October 2015

Given a triangulation of a polygon

P
P

with

n
n

vertices, we associate an ice quiver with potential such that the frozen part of the associated Jacobian algebra has the structure of a Gorenstein tiled

K
[
x
]

K[x]

-order

Λ
\Lambda

. Then we show that the stable category of the category of Cohen-Macaulay

Λ
\Lambda

-modules is equivalent to the cluster category

C

\mathcal {C}

of type

A

n
−
3

A_{n-3}

. It gives a natural interpretation of the usual indexation of cluster tilting objects of

C

\mathcal {C}

by triangulations of

P
P

. Moreover, it extends naturally the triangulated categorification by

C

\mathcal {C}

of the cluster algebra of type

A

n
−
3

A_{n-3}

to an exact categorification by adding coefficients corresponding to the sides of

P
P

. Finally, we lift the previous equivalence of categories to an equivalence between the stable category of graded Cohen-Macaulay

Λ
\Lambda

-modules and the bounded derived category of modules over a path algebra of type

A

n
−
3

A_{n-3}

.
In vivo quantitative analysis of Talin turnover in response to force
Authors: Katrín Hákonardóttir Guðlaug , López-Ceballos Pablo , Herrera-Reyes Alejandra Donají , Das Raibatak , Coombs Daniel , Tanentzapf Guy
Published: October 2015

Cell adhesion to the extracellular matrix (ECM) allows cells to form and maintain three-dimensional tissue architecture. Cell–ECM adhesions are stabilized upon exposure to mechanical force. In this study, we used quantitative imaging and mathematical modeling to gain mechanistic insight into how integrin-based adhesions respond to increased and decreased mechanical forces. A critical means of regulating integrin-based adhesion is provided by modulating the turnover of integrin and its adhesion complex (integrin adhesion complex [IAC]). The turnover of the IAC component Talin, a known mechanosensor, was analyzed using fluorescence recovery after photobleaching. Experiments were carried out in live, intact flies in genetic backgrounds that increased or decreased the force applied on sites of adhesion. This analysis showed that when force is elevated, the rate of assembly of new adhesions increases such that cell–ECM adhesion is stabilized. Moreover, under conditions of decreased force, the overall rate of turnover, but not the proportion of adhesion complex components undergoing turnover, increases. Using point mutations, we identify the key functional domains of Talin that mediate its response to force. Finally, by fitting a mathematical model to the data, we uncover the mechanisms that mediate the stabilization of ECM-based adhesion during development.
The two SAMP repeats and their phosphorylation state inDrosophilaAdenomatous polyposis coli-2 play mechanistically distinct roles in negatively regulating Wnt signaling
Authors: Kunttas-Tatli Ezgi , Von Kleeck Ryan A. , Greaves Bradford D. , Vinson David , Roberts David M. , McCartney Brooke M.
Published: October 2015

The tumor suppressor Adenomatous polyposis coli (APC) plays a key role in regulating the canonical Wnt signaling pathway as an essential component of the β-catenin destruction complex. C-terminal truncations of APC are strongly implicated in both sporadic and familial forms of colorectal cancer. However, many questions remain as to how these mutations interfere with APC’s tumor suppressor activity. One set of motifs frequently lost in these cancer-associated truncations is the SAMP repeats that mediate interactions between APC and Axin. APC proteins in both vertebrates and Drosophila contain multiple SAMP repeats that lack high sequence conservation outside of the Axin-binding motif. In this study, we tested the functional redundancy between different SAMPs and how these domains are regulated, using Drosophila APC2 and its two SAMP repeats as our model. Consistent with sequence conservation–based predictions, we show that SAMP2 has stronger binding activity to Axin in vitro, but SAMP1 also plays an essential role in the Wnt destruction complex in vivo. In addition, we demonstrate that the phosphorylation of SAMP repeats is a potential mechanism to regulate their activity. Overall our findings support a model in which each SAMP repeat plays a mechanistically distinct role but they cooperate for maximal destruction complex function.
Rust-Bio: a fast and safe bioinformatics library
Authors: Köster Johannes
Published: October 2015

Summary: We present Rust-Bio, the first general purpose bioinformatics library for the innovative Rust programming language. Rust-Bio leverages the unique combination of speed, memory safety and high-level syntax offered by Rust to provide a fast and safe set of bioinformatics algorithms and data structures with a focus on sequence analysis.

Availability and implementation: Rust-Bio is available open source under the MIT license at https://rust-bio.github.io.

Contact:  koester@jimmy.harvard.edu

Supplementary information:  Supplementary data are available at Bioinformatics online.
Residual Neuromuscular Block in the Elderly
Authors: Murphy Glenn S. , Szokol Joseph W. , Avram Michael J. , Greenberg Steven B. , Shear Torin D. , Vender Jeffery S. , Parikh Kruti N. , Patel Shivani S. , Patel Aashka
Published: October 2015

Background

Elderly patients are at increased risk for anesthesia-related complications. Postoperative residual neuromuscular block (PRNB) in the elderly, defined as a train-of-four ratio less than 0.9, may exacerbate preexisting muscle weakness and respiratory dysfunction. In this investigation, the incidence of PRNB and associated adverse events were assessed in an elderly (70 to 90 yr) and younger cohort (18 to 50 yr).

Methods

Data were prospectively collected on 150 younger and 150 elderly patients. Train-of-four ratios were measured on arrival to the postanesthesia care unit (PACU). After tracheal extubation, patients were examined for adverse respiratory events during transport to the PACU, for 30 min after PACU admission, and during hospital admission. Postoperative muscle weakness was quantified using a standardized examination, and PACU and hospital lengths of stay were determined.

Results

The incidence of PRNB was 57.7% in elderly and 30.0% in younger patients (difference, −27.7%; 99% CI, −41.2 to −13.1%; P < 0.001). Airway obstruction, hypoxemic events, signs and symptoms of muscle weakness, postoperative pulmonary complications, and increased PACU and hospital lengths of stay were observed more frequently in the elderly (all P < 0.01). Within each cohort, most adverse events were observed in patients with PRNB. Younger patients with PRNB received larger total doses of rocuronium than did those without it (60 vs. 50 mg, P < 0.01), but there were no differences in rocuronium dose between elderly patients with PRNB and those without it (both 50 mg).

Conclusion

The elderly are at increased risk for PRNB and associated adverse outcomes.
Plateletcrit in Ocular Pseudoexfoliation Syndrome
Authors: Yazgan Serpil , Celik Ugur , Kaldırım Havva , Ayar Orhan , Akdemir Mehmet Orcun
Published: October 2015

Purpose:

The aim of this study was to compare all platelet markers, especially plateletcrit (PCT, total platelet mass), in patients with and without ocular pseudoexfoliation (PEX) syndrome.

Methods:

One hundred six patients with ocular PEX syndrome (study group) and 106 individuals without ocular PEX syndrome (control group) were enrolled in this retrospective case-control study. The biochemical/hematological laboratory results of both the study and control groups were analyzed by a clinician blinded to the group assignments. The main outcome measures were the PCT, platelet count (PLT), mean platelet volume (MPV), and platelet distribution width (PDW).

Results:

The mean PCT in the study and control groups were 0.206%±0.520% and 0.171%±0.410%, respectively (P<0.001), and the mean PDW in the study and control groups were 16.12%±1.21% and 14.68%±1.40%, respectively (P<0.001). There were no differences in the MPV or mean PLT (P=0.138 and P=0.055, respectively). The PCT cutoff value was 0.180 (area under the receiver operating characteristics curve, 0.706; P<0.001; 65% sensitivity; 74% specificity).

Conclusions:

The PCT and PDW were significantly higher in patients with than without ocular PEX syndrome. These increased parameters may cause microvascular blood flow resistance and the heightened inflammatory response caused by excessive platelet activity, as with other cardiovascular diseases, and may also decrease aqueous humor outflow in ocular PEX syndrome.
The Expression of Cohesin Subunit SA2 Predicts Breast Cancer Survival
Authors: Repo Heli , Löyttyniemi Eliisa , Nykänen Marjukka , Lintunen Minnamaija , Karra Henna , Pitkänen Reino , Söderström Mirva , Kuopio Teijo , Kronqvist Pauliina
Published: October 2015

Cohesin is one of the main regulators of sister chromatid separation during the metaphase/anaphase transition. It is a multiprotein complex consisting of 4 core subunits, one of those being the SA2 subunit. SA2 plays the final role in dismantling the cohesion complex from the sister chromatids and also functions in DNA double-strand break repair and gene regulation. There is increasing evidence regarding the involvement of both overexpression and underexpression of cohesin in cancer. Here, we present expression patterns of SA2 in different types of human breast tissue, and the prognostic analysis in the material from breast cancer patients with long-term follow-up. SA2 immunoexpression was evaluated in benign, precancerous, and malignant breast tissue, and was classified into low-intensity or high-intensity groups. The DNA content was determined by image cytometry on breast cancer cell imprints. Prognostic analyses were based on 445 breast cancer patients with upto 20 years’ follow-up. SA2 immunoexpression was equally high in both benign and precancerous breast tissue. Instead, 72% of the invasive breast cancers showed deficient SA2 expression. These patients were also associated with an unfavorable outcome as indicated by a 1.6-fold risk of breast cancer death (P=0.0208). The majority (75%) of the patients with low SA2 expression were alive 6.0 years after the diagnosis, whereas the majority of the patients with high SA2 expression survived 17.6 years after the diagnosis. No statistically significant association could be detected between SA2 immunoexpression and DNA aneuploidy. Our results and previous literature indicate that decreased SA2 immunoexpression is associated with malignant breast disease and a particularly unfavorable course of disease.
Changing preferences: deformation of single position amino acid fitness landscapes and evolution of proteins
Authors: Bazykin Georgii A.
Published: October 2015

The fitness landscape—the function that relates genotypes to fitness—and its role in directing evolution are a central object of evolutionary biology. However, its huge dimensionality precludes understanding of even the basic aspects of its shape. One way to approach it is to ask a simpler question: what are the properties of a function that assigns fitness to each possible variant at just one particular site—a single position fitness landscape—and how does it change in the course of evolution? Analyses of genomic data from multiple species and multiple individuals within a species have proved beyond reasonable doubt that fitness functions of positions throughout the genome do themselves change with time, thus shaping protein evolution. Here, I will briefly review the literature that addresses these dynamics, focusing on recent genome-scale analyses of fitness functions of amino acid sites, i.e. vectors of fitnesses of 20 individual amino acid variants at a given position of a protein. The set of amino acids that confer high fitness at a particular position changes with time, and the rate of this change is comparable with the rate at which a position evolves, implying that this process plays a major role in evolutionary dynamics. However, the causes of these changes remain largely unclear.
Control of the dynamics and homeostasis of theDrosophilaHedgehog receptor Patched by two C2-WW-HECT-E3 Ubiquitin ligases
Authors: Brigui Amira , Hofmann Line , Argüelles Camilla , Sanial Matthieu , Holmgren Robert A. , Plessis Anne
Published: October 2015

The conserved Hedgehog (HH) signals control animal development, adult stem cell maintenance and oncogenesis. InDrosophila, the HH co-receptor Patched (PTC) controls both HH gradient formation and signalling. PTC is post-translationally downregulated by HH, which promotes its endocytosis and destabilization, but the mechanisms of PTC trafficking and its importance in the control of PTC remain to be understood. PTC interacts with E3 Ubiquitin (UB)-ligases of the C2-WW-HECT family; two of them—SMURF and NEDD4—are known to regulate its levels. We demonstrate that mutation of the PTC PY motif, which mediates binding of C2-WW-HECT family members, inhibits its internalization but not its autonomous and non-autonomous signalling activities. In addition, we show that the two related UB-C2-WW-HECT ligases NEDD4 and SU(DX) regulate PTC trafficking and finely tune its accumulation through partially redundant but distinct functions. While both NEDD4 and SU(DX) promote PTC endocytosis, only SU(DX) is able to induce its lysosomal targeting and degradation. In conclusion, PTC trafficking and homeostasis are tightly regulated by a family of UB-ligases.
Modality-specific attention in foraging bumblebees
Authors: Nityananda Vivek , Chittka Lars
Published: October 2015

Attentional demands can prevent humans and other animals from performing multiple tasks simultaneously. Some studies, however, show that tasks presented in different sensory modalities (e.g. visual and auditory) can be processed simultaneously. This suggests that, at least in these cases, attention might be modality-specific and divided differently between tasks when present in the same modality compared with different modalities. We investigated this possibility in bumblebees (
Bombus terrestris
) using a biologically relevant experimental set-up where they had to simultaneously choose more rewarding flowers and avoid simulated predatory attacks by robotic ‘spiders’. We found that when the tasks had to be performed using visual cues alone, bees failed to perform both tasks simultaneously. However, when highly rewarding flowers were indicated by olfactory cues and predators were indicated by visual cues, bees managed to perform both tasks successfully. Our results thus provide evidence for modality-specific attention in foraging bees and establish a novel framework for future studies of crossmodal attention in ecologically realistic settings.
Monkeys head-gaze following is fast, precise and not fully suppressible
Authors: Marciniak Karolina , Dicke Peter W. , Thier Peter
Published: October 2015

Human eye-gaze is a powerful stimulus, drawing the observer's attention to places and objects of interest to someone else (‘eye-gaze following’). The largely homogeneous eyes of monkeys, compromising the assessment of eye-gaze by conspecifics from larger distances, explain the absence of comparable eye-gaze following in these animals. Yet, monkeys are able to use peer head orientation to shift attention (‘head-gaze following’). How similar are monkeys' head-gaze and human eye-gaze following? To address this question, we trained rhesus monkeys to make saccades to targets, either identified by the head-gaze of demonstrator monkeys or, alternatively, identified by learned associations between the demonstrators' facial identities and the targets (gaze versus identity following). In a variant of this task that occurred at random, the instruction to follow head-gaze or identity was replaced in the course of a trial by the new rule to detect a change of luminance of one of the saccade targets. Although this change-of-rule rendered the demonstrator portraits irrelevant, they nevertheless influenced performance, reflecting a precise redistribution of spatial attention. The specific features depended on whether the initial rule was head-gaze or identity following: head-gaze caused an insuppressible shift of attention to the target gazed at by the demonstrator, whereas identity matching prompted much later shifts of attention, however, only if the initial rule had been identity following. Furthermore, shifts of attention prompted by head-gaze were spatially precise. Automaticity and swiftness, spatial precision and limited executive control characterizing monkeys' head-gaze following are key features of human eye-gaze following. This similarity supports the notion that both may rely on the same conserved neural circuitry.
Social interactions elicit rapid shifts in functional connectivity in the social decision-making network of zebrafish
Authors: Teles Magda C. , Almeida Olinda , Lopes João S. , Oliveira Rui F.
Published: October 2015

According to the social decision-making (SDM) network hypothesis, SDM is encoded in a network of forebrain and midbrain structures in a distributed and dynamic fashion, such that the expression of a given social behaviour is better reflected by the overall profile of activation across the different loci rather than by the activity of a single node. This proposal has the implicit assumption that SDM relies on integration across brain regions, rather than on regional specialization. Here we tested the occurrence of functional localization and of functional connectivity in the SDM network. For this purpose we used zebrafish to map different social behaviour states into patterns of neuronal activity, as indicated by the expression of the immediate early genesc-fosandegr-1, across the SDM network. The results did not support functional localization, as some loci had similar patterns of activity associated with different social behaviour states, and showed socially driven changes in functional connectivity. Thus, this study provides functional support to the SDM network hypothesis and suggests that the neural context in which a given node of the network is operating (i.e. the state of its interconnected areas) is central to its functional relevance.
Spring or string: does tendon elastic action influence wing muscle mechanics in bat flight?
Authors: Konow Nicolai , Cheney Jorn A. , Roberts Thomas J. , Waldman J. Rhea S. , Swartz Sharon M.
Published: October 2015

Tendon springs influence locomotor movements in many terrestrial animals, but their roles in locomotion through fluids as well as in small-bodied mammals are less clear. We measured muscle, tendon and joint mechanics in an elbow extensor of a small fruit bat during ascending flight. At the end of downstroke, the tendon was stretched by elbow flexion as the wing was folded. At the end of upstroke, elastic energy was recovered via tendon recoil and extended the elbow, contributing to unfurling the wing for downstroke. Compared with a hypothetical ‘string-like’ system lacking series elastic compliance, the tendon spring conferred a 22.5% decrease in muscle fascicle strain magnitude. Our findings demonstrate tendon elastic action in a small flying mammal and expand our understanding of the occurrence and action of series elastic actuator mechanisms in fluid-based locomotion.
Targeted predation of extrafloral nectaries by insects despite localized chemical defences
Authors: Gish Moshe , Mescher Mark C. , De Moraes Consuelo M.
Published: October 2015

Extrafloral (EF) nectaries recruit carnivorous arthropods that protect plants from herbivory, but they can also be exploited by nectar thieves. We studied the opportunistic, targeted predation (and destruction) of EF nectaries by insects, and the localized chemical defences that plants presumably use to minimize this effect. In field and laboratory experiments, we identified insects that were possibly responsible for EF nectary predation in
Vicia faba
(fava bean) and determined the extent and accuracy of the feeding damage done to the EF nectaries by these insects. We also performed biochemical analyses of plant tissue samples in order to detect microscale distribution patterns of chemical defences in the area of the EF nectary. We observed selective, targeted feeding on EF nectaries by several insect species, including some that are otherwise not primarily herbivorous. Biochemical analyses revealed high concentrations of
l
-3,4-dihydroxyphenylalanine, a non-protein amino acid that is toxic to insects, near and within the EF nectaries. These results suggest that plants allocate defences to the protection of EF nectaries from predation, consistent with expectations of optimal defence theory, and that this may not be entirely effective, as insects limit their exposure to these defences by consuming only the secreting tissue of the nectary.
Pelistega suis sp. nov., isolated from domestic and wild animals
Authors: Vela Ana I. , Perez Sancho Marta , Domínguez Lucas , Busse Hans-Jürgen , Fernández-Garayzábal Jose F.
Published: October 2015

Biochemical and molecular genetic studies were performed on three novel Gram-stain-negative, catalase- and oxidase-positive, bacilli-shaped organisms isolated from the tonsils of two pigs and one wild boar. The micro-organism was identified as a species of the genus Pelistega based on its cellular morphological and biochemical tests. The closest phylogenetic relative of the novel bacilli was Pelistega indica HM-7T (98.2 % 16S rRNA gene sequence similarity to the type strain). groEL and gyrB sequence analysis showed interspecies divergence from the closest 16S rRNA gene phylogenetic relative, P. indica of 87.0.% and 69 %, respectively. The polyamine pattern contains predominantly putrescine and 2-hydroxyputrescine. The major quinone is ubiquinone Q-8 and in the polar lipid profile, phosphatidylethanolamine, phosphatidylglycerol, an unidentified aminolipid and an unidentified lipid are predominant. The novel bacterial isolate can be distinguished from P. indica by several biochemical characteristics, such as the production of l-pyrrolydonil arylamidase but not gamma-glutamyl-transferase, and the utilization of different carbon sources. Based on both phenotypic and phylogenetic findings, the novel bacterium is classified as representing a novel species of the genus Pelistega, for which the name Pelistega suis sp. nov. is proposed. The type strain is 3340-03T ( = CECT 8400T = CCUG 64465T).
Zelda is differentially required for chromatin accessibility, transcription factor binding, and gene expression in the early Drosophila embryo
Authors: Schulz Katharine N. , Bondra Eliana R. , Moshe Arbel , Villalta Jacqueline E. , Lieb Jason D. , Kaplan Tommy , McKay Daniel J. , Harrison Melissa M.
Published: October 2015

The transition from a specified germ cell to a population of pluripotent cells occurs rapidly following fertilization. During this developmental transition, the zygotic genome is largely transcriptionally quiescent and undergoes significant chromatin remodeling. In Drosophila, the DNA-binding protein Zelda (also known as Vielfaltig) is required for this transition and for transcriptional activation of the zygotic genome. Open chromatin is associated with Zelda-bound loci, as well as more generally with regions of active transcription. Nonetheless, the extent to which Zelda influences chromatin accessibility across the genome is largely unknown. Here we used formaldehyde-assisted isolation of regulatory elements to determine the role of Zelda in regulating regions of open chromatin in the early embryo. We demonstrate that Zelda is essential for hundreds of regions of open chromatin. This Zelda-mediated chromatin accessibility facilitates transcription-factor recruitment and early gene expression. Thus, Zelda possesses some key characteristics of a pioneer factor. Unexpectedly, chromatin at a large subset of Zelda-bound regions remains open even in the absence of Zelda. The GAGA factor-binding motif and embryonic GAGA factor binding are specifically enriched in these regions. We propose that both Zelda and GAGA factor function to specify sites of open chromatin and together facilitate the remodeling of the early embryonic genome.
In situmicroradioscopy and microtomography of fatigue-loaded dental two-piece implants
Authors: Wiest Wolfram , Zabler Simon , Rack Alexander , Fella Christian , Balles Andreas , Nelson Katja , Schmelzeisen Rainer , Hanke Randolf
Published: October 2015

Synchrotron real-time radioscopy andin situmicrotomography are the only techniques providing direct visible information on a micrometre scale of local deformation in the implant–abutment connection (IAC) during and after cyclic loading. The microgap formation at the IAC has been subject to a number of studies as it has been proposed to be associated with long-term implant success. The next step in this scientific development is to focus on thein situfatigue procedure of two-component dental implants. Therefore, an apparatus has been developed which is optimized for thein situfatigue analysis of dental implants. This report demonstrates both the capability ofin situradioscopy and microtomography at the ID19 beamline for the study of cyclic deformation in dental implants. The first results show that it is possible to visualize fatigue loading of dental implants in real-time radioscopy in addition to thein situfatigue tomography. For the latter,in situmicrotomography is applied during the cyclic loading cycles in order to visualize the opening of the IAC microgap. These results concur with previousex situstudies on similar systems. The setup allows for easily increasing the bending force, to simulate different chewing situations, and is, therefore, a versatile tool for examining the fatigue processes of dental implants and possibly other specimens.
A modular and compact portable mini-endstation for high-precision, high-speed fixed target serial crystallography at FEL and synchrotron sources
Authors: Sherrell Darren A. , Foster Andrew J. , Hudson Lee , Nutter Brian , O'Hea James , Nelson Silke , Paré-Labrosse Olivier , Oghbaey Saeed , Miller R. J. Dwayne , Owen Robin L.
Published: October 2015

The design and implementation of a compact and portable sample alignment system suitable for use at both synchrotron and free-electron laser (FEL) sources and its performance are described. The system provides the ability to quickly and reliably deliver large numbers of samples using the minimum amount of sample possible, through positioning of fixed target arrays into the X-ray beam. The combination of high-precision stages, high-quality sample viewing, a fast controller and a software layer overcome many of the challenges associated with sample alignment. A straightforward interface that minimizes setup and sample changeover time as well as simplifying communication with the stages during the experiment is also described, together with an intuitive naming convention for defining, tracking and locating sample positions. The setup allows the precise delivery of samples in predefined locations to a specific position in space and time, reliably and simply.
Building analytic skills to drive improvements in patient care and organisational decision making
Authors: Howard Glen , Walker Alex , Shaw Dominick E , Hatton James
Published: October 2015

Purpose

– This paper briefly outlines a development programme designed to improve the skills of NHS Information Analysts and assesses the extent these skills have been developed. There are significant opportunities for the NHS to utilise information more effectively, and Analysts have a key role. However, training opportunities prior to the development of this programme have been limited for this professional group. The purpose of this paper is to explore the potential benefits to the organisations, patients and the NHS as a whole, that improvements in the quality of analysis can deliver.

Design/methodology/approach

– The authors compared pre-course and post-course self-assessment of skill levels of Analysts who attended the programme. The authors also considered general feedback and comments from participants.

Findings

– All of the 40 skills areas assessed demonstrated an increase in mean competency score. In cohorts 1 and 2, 38 of these were statistically significant (p
<
0.001-0.041, mean increase in score 1.0). For cohorts 3-5, 37 were statistically significant (p
<
0.001-0.012; mean increase 1.2). These findings were supported by the positive feedback from participants.

Practical implications

– The programme develops skills for NHS Information Analysts which can improve the quality of analysis in the NHS, offering significant potential to improve the effectiveness and efficiency of healthcare.

Originality/value

– The Information Analysts’ Development Programme provides the only training programme available for NHS Information Analysts, contributing to the development of data driven service improvement within the NHS. This may harness the power contained within data to drive improvement and ensure patients receive the highest quality of care.
Community care reaches out for the mobile moment
Authors: Wallace Simon
Published: October 2015

Purpose

– The purpose of this paper is to explore the quite extraordinary way the phenomena of mobile communication has gripped our society and the opportunities this provides for healthcare.

Design/methodology/approach

– It describes the ticking public health time bomb surrounding long term conditions and dementia and the need to radically overhaul how community services are delivered. It dissects the opportunities and challenges of providing a mobile health and social care service in the community and explores what a mobile moment means for these professionals.

Findings

– It stresses that the answer is NOT to simply provide an organisation’s IT back-office environment in the field and describes the concept of a dedicated organisation app platform tailored to meet this need.

Originality/value

– The paper concludes by reviewing recent evidence about the benefits and opportunities for health and social care organisations to embrace mobile working.