bluuebunny/crossref_metadata_2025 huggingface dataset:
A Sequence of Triangle-Free Pseudorandom Graphs
Authors: CONLON DAVID
Published: September 2016

A construction of Alon yields a sequence of highly pseudorandom triangle-free graphs with edge density significantly higher than one might expect from comparison with random graphs. We give an alternative construction for such graphs.
Elective amputation of a “healthy limb”
Authors: Blom Rianne M. , Guglielmi Valeria , Denys Damiaan
Published: September 2016

Patients with body integrity identity disorder (BIID) experience a strong desire for amputation from very early on. BIID patients are often dismissed when they share their wish for amputation with surgeons. Consequently, patients resort to self-amputation, including complications and sometimes death. BIID patients are not psychotic and are mentally competent to oversee the consequences of an elective amputation. The authors offer arguments in favor of elective amputation.
THE FAILURE OF UNIVERSAL THEORIES OF TORT LAW
Authors: Goudkamp James , Murphy John
Published: September 2016

Many scholars have offered theories that purport to explain the whole of the law of torts. At least some of these theories do not seem to be specific to a single jurisdiction. Several appear to endeavor to account for tort law in at least the major common law jurisdictions or even throughout the common law world. These include Ernest Weinrib's corrective justice theory, Robert Stevens's rights theory, and Richard Posner's economic theory. This article begins by explaining why it is appropriate to understand these three theories as universal theories of tort law and why it is important that they be so understood. This explanation draws upon various overt claims (or other strong intimations) made by the theorists themselves to the effect that this is how their respective accounts should be understood. The article then proceeds to test these theories, all of which are leading accounts of tort law, against the evidence in Australia, Canada, the United Kingdom, and the United States. The parts of tort law on which we focus are (1) the breach element of the action in negligence, (2) the law that determines when a duty of care will be owed in respect of pure economic loss, (3) the law that governs the availability of punitive damages, (4) the defense of illegality, and (5) the rule in Rylands v. Fletcher and its descendants. The article concludes that none of the theories is a satisfactory universal account of tort law. All of them suffer from significant problems of fit in that they cannot accommodate (often even approximately) the areas of law that we discuss. Although each of the theories contains a great many valuable insights, they all nonetheless fall well short of accomplishing that which they are held out as providing. In the course of this analysis, the article explains why this is an appropriate line of criticism and identifies the degree of lack of fit that we regard as being “significant.”
HOPF CYCLES IN ONE-SECTOR OPTIMAL GROWTH MODELS WITH TIME DELAY
Authors: Özbay Hitay , Sağlam Hüseyin Çağrı , Yüksel Mustafa Kerem
Published: September 2016

This paper analyzes the existence of Hopf bifurcation and establishes the conditions under which the equilibrium path converges toward periodic solutions in a one-sector optimal growth model with delay. We establish the limits and the possibilities of nonlinear dynamics (i.e., cycles) vis-à-vis delays. In particular, we formulate a new method to further comprehend the root distribution of the characteristic equation of a standard optimal growth model with delayed investment structure. We show that nonmonotonic dynamics (limit cycles, persistent oscillations) occurs when the delayed investment causes permanent adjustment failures among the economic variables in the economy.
Assessing the relative validity of the Scottish Collaborative Group FFQ for measuring dietary intake in adults
Authors: Hollis Jenna L , Craig Leone CA , Whybrow Stephen , Clark Heather , Kyle Janet AM , McNeill Geraldine
Published: September 2016

Objective

To assess the relative validity of the latest version of the Scottish Collaborative Group (SCG) FFQ (version 6.6) in adults living in Scotland.

Design

A cross-sectional validation study. Participants completed the self-administered, 169-item SCG FFQ followed by a 7 d, non-weighed food diary. Energy and energy-adjusted macronutrients and micronutrients were examined for relative validity through Spearman’s correlation, the percentage of classification into thirds of intake, Cohen’s weighted kappa (κw) and Bland–Altman analysis.

Setting

General population living in Scotland.

Subjects

Ninety-six adults aged 18–65 years.

Results

Spearman’s correlation coefficients ranged from 0·21 (retinol) to 0·71 (Mg). A median of 52 % of adults were correctly classified into thirds of intake (range: 42 % (PUFA, MUFA and Fe) to 64 % (percentage energy from carbohydrates)) and 8 % were grossly misclassified into opposite thirds of intake (range: 3 % (carbohydrates, percentage energy from carbohydrates) to 19 % (thiamin)). Values of κw ranged between 0·20 (PUFA, β-carotene) to 0·55 (percentage energy from carbohydrates). In the Bland–Altman analysis, the smallest limits of agreement, when expressed as a percentage of the mean intake from the FFQ and food diary, were seen for the main macronutrients carbohydrates, fat and protein.

Conclusions

As in the previous validation study more than 10 years ago, the FFQ gave higher estimates of energy and most nutrients than the food diary, but after adjustment for energy intake the FFQ could be used in place of non-weighed food diaries for most macronutrients and many micronutrients in large-scale epidemiological studies.
Seasonal variation of food security among the Batwa of Kanungu, Uganda
Authors: Patterson Kaitlin , Berrang-Ford Lea , Lwasa Shuaib , Namanya Didacus B , Ford James , Twebaze Fortunate , Clark Sierra , Donnelly Blánaid , Harper Sherilee L
Published: September 2016

Objective

Climate change is projected to increase the burden of food insecurity (FI) globally, particularly among populations that depend on subsistence agriculture. The impacts of climate change will have disproportionate effects on populations with higher existing vulnerability. Indigenous people consistently experience higher levels of FI than their non-Indigenous counterparts and are more likely to be dependent upon land-based resources. The present study aimed to understand the sensitivity of the food system of an Indigenous African population, the Batwa of Kanungu District, Uganda, to seasonal variation.

Design

A concurrent, mixed methods (quantitative and qualitative) design was used. Six cross-sectional retrospective surveys, conducted between January 2013 and April 2014, provided quantitative data to examine the seasonal variation of self-reported household FI. This was complemented by qualitative data from focus group discussions and semi-structured interviews collected between June and August 2014.

Setting

Ten rural Indigenous communities in Kanungu District, Uganda.

Subjects

FI data were collected from 130 Indigenous Batwa Pygmy households. Qualitative methods involved Batwa community members, local key informants, health workers and governmental representatives.

Results

The dry season was associated with increased FI among the Batwa in the quantitative surveys and in the qualitative interviews. During the dry season, the majority of Batwa households reported greater difficulty in acquiring sufficient quantities and quality of food. However, the qualitative data indicated that the effect of seasonal variation on FI was modified by employment, wealth and community location.

Conclusions

These findings highlight the role social factors play in mediating seasonal impacts on FI and support calls to treat climate associations with health outcomes as non-stationary and mediated by social sensitivity.
Nonlinear modeling, time-domain analysis and simulation of non-Foster elements
Authors: Khoshniyat Hamed , Abdipour Abdolali , Moradi Gholamreza
Published: September 2016

In this paper, the structure of a common field-effect transistor (FET)-based negative impedance converter (NIC) that behaves as a negative capacitor is presented. The nonlinear modeling, analysis, and simulation of this non-Foster structure are presented in the time domain and the transient response of the circuit can be used to study the stability of the circuit. For the analysis of the circuit performance, the linear time-dependent modeling approach is used. This method is based on determination of the circuit parameters at each step according to parameters of the previous steps, bias voltages, and the input signal. Results of the proposed method for analysis of non-Foster circuit are compared with those of nonlinear analysis using commercial software, which shows a good agreement together and the proposed method is validated. Based on the analysis, the nonlinear capacitance of non-Foster circuit is extracted and based on the simple second order model of current source of FET, the analytic model of negative capacitor is extracted and improved by curve fitting. The proposed model results have a good agreement with simulation results of NIC's circuit.
An Underlying Common Factor, Influenced by Genetics and Unique Environment, Explains the Covariation Between Major Depressive Disorder, Generalized Anxiety Disorder, and Burnout: A Swedish Twin Study
Authors: Mather Lisa , Blom Victoria , Bergström Gunnar , Svedberg Pia
Published: September 2016

Depression and anxiety are highly comorbid due to shared genetic risk factors, but less is known about whether burnout shares these risk factors. We aimed to examine whether the covariation between major depressive disorder (MDD), generalized anxiety disorder (GAD), and burnout is explained by common genetic and/or environmental factors. This cross-sectional study included 25,378 Swedish twins responding to a survey in 2005–2006. Structural equation models were used to analyze whether the trait variances and covariances were due to additive genetics, non-additive genetics, shared environment, and unique environment. Univariate analyses tested sex limitation models and multivariate analysis tested Cholesky, independent pathway, and common pathway models. The phenotypic correlations were 0.71 (0.69–0.74) between MDD and GAD, 0.58 (0.56–0.60) between MDD and burnout, and 0.53 (0.50–0.56) between GAD and burnout. Heritabilities were 45% for MDD, 49% for GAD, and 38% for burnout; no statistically significant sex differences were found. A common pathway model was chosen as the final model. The common factor was influenced by genetics (58%) and unique environment (42%), and explained 77% of the variation in MDD, 69% in GAD, and 44% in burnout. GAD and burnout had additive genetic factors unique to the phenotypes (11% each), while MDD did not. Unique environment explained 23% of the variability in MDD, 20% in GAD, and 45% in burnout. In conclusion, the covariation was explained by an underlying common factor, largely influenced by genetics. Burnout was to a large degree influenced by unique environmental factors not shared with MDD and GAD.
Parasympathetic Concomitants of Habitual, Spontaneous, and Instructed	Emotional Suppression
Authors: Gračanin Asmir , Kardum Igor , Hudek-Knežević Jasna
Published: September 2016

Abstract. The neurovisceral integration model proposes that different forms of self-regulation, including the emotional suppression, are characterized by the activation of neural network whose workings are also reflected in respiratory sinus arrhythmia (RSA). However, most of the previous studies failed to observe theoretically expected increases in RSA during emotional suppression. Even when such effects were observed, it was not clear whether they resulted from specific task demands, a decrease in muscle activity, or they were the consequence of more specific self-control processes. We investigated the relation between habitual or trait-like suppression, spontaneous, and instructed suppression with changes in RSA during negative emotion experience. A modest positive correlation between spontaneous situational and habitual suppression was observed across two experimental tasks. Furthermore, the results showed greater RSA increase among participants who experienced higher negative affect (NA) increase and reported higher spontaneous suppression than among those with higher NA increase and lower spontaneous suppression. Importantly, this effect was independent from the habitual suppression and observable facial expressions. The results of the additional task based on experimental manipulation, rather than spontaneous use of situational suppression, indicated a similar relation between suppression and RSA. Our results consistently demonstrate that emotional suppression, especially its self-regulation component, is followed by the increase in parasympathetic activity.
The Relationship Between Quality of Sleep and Emotional	Empathy
Authors: Guadagni Veronica , Burles Ford , Valera Silvana , Hardwicke-Brown Emeleigh , Ferrara Michele , Campbell Tavis , Iaria Giuseppe
Published: September 2016

Abstract. Sleep loss is known to severely disturb individuals’ mood and emotion processing. Here, we tested the hypothesis that quality of sleep is predictive of individuals’ performance on a task evaluating emotional empathy. We tested 34 healthy undergraduate students [19 males, mean (SD) age = 21.82 (3.26) years; mean (SD) education = 14.98 (1.91) years] recruited through the University of Calgary research participation system. We collected objective (actigraphy) and subjective (questionnaires and self-reports) sleep measures to characterize individuals’ sleep quality, and asked participants to solve a computerized emotional empathy task. We first performed a dimensionality reduction analysis on the sleep-related measures, which resulted in six principal components, and then ran a stepwise multiple regression analysis to investigate the sleep measures that best predicted participants’ scores on the emotional empathy task. We found that subjective sleep quality, together with sleep phase, best predicted participants’ empathic sensitivity to negative images while they explicitly evaluated the emotions of others (i.e., direct component of emotional empathy). Also, subjective sleep quality resulted to be the best predictor of participants’ arousal state in response to negative images, which is an implicit manifestation of their empathic experience (i.e., indirect component of emotional empathy). In both cases, lower subjective sleep quality was associated with lower empathic sensitivity to negative stimuli. Finally, sleep duration best predicted average empathic responses to stimuli of all valences, with shorter sleep durations associated with lower average empathic responses. Our findings provide evidence of a significant relationship between individuals’ quality of sleep and their ability to share the emotions experienced by others. These findings may have important implications for individuals employed in professions requiring social interaction and empathic experience coupled with schedules that interfere with nighttime sleep.
Self-Perceived Competence and Test Anxiety
Authors: Raufelder Diana , Ringeisen Tobias
Published: September 2016

Abstract. Extrapolating from social-cognitive theory, this research examined whether academic self-efficacy mediates the association between academic self-concept and the four facets of test anxiety (worry, interference, lack of confidence, emotionality) in a large sample of adolescent students (N = 845; Mage = 15.32; SD = 0.49) from Brandenburg, Germany. Quantitative data structural equation modeling (SEM) was employed to analyze these associations. Results showed that there are negative relations between academic self-concept and three facets of test anxiety (namely interference, lack of confidence, emotionality), which are mitigated through academic self-efficacy. All three identified indirect effects revealed full mediation. Overall, the current study extends the literature on test anxiety in education settings by highlighting the importance of academic self-efficacy for prevention and intervention strategies that aim to reduce adolescents’ feelings of test anxiety, as academic self-efficacy fully mediates the association between academic self-concept and three facets of test anxiety, except for worry.
Structural insight into the arginine-binding specificity of CASTOR1 in amino acid-dependent mTORC1 signaling
Authors: Xia Jing , Wang Rong , Zhang Tianlong , Ding Jianping
Published: September 2016

The mechanistic Target Of Rapamycin Complex 1 (mTORC1) is central to the cellular response to changes in nutrient signals such as amino acids. CASTOR1 is shown to be an arginine sensor, which plays an important role in the activation of the mTORC1 pathway. In the deficiency of arginine, CASTOR1 interacts with GATOR2, which together with GATOR1 and Rag GTPases controls the relocalization of mTORC1 to lysosomes. The binding of arginine to CASTOR1 disrupts its association with GATOR2 and hence activates the mTORC1 signaling. Here, we report the crystal structure of CASTOR1 in complex with arginine at 2.5 Å resolution. CASTOR1 comprises of four tandem ACT domains with an architecture resembling the C-terminal allosteric domains of aspartate kinases. ACT1 and ACT3 adopt the typical βαββαβ topology and function in dimerization via the conserved residues from helices α1 of ACT1 and α5 of ACT3; whereas ACT 2 and ACT4, both comprising of two non-sequential regions, assume the unusual ββαββα topology and contribute an arginine-binding pocket at the interface. The bound arginine makes a number of hydrogen-bonding interactions and extensive hydrophobic contacts with the surrounding residues of the binding pocket. The functional roles of the key residues are validated by mutagenesis and biochemical assays. Our structural and functional data together reveal the molecular basis for the arginine-binding specificity of CASTOR1 in the arginine-dependent activation of the mTORC1 signaling.
Anks1a regulates COPII-mediated anterograde transport of receptor tyrosine kinases critical for tumorigenesis
Authors: Lee Haeryung , Noh Hyuna , Mun Jiyoung , Gu Changkyu , Sever Sanja , Park Soochul
Published: September 2016

ErbB2 signalling, which is amplified by EphA2 binding, is an important therapeutic target for breast cancer. Despite the importance of the EphA2/ErbB2 complex in promoting breast tumorigenesis, the mechanism by which these receptor tyrosine kinases (RTKs) are exported from the endoplasmic reticulum (ER) remains poorly understood. Here we report that the PTB adaptor Anks1a is specifically localized to the ER on its own serine phosphorylation. Once there, Anks1a acts as an important regulator of COPII-mediated EphA2 ER export. The Anks1a ankyrin repeat domain binds EphA2 and causes it to accumulate at sites of ER exit. Simultaneously, the Anks1a PTB domain binds Sec23. This induces internalization of EphA2 via COPII vesicles, while Anks1a remains behind on the ER membrane. EphA2 also binds ErbB2 in the ER and seems to load ErbB2 into growing COPII carriers. Together, our study reveals a novel mechanism that regulates the loading of RTKs into COPII vesicles.
Multi-millijoule few-cycle mid-infrared pulses through nonlinear self-compression in bulk
Authors: Shumakova V. , Malevich P. , Ališauskas S. , Voronin A. , Zheltikov A. M. , Faccio D. , Kartashov D. , Baltuška A. , Pugžlys A.
Published: September 2016

The physics of strong-field applications requires driver laser pulses that are both energetic and extremely short. Whereas optical amplifiers, laser and parametric, boost the energy, their gain bandwidth restricts the attainable pulse duration, requiring additional nonlinear spectral broadening to enable few or even single cycle compression and a corresponding peak power increase. Here we demonstrate, in the mid-infrared wavelength range that is important for scaling the ponderomotive energy in strong-field interactions, a simple energy-efficient and scalable soliton-like pulse compression in a mm-long yttrium aluminium garnet crystal with no additional dispersion management. Sub-three-cycle pulses with >0.44 TW peak power are compressed and extracted before the onset of modulation instability and multiple filamentation as a result of a favourable interplay between strong anomalous dispersion and optical nonlinearity around the wavelength of 3.9 μm. As a manifestation of the increased peak power, we show the evidence of mid-infrared pulse filamentation in atmospheric air.
Discovery of a Metastatic Immune Escape Mechanism Initiated by the Loss of Expression of the Tumour Biomarker Interleukin-33
Authors: Saranchova Iryna , Han Jeffrey , Huang Hui , Fenninger Franz , Choi Kyung Bok , Munro Lonna , Pfeifer Cheryl , Welch Ian , Wyatt Alexander W. , Fazli Ladan , Gleave Martin E. , Jefferies Wilfred A.
Published: September 2016

A new paradigm for understanding immune-surveillance and immune escape in cancer is described here. Metastatic carcinomas express reduced levels of IL-33 and diminished levels of antigen processing machinery (APM), compared to syngeneic primary tumours. Complementation of IL-33 expression in metastatic tumours upregulates APM expression and functionality of major histocompatibility complex (MHC)-molecules, resulting in reduced tumour growth rates and a lower frequency of circulating tumour cells. Parallel studies in humans demonstrate that low tumour expression of IL-33 is an immune biomarker associated with recurrent prostate and kidney renal clear cell carcinomas. Thus, IL-33 has a significant role in cancer immune-surveillance against primary tumours, which is lost during the metastatic transition that actuates immune escape in cancer.
Maze learning by a hybrid brain-computer system
Authors: Wu Zhaohui , Zheng Nenggan , Zhang Shaowu , Zheng Xiaoxiang , Gao Liqiang , Su Lijuan
Published: September 2016

The combination of biological and artificial intelligence is particularly driven by two major strands of research: one involves the control of mechanical, usually prosthetic, devices by conscious biological subjects, whereas the other involves the control of animal behaviour by stimulating nervous systems electrically or optically. However, to our knowledge, no study has demonstrated that spatial learning in a computer-based system can affect the learning and decision making behaviour of the biological component, namely a rat, when these two types of intelligence are wired together to form a new intelligent entity. Here, we show how rule operations conducted by computing components contribute to a novel hybrid brain-computer system, i.e., ratbots, exhibit superior learning abilities in a maze learning task, even when their vision and whisker sensation were blocked. We anticipate that our study will encourage other researchers to investigate combinations of various rule operations and other artificial intelligence algorithms with the learning and memory processes of organic brains to develop more powerful cyborg intelligence systems. Our results potentially have profound implications for a variety of applications in intelligent systems and neural rehabilitation.
Sterilization Effects of Adult-targeted Baits Containing Insect Growth Regulators on Delia antiqua
Authors: Zhou Fangyuan , Zhu Guodong , Zhao Haipeng , Wang Zheng , Xue Ming , Li Xianxian , Xu Huaqiang , Ma Xiaodan , Liu Yanyan
Published: September 2016

The onion maggot, Delia antiqua, is a devastating pest of liliaceous crops and current control measures fail to avert pesticide residues, threats to agroecosystem, and costly expenditures. Insect growth regulators (IGRs) are used as trypetid pest chemosterilants for their suppression on adult fertility and fecundity, but their effects on onion flies are unknown. Here, three IGRs (lufenuron, cyromazine, pyriproxyfen) were incorporated into baits to evaluate their effects on onion fly survival, fecundity, fertility, susceptibility of adults in different ages and offspring development. Lufenuron and cyromazine did not affect survival of new-emerged adults, but lufenuron inhibited adult fertility without affecting fecundity, and cyromazine reduced fertility and fecundity. Differently, pyriproxyfen enhanced fecundity within 10 days after treatment, while it reduced adult survival without affecting fertility. The fertility of younger adults was affected by lufenuron and cyromazine whereas the fecundity was affected with cyromazine and pyriproxyfen. For offspring of onion flies treated with lufenuron or cyromazine, most of larvae died within 5 days after hatch, but surviving larvae pupated and emerged normally. Pyriproxyfen did not affect offspring larval survival or pupation but affected pupal emergence. Thus, lufenuron and cyromazine could be potential chemosterilants for onion flies.
Augmented 3D super-resolution of fluorescence-free nanoparticles using enhanced dark-field illumination based on wavelength-modulation and a least-cubic algorithm
Authors: Zhang Peng , Kim Kyungsoo , Lee Seungah , Chakkarapani Suresh Kumar , Fang Ning , Kang Seong Ho
Published: September 2016

Augmented three-dimensional (3D) subdiffraction-limited resolution of fluorescence-free single-nanoparticles was achieved with wavelength-dependent enhanced dark-field (EDF) illumination and a least-cubic algorithm. Various plasmonic nanoparticles on a glass slide (i.e., gold nanoparticles, GNPs; silver nanoparticles, SNPs; and gold nanorods, GNRs) were imaged and sliced in the z-direction to a thickness of 10 nm. Single-particle images were then compared with simulation data. The 3D coordinates of individual GNP, SNP, and GNR nanoparticles (x,y,z) were resolved by fitting the data with 3D point spread functions using a least-cubic algorithm and collation. Final, 3D super-resolution microscopy (SRM) images were obtained by resolving 3D coordinates and their Cramér-Rao lower bound-based localization precisions in an image space (530 nm × 530 nm × 300 nm) with a specific voxel size (2.5 nm × 2.5 nm × 5 nm). Compared with the commonly used least-square method, the least-cubic method was more useful for finding the center in asymmetric cases (i.e., nanorods) with high precision and accuracy. This novel 3D fluorescence-free SRM technique was successfully applied to resolve the positions of various nanoparticles on glass and gold nanospots (in vitro) as well as in a living single cell (in vivo) with subdiffraction limited resolution in 3D.
πSPIM: high NA high resolution isotropic light-sheet imaging in cell culture dishes
Authors: Theer Patrick , Dragneva Denitsa , Knop Michael
Published: September 2016

Light-sheet fluorescence microscopy (LSFM), also termed single plane illumination microscopy (SPIM), enables live cell fluorescence imaging with optical sectioning capabilities superior to confocal microscopy and without any out-of-focus exposure of the specimen. However, the need of two objective lenses, one for light-sheet illumination and one for imaging, imposes geometrical constraints that require LSFM setups to be adapted to the specific needs of different types of specimen in order to obtain optimal imaging conditions. Here we demonstrate the use of an oblique light-sheet configuration adapted to provide the highest possible Gaussian beam enabled resolution in LSFM. The oblique light-sheet configuration furthermore enables LSFM imaging at the surface of a cover slip, without the need of specific sample mounting. In addition, the system is compatible with simultaneous high NA wide-field epi-fluorescence imaging of the specimen contained in a glass-bottom cell culture dish. This prevents cumbersome sample mounting and enables rapid screening of large areas of the specimen followed by high-resolution LSFM imaging of selected cells. We demonstrate the application of this microscope for in toto imaging of endocytosis in yeast, showing for the first time imaging of all endocytic events of a given cell over a period of >5 minutes with sub-second resolution.
Linkages between atmospheric blocking, sea ice export through Fram Strait and the Atlantic Meridional Overturning Circulation
Authors: Ionita M. , Scholz P. , Lohmann G. , Dima M. , Prange M.
Published: September 2016

As a key persistent component of the atmospheric dynamics, the North Atlantic blocking activity has been linked to extreme climatic phenomena in the European sector. It has also been linked to Atlantic multidecadal ocean variability, but its potential links to rapid oceanic changes have not been investigated. Using a global ocean-sea ice model forced with atmospheric reanalysis data, here it is shown that the 1962–1966 period of enhanced blocking activity over Greenland resulted in anomalous sea ice accumulation in the Arctic and ended with a sea ice flush from the Arctic into the North Atlantic Ocean through Fram Strait. This event induced a significant decrease of Labrador Sea water surface salinity and an abrupt weakening of the Atlantic Meridional Overturning Circulation (AMOC) during the 1970s. These results have implications for the prediction of rapid AMOC changes and indicate that an important part of the atmosphere-ocean dynamics at mid- and high latitudes requires a proper representation of the Fram Strait sea ice transport and of the synoptic scale variability such as atmospheric blocking, which is a challenge for current coupled climate models.
From Biological Cilia to Artificial Flow Sensors: Biomimetic Soft Polymer Nanosensors with High Sensing Performance
Authors: Asadnia Mohsen , Kottapalli Ajay Giri Prakash , Karavitaki K. Domenica , Warkiani Majid Ebrahimi , Miao Jianmin , Corey David P. , Triantafyllou Michael
Published: September 2016

We report the development of a new class of miniature all-polymer flow sensors that closely mimic the intricate morphology of the mechanosensory ciliary bundles in biological hair cells. An artificial ciliary bundle is achieved by fabricating bundled polydimethylsiloxane (PDMS) micro-pillars with graded heights and electrospinning polyvinylidenefluoride (PVDF) piezoelectric nanofiber tip links. The piezoelectric nature of a single nanofiber tip link is confirmed by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Rheology and nanoindentation experiments are used to ensure that the viscous properties of the hyaluronic acid (HA)-based hydrogel are close to the biological cupula. A dome-shaped HA hydrogel cupula that encapsulates the artificial hair cell bundle is formed through precision drop-casting and swelling processes. Fluid drag force actuates the hydrogel cupula and deflects the micro-pillar bundle, stretching the nanofibers and generating electric charges. Functioning with principles analogous to the hair bundles, the sensors achieve a sensitivity and threshold detection limit of 300 mV/(m/s) and 8 μm/s, respectively. These self-powered, sensitive, flexible, biocompatibale and miniaturized sensors can find extensive applications in navigation and maneuvering of underwater robots, artificial hearing systems, biomedical and microfluidic devices.
Altered Intranetwork and Internetwork Functional Connectivity in Type 2 Diabetes Mellitus With and Without Cognitive Impairment
Authors: Yang Shi-Qi , Xu Zhi-Peng , Xiong Ying , Zhan Ya-Feng , Guo Lin-Ying , Zhang Shun , Jiang Ri-Feng , Yao Yi-Hao , Qin Yuan-Yuan , Wang Jian-Zhi , Liu Yong , Zhu Wen-Zhen
Published: September 2016

Type 2 diabetes mellitus (T2DM) is associated with cognitive impairment. We investigated whether alterations of intranetwork and internetwork functional connectivity with T2DM progression exist, by using resting-state functional MRI. MRI data were analysed from 19 T2DM patients with normal cognition (DMCN) and 19 T2DM patients with cognitive impairment (DMCI), 19 healthy controls (HC). Functional connectivity among 36 previously well-defined brain regions which consisted of 5 resting-state network (RSN) systems [default mode network (DMN), dorsal attention network (DAN), control network (CON), salience network (SAL) and sensorimotor network (SMN)] was investigated at 3 levels (integrity, network and connectivity). Impaired intranetwork and internetwork connectivity were found in T2DM, especially in DMCI, on the basis of the three levels of analysis. The bilateral posterior cerebellum, the right insula, the DMN and the CON were mainly involved in these changes. The functional connectivity strength of specific brain architectures in T2DM was found to be associated with haemoglobin A1c (HbA1c), cognitive score and illness duration. These network alterations in intergroup differences, which were associated with brain functional impairment due to T2DM, indicate that network organizations might be potential biomarkers for predicting the clinical progression, evaluating the cognitive impairment, and further understanding the pathophysiology of T2DM.
Controllable two-scale network architecture and enhanced mechanical properties of (Ti5Si3+TiBw)/Ti6Al4V composites
Authors: Jiao Y. , Huang L. J. , Duan T. B. , Wei S. L. , Kaveendran B. , Geng L.
Published: September 2016

Novel Ti6Al4V alloy matrix composites with a controllable two-scale network architecture were successfully fabricated by reaction hot pressing (RHP). TiB whiskers (TiBw) were in-situ synthesized around the Ti6Al4V matrix particles, and formed the first-scale network structure (FSNS). Ti5Si3 needles (Ti5Si3) precipitated in the β phase around the equiaxed α phase, and formed the secondary-scale network structure (SSNS). This resulted in increased deformation compatibility accompanied with enhanced mechanical properties. Apart from the reinforcement distribution and the volume fraction, the ratio between Ti5Si3 and TiBw fraction were controlled. The prepared (Ti5Si3 + TiBw)/Ti6Al4V composites showed higher tensile strength and ductility than the composites with a one-scale microstructure, and superior wear resistance over the Ti6Al4V alloy under dry sliding wear conditions at room temperature.
Changes in intracellular copper concentration and copper-regulating gene expression after PC12 differentiation into neurons
Authors: Ogra Yasumitsu , Tejima Aya , Hatakeyama Naohiro , Shiraiwa Moeko , Wu Siyuan , Ishikawa Tsutomu , Yawata Ayako , Anan Yasumi , Suzuki Noriyuki
Published: September 2016

It is suspected that some neurodegenerative diseases are a result of the disturbance of copper (Cu) homeostasis, although it remains unclear whether the disturbance of Cu homeostasis has aberrant effects on neurons. Herein, we investigated Cu metabolism specifically in neurons in terms of changes in the intracellular Cu concentration and the expression of Cu-regulating genes, such as Cu transporters and metallothioneins (MTs), before and after the differentiation of rat pheochromocytoma cells (PC12 cells) into neurons. After the differentiation, Cu and Zn imaging with fluorescent probes revealed an increase in intracellular Cu concentration. The concentrations of other essential metals, which were determined by an inductively coupled plasma mass spectrometer, were not altered. The mRNA expression of the Cu influx transporter, Ctr1, was decreased after the differentiation, and the differentiated cells acquired tolerance to Cu and cisplatin, another substrate of Ctr1. In addition, the expression of MT-3, a brain-specific isoform, was increased, contrary to the decreased expression of MT-1 and MT-2. Taken together, the differentiation of PC12 cells into neurons induced MT-3 expression, thereby resulting in intracellular Cu accumulation. The decrease in Ctr1 expression was assumed to be a response aimed at abolishing the physiological accumulation of Cu after the differentiation.
Light effect on Click reaction: Role of photonic quantum dot catalyst
Authors: Nandi Debkumar , Taher Abu , Islam Rafique Ul , Choudhary Meenakshi , Siwal Samarjeet , Mallick Kaushik
Published: September 2016

Due to the light excitation, the valence band electron of the copper (I) sulfide quantum dot transfer to the conduction band and act as a scavenger of the terminal proton of the alkyne in the presence of organic azide with the formation of 1,4-disubstituted 1,2,3-triazoles, where the copper(I) species of Cu2S act as a catalyst for the reaction. The above cycloaddition reaction between alkyne and azide is commonly known as the Click reaction. In this study, experiments were carried out under the exposure of ultra-violate and daylight and also dark environment. According to the original recommendation for the Click reaction, the role of the base was also considered for this experiment. We found that the effect of conduction band electron is more efficient than the recommended conventional base mediated reaction procedure.
Facile synthesis of pristine graphene-palladium nanocomposites with extraordinary catalytic activities using swollen liquid crystals
Authors: Vats T. , Dutt S. , Kumar R. , Siril P. F.
Published: September 2016

Amazing conductivity, perfect honeycomb sp2 arrangement and the high theoretical surface area make pristine graphene as one of the best materials suited for application as catalyst supports. Unfortunately, the low reactivity of the material makes the formation of nanocomposite with inorganic materials difficult. Here we report an easy approach to synthesize nanocomposites of pristine graphene with palladium (Pd-G) using swollen liquid crystals (SLCs) as a soft template. The SLC template gives the control to deposit very small Pd particles of uniform size on G as well as RGO. The synthesized nanocomposite (Pd-G) exhibited exceptionally better catalytic activity compared with Pd-RGO nanocomposite in the hydrogenation of nitrophenols and microwave assisted C-C coupling reactions. The catalytic activity of Pd-G nanocomposite during nitrophenol reduction reaction was sixteen times higher than Pd nanoparticles and more than double than Pd-RGO nanocomposite. The exceptionally high activity of pristine graphene supported catalysts in the organic reactions is explained on the basis of its better pi interacting property compared to partially reduced RGO. The Pd-G nanocomposite showed exceptional stability under the reaction conditions as it could be recycled upto a minimum of 15 cycles for the C-C coupling reactions without any loss in activity.
Creation of an anti-imaging system using binary optics
Authors: Wang Haifeng , Lin Jian , Zhang Dawei , Wang Yang , Gu Min , Urbach H. P. , Gan Fuxi , Zhuang Songlin
Published: September 2016

We present a concealing method in which an anti-point spread function (APSF) is generated using binary optics, which produces a large-scale dark area in the focal region that can hide any object located within it. This result is achieved by generating two identical PSFs of opposite signs, one consisting of positive electromagnetic waves from the zero-phase region of the binary optical element and the other consisting of negative electromagnetic waves from the pi-phase region of the binary optical element.
Nanoscale Chemical and Electrical Stabilities of Graphene-covered Silver Nanowire Networks for Transparent Conducting Electrodes
Authors: Kim Seong Heon , Choi Woon Ih , Kim Kwang Hee , Yang Dae Jin , Heo Sung , Yun Dong-Jin
Published: September 2016

The hybrid structure of Ag nanowires (AgNWs) covered with graphene (Gr) shows synergetic effects on the performance of transparent conducting electrodes (TCEs). However, these effects have been mainly observed via large-scale characterization, and precise analysis at the nanoscale level remains inadequate. Here, we present the nanoscale verification and visualization of the improved chemical and electrical stabilities of Gr-covered AgNW networks using conductive atomic force microscopy (C-AFM), Auger electron spectroscopy (AES), and X-ray photoelectron spectroscopy (XPS) combined with the gas cluster ion beam (GCIB) sputtering technique. Specifically by transferring island Gr on top of the AgNW network, we were able to create samples in which both covered and uncovered AgNWs are simultaneously accessible to various surface-characterization techniques. Furthermore, our ab initio molecular dynamics (AIMD) simulation elucidated the specific mechanistic pathway and a strong propensity for AgNW sulfidation, even in the presence of ambient oxidant gases.
Concurrent micro-RNA mediated silencing of tick-borne flavivirus replication in tick vector and in the brain of vertebrate host
Authors: Tsetsarkin Konstantin A. , Liu Guangping , Kenney Heather , Hermance Meghan , Thangamani Saravanan , Pletnev Alexander G.
Published: September 2016

Tick-borne viruses include medically important zoonotic pathogens that can cause life-threatening diseases. Unlike mosquito-borne viruses, whose impact can be restrained via mosquito population control programs, for tick-borne viruses only vaccination remains the reliable means of disease prevention. For live vaccine viruses a concern exists, that spillovers from viremic vaccinees could result in introduction of genetically modified viruses into sustainable tick-vertebrate host transmission cycle in nature. To restrict tick-borne flavivirus (Langat virus, LGTV) vector tropism, we inserted target sequences for tick-specific microRNAs (mir-1, mir-275 and mir-279) individually or in combination into several distant regions of LGTV genome. This caused selective attenuation of viral replication in tick-derived cells. LGTV expressing combinations of target sequences for tick- and vertebrate CNS-specific miRNAs were developed. The resulting viruses replicated efficiently and remained stable in simian Vero cells, which do not express these miRNAs, however were severely restricted to replicate in tick-derived cells. In addition, simultaneous dual miRNA targeting led to silencing of virus replication in live Ixodes ricinus ticks and abolished virus neurotropism in highly permissive newborn mice. The concurrent restriction of adverse replication events in vertebrate and invertebrate hosts will, therefore, ensure the environmental safety of live tick-borne virus vaccine candidates.
High-effective approach from amino acid esters to chiral amino alcohols over Cu/ZnO/Al2O3 catalyst and its catalytic reaction mechanism
Authors: Zhang Shuangshuang , Yu Jun , Li Huiying , Mao Dongsen , Lu Guanzhong
Published: September 2016

Developing the high-efficient and green synthetic method for chiral amino alcohols is an intriguing target. We have developed the Mg2+-doped Cu/ZnO/Al2O3 catalyst for hydrogenation of L-phenylalanine methyl ester to chiral L-phenylalaninol without racemization. The effect of different L-phenylalanine esters on this title reaction was studied, verifying that Cu/ZnO/Al2O3 is an excellent catalyst for the hydrogenation of amino acid esters to chiral amino alcohols. DFT calculation was used to study the adsorption of substrate on the catalyst, and showed that the substrate adsorbs on the surface active sites mainly by amino group (-NH2) absorbed on Al2O3, and carbonyl (C=O) and alkoxy (RO-) group oxygen absorbed on the boundary of Cu and Al2O3. This catalytic hydrogenation undergoes the formation of a hemiacetal intermediate and the cleavage of the C–O bond (rate-determining step) by reacting with dissociated H to obtain amino aldehyde and methanol ad-species. The former is further hydrogenated to amino alcohols, and the latter desorbs from the catalyst surface.
Vitamin B2 as a virulence factor in Pseudogymnoascus destructans skin infection
Authors: Flieger Miroslav , Bandouchova Hana , Cerny Jan , Chudíčková Milada , Kolarik Miroslav , Kovacova Veronika , Martínková Natália , Novák Petr , Šebesta Ondřej , Stodůlková Eva , Pikula Jiri
Published: September 2016

Pathogenic and non-pathogenic related microorganisms differ in secondary metabolite production. Here we show that riboflavin overproduction by a fungal pathogen and its hyperaccumulation in affected host tissue exacerbates a skin infection to necrosis. In white-nose syndrome (WNS) skin lesions caused byPseudogymnoascus destructans, maximum riboflavin concentrations reached up to 815 μg ml−1, indicating bioaccumulation and lack of excretion. We found that high riboflavin concentrations are cytotoxic under conditions specific for hibernation, affect bats’ primary fibroblasts and induce cell detachment, loss of mitochondrial membrane potential, polymerization of cortical actin, and cell necrosis. Our results explain molecular pathology of WNS, where a skin infection becomes fatal. Hyperaccumulation of vitamin B2coupled with reduced metabolism and low tissue oxygen saturation during hibernation prevents removal of excess riboflavin in infected bats. Upon reperfusion, oxygen reacts with riboflavin resulting in dramatic pathology after arousal. While multiple molecules enable invasive infection, riboflavin-associated extensive necrosis likely contributes to pathophysiology and altered arousal pattern in infected bats. Bioaccumulation of a vitamin under natural infection represents a novel condition in a complex host-pathogen interplay.
Early-life sexual segregation: ontogeny of isotopic niche differentiation in the Antarctic fur seal
Authors: Kernaléguen L. , Arnould J. P. Y. , Guinet C. , Cazelles B. , Richard P. , Cherel Y.
Published: September 2016

Investigating the ontogeny of niche differentiation enables to determine at which life-stages sexual segregation arises, providing insights into the main factors driving resource partitioning. We investigated the ontogeny of foraging ecology in Antarctic fur seals (Arctocephalus gazella), a highly dimorphic species with contrasting breeding strategies between sexes. Sequential δ13C and δ15N values of whiskers provided a longitudinal proxy of the foraging niche throughout the whole life of seals, from weaning, when size dimorphism is minimal to the age of 5. Females exhibited an early-life ontogenetic shift, from a total segregation during their first year at-sea, to a similar isotopic niche as breeding females as early as age 2. In contrast, males showed a progressive change in isotopic niche throughout their development such that 5-year-old males did not share the same niche as territorial bulls. Interestingly, males and females segregated straight after weaning with males appearing to feed in more southerly habitats than females. This spatial segregation was of similar amplitude as observed in breeding adults and was maintained throughout development. Such early-life niche differentiation is an unusual pattern and indicates size dimorphism and breeding constraints do not directly drive sexual segregation contrary to what has been assumed in otariid seals.
Morphology and Electric Conductance Change Induced by Voltage Pulse Excitation in (GeTe)2/Sb2Te3 Superlattices
Authors: Bolotov Leonid , Saito Yuta , Tada Tetsuya , Tominaga Junji
Published: September 2016

Chalcogenide superlattice (SL) phase-change memory materials are leading candidates for non-volatile, energy-efficient electric memory where the electric conductance switching is caused by the atom repositioning in the constituent layers. Here, we study the time evolution of the electric conductance in [(GeTe)2/(Sb2Te3)1]4 SLs upon the application of an external pulsed electric field by analysing the structural and electrical responses of the SL films with scanning probe microscopy (SPM) and scanning probe lithography (SPL). At a low pulse voltage (1.6–2.3 V), a conductance switching delay of a few seconds was observed in some SL areas, where the switch to the high conductance state (HCS) is accompanied with an SL expansion under the strong electric field of the SPM probe. At a high pulse voltage (2.5–3.0 V), the HCS current was unstable and decayed in a few seconds; this is ascribed to the degradation of the HCS crystal phase under excessive heating. The reversible conductance change under a pulse voltage of opposite polarity emphasised the role of the electric field in the phase-transition mechanism.