bluuebunny/crossref_metadata_2025 huggingface dataset:
Wildlife conservation and environmental economics
Authors: Hamilton Kirk
Published: June 2014

Conserving wildlife has been much in the news in early 2014, owing to the rapid growth of wildlife crime since 2000. This is now a problem measured in tens of billions of dollars, with large, organized and violent criminal activity pushing rhinos towards extinction, and losses of African elephants measured in the thousands per year. Tigers, lions and other top predators are under severe pressure as well.
Twenty years of environment and development economics: advice to graduate students
Authors: Zeeuw Aart de
Published: June 2014

My first advice to graduate students is always that they should follow their own motivation. That is, in my view, the key to success for the students and the main driver for scientific progress: only motivated researchers will make a difference, in academia and in society. But of course environment and development economics is a good choice: it is very relevant and intellectually challenging. Alleviating poverty and preserving a balance between the human sphere and the natural environment are the major issues of our world. The parts of the world that are still developing are also the parts of the world where important choices will be made on preserving this balance. This makes the field very relevant.
Developing the economics of change
Authors: Smulders Sjak
Published: June 2014

It was a visionary initiative, 20 years ago, to start a journal devoted to the intersection between environmental, resource and development economics. At the time, the ‘Brundtland Report’ was old enough to be recognized in policy discussions at many possible levels, IPCC had already published its first and second assessment reports, and the Kyoto Protocol was just shaping up. Over the first 20 years of EDE's life, interest in environment and development grew quickly if not explosively, both in research and in the (policy) field, as was witnessed by the Millennium Development Goals in 2000, ‘Green Growth’ initiatives (from 2008 onwards at UNEP, OECD and World Bank), and at Rio +20 in 2012; IPCC's fifth assessment report is expected this year.
MEMBRANE-COUPLED GRAVITY WAVE SCATTERING BY A VERTICAL BARRIER WITH A GAP
Authors: MANAM S. R. , KALIGATLA R. B.
Published: June 2014

We study the reflection of membrane-coupled gravity waves in deep water against a vertical barrier with a gap. A floating membrane is attached on both sides of the barrier. The associated mixed boundary value problem, which is not particularly well posed, is analysed. We utilize an orthogonal mode-coupling relation to reduce the problem to solving a set of dual integral equations with trigonometric kernel. We solve these by using a weakly singular integral equation. The reflection coefficient is determined explicitly, while having freedom to clamp the membrane with a spring of a certain stiffness on only one side of the vertical barrier. The physical problem is of capillary–gravity wave scattering by a vertical barrier with a gap, when the membrane density is neglected. In this case, the reflection coefficient is known up to an undetermined edge slope on either side of the barrier. The scattering quantity is computed and presented graphically against a wave parameter for different values of nondimensional parameters pertaining to the structures involved in the problem.
NEW DEVELOPMENT OF NONRIGID REGISTRATION
Authors: HSIAO HSI-YUE , HSIEH CHIH-YAO , CHEN XI , GONG YONGYI , LUO XIAONAN , LIAO GUOJUN
Published: June 2014

We propose a new nonrigid registration algorithm which is based on the optimal control approach. In our previously proposed methods, the Jacobian determinant and the curl vector were used as control functions. In this algorithm, we use a new set of control functions. A main advantage of using the new controls is that the positivity and normalization of the Jacobian determinant are satisfied automatically. Numerical results on large deformation brain images are provided to show the accuracy and efficiency of the algorithm.
RATIONAL POINTS ON INTERSECTIONS OF CUBIC AND QUADRIC HYPERSURFACES
Authors: Browning T. D. , Dietmann R. , Heath-Brown D. R.
Published: June 2014

We investigate the Hasse principle for complete intersections cut out by a quadric hypersurface and a cubic hypersurface defined over the rational numbers.
Hospice palliative care volunteers: The benefits for patients, family caregivers, and the volunteers
Authors: Claxton-Oldfield Stephen
Published: June 2014

Objective:

Terminally ill patients and family caregivers can benefit greatly from the support and care provided by trained hospice palliative care volunteers. The benefits of doing this kind of volunteer work also extend to the volunteers themselves, who often say they receive more than they give from the patients/families they are “privileged” to be with. The purpose of this article is to demonstrate how hospice palliative care volunteerism benefits both the patients and families who utilize this service as well as the volunteers.

Method:

A review of studies demonstrating how terminally ill patients, and especially family caregivers, can benefit from the use of hospice palliative care volunteers and how the volunteers themselves benefit from their experiences.

Results:

Terminally ill patients and families receive many benefits from using the services of hospice palliative care volunteers, including emotional support, companionship, and practical assistance (e.g., respite or breaks from caregiving). Volunteering in hospice palliative care also provides many benefits for the volunteers, including being able to make a difference in the lives of others, personal growth, and greater appreciation of what is really important in life.

Significance of results:

More needs to be done to promote the value of hospice palliative care volunteers to those who can really benefit from their support and care (i.e., patients and their families) as well as to help people recognize the potential rewards of being a hospice palliative care volunteer. It is a win–win situation.
Preliminary Results From an Examination of Episodic Planning in Suicidal Behavior
Authors: Anestis Michael D. , Pennings Stephanie M. , Williams Tabatha J.
Published: June 2014

Background: Prior research has reported that a substantial portion of suicidal behavior occurs impulsively. These studies, however, have been unable to assess for episodic planning. Aims: To provide preliminary support for the plausibility and utility of assessing episodic, nonlinear planning in suicidal behavior. Method: Fifty undergraduates with a prior history of suicidal behavior responded to a series of questions assessing level of attempt, method, and level of planning during their most recent self-reported suicide attempt. Results: Level of intent was positively associated with planning, and the modal individual whose most recent attempt involved clear intent to die endorsed planning for at least 1 year. Conclusion: These preliminary data support the plausibility and potential utility of assessing episodic planning and indicate that suicide attempts involving a clear intent to die typically require extensive levels of planning and rarely (if ever) emerge without forethought.
Measuring Trainer Fidelity in the Transfer of Suicide Prevention Training
Authors: Cross Wendi F. , Pisani Anthony R. , Schmeelk-Cone Karen , Xia Yinglin , Tu Xin , McMahon Marcie , Munfakh Jimmie Lou , Gould Madelyn S.
Published: June 2014

Background: Finding effective and efficient models to train large numbers of suicide prevention interventionists, including ’hotline’ crisis counselors, is a high priority. Train-the-trainer (TTT) models are widely used but understudied. Aims: To assess the extent to which trainers following TTT delivered the Applied Suicide Intervention Skills Training (ASIST) program with fidelity, and to examine fidelity across two trainings and seven training segments. Method: We recorded and reliably rated trainer fidelity, defined as adherence to program content and competence of program delivery, for 34 newly trained ASIST trainers delivering the program to crisis center staff on two separate occasions. A total of 324 observations were coded. Trainer demographics were also collected. Results: On average, trainers delivered two-thirds of the program. Previous training was associated with lower levels of trainer adherence to the program. In all, 18% of trainers’ observations were rated as solidly competent. Trainers did not improve fidelity from their first to second training. Significantly higher fidelity was found for lectures and lower fidelity was found for interactive training activities including asking about suicide and creating a safe plan. Conclusions: We found wide variability in trainer fidelity to the ASIST program following TTT and few trainers had high levels of both adherence and competence. More research is needed to examine the cost-effectiveness of TTT models.
High density GaN/AlN quantum dots for deep UV LED with high quantum efficiency and temperature stability
Authors: Yang Weihuang , Li Jinchai , Zhang Yong , Huang Po-Kai , Lu Tien-Chang , Kuo Hao-Chung , Li Shuping , Yang Xu , Chen Hangyang , Liu Dayi , Kang Junyong
Published: June 2014

High internal efficiency and high temperature stability ultraviolet (UV) light-emitting diodes (LEDs) at 308 nm were achieved using high density (2.5 × 109 cm−2) GaN/AlN quantum dots (QDs) grown by MOVPE. Photoluminescence shows the characteristic behaviors of QDs: nearly constant linewidth and emission energy and linear dependence of the intensity with varying excitation power. More significantly, the radiative recombination was found to dominant from 15 to 300 K, with a high internal quantum efficiency of 62% even at room temperature.
Gremlin-2 is a BMP antagonist that is regulated by the circadian clock
Authors: Yeung Ching-Yan Chloé , Gossan Nicole , Lu Yinhui , Hughes Alun , Hensman James J. , Bayer Monika L. , Kjær Michael , Kadler Karl E. , Meng Qing-Jun
Published: June 2014

Tendons are prominent members of the family of fibrous connective tissues (FCTs), which collectively are the most abundant tissues in vertebrates and have crucial roles in transmitting mechanical force and linking organs. Tendon diseases are among the most common arthropathy disorders; thus knowledge of tendon gene regulation is essential for a complete understanding of FCT biology. Here we show autonomous circadian rhythms in mouse tendon and primary human tenocytes, controlled by an intrinsic molecular circadian clock. Time-series microarrays identified the first circadian transcriptome of murine tendon, revealing that 4.6% of the transcripts (745 genes) are expressed in a circadian manner. One of these genes was Grem2, which oscillated in antiphase to BMP signaling. Moreover, recombinant human Gremlin-2 blocked BMP2-induced phosphorylation of Smad1/5 and osteogenic differentiation of human tenocytes in vitro. We observed dampened Grem2 expression, deregulated BMP signaling and spontaneously calcifying tendons in young CLOCKΔ19 arrhythmic mice and aged wild-type mice. Thus, disruption of circadian control, through mutations or aging, of Grem2/BMP signaling becomes a new focus for the study of calcific tendinopathy, which affects 1-in-5 people over the age of 50 years.
Trials and tribulations: student approaches and difficulties with proposing mechanisms using the electron-pushing formalism
Authors: Bhattacharyya Gautam
Published: June 2014

The skill of proposing mechanisms of reactions using the electron-pushing formalism (EPF) is not only of value to practicing organic chemists but it is also emphasized to students enrolled in organic chemistry courses at all levels. Several research studies in the past decade have documented the difficulties that undergraduate, and even graduate students, encounter when trying to propose mechanisms using the EPF. An examination of this work suggests the emergence of a preliminary, but coherent, picture of students' strategies and difficulties with using electron-pushing to solve a variety of organic chemistry tasks. The first two sections of this paper, I present (1) two factors that may underlie several of the students' difficulties as presented in the organic chemistry education research literature; and (2) a model of how students approach solving mechanism tasks using the EPF. This paper concludes with a section on potential implications for instruction and a set of research questions arising from this analysis that have yet to be answered.
Exploring inflammatory disease drug effects on neutrophil function
Authors: Wu Xiaojie , Kim Donghyuk , Young Ashlyn T. , Haynes Christy L.
Published: June 2014

Combined use of a novel platform and traditional approaches yield new insight into drug effects on neutrophil function.
Sampling and analysis of metabolomes in biological fluids
Authors: Nunes de Paiva Maria José , Menezes Helvécio Costa , de Lourdes Cardeal Zenilda
Published: June 2014

Metabolome analysis involves the study of small molecules that are involved in the metabolic responses that occur through patho-physiological changes caused by genetic stimuli or chemical agents.
Single-step and reagentless analysis of genetically modified soybean DNA with an electrochemical DNA biosensor
Authors: Ulianas Alizar , Heng Lee Yook , Lau Han-Yih , Ishak Zamri , Ling Tan Ling
Published: June 2014

A simple procedure for voltammetric determination of genetically modified DNA without introduction of a redox indicator into DNA hybridization medium is described. The DNA biosensor is designed where both DNA hybridization and indicator intercalation detections can be performed in a single-step.
Highly porous conjugated polymers for selective oxidation of organic sulfides under visible light
Authors: Wang Zi Jun , Ghasimi Saman , Landfester Katharina , Zhang Kai A. I.
Published: June 2014

High surface area porous conjugated polymers were synthesized via the high internal phase emulsion polymerization technique and micropore engineering as efficient heterogeneous photocatalysts for highly selective oxidation of organic sulfides to sulfoxides under visible light.
Shear induced fabrication of intertwined single walled carbon nanotube rings
Authors: Vimalanathan Kasturi , Chen Xianjue , Raston Colin L.
Published: June 2014

Stable nanorings of SWCNTs devoid of surfactants are accessible by combining liquid–liquid interfacial tension and mechanoenergy within an energy efficient thin film microfluidic vortex fluidic device (VFD).
Effect of salt on the formation of salt-bridges in β-hairpin peptides
Authors: Sukenik Shahar , Boyarski Yoav , Harries Daniel
Published: June 2014

The formation of salt-bridges in β-hairpin peptides is measured in increasing salt concentrations, indicating a decrease in the salt-bridged population due to charge–charge screening, as well as non-cooperative salt-bridge triads.
Controlling the sign and magnitude of screw-sense preference from the C-terminus of an achiral helical foldamer
Authors: Le Bailly Bryden A. F. , Clayden Jonathan
Published: June 2014

The global screw-sense preference of an achiral helical oligomer is best controlled from its C-terminus by a single Ala monomer.
Nanovalve activation by surface-attached photoacids
Authors: Guardado-Alvarez T. M. , Russell M. M. , Zink J. I.
Published: June 2014

Proton transfer caused by excitation of a photoacid attached to the surface of a mesoporous silica nanoparticle activates a nanovalve and causes release of trapped molecules.
A novel Affibody bioconjugate for dual-modality imaging of ovarian cancer
Authors: Wang Yihong , Miao Zheng , Ren Gang , Xu Yingding , Cheng Zhen
Published: June 2014

An Affibody based dual imaging probe (PET and optical imaging) has been successfully developed. Dendrimer PAMAM G0 was used as a platform to assemble an NIRF dye, a metal chelator, and Affibody for dual modality imaging of ovarian cancer. Excellent tumor imaging quality was achieved in both modalities in the living tumor mice models.
Cobalt-catalyzed carboxylation of propargyl acetates with carbon dioxide
Authors: Nogi Keisuke , Fujihara Tetsuaki , Terao Jun , Tsuji Yasushi
Published: June 2014

The cobalt-catalyzed carboxylation of propargyl acetates proceeds with CO2 (1 atm) at room temperature in the presence of Mn powder as a reductant.
An experimental and theoretical investigation of the N(4S) + C2(1Σg+) reaction at low temperature
Authors: Loison Jean-Christophe , Hu Xixi , Han Shanyu , Hickson Kevin M. , Guo Hua , Xie Daiqian
Published: June 2014

The N + C2 reaction is shown to be an important source of CN radicals in dense interstellar clouds.
Phyllobilins – the abundant bilin-type tetrapyrrolic catabolites of the green plant pigment chlorophyll
Authors: Kräutler Bernhard
Published: June 2014

Phyllobilins, the bilin-type chlorophyll catabolites, are a hardly known class of abundant linear tetrapyrroles in de-greening leaves and ripening fruit.
Enzyme-assisted target recycling (EATR) for nucleic acid detection
Authors: Gerasimova Yulia V. , Kolpashchikov Dmitry M.
Published: June 2014

Enzyme-assisted target recycling (EATR) is a signal amplification technique that can find application in PCR-free nucleic acid detection.
Aqueous stability of alumina and silica perhydrate hydrogels: experiments and computations
Authors: Wolanov Yitzhak , Shurki Avital , Prikhodchenko Petr V. , Tripoľskaya Tatiana A. , Novotortsev Vladimir M. , Pedahzur Rami , Lev Ovadia
Published: June 2014

Alumina and silica perhydrate hydrogels were synthesized.
Efficient synthesis of tertiary α-hydroxy ketones through CO2-promoted regioselective hydration of propargylic alcohols
Authors: He Haitao , Qi Chaorong , Hu Xiaohan , Guan Yuqi , Jiang Huanfeng
Published: June 2014

A CO2-promoted and silver-catalyzed hydration of propargylic alcohols for the efficient synthesis of α-hydroxy ketones has been developed.
Hydrogenation of levulinic acid to γ-valerolactone by Ni and MoOx co-loaded carbon catalysts
Authors: Shimizu Ken-ichi , Kanno Shota , Kon Kenichi
Published: June 2014

Ni–MoOx/C showed more than 300 times higher TON than previously reported noble metal-free catalysts for the title reaction.
A sheath-less combined optical and impedance micro-cytometer
Authors: Spencer Daniel , Elliott Gregor , Morgan Hywel
Published: June 2014

We present a micro-cytometer with excellent size accuracy, sensitivity and dynamic range and demonstrate its utility for accurate CD4 enumeration.
Circle-to-circle amplification on a digital microfluidic chip for amplified single molecule detection
Authors: Kühnemund Malte , Witters Daan , Nilsson Mats , Lammertyn Jeroen
Published: June 2014

We developed a novel highly efficient superparamagnetic particle extraction and shuttling protocol and integrated the isothermal circle-to-circle DNA amplification on a digital microfluidic chip for ultra-sensitive DNA detection.
Comparing systemic metabolic responses in mice to single or dual infection with Plasmodium berghei and Heligmosomoides bakeri
Authors: Tritten Lucienne , Keiser Jennifer , Karwa Tasneem , Utzinger Jürg , Holmes Elaine , Saric Jasmina
Published: June 2014

The purpose of this study was to give a comprehensive insight into the systemic metabolic phenotype of mice with a single or dual infection withPlasmodium bergheiandHeligmosomoides bakeri.
One-pot pseudo three-component reaction of nitroketene-N,S-acetals and aldehydes for synthesis of highly functionalized hexa-substituted 1,4-dihydropyridines
Authors: Surya Prakash Rao H. , Parthiban A.
Published: June 2014

Pseudo three-component condensation of aliphatic/aromatic/α,β-unsaturated aldehydes and nitroketene-N,S-acetals to afford diversely functionalized hexa-substituted 1,4-dihydropyridines under 2-aminopyridine catalysis was achieved.
Ester-substituted cyclometallated rhodium and iridium coordination assemblies with π-bonded dioxolene ligand: synthesis, structures and luminescent properties
Authors: Damas Aurelie , Sesolis Hugo , Rager Marie Noelle , Chamoreau Lise Marie , Gullo Maria Pia , Barbieri Andrea , Amouri Hani
Published: June 2014

A series of functionalized cyclometallated rhodium and iridium coordination assemblies2–7displaying a π-bonded dioxolene ligand is described.
Layered perovskite nanosheets bearing fluoroalkoxy groups: their preparation and application in epoxy-based hybrids
Authors: Asai Yuta , Ariake Yusuke , Saito Hitomi , Idota Naokazu , Matsukawa Kimihiro , Nishino Takashi , Sugahara Yoshiyuki
Published: June 2014

Nanosheets bearing fluoroalkoxy groups were prepared via exfoliation of a CF3(CF2)7C2H4O derivative of HLaNb2O7·xH2O for application in epoxy-based hybrids.
d-Glucosamine as a green ligand for copper catalyzed synthesis of aryl sulfones from aryl halides and sodium sulfinates
Authors: Yang Ming , Shen Hongyun , Li Yuanyuan , Shen Chao , Zhang Pengfei
Published: June 2014

d-Glucosamine is reported for the first time as a green ligand for copper catalyzed coupling of aryl halides and sodium sulfinates, which provides a simple and extremely efficient new route to unsymmetrical diaryl sulfones.
Structural modifications induced by the switch from an endogenous bis-histidyl to an exogenous cyanomet hexa-coordination in a tetrameric haemoglobin
Authors: Mazzarella Lelio , Merlino Antonello , Vitagliano Luigi , Verde Cinzia , di Prisco Guido , Peisach Jack , Vergara Alessandro
Published: June 2014

Two EPR- and structurally-distinct bis-histidyl conformers of the ferric haemoglobin fromTrematomus bernacchiireact differently with CN−
Polymer supported Pd catalyzed thioester synthesis via carbonylation of aryl halides under phosphine free conditions
Authors: Islam Sk Manirul , Molla Rostam Ali , Roy Anupam Singha , Ghosh Kajari
Published: June 2014

A new polymer anchored Pd(ii) complex has been synthesized and characterized. The catalytic performance of this complex has been tested for thioester synthesis via carbonylation of aryl halides and thiols under phosphine free conditions. This catalyst showed excellent catalytic activity and recyclability.
Self-assembled monolayers of thiolates on metals: a review article on sulfur-metal chemistry and surface structures
Authors: Vericat C. , Vela M. E. , Corthey G. , Pensa E. , Cortés E. , Fonticelli M. H. , Ibañez F. , Benitez G. E. , Carro P. , Salvarezza R. C.
Published: June 2014

A review article on fundamental aspects of thiolate self-assembled monolayers (SAMs) on the (111) and (100) surfaces of the Cu and Ni groups is presented.
Effects of substituent groups on the structures and luminescence properties of 2D/3D CdII complexes with mixed rigid and flexible carboxylate ligands
Authors: Wu Guo-Yun , Ren Yi-Xia , Yin Zheng , Sun Feng , Zeng Ming-Hua , Kurmoo Mohamedally
Published: June 2014

Three Cd(ii) coordination polymers employing rigid benzimidazole carboxylate and flexible adipate demonstrate the effect of substituent groups on the crystal structures and their luminescence properties.
Binding of amphiphilic and triphilic block copolymers to lipid model membranes: the role of perfluorinated moieties
Authors: Schwieger Christian , Achilles Anja , Scholz Sven , Rüger Jan , Bacia Kirsten , Saalwaechter Kay , Kressler Jörg , Blume Alfred
Published: June 2014

Attachment of fluorophilic end caps to amphiphilic block copolymers increases their interaction with lipid membranes and enables the polymer's translocation.
Influence of wetting on fingering patterns in lifting Hele-Shaw flows
Authors: Anjos Pedro H. A. , Miranda José A.
Published: June 2014

We study the pattern formation dynamics related to the displacement of a viscous wetting fluid by a less viscous nonwetting fluid in a lifting Hele-Shaw cell.
Binder-free rice husk-based silicon–graphene composite as energy efficient Li-ion battery anodes
Authors: Wong Deniz P. , Suriyaprabha Rangaraj , Yuvakumar Rathinam , Rajendran Venkatachalam , Chen Yit-Tsong , Hwang Bing-Joe , Chen Li-Chyong , Chen Kuei-Hsien
Published: June 2014

In this study, an energy efficient Li-ion battery anode composite system based on silicon nanoparticles and graphene has been demonstrated, wherein the raw materials were obtained from waste by-products such as rice husk.
Graphene derivatives: graphane, fluorographene, graphene oxide, graphyne and graphdiyne
Authors: Inagaki Michio , Kang Feiyu
Published: June 2014

New graphene derivatives, graphane, fluorographene, graphene oxide, graphyne and graphdiyne, are reviewed by emphasizing the experimental results.
A novel porous MgO sorbent fabricated through carbon insertion
Authors: Li Yan Yan , Wan Mi Mi , Lin Wei Gang , Wang Ying , Zhu Jian Hua
Published: June 2014

A new strategy of carbon insertion to synthesize an efficient CO2-capturer through self-dispersion of MgO is first reported.
Thermoresponsive elastin/laminin mimicking artificial protein for modifying PLLA scaffolds in nerve regeneration
Authors: Kakinoki Sachiro , Yamaoka Tetsuji
Published: June 2014

Poly(l-lactic acid) (PLLA) is widely used as a scaffold but does not possess biological functions.
Poly(imide-benzoxazole) gate insulators with high thermal resistance for solution-processed flexible indium-zinc oxide thin-film transistors
Authors: Wee Duyoung , Yoo Sungmi , Kang Young Hun , Kim Yun Ho , Ka Jae-Won , Cho Song Yun , Lee Changjin , Ryu Juwhan , Yi Mi Hye , Jang Kwang-Suk
Published: June 2014

We have developed poly(imide-benzoxazole) gate insulators with high thermal resistance. The 350 °C-annealed indium-zinc oxide/poly(imide-benzoxazole) thin-film transistors showed excellent performance.
TM4SF5 suppression disturbs integrin α5-related signalling and muscle development in zebrafish
Authors: Choi Yoon-Ju , Kim Hyun Ho , Kim Jeong-gyun , Kim Hye-Jin , Kang Minkyung , Lee Mi-Sook , Ryu Jihye , Song Haeng Eun , Nam Seo Hee , Lee Doohyung , Kim Kyu-Won , Lee Jung Weon
Published: June 2014

TM4SF5 (transmembrane 4 L six family member 5) is involved in EMT (epithelial–mesenchymal transition) for liver fibrosis and cancer metastasis; however, the function(s) of TM4SF5 during embryogenesis remains unknown. In the present study the effects of TM4SF5 on embryogenesis of zebrafish were investigated. tm4sf5 mRNA was expressed in the posterior somites during somitogenesis and in whole myotome 1 dpf (day post-fertilization). tm4sf5 suppression impaired development of the trunk with aberrant morphology of muscle fibres and altered expression of integrin α5. The arrangement and adhesion of muscle cells were abnormally disorganized in tm4sf5 morphants with reduced muscle fibre masses, where integrin α5-related signalling molecules, including fibronectin, FAK (focal adhesion kinase), vinculin and actin were aberrantly localized, compared with those in control fish. Aberrant muscle developments in tm4sf5 morphants were recovered by additional tm4sf5 or integrin α5 mRNA injection. Such a role for TM4SF5 was observed in the differentiation of C2C12 mouse myoblast cells to multinuclear muscle cells. Taken together, the results show that TM4SF5 controls muscle differentiation via co-operation with integrin α5-related signalling.
Rate of steroid double-bond reduction catalysed by the human steroid 5β-reductase (AKR1D1) is sensitive to steroid structure: implications for steroid metabolism and bile acid synthesis
Authors: Jin Yi , Chen Mo , Penning Trevor M.
Published: June 2014

Human AKR1D1 (steroid 5β-reductase/aldo-keto reductase 1D1) catalyses the stereospecific reduction of double bonds in Δ4-3-oxosteroids, a unique reaction that introduces a 90° bend at the A/B ring fusion to yield 5β-dihydrosteroids. AKR1D1 is the only enzyme capable of steroid 5β-reduction in humans and plays critical physiological roles. In steroid hormone metabolism, AKR1D1 serves mainly to inactivate the major classes of steroid hormones. AKR1D1 also catalyses key steps of the biosynthetic pathway of bile acids, which regulate lipid emulsification and cholesterol homoeostasis. Interestingly, AKR1D1 displayed a 20-fold variation in the kcat values, with steroid hormone substrates (e.g. aldosterone, testosterone and cortisone) having significantly higher kcat values than steroids with longer side chains (e.g. 7α-hydroxycholestenone, a bile acid precursor). Transient kinetic analysis revealed striking variations up to two orders of magnitude in the rate of the chemistry step (kchem), which resulted in different rate determining steps for the fast and slow substrates. By contrast, similar Kd values were observed for representative fast and slow substrates, suggesting similar rates of release for different steroid products. The release of NADP+ was shown to control the overall turnover for fast substrates, but not for slow substrates. Despite having high kchem values with steroid hormones, the kinetic control of AKR1D1 is consistent with the enzyme catalysing the slowest step in the catabolic sequence of steroid hormone transformation in the liver. The inherent slowness of the conversion of the bile acid precursor by AKR1D1 is also indicative of a regulatory role in bile acid synthesis.
Decentralised ranging method for orthogonal frequency division multiple access systems with amplify‐and‐forward relays
Authors: Jung Young‐Ho , Cho Sunghyun , You Cheolwoo
Published: June 2014

In this study, a decentralised ranging method for uplink orthogonal frequency division multiple access (OFDMA) systems with half‐duplex (HD) amplify‐and‐forward (AF) relay stations (RSs) is proposed. In the OFDMA systems with HD AF RSs, twice more resources and delays are required as ranging without RS. To reduce the required resources and delays for ranging, the authors propose a two‐phase ranging scheme based on the decentralised timing‐offset estimation at each ranging mobile station (MS). At the first phase, RS occasionally broadcasts timing reference signal, and at the second phase RS retransmits the collected ranging signals from the MSs. Then, each ranging MSs can individually estimate its own timing offset from the received signals. In the proposed ranging method, the base station does not need to send a timing‐adjustment message, and the overhead associated with ranging in the downlink resources, and computational complexity can be significantly reduced without degrading the timing‐offset‐estimation performance. Moreover, the delay associated with ranging can be maintained as same as ranging without RS.
Performance analysis for free‐space optical communications using parallel all‐optical relays over composite channels
Authors: Wang Jin‐Yuan , Wang Jun‐Bo , Chen Ming , Song Xiaoyu
Published: June 2014

In the last 2 years, all‐optical relaying techniques for free‐space optical (FSO) communications have drawn considerable attention. In this study, the outage performance of an FSO communication system with parallel all‐optical relays is investigated. A composite channel is established, which includes atmospheric loss, pointing error and atmospheric turbulence. To show the impact of the channel state information (CSI) on system performance, either full CSI or semi‐blind CSI at the relay nodes is considered. After that, the theoretical expressions of the outage probabilities for different scenarios are derived. Numerical results show that the derived expressions are quite accurate to evaluate the system performance. Moreover, the derived results demonstrate that the systems with semi‐blind CSI relaying can provide comparable performance to systems with full CSI relaying, and also indicate that the performance over strong turbulence channels with clear weather outperforms that over weak turbulence channels with light fog.
Inter-cage dynamics in structure I, II, and H fluoromethane hydrates as studied by NMR and molecular dynamics simulations
Authors: Trueba Alondra Torres , Kroon Maaike C. , Peters Cor J. , Moudrakovski Igor L. , Ratcliffe Christopher I. , Alavi Saman , Ripmeester John A.
Published: June 2014

Prospective industrial applications of clathrate hydrates as materials for gas separation require further knowledge of cavity distortion, cavity selectivity, and defects induction by guest-host interactions. The results presented in this contribution show that under certain temperature conditions the guest combination of CH3F and a large polar molecule induces defects on the clathrate hydrate framework that allow intercage guest dynamics. 13C NMR chemical shifts of a CH3F/CH4/TBME sH hydrate and a temperature analysis of the 2H NMR powder lineshapes of a CD3F/THF sII and CD3F/TBME sH hydrate, displayed evidence that the populations of CH4 and CH3F in the D and D′ cages were in a state of rapid exchange. A hydrogen bonding analysis using molecular dynamics simulations on the TBME/CH3F and TBME/CH4 sH hydrates showed that the presence of CH3F enhances the hydrogen bonding probability of the TBME molecule with the water molecules of the cavity. Similar results were obtained for THF/CH3F and THF/CH4 sII hydrates. The enhanced hydrogen bond formation leads to the formation of defects in the water hydrogen bonding lattice and this can enhance the migration of CH3F molecules between adjacent small cages.
Anomalous increase of the thermal emf in epitaxial graphene on size-quantized films
Authors: Alisultanov Z. Z. , Mirzegasanova N. A.
Published: June 2014

The thermoelectric effect in epitaxial graphene formed on the surface of a size-quantized metal film is examined in the context of a Davydov model. An approach based on the Kubo formula for the conductivity and differential thermal emf is used. It is shown that because of size quantization, near the edges of the energy levels the thermal emf of epitaxial graphene increases to gigantic values of 200 μV/K, or almost a factor of seven greater than the emf of isolated graphene (about 30 μV/K).
Equation of state and isentropic release of aluminum foam and polyvinylidene fluoride systems
Authors: Borg John P. , Maines Warren R. , Chhabildas Lalit C.
Published: June 2014

There is considerable interest in developing a better understanding of the dynamic behavior of multicomponent heterogeneous systems. This study investigates and compares the dynamic response of 21% dense aluminum foam, filled with polyvinylidene fluoride (PVDF or Kynar). Experiments were conduced in a 60 mm bore gun in a one-dimensional reverse plate impact configuration at velocities ranging from 350 m/s to 2200 m/s. The particle velocity of the backside of a thin anvil, also referred to as a witness plate, was monitored with a velocity interferometer. The resulting shock Hugoniot and isentropic release states are inferred from the particle velocity records using an impedance matching technique. The experiments indicate that the heterogeneous system achieves a wide distribution of states even though it was loaded in a one-dimensional plane-strain configuration. The system maintains its strength up to shock levels near 5 GPa, above which the PVDF appears to melt upon release. Simulations were conducted using an Eulerian hydrocode where the foam filled structures are computationally resolved, i.e., mesoscale simulations. The mesoscale simulations were used to resolve not only the average response but also characterize a wide range of stress and temperature distributions during both loading and release. These simulations are in good agreement with the available experimental data and give insight into the dynamic response not accessible via experimental measurements.
A study of shear banding in polymer solutions
Authors: Cromer Michael , Fredrickson Glenn H. , Leal L. Gary
Published: June 2014

In a recent letter [M. Cromer, M. C. Villet, G. H. Fredrickson, and L. G. Leal, “Shear banding in polymer solutions,” Phys. Fluids 25, 051703 (2013)], we showed the existence of a steady shear-banded velocity profile for a model polymer solution with an underlying monotonic constitutive curve. The driving mechanism is the coupling of the polymer stress to an inhomogeneous concentration profile. To further understand this phenomenon, in this paper we investigate the underlying linear instability as well as probe the model parameters and their effect on transient and steady state solutions. The linear stability analysis of the steady, base homogeneous model shows that, in opposition to diffusion, the polymer concentration moves up stress gradients in a shear flow creating a critical balance such that, for a range of parameters, an instability occurs that drives the system away from homogeneity. The simulation of the full nonlinear equations in planar one-dimensional shear reveals a window within which the linear instability manifests itself as a shear-banded flow. Unlike the case for a nonmonotonic constitutive curve for which two bands are predicted, there is no apparent selection process for a monotonic curve that sets the number of bands in planar shear. Thus, we find the possibility of greater than two bands, the number of which is determined by the ratio of the polymer correlation length to the channel width. In addition to steady shear banding, transient phenomena are also probed revealing a complicated band transition (i.e., number of bands changing in time) as well as elastic recoil in a Taylor-Couette cell, each of which have been observed in experiment. Finally, as we showed in our letter, a nonlinear subcritical instability exists resulting in multiple steady states depending upon the wall ramp speed. Here, we show that this phenomenon can occur for realistic parameter values, in particular those obtained for a particular polymer solution that has shown this multiple steady state behavior experimentally.
Surface tension and density of Si-Ge melts
Authors: Ricci Enrica , Amore Stefano , Giuranno Donatella , Novakovic Rada , Tuissi Ausonio , Sobczak Natalia , Nowak Rafal , Korpala Bartłomiej , Bruzda Grzegorz
Published: June 2014

In this work, the surface tension and density of Si-Ge liquid alloys were determined by the pendant drop method. Over the range of measurements, both properties show a linear temperature dependence and a nonlinear concentration dependence. Indeed, the density decreases with increasing silicon content exhibiting positive deviation from ideality, while the surface tension increases and deviates negatively with respect to the ideal solution model. Taking into account the Si-Ge phase diagram, a simple lens type, the surface tension behavior of the Si-Ge liquid alloys was analyzed in the framework of the Quasi-Chemical Approximation for the Regular Solutions model. The new experimental results were compared with a few data available in the literature, obtained by the containerless method.
Intermediate-energy differential and integral cross sections for vibrational excitation in α-tetrahydrofurfuryl alcohol
Authors: Duque H. V. , Chiari L. , Jones D. B. , Pettifer Z. , da Silva G. B. , Limão-Vieira P. , Blanco F. , García G. , White R. D. , Lopes M. C. A. , Brunger M. J.
Published: June 2014

Differential and integral cross section measurements, for incident electron energies in the 20–50 eV range, are reported for excitation of several composite vibrational modes in α-tetrahydrofurfuryl alcohol (THFA). Optimisation and frequency calculations, using GAUSSIAN 09 at the B3LYP/aug-cc-pVDZ level, were also undertaken for the two most abundant conformers of THFA, with results being reported for their respective mode classifications and excitation energies. Those calculations assisted us in the experimental assignments of the composite features observed in our measured energy loss spectra. There are, to the best of our knowledge, no other experimental or theoretical data currently available in the literature against which we can compare the present results.
Two-dimensional electronic spectroscopy based on conventional optics and fast dual chopper data acquisition
Authors: Heisler Ismael A. , Moca Roberta , Camargo Franco V. A. , Meech Stephen R.
Published: June 2014

We report an improved experimental scheme for two-dimensional electronic spectroscopy (2D-ES) based solely on conventional optical components and fast data acquisition. This is accomplished by working with two choppers synchronized to a 10 kHz repetition rate amplified laser system. We demonstrate how scattering and pump-probe contributions can be removed during 2D measurements and how the pump probe and local oscillator spectra can be generated and saved simultaneously with each population time measurement. As an example the 2D-ES spectra for cresyl violet were obtained. The resulting 2D spectra show a significant oscillating signal during population evolution time which can be assigned to an intramolecular vibrational mode.
Visual degradation in Leonardo da Vinci's iconic self-portrait: A nanoscale study
Authors: Conte A. Mosca , Pulci O. , Misiti M. C. , Lojewska J. , Teodonio L. , Violante C. , Missori M.
Published: June 2014

The discoloration of ancient paper, due to the development of oxidized groups acting as chromophores in its chief component, cellulose, is responsible for severe visual degradation in ancient artifacts. By adopting a non-destructive approach based on the combination of optical reflectance measurements and time-dependent density functional theory ab-initio calculations, we describe and quantify the chromophores affecting Leonardo da Vinci's iconic self-portrait. Their relative concentrations are very similar to those measured in modern and ancient samples aged in humid environments. This analysis quantifies the present level of optical degradation of the Leonardo da Vinci's self-portrait which, compared with future measurements, will assess its degradation rate. This is a fundamental information in order to plan appropriate conservation strategies.
Energy relaxation and separation of a hot electron-hole pair in organic aggregates from a time-dependent wavepacket diffusion method
Authors: Han Lu , Zhong Xinxin , Liang WanZhen , Zhao Yi
Published: June 2014

The time-dependent wavepacket diffusive method [X. Zhong and Y. Zhao, J. Chem. Phys. 138, 014111 (2013)] is extended to investigate the energy relaxation and separation of a hot electron-hole pair in organic aggregates with incorporation of Coulomb interaction and electron-phonon coupling. The pair initial condition generated by laser pulse is represented by a Gaussian wavepacket with a central momentum. The results reveal that the hot electron energy relaxation is very well described by two rate processes with the fast rate much larger than the slow one, consistent with experimental observations, and an efficient electron-hole separation is accomplished accompanying the fast energy relaxation. Furthermore, although the extra energy indeed helps the separation by overcoming the Coulomb interaction, the width of initial wavepacket is much sensitive to the separation efficiency and the narrower wavepacket generates the more separated charges. This behavior may be useful to understand the experimental controversy of the hot carrier effect on charge separation.
Ultrafast time-resolved magneto-optical imaging of all-optical switching in GdFeCo with femtosecond time-resolution and a μm spatial-resolution
Authors: Hashimoto Y. , Khorsand A. R. , Savoini M. , Koene B. , Bossini D. , Tsukamoto A. , Itoh A. , Ohtsuka Y. , Aoshima K. , Kimel A. V. , Kirilyuk A. , Rasing Th.
Published: June 2014

We developed an ultrafast time-resolved magneto-optical (MO) imaging system with several millidegree resolution of light polarization angle, 100 fs time-resolution, and a micrometer spatial resolution. A CCD camera with about 106 pixels is used for detection and MO images with an absolute angle of the light polarization are acquired by the rotating analyzer method. By optimizing the analysis procedure with a least square method and the help of graphical processor units, this novel system significantly improves the speed for MO imaging, allowing to obtain a MO map of a sample within 15 s. To demonstrate the strength of the technique, we applied the method in a pump-and-probe experiment of all-optical switching in a GdFeCo sample in which we were able to detect temporal evolution of the MO images with sub-picosecond resolution.
Role of filament annealing in the kinetics and thermodynamics of nucleated polymerization
Authors: Michaels Thomas C. T. , Knowles Tuomas P. J.
Published: June 2014

The formation of nanoscale protein filaments from soluble precursor molecules through nucleated polymerization is a common form of supra-molecular assembly phenomenon. This process underlies the generation of a range of both functional and pathological structures in nature. Filament breakage has emerged as a key process controlling the kinetics of the growth reaction since it increases the number of filament ends in the system that can act as growth sites. In order to ensure microscopic reversibility, however, the inverse process of fragmentation, end-to-end annealing of filaments, is a necessary component of a consistent description of such systems. Here, we combine Smoluchowski kinetics with nucleated polymerization models to generate a master equation description of protein fibrillization, where filamentous structures can undergo end-to-end association, in addition to elongation, fragmentation, and nucleation processes. We obtain self-consistent closed-form expressions for the growth kinetics and discuss the key physics that emerges from considering filament fusion relative to current fragmentation only models. Furthermore, we study the key time scales that describe relaxation to equilibrium.
Optical properties of nanocrystalline WO3 and WO3-x thin films prepared by DC magnetron sputtering
Authors: Johansson Malin B. , Zietz Burkhard , Niklasson Gunnar A. , Österlund Lars
Published: June 2014

The optical properties of tungsten trioxide thin films prepared by DC magnetron sputtering, with different oxygen vacancy (Vo) concentration, have been studied by spectrophotometry and photoluminescence (PL) emission spectroscopy. Absorption and PL spectra show that the films exhibit similar band gap energies, Eg ≈ 2.9 eV. The absorption spectra of the films show two pronounced absorption bands in the near-infrared region. One peak (P1) is located at approximately 0.7 eV, independent of Vo concentration. A second peak (P2) shifts from 0.96 eV to 1.16 eV with decreasing Vo concentration. Peak P1 is assigned to polaron absorption due to transitions between tungsten sites (W5+ → W6+), or an optical transition from a neutral vacancy state to the conduction band, Vo0 → W6+. The origin of peak P2 is more uncertain but may involve +1 and +2 charged vacancy sites. The PL spectra show several emission bands in the range 2.07 to 3.10 eV in the more sub-stoichiometric and 2.40 to 3.02 eV in the less sub-stoichiometric films. The low energy emission bands agree well with calculated optical transition energies of oxygen vacancy sites, with dominant contribution from neutral and singly charged vacancies in the less sub-stoichiometric films, and additional contributions from doubly charged vacancy sites in the more sub-stoichiometric films.
Communication: Structure characterization of hard sphere packings in amorphous and crystalline states
Authors: Ogarko Vitaliy , Rivas Nicolas , Luding Stefan
Published: June 2014

The channel size distribution in hard sphere systems, based on the local neighbor correlation of four particle positions, is investigated for all volume fractions up to jamming. For each particle, all three particle combinations of neighbors define channels, which are relevant for the concept of caging. The analysis of the channel size distribution is shown to be very useful in distinguishing between gaseous, liquid, partially and fully crystallized, and glassy (random) jammed states. A common microstructural feature of four coplanar particles is observed in crystalline and glassy jammed states, suggesting the presence of “hidden” two-dimensional order in three-dimensional random close packings.