bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamics of water, methanol, and ethanol in a room temperature ionic liquid
Authors: Kramer Patrick L. , Giammanco Chiara H. , Fayer Michael D.
Published: March 2015

The dynamics of a series of small molecule probes with increasing alkyl chain length: water, methanol, and ethanol, diluted to low concentration in the room temperature ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, was investigated with 2D infrared vibrational echo (2D IR) spectroscopy and polarization resolved pump-probe (PP) experiments on the deuterated hydroxyl (O–D) stretching mode of each of the solutes. The long timescale spectral diffusion observed by 2D IR, capturing complete loss of vibrational frequency correlation through structural fluctuation of the medium, shows a clear but not dramatic slowing as the probe alkyl chain length is increased: 23 ps for water, 28 ps for methanol, and 34 ps for ethanol. Although in each case, only a single population of hydroxyl oscillators contributes to the infrared line shapes, the isotropic pump-probe decays (normally caused by population relaxation) are markedly nonexponential at short times. The early time features correspond to the timescales of the fast spectral diffusion measured with 2D IR. These fast isotropic pump-probe decays are produced by unequal pumping of the OD absorption band to a nonequilibrium frequency dependent population distribution caused by significant non-Condon effects. Orientational correlation functions for these three systems, obtained from pump-probe anisotropy decays, display several periods of restricted angular motion (wobbling-in-a-cone) followed by complete orientational randomization. The cone half-angles, which characterize the angular potential, become larger as the experimental frequency moves to the blue. These results indicate weakening of the angular potential with decreasing hydrogen bond strength. The slowest components of the orientational anisotropy decays are frequency-independent and correspond to the complete orientational randomization of the solute molecule. These components slow appreciably with increasing chain length: 25 ps for water, 42 ps for methanol, and 88 ps for ethanol. The shape and volume of the probe, therefore, impact reorientation far more severely than they do spectral diffusion at long times, though these two processes occur on similar timescales at earlier times.
Experimental analysis on the effects of DC arc discharges at various flow regimes
Authors: Bianchi G. , Saracoglu B. H. , Paniagua G. , Regert T.
Published: March 2015

This paper addresses the control of the boundary layer on a compression ramp by means of DC electrical arc discharges. The development and realization of the control system are first described and then assessed in the wind tunnel. The objective of the research was to control the supersonic flow using the minimum amount of energy. The array of electrodes was located at the base of a ramp, where a low momentum flow develops. The electrical discharge was generated by a custom designed electronic facility based on high-voltage ignition coils. The slanted tungsten electrodes were insulated by mounting them in a ceramic support. The discharge evolution was studied through high-speed flow visualizations, while electrical measurements at the high-voltage section of the circuitry allowed to estimate the energy release. The development of a high-speed short exposure Schlieren imaging technique, based on a very short duration laser pulse illumination and a double shot CCD camera, allowed to observe the macroscopic effects associated with the arc establishment between the electrodes (glow, sound wave and heat release). Due to the long residence time, the thermal perturbation spread along the streamwise direction. Cross correlation of Schlieren images with short time separation revealed that in supersonic conditions, the discharges led to an overall acceleration of the flow field underneath the oblique shock wave.
Effect of solvent on the charging mechanisms of poly(ethylene glycol) in droplets
Authors: Soltani Sepideh , Oh Myong In , Consta Styliani
Published: March 2015

We examine the effect of solvent on the charging mechanisms of a macromolecule in a droplet by using molecular dynamics simulations. The droplet contains excess charge that is carried by sodium ions. To investigate the principles of the charging mechanisms of a macromolecule in a droplet, we simulate aqueous and methanol droplets that contain a poly(ethylene glycol) (PEG) molecule. We find that the solvent plays a critical role in the charging mechanism and in the manner that the sodiated PEG emerges from a droplet. In the aqueous droplets, the sodiated PEG is released from the droplet while it is being charged at a droplet charge state below the Rayleigh limit. The charging of PEG occurs on the surface of the droplet. In contrast to the aqueous droplets, in the methanol droplet, the sodiated PEG resides in the interior of the droplet and it may become charged at any location in the droplet, interior or surface. The sodiated PEG emerges from the droplet by drying-out of the solvent. Even though these two mechanisms appear to be phenomenologically similar to the widely accepted ion-evaporation and charge-residue mechanisms, they have fundamental differences from those. An integral part of the mechanism that the macromolecular ions emerge from droplets is the droplet morphology. Droplet morphologies give rise to different solvation interactions between the solvent and the macromolecule. In the water-sodiated PEG system, we find the extrusion of the PEG morphology, while in methanol-sodiated droplet, we find the “pearl-on-the-necklace” morphology and the extrusion of the sodiated PEG in the last stage of the desolvation process. These findings provide insight into the mechanisms that macromolecules acquire their charge in droplets produced in electrospray ionization experiments.
Unexpected bismuth concentration profiles in metal-organic vapor phase epitaxy-grown Ga(As1−xBix)/GaAs superlattices revealed by Z-contrast scanning transmission electron microscopy imaging
Authors: Wood A. W. , Guan Y. , Forghani K. , Anand A. , Kuech T. F. , Babcock S. E.
Published: March 2015

A set of GaAs1−xBix/GaAs multilayer quantum-well structures was deposited by metal-organic vapor phase epitaxy at 390 °C and 420 °C. The precursor fluxes were introduced with the intent of growing discrete and compositionally uniform GaAs1−xBix well and GaAs barrier layers in the epitaxial films. High-resolution high-angle annular-dark-field (or “Z-contrast”) scanning transmission electron microscopy imaging revealed concentration profiles that were periodic in the growth direction, but far more complicated in shape than the intended square wave. The observed composition profiles could explain various reports of physical properties measurements that suggest compositional inhomogeneity in GaAs1−xBix alloys as they currently are grown.
The role of interfacial metal silicates on the magnetism in FeCo/SiO2 and Fe49%Co49%V2%/SiO2 core/shell nanoparticles
Authors: Desautels R. D. , Freeland J. W. , Rowe M. P. , van Lierop J.
Published: March 2015

We have investigated the role of spontaneously formed interfacial metal silicates on the magnetism of FeCo/SiO2 and Fe49%Co49%V2%/SiO2 core/shell nanoparticles. Element specific x-ray absorption and photoelectron spectroscopy experiments have identified the characteristic spectral features of metallic iron and cobalt from within the nanoparticle core. In addition, metal silicates of iron, cobalt, and vanadium were found to have formed spontaneously at the interface between the nanoparticle core and silica shell. X-ray magnetic circular dichroism experiments indicated that the elemental magnetism was a result of metallic iron and cobalt with small components from the iron, cobalt, and vanadium silicates. Magnetometry experiments have shown that there was no exchange bias loop shift in the FeCo nanoparticles; however, exchange bias from antiferromagnetic vanadium oxide was measured in the V-doped nanoparticles. These results showed clearly that the interfacial metal silicates played a significant role in the magnetism of these core/shell nanoparticles, and that the vanadium percolated from the FeCo-cores into the SiO2-based interfacial shell.
Measuring charge carrier mobility in photovoltaic devices with micron-scale resolution
Authors: Ashraf A. , Dissanayake D. M. N. M. , Eisaman M. D.
Published: March 2015

We present a charge-extraction technique, micron-scale charge extraction by linearly increasing voltage, which enables simultaneous spatially resolved measurements of charge carrier mobility and photocurrent in thin-film photovoltaic devices with micron-scale resolution. An intensity-modulated laser with beam diameter near the optical diffraction limit is scanned over the device, while a linear voltage ramp in reverse bias is applied at each position of illumination. We calculate the majority carrier mobility, photocurrent, and number of photogenerated charge carriers from the resulting current transient. We demonstrate this technique on an organic photovoltaic device, but it is applicable to a wide range of photovoltaic materials.
Magnetometry of single ferromagnetic nanoparticles using magneto-optical indicator films with spatial amplification
Authors: Balk Andrew L. , Hangarter Carlos , Stavis Samuel M. , Unguris John
Published: March 2015

We present a magneto-optical technique to spatially amplify and image fringe fields from single ferromagnetic nanorods. The fringe fields nucleate magnetic domains in a low-coercivity, perpendicularly magnetized indicator film, which are expanded by an applied out-of-plane field from the nanoscale to the microscale for measurement with polar Kerr microscopy. The nucleation location and therefore magnetic orientation of the sample nanorod are detected as spatially dependent field biases in locally measured hysteresis loops of the indicator film. We first discuss our method to fabricate the high-sensitivity indicator film with low energy argon ion irradiation. We then present a map of the amplified signal produced from a single nanorod as measured by the indicator film and compare it with a simultaneously obtained, unamplified fringe field map. The comparison demonstrates the advantage of the amplification mechanism and the capability of the technique to be performed with single-spot magneto-optical Kerr effect magnetometers. Our signal-to-noise ratio determines a minimum measureable particle diameter of tens of nanometers for typical transition metals. We finally use our method to obtain hysteresis loops from multiple nanorods in parallel. Our technique is unperturbed by applied in-plane fields for magnetic manipulation of nanoparticles, is robust against many common noise sources, and is applicable in a variety of test environments. We conclude with a discussion of the future optimization and application of our indicator film technique.
Reversible exchange of stable nitroxyl radicals on nanosilver particles
Authors: Chappell Mark A. , Miller Lesley F. , Price Cynthia L.
Published: March 2015

Environmental context
Nanometre-sized silver particles promote unique chemical reactions on their surface. This work examines the ability of silver nanoparticles to collect and store unpaired electrons, called radicals, on their surface. This capability by silver nanoparticles could potentially serve to drive degradation reactions in the environment.

Abstract
Radicals drive important chemical reactions in the environment. These unpaired electron species can be generated by energetic inputs, such as electromagnetic radiation, or from ultrasonication processes, whereby oxygen radicals are generated in aqueous solution through a cavitation mechanism. Previous evidence has demonstrated the potential for radicals to be stored on the surface of metallic gold nanoparticles, thus suggesting a potential transference of radical species from the nanoparticle surface for catalytic reactions, particularly during preparations of nanoparticle suspensions through ultrasonication. This work investigates the potential for the nanosilver (nAg) particles to similarly scavenge radicals from solution. nAg suspensions were reacted with 0.3-mM solutions containing the stable nitroxy radicals 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO), 4-oxo-2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPONE) and 4-amino-2,2,6,6-tetramethylpiperidino-1-oxyl (TEMPAMINE) analysed by quantitative electron spin resonance (ESR) spectroscopy. In ambient air, the addition of a nAg suspension to the 0.3-mM solutions reduced the integrated ESR intensity of the stable radicals by 50–93% depending on radical species and nAg concentration, which we attributed to the sorption of the radicals onto the nAg surface. In separate experiments, the ESR intensities were further decreased under an Ar atmosphere, suggesting potential competition from ambient OH• to the sorption of the stable radicals. To verify this, we observed substantial increases in the integrated ESR intensity when the systems previously equilibrated under Ar atmosphere were exposed to ambient air. These results demonstrated that nAg scavenged the stable radicals from solution and were exchangeable from the metallic conduction band with OH•. Our work represents the first evidence for this mechanism to be demonstrated for nAg.
Landscape predictors of wolf attacks on bear-hunting dogs in Wisconsin, USA
Authors: Olson Erik R. , Treves Adrian , Wydeven Adrian P. , Ventura Stephen J.
Published: March 2015

Context In Europe and the United States, wolf–human conflict has increased as wolf populations have recovered and recolonised human-dominated ecosystems. These conflicts may lead to negative attitudes towards wolves and often complicate wolf management. Wolf attacks on bear-hunting hounds (hereafter, hounds) are the second-most common type of depredation on domestic animals in Wisconsin, USA, and, typically, the most costly in terms of compensation per individual animal. Understanding the geospatial patterns in which these depredations occur could promote alternative hunting practices or management strategies that could reduce the number of wolf–human conflicts. Aims We compared variables differentiating between wolf attacks on hounds and non-hounds (e.g., pets), we constructed a spatial, predictive model of wolf attacks on hounds, and we explored how the landscape of risk changed over time. Methods We characterised landscape features of hound depredations using logistic regression. We applied the spatial model to a geographic information system (GIS) to display spatial patterns and to predict areas of risk for wolf attack. Key results Our model correctly classified 84% of sites of past depredations, 1999–2008, and 78% of nearby random-unaffected sites. The model correctly predicted 82% of recent (2009–11) depredation sites not used in model construction, thereby validating its predictive power. Risk of wolf attack on hounds increased with percentage area of public-access land nearby, size of the nearest wolf pack, proximity of the nearest wolf pack, and decreased with percentage of human development. National and county forest lands had significantly (P < 0.001) more hound depredations than did other land-ownership types, whereas private lands had significantly fewer. Conclusions Risk of wolf attacks on hounds had distinctive temporal and spatial signatures, with peak risk occurring during the black bear hound training and hunting seasons and in areas closer to the centre of wolf pack territories, with larger wolf packs and more public access land and less developed land. Implications Our analysis can help bear hunters avoid high-risk areas, and help wildlife managers protect wildlife and recreational use of public lands, and reduce public costs of predator recovery. We present a risk-adjusted compensation equation. If wildlife managers choose, or are required, to provide compensation for hounds attacked by wolves, while hunting on public lands, we suggest that managers consider adjusting compensation payments on the basis of the relative landscape of risk.
Assessing the efficacy of medetomidine and tiletamine–zolazepam for remote immobilisation of feral horses (Equus caballus)
Authors: Zabek Magdalena A. , Wright John , Berman David M. , Hampton Jordan O. , Collins Christina W.
Published: March 2015

Context The study of any wild animal’s home range requires the collection of spatiotemporal data, obtained independently of climatic conditions or time of day. This can be achieved by the attachment of global positioning system (GPS) data loggers, which, in large species, is best achieved by remote immobilisation. Feral horses (Equus caballus) usually occupy remote areas of Australia; however, a considerable population increase has been observed in a close proximity to metropolitan areas of the Australian east coast, creating increasing conflict with human interests. Aim The aim of the present study was to investigate the efficacy of remote chemical immobilisation of feral horses with medetomidine combined with tiletamine–zolazepam to facilitate placement of satellite GPS collars. Methods Nine feral horses were darted from the ground with 60 mg (i.m.) medetomidine and 1500 mg (i.m.) tiletamine–zolazepam. The effects of medetomidine were reversed with 50–100 mg (i.m. or i.v.) atipamezole 30–40 min after induction (IV/IM). Physiological variables monitored during anaesthesia were heart rate, respiratory rate, temperature and oxygen haemoglobin saturation (Spo2). Key results All horses were successfully immobilised with between one and three darts (n = 9). The mean (± s.e.m.) dose of medetomidine was 0.15 ± 0.01 mg kg–1, whereas that of tiletamine–zolazepam was 3.61 ± 0.16 mg kg–1. Mean time from darting to lateral recumbency was 13.3 ± 2.7 min and mean recumbency time was 54 ± 13 min. Vital signs for all anaesthetised animals remained within the normal range during anaesthesia, with the exception of one animal exhibiting a transient drop in Spo2. There were no deaths. Key conclusions The combination of medetomidine and tiletamine–zolazepam provided adequate anaesthesia in feral horses in the field for application of GPS collars. Implications Although a limited number of horses was immobilised, the present study shows that the combination of medetomidine and tiletamine–zolazepam provides effective short-term anaesthesia for feral horses, affording a practical and field-accessible capture technique. This method could also be applied to other management actions requiring the safe and humane capture of feral horses.
A remark on the global dynamics of competitive systems on ordered Banach spaces
Authors: Lam King-Yeung , Munther Daniel
Published: March 2015

A well-known result in [Hsu-Smith-Waltman, Trans. Amer. Math. Soc. (1996)] states that in a competitive semiflow defined on

X
+

=

X
1
+

×

X
2
+

X^+ = X_1^+ \times X_2^+

, the product of two cones in respective Banach spaces, if

(

u
∗

,
0
)

(u^*,0)

and

(
0
,

v
∗

)

(0,v^*)

are the global attractors in

X
1
+

×
{
0
}

X_1^+ \times \{0\}

and

{
0
}
×

X
2
+

\{0\}\times X_2^+

respectively, then one of the following three outcomes is possible for the two competitors: either there is at least one coexistence steady state, or one of

(

u
∗

,
0
)
,
(
0
,

v
∗

)

(u^*,0), (0,v^*)

attracts all trajectories initiating in the order interval

I
=
[
0
,

u
∗

]
×
[
0
,

v
∗

]

I = [0,u^*] \times [0,v^*]

. However, it was demonstrated by an example that in some cases neither

(

u
∗

,
0
)

(u^*,0)

nor

(
0
,

v
∗

)

(0,v^*)

is globally asymptotically stable if we broaden our scope to all of

X
+

X^+

. In this paper, we give two sufficient conditions that guarantee, in the absence of coexistence steady states, the global asymptotic stability of one of

(

u
∗

,
0
)

(u^*,0)

or

(
0
,

v
∗

)

(0,v^*)

among all trajectories in

X
+

X^+

. Namely, one of

(

u
∗

,
0
)

(u^*,0)

or

(
0
,

v
∗

)

(0,v^*)

is (i) linearly unstable, or (ii) linearly neutrally stable but zero is a simple eigenvalue. Our results complement the counterexample mentioned in the above paper as well as applications that frequently arise in practice.
Alcohol Abuse Decreases Pelvic Control and Survival in Cervical Cancer
Authors: Mayadev Jyoti , Li Chin-Shang , Lim Jihoon , Valicenti Richard , Alvarez Edwin A.
Published: March 2015

Purpose:

We examined the incidence and the effect of alcohol abuse on pelvic control (PC), disease-free survival (DFS), and overall survival (OS) in locally advanced cervical cancer patients undergoing definitive radiation therapy (RT).

Methods:

Between 2007 and 2013, 95 patients treated with RT were reviewed, and the tumor characteristics, the RT dose, the treatment time, chemotherapy, and the number of cycles were recorded. The association between alcohol abuse and DFS, OS, and the duration of PC was analyzed using multivariable Cox proportional hazards models.

Results:

Of the 95 patients with an average age of 54.8 years (range, 27 to 91 y), 30% were FIGO stage 1B1, 1B2, 2A, 52% stage 2B, 3A; and 18% stage 3B; 86% of the patients were treated with weekly cisplatin chemotherapy. Alcohol history showed that 10 (10.5%) patients met the CDC criteria for heavy alcohol use. With a mean follow-up time of 2 years, 85 patients (88.5%) achieved PC and 86 patients (90.5%) were free of distant metastasis. A total of 82 patients (86.3%) were alive at the last follow-up. When controlling for the total treatment time, excessive alcohol abuse was significantly associated with a decrease in DFS (P=0.005; hazard ratio [HR], 6.19; 95% confidence interval [CI]: 1.73, 22.18), OS (P=0.001; HR, 6.68; 95% CI: 2.10, 21.26), and PC (P=0.029; HR, 3.10; 95% CI: 1.13, 8.56) on univariable analysis. On multivariable analysis, excessive alcohol abuse was significantly associated with a decrease in DFS (P=0.005; HR, 10.57; 95% CI: 2.07, 53.93) and OS (P=0.001; HR, 10.80; 95% CI: 2.57, 45.40).

Conclusions:

In this small hypothesis-generating series of patients with heavy alcohol use, the data support the association that heavy alcohol use increases the risk of cancer recurrence and mortality. Additional research is required to better define the patient- and treatment-related factors that may be targeted for intervention.
Treatment Toxicity in Elderly Patients With Advanced Non–Small Cell Lung Cancer
Authors: Kale Minal S. , Mhango Grace , Gomez Jorge E. , Sigel Keith , Smith Cardinale B. , Bonomi Marcelo , Wisnivesky Juan P.
Published: March 2015

Objectives:

Toxicity is a main concern limiting the use of chemotherapy and radiotherapy (RT) for elderly patients with non–small cell lung cancer (NSCLC). The objective of this study was to assess the rates of treatment-related toxicity among elderly stage IIIB and IV NSCLC patients.

Materials and Methods:

We used the Surveillance, Epidemiology, and End Results registry linked to Medicare records to identify 2596 stage IIIB and 14,803 stage IV NSCLC patients aged 70 years and above, diagnosed in 2000 or later. We compared rates of toxicity requiring hospitalization according to treatment (chemotherapy, RT, or chemoradiation [CRT]) in unadjusted and adjusted models controlling for selection bias using propensity scores.

Results:

Among stage IIIB patients, rates of any severe toxicity were 10.1%, 23.8%, 30.4%, and 39.2% for patients who received no treatment, RT, chemotherapy alone, and CRT, respectively. In stage IV patients, rates of any severe toxicity were 31.5% versus 13.5% among those treated with and without chemotherapy, respectively. In stage IIIB patients treated with CRT, the most common toxicities was esophagitis (odds ratio, 48.5; 95% confidence interval, 6.7-350.5). Among stage IV patients treated with chemotherapy, the risk of toxicity was highest for neutropenia (odds ratio, 8.4; 95% confidence interval, 6.1-11.5).

Conclusions:

Toxicity was relatively common among stage IIIB patients with up to a 6-fold increase in elderly individuals treated with CRT and a 4-fold increase in toxicities among stage IV patients. This information should be helpful to guide discussions about the risk-benefit ratio of chemotherapy and RT in elderly patients with advanced NSCLC.
Dietary Effects on Plasma Glycerophospholipids
Authors: Uhl Olaf , Hellmuth Christian , Demmelmair Hans , Zhou Shao J. , Makrides Maria , Prosser Colin , Lowry Dianne , Gibson Robert A. , Koletzko Berthold
Published: March 2015

Objective:

Human milk provides a complex mixture of animal lipids, whereas the fat supply of most modern infant formula is based on vegetable oils. We studied the effects of breast‐feeding and of feeding infant formula either without or with dairy goat lipids on the composition of infant plasma glycerophospholipids.

Methods:

Healthy‐term infants were randomized double blind to feeding with infant formula based on whole goats’ milk (GIF, approximately 60% milk fat and 40% vegetable oils) or a control cows’ milk infant formula based on vegetable oils (VIF) from 2 weeks after birth. A reference group of fully breast‐fed infants was also followed. At the age 4 months, blood samples were collected and plasma glycerophospholipids were analyzed with liquid chromatography coupled to triple quadrupole mass spectrometry.

Results:

The group of breast‐fed infants showed significantly higher contents of glycerophospholipid species containing sn‐2 palmitic acid [PC(16:0/16:0) and PC(18:0/16:0)] and significantly higher contents of glycerophospholipid species containing long‐chain polyunsaturated fatty acids than infants in both formula groups. The GIF group demonstrated significantly higher glycerophospholipid species containing myristic acid [LPC(14:0), PC(14:0/18:1), PC(16:0/14:0)] and palmitoleic acid [LPC(16:1), PC(16:0/16:1), and PC(16:1/18:1)] than the VIF group.

Conclusions:

We conclude that breast‐feeding induces marked differences in infant plasma glycerophospholipid profiles compared with formula feeding, whereas the studied different sources of formula fat resulted in limited effects on plasma glycerophospholipids.
Near-infrared light increases ATP, extends lifespan and improves mobility in aged
Drosophila melanogaster
Authors: Begum Rana , Calaza Karin , Kam Jaimie Hoh , Salt Thomas E. , Hogg Chris , Jeffery Glen
Published: March 2015

Ageing is an irreversible cellular decline partly driven by failing mitochondrial integrity. Mitochondria accumulate DNA mutations and reduce ATP production necessary for cellular metabolism. This is associated with inflammation. Near-infrared exposure increases retinal ATP in old mice via cytochrome
c
oxidase absorption and reduces inflammation. Here, we expose fruitflies daily to 670 nm radiation, revealing elevated ATP and reduced inflammation with age. Critically, there was a significant increase in average lifespan: 100–175% more flies survived into old age following 670 nm exposure and these had significantly improved mobility. This may be a simple route to extending lifespan and improving function in old age.
Regulation of dopamine system responsivity and its adaptive and pathological response to stress
Authors: Belujon Pauline , Grace Anthony A.
Published: March 2015

Although, historically, the norepinephrine system has attracted the majority of attention in the study of the stress response, the dopamine system has also been consistently implicated. It has long been established that stress plays a crucial role in the pathogenesis of psychiatric disorders. However, the neurobiological mechanisms that mediate the stress response and its effect in psychiatric diseases are not well understood. The dopamine system can play distinct roles in stress and psychiatric disorders. It is hypothesized that, even though the dopamine (DA) system forms the basis for a number of psychiatric disorders, the pathology is likely to originate in the afferent structures that are inducing dysregulation of the DA system. This review explores the current knowledge of afferent modulation of the stress/DA circuitry, and presents recent data focusing on the effect of stress on the DA system and its relevance to psychiatric disorders.
A fish that uses its hydrodynamic tongue to feed on land
Authors: Michel Krijn B. , Heiss Egon , Aerts Peter , Van Wassenbergh Sam
Published: March 2015

To capture and swallow food on land, a sticky tongue supported by the hyoid and gill arch skeleton has evolved in land vertebrates from aquatic ancestors that used mouth-cavity-expanding actions of the hyoid to suck food into the mouth. However, the evolutionary pathway bridging this drastic shift in feeding mechanism and associated hyoid motions remains unknown. Modern fish that feed on land may help to unravel the physical constraints and biomechanical solutions that led to terrestrialization of fish-feeding systems. Here, we show that the mudskipper emerges onto land with its mouth cavity filled with water, which it uses as a protruding and retracting ‘hydrodynamic tongue’ during the initial capture and subsequent intra-oral transport of food. Our analyses link this hydrodynamic action of the intra-oral water to a sequence of compressive and expansive cranial motions that diverge from the general pattern known for suction feeding in fishes. However, the hyoid motion pattern showed a remarkable resemblance to newts during tongue prehension. Consequently, although alternative scenarios cannot be excluded, hydrodynamic tongue usage may be a transitional step onto which the evolution of adhesive mucosa and intrinsic lingual muscles can be added to gain further independence from water for terrestrial foraging.
Desulfoplanes formicivorans gen. nov., sp. nov., a novel sulfate-reducing bacterium isolated from a blackish meromictic lake, and emended description of the family Desulfomicrobiaceae
Authors: Watanabe Miho , Kojima Hisaya , Fukui Manabu
Published: March 2015

A novel sulfate-reducing bacterium, designated strain Pf12BT, was isolated from sediment of meromictic Lake Harutori in Japan. Cells were vibroid (1.0 × 3.0–4.0 μm), motile and Gram-stain-negative. For growth, the optimum pH was 7.0–7.5 and the optimum temperature was 42–45 °C. Strain Pf12BTused sulfate, thiosulfate and sulfite as electron acceptors. The G+C content of the genomic DNA was 55.4 mol%. Major cellular fatty acids were C16 : 0and C18 : 0. The strain was desulfoviridin-positive. Phylogenetic analysis based on the 16S rRNA gene revealed that the novel strain belonged to the orderDesulfovibrionalesin the classDeltaproteobacteria. The closest relative wasDesulfomicrobium baculatumDSM 4028Twith which it shared 91  % 16S rRNA gene sequence similarity. On the basis of phylogenetic and phenotypic characterization, a novel species of a new genus belonging to the familyDesulfomicrobiaceaeis proposed,Desulfoplanes formicivoransgen. nov., sp. nov. The type strain ofDesulfoplanes formicivoransis Pf12BT( = NBRC 110391T= DSM 28890T).
Latent epistatic interaction model identifies loci associated with human working memory
Authors: Kelemen János Z , Vogler Christian , Heck Angela , de Quervain Dominique , Papassotiropoulos Andreas , Beerenwinkel Niko
Published: March 2015

Background

Epistatic interactions among genomic loci are expected to explain a large fraction of the heritability of complex diseases and phenotypic traits of living organisms.

Although epistasis detection methods are continually being developed, the current state of the art is exhaustive search methods, which become infeasible when the number of analyzed loci is large.

Results

We develop a novel latent interaction-based selection method for polymorphic loci as the first stage of a two-stage epistasis detection approach. Given a continuous phenotype and a single-nucleotide polymorphism (SNP), we rank the SNPs according to their interaction potential. When tested on simulated datasets and compared to standard marginal association and exhaustive search methods, our procedure significantly outperforms main-effect heuristics, especially in the presence of linkage disequilibrium (LD), which is explicitly accounted for in our model. Applied to real human genotype data, we prioritized several SNP pairs as candidates for epistatic interactions that influence human working memory performance, some of which are known to be connected to this phenotype.

Conclusions

The proposed method improves two-stage epistasis detection. Its linear runtime and increased statistical power contribute to reducing the computational complexity and to addressing some of the statistical challenges associated with the genome-wide search for epistatic loci.
The Arabidopsis RNA-Binding Protein AtRGGA Regulates Tolerance to Salt and Drought Stress
Authors: Ambrosone Alfredo , Batelli Giorgia , Nurcato Roberta , Aurilia Vincenzo , Punzo Paola , Bangarusamy Dhinoth Kumar , Ruberti Ida , Sassi Massimiliano , Leone Antonietta , Costa Antonello , Grillo Stefania
Published: March 2015

Salt and drought stress severely reduce plant growth and crop productivity worldwide. The identification of genes underlying stress response and tolerance is the subject of intense research in plant biology. Through microarray analyses, we previously identified in potato (Solanum tuberosum) StRGGA, coding for an Arginine Glycine Glycine (RGG) box-containing RNA-binding protein, whose expression was specifically induced in potato cell cultures gradually exposed to osmotic stress. Here, we show that the Arabidopsis (Arabidopsis thaliana) ortholog, AtRGGA, is a functional RNA-binding protein required for a proper response to osmotic stress. AtRGGA gene expression was up-regulated in seedlings after long-term exposure to abscisic acid (ABA) and polyethylene glycol, while treatments with NaCl resulted in AtRGGA down-regulation. AtRGGA promoter analysis showed activity in several tissues, including stomata, the organs controlling transpiration. Fusion of AtRGGA with yellow fluorescent protein indicated that AtRGGA is localized in the cytoplasm and the cytoplasmic perinuclear region. In addition, the rgga knockout mutant was hypersensitive to ABA in root growth and survival tests and to salt stress during germination and at the vegetative stage. AtRGGA-overexpressing plants showed higher tolerance to ABA and salt stress on plates and in soil, accumulating lower levels of proline when exposed to drought stress. Finally, a global analysis of gene expression revealed extensive alterations in the transcriptome under salt stress, including several genes such as ASCORBATE PEROXIDASE2, GLUTATHIONE S-TRANSFERASE TAU9, and several SMALL AUXIN UPREGULATED RNA-like genes showing opposite expression behavior in transgenic and knockout plants. Taken together, our results reveal an important role of AtRGGA in the mechanisms of plant response and adaptation to stress.
DENEDDYLASE1 Deconjugates NEDD8 from Non-Cullin Protein Substrates in Arabidopsis thaliana
Authors: Mergner Julia , Heinzlmeir Stephanie , Kuster Bernhard , Schwechheimer Claus
Published: March 2015

The evolutionarily conserved 8-kD protein NEDD8 (NEURAL PRECURSOR CELL EXPRESSED, DEVELOPMENTALLY DOWN-REGULATED8) belongs to the family of ubiquitin-like modifiers. Like ubiquitin, NEDD8 is conjugated to and deconjugated from target proteins. Many targets and functions of ubiquitylation have been described; by contrast, few targets of NEDD8 have been identified. In plants as well as in non-plant organisms, the cullin subunits of cullin-RING E3 ligases are NEDD8 conjugates with a demonstrated functional role for the NEDD8 modification. The existence of other non-cullin NEDD8 targets has generally been questioned. NEDD8 is translated as a precursor protein and proteolytic processing exposes a C-terminal glycine required for NEDD8 conjugation. In animals and yeast, DENEDDYLASE1 (DEN1) processes NEDD8. Here, we show that mutants of a DEN1 homolog from Arabidopsis thaliana have no detectable defects in NEDD8 processing but do accumulate a broad range of NEDD8 conjugates; this provides direct evidence for the existence of non-cullin NEDD8 conjugates. We further identify AUXIN RESISTANT1 (AXR1), a subunit of the heterodimeric NEDD8 E1 activating enzyme, as a NEDD8-modified protein in den1 mutants and wild type and provide evidence that AXR1 function may be compromised in the absence of DEN1 activity. Thus, in plants, neddylation may serve as a regulatory mechanism for cullin and non-cullin proteins.
SFX analysis of non-biological polycrystalline samples
Authors: Zhang Tao , Jin Shifeng , Gu Yuanxin , He Yao , Li Ming , Li Yang , Fan Haifu
Published: March 2015

Serial femtosecond crystallography (SFX) is capable of collecting three-dimensional single-crystal diffraction data using polycrystalline samples. This may dramatically enhance the power of X-ray powder diffraction. In this paper a test has been performed using simulated diffraction patterns. The test sample is a mixture of two zeolites with crystal grain sizes from 100 to 300 nm. X-ray diffraction snapshots by SFX were simulated and processed using the program suiteCrystFEL. Identification according to the primitive unit-cell volume determined from individual snapshots was able to separate the whole set of snapshots into two subsets, which correspond to the two zeolites in the sample. Monte Carlo integration inCrystFELwas then applied to them separately. This led to two sets of three-dimensional single-crystal diffraction intensities, based on which crystal structures of the two zeolites were solved easily by direct methods implemented in the programSHELXD.
Crystal structures of {[Cu(Lpn)2][Fe(CN)5(NO)]·H2O}nand {[Cu(Lpn)2]3[Cr(CN)6]2·5H2O}n[where Lpn = (R)-propane-1,2-diamine]: two heterometallic chiral cyanide-bridged coordination polymers
Authors: Sereda Olha , Stoeckli-Evans Helen
Published: March 2015

The title compounds,catena-poly[[[bis[(R)-propane-1,2-diamine-κ2N,N′]copper(II)]-μ-cyanido-κ2N:C-[tris(cyanido-κC)(nitroso-κN)iron(III)]-μ-cyanido-κ2C:N] monohydrate], {[Cu(Lpn)2][Fe(CN)5(NO)]·H2O}n, (I), and poly[[hexa-μ-cyanido-κ12C:N-hexacyanido-κ6C-hexakis[(R)-propane-1,2-diamine-κ2N,N′]dichromium(III)tricopper(II)] pentahydrate], {[Cu(Lpn)2]3[Cr(CN)6]2·5H2O}n, (II) [where Lpn = (R)-propane-1,2-diamine, C3H10N2], are new chiral cyanide-bridged bimetallic coordination polymers. The asymmetric unit of compound (I) is composed of two independent cation–anion units of {[Cu(Lpn)2][Fe(CN)5)(NO)]} and two water molecules. The FeIIIatoms have distorted octahedral geometries, while the CuIIatoms can be considered to be pentacoordinate. In the crystal, however, the units align to form zigzag cyanide-bridged chains propagating along [101]. Hence, the CuIIatoms have distorted octahedral coordination spheres with extremely long semicoordination Cu—N(cyanido) bridging bonds. The chains are linked by O—H...N and N—H...N hydrogen bonds, forming two-dimensional networks parallel to (010), and the networks are linkedviaN—H...O and N—H...N hydrogen bonds, forming a three-dimensional framework. Compound (II) is a two-dimensional cyanide-bridged coordination polymer. The asymmetric unit is composed of two chiral {[Cu(Lpn)2][Cr(CN)6]}−anions bridged by a chiral [Cu(Lpn)2]2+cation and five water molecules of crystallization. Both the CrIIIatoms and the central CuIIatom have distorted octahedral geometries. The coordination spheres of the outer CuIIatoms of the asymmetric unit can be considered to be pentacoordinate. In the crystal, these units are bridged by long semicoordination Cu—N(cyanide) bridging bonds forming a two-dimensional network, hence these CuIIatoms now have distorted octahedral geometries. The networks, which lie parallel to (10-1), are linkedviaO—H...O, O—H...N, N—H...O and N—H...N hydrogen bonds involving all five non-coordinating water molecules, the cyanide N atoms and the NH2groups of the Lpn ligands, forming a three-dimensional framework.
Structure cristalline de la triple molybdate Ag0.90Al1.06Co2.94(MoO4)5
Authors: Nasri Rawia , Chérif Saïda Fatma , Zid Mohamed Faouzi
Published: March 2015

Silver(I) aluminiun tricobalt(II) pentakis[tetraoxidomolybdate(VI)], Ag0.90Al1.06Co2.94(MoO4)5, was synthesized using a solid-state reaction at 845 K. The structure can be described as a three-dimensional framework formed from dimericM2O10(M= Co/Al) and trimericM3O14units linked to MoO4tetrahedra by sharing corners, with the cavities occupied by disordered Ag+cations. It is shown that the Co and Al atoms occupy common positions with different occupancies. The Ag+cations are located at two different sites with occupancies of 0.486 (1) and 0.408 (1). The title coumpond is isotypic with NaMg3Al(MoO4)5and NaFe4(MoO4)5. Differences and similarities with other related structures are discussed.
Crystal structure of {bis[2-(3,5-dimethylpyrazol-1-yl-κN2)ethyl]amine-κN}chloridoplatinum(II) chloride dihydrate
Authors: Mendoza María de los Angeles , Bernès Sylvain , Mendoza-Díaz Guillermo
Published: March 2015

The title complex, [PtCl(C14H23N5)]Cl·2H2O, is isomorphous with the PdIIcompound characterized previously [Mendoza, Bernès & Mendoza-Díaz (2006).Acta Cryst. E62, m2934–m2936]. The angle between pyrazole mean planes in the main ligand is 88.3 (4)°, similar to that observed in the PdIIanalogue [87.62 (11)°]. This tridentate ligand adopts a conformation approximating a twofold symmetry, allowing its coordination to the metal atom, together with a chloride ligand, in an almost perfect square-planar geometry. A chloride anion and two water molecules in the asymmetric unit form a hydrogen-bonded network connected to the complex molecules in the crystalviathe NH amine groups, forming chains along [100].
Innovation outcomes of knowledge-seeking Chinese foreign direct investment
Authors: Wu Xianming , Lupton Nathaniel C. , Du Yuping
Published: March 2015

Purpose

– The purpose of this paper is to investigates how organizational learning, absorptive capacity, cultural integration, specialization of the acquired firm and characteristics of transferred knowledge impact innovation performance subsequent to overseas acquisitions.

Design/methodology/approach

– Survey responses from 222 Chinese multinational enterprises engaged in overseas acquisitions.

Findings

– Differences between acquiring and acquired firms’ capabilities, while having a positive direct influence, suppress the positive impact of organizational learning and absorptive capacity, suggesting that multinationals require some basic level of capabilities to appropriate value from overseas acquisitions.

Research limitations/implications

– This paper investigates the impact of knowledge-seeking overseas acquisition of Chinese multinationals on innovation performance, as this appears to be the primary motive for making such acquisitions.

Practical implications

– Knowledge-seeking overseas acquisition should be based upon the absorptive capacity of the acquiring firm and complementarity between both firms. In knowledge-seeking overseas acquisitions, establishing an effective organizational learning mechanism is necessary for improving innovation performance.

Originality/value

– This paper reports on the behaviour and innovation performance of Chinese multinationals through analysis of primary data.
Creation of firm performance through resource orchestration: the case of ÜLKER
Authors: Kamasak Rifat
Published: March 2015

Purpose

– This study aims to investigate the complex interaction of different resource sets and capabilities in the process of performance creation within the context of resource-based theory.

Design/methodology/approach

– An inductive case study approach that included multiple data collection methods such as in-depth interviews, observation and documentation was utilized.

Findings

– Organizational culture, reputational assets, human capital, business processes and networking capabilities were found as the most important determinants of firm performance within the context of Ülker case study.

Originality/value

– Although large-scale empirical studies can be used to explore the direct resource–performance relationship, these quantitative methods bypass the complex and embedded nature of intangibles and provide only a limited understanding of why some resources are identified as strategic but others are not, what their roles are, and how these resources are converted into positions of competitive advantage. However, understanding of complex nature of resources that are embedded in organizations designates the need for more fieldwork-based qualitative studies. This study aims to address this gap by providing a thorough understanding about the managerial and organizational processes through which the resources become valuable.
Are the parents to blame? Predicting franchisee failure
Authors: Alon Ilan , Boulanger Michèle , Misati Everlyne , Madanoglu Melih
Published: March 2015

Purpose

– The purpose of this study is to show how franchisor characteristics influence franchisee failure. To achieve this aim, we developed a heuristic model using the methodology and power of predictive analytics.

Design/methodology/approach

– The authors use data from the World Franchising Council’s and from the Small Business Administration (SBA). The data cover 271 diverse USA franchise chains that are present in both databases.

Findings

– The model predicts potential defaults of SBA-backed loans issued to American franchisees, and the authors identify 13 variables that help explain franchisee failure.

Practical implications

– The authors offer guidance for stakeholder groups – lenders, franchisors and franchisees – to minimize the risk of lending and business failure.

Originality/value

– The paper contributes to the franchising literature by considering parent firms’ characteristics to predict franchisee failure.
Competition and competitiveness in the US airline industry
Authors: Hannigan T.J. , Hamilton III Robert D. , Mudambi Ram
Published: March 2015

Purpose

– This study aims to employ a resource-based lens to explore the competitive implications of firm strategies under conditions of market commonality and shared resource pools.

Design/methodology/approach

– The firms’ core capabilities in these environments may focus on operational efficiency, as firms seek to compete under significant resource heterogeneity constraints.

Findings

– Using data from the USA airline industry from 1996-2011, we find that price has a positive relationship with firm performance, whereas quality has a negative relationship. Operational efficiency is a driver of both strategies.

Research limitations/implications

– The study uses US data. Extending the findings to the global setting may require recognizing other competitive dimensions.

Originality/value

– Firms that focus on non-core activities perform less well. The results offer insights into an industry that has interested strategy researchers for many years and may suggest an application to other industries with similar characteristics.
Miniature and microrobots: a review of recent developments
Authors: Bogue Robert
Published: March 2015

Purpose

– This paper aims to provide an insight into recent miniaturised robot developments and applications.

Design/methodology/approach

– Following an introduction, this article discusses the technology and applications of miniature robots and considers swarm robotics, assembly robots, flying robots and their uses in healthcare. It concludes with a brief consideration of the emerging field of nanorobotics.

Findings

– This shows that all manners of miniaturised terrestrial, airborne and aquatic robots are being developed, but size and weight restraints pose considerable technological challenges, such as power sources, navigation, actuation and control. Prototypes have been developed for military, assembly, medical, environmental and other applications, as well as for furthering the understanding of swarm behaviour. In the longer term, microrobots and nanorobots offer prospects to revolutionise many aspects of healthcare, such as cancer treatment.

Originality/value

– This study provides details of a wide-ranging selection of miniaturised robot developments.