bluuebunny/crossref_metadata_2025 huggingface dataset:
Adaptive sensory coding of gaze direction in schizophrenia
Authors: Palmer Colin J. , Caruana Nathan , Clifford Colin W. G. , Seymour Kiley J.
Published: January 2019

Schizophrenia has been associated with differences in how the visual system processes sensory input. A fundamental mechanism that regulates sensory processing in the brain is gain control, whereby the responses of sensory neurons to a given stimulus are modulated in accordance with the spatial and temporal context. Some studies indicate an impairment of certain cortical gain control mechanisms in schizophrenia in low-level vision, reflected, for instance, in how the visual appearance of a stimulus is affected by the presence of other stimuli around it. In the present study, we investigated higher-level, social vision in schizophrenia, namely the perception of other people's direction of gaze (i.e. a type of face processing). Recent computational modelling work indicates that perceptual aftereffects—changes in perception that occur following repeated exposure to faces that display a specific direction of gaze—are indicative of two distinct forms of gain control involved in the coding of gaze direction across sensory neurons. We find that individuals with schizophrenia display strong perceptual aftereffects following repeated exposure to faces with averted gaze, and a modelling analysis indicates similarly robust gain control in the form of (i) short-term adjustment of channel sensitivities in response to the recent sensory history and (ii) divisive normalization of the encoded gaze direction. Together, this speaks to the typical coding of other people's direction of gaze in the visual system in schizophrenia, including flexible gain control, despite the social–cognitive impairments that can occur in this condition.
Rapidly assessing the risks of infectious diseases to wildlife species
Authors: Beauvais Wendy , Zuther Steffen , Villeneuve Chantal , Kock Richard , Guitian Javier
Published: January 2019

Predicting the likelihood of rare events is increasingly demanded by risk managers. A key challenge is dealing with different types of uncertainty, including epistemic uncertainties (lack of knowledge), stochasticity (inherent randomness) and natural variation. One potentially catastrophic event which is impacted by high levels of all three of these uncertainty types is the transmission of livestock pathogens to wildlife, particularly for endangered species. There is often a lack of basic information, e.g. about a given pathogen's presence in local livestock populations or the susceptibility of a given wildlife species to infection by the pathogen. We adapted the OIE (World Organisation for Animal Health) risk assessment framework to rapidly assess and prioritize the risks of livestock pathogens for wildlife, taking account of epistemic uncertainties, stochasticity, seasonal movement of animals and interaction between different species at different spatial and temporal scales. We demonstrate the approach using the endangered saiga antelope (
Saiga tatarica tatarica
) as a case study. We conclude that, in general, transmission events are likely to be rare and limited to small geographical areas; however, their impact could be high.
Brucella
spp. and foot-and-mouth disease virus are among those most likely to be transmitted from livestock to the Betpak-Dala saiga population.
Magnetoliposomes as model for signal transmission
Authors: Barreto G. R. , Kawai C. , Tofanello A. , Neves A. A. R. , Araujo-Chaves J. C. , Belleti E. , Lanfredi A. J. C. , Crespilho F. N. , Nantes-Cardoso I. L.
Published: January 2019

Liposomes containing magnetic nanoparticles (magnetoliposomes) have been extensively explored for targeted drug delivery. However, the magnetic effect of nanoparticles movement is also an attractive choice for the conduction of signals in communication systems at the nanoscale level because of the simple manipulation and efficient control. Here, we propose a model for the transmission of electrical and luminous signals taking advantage of magnetophoresis. The study involved three steps. Firstly, magnetite was synthesized and incorporated into fusogenic large unilamellar vesicles (LUVs) previously associated with a fluorescent label. Secondly, the fluorescent magnetite-containing LUVs delivered their contents to the giant unilamellar vesicles (GUVs), which were corroborated by magnetophoresis and fluorescence microscopy. In the third step, magnetophoresis of magnetic vesicles was used for the conduction of the luminous signal from a capillary to an optical fibre connected to a fluorescence detector. Also, the magnetophoresis effects on subsequent transmission of the electrochemical signal were demonstrated using magnetite associated with CTAB micelles modified with ferrocene. We glimpse that these magnetic supramolecular systems can be applied in micro- and nanoscale communication systems.
Cohesion, order and information flow in the collective motion of mixed-species shoals
Authors: Ward Ashley J. W. , Schaerf T. M. , Burns A. L. J. , Lizier J. T. , Crosato E. , Prokopenko M. , Webster M. M.
Published: January 2019

Despite the frequency with which mixed-species groups are observed in nature, studies of collective behaviour typically focus on single-species groups. Here, we quantify and compare the patterns of interactions between three fish species, threespine sticklebacks (Gasterosteus aculeatus), ninespine sticklebacks (Pungitius pungitius) and roach (Rutilus rutilus) in both single- and mixed-species shoals in the laboratory. Pilot data confirmed that the three species form both single- and mixed-species shoals in the wild. In our laboratory study, we found that single-species groups were more polarized than mixed-species groups, while single-species groups of threespine sticklebacks and roach were more cohesive than mixed shoals of these species. Furthermore, while there was no difference between the inter-individual distances between threespine and ninespine sticklebacks within mixed-species groups, there was some evidence of segregation by species in mixed groups of threespine sticklebacks and roach. There were differences between treatments in mean pairwise transfer entropy, and in particular we identify species-differences in information use within the mixed-species groups, and, similarly, differences in responses to conspecifics and heterospecifics in mixed-species groups. We speculate that differences in the patterns of interactions between species in mixed-species groups may determine patterns of fission and fusion in such groups.
Protective role of nano-selenium-enriched
Bifidobacterium longum
in delaying the onset of streptozotocin-induced diabetes
Authors: Lin Yan , Ren Yongzhe , Zhang Yan , Zhou Junjie , Zhou Feng , Zhao Quan , Xu Genxing , Hua Zichun
Published: January 2019

Bifidobacterium longum (B. longum)
could accumulate Selenium (Se) and nano-Se in the form of
Se-B. longum and Nano-Se-B. longum,
respectively
.
In this study, the effect of
Nano-Se-B. longum
in diabetic mice was evaluated. Physiological and metabolic parameters such as blood glucose, body weight, serum insulin level, intraperitoneal glucose tolerance test (IPGTT), food intake, water consumption and urine output were evaluated. The expression of insulin signalling pathway-related proteins was evaluated by western blotting. Haematoxylin and eosin (H&E) was used for histological examination of the liver, pancreas and kidney sections. Creatinine levels in serum (SCr) and blood urea nitrogen (BUN) were measured.
Nano-Se-B. longum
was the best in terms of delaying the onset of diabetes.
Nano-Se-B. longum
decreased blood glucose and body weight compared with those noted for the model group. IPGTT, food intake, water consumption and urine output significantly increased and serum insulin levels significantly decreased in the model group compared with those in all the
Nano-Se-B. longum
-treated mice. Histological results showed that the
Nano-Se-B. longum
-treated mice were better than the model group mice in terms of pathological changes. The expression of insulin signalling pathway-related proteins was upregulated in the
Nano-Se-B. longum
-treated groups. A significant increase in SCr and BUN levels was noted in the model group. This study for the first time reported the dose-dependent preventive effect of
Nano-Se-B. longum
on the onset of diabetes and renal damage. The mechanism may be related to changes in insulin signalling.
Adsorption of ethanol molecules on the Al (1 1 1) surface: a molecular dynamic study
Authors: Liu Pingan , Liu Junpeng , Wang Mengjun
Published: January 2019

The adsorption process of ethanol molecules on Al slabs was investigated by molecular dynamic simulations with a ReaxFF force field. The force field used in this paper has been validated by comparing adsorption energy results with quantum mechanical (QM) calculations. All simulations were performed under the canonical (NVT) ensemble. The single-molecule adsorption simulation shows that the hydroxyl group plays a more important role in the whole progress than the ethyl group. Besides, decomposition of hydroxyl groups was also observed during multimolecule adsorption processes. Simulations of adsorption processes of Al slab by ethanol molecules at different temperatures and pressures (controlled by the number of ethanol molecules) was also performed. System energy and radial distribution function (RDF) plots were invoked to describe adsorption processes and centro-symmetry parameter (CSP) analysis was adopted to study the surface properties with coating layers. Our results indicate that the whole adsorption process can be divided into two periods and the greater the pressure, the more ethanol molecules diffuse into the Al slab. How raising the temperature helps the adsorption processes is related to the initial number of molecules. The crystal structure of the Al surface will become amorphous under the constant impact of ethanol molecules.
An optical test to unveil twisting of birefringent crystals in spherulites
Authors: Raimo Maria
Published: January 2019

Helical conformations and structures are frequently observed in materials. The presence of helices at points of the unit cell of a crystal, on a larger size scale in the crystalline lattice or even in the microscopic structure of crystals, affects the chemico-physical properties of a solid and, hence, also interactions with light. Here, attention has been drawn to the geometrical properties of helices produced by a hypothetical torque of a transparent crystal, and optical properties of twisted crystals easily observed by a polarizing microscope have been discussed. Radially grown spherulites are obtained by most substances crystallized from melt. The circular arrangement of elongated crystals reflects the optical behaviour of each crystal and, because of the larger dimensions of spherulites, allows investigations otherwise hardly feasible on separate crystals. According to the torsional analysis of elongated bodies and the birefringence theory, information on the existence of helically shaped crystals can be deduced, as hereinafter explained, from the microscopic appearance and birefringence pattern of spherulites. Indeed, twisting decreases the birefringence throughout an elongated crystal and, therefore, also the birefringence of spherulites formed by twisted radial crystals is reduced.
Synthesis and investigation of physico-chemical properties of dicationic ionic liquids
Authors: Sun Yi-Xin , Wang Ying-Ying , Shen Bing-Bing , Zhang Bi-Xian , Hu Xiao-Mei
Published: January 2019

A series of dicationic ionic liquids (ILs) including [C
4
(MIM)
2
][PF
6
]
2
, [C
5
(MIM)
2
][PF
6
]
2
, [C
6
(MIM)
2
][PF
6
]
2
and [C
4
(PYR)
2
][PF
6
]
2
were synthesized. Their thermal stability and melting points were analysed. It was found that dicationic ILs presented important implications in the design of homogeneous and heterogeneous system with water. A homogeneous system of dicationic ILs with water could be formed at a relatively high temperature and then a heterogeneous system was formed when the solution was cooled to a low temperature. The ILs recovered by altering the temperature were obtained in high percentage yields of [C
4
(MIM)
2
][PF
6
]
2
(97.6%), [C
5
(MIM)
2
][PF
6
]
2
(97.3%), [C
6
(MIM)
2
][PF
6
]
2
(98.0%) and [C
4
(PYR)
2
][PF
6
]
2
(94.2%). On the other hand, [C
4
(MIM)
2
][PF
6
]
2
and [C
5
(MIM)
2
][PF
6
]
2
exhibited good solubility in acetonitrile and acetone. A homogeneous system could be achieved with imidazolium-based ILs with a relatively low amount of water and acetonitrile at room temperature. All of the properties of dicationic ILs have a strong correlation with the nature of dications, the linkage chain and the symmetry of dications. Dicationic ILs may provide a new opportunity for some specific applications in order to enable the effective separation and isolation of products.
Static landscape features predict uplift locations for soaring birds across Europe
Authors: Scacco Martina , Flack Andrea , Duriez Olivier , Wikelski Martin , Safi Kamran
Published: January 2019

Soaring flight is a remarkable adaptation to reduce movement costs by taking advantage of atmospheric uplifts. The movement pattern of soaring birds is shaped by the spatial and temporal availability and intensity of uplifts, which result from an interaction of local weather conditions with the underlying landscape structure. We used soaring flight locations and vertical speeds of an obligate soaring species, the white stork (
Ciconia ciconia
), as proxies for uplift availability and intensity. We then tested if static landscape features such as topography and land cover, instead of the commonly used weather information, could predict and map the occurrence and intensity of uplifts across Europe. We found that storks encountering fewer uplifts along their routes, as determined by static landscape features, suffered higher energy expenditures, approximated by their overall body dynamic acceleration. This result validates the use of static features as uplift predictors and suggests the existence of a direct link between energy expenditure and static landscape structure, thus far largely unquantified for flying animals. Our uplift availability map represents a computationally efficient proxy of the distribution of movement costs for soaring birds across the world's landscapes. It thus provides a base to explore the effects of changes in the landscape structure on the energy expenditure of soaring birds, identify low-cost movement corridors and ultimately inform the planning of anthropogenic developments.
Snap-jaw morphology is specialized for high-speed power amplification in the Dracula ant,
Mystrium camillae
Authors: Larabee Fredrick J. , Smith Adrian A. , Suarez Andrew V.
Published: January 2019

What is the limit of animal speed and what mechanisms produce the fastest movements? More than natural history trivia, the answer provides key insight into the form–function relationship of musculoskeletal movement and can determine the outcome of predator–prey interactions. The fastest known animal movements belong to arthropods, including trap-jaw ants, mantis shrimp and froghoppers, that have incorporated latches and springs into their appendage systems to overcome the limits of muscle power. In contrast to these examples of power amplification, where separate structures act as latch and spring to accelerate an appendage, some animals use a ‘snap-jaw’ mechanism that incorporates the latch and spring on the accelerating appendage itself. We examined the kinematics and functional morphology of the Dracula ant,
Mystrium camillae
, who use a snap-jaw mechanism to quickly slide their mandibles across each other similar to a finger snap. Kinematic analysis of high-speed video revealed that snap-jaw ant mandibles complete their strike in as little as 23 µsec and reach peak velocities of 90 m s
−1
, making them the fastest known animal appendage. Finite-element analysis demonstrated that snap-jaw mandibles were less stiff than biting non-power-amplified mandibles, consistent with their use as a flexible spring. These results extend our understanding of animal speed and demonstrate how small changes in morphology can result in dramatic differences in performance.
Determination of donepezil in spiked rabbit plasma by high-performance liquid chromatography with fluorescence detection
Authors: Mohamed Fardous A. , Khashaba Pakinaz Y. , Shahin Reem Y. , El-Wekil Mohamed M.
Published: January 2019

The aim of this paper is to develop sensitive, accurate, reproducible and robust RP-HPLC with fluorescence detection for estimation of donepezil (DZ) in rabbit plasma using silodosin as the internal standard (IS). The prepared samples were quantified on reversed phase column Luna C
18(2)
(150 × 4.6 mm i.d., 5 µm particle size) operated at room temperature using the mobile phase consisting of methanol: 0.1% acetic acid (50 : 50, v/v) at a flow rate of 1 ml min
−1
. The method was fully validated according to bioanalytical validation guidelines of FDA in terms of system suitability, selectivity, sensitivity, precision and stability. It was found that the increase in peak areas followed the increase of DZ concentration in the range of 2.56–200.00 ng ml
−1
with LOD of 0.85 ng ml
−1
. The method was successfully applied for the determination of DZ in rabbit plasma using manual shaking dispersive liquid–liquid microextraction.
Orangutans (
Pongo pygmaeus
) recognize their own past actions
Authors: Hanazuka Yuki , Shimizu Mika , Takaoka Hidemasa , Midorikawa Akira
Published: January 2019

The ability to recognize oneself in a mirror is known as self-recognition, whereas delayed self-recognition is the ability to recognize the relationship between current self and past actions. While 3-year-old human children have self-recognition without the ability for delayed self-recognition, 4-year-old human children demonstrate the capability for both. Chimpanzees, the most closely related species to humans, have displayed the ability for delayed self-recognition. However, little is known about whether this ability is shared among all hominid species. In this study, we examined whether orangutans, the most distantly related species to humans within the hominid group, could recognize their own past actions using the preferential-looking paradigm. Our results demonstrated that orangutans were able to discriminate between a delayed video of themselves presented after a 2-s delay and a recorded video of the day prior. This suggests that orangutans have the ability to relate their own past actions to current actions, although we found no evidence of self-directed behaviour. We believe these findings will contribute to our growing understanding of hominid self-recognition.
Effect of alumina shapes on dielectric properties of UV-cured epoxy acrylic composite with alumina
Authors: Bian Jiepeng , Zhao Qiuli , Hou Zhenzhong , Dong Jie , Yang Qinghao , Zhang Guanjun
Published: January 2019

Polymer-based composites with the advantages of ceramics and polymers exhibit high dielectric constant, good processing properties and low dielectric loss. The composites with a varied content of irregular alumina (
i
-Al
2
O
3
) filler were prepared by UV-cured epoxy acrylic (EA). Spherical alumina (
s
-Al
2
O
3
) was used as a filler to further investigate the effect of alumina (Al
2
O
3
) shapes on dielectric properties of composites in the frequency range of 50 Hz–1 MHz. Fourier transform infrared spectroscopy proved that the UV-cured epoxy acrylic/alumina (Al
2
O
3
/EA) composites were successfully fabricated. Scanning electron microscopy demonstrated that
i
-Al
2
O
3
particles have superior homodispersion in the matrix. Through testing, for all samples, with the addition of Al
2
O
3
, the relative permittivity of composites increased as expected, and the dielectric loss decreased accordingly. These data show that the incorporation of
i
-Al
2
O
3
particles presents better properties when compared with
s
-Al
2
O
3
/EA, which indicates that
i
-Al
2
O
3
particles have more influence on the dielectric properties of the composites than those of
s
-Al
2
O
3
particles. According to Weibull distribution, the characteristic breakdown strength of the Al
2
O
3
/EA composites was obtained and the results suggested that the composites of
i
-Al
2
O
3
/EA exhibited better breakdown performance.
Environmental fitness heterogeneity in the Moran process
Authors: Kaveh Kamran , McAvoy Alex , Nowak Martin A.
Published: January 2019

Many mathematical models of evolution assume that all individuals experience the same environment. Here, we study the Moran process in heterogeneous environments. The population is of finite size with two competing types, which are exposed to a fixed number of environmental conditions. Reproductive rate is determined by both the type and the environment. We first calculate the condition for selection to favour the mutant relative to the resident wild-type. In large populations, the mutant is favoured if and only if the mutant’s spatial average reproductive rate exceeds that of the resident. But environmental heterogeneity elucidates an interesting asymmetry between the mutant and the resident. Specifically, mutant heterogeneity suppresses its fixation probability; if this heterogeneity is strong enough, it can even completely offset the effects of selection (including in large populations). By contrast, resident heterogeneity has no effect on a mutant’s fixation probability in large populations and can amplify it in small populations.
Genomic approaches used to investigate an atypical outbreak of Salmonella Adjame
Authors: Chattaway Marie Anne , Chandra Nastassya , Painset Anaïs , Shah Victoria , Lamb Peter , Acheampong Elsie , Lo Janice , Patel Bharat , Larkin Lesley , Sergeant Martin , Cormican Martin , Litrup Eva , Crook Paul
Published: January 2019

In 2017, an outbreak of gastroenteritis in England attributed to

Salmonella

Adjame was detected and investigated. With the introduction of whole genome sequencing (WGS) for microbial typing, methods for comparing international outbreak data require evaluation. A case was defined as a person resident in England with a clinical sample from 1 June 2017 to 27 July 2017 from whom S. Adjame was isolated. Cases were interviewed and exposures analysed. Backward tracing of food provenance was undertaken. WGS was performed on isolates from cases and historical isolates and compared using Public Health England’s SnapperDB high-quality SNP pipeline and Enterobase’s

Salmonella

core genome multi-locus sequence typing (cgMLST) scheme. In total, 14 cases were identified. The majority were vegetarian, probably of South Asian descent, with a median age of 66.5 years with no recent international travel reported. Cases consumed a range of fresh food products including herbs and spices bought from South Asian grocers. Backward tracing did not identify a common source. WGS typing showed sub-clustering and considerable genetic variation across human samples. cgMLST allele-based analysis was comparable to SNP-derived phylogenetic analysis and clusters were defined using each method. Imported herbs or spices were suspected vehicles. The cases were linked in time and place but WGS showed marked heterogeneity, atypical of a point source

Salmonella

outbreak. The application of incorporating SNP or allelic differences into the case definition may not always be appropriate. With further validation, cgMLST could be used for international outbreak alerts when WGS analysis is being undertaken to facilitate comparison.
Transient Compartmentalization dynamics in the presence of mutations and noise
Authors: Blokhuis Alex , Nghe Philippe , Peliti Luca , Lacoste David
Published: January 2019

We extend a recently introduced framework for transient compartmentalization of replicators with selection dynamics, by including the effect of mutations and noise in such systems. In the presence of mutations, functional replicators (ribozymes) are turned into non-functional ones (parasites). We evaluate the phase diagram of a system undergoing transient compartmentalization with selection. The system can exhibit either coexistence of ribozymes and parasites, or a pure parasite phase. If the mutation rate exceeds a certain level called the error threshold, the only stable phase is the pure parasite one. Transient compartmentalization with selection can relax this error treshold with respect to a bulk quasispecies case, and even allow ribozymes to coexist with faster growing parasites.

In order to analyze the role of noise, we also introduce a model for the replication of a template by an enzyme. This model admits two regimes: a diffusion limited regime which generates a high noise, and a replication limited regime, which generates a low noise at the population level. Based on this model, we find that, since the ribozyme dynamics belongs to the replication limited regime, the effects of noise on the phase diagram of the system are mostly negligible. Our results underlines the importance of transient compartmentalization for prebiotic scenarios, and may have implications for directed evolution experiments.
Identification of potential new vaccine candidates in Salmonella typhi using reverse vaccinology and subtractive genomics-based approach
Authors: Mukherjee Sumit , Gangopadhyay Kaustav , Mukherjee Sunanda Biswas
Published: January 2019

Salmonella enterica serovar typhi is the causative agent of typhoid fever in human. The available vaccine lacks the effectiveness and further overuse of the antibiotics throughout the past decades lead to the emergence of antibiotic-resistant strains. To reduce the spread of antibiotic resistance, it is essential to develop new vaccines. In this study using an extensive bioinformatic analysis based on reverse vaccinology and subtractive genomics-based approach, we searched the genome of S typhi. We found that two outermost membrane proteins LptD and LptE, which are responsible for the final transport of the LPS across the membrane having most of the essential signature for being vaccine target. Both of these proteins are found highly conserved and possess shared surface epitopes among several species of Salmonella pathogens. This indicates that these two proteins could be the potential target for vaccine development, which could be effective for a broad range of Salmonella pathogens.
Computational deconvolution of gene expression in leukemic cell hierarchies
Authors: Jäarvstråt Linnea , Ajore Ram , Wihlborg Anna-Karin , Gullberg Urban , Nilsson Björn
Published: January 2019

Leukemias and some solid tumors are organized as cell hierarchies, sustained by cancer stem cells. We developed a computational method to study gene expression cancer cell hierarchies. Unlike traditional approaches based on physical cell sorting, our method extracts cell type-specific gene expression signals from gene expression profiles of unsorted tumor cells by deconvolution. We apply our method in the context of acute myeloid leukemia, and recover markers for acute myeloid leukemia stem cells (AML-LSC).
Genome-wide CRISPR screening identifies new regulators of glycoprotein secretion
Authors: Popa Stephanie J. , Villeneuve Julien , Stewart Sarah , Garcia Esther Perez , Harrison Anna Petrunkina , Moreau Kevin
Published: January 2019

The fundamental process of protein secretion from eukaryotic cells has been well described for many years, yet gaps in our understanding of how this process is regulated remain. With the aim of identifying novel genes involved in the secretion of glycoproteins, we used a screening pipeline consisting of a pooled genome-wide CRISPR screen followed by secondary siRNA screening of the hits to identify and validate several novel regulators of protein secretion. We present approximately 50 novel genes not previously associated with protein secretion, many of which also had an effect on the structure of the Golgi apparatus. We further studied a small selection of hits to investigate their subcellular localisation. One of these, GPR161, is a novel Golgi-resident protein that we propose maintains Golgi structure via an interaction with golgin A5.
The immediate extinction deficit occurs in a nonemotional learning paradigm
Authors: Merz Christian J. , Wolf Oliver T.
Published: January 2019

The immediate extinction deficit describes a higher return of fear when extinction takes place immediately after fear acquisition compared to a delayed extinction design. One explanation for this phenomenon encompasses the remaining emotional arousal evoked by fear acquisition to be still present during immediate, but not delayed extinction. In the present study, the predictive learning task, a learning task not involving arousal or stress, was used testing the hypothesis that no immediate extinction deficit should occur in this neutral task. Twenty-six participants underwent an immediate extinction procedure and were tested in a recall session 24 h later. For the delayed extinction group (n = 26), acquisition, extinction, and recall were realized 24 h apart from each other. Recall performance of a third group (n = 26) was tested 48 h after the immediate extinction procedure. The immediate extinction deficit was indeed observed for a stimulus not subject to a contextual change from acquisition to extinction, but not for other stimuli involving contextual changes or no extinction control stimuli. Even in a neutral learning task and without emotional arousal, the immediate extinction deficit could be detected but was restricted to the specific contextual embedding of stimuli. Thus, contextual processing appears to differentially modulate the emergence of the immediate extinction deficit.
Cocaine, nicotine, and their conditioned contexts enhance consolidation of object memory in rats
Authors: Wolter Michael , Huff Ethan , Speigel Talia , Winters Boyer D. , Leri Francesco
Published: January 2019

To test the hypothesis that drugs of abuse and their conditioned stimuli (CSs) enhance memory consolidation, the effects of post-training exposure to cocaine and nicotine were compared to the effects of post-training exposure to contextual stimuli that were paired with the effects of these drugs. Using the object recognition (OR) task, it was first demonstrated that both 10 and 20 mg/kg cocaine, and 0.2 and 0.4 mg/kg nicotine, enhanced recognition memory when administered immediately after, but not 6 h after the sample phase. To establish the drug CSs, rats were confined for 2 h in a chamber (the CS+) after injections of 20 mg/kg cocaine, or 0.4 mg/kg nicotine, and in another chamber (the CS−) after injections of vehicle. This was repeated over 10 d (5 drug/CS+ and 5 vehicle/CS− pairings in total). At the end of this conditioning period, when tested in a drug-free state, rats displayed conditioned hyperactivity in the CS+ relative to the CS−. More important, immediate, but not delayed, post-sample exposure to the cocaine CS+, or nicotine CS+, enhanced OR memory. Therefore, this study reports for the first time that contextual stimuli paired with cocaine and nicotine, like the drugs themselves, have the ability to enhance memory consolidation.
Succinic, fumaric, adipic and oxalic acid cocrystals of promethazine hydrochloride
Authors: Borodi Gheorghe , Turza Alexandru , Onija Oana , Bende Attila
Published: January 2019

Novel cocrystals of promethazine hydrochloride [PTZ-Cl; systematic name: N,N-dimethyl-1-(10H-phenothiazin-10-yl)propan-2-aminium chloride] with succinic acid (PTZ-Cl-succinic, C17H21N2S+·Cl−·0.5C4H6O4), fumaric acid (PTZ-Cl-fumaric, C17H21N2S+·Cl−·0.5C4H4O4) and adipic acid (PTZ-Cl-adipic, C17H21N2S+·Cl−·0.5C6H10O4) were prepared by solvent drop grinding and slow evaporation from acetonitrile solution, along with two oxalic acid cocrystals which were prepared in tetrahydrofuran (the oxalic acid hemisolvate, PTZ-Cl-oxalic, C17H21N2S+·Cl−·0.5C2H2O4) and nitromethane (the hydrogen oxalate salt, PTZ-oxalic, C17H21N2S+·C2HO4
−). The crystal structures obtained by crystallization from tetrahydrofuran and acetonitrile include the Cl− ion in the lattice structures, while the Cl− ion is missing from the crystal structure obtained by crystallization from nitromethane (PTZ-oxalic). In order to explain the formation of the two types of supramolecular configurations with oxalic acid, the intermolecular interaction energies were calculated in the presence of the two solvents and the equilibrium configurations were determined using density functional theory (DFT). The cocrystals were studied by X-ray diffraction, IR spectroscopy and differential scanning calorimetry. Additionally, a stability test under special conditions and water solubility were also investigated. PTZ-Cl-succinic, PTZ-Cl-fumaric and PTZ-Cl-adipic crystallized having similar lattice parameter values, and showed a 2:1 PTZ-Cl to dicarboxylic acid stoichiometry. PTZ-Cl-oxalic crystallized in a 2:1 stoichiometric ratio, while the structure lacking the Cl atom belongs has a 1:1 stoichiometry. All the obtained crystals exhibit hydrogen bonds of the type PTZ...Cl...(dicarboxylic acid)...Cl...PTZ, except for PTZ-oxalic, which forms bifurcated bonds between the hydrogen oxalate and promethazinium ions, along with an infinite hydrogen-bonded chain between the hydrogen oxalate anions.
Remarks about factors shaping the heliosphere
Authors: Ratkiewicz Romana , Konior Wojciech , Kotlarz Jan
Published: January 2019

Purpose

The purpose of the paper is to give a brief description of the new topic introduced for the first time at the EASN Conferences.

Design/methodology/approach

The topic concerns the heliosphere, the nearest surrounding of the Sun and thus the nearest vicinity of the Earth. The heliosphere is created due to the interaction between the solar wind and the local interstellar medium.

Findings

This paper does not include any new information about the heliosphere and only introduces a new topic to this journal. It is briefly shown how heliospheric structures are formed, what factors affect a shape of the heliosphere, what measurements are made by Ulysses, Voyager and IBEX space missions (important for the heliosphere modeling) and how obtained data are used to validate theoretical results.

Practical implications

To categorize the paper under one of these classifications, research paper, viewpoint, technical paper, conceptual paper, case study, literature review or general review, the authors chose a paper type, general review, as the closest category to this paper. However, it is not a purpose of this paper to provide an extensive review of the community efforts to investigate the physical processes in the vicinity of the heliosphere interface. This is mostly a status report.

Originality/value

As the new topic in this journal, the article introduces in detail only a small number of aspects connected with heliosphere models. Interplanetary and interstellar magnetic field structures are primarily described. Other factors are only mentioned.
Achieving sustainable competitive advantage through green entrepreneurial orientation and market orientation
Authors: Pratono Aluisius Hery , Darmasetiawan Noviaty Kresna , Yudiarso Ananta , Jeong Bok Gyo
Published: January 2019

Purpose

This paper aims to examine the role of the inter-organizational learning contributing in transforming the green entrepreneurial orientation and market orientation to the improvement of sustainable competitive advantages.

Design/methodology/approach

The structural equation model was established to explain the complex relationship between green entrepreneurial orientation, market orientation and sustainable competitive advantage. To test the hypothesis, this study used partial least square with data from a survey of 280 firms.

Findings

There is a strong tendency that the inter-organizational learning plays a pivotal role as an intervening variable that operates by receiving the input from green entrepreneurial orientation and market orientation, which plays as the exogenous construct. Hence, the greater inter-organizational learning leads the firms to achieve the greater sustainable competitive advantage.

Originality/value

This study extends the discussion on how organization should contribute to the well-being of the economic, social and environmental system by investigating the role of inter-organizational learning in achieving the sustainable competitive advantage.
The thinking process of the theory of constraints applied to public healthcare
Authors: Bauer Jéssica Mariela , Vargas Andrea , Sellitto Miguel Afonso , Souza Mariane Cásseres , Vaccaro Guilherme Luís
Published: January 2019

Purpose

The purpose of this paper is to present an approach based on the thinking process of the theory of constraints (TP–TOC) to support decision-makers, managers and professionals of health to diagnose and improve healthcare systems focusing on the service quality deployed to patients.

Design/methodology/approach

A case study was developed in a SUS-affiliated philanthropic hospital in southern Brazil, through the analysis of its ED processes and application of the TP–TOC. The Current Reality Tree and the Evaporating Cloud tools of the TOC were used to identify the root causes (RC) and their connections with undesirable effects.

Findings

The analysis of this case helped to understand and identify the causes of the current problems in the analyzed processes related to internal management and external causes. The proposed approach allowed the hospital team to progress in the understanding of such causes in a sequential manner, giving conditions to apport different perceptions and to identify relevant facets and causes related to the problem. The research provided a systemic and an integrated vision of the losses in the organizational processes and indicated the steps to be prioritized in order to eliminate such losses.

Originality/value

The paper proposed an approach that allowed the systematic and systemic analysis of organizational processes through the application of the TP–TOC. The recognition of the existence of RC responsible for processes losses represents an excellent opportunity for improvement because it allows managers to focus their efforts on the more productive areas.
A paradoxical approach symbiotic to postmerger integration: a French longitudinal case study
Authors: Thelisson Anne-Sophie , Missonier Audrey , Guieu Gilles , Luscher Lotte S.
Published: January 2019

Purpose

This paper aims to examine post-merger integration (PMI) through the lens of paradox to determine how paradoxes contribute to successful integration. Although PMI has been identified as crucial to understand merger success or failure, the literature on PMI drivers remains inconclusive.

Design/methodology/approach

Drawing on the theory of paradox and two key elements of PMI, strategic interdependency (SI) and organizational autonomy (OA), the authors describe the merger of two listed French companies using longitudinal data.

Findings

The authors identify how the paradox between OA and SI was triggered and fostered PMI success by leading to symbiotic integration. They also show that two capabilities were central in helping the paradox to evolve: preserving the specificities of the organizations and pooling their respective capabilities. These capabilities result from basic decisions and actions during the integration implementation, such as highlighting the expertise of the target firm, refocusing the core activity while valorizing each company’s expertise, clarifying the identity of the new organization on the market and enhancing joint piloting and transferring both general management capacity and functional abilities during the reorganization period.

Practical implications

The authors offer several useful insights for managers trying to manage paradoxical tension throughout the merger process. This study encourages managers to embrace inconsistencies as they make decisions and to shift to dynamic decision-making as a way to adapt to complex contexts.

Originality/value

This study adopts a global and inclusive approach to focus on OA and SI and flesh out a picture of the integration process. It proposes a dynamic process model to conceptualize the stage-wise nature of the PMI process by highlighting the interrelations between OA and SI dynamics.
Waiting longer before claiming, and activating youth: no point?
Authors: Cockx Bart , Van Belle Eva
Published: January 2019

Purpose

The purpose of this paper is to estimate the impact of two policies (an extension of the waiting period before entitlement to unemployment insurance (UI) and an intensification of counselling) targeted at unemployed school-leavers in Belgium on unemployment duration and on the quality of work.

Design/methodology/approach

The length of both policies is sharply determined by two distinct age thresholds. These thresholds are exploited to estimate the impact within a regression discontinuity design using a large administrative data set of all recent labour market entrants.

Findings

The longer waiting period does not significantly impact job finding while the Youth Work Plan does increase the job-finding rate eight months after the onset of the programme. The accepted wage is unaffected, but both policies lower the number of working days resulting in lower earnings. This effect is especially prevalent for youth from low-income households.

Research limitations/implications

For both policies, participation was delineated by an age cut-off which was only four months apart. This sizeably reduced the width of the age window to detect a corresponding discontinuity in behaviour and hereby also the statistical power of the estimator. Additionally, due to confounding policies the estimated effects are local treatment effects for highly educated youth around the age cut-offs.

Social implications

The findings suggest that threatening with a sanction is not the right instrument to activate highly educated unemployed school-leavers. While supportive measures appear to be more effective, this may be partly a consequence of acceptance of lower quality jobs due to liquidity constraints and of caseworkers giving misleading advice that temporary jobs are stepping stones to long-term employment.

Originality/value

To the best of the authors’ knowledge, this is the first paper to estimate the impact of changing the waiting period in UI. The paper adds to the existing literature on the effects of counselling and UI design on employment and job quality.
Does welfare drive international migration? – a European experience
Authors: Jakubiak Igor Jerzy
Published: January 2019

Purpose

The purpose of this paper is to provide a summary of empirical research on welfare magnetism and to assess the size and scope of the welfare magnet effect on the non-EU migrants in selected immigration countries of the European Union.

Design/methodology/approach

A conditional logistic regression model with interactions is used to estimate the strength of the welfare magnet effect, while controlling for demographic characteristics of the migrants and country-specific economic indicators. Data, used for estimation, comes from the Immigrant Citizen Survey, which provides a large, representative sample of first-generation (i.e. non-EU born) migrants. Various measures of welfare generosity are tested to assure the robustness of the results.

Findings

The coefficients suggest that the welfare magnet effect is present and significant in some immigrant groups, although it can have a negative impact on location decisions in other cases. Similar results are obtained for wage and unemployment indicators.

Research limitations/implications

Results corroborate the welfare magnet hypothesis, which states that more generous welfare states should expect greater clustering of negatively-selected (i.e. lower educated) migrants. One potential limitation comes from the sample size, which does not allow for more general conclusions.

Practical implications

Heterogeneous effects of basic economic indicators in different demographic groups show that aggregate immigrant flows, used widely in the literature, can provide biased estimates of welfare magnet effect.

Originality/value

This paper adds to the available literature by using representative, recently collected data and employing a more complete list of controls in a quantitative analysis of migration decisions.
Latecomers’ path-creating catch-up strategy in ICT industry
Authors: Kim Dae Bong , Park Min Jae
Published: January 2019

Purpose

This study aims to empirically examine the conditions for latecomers to successfully pursue path-creating catch-up strategies. In particular, the company is divided into two conditions: the external environment, which refers to the gap in the market share between the leaders and latecomers, and the internal capacities of the company, such as the company’s absorptive capacity, re-combinative capabilities and technological innovation leadership.

Design/methodology/approach

Because firms supported by the government tend to be conservative in their decision-making and technology development strategies, governmental assistance is likely to negatively affect path-creating catch-up strategies. This study surveyed small to medium enterprises in the Korea IT industry and analyzed the latecomers’ catch-up strategies from internal and external environment perspectives.

Findings

After ensuring its innovation capacity by developing of internal capacity, it turned out to lead to path-creative catch-up strategy and market disparity and government dependence moderates this relation. While market disparity has a positive moderation effect, government dependence showed a negative moderation effect.

Originality/value

The authors proposed and tested hypotheses of how a firm’s path-creative catch-up strategy is adopted and succeeds. Regarding the internal conditions, the authors statistically proved that absorptive capabilities, re-combinative capabilities and technology innovation leadership are important factors for a firm’s technology innovation capacity.
Impact of information and communication technology in Nigerian small-to medium-sized enterprises
Authors: Okundaye Kessington , Fan Susan K. , Dwyer Rocky J.
Published: January 2019

Purpose

The purpose of this (qualitative, multiple-case) study is to determine how small-to medium-sized enterprise (SME) leaders in Nigeria use information and communication technology (ICT) adoption as a business strategy to increase profitability and compete globally.

Design/methodology/approach

The participants for this study consisted of executive-level SME leaders who had the authority to approve ICT implementation within their respective organizations. Individual interviews were undertaken with participants to gain an understanding of their experience of determining the merits of and implementing ICT. The technology acceptance model, which specifies the relationship between perceived usefulness, perceived ease of use, attitude toward computer use and intention to use technology, was applied as a framework to explain the Nigerian SME’s ICT adoption strategies.

Findings

Four major themes emerged from the data analysis: ICT adoption factors, ICT roles and benefits, role of government and SME success factors. The findings of this study may help SME leaders and government leaders address many of the factors inhibiting the adoption of ICT in SMEs in Nigeria.

Practical implications

This study may ensure that SMEs are successful and able to create jobs, which in turn may help to promote socioeconomic development through adoption of ICT.

Originality/value

The findings from this study contribute to the knowledge base regarding factors that affect ICT adoption by SME leaders as a business strategy to increase profitability and compete globally, particularly within SMEs in Lagos, Nigeria. It further addressed the gap in existing literature regarding other factors such as the influence of culture on ICT adoption, cost of ICT implementation, available ICT skills, infrastructure and ICT knowledge gap as the primary impeding factors of ICT adoption in Nigerian SMEs.