bluuebunny/crossref_metadata_2025_split huggingface dataset:
Purinergic control of hippocampal circuit hyperexcitability in Dravet syndrome
Authors: Gu Feng , Hazra Anupam , Aulakh Ahmad , Žiburkus Jokūbas 
Published: January 2014

SummaryObjectiveSevere myoclonic epilepsy in infancy (SMEI) or Dravet syndrome is one of the most devastating childhood epilepsies. Children with SMEI have febrile and afebrile seizures (FS and aFS), ataxia, and social and cognitive dysfunctions. SMEI is pharmacologically intractable and can be fatal in 10–20% of patients. It remains to be elucidated how channelopathies that cause SMEI impact synaptic activities in key neural circuits, and there is an ongoing critical need for alternative methods of controlling seizures in SMEI. Using the SCN1A gene knock‐in mouse model of SMEI (mSMEI), we studied hippocampal cell and circuit excitability, particularly during hyperthermia, and tested whether an adenosine A1 receptor (A1R) agonist can reliably control hippocampal circuit hyperexcitability.MethodsUsing a combination of electrophysiology (extracellular and whole‐cell voltage clamp) and fast voltage‐sensitive dye imaging (VSDI), we quantified synaptic excitation and inhibition, spatiotemporal characteristics of neural circuit activity, and hyperthermia‐induced febrile seizure‐like events (FSLEs) in juvenile mouse hippocampal slices. We used hyperthermia to elicit FSLEs in hippocampal slices, while making use of adenosine A1R agonist N6‐cyclopentyladenosine (CPA) to control abnormally widespread neural activity and FSLEs.ResultsWe discovered a significant excitation/inhibition (E/I) imbalance in mSMEI hippocampi, in which inhibition was decreased and excitation increased. This imbalance was associated with an increased spatial extent of evoked neural circuit activation and a lowered FSLE threshold. We found that a low concentration (50 nm) of CPA blocked FSLEs and reduced the spatial extent of abnormal neural activity spread while preserving basal levels of excitatory synaptic transmission.SignificanceOur study reveals significant hippocampal synapse and circuit dysfunctions in mSMEI and demonstrates that the A1R agonist CPA can reliably control hippocampal hyperexcitability and FSLEs in vitro. These findings may warrant further investigations of purinergic agonists as part of the development of new therapeutic approaches for Dravet syndrome.
Identification of the rate‐limiting step of the peroxygenase reactions catalyzed by the thermophilic cytochrome P450 from Sulfolobus tokodaii strain 7
Authors: Hayakawa Shohei , Matsumura Hirotoshi , Nakamura Nobuhumi , Yohda Masafumi , Ohno Hiroyuki 
Published: January 2014

Cytochrome P450 from the thermoacidophilic crenarchaeon Sulfolobus tokodaii strain 7 (P450st) is a thermophilic cytochrome P450 that shows high tolerance of harsh conditions and is capable of catalyzing some peroxygenase reactions. Here, we investigated the pH dependence of the peroxygenase reactions catalyzed by wild‐type P450st and a mutant in which the residues located close to the proximal heme ligand are mutated. Both hydrogen peroxide‐driven ethylbenzene hydroxylation and styrene epoxidation by wild‐type P450st were found to be activated in weak acidic and weak basic solutions. Under these conditions, the Michaelis constant for hydrogen peroxide ( ) was decreased. The turnover rate (kcat) of ethylbenzene hydroxylation was increased and followed an S‐shaped curve, with an increase in the pH value. The apparent acid dissociation constant (pKaapp) of the kcat was 7.0, which suggests that the rate‐limiting step of this reaction is deprotonation of the FeIII–H2O2 complex. By introducing a double mutation around the proximal heme ligand, the peroxygenase activity was increased over a wide pH range, and was dramatically increased at pH 5. The spectroscopic properties of this F310A/A320Q mutant indicated that the Lewis acidity of the heme was increased by this mutation. Kinetic investigations showed that the increase in the Lewis acidity of the heme facilitates the reaction rate of the rate‐limiting step of peroxygenase reactions and decreases the value. Differences in the pH dependence of the kcat value between wild‐type P450st and the mutant suggest that the rate‐limiting step switches to protonation of the ferric‐hydroperoxo species (compound 0) under alkaline conditions.
Climate change effects on animal and plant phylogenetic diversity in southern Africa
Authors: Pio Dorothea V. , Engler Robin , Linder H. Peter , Monadjem Ara , Cotterill Fenton P.D. , Taylor Peter J. , Schoeman M. Corrie , Price Benjamin W. , Villet Martin H. , Eick Geeta , Salamin Nicolas , Guisan Antoine 
Published: January 2014

AbstractMuch attention has been paid to the effects of climate change on species' range reductions and extinctions. There is however surprisingly little information on how climate change driven threat may impact the tree of life and result in loss of phylogenetic diversity (PD). Some plant families and mammalian orders reveal nonrandom extinction patterns, but many other plant families do not. Do these discrepancies reflect different speciation histories and does climate induced extinction result in the same discrepancies among different groups? Answers to these questions require representative taxon sampling. Here, we combine phylogenetic analyses, species distribution modeling, and climate change projections on two of the largest plant families in the Cape Floristic Region (Proteaceae and Restionaceae), as well as the second most diverse mammalian order in Southern Africa (Chiroptera), and an herbivorous insect genus (Platypleura) in the family Cicadidae to answer this question. We model current and future species distributions to assess species threat levels over the next 70 years, and then compare projected with random PD survival. Results for these animal and plant clades reveal congruence. PD losses are not significantly higher under predicted extinction than under random extinction simulations. So far the evidence suggests that focusing resources on climate threatened species alone may not result in disproportionate benefits for the preservation of evolutionary history.
The subtle role of climate change on population genetic structure in Canada lynx
Authors: Row Jeffrey R. , Wilson Paul J. , Gomez Celine , Koen Erin L. , Bowman Jeff , Thornton Daniel , Murray Dennis L. 
Published: January 2014

AbstractAnthropogenically driven climatic change is expected to reshape global patterns of species distribution and abundance. Given recent links between genetic variation and environmental patterns, climate change may similarly impact genetic population structure, but we lack information on the spatial and mechanistic underpinnings of genetic–climate associations. Here, we show that current genetic variability of Canada lynx (Lynx canadensis) is strongly correlated with a winter climate gradient (i.e. increasing snow depth and winter precipitation from west‐to‐east) across the Pacific‐North American (PNO) to North Atlantic Oscillation (NAO) climatic systems. This relationship was stronger than isolation by distance and not explained by landscape variables or changes in abundance. Thus, these patterns suggest that individuals restricted dispersal across the climate boundary, likely in the absence of changes in habitat quality. We propose habitat imprinting on snow conditions as one possible explanation for this unusual phenomenon. Coupling historical climate data with future projections, we also found increasingly diverging snow conditions between the two climate systems. Based on genetic simulations using projected climate data (2041–2070), we predicted that this divergence could lead to a threefold increase in genetic differentiation, potentially leading to isolated east–west populations of lynx in North America. Our results imply that subtle genetic structure can be governed by current climate and that substantive genetic differentiation and related ecological divergence may arise from changing climate patterns.
Characterisation of spray‐dried microparticles containing iron coated by pectin/resistant starch
Authors: Moslemi Masoumeh , Hosseini Hedayat , Erfan Mohammad , Mortazavian Amir Mohammad , Fard Ramin Mazaheri Nezhad , Neyestani Tirang Reza , Komeyli Rozita 
Published: January 2014

SummaryIron is one of three major minerals in human body. However, the iron deficiency is a medical problem in developed and underdeveloped countries due to its poor oral absorption or insufficient iron intake. Encapsulation could solve problems associated with oral iron consumption. Various advantages including low cost, biodegradability, biocompatibility and large‐scale production have been included in the current study. In a modified encapsulation method, iron microparticles were prepared using low methoxy pectin and resistant starch during spray drying. Covalent and hydrogen bonds were formed between iron and pectin and between polymers, respectively. Particles sized 3.5 ± 1.14 μm and showed spherical shapes. The yield of particles was 72.07%, and solubility and loading efficiency were 33.64% ± 0.88 and 34.79%, respectively. In conclusion, using iron as a cross‐linker of pectin molecules resulted in microparticles with appropriate properties of lowering organoleptic changes and a better bioavailability especially in dairy‐based products for food fortification.
Role of Interface(s) for the Growth of Ultra‐Thin Amorphous Oxides on Al–Si Alloys: A Thermodynamic Analysis
Authors: Panda Emila , Manwani Krishna 
Published: January 2014

This study presents a thermodynamic analysis to predict the type of initial, amorphous oxide overgrowth (i.e., am‐Al2O3 or am‐SiO2) on bare Al–Si alloy substrates. This analysis have taken into account the energies associated with both its interfaces (interface between the Al–Si alloy substrate and the thin oxide film and interface between the thin oxide film and vacuum) along with the bulk Gibbs free energy of oxide formation. This developed analysis is then applied for various parameters, such as, Si alloying element content at the substrate/oxide interface, the growth temperature, the oxide film thickness (up to 1 nm), and various low‐index crystallographic surfaces of the substrate. It is found that am‐SiO2 overgrowth is thermodynamically preferred for a combination of lower oxide film thickness, lower growth temperature, and lower Si alloying content at the alloy/oxide interface. This is because of the overcompensation of the lower energies of both the interfaces over the bulk Gibbs free energy. Furthermore, it is found that for all cases, am‐Al2O3 forms a more stable interface with Al–Si alloy than am‐SiO2.
Longitudinal trajectories of peer relations in children with specific language impairment
Authors: Mok Pearl L. H. , Pickles Andrew , Durkin Kevin , Conti‐Ramsden Gina 
Published: January 2014

BackgroundPeer relations is a vulnerable area of functioning in children with specific language impairment (SLI), but little is known about the developmental trajectories of individuals.MethodsPeer problems were investigated over a 9‐year period (from 7 to 16 years of age) in 171 children with a history of SLI. Discrete factor growth modelling was used to chart developmental trajectories. Multinomial logistic regression analysis was conducted to investigate factors associated with group membership.ResultsFour distinct developmental trajectories were identified: low‐level/no problems in peer relations (22.2% of participants), childhood‐limited problems (12.3%), childhood‐onset persistent problems (39.2%) and adolescent‐onset problems (26.3%). Risk of poor trajectories of peer relations was greater for those children with pragmatic language difficulties. Prosocial behaviour was the factor most strongly associated with trajectory group membership. Overall, the more prosocial children with better pragmatic language skills and lower levels of emotional problems had less difficulty in developing peer relations.ConclusionsAnalysis of developmental trajectories enriches our understanding of social development. A sizeable minority in the present sample sustained positive relations through childhood and adolescence, and others overcame early difficulties to achieve low levels of problems by their early teens; the majority, however, showed childhood‐onset persistent or adolescent‐onset problems.
Early Development and Tissue Distribution of Pseudoloma neurophilia in the Zebrafish, Danio rerio
Authors: Sanders Justin L. , Peterson Tracy S. , Kent Michael L. 
Published: January 2014

AbstractThe early proliferative stages of the microsporidian parasite, Pseudoloma neurophilia were visualized in larval zebrafish, Danio rerio, using histological sections with a combination of an in situ hybridization probe specific to the P. neurophilia small‐subunit ribosomal RNA gene, standard hematoxylin‐eosin stain, and the Luna stain to visualize spores. Beginning at 5 d post fertilization, fish were exposed to P. neurophilia and examined at 12, 24, 36, 48, 72, 96, and 120 h post exposure (hpe). At 12 hpe, intact spores in the intestinal lumen and proliferative stages developing in the epithelial cells of the anterior intestine and the pharynx and within hepatocytes were observed. Proliferative stages were visualized in the pancreas and kidney at 36–48 hpe and in the spinal cord, eye, and skeletal muscle beginning at 72 hpe. The first spore stages of P. neurophilia were observed at 96 hpe in the pharyngeal epithelium, liver, spinal cord, and skeletal muscle. The parasite was only observed in the brain of larval fish at 120 hpe. The distribution of the early stages of P. neurophilia and the lack of mature spores until 96 hpe indicates that the parasite gains access to organs distant from the initial site of entry, likely by penetrating the intestinal wall with the polar tube.
A survey of practices of tunnel preparation among dentists who attended the 100th FDI Annual World Dental Congress
Authors: Chu Chun‐Hung , Mei May L. , Nalliah Romesh P. 
Published: January 2014

AbstractAimTo study the practice of tunnel restoration (TR) among dentists who attended the 100th World Dental Federation (FDI) Annual World Dental Congress (AWDC).MethodsAn anonymous questionnaire was administered to a sample of 150 dentists who attended the 100th FDI AWDC in 2012. The participants were asked about TR and their practice of TR. They were also asked to provide their years of dental practice and the countries in which they received their dental training.ResultsFifteen respondents were not performing restoration, and they were excluded from analysis. Most respondents (123/135) practiced general dentistry. Their basic dental training was from 46 countries and regions. Most of them (n = 117, 87%) knew about TR, and 53% (n = 71) practiced it. There were 12 dentists (9%) who had performed more than 10 TRs in the previous 12 months. Practice of TR among dentists who graduated more than 10 years previously was more common (odds ratio 5.87–5.98) than those who graduated <3 years previously.ConclusionsThe current study found that about half of the surveyed dentists practiced TR, although most of them knew about it. Tunnel restoration was performed more frequently among dentists who had more than 10 years of clinical experience.
Effect of experimental silane‐based primers with various contents of 2‐hydroxyethyl methacrylate on the bond strength of orthodontic adhesives
Authors: Mustafa Ammar A. , Matinlinna Jukka P. , Razak Aziz A. , Hussin Akbar S. 
Published: January 2014

AbstractAimTo evaluate in vitro the effect of different concentrations of 2‐hydroxyethyl methacrylate (HEMA) in experimental silane‐based primers on shear bond strength of orthodontic adhesives.MethodsDifferent volume percentages of HEMA were tested in four experimental silane‐based primer solutions (additions of HEMA: 0, 5.0 vol%, 25.0 vol% and 50.0 vol%). An experimental silane blend (primer) of 1.0 vol% 3‐isocyanatopropyltrimethoxysilane (ICMS) + 0.5% bis‐1,2‐(triethoxysilyl) ethane (BTSE) was prepared and used. The experimental primers together with the control group were applied onto acid‐etched premolars for attachment of orthodontic brackets. After artificial aging by thermocycling the shear‐bond strength was measured. The fractured surfaces of all specimens were examined under scanning electron microscopy (SEM) to evaluate the failure mode on the enamel surface.ResultsThe experimental primers showed the highest shear‐bond strength of 21.15 MPa (SD ± 2.70 MPa) and with 25 vol% showed a highly significant increase (P < 0.05) in bond strength. The SEM images showed full penetration of adhesive agents when using silane‐based primers. In addition, the SEM images suggested that the predominant failure type was not necessarily the same as for the failure propagation.ConclusionsThis preliminary study suggested that nonacidic silane‐based primers with HEMA addition might be an alternative to for use as adhesion promoting primers.
Lawsonite metasomatism and trace element recycling in subduction zones
Authors: Vitale Brovarone A. , Alard O. , Beyssac O. , Martin L. , Picatto M. 
Published: January 2014

AbstractAlthough lawsonite‐bearing rocks are rare in exhumed high‐pressure (HP) terranes, they are considered to exert a primary role in subduction dynamics. Recent observations in natural settings have shown that fluid–rock interaction at HP conditions, including metasomatism, may lead to unusually high lawsonite amounts even in rocks that originally contained little or no lawsonite. This process may therefore bear important implications for element recycling in subduction zones. A detailed characterization of the geochemical fingerprints associated with lawsonite metasomatism is presented in this contribution. The studied rocks belong to the HP terranes of Alpine Corsica (France), which is the largest documented exposure for lawsonite metasomatism. Metasomatic lawsonite displays complex compositional zoning, including high trace element, Cr and Ti content. The trace element content is much higher compared with the average of non‐metasomatic lawsonite, and is in line with the re‐incorporation of large amounts of trace elements (e.g. REE, Sr, Pb, Th) in the rock during metasomatism, as shown by mass transfer calculations. Our data suggest that serpentinites represented the main fluid source for the metasomatism, with concurrent contribution of other, possibly Ca‐rich lithologies, such as mafic or meta‐sedimentary rocks. We propose that the breakdown of metasomatic lawsonite may contribute to the genesis of magmas and their characteristic geochemical signatures.
Submitting a manuscript for peer review–integrity, integrity, integrity
Authors: Murphy Sean P. , Bulman Christopher , Shariati Behnam , Hausmann Laura ,   the ISN Publications Committee
Published: January 2014

AbstractPublication of a flawed manuscript has significant consequences for the progress of science. When this proves to be intentional, science is brought into disrepute and this puts even more pressure on the shrinking resources that society is prepared to invest in research. All scientific journals, including the Journal of Neurochemistry, have witnessed a marked increase in the number of corrections and retractions of published articles over the last 10 years, and uncovered a depressingly large number of fabrications among submitted manuscripts. The increase in number of ‘spoiled’ manuscripts reflects not only the improved methods that journals employ to detect plagiarism in its many forms but also suggests a measurable change in the behavior of authors. The increased policing of submissions by reviewers, editors, and publishers expends time and money. The sanctions imposed by journal editors on authors found guilty of malpractice are transparent and severe.
ser31 tyrosine hydroxylase phosphorylation parallels differences in dopamine recovery in nigrostriatal pathway following 6‐OHDA lesion
Authors: Salvatore Michael F. 
Published: January 2014

AbstractCompensatory mechanisms in dopamine (DA) signaling have long been proposed to delay onset of locomotor symptoms during Parkinson's disease progression until ~ 80% loss of striatal DA occurs. Increased striatal dopamine turnover has been proposed to be a part of this compensatory response, but may occur after locomotor symptoms. Increased tyrosine hydroxylase (TH) activity has also been proposed as a mechanism, but the impact of TH protein loss upon site‐specific TH phosphorylation in conjunction with the impact on DA tissue content is not known. The tissue content of DA was determined against TH protein loss in the striatum and substantia nigra (SN) following 6‐hydroxydopamine lesion in the medial forebrain bundle in young Sprague–Dawley male rats. Although DA predictably decreased in both regions following 6‐hydroxydopamine, there was a significant difference in DA loss between the striatum (75%) and SN (40%), despite similar TH protein loss. Paradoxically, there was a significant decrease in DA against remaining TH protein in striatum, but a significant increase in DA against remaining TH in SN. In the SN, increased DA per remaining TH protein was matched by increased ser31, but not ser40, TH phosphorylation. In striatum, both ser31 and ser40 phosphorylation decreased, reflecting decreased DA per TH. However, in control nigral and striatal tissue, only ser31 phosphorylation correlated with DA per TH protein. Combined, these results suggest that the phosphorylation of ser31 in the SN may be a mechanism to increase DA biosynthesis against TH protein loss in an in vivo model of Parkinson's disease.
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Properties of dopamine biosynthesis were evaluated in the 6‐OHDA model of Parkinson's disease by studying the impact of tyrosine hydroxylase (TH) protein loss on its own phosphorylation and dopamine (DA) tissue content in rat nigrostriatal pathway. A dichotomous response was observed between striatum and substantia nigra in that dopamine per remaining TH decreased in striatum, but increased in substantia nigra. Phosphorylation at ser31 reflected these differences, indicating that ser31 phosphorylation may be critical to maintain dopamine with progressive TH protein loss. Drawings are from slides purchased from Motifolio (http://motifolio.com/).