bluuebunny/crossref_metadata_2025 huggingface dataset:
Scaling performance of Ga2O3/GaN nanowire field effect transistor
Authors: Li Chi-Kang , Yeh Po-Chun , Yu Jeng-Wei , Peng Lung-Han , Wu Yuh-Renn
Published: October 2013

A three-dimensional finite element solver is applied to investigate the performance of Ga2O3/GaN nanowire transistors. Experimental nanowire results of 50 nm gate length are provided to compare with the simulation, and they show good agreement. The performance of a shorter gate length (<50 nm) is studied and scaling issues of the short-channel effect are analyzed. With a better surrounding gate design and a recessed gate approach, the optimal conditions for a 20 nm gate length are explored in this paper.
Active near infrared linear polarizer based on VO2 phase transition
Authors: Peng Xiao-Yu , Wang Bing , Teng Jinghua , Kana Kana J. B. , Zhang Xinhai
Published: October 2013

We demonstrate via the numerical simulation the modulation of the transmission of visible and near-infrared light through a hybrid grating structure containing a gold metallic wire-grid grating patterned on a thermochromic vanadium dioxide (VO2) thin film. We find that the transmission through the subwavelength slits of this hybrid device is significantly modulated in the near-infrared region due to the phase transition of VO2 film from insulator to metal when the temperature increases from 30 °C to 85 °C. By optimizing the hybrid-grating architecture parameters, the best switching efficiency of our hybrid grating at 1.5 μm reaches to 40%, and extinction ratio is larger than 1013. The capability of switching on/off and fine tuning of the thick hybrid grating parameters make our hybrid-grating structure a promising candidate of an active broadband linear polarizer with high switching efficiency and extinction ratio.
Curling graphene ribbons through thermal annealing
Authors: Cao Yunhao , Flores Roel L. , Xu Ya-Qiong
Published: October 2013

A simple process is developed to curl graphene membranes through thermal annealing. The resulting curled graphene ribbons displayed enhanced photocurrent response compared to flat graphene ribbons. The annealing temperature, the thickness of the graphene, and the type of poly-methyl methacrylate used were the three key factors that influenced the morphology of graphene during thermal annealing. Each of the factors has been systematically investigated, and the transition from flat to curled graphene ribbons was observed. This work has shown a facile method to alter graphene morphology and to develop promising graphene structures for future optoelectronics.
High thermoelectric performance of nonequilibrium synthesized CeFe4Sb12 composite with multi-scaled nanostructures
Authors: Tan Gangjian , Zheng Yun , Tang Xinfeng
Published: October 2013

High thermoelectric performance p-type CeFe4Sb12 composite with rich nanostructures are rapidly prepared by a melt spinning coupled with spark plasma sintering technique. Melt spinning markedly refines the matrix grain size (200–500 nm). We also find evenly distributed FeSb2 nanodots (<50 nm) inside the skutterudite grains due to the inherent structural instability of Fe-containing skutterudites. Meanwhile, by adding excessive Ce into the CeFe4Sb12 matrix, unique CeSb2 nanoinclusions (50–150 nm) are in-situ formed on the grain boundaries. The multi-scaled nanostructures scatter a broad spectrum of heat-carrying phonons, leading to a maximum thermoelectric figure of merit ZT above unity in the skutterudite nanocomposite.
Strong energy-transfer-induced enhancement of Er3+ luminescence in In2O3 nanocrystal codoped silica films
Authors: Lin Tao , Zhang Xiaowei , Xu Jun , Liu Xin , Swihart Mark T. , Xu Ling , Chen Kunji
Published: October 2013

Co-doping of sol-gel processed SiO2 thin films with Er3+ ions and In2O3 nanocrystals produced a 100-fold enhancement of Er3+-related 1.54 μm emission compared to films doped only with Er3+. Quantitative studies of temperature-dependent photoluminescence spectra show that this dopant-concentration-dependent luminescence enhancement is a result of energy transfer from In2O3 to Er3+ ions. The dominant nonradiative recombination for Er3+ is energy transfer to hydroxyl groups, which is suppressed by proper thermal treatment. These results demonstrate that In2O3 nanocrystals have high potential for use as a sensitizer of Er3+ ions in high-performance fiber amplifiers.
Study of stopping power for a proton moving in a plasma with arbitrary degeneracy
Authors: Zhang Ya , Song Yuan-Hong , Wang You-Nian
Published: October 2013

Excitation of bulk solid electrons with arbitrary degeneracy, by external charged particles, is investigated by a two-dimensional nonlinear quantum hydrodynamic (QHD) model. The nonlinear stopping power and wake potential are calculated by solving the nonlinear QHD equations with the flux corrected transport numerical method. Two cases of fully degenerated and partially degenerated electrons are compared and discussed in the same self-consistent QHD model. Our results are consistent with the well known dielectric calculation of the stopping power at higher velocity, but include the nonlinear terms of the interactions and give larger stopping power at smaller velocity.
Thermal and Photocatalytic Production of Hydrogen Peroxide and its Use in Hydrogen Peroxide Fuel Cells
Authors: Fukuzumi Shunichi , Yamada Yusuke
Published: October 2013

This mini review describes our recent developments on the thermal and photocatalytic production of hydrogen peroxide and its use in hydrogen peroxide fuel cells. Selective two-electron reduction of dioxygen to hydrogen peroxide by one-electron reductants has been made possible by using appropriate metal complexes with an acid. Protonation of the ligands of the complexes facilitates the reduction of O2. The photocatalytic two-electron reduction of dioxygen to hydrogen peroxide also occurs using organic photocatalysts and oxalic acid as an electron source in buffer solutions. The control of the water content and pH of a reaction solution is significant for improving the catalytic activity and durability. A hydrogen peroxide fuel cell can be operated with a one-compartment structure without a membrane, which is certainly more promising for the development of low-cost fuel cells as compared with two compartment hydrogen fuel cells that require membranes. Utilisation of iron complexes as cathode materials are reviewed.
Australian children lack the basic movement skills to be active and healthy
Authors: Barnett L. M. , Hardy L. L. , Lubans D. R. , Cliff D. P. , Okely A. D. , Hills A. P. , Morgan P. J. ,   Physical Activity and Sedentary Behaviour Stream of the Australasian Child and Adolescent Obesity Research Network (ACAORN)
Published: October 2013

The authors make a case for urgent action to ensure all Australian children are provided with the opportunity to develop competence and confidence in fundamental movement skills (FMS), which will help them to be physically active, fit and to have a healthy body composition. It is suggested that cooperation and commitment between public health, education and early childhood sectors is required. The authors advocate that FMS development should be highlighted in all relevant policy documents, that children should be given opportunities to be taught FMS during the preschool years and that primary schools should provide a quality health and physical education programs.
Smoking mull: a grounded theory model on the dynamics of combined tobacco and cannabis use among adult men
Authors: Banbury A. , Zask A. , Carter S. M. , van Beurden E. , Tokley R. , Passey M. , Copeland J.
Published: October 2013

Issue addressed

Australians' use of cannabis has been increasing. Over a third of Australians (35.4%) have used cannabis at some time in their lives and 10.3% are recent users. Almost two‐thirds of cannabis users combine cannabis with tobacco. The aim of this study was to understand the process of mulling – smoking tobacco and cannabis together – using a grounded theory approach.

Methods

Twenty‐one in‐depth semistructured interviews were conducted with men aged 25–34 and living on the North Coast of New South Wales. Interviews explored participants' smoking practices, histories and cessation attempts.

Results

A model describing mulling behaviour and the dynamics of smoking cannabis and tobacco was developed. It provides an explanatory framework that demonstrates the flexibility in smoking practices, including substance substitution – participants changed the type of cannabis they smoked, the amount of tobacco they mixed with it and the devices they used to smoke according to the situations they were in and the effects sought.

Conclusion

Understanding these dynamic smoking practices and the importance of situations and effects, as well as the specific role of tobacco in mulling, may allow health workers to design more relevant and appropriate interventions.

So what?

Combining tobacco with cannabis is the most common way of smoking cannabis in Australia. However, tobacco cessation programmes rarely address cannabis use. Further research to develop evidence‐based approaches for mull use would improve cessation outcomes.
The aberrant millipede genus Pteridoiulus and its position in a revised molecular phylogeny of the family Julidae (Diplopoda : Julida)
Authors: Enghoff Henrik , Petersen Gitte , Seberg Ole
Published: October 2013

A phylogenetic analysis of 62 species (32 genera) of the Palaearctic millipede family Julidae, including the aberrant alpine genus Pteridoiulus Verhoeff, 1913, was made based on partial sequences of the mitochondrial 16S rRNA (16S) gene and the nuclear 28S rRNA (28S) gene, respectively. The two datasets (16S rDNA and 28S rDNA) were analysed in combination but treated as different partitions using direct optimisation as implemented in POY. The 16S rDNA and the 28S rDNA sequences vary from 410 to 449 bp and from 467 to 525 bp in length, respectively. All searches were performed under six different gap opening costs, an extension gap cost of 1, and a substitution cost of 2. Based on previous investigations the optimal gap opening cost was set to 4, and the robustness of different gap opening costs ranging from 1 to 6 investigated. Additionally, the two data partitions were aligned individually using MAFTT and run in TNT both with gaps treated as a fifth state, and as missing, and finally the alignments were used as input in a maximum likelihood (ML) analysis. The order Julida and the family Julidae were recovered as monophyletic under all weight sets in POY, as well as in the TNT and ML analyses. Likewise, in all analyses Pteridoiulus was found to be sister to another monotypic alpine genus, Heteroiulus Verhoeff, 1897. The Pteridoiulus + Heteroiulus clade is robust to parameter changes but lacks morphological support. The distribution pattern of the clade, Pteridoiulus in the eastern Alps (mainly Austria), Heteroiulus in the southern Alps (Italy) seems unique, since similar patterns all involve very similar, closely related species pairs.
Region-specific restoration of striatal synaptic plasticity by dopamine grafts in experimental parkinsonism
Authors: Rylander Daniella , Bagetta Vincenza , Pendolino Valentina , Zianni Elisa , Grealish Shane , Gardoni Fabrizio , Di Luca Monica , Calabresi Paolo , Cenci M. Angela , Picconi Barbara
Published: October 2013

Significance

This paper identifies long-term synaptic plasticity restoration as an underlying mechanism of progressive motor improvement after neuronal transplantation in a rat Parkinson model. A Parkinson-associated loss of plasticity in the host striatum could be restored by transplanted dopamine neurons with sufficient fiber innervation, suggesting that functional innervation with possible synapse formation is required for the long-term effect of neural transplants. These data support a multisite-grafting procedure to more extensively restore the plasticity in the host parkinsonian brain. Dopamine neuron transplantation could be a future therapy for Parkinson disease and is currently being evaluated in a European Union-sponsored project.
Compressed modes for variational problems in mathematics and physics
Authors: Ozoliņš Vidvuds , Lai Rongjie , Caflisch Russel , Osher Stanley
Published: October 2013

Significance

Intuition suggests that many interesting phenomena in physics, chemistry, and materials science are “short-sighted”—that is, perturbation in a small spatial region only affects its immediate surroundings. In mathematical terms, near-sightedness is described by functions of finite range. As an example, the so-called Wannier functions in quantum mechanics are localized functions, which contain all the information about the properties of the system, including its spectral properties. This work’s main research objective is to develop theory and numerical methods that can systematically derive functions that span the energy spectrum of a given quantum-mechanical system and are nonzero only in a finite spatial region. These ideas hold the key for developing efficient methods for solving partial differential equations of mathematical physics.
Agentivity as a determinant of lexico-grammatical variation in L2 academic writing
Authors: Callies Marcus
Published: October 2013

This paper examines novice writers’ strategies in the (non-)representation of authorship in academic writing drawing on data from the Corpus of Academic Learner English and a native-speaker control corpus. The analysis focuses on the quantitative and qualitative use of pronouns, subject placeholders, as well as verbs and inanimate nouns that frequently occur in academic writing. The findings indicate that even advanced learners are insecure about the (non-)representation of authorship in academic texts, but lack the resources to report events and findings without mentioning an author-agent. The learner data evidence a significant overrepresentation of first person pronouns and subject placeholders as default strategies to suppress the author-agent. This imbalanced clustering is argued to be due to a significant underrepresentation of constructions with inanimate nouns as subjects that are preferred reporting devices in abstracts and research articles in the humanities. The paper concludes by addressing implications for language teaching, testing and assessment.
Overuse or underuse
Authors: Chen Meilin
Published: October 2013

This study explores Chinese university students’ use of phrasal verbs in comparison with their American and British counterparts by utilizing a corpus of learner English and four native corpora of two English varieties and two genres (argumentative and academic writing). The results show that it is difficult to state whether the Chinese learners of English over- or underuse phrasal verbs in writing because a more striking difference emerges between the British and American students. American students tend to use many more phrasal verbs in both genres than British students and they also use a greater variety of phrasal verbs. Notwithstanding the differences, both American and British students tend to use fewer phrasal verbs in academic writing than in argumentative writing. The learners do not show a fundamental difference from the British students regarding overall frequencies of phrasal verbs; however, the learner-native writer gap does exist between the Chinese and American students.
Orthography Facilitates Vocabulary Learning for Children with Autism Spectrum Disorders (ASD)
Authors: Lucas Rebecca , Norbury Courtenay Frazier
Published: October 2013

This study investigated the extent to which children with autism spectrum disorders (ASD) can use orthography to facilitate vocabulary learning, as is the case for typically developing (TD) children. Forty-one children aged 7–12 years, 20 with a formal diagnosis of ASD and 21 TD peers, were taught 16 low-frequency concrete science words, such as “breccia”. Half of the stimuli had the written word presented alongside a picture of the target item (orthography present: OP) while the remaining items were taught with orthography absent (OA). During the learning phase, eye movements were recorded; there were no group differences in the time spent fixating the written form. Production, comprehension, and recognition of orthographic forms of new words were assessed immediately after learning and again after a 24-hour delay. The vocabulary learning of both groups was facilitated by the presence of orthography. Overall, the groups did not differ in comprehension of new words or recognition of new orthographic forms, although the children with ASD demonstrated superior phonological learning (as measured by a picture naming task) relative to TD peers. Additionally, both groups retained or increased new knowledge after 24 hours. The results suggest that presenting the written form during oral vocabulary teaching will enhance learning and provide a mechanism for children with ASD to increase word knowledge despite potential limitations in social learning.
A chemist building paths to cell biology
Authors: Weibel Douglas B.
Published: October 2013

Galileo is reported to have stated, “Measure what is measurable and make measurable what is not so.” My group's trajectory in cell biology has closely followed this philosophy, although it took some searching to find this path.
Effect of Sequencing of Complementary Feeding in Relation to Breast‐Feeding on Total Intake in Infants
Authors: Shah Dheeraj , Singh Meenakshi , Gupta Piyush , Faridi M.M.A.
Published: October 2013

Objective:

The aim of the present study was to evaluate whether the order of complementary feeding in relation to breast‐feeding affects breast milk, semisolid, or total energy intake in infants.

Methods:

The present study was designed as a randomized crossover trial. The study was conducted in a tertiary care hospital. The study participants were 25 healthy infants between the ages of 7 and 11 months who were exclusively breast‐fed for at least 6 months and were now receiving complementary foods for at least 1 month in addition to breast‐feeding. Infants were randomized to follow a sequence of either complementary feeding before breast‐feeding (sequence A) or complementary feeding after breast‐feeding (sequence B) for the first day (24 hours) of the study period using simple randomization. For the next day, the sequence was reversed for each child. All babies received 3 actively fed complementary food meals per day (morning, afternoon, and evening). A semisolid study diet was prepared in the hospital by cooking rice and pulse with oil using a standard method, ensuring the energy density of at least 0.6 kcal/g. The infants were allowed ad libitum breast‐feeding during the observation period. Semisolid intake was directly measured and breast milk intake was quantified by test weighing method. Energy intake from complementary foods was calculated from the product of energy density of the diet served on that day and the total amount consumed. The total energy intake and energy intake from breast milk and complementary foods between the 2 sequences were compared.

Results:

The mean (standard deviation) energy intake from breast milk during 12 hours of daytime by following sequence A (complementary feeding before breast‐feeding) was 132.0 (67.4) kcal in comparison with 135.9 (56.2) kcal in sequence B, which was not statistically different (P = 0.83). The mean (standard deviation) energy consumed from semisolids in sequences A and B was also comparable (88.6 [75.5] kcal vs 85.5 [89.7] kcal; P = 0.58). The total energy intake during daytime in sequence A was 220.6 (96.2) kcal in comparison with 221.5 (94.0) kcal in sequence B, which was also comparable (P = 0.97). The results related to energy intake through breast milk and total energy intake were not different when insensible losses during feeding were adjusted in both groups.

Conclusions:

Altering the sequence of complementary feeding in relation to breast‐feeding does not affect total energy intake.
Fructose Intolerance/Malabsorption and Recurrent Abdominal Pain in Children
Authors: Escobar Mauricio A. , Lustig Daniel , Pflugeisen Bethann M. , Amoroso Paul J. , Sherif Dalia , Saeed Rasha , Shamdeen Shaza , Tuider Judith , Abdullah Bisher
Published: October 2013

Objectives:

The purpose of the present study was to ascertain whether pediatric patients with chronic abdominal pain had concurrent fructose intolerance as determined by a standardized dose breath hydrogen test (BHT), and whether symptoms would improve with a low‐fructose diet.

Methods:

The fructose BHT test was administered to patients evaluated in clinic with unexplained chronic abdominal pain alone or associated with constipation, gas or bloating, and/or diarrhea. The patients were given a standard dose of 1 g/kg fructose to maximum of 25 g. Hydrogen and methane were measured at 8 time points. The test was presumed positive if breath hydrogen exceeded 20 ppm above baseline. If positive, patients were given a dietitian‐prescribed low‐fructose diet.

Results:

A total of 222 patients were part of the study. Ages ranged from 2 to 19 years with a mean of 10.5. BHT for fructose was performed in all of the patients and it was positive for fructose intolerance in 121 of 222 patients (54.5%). A total of 101 of 222 (45.5%) patients had negative BHT for fructose intolerance. All BHT‐positive patients had a nutrition consult with a registered dietitian and were placed on a low‐fructose diet. Using a standard pain scale for children, 93 of 121 patients (76.9%) reported resolution of symptoms on a low‐fructose diet (P < 0.0001). Furthermore, 55 of 101 patients (54.4%) with negative BHT for fructose reported resolution of symptoms without a low‐fructose diet (P = 0.37).

Conclusions:

Fructose intolerance/malabsorption is common in children with recurrent/functional abdominal pain and a low‐fructose diet is an effective treatment.
Indirect food web interactions mediated by predator–rodent dynamics: relative roles of lemmings and voles
Authors: Ims Rolf A. , Henden John-André , Thingnes Anders V. , Killengreen Siw T.
Published: October 2013

Production cycles in birds are proposed as prime cases of indirect interactions in food webs. They are thought to be driven by predators switching from rodents to bird nests in the crash phase of rodent population cycles. Although rodent cycles are geographically widespread and found in different rodent taxa, bird production cycles appear to be most profound in the high Arctic where lemmings dominate. We hypothesized that this may be due to arctic lemmings inducing stronger predator responses than boreal voles. We tested this hypothesis by estimating predation rates in dummy bird nests during a rodent cycle in low-Arctic tundra. Here, the rodent community consists of a spatially variable mix of one lemming (
Lemmus lemmus
) and two vole species (
Myodes rufocanus
and
Microtus oeconomus
) with similar abundances. In consistence with our hypothesis, lemming peak abundances predicted well crash-phase nest predation rates, whereas the vole abundances had no predictive ability. Corvids were found to be the most important nest predators. Lemmings appear to be accessible to the whole predator community which makes them particularly powerful drivers of food web dynamics.
Plasticity and non-Schmid effects
Authors: Soare Stefan C.
Published: October 2013

The structure of the overall response of a metal polycrystal is analysed under the assumption that activity on the slip systems of its constituents is governed by a generalized Schmid law. In the resulting macromodel of metal plasticity, the overall rate of plastic deformation is related to the stress gradient of the yield surface via a generalized, but still associated, flow rule. While the overall rate of plastic deformation is no longer collinear with the stress gradient of the yield surface, its deviation is characterized by an additional macrovariable, representative of the rate of the non-Schmid effects taking place at constituent level.
Transversally periodic solitary gravity–capillary waves
Authors: Milewski Paul A. , Wang Zhan
Published: October 2013

When both gravity and surface tension effects are present, surface solitary water waves are known to exist in both two- and three-dimensional infinitely deep fluids. We describe here solutions bridging these two cases: travelling waves which are localized in the propagation direction and periodic in the transverse direction. These transversally periodic gravity–capillary solitary waves are found to be of either elevation or depression type, tend to plane waves below a critical transverse period and tend to solitary lumps as the transverse period tends to infinity. The waves are found numerically in a Hamiltonian system for water waves simplified by a cubic truncation of the Dirichlet-to-Neumann operator. This approximation has been proved to be very accurate for both two- and three-dimensional computations of fully localized gravity–capillary solitary waves. The stability properties of these waves are then investigated via the time evolution of perturbed wave profiles.
Evolutionary conservatism and convergence both lead to striking similarity in ecology, morphology and performance across continents in frogs
Authors: Moen Daniel S. , Irschick Duncan J. , Wiens John J.
Published: October 2013

Many clades contain ecologically and phenotypically similar species across continents, yet the processes generating this similarity are largely unstudied, leaving fundamental questions unanswered. Is similarity in morphology and performance across assemblages caused by evolutionary convergence or by biogeographic dispersal of evolutionarily conserved ecotypes? Does convergence to new ecological conditions erase evidence of past adaptation? Here, we analyse ecology, morphology and performance in frog assemblages from three continents (Asia, Australia and South America), assessing the importance of dispersal and convergent evolution in explaining similarity across regions. We find three striking results. First, species using the same microhabitat type are highly similar in morphology and performance across both clades and continents. Second, some species on different continents owe their similarity to dispersal and evolutionary conservatism (rather than evolutionary convergence), even over vast temporal and spatial scales. Third, in one case, an ecologically specialized ancestor radiated into diverse ecotypes that have converged with those on other continents, largely erasing traces of past adaptation to their ancestral ecology. Overall, our study highlights the roles of both evolutionary conservatism and convergence in explaining similarity in species traits over large spatial and temporal scales and demonstrates a statistical framework for addressing these questions in other systems.
Familiarity adds to attractiveness in matters of siskin mate choice
Authors: Senar J. C. , Mateos-Gonzalez F. , Uribe F. , Arroyo L.
Published: October 2013

There is currently considerable controversy in evolutionary ecology revolving around whether social familiarity brings attraction when a female chooses a mate. The topic of familiarity is significant because by avoiding or preferring familiar individuals as mates, the potential for local adaptation may be reduced or favoured. The topic becomes even more interesting if we simultaneously analyse preferences for familiarity and sexual ornaments, because when familiarity influences female mating preferences, this could very significantly affect the strength of sexual selection on male ornamentation. Here, we have used mate-choice experiments in siskinsCarduelis spinusto analyse how familiarity and patterns of ornamentation (i.e. the size of wing patches) interact to influence mating success. Our results show that females clearly prefer familiar individuals when choosing between familiar and unfamiliar males with similar-sized wing patches. Furthermore, when females were given the choice between a highly ornamented unfamiliar male and a less ornamented familiar male, half of the females still preferred the socially familiar birds as mates. Our finding suggests that male familiarity may be as important as sexual ornaments in affecting female behaviour in mate choice. Given that the potential for local adaptation may be favoured by preferring familiar individuals as mates, social familiarity as a mate-choice criterion may become a potential area of fruitful research on sympatric speciation processes.
Shifting mirrors: adaptive changes in retinal reflections to winter darkness in Arctic reindeer
Authors: Stokkan Karl-Arne , Folkow Lars , Dukes Juliet , Neveu Magella , Hogg Chris , Siefken Sandra , Dakin Steven C. , Jeffery Glen
Published: October 2013

Arctic reindeer experience extreme changes in environmental light from continuous summer daylight to continuous winter darkness. Here, we show that they may have a unique mechanism to cope with winter darkness by changing the wavelength reflection from their tapetum lucidum (TL). In summer, it is golden with most light reflected back directly through the retina, whereas in winter it is deep blue with less light reflected out of the eye. The blue reflection in winter is associated with significantly increased retinal sensitivity compared with summer animals. The wavelength of reflection depends on TL collagen spacing, with reduced spacing resulting in shorter wavelengths, which we confirmed in summer and winter animals. Winter animals have significantly increased intra-ocular pressure, probably produced by permanent pupil dilation blocking ocular drainage. This may explain the collagen compression. The resulting shift to a blue reflection may scatter light through photoreceptors rather than directly reflecting it, resulting in elevated retinal sensitivity via increased photon capture. This is, to our knowledge, the first description of a retinal structural adaptation to seasonal changes in environmental light. Increased sensitivity occurs at the cost of reduced acuity, but may be an important adaptation in reindeer to detect moving predators in the dark Arctic winter.
Evidence for large-scale effects of competition: niche displacement in Canada lynx and bobcat
Authors: Peers Michael J. L. , Thornton Daniel H. , Murray Dennis L.
Published: October 2013

Determining the patterns, causes and consequences of character displacement is central to our understanding of competition in ecological communities. However, the majority of competition research has occurred over small spatial extents or focused on fine-scale differences in morphology or behaviour. The effects of competition on broad-scale distribution and niche characteristics of species remain poorly understood but critically important. Using range-wide species distribution models, we evaluated whether Canada lynx (Lynx canadensis) or bobcat (Lynx rufus) were displaced in regions of sympatry. Consistent with our prediction, we found that lynx niches were less similar to those of bobcat in areas of sympatry versus allopatry, with a stronger reliance on snow cover driving lynx niche divergence in the sympatric zone. By contrast, bobcat increased niche breadth in zones of sympatry, and bobcat niches were equally similar to those of lynx in zones of sympatry and allopatry. These findings suggest that competitively disadvantaged species avoid competition at large scales by restricting their niche to highly suitable conditions, while superior competitors expand the diversity of environments used. Our results indicate that competition can manifest within climatic niche space across species’ ranges, highlighting the importance of biotic interactions occurring at large spatial scales on niche dynamics.
Di-μ-oxido-bis({2,2′-[ethane-1,2-diylbis(nitrilomethanylylidene)]diphenolato}titanium(IV)) chloroform disolvate
Authors: Zaitsev Kirill V. , Karlov Sergey S. , Zaitseva Galina S. , Lermontova Elmira Kh. , Churakov Andrei V.
Published: October 2013

In the title compound, [Ti2(C16H14N2O2)2O2]·2CHCl3, the TiIVatom in the centrosymmetric complex has a distorted octahedral N2O4coordination environment and is linkedviatwo μ2-oxido bridges into a dinuclear centrosymmetric complex, with a Ti...Ti separation of 2.7794 (8) Å. In the salen (N,N′-ethylenebis(salicylimine)) ligand, the two salicylimine units make a dihedral angle of 45.31 (5)°. The complex molecules are stacked parallel to [100], forming channels in which the solvent chloroform molecules are located. C—H...O hydrogen-bonding interactions between the complex molecules and the solvent molecules consolidate the crystal packing.
Interactions between C : N : P stoichiometry and soil macrofauna control dung decomposition of savanna herbivores
Authors: Sitters Judith , Maechler Marc‐Jacques , Edwards Peter J. , Suter Werner , Olde Venterink Harry
Published: October 2013

Although dung of mammalian herbivores is an important pathway for nutrient return in savanna ecosystems, differences in dung decomposition rates among species have been little studied.

We measured the rates of dung deposition and decomposition for various herbivores in a moist Tanzanian savanna and the related differences among species to nutrient concentrations and the activities of soil macrofauna (e.g. different mesh sizes of decomposition bags, or presence and absence of dung beetles).

Dung C : N : P stoichiometry varied widely among species, which could in part be explained by differences in feeding strategy (browsers vs. grazers) and digestive physiology (ruminants vs. non‐ruminants). Rates of both decomposition and nutrient release were influenced by the C : N : P stoichiometry of dung, with lower relative losses of the least abundant nutrient in the dung. Surprisingly, soil macrofauna increased the relative losses of the least abundant nutrient, thereby stabilizing the ratio of N loss to P loss. Dung beetles increased rates of N and P release from wildebeest dung significantly and also increased N availability in the soil.

We conclude that rates of nutrient return in dung depend not only on where herbivores deposit their dung, but also on its C : N : P stoichiometry, the activity of soil macrofauna and interactions between these factors. These factors may therefore influence the relative availabilities of N and P in the soil and hence the functioning of savanna ecosystems.
Methoprene application and diet protein supplementation to male melon fly, Bactrocera cucurbitae, modifies female remating behavior
Authors: ul Haq Ihsan , Vreysen Marc J. B. , Teal P. E. A. , Hendrichs Jorge
Published: October 2013

Methoprene (an analogue of juvenile hormone) application and feeding on a protein diet is known to enhance male melon fly, Bactrocera cucurbitae Coquillett (Diptera: Tephritidae), mating success. In this study, we investigated the effect of these treatments on male B. cucurbitae's ability to inhibit female remating. While 14‐d‐old females were fed on protein diet, 6‐d‐old males were exposed to one of the following treatments: (i) topical application of methoprene and fed on a protein diet; (ii) no methoprene but fed on a protein diet; (iii) methoprene and sugar‐fed only; and (iv) sugar‐fed, 14‐d‐old males acted as controls. Treatments had no effect on a male's ability to depress the female remating receptivity in comparison to the control. Females mated with protein‐deprived males showed higher remating receptivity than females first mated with protein‐fed males. Methoprene and protein diet interaction had a positive effect on male mating success during the first and second mating of females. Significantly more females first mated with sugar‐fed males remated with protein‐fed males and females first mated with methoprene treated and protein‐fed males were more likely to remate with similarly treated males. Females mating latency (time to start mating) was significantly shorter with protein‐fed males, and mating duration was significantly longer with protein‐fed males compared with protein‐deprived males. These results are discussed in the context of methoprene and/or dietary protein as prerelease treatment of sterile males in area‐wide control of melon fly integrating the sterile insect technique (SIT).
Molecular characterization and phylogenetic analysis of three odorant binding protein gene transcripts in Dendrolimus species (Lepidoptera: Lasiocampidae)
Authors: Zhang Su‐Fang , Zhang Zhen , Kong Xiang‐Bo , Wang Hong‐Bin
Published: October 2013

Pine caterpillar moths, Dendrolimus spp. (Lepidoptera: Lasiocampidae), are serious economic pest of pines. Previously, phylogenetic analyses of Dendrolimus using different methods yielded inconsistent results. The chemosensory systems of insects may play fundamental roles in promoting speciation. Odorant‐binding proteins (OBPs) participate in the first step of odor detection. Studying the evolution of OBPs in closely related species may help us to identify their role in speciation. We identified three OBPs – one pheromone‐binding protein and two general odorant‐binding proteins – from male antennae of four Dendrolimus species, D. superans (Butler), D. punctatus (Walker), D. kikuchii Matsumura, and D. houi Lajonquiere, the olfactory recognition systems of which had not been previously investigated. We analyzed their molecular characteristics and compared their sequences to those of OBPs in D. tabulaeformis Tsai et Liu. Ka/Ks ratio analyses among the five Dendrolimus species indicate that PBP1 genes experienced more evolutionary pressure than the GOBPs. Phylogenetic relationships of PBP1 and GOBP1 both indicated that D. houi was the basal species, then branched D. kikuchii, while D. tabulaeformis, D. punctatus, and D. superans evolved more recently. These relationships are consistent with the changes in sex pheromone components of these five species. Dendrolimus tabulaeformis and D. punctatus are closely related sister species. However, the distances among GOBP2 sequences in the five Dendrolimus were very short, and the relationships of D. houi and D. kikuchii could not be resolved. Integrating our results with those of previous studies, we hypothesized that D. kikuchii, D. punctatus and D. superans evolved from the basal ancestor because of sex pheromone mutations and environmental pressure.
Relevance of wide‐field autofluorescence imaging in Birdshot retinochoroidopathy: descriptive analysis of 76 eyes
Authors: Piffer Anne‐Laure Le , Boissonnot Michèle , Gobert Frédéric , Zenger Anita , Wolf Sebastian , Wolf Ute , Korobelnik Jean‐François , Rougier Marie‐Bénédicte
Published: October 2013

Purpose

To study and classify retinal lesions in patients with birdshot disease using wide‐field autofluorescence imaging and correlate them according to patients' visual status.

Methods

A multicentre study was carried out on 76 eyes of 39 patients with birdshot disease, analysing colour images and under autofluorescence using the wide‐field Optomap® imaging system. This was combined with a complete clinical exam and analysis of the macula with OCT.

Results

In over 80% of the eyes, a chorioretinal lesion has been observed under autofluorescence with a direct correlation between the extent of the lesion and visual status. The presence of macular hypo‐autofluorescence was correlated with a decreased visual acuity, due to the presence of a macular oedema, active clinical inflammation or an epiretinal membrane. The hypo‐autofluorescence observed correlated with the duration of the disease and the degree of inflammation in the affected eye, indicating a secondary lesion in the pigment epithelium in relation to the choroid. The pigment epithelium was affected in a diffuse manner, as in almost 50% of the eyes the wider peripheral retina was affected.

Conclusion

Wide‐field autofluorescence imaging could appear to be a useful examination when monitoring patients, to look for areas of macular hypo‐autofluorescence responsible for an irreversible loss of vision.
Novel anti‐tumor mechanism of galanin receptor type 2 in head and neck squamous cell carcinoma cells
Authors: Uehara Takayuki , Kanazawa Takeharu , Mizukami Hiroaki , Uchibori Ryosuke , Tsukahara Tomonori , Urabe Masashi , Kume Akihiro , Misawa Kiyoshi , Carey Thomas E. , Suzuki Mikio , Ichimura Keiichi , Ozawa Keiya
Published: October 2013

Galanin and its receptors, GALR1 and GALR2, are known tumor suppressors and potential therapeutic targets in head and neck squamous cell carcinoma (HNSCC). Previously, we demonstrated that, in GALR1‐expressing HNSCC cells, the addition of galanin suppressed tumor proliferation via upregulation of ERK1/2 and cyclin‐dependent kinase inhibitors, whereas, in GALR2‐expressing cells, the addition of galanin not only suppressed proliferation, but also induced apoptosis. In this study, we first transduced HEp‐2 and KB cell lines using a recombinant adeno‐associated virus (rAAV)‐green fluorescent protein (GFP) vector and confirmed a high GFP expression rate (>90%) in both cell lines at the standard vector dose. Next, we demonstrated that GALR2 expression in the presence of galanin suppressed cell viability to 40–60% after 72 h in both cell lines. Additionally, the annexin V‐positive rate and sub‐G0/G1 phase population were significantly elevated in HEp‐2 cells (mock vs GALR2: 12.3 vs 25.0% (P < 0.01) and 9.1 vs 32.0% (P < 0.05), respectively) after 48 h. These changes were also observed in KB cells, although to a lesser extent. Furthermore, in HEp‐2 cells, GALR2‐mediated apoptosis was caspase‐independent, involving downregulation of ERK1/2, followed by induction of the pro‐apoptotic Bcl‐2 protein, Bim. These results illustrate that transient GALR2 expression in the presence of galanin induces apoptosis via diverse pathways and serves as a platform for suicide gene therapy against HNSCC.
NRD1, which encodes nardilysin protein, promotes esophageal cancer cell invasion through induction of MMP2 and MMP3 expression
Authors: Uraoka Naohiro , Oue Naohide , Sakamoto Naoya , Sentani Kazuhiro , Oo Htoo Zarni , Naito Yutaka , Noguchi Tsuyoshi , Yasui Wataru
Published: October 2013

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignancies worldwide. In the present study, to identify novel prognostic markers or therapeutic targets for ESCC, we reviewed a list of genes with upregulated expression in ESCC compared with normal esophagus, as identified by our serial analysis of gene expression (SAGE) analysis. We focused on the NRD1 gene, which encodes the nardilysin protein. Quantitative reverse transcription–polymerase chain reaction (qRT‐PCR) in 34 ESCC tissue samples revealed that mRNA expression of NRD1 was upregulated in 56% of ESCC tissue samples. Immunohistochemical analysis of nardilysin in 109 ESCC tissue samples demonstrated that 43 (39%) ESCC cases were positive for nardilysin. Nardilysin‐positive ESCC cases were more advanced in terms of T classification (P = 0.0007), N classification (P = 0.0164), and tumor stage (P < 0.0001) than nardilysin‐negative ESCC cases. Furthermore, nardilysin expression was significantly associated with poorer prognosis (P = 0.0258). Univariate and multivariate analyses revealed that nardilysin expression is an independent prognostic classifier of patients with ESCC. The invasiveness of NRD1‐knockdown TE1 and TE5 esophageal cancer cell lines was less than that of the negative control siRNA‐transfected cell lines. Expression of MMP2 and MMP3 mRNA was significantly lower in NRD1‐knockdown TE5 cells than in negative control siRNA‐transfected cells. These results suggest that nardilysin is involved in tumor progression, and is an independent prognostic classifier in patients with ESCC.
Effect of Chain Elongation on Biological Properties of the Toxin Paralysin β‐Alanyl‐tyrosine
Authors: Macurkova Anna , Neubauerova Tereza , Poncova Kristyna , Jezek Rudolf , Lovecka Petra , Spiwok Vojtech , Mackova Martina , Macek Tomas
Published: October 2013

In hemolymph of insect species, compounds with remarkable properties for pharmaceutical industry are present. At the first line, there were found compounds of low molecular mass, less than 1 kDa. One of such compounds, β‐alanyl‐tyrosine (252 Da), was isolated from larval hemolymph of some species of holometabolous insects (e.g. Neobellieria bullata). Its paralytic activity and antimicrobial properties were described until now. In this study, we present the effect of elongation of β‐alanyl‐tyrosine by repeating of this motive on the biological and physical properties of prepared analogues. For assessment of antimicrobial properties of these new compounds strains of Gram‐positive, Gram‐negative bacteria and fungi were used, we also followed the haemolytic activity and toxic effect on human cell culture HepG2. On the base of ECD spectroscopy measurement, subsequent molecular modelling and known secondary structure of original β‐alanyl‐tyrosine dipeptide, the secondary structures of repeating sequences of β‐AY were specified. The repeating structures of β‐alanyl‐tyrosine show increase in antimicrobial activity; for Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa, minimal inhibitory concentration was decreased from 30 to 15 mm for 2xβ‐AY, 0.4 mm for 4xβ‐AY and 0.25 mm for 6xβ‐AY.
Clinical and radiographic evaluation of early loaded narrow‐diameter implants: 3 years follow‐up
Authors: Maiorana Carlo , King Paul , Quaas Sebastian , Sondell Katarina , Worsaae Nils , Galindo‐Moreno Pablo
Published: October 2013

Objective

To evaluate the clinical reliability of narrow implants placed in a one‐stage procedure and early loaded in the upper and lower incisor region.

Material and methods

This is a prospective, single‐arm, multicenter study in which patients with missing natural dentition in upper lateral and lower incisor positions were enrolled. Eligible implants (OsseoSpeed™ TX 3.0S, DENTSPLY Implants) were of three different lengths and of 3.0 mm in diameter. One‐stage surgery was performed and healing abutment connection took place. Placement of the permanent single crown took place after a 6–10 weeks healing period. Clinical and radiographic checks were performed at implant placement, loading, and at the 6, 12, 24, and 36 months follow‐up visits.

Results

A total of 69 subjects with 97 implants have been included in this study. From surgery to 36 months follow‐up, 5.6% of the implants showed bone loss of more than 1 mm, while no bone loss at all were observed for 57.3% of the implants. The mean marginal bone level change from surgery to the 6, 12, and 36 months follow‐up visits was −0.27, −0.11, and −0.09 mm, respectively. The total survival rate after 3 years is 95.5%.

Conclusions

The data presented show stable marginal bone levels as well as healthy soft tissue around OsseoSpeed™ TX 3.0S implants, after 3 years of function. An interesting finding from this investigation was that a longer healing period before crown placement and loading contributed to statistically significant less marginal bone loss between loading and the 1‐year follow‐up visit (Galindo‐Moreno et al. 2012). This finding, associated with a stable probing pocket depth and a stable crown–gingiva distance, using a one‐stage surgical procedure helps to maintain the integrity of the peri‐implant soft tissues. Narrow implants can be considered as a valid solution in the treatment of the localized narrow bony defects in the anterior area with reduced spaces between the natural teeth.
The Impact of the Transition to HE: emotions, feelings and sensations
Authors: Dias Diana , Sá Maria José
Published: October 2013

Transition to Higher Education (HE) is a significant life event and it is supposed to be a very agreeable experience to students. However, such impact is not linear, being mediated by students' psychosocial variables and by their own perceptions concerning the HE environment.

Transition to HE encompasses many tasks to cope with changes: dealing with new kinds of responsibilities and managing emotions. A wide variety of emotions take place in the HE transition, either of a positive or negative nature, such as joy of enrolment success and fears of social rejection.

This research focused on the transition to HE, approaching freshmen's personal and developmental variables. Results confirm that the impact of transition has a mostly emotional nature and that related concerns differ according to students' gender and socio‐cultural background. With greater joy or greater anxiety, HE transition may be perceived as a stage of a long process towards adulthood.