bluuebunny/crossref_metadata_2025_split huggingface dataset:
Observed correlation between pulsating aurora and chorus waves at Syowa Station in Antarctica: A case study
Authors: Ozaki Mitsunori , Yagitani Satoshi , Ishizaka Kazumasa , Shiokawa Kazuo , Miyoshi Yoshizumi , Kadokura Akira , Yamagishi Hisao , Kataoka Ryuho , Ieda Akimasa , Ebihara Yusuke , Sato Natsuo , Nagano Isamu 
Published: July 2012

A high correlation between a pulsating auroral patch and grouped chorus waves was observed on 17 April 2006 at Syowa Station in Antarctica. The spatial distribution of aurora–chorus correlation coefficients is evaluated in order to determine the source region. A pulsating patch at the highest‐correlation pixel shows a one‐to‐one correspondence with the intensity variation of the grouped chorus waves, consisting of successive rising‐tone elements with a duration and spacing of 2–3 s and 20–30 s, respectively. The generation region of the chorus waves is estimated from the latitude and longitude dependence of the equatorial electron gyrofrequencies using the IGRF geomagnetic field model. The extent of the estimated latitude and longitude is consistent with the spatial distribution of the high‐correlation aurora–chorus region. The time difference between the chorus waves and the scattered electrons is also evaluated to discuss the validity of the source region. It shows that electrons reached the ionosphere sooner than the associated chorus waves by ∼1 s, consistent with the theoretical value for conjugate pulsating aurora generated at the equator. These results support the hypothesis that pulsating aurora is caused by pitch angle scattering of high‐energy electrons by whistler mode chorus waves, via a cyclotron resonance at the equator. These results are the first ground‐based observations of high correlations between a spatially extended aurora and chorus waves.
Variability of phytoplankton light absorption in Canadian Arctic seas
Authors: Brunelle Corinne B. , Larouche Pierre , Gosselin Michel 
Published: July 2012

Phytoplankton light absorption spectra (aϕ(λ)) were measured in the Canadian Arctic (i.e., the Amundsen Gulf, Canadian Arctic Archipelago, northern Baffin Bay and the Hudson Bay system) to improve algorithms used in remote‐sensing models of primary production. The absorption by algae, dominated by picophytoplankton (<5 μm), was not the major light absorption factor in the four provinces; the colored dissolved organic matter (CDOM) contributed up to 70% of total light absorption. During the fall, the low total chlorophyll a‐specific aϕ*(443) (aϕ(443)/TChl a) coefficients of the Canadian High Arctic were associated with photoacclimation processes (i.e., the package effect) occurring in light‐limited environments. Low light availability and high proportion of CDOM (absorbing strongly the ultraviolet) seem to allow the growth of phytoplankton with accessory pigments absorbing light at longer wavelengths. The ratio of photoprotective and photosynthetic carotenoids (PPC:PSC) was inversely proportional with the salinity and the cell size, and mostly decreases throughout the Canadian High Arctic during fall. In return, the highest TChla‐specific phytoplankton light absorption coefficients at the blue peak (aϕ*(443)) were observed in the Hudson Bay system from September to October (i.e., fall) as well as in the Amundsen Gulf from May to July (i.e., spring/summer). These results will ultimately allow the accurate monitoring of phytoplankton biomass and productivity evolution that is likely to take place as a result of the fast‐changing Arctic environment.
The fixed oxide trap modelling during isothermal and isochronal annealing of irradiated RADFETs
Authors: Ristić Goran S , Vasović Nikola D , Jakšić Aleksandar B 
Published: July 2012

Abstract
The density of fixed traps (FTs), ΔN
ft (cm−2), during isothermal annealing of irradiated radiation-sensitive field-effect transistors (RADFETs) from room temperature to 200 °C has been modelled. The modelling has shown that a simple, two-defect model (2DM), containing two defect types: one defect type for positively charged FTs (PCFTs), and another for negatively charged FTs (NCFTs), is applicable for the temperatures up to 100 °C. However, the three-defect model (3DM), which includes additional PCFT type, should be used for temperatures from 100 to 200 °C. The models describing the behaviour of NCFTs during isothermal annealing have also been analysed. The activation energies of

,

and

, for two PCFT types and one NCFT type, respectively, have been found. In addition, isochronal unannealed curves have been well fitted using logistic function. The modelling of isochronal annealing has also shown that one PCFT type up to 100 °C, and two PCFT types for 100–200 °C, respectively, are active, and additional defect(s) should be included for the temperatures higher than 200 °C. The isochronal annealing, which is significantly less time consuming than isothermal annealing, could be very good tool for the revealing of defects created by various stress types.
Lead phthalocyanine films deposited by ECR plasma-induced sublimation
Authors: Aliev V Sh , Badmaeva I A , Pokrovsky L D 
Published: July 2012

Abstract
Lead phthalocyanine (PbPc) thin films deposited by vacuum sublimation with Ar low-temperature electron cyclotron resonance (ECR) plasma treatment are investigated by means of reflection high-energy electron diffraction, atomic force microscopy, infrared spectroscopy, x-ray photoelectron spectroscopy and spectral ellipsometry. The intensity of plasma treatment is varied by the radio-frequency power input and the value of electrical bias applied to the sample. The films grown with and without plasma assistance are compared. The plasma intensity is considered to significantly influence the crystalline structure, surface morphology and film composition. At a low intensity the plasma assistance is analogous to vacuum annealing of films. At a medium intensity, a porous polymer matrix filled with PbPc in crystalline phases (monoclinic and triclinic) is formed in the films. At a high intensity, all the films consist of a compact polymer matrix, similar to a glassy solid, with small inclusions of PbPc molecules. The succession of PbPc molecule destructions in the growing film layer with plasma intensity increase is established by IR spectroscopy. The mechanism of polymer matrix formation is suggested.
Synthesis and frequency-dependent dielectric properties of epitaxial La1.875Sr0.125NiO4 thin films
Authors: Podpirka Adrian , Tselev Alexander , Ramanathan Shriram 
Published: July 2012

Abstract
Epitaxial thin films of La1.875Sr0.125NiO4 (lanthanum strontium nickelate, LSNO) have been synthesized by sputtering onto single crystal oxide substrates and their structural and dielectric properties are reported. High dielectric constants on the order of 107 have been measured up to 1 MHz in interdigitated capacitors with a frequency dependence that correlates with substrate imposed strain and texture. The observation of a high dielectric constant albeit with moderate loss tangent at high frequencies motivates further explorations of charge ordering phenomena in such complex oxides and serves to examine size effects on dielectric response by comparison with studies on bulk single crystal LSNO.
Psychosocial and somatic outcomes of sleep problems in children: a 4‐year follow‐up study
Authors: Simola P. , Liukkonen K. , Pitkäranta A. , Pirinen T. , Aronen E. T. 
Published: July 2012

AbstractBackgroundInadequate sleep in children relates to medical and psychosocial problems. However, not much is known about the effects of sleep problems persisting from pre‐school to school age on somatic and psychosocial symptoms.ObjectivesTo examine the associations between sleep disturbances and psychosocial symptoms, somatic complaints, medical problems at school age.MethodsThis was a population‐based 4‐year follow‐up study of sleep problems in Finnish children (n = 470). Parents filled in Sleep Disturbance Scale for Children during pre‐school and school years. Children were categorized into four groups: no sleep problems, sleep problems only at pre‐school or only at school age, and persistent sleep problems. At follow‐up the parents filled in Child Behavior Checklist and a background questionnaire.ResultsThe children with persistent sleep problems (9%) had a 16‐fold risk of having psychosocial symptoms on subclinical/clinical range compared with the children without sleep problems. The psychosocial symptoms that were related strongest to prolonged sleep problems were aggression, social and attention problems, and anxious/depressed mood. Also, somatic complaints (ninefold risk) and medical problems (P < 0.001) were typical for children with persistent sleep problems.ConclusionsPersistent sleep problems in children associate with high levels of psychosocial, somatic and medical problems. In paediatric health care more attention should be paid to recognizing, monitoring of the persistence and treatment of sleep problems before school transition period.
Pretreatment with glycomacropeptide reduces allergen sensitization, alleviates immediate cutaneous hypersensitivity and protects from anaphylaxis
Authors: Jiménez M , Chávez N A , Salinas E 
Published: July 2012

SummaryAllergic disorders are characterized by the involvement of allergen-specific immunoglobulin (Ig)E antibodies and T helper type 2 (Th2) cells. The search for new therapies for allergic diseases has been the primary focus of interest for many investigators in recent years. Glycomacropeptide (GMP) is a biologically active component of milk that exhibits a range of immunomodulatory functions. We examined whether oral administration of GMP could affect the development of allergic sensitization and the severity of immediate cutaneous hypersensitivity reactions and of anaphylaxis. Rats treated with or without GMP were ovalbumin (OVA)-sensitized and several indicators of allergy were evaluated. Pretreatment with GMP resulted in reduction of antigen-specific IgE titre in rats when sensitized with OVA. GMP administration also markedly suppressed the proliferative response of splenocytes to antigen and the production of interleukin (IL)-13 by splenocytes of sensitized animals. In addition, GMP pretreatment attenuated the intensity of the immediate cutaneous reaction induced by antigen and protected the sensitized rats from severe anaphylaxis. These data demonstrate, for the first time, that the administration of GMP prevents allergen sensitization and reduces the severity of the early-phase reaction induced by antigen in cutaneous hypersensitivity and in anaphylaxis. GMP may be used as a novel prophylactic agent for the control of allergic diseases.
Critical mass of splenic autotransplant needed for the development of phagocytic activity in rats
Authors: Marques R G , Caetano C E R , Diestel C F , Lima E , Portela M C , Oliveira A V , Oliveira M B N , Bernardo-Filho M 
Published: July 2012

Summary
When total splenectomy is inevitable, heterotopic splenic autotransplantation seems to be the only alternative to maintain the functions of the spleen. The present study was carried out to analyse the critical mass of splenic autotransplant (SAT) for the development of phagocytic activity in rats. Wistar rats were submitted to total splenectomy (TS) alone or in combination with slices of SAT ranging from an average rate of 21·9% (one slice) to 100% (five slices) of the total splenic mass implanted into the greater omentum. Sixteen weeks after the beginning of the experiment, the animals were inoculated intravenously with a suspension of Escherichia coli labelled with Tc-99m. After 20 min, the rats were killed and the liver, lung and spleen or SAT, as well as blood samples were removed to determine the percentage of labelled bacteria uptake in these tissues. As the percentage of the total splenic mass contained in the SAT increased, the bacteria remaining in the blood decreased. From the implant of 26% up to the implant of the total splenic mass (100%) there was no difference in the bacteria remaining in the blood between the healthy animals of the control group and those submitted to TS combined with SAT. This finding shows that the critical mass needed for the development of phagocytic activity of macrophages in splenic autotransplants in adult rats is 26% of the total splenic mass.
Bacillus-derived poly-γ-glutamic acid reciprocally regulates the differentiation of T helper 17 and regulatory T cells and attenuates experimental autoimmune encephalomyelitis
Authors: Lee K , Hwang S , Paik D J , Kim W K , Kim J M , Youn J 
Published: July 2012

SummaryForkhead box protein 3 (FoxP3+) regulatory T (Treg) cells and interleukin (IL)-17-producing T helper 17 (Th17) cells have opposing effects on autoimmunity, as the former are crucial for maintaining self-tolerance while the latter play a key role in precipitating inflammatory autoimmune diseases. Here we report that Bacillus-derived poly-γ-glutamic acid (γ-PGA) signals naive CD4+ T cells to promote the selective differentiation of Treg cells and to suppress the differentiation of Th17 cells. The γ-PGA inducibility of FoxP3 expression was due partially to transforming growth factor (TGF)-β induction through a Toll-like receptor (TLR)-4/myeloid differentiating factor 88 (MyD88)-dependent pathway. However, this pathway was dispensable for γ-PGA suppression of Th17 differentiation. γ-PGA inhibited IL-6-driven induction of Th17-specific factors including signal transducer and activator of transcription-3 (STAT-3) and retinoic acid-related orphan receptor γt (RORγt) while up-regulating the STAT-3 inhibitor suppressor of cytokine signalling 3 (SOCS3). Importantly, in vivo administration of γ-PGA attenuated the symptoms of experimental autoimmune encephalomyelitis and at the same time reduced Th17 cell infiltrates in the central nervous system. Thus, we have identified the microbe-associated molecular pattern, γ-PGA, as a novel regulator of autoimmune responses, capable of promoting the differentiation of anti-inflammatory Treg cells and suppressing the differentiation of proinflammatory Th17 cells. These findings draw attention to the potential of γ-PGA for treating Th17 cell-mediated autoimmune diseases.
Effects of tibolone or continuous combined oestradiol/norethisterone acetate on glucose and insulin metabolism
Authors: Manassiev Nik , Godsland Ian F. , Proudler Anthony J. , Whitehead Malcolm I. , Stevenson John C. 
Published: July 2012

SummaryObjectiveTo determine the effects of tibolone or oestradiol (E2)/norethisterone acetate (NETA) hormone replacement therapy on glucose and insulin metabolism in postmenopausal women.DesignSingle‐centre double‐blind placebo‐controlled randomized clinical trial.Subjects/MethodsWe randomized 105 healthy postmenopausal women to tibolone 2·5 mg daily, continuous combined oral E2 2 mg/NETA 1 mg daily or placebo over a 2‐year study. We performed intravenous glucose tolerance tests (IVGTT) with measurements of plasma glucose, insulin and C‐peptide concentrations and the IVGTT glucose elimination rate, k. Mathematical modelling was performed to determine measures of insulin sensitivity, Si, pancreatic insulin secretion and hepatic and plasma insulin elimination.ResultsTibolone decreased Si to 53–63% and k to 72–79% of baseline values but increased IVGTT phase 2 C‐peptide concentrations 1·6–1·8‐fold and pancreatic insulin secretion 2·2–2·4‐fold, so overall IVGTT glucose concentrations were unaffected. Similar, but for k, significantly smaller changes in insulin and C‐peptide secretion were seen with E2/NETA, also with no effect on overall IVGTT glucose concentrations.ConclusionsTibolone reduces insulin sensitivity. Healthy postmenopausal women seem able to compensate for this and maintain normal postload glucose concentrations, but it may not be advisable to prescribe tibolone to women with, or at increased risk for, diabetes.
Delayed setting of the photoperiodic response in recombinant clones of the aphid species Sitobion avenae
Authors: DEDRYVER CHARLES‐ANTOINE , LE GALLIC JEAN‐FRANÇOIS , MAHÉO FRÉDÉRIQUE , PARISEY NICOLAS , TAGU DENIS 
Published: July 2012

1. To explore the possible causes of apparent changes in reproductive mode from obligate to cyclical parthenogenesis over time in recombinant clones of the aphid Sitobion avenae Fabricius, all F1 progenies from various crosses were tested for several consecutive years for sexual morph production, after several weeks' exposure to a short photoperiod.2. Variable proportions of the F1 progenies from selfing and outcrossing holocyclic clones did not produce mating females when induction was attempted in the year of hatching, but only after further induction, the following year or after. This ‘delayed setting of the photoperiodic response’ (DSPR) was much stronger in recombinants from crosses involving only clones from oceanic regions than in those involving one clone from a region with a continental climate.3. F1 progenies resulting from crosses between one holocyclic and one intermediate clone did not show DSPR. It appeared again in the F2.4. DSPR preferentially affected the latest hatched clones in a given progeny.5. This phenomenon is neither an experimental artefact nor as a result of clone contamination. It appears to be because of a genetically controlled quantitative trait affecting the length of the ‘interval timer’, and may represent an adaptation of holocyclic aphid clones from oceanic regions to unpredictable winter climates.
Plant‐mediated effects of soil nitrogen enrichment on a chemically defended specialist herbivore,Calophasia lunula
Authors: JAMIESON MARY A. , DEANE BOWERS M. 
Published: July 2012

1. Nitrogen enrichment is an important driver of environmental change. In the present study, plant‐mediated effects of increased nitrogen on a specialist herbivore,Calophasia lunulaHufnagel, which sequesters antirrhinoside, an iridoid glycoside produced by its host plants, were examined.2. Caterpillars were reared onLinaria dalmaticaplants grown under low or high N treatments, andC. lunulaperformance traits and antirrhinoside levels were measured. Additionally, a bioassay was conducted with predatory ants to examine their response to antirrhinoside.3. Nitrogen enrichment increased larval biomass and decreased larval antirrhinoside concentrations, but had no effect on plant iridoid glycoside concentrations or larval antirrhinoside content. Thus, differences in larval antirrhinoside concentrations were evidently a consequence of increased larval biomass. Additionally, nitrogen treatment had no effects on pupal performance or defence traits.4. Bioassay results demonstrated a deterrent effect of antirrhinoside, but additional tests are necessary to evaluate the defensive role of this compound in insects.5. Surprisingly, this study demonstrated little effect of a six‐fold increase in nitrogen availability onL. dalmaticairidoid glycoside concentrations or sequestration byC. lunula.Moreover, the results suggested that changes in plant primary chemistry were more important than secondary chemistry for this specialist herbivore, and that some insects may be insensitive to N enrichment.
Pollen use by Megalopta sweat bees in relation to resource availability in a tropical forest
Authors: SMITH ADAM R. , LÓPEZ QUINTERO ISIS J. , MORENO PATIÑO JORGE ENRIQUE , ROUBIK DAVID W. , WCISLO WILLIAM T. 
Published: July 2012

1. Spatial and temporal availability of pollen helps shape bee foraging behaviour and productivity, which has been studied in great detail at the landscape level, but never in a diverse tropical forest.2. To study the effect of spatio‐temporal variation in resource distribution on pollen use and productivity, we identified pollen from spatially explicit nest collections of two generalist sweat bees, Megalopta genalis Meade‐Waldo and M. centralis Friese, from Barro Colorado Island, Panama, a 50‐ha forest dynamics plot during the 2007 dry and early wet seasons. Pollen from nests collected in 1998–1999 without spatial information was also identified.3. Bees used pollen of at least 64 species; many of these occurred in only one collection. The 2007 collections contained pollen of 35 different species, but were dominated by five species, especially Hura crepitans L. and Pseudobombax septenatum (Jacq.) Dugand.4. Temporal availability, but not distance from nest, influenced flower use at a 50‐ha scale.5. Body size was not associated with minimum flight distance as inferred from pollen collections.6. Nest productivity and pollen diversity decreased from the dry to wet seasons, mirroring community‐level availability of floral resources.7. Results suggest that on a scale of 50 ha, bees are choosing certain host plant species regardless of distance from the nest, but adjusting foraging behaviour opportunistically based on the temporal availability of host flowers.
Poro‐acoustoelasticity of fluid‐saturated rocks
Authors: Ba Jing , Carcione José M. , Cao Hong , Yao Fengchang , Du Qizhen 
Published: July 2012

ABSTRACTWe generalize the classical theory of acoustoelasticity to the porous case (one fluid and a solid frame) and finite deformations. A unified treatment of non‐linear acoustoelasticity of finite strains in fluid‐saturated porous rocks is developed on the basis of Biot’s theory. A strain‐energy function, formed with eleven terms, combined with Biot’s kinetic and dissipation energies, yields Lagrange’s equations and consequently the wave equation of the medium. The velocities and dissipation factors of the P‐ and S‐waves are obtained as a function of the 2nd‐ and 3rd‐order elastic constants for hydrostatic and uniaxial loading. The theory yields the limit to the classical theory if the fluid is replaced with a solid with the same properties of the frame. We consider sandstone and obtain results for open‐pore jacketed and closed‐pore jacketed ‘gedanken’ experiments. Finally, we compare the theoretical results with experimental data.
Eating habits and physical activity of adolescents in Katowice – the teenagers’ declarations vs. their parents’ beliefs
Authors: Bąk‐Sosnowska Monika , Skrzypulec‐Plinta Violetta 
Published: July 2012

Aims and objectives.  To analyse eating and physical activity preferences among adolescent school children and to compare the teenagers’ lifestyle declarations with their parents’ beliefs.Background.  Unfavorable behavior in eating habits and physical activity may result in serious dysfunctions and diseases, such as eating disorders and incorrect body mass.Design.  A retrospective cross‐sectional study conducted in 2010–2011.Methods.  The data was collated from 711 pupils and 266 parents. The survey included questions on: breakfast consumption, types of food eaten for breakfast, time of supper, the daily number of meals, the quantity of fruit and vegetables, food products purchased in the school shop, as well as the type and level of physical activity.Results.  In the population of children aged 14–15 years, 10% do not eat 1st breakfast and 15% do not eat 2nd breakfast, 50% eat dairy products for 1st breakfast, 70% have sandwiches for 2nd breakfast, 45% most frequently buy snacks in the school shop, 65% prefer physical activity in the form of team games, and 90% willingly participate in PE classes. The parents’ beliefs differ from their children’s declarations with regard to: breakfast consumption, the number of meals a day, the quantity of fruit, and participation in PE classes.Conclusions.  The lifestyle of the studied adolescents is within the norms recommended for their age group, although there is a tendency to skip breakfast. A positive aspect is the adolescents’ engagement in physical activity. Parents underestimate their children’s level of physical activity and overestimate their daily number of meals.Relevance to clinical practice.  The study confirms the validity of conducting health education, addressed to both children and their parents, with regard to correct eating habits and physical activity, as well as prevention of eating disorders.