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This is a copy of the slides presented at the meeting but not formally written up for the volume.
Recently, the telecommunication market experiences an explosion in the subscribers of emergent high-debit services which require bandwidth that exceeds the one provided by actual copper based access networks . To cope with these demands and keep competitive, great efforts have been done to develop access networks based on optical technology, such as passive all-optical networks due to their intrinsic low cost . Sol-gel processing is suitable for the development of organic-inorganic hybrid (OIH) materials for the production of functional integrated optic (IO) devices in a cost effective way. Urea cross-linked OIH show acceptable transparency, mechanical flexibility and thermal stability [3-6]. The control over the refractive index is achieved by zirconium (IV) n-propoxide (ZPO) doping stabilized with methacrylic acid (MA) [3-5]. The combination in a single material of urea cross-linked OIH and ZPO allowed the preparation of UV written low losses planar waveguides  and low rugosity diffraction grating [4,5]. It has been demonstrated that MA acts not only as ZPO stabilizer but impacts directly on the photopolimerization properties as it contains a photopolymerizable group making the OIH easily UV patterned without photoinitiator . Moreover, it also impacts on the OHIs local structure as it forms a complex with ZPO, that originate ordered clusters dispersed within the OIH host [4,5]. Besides the potential of this OIH as IO components, the hybrid hosts are room-temperature efficient white light emitters lacking metal activator ions, presenting quantum yields as higher as 20 % . In this work, a series of OIH, so called di-ureasils, formed of a siliceous skeleton to which oligopolyether chains of different lengths are covalently grafted by means of urea bridges and modified by ZPO and MA will be prepared and characterized by X-ray and small angle X-ray diffractions, Raman, infrared, atomic force and photoluminescence spectroscopies. The use of the proposed OIH in the development of IO functionalities such as optical filters will be evaluated based on waveguide numerical simulation methods (beam propagation method). Waveguides will be written and characterized using the OIH aforementioned. The recording of a Bragg grating in the waveguides allow the implementation of a wavelength discrimination device with applications on optical filtering. The relevant properties of the devices, such as spectral rejection and insertion losses will be characterized.  S-J Park et al. Journal of Lightwave Tech. 22, 2004.  D.J. Shin et al., Journal of Lightwave Tech. 23, 2005.  C. Molina et al., J. Mater. Chem. 15, 3937, 2005.  R.A. Sá Ferreira et al., Proceedings of the International Conference on Telecomunications, 2006.  P.S. André et al. Proceedings ICTON, 1, We.C1.6, 223, 2006.  a) L.D. Carlos et al., Adv. Func. Mater. 11, 111, 2001; b) J. Chem. Phys. B. 108, 14924, 2004. Siemens SA and FCT (POCTI/CTM/59075/2004) is gratefully acknowledged.
Chondrules contain ferromagnetic minerals that may retain a record of the magnetic field environments in which they cooled. Paleomagnetic experiments on separated chondrules can potentially reveal the presence of remanent magnetization from the time of chondrule formation. The existence of such a magnetization places quantitative bounds on the frequency of interchondrule collisions, while the intensity of magnetization may be used to infer the strength of nebular magnetic fields and thereby constrain the mechanism of chondrule formation. Recent advances in laboratory instrumentation and techniques have permitted the isolation of nebular remanent magnetization in chondrules, providing the potential basis to probe the formation environments of chondrules from a range of chondrite classes.
An experiment was conducted to investigate the effect of acetate treatment on lipid metabolism in rabbits. New Zealand Rabbits (30 days, n=80) randomly received a subcutaneous injection (2 ml/injection) of 0, 0.5, 1.0 or 2.0 g/kg per day body mass acetate (dissolved in saline) for 4 days. Our results showed that acetate induced a dose-dependent decrease in shoulder adipose (P<0.05). Although acetate injection did not alter the plasma leptin and glucose concentration (P>0.05), acetate treatment significantly decreased the plasma adiponectin, insulin and triglyceride concentrations (P<0.05). In adipose, acetate injection significantly up-regulated the gene expression of peroxisome proliferator-activated receptor gamma (PPARγ), CCAAT/enhancer-binding protein α (C/EBPα), differentiation-dependent factor 1 (ADD1), adipocyte protein 2 (aP2), carnitine palmitoyltransferase 1 (CPT1), CPT2, hormone-sensitive lipase (HSL), G protein-coupled receptor (GPR41), GPR43, adenosine monophosphate-activated protein kinase α1 (AMPKα1), adiponectin receptor (AdipoR1), AdipoR2 and leptin receptor. In addition, acetate treatment significantly increased the protein levels of phosphorylated AMPKα, extracellular signaling-regulated kinases 1 and 2 (ERK1/2), p38 mitogen-activated protein kinase (P38 MAPK) and c-jun amino-terminal kinase (JNK). In conclusion, acetate up-regulated the adipocyte-specific transcription factors (PPARγ, C/EBPα, aP2 and ADD1), which were associated with the activated GPR41/43 and MAPKs signaling. Meanwhile, acetate decreased fat content via the upregulation of the steatolysis-related factors (HSL, CPT1 and CPT2), and AMPK signaling may be involved in the process.
The brain-derived neurotrophic factor (BDNF) Val66Met polymorphism Met allele exacerbates amyloid (Aβ) related decline in episodic memory (EM) and hippocampal volume (HV) over 36–54 months in preclinical Alzheimer's disease (AD). However, the extent to which Aβ+ and BDNF Val66Met is related to circulating markers of BDNF (e.g. serum) is unknown. We aimed to determine the effect of Aβ and the BDNF Val66Met polymorphism on levels of serum mBDNF, EM, and HV at baseline and over 18-months.
Non-demented older adults (n = 446) underwent Aβ neuroimaging and BDNF Val66Met genotyping. EM and HV were assessed at baseline and 18 months later. Fasted blood samples were obtained from each participant at baseline and at 18-month follow-up. Aβ PET neuroimaging was used to classify participants as Aβ– or Aβ+.
At baseline, Aβ+ adults showed worse EM impairment and lower serum mBDNF levels relative to Aβ- adults. BDNF Val66Met polymorphism did not affect serum mBDNF, EM, or HV at baseline. When considered over 18-months, compared to Aβ– Val homozygotes, Aβ+ Val homozygotes showed significant decline in EM and HV but not serum mBDNF. Similarly, compared to Aβ+ Val homozygotes, Aβ+ Met carriers showed significant decline in EM and HV over 18-months but showed no change in serum mBDNF.
While allelic variation in BDNF Val66Met may influence Aβ+ related neurodegeneration and memory loss over the short term, this is not related to serum mBDNF. Longer follow-up intervals may be required to further determine any relationships between serum mBDNF, EM, and HV in preclinical AD.
Short-chain fatty acids (SCFAs) play a regulatory role in various physiological processes in mammals and act as endogenous ligands for the G protein-coupled receptors (GPR) 41 and 43. The role of GPR41 and GPR43 in mediating SCFA signaling in the rabbit remains unclear. The present study was to investigate the sequence of the GPR41 and GPR43 messenger RNA (mRNA) and their expression pattern in different tissues and developmental stages in New Zealand rabbit. Comparison of genomic sequences in GenBank using the Basic Local Alignment Search Tool program suggested that the New Zealand rabbit GPR41 mRNA has high similarities with the human (84%), bovine (84%) and Capra hircus (84%) genes. Similarly, GPR43 mRNA has high similarity with the rat (84%) and mouse (84%) genes. Real-time PCR results indicated that GPR41 and GPR43 mRNA were expressed throughout rabbit’s whole development and were expressed in several tissues. G protein-coupled receptor 41 and GPR43 mRNA were most highly expressed in pancreas (P<0.05) and s.c. adipose tissue (P<0.05), respectively. The expression levels of GPR41 mRNA was down-regulated in duodenum, cecum (P<0.05) and pancreas and up-regulated in jejunum, ileum, adipose tissue and spleen during growth. G protein-coupled receptor 43GPR43 mRNA was highly expressed in the duodenum, jejunum, ileum, colon, cecum and lung at 15th day (P<0.05), whereas the expression levels in the pancreas and spleen increased later after birth, with the highest expression at 60th day (P<0.05).
Studies of schizophrenia at drug-naive state and on antipsychotic medication have reported a number of regions of gray-matter (GM) abnormalities but the reports have been inconsistent. The aim of this study was to conduct multimodal meta-analysis to compare the cross-sectional voxel-based morphometry studies of brain GM in antipsychotic-naive first-episode schizophrenia (AN-FES) and those with antipsychotic treatment within 1 year (AT-FES) to determine the similarities and differences in these groups. We conducted two separate meta-analyses containing 24 studies with a sample size of 801 patients and 957 healthy controls. A multimodal meta-analysis method was used to compare the findings between AN-FES and AT-FES. Meta-regression analyses were done to determine the influence of different variables including age, duration of illness, and positive and negative symptom scores. Finally, jack-knife analyses were done to test the robustness of the results. AN-FES and AT-FES showed common patterns of GM abnormalities in frontal (gyrus rectus), superior temporal, left hippocampal and insular cortex. GM in the left supramarginal gyrus and left middle temporal gyrus were found to be increased in AN-FES but decreased in AT-FES, whereas left median cingulate/paracingulate gyri and right hippocampus GM was decreased in AN-FES but increased in AT-FES. Findings suggest that both AN-FES and AT-FES share frontal, temporal and insular regions as common anatomical regions to be affected indicating these to be the primary regions of GM abnormalities in both groups.
Association mapping based on linkage disequilibrium is an effective approach for dissecting the inheritance of complex multi-gene traits. In the present study, association mapping was performed for yield traits based on 172 popular Upland cotton (Gossypium hirsutum L.) cultivars in China and 331 polymorphic simple sequence repeat (SSR) markers. The gene diversity index of 331 markers ranged from 0·0387 to 0·7799 with an average of 0·4002, and the polymorphism information content ranged from 0·0379 to 0·7473 with an average of 0·3375. A total of 93 significantly associated markers for seven yield traits were identified across more than one environment, among which 11 were for seed cotton yield, 12 for lint yield, 11 for boll number per plant, 13 for boll weight, 21 for lint percentage, 14 for lint index and 11 for seed index. The corresponding ranges in phenotypic variation explained by markers across four environments for these seven traits were 1·75–10·49, 1·75–9·34, 2·84–11·80, 2·59–9·89, 2·38–13·97, 2·73–14·82 and 2·50–11·88%, respectively. Some of the yield-associated markers detected were found to be linked to or associated with the same traits identified in previous studies. Furthermore, elite alleles for yield traits were also mined. The present study can provide useful information for further understanding the genetic basis of yield traits, and facilitate high-yield breeding by molecular design in Upland cotton.
This paper examines the carbon isotopes (13C, 14C) of soil organic carbon (SOC) and soil CO2 from an evergreen broadleaf forest in southern China during the rainy season. The distribution of SOC δ13C, and SOC content with depth, exhibits a regular decomposition of SOC compartments with different turnover rates. Labile carbon is the main component in the topsoil (0–12 cm) and has a turnover rate between 0.1 and 0.01 yr–1. In the middle section (12–35 cm), SOC was mainly comprised of mediate carbon with turnover rates ranging between 0.01 and 0.025. Below 35 cm depth (underlayer section), the SOC turnover rate is slower than 0.001 yr–1, indicating that passive carbon is the main component of SOC in this section. The total production of humus-derived CO2 is 123.84 g C m–2 yr–1, from which 88% originated in the topsoil. The middle and underlayer sections contribute only 10% and 2% to the total humus-derived CO2 production, respectively. Soil CO2 δ13C varies from –24.7‰ to –24.0‰, showing a slight isotopic depth gradient. Similar to soil CO2 δ13C, Δ14C values, which range from 100.0‰ to 107.2‰, are obviously higher than that of atmospheric CO2 (60–70‰) and SOC in the middle and underlayer section, suggesting that soil CO2 in the profile most likely originates mainly from SOC decomposition in the topsoil. A model of soil CO2 Δ14C indicates that the humus-derived CO2 from the topsoil contributes about 65–78% to soil CO2 in each soil gas sampling layer. In addition, the humus-derived CO2 contributes ∼81% on average to total soil CO2 in the profile, in good agreement with the field observation. The distribution and origin of soil 14CO2 imply that soil CO2 will be an important source of atmospheric 14CO2 well into the future.
The historical evolution of an ancient forest that developed at Gaoyao, south China, can be divided into 4 stages of radiocarbon intervals (1.1–1.5, 2.0–3.5, 3.6–4.0, and 4.3–4.9 ka) in which the last 3 stages all developed in a wetland and formed humic layers of 2.0, 0.5, and 0.7 m depth, respectively. The humic layers were interrupted by 2 white-gray silty clay layers that most likely formed during climate fluctuations. Four drought events were identified during the evolution of the ancient forest, occurring around 4.3, 3.6, 2.0, and 1.1 ka, respectively, with durations of ∼1000 14C yr. These events are consistent with other records both in low- and high-latitude areas, in particular with the little ice ages occurring since the mid-Holocene. Precipitation likely increased from 5.0 to 3.6 ka in south China, then decreased, which is probably the main cause for the development as well as the demise of the ancient forest.
While radiocarbon is widely applied in dating ancient samples, recent studies reveal that 14C concentrations in modern samples can also yield precise ages due to the atmospheric testing of thermonuclear devices between 1950 and 1963. 14C concentrations in both enamel and organic matter of 13 teeth from 2 areas in China were examined to evaluate and improve this method of forensic investigation. Choosing enamel near the cervix of the tooth can reduce the error caused by the difference between the sample formation time and whole enamel formation time because tooth enamel formations take a long time to complete. A proper regional data set will be helpful to get an accurate result when calculating the age of the sample (T1) by the CALIBomb program. By subtracting the enamel formation time (t), the birth date of an individual (T2) can be confirmed by enamel F14C from 2 teeth formed at different ages. Calculated enamel formation dates by 14C concentration are basically consistent with corresponding actual values, with a mean error of 1.9 yr for all results and 0.2 yr for the samples formed after AD 1960. This method is more effective for dating samples completed after AD 1960. We also found that 14C concentrations in organic matter of tooth roots are much lower than atmospheric concentrations in root formation years, suggesting that the organic material keeps turning over even after tooth formation is complete. This might be a potential tool for identification of death age to extract a proper component for 14C dating. We also observed that δ13C values between hydroxyapatite and organic matter indicate that isotopic fractionation during the biomineralization is 8–9%‰ more positive in mineral fractions than in organic matter.
We investigate some basic properties of Damped Lyman alpha systems based on the Semi-Analytical model of disk galaxy formation theory. We derive the DLA metallicity, column density, number density, gas content and cosmic star formation rate by assuming that disks form at the center of dark halos, and the modelled DLAs are selected by Monte Carlo simulation according to the distributions of halo properties. We find that DLA hosts are dominated by small galaxies and biased to extended galaxies. In terms of model results, DLAs could naturally arise in a ACDM universe from radiatively cooled gas in dark matter halos. However, model predicts a reverse correlation between metallicity and the column density when compared with observations, regardless of the proposed observational bias. We argue that this could be resulted from the model limitations, or the inadequacy of Schmidt-type star formation mode at high redshift, or/and the diversities of DLA populations.
The δ Scuti stars are pulsating variables located in the lower part of the Cepheid instability strip with spectral types from A2 to F0 on the main sequence, and from A3 to F5 at luminosity class III. These variables show short periods (< 0.3day) and luminosity amplitudes ranging from a few thousandths of a magnitude to several tenths. Over the last few years, significant progress has been made in the detection of pulsating modes in the framework of the multisite campaigns, e.g. STACC (Frandsen et al. 1996), DSN (Breger et al. 1998), STEPHI (Michel et al. 2000). For the 1998 STEPHI IX photometry campaign, the δ Scuti star V534 Tau of the Pleiades cluster (see Table 1) was monitored during a three week, three continent run. Preliminary results are reported here.
Guided by simulations using SIMION 8.1, a series of modifications were made to an experimental version of an Isobar Separator for Anions (ISA). The resulting improved version of the ISA provides a means of re-energizing the ions after they are cooled by gas collisions as they pass through the gas-filled radiofrequency quadrupoles (RFQ), and also provides higher transmission efficiencies. Reinvestigation of the separation of CaF3− and KF3− with this refined apparatus resulted in a better balance between isobar suppression and analyte transmission. KF3− was attenuated at eV energies by 4 orders of magnitude while 40% transmission of CaF3− was retained, for a 20keV CaF3− beam of Φ2mm and ±12mr. These results advance the possibility of an efficient small ISA-AMS system for both cosmogenic and medical applications of 41Ca.
The Asian corn borer, Ostrinia furnacalis enters diapause as fully grown larvae. Owing to geographical variation in photoperiodic control of diapause, the subtropical strain from Hefei city (HF) enters diapause in response to short daylengths, whereas the tropical strain from Ledong county (LD) exhibits almost no diapause under the same conditions. The two strains were used in crosses to study the inheritance of diapause. The HF strain showed a typical long-day response with a critical daylength of approximately14.97 h at 22 °C, 14.60 h at 25 °C and 13.68 h at 28 °C. The LD strain showed weak photoperiodic responses at 22 and 25 °C; and the F1 progeny also showed a long-day response with significantly shorter critical daylength compared with the HF strain. However, the LD × HF (F × M) crosses had significantly longer critical daylengths than HF × LD crosses, indicating a sexual bias in the inheritance of diapause induction, with the male parent having more influence on the F1 progeny. The critical daylength in a backcross to HF was significantly longer than a backcross to LD. Whether the inheritance of diapause fits an additive hypothesis or not depended on photoperiod, with results from different photoperiods showing additive inheritance or incomplete dominance of either diapause or non-diapause. Unlike diapause induction, the duration of diapause for reciprocal crosses was equally influenced by each parent, suggesting that diapause incidence and maintenance are controlled by separate systems in O. furnacalis.
We carried out an extensive photometric and spectroscopic investigation of the SPB binary, HD 25558 (see Fig. 1 for the time and geographic distribution of the observations). The ~2000 spectra obtained at 13 observatories during 5 observing seasons, the ground-based multi-colour light curves and the photometric data from the MOST satellite revealed that this object is a double-lined spectroscopic binary with a very long orbital period of about 9 years. We determined the physical parameters of the components, and have found that both lie within the SPB instability strip. Accordingly, both components show line-profile variations consistent with stellar pulsations. Altogether, 11 independent frequencies and one harmonic frequency were identified in the data. The observational data do not allow the inference of a reliable orbital solution, thus, disentangling cannot be performed on the spectra. Since the lines of the two components are never completely separated, the analysis is very complicated. Nevertheless, pixel-by-pixel variability analysis of the cross-correlated line profiles was successful, and we were able to attribute all the frequencies to the primary or secondary component. Spectroscopic and photometric mode-identification was also performed for several of these frequencies of both binary components. The spectroscopic mode-identification results suggest that the inclination and rotation of the two components are rather different. While the primary is a slow rotator with ~6 d rotation period, seen at ~60° inclination, the secondary rotates fast with ~1.2 d rotation period, and is seen at ~20° inclination. Our spectropolarimetric measurements revealed that the secondary component has a magnetic field with at least a few hundred Gauss strength, while no magnetic field was detected in the primary.
The detailed analysis and results of this study will be published elsewhere.
Gattini and CSTAR have been installed at Dome A, Antarctica, which provide time-series photometric data for a large number of pulsating variable stars. We present the study for several variable stars with the data collected with the two facilities in 2009 to demonstrate the scientific potential of observations from Dome A for asteroseismology.
Turbulent particle transport is investigated with a quasilinear theory that is motivated by the boron impurity transport experiments in the Alcator C-Mod. Eigenvalue problems for sets of reduced fluid equations for multi-component plasmas are solved for the self-consistent fluctuating field vectors composed of the electric potential φ, the main ion density δni, the impurity density δnz and the ion temperature fluctuation δTi. For Alcator C-Mod parameters, we investigate two drift wave models: (1) the density-gradient-driven impurity drift wave and (2) the ion-temperature-gradient-driven ion temperature gradient (ITG) mode. Analytic and numerical results for particle transport coefficients are derived and compared with the transport data and the neoclassical theory. We explore the ability of the model to explain impurity density profiles in three confinement regimes: H-mode, I-mode and internal transport barrier (ITB) regime in C-Mod. Related experiments reported on the Large Helical Device are briefly discussed.