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The aim of our study was twofold: to examine (a) whether the link between racial discrimination and adjustment showed age-related changes across early to late adolescence for Chinese-heritage youth and (b) whether the age-related associations of the discrimination–adjustment link differed by gender, nativity, and geographical region. We pooled two independently collected longitudinal data sets in the United States and Canada (N = 498, ages 12–19 at Wave 1) and used time-varying effect modeling to show that discrimination is consistently associated with poorer adjustment across all ages. These associations were stronger at certain ages, but for males and females, first- and second-generation adolescents, and US and Canadian adolescents they differed. There were stronger relations between discrimination and adjustment in early adolescence for males compared to females, in middle adolescence for first-generation compared to second-generation adolescents, and in early adolescence for US adolescents compared to Canadian adolescents. In general, negative implications for adjustment associated with discrimination diminished across the span of adolescence for females, second-generation, and US and Canadian adolescents, but not for males or first-generation adolescents. The results show that the discrimination–adjustment link must be considered with regard to age, gender, nativity, and region, and that attention to discrimination in early adolescence may be especially important.
The role that vitamin D plays in pulmonary function remains uncertain. Epidemiological studies reported mixed findings for serum 25-hydroxyvitamin D (25(OH)D)–pulmonary function association. We conducted the largest cross-sectional meta-analysis of the 25(OH)D–pulmonary function association to date, based on nine European ancestry (EA) cohorts (n 22 838) and five African ancestry (AA) cohorts (n 4290) in the Cohorts for Heart and Aging Research in Genomic Epidemiology Consortium. Data were analysed using linear models by cohort and ancestry. Effect modification by smoking status (current/former/never) was tested. Results were combined using fixed-effects meta-analysis. Mean serum 25(OH)D was 68 (sd 29) nmol/l for EA and 49 (sd 21) nmol/l for AA. For each 1 nmol/l higher 25(OH)D, forced expiratory volume in the 1st second (FEV1) was higher by 1·1 ml in EA (95 % CI 0·9, 1·3; P<0·0001) and 1·8 ml (95 % CI 1·1, 2·5; P<0·0001) in AA (Prace difference=0·06), and forced vital capacity (FVC) was higher by 1·3 ml in EA (95 % CI 1·0, 1·6; P<0·0001) and 1·5 ml (95 % CI 0·8, 2·3; P=0·0001) in AA (Prace difference=0·56). Among EA, the 25(OH)D–FVC association was stronger in smokers: per 1 nmol/l higher 25(OH)D, FVC was higher by 1·7 ml (95 % CI 1·1, 2·3) for current smokers and 1·7 ml (95 % CI 1·2, 2·1) for former smokers, compared with 0·8 ml (95 % CI 0·4, 1·2) for never smokers. In summary, the 25(OH)D associations with FEV1 and FVC were positive in both ancestries. In EA, a stronger association was observed for smokers compared with never smokers, which supports the importance of vitamin D in vulnerable populations.
The development of laser wakefield accelerators (LWFA) over the past several years has led to an interest in very compact sources of X-ray radiation – such as “table-top” free electron lasers. However, the use of conventional undulators using permanent magnets also implies system sizes which are large. In this work, we assess the possibilities for the use of novel mini-undulators in conjunction with a LWFA so that the dimensions of the undulator become comparable with the acceleration distances for LWFA experiments (i.e., centimeters). The use of a prototype undulator using laser machining of permanent magnets for this application is described and the emission characteristics and limitations of such a system are determined. Preliminary electron propagation and X-ray emission measurements are taken with a LWFA electron beam at the University of Michigan.
Good canopy structure is essential for optimal maize (Zea mays L.) production. However, creating appropriate maize canopy structure can be difficult, because the characteristics of individual plants are altered by changes in plant age, density and interactions with neighbouring plants. The objective of the current study was to find a reliable method for building good maize canopy structure by analysing changes in canopy structure, light distribution and grain yield (GY). A modern maize cultivar (ZhengDan958) was planted at 12 densities ranging from 1.5 to 18 plants/m2 at two field locations in Xinjiang, China. At the silking stage (R1), plant and ear height increased with plant density as well as leaf area index (LAI), whereas leaf area per plant decreased logarithmically. The fraction of light intercepted by the plant (F) increased with increasing plant density, but the light extinction coefficient (K) decreased linearly from 0.61 to 0.39. Taking the optimum value of F (95%) as an example, and using measured values of K for each plant density at R1 and the equation from Beer's law, the corresponding (theoretical) LAI for each plant density was calculated and optimum plant density (9.72 plants/m2) obtained by calculating the difference between theoretical LAIs and actual observations. Further analysis showed that plant density ranging from 10.64 to 11.55 plants/m2 yielded a stable GY range. Therefore, taking into account the persistence time for maximum LAI, the plant density required to obtain an ideal GY maize canopy structure should be increased by 10–18% from 9.72 plants/m2.
Introduction: The increased availability and increased utilization of Computed Tomography (CT) imaging as a diagnostic tool has in the past several years led to concerns regarding the unknown and potentially harmful effects of ionizing radiation exposure to patients, as well as the increased cost to the health care system. Multiple education campaigns (e.g. Choosing Wisely) and institution-wide interventions have been implemented in order to limit the use of potentially unnecessary CT imaging. Two specific modalities CT head and CT angiography to rule out pulmonary embolism (CT PE) have been identified as potential targets of these interventions due to their likely overutilization in the clinical ED setting. The objective of this study was to determine the interphysician variability in the ordering rates of CT head and CT PE, and to determine if any correlation existed between CT head and CT PE ordering rates among physicians. Methods: Data was collected on all diagnostic imaging ordered by ED physicians at two very high volume community hospitals during the 4-year period between 2013 and 2016. Analysis was limited to those physicians who worked at least 3 of the 4 years at either site and saw at least 1000 patients per year. The ordering rates for each physician were calculated by dividing the number of the imaging modality ordered over the total number of patients seen. Correlation coefficients (r values) were calculated to determine if a linear correlation existed between increased CT head and increased CT PE ordering rates. Results: The DI ordering data for a total of 44 ED physicians were analyzed. Results show average 4-year ordering rates for CT heads among ED physicians ranging from 4.0% to 13.9%, and CT PE ordering rates ranging from 0.1% - 1.7%. The correlation coefficient between CT head and CT PE ordering rates was positive for all 4 years, with a statistically significant (p<0.05) correlation coefficient of 0.53. Conclusion: There is a wide degree of variability in DI ordering patterns among physicians working within the same clinical environment. Further exploration of this interphysician variability will be helpful in designing strategies to mitigate overutilization of diagnostic imaging.
J. Hou, European Patent Office Munich,
G. Kramer, Chair of Communications Engineering, Technische Universität München,
M. Bloch, School of Electrical and Computer Engineering, Georgia Institute of Technology
Background: Effects of stroke at the cellular and sub-cellular level remain poorly understood by conventional techniques. We use synchrotron-based imaging techniques to study elemental and biochemical changes in the infarct and penumbra after stroke in an experimental model. Methods: Ischemic stroke is induced in mice using the previously validated photothrombotic model. Animals are sacrificed at various time-points after stroke. Fourier transform infrared spectroscopic imaging (FTIRI) is used to gather sub-cellular (<1 µm spatial resolution) imaging data of lipid oxidation and protein aggregation in the areas of interest. X-ray fluorescence (XRF) imaging is used to image the distribution of bio-important elements at the cellular and sub-cellular spatial resolutions. Routine histology and immunohistochemistry are used to co-localize cell-types to areas of interest. Results: Preliminary XRF results indicate significant reduction in the concentration of multiple elements in the infarct, compared to the penumbra, at day 1 post-stroke. Some elements begin to return to normal concentration in the penumbra at day 3. FTIRI data shows that lipid and total protein levels decrease, while aggregate protein levels increase in the penumbra. Conclusions: Multi-modality synchrotron imaging can be used to map elements as well as bio-molecules in a stroke model. A better understanding of these changes can guide therapeutic interventions after stroke.
In order to avoid excess feed consumption during the force-feeding period in foie gras production, a dose-response experiment with seven feed consumption levels (450, 540, 630, 720, 810, 900, 990 g/day per bird) was conducted to evaluate the effects of feed consumption levels on growth performance and carcass composition of male Mule ducks from 91 to 102 days of age. One-day-old Mule ducklings (sterile and artificial hybrid of male Albatre Muscovy duck and female Pekin duck were fed a two-phase commercial diets for ad libitum intake from hatching to 91 days of age, followed by graded feeding levels of a corn diet by force-feeding from 91 to 102 days of age. Fifty-six 91-day-old male Mule ducks with similar BW were randomly assigned to seven treatments, with eight birds per treatment. Birds were housed in individual pens. At 102 days of age, final BW was measured and BW gain and feed conversion ratio of ducks from each treatment were calculated from day 91 to 102, and then all ducks were slaughtered to evaluate the yields of skin with subcutaneous fat, abdominal fat, breast meat (including pectoralis major and pectoralis minor), leg meat (including thigh and drum stick), and liver. Significant differences in BW gain, total liver weight and liver relative weight were observed among the treatments (P<0.001). According to the broken-line regression analysis, the optimal feed consumption levels of male Mule ducks from 91 to 102 days of age for maximum BW gain, total liver weight and liver relative weight were 217, 227 and 216 g feed/kg BW0.75·per day, respectively.
The transient, growth and nonlinear saturation stages in the evolution of the electrostatic two-stream instabilities as described by the Vlasov–Poisson system are reconsidered by numerically following the evolution of the total wave energy of the plasma oscillations excited from (numerical) noise. Except for peculiarities related to the necessarily finite (even though very small) magnitude of the perturbations in the numerical simulation, the existence and initial growth properties of the instabilities from the numerical results are found to be consistent with those from linear normal mode analysis and the Penrose criteria. However, contradictory to the traditional point of view, the growth of instability before saturation is not always linear. The initial stage of the growth can exhibit fine structures that can be attributed to the harmonics of the excited plasma oscillations, whose wavelengths are determined by the system size and the numerical noise. As expected, saturation of the unstable oscillations is due to electron trapping when they reach sufficiently large amplitudes.
In this work, we present a set of M-type star candidates selected from the LAMOST DR1. A discrimination method with the spectral index diagram is used to separate M giants and M dwarfs. Then, we have successfully assembled a set of M giants templates from M0 to M6, using the spectra identified from the LAMOST spectral database. After combining the M dwarf templates in Zhong et al. (2015a) and the new created M giant templates, we use the M-type spectral library to perform the template-fit method to classify and identify M-type stars in the LAMOST DR1. A catalog of M-type star candidates including 8639 M giants and 101690 M dwarfs/subdwarfs is provided. As an additional results, we also present other fundamental parameters like proper motion, photometry, radial velocity and spectroscopic distance.
The unique properties of silicon oxide materials, no matter intrinsic or doped, utilized in thin film solar cells (TFSCs) in the area of photovoltaic (PV) are making TFSCs one of the most attractive photovoltaic technologies for the development of high-performing electricity production units to be integrated in everyday life. In comparison to other silicon materials, the particular diphasic structure of silicon oxide materials, in which hydrogenated microcrystalline silicon (μc-Si:H) crystallites are surrounded by an oxygen-rich hydrogenated amorphous silicon (a-Si:H) phase, causes them present excellent photoelectrical material properties, such as a low-parasitic absorption in the broadband spectral range, independent controllability of longitudinal and lateral conductivity, refractive indices (3.5-2.0), band gap (2.0-2.6 eV) and conductivity tenability (with orders of 1-10-9 S/cm) with oxygen doping, and so on. Various types of silicon oxide materials, including intrinsic, p- or n- type, further applied in TFSCs have also played significant roles in improving the efficiency of various types of single-, dual-, and triple-junction thin-film solar cells from both the optical and electrical points of view. In this paper, we present our latest progress in studying the performance improvement role of intrinsic or doped silicon oxide materials in pin-type a-Si:H, a-SiGe:H, and μc-Si:H single-junction solar cells. By effectively tuning the band gap values of intrinsic a-SiOx:H materials with oxygen doping and adopting the layers with a suitable band gap (1.86 eV) as the P/I buffer layers of a-Si:H solar cells fabricated on metal organic chemical vapor deposition (MOCVD) boron-doped zinc oxide (ZnO:B) substrates, a significant Voc increases up to 909 mV and an excellent external quantum efficiency (EQE) response of 75% at the 400 nm typical wavelength can be achieved by matching the band gap discontinuity between the p-type nc-SiOx:H window and a-Si:H intrinsic layers. The serious leakage current characteristics of pin-type narrow-gap (Eg<1.5 eV) a-SiGe:H single-junction solar cells can also be finely tuned by integrating an n-type μc-SiOx:H layer with a small oxygen content in addition to improving the long-wavelength response, an effective approach gives rise to the highest FF of 70.62% for pin-type a-SiGe:H single-junction solar cells with an average band gap of 1.48 eV. In addition, our studies proved that the application of p-type μc-SiOx:H window layers in μc-Si:H single-junction solar cells can effectively improve the short-wavelength light coupling by suppressing the parasitic absorption and promoting the anti-reflectivity with a graded refractive index profile. On the basis of the optimum single-junction solar cells with omnipotent silicon oxide materials, an initial efficiency of 16.07% has been achieved for pin-type a-Si:H/a-SiGe:H/μc-Si:H triple-junction solar cells with an active area of 0.25 cm2. The omnipotent properties of silicon oxide layers in TFSCs, including effective optical coupling and trapping, suitability in compensating for the band gap discontinuity, the shunt-quenching capacity, and so on, make them likely to be extended to other types of solar cells such as polycrystalline chalcopyrite Cu(In,Ga)Se2 (CIGS) and perovskite-sensitized solar cells, opening up new opportunities for acquiring solar cells with higher performance.
Rhynchophorus ferrugineus (Coleoptera, Curculionidae) is the most destructive pest of palm trees worldwide containing it invasive areas, such as the southern part of China. It is always emphasized to develop integrated pest management based on biological agents, but their success is not very exciting. Presently, the immune defenses of this pest against biological agents attract scarce attention. It is still unclear whether immune priming also generally occurs in insect pests and in response to different pathogens. Our results indicated that previous challenge of bacteria pathogen enhanced the magnitude of phenoloxidase activity and antibacterial activity in R. ferrugineus larvae against the secondary infection. Furthermore, trans-generational immune priming was also determined in this pest, and only challenged R. ferrugineus mothers transferred the immune protection to their offspring which suggested males and females of this pest might have evolved different strategies on the investment of delivering immune protection to their offspring. Importantly, our data provide the evidence to suggest that different kinds of biological control agents might be used alternatively or in combination to fight against R. ferrugineus because of the existence of immune priming with low species-specific level. On the other hand, for this invasive pest, the immune priming may also facilitate its adaptation and dispersal in the new regions.
Stoichiometric 4H-SrMnO3.0 nanoparticles have been successfully synthesized for the first time from thermal decomposition of a new heterometallic precursor [SrMn(edta)(H2O)5]·3/2H2O. From this precursor, highly homogeneous 4H-SrMnO3.0 nanoparticles with average particle size 70 nm are obtained. Local structural information, provided by atomically-resolved microscopy techniques, shows that 4H-SrMnO3.0 nanoparticles exhibit the same general structural features than the bulk material, although structural disorder, due to edge-dislocations, is observed. The nanometric size of particles enables a topotactic reduction process at low temperature stabilizing a metastable 4H-SrMnO2.82 phase. The oxygen deficiency is accommodated through extra cubic layers breaking the …hchc… 4H-sequence. These defect areas are Mn3+ rich as evidenced by high energy resolution EELS data. Magnetic characterization of nano-4H-SrMnO3-δ shows significant variations with respect to the bulk material.
Magnetite nanoparticles were produced by the chemical co-precipitation of iron sulfates at alkaline conditions and were tested as a Cr(VI) adsorbent from water. Batch adsorption experiments showed a high removal efficiency, which is maximized at pH values below 6. This behavior was also verified in a continuous flow reactor, where nanoparticles were in contact with the polluted water. In particular, using a particle concentration of 1 g/L in water containing 100 μg Cr(VI)/L, a contact time of at least 2 h was required to achieve complete removal of Cr(VI). The recovery of nanoparticles after their use was accomplished using their magnetic nature. Application of an external magnetic field at the sides of the tube in which the suspension was flowing was sufficient to completely collect the nanoparticles in the outflow of the contact reactor, thus, providing water free of Cr(VI) and a solid phase.
An experiment was conducted to investigate the effect of arginine on feed intake regulation. One hundred and twenty six 1-day-old male White Pekin ducks (Anas platyrhynchos domestica) were randomly were allotted to one of two dietary treatments. The birds were fed diets containing 0.71% (deficient) or 1.27% (sufficient) arginine for 3 weeks. At 21 days of age, feed intake was determined and hypothalamic protein profiles were analyzed using isobaric tags for relative and absolute quantification technique. The birds fed with arginine-deficient diet had a lower final live BW and cumulative feed intake (P<0.01) than those fed with arginine-sufficient diet. A total of 16 proteins were identified in the hypothalamus with >1.5-fold expressional changes between arginine-deficient and -sufficient dietary treatments. Nine of these proteins were upregulated and seven of them were downregulated. The identified proteins could be regrouped into six categories: protein processing, carbohydrate metabolism and energy production, transporter, cytoskeleton, immunity and neuronal development. Dietary arginine deficiency decreased expression of proteins involved in energy production (glycine amidinotransferase, aldolase B fructose-bisphosphate, aconitase, transaldolase, 6-phosphofructokinase type C-like) and oxygen transportation (haemoglobin subunit α expression). The proteomic alterations described here provides valuable insights into the interactions of arginine with appetite.