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Observation of the ion source generated background has been an area of focus during our routine analytical work. It is noted that the results of very-low-ratio samples are dependent upon the particular procedures for measurement using the present-day Cs+ sputter ion sources. When measured without excessive Cs+ fluxes and without interleafing with other higher-ratio samples and references, the accelerator mass spectrometry (AMS) sensitivity can be somewhat improved. In some cases, it appears possible to assess old radiocarbon (14C) samples to beyond the long-standing 60 kyr limit. A number of observational studies are made for the sole purpose of minimizing the final contamination to the rare isotopes that is generated within the ion source.
England has recently started a new paediatric influenza vaccine programme using a live-attenuated influenza vaccine (LAIV). There is uncertainty over how well the vaccine protects against more severe end-points. A test-negative case–control study was used to estimate vaccine effectiveness (VE) in vaccine-eligible children aged 2–16 years of age in preventing laboratory-confirmed influenza hospitalisation in England in the 2015–2016 season using a national sentinel laboratory surveillance system. Logistic regression was used to estimate the VE with adjustment for sex, risk-group, age group, region, ethnicity, deprivation and month of sample collection. A total of 977 individuals were included in the study (348 cases and 629 controls). The overall adjusted VE for all study ages and vaccine types was 33.4% (95% confidence interval (CI) 2.3–54.6) after adjusting for age group, sex, index of multiple deprivation, ethnicity, region, sample month and risk group. Risk group was shown to be an important confounder. The adjusted VE for all influenza types for the live-attenuated vaccine was 41.9% (95% CI 7.3–63.6) and 28.8% (95% CI −31.1 to 61.3) for the inactivated vaccine. The study provides evidence of the effectiveness of influenza vaccination in preventing hospitalisation due to laboratory-confirmed influenza in children in 2015–2016 and continues to support the rollout of the LAIV childhood programme.
An algorithm for Global Navigation Satellite System satellite atomic clock integrity monitoring based on an extended measurement model is proposed. A detection statistic achieved by parity transformation is used to detect clock anomalies, and the concept of the optimal accumulation number, with a method to find it, is provided. Numerical simulations are adopted to verify the validity of detecting two typical anomalies.
A layer of silver nanoparticles created by thermal annealing of evaporated silver films can increase the photocurrents in silicon-on-insulator (SOI) devices by fivefold or more, but significant enhancements have been restricted to wavelengths greater than 800 nm. Here we report a significant enhancement of photoconductance at shorter wavelengths (500-750 nm) by using a monolayer of silver nanoparticles transferred from a colloidal suspension. Photocurrents on SOI increased in the 500-750 nm spectral range with the addition of silver nanoparticles, with enhancements more than two times; enhancements at longer wavelengths were small, in contrast to results with annealed silver films. We prepared similar colloidal silver nanoparticle monolayers layers on nanocrystalline silicon solar cells with conducting oxide top layers. There is an overall decrease in the quantum efficiency of these cells with the deposition of silver nanoparticles. We attribute these effects to the substantial substrate-mediated changes in the localized surface plasmon resonance frequencies of the differing nanoparticle configurations.
Music or other background sounds are often played in barns as environmental enrichment for animals on farms or to mask sudden disruptive noises. Previous studies looking at the effects of this practice on non-human animal well-being and productivity have found contradictory results. However, there is still a lack of discussion on whether piglets have the ability to distinguish different types of music. In this study, we exposed piglets to different music conditions to investigate whether the piglets preferred certain music types, in which case those types would have the potential to be used as environmental enrichment. In total, 30 piglets were tested for music type preference to determine whether growing pigs respond differently to different types of music. We used music from two families of instruments (S: string, W: wind) and with two tempos (S: slow, 65 beats/min (bpm); F: fast, 200 bpm), providing four music-type combinations (SS: string-slow; SF: string-fast; WS: wind-slow; WF: wind-fast). The piglets were given a choice between two chambers, one with no music and the other with one of the four types of music, and their behaviour was observed. The results showed that SS and WF music significantly increased residence time (P<0.01) compared with the other music conditions. Compared with the control group (with no music), the different music conditions led to different behavioural responses, where SS music significantly increased lying (P<0.01) and exploration behaviour (P<0.01); SF music significantly increased tail-wagging behaviour (P<0.01); WS music significantly increased exploration (P<0.01); and WF music significantly increased walking, lying, standing and exploration (all P<0.01). The results also showed that musical instruments and tempo had little effect on most of the behaviours. Fast-tempo music significantly increased walking (P=0.02), standing (P<0.01) and tail wagging (P=0.04) compared with slow-tempo music. In conclusion, the results of this experiment show that piglets are more sensitive to tempo than to musical instruments in their response to musical stimulation and seem to prefer SS and WF music to the other two types. The results also suggest a need for further research on the effect of music types on animals.
Radio frequency identification (RFID) technology offers a real-time solution to monitor behavioral responses of individual animals to various stimuli, which provides crucial implications on farm management and animal well-being. The objectives of this study were to (1) develop and describe an ultra-high frequency radio frequency identification (UHF-RFID) system for continuously monitoring feeding and drinking behaviors of individual broilers in group settings; and (2) validate the performance of the UHF-RFID system against video analysis in determining the instantaneous bird number (IBN) and time spent (TS) at feeder and drinker. The UHF-RFID system consisted of cable-tie tags, antennas, a reader and a data acquisition (DAQ) system. The antennas generated electromagnetic fields where tags were detected and registered by the DAQ system. Electromagnetic fields of the antennas were modified to cover areas of concern (i.e. tube feeders and nipple drinkers) through a series of system evaluations and customizations including tag sensitivity test, power adjustment, radio wave shielding, and assessment of interference by add-ons (e.g. plastic wraps for protecting antennas and an empty carton box for zoning out broilers) and feed/feeder. System validation was performed in two experimental rooms, each with 60 tagged broilers. The results showed that the max reading distances of tags with an identical manufacturer’s specification were markedly different, indicating large variations in sensitivity among the tags. Desired electromagnetic fields could be achieved by adjusting the power supplied to antennas and by partially shielding antennas with customized stainless steel sheets. The protection materials and fully loaded feeder had little effect on electromagnetic fields of the antennas. The accuracies of the UHF-RFID system for determining IBN and TS were, respectively, 92.5±4.2% and 99.0±1.2% by the feeder antennas and 94.7±4.2% and 93.7±6.9% by the drinker antennas. It is concluded that the UHF-RIFD system can accurately detect and record feeding and drinking behaviors of individual broilers in group settings and thus is a useful tool for investigating impacts of resource allocations and management practices on these behaviors.
Heading date (HD) and flowering date (FD) are critical for yield potential and stability, so understanding their genetic foundation is of great significance in wheat breeding. Three related recombinant inbred line populations with a common female parent were developed to identify quantitative trait loci (QTL) for HD and FD in four environments. In total, 25 putative additive QTL and 20 pairwise epistatic effect QTL were detected in four environments. The additive QTL were distributed across 17 wheat chromosomes. Of these, QHd-1A, QHd-1D, QHd-2B, QHd-3B, QHd-4A, QHd-4B and QHd-6D were major and stable QTL for HD. QFd-1A, QFd-2B, QFd-4A and QFd-4B were major and stable QTL for FD. In addition, an epistatic interaction test showed that epistasis played important roles in controlling wheat HD and FD. Genetic relationships between HD/FD and five yield-related traits (YRTs) were characterized and ten QTL clusters (C1–C10) simultaneously controlling YRTs and HD/FD were identified. The present work laid a genetic foundation for improving yield potential in wheat molecular breeding programmes.
Although application of organic fertilizers has become a recommended way for developing sustainable agriculture, it is still unclear whether above-ground and below-ground crops have similar responses to chemical fertilizers (CF) and organic manure (OM) under the same farming conditions. The current study investigated soil quality and crop yield response to fertilization of a double-cropping system with rapeseed (above-ground) and sweet potato (below-ground) in an infertile red soil for 2 years (2014–16). Three fertilizer treatments were compared, including CF, OM and organic manure plus chemical fertilizer (MCF). Organic fertilizers (OM and MCF) increased the yield of both above- and below-ground crops and improved soil biochemical properties significantly. The current study also found that soil-chemical properties were the most important and direct factors in increasing crop yields. Also, crop yield was affected indirectly by soil-biological properties, because no significant effects of soil-biological activities on yield were detected after controlling the positive effects of soil-chemical properties. Since organic fertilizers could not only increase crop yield, but also improve soil nutrients and microbial activities efficiently and continuously, OM application is a reliable agricultural practice for both above- and below-ground crops in the red soils of China.
Light colors may affect poultry behaviors, well-being and performance. However, preferences of layer pullets for light colors are not fully understood. This study was conducted to investigate the pullet preferences for four light-emitting diode colors, including white, red, green and blue, in a lighting preference test system. The system contained four identical compartments each provided with a respective light color. The pullets were able to move freely between the adjacent compartments. A total of three groups of 20 Chinese domestic Jingfen layer pullets (54 to 82 days of age) were used for the test. Pullet behaviors were continuously recorded and summarized for each light color/compartment into daily time spent (DTS), daily percentage of time spent (DPTS), daily times of visit (DTV), duration per visit, daily feed intake (DFI), daily feeding time (DFT), feeding rate (FR), distribution of pullet occupancy and hourly time spent. The results showed that the DTS (h/pullet·per day) were 3.9±0.4 under white, 1.4±0.3 under red, 2.2±0.3 under green and 4.5±0.4 under blue light, respectively. The DTS corresponded to 11.7% to 37.6% DPTS in 12-h lighting periods. The DTV (times/pullet·per day) were 84±5 under white, 48±10 under red, 88±10 under green and 94±8 under blue light. Each visit lasted 1.5 to 3.2 min. The DFI (g/pullet·per day) were 27.6±1.7 under white, 7.1±1.6 under red, 15.1±1.1 under green and 23.1±2.0 under blue light. The DFT was 0.18 to 0.65 h/pullet·per day and the FR was 0.57 to 0.75 g/min. For most of the time during the lighting periods, six to 10 birds stayed under white, and one to five birds stayed under red, green and blue light. Pullets preferred to stay under blue light when the light was on and under white light 4 h before the light off. Overall, pullets preferred blue light the most and red light the least. These findings substantiate the preferences of layer pullets for light colors, providing insights for use in the management of light-emitting diode colors to meet pullet needs.
Dietary supplementation with the organic chromium (Cr) has been shown to positively affect the immune function of poultry. However, to our knowledge, no experiment has been done to directly compare the impacts of Cr chloride and chromium picolinate (CrPic) on the immune responses of broilers vaccinated with Avian Influenza (AI) virus vaccine. Therefore, the present experiment was conducted to investigate the effects of supplemental Cr sources (Cr chloride and CrPic) and levels on the growth performance and immune responses of broilers vaccinated with AI virus vaccine so as to provide an effective nutritional strategy for improving immune function of broilers. A total of 432 1-day (d)-old male broiler chicks were used in a 1 plus 2×4 design. Chickens were given either a diet without Cr supplementation (control) or diets supplemented with 0.4, 0.8, 1.6, or 3.2 mg Cr/kg as either Cr chloride or CrPic for 42 d. Compared to the control, dietary Cr supplementation had no effect (P>0.05) on average daily gain, average daily feed intake and gain : feed of broilers during the starter and grower phases, but increased (P<0.05) the relative weights of bursa of fabricius on d 21 and thymus, spleen, or bursa of fabricius on d 42, serum antibody titers against AI virus on d 21, 28, 35 and 42, blood T-lymphocyte transformation rate on d 28 and 42, blood T-lymphocyte percentage on d 42, and serum interleukin-2 contents on d 28. Broilers fed the diets supplemented with the inorganic Cr chloride had higher (P<0.05) weights of thymus, spleen and bursa of fabricius than those fed the diets supplemented with the CrPic on d 42. In addition, broilers fed the diets supplemented with the CrPic had higher (P<0.05) antibody titers against AI virus than those fed the diets supplemented with the inorganic Cr chloride on d 21 and 35. These results indicate that dietary Cr supplementation improved immune responses of broilers vaccinated with AI virus, and the inorganic Cr chloride was more effective than the CrPic in increasing the relative weights of lymphoid organs, however, the CrPic was more effective than the inorganic Cr chloride in enhancing the serum antibody titer against AI virus.
In this paper new materials and substrate approaches are discussed which have potential to provide (Al)GaN buffers with a better crystal quality, higher critical electrical field, or thickness and have the potential to offer co-integration of GaN switches at different reference potentials, while maintaining lower wafer bow and maintaining complementary metal–oxide semiconductor (CMOS) compatibility. Engineered silicon substrates, silicon on insulator (SOI) and coefficient of thermal expansion (CTE)-matched substrates have been investigated and benchmarked with respect to each other. SOI and CTE-matched offer benefits for scaling to higher voltage, while a trench isolation process combined with an oxide interlayer substrate allows co-integration of GaN components in a GaN-integrated circuit (IC).
Lateral memristors consisting of planar Ag electrodes (with sub-micrometer separation) supported on thin films of amorphous zinc-tin-oxide have been characterized. After an initial filament-forming process, each device exhibited volatile, resistive switching. In the low resistance state, the transport mechanism and conductance depended on prior activity and on the imposed current limit, mimicking biologic synaptic plasticity. Microscopic observations performed on each device revealed nanoscale filaments between the electrodes. These filaments were subject to Rayleigh instability and exhibited relaxation times determined by their effective radii. The relaxation times and on:off resistance ratios suggest suitability for threshold switching selector devices.
To investigate the control effect of the synthetic jet on the aerodynamic characteristic of rotors, a numerical simulation procedure for the rotor flowfield is established. First, a moving-embedded grid method and an unsteady Reynolds Averaged Navier–Stokes (URANS) solver are established for predicting the complex flowfield of rotors. A velocity jet boundary condition over the jet actuator orifice is constructed, and a numerical method for simulating the active flow control on rotors is developed. Then, the effectiveness of the simulation method is validated by comparing the numerical results of jet control on NACA 0015 aerofoil with the experimental data. At last, the aerodynamic characteristic of rotors with synthetic jet actuators located on the suction surface of the blade in forward flight is calculated. The results indicate that the synthetic jet has the capability of improving the aerodynamic characteristic of rotors, especially in inhibiting the flow separation over the surface. In addition, the increase of the jet momentum coefficient and the jet angle can both enhance the lift coefficient in the retreating side. Compared with a single jet, jet arrays have better control effects on improving the aerodynamic characteristic of rotors in forward flight.
Hand-foot-mouth disease (HFMD) is an acute infectious disease caused by serotypes of the enterovirus (EV) family. HFMD reinfection occurs commonly in lack of cross-protection between different EV serotypes. In this study, we investigated the hazards of HFMD reinfection using Cox-proportional hazard model. Retrospective data of 95 209 HFMD cases in Wuhan during 2008–2015 was used. Kaplan–Meier survival methods and Cox-proportional hazard model were used to estimate the hazard probabilities. Of the all HFMD cases, about 2% experienced reinfection (1842/95 209). Kaplan–Meier curves revealed the reinfection risk sharply increased before 40 months from first infection. Higher hazards of reinfection were detected among those who were males, aged 3 years and below, scattered children, belonging to urban areas and first infected with coxsackievirus (CV)-A16 compared with their respective counterparts. Cox-proportional hazard model suggested that gender, age, group, living area and serotypes of first infection had significant effect on reinfection even after adjusting for potential confounding effects of other selected factors considered in the study. These results indicate that boys aged 3 years and below, especially those living in urban areas and first infected with CV-A16 are more prone to reinfection. Interventions should be imposed on these high-risk populations.
In ovo feeding (IOF) of l-arginine (Arg) can affect growth performance of broilers, but the response of IOF of Arg on breast muscle growth is unclear, and the mechanism involved in protein deposition remains unknown. Hense, this experiment was conducted to evaluate the effects of IOF of Arg on breast muscle growth and protein-deposited signalling in post-hatch broilers. A total of 720 fertile eggs were collected from 34-week-old Arbor Acres breeder hens and distributed to three treatments: (1) non-injected control group; (2) 7.5 g/l (w/v) NaCl diluent-injected control group; (3) 0.6 mg Arg/egg solution-injected group. At 17.5 days of incubation, fertile eggs were injected 0.6 ml solutions into the amnion of the injected groups. Upon hatching, 80 male chicks were randomly assigned to eight replicates of 10 birds each and fed ad libitum for 21 days. The results indicated that IOF of Arg increased relative breast muscle weight compared with those of control groups at hatch, 3-, 7- and 21-day post-hatch (P<0.05). In the Arg-injected group, the plasma total protein and albumen concentrations were higher at 7- and 21-day post-hatch than those of control groups (P<0.05). The alanine aminotransferase activity in Arg group was higher at hatch than that of control groups (P<0.05). The levels of triiodothyronine at four time points and thyroxine hormones at hatch, 7- and 21-day post-hatch in Arg group were higher than those of control groups (P<0.05). In addition, IOF of Arg increased the amino acid concentrations of breast muscle at hatch, 7- and 21-day post-hatch (P<0.05). In ovo feeding of Arg also enhanced mammalian target of rapamycin, ribosomal protein S6 kinase-1 and eIF4E-bindingprotein-1 messenger RNA expression levels at hatch compared with those of control groups (P<0.05). It was concluded that IOF of Arg treatment improved breast muscle growth, which might be associated with the enhancement of protein deposition.
This paper reports the measurement of the energy loss of protons at the energy of 100 keV penetrating a partially ionized hydrogen plasma. The plasma of ne ≈ 1015–16 cm−3; Te ≈ 1–2 eV and lifetime of about 8 µs is created by the hydrogen gas discharge. The experimental results show an increase of a factor of 2.8 in the energy loss, which are in good agreement with the Bethe, Standard Stopping Model, Li–Petrasso and Vlasov models’ predictions within the error limit. The Bethe–Bloch Coulomb logarithm term is found to increase by a factor of 4.0 for free electrons as compared with the situation where bound electrons prevail. The potential application of protons energy loss for diagnosing the electron density in plasma is proposed too.