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Triploid and pentaploid breeding is of great importance in agricultural production, but it is not always easy to obtain double ploidy parents. However, in fishes, chromosome ploidy is diversiform, which may provide natural parental resources for triploid and pentaploid breeding. Both tetraploid and hexaploid exist in Schizothorax fishes, which were thought to belong to different subfamilies with tetraploid Percocypris fishes in morphology, but they are sister genera in molecule. Fortunately, the pentaploid hybrid fishes have been successfully obtained by hybridization of Schizothorax wangchiachii (♀, 2n = 6X = 148) × Percocypris pingi (♂, 2n = 4X = 98). To understand the genetic and morphological difference among the hybrid fishes and their parents, four methods were used in this study: morphology, karyotype, red blood cell (RBC) DNA content determination and inter-simple sequence repeat (ISSR). In morphology, the hybrid fishes were steady, and between their parents with no obvious preference. The chromosome numbers of P. pingi have been reported as 2n = 4X = 98. In this study, the karyotype of S. wangchiachii was 2n = 6X = 148 = 36m + 34sm + 12st + 66t, while that the hybrid fishes was 2n = 5X = 123 = 39m + 28sm + 5st + 51t. Similarly, the RBC DNA content of the hybrid fishes was intermediate among their parents. In ISSR, the within-group genetic diversity of hybrid fishes was higher than that of their parents. Moreover, the genetic distance of hybrid fishes between P. pingi and S.wangchiachii was closely related to that of their parental ploidy, suggesting that parental genetic material stably coexisted in the hybrid fishes. This is the first report to show a stable pentaploid F1 hybrids produced by hybridization of a hexaploid and a tetraploid in aquaculture.
Iron-deficiency anemia is a public health concern that frequently occurs in pregnant mammals and neonatal offspring. Ferrous N-carbamylglycinate chelate (Fe-CGly) is a newly designed iron fortifier with proven effects in iron-deficient rats and weanling piglets. However, the effects of this new compound on pregnant mammals are unknown. Therefore, this experiment was conducted to evaluate the effects of Fe-CGly on sow reproductive performance and iron status of both sows and neonatal piglets. A total of 40 large-white sows after second parity were randomly assigned to two groups (n=20). They were receiving a diet including 80 mg Fe/kg as FeSO4 or Fe-CGly, respectively, from day 85 of gestation to parturition. The serum (day 110 of pregnancy) and placentas of sows were sampled. Litter size, mean weight of live born piglets, birth (live) litter weight, number of live born piglets, and the number of still-born piglets, mummies, and weak-born piglets were recorded. Once delivered, eight litters were randomly selected from the 20 litters per treatment, and one new-born male piglet (1.503±0.142 kg) from each selected litter was slaughtered within 3 h after birth from the selected litters, without colostrum ingestion. The serum, longissimus muscle, liver and kidneys of the piglets were collected. The iron status of the serum samples and the messenger RNA level of iron-related genes in the placenta, liver and kidney were analyzed. The results showed that litter weight of live born piglets was higher (P=0.030) in the Fe-CGly group (19.86 kg) than in the FeSO4 group (17.34 kg). Fe-CGly significantly increased placental iron concentration (P<0.05) of sows. It also significantly increased iron saturation and reduced the total iron-binding capacity of piglets (P<0.05) at birth. However, the results revealed that supplementation of Fe-CGly in sows reduced liver and kidney iron concentration of neonatal piglets (P<0.05), indicating decreased iron storage. In addition, the concentration of iron in the colostrum was not significantly changed. Therefore, the present results suggested that replacement of maternal FeSO4 supplement with Fe-CGly in the late-gestating period for sows could improve litter birth weight, probably via enhanced iron transportation in the placenta.
Since 1992 we have been conducting a 5-GHz VLBI imaging survey of southern and equatorial radio sources. So far, we have published the results of two observing sessions with 26 southern radio sources imaged in total (Shen et al. 1997; 1998). In this paper, we present the preliminary results of the third session of observations of 7 equatorial sources in the sample.
Phosphatidylinositol-3 kinases (PI3K)-Protein kinase B (Akt)-mammalian target of rapamycin (mTOR) pathway plays an important role in the synthesis and secretion of triacylglycerol. However, the mechanism of PI3K-Akt-mTOR pathway in regulating lipid metabolism of goose liver was poorly understood. The purpose of this study was to determine how PI3K-Akt-mTOR pathway regulating lipid metabolic homeostasis in goose hepatocytes. Goose primary hepatocytes were treated with different PI3K-Akt-mTOR signal inhibitors (LY294002, rapamycin and NVP-BEZ235) for 24 h. The results showed that these inhibitors evidently inhibited PI3K-Akt-mTOR downstream signaling. Meanwhile, these PI3K-Akt-mTOR inhibitors reduced intracellular lipid accumulation, decreased the mRNA expression and protein content of genes involved in the de novo fatty acid synthesis, while increased the transcriptional and protein level of key factors involved in fatty acid oxidation and very low density lipoprotein (VLDL) assembly and secretion. Conclusion: These findings suggested that the reduction of lipids accumulation induced-by inhibiting PI3K-Akt-mTOR pathway was closely linked to the decrease of lipogenesis, the increase of fatty acids oxidation, and the increase of VLDL assembly and secretion in goose hepatocytes.
The ‘Ornicopter’ is a single-rotor helicopter without anti-torque rotor developed since 2002 at Delft University of Technology in The Netherlands. The Ornicopter’s principle is similar to the movement of a bird’s wing and is based on actively flapping the blades up and down while rotating them around a shaft to generate both the required lift and the propulsive force. The shaft torque is no longer needed and thus the anti-torque rotor is redundant. The present paper describes the basic principles of the Ornicopter’s forced flapping, discussing the feasibility of the Ornicopter concept with respect to the power required, performance, stability, and vibratory loads. On the one side it is shown that the Ornicopter has a similar power requirement to a conventional helicopter, as well as very similar longitudinal and lateral stability and controllability characteristics to a conventional helicopter. On the other side, the Ornicopter generates higher vibratory loads than in a conventional helicopter, and its performance is strongly limited by the stall effect.
Control of the malaria vector An. gambiae is still largely obtained through chemical intervention using pyrethroids, such as permethrin. However, strains of An. gambiae that are resistant to the toxic effects of pyrethroids have become widespread in several endemic areas over the last decade. The objective of this study was to assess differences in five life-history traits (larval developmental time and the body weight, fecundity, hatch rate, and longevity of adult females) and energy metabolism between a strain of An. gambiae that is resistant to permethrin (RSP), due to knockdown resistance and enhanced metabolic detoxification, and a permethrin susceptible strain reared under laboratory conditions. We also quantified the expression levels of five antioxidant enzyme genes: GSTe3, CAT, GPXH1, SOD1, and SOD2. We found that the RSP strain had a longer developmental time than the susceptible strain. Additionally, RSP adult females had higher wet body weight and increased water and glycogen levels. Compared to permethrin susceptible females, RSP females displayed reduced metabolic rate and mitochondrial coupling efficiency and higher mitochondrial ROS production. Furthermore, despite higher levels of GSTe3 and CAT transcripts, RSP females had a shorter adult life span than susceptible females. Collectively, these results suggest that permethrin resistance alleles might affect energy metabolism, oxidative stress, and adult survival of An. gambiae. However, because the strains used in this study differ in their genetic backgrounds, the results need to be interpreted with caution and replicated in other strains to have significant implications for malaria transmission and vector control.
Applications of aminocyclopyrachlor in 2011 to turf resulted in brown and twisted shoots, leaves, and needles; shoot dieback; and in some cases, death of trees and ornamental plants adjacent to treated turf areas. Our research objective was to determine if a sensitive plant could be injured from wood chips (mulch) obtained from aminocyclopyrachlor-damaged trees, and to quantify movement of aminocyclopyrachlor from contaminated wood chips into soil and its subsequent uptake by roots into landscape plant tissues. Tomatoes were grown under greenhouse conditions and mulched with chipped tree branches collected from honey locust and Norway spruce damaged 12 mo previously by aminocyclopyrachlor. Analysis of tomato tissue for aminocyclopyrachlor residues 32 d after mulching found aminocyclopyrachlor in all mulched tomato plants, which was consistent with observations of epinasty on tomato leaflets. Aminocyclopyrachlor residues ranged from 0.5 to 8.0 ppb in tomato plants while chipped tree branches contained 1.7 to 14.7 ppb. Aminocyclopyrachlor residues in the potting soil below the mulch ranged from below the quantifiable limit to 0.63 ppb, indicating that aminocyclopyrachlor can leach from wood chips into soil, causing plant injury. These results indicate that trees damaged by aminocyclopyrachlor should not be chipped and used for mulch or as an ingredient in compost.
Structural Health Monitoring (SHM) takes advantage of the recent advances in nanotechnology and sensing in order to monitor the behavior of a structure, assess its performance and identify damage at an early stage. Monitoring the state of strain throughout an entire structure is essential to determine its state of stress, detect potential residual stresses after fabrication, and also to help to establish its integrity. The Carbon nanotube thread was integrated into three-dimensional braiding materials and used for the first time as a sensor to monitor strain and also to detect damage in the three-dimensional braided composite material.
In this paper a literature review about the application of carbon nanotubes thread for sensors and smart materials used for SHM of braiding structures is presented. The test data show the braided angle is important parameter for structural health monitoring of three-dimensional. The research will provide a new integrated and distributed technologies for the built-in carbon nanotube sensor to detect the health of composite. The subject will provide the new idea and method for the development of smart composite materials research and application.
In order to achieve waste heat recovery using thermoelectric systems, thermoelectric materials showing high conversion efficiency over wide temperature range and high resistance against oxidation are indispensable. A silicide material with good n-type thermoelectric properties and oxidation resistance has been discovered. The composition and crystal structure of the silicide are found out Mn3Si4Al2 (abbreviated as 342 phase) and hexagonal CrSi2 structure, respectively. Element substitution of Mn with 3d transition metals is succeeded. Enhancement of Seebeck coefficient is observed in a Cr-substituted sample. The maximum dimensionless thermoelectric figure of merit ZT is 0.3 at 573 K in air for the Mn2.7Cr0.3Si4Al2 sample. Electrical resistivity of the Mn3Si4Al2 bulk sample holds constant value for 48 h at 873 K in air. This is due to formation of oxide passive layer on the surface of the bulk sample. The 342 phase is a promising n-type material with a good oxidation resistance in the middle temperature range of 500-800 K.
We investigated the presence of Mycobacterium spp. in livestock in northern China. Of the 163 clinical samples selected for this study, 20 were from throat swabs of dairy cows, and 143 were tissue samples (including lung tissue from one reindeer, hilar lymph node tissue from 55 cows, and liver tissue from 87 sheep). A total of 41 mycobacterial isolates were identified including two isolates of M. caprae and 39 non-tuberculous mycobacteria (NTM) isolates. Multi-locus variable-number tandem repeat analysis (MLVA) profiles of the two M. caprae isolates proved to be unique. This is the first report of M. caprae isolates from livestock in China. This study also confirms previous reports that NTM is common in livestock in northern China.
In this paper, an integrated multifunctional biochip detection system, which we call “OBMorph“, are presented. This unique system integrates several optoelectronic-based biological diagnostic tools such as an ellipsometer, a laser Doppler vibrometer/interferometer, a SPR (surface plasmon resonance) analyzer, an interference microscope, a photon tunneling microscope, an optical coherence tomography unit and a confocal scanning microscope. This OBMorph system, useful as a powerful optical metrology diagnostic tool, can be used at the beginning of sensor chip fabrication, on to signal detecting and monitoring, and to the final biological analysis. The principles and experimental results of this multifunctional biochip detection OBMorph system are presented.
In addition, an innovative SARS (Severe Acute Respiratory Syndrome) virus denaturing chemical compound that was derived using the OBMorph system to study biolinker fabrication in biochips, are discussed. Several testing strategies are presented herein which proves the effectiveness of the new chemical compound, biochip technology in denaturing the SARS virus. Analysis under an atomic force microscope confirms the actual breaking down of the virus treated by the chemical compound. The fundamentals of how the chemical compound denatures the virus and renders it toxicity useless, is based on principles of nanotechnology and bio-mechanics. Results from preliminary studies show that this denaturing principle can be also effective against other deadly viruses and even bacteria. Some design strategies and innovative working mechanisms derived from study of this chemical compound which can denature the SARS-CoV, are also discussed.
Secondary electron emission from a cathode material in AC PDP (Plasma Display Panel) is dominated by potential emission mechanism, which is sensitive to band structure of a protective layer. Therefore, the secondary electron emission property can be modified by a change in the energy band structure of the protective layer. Mg2-2xTixO2 films were prepared by e-beam evaporation method to be used as possible substitutes for the conventional MgO protective layer. The oxygen content in the films and in turn, the ratio of metal to oxygen gradually increased with the increasing TiO2 content in the starting materials. The pure MgO films exhibited the crystallinity with strong (111) orientation. The Mg2-2xTixO2 films, however, had the crystallinity with (311) preferred orientation. The stress relaxation, when the [TiO2/(MgO+TiO2)] ratio in the evaporation starting materials was 0.15, seems to be related to inhomogeneous film surface due to an excessive addition of TiO2 to MgO. When the [TiO2/(MgO+TiO2)] ratios of 0.1 and 0.15 were used, the deposited films exhibited the secondary electron emission yields improved by 50% compared to that of the conventional MgO protective layer, which resulted in reduction in discharge voltage by 12%.
Silicon nitride/silicon carbide nanocomposites and alumina-based nanocomposites were investigated in an effort to produce materials with high structural integrity and service properties. Bulk nano-nano composites of silicon nitride and silicon carbide were processed by crystallization of amorphous Si-C-N ceramics that were consolidated in-situ during pyrolysis of a polymer precursor. This material was developed for the purpose of examining the creep behavior of covalent ceramics when there is no oxide glassy phase at grain boundaries. Si3N4/SiC micro-nano composites were sintered by spark plasma sintering (SPS), aiming at better microstructural control and improved creep resistance. Composites of alumina with diamond, silicon carbide and metal (Nb) were developed by high pressure sintering and SPS. These composites maintain microstructures with a nanometric alumina matrix and are targeted for studying the toughening mechanisms and superplastic deformation mechanisms.
Effect of surface treatment on the formation of oxygen enriched brittle layer in a Ti3Al-Nb alloy was investigated. The results show that a mixed Ti2N and TiN layer was formed at the surface by the titanium nitride vapor deposit treatment, and this titanium nitride layer makes it possible to suppress the formation of the oxygen enriched brittle layer during thermal exposure. An Al2O3 film was formed at the surface of the alloy, when the surface treatment was conducted under a low partial pressure oxygen atmosphere. However, such surface treatment is not able to depress the formation of the oxygen enriched brittle layer during thermal exposure, due to the higher affinity of α2 phase for oxygen as well as the higher diffusivity of titanium in Al2O3.
MeV ion induced damage and annealing behavior in Si are reported using 3 ion species such as B, P and Si. Si self implantations were done to reveal the intrinsic behavior of secondary defect formation by excluding the possibility of chemical interactions between substrate atoms and dopant atoms. Experimental results of B and P implantations were compared to those of Si. TEM observations showed that interstitial type secondary defects are exclusively formed at around Rp. DCXRD rocking curve analyses indicated that an isolated layer of (+) strain is built up at around Rp after strain relaxation by annealing. Sources for secondary defects were thought to be Si self interstitials. Atomistic mechanisms of secondary defect formation and the effect of ion species on them are discussed.
The percentage infection of secondary symbionts (SS) (Wolbachia, Arsenophonus, Rickettsia, Hamiltonella, Fritschea and Cardinium) in the exotic Bemisia tabaci (Genn.) invaders, commonly known as biotypes B and Q from China, were determined by PCR. In total, 373 biotype B and 1830 biotype Q individuals were screened for the presence of SS. Biotype B was more abundant than biotype Q from 2005 to 2006, and biotype Q was more abundant from 2007 to 2009. Each of the SS, with the exception of Fritschea, was detected in both biotypes B and Q; Fritschea was found in none of the samples examined. For biotype B, the percentage infection of Hamiltonella was the highest (92.0%) followed by Rickettsia (70.2%). For biotype Q, the percentage infection of Hamiltonella was again the highest (73.3%). Arsenophonus was the least common of the SS observed in both biotypes B and Q. The percentage infection of Wolbachia, Rickettsia and Hamiltonella in biotype B was each significantly higher than in biotype Q, whereas the percentage infection of Cardinium in biotype B was significantly lower than in biotype Q. The percentage infection of SS in biotypes B and Q varied from year to year over the period 2005–2009. Furthermore, within biotype Q, two distinct subgroups were identified which differ from each other in terms of their SS complement. We discuss these results in the light of the potentially influential factors and roles of the SS.
The architecture of an engineered scaffold is an important consideration in the design of a synthetic tissue replacement. We have begun to explore the use of heirarchical fiber scale design ranging from microscale nonwoven to 3-D integrated fiber bundles in orthopaedic tissue engineering applications. The use of heirarchical fiber and design includes the following advantages: 1) the ability to tailor a broad spectrum of substrates with a wide range of mechanical properties, and 2) the ability to create structures capable of supporting cell proliferation as well as the micro-diffusion of nutrients throughout the structure. Using the bioresorbable copolymer, poly(D,L-lactide-co-glycolide) [PLAGA], we have fabricated two matrices based on fiber technology: 1) a microfiber non-woven mesh composed of 50:50 PLAGA and 2) a 3-dimensional braided structure composed of 5:95 PLAGA. These structures were examined by scanning electron microscopy [SEM] in an in vitro cell culture environment. Matrices were seeded with two types of cells (osteoblasts from neonatal rat calvaria and fibroblasts from the BALB/C cell line) to determine the effect of matrix architecture on cellular morphology and proliferation. SEM analysis of the microfiber matrix indicated a highly porous, structure resulting from the random arrangement of the microfibers. PLAGA fibers appear to have a range in diameter from approximately 2-7 μm. The 3-D braided matrix was shown to have a organized fibrous structure resulting from the 3-D braiding process. Examination of the attachment and proliferation of cells on the matrices revealed that cell morphology and proliferation patterns were dependent on cell type and matrix geometry. SEM analysis also indicated that cells responded dynamically to changes in structure due to the onset of degradation.