An improved shear lag model for predicting stress distribution in hybrid fiber reinforced rubber composites     

Bin Zhang  Xiaoming Yu  Boqin Gu 《Fibers and Polymers》2017,18(2):349-356

An improved micromechanical shear lag model, which considers the interphase and bonded fiber end, is developed to investigate the load-carrying characteristics and stress profiles in hybrid aramid/sepiolite fiber reinforced rubber composites. The properties of the equivalent matrix, which is combination of sepiolite fiber and rubber matrix, are determined by Mori-Tanaka method. The axial and shear stresses at the fiber end are resolved by the imaginary fiber technique. The results obtained from the improved model show the tensile stress has a maximal at the real fiber center and the interfacial shear stress has a maximal at the end of the real fiber. Comparing with the results from Tsai’s model, the improved model has a better agreement with the numerical simualtion results. The effects of the imaginary fiber length on the stress transfer are analyzed and the results show that the effects can be ignored when the imaginary fiber length is greater than twice of the fiber radius. The effects of interphase modulus and thickness on the maximal axial and shear stresses are discussed. The results show that the interphase modulus and thickness of about 106.3 MPa and 0.2 μm are optimal to prevent interfacial debonding and improve the strength of hybrid fiber reinforced rubber composites.  相似文献   

Todd LeVasseur,Pramod Parajuli and Norman Wirzba (eds.): Religion and sustainable agriculture: world spiritual traditions and food ethics     

Christian Kelly Scott 《Agriculture and Human Values》2018,35(2):537-538

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An Electrothermochromic Fabric Prepared by Electrodeposition of Polypyrrole on Single Side     

Zeqi Chen  Chengzhuo Wei  Weida Rao  Lingling Fan  Jie Xu 《Fibers and Polymers》2018,19(11):2344-2350

An electrothermochromic fabric triggered by electric voltages was prepared by combining the electric heating feature of conductive polypyrrole (PPy) and the temperature-response color-changing feature of thermochromic inks. PPy was deposited selectively on the carbon-coated side of the sailcloth fabric via electrochemical polymerization. Thermochromic inks were painted on the reverse side with white color. The obtained fabric could be heated to about 48 °C and change its color significantly under an applied voltage of 3 V.  相似文献   

Bioinformatics resources for deciphering the biogenesis and action pathways of plant small RNAs     

Dongliang Yu  Xiaoxia Ma  Ziwei Zuo  Weishan Shao  Huizhong Wang  Yijun Meng 《Rice》2017,10(1):38

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Erratum to: Population genetic analysis of hyacinth bean (<Emphasis Type="Italic">Lablab purpureus</Emphasis> (L.) Sweet,Leguminosae) indicates an East African origin and variation in drought tolerance     

Oliver Robotham  Mark Chapman 《Genetic Resources and Crop Evolution》2017,64(2):441-441

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Influence of climate and abundance on migration timing of adult Atlantic salmon (Salmo salar) among rivers in Newfoundland and Labrador          下载免费PDF全文

Brian Dempson  Carl J. Schwarz  Ian R. Bradbury  Martha J. Robertson  Geoffrey Veinott  Rebecca Poole  Eugene Colbourne 《Ecology of Freshwater Fish》2017,26(2):247-259

Evidence mounts for the influence of climate variability on temporal trends in the phenology of many organisms including various species of fish. Accordingly, we examined variation in adult Atlantic salmon Salmo salar run timing in thirteen Newfoundland and Labrador rivers where returns were monitored at fishways or fish‐counting fences. Run timing varied significantly among rivers with the median date of return differing by up to 5 weeks. Duration of runs was generally short with most adults returning over a period of three to 5 weeks. A mixed model analysis incorporating a first‐order autoregressive error structure was used to generalise changes in run timing among all monitored rivers. Results indicated that the median date of return has advanced by almost 12 days over a 35‐year interval from 1978 to 2012, while several individual rivers have advanced by almost 21 days. The influence of climate on median timing was evident when the simultaneous effects of both climate and salmon abundance were controlled. We found earlier runs associated with overall warmer climate conditions on the Newfoundland and Labrador Shelf. Results contrast with those from the north‐east Atlantic where Atlantic salmon are returning later in some rivers coincident with warming climate conditions.  相似文献   

Differential role for low pH and cathepsin-mediated cleavage of the viral spike protein during entry of serotype II feline coronaviruses     

Regan AD  Shraybman R  Cohen RD  Whittaker GR 《Veterinary microbiology》2008,132(3-4):235-248

Feline infectious peritonitis (FIP) is a terminal disease of cats caused by systemic infection with a feline coronavirus (FCoV). FCoV biotypes that cause FIP are designated feline infectious peritonitis virus (FIPV), and are distinguished by their ability to infect macrophages and monocytes. Antigenically similar to their virulent counterparts are FCoV biotypes designated feline enteric coronavirus (FECV), which usually cause only mild enteritis and are unable to efficiently infect macrophages and monocytes. The FCoV spike protein mediates viral entry into the host cell and has previously been shown to determine the distinct tropism exhibited by certain isolates of FIPV and FECV, however, the molecular mechanism underlying viral pathogenesis has yet to be determined. Here we show that the FECV strain WSU 79-1683 (FECV-1683) is highly dependent on host cell cathepsin B and cathepsin L activity for entry into the host cell, as well as on the low pH of endocytic compartments. In addition, both cathepsin B and cathepsin L are able to induce a specific cleavage event in the FECV-1683 spike protein. In contrast, host cell entry by the FIPV strains WSU 79-1146 (FIPV-1146) and FIPV-DF2 proceeds independently of cathepsin L activity and low pH, but is still highly dependent on cathepsin B activity. In the case of FIPV-1146 and FIPV-DF2, infection of primary feline monocytes was also dependent on host cell cathepsin B activity, indicating that host cell cathepsins may play a role in the distinct tropisms displayed by different feline coronavirus biotypes.  相似文献   

PCR-based coprodiagnostic tools reveal dogs as reservoirs of zoonotic ancylostomiasis caused by Ancylostoma ceylanicum in temple communities in Bangkok     

Traub RJ  Inpankaew T  Sutthikornchai C  Sukthana Y  Thompson RC 《Veterinary parasitology》2008,155(1-2):67-73

A survey of gastrointestinal parasites of dogs and humans from temple communities in Bangkok revealed that 58% of dogs and 3.4% of humans, among those sampled, were infected with hookworms utilising faecal flotation techniques and microscopy. A previously established polymerase chain reaction (PCR)-RFLP approach was utilised to determine the species of hookworms infecting dogs found positive for hookworm eggs. Single infections with Ancylostoma ceylanicum and Ancylostoma caninum were recorded in 77% and 9% of hookworm positive dogs, respectively and mixed infections with both species of Ancylostoma were recorded in 14% of dogs. A single-step PCR for the multiplex detection of Ancylostoma species and Necator americanus DNA in human faeces was developed and applied to characterise the species of hookworms in microscopy positive individuals. Single infection with N. americanus was recorded in five and A.ceylanicum infection in two, out of seven individuals positive for hookworm. This study demonstrates that humans are at risk of acquiring infection with A. ceylanicum in communities where this species of hookworm is endemic in dogs.  相似文献   

Molecular epidemiology of Mycobacterium avium subsp. avium and Mycobacterium intracellulare in captive birds     

Schrenzel M  Nicolas M  Witte C  Papendick R  Tucker T  Keener L  Sutherland-Smith M  Lamberski N  Orndorff D  Heckard D  Witman P  Mace M  Rimlinger D  Reed S  Rideout B 《Veterinary microbiology》2008,126(1-3):122-131

Mycobacterium avium subsp. avium and Mycobacterium intracellulare are primary causes of mycobacteriosis in captive birds throughout the world, but little is known about how they are transmitted. To define the local epidemiology of infection, we strain-typed 70 M. avium subsp. avium and 15 M. intracellulare culture isolates obtained over a 4-year period from captive birds. Typing was performed using randomly amplified polymorphic DNA (RAPD) PCR, amplified fragment length polymorphic (AFLP) fragment analyses, and for a subset of isolates, DNA sequencing of a segment of the 16S-23S rRNA internal transcribed spacer region. Six strain clusters comprising 43 M. avium subsp. avium, isolates were identified; 42 isolates had unique typing patterns, including all M. intracellulare isolates. Phylo-geographical analyses using RAPD and AFLP fingerprints and animal confinement histories showed no correlation between housing of infected birds and mycobacterial strain-type, except for two animals. The diversity of M. avium subsp. avium and M. intracellulare isolates and minimal evidence for bird-to-bird transmission suggest that environmental reservoirs may be important sources of infection in captivity.  相似文献   

Veterinary medicine is public health     

Blackwell MJ  Leap RL 《Journal of veterinary medical education》2008,35(2):148-149

The symposium Partnerships for Preparedness: Future Directions of Schools of Public Health and Colleges of Veterinary Medicine documents the importance of further integration between the fields of veterinary medicine and public health to protect our nation from public-health emergencies. Current areas targeted for improved collaboration include academic programs, public policy, workforce training, and research.  相似文献