量ρ(a,M,p,u)的算法

量vp(a,M)是细分算法里需要研究的一个重要的量,它对Sobolev空间里Cascade算法收敛性的研究以及细分函数在Lp空间的光滑性有重要的应用价值。量ρ(a,M,p,u)是用来定义量vp(a,M)的。因而要研究量vp(a,M),可以转化为对量ρ(a,M,p,u)的研究。本文讨论了这个量ρ(a,M,p,u)的算法问题。     

Impact of a Mastitis control program in Valdres,Norway, during 1982–1985

The present study examined the effect of the mastitis control program (MCP) on milk production, incidence of mastitis, incidence of teat lesions, culling, log₁₀ of the bulk tank milk somatic cell count (LBMSC) and economic returns in Valdres, Norway, during 1982–1985. The major economic impact of the MCP was due to improved milk quality and to a lesser degree due to increased milk production. This might be explained by the Norwegian policy aimed at reducing the milk surplus through production quotas. The net present value of MCP, using a 15% discount rate, for an average 12-cow herd was 5599-3372 Nkr ($800-482) for production within or above the milk production quota, respectively. Since the program was provided free of charge to the individual farmer, this was also the net benefit to the MCP-participating farmer.     

Incidence and knowledge of bovine brucellosis in Kahuro district,Murang’a County,Kenya

Brucellosis in cattle is a zoonosis mainly caused by Brucella abortus. In Kenya, the disease is widespread, but its prevalence is largely unknown. The objective of this study was to investigate incidence rates of brucellosis and farmers’ knowledge on the disease in Kahuro district, Murang’a County. In this study, 150 pooled milk samples were collected from 75 milk collection centers and tested. Subsequently, 230 milk samples were collected from farmers in 16 collection centers in Wangu and Mugoiri divisions whose pooled samples gave positive results. Five cow owners in each of the 16 collection centers were interviewed using a questionnaire to assess their knowledge levels. Wangu division had the highest incidence rate 19% with positive samples observed from 14 collection centers. Mugoiri division recorded 3% with two collection centers having positive samples, while Murarandia had none. All respondents with no formal education were unaware of the causative agent of brucellosis. There was a significant difference in incidence between Mugoiri and Wangu divisions (p < 0.05). Knowledge levels were high in the young and educated farmers compared to the old and uneducated. Frequent screening for brucellosis to identify infected animals should be initiated thus prevent transmission to other animals and humans.     

Zika virus – emergence,evolution, pathology,diagnosis, and control: current global scenario and future perspectives – a comprehensive review

This review converses the Zika virus which has attained global concern due to its rapid pandemic potential and impact on humans. Though Zika virus was first isolated in 1947, till the recent large-scale outbreak which occurred in Micronesia, in 2007, the virus was placed into the innocuous pathogen category. The World Health Organization on 1 February 2016 declared it as a ‘Public Health Emergency of International Concern.’ Of the note, American as well as Pacific Island strains/isolates is relatively closer to Asian lineage strains. The African and American strains share more than 87.5% and 95% homologies with Asian strains/isolates, respectively. Asian strains form independent clusters, except those isolated from China, suggesting relatively more diversity than African strains. Prevention and control are mainly aimed at the vector population (mosquitoes) with Aedes aegypti being the main species. Surveys in Africa and Asia indicated seropositivity in various animal species. However, so far its natural reservoir is unknown. There is an urgent need to understand why Zika virus has shifted from being a virus that caused mild illness to unforeseen birth defects as well as autoimmune-neurological problems. Unfortunately, an effective vaccine is not available yet. Availability of cryo-electron microscopy based on 3.8 Å resolution revealing mature Zika virus structure and the probable virus attachment site to host cell would provide critical insights into the development of antiviral treatments and vaccines.     

Health and survival of red abalone Haliotis rufescens from San Miguel Island, California, USA, in a laboratory simulation of La Niña and El Niño conditions

The variability in Southern California's marine climate is dominated by the El Ni?o-Southern Oscillation, with cycling between El Ni?o events (characterized by warm water, low productivity, and frequent storms) and La Ni?a events (which exhibit the opposite conditions). Relative to the mainland and other Channel Islands, San Miguel Island (SMI) consistently maintains cooler water temperatures and supports significant populations of red abalone Haliotis rufescens, presumably owing to increased food production and diminished expression of the bacterial disease known as withering syndrome. We conducted a laboratory experiment to examine the effects of La Ni?a and El Ni?o conditions on the health and survival of red abalone from SMI. Six replicate tanks per treatment, each containing six abalone, were subjected to one of the following three temperature regimes (treatments): Bodega Bay, California ambient (AMB; mean, 11.4 degrees C), SMI La Ni?a regime (LAN; mean, 13.8 degrees C), and SMI El Ni?o regime (ELN; mean, 16.5 degrees C). After 328 d, survival in the ELN treatment was significantly lower than in the AMB and LAN groups. A body condition index was significantly lower in the ELN group than in the AMB group, and the LAN group was in between. A visual score of body shrinkage was significantly higher in both the LAN and ELN groups than in the AMB group. Other clinical signs of withering syndrome and the prevalence and infection intensity of the causative agent, Candidatus Xenohaliotis californiensis, increased as temperature increased in the three treatment groups from AMB to LAN to ELN, although the differences were not statistically significant. Generally, we found that increased temperature resulted in elevated disease expression, although less than observed in previous studies that used farmed abalone and higher, less variable temperature regimes. Water temperature modulates the effect of withering syndrome in wild red abalone, and very strong El Ni?o events are predicted to result in significant mortality at San Miguel Island.     

Health and Survival of Red Abalone Haliotis rufescens from San Miguel Island,California, USA,in a Laboratory Simulation of La Niña and El Niño Conditions

Abstract

The variability in Southern California's marine climate is dominated by the El Niño–Southern Oscillation, with cycling between El Niño events (characterized by warm water, low productivity, and frequent storms) and La Niña events (which exhibit the opposite conditions). Relative to the mainland and other Channel Islands, San Miguel Island (SMI) consistently maintains cooler water temperatures and supports significant populations of red abalone Haliotis rufescens, presumably owing to increased food production and diminished expression of the bacterial disease known as withering syndrome. We conducted a laboratory experiment to examine the effects of La Niña and El Niño conditions on the health and survival of red abalone from SMI. Six replicate tanks per treatment, each containing six abalone, were subjected to one of the following three temperature regimes (treatments): Bodega Bay, California ambient (AMB; mean, 11.4°C), SMI La Niña regime (LAN; mean, 13.8°C), and SMI El Niño regime (ELN; mean, 16.5°C). After 328 d, survival in the ELN treatment was significantly lower than in the AMB and LAN groups. A body condition index was significantly lower in the ELN group than in the AMB group, and the LAN group was in between. A visual score of body shrinkage was significantly higher in both the LAN and ELN groups than in the AMB group. Other clinical signs of withering syndrome and the prevalence and infection intensity of the causative agent, Candidatus Xenohaliotis californiensis, increased as temperature increased in the three treatment groups from AMB to LAN to ELN, although the differences were not statistically significant. Generally, we found that increased temperature resulted in elevated disease expression, although less than observed in previous studies that used farmed abalone and higher, less variable temperature regimes. Water temperature modulates the effect of withering syndrome in wild red abalone, and very strong El Niño events are predicted to result in significant mortality at San Miguel Island.

Received September 10, 2010; accepted December 16, 2010     

Nipah virus: epidemiology,pathology, immunobiology and advances in diagnosis,vaccine designing and control strategies – a comprehensive review

Nipah (Nee-pa) viral disease is a zoonotic infection caused by Nipah virus (NiV), a paramyxovirus belonging to the genus Henipavirus of the family Paramyxoviridae. It is a biosafety level-4 pathogen, which is transmitted by specific types of fruit bats, mainly Pteropus spp. which are natural reservoir host. The disease was reported for the first time from the Kampung Sungai Nipah village of Malaysia in 1998. Human-to-human transmission also occurs. Outbreaks have been reported also from other countries in South and Southeast Asia. Phylogenetic analysis affirmed the circulation of two major clades of NiV as based on currently available complete N and G gene sequences. NiV isolates from Malaysia and Cambodia clustered together in NiV-MY clade, whereas isolates from Bangladesh and India clusterered within NiV-BD clade. NiV isolates from Thailand harboured mixed population of sequences. In humans, the virus is responsible for causing rapidly progressing severe illness which might be characterized by severe respiratory illness and/or deadly encephalitis. In pigs below six months of age, respiratory illness along with nervous symptoms may develop. Different types of enzyme-linked immunosorbent assays along with molecular methods based on polymerase chain reaction have been developed for diagnostic purposes. Due to the expensive nature of the antibody drugs, identification of broad-spectrum antivirals is essential along with focusing on small interfering RNAs (siRNAs). High pathogenicity of NiV in humans, and lack of vaccines or therapeutics to counter this disease have attracted attention of researchers worldwide for developing effective NiV vaccine and treatment regimens.     

Turritella declivis Adams & Reeve,in Reeve, 1849 (Mollusca: Gastropoda) – a South African not an Australian species,and a characteristic component of the Agulhas Bank benthos

The name Turritella declivis, as described by Adams and Reeve in the ‘The Zoology of the Voyage of HMS Samarang’ (Adams & Reeve 1848-1850), is currently used for two distinct species of turritellid gastropod, one inhabiting the Agulhas Bank off South Africa and the other occurring off the Australian coast. Examination of the type material clearly shows that the name is referable to the southern African species. The Australian species must henceforth be known as Turritella captiva Hedley, 1987, a name previously regarded as a junior synonym of T. declivis. The original type locality ‘China Seas’ is erroneous, as was often the case with material collected during the voyage of the Samarang. It is emended to be the Agulhas Bank, over much of which T. declivis is common and may, in places, be hugely abundant, forming Turritella-dominated benthic communities. Such communities have been recorded in other parts of the world and are frequently associated with seasonal upwelling events, but have not previously been documented off South Africa.