Palletized handling and storage of potatoes     

Sam Kennedy 《American Journal of Potato Research》1953,30(3):78-81

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Genetic diversity of Korean Bacillus anthracis isolates from soil evaluated with a single nucleotide repeat analysis     

Sang Hoon Kim  Kyoung Hwa Jung  Se Kye Kim  Seong-Joo Kim  Ji-Cheon Kim  Soo Young Cho  Jin Choul Chai  Young Seek Lee  Yun Ki Kim  Hyun Chul Hwang  Sam Gon Ryu  Young Gyu Chai 《Journal of veterinary science (Suw?n-si, Korea)》2013,14(4):457-465

Bacillus (B.) anthracis, the etiological agent of anthrax, is one of the most genetically monomorphic bacteria species in the world. Due to the very limited genetic diversity of this species, classification of isolates of this bacterium requires methods with high discriminatory power. Single nucleotide repeat (SNR) analysis is a type of variable-number tandem repeat assay that evaluates regions with very high mutation rates. To subtype a collection of 21 isolates that were obtained during a B. anthracis outbreak in Korea, we analyzed four SNR marker loci using nucleotide sequencing analysis. These isolates were obtained from soil samples and the Korean Center for Disease Control and Prevention. The SNR analysis was able to detect 13 subgenotypes, which allowed a detailed evaluation of the Korean isolates. Our study demonstrated that the SNR analysis was able to discriminate between strains with the same multiple-locus variable-number tandem repeat analysis genotypes. In summary, we obtained SNR results for four SNR marker loci of newly acquired strains from Korea. Our findings will be helpful for creating marker systems and help identify markers that could be used for future forensic studies.  相似文献   

Performance of shrimp futures markets as price discovery and hedging mechanisms     

Leigh J. Maynard  Sam Hancock  Heath Hoagland 《Aquaculture Economics & Management (Blackwell Science)》2013,17(3-4):115-128

Abstract

Granger causality tests revealed leading indicators of shrimp futures prices, implying that futures prices do not reflect all available market information and potentially fail to be an exemplary price discovery mechanism. Trading simulations confirmed that the use of some leading indicators allowed profitable arbitrage in shrimp futures trading. Shrimp futures were deficient as a hedging tool, as well. Correlations between futures and wholesale cash prices were often low, and basis risk rivaled price risk. Lack of liquidity is a likely explanation for shrimp futures’ shortcomings as a hedging tool and price discovery mechanism.  相似文献   

Beach nourishment: an ecologically sound coastal defence alternative? A review     

Jeroen Speybroeck  Dries Bonte  Wouter Courtens  Tom Gheskiere  Patrick Grootaert  Jean‐Pierre Maelfait  Mieke Mathys  Sam Provoost  Koen Sabbe  Eric W.M. Stienen  Vera Van Lancker  Magda Vincx  Steven Degraer 《水产资源保护:海洋与淡水生态系统》2006,16(4):419-435

• 1. Even though beach nourishment is generally considered as an environment‐friendly option for coastal protection and beach restoration, sizeable impacts on several beach ecosystem components (microphytobenthos, vascular plants, terrestrial arthropods, marine zoobenthos and avifauna) are described in the literature, as reviewed in this paper.
• 2. Negative, ecosystem‐component specific effects of beach nourishment dominate in the short to medium term, with the size of the impact being determined by (1) activities during the construction phase, (2) the quality and (3) the quantity of the nourishment sand, (4) the timing, place and size of project, and (5) the nourishment technique and strategy applied. Over the long term the speed and degree of ecological recovery largely depend on the physical characteristics of the beach habitat, mainly determined by (1) sediment quality and quantity, (2) the nourishment technique and strategy applied, (3) the place and the size of nourishment and (4) the physical environment prior to nourishment.
• 3. The limited information available on indirect and cumulative ecological effects indicates that these effects cannot be neglected in an overall impact assessment. Hence, for ecologically good practice of beach nourishment it is advised (1) to choose nourishment sands with a sediment composition comparable to that of the natural sediment, (2) to avoid short‐term compaction by ploughing immediately after construction, (3) to execute the nourishment in a period of low beach use by birds and other mobile organisms, (4) to choose a number of smaller projects rather than a single large nourishment project and (5) to select the nourishment technique with respect to the local natural values.
• 4. In order to allow an objective, scientifically sound, ecological adjustment of future nourishments, research should aim at (1) taking into account the full sandy beach ecosystem, (2) avoiding strategic imperfections in experimental design and (3) elucidating the biological processes behind impact and recovery of all ecosystem components.

Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

Prevalence and risk factors associated with Cryptosporidium oocysts shedding in pigs in Central Vietnam     

Nguyen ST  Honma H  Geurden T  Ikarash M  Fukuda Y  Huynh VV  Nguyen DT  Nakai Y 《Research in veterinary science》2012,93(2):848-852

We investigated the prevalence and risk factors associated with Cryptosporidium oocysts shedding in pigs in Central Vietnam. A total of 740 single fecal samples collected from diarrheic and non-diarrheic pigs on 89 farms were screened by the modified Ziehl-Neelsen staining method. Prevalence at the animal and the farm levels were 18.1% (134/740) and 71.9% (64/89), respectively. Risk factors for the infection were identified using univariate and multivariate logistic regression analysis. The results revealed that age, sanitary condition and topography were significantly associated with oocyst shedding (P<0.05). Pre-weaned piglets were at the highest risk for infection, followed by post-weaners, sows and finishing pigs. Good sanitary conditions showed positive effects in decreasing oocysts shedding. Topographically, Cryptosporidium was more common in mountainous zone than that in coastal delta zone. There was an association between the occurrence of diarrhea and the level of Cryptosporidium oocyst excretion within infected pigs. This is the first epidemiological investigation of prevalence and risk factors of Cryptosporidium in pigs in Vietnam.  相似文献   

Prevalence of Fasciola in cattle and of its intermediate host Lymnaea snails in central Vietnam     

Sam Thi Nguyen  Duc Tan Nguyen  Thoai Van Nguyen  Vu Vy Huynh  Duc Quyet Le  Yasuhiro Fukuda  Yutaka Nakai 《Tropical animal health and production》2012,44(8):1847-1853

The aims of this study were to investigate the prevalence of natural Fasciola infections in both the definitive hosts (cattle) and the intermediate hosts (Lymnaea snails) in central Vietnam. A total of 1,075 fecal samples, randomly collected from cattle in Binh Dinh, Khanh Hoa, and Phu Yen provinces, were examined for Fasciola eggs by a sedimentation method. The overall prevalence of Fasciola was 45.3?%. A subset of the animals (235) was also screened for antibodies against Fasciola by an enzyme-linked immunosorbent assay. Overall, 46.3?% of these animals were shedding Fasciola eggs while 87.2?% were Fasciola seropositive. A lower prevalence of Fasciola was observed in calves ??2?years of age (37.6?%) compared to that in cattle >2?years of age (53.7?%) (p?<?0.05). The prevalence in the rainy season (50.8?%) was significantly different to that in the dry season (38.1?%) (p?<?0.05). Of the 3.269 Lymnaea viridis and 1.128 Lymnaea swinhoei examined, 31 (0.95?%) and seven (0.62?%), respectively, were found to be infected with Fasciola. This appears to be the first epidemiological survey of the prevalence of Fasciola in cattle and snails in these three provinces in central Vietnam.  相似文献   

Winter curing of <Emphasis Type="Italic">Prunus dulcis</Emphasis> cv ‘Butte,’ <Emphasis Type="Italic">P. webbii</Emphasis> and their interspecific hybrid in response to <Emphasis Type="Italic">Xylella fastidiosa</Emphasis> infections     

Craig A. Ledbetter  Jianchi Chen  Sam Livingston  Russell L. Groves 《Euphytica》2009,165(1):113-122

In traditional quantitative genetics, additive effects of genes acting in a population of biparental homozygous lines are estimated on the basis of the phenotypic observations only, usually by taking a difference between mean values for extreme lines. Current molecular methods allow to estimate the additive effects by additionally taking into account the marker data. In this paper we compare these two methods of estimation of additive gene action effects analytically, by simulations and by analysis of real data sets for doubled haploid lines and recombinant inbred lines. The analytic comparison shows under which conditions an agreement of the two methods can be achieved. In most of the considered experimental data and in simulations we observe that the additive effect calculated on the basis of the marker observations is smaller than the total additive effect obtained from phenotypic observations only. This result is discussed, and a weighted regression approach is proposed as a method which can close the gap between the purely phenotypic and genotypic approaches.  相似文献   

Monitoring the impacts of mountain pine beetle mitigation     

Michael A. Wulder  Stephanie M. Ortlepp  Joanne C. White  Nicholas C. Coops  Sam B. Coggins 《Forest Ecology and Management》2009,258(7):1181-1187

Since 1999, the mountain pine beetle (Dendroctonus ponderosae Hopk. [Coleoptera: Scolytidae]) has impacted over 13 million hectares of pine forests in western Canada. Successful mitigation of the beetle depends on the accurate and timely identification of currently infested trees and on sustained control activities over several successive years. We monitored the success of mitigation activities in reducing damage caused by mountain pine beetle at two sites (A and B) on the leading edge of the current beetle epidemic in western Canada. Using three years of digital high spatial resolution aerial imagery (2006–2008) and one season of field measurements (2008), we estimated retrospective ratios of trees attacked by beetle in the current year (green attack) to trees attacked in the previous year (red attack), hereafter referred to as G:R. Our results indicate that mitigation activities slowed the rate of population growth, with G:R found to be decreasing or stable over sites A and B while mitigation was ongoing in 2005 and 2006 (site A 1.06:1; site B 0.32:1). When mitigation was discontinued over site A in 2007, the G:R increased markedly (1.94:1), while continued mitigation at site B in 2007 further reduced the G:R (0.22:1). Despite the cost associated with mitigation, its efficacy is rarely assessed and even more rarely documented. The approach presented herein enables a sample-based appraisal of mitigation efforts.  相似文献   

Beyond culinary colonialism: indigenous food sovereignty,liberal multiculturalism,and the control of gastronomic capital     

Sam Grey  Lenore Newman 《Agriculture and Human Values》2018,35(3):717-730

This article builds on the food sovereignty literature to ask pointed questions about the interplay of market forces and political liberalism. Specifically, we use cuisine as a lens to interrogate the assumption that multiculturalism is compatible with Indigenous food sovereignty. Because multicultural inclusion is the means by which Indigenous Peoples’ gastronomies are commodified and alienated, they experience not gastronomic multiculturalism but culinary colonialism. Accordingly, food sovereignty in colonial contexts must embrace both the active sharing and the mindful withholding of food as political acts, and acknowledge that culinary culture is not simply a market commodity but also a politically-embedded process. In drawing together the threads of this argument, we advocate for a broadening of the discussion on Indigenous food sovereignty to include the resistance and resurgence enacted through gastronomy.  相似文献   

Yield improvement in maize for tolerance to low soil nitrogen          下载免费PDF全文

Sam Oyewole Ajala  Amudalat Bolanle Olaniyan  Muyideen Oluseyi Olayiwola  Anthony Oluwatoyosi Job 《Plant Breeding》2018,137(2):118-126

Low soil nitrogen limits maize (Zea mays L.) production in the West and Central African subregion. Levels of residual genetic variability were determined in two low‐N populations using selfed progeny evaluations, and results obtained indicate large genotypic and phenotypic variances for grain yield under both low‐ and high‐N environments for effective selection, while heritability estimates were generally low. Ear aspect and stay green were the most important traits contributing to grain yield for both populations. Selection reduced days to flowering, ASI and ear aspect, but increased plant height and yield. Yield gains of more than 25% occurred for the two populations under both low and high N with the most significant change of 42% occurring in one population under high N.  相似文献