Comparison of sample collection methods for the PCR detection of oral anaerobic pathogens

AIMS: To provide evidence that DNA-PCR diagnostics of oral pathogens based on standard sample collection by paper point insertion from the depth of the periodontal pocket can be replaced by a novel non-invasive collection method based on swab technique from the gingiva. METHODS AND RESULTS: In this study we compared the results from two collection methods performed in 35 patients with chronic adult periodontitis. Statistical analysis showed a highly significant association of diagnostic results between both collection techniques. CONCLUSIONS: The Pocket-out method represents a reliable alternative to the standard collection technique for PCR diagnosis of oral pathogens. SIGNIFICANCE AND IMPACT OF THE STUDY: Due to its simplicity and non-invasiveness, the Pocket-out collection could be performed in any physician office, or even by the patient himself. With respect to the putative association between periodontal disease and various systemic illnesses, this method could be integrated with various screening programs of oral pathogens.     

Rapid data collection and assessment of the biology of Acanthurus nigrofuscus at Woleai Atoll, Micronesia

Traditional community fishing methods commonly employed in the tropical Pacific were used to generate information on the fishery biology of Acanthurus nigrofuscus at Woleai Atoll, Micronesia, over a short time period. A simple depletion model was used to estimate the biomass of A. nigrofuscus at four back reef lagoon sites at Woleai, using two different fishing methods; spear fishing and drive-in-net fishing. The mean biomass and density of A. nigrofuscus on the lagoon reefs was 8000 g ha ⁻¹ and 183 fish ha ⁻¹ respectively, with a total estimated standing stock for the lagoon of 91 500 fish or a biomass of 4·0 t. The size frequencies of fish caught by spear fishing were biased towards larger sized individuals, while those from drive-in-net fishing were thought to be more representative of the true population size frequencies. Variation in the density and biomass of A. nigrofuscus at the four reef sites was thought to be due to the length of time between episodes of community fishing at each reef site. The sex ratio (male: female) of A. nigrofuscus was significantly different from unity (1: 0·47) and males grew larger than females. Sexually mature fish were present in all size classes above the minimum capture length and spawning activity was greatest during the period of the full moon.     

Sample size for collecting seeds in germplasm conservation: the case of the Lima bean (Phaseolus lunatus L.)

 The design of optimum sampling strategies integrating criteria of efficiency relevant to multilocus models and many target populations has been investigated with respect to the number of plants and the number of seeds per plant to be sampled for a Lima bean (Phaseolus lunatus L.) gene pool. This study, using five populations and six polymorphic enzyme loci, shows that the number of plants rather than the number of seeds collected per plant primarily determines the success of seed sampling, suggesting that plant number plays an essential part in maintaining the allelic multiplicity of predominantly selfing species like Lima bean. According to the results, it appears that among Lima bean populations an efficient sampling procedure is achieved by collecting 1–4 seeds from 200 to 300 plants. These sample sizes will retain 8–10 alleles, regardless of their frequencies. When we consider polymorphism at the 5% level, it is expected that sampling 10–80 plants will collect combinations of 4–8 alleles. Based on data from genetic and demographic studies, we suggest an efficient sampling scheme for Lima bean germplasm at both population and geographical levels. Received: 10 March 1998 / Accepted: 1 April 1998     

Mapping the geographical distribution of genetic variation in the genus Lens for the enhanced conservation of plant genetic diversity

Plant genetic resource conservation strategies, informed by an understanding of the geographical distribution of genetic variation within species, are likely to result in a wider representation of conserved diversity in ex situ gene banks and in situ genetic reserves. The main objective of this study was to map the geographical distribution of genetic variation, as revealed by randomly amplified polymorphic DNA (RAPDs), in four wild relatives of the cultivated lentil, namely Lens culinaris ssp. orientalis, L. odemensis, L. ervoides and L. nigricans . Areas of high diversity and unique diversity were located for each taxon, and regions where further germplasm collection was most likely to yield novel genetic variation were identified. There were centres of diversity for L. culinaris ssp. orientalis in southeast Turkey and northwest Syria, and in south Syria and Jordan. A centre of diversity was found to exist in Sweida province, south Syria, for L. odemensis , and for L. ervoides along the coastal border region between Syria and Turkey stretching down along the Syrian coast. There was a centre of diversity for L. nigricans in west Turkey. Analytical techniques previously used at the species level were found to be useful at the genotypic level to objectively target areas for future collection missions, to increase diversity in ex situ collections and to target areas for in situ conservation.     

大豆微核心种质对草甘膦的耐受性鉴定

以萌发初期大豆弯曲的子叶节为靶点,利用草甘膦(Roundup)点施鉴定法,分析了221份大豆微核心种质的草甘膦耐受性及其与抗草甘膦转CP4-EPSPS基因大豆AG5601的差异,结果表明,草甘膦对不同大豆种质的抑制程度与点施的草甘膦浓度呈正相关,Roundup稀释浓度为1/1000、1/10000时,草甘膦对大豆生长几乎无影响;Roundup稀释浓度为1/10时,草甘膦显著抑制大豆生长,导致植株死亡;Roundup稀释浓度为1/100时,不同大豆种质对草甘膦耐受性差异显著,并鉴定出对草甘膦具有较好耐受性的种质10份。虽然大豆微核心种质对草甘膦的耐受程度远远低于AG5601,但不同大豆种质对草甘膦耐受性存在显著差异,这为利用转基因和杂交转育技术培育抗草甘膦转基因大豆的受体或轮回亲本的选择提供了理论依据。     

EPA Method 1615. Measurement of Enterovirus and Norovirus Occurrence in Water by Culture and RT-qPCR. I. Collection of Virus Samples

EPA Method 1615 was developed with a goal of providing a standard method for measuring enteroviruses and noroviruses in environmental and drinking waters. The standardized sampling component of the method concentrates viruses that may be present in water by passage of a minimum specified volume of water through an electropositive cartridge filter. The minimum specified volumes for surface and finished/ground water are 300 L and 1,500 L, respectively. A major method limitation is the tendency for the filters to clog before meeting the sample volume requirement. Studies using two different, but equivalent, cartridge filter options showed that filter clogging was a problem with 10% of the samples with one of the filter types compared to 6% with the other filter type. Clogging tends to increase with turbidity, but cannot be predicted based on turbidity measurements only. From a cost standpoint one of the filter options is preferable over the other, but the water quality and experience with the water system to be sampled should be taken into consideration in making filter selections.     

中国绿豆应用型核心样本农艺性状的分析

为提高种质资源在育种中的利用效率,建立了我国绿豆(Vigna radiata)应用型核心样本。该样本既包括了资源库中具特异性状的种质和曾经在生产上大面积种植的品种,也包括了在育种中使用频繁的亲本及苗头品系等。农艺性状变异分析表明,该核心样本具有丰富的表型变异,是绿豆种质资源的代表性样本。聚类分析可将核心样本分为4大类,但类别内种质与其地理来源相关不明显。不同来源表型数据的分析发现,不同性状间的一致性存在差异。但产量相关性状的表现均与当前育种目标相接近,说明该核心样本具有较高的实用性。     

Distribution,occurrence and natural invertebrate hosts of indigenous entomopathogenic fungi of Central India

We report here that, during periodical surveys of insects inhabiting diverse habitats for the collection of entomopathogenic fungi; a large number of isolates were recovered belonging to seven species, from various regions of Madhya Pradesh and Chhattisgarh forest areas and agricultural fields. The most common entomopathogenic fungi such as Beauveria bassiana, Nomuraea rileyi, Paecilomyces farinosus and Paecilomyces fumosoroseus were found to infect various insect hosts species naturally viz. Hyblaea puera, Eutectona machaeralis, Diachrysia orichalcea, Spodoptera litura, and few new insect hosts of these fungal pathogens among Indian insect population were collected for the first time from Central India, such as beetles of Agrilus species, hairy caterpillars of Lymantria species. The isolation, identification, maintenance and pathogenicity assay of these isolates was performed prior to deposition in culture collection center.     

举证责任倒置对医生影响的调查分析

目的:了解举证责任倒置实施以来,该政策对医生的影响及实施中存在的问题。方法:应用自制问卷,对青岛、西安两地9家三甲综合性医院共256名医生进行问卷调查,运用spss16.0进行统计分析。结果:举证责任倒置一方面给医生的医疗行为带来了积极影响,另一方面也给医生带来了较大的心理压力,尤其是发生过纠纷、被起诉的医生,对其以后的行为产生了消极影响。结论:医院除应加强对医生医疗技术、法律知识培训外,还应成立专门的机构来缓解医生的心理压力,解除其心理问题。     

Gas chromatography column as an ambient‐temperature volatile trap

Open‐tube volatile traps have largely been shunned in favor of solid adsorbent containing traps for the collection of volatile pheromones and attractants. Solid adsorbents require large solvent rinses and glass capillaries can be difficult to maneuver for the collection of volatiles from small or hard‐to‐reach odor sources. A gas chromatograph (GC) column (DB‐1), an open‐tube glass capillary, and a SuperQ^®‐containing capillary were compared for their collection efficiencies from rubber septa and live calling insects. All three traps captured similar ratios of test compounds from septa at airflows >10 ml per min. Eluting analytes from a packed adsorbent, SuperQ, required at least 30× more solvent than was required to collect all the pheromone from the open‐tube glass capillaries, and the GC column enjoyed an additional three‐fold reduced solvent volume compared to the glass capillary. Thus, analytes could be eluted from the GC‐column trap and directly analyzed on GC without solvent evaporation. We placed glass wool ‘plugs’ in both GC columns and glass capillaries and found no volatiles in these plugs, indicating that breakthrough did not occur during 1‐h collections at 25 ml per min. We demonstrate here that at ambient laboratory temperatures, a DB‐1 GC column effectively collects Oriental fruit moth sex pheromone volatiles from a rubber septum and live pheromone‐releasing moths. Release ratios of pheromone from rubber septa are consistent with earlier reports from static air systems, whereas the release ratio of the (Z)‐8‐dodecenyl alcohol (Z8‐12:OH) from female Grapholita molesta Busck (Lepidoptera: Tortricidae) differed from published results and is likely due to different collection methods or moth‐strain origin.