A marine algal bioassay method: Results with pesticides and industrial wastes

A simple marine algal bioassay method is described for short- and long-term studies on pesticides and industrial wastes. It can be used for rapid screening of a variety of substances with single-species and multiplespecies tests and gives relative toxicities of the pollutants tested. Algae are grown in optically matched culture tubes that fit directly into a spectrophotometer, allowing population density to be estimated by absorbance without removal of samples. 96 h EC50 values for some pesticides and the diatomSkeletonema costatum are: EPN, 340 μg l^?1; carbophenothion, 109 μg l^?1; DEF, 366ug l^?1; ethoprop, 8.4 mg l^?1; methyl parathion, 5.3 mg l^?1; and phorate, 1.3 mg l^?1. Presence of the chelator EDTA in medium had no effect on toxicity of carbaryl toS. costatum, Nitzschia angularum, Chlorococcum sp. andChlorella sp. Liquid industrial wastes either stimulated growth, inhibited growth, or stimulated growth at low concentrations but inhibited it at higher concentrations. In mixed-species studies with the herbicide neburon, presence of a resistant species protected the sensitive species. Liquid industrial waste from a paper products plant caused changes in relative numbers, as compared to controls, whenS. costatum andPorphyridium cruentum were grown together.     

A bacterium that can grow by using arsenic instead of phosphorus

Life is mostly composed of the elements carbon, hydrogen, nitrogen, oxygen, sulfur, and phosphorus. Although these six elements make up nucleic acids, proteins, and lipids and thus the bulk of living matter, it is theoretically possible that some other elements in the periodic table could serve the same functions. Here, we describe a bacterium, strain GFAJ-1 of the Halomonadaceae, isolated from Mono Lake, California, that is able to substitute arsenic for phosphorus to sustain its growth. Our data show evidence for arsenate in macromolecules that normally contain phosphate, most notably nucleic acids and proteins. Exchange of one of the major bio-elements may have profound evolutionary and geochemical importance.     

Understanding pressures on fishery resources through trade statistics: a pilot study of four products in the Chinese dried seafood market

This study investigates the dried seafood trade, centred in Chinese markets, in order to better understand the pressures its demand exerts on global marine resource stocks. Using Hong Kong, the region's largest entrepôt, as a focal point, the trade in shark fins, abalone, bêche‐de‐mer and dried fish is characterized in terms of product history, volume, source fisheries and species composition. Trends identified in the Hong Kong market are interpreted in the context of the larger Chinese market. Shark fin imports grew 6% per year between 1991 and 2000, most likely because of market expansion in Mainland China, posing increasingly greater pressures on global shark resources. In contrast, the quantities of dried abalone traded through Hong Kong remained steady, but inferences based on this trend are discouraged by suggestions of increasing preferences for fresh product forms and growing domestic production in Mainland China. Hong Kong's imports of dried bêche‐de‐mer (sea cucumber) have decreased, while the percentage of imports re‐exported has remained steady, suggesting that Hong Kong continues as an entrepôt for Mainland China despite declining domestic consumption. Few conclusions can be drawn regarding dried fish products, including whole fish and fish maws, because of a lack of product differentiation in customs data, but a market survey was conducted to provide information on species composition. Comparison of Hong Kong dried seafood trade statistics to those of other key trading partners indicates that, in general, Hong Kong's duty‐free status appears to encourage more accurate reporting of traded quantities. Under‐reporting biases ranged from 24 to 49% for shark fin and bêche‐de‐mer, respectively. Comparison to United Nations (UN) Food and Agriculture Organization (FAO) databases indicates additional under‐reporting for shark fin such that an alternative minimum estimate of world trade is at least twice the FAO estimates in 1998–2000. The results of a survey of Hong Kong traders provide insight into their attitudes toward harvest, economic and regulatory factors, and suggest that conservation efforts are unlikely to emerge from, or be actively supported by, dried seafood trade organizations. The market's apparent sensitivity to economic sentiment, however, reveals an opportunity for consumer education to play a role in shaping future market growth and resource conservation. Recommendations are provided for improving trade statistics and for developing better analytical techniques to complement traditional methods for monitoring the exploitation and management of fisheries resources.     

Tuber yield and tuber traits of haploid-wild species F1 hybrids

Summary Haploid-wild species hybrids have been produced that incorporate desirable traits and genetic diversity from wild species into the cultivated potato. Nine wild species were represented in 210 hybrids which were evaluated in a yield trial with ten haploid parents and four cultivars. Haploid-wild species hybrids yielded up to 3.1 kg/hill, compared to 1.8 kg/hill for the haploids; the species parents did not tuberize. Some 2x hybrids outyielded three of the 4x cultivars. Tubers of most hybrids, especially those withSolanum berthaultii, S. canasense, S. chacoense, andS. tarijense as parents, were very smooth. Tuber set in many haploid-wild species hybrids was low. Extensive variability for dormancy and mass density (specific gravity) was also observed. Haploid-wild species hybrids which produce 2n pollen have been brought to the 4x level via 4x×2x crosses.

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Zusammenfassung Es wurden Haploid-Wildarten F₁-Hybriden erzeugt, um aus Wildarten in Zuchtkartoffeln wünschenswerte Merkmale und genetische Mannigfaltigkeit hineinzubringen. Vier Sorten, zehn Haploide und 210 Haploid-Wildarten F₁-Hybriden, einschliesslich der folgenden 2x-Wildarten, wurden in einen Ertragsversuch einbezogen:S. berthaultii (ber),S. boliviense (blv),S. canasense (can),S. chacoense (chc),S. infundibuliforme (ifd),S. microdontum (mcd),S. sanctae-rosae (sct),S. raphanifolium (rap), andS. tarijense (tar). Die Ertr?ge vieler Haploid-Wildarten Hybriden waren erstaunlich hoch, bis zu 3,1 kg/Hügel und gr?sser als bei jeweils beiden Eltern (Tabelle 1). Haploide ergaben bis zu 1,8 kg/Hügel, die Arten-Eltern bildeten keine Knollen. Die Abb. 1 veranschaulicht den Unterschied zwischen dem Ertrag einer Hybride und ihrer Eltern. Einige 2x-Hybriden übertrafen 4x-Sorten (Tabelle 2): Gr?ssere Pflanzweiten und eine lange Wachstumszeit m?gen den Hybriden einen Vorteil gegenüber den Sorten gegeben haben. Die Knollen der meisten Haploid-Wildarten Hybriden waren sehr weich, besonders diejenigen mit ber, can, che und tar als Eltern. Bei einigen Haploid-Wildarten Hybriden hatten alle Klone gleicher Abstammung eine lange Knollenkeimruhe, bei anderen waren einige Klone innerhalb der gleichen Abstammung mit langer, andere mit kurzer Keimruhe (Tabelle 3). Die Massendichte (spezifische Gewicht) variierte innerhalb der Haploid-Wildarten Hybriden von 1,050 für eine US-W2838 x tar Hybride und eine US-W457 x tar Hybride bis 1,110 für eine US-W2236 x tar Hybride; Haploide variieren von 1,058 bis 1,079 und Sorten von 1,051 bis 1,076. Die Erzeugung von Haploid-Wildarten Hybriden ist eine wirkungsvolle Methode, um nicht adaptiertes Wildarten-Erbgut in eine Form zu bringen, die Knollen ausbilden wird. Dies erlaubt die leichte Erhaltung wertvoller Genotypen und die Absch?tzung der Beitr?ge von Wildarten-Genotypen zum Ertrag und zu den Knollenmerkmalen. Auch erh?lt man damit ein hoch variables Material für genetische Untersuchungen. Haploid-Wildarten Hybriden, die 2n-Pollen erzeugen, wurden in 4x×2x Kreuzungen verwendet, um 4x-Hybriden herzustellen, die in Kartoffelzuchtprogrammen eingesetzt werden k?nnen.

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Résumé Des hybrides F₁ issus d'espèces haplo?des sauvages ont été produits dans le but d'introduire des caractères désirables et la diversité génétique dans les pommes de terre cultivées. Quatre variétés, dix haplo?des et 210 hybrides F₁ issus d'espèces haplo?des sauvages, incluant les espèces sauvages 2x, entraient dans l'essai de productivité:S. berthaultii (ber),S. boliviense (blv),S. canasense (can),S. chacoense (chc),S. infundibuliforme (ifd),S. microdontum (mcd),S. sanctae-rosae (sct),S. raphanifolium (rap) etS. tarijense (tar). La production de nombreux hybrides issus d'espèces haplo?des sauvages était notablement élevée, plus de 3.1 par pied, et plus forte que celle de leurs parents (tableau 1). Les haplo?des produisaient 1.8 kg/pied; les espèces parentales ne tubérisaient pas. La figure 1 illustre les différences observées entre le rendement de l'hybride et celui de ses parents. Quelques hybrides 2x surpassaient les variétés 4x (tableau 2). Un espacement important et une longue durée de végétation pourraient avoir donné un avantage aux hybrides sur les variétés. Les tubercules de la plupart des hybrides issus d'espèces haplo?des sauvages, notamment de ceux dont les parents étaient ber, can, chc et tar, étaient lisses. Quelques hybrides d'espèces haplo?des sauvages, tous apparentés, présentaient une longue dormance; pour d'autres la dormance était courte (tableau 3). Parmi les hybrides issus d'espèces haplo?des sauvages, la densité (le poids spécifique) variait de 1.050 pour US-W2838 x tar et US-W457 x tar à 1.100 pour US-W2236 x tar; les haplo?des s'échelonnaient de 1.058 à 1.079 et les variétés de 1.051 à 1.076. La production d'hybrides à partir d'espèces haplo?des sauvages est une méthode efficace pour introduire le caractère tubérifère chez des espèces sauvages qui ne le sont pas. Elle permet la maintenance facile de génotypes valables et l'évaluation de l'apport des génotypes d'espèces sauvages au rendement et aux caractéristiques des tubercules. Elle fournit aussi un matériel hautement variable pour les études génétiques. Des hybrides issus d'espèces haplo?des sauvages produisant du pollen 2n étaient utilisés dans les croisements 4x et 2x pour obtenir des hybrides 4x qui pourront contribuer aux programmes d'hybridation de la pomme de terre.

     

Case–control study of Staphylococcus lugdunensis infection isolates from small companion animals

Background – Coagulase‐negative Staphylococcus lugdunensis has recently been shown to cause invasive infections of people, which are similar in pathogenic effect to those caused by Staphylococcus aureus. Little is known about the pathogenicity of S. lugdunensis in companion animals. Objectives – To compare potential risk factors for infection, body sites affected, and whether cases and controls had been treated with antimicrobial drugs based upon susceptibility test results. Animals – Thirty‐three cases of S. lugdunensis infection (25 dogs, six cats and two small mammals) were identified between January 2003 and August 2011. Two Staphylococcus pseudintermedius controls, which were identified by the microbiology laboratory immediately before and after each S. lugdunensis case, were host‐species matched to each case. Methods – A retrospective case–control analysis. Results – During the period evaluated, the prevalence of S. lugdunensis infection was 1.3 cases per 10,000 hospital admissions for dogs and 0.95 cases per 10,000 admissions for cats (P = 0.453). In univariate analyses, S. pseudintermedius isolation was significantly associated with skin infections (P < 0.0001), while S. lugdunensis isolation was associated with the respiratory tract (P = 0.03) and other deep tissues (P = 0.005). Cases were less likely than controls to have been treated based upon susceptibility test results (P = 0.02). A conditional logistic regression analysis showed isolation of S. lugdunensis to be associated with recent (≤ 30 days) steroid administration (odds ratio, 17.72; 95% confidence interval, 2.35–132.82; P = 0.005); and in‐patient status (odds ratio, 9.67; 95% confidence interval, 2.18–42.88; P = 0.003). Conclusions – These results suggest that S. lugdunensis may cause invasive infections in companion animals, which should be treated with antimicrobials based upon susceptibility tests when available.