2,409 research outputs found

    Expression of a barley cystatin gene in maize enhances resistance against phytophagous mites by altering their cysteine-proteases

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    Phytocystatins are inhibitors of cysteine-proteases from plants putatively involved in plant defence based on their capability of inhibit heterologous enzymes. We have previously characterised the whole cystatin gene family members from barley (HvCPI-1 to HvCPI-13). The aim of this study was to assess the effects of barley cystatins on two phytophagous spider mites, Tetranychus urticae and Brevipalpus chilensis. The determination of proteolytic activity profile in both mite species showed the presence of the cysteine-proteases, putative targets of cystatins, among other enzymatic activities. All barley cystatins, except HvCPI-1 and HvCPI-7, inhibited in vitro mite cathepsin L- and/or cathepsin B-like activities, HvCPI-6 being the strongest inhibitor for both mite species. Transgenic maize plants expressing HvCPI-6 protein were generated and the functional integrity of the cystatin transgene was confirmed by in vitro inhibitory effect observed against T. urticae and B. chilensis protein extracts. Feeding experiments impaired on transgenic lines performed with T. urticae impaired mite development and reproductive performance. Besides, a significant reduction of cathepsin L-like and/or cathepsin B-like activities was observed when the spider mite fed on maize plants expressing HvCPI-6 cystatin. These findings reveal the potential of barley cystatins as acaricide proteins to protect plants against two important mite pests

    Occupational health legislation and practices related to seafarers on passenger ships focused on communicable diseases: results from a European cross-sectional study (EU SHIPSAN PROJECT)

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    <p>Abstract</p> <p>Background</p> <p>Seafarers play an important role in the transmission of communicable diseases. The aim of the present study is to draw information and identify possible gaps on occupational health practices related to seafarers sailing on ships within the European Union Member States (EU MS) with focus on communicable diseases.</p> <p>Methods</p> <p>A structured questionnaire was sent to competent authorities from 21 EU MS. The questionnaire included questions about occupational health policies, medical certification of seafarers, communicable diseases reporting and relevant legislation. Descriptive analysis of the data was conducted by the use of Epi Info software: EU MS were categorized in four priority groups (A, B, C, D) based on: number of passenger ships visits, volume of passengers, and number of ports in each country. Moreover, EU MS were categorized to old and new, based on the date of entry in the EU.</p> <p>Results</p> <p>All 21 countries with relevant competent authorities responded to the questionnaire. The existence of specific national legislation/regulation/guidelines related to vaccination of seafarers was reported by three out of the 21 (14%) responding authorities. Surveillance data of communicable diseases related to seafarers are collected and analyzed by 4 (19%) authorities. Five out of 21 of the responding countries (24%) reported that tuberculin test result is required for the issuance of seafarer's medical certificate while a great variety of medical examination is required for the issuance of this certificate among countries.</p> <p>Gaps on occupational health services focused on communicable diseases related to maritime occupation have been reported by 33% of the responding countries.</p> <p>Responding authorities from Group A and B had the highest percentage of reported gaps followed by groups C and D. Old MS reported a higher frequency regarding gaps on occupational health services in comparison to new MS.</p> <p>Conclusion</p> <p>Our results revealed heterogeneity regarding occupational health of maritime employees in EU MS. This work provides some evidence that further work at international and European level could be considered, in order to explore the potential for harmonized initiatives regarding occupational health of seafarers.</p

    An observational prospective study of topical acidified nitrite for killing methicillin-resistant Staphylococcus aureus (MRSA) in contaminated wounds

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    Background Endogenous nitric oxide (NO) kills bacteria and other organisms as part of the innate immune response. When nitrite is exposed to low pH, NO is generated and has been used as an NO delivery system to treat skin infections. We demonstrated eradication of MRSA carriage from wounds using a topical formulation of citric acid (4.5%) and sodium nitrite (3%) creams co-applied for 5 days to 15 wounds in an observational prospective pilot study of 8 patients. Findings Following treatment with topical citric acid and sodium nitrite, 9 of 15 wounds (60%) and 3 of 8 patients (37%) were cleared of infection. MRSA isolates from these patients were all sensitive to acidified nitrite in vitro compared to methicillin-sensitive S. aureus and a reference strain of MRSA. Conclusions Nitric oxide and acidified nitrite offer a novel therapy for control of MRSA in wounds. Wounds that were not cleared of infection may have been re-contaminated or the bioavailability of acidified nitrite impaired by local factors in the tissue

    Echinoderms have bilateral tendencies

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    Echinoderms take many forms of symmetry. Pentameral symmetry is the major form and the other forms are derived from it. However, the ancestors of echinoderms, which originated from Cambrian period, were believed to be bilaterians. Echinoderm larvae are bilateral during their early development. During embryonic development of starfish and sea urchins, the position and the developmental sequence of each arm are fixed, implying an auxological anterior/posterior axis. Starfish also possess the Hox gene cluster, which controls symmetrical development. Overall, echinoderms are thought to have a bilateral developmental mechanism and process. In this article, we focused on adult starfish behaviors to corroborate its bilateral tendency. We weighed their central disk and each arm to measure the position of the center of gravity. We then studied their turning-over behavior, crawling behavior and fleeing behavior statistically to obtain the center of frequency of each behavior. By joining the center of gravity and each center of frequency, we obtained three behavioral symmetric planes. These behavioral bilateral tendencies might be related to the A/P axis during the embryonic development of the starfish. It is very likely that the adult starfish is, to some extent, bilaterian because it displays some bilateral propensity and has a definite behavioral symmetric plane. The remainder of bilateral symmetry may have benefited echinoderms during their evolution from the Cambrian period to the present

    Surveillance and control of communicable diseases related to passenger ships in Europe

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    This study was conducted within the European SHIPSAN (ship sanitation) project and aims at exploring the legislative framework and current practices related to surveillance of communicable diseases and response aboard passenger ships in Europe. A detailed questionnaire was disseminated and completed by 59 competent authorities in 27 European countries. The majority of competent authorities used national legislation without special provisions for passenger ships. Only 20% had specific provisions for ships regarding quarantine, while a smaller proportion of new Member States (MS) have specific legislation in comparison with old MS (p = 0.01). The Maritime Declaration of Health (MDH) was the main reporting tool used. About 30.5% of the competent authorities declared that they require submission of MDH by all arriving ships, but 28.8% only from affected areas, and 11.9% never require MDH. A total of 45 outbreaks or incidents (36 gastrointestinal, 1 incident of legionellosis, 3 respiratory, and 1 influenza-like illness outbreak, occupational tuberculosis, varicella, scabies, and meningitis) were reported to EU competent authorities during 2006. About 75% of the responders stated that there are gaps in the surveillance and control of communicable diseases. A diversity of approaches in EU countries, and gaps regarding surveillance and response and training needs of personnel were identified. (Int Marit Health 2011; 62, 2: 138&#8211;147

    Conditional Facilitation of an Aphid Vector, Acyrthosiphon pisum, by the Plant Pathogen, Pea Enation Mosaic Virus

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    Plant pathogens can induce symptoms that affect the performance of insect herbivores utilizing the same host plant. Previous studies examining the effects of infection of tic bean, Vicia faba L. (Fabales: Fabaceae), by pea enation mosaic virus (PEMV), an important disease of legume crops, indicated there were no changes in the growth and reproductive rate of its primary vector the pea aphid, Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae). Here, we report the results of laboratory experiments investigating how A. pisum responded to PEMV infection of a different host plant, Pisum sativum L., at different stages of symptom development. Aphid growth rate was negatively related to the age of the host plant, but when they were introduced onto older plants with well-developed PEMV symptoms they exhibited a higher growth rate compared to those developing on uninfected plants of the same age. In choice tests using leaf discs A. pisum showed a strong preference for discs from PEMV-infected peas, probably in response to visual cues from the yellowed and mottled infected leaves. When adults were crowded onto leaves using clip-cages they produced more winged progeny on PEMV-infected plants. The results indicate that PEMV produces symptoms in the host plant that can enhance the performance of A. pisum as a vector, modify the production of winged progeny and affect their spatial distribution. The findings provide further evidence that some insect vector/plant pathogen interactions could be regarded as mutualistic rather than commensal when certain conditions regarding the age, stage of infection and species of host plant are met

    Tricholithobezoar Causing Gastric Perforation

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    A bezoar is an intraluminal mass formed by the accumulation of undigested material in the gastrointestinal tract. Trichobezoar is a rare condition seen almost exclusively in young women with trichotillomania and trichotillophagia. When not recognized, the trichobezoar continues to grow, which increases the risk of severe complications such as gastric ulceration and even perforation. Formation of a gallstone within the trichobezoar (tricholithobezoar) is an event that has not yet been described. We report the case of a 22-year-old woman admitted to the emergency room with signals and symptoms of an epigastric mass and perforative acute abdomen. Radiological study revealed bilateral pneumoperitoneum. Personal history revealed depressive syndrome, trichotillomania and trichophagia. With a diagnosis of visceral perforation, an urgent exploratory laparotomy was performed. This confirmed the diagnosis of gastric perforation due to a large trichobezoar with the formation of a gastrolith that was removed by anterior gastrotomy. Biochemical study of the gastric stone revealed that it was composed of bile salts. There were no complications. The patient was discharged on the 5th postoperative day and was referred for psychiatric treatment

    Network 'small-world-ness': a quantitative method for determining canonical network equivalence

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    Background: Many technological, biological, social, and information networks fall into the broad class of 'small-world' networks: they have tightly interconnected clusters of nodes, and a shortest mean path length that is similar to a matched random graph (same number of nodes and edges). This semi-quantitative definition leads to a categorical distinction ('small/not-small') rather than a quantitative, continuous grading of networks, and can lead to uncertainty about a network's small-world status. Moreover, systems described by small-world networks are often studied using an equivalent canonical network model-the Watts-Strogatz (WS) model. However, the process of establishing an equivalent WS model is imprecise and there is a pressing need to discover ways in which this equivalence may be quantified. Methodology/Principal Findings: We defined a precise measure of 'small-world-ness' S based on the trade off between high local clustering and short path length. A network is now deemed a 'small-world' if S. 1-an assertion which may be tested statistically. We then examined the behavior of S on a large data-set of real-world systems. We found that all these systems were linked by a linear relationship between their S values and the network size n. Moreover, we show a method for assigning a unique Watts-Strogatz (WS) model to any real-world network, and show analytically that the WS models associated with our sample of networks also show linearity between S and n. Linearity between S and n is not, however, inevitable, and neither is S maximal for an arbitrary network of given size. Linearity may, however, be explained by a common limiting growth process. Conclusions/Significance: We have shown how the notion of a small-world network may be quantified. Several key properties of the metric are described and the use of WS canonical models is placed on a more secure footing
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