3,761 research outputs found
Hatching Strategies in Monogenean (Platyhelminth) Parasites that Facilitate Host Infection
In parasites, environmental cues may influence hatching of eggs and enhance the success of infections. The two major endoparasitic groups of parasitic platyhelminths, cestodes (tapeworms) and digeneans (flukes), typically have high fecundity, infect more than one host species, and transmit trophically. Monogeneans are parasitic flatworms that are among the most host specific of all parasites. Most are ectoparasites with relatively low fecundity and direct life cycles tied to water. They infect a single host species, usually a fish, although some are endoparasites of amphibians and aquatic chelonian reptiles. Monogenean eggs have strong shells and mostly release ciliated larvae, which, against all odds, must find, identify, and infect a suitable specific host. Some monogeneans increase their chances of finding a host by greatly extending the hatching period (possible bet-hedging). Others respond to cues for hatching such as shadows, chemicals, mechanical disturbance, and osmotic changes, most of which may be generated by the host. Hatching may be rhythmical, larvae emerging at times when the host is more vulnerable to invasion, and this may be combined with responses to other environmental cues. Different monogenean species that infect the same host species may adopt different strategies of hatching, indicating that tactics may be more complex than first thought. Control of egg assembly and egg-laying, possibly by host hormones, has permitted colonization of frogs and toads by polystomatid monogeneans. Some monogeneans further improve the chances of infection by attaching eggs to the host or by retaining eggs on, or in, the body of the parasite. The latter adaptation has led ultimately to viviparity in gyrodactylid monogeneans
A Panzer Commander Working Toward the Fuhrer : The World War II Career of General oberst Hermann Hoth
Water resources management in the Nile basin: The economic value of cooperation
Water Policy73227-252WPAO
From STEM to STEAM: strategies for enhancing engineering & technology education
This paper sets out to challenge the common pedagogies found in STEM (Science, Technology, Engineering and Mathematics) education with a particular focus on engineering. The dominant engineering pedagogy remains “chalk and talk”; despite research evidence that demonstrates its ineffectiveness. Such pedagogical approaches do not embrace the possibilities provided by more student-centric approaches and more active learning. The paper argues that there is a potential confusion in engineering education around the role of active learning approaches, and that the adoption of these approaches may be limited as a result of this confusion, combined with a degree of disciplinary egocentrism. The paper presents examples of design, engineering and technology projects that demonstrate the effectiveness of adopting pedagogies and delivery methods more usually attributed to the liberal arts such as studio based learning. The paper concludes with some suggestions about how best to create a fertile environment from which inquiry based learning can emerge as well as a reflection on whether the only real limitation on cultivating such approaches is the disciplinary egocentrism of traditional engineering educators
Full STEAM ahead: a manifesto for integrating arts pedagogics in to STEM education
This paper sets out to challenge the common pedagogies found in STEM education with a particular focus on engineering. The dominant engineering pedagogy remains “chalk and talk”; despite research evidence that demonstrates its ineffectiveness. The paper argues that there is a potential confusion in engineering education around the role of active learning approaches, and that the adoption of these approaches may be limited as a result of this confusion, combined with a degree of disciplinary egocentrism. The paper presents examples of engineering and “engineering like” projects that demonstrate the effectiveness of adopting pedagogies and delivery methods more usually attributed to the liberal arts such as studio based learning. The paper concludes with some suggestions about how best to create a fertile environment from which inquiry based learning can emerge as well as a reflection on whether the only real limitation on cultivating such approaches is the disciplinary egocentrism of traditional engineering educators
Evaluation of arts based courses within a UK recovery college for people with mental health challenges
No previous studies have evaluated arts based recovery college courses. Yet arts may assist in personal recovery, as often defined by service users, through social connection and personal meaning.
This interdisciplinary study evaluated (i) whether self-reported wellbeing and arts activities increased following arts based recovery college courses, and (ii) how students, peer trainers and artist-trainers understood courses’ impact. The design was mixed-methods. Of 42 service-user students enrolling, 39 completed a course and 37 consented to provide data. Of these, 14 completed pre and post course questionnaires on mental wellbeing and 28 on arts participation. Post course focus groups were held with 6 of 8 peer-trainers and 5 of 7 artist-trainers, and 28 students gave written feedback. Twenty-four students were interviewed up to three times in the subsequent nine months. There were statistically significant increases in self-reported mental wellbeing and range of arts activities following course attendance. At follow-up 17 of 24 students reported improved mental wellbeing, while 7 reported little or no change. Some spoke of increased social inclusion and continuing to use skills learned in the course to maintain wellbeing. Initial in course experience of ‘artistic growth’ predicted follow-up reports of improvement.
Future controlled studies should employ standardized measures of social inclusion and arts participation
Cross species transmission of ovine Johnes Disease - Phase 1 : National Ovine Johne’s Disease Control and Evaluation Program.
Johne’s disease was investigated in fibre goats on several farms. The disease was caused by sheep [S] strains of Mycobacterium avium subsp. paratuberculosis. The infection appeared to be less severe than the same infection in sheep in that fewer goats than sheep became infected, and fewer goats than sheep developed obvious signs of the infection. However, infected goats shed the organism in their faeces and therefore were able to spread the infection to other goats and sheep. Therefore inclusion of goats in the control program for ovine Johne’s disease is justified. A communication program is recommended to advise producers that ovine Johne’s disease in goats may not be obvious and that testing should be undertaken to ensure disease is not present. The impact of ovine Johne’s disease on the fibre goat industry is projected not to be great due to the small number of herds likely to be infected
A new species of Dermopristis Kearn, Whittington & Evans-Gowing, 2010 (Monogenea: Microbothriidae), with observations on associations between the gut diverticula and reproductive system and on the presence of denticles in the nasal fossae of the host Glaucostegus typus (Bennett) (Elasmobranchii: Rhinobatidae)
Dermopristis cairae n. sp. (Microbothriidae) is described from the skin and possibly from the nasal fossae of the giant shovelnosed ray Glaucostegus typus (Bennett). The new species is distinguished from D. paradoxus Kearn, Whittington & Evans-Gowing, 2010 by its larger size, body shape, lack of transverse ridges on the ventral surface and absence of a seminal receptacle. Extensive short gut branches lie dorsal to the testes and adjacent to the coiled region of the vas deferens and the oo¨type, possibly reflecting high metabolic demand in these areas. Denticles are present in the lining of the nasal fossae of G. typus, providing a firm substrate for the cement-based attachment of a microbothriid. However, confirmation that D. cairae inhabits the nasal fossae of G. typus is required
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