Search

Parasites use host behavior to increase their rate of multiplication through a population. Cytoplasmic microorganisms, Wolbachia pipientis, infest themselves in several insect species, and it is observed that males infected with them are reproductively incompatible with uninfected females. Fertilization was non-random in the presence of the parasite and this benefited the parasite. These parasites come under the alpha-subdivision of the proteobacteria and are associated with the rickettsia. Molecular biological assay showed seven other species harboring these parasites.

Abstract Background The Andean valleys of Bolivia are the only reported location of sylvatic Triatoma infestans, the main vector of Chagas disease in this country, and the high human prevalence of Trypanosoma cruzi infection in this region is hypothesized to result from the ability of vectors to persist in domestic, peri-domestic, and sylvatic environments. Determination of the rate of Trypanosoma infection in its triatomine vectors is an important element in programs directed at reducing human infections. Traditionally, T. cruzi has been detected in insect vectors by direct microscopic examination of extruded feces, or dissection and analysis of the entire bug. Although this technique has proven to be useful, several drawbacks related to its sensitivity especially in the case of small instars and applicability to large numbers of insects and dead specimens have motivated researchers to look for a molecular assay based on the polymerase chain reaction (PCR) as an alternative for parasitic detection of T. cruzi infection in vectors. In the work presented here, we have compared a PCR assay and direct microscopic observation for diagnosis of T. cruzi infection in T. infestans collected in the field from five localities and four habitats in Chuquisaca, Bolivia. The efficacy of the methods was compared across nymphal stages, localities and habitats. Methods We examined 152 nymph and adult T. infestans collected from rural areas in the department of Chuquisaca, Bolivia. For microscopic observation, a few drops of rectal content obtained by abdominal extrusion were diluted with saline solution and compressed between a slide and a cover slip. The presence of motile parasites in 50 microscopic fields was registered using 400× magnification. For the molecular analysis, dissection of the posterior part of the abdomen of each insect followed by DNA extraction and PCR amplification was performed using the TCZ1 (5' – CGA GCT CTT GCC CAC ACG GGT GCT – 3') and TCZ2 (5' – CCT CCA AGC AGC GGA TAG TTC AGG – 3') primers. Amplicons were chromatographed on a 2% agarose gel with a 100 bp size standard, stained with ethidium bromide and viewed with UV fluorescence. For both the microscopy and PCR assays, we calculated sensitivity (number of positives by a method divided by the number of positives by either method) and discrepancy (one method was negative and the other was positive) at the locality, life stage and habitat level. The degree of agreement between PCR and microscopy was determined by calculating Kappa (k) values with 95% confidence intervals. Results We observed a high prevalence of T. cruzi infection in T. infestans (81.16% by PCR and 56.52% by microscopy) and discovered that PCR is significantly more sensitive than microscopic observation. The overall degree of agreement between the two methods was moderate (Kappa = 0.43 ± 0.07). The level of infection is significantly different among communities; however, prevalence was similar among habitats and life stages. Conclusion PCR was significantly more sensitive than microscopy in all habitats, developmental stages and localities in Chuquisaca, Bolivia. Overall we observed a high prevalence of T. cruzi infection in T. infestans in this area of Bolivia; however, microscopy underestimated infection at all levels examined.

A study was conducted to investigate the correlation between cannibalistic behavior and relatedness in willow leaf beetles. Data were based on the cannibalism rate and relatedness of 74 beetles from 198 clutches. An analysis of data using statistical methods failed to provide a positive relationship between cannibalism and relatedness. This suggests that other factors such as competition, conflicts within the population and selection, influenced the cannibalistic behavior exhibited by beetles.

Ed Ruscha's exhibit at the Museum of Modern Art in San Francisco presented a fantastic and challenging teaching approach not just to art creation, but also to the whole definition of art. Ruscha painted with pastels and drew with pencils, but he also made art using Pepto Bismol, carrots, and spinach. In this article, the author describes an art project inspired by Ruscha's art. (Contains 1 online resource.)

Orland is a small agricultural town in Northern California. The community has been deluged with fundraisers and requests for money. The author knew there must be a way to self-fund. She took a closer look at what made some of their community artists successful, and she looked at what the public bought. Her challenge was to put together a project that would sell. She traveled to local studios, talked to thriving artists, and got their views on the local market. In this article, the author describes an approach to self-funding an art program with art. (Contains 1 online resource.)

Visitors to the campus of Orland High School (OHS) will never question that they have stepped into a world of the masses: kids, activity, personalities, busyness, and playfulness--a veritable cloud of mild bedlam. The wall of ceramic faces that greets a visitor in the school office is another reminder of the organized chaos that the teachers adore. For years they had a principal who would only allow them to display temporary art in designated locations. No murals were permitted, no matter the quality or the goal. This article describes how students from art classes made the ceramic faces on the wall of OHS. (Contains 1 online resource.)

In this article, the author describes how she introduced an art project to her students that incorporates balance. She relates that she initially allowed brainstorming before they carried on with the project. She states that many rough sketches were done before students were able to figure out the details needed for the success of their project. (Contains 1 online resource.)

Teaching high school students the "grammar" of art--the principles and elements of art and design--while also teaching them about creativity and concept can be difficult. This author has found that combining beginning lessons in line, shape, value, texture, form, and color with projects requiring innovation and inspiration, though challenging, is achievable with experimentation and time. The author describes an activity that encourages students to explore the many varieties of textures in the visual arts, both historical and contemporary, and in their own environment.

The author describes a lesson she did on abstract art with her high school art classes. She passed out a required step-by-step outline of the project process. She asked each of them to look at abstract art. They were to list five or six abstract artists they thought were interesting, narrow their list down to the one most personally intriguing, and do a bit of research, and finally complete a paper in which they included a little biography, information regarding the timely importance of their artist, and short critiques of two artworks they photocopy or print. Their personal critiques were imperative. They structured their final painting to resemble the style of their chosen artist in their final project. A "Web Link" list of web sites related to topics discussed in the article is included.