The Demonstration of Mitotic Figures in Green Algae

Wittman\u27s aceto-iron-haematoxylin stain was combined with Hoyer\u27s mounting medium in a rapid method for demonstrating mitosis in the green algae. Both filamentous and unicellular forms were killed, fixed, and stained in one step with the self-mordanting stain. Cells were then washed with acetic acid and transferred directly to the water-soluble Hoyer\u27s medium. Slides prepared in this manner are permanent. Chlorophyll was bleached from the algal cells by this medium. This revealed the stained nuclei and mitotic figures. This simplified technique is particularly suitable for student use

Progressives, the COVID Pandemic, and the Laboratories of Democracy: Is the Left Saying “Goodbye” to Cooperative Federalism?

Events surrounding the COVID pandemic draw into question the progressive commitment to cooperative federalism. This is evidenced by their espousing the virtues of the tenth amendment, “states rights,” and ample use of the expression the “laboratories of democracy.” These references signal a possible move toward a view of federalism that champions state innovation and initiative irrespective of direction from Washington. This paper will explore the apparent retreat of progressives from their commitments to cooperative federalism, specifically, whether these references signal a tactical shift for short-term political gains or a more fundamental shift in progressive ideology

Development of Sporangia in Polypodium aureum var. undulatum: Initial Scanning Electron Microscopial Observations

Preliminary SEM observations of developing sori of P. aureum revealed several potential areas for future ultrastructural (SEM and TEM) study, including ontogeny of sporangial initials, annulus differentiation, and sport wall development

NSF-style peer review for teaching undergraduate grant-writing

The Biology Department at Jacksonville State University (JSU) in Alabama has incorporated an undergraduate research experience (URE) into its curriculum for both BA and BS degree programs . This experience involves the following semester courses: • BY 370 (Introduction to Research in Biology): two semester credits, sophomore level • BY 327 (Directed Studies in Biology) or BY 427 (Independent Study in Biology): variable credits, junior year • BY 496 (Senior Seminar) two credits, senior level The Department has recognized the need for both substantive coursework and an undergraduate research experience in its biology curriculum . The JSU URE is the outcome of curricular revision over the past 14 years . BY 370 and BY 496 are required courses, whereas independent research involves optional courses intended to interest students in research. BY 327 and BY 427 had been in the curriculum for some time, available for student research projects under the tutelage of a faculty mentor . BY 370 was initiated in 1991 to introduce majors to the science and art of biological research and grant-writing in an effort to strengthen the outcome of BY 327 and BY 427 . This course is now offered with multiple sections and instructors both semesters every year . Today, BY 327 and BY 427 enable students to conduct original field and/or laboratory research, educational research in biology, or substantive library-based research of an approved biological topic . BY 496, a required course since 2002, involves both a senior thesis and an oral presentation, the latter given in a department-wide symposium format . BY 496 is the Biology Department’s capstone course for all matriculating biology majors . The overall URE Experience has enabled the Department to integrate “communication across its curriculum” in a way that was never possible before . This paper concerns a modification to BY 370 . In this course, students now actively participate in an NSF-style peer review of their own undergraduate research proposals in biology

Interference of coarse and fine particles of different shape in mixed porous beds and filter cakes

In solid–liquid separation the knowledge of solids packing structure is important to control permeability and dewaterability. In particular, cakes formed in filtration are often represented by the composition in coarse and fine particles. In this work cakes were modelled by mixing a bed of coarse (spheres) and fine (kieselguhr of three types and kieselgel) particles with a wide size distribution, in order to obtain beds with different proportions of plate and rod-like particles. Size ratio of glass beads to kieselguhr particles were in the range 23–30. Porosity and permeability were measured for a range of large particle fraction in the mixture from 0 up to 1.0. The fractional porosity of each particle fraction was introduced as a parameter. The approach proposed in this work was also successfully applied to different published filtration data. It was found that (1) the presence of more than 10% of fines in the coarse granular bed significantly reduces the cake permeability; (2) to improve cake permeability the volume fraction of filter aid in suspension must be at least 50–60% of total solid volume; (3) obtained data may be used to control the porosity of a mixture, if the fractional porosity of large and small particles is known or to estimate mixture tortuosity.Fundação para a Ciência e a Tecnologia (FCT) – POCTI/EQU/37500/2001

Mermithid Nematodes: SEM Observations Comparing Hexamethyldisilazane and Critical Point Drying Methods

Morphological features of mermithid nematodes (Mermithidae) were studied with scanning electron microscopy, using hexamethyldisilazane-air drying in comparison with critical point drying via liquid carbon dioxide. Although general morphologic preservation of both HMDS-dried and CP-dried specimens was similar, structural features of the complex cuticle and internal organization were more easily resolved at higher magnifications in the HMDS-dried nematodes. These features include the superficial cuticular annulations, the fibrillar inner cuticle and peg-like microtrabeculae. The previously undescribed microtrabeculae are of special interest since they may facilitate an interaction of the mermithid (and perhaps nameatodes in general) musculature with its body wall that, at least in part, may account for the unique thrashing locomotion so characteristic of these organisms