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Winter biology & freeze tolerance in the goldenrod gall fly
No full textBirds migrate. Bears hibernate. Turtles and
frogs retreat to the bottom of lakes. Most animals must
avoid harsh winter conditions; few can survive freezing.
Larvae of the goldenrod gall fly (Eurosta solidaginis),
can survive freezing to -40°C or below. The study of
survival at low temperature is called cryobiology. This
article provides an introduction to the winter biology of
this widely distributed and unusual species, and suggests
classroom activities that illuminate principles of
cryobiology through insect overwintering.
A variety of opportunities for educational activities
are found in the complex, yet easy-to-manipulate,
trophic relationships between goldenrod plants,
insects that induce gall formation, and the natural enemies
of these gallmakers. Gall collection, measurement,
and observation (exit holes, larval response, temperature,
etc.) can help students develop scientific process
skills including observation, classification, measurement,
inference, prediction, control of experimental
variables, and material manipulation (Peard, 1994).
Galls can also be studied to learn about insect ovipositing
behavior and plant responses to three types of
gallmakers—each with its own distinct gall type
(Newell, 1994). Likewise, classroom activities can focus
on the collection and study of galls to discover principles
of ecology and insect life cycles (Kahn, 1997).
One aspect of goldenrod gallmakers that has
received little attention in the science education literature
is the winter biology of these unusual insects. In
autumn, the overwintering larva enters a state of dormancy,
called diapause, and gradually acquires the
capacity to survive freezing to temperatures of -40°C
and below (Baust & Lee, 1981). In contrast, a beetle
larva and two parasitic wasps that also overwinter in
goldenrod galls are intolerant of freezing and must
avoid internal ice formation
What Do Students Want? Small Group Instructional Diagnoses of STEM Faculty
Get PDFSmall Group Instructional Diagnoses (SGIDs) are informal, mid-semester evaluations of courses, which the
instructors request voluntarily. The facilitator of the SGID comes into a class, the instructor leaves, and the facilitator spends about 30 minutes with the students. The first part of the SGID is done in small groups of students. The facilitator asks students to consider two questions, "What are the strengths of this course?" and "What suggestions do you have to improve the course?" After students work in groups for 10 minutes to compose lists of strengths and suggestions, the facilitator calls the class back together as a whole, records the most important strengths and suggestions, and has the class vote on them. These results are then shared privately with the instructor of the course. We collected and analyzed student comments from 45 courses taught by 27 STEM instructors. We found that students value clear lecture and hands-on learning, fair and frequent feedback, flexible and caring instructors, organized classes and resources, and clear alignment between instruction and evaluation. Looking in more detail, we found that students perceived small classes to be more organized than large ones. Students in introductory classes provided the least amount of feedback. Students in introductory classes placed the most value on instructor characteristics such as support and caring about their success, while graduate students placed the least value on instructor characteristics. Finally, female STEM instructors received a disproportionately high number of comments
Enzymatic regulation of glycogenolysis in a subarctic population of the wood frog: implications for extreme freeze tolerance
Get PDFThe wood frog, Rana sylvatica, from Interior Alaska survives freezing at –16°C, a temperature 10–13°C below that tolerated by its southern conspecifics. We investigated the hepatic freezing response in this northern phenotype to determine if its profound freeze tolerance is associated with an enhanced glucosic cryoprotectant system. Alaskan frogs had a larger liver glycogen reserve that was mobilized faster during early freezing as compared to conspecifics from a cool-temperate region (southern Ohio, USA). In Alaskan frogs the rapid glucose production in the first hours of freezing was associated with a 7-fold increase in glycogen phosphorylase activity above unfrozen frog levels, and the activity of this enzyme was higher than that of frozen Ohioan frogs. Freezing of Ohioan frogs induced a more modest (4-fold) increase in glycogen phosphorylase activity above unfrozen frog values. Relative to the Ohioan frogs, Alaskan frogs maintained a higher total protein kinase A activity throughout an experimental freezing/thawing time course, and this may have potentiated glycogenolysis during early freezing. We found populational variation in the activity and protein level of protein kinase A which suggested that the Alaskan population had a more efficient form of this enzyme. Alaskan frogs modulated their glycogenolytic response by decreasing the activity of glycogen phosphorylase after cryoprotectant mobilization was well under way, thereby conserving their hepatic glycogen reserve. Ohioan frogs, however, sustained high glycogen phosphorylase activity until early thawing and consumed nearly all their liver glycogen. These unique hepatic responses of Alaskan R. sylvatica likely contribute to this phenotype’s exceptional freeze tolerance, which is necessary for their survival in a subarctic climate
Compact genome of the Antarctic midge is likely an adaptation to an extreme environment
Get PDFThe midge, Belgica antarctica, is the only insect endemic to Antarctica, and thus it offers a powerful model for probing responses to extreme temperatures, freeze tolerance, dehydration, osmotic stress, ultraviolet radiation and other forms of environmental stress. Here we present the first genome assembly of an extremophile, the first dipteran in the family Chironomidae, and the first Antarctic eukaryote to be sequenced. At 99 megabases, B. antarctica has the smallest insect genome sequenced thus far. Although it has a similar number of genes as other Diptera, the midge genome has very low repeat density and a reduction in intron length. Environmental extremes appear to constrain genome architecture, not gene content. The few transposable elements present are mainly ancient, inactive retroelements. An abundance of genes associated with development, regulation of metabolism and responses to external stimuli may reflect adaptations for surviving in this harsh environment
Neurophysiological Assessment of Rapid Cold-hardening-induced Resistance to the Disruption of Resting Neuronal Membrane Potential
No full textThis study highlights a novel approach to the study of rapid cold-hardening. Examination at the neuronal level allows for further understanding of the physiological mechanisms underlying this acclimatory response to environmental stress
The Effect of Offspring Gender on Levels of Parent Strictness
Get PDFThis poster depicts the research findings of a study conducted to determine if parents have different levels of strictness for their offspring based on gender
"Ecocrítica y epistemología subalterna en Eduardo Galeano"
Get PDFEl presente ensayo articula un análisis ecocrítico de algunas de las narraciones breves del escritor uruguayo Eduardo Galeano seleccionadas de El libro de los abrazos (1989) y Patas arriba. La escuela del mundo al revés (1998). En primer lugar, se hace hincapié en la representación de la subalternización sistemática de epistemologías ecocéntricas por parte del discurso occidental. En segundo lugar, se muestra la manera en que la obra de Galeano revisita y recrea dichas formas de conocimiento alternativo que fueron excluidas al ser consideradas premodernas. Por último, se destaca la paradoja de que, recientemente, el pensamiento (pos)moderno y poshumanista esté llegando a las mismas conclusiones que eran obvias para algunas epistemologías indígenas latinoamericanas premodernas. De esta manera, se explora la convergencia de la ecocrítica “posmoderna” y la epistemología ecocéntrica “premoderna” en la obra de Galeano. Ambas reconocen la imposibilidad teórica y práctica de separarse de la naturaleza y, en consecuencia, critican el reduccionismo instrumentalista de un capitalismo global social y ecológicamente insostenible
Small Samples, Broad Applications: Using Bibliographies to Support Instruction, Collections, and Budgets
Get PDFStudents in Organic Chemistry for Majors were required to write a paper as the culminating course assignment. Prior to completing this assignment, students were given the option of attending a library instruction session covering relevant databases and resources. Upon submission of their papers, bibliographies from 53 students were collected and evaluated. Bibliographies of students who attended an instruction session showed improvement in several key areas in comparison to the bibliographies of those students who chose not to attend.
Subsequently, calculations were made to attempt a holistic account of costs associated with completing the assignment. Factors such as the cost of journals, databases, and librarian time were all included in the overall cost estimate. Instruction librarians can use bibliographies to quantify their impact on student success, thereby justifying their value to potentially reticent faculty members. This method of comprehensive accounting can help justify collections and staff budgets to library and university administration, and with a larger sample size could also help guide collections decisions in the particular subject area
Campus-wide partnerships to improve students’ academic integrity iQ
Get PDFMiami University’s iQ (short for integrity Quickstart) is a newly created online tutorial that guides students through different scenarios about academic integrity and research issues. Each scenario introduces the student to a new topic with animated Flash video, additional resources and short quizzes to assess their understanding. iQ was created through a partnership between the Libraries, University IT and Student Affairs. Instructional designers from IT helped us to transform the content into short video-based snippets. The presentation tools from Prezi.com give iQ its visually appealing, non-linear structure. Additionally, staff from Student Affairs help us to tailor the content on academic integrity and consequences for violation. Numerous challenges were encountered to ensure that the end product was something exemplary of Miami’s commitment to these topics.
This poster will cover the creation and implementation of iQ at Miami University. We will discuss how iQ works as both a standalone learning tool and as part of a bibliographic information session and how campus partnerships can help foster institutional buy-in for academic integrity and information literacy