San Diego State University

About: San Diego State University is a education organization based out in San Diego, California, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 12418 authors who have published 27950 publications receiving 1192375 citations. The organization is also known as: SDSU & San Diego State College.

Humorous lectures and humorous examples: Some effects upon comprehension and retention.

Abstract: versions of a humorous lecture. The three versions of the humorous lecture included humorous examples related to the concepts in the lecture (concept humor), unrelated to the concepts (nonconcept humor), or a combination of concept and nonconcept examples (mixed humor). A test of comprehension and retention was given twice: immediately after the lecture and 6 weeks later. Results indicated that immediate comprehension was not facilitated by the use of humorous examples. Upon retesting, however, retention of concept humor material was significantly improved by viewing a lecture with humorous examples illustrating concepts. Earlier research findings are accounted for in terms of these results. The advice to use humor for communica, lated to the persuasive or educational mestion enhancement has been considered in sage. several empirical studies (Berlo & Ku- Another difficulty with the research on mata, 1956; Gruner, 1965, 1966). Only a humor and learning has been the method handful of studies, however, have focused of evaluating learning. No experimenter upon the efficacy of humor for lectures in a stated exactly from where in the message teaching situation. Although several stud- that test items were taken. Because of ies have shown that humor can increase this, two important questions become obattention and interest in a topic (Gruner, vious: Did any test questions assess recall 1970; Markiewicz, 1974), comprehension of material presented immediately before and acceptance of a message have not been or after a humor item? Was humor associdemonstrated to improve when the mes- ated in some way with the major points on sage includes humor (Gruner, 1967, 1970; which a listener was to be tested? KnowKennedy, 1972; Markiewicz, 1974; Taylor, ing how the humorous items in a message 1964). corresponded to subsequent test questions One problem with humor studies that would allow a more accurate appraisal of focus on learning is determining the na- hum0r's effect on learning. ture of the humor the investigators used. The purpose of the present study was to Subjects' ratings of the perceived humor- explore the effect of two types of humor ": ousness of a message were taken in only a upon learning in a lecture situation. The minority of studies (Gruner, 1967, 1970; two types of humor are humor related to Kennedy, 1972; Lull, 1940). Most reports the concepts presented in the lecture (or omit discussions of fundamental ques- humorous examples) and humor unrelated tions, such as how the humor was chosen to the lecture's content. The primary conin the first place and how the humor re- cern is to determine how varying correspondence of humor with the topics of a classroom lecture moderates the compreA similar version of this article was presented at _ hension and retention of lecture material. the meeting of the Western Psychological Associa- It is our hypothesis that people have

Microbial growth under the snow: Implications for nutrient and allelochemical availability in temperate soils

Abstract: Recent work has shown that plant litter inputs fuel microbial growth in autumn and winter resulting in a large increase of microbial biomass under the snow pack in tundra soils. This winter-adapted microbial community can grow at low temperatures (−5 to 3 °C) and depletes the litter of easily degraded constituents, such as simple phenolic compounds, and immobilizes nitrogen. During snowmelt there is a die-off of this winter microbial community (due to starvation and intolerance to higher soil temperature) resulting in a release of nitrogen that can be utilized by plants and the summer microbial community. The summer microbial community can tolerate higher temperatures (5 to 20 °C) and utilizes mostly plant root exudates for growth. These yearly cycles of microbial growth dynamics have profound implications for both nutrient and alleochemical availability to plants. Firstly, these results show that release (from litter) and degradation of plant phenolic compounds (potential alleochemicals) occurs before plant growth commences in the spring. Secondly, nitrogen (N) immobilized by over-winter microbial growth is released back to the soil during and after snowmelt, thus becoming available to plants. Both of these results need to be incorporated in the design of experiments to explore plant-plant interactions. Many experiments in which chemicals (or fresh litter) are incorporated during plant growth do not reflect the fact that these two events are temporally uncoupled in many natural systems.

Autophagy in health and disease. 5. Mitophagy as a way of life

Abstract: Our understanding of autophagy has expanded greatly in recent years, largely due to the identification of the many genes involved in the process and to the development of better methods to monitor the process, such as green fluorescent protein-LC3 to visualize autophagosomes in vivo. A number of groups have demonstrated a tight connection between autophagy and mitochondrial turnover. Mitochondrial quality control is the process whereby mitochondria undergo successive rounds of fusion and fission with a dynamic exchange of components to segregate functional and damaged elements. Removal of the mitochondrion that contains damaged components is accomplished via autophagy (mitophagy). Mitophagy also serves to eliminate the subset of mitochondria producing the most reactive oxygen species, and episodic removal of mitochondria will reduce the oxidative burden, thus linking the mitochondrial free radical theory of aging with longevity achieved through caloric restriction. Mitophagy must be balanced by biogenesis to meet tissue energy needs, but the system is tunable and highly dynamic. This process is of greatest importance in long-lived cells such as cardiomyocytes, neurons, and memory T cells. Autophagy is known to decrease with age, and the failure to maintain mitochondrial quality control through mitophagy may explain why the heart, brain, and components of the immune system are most vulnerable to dysfunction as organisms age.

TYPE Ia SUPERNOVAE STRONGLY INTERACTING WITH THEIR CIRCUMSTELLAR MEDIUM

Abstract: Owing to their utility for measurements of cosmic acceleration, Type Ia supernovae (SNe Ia) are perhaps the best-studied class of SNe, yet the progenitor systems of these explosions largely remain a mystery. A rare subclass of SNe Ia shows evidence of strong interaction with their circumstellar medium (CSM), and in particular, a hydrogen-rich CSM; we refer to them as SNe Ia-CSM. In the first systematic search for such systems, we have identified 16 SNe Ia-CSM, and here we present new spectra of 13 of them. Six SNe Ia-CSM have been well studied previously, three were previously known but are analyzed in depth for the first time here, and seven are new discoveries from the Palomar Transient Factory. The spectra of all SNe Ia-CSM are dominated by Hα emission (with widths of ~2000 km s^(–1)) and exhibit large Hα/Hβ intensity ratios (perhaps due to collisional excitation of hydrogen via the SN ejecta overtaking slower-moving CSM shells); moreover, they have an almost complete lack of He I emission. They also show possible evidence of dust formation through a decrease in the red wing of Hα 75-100 days past maximum brightness, and nearly all SNe Ia-CSM exhibit strong Na I D absorption from the host galaxy. The absolute magnitudes (uncorrected for host-galaxy extinction) of SNe Ia-CSM are found to be –21.3 mag ≤ M_R ≤ –19 mag, and they also seem to show ultraviolet emission at early times and strong infrared emission at late times (but no detected radio or X-ray emission). Finally, the host galaxies of SNe Ia-CSM are all late-type spirals similar to the Milky Way, or dwarf irregulars like the Large Magellanic Cloud, which implies that these objects come from a relatively young stellar population. This work represents the most detailed analysis of the SN Ia-CSM class to date.