We report a new Cretaceous multituberculate mammal with 3D auditory bones preserved. Along with other fossil and extant mammals, the unequivocal auditory bones display features potentially representing ancestral phenotypes of the mammalian middle ear. These phenotypes show that the ectotympanic and the malleus-incus complex changed notably during their retreating from the dentary at various evolutionary stages and suggest convergent evolution of some features to extant mammals. In contrast, the incudomalleolar joint was conservative in having a braced hinge configuration, which narrows the morphological gap between the quadroarticular jaw joint of non-mammalian cynodonts and the incudomalleolar articulations of extant mammals. The saddle-shaped and abutting malleus-incus complexes in therians and monotremes, respectively, could have evolved from the braced hinge joint independently. The evolutionary changes recorded in the Mesozoic mammals are largely consistent with the middle ear morphogenesis during the ontogeny of extant mammals, supporting the relation between evolution and development. 相似文献
The effects of teacher-delivered social reinforcers on the task persistent behavior of children enrolled in an intermediate class for the educable mentally retarded were studied. These children were grouped with a regular fourth grade class during a social studies period in which the study was conducted. The special education children were randomly divided into two groups, with seven children in each group. Using a reversal design, social reinforcers were delivered contingent upon the task persistent behavior of the seven target children. The seven youngsters in the control, or nonreinforcement, group were essentially ignored as they engaged in appropriate task-related behaviors. The results clearly show that increases in the level of task persistent behavior and the administration of social reinforcement were functionally related. The level of task persistent behavior emitted by the control children was not affected by reinforcement delivered to their peers. 相似文献
Prior research on pretrial publicity has produced mixed results and a roughly equal number of studies show an effect, show no effect, or show mixed results. We explored the effects of (a) homogenous vs. heterogeneous exposure (whether deliberating jurors were all exposed to the same publicity or not) and (b) pre-deliberation queries as potential contributors to mixed results. We found an effect for positive but not negative publicity on conviction rates but not evidence ratings. Exposure heterogeneity appears to explain these differences and pre-deliberation queries did appear to play some role in the obtained outcomes. Overall these findings do not replicate a robust publicity effect and future research should consider how homogeneous exposure and pre-deliberation opinion queries influence results. 相似文献
Gamified teaching is a pedagogical strategy that utilizes principles of gaming in the structure of assignments and grading. When students are allowed to engage in gameful educational experiences, they are given the freedom to choose their own pathway through assignments in order to better customize their learning. This article presents a rationale for gamified teaching and outlines the various elements of this instructional approach. In addition, guidance is provided on how to convert a traditional course to a gamified class. 相似文献
Purpose: This paper reports the results of survey research conducted with tribal producers between 2011 and 2012 on 19 of the largest American Indian reservations in Idaho, Nevada, North Dakota, Oregon, South Dakota, and Washington. The purpose of the research was to identify potential barriers to sustainable agriculture on reservation lands. This article reports the results of this research in an effort to promote Extension professionals' understanding of these barriers, which may help to improve outreach programs on American Indian reservations. Understanding the obstacles to sustaining agriculture that American Indian tribes face may inform international agricultural outreach efforts to increase food security targeting indigenous and tribal peoples worldwide.
Design/Methodology/Approach: American Indian agricultural producers comprised the study group. Study objectives included: (1) identify agricultural and natural resource issues of greatest concern to a self-selected sample of tribal agricultural producers on reservation lands; (2) evaluate access to Extension and other US Department of Agriculture outreach and assistance programs; and (3) evaluate the quality of these programs in terms of their relativity to tribal needs.
Findings: Study results indicate that tribal agricultural producers surveyed ranked 29 of 39 agricultural and natural resource issues as a concern. Similarly, they rated access to and quality of outreach programs as fair. Further, tribal producers operating on reservation trust land rated issues more severely than did tribal producers operating on fee simple lands.
Practical Implications: Results of this research will help Extension and other outreach professionals to understand the barriers indigenous and tribal peoples face in sustaining agricultural operations, particularly tribal groups living on federally reserved trust lands, such as American Indians. An increased understanding can inform agricultural policy-makers and outreach professionals in improving programs designed to increase agricultural sustainability, improve food security, enhance economic well-being and improve quality of life of indigenous and tribal peoples worldwide.
Originality/Value: This research provides important information to agricultural policy-makers and Extension professionals striving to sustain agricultural productivity and enhance food security with indigenous and tribal peoples. 相似文献
ABSTRACTBlended learning has been a feature of higher education practice and research for almost two decades. This article takes stock of current blended learning research, contributing to the growing number of meta-analyses of higher education and blended learning research more generally, through a review of ninety-seven articles relating to blended learning in higher education published in fifteen journals between 2012 and mid-2017. The review focused on where and when the articles were published; their provenance, scale, scope; methodological approach; the broad research themes; and definition of blended learning used. The review shows that despite its ubiquity, blended learning’s definition is all-encompassing; its spread is global but research is dominated by key players; it is of technical interest; and its research is small-scale, individually focused, seeking to evidence the benefits of blended learning. The article concludes with recommendations of how higher education research could provide institutions with evidence to ensure their ‘best of blends’. 相似文献
This article reports on the experiences of two lecturers working at the University of Tasmania required to teach outdoor and sustainability education (O&SE) courses online. Using an (auto)ethonographic case-study approach, the lecturers were interviewed with a view to exploring their perceptions, challenges, ethical dilemmas, tensions, opportunities and experiences in this space. A number of themes emerged, including commitment to quality teaching and learning, the role of experience, and experiential learning, in the online space, the challenge of fostering a connection to place, difficulties faced when trying to develop a learning community, and the role of professional learning and support in terms of pedagogy and technology in the online space. These themes, and their implications for teaching and learning in higher education both generally, and specifically in O&SE, are discussed in light of what is a mounting body of literature exploring the move to online delivery in higher education. 相似文献