2,010 research outputs found
Ten polymorphic microsatellite primers in the tropical tree caimito, Chrysophyllum cainito (Sapotaceae).
UnlabelledPremise of the studyWe developed microsatellite primers for the tropical tree Chrysophyllum cainito (Sapotaceae) to determine the native range of the species, investigate the origin of cultivated populations, and examine the partitioning of genetic diversity in wild and cultivated populations. •Methods and resultsWe developed 10 polymorphic primers from C. cainito genomic DNA libraries enriched for di-, tri-, and tetranucleotide repeat motifs. The loci amplified were polymorphic in samples collected from Jamaica and Panama. The number of alleles per locus ranged from two to 10 and three to 12, while observed heterozygosities ranged from 0.074 to 0.704 and 0.407 to 0.852 in Jamaica and Panama, respectively. •ConclusionsThe microsatellite primers will be useful in future population genetic studies as well as those aimed at understanding the geographic origin(s) of wild and cultivated populations
Can Moving Pictures Speak? Silent Film, Free Speech, and Social Science in Early 20th Century Law
When the Supreme Court was first confronted with a First Amendment case involving film, it was confronted with a difficult and fascinating question: were silent films speech? The decision in the case, Mutual v. Ohio (1915), famously answered no. The decision is usually understood to be part of a tradition of interpretations of the First Amendment as applying primarily to political opinion; in this reading, film was not protected because it was entertainment and/or commerce. However, Mutual also contains a set of arguments about the nature of film as more akin to action than to speech — arguments embedded in contemporaneous discussions of influence in the emerging social sciences. In order to highlight these ideas, the paper re-reads the Mutual and two other related decisions (Kalem Co. v. Harper Bros. [1911] and Pathé Exchange v. Cobb [1922]), contextualizing them within the history of ideas about communication, influence, and society in the United States. The cases all discuss film in terms of action, using the supposed physicality of the medium to distance it from opinion and expression. This discussion of film makes sense within the context of contemporaneous social scientific discourse on communication and technology
Variasjon i vaginaltemperatur og aktivitet sett i sammenheng med fekale progestagener hos elg i innhegning
Accurate detection of specific reproductive events presents a challenge to scientists studying wild species, including moose. There are several established methods for monitoring reproductive activity in domestic ruminants, including the use of biologging devices. The main objective of this study was to determine whether moose show a distinct thermal and activity pattern associated with luteal activity during the estrous cycle, as documented in cattle. We measured fecal progestagen, vaginal temperature, and activity of 12 captive female moose on the Kenai Peninsula, Alaska, USA, early in the breeding season to examine the relationships between these variables. Individual fecal samples were collected from August 23rd to October 15th, 2021, to classify luteal activity. Our results support that moose display an identifiable thermal pattern during the onset of luteal activity from mid-September to mid-October, which is associated with the presumed first estrous cycle of the breeding season. We developed an algorithm to detect luteal activity based on this pattern, with a sensitivity of 71%. In contrast, we did not observe a distinct pattern in activity during this period. However, subsequent, recurring patterns in both temperature and activity were identified between mid-October and mid-November, which were likely associated with following estrous cycles.This work was supported by the Alaska Department of Fish and Game Federal Wildlife Restoration Grant (grant number AKW-4 Project No. 1.63), the Ecophysiology and One Health Research Group at Inland Norway University of Applied Sciences, and the Norwegian University of Life Sciences.submittedVersio
Item-writing Rules: Collective Wisdom
In student assessment, teachers place the greatest weight on tests they have constructed themselves and have an equally great interest in the quality of those tests. To increase the validity of teacher-made tests, many item-writing rules-of-thumb are available in the literature, but few rules have been tested experimentally. In light of the paucity of empirical studies, the validity of any given guideline might best be established by relying on experts. This study analyzed twenty classroom assessment textbooks to identify a consensus list of item-writing rules. Forty rules for which there was agreement among textbook authors are presented. The rules address four different validity concerns-potentially confusing wording or ambiguous requirements, the problem of guessing, test-taking efficiency, and controlling for testwiseness
The Golden Age? What the 100 Most Cited Articles in Terrorism Studies Tell Us
In a context where widespread failings in the nature of terrorism research are well recognised—yet where the quantity of work is still enormous—is it possible to fairly assess whether the field is progressing or if it has become mired in mediocre research? Citation analysis is widely used to reveal the evolution and extent of progress in fields of study and to provide valuable insight into major trends and achievements. This study identifies and analyses the current 100 most cited journal articles in terrorism studies. A search was performed using Google Scholar for peer-reviewed journal articles on subjects related to terrorism and counter-terrorism. The most cited articles were published across sixty-two journals, which reflected the interdisciplinary nature of terrorism studies. Compared to other articles, the most cited articles were more likely to be the result of collaborative research and were also more likely to provide new data. Sixty-three of the top 100 articles have been published since 2001. The findings are discussed in relation to the evolution of terrorism research and current debates on progress in the field
Envelope structure of Synechococcus sp. WH8113, a nonflagellated swimming cyanobacterium
BACKGROUND: Many bacteria swim by rotating helical flagellar filaments [1]. Waterbury et al. [15] discovered an exception, strains of the cyanobacterium Synechococcus that swim without flagella or visible changes in shape. Other species of cyanobacteria glide on surfaces [2,7]. The hypothesis that Synechococcus might swim using traveling surface waves [6,13] prompted this investigation. RESULTS: Using quick-freeze electron microscopy, we have identified a crystalline surface layer that encloses the outer membrane of the motile strain Synechococcus sp. WH8113, the components of which are arranged in a rhomboid lattice. Spicules emerge in profusion from the layer and extend up to 150 nm into the surrounding fluid. These spicules also send extensions inwards to the inner cell membrane where motility is powered by an ion-motive force [17]. CONCLUSION: The envelope structure of Synechococcus sp. WH8113 provides new constraints on its motile mechanism. The spicules are well positioned to transduce energy at the cell membrane into mechanical work at the cell surface. One model is that an unidentified motor embedded in the cell membrane utilizes the spicules as oars to generate a traveling wave external to the surface layer in the manner of ciliated eukaryotes
Identification of \u3ci\u3eFrancisella tularensis\u3c/i\u3e subsp. \u3ci\u3etularensis \u3c/i\u3eA1 and A2 Infections by Real-Time Polymerase Chain Reaction
Francisella tularensis subsp. tularensis (type A) is subdivided into clades A1 and A2. Human tularemia infections caused by A1 and A2 differ with respect to clinical outcome; A1 infections are associated with a higher case fatality rate. In this study, we develop and evaluate TaqMan polymerase chain reaction (PCR) assays for identification of A1 and A2. Both assays were shown to be specific to either A1 or A2, with sensitivities of 10 genomic equivalents. Real-time PCR results for identification of A1 and A2 were in complete agreement with results obtained by pulsed field gel electrophoresis analysis or conventional PCR when specimens from sporadic tularemia cases and a tularemia outbreak involving both A1 and A2 were tested. In addition, outbreak samples not previously typed to the clade level could be classified as A1 or A2. The assays described here provide new diagnostic tools with a level of sensitivity not previously available for identification of A1 and A2 infections
Identification of \u3ci\u3eFrancisella tularensis\u3c/i\u3e subsp. \u3ci\u3etularensis \u3c/i\u3eA1 and A2 Infections by Real-Time Polymerase Chain Reaction
Francisella tularensis subsp. tularensis (type A) is subdivided into clades A1 and A2. Human tularemia infections caused by A1 and A2 differ with respect to clinical outcome; A1 infections are associated with a higher case fatality rate. In this study, we develop and evaluate TaqMan polymerase chain reaction (PCR) assays for identification of A1 and A2. Both assays were shown to be specific to either A1 or A2, with sensitivities of 10 genomic equivalents. Real-time PCR results for identification of A1 and A2 were in complete agreement with results obtained by pulsed field gel electrophoresis analysis or conventional PCR when specimens from sporadic tularemia cases and a tularemia outbreak involving both A1 and A2 were tested. In addition, outbreak samples not previously typed to the clade level could be classified as A1 or A2. The assays described here provide new diagnostic tools with a level of sensitivity not previously available for identification of A1 and A2 infections
- …