46 research outputs found
Do Item Writing Best Practices Improve Multiple Choice Questions for University Students?
Up-regulation of multiple proteins and biological processes during maxillary expansion in rats
<p>Abstract</p> <p>Background</p> <p>Maxillary expansion (ME) is a common practice in orthodontics that aims to increase the constricted maxillary arch width. Relapse often occurs, however, and better treatment strategies are needed. In order to develop a more effective method, this study was designed to further examine the process of tissue remodeling during ME, to identify the changes in expression of several proteins of interest, and to clarify the molecular mechanism responsible for tissue remodeling.</p> <p>Methods</p> <p>Male Wistar rats were randomly divided into control and ME groups. The rats were euthanized at various intervals over 11 days, and the dissected palates were prepared for histological examination. The structure of the midpalatal sutures changed little during the first three days. Proteins from samples in the ground midpalatal tissues obtained on the third day were subjected to two-dimensional polyacrylamide gel electrophoresis (2-DE) and matrix assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) analysis. Validation of protein expression was performed by Western blot analyses.</p> <p>Results</p> <p>From day 5, chondrocytes in the inner layer of suture cartilage and osteoblasts at the end of the suture cartilage began to proliferate, and the skeletal matrix increased later adjacent to the cartilage in the ME group. Comparative proteomic analysis showed increases in 22 protein spots present in the ME group. The changes in three proteins closely related to osteogenesis (parathyroid hormone, osteoprotegerin and vimentin) were confirmed by Western blotting.</p> <p>Conclusion</p> <p>Many proteins are over-expressed during ME, and they may play an important role in the remodeling process.</p
A new species of cosmocercoides (Nematoda; cosmocercidae) and other helminths in leptodactylus latrans (anura; leptodactylidae) from Argentina
Cosmocercoides latrans n. sp. (Cosmocercidae) from the small intestine of Leptodactylus latrans (Anura: Leptodactylidae) from Northeastern Province of Buenos Aires, Argentina is described. The new species can be distinguished from their congeners by a combination of the characters, among which stands out the number of rosette papillae, the lack of gubernaculum and the presence of lateral alae in both sexes. There are over 20 species in the genus Cosmocercoides, and Cosmocercoides latrans n. sp. represents the third species from the Neotropical realm and the second for Argentina. Additionally, seven previously known taxa are reported; Pseudoacanthocephalus cf. lutzi, Catadiscus uruguayensis, Rauschiella palmipedis, Aplectana hylambatis, Cosmocerca parva, Schrankiana sp. and Rhabdias elegans; providing literature records and information on distribution and host-parasite relationships.Fil: Draghi, Regina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. DivisiĂłn ZoologĂa Invertebrados; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata; ArgentinaFil: Drago, Fabiana Beatriz. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. DivisiĂłn ZoologĂa Invertebrados; Argentina. Provincia de Buenos Aires. GobernaciĂłn. ComisiĂłn de Investigaciones CientĂficas; ArgentinaFil: Lunaschi, LĂa InĂ©s. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. DivisiĂłn ZoologĂa Invertebrados; Argentin
U.S. monetary policy and herding: Evidence from commodity markets
This paper investigates the presence of herding behavior across a spectrum of commodities (i.e., agricultural, energy, precious metals, and metals) futures prices obtained from Datastream. The main novelty of this study is, for the first time in the literature, the explicit investigation of the role of deviations of U.S. monetary policy decisions from a standard Taylor-type monetary rule, in driving herding behavior with respect to commodity futures prices, spanning the period 1990-2017. The results document that the commodity markets are characterized by herding, while such herding behavior is not only driven by U.S. monetary policy decisions, but also such decisions exert asymmetric effects this behavior. An additional novelty of the results is that they document that herding is stronger in discretionary monetary policy regimes.N/
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Non-standard errors
In statistics, samples are drawn from a population in a data-generating process (DGP). Standard errors measure the uncertainty in estimates of population parameters. In science, evidence is generated to test hypotheses in an evidence generating process (EGP). We claim that EGP variation across researchers adds uncertainty: Non-standard errors (NSEs). We study NSEs by letting 164 teams test the same hypotheses on the same data. NSEs turn out to be sizable, but smaller for better reproducible or higher rated research. Adding peer-review stages reduces NSEs. We further find that this type of uncertainty is underestimated by participants
Acanthocephalans from Australian elasmobranchs (Chondrichthyes) with a description of a new species in the genus Gorgorhynchus Chandler, 1934 (Rhadinorhynchidae)
Gorgorhynchus occultus n. sp. is described from Sutorectus tentaculatus (Peters) (Orectolobidae) collected off Bunbury, Western Australia in 1986. The new species differs from all other species of Gorgorhynchus Chandler, 1934 by having a suite of characters including a proboscis hook formula of 18â20 rows of 8â9 hooks, a well-developed neck, irregular circles of small spines in a single anterior field, the male reproductive system limited to the posterior quarter of the trunk and three cement glands. In a survey of 284 sharks collected between 2015 and 2018 from 10 localities in Australian waters, 11 individuals were infected with acanthocephalan cystacanths. One individual of Sphyrna mokarran (Rupell) (Sphyrnidae) was infected with Corynosoma cetaceum Johnston & Best, 1931. Serrasentis sagittifer (Linton, 1889) (Rhadinorhynchidae) was found in five individuals of S. mokarran, four individuals of Syphyrna lewini (Griffith & Smith) and one individual of Carcharhinus coatesi (Whitley) (Carcharhinidae). These infections may be accidental because it has been suggested that acanthocephalans cannot tolerate the high levels of urea used by marine and esturine elasmobranchs for osmoregulation. The two most common host species examined, S. mokarran and S. lewini had the highest intensities and prevalences of infection with S. sagittifer. Although more individuals of S. lewini were examined, S. mokarran had the higher prevalence of infection. © 2019, Springer Nature B.V
Cranial and postcranial remains of a new species of Prochelidella (Testudines: Pleurodira: Chelidae) from âLa Buitreraâ (Cenomanian of Patagonia, Argentina), with comments on the monophyly of this extinct chelid genus from southern Gondwana
The genus Prochelidella is the oldest known panchelid taxon. It is widely distributed in several Cretaceous basins throughout Patagonia, Argentina. It was previously known from three named species. A fourth species presented herein, Prochelidella buitreraensis sp. nov., preserves both cranial and postcranial material from the Candeleros Formation (La Buitrera Area) of RĂo Negro Province, Argentina. Features observed in the nuchal bone (i.e. wide, trapezoidal cervical vertebrae, shallow nuchal notch) allow us to assign this specimen to the genus Prochelidella. Several specific traits (i.e. a large open retropterygoideum foramen, and a strongly developed muscle attachment site on the basisphenoid) suggest that the form from the Candeleros Formation is a new species of the genus Prochelidella. A phylogenetic analysis that includes the three best-preserved species of Prochelidella recovers this taxon as monophyletic. The Cenomanian age of this new taxon allows us to compare the panchelid turtles from the Patagonian (Neuquen) and Australian (Surat) basins.Fil: Maniel, Ignacio Jorge. Universidad Tecnologica Nacional. Facultad Reg.san Rafael. Instituto de Evolucion, Ecologia Historica y Ambiente. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Mendoza. Instituto de Evolucion, Ecologia Historica y Ambiente.; ArgentinaFil: de la Fuente, Marcelo Saul. Universidad Tecnologica Nacional. Facultad Reg.san Rafael. Instituto de Evolucion, Ecologia Historica y Ambiente. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Mendoza. Instituto de Evolucion, Ecologia Historica y Ambiente.; ArgentinaFil: ApesteguĂa, Sebastian. FundaciĂłn de Historia Natural FĂ©lix de Azara; ArgentinaFil: Mayoral, Joaquin PĂ©rez. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; ArgentinaFil: Sanchez, Maria L.. Universidad Nacional de RĂo Cuarto; ArgentinaFil: Veiga, Gonzalo Diego. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Centro de Investigaciones GeolĂłgicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones GeolĂłgicas; ArgentinaFil: Smales, Ian. No especifĂca