1,126 research outputs found
The sensitivity of an immature vestibular system to altered gravity
No full textStimulus deprivation or stimulus augmentation can induce long-lasting modifications to sensory and motor systems. If deprivation is effective only during a limited period of life this phase is called "critical period." A critical period was described for the development of the roll-induced vestibuloocular reflex (rVOR) of Xenopus laevis using spaceflights. Spaceflight durations and basic conditions of Xenopus' development did not make it possible to answer the question whether exposure of the immature vestibular organ to weightlessness affects rVOR development. The embryonic development of Pleurodeles waltl is slow enough to solve this problem because the rVOR cannot be induced before 15 dpf. Stage 20-21 embryos (4 dpf) were exposed to microgravity during a 10-day spaceflight, or to 3g hypergravity following the same time schedule. After termination of altered gravity, the rVOR was recorded twice in most animals. The main observations were as follows: (1) after the first rVOR appearance at stage 37 (16 dpf), both rVOR gain and amplitude increased steadily up to saturation levels of 0.22 and 20°, respectively. (2) Three days after termination of microgravity, flight and ground larvae showed no rVOR; 1 day later, the rVOR could be induced only in ground larvae. Differences disappeared after 3 weeks. (3) For 10 days after 3g exposure, rVOR development was similar to that of 1g-controls but 3 weeks later, 3g-larvae showed a larger rVOR than 1g-controls. These observations indicate that the immature vestibular system is transiently sensitive to microgravity exposure and that exposure of the immature vestibular system to hypergravity leads to a slowly growing vestibular sensitization
Jon Frey, Michigan State University professor of Art and Art History talks about the reuse of building materials in late Roman and Byzantine buildings and into the Medieval period
No full textJon Frey, Michigan State University professor of Art and Art History and author of "Spolia in fortifications and the common builder in late antiquity", talks about the reuse of building materials in late Roman and Byzantine buildings and into the Medieval period, especially those elements with Latin or Greek inscriptions. Frey talks about literacy rates during those periods and asks if the elements were actually meant to be read or if it was sufficient to the builder that they be recognized simply as ancient writing. Frey is introduced by the Head of the Fine Arts Library, Terrie Wilson
An ichthyosaurian forefin from the Lower Cretaceous Zapata Formation of southern Chile: implications for morphological variability within Platypterygius
No full textFil: Pardo-Pérez, Judith. Institut für Geowissenschaften. Ruprecht Karls Universität Heidelberg. Heidelberg; GermanyFil: Frey, Eberhard. Staatliches Museum für Naturkunde Karlsruhe; GermanyFil: Stinnesbeck, Wolfgang. Institut für Geowissenschaften. Ruprecht Karls Universität Heidelberg. Heidelberg; GermanyFil: Fernández, Marta Susana. División Paleontología Vertebrados. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Rivas, Luis. Departamento Ciencias de la Tierra. Universidad de Concepción; ChileFil: Salazar, Christian. Institut für Geowissenschaften. Ruprecht Karls Universität Heidelberg. Heidelberg; GermanyFil: Leppe, Marcelo. Instituto Antártico Chileno. Punta Arenas; Chil
Millenium. Deutungen zum christlichen Mythos der Jahrtausendwende. Mit Beiträgen von Christoph Bochinger, Jörg Frey, Eberhard Hauschildt, Thomas Kaufmann und Hermann Timm, Gütersloh : Gütersloher Verlagshaus Chr. Kaiser, 1999, ISBN 3-579-05171-7, 34 DM
No full textArnold Matthieu. Millenium. Deutungen zum christlichen Mythos der Jahrtausendwende. Mit Beiträgen von Christoph Bochinger, Jörg Frey, Eberhard Hauschildt, Thomas Kaufmann und Hermann Timm, Gütersloh : Gütersloher Verlagshaus Chr. Kaiser, 1999, ISBN 3-579-05171-7, 34 DM. In: Revue d'histoire et de philosophie religieuses, 80e année n°3, Juillet-septembre 2000. p. 414
Laufen, Springen, Werfen
No full textFrey G, Hildenbrandt E, Kurz D. Laufen, Springen, Werfen. Rororo-Sachbuch, 7616: Schulsport Praxis. Reinbek b. Hamburg: Rowohlt; 1984
Aphaniosoma suboculicauda Frey 1958
No full text<i>Aphaniosoma suboculicauda</i> Frey, 1958 Material examined <p>YEMEN • 1 ♂; Ta‘Izz; Aug.1999; A. van Harten and A. Awad leg.; light trap; NMWC • 1 ♀; same collection data as for preceding; Oct.1999; NMWC • 1 ♀; same collection data as for preceding; 5 Jan.– 2 Feb. 1998; NMWC.</p> Remarks <p> Frey’s description is accurate, and he likens this species to <i>A. oculicauda</i> based on colour pattern, but this is now known to be unreliable. However, the general appearance and the chaetotaxy (fronto-orbitals, pair of setae in front of ocellar triangle and 1 strong dorsocentral) place it in the same group of species as <i>A. fissum</i>, <i>A. lamellatum</i> and <i>A. oculicauda</i>. Frey’s figure of the hypopygium is difficult to interpret. The type series was examined by the present author and the hyopygium illustrated in more detail (Ebejer 2009: 408, fig. 52). Until now this species was thought to be endemic to the Cape Verde Islands. Its presence in Yemen would suggest that it is probably more widespread in the eremic zone between West Africa and Arabia.</p> Distribution <p>Cape Verde Islands (Frey 1958b). New record for Yemen.</p>Published as part of <i>Ebejer, Martin J., 2023, The genus Aphaniosoma Becker, 1903 (Diptera: Chyromyidae) in the Eastern Mediterranean and Middle East, with descriptions of new species, pp. 1-161 in European Journal of Taxonomy 872</i> on page 141, DOI: 10.5852/ejt.2023.872.2131, <a href="http://zenodo.org/record/8018303">http://zenodo.org/record/8018303</a>
A new species of a snapping turtle (Pan-Chelydridae/Chelydropsis) from the Upper Miocene (MN9, early Vallesian) of Southwest Germany
No full textChelydropsis is a genus of the clade Pan-Chelydridae, which existed and was distributed in Eurasia from the Eocene to the end of the Pliocene. The Chelydropsis fossil record of North of the Alps is particularly rich throughout the Miocene. In this study, we describe a new Chelydropsis species from the Late Miocene (Vallesian, MN9) fossiliferous site of Höwenegg in southwestern Germany. The new species is based on a nearly complete Chelydropsis skeleton, which stands out among the best preserved and most complete specimens ever found until now. The new species, Chelydropsis heweneggensis sp. nov. is of particular importance. It differs from the coeval Chelydropsis murchisoni, which recent studies suggest is the only Chelydropsis species known to have existed in Europe from the Middle Miocene to the Pliocene. The species described herein thus adds to the diversity of the European Neogene Chelydropsis record.Fil: Pappa, Irena. University Of Patras (university Of Patras);Fil: Vlachos, Evangelos. Museo Paleontológico Egidio Feruglio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Frey, Eberhard. Albert Ludwigs University of Freiburg; AlemaniaFil: Iliopoulos, George. University Of Patras (university Of Patras)
Liogenys rectangula Frey 1969
No full textLiogenys rectangula Frey, 1969 Figs. 19; 25 Liogenys rectangulus Frey, 1969: 47, 59–60; Krajčík 2012: 145 (checklist); Cherman et al. 2017: 5 (generic history); Liogenys rectangula: Cherman et al. 2017: 13, 20, 75 (illustration; natural history, taxonomy); Cherman et al. 2019: 36 (taxonomy). Type material. Liogenys rectangulus male holotype (USNM): [white handwritten] “Formosa / P [Puerto] Pilcomayo / Argent. 1950”, [red typeset] “ PARATYPE ”, [white, typeset and handwritten] “ Liogenys rectangu / lus n. sp / det. G. Frey, 1968”, [white, typeset in red] “Smithson., / Cartwr.”, [white handwritten] “ +1”, genitalia mounted. Paratypes (3): One male (NHMB): [white typeset] “San José Chiq. / X.26. Lind. [Lindner] / D. Chaco-Exped. [Deutchen Chaco-Expedition]”, [red typeset] “TYPUS”, [white, typeset and handwritten] “ Liogenys rectangu / lus n sp / Type / det. G. Frey, 1968”, genitalia mounted. One female (NHMB): [white handwritten] “ Salta, Argent. / Dep. Rivadavia”, [red typeset] “ PARATYPE ”, [white typeset] “ ♀ ”, [white, typeset and handwritten] “ Liogenys rectangu- / lus n sp / det. G. Frey, 1968”, [white, typeset in red] “Smithson., / Cartwright”, [white typeset] “Museum Frey / Tutzing”. One male (MZSP): [white typeset] “ Argentina / Formosa / Ciudad XII.1949 / A. Martinez leg.”, [red typeset] “ PARATYPE ”, [white, typeset and handwritten] “ Liogenys / rectangu- / lus n sp / det. G. Frey, 1968”, genitalia mounted. Non-type material (8). BOLIVIA. Santa Cruz, San José de Chiquitos [17°50’04.6’’S, 60°45’01.7’’W], X.26, Lindner, 1 male (NHMB). ARGENTINA. Formosa: Ingeniero Juárez, 24º05’27’’S 61º56’49’’W, 13.XII.2008, Ocampo, San Blas, & Campón, mercury vapor & ultraviolet light, 4 males and 3 females (IADIZA). Diagnosis. Length: 9.0– 10.2 mm; width: 4.2–4.7 mm. Body and pronotum reddish brown, elongate, sides almost parallel; elytra testaceous, glabrous, opaque, somewhat pruinose (Fig. 19A); clypeal emargination very shallow, rounded and wide, in males as wide as the distance between eyes; outer sides of anterior teeth following the clypeal lateral margin; clypeal lateral margin straight or concave; antennae with 10 antennomeres; pronotal posterior corners sharp, in obtuse angle (Fig. 19B); mesotibia quadrate in cross section; two transverse carinae posteriorly, the apical incomplete or weakly complete; pygidium flat; subtrapezoidal; pygidial disc with short, thick, erect bristles throughout (Fig. 19D); in males, inner margin of metatibia strongly carinate straight towards apex; tarsi abundantly with bristles dorsally, protarsomere II as long as it is wide; parameres widened medially and abruptly narrowed sub-basally; parameral split slightly beyond the midline; apex spatulate (Fig. 19E); parameres in lateral view straight, not coplanar (Fig. 19F). Type locality. ARGENTINA, Formosa, Puerto Pilcomayo. Geographical distribution. BOLIVIA (Santa Cruz); ARGENTINA (Salta, Formosa). Remarks. Liogenys rectangula resembles L. moseri Frey, 1969 (Cherman et al. 2017, 2019a) in the body size and color, in the shape and vestiture of pygidium, and in the protarsi abundantly with bristles. Liogenys rectangula differs from L. moseri (in parenthesis) mainly in the clypeus laterally straight, without tooth-like projection (convex, with a sharp tooth-like projection) and in the elytra in general pruinose (shiny or slightly semiopaque in some specimens). Frey (1969) described L. rectangula from a series collected in Pilcomayo, Formosa, Argentina; the holotype was deposited at the USNM and the paratypes (Frey did not state the number) at NHMB. At the USNM the specimen deposited by Frey bears a paratype label instead. At the NHMB, specimens with type label found are from other localities but the one stated by Frey (1969): one specimen is from “San José Chiquitos” (Bolivia) and other is from “ Salta, Dep. Rivadavia” (Argentina), with holotype and paratype labels, respectively. As they are not from the type locality stated by the author, they are not considered types. There is another paratype specimen deposited at the MZSP, which is from Formosa Ciudad (Argentina). As the author did not state the ocurrences from Chiquitos (Bolivia) and Salta (Argentina) in the original description, we consider them as new L. rectangula state and country records, respectively.Published as part of Cherman, Mariana Alejandra, Basílio, Daniel Silva, Mise, Kleber Makoto, Frisch, Johannes & Almeida, Lúcia Massutti De, 2021, Liogenys Guérin-Méneville, 1831 (Coleoptera: Scarabaeidae: Melolonthinae Diplotaxini) from the Chacoan Province and its boundaries: taxonomic overview with four new species, pp. 1-59 in Zootaxa 4938 (1) on pages 43-45, DOI: 10.11646/zootaxa.4938.1.1, http://zenodo.org/record/456125
A new pterodactyloid pterosaur with a unique filter‑feeding apparatus from the Late Jurassic of Germany
No full textA new long-legged, spatula-beaked, filter-feeding pterodactyloid pterosaur from Upper Jurassic plattenkalk limestones at Wattendorf, Bavaria, Southern Germany, is remarkable for its completeness, unusual dentition and hints of the preservation of soft tissues, including wing membranes. The fully articulated specimen displays both jaws each side with over one hundred sub-parallel-sided teeth with a small, slightly hooked expansion at the crown tip. There are at least 480 teeth in total. The tip of the rostrum widens to a spatula-like, laterally concave structure with teeth only along its lateral margins. The straight anterior margin is devoid of teeth allowing plankton-rich water to stream in, while the teeth interdigitate forming a fine mesh trap. A slightly up swept rostrum assisted filtering by probable pulsating movements of the long neck, while wading or swimming through shallow water
Weak and Strong Type A 1 –A ∞ Estimates for Sparsely Dominated Operators
No full textWe consider operators T satisfying a sparse domination property (Formula presented.)with averaging exponents (Formula presented.). We prove weighted strong type boundedness for (Formula presented.) and use new techniques to prove weighted weak type (Formula presented.) boundedness with quantitative mixed (Formula presented.)–(Formula presented.) estimates, generalizing results of Lerner, Ombrosi, and Pérez and Hytönen and Pérez. Even in the case (Formula presented.) we improve upon their results as we do not make use of a Hörmander condition of the operator T. Moreover, we also establish a dual weak type (Formula presented.) estimate. In a last part, we give a result on the optimality of the weighted strong type bounds including those previously obtained by Bernicot, Frey, and Petermichl.Analysi
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