2,517 research outputs found
On the phylogeny of Paleogene planktonic foraminifera: wall texture structure and a new genus name for the broedermanni lineage
No full textThe broedermanni lineage has been traditionally placed in the genus Igorina (see Berggren and others, 2006) being characterized by possessing a biconvex globorotaliid morphology, subglobular to subquadrate chambers, and by having a nonspinose wall texture with thin muricae on the test surface. Our analysis of specimens from the Pacific Ocean (ODP Leg 198, Shatsky Rise and ODP Leg 143, Alllison Guyot) suggest that the broedermanni group is phylogenetically related to Acarinina as the calcite structures of the wall are similar to the muricae rather than to the short pustules of the Paleocene igorinids (i. e., I. pusilla, I. albeari). In particular, the oldest species lodoensis shows a typical coarse muricate test similar to Acarinina while in its descendants, broedermanni and anapetes, the muricae are finer on the spiral side, and heavier muricae are developed only around the umbilicus. Moreover, in the broedermanni group the shell is not encrusted as in Igorina because the pustules remained isolated and increased in size to become thick muricae. The analysis of the pore structure in cross section seems to confirm the similarities and affinities between the wall texture of the broedermanni group and Acarinina. Both show an hourglass shape of the pores that become narrow in the outer calcite layer whereas in Igorina species the pores are tight in the inner calcite layer. In addition, the results from parsimony analysis (Soldan and other, 2011) confirm that the broedermanni group evolved in the late Paleocene/early Eocene from the group of round acarininids (A. mckannai and A. soldadoensis).
The new genus Pearsonites (named in honor of Professor Paul N. Pearson) with Pearsonites broedermanni as type species, is here proposed to accommodate the early-middle Eocene globorotaliid taxa of the broedermanni lineage with a wall texture bearing muricae. Three species previously considered morphologically and evolutionary related to the Paleocene genus Igorina are here included in Pearsonites nov. gen., P. lodoensis, P. broedermanni, and P. anapetes. Species assigned to Pearsonites nov. gen. are relatively common in the stratigraphic interval from the upper Paleocene (Zone P5) to the middle Eocene (Zone E9).
References
Berggren W.A., Pearson P.N., Huber B.T., Wade B.S., 2006. Chapter 19: Taxonomy, biostratigraphy and phylogenetic affinities of Eocene Acarinina, in Pearson P. N., Olsson R.K, Huber B.T., Hemleben C., Berggren W.A (eds), Atlas of Eocene Planktonic Foraminifera: Cushman Foundation Special Pubblication, v. 41, p. 257-326.
Soldan D.M., Petrizzo M.R., Premoli Silva I., Cau A., 2011. Phylogenetic relationships and evolutionary history of the Paleogene genus Igorina through parsimony analysis: Journal of Foraminiferal Research, v. 41, p. 260-284
Esperienza ed evento della verità. Pratica filosofica e astrazione scientifica nel pensiero di A.N. Whitehead
No full textThis article analyzes the relationship between philosophy, experience and event in A.N. Whitehead’s thought. From the critics of the concept of object, the author retraces and describes the peculiar “abstract-concrete dialectic”, at the center of the researches concerning the perceptual experience.
Furthermore, according to Whitehead’s later works, she demonstrates how the philosophical practice is different from all other kinds of science, although it requires science itself because of the co-implication of object and event, abstraction and recognition
Il "Guerrin Meschino" di Gesualdo Bufalino : un'"opra" in versi
No full textGesualdo Bufalino first published Il Guerrin Meschino in 1991 in a non-commercial edition. In 1993, after a deep revision, he re-published his work with publisher Bompiani: the novel has a modified plot, and the author decided to insert three new poems in addition to the opening and closing poems, formerly present in 1991’s edition. This paper, in its entirety supported by handwritten material preserved at Fondazione Gesualdo Bufalino (Comiso), is divided in two parts: the first part illustrates the differences between the first and the second edition, the second part provides a critical edition of the five poems
Pforams@microtax : Anew online taxonomic database for planktonic foraminifera
No full textA new relational taxonomic database for planktonic foraminifera (“pforams@mikrotax”) has been constructed and is now
freely available online at http://www.mikrotax.org. It represents amajor advance from its predecessor, the CHRONOS online taxonomic
database, which has served the research community since 2005. The benefits of the new database to the research and industrial
biostratigraphic communities are many, as it will serve as an immediately accessible taxonomic guide and reference for specialists and
non-specialists alike by providing access to a wealth of information and images from original authors and from expertswho have inserted
recent authoritative updates to planktonic foraminiferal taxonomy, phylogeny and biostratigraphy. The database will be continually updated and used as a guide for training current and future generations of students and professionals who will be able to self-educate on
planktonic foraminiferal taxonomy and biostratigraphy. Further investigation of species traditionally included in the Cretaceous genera
Heterohelix, Globigerinelloides, Marginotruncana, and Globotruncana is required to exclude the use of polyphyletic morphotaxa. The
taxonomy for Paleogene planktonic foraminifera is quite stable following publication of the Paleocene, Eocene, and Oligocene taxonomic
atlases, but revisions to the taxonomy and phylogeny of Neogene taxa are needed to incorporate results from genetic sequencing
studies and recent biostratigraphic observations
A FEW WORDS ABOUT THE TEACHER. IN MEMORY OF THE EXCELLENT TEACHER AND SCIENTIST M.R. SAPIN
No full textM.R. Sapin (1925–2015) was a professor at I.M. Sechenov First Moscow State Medical University, honorary academician of Russian academy of medical sciences (1988), and an outstanding representative of the Moscow anatomical school of the middle of XX – early XXI century. From the very beginning of his medical training, Mikhail Romanovich got interested in anatomy, especially in angiology and lymphology, and later concentrated on its studying. The author of more than 30 text books and guidelines for schools, universities, and colleges, Mikhail Romanovich was the doctoral and thesis advisor of 51 Ph.D. and approximately 70 MD dissertations. M.R. Sapin made a significant contribution to the development of anatomical education providing the departments with a various range of dry and wet specimens. His stunning and effective work as a tutor was highly appreciated by his students and colleagues, Russian and foreign anatomists. M.R. Sapin was the leader of the Laboratory of Functional Anatomy since 1972, president of the International Association of Morphologists (1992–2006), chairman of the expert commission of Higher Attestation Commission (1959–1994), etc. A man of a great willpower, M.R. Sapin faced a lot of obstacles in his life and research work but overcame that all successfully. The article presents the most important facts of anatomist’s career and lifetime.</jats:p
Planktonic foraminifera in biostratigraphy and biochronology
No full textPlanktonic foraminifera, single-celled protists, are extensively used in biostratigraphy and biochronology thanks to their abundance in marine sediments, widespread distribution and extensive fossil record in the Cretaceous and Cenozoic. We present an overview of planktonic foraminiferal taxonomy, and evolutionary trends that are relevant to the practice and application of biostratigraphy. Additionally, we present the key features in planktonic foraminiferal paleoecology and paleogeography that characterise Cretaceous-Cenozoic species diversity and geographic distributions. The types of bioevents and biozone definitions, morphologic terminology and species identification in evolutionary lineages are illustrated through examples. Planktonic foraminifera are crucial in the development of geological timescales and their value and reliability in chronostratigraphic correlations is demonstrated by the identification of 14 primary and secondary boundary events applied in the definition of the Global Stratotype Section and Points (GSSP). The presentation of the methodologies used in biochronological studies is aimed to describe the significance of planktonic foraminifera for correlation and integration with magnetostratigraphy, chemostratigraphy and orbital tuning. Calibration difficulties such as diachroneity of species occurrences are discussed, and examples of astronomical calibrations are provided for the Late Cretaceous and Late Miocene
Verslag van het voorgevallene tijdens het hooge opperwater op de Nederlandsche rivieren in den winter van 1919 op 1920
No full textNadat de Rijn op 20 December 1919 tot even beneden den middelbaren zomerstand 1901-1910 (M.R.) was gedaald vertoonde zich op die rivier een sterke en vrij snelle was, waardoor het water te Keulen tot 6m +M.R. bij het einde van het jaar steeg. In de daarop volgende 11 dagen daalde de waterstand tot 1.5m +M.R. om daarna in 5 dagen weder te rijzen tot den zeer hoogen stand van 7m +M.R. Door een aanvankelijk sterken later flauweren val liep de stand weder terug tot 1.5m +M.R. op 30 Januari. Ook op de Maas vertoonden zich twee dicht op elkaar volgende sterke wassen. Bij den aanvang van den eersten was op 19 december stond het water te Maastricht op ruim 1m +M.R. en steeg het in 6 dagen tot 4.37m +M.R.; in de daaropvolgende 9 dagen bleef de stand steeds hoger dan 4m +M.R. en daalde toen tot ongeveer 2m +M.R. op 10 Januari 1920. De tweede was trad op laatsgenoemde datum in waarbij het water oplied tot 4.94m +M.R. op 15 Januari. Het water daalde daarna dadelijk en was op 29 Januari tot ongeveer 2m +M.R. weggevallen. Bij den tweeden was op Rijn en Maas werden de hoogst bekende waterstanden bij open rivieren overtroffen te Keulen met 7 cm en te Maastricht met 2 cm. De rivieren waren ijsvrij.Hoogwaterversla
A spine of information headings for emblem-related electronic resources
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Review and revision of Cenozoic tropical planktonic foraminiferal biostratigraphy and calibration to the Geomagnetic Polarity and Astronomical Time Scale
No full textPlanktonic foraminifera are widely utilized for the biostratigraphy of Cretaceous and Cenozoic marine sediments and are a fundamental component of Cenozoic chronostratigraphy. The recent enhancements in deep sea drilling recovery, multiple coring and high resolution sampling both offshore and onshore, has improved the planktonic foraminiferal calibrations to magnetostratigraphy and/or modified species ranges. This accumulated new information has allowed many of the planktonic foraminiferal bioevents of the Cenozoic to be revised and a reassessment of the planktonic foraminiferal calibrations. We incorporate these developments and amendments into the existing biostratigraphic zonal scheme.In this paper we present an amended low-latitude (tropical and subtropical) Cenozoic planktonic foraminiferal zonation. We compile 187 revised calibrations of planktonic foraminiferal bioevents from multiple sources for the Cenozoic and have incorporated these recalibrations into a revised Cenozoic planktonic foraminiferal biochronology. We review and synthesize these calibrations to both the geomagnetic polarity time scale (GPTS) of the Cenozoic and astronomical time scale (ATS) of the Neogene and late Paleogene. On the whole, these recalibrations are consistent with previous work; however, in some cases, they have led to major adjustments to the duration of biochrons. Recalibrations of the early middle Eocene first appearance datums of Globigerinatheka kugleri, Hantkenina singanoae, Guembelitrioides nuttalli and Turborotalia frontosa have resulted in large changes in the durations of Biochrons E7, E8 and E9. We have introduced (upper Oligocene) Zone O7 utilizing the biostratigraphic utility of 'Paragloborotalia' pseudokugleri. For the Neogene Period, major revisions are applied to the fohsellid lineage of the middle Miocene and we have modified the criteria for recognition of Zones M7, M8 and M9, with additional adjustments regarding the Globigerinatella lineage to Zones M2 and M3. The revised and recalibrated datums provide a major advance in biochronologic resolution and a template for future progress to the Cenozoic time scale
Task-technology fit theory: A survey and synopsis of the literature
No full textOver the past decade there has been a notable increase in the use of task-technology fit (ttf) theory within the field of information systems. This theory argues that information system use and performance benefits are attained when an information system is well-suited to the tasks that must be performed. As such, it seeks to offer an account of two of the key outcomes of interest to information systems (is) researchers. Continued interest in the application of ttf theory is therefore expected and, as a result, the following chapter aims to provide a brief overview of the theory and how it has been applied in prior work. Readers are presented with an overview of the diverse range of research contexts and methodologies that have been used to test and extend ttf theory. Key outcomes of interest to ttf researchers are also examined as are the various approaches that researchers have used to operationalize the notion of ttf. It is hoped that this overview will serve as a sound basis for future research and simultaneously help to ensure that is research does not continue to tread the same ground
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