Ichnological record of the Frasnian-Famennian boundary interval : two examples from the Holy Cross Mts (Central Poland)

The Frasnian-Famennian (Late Devonian) boundary interval within the carbonate-siliciclastic series in the Kowala and Płucki sections (Holy Cross Mts, Central Poland) has been analysed to evaluate the influence of the Kellwasser event on the macrobenthic tracemaker community. The Upper Kellwasser event has a lithologically variable record, as horizons of flints (Kowala) and as a bed of bituminous, black, cephalopod limestone (Płucki). Both sections show mostly laminated, unbioturbated beds of marlstones or shales just above the Frasnian-Famennian boundary, which point to events of anoxia on the sea floor. However, the first anoxic horizon occurs below the Frasnian-Famennian boundary. The trace fossils and bioturbational structures are uncommon and poorly diversified. Trichichnus and Multina are the only frequent trace fossils in some beds. Moreover, one horizon above the Frasnian-Famennian boundary contains numerous Multina and a single? Planolites. Such poorly diversified trace fossil assemblage suggests an unfavourable environment for most of burrowing organisms and fluctuations in oxygenation from anoxic, to dysoxic conditions. The occurrence of the trace fossils and bioturbational structures as spotted and mottled ichnofabrics from the 1.3 m above the Frasnian-Famennian boundary is interpreted as an improvement in bottom water oxygen conditions after the Upper Kellwasser event

Changes in the composition of trace fossil assemblages across the Paleocene-Eocene transition in the north-western Tethys (Untersberg section, Austria)

The Untersberg section (Northern Calcareous Alps, Austria) provides an expanded and biostratigraphically well constrained deep-sea record of the Paleocene-Eocene transition in the north-western Tethyan realm. At the base of the Eocene, massive carbonate dissolution and a shoaling of the calcite compensation depth (CCD) by at least 1 km is recorded by 5.5 m-thick red claystone, which is intercalated into a grey marlstone succession. Previous studies documented the benthic foraminifera extinction event (BEE) in this claystone. Now biodeformational structures and trace fossils were investigated in this interval to evaluate the impact of the extinction event on the macrobenthic tracemaker fauna. Using the stratigraphic distribution pattern of trace fossils, the lowermost Eocene claystone can be subdivided into three parts: (1) the lower part shows a trace fossil assemblage consisting of Chondrites isp., Planolites isp., Thalassinoides isp., and Zoophycos isp., (2) the middle part is characterized by primary sedimentary lamination and exceedingly rare ichnofossils, and (3) the upper part shows a less abundant and less diverse trace fossil assemblage than the lower part, indicating a slow recovery of the macrobenthic tracemaker community. This pattern demonstrates that macrobenthic communities were severely affected by the ecological perturbations in the earliest Eocene. The change in sediment colouration towards red colour in the middle part of the Paleocene-Eocene transition at the Untersberg section, together with decrease in bioturbation degree indicate that oxygen consumption was rather reduced during the PETM, and the loss in bioturbation is thus unrelated to oxygen limitation. Trace fossils can be used to improve the resolution of the benthic extinction interval and provide an excellent proxy for the precise determination of timing of the climax of this global event

A virtual dairy herd as a tool to teach dairy production and management

The objective of this project was to develop and test a web-based virtual dairy herd to help students understand the structure and functioning of a dairy herd, and to promote active learning. At the beginning of the course, the instructor defines the profiles of herds to be assigned to students (e.g., herd size, production, diets, fertility). Each student has a unique herd and engages in decision-making for desired management practices in the herd. Modeled events are based on cow physiology and normal dairy herd management practices. Students' activities and decisions include heat detection, insemination, pregnancy diagnosis, dry-off, diet specifications, feeding groups, colostrum and milk-replacer feeding, weaning, treatment of diseases, and milk withdrawal from the tank if antibiotics are used, among others. The daily output provides information on technical indexes, economic performance, counters of incorrect decisions as feedback for students, and score. Time in class can be devoted to discussions of dairy management issues. Additional exercises based on students' own herds (e.g., calculating required space for cows, land for forage production, manure management) can also be implemented. Students' performance in the virtual dairy farm was monitored over 3 years. The average score (n = 326) was 87.8 ± 1.1 over 100 points, suggesting that self-learning with the virtual dairy farm was highly successful. At the end of each semester, students (n = 277) responded to a survey on the experience of working with the virtual dairy herd. Most students (>87%) agreed that the virtual dairy herd was more effective and motivating than traditional lectures and helped them understand dairy production better. In an unannounced test conducted at least 2 wk before the final exam, students (n = 207) were asked 14 questions on dairy cattle and 14 similar questions on other species taught in the same class through traditional lectures. A similar test on the same students (n = 142) was conducted in their fifth semester (2 years later). Results were better in dairy compared with other species questions in the first (9.6 vs. 3.7) and fifth (8.0 vs. 3.8) semesters. The virtual dairy herd is an effective tool for teaching introductory courses in dairy production. The program can be accessed at www.virtualdairyfarm.org, and a manual and videos with instructions for instructors and students are available online

Sobre la imagen naipesca del comienzo del «Buscón»

El ensayo pretende documentar una interpretación sexual para una metáfora naipesca de El buscón a la que tradicionalmente se le adjudica un valor ladronesco. Si, como los autores esperan demostrar, la interpretación sexual mejora el texto de Quevedo, así estética como estructuralmente, ello representaría una significativa reacción contra la prevalente noción crítica de un Buscón de creación extemporánea y estructura desarticulada. The article hopes to document a sexual interpretation for a card-playing metaphor in El buscón that is generally attributed a criminal (pickpocket) meaning. If as the authors hope to prove, the sexual interpretation they propose aesthetically and structurally enhances Quevedo 's text, it would represent an important reaction to the prevalent critical notion of a Buscón created extemporaneously and reflecting a thoroughly fragmented structure

El fondo tradicional del Cuento del cautivo

Se pretende subrayar y ampliar los antecedentes que posee el núcleo amoroso del cuento que Cervantes ponen en el Quijote en boca del capitán Ruy Pérez de Viedma en el repertorio de la narrativa tradicional. Se señala su contigüidad temático-narrativa con el esquema de ‘la hija convertida del padre ogro’ y se lo relaciona con la intensidad conflictiva con que Europa vivía por entonces la cuestión religiosa. This article pretends to highlight and extend the antecedents of the loving main plot of this tale by Cervantes, appearing in the Quixote in mouth of captain Ruy Pérez de Viedma, on the repertory of traditional narrative. Its thematic and narrative continuity with the scheme “converted daughter of the ogre father” is underlined, and it is shown as related with the conflictive intensity with which Europe was living the religious matter in those days

Computing Discrete Logarithms in F_{3^{6*137}} and F_{3^{6*163}} using Magma

We show that a Magma implementation of Joux\u27s L[1/4+o(1)] algorithm can be used to compute discrete logarithms in the 1303-bit finite field F_{3^{6*137}} and the 1551-bit finite field F_{3^{6*163}} with very modest computational resources. Our F_{3^{6*137}} implementation was the first to illustrate the effectiveness of Joux\u27s algorithm for computing discrete logarithms in small-characteristic finite fields that are not Kummer or twisted-Kummer extensions

Weakness of F_{3^{6*509}} for Discrete Logarithm Cryptography

In 2013, Joux, and then Barbulescu, Gaudry, Joux and Thomé, presented new algorithms for computing discrete logarithms in finite fields of small and medium characteristic. We show that these new algorithms render the finite field F_{3^{6*509}} = F_{3^{3054}} weak for discrete logarithm cryptography in the sense that discrete logarithms in this field can be computed significantly faster than with the previous fastest algorithms. Our concrete analysis shows that the supersingular elliptic curve over F_{3^{509}} with embedding degree 6 that had been considered for implementing pairing-based cryptosystems at the 128-bit security level in fact provides only a significantly lower level of security. Our work provides a convenient framework and tools for performing a concrete analysis of the new discrete logarithm algorithms and their variants

Effect of feeding method on intake and behaviour of individually reared beef heifers fed a concentrate diet from 115 to 185 kg of body weight

A total of eight Simmental heifers (114 ± 3.2 days old and weighing 118 ± 3.8 kg BW) were used to study the effects of feeding method on intake and animal behaviour in a crossover design experiment. Treatments consisted of feeding concentrate and chopped barley straw as (1) choice (CH; concentrate and straw in separate feedbunks) or (2) total mixed ration (TMR; concentrate and straw in one feedbunk). Feeds were offered on an ad libitum basis, but always maintaining a concentrate to straw ratio of 90 to 10. The experiment was performed in two 21-day periods, and sampling was carried out in the last week of each period. At the end of each period, treatment was changed for heifers; hence, the final number of animals per treatment was eight. Intake was recorded over 7 consecutive days. BW was recorded at the beginning and the end of the experiment and on day 21 of each experimental period. Barley straw was coarsely chopped with a chopping machine. Once chopped, all the straw was handled for particle size separation using the 2-screen Penn State Particle Separator and only material of more than 8 mm was used to feed the heifers. Animal behaviour was video-recorded for 24 h on day 2 and day 6 of each experimental period. Concentrate intake and total dry matter intake of heifers fed with the CH feeding method were higher (P < 0.01 and P < 0.05) than when fed with TMR (5.1 and 5.3 v. 4.7 and 5.0 kg dry matter (DM)/day, respectively). Conversely, barley straw was consumed in higher amounts in heifers fed with the TMR feeding method (0.3 v. 0.2 kg DM/day, respectively; P = 0.001). The total NDF intake was similar in both treatments. In contrast, NDF intake from barley straw and physically effective NDF intake were higher in heifers fed with the TMR feeding method than when fed with CH. Feeding method used to feed heifers did not affect the consumption of the different kinds of barley straw particles and eating and drinking behaviours but affected ruminating behaviour. Heifers fed TMR spent more time ruminating than heifers fed concentrate and barley straw separately (376 v. 287 min/day, respectively; P < 0.01). TMR as the feeding method in intensive beef production systems could be a good approach to promote roughage intake