Multicusped crocodyliform teeth from the Upper Cretaceous (São José do Rio Preto Formation,Bauru Group) of São Paulo,Brazil

The six peculiar multicusped teeth described here were collected from sediments of the Upper Cretaceous of São José do Rio Preto Formation, near Ibirá (northeastern São Paulo, Brazil). Their bulbous crowns are slightly labio-lingual compressed, and bear a main plus two accessory cusps, which conceal a well developed cingulum. Wear facets are seen on the main and distal accessory cusps. Comparison to the known Crocodyliformes with multicusped teeth show that the new material is not referable to “protosuchians” or eusuchians, nor related to two unnamed forms from Morocco and “notosuchians” such as Uruguaysuchus, Chiamaerasuchus, and Simosuchus. On the other hand, possible affinities with Candidodon and Malawisuchus were maintained based on shared traits. This includes teeth with the main cusp and some accessory cusps arranged in more than one axis, a previously defined unambiguous apomorphy of the putative clade composed of Candidodon plus Malawisuchus. The term Candidodontidae can be applied to this group, and defined as all taxa closer to Candidodon itapecuruensis than to Notosuchus terrestris, Uruguaysuchus aznarezi, Comahuesuchus brachybuccalis, Sphagesaurus huenei, Baurusuchus pachecoi, and Crocodylus niloticus.     

Corrections to the Mathematical Formulation of a Backwards Lagrangian Particle Dispersion Model

This technical note introduces some corrections to the Lagrangian particle dispersion model of Rotach et al. (Q J R Meteorol Soc 122:367–389, 1986). Careful mathematical derivation following the detailed explanations in that paper uncovered some unit inconsistencies that were the result of mistaken function definitions. Errors are noted in the drift correction, or “probability current” of the particle dispersion model as well as in parameterization of turbulence terms, which are necessary inputs to the model. The probability current comprises Gaussian, convective, and solenoidal components, with derivation errors discovered in the latter two components. All errors are presented along with new formulations that are mathematically consistent, correct the original problems, and adhere to the underlying Gaussian nature of the particle dispersion phenomenon. The corrections shown here should provide more accurate results for particle dispersion models based upon the work of Rotach et al., as well as resolve points of confusion for future researchers referring to that work.     

UV photolysis of quinoline in interstellar ice analogs

Abstract— The polycyclic aromatic nitrogen heterocycle (PANH) quinoline (C₉H₇N) was frozen at 20 K in interstellar ice analogs containing either pure water or water mixed with methanol or methane and exposed to ultraviolet (UV) radiation. Upon warming, the photolysis products were analyzed by high‐performance liquid chromatography and nanoscale liquid chromatography‐electrospray ionization mass spectrometry. A suite of hydroxyquinolines, which were formed by the addition of oxygen atoms to quinoline, was observed as the primary product in all the ices. Quinoline N oxide was not formed, but five hydroxyquinoline isomers were produced with no clear dominance of one isomer. Reduction products, formed by hydrogen atom addition, were also created. Ices created at 20 K with H₂O: quinoline ratios of 10:1 to 100:1 showed similar product distributions to those at 122 K, with no apparent temperature or concentration dependence. Increasing the UV dose led to a decrease in overall yield, indicating that quinoline and its products may be photo‐destroyed. Methylquinolines were formed upon photolysis of the methanol‐ and methane‐containing ices. In addition, possible methoxyquinolines or quinoline methylene alcohols were formed in the methanol‐containing ice, while methylhydroxyquinolines were created in the methane‐containing ice. This work indicates that oxidation of PANHs could occur in icy extraterrestrial environments and suggests that a search for such compounds in carbonaceous meteorites could illuminate the possible link between interstellar ice chemistry and meteoritic organics. Given the importance of oxidized and alkylated PANHs to biochemistry, the formation and delivery of such molecules to the early Earth may have played a role in the origin and evolution of life.     

Die abschnittweise Darstellung einer gemessenen Laufzeitkurve mit abgebrochenen Potenzreihen und ihre Auswertung in der Refraktionsseismik

Zusammenfassung Es wird eine einfache und für numerische Rechnungen besonders geeignete Methode zur direkten Auswertung von seismischen Refraktionsmessungen entwickelt und an einem Beispiel [Eisdickenmessungen in Baffin Island,Röthlisberger (3)] erläutert.

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Summary A simple and for numerical calculation especially convenient method is developped for the direct inerpretation of travel-time curves in refraction seismic. Finally an example [Firn and ice thickness measurements in Baffin Island, byH. Röthlisberger (3)] is given.

     

La fréquence des orages dans les Alpes de la Suisse Occidentale

Résumé Des observations inédites permettent d'établir un nouveau profil des fréquences orageuses dans les Alpes occidentales de la Suisse. Le nombre de jours d'orage, notablement plus élevé qu'on ne l'admettait jusqu'ici, décroit de l'extérieur vers l'intérieur du massif alpin et jusque dans sa chaine la plus méridionale. Quelques données numériques documentent la variation diurne et annuelle de l'activité orageuse en Valais.

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Summary Unpublished observations allow the etablishment of a new cross section of the thunderstorm frequency in the western Alps of Switzerland. The number of thunderstorm days is much more frequent than has yet been admitted, diminishing from the outer towards the inner region of the alpine massive as far as the extreme southern chain. Some statistics record the diurnal and annual variations of the activity of thunderstorms in Valais.

     

Large-scale mass wasting on the north Spitsbergen continental margin, Arctic Ocean

 Closely spaced, single-beam bathymetric and side-scan sonar investigations on the northern slope of the western Svalbard insular platform have revealed the presence of a Late Quaternary slump complex forming a hanging-wall slump canyon near the head of the Malene Bukta (Malene Bay) bathymetric embayment in the northern continental margin. Repeated slump erosion may be responsible for development of this young feature and the Malene Bukta Embayment. Focusing of the slumping may be due to the trapping of gas at shallow sea-floor depths by gas hydrate, with the consequent formation of subjacent gas-rich, low shear-strength decollement zones. Faults have likely controlled the upward migration of gas into the younger sedimentary prism.     

Acoustic mapping as an environmental management tool: I. Detection of barrels of low-level radioactive waste, Gulf of the Farallones National Marine Sanctuary, California

The oceans have been and will continue to be disposal sites for a wide variety of waste products. Often these wastes are not dumped at the designated sites or transport occurs during or after dumping, and, subsequent attempts to monitor the effects the waste products have on the environment are inadequate because the actual location of the waste is not known. Acoustic mapping of the seafloor with sidescan sonar is a very effective technique for locating and monitoring dredge-spoil material and other debris. Sidescan sonar provides an acoustic image or sonograph of the sea floor that is similar to a satellite image of the Earth's land surface. In effect sidescan sonar allows the water column to be stripped from the sea floor, thereby providing a clear, unobstructed view of the sea bed.An example of the potential of this technique is summarized herein for the Gulf of the Farallones region. More than 47 800 drums (55 gallon) and other containers of low-level radioactive waste were dumped on the continental margin offshore the San Francisco Bay between 1946 and 1970. These drums now litter a large area (1200 km²) of the sea floor within the Gulf of the Farallones National Marine Sanctuary (GFNMS). The exact location of the drums and the potential hazard the drums pose to the environment are unknown. To evaluate the risk, samples of the sediment, biota and water must be collected near and distant from the concentrations of barrels. To do this the exact location of the barrels must be known prior to sampling. The USGS, through a cooperative research agreement with GFNMS, used sidescan sonar to map two areas within the sanctuary. Total sea-floor coverage was obtained and computer-processed sonographic mosaics were constructed on board ship. Many small nongeologic targets were distributed throughout the survey areas that covered about 70 km² on the shelf and 120 km² on the slope. Analysis of the sidescan data suggests that the targets are 55-gallon drums. This interpretation was confirmed at one site with an underwater video and 35-mm camera system. Data were collected with both a 30-kHz and a 120-kHz sidescan system within a 15-km² area on the shelf. We found that the barrels were more easily detected with the mid-range 30-kHz system than with the higher resolution 120-kHz system. Maps of barrel distribution derived from the sonographs are being used to design sampling schemes to evaluate the risk that the radioactivity may have on the biota and environment.     

Exposure to hydrocarbons 10 years after the Exxon Valdez oil spill: evidence from cytochrome P4501A expression and biliary FACs in nearshore demersal fishes

Three biomarkers of hydrocarbon exposure, CYP1A in liver vascular endothelium, liver ethoxyresorufin O-deethylase (EROD), and biliary fluorescent aromatic compounds (FACs), were examined in the nearshore fishes, masked greenling (Hexagrammos octogrammus) and crescent gunnel (Pholis laeta), collected in Prince William Sound, Alaska, 7-10 years after the Exxon Valdez oil spill (EVOS). All biomarkers were elevated in fish collected from sites originally oiled, in comparison to fish from unoiled sites. In 1998, endothelial CYP1A in masked greenling from sites that were heavily oiled in 1989 was significantly higher than in fish collected outside the spill trajectory. In 1999, fishes collected from sites adjacent to intertidal mussel beds containing lingering Exxon Valdez oil had elevated endothelial CYP1A and EROD, and high concentrations of biliary FACs. Fishes from sites near unoiled mussel beds, but within the original spill trajectory, also showed evidence of hydrocarbon exposure, although there were no correlations between sediment petroleum hydrocarbon and any of the biomarkers. Our data show that 10 years after the spill, nearshore fishes within the original spill zone were still exposed to residual EVOS hydrocarbons.     

Has wind–wave modeling reached its limit?

This article uses a comparison of four different numerical wave prediction models for hindcast wave conditions in Lake Michigan during a 10-day episode in October 1988 to illustrate that typical wave prediction models based on the concept of a wave energy spectrum may have reached a limit in the accuracy with which they can simulate realistic wave generation and growth conditions. In the hindcast study we compared the model results to observed wave height and period measurements from two deep water NOAA/NDBC weather buoys and from a nearshore Waverider buoy. Hourly wind fields interpolated from a large number of coastal and overlake observations were used to drive the models. The same numerical grid was used for all the models. The results show that while the individual model predictions deviate from the measurements by various amounts, they all tend to reflect the general trend and patterns of the wave measurements. The differences between the model results are often similar in magnitude to differences between model results and observations. Although the four models tested represent a wide range of sophistication in their treatment of wave growth dynamics, they are all based on the assumption that the sea state can be represented by a wave energy spectrum. Because there are more similarities among the model results than significant differences, we believe that this assumption may be the limiting factor for substantial improvements in wave modeling.