Representatives of genera <Emphasis Type="Italic">Malbosiceras</Emphasis> and <Emphasis Type="Italic">Pomeliceras</Emphasis> (Neocomitidae,Ammonoidea) from the Berriasian of the Crimean Mountains

The revised representatives of ammonite genera Malbosiceras and Pomeliceras from the Berriasian of the Crimean Mountains are classed with seven species, four of the first genus [M. malbosi (Pictet), M. chaperi (Pictet), M. broussei (Mazenot), M. pictetiforme Tavera] and three of the second one [P. aff. boisseti Nikolov, P. breveti (Pomel), P. (?) funduklense Lysenko et Arkadiev sp. nov.]. The identified species are described. The genus Mazenoticeras is considered as synonym of Malbosiceras. The above species prove that all the Berriasian zones (jacobi, occitanica and boissieri) are characteristic of corresponding deposits in the Crimean Mountains.     

Aptian (Lower Cretaceous) biostratigraphy and cephalopods from north central Tunisia

Thick Aptian deposits in north central Tunisia comprise hemipelagic lower Aptian, reflecting the sea-level rise of OAE 1a, and an upper Aptian shallow marine environment characterized by the establishment of a carbonate platform facies. Carbon stable isotope data permit recognition of the OAE 1a event in the Djebel Serdj section. Cephalopods are rare throughout these successions, but occurrences are sufficient to date the facies changes and the position of the OAE1a event. Ammonite genera include lower Aptian Deshayesites, Dufrenoyia, Pseudohaploceras, Toxoceratoides and ?Ancyloceras; and upper Aptian Zuercherella, Riedelites and Parahoplites. Correlation of carbon isotope data with those of other Tethyan sections is undertaken together with the integration of planktonic foraminiferal data.     

Berriasian (Lower Cretaceous) brachiopods from the Crimea

Four successive assemblages of Berriasian brachiopods distinguished for the first time in the Crimea are correlated with concurrent subdivisions of the ammonoid scale. Berriasian brachiopods are represented by 44 species of 27 genera and 14 families, which are most complete in terms of taxonomic composition as compared to other concurrent brachiopod faunas known elsewhere. The assemblages are dominated by local species. As is proved, the Berriasian brachiopods studied are appropriate for age determination, subdivision and correlation of their host deposits. Their geographic distribution that has been analyzed elucidates connections of the Berriasian sea basins within the Mediterranean paleozoogeographic region.     

New data on ammonoids of the genus <Emphasis Type="Italic">Paraulacosphinctes</Emphasis> from the Upper Tithonian of the Mountainous Crimea

The Late Tithonian ammonites Paraulacosphinctes cf. transitorius (Oppel) and P. cf. senoides Tavera from the Feodosiya section boundary Tithonian-Berriasian beds of the Crimea are described. These species allow the correlation of the beds with P. cf. transitorius recognized in the Crimea with the Upper Tithonian Substage of the Western European scale. Based on magnetostratigraphic data, these beds supposedly correlate with the Durangites Zone.     

Towards an Aptian (Lower Cretaceous) ammonite biostratigraphy of the Mina Texali section,Central Atlantic province (Puebla State,Central Mexico)

This work is a study of the ammonite record of a new stratigraphic section of Aptian age, at the Mina Texali (Puebla State, Central Mexico). A detailed biostratigraphic analysis was carried out on 309 specimens systematically sampled on a bed-by-bed basis. An Aptian ammonite zonation is proposed for the Mina Texali (= MT) section with two interval zones, Dufrenoyia justinae and Caseyella sp., and one informal biostratigraphic unit represented by the Huastecoceras trispinosoides beds. We also analyze the taxonomic composition, paleoecology and some systematic issues of the ammonite record of the MT section. The first record in Mexico of the genera Pseudosaynella, Xerticeras and the nautiloid Heminautilus is identified in this section. The ammonite assemblage is assigned to the proximal part of the outer neritic region of the continental shelf. The ammonite record of the studied section is diagnostic in establishing the lower-upper Aptian transition, and the local zonation of the MT provides important data for the development of an Aptian standard ammonite zonation for the Central Atlantic province.     

Ammonite <Emphasis Type="Italic">Fauriella boissieri</Emphasis> (Pictet), the index species of the Berriasian upper zone from the Crimean Mountains

Ammonite Fauriella boissieri (Pictet), the index species of the Berriasian upper zone, is described for the first time as taxon occurring in the Crimean Mountains. In the Berriasian sections of the central Crimea and Chatyr-Dag massif, species F. boissieri are encountered only in association with upper Berriasian ammonites. The Berriasian-Valanginian boundary has not been identified based on ammonites in the Crimean Mountains. Consequently, there is no reason to include the otopeta Zone into the boissieri Zone in the rank of its upper subzone.     

Toxicity of vegetable tannin extract from <Emphasis Type="Italic">Acacia mearnsii</Emphasis> in <Emphasis Type="Italic">Saccharomyces cerevisiae</Emphasis>

Vegetable tannins are complex polyphenols, which occur widely in nature. Traditionally, natural tannins have been used for tanning leather. In Brazil, the main tannin-based products are obtained from Acacia mearnsii, which is a leguminous tree native to Southeastern of Australia, and the first seeds were brought to Brazil in 1928. The main cultivation of acacia was established in Rio Grande do Sul state due to the possibility of raw material for charcoal, adhesives to fuel and for tanning leather. The leather tanning processes based on plant tannins are thought to be less harmful than chromium-based tanning, and it has been used as a sustainable alternative. However, there is scarce information about the environmental impact of the leather tanning processes, with most studies reporting inhibitory effects against microorganisms at high doses and stimulatory and positive health effects at low concentrations. The aim of this study was to evaluate the toxicity of tannin preparations extracted from A. mearnsii in Saccharomyces cerevisiae. Vegetable tannin toxicity in yeast was tested using two tannin treatments in different concentrations. In general, the results showed toxicity of vegetable in yeast, BY4741 and gsh1Δ strains.     

Even-numbered <Emphasis Type="Italic">n</Emphasis>-alkanes/<Emphasis Type="Italic">n</Emphasis>-alkenes predominance in surface sediments of Gabes Gulf in Tunisia

We investigated the mineral composition and trace element contents of dustfall with different deposited phases at the Minqin Oasis, in China’s Hexi Corridor. The contents of elements such as Pb, Cd, Cu, As, Sb, Se, Rb, Cs, and Ba (believed to be of anthropogenic origin) indicated that the significance of human impacts on dust emissions increased from 1970s to the early 2000s. However, variations in the content of elements including Sc, Mn, Na, Cr, V, Eu, Ce, Nb, Zr, La, and Ce (believed to originate from natural processes such as physical and chemical weathering) show no obvious changes in the major potential dust source areas (PSAs) in this region. In addition, analysis of the assemblage of trace elements in dustfall indicated that the elements assumed to originate from anthropogenic and natural processes appear to be intertwined, leading to difficulties and uncertainties in identifying the PSAs and evaluating the significance of human impacts on dust emissions. Comparisons of the element contents of dustfall collected in Beijing and Minqin with similar data for Beijing show that under different conditions some differences in ranges are permitted; the contents of most trace elements were similar even though the dustfall in the two areas came from different sources. These results suggest that before attempting to identify major PSAs, researchers should perform an integrated analysis that includes the mineral, elemental, geomorphological, vegetation cover, climatic conditions, and other characteristics of the regions being studied.     

Toxicity effects of four typical nanomaterials on the growth of <Emphasis Type="Italic">Escherichia coli</Emphasis>, <Emphasis Type="Italic">Bacillus subtilis</Emphasis> and <Emphasis Type="Italic">Agrobacterium tumefaciens</Emphasis>

To offer an insight into the toxicity of nanomaterials (NM) on the growth of bacteria, Escherichia coli (E. coli), Bacillus subtilis (B. subtilis) and Agrobacterium tumefaciens (A. tumefaciens) were exposed to nano-Au, nano-Ag, nano-Fe and fullerene (C₆₀) in this study. As an effective bactericide, nano-Ag induced high toxicity on these three bacteria; C₆₀ could inhibit their growth; however, B. subtilis and E. coli could recover as exposure time extended. Nano-Au and nano-Fe had hardly any effect on three bacteria. A. tumefaciens showed the lowest resistance and slowest growth rate during exposure. Images obtained by scanning electron microscope (SEM) revealed that nano-Ag could cause damage to the cell structure of three bacteria at 1 μg/mL. Slight damage on E. coli was found when exposed to C₆₀, whereas no obvious physical damage was found after exposure to nano-Au or nano-Fe. It is assumed that surface activities of NM might be responsible for the different toxic effects on these bacteria.     

<Emphasis Type="Italic">Salpingoporella</Emphasis> (dasycladalean algae) species from the Lower Cretaceous carbonate facies of Kopet Dagh basin (NE Iran)

Salpingoporella species from algal bearing of Barremian-Aptian limestones in the Kopet Dagh basin (NE of Iran) are described. Different species (S. cemi, S. hasi, S. heraldica, S. hispanica, S. milovanovici, S. muehlmbergi, S. parapiriniae, S. piriniae, S. cf. biokovensis, S. steinhauseri, S. polygonalis) are investigated from different biometrical aspects such as depositional environments and biogeographical distribution as well as their systematic palaeontology from two formations (the Tirgan and Sarcheshmeh formations) in nine stratigraphic sections.     

<Emphasis Type="Italic">Equisetum</Emphasis> cf. <Emphasis Type="Italic">oppositum</Emphasis> (Equisetaceae) from the Paleocene-Eocene of Tibet in southwestern China and its paleoenvironmental implications

Rhizomes with tubers of Equisetum cf. oppositum Ma, Su et Zhang are described for the first time from the Paleocene-Eocene of North Nima Basin, the Tibet Autonomous Region, southwestern China. The fossils are preserved as rows of 6 tubers and rhizome consisting of distinct node and internodes; the tubers are elliptical, ovate, and more or less rounded with distinct longitudinal ribs and grooves on the surface of internodes. According to the similarity of the morphology and arrangement with fossil Equisetum subgenus Equisetum, the present fossils are assigned to Equisetum cf. oppositum Ma, Su et Zhang. Vegetative reproduction and energy storage are the main two functions of tubers, and the presence of tubers implies that burial occurred during the late fall or winter. Based on the occurrence of fossil Equisetum in the forth sequence and the ichthyolite in Nima Basin, associated with zoolite, fossil plant, and palynological assemblages in Lunpola Basin, it would suggest a locally warm, wet environment, probably a lacustrine depositional environment during the Paleocene-Eocene in the Nima Basin of geographic center of Tibetan Plateau. Furthermore, the molasse characteristic of Niubao Formation shows that the Nima Basin situated in the hinterland of Tibetan Plateau might uplifted during the Paleocene-Eocene and have become land from sea. The study is of great significance for further interpretation of the history of uplift in the Paleocene-Eocene of the Tibetan Plateau.     

Utilization of <Emphasis Type="Italic">Spartina</Emphasis>- and <Emphasis Type="Italic">Phragmites</Emphasis>-Derived Dissolved Organic Matter by Bacteria and Ribbed Mussels (<Emphasis Type="Italic">Geukensia demissa</Emphasis>) from Delaware Bay Salt Marshes

Phragmites australis has been invading Spartina-alterniflora-dominated salt marshes throughout the mid-Atlantic. Although, Phragmites has high rates of primary production, it is not known whether this species supports lower trophic levels of a marsh food web in the same manner as Spartina. Using several related photochemical and biological assays, we compared patterns of organic matter flow of plant primary production through a key salt marsh metazoan, the ribbed mussel (Geukensia demissa), using a bacterial intermediate. Dissolved organic matter (DOM) was derived from plants collected from a Delaware Bay salt marsh and grown in the laboratory with ¹⁴C-CO₂. Bacterial utilization of plant-derived DOM measured as carbon mineralization revealed that both species provided bioavailable DOM to native salt marsh bacteria. Total carbon mineralization after 19 days was higher for Spartina treatments (36% ¹⁴CO₂ ± 3 SE) compared with Phragmites treatments (29% ±2 SE; Wilcoxon–Kruskal–Wallis rank sums test, P < 0.01). Pre-exposing DOM to natural sunlight only enhanced or decreased bioavailability of the DOM to the bacterioplankton during initial measurements (e.g., 7 days or less) but these differences were not significant over the course of the incubations. Mixtures of ¹⁴C-labeled bacterioplankton (and possibly organic flocs) from ¹⁴C-DOM treatments were cleared by G. demissa at similar rates between Spartina and Phragmites treatments. Moreover, ¹⁴C assimilation efficiencies for material ingested by mussels were high for both plant sources ranging from 74% to 90% and not significantly different between plant sources. Sunlight exposure did not affect the nutritional value of the bacterioplankton DOM assemblage for mussels. There are many possible trophic and habitat differences between Spartina- and Phragmites-dominated marshes that could affect G. demissa but the fate of vascular plant dissolved organic carbon in the DOM to bacterioplankton to mussel trophic pathway appears comparable between these marsh types.     

Life and death of <Emphasis Type="Italic">Saccocoma tenella</Emphasis> (G<Emphasis Type="SmallCaps">oldfuss</Emphasis>)

The morphology of the small stalkless Saccocoma tenella is unique among crinoids. It is characterized by an extremely light skeleton with dish-like lateral wings on the proximal brachials and peculiar paired vertical processes flanking the food grooves of more distal brachials. The arms are heavily branched. The lateral wings obviously were involved in vertical movement. For the vertical processes a “baffle rail” function for arm curling and “snap swimming” has been postulated, with muscles between the processes. However, there is no evidence that the processes were connected by muscles. For food collection a “pulsating funnel” model in the water column is advocated, with the processes serving to collect plankton during upward movement of the arms. The resulting mouth-up position is supported by the biostratinomy. Saccocoma tenella is considered to have been pelagic, a benthic lifestyle is rejected on ecologic and taphonomic grounds. Adorally-curled arms are considered a reaction to hostile environment before death, not a taphonomic artefact.     

Co-occurrence of <Emphasis Type="Italic">Neusticosaurus edwardsii</Emphasis> and <Emphasis Type="Italic">N. peyeri</Emphasis> (Reptilia) in the Lower Meride Limestone (Middle Triassic,Monte San Giorgio)

A newly opened excavation in the Cassina beds of the Lower Meride Limestone (Monte San Giorgio UNESCO World Heritage List, Canton Ticino, Switzerland), has yielded a pachypleurosaurid (Reptilia: Sauropterygia) specimen which is identified as Neusticosaurus peyeri. The resulting co-occurrence of N. peyeri and N. edwardsii, the latter so far regarded as the sole species of the genus present in this horizon, challenges the hypothesis of a single anagenetic lineage in Neusticosaurus species from Monte San Giorgio. In addition, it leads to a reconsideration of the phylogenetic inferences about Neusticosaurus evolution in the Monte San Giorgio area. The stratigraphic distribution of the Neusticosaurus species in the Monte San Giorgio basin is updated on the basis of recent finds.     

New thermoelastic parameters of natural <Emphasis Type="Italic">C</Emphasis>2/<Emphasis Type="Italic">c</Emphasis> omphacite

The compressibility at room temperature and the thermal expansion at room pressure of two disordered crystals (space group C2/c) obtained by annealing a natural omphacite sample (space group P2/n) of composition close to Jd₅₆Di₄₄ and Jd₅₅Di₄₅, respectively, have been studied by single-crystal X-ray diffraction. Using a Birch–Murnaghan equation of state truncated at the third order [BM3-EoS], we have obtained the following coefficients: V ₀ = 421.04(7) Å³, K _T0 = 119(2) GPa, K′ = 5.7(6). A parameterized form of the BM3 EoS was used to determine the axial moduli of a, b and c. The anisotropy scheme is β _c  ≤ β _a  ≤ β _b , with an anisotropy ratio 1.05:1.00:1.07. A fitting of the lattice variation as a function of temperature, allowing for linear dependency of the thermal expansion coefficient on the temperature, yielded α_V(1bar,303K) = 2.64(2) × 10⁻⁵ K⁻¹ and an axial thermal expansion anisotropy of α _b  ≫ α _a  > α _c . Comparison of our results with available data on compressibility and thermal expansion shows that while a reasonable ideal behaviour can be proposed for the compressibility of clinopyroxenes in the jadeite–diopside binary join [K _T0 as a function of Jd molar %: K _T0 = 106(1) GPa + 0.28(2) × Jd_(mol%)], the available data have not sufficient quality to extract the behaviour of thermal expansion for the same binary join in terms of composition.     

Physiological Constraints in Juvenile <Emphasis Type="Italic">Ostrea chilensis</Emphasis> Fed the Toxic Dinoflagellate <Emphasis Type="Italic">Alexandrium catenella</Emphasis>

Frequent blooms of the dinoflagellate Alexandrium catenella in southern Chile encouraged undertaking the present study which uses the oyster Ostrea chilensis as a model for evaluating the feeding, growth, lipid storage and mortality responses to diets containing paralytic shellfish poisoning (PSP) produced by A. catenella. Medium-term (30 days) physiological responses of two groups of juvenile oysters were measured every 10 days. Five replicates were exposed to diets containing A. catenella and other five replicates were fed with a diet containing the non-toxic algae Isochrysis galbana. Diets were continuously supplied at a concentration of 2 mg L^?1, in which the feeding and metabolic activity was measured, and the scope for growth calculated. Lipids storage, actual growth and mortality were also measured every 10 days. The results showed that the toxic diet has dramatic negative effects on feeding and metabolism of the juvenile individuals of O. chilensis, with high reduction of the lipid storage and growth. Mortality was also increased in individuals fed with the contaminated diet. This study supports the conclusion that the toxic dinoflagellate A. catenella restricts the energy acquisition in the juvenile O. chilensis, an important fishery and aquaculture resource in southern Chile.     

The Intertidal Burrowing Crab <Emphasis Type="Italic">Neohelice</Emphasis> (=<Emphasis Type="Italic">Chasmagnathus</Emphasis>) <Emphasis Type="Italic">granulata</Emphasis> Positively Affects Foraging of Rodents in South Western Atlantic Salt Marshes

The role of positive and indirect interactions is often crucial in communities with intense abiotic stress such as salt marshes. The burrowing crab, Neohelice (=Chasmagnathus) granulata, is the dominant benthic macroinvertebrate of southwest Atlantic marshes (southern Brazil to Northern Argentinean Patagonia), having strong direct and indirect effects on marsh soil and, in consequence, on marsh vegetation and primary consumers. In this work, we investigate if this crab indirectly modifies habitat use by the granivorous rodents, Akodon azarae and Oligoryzomys flavescens, by increasing nutrient availability and thus enhancing seed production by the marsh plant Spartina densiflora. The study was conducted at the Mar Chiquita Coastal Lagoon, Argentina (37°32′ S). Rodent frequencies in S. densiflora were positively correlated with crab densities throughout the low and middle marsh. Additionally, the highest quality of S. densiflora and inflorescence density was recorded at the highest crab densities. Experimental manipulation of crab densities shows that N. granulata indirectly enhances the performance of S. densiflora (e.g., decreased fiber content and C/N ratios) and increases density of seeds. Moreover, N. granulata also facilitates S. densiflora seed availability to rodents by concentrating them in sediment mound at their burrows entrances. Experimental rodent exclusions showed that rodent species used S. densiflora seeds, a variable positively related to crab burrow density. Thus, our results show that N. granulata drives the granivorous rodent distribution and the intensity of seeds–rodent interaction trough facilitative and indirect interactions in marsh community.     

<Emphasis Type="Italic">BV I</Emphasis><Subscript><Emphasis Type="Italic">c</Emphasis></Subscript> photometry of RR Lyrae stars

We have obtained 26 372 CCD frames in the B, V, and I _c filters for 81 RR Lyrae stars in 2008–2010, using the 76-cm telescope of the South African Astronomical Observatory and the 40-cm telescope of the Cerro Armazones Observatory, North Catholic University (Chile) using an SBIG ST-10XME CCD camera. For 12 of these RR Lyrae stars, we also obtained 337 brightness measurements in the B and V bands in 2000–2001 using the 60-cm telescope of the High Altitude Mt. Maidanak Observatory (Republic of Uzbekistan). We present tables of observations, light curves, and improved light-curve elements for all these RR Lyrae stars. The Blazhko effect was detected for SU Hor.     

Gulf Ribbed Mussels (<Emphasis Type="Italic">Geukensia granosissima</Emphasis>) Increase Methane Emissions from a Coastal <Emphasis Type="Italic">Spartina alterniflora</Emphasis> Marsh

Understanding methane emissions from natural sources is becoming increasingly important with future climactic uncertainty. Wetlands are the single largest natural source of methane; however, little attention has been given to how biota and interactions between aboveground and belowground communities may affect methane emission rates in these systems. To investigate the effects of vegetative disturbance and belowground biogeochemical alterations induced by biota on methane emissions in situ, we manipulated densities of Littoraria irrorata (marsh periwinkle snails) and Geukensia granosissima (gulf ribbed mussels) inside fenced enclosures within a Spartina alterniflora salt marsh and measured methane emissions and sediment extracellular enzyme activity (phosphatase, β-glucosidase, cellobiohydrolase, N-acetyl-β-D-glucosaminidase, peroxidase, and phenol oxidase) over the course of a year. Changes in snail density did not have an effect on methane emission; however, increased densities of ribbed mussels significantly increased the emission of methane. Sediment extracellular enzyme activities for phosphatase, cellobiohydrolase, N-acetyl-β-D-glucosaminidase, and phenol oxidase were correlated to methane emission, and none of the enzymes assayed were affected by the snail and mussel density treatments. While methane emissions from salt marsh ecosystems are lower than those from freshwater systems, the high degree of variability in emission rates and the potential for interactions with naturally occurring biota that increase emissions warrant further investigations into salt marsh methane dynamics.