New snakeflies (Insecta: Raphidioptera) from the Lower Cretaceous of the UK,Spain and Brazil

Abstract: Several new taxa of snakeflies (Raphidioptera) are described from the Lower Cretaceous deposits of the Wealden, UK (Barremian), Montsec, Spain (Barremian) and the Crato Formation, Brazil (Aptian). Mesoraphidia ednae sp. nov. and M. hilli sp. nov. are described from the Wealden; Nanoraphidia lithographica sp. nov. and Iberoraphidia dividua gen. et sp. nov. are described from Montsec, and Baissoptera lisae sp. nov. is described from the Crato Formation. The geographical range of Nanoraphidia has potentially been extended.     

The identity of the Ordovician (Darriwilian) graptolite Fucoides dentatus Brongniart, 1828

Abstract: The biostratigraphically important Middle Ordovician (Darriwilian) biserial graptolite Fucoides dentatus Brongniart, 1828 is redescribed and illustrated from its type material and from additional specimens collected at the type locality – Lévis, Quebec, Canada. It is referred to Levisograptus gen. nov., which includes also the austrodentatus group of early axonophoran graptolites. The species has previously been confused with a younger, mid‐Darriwilian species, now referred to as Eoglyptograptus gerhardi sp. nov., and recognized as the type species of the genus Eoglyptograptus Mitchell. Both species can be differentiated easily by their respective proximal development types and show nonoverlapping biostratigraphical ranges. Levisograptus dentatus (Brongniart) is an important biostratigraphical index species in the early Darriwilian. Eoglyptograptus species are found in the higher Darriwilian and are biogeographically restricted to the Atlantic Faunal Realm.     

Phytoplankton patchiness in Winam Gulf,Lake Victoria: a study using principal component analysis of in situ fluorescent excitation spectra

1. In order to characterise phytoplankton patchiness at fine scales, a profiling multiwavelength fluorometer was cast at numerous locations throughout Winam Gulf in Lake Victoria to measure fluorescent excitation spectra, which are indicators of both phytoplankton diversity and coloured dissolved organic matter (CDOM). 2. Processing the spectral data with principal component analysis (PCA) revealed that linear combinations of four fundamental ‘base’ spectra could explain almost all of the variation in spectral measurements. Three of the base spectra were associated with spatially distinct patches of phytoplankton containing different species assemblages, while the fourth base spectrum was due to CDOM fluorescence. 3. The locations of the phytoplankton patches were traced to the south‐east of Winam Gulf, the western end of the Rusinga Channel and the open waters of Lake Victoria adjacent to Winam Gulf, respectively. The high CDOM fluorescence was traced mainly to relatively deep water in the Rusinga Channel. 4. The phytoplankton and CDOM patchiness were interpreted in the context of physical and chemical gradients that were measured at the site at the same scale as the spectral data. Strong relationships were found between the gradients in spectral data and other environmental variables, which suggested several underlying explanations for the phytoplankton and CDOM patchiness.     

Why only some plants emit isoprene

Isoprene (2‐methyl‐1,3‐butadiene) is emitted from many plants and it appears to have an adaptive role in protecting leaves from abiotic stress. However, only some species emit isoprene. Isoprene emission has appeared and been lost many times independently during the evolution of plants. As an example, our phylogenetic analysis shows that isoprene emission is likely ancestral within the family Fabaceae (= Leguminosae), but that it has been lost at least 16 times and secondarily gained at least 10 times through independent evolutionary events. Within the division Pteridophyta (ferns), we conservatively estimate that isoprene emissions have been gained five times and lost two times through independent evolutionary events. Within the genus Quercus (oaks), isoprene emissions have been lost from one clade, but replaced by a novel type of light‐dependent monoterpene emissions that uses the same metabolic pathways and substrates as isoprene emissions. This novel type of monoterpene emissions has appeared at least twice independently within Quercus, and has been lost from 9% of the individuals within a single population of Quercus suber. Gain and loss of gene function for isoprene synthase is possible through relatively few mutations. Thus, this trait appears frequently in lineages; but, once it appears, the time available for evolutionary radiation into environments that select for the trait is short relative to the time required for mutations capable of producing a non‐functional isoprene synthase gene. The high frequency of gains and losses of the trait and its heterogeneous taxonomic distribution in plants may be explained by the relatively few mutations necessary to produce or lose the isoprene synthase gene combined with the assumption that isoprene emission is advantageous in a narrow range of environments and phenotypes.     

EARLY MIDDLE ORDOVICIAN GRAPTOLITE BIOSTRATIGRAPHY OF THE LOVISEFRED AND ALBJÄRA DRILL CORES (SCANIA, SOUTHERN SWEDEN)

Abstract:  Early Middle Ordovician graptolites from the Albjära and Lovisefred drill cores (Scania, southern Sweden) can be differentiated into the Isograptus victoriae , Isograptus sp. nov. 2 and Maeandrograptus schmalenseei , Arienigraptus dumosus type/ Pseudisograptus manubriatus biozones of Castlemainian and Yapeenian age and the Arienigraptus zhejiangensis and Undulograptus sinicus biozones of early Darriwilian age, replacing the old, long-ranging Didymograptus hirundo Biozone. Faunas from the drill cores include a number of species not previously recognized in Scandinavia.     

The focal adhesion protein Hic-5 is highly expressed in the rat myometrium during late pregnancy and labour and co-localizes with FAK

Background  

Myometrial growth and remodeling of the cytoskeleton and focal adhesions during late pregnancy may be critical aspects of myometrial activation and thus labour. Yet our understanding of these aspects is inhibited by the paucity of information concerning the components of focal adhesions in the myometrium. The focal adhesion protein hydrogen peroxide-inducible clone-5 (Hic-5) has recently been found in mononuclear smooth muscle but was not examined in the myometrium during pregnancy. Thus, the goal of this study was to characterize Hic-5 mRNA and protein expression in the rat myometrium during pregnancy and labour.     

Diabetes and arterial extracellular matrix changes in a porcine model of atherosclerosis.

Patients with diabetes are at substantially increased risk for atherosclerosis and clinical cardiovascular events. Because arterial extracellular matrix contains several molecules, including biglycan, versican, hyaluronan, and elastin, that may affect plaque lipid retention and stability, we determined whether diabetes affects plaque content of these molecules in a porcine model of hyperlipidemia and diabetes. Coronary artery sections were studied from non-diabetic normolipidemic (n=11, N-NL), diabetic normolipidemic (n=10, DM-NL), non-diabetic hyperlipidemic (n=16, N-HL), and diabetic hyperlipidemic (n=15, DM-HL) animals. Hyaluronan, biglycan, versican, and apolipoprotein B (apoB) were detected with monospecific peptides or antisera, and elastin with Movat's pentachrome stain, and contents of each were quantified by computer-assisted morphometry. In the hyperlipidemic groups, diabetes was associated with a 4-fold increase in intimal area, with strong correlations between intimal area and immunostained areas for hyaluronan (R(2) = 0.83, p<0.0001), biglycan (R(2) = 0.72, p<0.0001), and apoB (R(2) = 0.23, p=0.0069). In contrast, median (interquartile range) intimal elastin content was significantly lower with diabetes [N-HL: 5.2% (2.4-8.2%) vs DM-HL: 1.5% (0.5-4.2%), p=0.01], and there was a strong negative correlation between intimal total and elastin areas (Spearman r = -0.62, p=0.001). In this porcine model, diabetes was associated with multiple extracellular matrix changes that have been associated with increased lesion instability, greater atherogenic lipoprotein retention, and accelerated atherogenesis.     

The relationship between Chironomus plumosus burrows and the spatial distribution of pore-water phosphate, iron and ammonium in lake sediments

1. To study the influence of chironomids on the distribution of pore‐water concentrations of phosphate, iron and ammonium, we conducted a laboratory experiment using mesocosms equipped with two‐dimensional pore‐water samplers, filled with lake sediment and populated with different densities of Chironomus plumosus. 2. Specially designed mesocosms were used in the study. A 6‐mm deep space between the front plate and the pore‐water sampler at the back plate was just thick enough to allow the chironomids to live undisturbed, yet thin enough to force all the burrows into a two‐dimensional plane. 3. The courses of the burrows were observed during the experiment as oxidised zones surrounding them, as well as being identified with an X‐ray image taken at the end of the experiment. 4. We investigated the relationship between C. plumosus burrows and spatial patterns of pore‐water composition. Concentrations of the three ions were significantly less around ventilated burrows (54% to 24%), as bioirrigation caused a convective exchange of pore‐water enriched with dissolved species compared with the overlying water, and also because oxygen imported into the sediment resulting in nitrification of ammonium, oxidation of iron(II) and a co‐precipitation of phosphate with Fe(III) oxyhydroxides. 5. In mesocosms with chironomids, new (redox) interfaces occurred with diffusive pore‐water gradients perpendicular to the course of burrows and the site of major phosphate, ammonium and iron(II) release shifted from the sediment surface to the burrow walls.     

Extrathoracic and intrathoracic removal of O3 in tidal-breathing humans

We measured the efficiency of O3 removal from inspired air by the extrathoracic and intrathoracic airways in 18 healthy, nonsmoking, young male volunteers. Removal efficiencies were measured as a function of O3 concentration (0.1, 0.2, and 0.4 ppm), mode of breathing (nose only, mouth only, and oronasal), and respiration frequency (12 and 24 breaths/min). Subjects were placed in a controlled environmental chamber into which O3 was introduced. A small polyethylene tube was then inserted into the nose of each subject, with the tip positioned in the posterior pharynx. Samples of air were collected from the posterior pharynx through the tube and into a rapidly responding O3 analyzer yielding inspiratory and expiratory O3 concentrations in the posterior pharynx. The O3 removal efficiency of the extrathoracic airways was computed with the use of the inspiratory concentration and the chamber concentration, and intrathoracic removal efficiency was computed with the use of the inspiratory and expiratory concentrations. The mean extrathoracic removal efficiency for all measurements was 39.6 +/- 0.7% (SE), and the mean intrathoracic removal efficiency was 91.0 +/- 0.5%. Significantly less O3 was removed both extrathoracically and intrathoracically when subjects breathed at 24 breaths/min compared with 12 breaths/min (P less than 0.001). O3 concentration had no effect on extrathoracic removal efficiency, but there was a significantly greater intrathoracic removal efficiency at 0.4 ppm than at 0.1 ppm (P less than 0.05). Mode of breathing significantly affected extrathoracic removal efficiency, with less O3 removed during nasal breathing than during either mouth breathing or oronasal breathing (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)