Current research on coral reefs seeks to link the responses to anthropogenic stressors (such as global warming and ocean acidification OA) among differing functional levels of biological ...organization. While experimental studies have identified ex situ taxon-specific responses to OA and global warming, isolating and connecting these effects in situ at the community-level has proved difficult. The difficulties arise from the large number of naturally varying parameters affecting corals reefs, such as light intensity and seawater residence time that affect net community production and calcification. To control variation in seawater residence time and allow light intensity to vary naturally, experimental outer reef (17-m depth) benthic communities composed of calcified algae, corals, and reef pavement were constructed in large outdoor flumes in Mo’orea, French Polynesia. Net community production (P), net community calcification (G), the ratio of P/G (P/Gratio), and slope of P regressed on G (P/Gslope) were calculated for the communities, and concurrently for the constituent members under the same temperature, light, and flow conditions. P and G, for both the communities and constituent members, were correlated positively with light intensity, whereas P/Gratio and P/Gslope were unaffected by light intensity. P/Gratios and P/Gslopes exhibited values that were specific to each community member. These results suggest that the P/Gratio and P/Gslope may be unaffected by natural variability in light intensity and could serve as useful metrics to relate responses at the taxon and community level, which is an important step in assessing the effects of environmental changes on coral reefs.
The effect of narrowband interference on pilot symbol assisted detection and synchronization is discussed. It is shown both analytically and by computer simulation that pilot symbol detectors are ...particularly susceptible to narrowband interference. It is shown also that pilot symbol assisted frequency offset estimation is detrimentally affected by narrowband interference. The normalized least mean squares (N-LMS) adaptive noise cancellation algorithm, with only a small number of filter taps, is shown to perform well in suppressing narrowband interference in pilot symbol detectors. The combination of two-stage detection and the N-LMS algorithm is shown to be effective in producing interference-tolerant pilot symbol detection in OFDM systems.
The diversity of metazoan cell shapes is influenced by the dynamic cytoskeletal network. With the advent of RNA-interference (RNAi) technology, it is now possible to screen systematically for genes ...controlling specific cell-biological processes, including those required to generate distinct morphologies.
We adapted existing RNAi technology in Drosophila cell culture for use in high-throughput screens to enable a comprehensive genetic dissection of cell morphogenesis. To identify genes responsible for the characteristic shape of two morphologically distinct cell lines, we performed RNAi screens in each line with a set of double-stranded RNAs (dsRNAs) targeting 994 predicted cell shape regulators. Using automated fluorescence microscopy to visualize actin filaments, microtubules and DNA, we detected morphological phenotypes for 160 genes, one-third of which have not been previously characterized in vivo. Genes with similar phenotypes corresponded to known components of pathways controlling cytoskeletal organization and cell shape, leading us to propose similar functions for previously uncharacterized genes. Furthermore, we were able to uncover genes acting within a specific pathway using a co-RNAi screen to identify dsRNA suppressors of a cell shape change induced by Pten dsRNA.
Using RNAi, we identified genes that influence cytoskeletal organization and morphology in two distinct cell types. Some genes exhibited similar RNAi phenotypes in both cell types, while others appeared to have cell-type-specific functions, in part reflecting the different mechanisms used to generate a round or a flat cell morphology.
Abstract The variation of refractive index (RI) over a non-toughened, float pane of glass and a toughened, float pane of glass was investigated. The two panes of colourless, float glass were cut into ...150 5 cm × 5 cm squares. The pre- and post-annealing RI values from three random areas from each square were measured. Bayesian statistical hierarchical modelling of the results showed that for the non-toughened, float glass pane annealing increased the variability in RI by a factor of 1.29–1.58, with a mean of 1.43 (with 95% probability); and for the toughened, float pane of glass annealing decreased the variability in RI by a factor of 0.63–0.76, with a mean of 0.69 (with 95% probability). In addition it was found that although there were no systematic differences in Δ RI across either pane of glass, there were observable differences across both panes of glass. These results provide information regarding the expected RI variation over entire panes of both non-toughened and toughened float window glass for both pre- and post-annealing RI measurements.
Capsule Earthworms can be an important food of birds breeding inland and on the coast.
Aims To identify food and feeding sites of Lesser Black-backed Gulls Larus fuscus breeding on buildings in ...Dumfries, Scotland.
Methods Direct observations were made of feeding behaviour, and 181 regurgitated pellets, obtained from flat roofs where only Lesser Black-backed Gulls nested, were analysed. Food items were identified using standard techniques with microscopic examination used to identify the presence of earthworm chaetae.
Results Lesser Black-backed Gulls breeding in Dumfries fed extensively on earthworms and insects obtained from agricultural land (55% of pellets). They also fed on landfill (23% of pellets) and marine sites (12% of pellets), but they did not take fish or fish offal.
Conclusions Previous studies on the food of large gulls have often overlooked the importance of earthworms because of the lack of macro-remains in stomachs and pellets. New studies are required to establish the general extent of earthworm consumption in these large gulls.
The switching behavior of the novel hybrid material (FA)NaFe(CN)5(NO).H2O (1) in response to temperature (T), light irradiation and electric field (E) is studied using in situ X‐ray diffraction ...(XRD). Crystals of 1 display piezoelectricity, pyroelectricity, second and third harmonic generation. XRD shows that the FA+ are disordered at room‐temperature, but stepwise cooling from 273–100 K induces gradual ordering, while cooling under an applied field (E=+40 kVcm−1) induces a sudden phase change at 140 K. Structural‐dynamics calculations suggest the field pushes the system into a region of the structural potential‐energy surface that is otherwise inaccessible, demonstrating that application of T and E offers an effective route to manipulating the crystal chemistry of these materials. Photocrystallography also reveals photoinduced linkage isomerism, which coexists with but is not correlated to other switching behaviors. These experiments highlight a new approach to in situ studies of hybrid materials, providing insight into the structure–property relationships that underpin their functionality.
Hybrid materials based on known molecular photoswitches show great potential for the rational design of new pyro‐ and ferroelectric photoswitches. This article shows how in situ X‐ray diffraction using thermal, photochemical and electrical stimuli can explore structure–property relationships in the novel pyroelectric (FA)NaFe(CN)6(NO).H2O, enabling a deeper understanding of its complex energy landscape via structural‐dynamics calculations.
beta -Lactamases catalyse the hydrolysis of the beta -lactam ring of penicillins, cephalosporins and related compounds, and thereby protect the bacteria which elaborate the enzymes against the action ...of these antibiotics. In order to avoid the confusion and inconvenience that arises in the comparison of molecular studies of different Class A enzymes, we propose here a standard numbering scheme for this group of proteins.
Chlamydia pneumoniae has been demonstrated in atherosclerotic lesions of coronary arteries and aorta. A seroepidemiological study found C pneumoniae-specific antibody more frequently in persons with ...significant carotid artery wall thickening than in matched control subjects.
Fresh-frozen or formalin-fixed tissue obtained at carotid endarterectomy was examined by immunocytochemistry (ICC) and the polymerase chain reaction (PCR) for the presence of C pneumoniae. Five of five fresh-frozen and formalin-fixed carotid endarterectomy specimens were positive for C pneumoniae by ICC (three of five by PCR). A total of 56 archival formalin-fixed, paraffin-embedded carotid endarterectomy tissues from three hospitals were examined by ICC. Thirty-two were positive. Thirteen normal carotid artery tissue sections from six patients were negative for C pneumoniae.
C pneumoniae organisms are frequently found in the advanced carotid atherosclerotic lesions of persons undergoing endarterectomy. Although these findings do not establish causality for C pneumoniae in carotid artery atherosclerosis, they should stimulate investigation of a possible causal or pathogenic role for the organism in the disease.
Interactions between predator and prey act to shape the structure of ecological communities, and these interactions can differ across space. California sheepheadSemicossyphus pulcherare common ...predators of benthic invertebrates in kelp beds and rocky reefs in southern California, USA. Through gut content and stable isotope (δ13C and δ15N) analyses, we investigated geographic and ontogenetic variation in trophic ecology across 9 populations located at island and mainland sites throughout southern California. We found extensive geographic variation in California sheephead diet composition over small spatial scales. Populations differed in the proportion of sessile filter/suspension feeders or mobile invertebrates in the diet. Spatial variation in diet was highly correlated with other life history and demographic traits (e.g. growth, survivorship, reproductive condition, and energy storage), in addition to proxies of prey availability from community surveys. Multivariate descriptions of the diet from gut contents roughly agreed with the spatial groupings of sites based on stable isotope analysis of both California sheephead and their prey. Ontogenetic changes in diet occurred consistently across populations, despite spatial differences in size structure. As California sheephead increase in size, diets shift from small filter feeders, like bivalves, to larger mobile invertebrates, such as sea urchins. Our results indicate that locations with large California sheephead present, such as many marine reserves, may experience increased predation pressure on sea urchins, which could ultimately affect kelp persistence.
Persistence of Polydimethylsiloxane Condom Lubricants Tottey, Leah S.; Coulson, Sally A.; Wevers, Gerhard E. ...
Journal of forensic sciences,
January 2019, 2019-Jan, 2019-01-00, 20190101, Letnik:
64, Številka:
1
Journal Article
Recenzirano
Polydimethylsiloxane (PDMS) is commonly used to lubricate condoms. The detection of PDMS on swabs from complainants can be used to support an allegation of sexual assault. Previous research has ...focused on establishing analytical techniques for detecting PDMS. This research examined the persistence of PDMS on the penis, in the vagina, in the mouth, and on skin. The longest PDMS detection times were 20 h on the penis, 35 h in the vagina, and 52 h on skin. PDMS was detected up to 4 h in the mouth if the participant did not eat or drink and up to 9 h if the participant slept. PDMS was not detected in the mouth after eating or drinking. The presence of biological fluids had no detrimental effect on the analysis. Aqueous extraction of swabs for DNA did not remove any significant amount of PDMS; hence, swab remains could be subsequently analyzed for PDMS.
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