581 research outputs found
Dimethyl 2,2'-di-nitro-biphenyl-4,4'-di-carboxyl-ate.
The title compound, C16H12N2O8, exhibits two near-planar aromatic ester groups with ar-yl-ester dihedral angles of 2.1 (2) and 4.2 (3)°. The dihedral angle between the aromatic rings is 58.0 (1)°. The two nitro groups are tilted slightly from the plane of the aromatic rings, making dihedral angles of 14.1 (1) and 8.2 (2)°. In the crystal, mol-ecules are connected by weak C-H⋯O inter-actions, forming a three-dimensional network
Crystal structure of dimethyl 9H-carbazole-2,7-di-carb-oxy-late.
In the title compound, C16H13NO4, the carbazole ring system is almost planar with non-H atoms possessing a mean deviation from planarity of 0.037 Å. The two ester groups are orientated trans to one another and tilted slightly from the mean plane of the carbazole ring system, making dihedral angles of 8.12 (6) and 8.21 (5)°. In the crystal, mol-ecules are linked by pairs of N-H⋯O hydrogen bonds forming inversion dimers. The dimers are linked by parallel slipped π-π inter-actions, forming slabs propagating along the b-axis direction [inter-centroid distance = 3.6042 (8) Å, inter-planar distance = 3.3437 (5) Å, slippage = 1.345 Å]
Scientific Standards and the Regulation of Genetically Modified Insects
Experimental releases of genetically modified (GM) insects are reportedly being evaluated in various countries, including Brazil, the Cayman Islands (United Kingdom), France, Guatemala, India, Malaysia, Mexico, Panama, Philippines, Singapore, Thailand, the United States of America, and Vietnam. GM mosquitoes (Aedes aegypti) have already been released for field trials into inhabited areas in the Cayman Islands (2009–?), Malaysia (2010–2011), and Brazil (2011–2012). Here, we assess the regulatory process in the first three countries permitting releases (Malaysia, US, and the Cayman Islands) in terms of pre-release transparency and scientific quality. We find that, despite 14 US government–funded field trials over the last 9 years (on a moth pest of cotton), there has been no scientific publication of experimental data, and in only two instances have permit applications been published. The world's first environmental impact statement (EIS) on GM insects, produced by US authorities in 2008, is found to be scientifically deficient on the basis that (1) most consideration of environmental risk is too generic to be scientifically meaningful; (2) it relies on unpublished data to establish central scientific points; and (3) of the approximately 170 scientific publications cited, the endorsement of the majority of novel transgenic approaches is based on just two laboratory studies in only one of the four species covered by the document. We find that it is not possible to determine from documents publically available prior to the start of releases if obvious hazards of the particular GM mosquitoes released in Malaysia, the Cayman Islands, and Brazil received expert examination. Simple regulatory measures are proposed that would build public confidence and stimulate the independent experimental studies that environmental risk assessments require. Finally, a checklist is provided to assist the general public, journalists, and lawmakers in determining, from documents issued by regulators prior to the start of releases, whether permit approval is likely to have a scientifically high quality basi
Professional Concerns
Have you ever wished that you could introduce your young kids to the classics in an exciting way? Have you ever wished that you could do a better job in merging writing and reading activities? Have you ever wished that you could do more to individualize reading instruction for your students? Stephan Lehane, who teaches Elementary Education at Duke University, and Elsa Woods, who is Reading Supervisor for the Durham County Schools of North Carolina, have devised an intriguing plan by which students are quickly motivated both to reading and to composition in the broadest sense of the word
Epoxy resin blends and composites from waste vegetable oil
Thermosets and composites were prepared from blends of epoxidized waste vegetable oils and diglycidyl ether of bisphenol-A to investigate this material as an alternative triglyceride source for epoxy resins. Purification of the waste oil was developed to remove impurities derived from thermal degradation in the frying process and different epoxidation methodologies were investigated. Effects of epoxidized vegetable oil content (up to 30 wt%) and origin on the tensile properties were studied and revealed that purified waste oils performed similarly to neat oil in contents up to 10 wt%, proving that this strategy does not compromise tensile properties when waste oils are used in suitable proportions. Furthermore, a more prominent plasticizing effect was observed when more than 15 wt% of bio-based resin was used as confirmed by DMA. Composites were prepared with recycled carbon fibres (up to 30 wt%) and thermosets with 10 wt% of bio-based epoxy resins, significantly improving the mechanical properties
Bearing Capacity and Load-Displacement Behavior of Rigid Pads on Soft, Sensitive, Clay
The paper describes tests on rigid square pads at the UK national soft clay research site at Bothkennar, Scotland. The work was performed as a low cost adjunct to the instrumented pile research described by Lehane and Jardine (1992). Its aims were to investigate (i} bearing capacity, (ii) load-displacement response to short and long term loading, (iii) the applicability of relevant theories and (iv) relationships between soil properties determined in-situ and those measured in high quality laboratory tests
Mothers' voices: hearing and assessing the contributions of 'birth mothers' to the development of social work interventions and family support
This paper focuses on interviews with ‘birth mothers’ who experienced successive losses of their children to public care in one local area of London, England. Interviews were conducted during a project partnership between a London borough and university staff, aiming to provide a localised, pilot support initiative which responded to mothers’ viewpoints. To ‘hear’ mothers’ own voices more clearly, we analysed interview transcripts using a methodology which separates out elements of how the interviewee tells her story, how she speaks about herself and about her relationships, taking into account surrounding social complexities and researchers’ reactions to the story. To explain how professionals could subsequently draw upon these ‘mothers’ voices’ for a pilot support initiative, we identify some key messages for professionals from these interviews, including: women wanting clear and honest communication between themselves and workers, and between staff; women often feeling ‘let down’ by professional procedures and court processes that were moving too fast for them to keep up; women wanting to be treated with more respect. Women respected some professionals but not others and this seemed to relate partly to personalities. Some mothers experienced being ‘left alone’ or ‘abandoned’ to deal with the aftermath of children’s removal and/or adoption
An Investigation into the Protein Composition of the Teneral Glossina morsitans morsitans Peritrophic Matrix.
BACKGROUND
Tsetse flies serve as biological vectors for several species of African trypanosomes. In order to survive, proliferate and establish a midgut infection, trypanosomes must cross the tsetse fly peritrophic matrix (PM), which is an acellular gut lining surrounding the blood meal. Crossing of this multi-layered structure occurs at least twice during parasite migration and development, but the mechanism of how trypanosomes do so is not understood. In order to better comprehend the molecular events surrounding trypanosome penetration of the tsetse PM, a mass spectrometry-based approach was applied to investigate the PM protein composition using Glossina morsitans morsitans as a model organism.
METHODS
PMs from male teneral (young, unfed) flies were dissected, solubilised in urea/SDS buffer and the proteins precipitated with cold acetone/TCA. The PM proteins were either subjected to an in-solution tryptic digestion or fractionated on 1D SDS-PAGE, and the resulting bands digested using trypsin. The tryptic fragments from both preparations were purified and analysed by LC-MS/MS.
RESULTS
Overall, nearly 300 proteins were identified from both analyses, several of those containing signature Chitin Binding Domains (CBD), including novel peritrophins and peritrophin-like glycoproteins, which are essential in maintaining PM architecture and may act as trypanosome adhesins. Furthermore, 27 proteins from the tsetse secondary endosymbiont, Sodalis glossinidius, were also identified, suggesting this bacterium is probably in close association with the tsetse PM.
CONCLUSION
To our knowledge this is the first report on the protein composition of teneral G. m. morsitans, an important vector of African trypanosomes. Further functional analyses of these proteins will lead to a better understanding of the tsetse physiology and may help identify potential molecular targets to block trypanosome development within the tsetse
An insight into the sialome of Glossina morsitans morsitans
<p>Abstract</p> <p>Background</p> <p>Blood feeding evolved independently in worms, arthropods and mammals. Among the adaptations to this peculiar diet, these animals developed an armament of salivary molecules that disarm their host's anti-bleeding defenses (hemostasis), inflammatory and immune reactions. Recent sialotranscriptome analyses (from the Greek <it>sialo </it>= saliva) of blood feeding insects and ticks have revealed that the saliva contains hundreds of polypeptides, many unique to their genus or family. Adult tsetse flies feed exclusively on vertebrate blood and are important vectors of human and animal diseases. Thus far, only limited information exists regarding the Glossina sialome, or any other fly belonging to the Hippoboscidae.</p> <p>Results</p> <p>As part of the effort to sequence the genome of <it>Glossina morsitans morsitans</it>, several organ specific, high quality normalized cDNA libraries have been constructed, from which over 20,000 ESTs from an adult salivary gland library were sequenced. These ESTs have been assembled using previously described ESTs from the fat body and midgut libraries of the same fly, thus totaling 62,251 ESTs, which have been assembled into 16,743 clusters (8,506 of which had one or more EST from the salivary gland library). Coding sequences were obtained for 2,509 novel proteins, 1,792 of which had at least one EST expressed in the salivary glands. Despite library normalization, 59 transcripts were overrepresented in the salivary library indicating high levels of expression. This work presents a detailed analysis of the salivary protein families identified. Protein expression was confirmed by 2D gel electrophoresis, enzymatic digestion and mass spectrometry. Concurrently, an initial attempt to determine the immunogenic properties of selected salivary proteins was undertaken.</p> <p>Conclusions</p> <p>The sialome of <it>G. m. morsitans </it>contains over 250 proteins that are possibly associated with blood feeding. This set includes alleles of previously described gene products, reveals new evidence that several salivary proteins are multigenic and identifies at least seven new polypeptide families unique to <it>Glossina</it>. Most of these proteins have no known function and thus, provide a discovery platform for the identification of novel pharmacologically active compounds, innovative vector-based vaccine targets, and immunological markers of vector exposure.</p
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