Aspects of the breeding biology of common terns (Sterna Hirundo) on Rockcliffe Marsh, Cumbria.

Not availabl

New ⁴⁰Ar/³⁹Ar dating of the Grande Ronde lavas, Columbia River Basalts, USA: Implications for duration of flood basalt eruption episodes

Grande Ronde Basalt (GRB) lavas represent the most voluminous eruptive pulse of the Columbia River-Snake River-Yellowstone hotspot volcanism. With an estimated eruptive volume of 150,000 km3, GRB lavas form at least 66% of the total volume of the Columbia River Basalt Group. New 40Ar/39Ar dates for GRB lavas reveal they were emplaced within a maximum period of 0.42 ± 0.18 My. A well-documented stratigraphy indicates at least 110 GRB flow fields (or individual eruptions), and on this basis suggests an average inter-eruption hiatus of less than 4,000 years. Isotopic age-dating cannot resolve time gaps between GRB eruptions, and it is difficult to otherwise form a picture of the durations of eruptions because of non-uniform weathering in the top of flow fields and a general paucity of sediments between GR lavas. Where sediment has formed on top of the GRB, it varies in thickness from zero to 20-30 cm of silty to fine-sandy material, with occasional diatomaceous sediment. Individual GRB eruptions varied considerably in volume but many were greater than 1000 km3 in size. Most probably eruptive events were not equally spaced in time; some eruptions may have followed short periods of volcanic repose (perhaps 102 to 103 of yrs), whilst others could have been considerably longer (many 1000 s to > 104 yrs). Recent improvements in age-dating for other continental flood basalt (CFB) lava sequences have yielded estimates of total eruptive durations of less than 1 My for high-volume pulses of lava production. The GRB appears to be a similar example, where the main pulse occupied a brief period. Even allowing for moderate to long-duration pahoehoe flow field production, the amount of time the system spends in active lava-producing mode is small – less than c. 2.6% (based on eruption durations of approximately 10,000 yrs, as compared to the duration of the entire eruptive pulse of c. 420,000 yrs). A review of available 40Ar/39Ar data for the major voluminous phases of the Columbia River Basalt Group suggests that activity of the Steens Basalt-Imnaha Basalt-GRB may have, at times, been simultaneous, with obvious implications for climatic effects. Resolving intervals between successive eruptions during CFB province construction, and durations of main eruptive pulses, remains vital to determining the environmental impact of these huge eruptions

Available-sulfur status of some representative Iowa soils

Greenhouse experiments with ryegrass were conducted to evaluate and characterize plant availability of native and added sulfur in samples of Iowa soils. Fourteen surface soil (0-6 inches) and five subsoil (18-24 inches) samples from different sites in Iowa and two surface soil samples from S-deficient out-of-state sites were studied. Laboratory analyses were made to characterize the soil samples and to evaluate the results of different extractants as indexes of the S-supplying abilities of the soils. Plant uptake of S from the soil samples with no added S during a 202-day cropping period (five harvests) varied from 1 to 39 mg S/1500 g of soil (39 mg S/1500 g of soil is approximately equivalent to 50 lb S/acre six inches of soil in the field). Sulfur uptake was greatest during the first 70 days of cropping (two harvests), but continued at a slower, essentially constant daily rate throughout the rest of the cropping period. Although relatively slow for all soil samples, the rate of S uptake during this later cropping varied markedly among the different soil samples, with the rates for the surface soil samples being directly related to the amounts of S taken up by the plants in the earlier cropping period. The rates of uptake were very slow from most of the subsoil samples, and many plants on these subsoils died. Air-drying the soil samples before cropping resulted in increased plant yields and increased S uptake by the plants

Emergence of the M phenotype of erythromycin-resistant pneumococci in South Africa.

Erythromycin-resistant pneumococci have been isolated in South Africa since 1978; however, from 1987 to 1996, resistance to macrolides was only detected in 270 (2.7%) of 9,868 blood or cerebrospinal fluid (CSF) pneumococcal isolates, most of which were obtained from the public sector. In South Africa, macrolide use in the public sector is estimated at 56% of that in the private sector. Most erythromycin-resistant strains (89%) exhibited resistance to erythromycin and clindamycin (macrolide-lincosamide-streptogramin B phenotype). In the United States, most erythromycin-resistant pneumococci exhibit the newly described M phenotype (resistance to erythromycin alone), associated with the mefE gene. The M phenotype in South Africa increased significantly in the last 10 years, from 1 of 5,115 to 28 of 4,735 of blood and CSF isolates received from 1987 to 1991 compared with 1992 to 1996 (p = 5 x 10(-7)). These data suggest that, although macrolide resistance in pneumococci remains low in the public sector, the mefE gene is rapidly emerging in South Africa

Structures of Two Diastereomeric Aldol Products from a New Silicon-Directed Condensation

Hexahydro-3,3,6-trimethyl-5-phenyl- 1 H,7H-pyrrolo[2,1-e][1,3,6,2]dioxazasilonin-7-one, C17H25NO3Si, Mr=319.48. (2S,3R)-anti-Diastereomer (I), orthorhombic, P212121, a= 8-716(4), b=11-677(3), c=17.161(6)A, V=1746(1)A3, Z=4, Dx=1.22 g cm-3, wavelength(Mo Kce) = 0.71073 A, u=1.50 cm-1 F(000)=688, room temperature, final R=0.040 for 1683 reflections with Fo2 greater than 0. (2S,3S)-syn- Diastereomer (II), monoclinic, P21, a=6.633(2), b=14.645(3), c=9.630(2) A, Beta=109.96(2)o, V=879.3(4) A3, Z=2, Dx=1.21 g cm-3, wavelength(Mo Ka)=0.71073 A,u = 1-49 cm-1, F(000)=344, room temperature, final R = 0.042 for 2537 reflections with F2o greater than 0. The compounds have a nine-membered hetero-cyclic ring containing the Si atom, the N atom of the pyrrolidine ring, two O atoms bonded to silicon and a carbonyl C atom. Bond distances in the molecules are normal and equivalent bonds are equal within three times their e.s.d.'s. Isomer (I) shows a disorder in the pyrrolidine ring that is absent in isomer (II).Chemistry and Chemical Biolog

Impact of the application of redecision methods in executive coaching workshops on psychological wellbeing : a quantitative evaluation of effectiveness

Previous research has found that participants in redecision marathons experience increased personal growth and improvements in psychological well-being (McNeel, 1982; Noriega-Gayol, 1997; Widdowson & Rosseau, 2014). In this article, the authors conducted a quantitative analysis based on the use of the Ryff Scales of Psychological Wellbeing to determine whether participants (n=49) at an executive coaching redecision marathon would experience an increase in psychological well-being. The findings show statistically significant improvements in psychological well-being overall, and specifically within the sub-scales of autonomy, environmental mastery, personal growth and self-acceptance, suggesting that redecision- based workshops are effective for improving subjective psychological well-being

Electrospinning of Functional Nanofibers for Regenerative Medicine: From Bench to Commercial Scale

Nanofibers are an important material for regenerative medicine as they have a commensurate morphology to that of the macromolecular matrix that supports and houses the growth of cells and tissues within the body. Electrospinning is widely used to fabricate non-woven structures on the nanoscale and the versatility of the technique has widened the application of nanofibers. This is due to ease of extending nanofiber functionality through the incorporation of active materials both during and after electrospinning. Recent developments in electrospinning devices, such as needle-free systems, have reinvigorated research as these advances now allow fabrication of nanofibers at commercial scales. The process of electrospinning has a number of operating parameters that are adjusted in optimisation to achieve ideal fibres and a multitude of instrument configurations can be adopted to achieve the required manufacture. The innate properties of nanofibers, such as high surface area to volume ratio, have many proven benefits for regenerative medicine and the chapter examines these before discussing how functionality can be further improved. Numerous materials can be incorporated in the manufacture of electrospun mats, however when choosing materials for regenerative medicine, biocompatibility and biodegradability are the dominant functionalities that are required

Structure of an anti-Aldol Addition Product of Benzaldehyde and a Pseudoephedrine-Derived O-Silyl Ketene N,O-Acetal

[4S-(4R*,5R*,8R*,9S*)]-2,2,5,6,8-Penta- methyl-4,9-diphenyl- 1,3-dioxa-6-aza-2-silacyclono-nan-7-one, CE2H29NO3Si, Mr = 383.56, monoclinic, P21, a = 6.550 (3), b = 17.318 (6), c = 20.129 (6) A, /3=98.83(3)° , V =2256.2(14) A 3, Z=4, Dx= 1.13 gcm -3, A(Mo Ka) = 0.71073 A,/z = 1.18 cm -1, F(000) = 824, room temperature, R on F = 0.039 for 4305 reflections with Fo 2 > 3cr(Fo2). The two independent molecules in this structure have nearly the same configuration and geometry. The Si atoms are tetrahedrally coordinated, with average Si--C bond distances of 1.842(3)/~ and average Si---O bond distances of 1.636 (7)A; angles at Si differ from 109.5 ° by an average of 3.5 °. The nine-membered rings are fully extended and the planes of the phenyl groups are approximately perpendicular to the nine- membered ring.Chemistry and Chemical Biolog

Sedimentation record in the Konkan-Kerala Basin: implications for the evolution of the Western Ghats and the Western Indian passive margin

The Konkan and Kerala Basins constitute a major depocentre for sediment from the onshore hinterland of Western India and as such provide a valuable record of the timing and magnitude of Cenozoic denudation along the continental margin. This paper presents an analysis of sedimentation in the Konkan-Kerala Basin, coupledwith a mass balance study, and numerical modelling of flexural responses to onshore denudational unloading and o¡shore sediment loading in order to test competing conceptual models for the development of high-elevation passive margins. The Konkan-Kerala Basin contains an estimated 109,000 km<sup>3</sup>; of Cenozoic clastic sediment, a volume difficult to reconcile with the denudation of a downwarped rift flank onshore, and more consistent with denudation of an elevated rift flank. We infer from modelling of the isostatic response of the lithosphere to sediment loading offshore and denudation onshore that flexure is an important component in the development of the Western Indian Margin.There is evidence for two major pulses in sedimentation: an early phase in the Palaeocene, and a second beginning in the Pliocene. The Palaeocene increase in sedimentation can be interpreted in terms of a denudational response to the rifting between India and the Seychelles, whereas the mechanism responsible for the Pliocene pulse is more enigmatic

Towards Global Characterization of Environmental and Climatic Determinants for Seasonal Influenza

No abstract availabl