The Solar Acoustic Spectrum and Eigenmode Parameters

The Global Oscillation Network Group (GONG) project estimates the frequencies, amplitudes, and linewidths of more than 250,000 acoustic resonances of the sun from data sets lasting 36 days. The frequency resolution of a single data set is 0.321 microhertz. For frequencies averaged over the azimuthal order m, the median formal error is 0.044 microhertz, and the associated median fractional error is 1.6 x 10(-5). For a 3-year data set, the fractional error is expected to be 3 x 10(-6). The GONG m-averaged frequency measurements differ from other helioseismic data sets by 0.03 to 0.08 microhertz. The differences arise from a combination of systematic errors, random errors, and possible changes in solar structure.     

A method for applying fluvial geomorphology in support of catchment‐scale river restoration planning

• 1. This paper reports on an extension to the use of Fluvial Audit survey to include a subjective and adaptive multi‐criteria assessment (MCA) process that integrates scientific literature and observational data to develop three reach‐scale indices of: (a) channel modification; (b) channel function (sediment store or source); and (c) naturalness. These indices are nested within an overall conceptual model of channel evolution and used to underpin catchment scale river restoration.
• 2. The approach is described and applied to a small groundwater dominated river in the UK. The results show that over 48% of the total main river was in a degraded state relative to a conceptual model of a natural reference state. Only 23% of the river was in a near‐natural state.
• 3. MCA classifications were translated into a set of management actions necessary to return each reach to a near‐natural condition. These are described.
• 4. The method offers a transparent decision support for stakeholders that can incorporate differing scientific evidence. The use of MCA enables flexibility in terms of the relative importance of scores and weights placed upon factors in the final classification. This makes the approach amenable to stakeholder and public consultation.

Copyright © 2009 John Wiley & Sons, Ltd.     

Comparison between sequential and concurrent matings of two females and one male channel catfish, Ictalurus punctatus, in spawning pens

In selective breeding of channel catfish, it is desirable to mate, in the same breeding season, each one of a large number of males to more than one female. This experiment compared sequential and concurrent matings of two females and one male in 36 individual spawning pens. The number of females that spawned in the former group was higher (74%) than in the latter (57%); the numbers of males spawning in each group were similar (135 vs 130%, respectively). These differences are associated with (1) a higher female mortality in concurrent (30%) than sequential matings (3%), and (2) a smaller difference in frequencies of double-spawning males (40 vs 47%, respectively). It was concluded that neither the sequential nor concurrent methods tested could satisfy the needs of selective breeding, even though the former method was closer to this objective.     

Roach (<Emphasis Type="Italic">Rutilus rutilus</Emphasis>) reproductive cycle: a study of biochemical and histological parameters in a low contaminated site

Fish reproduction is subjected to worrying trends in many aquatic environments. In this study, we report the absence of histological and biochemical alterations in fish sampled in a low contaminated site (characterised by the absence of detectable oestrogenic activity and mutagenicity in sediment extracts). A total of 474 roach (Rutilus rutilus) were monthly sampled during 18 months, and no intersex fish were recorded after careful histological examination, thus indicating that the incidence of this phenomenon may be very low under natural conditions. Furthermore, mean male plasma vitellogenin concentration was 24 ng ml⁻¹ and was only slightly elevated during the spawning period (up to 120 ng ml⁻¹) indicating that these low values may be characteristic of a low contaminated site. Of the male roach, 45.3% were sampled, a sex-ratio that did not significantly deviated from the expected 1:1 ratio between male and female. Results also showed that natural conditions can greatly affect the reproductive cycle of roach. Gametogenesis showed a biphasic pattern with first gonad maturation between September and December and a final maturation occurring at the end of winter/early spring. Under decreasing temperatures, particularly below 6°C, gametogenesis was stopped or even regressed with secondary oocytes becoming rare under histological observation. Conversely, elevated temperatures during the winter lead to an earlier gonad maturation.     

A large scale BACI experiment to test the effects of prawn trawling on seabed biota in a closed area of the Great Barrier Reef Marine Park, Australia

A multiple Before-After-Control-Impact experiment was conducted to estimate the large scale effects of a single coverage by prawn trawlers on an offshore inter-reef area in the northern Great Barrier Reef that was closed to fishing. Prospective power and cost-benefit analyses facilitated the design and optimization of the experiment, the effect size of which was guided by prior publications at the time that had indicated impacts of 10–100×. The optimal design, given the number of factors to be tested and the constraint of available ship time (100 days) and resources needed to process samples, was for 12 control and 12 impact plots each measuring 2.8 km × 1.2 km. The final design specification was capable of detecting an average −80% effect size (5×). The experiment was divided over two seasons, wet and dry. During the experimental trawl impact phase, a total of 32 t of benthic biota was removed from six shallow plots (15–25 m depth) and 6 t from six deep plots (30–50 m depth). Sampling before and 6 months after impact was conducted by an epibenthic dredge, a prawn trawl and a fish trawl. Analysis of means before and after impact, relative to controls, showed very few significant differences. This indicated that the impact of a single prawn trawl was less than the design specification. The lower than expected impact, compared to previous studies, may have been partly because this study included all benthic groups, not just the most sensitive as earlier studies had focussed on. Comparison of catch rates from the prawn trawl and the dredge indicated the overall impact on total biomass was around −3% but ranged from close to 0% for some species to around −20% for sensitive sessile species. A review of effect sizes in 30 other recent trawl experiments indicated that this result was not exceptional; i.e. the reported effects of single trawls generally were not large, and prawn trawls appeared to have smaller effect sizes than fish trawls, beam trawls and scallop dredges—also, several studies reported recovery within ca. 6 months. Analysis of fishery effort data indicated that this result was appropriate for the majority of trawl fishing grounds, where effort is sparse and infrequent. Many published experiments had confounded designs and most had not used a priori power analyses or pre-specified effect sizes. Nevertheless, recurrent trawling can be expected to have cumulative impacts on benthos, as has been demonstrated by repeat-trawl depletion experiments. On the other hand, the spatial extent of fishing grounds trawled as intensively as these depletion experiments is quite limited.     

Preliminary investigations into the interactions of herbicides with aqueous humic substances

The binding of the herbicides to aqueous humic substances was investigated using the herbicide mecoprop and a reference humic substance ‘Hohlohsee’. Initial results from 2D fluorescence spectrometry, infra-red spectroscopy and Curie-point pyrolysis gas chromatography/infra-red spectroscopy tentatively characterise the nature of the interaction. ©1997 SCI     

A comparision of the competitive effects and nutrient accumulation of fat‐hen and groundsel

The competitive effects of fat‐hen (chenopodium album L.) and groundsel (Senecio vulgaris L.) on tomato (Lycopersicon esculentum Mill), lettuce (Lactuca sativa L.) and cabbage (Brassica oleracea L. var. Capitata) were investigated under glasshouse conditions. Weed competition severely reduced growth of the three food crops, the reduction being more pronounced with the longer exposure to the competition. Chenopodium album and 5. vulgaris were considerably different in their competitive abilities, although similar differences among the three food‐crop species were found. Senecio vulgaris was affected more by the competition than C. album and had lower tissue concentrations of N, K, and Mg. Growth of both weeds was greatly suppressed when tomato emerged two weeks earlier than the weeds, but the crop plants were severely stunted when the weeds had two weeks initial advantage. It appeared that C. album competed with the three food crops more for K than other elements, while S. vulgaris competed better for P. Cabbage was more competitive with both weed species than tomato while lettuce was the least competitor. Some aspects of these differences in competitive ability among the species could be related to their nutrient use.     

Percutaneous absorption of methimazole: an in vitro study of the absorption pharmacokinetics for two different vehicles

The use of transdermal medications in cats has become popular in veterinary medicine due to the ease of administration compared to oral medication. However, the research to support systemic absorption of drugs applied to the pinna after transdermal administration in cats is limited. The aim of this study was to characterize the percutaneous absorption pharmacokinetics of methimazole in a lipophilic vehicle compared to methimazole in Pluronic^® lecithin organogel (PLO) using a finite dose applied to feline ear skin in an in vitro Franz cell model. The two formulations of methimazole (10 mg) were applied to the inner stratum corneum of six pairs of feline ears. The receptor medium was sampled up to 30 h post–administration, and methimazole concentrations were measured using high‐performance liquid chromatography (HPLC). Histological examination of all ears was undertaken as small differences in the thickness of ear skin may have contributed to inter‐individual differences in methimazole absorption between six cats. Methimazole was absorbed more completely across the pinnal skin when administered in the lipophilic vehicle compared to administration in the PLO gel (P < 0.001).     

Two Methods of Vitrification Followed by In Vitro Culture of the Ovine Ovary: Evaluation of the Follicular Development and Ovarian Extracellular Matrix

The aim of this study was to evaluate the influence of two vitrification techniques on the extra cellular matrix (ECM) and ovarian follicular development. The ovarian cortex was fragmented (9 mm³) and divided into six groups, viz. fresh control, cultured control, vitrified by the Ovarian Tissue Cryosystem (OTC) method, conventional solid surface vitrification (SSV) method, OTC/cultured and SSV/cultured. Follicles from all the fragments were analysed for morphology, development and viability. The ECM was evaluated based on the condition of collagen and reticular fibres and the immunolocalization of type I collagen and fibronectin. After 7 days of culture, the tissue vitrified by OTC revealed a higher percentage (p < 0.05) of morphologically normal (30.66%) and viable (60.00%) follicles when compared with those vitrified using the SSV technique (21.33% and 23.00%). In all the fragments cultured, regardless of the vitrification method, a significantly higher percentage of developing follicles was observed when compared with the non‐cultured tissue. Analysis of the type I collagen showed increased immunostaining after the in vitro culture in the vitrified fragments. In conclusion, the OTC is better for preserving the follicular viability and morphology and maintaining the integrity of the extracellular matrix components of the ovine ovary.     

Chemical modification employed as a means of probing the cell-wall micropore of pine sapwood

The cell-wall micropore network of oven-dried Corsican and Scots pine sapwood has been investigated by reaction with acetic and propionic anhydride in a non-swelling solvent (xylene). No significant reaction occurred, except in the case of reaction between Corsican pine and acetic anhydride. However, when the wood samples were in a swollen state, reaction occurred between the wood and both anhydrides. It is concluded that the cell-wall micropores of Corsican pine are sufficiently large to allow access of acetic anhydride, but not propionic into the unswollen cell wall; however, with Scots pine, both reagents are too large to gain access. A further series of experiments was performed whereby the volumetric changes of pine sapwood samples due to modification with a range of linear chain anhydrides were determined. With Corsican pine, larger volume changes than theoretically predicted were observed, whereas, with the Scots pine samples, the volume changes were close to those predicted. When account is taken of the volume that the reagent occupies within the cell wall, it was found that larger void volumes occurred in the Corsican pine samples. This result indicates that the cell-wall polymeric environment surrounding a reagent molecule is more compliant in the case of Corsican pine.