Predominance of genetic monogamy by females in a hammerhead shark, Sphyrna tiburo: Implications for shark conservation.

There is growing interest in the mating systems of sharks and their relatives (Class Chondrichthyes) because these ancient fishes occupy a key position in vertebrate phylogeny and are increasingly in need of conservation due to widespread overexploitation. Based on precious few genetic and field observational studies, current speculation is that polyandrous mating strategies and multiple paternity may be common in sharks as they are in most other vertebrates. Here, we test this hypothesis by examining the genetic mating system of the bonnethead shark, Sphyrna tiburo, using microsatellite DNA profiling of 22 litters (22 mothers, 188 embryos genotyped at four polymorphic loci) obtained from multiple locations along the west coast of Florida. Contrary to expectations based on the ability of female S. tiburo to store sperm, the social nature of this species and the 100% multiple paternity observed in two other coastal shark species, over 81% of sampled bonnethead females produced litters sired by a single male (i.e. genetic monogamy). When multiple paternity occurred in S. tiburo, there was an indication of increased incidence in larger mothers with bigger litters. Our data suggest that sharks may exhibit complex genetic mating systems with a high degree of interspecific variability, and as a result some species may be more susceptible to loss of genetic variation in the face of escalating fishing pressure. Based on these findings, we suggest that knowledge of elasmobranch mating systems should be an important component of conservation and management programmes for these heavily exploited species.

Culturing freshwater pearl mussel Margaritifera margaritifera: a breakthrough in the conservation of an endangered species.

1. The freshwater pearl mussel Margaritifera margaritifera L. is globally endangered and is threatened by commercial exploitation, pollution and habitat loss throughout its range. Captive breeding would be a valuable tool in enhancing the status of M. margaritifera in the UK. 2. We have developed a semi-natural system for successfully infecting juvenile brown trout with glochidial M. margaritifera, and culturing juvenile mussels in experimental tanks where glochidial M. margaritifera can excyst from fish gills and settle into sediment. 3. Infected fish had less than 1% mortality. Levels of infection varied among fish. Two yearly cohorts of juvenile M. margaritifera were identified from samples of sediment taken from each experimental tank. Individuals range in size from 1.4 mm (2000 cohort) to >3 mm in length (1999 cohort). 4. The number of juvenile M. margaritifera present in the two experimental tanks are estimated to be between 3600 (tank A) and 0 (tank B) for the putative 1999 cohort and between 6000 (tank A) and 13 000 (tank B) for the putative 2000 cohort. 5. This pioneering method for large-scale cultivation of juvenile M. margaritifera is intermediate between the release of infected fish into rivers and the intensive cultivation systems developed in continental Europe and the USA for other species of unionid. This is the first time that large numbers of M. margaritifera have been cultured and represents a significant breakthrough in the conservation of this globally endangered Red Data List species. The method is straightforward and is most cost-effective when undertaken alongside established hatchery processes.

Estimation of the size of onset of sexual maturity in Nephrops norvegicus (L.).

Size at onset of maturity (SOM) was estimated for both male and female Nephrops from primary sexual characteristics and morphometric traits. SOM estimated from primary sexual characteristics based on histological examination of the gonad ranged from 15.1 mm carapace length (CL) in males to 22.9 mm CL in females. Nephrops morphometric maturity, or change in allometric growth of body parts, was estimated from appendix masculina and cutter claw lengths in males and abdomen width in females from two sites in the Irish Sea. Two regression techniques were used to estimate morphometric maturity. Estimated SOM from morphometric characteristics ranged from 23.2 to 27.6 mm CL in females and from 25.9 to 31.0 mm CL in males. Spatial variation in SOM was observed in Nephrops from different parts of the Irish Sea.

Electrooxidation of the iodides [C(4)mim]I, LiI, NaI, KI, RbI, and CsI in the room temperature ionic liquid [C(4)mim][NTf2]

The electrochemical oxidation of 1-butyl-3-methylimidazolium iodide, [C(4)mim]I, has been investigated by cyclic voltammetry at a platinum microelectrode at varying concentrations in the RTIL 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [C(4)mim][NTf2]. Two oxidation peaks were observed. The first peak is assigned to the oxidation of iodide to triiodide, in an overall two-electron process: 3I(-)- 2e(-) -> I-3(-). At higher potentials, the electrogenerated triiodide oxidizes to iodine, in an overall one-electron process: I-3(-) - e(-) -> 3/2I(2). An average diffusion coefficient, D, for I- of 1.55 x 10(-11) m(2) s(-1) was obtained. A digital simulation program was used to simulate the voltammetric response, and kinetic parameters were successfully extracted. The parameters deduced from the simulation include D for I-, I-3(-), and I-2 and K-eq,K-2, the equilibrium constant for the reaction of iodide and iodine to form triiodide. Values for these parameters are of the same order as those previously published for the oxidation of Br- in the same RTIL [Allen et al. J. Electroanal. Chem. 2005, 575, 311]. Next, the cyclic voltammetry of five different inorganic iodide salts was studied by dissolving small amounts of the solid in [C(4)mim][NTf2]. Similar oxidation peaks were observed, revealing diffusion coefficients of ca. 0.55, 1.14, 1.23, 1.44, and 1.33 x 10(-11) m(2) s(-1) and solubilities of 714, 246, 54, 83, and 36 mM for LiI, NaI, KI, RbI, and CsI, respectively. The slightly smaller diffusion coefficients for the XI salts (compared to [C(4)mim]I) may indicate that I- is ion-paired with Li+, Na+, K+, Rb+, and Cs+ in the RTIL medium.

Photodissociation of D-3(+) in an intense, femtosecond laser field

H-3(+) is the simplest triatomic molecule and plays an important role in laboratory and astrophysical plasmas. It is very stable both in terms of its electronic and nuclear degrees of freedom but is difficult to study in depth in the laboratory due to its ionic nature. In this communication, experimental results are presented for the strong field dissociation of the isotopic analogue D-3(+), using 30 fs, 800 nm laser pulses with intensities up to 10(16) W cm(-2). By employing a novel experimental set-up, ions were confined in an electrostatic ion trap so that dissociation of the molecule could be studied as it radiatively cools. It was determined that dissociation could only be observed for molecules in ro-vibrational states relatively close to the dissociation limit, while more tightly bound states demonstrated remarkable stability in even the strongest fields.

A study of magnetic bright points in the Na I D1 line.

High-cadence, multiwavelength, optical observations of solar magnetic bright points (MBPs), captured at the disk center using the ROSA and IBIS imaging systems on the Dunn Solar Telescope, are presented. MBPs manifesting in the Na I D-1 core are found to preferentially exist in regions containing strong downflows, in addition to cospatial underlying photospheric magnetic field concentrations. Downdrafts within Na I D-1 bright points exhibit speeds of up to 7 km s(-1), with preferred structural symmetry in intensity, magnetic field, and velocity profiles about the bright point center. Excess intensities associated with G-band and Ca II K observations of MBPs reveal a power-law trend when plotted as a function of the magnetic flux density. However, Na I D-1 observations of the same magnetic features indicate an intensity plateau at weak magnetic field strengths below approximate to 150 G, suggesting the presence of a two-component heating process: one which is primarily acoustic and the other predominantly magnetic. We suggest that this finding is related to the physical expansion of magnetic flux tubes, with weak field strengths (approximate to 50 G) expanding by similar to 76%, compared to a similar to 44% expansion when higher field strengths (approximate to 150 G) are present. These observations provide the first experimental evidence of rapid downdrafts in Na I D-1 MBPs and reveal the nature of a previously unresolved intensity plateau associated with these structures.

Annotation of Case C-272/94, Criminal proceedings against Michel Guiot and Climatec SA, ECR 1996 I-1905

Employer's contributions - Loyalty stamps - Bad-weather stamps - Freedom to provide services - Posted Workers

Annotation of Case C-43/93, Raymond Vander Elst v Office des Migrations Internationales, ECR I-3803

Freedom to provide services - Nationals of a non-member country - Posted Workers

Annotation of Case C-353/92, Hellenic Republic v Council, ECR 1994 I-3411, and Case C-358/92, Hellenic Republic v Commission, ECR I-3507

Action for annulment - Council Regulation (EEC) Nº 1765/92 of 30 June 1992 establishing a support system for producers of certain arable crops - Commission Regulation (EEC) Nº 2294/92 of 31 July 1992 on detailed rules for the application of the support system for producers of the oil seeds referred to in Council Regulation (EEC) Nº 1765/92 - Obligation to observe a final date for sowing and for lodging an application for a compensatory payment

Annotation of Case C-375/92, Commission v Kingdom of Spain, ECR 1994 I-923, and Case C-45/93, Commission v Kingdom of Spain, ECR 1994 I-911

Failure to fulfil obligations - Freedom to provide services - Tourist guides - Professional qualification required by national rule - Discrimination - Museum admission