Updated and novel limits on double beta decay and dark matter-induced processes in platinum.

A 510 day long-term measurement of a 45.3 g platinum foil acting as the sample and high voltage contact in an ultra-low-background high purity germanium detector was performed at Laboratori Nazionali del Gran Sasso (Italy). The data was used for a detailed study of double beta decay modes in natural platinum isotopes. Limits are set in the range O(1014-1019) years (90% C.L.) for several double beta decay transitions to excited states confirming, and partially extending existing limits. The highest sensitivity of the measurement, greater than 1019 years, was achieved for the two neutrino and neutrinoless double beta decay modes of the isotope 198Pt. Additionally, novel limits for inelastic dark matter scattering on 195Pt are placed up to mass splittings of approximately 500 keV. We analyze several techniques to extend the sensitivity and propose a few approaches for future medium-scale experiments with platinum-group elements.

An assessment of West African seahorses in fisheries catch and trade.

This study provides the first assessment of a heavily traded West African seahorse species, Hippocampus algiricus, and the first information on short-snouted seahorse Hippocampus hippocampus biology in Africa. A total of 219 seahorses were sampled from fisher catch in Senegal and The Gambia, with estimated height at reproductive activity for H. algiricus (161 mm) larger than mean ± S.D. catch height (150 ± 31 mm). Catch composition, height at reproductive activity and potential biases in fishery retention are discussed with regard to the current Convention on International Trade of Endangered Species (CITES) guidelines.

BAYESIAN ANALYSIS OF COSMIC RAY PROPAGATION: EVIDENCE AGAINST HOMOGENEOUS DIFFUSION.

We present the results of the most complete scan of the parameter space for cosmic ray (CR) injection and propagation. We perform a Bayesian search of the main GALPROP parameters, using the MultiNest nested sampling algorithm, augmented by the BAMBI neural network machine-learning package. This is the first study to separate out low-mass isotopes (p, p ¯ , and He) from the usual light elements (Be, B, C, N, and O). We find that the propagation parameters that best-fit p, p ¯ , and He data are significantly different from those that fit light elements, including the B/C and 10Be/9Be secondary-to-primary ratios normally used to calibrate propagation parameters. This suggests that each set of species is probing a very different interstellar medium, and that the standard approach of calibrating propagation parameters using B/C can lead to incorrect results. We present posterior distributions and best-fit parameters for propagation of both sets of nuclei, as well as for the injection abundances of elements from H to Si. The input GALDEF files with these new parameters will be included in an upcoming public GALPROP update.

Novel life-history data for threatened seahorses provide insight into fishery effects.

Life-history variables for three incidentally captured species of seahorse (Kellogg's seahorse Hippocampus kelloggi, the hedgehog seahorse Hippocampus spinosissimus and the three-spot seahorse Hippocampus trimaculatus) were established using specimens obtained from 33 fisheries landing sites in Peninsular Malaysia. When samples were pooled by species across the peninsula, sex ratios were not significantly different from unity, and height and mass relationships were significant for all species. For two of these species, height at physical maturity (HM ) was smaller than the height at which reproductive activity (HR ) commenced: H. spinosissimus (HM = 99·6 mm, HR = 123·2 mm) and H. trimaculatus (HM = 90·5 mm, HR = 121·8 mm). For H. kelloggi, HM could not be estimated as all individuals were physically mature, while HR = 167·4 mm. It appears that all three Hippocampus spp. were, on average, caught before reproducing; height at 50% capture (HC ) was ≥HM but ≤HR . The results from this study probe the effectiveness of assessment techniques for data-poor fisheries that rely heavily on estimates of length at maturity, especially if maturity is poorly defined. Findings also question the sustainability of H. trimaculatus catches in the south-west region of Peninsular Malaysia, where landed specimens had a notably smaller mean height (86·2 mm) and markedly skewed sex ratio (6% males) compared with samples from the south-east and north-west of the peninsula.

Conservation and management of seahorses and other Syngnathidae.

This article analyses the pressures on seahorses and explores conservation responses. It focuses on seahorses (Hippocampus spp.) but also considers pipefishes and seadragons, especially where they can fill gaps in seahorse knowledge. The charisma of many syngnathids can make them good flagship species for threats and solutions in marine conservation. The article combines a synthesis of published literature with new data on the trade in seahorses for traditional medicine, aquarium display and curiosities. Most traded seahorses come from trawl by-catch, although seahorses are also targeted. The total extraction is large, tens of millions of animals annually, and unsustainable. A first review of the effect of habitat change on syngnathids raises many questions, while suggesting that some species may cope better than others. The combination of pressures means that many species of syngnathid are now included in the IUCN Red List of Threatened Species or national equivalents. In addition, seahorse exports from 175 countries are limited to sustainable levels under the Convention on International Trade in Endangered Species (CITES) of Wild Fauna and Flora. Possible conservation measures include marine protected areas, fisheries management, select aquaculture ventures, trade regulation, improved governance (particularly) and consumer engagement.

Advances in tagging syngnathids, with the effects of dummy tags on behaviour of Hippocampus guttulatus.

Artificial marking and tagging techniques have been used to study movement, population dynamics, behaviour, ecology, survival and growth of at least 25 syngnathid species. External necklace-style tags and injection of visible implant elastomer have been the most used techniques, uniquely identifying hundreds of individual syngnathids to study population dynamics, mortality, behaviour, ecology and growth in at least 13 and 12 species, respectively. Only two studies, both on larger syngnathid species, have tested the use of internal or electronic tags. This new case study reveals that dummy tags, weighing up to 6% of individual body mass, have minimal effect on normal ex situ behaviour of the long-snouted seahorse Hippocampus guttulatus, a smaller syngnathid. In paired aquarium trials, tags did not affect movement, holdfast use or general behavioural state, and only had a short-term effect (1 day) on vertical orientation. Tagged H. guttulatus gained more mass during the 5 day trials, a result which warrants further exploration but indicates that tags did not reduce feeding. This study shows promise for using electronic tagging to study H. guttulatus and similarly sized syngnathids in the wild.

Using life-history information to assess potential effects of shrimp trawling on small fishes.

The current study presents information on size distributions, size at recruitment to the fishery, size at maturity and patterns of reproduction for several small benthic fishes caught as by-catch in the southern Gulf of California (Mexico) shrimp trawl fishery: sand perch Diplectrum spp., lumptail searobin Prionotus stephanophrys, bigscale goatfish Pseudupeneus grandisquamis and silver stardrum Stellifer illecebrosus. Pseudupeneus grandisquamis, P. stephanophrys and S. illecebrosus populations were all sexually dimorphic in size. Total-length (L(T))-based analyses did not provide reliable information on survival and growth. The majority of sampled P. grandisquamis and S. illecebrosus were caught before reproductive maturity, whereas the majority of Diplectrum spp. and almost all P. stephanophrys were mature when caught. L(T) at 50% gear retention (L(Tc), mm) v. 50% maturity (L(Tm), mm): Diplectrum spp. 124.53 v. 131.43; P. grandisquamis 90.98 v. 135.20; S. illecebrosus 82.55 v. 137.30. L(Tc) for P. stephanophrys was 104.73, but L(Tm) could not be modelled for this species as almost all captured individuals were mature. Diplectrum spp., P. grandisquamis and S. illecebrosus were indeterminate spawners, whereas P. stephanophrys appeared to be a determinate spawner. Sex ratios were equal for each of the gonochoristic species. In general, the gonado-somatic index (I(G)) increased with increasing L(T) for all except P. stephanophrys, where I(G) decreased with increasing L(T) for both males and females. Mature individuals of all taxa were found throughout the sampling period (September to March), and I(G) increased with sample day for all except females of P. grandisquamis. The current data suggest the potential for fishery effects on sampled populations of P. grandisquamis and S. illecebrosus.

Benthic status of near-shore fishing grounds in the central Philippines and associated seahorse densities.

Benthic status of 28 near-shore, artisanal, coral reef fishing grounds in the central Philippines was assessed (2000-2002) together with surveys of the seahorse, Hippocampus comes. Our measures of benthic quality and seahorse densities reveal some of the most degraded coral reefs in the world. Abiotic structure dominated the fishing grounds: 69% of the benthos comprised rubble (32%), sand/silt (28%) and dead coral (9%). Predominant biotic structure included live coral (12%) and Sargassum (11%). Rubble cover increased with increasing distance from municipal enforcement centers and coincided with substantial blast fishing in this region of the Philippines. Over 2 years, we measured a significant decrease in benthic 'heterogeneity' and a 16% increase in rubble cover. Poor benthic quality was concomitant with extremely low seahorse densities (524 fish per km(2)). Spatial management, such as marine reserves, may help to minimize habitat damage and to rebuild depleted populations of seahorses and other reef fauna.

Dispersal, habitat differences, and comparative phylogeography of Southeast Asian seahorses (Syngnathidae: Hippocampus).

Four distinct phylogeographical patterns across Southeast Asia were observed for four species of seahorse (genus Hippocampus) with differing ecologies. For all species, genetic differentiation (based on cytochrome b sequence comparisons) was significantly associated with sample site (Phi(ST) = 0.190-0.810, P < 0.0001) and with geographical distance (Mantel's r = 0.37-0.59, P < 0.019). Geographic locations of genetic breaks were inconsistent across species in 7/10 comparisons, although some similarities across species were also observed. The two shallow-water species (Hippocampus barbouri and Hippocampus kuda) have colonized the Sunda Shelf to a lesser degree than the two deeper-water species (Hippocampus spinosissimus and Hippocampus trimaculatus). In all species the presence of geographically restricted haplotypes in the Philippines could indicate past population fragmentation and/or long-distance colonization. A nested clade analysis (NCA) revealed that long-distance colonization and/or fragmentation were likely the dominant forces that structure populations of the two shallow-water species, whereas range expansion and restricted dispersal with isolation by distance were proportionally more important in the history of the two deeper-water species. H. trimaculatus has the most widespread haplotypes [average clade distance (D(c)) of nonsingleton haplotypes = 1169 km], indicating potentially high dispersal capabilities, whereas H. barbouri has the least widespread haplotypes (average D(c) = 67 km) indicating potentially lower dispersal capabilities. Pleistocene separation of marine basins and postglacial flooding of the Sunda Shelf are extrinsic factors likely to have contributed to the phylogeographical structure observed, whereas differences among the species appear to reflect their individual ecologies.

Freshwater Protected Areas: Strategies for Conservation.

Freshwater species and habitats are among the most threatened in the world. One way in which this growing conservation concern can be addressed is the creation of freshwater protected areas. Here, we present three strategies for freshwater protected-area design and management: whole-catchment management, natural-flow maintenance, and exclusion of non-native species. These strategies are based on the three primary threats to fresh waters: land-use disturbances, altered hydrologies, and introduction of non-native species. Each strategy draws from research in limnology and river and wetland ecology. Ideally, freshwater protected areas should be located in intact catchments, should have natural hydrological regimes, and should contain no non-native species. Because optimal conservation conditions are often difficult to attain, we also suggest alternative management strategies, including multiple-use modules, use of the river continuum concept, vegetated buffer strips, partial water discharges, and eradication of exotic species. Under some circumstances it may be possible to focus freshwater conservation efforts on two key zones: adjacent terrestrial areas and headwaters.

RESUMEN: Las especies y hábitats de agua dulce se encuentran entre los más amenazados del mundo. Una forma en la que esta creciente preocupación por la conservación puede ser abordada es la creación de áreas protegidas de agua dulce. Aquí presentamos el diseño de tres áreas protegidas de agua dulce y las estrategias de manejo: manejo global de la cuenca de captación, mantenimiento del flujo natural y exclusión de las especies no nativas. Estas estrategias están basadas en las tres amenazas principales que tienen las aguas dulces: perturbaciones por uso del suelo, hidrologías alteradas e introducciones de especies no nativas. Cada estrategia está planteada como resultado de la investigación en limnología y ecología de ríos y pantanos. Idealmente, las aguas protegidas de agua dulce deberán ser ubicadas en cuencas de captación intactos, que tengan regímenes hidrológicos naturales y que no contengan especies no nativas. Puesto que las condiciones óptimas de conservación son frecuentemente difíciles de alcanzar, también sugerimos estrategias alternativas de manejo que incluyen módulos de uso múltiple, uso del concepto de río continuo, bandas de amortiguamiento con vegetación, descargas parciales de agua y erradicación de especies exóticas. Bajo ciertas circunstancias, puede ser posible enfocar los esfuerzos de conservación de aguas dulces en dos zonas clave: áreas adyacentes terrestres y nacientes.

Amino- and urea-substituted thiazoles inhibit photosynthetic electron transfer.

Amino- and urea-substituted thiazoles exhibited in vivo herbicidal activity on duckweed (Lemna paucicostata Hegelm. strain 6746) cultures and appeared to act via inhibition of photosynthetic electron transport system. A small number of the thiazole derivatives tested were active but only at relatively high concentrations. The most active structures were the amino-substituted thiazoles with isopropyl and n-butyl side chains and the urea-substituted thiazole with p-chlorophenyl side chain. Decreasing the length of the side chain had a negative effect on the PSII inhibitory activity. The urea-substituted series was as a group less active than the amino series, and the free acid series had no biological activity. The most active compounds competed for the same binding site as atrazine on PSII. Computer modeling highlighted the structural similarities between some of the thiazoles and the commercial herbicides diuron and atrazine.

Molecular cloning and characterization of a novel liver-specific transport protein.

Monoclonal antibodies that specifically recognize a membrane component located on the sinusoidal domain of the hepatocyte have been used to screen a rat liver cDNA expression library and a clone encoding a novel transporter (NLT) protein has been identified. Analysis of the deduced 535 amino acid protein sequence indicates that it is unique, but shares the twelve-transmembrane domain hydrophathicity profile as well as the presence of transporter-specific amino acid motifs with bacterial and mammalian transporters. Since overall homology of NLT to known transporter genes is low (20-25% identity) it may represent a new subgroup within the transporter family of proteins. The NLT was characterized further with respect to its tissue distribution and its expression during liver development. A 2.1 kb transcript has been found in liver and at lower levels in kidney, but not in several other tissues tested. Studies on the developing liver indicate that NLT transcripts are present at a very low level from 19 through 21 gestation days with a 4- to 5-fold increase within two weeks after birth. Overall, we have cloned a novel transporter that is preferentially expressed in liver, is located on the sinusoidal domain of the plasma membrane and represents a marker for the late stage of liver development.

ACR1, a yeast ATF/CREB repressor.

Members of the mammalian ATF/CREB family of transcription factors, which are associated with regulation by cyclic AMP and viral oncogenes, bind common DNA sequences (consensus TGACGTCA) via a bZIP domain. In the yeast Saccharomyces cerevisiae, ATF/CREB-like sequences confer either repression or activation of transcription, depending on the promoter context. By isolating mutations that alleviate the repression mediated by ATF/CREB sites, we define a new yeast gene, ACR1, which encodes an ATF/CREB transcriptional repressor. ACR1 contains a bZIP domain that is necessary for homodimer formation and specific DNA binding to an ATF/CREB site. Within the bZIP domain, ACR1 most strongly resembles the mammalian cyclic AMP-responsive transcriptional regulators CREB and CREM; it is less similar to GCN4 and YAP1, two previously described yeast bZIP transcriptional activators that recognize the related AP-1 sequence (consensus TGACTCA). Interestingly, deletion of the ACR1 gene causes increased transcription through ATF/CREB sites that does not depend on GCN4 or YAP1. Moreover, extracts from acr1 deletion strains contain one or more ATF/CREB-like DNA-binding activities. These genetic and biochemical observations suggest that S. cerevisiae contains a family of ATF/CREB proteins that function as transcriptional repressors or activators.

Characterization of the glucagon receptor and its functional domains using monoclonal antibodies.

Four monoclonal antibodies, designated 4H11, 6E10, 2C5, and 3E9 were prepared against partially purified rat hepatic glucagon receptor. These antibodies were characterized by their ability to recognize the glucagon receptor in target tissues using immunoblot and immunoprecipitation procedures. The antibodies recognized a 62-kDa receptor band in rat liver, kidney, and adipose tissue but not in lung, adrenals, and erythrocytes, indicating a high degree of specificity. These antibodies recognize different antigenic determinants; the 6E10 and 2C5 bind protein epitopes, while 4H11 and 3E9 bind carbohydrate epitopes. Furthermore, proteolytic mapping of the glucagon receptor established that monoclonal antibodies 6E10 and 2C5 recognize different domains of the receptor molecule. These antibodies were used to study the immunochemical similarities among the receptors from different species and to assess the topological location of the ligand-binding site. By combining the techniques of affinity cross-linking, proteolytic mapping, and antibody binding, we have identified the location of the glucagon-binding site near to the COOH-terminal domain of the receptor.

Mutations that define the optimal half-site for binding yeast GCN4 activator protein and identify an ATF/CREB-like repressor that recognizes similar DNA sites.

The yeast GCN4 transcriptional activator protein binds as a dimer to a dyad-symmetric sequence, indicative of a protein-DNA complex in which two protein monomers interact with adjacent half-sites. However, the optimal GCN4 recognition site, ATGA(C/G)TCAT, is inherently asymmetric because it contains an odd number of base pairs and because mutation of the central C.G base pair strongly reduces specific DNA binding. From this asymmetry, we suggested previously that GCN4 interacts with nonequivalent and possibly overlapping half-sites (ATGAC and ATGAG) that have different affinities. Here, we examine the nature of GCN4 half-sites by creating symmetrical derivatives of the optimal GCN4 binding sequence that delete or insert a single base pair at the center of the site. In vitro, GCN4 bound efficiently to the sequence ATGACGTCAT, whereas it failed to bind to ATGAGCTCAT or ATGATCAT. These observations strongly suggest that (i) GCN4 specifically recognizes the central base pair, (ii) the optimal half-site for GCN4 binding is ATGAC, not ATGAG, and (iii) GCN4 is a surprisingly flexible protein that can accommodate the insertion of a single base pair in the center of its compact binding site. The ATGACGTCAT sequence strongly resembles sites bound by the yeast and mammalian ATF/CREB family of proteins, suggesting that GCN4 and the ATF/CREB proteins recognize similar half-sites but have different spacing requirements. Unexpectedly, in the context of the his3 promoter, the ATGACGTCAT derivative reduced transcription below the basal level in a GCN4-independent manner, presumably reflecting DNA binding by a distinct ATF/CREB-like repressor protein. In other promoter contexts, however, the same site acted as a weak upstream activating sequence.

Experimental autoimmune myasthenia gravis induced in mice without adjuvant: genetic susceptibility and adoptive transfer of weakness.

The induction of experimental autoimmune myasthenia gravis (EAMG) in mice in the absence of adjuvant was investigated. The essential biochemical features of the disease were induced using a protocol including a primary intrasplenic immunization (1 microgram Torpedo acetylcholine receptor, AChR) followed by booster immunizations with the same dose at 2 and 6 weeks (intraperitoneal) and at 14 weeks (intrasplenic). These features included serum antibodies reactive with mouse AChR, antibody complexed with AChR in vivo, and AChR loss from motor endplates. None of the mice immunized with AChR in adjuvant developed weakness. By contrast, a few mice (less than 5%) immunized without adjuvant became overtly weak and these clinical signs could be adoptively transferred to irradiated recipients, suggesting a possible model for testing immunotherapeutic strategies. Of the nine mouse strains immunized (on six different H-2 haplotypes: a, b, d, k, q, and s) only those with the H-2k haplotype did not develop the biochemical features associated with EAMG. In an F1 cross the genotype (H-2b) was dominant in conferring susceptibility to CBA mice (H-2k).

Parasitic infection of the seahorse (Hippocampus erectus)--a case report.

This report details the development of a microsporidan infection in a colony of seahorses (Hippocampus erectus) caused by Glugea heraldi. Of 76 animals imported from Florida Bay (USA), two survived. A myxosporidan (Sphaeromyxa sp.) and an unidentified nematode infection were also diagnosed in the same colony, but these infections were not considered important, causative factors in the mortalities.

Are spontaneous anti-idiotypic antibodies against anti-acetylcholine receptor antibodies present in myasthenia gravis?

The presence of anti-acetylcholine receptor anti-idiotypic antibodies in sera from 102 myasthenia gravis patients and from 33 first-degree relatives was investigated by: (a) Enzyme linked immunosorbent assay (ELISA) using monoclonal antibodies raised against human acetylcholine receptor, (b) immunoprecipitation of 125I-monoclonal anti-acetylcholine receptor antibodies; (c) inhibition of anti-acetylcholine receptor monoclonal antibody binding to the receptor and/or (d) inhibition of autologous and heterologous anti-acetylcholine receptor antibody binding to the receptor. No clear evidence for the presence of abnormal levels of spontaneous anti-idiotypic antibodies to anti-acetylcholine receptor antibodies was found.