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1.
Environ Sci Technol ; 58(12): 5512-5523, 2024 Mar 26.
Article in English | MEDLINE | ID: mdl-38478581

ABSTRACT

The investigation of pharmaceuticals as emerging contaminants in marine biota has been insufficient. In this study, we examined the presence of 51 pharmaceuticals in edible oysters along the coasts of the East and South China Seas. Only nine pharmaceuticals were detected. The mean concentrations of all measured pharmaceuticals in oysters per site ranged from 0.804 to 15.1 ng g-1 of dry weight, with antihistamines being the most common. Brompheniramine and promethazine were identified in biota samples for the first time. Although no significant health risks to humans were identified through consumption of oysters, 100-1000 times higher health risks were observed for wildlife like water birds, seasnails, and starfishes. Specifically, sea snails that primarily feed on oysters were found to be at risk of exposure to ciprofloxacin, brompheniramine, and promethazine. These high risks could be attributed to the monotonous diet habits and relatively limited food sources of these organisms. Furthermore, taking chirality into consideration, chlorpheniramine in the oysters was enriched by the S-enantiomer, with a relative potency 1.1-1.3 times higher when chlorpheniramine was considered as a racemate. Overall, this study highlights the prevalence of antihistamines in seafood and underscores the importance of studying enantioselectivities of pharmaceuticals in health risk assessments.


Subject(s)
Environmental Monitoring , Ostreidae , Pharmaceutical Preparations , Water Pollutants, Chemical , Animals , Humans , Brompheniramine/analysis , China , Chlorpheniramine/analysis , Histamine Antagonists/analysis , Oceans and Seas , Ostreidae/chemistry , Pharmaceutical Preparations/analysis , Promethazine/analysis , Water Pollutants, Chemical/analysis
2.
Mol Ecol ; 32(18): 5071-5088, 2023 09.
Article in English | MEDLINE | ID: mdl-37584177

ABSTRACT

Acquisition of new genes often results in the emergence of novel functions and is a key step in lineage-specific adaptation. As a group of sessile crustaceans, barnacles establish permanent attachment through initial cement secretion at the larval phase followed by continuous cement secretion in juveniles and adults. However, the origins and evolution of barnacle larval and adult cement proteins remain poorly understood. By performing microdissection of larval cement glands, transcriptome and shotgun proteomics and immunohistochemistry validation, we identified 30 larval and 27 adult cement proteins of the epibiotic turtle barnacle Chelonibia testudinaria, of which the majority are stage- and barnacle-specific. While only two proteins, SIPC and CP100K, were expressed in both larvae and adults, detection of protease inhibitors and the cross-linking enzyme lysyl oxidase paralogs in larvae and adult cement. Other barnacle-specific cement proteins such as CP100k and CP52k likely share a common origin dating back at least to the divergence of Rhizocephala and Thoracica. Different CP52k paralogues could be detected in larval and adult cement, suggesting stage-specific cement proteins may arise from duplication followed by changes in expression timing of the duplicates. Interestingly, the biochemical properties of larval- and adult-specific CP52k paralogues exhibited remarkable differences. We conclude that barnacle larval and adult cement systems evolved independently, and both emerged from co-option of existing genes and de novo formation, duplication and functional divergence of lineage-specific cement protein genes. Our findings provide important insights into the evolutionary mechanisms of bioadhesives in sessile marine invertebrates.


Subject(s)
Thoracica , Animals , Thoracica/genetics , Thoracica/metabolism , Proteins/genetics , Larva/genetics , Larva/metabolism , Transcriptome/genetics
3.
Mol Phylogenet Evol ; 184: 107780, 2023 07.
Article in English | MEDLINE | ID: mdl-37031710

ABSTRACT

Resolving the evolutionary history of organisms is a major goal in biology. Yet for some taxa the diversity, phylogeny, and even adult stages remain unknown. The enigmatic crustacean "y-larvae" (Facetotecta) are one particularly striking example. Here, we use extensive video-imaging and single-specimen molecular sequencing of >200 y-larval specimens to comprehensively explore for the first time their evolutionary history and diversity. This integrative approach revealed five major clades of Facetotecta, four of which encompass a considerable larval diversity. Whereas morphological analyses recognized 35 y-naupliar "morphospecies", molecular species-delimitation analyses suggested the existence of between 88 and 127 species. The phenotypic and genetic diversity between the morphospecies suggests that a more elaborate classification than the current one-genus approach is needed. Morphology and molecular data were highly congruent at shallower phylogenetic levels, but no morphological synapomorphies could be unambiguously identified for major clades, which mostly comprise both planktotrophic and lecithotrophic y-nauplii. We argue that lecithotrophy arose several times independently whereas planktotrophic y-nauplii, which are structurally more similar across clades, most likely display the ancestral feeding mode of Facetotecta. We document a remarkably complex and highly diverse phylogenetic backbone for a taxon of larval marine crustaceans, the full life cycle of which remains a mystery.


Subject(s)
Biological Evolution , Crustacea , Animals , Phylogeny , Larva/anatomy & histology , Life Cycle Stages
4.
Mol Phylogenet Evol ; 169: 107391, 2022 04.
Article in English | MEDLINE | ID: mdl-35026427

ABSTRACT

Imbricaverruca and Neoverruca are two genera of hydrothermal vent asymmetrical barnacles in Neoverrucidae, but found in vents of the Southwest Pacific and Northwest Pacific Oceans, respectively. Imbricaverruca has a flattened operculum and the shell base with multiple whorls of imbricating plates, while Neoverruca has an inclined operculum and the shell base with fewer developed imbricating plates. It has been hypothesized that Imbricaverruca has apomorphic shell characters in Neoverrucidae. Although the monophyletic relationship of the vent barnacle members in the superfamily Neolepadoidea were confirmed based on molecular phylogeny, the relationships between Neobrachylepadidae and Neoverrucidae, and between Neoverruca and Imbricaverruca have not been determined because there are no molecular data on Imbricaverruca. In this study, we sequenced three nuclear (18S rDNA, 28S rDNA, histone 3) and one mitochondrial (CO1) genes of I. yamaguchii from the Southwest Pacific. Our phylogenetic results showed that Neobrahchylepadidae is the sister taxon to Neoverrucidae (Imbricaverruca + Neoverruca), and Imbricaverruca and Neoverruca are monophyletic sister taxa each other, which not supporting the previous hypothesis that Neoverruca is sister to the clade containing Neobrahchylepadidae and Neolepadidae. These implied that the differences in shell forms between Neoverruca and Imbricaverruca are a result of independent divergent evolution in different deep-sea basins.


Subject(s)
Hydrothermal Vents , Thoracica , Animals , Base Sequence , DNA, Ribosomal/genetics , Phylogeny , Thoracica/genetics
5.
BMC Genomics ; 22(1): 783, 2021 Nov 01.
Article in English | MEDLINE | ID: mdl-34724896

ABSTRACT

BACKGROUND: Barnacles are sessile crustaceans that attach to underwater surfaces using barnacle cement proteins. Barnacles have a calcareous or chitinous membranous base, and their substratum varies from biotic (e.g. corals/sponges) to abiotic surfaces. In this study, we tested the hypothesis that the cement protein (CP) composition and chemical properties of different species vary according to the attachment substrate and/or the basal structure. We examined the histological structure of cement glands and explored the variations in cement protein homologs of 12 barnacle species with different attachment habitats and base materials. RESULTS: Cement gland cells in the rocky shore barnacles Tetraclita japonica formosana and Amphibalanus amphitrite are eosinophilic, while others are basophilic. Transcriptome analyses recovered CP homologs from all species except the scleractinian coral barnacle Galkinia sp. A phylogenomic analysis based on sequences of CP homologs did not reflect a clear phylogenetic pattern in attachment substrates. In some species, certain CPs have a remarkable number of paralogous sequences, suggesting that major duplication events occurred in CP genes. The examined CPs across taxa show consistent bias toward particular sets of amino acid. However, the predicted isoelectric point (pI) and hydropathy are highly divergent. In some species, conserved regions are highly repetitive. CONCLUSIONS: Instead of developing specific cement proteins for different attachment substrata, barnacles attached to different substrata rely on a highly duplicated cementation genetic toolkit to generate paralogous CP sequences with diverse chemical and biochemical properties. This general CP cocktail might be the key genetic feature enabling barnacles to adapt to a wide variety of substrata.


Subject(s)
Thoracica , Animals , Ecosystem , Gene Expression Profiling , Phylogeny , Thoracica/genetics , Transcriptome
6.
Proc Biol Sci ; 288(1960): 20211620, 2021 10 13.
Article in English | MEDLINE | ID: mdl-34610769

ABSTRACT

Movement is a fundamental characteristic of life, yet some invertebrate taxa, such as barnacles, permanently affix to a substratum as adults. Adult barnacles became 'sessile' over 500 Ma; however, we confirm that the epizoic sea turtle barnacle, Chelonibia testudinaria, has evolved the capacity for self-directed locomotion as adults. We also assess how these movements are affected by water currents and the distance between conspecifics. Finally, we microscopically examine the barnacle cement. Chelonibia testudinaria moved distances up to 78.6 mm yr-1 on loggerhead and green sea turtle hosts. Movements on live hosts and on acrylic panels occasionally involved abrupt course alterations of up to 90°. Our findings showed that barnacles tended to move directly against water flow and independent of nearby conspecifics. This suggests that these movements are not passively driven by external forces and instead are behaviourally directed. In addition, it indicates that these movements function primarily to facilitate feeding, not reproduction. While the mechanism enabling movement remained elusive, we observed that trails of cement bore signs of multi-layered, episodic secretion. We speculate that proximal causes of movement involve one or a combination of rapid shell growth, cement secretion coordinated with basal membrane lifting, and directed contraction of basal perimeter muscles.


Subject(s)
Thoracica , Turtles , Animals , Locomotion , Reproduction
7.
Mol Phylogenet Evol ; 157: 107037, 2021 04.
Article in English | MEDLINE | ID: mdl-33278586

ABSTRACT

The purplish bifurcate mussel Mytilisepta virgata is widely distributed and represents one of the major components of the intertidal community in the northwestern Pacific (NWP). Here, we characterized population genetic structure of NWP populations throughout nearly their whole distribution range using both mitochondrial (mtDNA cox1) and nuclear (ITS1) markers. Population genetic analyses for mtDNA cox 1 sequences revealed two monophyletic lineages (i.e., southern and northern lineages) geographically distributed according to the two different surface water temperature zones in the NWP. The timing of the lineage split is estimated at the Pliocene- mid-Pleistocene (5.49-1.61 Mya), which is consistent with the timing of the historical isolation of the East Sea/Sea of Japan from the South and East China Seas due to sea level decline during glacial cycles. Historical sea level fluctuation during the Pliocene-Pleistocene and subsequent adaptation of mussels to different surface water temperature zones may have contributed to shaping the contemporary genetic diversity and deep divergence of the two mitochondrial lineages. In contrast to mtDNA sequences, a clear lineage split between the two mitochondrial lineages was not found in ITS1 sequences, which showed a star-like structure composed of a mixture of southern and northern mitochondrial lineages. Possible reasons for this type of mito-nuclear discordance include stochastic divergence in the coalescent processes of the two molecular markers, or balancing selection under different marine environments. Cryptic speciation cannot be ruled out from these results, and future work using genomic analyses is required to address whether the thermal physiology of these mussels corresponds to the deep divergence of their mitochondrial genes and to test for the existence of morphologically indistinguishable but genetically separate cryptic species.


Subject(s)
Cell Nucleus/genetics , Mitochondria/genetics , Mytilidae/genetics , Phylogeography , Animals , DNA, Mitochondrial/genetics , Electron Transport Complex IV/genetics , Genes, Mitochondrial , Genetic Variation , Genetics, Population , Haplotypes/genetics , Pacific Ocean , Phylogeny , Principal Component Analysis , Time Factors
8.
Am J Law Med ; 47(4): 351-385, 2021 12.
Article in English | MEDLINE | ID: mdl-35297752

ABSTRACT

The advent of artificial intelligence ("AI") holds great potential to improve clinical diagnostics. At the same time, there are important questions of liability for harms arising from the use of this technology. Due to their complexity, opacity, and lack of foreseeability, AI systems are not easily accommodated by traditional liability frameworks. This difficulty is compounded in the health care space where various actors, namely physicians and health care organizations, are subject to distinct but interrelated legal duties regarding the use of health technology. Without a principled way to apportion responsibility among these actors, patients may find it difficult to recover for injuries. In this Article, I propose that physicians, manufacturers of clinical AI systems, and hospitals be considered a common enterprise for the purposes of liability. This proposed framework helps facilitate the apportioning of responsibility among disparate actors under a single legal theory. Such an approach responds to concerns about the responsibility gap engendered by clinical AI technology as it shifts away from individualistic notions of responsibility, embodied by negligence and products liability, toward a more distributed conception. In addition to favoring plaintiff recovery, a common enterprise strict liability approach would create strong incentives for the relevant actors to take care.


Subject(s)
Malpractice , Physicians , Artificial Intelligence , Delivery of Health Care , Humans , Liability, Legal
9.
Proc Biol Sci ; 287(1936): 20201360, 2020 10 14.
Article in English | MEDLINE | ID: mdl-33049170

ABSTRACT

Changes in size strongly influence organisms' ecological performances. For aquatic organisms, they can transition from viscosity- to inertia-dominated fluid regimes as they grow. Such transitions are often associated with changes in morphology, swimming speed and kinematics. Barnacles do not fit into this norm as they have two morphologically distinct planktonic larval phases that swim differently but are of comparable sizes and operate in the same fluid regime (Reynolds number 100-101). We quantified the hydrodynamics of the rocky intertidal stalked barnacle Capitulum mitella from the nauplius II to cyprid stage and examined how kinematics and size increases affect its swimming performance. Cyprids beat their appendages in a metachronal wave to swim faster, more smoothly, and with less backwards slip per beat cycle than did all naupliar stages. Micro-particle image velocimetry showed that cyprids generated trailing viscous vortex rings that pushed water backwards for propulsion, contrary to the nauplii's forward suction current for particle capture. Our observations highlight that zooplankton swimming performance can shift via morphological and kinematic modifications without a significant size increase. The divergence in ecological functions through ontogeny in barnacles and the removal of feeding requirement likely contributed to the evolution of the specialized, taxonomically unique cyprid phase.


Subject(s)
Swimming/physiology , Thoracica/physiology , Animals , Biomechanical Phenomena , Extremities , Hydrodynamics , Larva/physiology , Rheology , Zooplankton
10.
Proc Biol Sci ; 287(1927): 20200300, 2020 05 27.
Article in English | MEDLINE | ID: mdl-32396804

ABSTRACT

Symbiotic relations and range of host usage are prominent in coral reefs and crucial to the stability of such systems. In order to explain how symbiotic relations are established and evolve, we used sponge-associated barnacles to ask three questions. (1) Does larval settlement on sponge hosts require novel adaptations facilitating symbiosis? (2) How do larvae settle and start life on their hosts? (3) How has this remarkable symbiotic lifestyle involving many barnacle species evolved? We found that the larvae (cyprids) of sponge-associated barnacles show a remarkably high level of interspecific variation compared with other barnacles. We document that variation in larval attachment devices are specifically related to properties of the surface on which they attach and metamorphose. Mapping of the larval and sponge surface features onto a molecular-based phylogeny showed that sponge symbiosis evolved separately at least three times within barnacles, with the same adaptive features being found in all larvae irrespective of phylogenetic relatedness. Furthermore, the metamorphosis of two species proceeded very differently, with one species remaining superficially on the host and developing a set of white calcareous structures, the other embedding itself into the live host tissue almost immediately after settlement. We argue that such a high degree of evolutionary flexibility of barnacle larvae played an important role in the successful evolution of complex symbiotic relationships in both coral reefs and other marine systems.


Subject(s)
Coral Reefs , Porifera/physiology , Thoracica/physiology , Animals , Larva , Metamorphosis, Biological , Phylogeny , Symbiosis
11.
Ecotoxicol Environ Saf ; 194: 110362, 2020 May.
Article in English | MEDLINE | ID: mdl-32171964

ABSTRACT

The effects of microplastic on mortality and sublethal responses on larval development of meroplankton are still largely unknown. Present study investigated the effects of four sizes of virgin spherical polystyrene microplastics (diameter 1.7, 6.8, 10.4, 19.0 µm) on naupliar (stage II-VI) and cypris larvae of barnacle Amphibalanus amphitrite at environmentally relevant concentrations (1, 10, 100, 1000 beads mL-1). Essential life-history traits, including mortality, development time and rates of growth, settling, and metamorphosis were measured throughout the entire larval development. Feeding experiments were conducted to evaluate if microplastics decreased naupliar feeding due to physical impacts or selective feeding of nauplii. The results showed that A. amphitrite stage II nauplii were able to ingest and efficiently egest all sizes of microplastics. All the life-history endpoints measured were not significantly affected by all sizes of microplastics at any concentration tested. Presence of all sizes of microplastics did not cause physical interference on naupliar feeding and all stages of nauplius larvae (stage III-VI) did not selectively feed on microplastics. However, the feeding ability of stage III nauplius appeared to be affected by 1.7 µm at 1000 beads mL-1 which was possibly due to individual variations rather than microplastics' impacts. Overall, the full larval development of barnacle A. amphitrite was not affected by microplastics at environmentally relevant concentrations under laboratory condition.


Subject(s)
Microplastics/toxicity , Polystyrenes/toxicity , Thoracica/physiology , Animals , Larva/drug effects , Metamorphosis, Biological/drug effects , Plastics , Thoracica/drug effects , Toxicity Tests
12.
J Pediatr ; 181: 242-247.e2, 2017 02.
Article in English | MEDLINE | ID: mdl-27939124

ABSTRACT

OBJECTIVES: To assess whether ad libitum consumption of thiamin-fortified fish sauce over 6 months yields higher erythrocyte thiamin diphosphate concentrations (eTDP) among women of childbearing age and their children aged 12-59 months compared with control sauce containing no thiamin. STUDY DESIGN: In this double-blind, randomized controlled efficacy trial, 276 nonpregnant, nonlactating women (18-45 years of age) and their families in Prey Veng, Cambodia, were randomized to receive 1 of 3 fish sauce formulations: low thiamin concentration (low, 2 g/L), high thiamin concentration (high, 8 g/L), or a control (no thiamin) fish sauce. Baseline (t = 0) and endline (t = 6 months) eTDP were measured with the use of high-performance liquid chromatography with a fluorescence detector. RESULTS: Fish sauce consumption did not differ between treatment groups (P = .19). In intent-to-treat analysis, women's baseline-adjusted endline eTDP (mean; 95% CI) was higher among women in the low (259; 245-274 nmol/L) and high (257; 237-276 nmol/L) groups compared with control (184; 169-198 nmol/L; P < .001); low and high groups did not differ (P = .83). Similarly, children's baseline-adjusted eTDP was higher in the low (259; 246-271 nmol/L) and high (257; 243-270 nmol/L) groups compared with control (213; 202-224 nmol/L; P < .001). CONCLUSION: Fortified fish sauce appears to be an efficacious means of improving biochemical thiamin status in nonpregnant, nonlactating women and their children (1-5 years of age) living in rural Cambodia. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02221063.


Subject(s)
Erythrocytes/metabolism , Fish Products , Food, Fortified , Thiamine/administration & dosage , Adolescent , Adult , Animals , Cambodia , Child , Child, Preschool , Chromatography, Liquid , Double-Blind Method , Female , Humans , Infant , Middle Aged , Nutritional Status , Rural Population , Thiamine/blood , Young Adult
13.
Mol Phylogenet Evol ; 100: 292-302, 2016 07.
Article in English | MEDLINE | ID: mdl-26988415

ABSTRACT

The barnacles of the superorder Acrothoracica are small, burrowing, epibiotic, and dioecious (large female with dwarf male) crustaceans largely found in the carbonate sediments and skeletons of marine invertebrates. The acrothoracicans represent the Cirripedia with the most plesiomorphic characters and have prominently featured in phylogenetic speculations concerning these crustaceans. Traditionally, Acrothoracica was divided into two main orders, Pygophora and Apygophora. The Apygophora had uniramus cirri and no anus. The Pygophora had biramus terminal cirri and an anus and was further divided into two families, Lithoglyptidae and Cryptophialidae. Kolbasov (2009) revised the superorder Acrothoracica on the basis of morphological examinations of females, dwarf males, and cyprids and rearranged the acrothoracican species into two new orders, Lithoglyptida and Cryptophialida. The present study is the first attempt to reconstruct the phylogenetic relationships of acrothoracican barnacles by sequencing two mitochondrial (cytochrome C oxidase I and 16S ribosomal DNA) and two nuclear (18S ribosomal DNA and histone H3) markers of 8 of the 11 genera comprising 23 acrothoracican species. All monophylies of the eight acrothoracican genera sampled in this study were strongly supported. The deep interfamilial relationship constructed is consistent with the recent morphological phylogenetic relationship proposed by Kolbasov, Newman, and Høeg (Kolbasov, 2009) that Cryptophialidae (order Cryptophialida) is the sister group to all other acrothoracicans (order Lithoglyptida). According to an ancestral character state reconstruction analysis, the posterior lobes of females; armament of opercular bars, attachment stalk, lateral projections of the body, and aperture slits in dwarf males; and habitat use appear to have phylogenetic importance.


Subject(s)
Thoracica/genetics , Animals , DNA, Mitochondrial/genetics , DNA, Ribosomal/genetics , Evolution, Molecular , Female , Male , Multilocus Sequence Typing , Phylogeny , Thoracica/anatomy & histology , Thoracica/classification
14.
Biol Lett ; 12(6)2016 06.
Article in English | MEDLINE | ID: mdl-27330170

ABSTRACT

Coral-associated invertebrates are the most significant contributors to the diversity of reef ecosystems, but no studies have examined how larvae manage to settle and grow in their coral hosts. Video recordings were used to document this process in the coral barnacle Darwiniella angularis associated with the coral Cyphastrea chalcidicum Settlement and metamorphosis in feeding juveniles lasted 8-11 days and comprised six phases. The settling cyprid starts by poking its antennules into the tissue of the prospective host (I: probing stage). The coral releases digestive filaments for defence, but tolerating such attack the cyprid penetrates further (II: battling stage). Ecdysis is completed 2 days after settlement (III: carapace detachment). The barnacle becomes embedded deep in the coral tissue while completing metamorphosis between 4 and 6 days (IV: embedding stage), but reappears as a feeding juvenile 8-11 days after settlement (V: emerging stage; VI: feeding stage). Cyprids preferably settle in areas between the coral polyps, where they have a much higher survival rate than on the polyp surfaces.


Subject(s)
Anthozoa/physiology , Metamorphosis, Biological , Thoracica/physiology , Animals , Larva/growth & development , Symbiosis , Thoracica/growth & development
15.
Inorg Chem ; 55(16): 7920-7, 2016 Aug 15.
Article in English | MEDLINE | ID: mdl-27472192

ABSTRACT

A coordination polymer [Ln(C15H9O9)3(H2O)3]n (1-Ln = Eu(III), Tb(III)) assembled from benzophenonedicarboxylate was synthesized and characterized. The organic component is shown to sensitize lanthanide-based emission in both compounds, with quantum yields of 36% (Eu) and 6% (Tb). Luminescence of lanthanide coordination polymers is currently described from a molecular approach. This methodology fails to explain the luminescence of this system. It was found that the band structure of the organic component rather than the molecular triplet state was able to explain the observed luminescence. Deuterated (Ln(C15H9O9)3(D2O)3) and dehydrated (Ln(C15H9O9)3) analogues were also studied. When bound H2O was replaced by D2O, lifetime and emission increased as expected. Upon dehydration, lifetimes increased again, but emission of 1-Eu unexpectedly decreased. This reduction is reasoned through an unprecedented enhancement effect of the compound's luminescence by the OH/OD oscillators in the organic-to-Eu(III) energy transfer process.

16.
Med Law Rev ; 24(2): 143-75, 2016.
Article in English | MEDLINE | ID: mdl-27099364

ABSTRACT

In its landmark decision Carter v Canada (Attorney General), the Supreme Court of Canada ruled that the criminal prohibition on physician-assisted suicide and euthanasia for certain persons in certain circumstances violated their rights to life, liberty, and security of the person in sec. 7 of the Canadian Charter of Rights and Freedoms and thus was unconstitutional. The Supreme Court in effect overruled its earlier decision, Rodriguez v British Columbia (Attorney General), which upheld the prohibition as constitutionally valid, on the basis of changes in Charter jurisprudence and in the social facts since Rodriguez was decided. We argue that the Supreme Court's Carter decision shows conceptual disagreements with its Rodriguez decision concerning the nature and scope of the sec. 7-protected interests and the accompanying principles of fundamental justice. Not only do these conceptual differences have little to do with the changes that the Court in Carter invoked for 'revisiting' Rodriguez, the Court's articulation of the sec. 7 interests, particularly the right to life, and the principles of fundamental justice, especially the principle of over breadth, are problematic on their own terms. Furthermore, the way in which the Court dealt with evidence regarding abuses in permissive jurisdictions is also subject to criticism. We recommend that if, as now seems inevitable, legislation is introduced, it should mandate that assisted suicide and euthanasia be performed by specially licensed non-medical personnel and only on the authorization of a Superior Court judge. We also reject the key recommendations recently issued by the Provincial-Territorial Expert Advisory Group on Physician-Assisted Dying.


Subject(s)
Personal Autonomy , Right to Die , Suicide, Assisted , Canada , Euthanasia , Humans , Lawyers , Value of Life
17.
Mol Phylogenet Evol ; 82 Pt A: 324-9, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25263422

ABSTRACT

Shell structure is a crucial aspect of barnacle systematics. Within Tetraclitidae, the diametric and monometric growth patterns and number of rows of parietal tubes in the shells are key characteristics used to infer evolutionary trends. We used molecular analysis based on seven genes (mitochondrial COI, 16S and 12S rRNA, and nuclear EF1, RPII, H3, and 18S rRNA) to test two traditional phylogenetic hypothesis: (1) Tetraclitid barnacles are divided into two major lineages, which are distinguished according to monometric and diametric shell growth patterns, and (2) the evolutionary trend in shell parietal development began with a solid shell, which developed into a single tubiferous shell, which then developed into multitubiferous shells. The results indicated that Tetraclitinae and Newmanellinae are not monophyletic, but that Austrobalaninae and Tetraclitellinae are. The phylogram based on the genetic data suggested that Bathylasmatidae is nested within the Tetraclitidae, forming a sister relationship with the Austrobalaninae and Tetraclitinae/Newmanellinae clade. Within the Tetraclitinae/Newmanellinae clade, the genera Tetraclita (multitubiferous shell), Tesseropora (single tubiferous shell), and Yamaguchiella (multitubiferous shell) are polyphyletic. The results suggested that shell morphology and growth patterns do not reflect the evolutionary history of Tetraclitidae, whereas the arthropodal characteristics are informative.


Subject(s)
Animal Shells/anatomy & histology , Biological Evolution , Phylogeny , Thoracica/classification , Animals , Bayes Theorem , Cell Nucleus/genetics , DNA, Mitochondrial/genetics , Female , Likelihood Functions , Models, Genetic , Sequence Analysis, DNA , Thoracica/anatomy & histology , Thoracica/genetics
18.
Mol Phylogenet Evol ; 91: 1-11, 2015 Oct.
Article in English | MEDLINE | ID: mdl-25979758

ABSTRACT

Barnacles are exceptional in having various sexual systems (androdioecy, hermaphroditism, dioecy) and with a high morphological diversity of males, though these are always minute (dwarf) compared to their female or hermaphrodite partners. For the first time, we use a multiple DNA marker-based phylogeny to elucidate the ancestral states and evolution of (1) dwarf males, (2) their morphology when present, (3) their attachment site on the partner, and (4) habitat use in thoracican barnacles. Our taxon sampling was especially rich in rare deep-sea Scalpelliformes and comprised species with diverse sexual systems and dwarf male morphologies. Within the thoracican barnacles dwarf male evolution is subject to extensive convergence, but always correlated to similar ecological conditions. Males evolved convergently at least four times from purely hermaphroditic ancestors, in each case correlated with the invasion into habitats with low mating group sizes. The independent evolution of dwarf males in these lineages dovetails with the males having different morphologies and occurring in several different locations on their sexual partner.


Subject(s)
Biological Evolution , Thoracica/physiology , Animals , Disorders of Sex Development , Ecosystem , Female , Male , Phylogeny , Reproduction/genetics , Thoracica/anatomy & histology , Thoracica/classification , Thoracica/genetics
19.
Zootaxa ; 3972(3): 328-42, 2015 Jun 12.
Article in English | MEDLINE | ID: mdl-26249496

ABSTRACT

A new ascothoracidan species, Gorgonolaureus bicornutus sp. nov., has been discovered off south-eastern Taiwan at a depth of 227 m. Five females were found in permanent cysts on the branches of a plexaurid octocoralian alcyonacean (former "gorgonian"), Echinogorgia sp. These specimens are assigned to the genus Gorgonolaureus on account of their having an enlarged and inflated carapace with a long, slit-like aperture, long dorsal thoracic horns, no filamentary appendages associated with the first pair of thoracopods, and rudimentary telsonic spines. Gorgonolaureus bicornutus differs from its congeners in having two long, naked dorsal horns on thoracomeres 2 and 3, the number of seminal receptacles in the thoracopods, and the higher number of stout setae on the fifth antennular segment. The characters that unite the genus Gorgonolaureus are redefined as follows: i) the absence of filamentary appendages associated with the first pair of thoracopods; ii) the possession of 1-3 dorsal horns distributed singly among thoracomeres 1-3; iii) the absence of prominent proximal teeth medially on the mandibles; iv) the possession of short or rudimentary telsonic spines; and v) host preference, with most species infecting octocorals of the suborder Halaxonia (mostly of the family Plexauridae) and never the calcaxonian families Chrysogorgiidae and Isididae. The gorgonian-infecting genera Gorgonolaureus and Isidascus are Tethyan relics that have survived only in the Western Pacific and the Eastern Atlantic, respectively, while their relatives in the genera Cardomanica and Thalassomembracis have disjunct Western Atlantic/Western Pacific distributions, thus exemplifying a major pattern of Tethyan reliction.


Subject(s)
Crustacea/anatomy & histology , Animal Distribution , Animal Structures/anatomy & histology , Animal Structures/growth & development , Animals , Body Size , Crustacea/classification , Crustacea/growth & development , Female , Male , Organ Size , Taiwan
20.
Mol Phylogenet Evol ; 77: 11-22, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24636895

ABSTRACT

Coral-inhabiting barnacles (Thoracica: Pyrgomatidae) are obligatory symbionts of scleractinian and fire corals. We attempted to reconstruct the phylogeny of coral-inhabiting barnacles using a multi-locus approach (mitochondrial 12S and 16S rRNA, and nuclear EF1, H3 and RP gene sequences, total 3532bp), which recovered a paraphyletic pattern. The fire-coral inhabiting barnacle Wanella milleporae occupied a basal position with respect to the other coral inhabiting barnacles. Pyrgomatids along with the coral-inhabiting archaeobalanid Armatobalanus nested within the same clade and this clade was subdivided into two major lineages: Armatobalanus+Cantellius with species proposed to be the ancestral stock of extant coral barnacles, and the other comprising the remaining genera studied. Ancestral state reconstruction (ASR) suggested multiple independent fusions and separations of shell plates and opercular valves in coral barnacle evolution, which counters the traditional hypothesis founded on a scheme of morphological similarities. Most of the coral barnacles are restricted to one or two coral host families only, suggesting a trend toward narrow host range and more specific adaptation. Furthermore, there is a close linkage between coral host usage and phylogenetic relationships with sister taxa usually being found on the same coral host family. This suggests that symbiotic relationships in coral-inhabiting barnacles are phylogenetically conserved and that host associated specialization plays an important role in their diversification.


Subject(s)
Anthozoa/physiology , Phylogeny , Thoracica/genetics , Animals , Genetic Loci , Host Specificity , Symbiosis , Thoracica/anatomy & histology
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