Publications by authors named "Douglas Adams"

Article Synopsis
  • The study examines the genetic diversity and distribution of the endangered bonnethead shark, Sphyrna tiburo, in the western Atlantic, revealing it consists of three independent lineages, particularly distinguishing a unique Brazilian cluster.
  • Researchers utilized mitochondrial sequences and Bayesian analyses to trace the evolutionary history and dispersal of S. tiburo, suggesting it originated in the northern region and spread southward due to geological changes over the last 5 million years.
  • Findings indicate that environmental factors like ocean currents and freshwater discharge (especially from the Amazon-Orinoco Plume) played significant roles in the diversification and genetic structuring of the bonnethead shark populations.
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Genome-wide association studies typically evaluate the autosomes and sometimes the X Chromosome, but seldom consider the Y or mitochondrial (MT) Chromosomes. We genotyped the Y and MT Chromosomes in heterogeneous stock (HS) rats (Rattus norvegicus), an outbred population created from 8 inbred strains. We identified 8 distinct Y and 4 distinct MT Chromosomes among the 8 founders.

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Article Synopsis
  • The study examines genetic variation in gafftopsail catfish from the U.S. Atlantic and Gulf of Mexico, using genomic data to identify both neutral and adaptive patterns.
  • Four distinct genetic groups were identified: the U.S. Atlantic, northeastern Gulf, northwestern Gulf, and southern Gulf.
  • Results indicate a recent decline in effective population size in the Atlantic region, likely linked to a population reduction driven by an epizootic, highlighting the role of habitat and life stages in shaping genetic structure.
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The ecology and life-histories of white sharks make this species susceptible to mercury bioaccumulation; however, the health consequences of mercury exposure are understudied. We measured muscle and plasma total mercury (THg), health markers, and trace minerals in Northwest Atlantic white sharks. THg in muscle tissue averaged 10.

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Differentiation and optimal function of osteoblasts and osteoclasts are contingent on synthesis and maintenance of a healthy proteome. Impaired and/or altered secretory capacity of these skeletal cells is a primary driver of most skeletal diseases. The endoplasmic reticulum (ER) orchestrates the folding and maturation of membrane as well as secreted proteins at high rates within a calcium rich and oxidative organellar niche.

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Isolated cases of skin pigment disorders, including leucism, in sharks and rays have been reported for multiple species. Nonetheless, the morphological basis behind these chromatic anomalies has not been examined histologically. In this study, the authors quantified and compared the presence of melanin in multiple tissue samples of leucistic and fully pigmented blacktip sharks Carcharhinus limbatus.

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Background: The Brazilian cownose ray, Rhinoptera brasiliensis has undergone a global population reduction and is currently classified by IUCN as Vulnerable. This species is sometimes confused with Rhinoptera bonasus, the only external diagnostic characteristic to distinguish between both species is the number of rows of tooth plates. Both cownose rays overlap geographically from Rio de Janeiro to the western North Atlantic.

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1-Aminocyclopropanecarboxylate (ACC) synthase, which catalyzes the conversion of S-adenosylmethionine (SAM) to ACC and methylthioadenosine, was demonstrated in tomato extract. Methylthioadenosine was then rapidly hydrolyzed to methylthioribose by a nucleosidase present in the extract. ACC synthase had an optimum pH of 8.

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Following the discontinuation of commercial polybrominated diphenyl ether (PBDE) mixtures, a variety of alternative flame retardants (FRs) have been developed and employed. To understand the contamination status of these emerging FRs in marine fish and wildlife, we investigated their bioaccumulation in four shark species, including shortfin mako shark (Isurus oxyrhinchus; n = 26), porbeagle (Lamna nasus; n = 4), sandbar shark (Carcharhinus plumbeus; n = 6), and common thresher (Alopias vulpinus; n = 4), from coastal and offshore waters of the western North Atlantic Ocean. Median concentrations of emerging FRs, including dechlorane analogues (i.

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Halogenated organic compounds (HOCs) in marine species collected from the Atlantic Ocean [3 shortfin mako () and 1 porbeagle ()], and 12 sea turtles collected from the Pacific Ocean [3 loggerhead (), 3 green (), 3 olive ridley (), and 3 hawksbill ()] were analyzed with a nontargeted analytical method using two-dimensional gas chromatography coupled to high-resolution time-of-flight mass spectrometry. Sharks and sea turtles had distinct HOC profiles. Halogenated methoxyphenols (halo-MeOPs) were the most abundant compound class identified in sea turtle livers, while polychlorinated biphenyls (PCBs) were the most abundant in shark livers.

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Background: Elasmobranchs are particularly vulnerable to environmental metal contamination, accumulating these contaminants at high rates and excreting them slowly. The blue shark Prionace glauca L. is one of the most heavily fished elasmobranchs, although information regarding metal contamination and detoxification in this species is notably lacking.

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Elasmobranch ecotoxicological investigations are complicated because accessing organs that accumulate organic contaminants is usually lethal. Several metrics among liver, muscle, and brain were evaluated to determine their relative organic contaminant loads and the efficacy of using muscle as a non-lethal proxy for liver. Liver contained the highest concentrations (368-4020 ng/g wet weigth [ww]) and greatest estimated total load of contaminants.

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We report for the first time a highly divergent lineage in the Caribbean Sea for the bull shark (Carcharhinus leucas) based on the analysis of 51 mitochondrial DNA genomes of individuals collected in the western North Atlantic. When comparing the mtDNA control region obtained from the mitogenomes to sequences reported previously for Brazil, the Caribbean lineage remained highly divergent. These results support the existence of a discrete population in Central America due to a phylogeographic break separating the Caribbean Sea from the western North Atlantic, Gulf of Mexico and South America.

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Congenital methemoglobinemia is a rare disease characterized by cyanosis and a left shifting of the oxyhemoglobin dissociation curve. The disease necessitates avoidance of certain medications commonly used in obstetrics, making labor analgesia and anesthesia challenging. We present a case report of peripartum anesthetic management of a pregnant patient with congenital methemoglobinemia type 1 who received remifentanil labor analgesia and continuous methemoglobin monitoring.

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The Indian River Lagoon (IRL), located on the east coast of Florida, is a complex estuarine ecosystem that is negatively affected by recurring harmful algal blooms (HABs) from distinct taxonomic/functional groups. Enhanced monitoring was established to facilitate rapid quantification of three recurrent bloom taxa, , , and spp., and included corroborating techniques to improve the identification of small-celled nanoplankton (<10 μm in diameter).

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Given the prevalence and the scope of the personal and societal burden of osteoarthritis (OA), investigators continue to be deeply interested in understanding the pathogenic basis of disease and developing novel disease modifying OA therapies. Because joint trauma/injury is considered a leading predisposing factor in the development of OA, and since posttraumatic OA is one of the most common forms of OA in general, large animal and rodent models of knee injury that accurately recapitulate the OA disease process have become increasingly widespread over the past decade. To enable study in the context of defined genetic backgrounds, investigative teams have developed standardized protocols for injuring the mouse knee that aim to induce a reproducible degenerative process both in terms of severity and temporal pacing of disease progression.

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The IMPC/KOMP program provides the opportunity to screen mice harboring well defined gene-inactivation mutations in a uniform genetic background. The program performs a global tissue phenotyping survey that includes skeletal x-rays and bone density measurements. Because of the relative insensitivity of the two screening tests for detecting variance in bone architecture, we initiated a secondary screen based on μCT and a cryohistolomorphological workflow that was performed on the femur and vertebral compartments on 220 randomly selected knockouts (KOs) and 36 control bone samples over a 2 1/2 year collection period provided by one of the production/phenotyping centers.

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Despite indications that sharks have an exceptional capacity to heal from traumatic injuries, no detailed microscopic observations of integumental wounds have been reported for sharks. This study details the histopathological features of such wounds in a free-ranging shark. An adult male Blacktip Shark Carcharhinus limbatus was collected in 2017 during fisheries-independent sampling efforts in the coastal southeastern U.

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Two of the world most endangered marine and terrestrial species are at the brink of extinction. The vaquita (Phocoena sinus) is the smallest existing cetacean and the population has declined to barely 22 individuals now remaining in Mexico's Gulf of California. With the ongoing decline, it is likely to go extinct within few years.

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Objective: To compare postoperative arterial blood gas samples and requirement for respiratory support between patients who received sugammadex versus neostigmine reversal before extubation after congenital cardiac surgery.

Design: Retrospective, cross-sectional study.

Setting: Single-center, university-based, tertiary care hospital.

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Fracture healing involves interactions of different cell types, driven by various growth factors, and signaling cascades. Periosteal mesenchymal progenitor cells give rise to the majority of osteoblasts and chondrocytes in a fracture callus. Notch signaling has emerged as an important regulator of skeletal cell proliferation and differentiation.

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