ALBERT

Description: In type 2 diabetes, hyperuricemia is associated with cardiovascular disease (CVD) and the metabolic syndrome (MetS), but associations in type 1 diabetes (T1D) have not been well-defined. This study examined the relationships between serum urate (SU) concentrations, clinical and biochemical factors, and subsequent cardiovascular events in a well-characterized cohort of adults with T1D. In 973 participants with T1D in the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications Study (DCCT/EDIC), associations were defined between SU, measured once in blood collected 1997–2000, and (a) concurrent MetS and (b) incident ‘any CVD’ and major adverse cardiovascular events (MACE) through 2013. SU was higher in men than women [mean (SD): 4.47 (0.99) vs. 3.39 (0.97) mg/dl, respectively, p 

Description: Chronic natural killer large granular lymphocyte (NK-LGL) leukemia, also referred to as chronic lymphoproliferative disorder of NK cells, is a rare disorder defined by prolonged expansion of clonal NK cells. Similar prevalence of STAT3 mutations in chronic T-LGL and NK-LGL leukemia is suggestive of common pathogenesis. We undertook whole-genome sequencing to identify mutations unique to NK-LGL leukemia. The results were analyzed to develop a resequencing panel that was applied to 58 patients. Phosphatidylinositol 3-kinase pathway gene mutations (PIK3CD/PIK3AP1) and TNFAIP3 mutations were seen in 5% and 10% of patients, respectively. TET2 was exceptional in that mutations were present in 16 (28%) of 58 patient samples, with evidence that TET2 mutations can be dominant and exclusive to the NK compartment. Reduced-representation bisulfite sequencing revealed that methylation patterns were significantly altered in TET2 mutant samples. The promoter of TET2 and that of PTPRD, a negative regulator of STAT3, were found to be methylated in additional cohort samples, largely confined to the TET2 mutant group. Mutations in STAT3 were observed in 19 (33%) of 58 patient samples, 7 of which had concurrent TET2 mutations. Thrombocytopenia and resistance to immunosuppressive agents were uniquely observed in those patients with only TET2 mutation (Games-Howell post hoc test, P = .0074; Fisher’s exact test, P = .00466). Patients with STAT3 mutation, inclusive of those with TET2 comutation, had lower hematocrit, hemoglobin, and absolute neutrophil count compared with STAT3 wild-type patients (Welch’s t test, P ≤ .015). We present the discovery of TET2 mutations in chronic NK-LGL leukemia and evidence that it identifies a unique molecular subtype.

Description: The large declines in Arctic sea-ice age and extent over the last decades could have altered the diversity of sea-ice associated unicellular eukaryotes (referred to as seaice protists). A time series from the Russian ice-drift stations from the 1980s to the 2010s revealed changes in community composition and diversity of sea-ice protists from the Central Arctic Ocean. However, these observations have been biased by varying levels of taxonomic resolution and sampling effort, both of which were higher in the early years at drift stations on multiyear sea ice (MYI) in the Central Arctic Ocean. We here combine the Russian ice-drift station data with more recent data to (1) identify common sea-ice protists (in particular diatoms) in drifting sea ice of the Central Arctic Ocean; (2) characterize the potential change in such communities over 35 years in terms of species number and/or community structure; and (3) relate those shifts to relevant environmental factors. In terms of relative abundance, pennate diatoms were the most abundant sea-ice protists across the Arctic, contributing 60% on average of counted cells. Two pennate colony-forming diatom species, Nitzschia frigida and Fragilariopsis cylindrus, dominated at all times, but solitary diatom species were also frequently encountered, e.g., Cylindrotheca closterium and Navicula directa. Multiyear sea ice contained 39% more diatom species than first-year ice (FYI) and showed a relatively even distribution along entire sea-ice cores. The decrease in MYI over the last decades explained the previously reported decreases in sea-ice protist diversity. Our results also indicate that up to 75% of diatom species are incorporated into FYI from the surrounding sea ice and the water column within a few months after the initial formation of the ice, while the remaining 25% are incorporated during ice drift. Thus, changing freeze-up scenarios, as currently witnessed in the Central Arctic, might result in long-term changes of the biodiversity of sea-ice protists in this region.

Description: An ecosystem approach to fisheries management requires an understanding of the impact of predatory fishes on the underlying prey resources. Defining trophic connections and measuring rates of food consumption by apex predators lays the groundwork for gaining insight into the role of predators and commercial fisheries in influencing food web structure and ecosystem dynamics.We analyzed the stomach contents of 545 common dolphinfish (Coryphaena hippurus) sampled from 74 sets of tuna purse-seine vessels fishing in the eastern Pacific Ocean (EPO) over a 22-month period. Stomach fullness of these dolphinfish and digestion state of the prey indicated that diel feeding periodicity varied by area and may be related to the digestibility and energy content of the prey. Common dolphinfish in the EPO appear to feed at night, as well as during the daytime. We analyzed prey importance by weight, numbers, and frequency of occurrence for five regions of the EPO. Prey importance varied by area. Flyingfishes, epipelagic cephalopods, tetraodontiform fishes, several mesopelagic fishes, Auxis spp., and gempylid fishes predominated in the diet. Ratios of prey length to predator length ranged from 0.014 to 0.720. Consumption-rate estimates averaged 5.6% of body weight per day. Stratified by sex, area, and length class, daily rations ranged up to 9.6% for large males and up to 19.8% for small dolphinfish in the east area (0–15°N, 111°W–coastline). Because common dolphinfish exert substantial predation pressure on several important prey groups, we concluded that their feeding ecology provides important clues to the pelagic food web and ecosystem structure in the EPO.

Description: Paper presented at: Caribbean Marine Protected Areas : Proceedings of a Symposium at the 54th Annual Meeting of the Gulf and Caribbean Fisheries Institute, Turks and Caicos, November 2001.

Description: English:Recent calls for a more holistic approach to fisheries management have motivated developmentof trophic mass-balance models of ecosystems that underlie fisheries production. We developeda model hypothesis of the pelagic ecosystem in the eastern tropical Pacific Ocean (ETP) togain insight into the relationships among the various species in the system and to explore the ecologicalimplications of alternative methods of harvesting tunas. We represented the biomasses ofand fluxes between the principal elements in the ecosystem with Ecopath, and examined theecosystem's dynamic, time-series behavior with Ecosim. We parameterized the model for 38species or groups of species, and described the sources, justifications, assumptions, and revisionsof our estimates of the various parameters, diet relations, fisheries landings, and fisheries discardsin the model. We conducted sensitivity analyses with an intermediate version of the model,for both the Ecopath mass-balance and the dynamic trajectories predicted by Ecosim. The analysisshowed that changes in the basic parameters for two components at middle trophic levels,Cephalopods and Auxis spp., exert the greatest influence on the system. When the CephalopodQ/B and Auxis spp. P/B were altered from their initial values and the model was rebalanced, thetrends of the biomass trajectories predicted by Ecosim were not sensitive, but the scaling was sensitivefor several components. We described the review process the model was subjected to, whichincluded reviews by the IATTC Purse-seine Bycatch Working Group and by a working group supportedby the National Center for Ecological Analysis and Synthesis. We fitted the model to historicaltime series of catches per unit of effort and mortality rates for yellowfin and bigeye tunasin simulations that incorporated historical fishing effort and a climate driver to represent theeffect of El Niño-Southern Oscillation-scale variation on the system. The model was designed toevaluate the possible ecological implications of fishing for tunas in various ways. We recognizethat a model cannot possibly represent all the complexity of a pelagic ocean ecosystem, but webelieve that the ETP model provides insight into the structure and function of the pelagic ETP.Spanish:Llamamientos recientes hacia un enfoque más holístico al ordenamiento de la pesca hanmotivado el desarrollo de modelos tróficos de balance de masas de los ecosistemas que sostienenla producción pesquera. Desarrollamos una hipótesis modelo del ecosistema pelágico en el OcéanoPacífico oriental tropical (POT) con miras a mejorar los conocimientos de las relaciones entre lasdistintas especies en el sistema y explorar las implicaciones ecológicas de métodos alternativos decapturar atunes. Con Ecopath representamos las biomasas de los elementos principales en el ecosistema,y los flujos entre los mismos, y con Ecosim examinamos el comportamiento dinámico delecosistema con el tiempo. Parametrizamos el modelo para 38 especies o grupos de especies(denominados “componentes” del modelo), y describimos las fuentes, justificaciones, supuestos, yrevisiones de nuestras estimaciones de los distintos parámetros, relaciones basadas en dieta, capturasretenidas de las pesquerías, y descartes de las mismas en el modelo. Realizamos análisis desensibilidad con una versión intermedia del modelo, para el balance de masas de Ecopath y lastrayectorias dinámicas predichas por Ecosim también. El análisis demostró que cambios en losparámetros básicos para dos componentes en niveles tróficos medianos, Cefalópodos y Auxis spp.,ejercieron la mayor influencia sobre el sistema. Cuando se alteraron el Q/B de los Cefalópodos yel P/B de los Auxis spp. de sus valores iniciales y se balanceó el modelo de nuevo, las tendenciasde las trayectorias de la biomasa predichas por Ecosim no fueron sensibles, pero la escala fue sensiblepara varios componentes. Describimos el proceso de revisión al que fue sujeto el modelo,inclusive revisiones por el Grupo de Trabajo sobre Captura Incidental de la CIAT y un grupo detrabajo apoyado por el Centro Nacional para Síntesis y Análisis Ecológicos. Ajustamos el modeloa series de tiempo históricas de capturas por unidad de esfuerzo y tasas de mortalidad de atunesaleta amarilla y patudo en simulaciones que incorporaron esfuerzo de pesca histórico e impulsosclimáticos para representar el efecto de variaciones a escala de El Niño-Oscilación del Sur sobreel sistema. El modelo fue diseñado para evaluar las posibles implicaciones ecológicas de la pescaatunera de varias formas. Reconocemos la imposibilidad de que el modelo represente toda la complejidadde un ecosistema oceánico pelágico, pero creemos que el modelo del POT mejora losconocimientos de la estructura y función del POT pelágico.

Description: This article is bilingual and contains both English and Spanish translations.

Description: Distribution and prevalence of the phoretic barnacle Xenobalanus on cetacean species are reported for 22 cetaceans in the eastern tropical Pacific Ocean (21 million km2). Four cetacean species are newly reported hosts for Xenobalanus: Bryde’s whale (Balaenoptera edeni), long-beakedcommon dolphin (Delphinus capensis), humpback whale (Megaptera novaeangliae), and spinner dolphin (Stenella longirostris). Sightings of Xenobalanus in pelagic waters are reported for the first time, and concentrations were located within three productive zones: near the Baja California peninsula, the Costa Rica Dome and waters extending west along the 10°N Thermocline Ridge, and nearPeru and the Galapagos Archipelago. Greatest prevalence was observed on blue whales (Balaenoptera musculus) indicating that slow swim speeds are not necessary for effective barnacle settlement. Overall, prevalence and prevalence per sighting were generally lower than previously reported.The number of barnacles present on an individual whale was greatest for killer whales, indicating that Xenobalanus larvae may be patchily distributed. The broad geographicdistribution and large number of cetacean hosts, indicate an extremely cosmopolitan distribution. A betterunderstanding of the biology of Xenobalanus is needed before this species can be used as a biological tag.

Description: In this study we describe the courtship and spawning behaviors of captive yellowfin tuna (Thunnus albacares), their spawning periodicity, the influence of physical and biological factors on spawning and hatching, and egg and early-larval development of this species at the Achotines Laboratory, Republic of Panama, during October 1996 through March 2000. Spawning occurred almost daily over extended periods and at water temperatures from 23.3° to 29.7°C. Water temperature appeared to be the main exogenous factor controlling the occurrence and timing of spawning. Courtship and spawning behaviors were ritualized and consistent among three groups of broodstock over 3.5 years. For any date, the time of day of spawning (range: 1330 to 2130 h) was predictable from mean daily water temperature, and 95% of hatching occurred the next day between 1500 and 1900 h. We estimated that females at first spawning averaged 1.6−2.0 years of age. Over short time periods (〈1 month), spawning females increased their egg production from 30% to 234% in response to shortterm increases in daily food ration of 9% to 33%. Egg diameter, notochord length (NL) at hatching, NL at first feeding, and dry weights of these stages were estimated. Water temperature was significantly, inversely related to egg size, egg-stage duration, larval size at hatching, and yolksac larval duration.