Carmel Bay : oceanographic dynamics and nutrient transport in a small embayment of the central California coast

Using an extensive mooring time series from the outer edge of Stillwater Cove, this study investigated the oceanographic dynamics and their contribution to nutrient delivery in Carmel Bay. Carmel Bay is small embayment located at the northern end of the Big Sur coast, and it is distinguished by having a submarine canyon within extremely close proximity to the beach. This embayment is open to open ocean coastal California Current conditions; however, it also provides a sheltered environment from wind and swell. No previous studies have been conducted on the circulation features of Carmel Bay and Stillwater Cove, and HF radar coverage does not extend into Carmel Bay. Point source mooring time series measurements were used to explain in great detail the temporal variability of hydrographic conditions and nutrient delivery to Stillwater Cove and Carmel Bay. A model was developed to estimate the annual nutrient delivery budget in Stillwater Cove due to internal waves, upwelling, and terrestrial sources. Consistent internal waves were observed in Stillwater Cove during stratified conditions, and vertical velocities due to internal tidal pumping in Carmel Canyon were 15 m/hr. The spatial variability of the internal tide at locations spanning the greater Monterey Bay was also examined. Locations within close proximity to submarine canyons had an additional source of nutrients via internal waves, while locations on the shelf lacked this mechanism and had to rely on upwelling alone

TARGETING THE CELLULAR REDOX ENVIRONMENT: A NOVEL APPROACH FOR THE TREATMENT OF HEMATOPOIETIC NEOPLASMS

Hematopoietic stem cells (HSCs) that function to maintain the hematopoietic compartment through self-renewal and differentiation capacities, as well as their downstream progeny, are susceptible to transformation resulting in the generation of the leukemic stem cell (LSC). Chief in the factors that control HSC regulation and protection of the HSC compartment is the cellular redox environment. Deregulation of the Hematopoietic Stem/Progenitor Cell (HSPC) redox environment results in loss of HSPC function and exhaustion. The characteristic developments of HSPC exhaustion via exposure to redox stress closely mirror phenotypic traits of hematopoietic malignancies, presenting the HSPC/LSC redox environment as a potential therapeutic target. While myelosuppression and HSPC exhaustion are detrimental side effects of classical chemotherapies, new approaches that differentially modify the HSPC/LSC redox environment may demonstrate LSC cytotoxicity while offering protection of normal HSPC function via differential activation of internal signaling pathways. Precisely how the redox environment and downstream signaling events are affected by these treatments remains unclear; thus highlighting the need for robust methods that evaluate the HSPC/LSC redox state. Because the glutathione (GSH), glutathione disulfide (GSSG) redox couple heavily contributes to the management of HSPC function and redox environment, characterizing the GSH/GSSG redox potential at the HSPC level would provide great insight for therapeutic opportunities. However, accurate measurement the GSH/GSSG redox potential within HSPCs/LSCs has been difficult due to their inherently low numbers. Here, we describe the development and validation of a sensitive method used for the direct and simultaneous quantitation of both oxidized and reduced GSH via LC-MS/MS. We use these methodologies to establish a difference in GSH-GSSG half-cell reduction potentials between normal and malignant HSPCs and examine the therapeutic effect of a redox active MnSOD mimetic, Mn(III) mesotetrakis (N-n-butoxyethylpyridinium-2yl) porphyrin, MnTnBuOE-2-PyP5+ (MnP), within these populations in vitro as well as within a human xenograft model in vivo. MnP demonstrates significant cytotoxic effects in several malignant models, while inducing an opposite cytoprotective effect in normal HSPC populations. The GSH/GSSG redox balance, specifically managed by glutathione reductase activity, is identified as a determining factor of MnP efficacy in various malignant populations. Treatment of the human myelodysplastic cell line (MDSL) offers mechanistic insights into MnP efficacy through hydrogen peroxide mediated activation of activator protein 1 (AP-1) signaling. We identify the redox dependent activation of JunB, a known regulator of normal myeloid lineage HSC proliferation, as a transcriptional mechanistic mediator of MnP treatment induced AP-1 signaling resulting in malignant cytotoxicity. The development of this novel method allowing for the identification of targetable differences between normal and malignant cell populations has provided insight to the underpinnings of potential redox based therapies. Additionally, the finding that MnP can target varying cellular redox states and exert selective cytotoxicity in malignant over normal populations by re-gaining lost control of AP-1 signaling demonstrates the potential for development of safe therapeutics within a variety of clinical applications

Thermal Characteristics of Lithium Indium Diselenide and Lithium Indium Gallium Diselenide Neutron Detection Crystals

Tracking special nuclear materials (SNM) has never been more important than in the 21st century where information is transferred rapidly around the globe. Tracking SNM is important to nuclear power, weapons, medicine, and science. Neutron and gamma ray detection are the primary methods of detecting SNM. Increased movement and availability of SNM have increased the demand for radiation detection systems beyond the capacity of traditional neutron detection technologies (3He) [Helium three]. Many alternative neutron detection materials are being considered, including 6LiInSe2 [Lithium Indium Diselenide grown with lithium enriched in lithium six] and its derivative 6LiIn1-xGaxSe2 [Lithium Indium Gallium Diselenide: where the x represents varying concentrations of each constituent]. The research herein describes thermal transport and expansion properties of these materials to help better inform both crystal growers and detection designers. While preliminary reports indicate promising detection properties, improvements in crystal size and quality are required to improve neutron detection charge collection efficiency for nonproliferation applications

Tendencias en la variabilidad de la temperatura superficial del mar en la costa de Ecuador: Tendencies in the variability of the sea surface temperature in the coast of Ecuador

Datos  de  temperatura superficial  del  mar  de  siete  regiones adyacentes (Boxes) que abarcan la costa de Ecuador han sido examinados en busca de tenencias a largo plazo y características relacionadas. El área de estudio se extiende desde los 84°W y entre las latitudes 4° S a 2° N. La información fue promediada mensualmente cubriendo un período comprendido entre los años 1900 hasta 2014. La temperatura superficial del mar  generalmente en  Ecuador aumenta hacia la costa y disminuye hacia  el sur. Se identifican los principales eventos de calentamiento de “El Niño Oscilación del Sur”, en  particular  los  ocurridos  entre  1982-1983  y  1997-1998. En la mayoría de los casos las tendencias muestran que la temperatura superficial   del  mar aumentó más   rápidamente durante los primeros años de los registros que durante los años posteriores. Palabras clave: Variabilidad de la TSM, ENOS, Descomposición de modo empírico, Regresión Lowess, Ecosistemas marinos

Mangrove dispersal disrupted by projected changes in global seawater density

The degree to which the distribution of mangrove forests will be impacted by climate change depends on the dispersal and establishment of sea-faring propagules, which drive forest rejuvenation, gene flow and range expansion. Climate change affects sea surface density via changes in temperature and salinity. However, these changes have not been mapped and it remains unclear how these factors may impact mangrove propagule dispersal. Here, we provide evidence for strong warming of coastal mangrove waters and elevated geographic variability in surface ocean density under representative concentration pathway RCP 8.5 by 2100. The largest changes will occur in the Indo West Pacific region, the primary hotspot of mangrove diversity. By comparing propagule densities to predicted sea surface density, we assessed potential effects on mangrove propagule dispersal. In the future, a warmer and fresher ocean is likely to alter dispersal trajectories of mangrove propagules and increase rates of sinking in unsuitable offshore locations, potentially reducing the resilience of mangrove forests

Greenland Subglacial Discharge as a Driver of Hotspots of Increasing Coastal Chlorophyll Since the Early 2000s

Subglacial discharge emerging from the base of Greenland\u27s marine-terminating glaciers drives upwelling of nutrient-rich bottom waters to the euphotic zone, which can fuel nitrate-limited phytoplankton growth. Here, we use buoyant plume theory to quantify this subglacial discharge-driven nutrient supply on a pan-Greenland scale. The modeled nitrate fluxes were concentrated in a few critical systems, with half of the total modeled nitrate flux anomaly occurring at just 14% of marine-terminating glaciers. Increasing subglacial discharge fluxes results in elevated nitrate fluxes, with the largest flux occurring at Jakobshavn Isbræ in Disko Bay, where subglacial discharge is largest. Subglacial discharge and nitrate flux anomaly also account for significant temporal variability in summer satellite chlorophyll a (Chl) within 50 km of Greenland\u27s coast, particularly in some regions in central west and northwest Greenland

Codesigned Shared Decision-Making Diabetes Management Plan Tool for Adolescents With Type 1 Diabetes Mellitus and Their Parents: Prototype Development and Pilot Test

Background: Adolescents with type 1 diabetes mellitus have difficulty achieving optimal glycemic control, partly due to competing priorities that interfere with diabetes self-care. Often, significant diabetes-related family conflict occurs, and adolescents’ thoughts and feelings about diabetes management may be disregarded. Patient-centered diabetes outcomes may be better when adolescents feel engaged in the decision-making process. Objective: The objective of our study was to codesign a clinic intervention using shared decision making for addressing diabetes self-care with an adolescent patient and parent advisory board. Methods: The patient and parent advisory board consisted of 6 adolescents (teens) between the ages 12 and 18 years with type 1 diabetes mellitus and their parents recruited through our institution’s Pediatric Diabetes Program. Teens and parents provided informed consent and participated in 1 or both of 2 patient and parent advisory board sessions, lasting 3 to 4 hours each. Session 1 topics were (1) patient-centered outcomes related to quality of life, parent-teen shared diabetes management, and shared family experiences; and (2) implementation and acceptability of a patient-centered diabetes care plan intervention where shared decision making was used. We analyzed audio recordings, notes, and other materials to identify and extract ideas relevant to the development of a patient-centered diabetes management plan. These data were visually coded into similar themes. We used the information to develop a prototype for a diabetes management plan tool that we pilot tested during session 2. Results: Session 1 identified 6 principal patient-centered quality-of-life measurement domains: stress, fear and worry, mealtime struggles, assumptions and judgments, feeling abnormal, and conflict. We determined 2 objectives to be principally important for a diabetes management plan intervention: (1) focusing the intervention on diabetes distress and conflict resolution strategies, and (2) working toward a verbalized common goal. In session 2, we created the diabetes management plan tool according to these findings and will use it in a clinical trial with the aim of assisting with patient-centered goal setting. Conclusions: Patients with type 1 diabetes mellitus can be effectively engaged and involved in patient-centered research design. Teens with type 1 diabetes mellitus prioritize reducing family conflict and fitting into their social milieu over health outcomes at this time in their lives. It is important to acknowledge this when designing interventions to improve health outcomes in teens with type 1 diabetes mellitus

Improved representation of river runoff in Estimating the Circulation and Climate of the Ocean Version 4 (ECCOv4) simulations: Implementation, evaluation, and impacts to coastal plume regions

In this study, we improve the representation of global river runoff in the Estimating the Circulation and Climate of the Ocean Version 4 (ECCOv4) framework, allowing for a more realistic treatment of coastal plume dynamics. We use a suite of experiments to explore the sensitivity of coastal plume regions to runoff forcing, model grid resolution, and grid type. The results show that simulated sea surface salinity (SSS) is reduced as the model grid resolution increases. Compared to Soil Moisture Active Passive (SMAP) observations, simulated SSS is closest to SMAP when using daily, point-source runoff (DPR) and the intermediate-resolution LLC270 grid. The Willmott skill score, which quantifies agreement between models and SMAP, yields up to 0.92 for large rivers such as the Amazon. There was no major difference in SSS for tropical and temperate coastal rivers when the model grid type was changed from the ECCO v4 latitude-longitude-polar-cap grid to the ECCO2 cube-sphere grid. We also found that using DPR forcing and increasing model resolution from the coarse-resolution LLC90 grid to the intermediate-resolution LLC270 grid elevated the river plume area, volume, stabilized the stratification and shoal the mixed layer depth (MLD). Additionally, we find that the impacts of increasing model resolution from the intermediate-resolution LLC270 grid to the high-resolution LLC540 grid are regionally dependent. The Mississippi River Plume is more sensitive than other regions, possibly because the wider and shallower Texas-Louisiana shelf drives a stronger baroclinic effect, as well as relatively weak sub-grid vertical mixing and adjustment in this region. Since rivers deliver large amounts of freshwater and anthropogenic materials to coastal regions, improving the representation of river runoff in global, high-resolution models will advance studies of coastal hypoxia, carbon cycling, and regional weather and climate and will ultimately help to predict land-ocean-atmospheric feedbacks seamlessly in the next generation of Earth system models

Eubacterial SpoVG homologs constitute a new family of site-specific DNA-binding proteins

A site-specific DNA-binding protein was purified from Borrelia burgdorferi cytoplasmic extracts, and determined to be a member of the highly conserved SpoVG family. This is the first time a function has been attributed to any of these ubiquitous bacterial proteins. Further investigations into SpoVG orthologues indicated that the Staphylococcus aureus protein also binds DNA, but interacts preferentially with a distinct nucleic acid sequence. Site-directed mutagenesis and domain swapping between the S. aureus and B. burgdorferi proteins identified that a 6-residue stretch of the SpoVG α-helix contributes to DNA sequence specificity. Two additional, highly conserved amino acid residues on an adjacent β-sheet are essential for DNA-binding, apparently by contacts with the DNA phosphate backbone. Results of these studies thus identified a novel family of bacterial DNA-binding proteins, developed a model of SpoVG-DNA interactions, and provide direction for future functional studies on these wide-spread proteins

Electrochemical Oxidation of Metal Carbides in Aqueous Solutions

Transition metal carbides have unique properties such as high hardness, high melting temperatures, high thermal conductivity, and high chemical stability. In this report, we investigate the electrochemical oxidation of a series of metal carbides including NbC, Nb2C, TaC, Ta2C, VC, VCrC, TiC and TiCrC in neutral, basic, or acidic aqueous solutions. Cyclic voltammetry and elemental analysis demonstrated that many of these metal carbides can be electrochemically oxidized at low electrode potentials to produce soluble metal ions in the solutions. Carbon in the metal carbides remains on the electrode substrates and forms porous carbide-derived carbon (CDC). The surface morphology of the CDC and specific surface area depend on the metal carbide precursors and the electrochemical oxidation conditions