Forecasted Shifts in Thermal Habitat for Cod Species in the Northwest Atlantic and Eastern Canadian Arctic

Climate change will alter ecosystems and impose hardships on marine resource users as fish assemblages redistribute to habitats that meet their physiological requirements. Marine gadids represent some of the most ecologically and socio-economically important species in the North Atlantic, but face an uncertain future in the wake of rising ocean temperatures. We applied CMIP5 ocean temperature projections to egg survival and juvenile growth models of three northwest Atlantic coastal species of gadids (Atlantic cod, Polar cod, and Greenland cod), each with different thermal affinities and life histories. We illustrate how physiologically based species distribution models (SDMs) can be used to predict habitat distribution shifts and compare vulnerabilities of species and life stages with changing ocean conditions. We also derived an integrated habitat suitability index from the combined surfaces of each metric to predict areas and periods where thermal conditions were suitable for both life stages. Suitable thermal habitat shifted poleward for the juvenile life stages of all three species, but the area remaining differed across species and life stages through time. Arctic specialists like Polar cod are predicted to experience reductions in suitable juvenile habitat based on metrics of egg survival and growth potential. In contrast, habitat loss in boreal and subarctic species like Atlantic cod and Greenland cod may be dampened due to increases in suitable egg survival habitats as suitable juvenile growth potential habitats decrease. These results emphasize the need for mechanistic SDMs that can account for the combined effects of changing seasonal thermal requirements under varying climate change scenarios.publishedVersio

Evaluation of liposomes for the enrichment of rotifers (Brachionus sp.) with taurine and their subsequent effects on the growth and development of northern rock sole (Lepidopsetta polyxystra) larvae

The naturally occurring taurine concentrations of rotifers (Brachionus sp.) may not be sufficient to meet the nutritional demands of several species of marine fish larvae. In this study, we evaluated the use of liposomes for taurine-enrichment of rotifers and compared them with standard methods in which taurine was dissolved in the rotifer enrichment water i.e., the “dissolved method”. Each enrichment method was further evaluated by determining the growth performance of northern rock sole (Lepidopsetta polyxystra) larvae fed on the taurine-enriched rotifers. Results indicated that rotifers enriched with taurine-containing liposomes obtained approximately 1.2% taurine on a dry weight basis, similar to the upper concentrations reported in wild copepods and approximately 10-fold higher than in control rotifers. Northern rock sole larvae grew significantly larger, were more developed and had higher whole body taurine concentrations when fed rotifers enriched with taurine-containing liposomes, compared to larvae fed either unenriched rotifers or rotifers enriched with equivalent concentrations of taurine using the dissolved method. The dissolved method required 60 × more taurine to achieve rotifer enrichment levels and larval growth performance observed using the liposome-enrichment method. Fluorescent markers indicated that rotifers were able to break down liposomes, liberating water-soluble nutrients into their guts and body cavity. Differences and similarities are discussed between the efficacy of liposomes and previously studied wax spray beads (WSB) for rotifer enrichment and subsequent nutritional effects on fish larvae.Keywords: Enrichment, Microparticles, Liposomes, Taurine, Rotifers, Fish larva

Degradable thioester core-crosslinked star-shaped polymers

Degradable polymers are considered to present a promising solution to combat plastic pollution. However, many polymers are based on ester and amide bonds, which often require high temperatures and acidic/basic catalysis and hence do not easily degrade under typical environmental conditions. Thus, more readily degradable polymer structures that enable the use of milder conditions are highly sought after. Herein, degradable core-crosslinked star-shaped branched polymers have been synthesised via a two-step one-pot reversible addition–fragmentation chain transfer polymerisation. For the first time, a bifunctional thiomethacrylate crosslinker was used to prepare a range of star-shaped poly(methyl methacrylate) structures which were characterised by advanced viscometry gel permeation chromatography. The increased reactivity of thioesters over their oxoester analogues was exploited to degrade the resulting star-shaped polymers via amidation, as evidenced by the complete degradation of the crosslinked core upon heating in the presence of amines. The successful degradation of polymers containing thioesters shows the potential of thioester chemistry for producing more sustainable/degradable polymers with more complex and defined architectures

Junior Recital: Andrew J. Yi, Percussion

This recital is presented in partial fulfillment of requirements for the degree Bachelor of Music in Music Performance. Mr. Yi studies percussion with John Lawless.https://digitalcommons.kennesaw.edu/musicprograms/2286/thumbnail.jp

Small Molecule Inhibition of HIV-1–Induced MHC-I Down-Regulation Identifies a Temporally Regulated Switch in Nef Action

Nef assembles a multi-kinase complex triggering MHC-I down-regulation. We identify an inhibitor that blocks MHC-I down-regulation, identifying a temporally regulated switch in Nef action from directing MHC-I endocytosis to blocking cell surface delivery. These findings challenge current dogma and reveal a regulated immune evasion program

Financial Incentives and Maternal Health: Where Do We Go from Here?

Health financing strategies that incorporate financial incentives are being applied in many low- and middle-income countries, and improving maternal and neonatal health is often a central goal. As yet, there have been few reviews of such programmes and their impact on maternal health. The US Government Evidence Summit on Enhancing Provision and use of Maternal Health Services through Financial Incentives was convened on 24-25 April 2012 to address this gap. This article, the final in a series assessing the effects of financial incentives\u2014performance-based incentives (PBIs), insurance, user fee exemption programmes, conditional cash transfers, and vouchers\u2014summarizes the evidence and discusses issues of context, programme design and implementation, cost-effectiveness, and sustainability. We suggest key areas to consider when designing and implementing financial incentive programmes for enhancing maternal health and highlight gaps in evidence that could benefit from additional research. Although the methodological rigor of studies varies, the evidence, overall, suggests that financial incentives can enhance demand for and improve the supply of maternal health services. Definitive evidence demonstrating a link between incentives and improved health outcomes is lacking; however, the evidence suggests that financial incentives can increase the quantity and quality of maternal health services and address health systems and financial barriers that prevent women from accessing and providers from delivering quality, lifesaving maternal healthcare

UAS Chromatograph for Atmospheric Trace Species (UCATS) – a versatile instrument for trace gas measurements on airborne platforms

UCATS (the UAS Chromatograph for Atmospheric Trace Species) was designed and built for observations of important atmospheric trace gases from unmanned aircraft systems (UAS) in the upper troposphere and lower stratosphere (UTLS). Initially it measured major chlorofluorocarbons (CFCs) and the stratospheric transport tracers nitrous oxide (N2O) and sulfur hexafluoride (SF6), using gas chromatography with electron capture detection. Compact commercial absorption spectrometers for ozone (O3) and water vapor (H2O) were added to enhance its capabilities on platforms with relatively small payloads. UCATS has since been reconfigured to measure methane (CH4), carbon monoxide (CO), and molecular hydrogen (H2) instead of CFCs and has undergone numerous upgrades to its subsystems. It has served as part of large payloads on stratospheric UAS missions to probe the tropical tropopause region and transport of air into the stratosphere; in piloted aircraft studies of greenhouse gases, transport, and chemistry in the troposphere; and in 2021 is scheduled to return to the study of stratospheric ozone and halogen compounds, one of its original goals. Each deployment brought different challenges, which were largely met or resolved. The design, capabilities, modifications, and some results from UCATS are shown and described here, including changes for future missions.Support was provided for HIPPO by NSF award no. AGS-0628452, for ATTREX by NASA Earth Venture program award no. NNA11AA55I, and for ATom by NASA award no. NNH17AE26I; additional support was provided by NASA Upper Atmosphere Research Program award no. NNH13AV69I. This work was also supported in part by the NOAA Cooperative Agreement with CIRES, NA17OAR4320101

The circumpolar impacts of climate change and anthropogenic stressors on Arctic cod (Boreogadus saida) and its ecosystem

Arctic cod biomass are predicted. In most Arctic seas, the relative abundance of Arctic cod within the fish community will likely fluctuate in accordance with cold and warm periods. A reduced abundance of Arctic cod will negatively affect the abundance, distribution, and physiological condition of certain predators, whereas some predators will successfully adapt to a more boreal diet. Regional management measures that recognize thecritical roleof Arcticcod arerequiredtoensure that increased anthropogenic activities do not exacerbate the impacts of climate change on Arctic marine ecosystems. Ultimately, the mitigation of habitat loss for Arctic cod will only be achieved through a global reduction in carbon emissions