Carbonate chemistry covariation with temperature and oxygen in the Salish Sea and California Current Ecosystems: implications for the design of ocean acidification experiments

A central goal of ocean acidification (OA) research is to understand the ecological consequences that future changes in ocean chemistry will have on marine ecosystems. To address this uncertainty researchers rely heavily on manipulative experiments where biological responses are evaluated across different pCO2 treatments. In coastal systems, however, contemporary carbonate chemistry variability remains only partially characterized and patterns of covariation with other biologically important variables such as temperature and oxygen are rarely evaluated or incorporated into experimental design. Here, we compiled a large carbonate chemistry data set that consists of measurements from multiple moorings and ship-based sampling campaigns from the Salish Sea and larger California Current Ecosystem (CCE). We evaluated patterns of pCO2 variability and highlight important covariation between pCO2, temperature, and oxygen. We subsequently compared environmental pCO2-temperature measurements with conditions maintained in OA experiments that used organisms from the Salish Sea and CCE. By drawing such comparisons, researchers can gain insight into the ecological relevancy of previously published OA experimental designs, but also identify species or life history stages that may already be influenced by contemporary carbonate chemistry conditions. We illustrate the implications that covariation among environmental variables can have for the interpretation of OA experimental results and suggest an approach for developing experimental designs with pCO2 levels that better reflect OA hypotheses while simultaneously recognizing natural covariation with other biologically relevant variables

Interpretation and design of ocean acidification experiments in upwelling systems in the context of carbonate chemistry co-variation with temperature and oxygen

Coastal upwelling regimes are some of the most productive ecosystems in the ocean but are also among the most vulnerable to ocean acidification (OA) due to naturally high background concentrations of CO₂. Yet our ability to predict how these ecosystems will respond to additional CO₂ resulting from anthropogenic emissions is poor. To help address this uncertainty, researchers perform manipulative experiments where biological responses are evaluated across different CO₂ partial pressure (pCO₂) levels. In upwelling systems, however, contemporary carbonate chemistry variability remains only partly characterized and patterns of co-variation with other biologically important variables such as temperature and oxygen are just beginning to be explored in the context of OA experimental design. If co-variation among variables is prevalent, researchers risk performing OA experiments with control conditions that are not experienced by the focal species, potentially diminishing the ecological relevance of the experiment. Here, we synthesized a large carbonate chemistry dataset that consists of carbonate chemistry, temperature, and oxygen measurements from multiple moorings and ship-based sampling campaigns from the California Current Ecosystem (CCE), and includes fjord and tidal estuaries and open coastal waters. We evaluated patterns of pCO₂ variability and highlight important co-variation between pCO₂, temperature, and oxygen. We subsequently compared environmental pCO₂–temperature measurements with conditions maintained in OA experiments that used organisms from the CCE. By drawing such comparisons, researchers can gain insight into the ecological relevance of previously published OA experiments, but also identify species or life history stages that may already be influenced by contemporary carbonate chemistry conditions. We illustrate the implications co-variation among environmental variables can have for the interpretation of OA experimental results and suggest an approach for designing experiments with pCO₂ levels that better reflect OA hypotheses while simultaneously recognizing natural co-variation with other biologically relevant variables.Keywords: hypoxia, multistressor experiment, California Current, pH, climate chang

Seasonal and Ontogenetic Changes in Movement Patterns of Sixgill Sharks

Understanding movement patterns is fundamental to population and conservation biology. The way an animal moves through its environment influences the dynamics of local populations and will determine how susceptible it is to natural or anthropogenic perturbations. It is of particular interest to understand the patterns of movement for species which are susceptible to human activities (e.g. fishing), or that exert a large influence on community structure, such as sharks.We monitored the patterns of movement of 34 sixgill sharks Hexanchus griseus using two large-scale acoustic arrays inside and outside Puget Sound, Washington, USA. Sixgill sharks were residents in Puget Sound for up to at least four years before making large movements out of the estuary. Within Puget Sound, sixgills inhabited sites for several weeks at a time and returned to the same sites annually. Across four years, sixgills had consistent seasonal movements in which they moved to the north from winter to spring and moved to the south from summer to fall. Just prior to leaving Puget Sound, sixgills altered their behavior and moved twice as fast among sites. Nineteen of the thirty-four sixgills were detected leaving Puget Sound for the outer coast. Three of these sharks returned to Puget Sound.For most large marine predators, we have a limited understanding of how they move through their environment, and this clouds our ability to successfully manage their populations and their communities. With detailed movement information, such as that being uncovered with acoustic monitoring, we can begin to quantify the spatial and temporal impacts of large predators within the framework of their ecosystems

Biomarker candidates of neurodegeneration in Parkinson’s disease for the evaluation of disease-modifying therapeutics

Reliable biomarkers that can be used for early diagnosis and tracking disease progression are the cornerstone of the development of disease-modifying treatments for Parkinson’s disease (PD). The German Society of Experimental and Clinical Neurotherapeutics (GESENT) has convened a Working Group to review the current status of proposed biomarkers of neurodegeneration according to the following criteria and to develop a consensus statement on biomarker candidates for evaluation of disease-modifying therapeutics in PD. The criteria proposed are that the biomarker should be linked to fundamental features of PD neuropathology and mechanisms underlying neurodegeneration in PD, should be correlated to disease progression assessed by clinical rating scales, should monitor the actual disease status, should be pre-clinically validated, and confirmed by at least two independent studies conducted by qualified investigators with the results published in peer-reviewed journals. To date, available data have not yet revealed one reliable biomarker to detect early neurodegeneration in PD and to detect and monitor effects of drug candidates on the disease process, but some promising biomarker candidates, such as antibodies against neuromelanin, pathological forms of α-synuclein, DJ-1, and patterns of gene expression, metabolomic and protein profiling exist. Almost all of the biomarker candidates were not investigated in relation to effects of treatment, validated in experimental models of PD and confirmed in independent studies

Heterologous expression of tylosin polyketide synthase and production of a hybrid bioactive macrolide in Streptomyces venezuelae

Tylosin polyketide synthase (Tyl PKS) was heterologously expressed in an engineered strain of Streptomyces venezuelae bearing a deletion of pikromycin PKS gene cluster using two compatible low-copy plasmids, each under the control of a pikAI promoter. The mutant strain produced 0.5 mg/l of the 16-membered ring macrolactone, tylactone, after a 4-day culture, which is a considerably reduced culture period to reach the maximum production level compared to other Streptomyces hosts. To improve the production level of tylactone, several precursors for ethylmalonyl-CoA were fed to the growing medium, leading to a 2.8-fold improvement (1.4 mg/ml); however, switching the pikAI promoter to an actI promoter had no observable effect. In addition, a small amount of desosamine-glycosylated tylactone was detected from the extract of the mutant strain, revealing that the native glycosyltransferase DesVII displayed relaxed substrate specificity in accepting the 16-membered ring macrolactone to produce the glycosylated tylactone. These results demonstrate a successful attempt for a heterologous expression of Tyl PKS in S. venezuelae and introduce S. venezuelae as a rapid heterologous expression system for the production of secondary metabolites.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45861/1/253_2006_Article_318.pd

Painted Goby Larvae under high-CO2 fail to recognize reef sounds

Atmospheric CO2 levels have been increasing at an unprecedented rate due to anthropogenic activity. Consequently, ocean pCO2 is increasing and pH decreasing, affecting marine life, including fish. For many coastal marine fishes, selection of the adult habitat occurs at the end of the pelagic larval phase. Fish larvae use a range of sensory cues, including sound, for locating settlement habitat. This study tested the effect of elevated CO2 on the ability of settlement-stage temperate fish to use auditory cues from adult coastal reef habitats. Wild late larval stages of painted goby (Pomatoschistus pictus) were exposed to control pCO2 (532 μatm, pH 8.06) and high pCO2 (1503 μatm, pH 7.66) conditions, likely to occur in nearshore regions subjected to upwelling events by the end of the century, and tested in an auditory choice chamber for their preference or avoidance to nighttime reef recordings. Fish reared in control pCO2 conditions discriminated reef soundscapes and were attracted by reef recordings. This behaviour changed in fish reared in the high CO2 conditions, with settlement-stage larvae strongly avoiding reef recordings. This study provides evidence that ocean acidification might affect the auditory responses of larval stages of temperate reef fish species, with potentially significant impacts on their survival.Fundação para a Ciência e a Tecnologia (FCT)info:eu-repo/semantics/publishedVersio

DiffusionParametersintheStriatumofRats

ando singlemacrografts,presumablybecauseofmoreextensivetissuedamage, cellloss,andastrogliosis. 2002Wiley-Liss,Inc. Keywords:extrasynaptictransmission;Parkinson'sdis- ease;tortuosity;transplantation;volumefraction Volumetransmissionofdopamine(DA)playsan importantroleinthenigrostriatalsystem(FuxeandAgnati, 1991;Yungetal.,1995;ZoliandAgnati,1996; Gonon,1997;Zolietal.,1998;NicholsonandSykova, 1998).Althoughdopaminergicterminalsformsmallsymmetricsynapsesenpassantonspinesofstriatalmedium spinyneurons(Freundetal.,1985;Grovesetal.,1994), onlyafractionofDAreceptorsinthestriatumisdirectly associatedwithsynapticstructures(Sesacketal.,1994; Yungetal.,1995).TheimpactofDAonD1receptors (Gonon,1997)aswellasneuronalhigh-affinityuptakeof DAoccursoutsidethesynapticcleft(Garrisetal.,1994; Nirenbergetal.,1996).Volumetransmissionisofgreat importanceinstatesofstriatalDAdepletion(Bjelkeetal., 1994;Zolietal.,1998;Strombergetal.,2000),and sufficientDAdiffusionuptodistancesofseveralmillimetershasbeenobserved

Requirements for Forming Efficient 3‑D Charge Transport Pathway in Diketopyrrolopyrrole-Based Copolymers: Film Morphology vs Molecular Packing

To achieve extremely high planarity and processability simultaneously, we have newly designed and synthesized copolymers composed of donor units of 2,2'-(2,5-dialkoxy-1,4-phenylene)dithieno[3,2-b]thiophene (TT-P-TT) and acceptor units of diketopyrrolopyrrole (DPP). These copolymers consist of a highly planar backbone due to intramolecular interactions. We have systematically investigated the effects of intermolecular interactions by controlling the side chain bulkiness on the polymer thin-film morphologies, packing structures, and charge transport. The thin-film microstructures of the copolymers are found to be critically dependent upon subtle changes in the intermolecular interactions, and :charge transport dynamics of the copolymer based field-effect transistors (FETs) has been investigated by in-depth structure property relationship study. Although the size of the fibrillar structures increases as the bulkiness of the side chains in the copolymer increases, the copolymer with the smallest side chain shows remarkably high charge carrier mobility. Our findings reveal the requirement for forming efficient 3-D charge transport pathway and highlight the importance of the molecular packing and interdomain connectivity, rather than the crystalline domain size. The results obtained herein demonstrate the importance of tailoring the side chain bulkiness and provide new insights into the molecular design for high performance polymer semiconductors.1199Nsciescopu