MacImage: a user-friendly image-analysis system for the accurate mensuration of marine organisms

Changes in abundance, dimensions, and biovolume of manne microorganisms are important parameters used in the estimation of a wide range of biological processes, including cell activity, growth rate, predation, and nutrient cycling. Routine measurement of these parameters has been hampered by the tedium of counting and measuring large numbers of microorganisms, the subjechvity of visual measurement using the eyepiece micrometer, cell shrinkage during preparahon for electron microscopy, and the small size of marine bacteria and some protists. Image-analysed microscopy overcomes these problems, but extant equipment and programs are cumbersome. MacImage, an image-analysis system that interfaces an Artek 810V image-analysis computer and a Macintosh computer, has been developed using the language Forth to improve operator-machine control and versatility. By using a combination of a more sensitive camera tube, additional magnification lenses. and a software system for the Macintosh computer specifically tailored for the measurement of marine microorganisms, we are now able to accurately and rapidly determine the abundance, size, shape, volume, and surface area of microorganisms ranging from marine bactena to fish larvae. Data collected by this system can be transferred directly to other Macintosh spreadsheet and graphics programs. To dustrate the versawity of MacImage, we present data on size, biovolume, biosurface area, and abundance of a natural sample of picoplankton from Narragansett Bay, Rhode Island; size and biovolume data on a cultured clone of Synechococcus; and size, shape and area on the larvae of the winter flounder Pseudopleuronectes amencanus

Mechanisms and consequences of life cycle diversity of beaked redfish, Sebastes mentella

Recent genetic research, supported by life history information, indicates that there are three biological stocks of S. mentella in the Irminger Sea and adjacent waters: a ‘Deep Pelagic’ stock (>500m), a ‘Shallow Pelagic’ stock (<500m), and an ‘Icelandic Slope’ stock. Throughout their range, Sebastes species are adapted to a diversity of ecological niches, with overlapping spatial distributions of different species that have little or no morphological differences. Divergence of behavioral groups into depth-defined adult habitats has led to reproductive isolation, adaptive radiation and speciation of several Sebastes species. Congruent differences in fatty acid composition and parasites suggests that the three genetically distinct populations of S. mentella are adapted to disparate trophic habitats in pelagic waters (shallower and deeper than the deep-scattering layer), and in demersal habitats on the continental slope. Patterns of morphology are also consistent with adaptation to different habitats, because pelagic forms are more streamlined. Although genetic differences and evidence for reproductive isolation are clear, these populations appear to share common nursery habitats on the Greenlandic Shelf. Spatial overlap at early life stages and depth-defined adult populations present challenges for stock identification and fishery management. Effective resource monitoring, conservation and fishery management requires that the spatial definition of management units reflects biological stock structure. We describe a proposal for a redefinition of practical management units that are based on geographic proxies for biological stocks which minimizes mixed-stock catches according to spatial patterns of the recent fishery

Growth portfolios buffer climate-linked environmental change in marine systems

Large-scale, climate-induced synchrony in the productivity of fish populations is becoming more pronounced in the world's oceans. As synchrony increases, a population's “portfolio” of responses can be diminished, in turn reducing its resilience to strong perturbation. Here we argue that the costs and benefits of trait synchronization, such as the expression of growth rate, are context dependent. Contrary to prevailing views, synchrony among individuals could actually be beneficial for populations if growth synchrony increases during favorable conditions, and then declines under poor conditions when a broader portfolio of responses could be useful. Importantly, growth synchrony among individuals within populations has seldom been measured, despite well-documented evidence of synchrony across populations. Here, we used century-scale time series of annual otolith growth to test for changes in growth synchronization among individuals within multiple populations of a marine keystone species (Atlantic cod, Gadus morhua). On the basis of 74,662 annual growth increments recorded in 13,749 otoliths, we detected a rising conformity in long-term growth rates within five northeast Atlantic cod populations in response to both favorable growth conditions and a large-scale, multidecadal mode of climate variability similar to the East Atlantic Pattern. The within-population synchrony was distinct from the across-population synchrony commonly reported for large-scale environmental drivers. Climate-linked, among-individual growth synchrony was also identified in other Northeast Atlantic pelagic, deep-sea and bivalve species. We hypothesize that growth synchrony in good years and growth asynchrony in poorer years reflects adaptive trait optimization and bet hedging, respectively, that could confer an unexpected, but pervasive and stabilizing, impact on marine population productivity in response to large-scale environmental change.publishedVersio

Viðbragðstími lögreglunnar á Suðurnesjum: Líkan unnið út frá landupplýsingum

Markmið verkefnisins var að útbúa umferðarlíkan af lögregluumdæmi lögreglustjórans á Suðurnesjum og út frá því reikna ferða- og viðbragðstíma lögreglu. Líkanið var unnið með því að sameina og samræma gögn um vegi frá Landmælingum Íslands og Reykjavíkurborg auk þess sem 151 götubútum var bætt við út frá loftmyndum. Skilgreindur var hámarkshraði vega svæðisins út frá gögnum frá Vegagerðinni og sveitarfélögum á svæðinu. Líkanið var aðlagað að lögreglu eftir fund með fulltrúum lögreglustjórans á Suðurnesjum. Þar var horft til ólíkra forgangsviðmiða auk þess sem farið var yfir skipulag útkallseininga í embættinu. Áætlaður viðbragðstími var reiknaður með netgreini í landgagnasafnsforritinu ArcGis 9.3. Niðurstöður líkansins eru birtar á kortum og gefa góða yfirsýn yfir stöðuna í dag. Ljóst er að munur er á viðbragðstíma milli sveitarfélaga svæðisins og tel ég að lögregla sé meðvituð um þá stöðu. Niðurstöðurnar leiða til betri skilnings á löggæslu í landfræðilegu rými og ég vona að það geti leitt til betri og markvissari skipulagningar í framtíðinni

Sundrun landslagsheilda Íslands

Landscape fragmentation measurements provide baseline data of direct human influence on landscape and habitat systems through land use. In 2011, the European Environment Agency, the EEA and the Swiss Federal Office for the Environment or FOEN created a comprehensive report on the status of landscape fragmentation in 28 European countries, excluding Iceland. This thesis builds on EEA and FOEN methodology in order to create comparable data for Iceland. The Icelandic data set had to be adjusted to the European format to ensure that the results could be compared. The calculations were obtained using GIS software technology, where five types of reporting units were used with six different fragmentation geometries. Three of the six fragmentation geometries were created considering local environmental factors, amending the constraining factors used in the European research. The results indicate that landscape fragmentation in Iceland is low. By revealing the baseline data now, one can account for fragmentation in future infrastructure development planning through monitoring. This can be achieved on a country level e.g. by implementing the base line indicators as one of the factors considered in the newly proposed country planning policy. The effects of fragmentation to ecosystems accrue in a gradual manner. Addressing the issue beforehand can limit costly mitigation measures in the future and furthermore strengthen Iceland’s ability to provide various landscape habitats to the country´s particular flora and fauna.Sundrun landslagsheilda er það þegar stórum landslagssvæðum er skipt upp í minni og einangraðari svæði (EEA & FOEN, 2011). Helstu áhrifaþættir eru mannlegir þættir eins borgvæðing sem og línulegir þættir eins og lestarteinar og vegir. Sundrun landslags hefur margvísleg áhrif á búsvæða lífvera, þar sem þau bæði skerðast en einnig breytast að innri gerð. Umhverfisstofnun Evrópu og Umhverfisstofnun Sviss reiknuðu megindlega hver sundrun landslagsheilda væri innan 28 landa í Evrópu (EEA & FOEN, 2011) og var Ísland ekki haft með í þeim útreikningi. Markmið þessarar ritgerðar er að skapa samanburðarhæfar niðurstöður við Evrópsku rannsóknina en jafnframt að skapa heilstæð grunnlínugögn sem gætu nýst innanlands t.d. sem umhverfisþáttur í umhverfismati áætlana eða sem sambærilegur þáttur í umhverfisvöktun skipulagsyfirvalda tengdu nýju landsskipulagi. Mæld sundrun var reiknuð með hjálp landfræðilegra upplýsingakerfa, þar sem sex frábrugðnar formgerðir sundrunar voru metnar með tilliti til fimm samanburðaeininga. Niðurstöðurnar benda til minni sundrunar en víðast hvar í Evrópu. Þó bendir ýmislegt til þess að ástæða sé til þess að vakta áframhaldandi þróun. Áhrifum sundrunar hefur verið lýst sem stigmagnandi vandamáli í Evrópu, þar sem brugðist var við of seint og nú er unnið að því að auka tengingu svæða með dýrum mótvægisaðgerðum. Þar er vandmálið að stórum hluta tengt landspendýrum. Hér á landi hafa áhrif sundrunar búsvæða á tegundahópa ekki verið könnuð. Með því að vakta sundrun landslags við gætum við gætt að því; að á meðan við byggjum upp innviði samfélagsins röskum við ekki samheldni landslagsheilda með sama hætti og á meginlandi Evrópu

Greiningargeta blóðprufa og afdrif sjúklinga með Disseminated Intravascular Coagulation

Inngangur: Disseminated Intravascular Coagulation (DIC) er sjúkdómsástand sem fylgir sjúkdómum sem valda kerfisbundinni virkjun á blóðstorku. Við slíka virkjun myndast blóðtappar í smáum æðum sem valda skertu blóðflæði og súrefnisskorti í vef með vefjaskemmdum. Við það verður einnig aukin notkun á storkuþáttum sem getur valdið aukinni blæðingarhneigð Þó svo sýnt hafi verið fram á minnkað magn prótein C, antiplasmin og antithrombin í blóði sjúklinga með DIC hefur ekki verið sýnt fram á forspárgildi þeirra til að meta hvort sjúklingar sem eiga á hættu að fá DIC muni þróa með sér DIC. Tilgangur þessarar rannsóknar er að skoða forspárgildi prótein C, antiplasmin og antithrombin mælinga og skoða samband þeirra við dánartíðni og versnandi sjúkdómsástand. Einnig var skoðað nýgengi DIC á Íslandi á árunum 2004-2008 og horfur sjúklinga með DIC Efni og aðferðir: Fram til ársins 2009 var antiplasmin nær eingöngu mælt í svokölluðum DIC panel sem notaður var til að greina hvort einstaklingur var með DIC. Teknar voru saman allar blóðprufur sem framkvæmdar höfðu verið þar sem antiplasmin var mælt á árunum 2004-2008 og þær stigaðar eftir ISTH stigunarkerfi fyrir DIC. Prótein C, antithrombin og antiplasmin mælingum var svo raðað í tímaröð til að skoða hvort meðaltöl þeirra skildust að fyrir greiningu DIC á milli sjúklingahópa. Teiknaðar voru ROC kúrfur til að meta næmni og sértækni blóðprufanna. Auk þess voru 114 sjúklingar sem höfðu fengið antiplasmin mælingu en voru ekki með DIC samkvæmt ISTH stigun valdir í DIC- hóp til frekari greiningar. Sjúkraskrár þeirra auk þeirra sem greindust með DIC voru skoðaðar og lesin út dánartíðni, lengd sjúkrahúslegu, APACHE II stigun, RIFLE stigun og hvort sjúklingar fengu ARDS. Niðurstöður: Af þeim 114 einstaklingum sem greindust með DIC samkvæmt ISTH stigun voru 111 með undirliggjandi sjúkdóm sem tengdist DIC. Nýgengi var 10 sjúklingar á ári/100 þúsund íbúa. Sjúklingar með sem fengu DIC höfðu marktækt verri lífslíkur. Prótein C gildi sjúklinga með DIC voru marktækt lægri 6 dögum fyrir greiningu DIC, antithrombin gildi voru marktækt lægri 4 dögum fyrir greiningu DIC og antiplasmin gildi voru marktækt lægri 1 degi fyrir greiningu DIC. Prótein C sýndi mesta næmi og sértækni til greiningar á DIC, bæði við greiningu DIC og einnig fyrir greiningu DIC. Antithrombin greindi best í sundur sjúklinga m.t.t. lifunar. Prótein C hafði mesta tengingu við RIFLE stigun. Ályktanir: Prótein C, antithrombin og antiplasmin er hægt að nota til að meta hvort sjúklingur er með DIC. Prótein C og antithrombin er hægt að nota til að meta hvort sjúklingur sé líklegur til að fá DIC áður en ástandið greinist

Sveitasögur gamlar og nýjar.

Sveinn káti.--Bruín.--Alt af að tapa?--Sigriŏur á Bustöðum.--Móri.Mode of access: Internet

Century-long cod otolith biochronology reveals individual growth plasticity in response to temperature

Otolith biochronologies combine growth records from individual fish to produce long-term growth sequences, which can help to disentangle individual from population-level responses to environmental variability. This study assessed individual thermal plasticity of Atlantic cod (Gadus morhua) growth in Icelandic waters based on measurements of otolith increments. We applied linear mixed-effects models and developed a century-long growth biochronology (1908–2014). We demonstrated interannual and cohort-specific changes in the growth of Icelandic cod over the last century which were mainly driven by temperature variation. Temperature had contrasting relationships with growth—positive for the fish during the youngest ages and negative during the oldest ages. We decomposed the effects of temperature on growth observed at the population level into within-individual effects and among‐individual effects and detected significant individual variation in the thermal plasticity of growth. Variance in the individual plasticity differed across cohorts and may be related to the mean environmental conditions experienced by the group. Our results underscore the complexity of the relationships between climatic conditions and the growth of fish at both the population and individual level, and highlight the need to distinguish between average population responses and growth plasticity of the individuals for accurate growth predictions

Century-long cod otolith biochronology reveals individual growth plasticity in response to temperature

Otolith biochronologies combine growth records from individual fish to produce long-term growth sequences, which can help to disentangle individual from population-level responses to environmental variability. This study assessed individual thermal plasticity of Atlantic cod (Gadus morhua) growth in Icelandic waters based on measurements of otolith increments. We applied linear mixed-effects models and developed a century-long growth biochronology (1908–2014). We demonstrated interannual and cohort-specific changes in the growth of Icelandic cod over the last century which were mainly driven by temperature variation. Temperature had contrasting relationships with growth—positive for the fish during the youngest ages and negative during the oldest ages. We decomposed the effects of temperature on growth observed at the population level into within-individual effects and among‐individual effects and detected significant individual variation in the thermal plasticity of growth. Variance in the individual plasticity differed across cohorts and may be related to the mean environmental conditions experienced by the group. Our results underscore the complexity of the relationships between climatic conditions and the growth of fish at both the population and individual level, and highlight the need to distinguish between average population responses and growth plasticity of the individuals for accurate growth predictions