543 research outputs found
Multi-frequency polarimetric SAR signatures of lead sea ice and oil spills
Synthetic aperture radar is used to identify and monitor oil spills. Separation from oil spill look-alikes is an important part of a fully automatic oil spill detection scheme. Here we investigate the polarimetric signatures for oil spills and newly formed sea ice (a well-known look-alike) in fully polarimetric Radarsat-2 satellite scenes. Using the fully polarimetric scenes we calculate four different parameters, co-polarization ratio, polarization difference, scattering entropy, and mean alpha angle. Three pairs of satellite scenes with comparable incidence angles are used. We observe that a combination of the co-polarization ratio and the polarization difference enables us to delineate the spills from their surrounding and also to discriminate the oil spills from the newly formed sea ice. The scattering entropy and the alpha values provide additional information about the scattering mechanisms of sea ice and oil spills
Observing Oil Releases from Platforms Using Synthetic Aperture Radar
Poster presented at the SeaSAR2018 workshop, 7-10 May 2018, Rome, Italy. https://seasar2018.esa.int/.Synthetic aperture radar (SAR) is used for operational surveillance of ocean areas and oil spill detection. Oil spills are frequently detected around oil platforms due to the releases of so-called produced water (PW), which is water containing low concentrations of oil that can form surface slicks similar to other oil spills. PW releases are legal within given limits. Understanding the signatures of produced water and how they are related to, e.g., the relative oil volume and/or concentration can be helpful for the operational services. For example, distinguishing a “normal” release of produced water from an “abnormal” release (elevated amounts) in a SAR image is currently an unsolved problem. Very little research on these topics have been done before. The objectiveofthisstudy is to investigate the characteristics of produced water SAR signatures and how they depend on, e.g., the properties of the release (oil volume, concentration), environmental conditions and sensor properties
Avlivning av häst
Today there are various methods to use when euthanizing horses. Earlier the use of free or captive bullet was the most common method, but in recent decades this has changed and chemical euthanasia is now considered the most common method. The chemical euthanasia has in Sweden been dominated by the use of barbiturates. Somulose® entered the market in the beginning of the 90’s as an alternative to previous chemical euthanasia. During the years that Somulose has been available on the market there have been reports, for example in The Veterinary Record, that Somulose® has not given a satisfactory euthanasia. Conversations with clinics show that it is not uncommon to exclude Somulose® because of the documented risk of non-effect and the concern about toxic side effects in humans due to waste. The purpose of this study was to, through a questionnaire, investigate Swedish veterinarian’s choice of method for euthanasia and their attitude towards Somulose®.
The survey showed that 78 % of the responding veterinarians used chemical methods, 20 % used physical methods and 6 % said they used a combination of methods (there was a possibility to choose several answers to each question). Among the veterinarians that answered the survey, 58 % stated that they use Somulose®, 27 % uses mainly pentobarbital vet APL and 30 % uses methods such as thiopental (Pentothal®Natrium) + pentobarbital vet APL (100 mg/ml), euthanasia after inducing anesthesia or another chemical method. Forty-six percent of the veterinarians stated that they had experienced non-satisfactory euthanasia by Somulose® and 26 % stated that a non-satisfactory result had occurred with other methods of euthanasia. The study shows that no method or substances are a hundred percent reliable. Among those who have had bad experiences half of the veterinarians continued to use Somulose®. In this survey statistically significant differences could not be found in the choice of method for euthanasia and the veterinarian’s experience, education, workplace or where in the country they were active
Air pollution episodes in Stockholm regional background air due to sources in Europe and their effects on human population
Using air quality measurements, we categorized air pollution according to source sectors in a rural background environment in southern Sweden based on hourly air-mass backward trajectories during 1997-2010. Concentrations of fine (PM2.5) and sum of fine and coarse particulate matter (PM10), accumulation mode particle number, black carbon and surface ozone were 4.0, 3.9, 4.5, 6.8 and 1.3 times higher, respectively, in air masses from the southeast as compared with those in air masses from the cleanest sector in the northwest, consistent with air-mass transport over areas with relatively high emissions of primary particulate matter (PM) and secondary PM precursors. The highest ultrafine particle numbers were associated with clean air from the northwest. We estimate that almost 7.8% and 0.6% higher premature human mortality is caused by PM2.5 and ozone exposure, respectively, when air originates from the southeast as compared with that when air originates from the northwest. Reductions of emissions in eastern Europe would reduce the highest air pollution concentrations and associated health risks. However, since air masses from the southwest are more frequent, emissions in the western part of Europe are more important for annual mean premature mortality
Autophagy and ER-stress contribute to photoreceptor degeneration in cultured adult porcine retina.
The aim of this study was to investigate rod and cone photoreceptor degeneration in organotypic cultures of adult porcine retina. Our hypothesis was that the photoreceptors accumulate opsins, which, together with exposure to cyclic dim light illumination, induce autophagy and endoplasmic reticulum stress (ER-stress) to overcome damaging protein overload. For this purpose, retinas were cultured for 48h and 72h during which they were illuminated with dim light for 8h/day; specimens were analyzed by means of immunohistochemistry, Western blot, real-time polymerase chain reaction (PCR) and transmission electron microscopy. ER-stress and photoreceptor degeneration was observed in conventionally cultured retinas. The additional stress in the form of dim light illumination for 8h/day resulted in increased levels of the ER-stress markers GRP78/BiP and CHOP, as well as increased level of active caspase-12. Increased autophagic processes in cone and rod photoreceptors were detected by LC3B-II increases and occurrence of autophagosomes at the ultrastructural level. Illumination also resulted in altered protein expression for autophagy inducers such as p62 and Beclin-1. Moreover, there was a decrease in phosphorylated mammalian target of rapamycin (mTOR), which further indicate an increase of autophagy. Rod and cone photoreceptors in retinas from a diurnal animal that were exposed to dim light illumination in vitro displayed autophagy and ER-stress processes. As no alteration of rhodopsin mRNA was observed, autophagy and ER-stress are suggested to decrease rhodopsin protein at the posttranscriptional level
Automatic Detection of Low-Backscatter Targets in the Arctic Using Wide Swath Sentinel-1 Imagery
Low backscatter signatures in synthetic aperture radar (SAR) imagery are characteristic to surfaces that are highly smooth and specular reflective of microwave radiation. In the Arctic, these typically represent newly formed sea ice, oil spills, and localized weather phenomena such as low wind or rain cells. The operational monitoring of low backscatter targets can benefit from a stronger integration of freely available SAR imagery from Sentinel-1. We, therefore, propose a detection method applicable to Sentinel-1 extra wide-swath (EW) SAR scenes. Using intensity values coupled with incidence angle and noise-equivalent sigma zero (NESZ) information, the image segmentation method is able to detect the low backscatter targets as one segment across subswaths. We use the Barents Sea as a test site due to the abundant presence of low backscatter targets with different origins, and of long-term operational monitoring services that help cross-validate our observations. Utilizing a large set of scenes acquired in the Barents Sea during the freezing season (November–April), we demonstrate the potential of performing large-scale operational monitoring of local phenomena with low backscatter signatures
Expectations about voluntary efforts in collaborative governance and the fit with perceived prerequisites of intrinsic motivation in Sweden’s ecosystem-based moose management system
Collaborative governance regimes may be vulnerable because of dependency on stakeholders??? voluntary engagement and efforts. This study focuses on the Swedish moose management system, a multi-level collaborative governance regime inspired by the ecosystem approach. Self-determination theory is used to explore perceived prerequisites of basic needs for intrinsic motivation across sub-groups of stakeholder representatives who are engaged across different social-ecological contexts. Questionnaire data collected among representatives at two governance levels, moose management groups (n = 624) and moose management units (n = 979), were subjected to two-step cluster analysis. The analyses revealed two sub-groups of representatives, characterized by differences in species composition and land ownership structure: managers of multi-ungulate areas and managers of large-carnivore areas. In several respects, these groups significantly differed in how they perceived the prerequisites. This included prerequisites of perceived competence with regard to their need for knowledge of topics and usefulness of monitoring methods, perceived autonomy operationalized as possibilities to perform their tasks with sufficient time, resources, and support from their organizations, and perceived relatedness to different groups of actors. Further efforts should be made to understand the conditions required for representatives to energize and direct their behavior. The institutional system must better fit the needs of stakeholder representatives across various local contexts, otherwise the space for local voluntary engagement might be hampered
Nuclear medicine technologists are able to accurately determine when a myocardial perfusion rest study is necessary.
ABSTRACT
Achieving Social and Ecological Outcomes in Collaborative Environmental Governance: Good Examples from Swedish Moose Management
Collaborative governance approaches have been suggested as strategies to handle wicked environmental problems. Evaluations have found promising examples of effective natural resource governance, but also highlighted the importance of social-ecological context and institutional design. The aim of this study was to identify factors that contribute to the achievement of social and ecological sustainability within Swedish moose (Alces alces) management. In 2012, a multi-level collaborative governance regime was implemented to decrease conflicts among stakeholders. We carried out semi-structured interviews with six 'good examples' (i.e., Moose Management Groups that showed positive social and ecological outcomes). We found that 'good examples' collectively identified existing knowledge gaps and management challenges and used their discretionary power to develop procedural arrangements that are adapted to the social-ecological context, their theory of change, and attributes of local actors. This contributed to the creation of bridging social capital and principled engagement across governance levels. Thus, our results indicate the existence of higher-order social learning as well as a positive feedback from within-level collaboration dynamics to between-level collaboration. Furthermore, our study illustrates the importance of institutional flexibility to utilize the existing knowledge across stakeholder groups and to allow for adaptations based on the social learning process
En enkätstudie om treårstestets regelförändringar år 2013
År 1999 införde ASVH (Avelsföreningen för den svenska varmblodiga hästen) treårs-testet i syfte att tidigt kunna göra en avkommebedömning och därmed få ett snabbare avelsframsteg. Fram till år 2013 har totalt cirka 15 400 hästar visats. Treåriga hästar som visas på treårstest poängsätts på åtta bedömningspunkter: typ; huvud, hals & bål; extremiteter; skritt; trav; galopp; löshoppning teknik & förmåga samt lös-hoppning temperament & allmänt intryck. År 2013 infördes en del förändringar för att ytterligare utveckla treårstestet. Som komplement till den värderande poängbedömningen infördes linjär beskrivning, löshoppningen ändrade system från två hinder till tre hinder, ridprovet poängbedömdes på försök och domarna gavs möjlighet till att ge halvpoäng.
För att uppnå ett avelsframsteg krävs det att rätt individer sätts i avel tidigt, det betyder att en stor del av populationen måste testas efter de egenskaper som eftersträvas i avelsmålet. Sedan toppåren 2007-2008 med 49 % visade hästar av den totala årgången har deltagar-antalet på SWB treårstest minskat till att år 2013 endast innefatta 38 % av den totala årgången.
Syftet med denna studie var att undersöka vad de som visade häst på treårstest år 2013 anser om de nya reglerna. Ett negativt gensvar skulle kunna leda till ett lägre deltagarantal och därmed en osäkrare avkommebedömning samt ett långsammare avels-framsteg.
Studiens frågeställningar var: Ser respondenterna positivt eller negativt på de nya reglerna? Har de nya reglerna gett ett ökat intresse för att visa häst på treårstest? Påverkar hästens avelsinriktning respondenternas syn på de nya reglerna?
En enkät skickades via mail till 858 personer som anmält minst en häst till treårstest år 2013. Svarsfrekvensen var 39 % vilket motsvarade 338 personer.
Resultatet visade att 84 % av respondenterna generellt är positivt eller mycket positivt inställda till de nya reglerna införda år 2013. Av de som besvarade enkäten kom 97 % till start med sin treåring, för 31 % av respondenterna var det första gången de visade på treårstest. Motiv till att visa häst på treårstest ansågs framförallt vara ett utbildningsmål för den treåriga hästen. De nya reglerna har dock inte bidragit till ett ökat intresse för att visa häst på treårstestet hos respondenterna då 62 % ansåg att intresset var oförändrat.
Slutsatsen är att majoriteten av respondenterna är positiva till de nya regelförändringarna som infördes på treårstest för svenska varmblodiga hästen år 2013. De nya reglerna har dock inte påverkat respondenterna till att bli mer positivt inställda till att visa häst på treårstest. En viss skillnad (p<0,05) i respondenternas åsikt angående ridprovet kunde ses beroende på avelsinriktning. Respondenter med häst avlad mot dressyr var mer positivt inställda till införandet av poängbedömning av ridprov än respondenter med häst avlad mot hoppning. De respondenter som angav att deras häst/ar var avlade mot dressyr ansåg också i större utsträckning att poängbedömningen var av värde för dem
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