66 research outputs found
Different Carotenoids and Potential Information Content of Red Coloration of Male Three-Spined Stickleback
Female sticklebacks (Gasterosteus aculeatus) use the red coloration of males as a criterion for mate choice. Redder males are more attractive. However, males often differ not only in the intensity of their coloration (from dull to bright red) but also in color quality (from yellowish to purple-red). We investigated whether the red coloration of the stickleback is actually a multiple signal made by several pigments. We kept wild caught males singly in tanks until they had built a nest and were ready to accept females. Then, we took standard photographs and measured their colors by spectrometer analyses of the slides and by descriptions of human observers. These two measurements were highly correlated. When analyzing the carotenoid content of the sticklebacks' skin we found two groups of carotenoids (astaxanthin and tunaxanthin/lutein) that were quantified for each individual. The differences in color observed in the fish are correlated to this pigment quantification. Redder fish have more astaxanthin in their skin than yellowish fish, while the color of the yellowish fish appears to be made by tunaxanthin/lutein. Our results suggest that the red coloration of sticklebacks is a multiple trait that is made of at least two different carotenoids. This opens the possibility that male sticklebacks signal more detailed information to females than a one-dimensional trait would allo
Cryoelectron tomography reveals periodic material at the inner side of subpellicular microtubules in apicomplexan parasites
Microtubules are dynamic cytoskeletal structures important for cell division, polarity, and motility and are therefore major targets for anticancer and antiparasite drugs. In the invasive forms of apicomplexan parasites, which are highly polarized and often motile cells, exceptionally stable subpellicular microtubules determine the shape of the parasite, and serve as tracks for vesicle transport. We used cryoelectron tomography to image cytoplasmic structures in three dimensions within intact, rapidly frozen Plasmodium sporozoites. This approach revealed microtubule walls that are extended at the luminal side by an additional 3 nm compared to microtubules of mammalian cells. Fourier analysis revealed an 8-nm longitudinal periodicity of the luminal constituent, suggesting the presence of a molecule interacting with tubulin dimers. In silico generation and analysis of microtubule models confirmed this unexpected topology. Microtubules from extracted sporozoites and Toxoplasma gondii tachyzoites showed a similar density distribution, suggesting that the putative protein is conserved among Apicomplexa and serves to stabilize microtubules
Review of methods addressing freshwater use in life cycle inventory and impact assessment
Purpose: In recent years, several methods have been developed which propose different freshwater use inventory schemes and impact assessment characterization models considering various cause-effect chain relationships. This work reviewed a multitude of methods and indicators for freshwater use potentially applicable in life cycle assessment (LCA). This review is used as a basis to identify the key elements to build a scientific consensus for operational characterization methods for LCA. Methods: This evaluation builds on the criteria and procedure developed within the International Reference Life Cycle Data System Handbook and has been adapted for the purpose of this project. It therefore includes (1) description of relevant cause-effect chains, (2) definition of criteria to evaluate the existing methods, (3) development of sub-criteria specific to freshwater use, and (4) description and review of existing methods addressing freshwater in LCA. Results and discussion: No single method is available which comprehensively describes all potential impacts derived from freshwater use. However, this review highlights several key findings to design a characterization method encompassing all the impact pathways of the assessment of freshwater use and consumption in life cycle assessment framework as the following: (1) in most of databases and methods, consistent freshwater balances are not reported either because output is not considered or because polluted freshwater is recalculated based on a critical dilution approach; (2) at the midpoint level, most methods are related to water scarcity index and correspond to the methodological choice of an indicator simplified in terms of the number of parameters (scarcity) and freshwater uses (freshwater consumption or freshwater withdrawal) considered. More comprehensive scarcity indices distinguish different freshwater types and functionalities. (3) At the endpoint level, several methods already exist which report results in units compatible with traditional human health and ecosystem quality damage and cover various cause-effect chains, e.g., the decrease of terrestrial biodiversity due to freshwater consumption. (4) Midpoint and endpoint indicators have various levels of spatial differentiation, i.e., generic factors with no differentiation at all, or country, watershed, and grid cell differentiation. Conclusions: Existing databases should be (1) completed with input and output freshwater flow differentiated according to water types based on its origin (surface water, groundwater, and precipitation water stored as soil moisture), (2) regionalized, and (3) if possible, characterized with a set of quality parameters. The assessment of impacts related to freshwater use is possible by assembling methods in a comprehensive methodology to characterize each use adequatel
Neutral sphingomyelinase mediates the co-morbidity trias of alcohol abuse, major depression and bone defects
Mental disorders are highly comorbid and occur together with physical diseases, which are often considered to arise from separate pathogenic pathways. We observed in alcohol-dependent patients increased serum activity of neutral sphingomyelinase. A genetic association analysis in 456,693 volunteers found associations of haplotypes of SMPD3 coding for NSM-2 (NSM) with alcohol consumption, but also with affective state, and bone mineralisation. Functional analysis in mice showed that NSM controls alcohol consumption, affective behaviour, and their interaction by regulating hippocampal volume, cortical connectivity, and monoaminergic responses. Furthermore, NSM controlled bone–brain communication by enhancing osteocalcin signalling, which can independently supress alcohol consumption and reduce depressive behaviour. Altogether, we identified a single gene source for multiple pathways originating in the brain and bone, which interlink disorders of a mental–physical co-morbidity trias of alcohol abuse—depression/anxiety—bone disorder. Targeting NSM and osteocalcin signalling may, thus, provide a new systems approach in the treatment of a mental–physical co-morbidity trias
Neutral sphingomyelinase mediates the co-morbidity trias of alcohol abuse, major depression and bone defects
Abstract
Mental disorders are highly comorbid and occur together with physical diseases, which are often considered to arise from separate pathogenic pathways. We observed in alcohol-dependent patients increased serum activity of neutral sphingomyelinase. A genetic association analysis in 456,693 volunteers found associations of haplotypes of SMPD3 coding for NSM-2 (NSM) with alcohol consumption, but also with affective state, and bone mineralisation. Functional analysis in mice showed that NSM controls alcohol consumption, affective behaviour, and their interaction by regulating hippocampal volume, cortical connectivity, and monoaminergic responses. Furthermore, NSM controlled bone–brain communication by enhancing osteocalcin signalling, which can independently supress alcohol consumption and reduce depressive behaviour. Altogether, we identified a single gene source for multiple pathways originating in the brain and bone, which interlink disorders of a mental–physical co-morbidity trias of alcohol abuse—depression/anxiety—bone disorder. Targeting NSM and osteocalcin signalling may, thus, provide a new systems approach in the treatment of a mental–physical co-morbidity trias
Evaluation der Bachelor-ErstSemestrigen-Tage (BEST) im Studiengang Umweltnaturwissenschaften: Ergebnisse einer Online Befragung ehemaliger Teilnehmer/innen mit besonderer Berücksichtigung des New Commons Game „Fischerei-Spiels“
Zu Beginn des ersten Semesters des Bachelor-Studiums in Umweltnaturwissenschaften an der ETH Zürich finden die Bachelor-ErstSemestrigen-Tage (BEST) statt, ein „Willkommens-Wochenende“ an dem die Studienanfänger(innen) sich gegenseitig besser kennenlernen und wechselseitig über das Studium aus¬tauschen können und auch etwas über die Forschungsthemen am Departement erfahren und über mögliche Berufstätigkeiten im Anschluss an das Studium. Mittels einer Online-Umfrage bei den Teil¬nehmenden der BEST-Tage 2015 und 2016 wurde erstmals eine Evaluation dieser Veranstaltung durchgeführt. Insgesamt 74 Studierende beteiligten sich an der Umfrage. Es wurde analysiert, ob die BEST-Tage und ihre einzelnen Teile die jeweils angestrebten Ziele erreichen und zudem sollten mögliche Probleme und Möglichkeiten für eine Verbesserung der Durchführung der BEST-Tage identifi¬ziert werden.
Die Ergebnisse zeigen, dass die BEST-Tage für die Teilnehmenden interessant waren, ihnen Spass gemacht haben und ermöglichten, Kontakte zu knüpfen und Mitstudent(inn)en kennen zu lernen. Auch die vier einzelnen Teile der BEST-Tage wurden im Hinblick auf die Erreichung ihrer jeweiligen Ziele positiv beurteilt. Das New Commons Game (NCG) bzw. „Fischerei-Spiel“ machte den Teilnehmenden Spass und förderte auf spielerische Art und Weise das Verständnis des Konzepts der Nachhaltigkeit und der dynamischen Pro¬zesse in Mensch-Umweltsystemen. Komplementär dazu vermittelten die Exkurs¬ionen zur Prä¬sentation von Forschungsprojekten einen Einblick in die Themenfelder und Forschungs¬aktivitäten am Departement Umweltsystemwissenschaften. Bei den Diskussionsrunden zu Motiva¬tionen und Erwartungen für das Studium wurde immerhin von der Hälfte der Antwortenden eher bejaht oder bejaht, dass diese für die Klärung der Frage, ob der Studiengang der richtige ist, hilfreich waren. Die Podiumsdiskussionen gaben aus Sicht der meisten Teilnehmenden einen Einblick in mögliche berufliche Aktivitäten nach dem Studium
Different carotenoids and potential information content of red coloration of male three-spined stickleback
Abstract—Female sticklebacks (Gasterosteus aculeatus) use the red coloration of males as a criterion for mate choice. Redder males are more attractive. However, males often differ not only in the intensity of their coloration (from dull to bright red) but also in color quality (from yellowish to purple-red). We investigated whether the red coloration of the stickleback is actually a multiple signal made by several pigments. We kept wild caught males singly in tanks until they had built a nest and were ready to accept females. Then, we took standard photographs and measured their colors by spectrometer analyses of the slides and by descriptions of human observers. These two measurements were highly correlated. When analyzing the carotenoid content of the sticklebacks ' skin we found two groups of carotenoids (astaxanthin and tunaxanthin/lutein) that were quantified for each individual. The differences in color observed in the fish are correlated to this pigment quantification. Redder fish have more astaxanthin in their skin than yellowish fish, while the color of the yellowish fish appears to be made by tunaxanthin/lutein. Our results suggest that the red coloration of sticklebacks is a multiple trait that is made of at least two different carotenoids. This opens the possibility that male sticklebacks signal more detailed information to females than a onedimensional trait would allow. Key Words—Breeding coloration, Gasterosteus aculeatus, stickleback, fish, multiple ornaments, signalling, carotenoids, astaxanthin, tunaxanthin, lutein
A classification system for identifying patients dead on ambulance arrival: a prehospital medical record review
Abstract Background Patients dead before arrival of the ambulance or before arrival at hospital may be in- or excluded in mortality analyses, making comparison of mortality difficult. Often only physicians are allowed to declare death, thereby impeding uniform registration of prehospital death. Many studies do not report detailed definitions of prehospital mortality. Our aim was to define criteria to identify and categorize prehospital patients’ vital status, and to estimate the proportion of these groups, primarily the proportion of patients dead on ambulance arrival. Methods Prehospital medical records review for patients receiving an ambulance in the North Denmark Region from 2019 to 2021 and registered dead on the same or the following day. We defined three vital status categories: (1) Dead on Ambulance Arrival (DOAA), (2) Out-of-Hospital Cardiac Arrest (OHCA) divided into OHCA Basic Life Support (OHCA BLS) and OHCA Advanced treatment, and 3) Alive on Ambulance Arrival. Results Among 3 174 dead patients, DOAA constituted 28.8%, OHCA BLS 13.4%, OHCA Advanced treatment 31.3%, and Alive on Ambulance Arrival 26.6%. Conclusion We defined exhaustive and mutually exclusive criteria to define vital status, DOAA, OHCA, and Alive on Ambulance Arrival based on prehospital medical records. More than one out of four patients receiving an ambulance and registered dead on the same or the following day were dead already at ambulance arrival. Adding OHCA BLS where resuscitation was terminated without defibrillation or other treatment, increased the proportion of patients dead on ambulance arrival to 42%. We recommend reporting similar categories of vital status to improve valid comparisons of prehospital mortality rates
- …