Complex Interactions of Temperature, Light and Tissue Damage on Seagrass Wasting Disease in Zostera marina

The temperate seagrass species eelgrass Zostera marina can be infected by the wasting disease pathogen Labyrinthula zosterae, which is believed to have killed about 90% of the seagrass in the Atlantic Ocean in the 1930s. It is not known why this opportunistic pathogen sometimes becomes virulent, but the recurrent outbreaks may be due to a weakening of the Z. marina plants from adverse environmental changes. This study investigated the individual and interactive effects of multiple extrinsic factors (temperature, light, and tissue damage) on the host-pathogen interaction between Z. marina and L. zosterae in a fully crossed infection experiment. The degree of infection was measured as both lesion coverage and L. zosterae cell concentration. We also investigated if the treatment factors affect the chemical defense of the host, measured as the inhibitory capacity of seagrass extracts in bioassays with L. zosterae. Finally, gene expression of a set of targeted genes was quantified in order to investigate how the treatments change Z. marina’s response to infection. Light had a pronounced effect on L. zosterae infection measured as lesion coverage, where reduced light conditions increased lesions by 35%. The response to light on L. zosterae cell concentration was more complex and showed significant interaction with the temperature treatment. Cell concentration was also significantly affected by physical damage, where damage surprisingly resulted in a reduced cell concentration of the pathogen. No treatment factor caused detectable decrease in the inhibitory capacity of the seagrass extracts. There were several interactive effects between L. zosterae infection and the treatment factors on Z. marina growth, and on the expression of genes associated with immune defense, phenol synthesis and primary metabolism, showing that the molecular reaction toward L. zosterae infection depends on prevailing environmental conditions. Our study shows that individual or interactive effects of light, temperature and tissue damage can affect multiple aspects of host-pathogen interactions in seagrasses. These results highlight the complexity of marine host-pathogen systems, showing that more multi-factorial investigations are needed to gain a better understanding of disease in marine plants under different environmental conditions

Seagrass wasting disease varies with salinity and depth in natural Zostera marina populations

In the 1930s the wasting disease pathogen Labyrinthula zosterae is believed to have killed 90% of the temperate seagrass Zostera marina in the Atlantic Ocean. Despite the devastating impact of this disease the host–pathogen interaction is still poorly understood, and few field studies have investigated factors correlating with the prevalence and abundance of L. zosterae. This study measures wasting disease in natural populations of Z. marina, showing a strong correlation between the disease and both salinity and water depth. No infection was detected in Z. marina shoots from low salinity (13–25 PSU) meadows, whereas most shoots carried the disease in high salinity (25–29 PSU). Shallow (1 m) living Z. marina shoots were also more infected compared to shoots in deeper (5 m) meadows. In addition, infection and transplantation experiments showed that Z. marina shoots from low salinity meadows with low pathogen pressure were more susceptible to L. zosterae infection. The higher susceptibility could not be explained by lower content of inhibitory defense compounds in the shoots. Instead, extracts from all Z. marina shoots significantly reduced pathogen growth, suggesting that Z. marina contains inhibitory compounds that function as a constitutive defense. Overall, the results show that seagrass wasting disease is common in natural Z. marina populations in the study area and that it increases with salinity and decreases with depth. Our findings also suggest that low salinity areas can act as a refuge against seagrass wasting disease

Modulation of the Eelgrass – Labyrinthula zosterae Interaction Under Predicted Ocean Warming, Salinity Change and Light Limitation

Marine infectious diseases can have large-scale impacts when they affect foundation species such as seagrasses and corals. Interactions between host and disease, in turn, may be modulated by multiple perturbations associated with global change. A case in point is the infection of the foundation species Zostera marina (eelgrass) with endophytic net slime molds (Labyrinthula zosterae), the putative agent of eelgrass wasting disease that caused one of the most severe marine pandemics across the North-Atlantic in the 1930s. The contemporary presence of L. zosterae in many eelgrass meadows throughout Europe raises the question whether such a pandemic may re-appear if coastal waters become more eutrophic, warmer and less saline. Accordingly, we exposed uninfected Baltic Sea Z. marina plants raised from seeds to full factorial combinations of controlled L. zosterae inoculation, heat stress, light limitation (mimicking one consequence of eutrophication) and two salinity levels. We followed eelgrass wasting disease dynamics, along with several eelgrass responses such as leaf growth, mortality and carbohydrate storage, as well as the ability of plants to chemically inhibit L. zosterae growth. Contrary to our expectation, inoculation with L. zosterae reduced leaf growth and survival only under the most adverse condition to eelgrass (reduced light and warm temperatures). We detected a strong interaction between salinity and temperature on L. zosterae abundance and pathogenicity. The protist was unable to infect eelgrass under high temperature (27°C) in combination with low salinity (12 psu). With the exception of a small positive effect of temperature alone, no further effects of any of the treatment combinations on the defense capacity of eelgrass against L. zosterae were detectable. This work supports the idea that contemporary L. zosterae isolates neither represent an immediate risk for eelgrass beds in the Baltic Sea, nor a future one under the predicted salinity decrease and warming of the Baltic Sea

Response of foundation macrophytes to near‐natural simulated marine heatwaves

Marine heatwaves have been observed worldwide and are expected to increase in both frequency and intensity due to climate change. Such events may cause ecosystem reconfigurations arising from species range contraction or redistribution, with ecological, economic and social implications. Macrophytes such as the brown seaweed Fucus vesiculosus and the seagrass Zostera marina are foundation species in many coastal ecosystems of the temperate northern hemisphere. Hence, their response to extreme events can potentially determine the fate of associated ecosystems. Macrophyte functioning is intimately linked to the maintenance of photosynthesis, growth and reproduction, and resistance against pathogens, epibionts and grazers. We investigated morphological, physiological, pathological and chemical defence responses of western Baltic Sea F. vesiculosus and Z. marina populations to simulated near‐natural marine heatwaves. Along with (a) the control, which constituted no heatwave but natural stochastic temperature variability (0HW), two treatments were applied: (b) two late‐spring heatwaves (June, July) followed by a summer heatwave (August; 3HW) and (c) a summer heatwave only (1HW). The 3HW treatment was applied to test whether preconditioning events can modulate the potential sensitivity to the summer heatwave. Despite the variety of responses measured in both species, only Z. marina growth was impaired by the accumulative heat stress imposed by the 3HW treatment. Photosynthetic rate, however, remained high after the last heatwave indicating potential for recovery. Only epibacterial abundance was significantly affected in F. vesiculosus. Hence both macrophytes, and in particular F. vesiculosus, seem to be fairly tolerant to short‐term marine heatwaves at least at the intensities applied in this experiment (up to 5°C above mean temperature over a period of 9 days). This may partly be due to the fact that F. vesiculosus grows in a highly variable environment, and may have a high phenotypic plasticity

Seagrass Wasting Disease Impact of abiotic factors and chemical defense

Eelgrass, Zostera marina, is the dominant seagrass species in the northern hemisphere, and forms large meadows that provide several important ecosystem services. In the 1930s about 90% of the Z. marina populations in the Atlantic Ocean were killed in an epidemic caused by the wasting disease pathogen Labyrinthula zosterae. Despite the devastating impact of this disease the host-pathogen interaction is still poorly understood, and there is limited knowledge about factors that influence the disease. In this thesis I study how abiotic factors can impact the relationship between Z. marina and L. zosterae, and investigate if the seagrass can defend itself against the pathogen through production of inhibitory compounds. In two field studies I investigated if laboratory results, showing that low salinity mitigate L. zosterae infection, can be translated to the field. Surveys along the salinity gradient of the Swedish coast show that L. zosterae infection is high in high salinity areas (20 - 25 PSU), and that infection generally decreases or disappears at low salinity (<10 PSU). These findings suggest that low salinity areas can act as a refuge against seagrass wasting disease. However, in contrast to previous studies, salinities as low as 6 PSU do not always exclude infection in Z. marina meadows. The disease was detected, in low concentrations through DNA-based methods,, in several meadows in the Baltic proper. Thus, it is possible that a L. zosterae strain has adapted to the low salinity environment of the Baltic Sea. This could lead to an increased distribution of the pathogen in areas previously considered to be protected from the pathogen, and potentially result in wasting disease outbreaks also in low salinity Z. marina meadows. One way for Z. marina to withstand infection by L. zosterae is to be chemically defended through the production of secondary metabolites. All Z. marina shoots investigated in this thesis produced chemical compounds that inhibited L. zosterae growth. Laboratory experiments implied that the production is not induced by a high pathogen pressure, as previously suggested, but rather that Z. marina contains inhibitory compounds that function as a constitutive defense. Chemical analyses further detected three partially purified inhibitory fractions against the pathogen, and characterization of the compounds showed that these are new, yet unknown, compounds from Z. marina. A laboratory infection experiment was performed to investigate how individual and interactive effects of extrinsic factors affect L. zosterae infection in Z. marina. The results showed a complex host-pathogen interaction, with several interactions between light, temperature, tissue damage, and infection that affected growth, production of inhibitory compounds, and gene expression in Z. marina. Overall, light intensity had the strongest effect on wasting disease, where reduced light intensity resulted in a significant increase in lesion coverage

Att arbeta med textanalys och tolkning av text i populärmusikaliska genrer

Syftet med detta arbete är att utforma, pröva och utvärdera ett arbetssätt för textanalys och tolkning av text i sångundervisning inom populärmusikaliska genrer. Utvecklandet av arbetssättet tar utgångspunkt i två olika sångpedagogers syn på hur arbetet med text ska genomföras. Undersökningen har genomförts med två deltagare som deltar på två sånglektioner och i en intervju, vilka har dokumenterats med videoinspelning. Resultatet indikerar att arbeta med textanalys i sångundervisning kan leda till ett mer närvarande och nyanserat uttryck hos sångeleven, och i samma veva att även tekniska detaljer i sången kan komma av sig självt på köpet. Dessutom kan fokuset på texten leda till att sångeleven får nya perspektiv på sig själv som sångare och genom det befrias från en del prestationskrav kopplat till sångteknik. Samtidigt kan analysarbetet uppfattas som att fokus blir mer på att förstå, och realisera vad textförfattaren vill säga snarare än på sångarens egen intention med texten. Detta strider till viss del mot idealet inom populärmusikaliska genrer där sångaren förväntas vara mer fri och personlig i sin tolkningav texten. Konkreta verktyg som underlättar arbetet med tolkande av text är t.ex. att arbeta med känslor utifrån slumpmässigt dragna känsloord, att markera olika känslolägen eller stämningari texten och att leta efter känslomässiga vändpunkter i en text

Cardiovascular disease and diabetes or renal insufficiency : the risk of ischemic stroke and risk factor intervention

Background In patients with diabetes mellitus (DM) or chronic kidney disease (CKD), established cardiovascular disease (CVD) is associated with an increased risk of recurrent events and poor outcome. Ischemic stroke after an acute myocardial infarction (AMI) is a devastating event that carries high risks of decreased patient independence and death. Among patients with DM or CKD, the risk of an ischemic stroke within a year following an AMI is not known. Improved risk factor control is required to reduce the likelihood of CVD recurrence. Guidelines recommend target lipid profile and blood pressure values; however, data show that these targets are often not met. Therefore, there remains an urgent need for improved cardiovascular secondary preventive follow- up. Aims The aims of the present studies were to define trends in the incidence and predictors of ischemic stroke after an AMI in patients with DM or CKD. Furthermore to assess whether secondary preventive follow-up with nurse-based telephone follow-up including medication titration after CVD improves risk factor values in patients with DM or CKD and to investigate if this method performs better than usual care to implement a new treatment guideline in diabetic patients. Methods To assess the risk of post-AMI ischemic stroke, patient data were obtained from the Swedish Register of Information and Knowledge about Swedish Heart Intensive Care Admissions (RIKS-HIA). In separate studies, we compared a total of 173 233 AMI patients with and without DM, and 118 434 AMI patients with and without CKD. Within the nurse-based age-independent intervention to limit evolution of disease (NAILED) trial, we investigated a nurse-based cardiovascular secondary preventive follow-up protocol. Patients with acute coronary syndrome, stroke, or transient ischemic attack were randomized to receive either nurse-based telephone follow-up (intervention) or usual care (control). Low-density lipoprotein (LDL-C) levels and blood pressure (BP) were measured at 1 month (baseline) and 12 months post- discharge. Intervention patients with above-target baseline values received medication titration to achieve treatment goals, while the measurements for control patients were forwarded to their general practitioners for assessment. We calculated the changes in LDL-C level and BP between baseline and 12 months post-discharge, and compared  these changes between 225 intervention patients and 215 control patients with concurrent DM or CKD. During the course of the NAILED trial, new secondary preventive guidelines for DM patients were released, including a new LDL-C target value. To assess adherence to the new guidelines within the NAILED trial, we compared LDL-C levels in the 101 intervention patients and 100 control patients with DM. Results Ischemic stroke after AMI The rates of ischemic stroke within one-year after admission for an AMI decreased over time, from 7.1% in 1998–2000 to 4.7% in 2007–2008 among DM patients, and from 4.2% to 3.7% during the same time periods for non-diabetic patients. Lower stroke risk was associated with percutaneous coronary intervention (PCI) and initiation of secondary preventive treatments in-hospital. In-hospital ischemic stroke occurred in 2.3% of CKD patients and 1.2% of non-CKD patients, with no change in these incidences over time. The rates of one-year post- discharge ischemic stroke decreased between 2003–2004 and 2009–2010 from 4.1% to 2.5% among CKD patients, and from 2.0% to 1.3% among non-CKD patients. Lower rates of post-discharge stroke were associated with PCI and statins. Cardiovascular secondary preventive follow-up Among DM and CKD patients with above-target baseline values in the NAILED trial, the median LDL-C value at 12 months was 2.2 versus 3.0 mmol/L (p&lt;0.001) and median systolic BP was 140 versus 145 mmHg (p=0.26) for intervention and control patients, respectively. Before the guideline change, 96% of the intervention and 70% of the control patients reached the target LDL-C value (p&lt;0.001). After the guideline change, the corresponding respective proportions were 65% and 36% (p&lt;0.001). Conclusion Ischemic stroke is a fairly common post-AMI complication among patients with DM and CKD. This risk of stroke has decreased during recent years, possibly due to the increased use of evidence-based therapies. Compared with usual care, cardiovascular secondary prevention including nurse-based telephone follow-up improved LDL-C values at 12 months after discharge in patients with DM or CVD, and led to more efficient implementation of new secondary preventive guidelines.

Att arbeta med textanalys och tolkning av text i populärmusikaliska genrer

Syftet med detta arbete är att utforma, pröva och utvärdera ett arbetssätt för textanalys och tolkning av text i sångundervisning inom populärmusikaliska genrer. Utvecklandet av arbetssättet tar utgångspunkt i två olika sångpedagogers syn på hur arbetet med text ska genomföras. Undersökningen har genomförts med två deltagare som deltar på två sånglektioner och i en intervju, vilka har dokumenterats med videoinspelning. Resultatet indikerar att arbeta med textanalys i sångundervisning kan leda till ett mer närvarande och nyanserat uttryck hos sångeleven, och i samma veva att även tekniska detaljer i sången kan komma av sig självt på köpet. Dessutom kan fokuset på texten leda till att sångeleven får nya perspektiv på sig själv som sångare och genom det befrias från en del prestationskrav kopplat till sångteknik. Samtidigt kan analysarbetet uppfattas som att fokus blir mer på att förstå, och realisera vad textförfattaren vill säga snarare än på sångarens egen intention med texten. Detta strider till viss del mot idealet inom populärmusikaliska genrer där sångaren förväntas vara mer fri och personlig i sin tolkningav texten. Konkreta verktyg som underlättar arbetet med tolkande av text är t.ex. att arbeta med känslor utifrån slumpmässigt dragna känsloord, att markera olika känslolägen eller stämningari texten och att leta efter känslomässiga vändpunkter i en text

Samhällsinstanser i arbetet med barn som bevittnar våld mot mamma

The aim with this study is to investigate how social agencies work with children that are whitnessing physical violence against their mother by a man they have a close relationship with. The study is focusing on what kind of interventions that are directed to those children, in some cases also the whole family, and what effects these have on them. The study is also focusing on the cooperation between different social agencies that are working with the target group and what effects a wellworking cooperation may have. A qualitative method has been used for the study, based on semi-structured interviews with different kind of social workers that work with the target group in question. The selection of social workers consisted on five different interviewees within four different departments.The results of the study shows what interventions are the most common ones and what effects these are having on the children and their families according to previous research and according to the interviewed social workers. It also shows the importance of having a wellworking cooperation between relevant social agencies according to previous research and how the cooperation is working in practical social work according to the interviewed social workers. Eventually the results have been analysed by the three theories: attachment theory, Antonovsky’s KASAM and risk- and protection factors. The study shows the importance of aiming the right interventions to those who are exposed and how important it is with a good cooperation between different social agencies so that the interventions are far-reaching enough to support the exposed in every part of their life and to meet their every need of support. This also so those who are exposed suffer from less symptoms followed by witnessing physical violence and provide good conditions to have a healthy physical, social and psychological development