Seawater carbonate chemistry and net calcification during experiments with coral communities, 2009

Acidification of seawater owing to oceanic uptake of atmospheric CO2 originating from human activities such as burning of fossil fuels and land-use changes has raised serious concerns regarding its adverse effects on corals and calcifying communities. Here we demonstrate a net loss of calcium carbonate (CaCO3) material as a result of decreased calcification and increased carbonate dissolution from replicated subtropical coral reef communities (n=3) incubated in continuous-flow mesocosms subject to future seawater conditions. The calcifying community was dominated by the coral Montipora capitata. Daily average community calcification or Net Ecosystem Calcification (NEC=CaCO3 production - dissolution) was positive at 3.3 mmol CaCO3 m-2 h-1 under ambient seawater pCO2 conditions as opposed to negative at -0.04 mmol CaCO3 m-2 h-1 under seawater conditions of double the ambient pCO2. These experimental results provide support for the conclusion that some net calcifying communities could become subject to net dissolution in response to anthropogenic ocean acidification within this century. Nevertheless, individual corals remained healthy, actively calcified (albeit slower than at present rates), and deposited significant amounts of CaCO3 under the prevailing experimental seawater conditions of elevated pCO2.

Seawater carbonate chemistry in Hog reef, Bermuda reef community, 2010

Despite the potential impact of ocean acidification on ecosystems such as coral reefs, surprisingly, there is very limited field data on the relationships between calcification and seawater carbonate chemistry. In this study, contemporaneous in situ datasets of seawater carbonate chemistry and calcification rates from the high-latitude coral reef of Bermuda over annual timescales provide a framework for investigating the present and future potential impact of rising carbon dioxide (CO2) levels and ocean acidification on coral reef ecosystems in their natural environment. A strong correlation was found between the in situ rates of calcification for the major framework building coral species Diploria labyrinthiformis and the seasonal variability of [CO32-] and aragonite saturation state omega aragonite, rather than other environmental factors such as light and temperature. These field observations provide sufficient data to hypothesize that there is a seasonal "Carbonate Chemistry Coral Reef Ecosystem Feedback" (CREF hypothesis) between the primary components of the reef ecosystem (i.e., scleractinian hard corals and macroalgae) and seawater carbonate chemistry. In early summer, strong net autotrophy from benthic components of the reef system enhance [CO32-] and omega aragonite conditions, and rates of coral calcification due to the photosynthetic uptake of CO2. In late summer, rates of coral calcification are suppressed by release of CO2 from reef metabolism during a period of strong net heterotrophy. It is likely that this seasonal CREF mechanism is present in other tropical reefs although attenuated compared to high-latitude reefs such as Bermuda. Due to lower annual mean surface seawater [CO32-] and omega aragonite in Bermuda compared to tropical regions, we anticipate that Bermuda corals will experience seasonal periods of zero net calcification within the next decade at [CO32-] and omega aragonite thresholds of ~184 micro moles kg-1 and 2.65. However, net autotrophy of the reef during winter and spring (as part of the CREF hypothesis) may delay the onset of zero NEC or decalcification going forward by enhancing [CO32-] and omega aragonite. The Bermuda coral reef is one of the first responders to the negative impacts of ocean acidification, and we estimate that calcification rates for D. labyrinthiformis have declined by >50% compared to pre-industrial times.

Grain size distribution and sea level changes in Gåsfjärden fjord

We analysed long-term variations in grain-size distribution in sediments from Gåsfjärden, a fjord-like inlet on the south-west Baltic Sea, and explored potential drivers of the recorded changes in sediment grain-size data. Over the last 5.4 thousand years (ka), the relative sea level decreased 17 m in the study region, caused by isostatic land uplift. As a consequence, Gåsfjärden has been transformed from an open coastal setting into a semi-closed inlet surrounded on the east by numerous small islands. To quantitatively estimate the morphological changes in Gåsfjärden over the last 5.4 ka and to further link the changes to our grain-size data, a digital elevation model (DEM)-based openness index was calculated. In the period between 5.4 and 4.4 ka BP, the inlet was characterised by the largest openness index. During this interval, the highest sand contents (~0.4 %) and silt/clay ratios (~0. 3) in the sediment sequence were recorded, indicating relatively high bottom water energy. After 4.4 ka BP, the average sand content was halved to ~0.2 % and the silt/clay ratios showed a significant decreasing trend over the last 4 ka. These changes are found to be associated with the gradual embayment of Gåsfjärden as represented in the openness index. The silt/clay ratios exhibited a delayed and slower change compared with the sand contents, which further suggest that finer particles are less sensitive to changes in hydrodynamic energy. Our DEM-based coastal openness index has proved to be a useful tool for interpreting the sedimentary grain-size record.

Seawater carbonate chemistry and calcification rate during mesocosm experiments with coral Montipora capitata, 2008

A long-term (10 months) controlled experiment was conducted to test the impact of increased partial pressure of carbon dioxide (pCO2) on common calcifying coral reef organisms. The experiment was conducted in replicate continuous flow coral reef mesocosms flushed with unfiltered sea water from Kaneohe Bay, Oahu, Hawaii. Mesocosms were located in full sunlight and experienced diurnal and seasonal fluctuations in temperature and sea water chemistry characteristic of the adjacent reef flat. Treatment mesocosms were manipulated to simulate an increase in pCO2 to levels expected in this century [midday pCO2 levels exceeding control mesocosms by 365 ± 130 µatm (mean ± sd)]. Acidification had a profound impact on the development and growth of crustose coralline algae (CCA) populations. During the experiment, CCA developed 25% cover in the control mesocosms and only 4% in the acidified mesocosms, representing an 86% relative reduction. Free-living associations of CCA known as rhodoliths living in the control mesocosms grew at a rate of 0.6 g buoyant weight per year while those in the acidified experimental treatment decreased in weight at a rate of 0.9 g buoyant weight per year, representing a 250% difference. CCA play an important role in the growth and stabilization of carbonate reefs, so future changes of this magnitude could greatly impact coral reefs throughout the world. Coral calcification decreased between 15% and 20% under acidified conditions. Linear extension decreased by 14% under acidified conditions in one experiment. Larvae of the coral Pocillopora damicornis were able to recruit under the acidified conditions. In addition, there was no significant difference in production of gametes by the coral Montipora capitata after 6 months of exposure to the treatments.

Late-career international migration and reproductive work. A comparison between Peruvian and Ukrainian women in the Southern Europe

Research on the relationship between reproductive work and women´s life trajectories including the experience of labour migration has mainly focused on the case of relatively young mothers who leave behind, or later re-join, their children. While it is true that most women migrate at a younger age, there are a significant number of cases of men and women who move abroad for labour purposes at a more advanced stage, undertaking a late-career migration. This is still an under-estimated and under-researched sub-field that uncovers a varied range of issues, including the global organization of reproductive work and the employment of migrant women as domestic workers late in their lives. By pooling the findings of two qualitative studies, this article focuses on Peruvian and Ukrainian women who seek employment in Spain and Italy when they are well into their forties, or older. A commonality the two groups of women share is that, independently of their level of education and professional experience, more often than not they end up as domestic and care workers. The article initially discusses the reasons for late-career female migration, taking into consideration the structural and personal determinants that have affected Peruvian and Ukrainian women’s careers in their countries of origin and settlement. After this, the focus is set on the characteristics of domestic employment at later life, on the impact on their current lives, including the transnational family organization, and on future labour and retirement prospects. Apart from an evaluation of objective working and living conditions, we discuss women’s personal impressions of being domestic workers in the context of their occupational experiences and family commitments. In this regard, women report varying levels of personal and professional satisfaction, as well as different patterns of continuity-discontinuity in their work and family lives, and of optimism towards the future. Divergences could be, to some extent, explained by the effect of migrants´ transnational social practices and policies of states.

Effektiv lagerstyrning med AHP och tvådimensionell artikelklassificering : En fallstudie på Permobil AB, Timrå

Costs related to inventory are usually a significant amount of the company’s total assets. Despite this, companies in general don’t pay a lot of interest in it, even if the benefits from effective inventory are obvious when it comes to less tied up capital, increased customer satisfaction and better working environment. Permobil AB, Timrå is in an intense period when it comes to revenue and growth. The production unit is aiming for an increased output of 30 % in the next two years. To make this possible the company has to improve their way to distribute and handle material,The purpose of the study is to provide useful information and concrete proposals for action, so that the company can build a strategy for an effective and sustainable solution when it comes to inventory management. Alternative methods for making forecasts are suggested, in order to reach a more nuanced perception of different articles, and how they should be managed. Analytic Hierarchy Process (AHP) was used in order to give specially selected persons the chance to decide criteria for how the article should be valued. The criteria they agreed about were annual volume value, lead time, frequency rate and purchase price. The other method that was proposed was a two-dimensional model where annual volume value and frequency was the criteria that specified in which class an article should be placed. Both methods resulted in significant changes in comparison to the current solution. For the spare part inventory different forecast methods were tested and compared with the current solution. It turned out that the current forecast method performed worse than both moving average and exponential smoothing with trend. The small sample of ten random articles is not big enough to reject the current solution, but still the result is a reason enough, for the company to control the quality of the forecasts.

Energy, emergy, and the city

In his book “Environment, Power, and Society” (1971) H.T. Odum introduced a picture of the energy metabolism of a city based on Wolman's paper from 1965 (Sci. Am., 213: 179-190). With the development of the emergy analysis--a branch of energy systems accounting--several authors have contributed to develop quantitative measures of HT Odum’s picture, which from many perspectives are diverging from traditional energy studies. In this paper, studies using emergy analysis to study cities are reviewed. The research regarding emergy and cities had during the period 1975-1995 its focus on cities in the United States, e.g. Miami, Jacksonville, San Francisco and Chicago. The research during 1995-2005 was almost exclusively focused on Taipei. From approximately 2006 up till 2015 the research focus has been on Chinese cities; Macao, Beijing and 37 other Chinese cities have been investigated. But there are resent also studies made on Rome (Italy) and Montreal (Canada). Studies up to about 2007/2008 were generally concerned with understanding spatial aspects of the cities investigated. After that, evaluating the sustainability of cities has become a main research focus.

Simulations in 3D research : Can Unity3D be used to simulate a 3D display system?

Mid Sweden University is currently researching how to capture more of a scene with a camera and how to create 3D images that does not require extra equipment for the viewer. In the process of this research they have started looking into simulating some of the tests that they wish to conduct. The goal of this project is to research whether the 3D graphics engine Unity3D could be used to simulate these tests, and to what degree. To test this a simulation was designed and implemented. The simulation used a split display system where each camera is directly connected to a part of the screen and using the position of the viewer the correct part of the camera feed is shown. Some literary studies were also done into how current 3D technology works. The simulation was successfully implemented and shows that simple simulation can be done in Unity3D, however, some problems were encountered in the process. The conclusion of the project show that there is much work left before simulation is viable but that there is potential in the technology and that the research team should continue to investigate it.

Problematiken med estimering i projekt inom agil systemutveckling : Analys och undersökning av agil systemutveckling hos SDC

In today’s society, IT-Companies often have a hard time estimating changed requirements. This leads to that the clients’ confidence is negatively affected and is one of the main reasons why this has to be improved. The goal with this study was to find out what the most common problems regarding this issue are in IT-companies that works with agile software development. By analyzing one IT-company through a SWOT- and pareto-analysis the most common problems have been ascertained. The SWOT analysis have been created through interviews with selected employees to get a better understanding of the problems that the IT-company is facing. Furthermore was the pareto-analysis based on a survey that was sent out to many different employees to prioritize the problems. The reason why the survey was sent to different employees was to get a more objective input. The study showed that there was many different problems that needed attention. The most important problems was that the communication towards the client regarding requirements needed to be improved, better communication internally between different departments needed to be established, a method to quickly adapt and estimate change in requirements needed to be implemented and finally a method regarding witch key employees whom need to attend the planning of the program backlog. These problems have then been studied through interviews with other IT-companies and through a literature study. The conclusions that where drawn was that the client needs to be involved and updated through the whole project. Constant monitoring and communication regarding changed requirements needs to be processed and mediated. High standards needs to be set early towards the client in order to obtain as clear an image of the requirements as possible. Many different parties need to attend to the planning process for the program backlog before the start of the project. The client needs to be aware of that changed requirements will arise and that this will lead to that the first estimation may not necessarily be absolute. As long as the client is held up to date as well as participant through the whole project and problems are detected and mediated early, change in requirements should not be a huge problem. This is after all the purpose of being agile.

Praktisk eller teoretisk undervisning i naturvetenskap? : Vilket sätt gynnar eleverna?

Målet med denna studie var att studera hur elever lär sig på bästa sätt, om det är genom praktisk eller teoretisk inlärning i ämnet naturvetenskap eller om det är genom att använda sig av båda inlärningsformerna. Studien är baserad på observationer och intervjuer i en klass i årskurs tre. Eleverna fick göra ett för- och eftertest som analyserades. Testerna kompletteras med hjälp av analyserade intervjuer.   Studien visade blandade resultat. Vid några frågor sågs det tydligt att eleverna som hade haft en praktisk undervisning hade förstått, medan eleverna i den andra gruppen med teoretisk undervisning inte hade förstått. Resultatet visade också att vid vissa fall var resultaten tvärtom. Intervjuerna visade att majoriteten av eleverna tyckte att det praktiska arbetet var mer intressant och roligt. En slutsats var att vissa uppgifter förstår eleverna lättare med hjälp av praktisk undervisning och ibland tvärtom.   Resultaten diskuteras sedan i relation till den tidigare forskning som presenteras i del nummer två i uppsatsen. Diskussionsdelen i uppsatsen kommer att presentera metoddiskussionen, praktisk inlärning, teoretisk inlärning och ämnet naturvetenskap.

Erfarenheter av att vårda personer med demenssjukdom : En kvalitativ intervjustudie med distriktssköterskor

Bakgrund: Demenssjukdom är vanligt förekommande och denna patientgrupp ingår i distriktssköterskors uppdrag. Syfte: Att belysa distriktssköterskors erfarenheter av att möta personer med demensdiagnos och hur de anpassar vården utifrån vårdtagarens behov. Metod: En kvalitativ intervjustudie genomfördes med fyra stycken distriktssköterskor. För bearbetning av insamlad data användes innehållsanalys. Resultat: Analysen ledde till fram till fyra stycken kategorier: att möta en komplex vårdsituation, att bli utmanad, att ta till vara resurser och att anpassa sina vårdåtgärder till den enskilde eller till demenssjukdomen. Deltagarna förmedlade att personer med demenssjukdom är en utsatt och sårbar grupp och att vårda dem innebar en utmaning på flera olika plan. Det kräver fördjupade kunskaper och en förmåga att se till alla faktorer som omger denna patientgrupp, det är både utmanande, komplext och spännande. Att arbeta personcentrerat är något som både eftersträvas och görs i praktiken, även att ta till vara resurser som kommer vårdtagaren till godo. Slutsats: Distriktssköterskornas glädje och engagemang var framträdande och verkade vara kopplat till att de hade utbildning och kunskap. Forskning på personer med demenssjukdom och andra med nedsatt beslutsförmåga behövs och är önskvärt. Deras deltagande skulle ge värdefull kunskap som kan leda till att utveckla vården för denna patientgrupp.

Undervisa särbegåvade elever : Lärares förmåga att undervisa och stimulera särbegåvade elever i undervisningen

Den här studien berör lärares förmåga att undervisa och stimulera särbegåvade elever i skolan. Studien har genomförts genom formella kvalitativa intervjuer med lärare i årskurs ett till tre på en skola i ett mindre samhälle. Efter intervjuer och litteraturstudier har det visat sig att mycket av lärarnas tid många gånger koncentreras till elever som har svårt att nå målen. I skolan försöker man på olika sätt individualisera undervisningen och uppgifterna genom att låta eleverna få arbeta ofta med problemlösningar, men också erbjuda eleverna andra läromedel från högre årskurser. Särbegåvade elever har efter olika tester, som visar var de ligger kunskapsmässigt, fått flytta upp en årskurs om det visat att kunskapsnivån är långt mycket högre än övriga klasskamrater. Vidare visar det sig att det inte finns tillräckligt med tid och resurser för att kunna vara behjälplig alla elever och ofta hamnar de särbegåvade eleverna i skymundan då svaga elever kräver stor del av lärarnas tid och planering.