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Vägen till helvetet är kantad av defekta humlor Pollination är avgörande både för grödor och vilda växter, men de senaste decennierna har antalet pollinatörer minskat, särskilt de viktiga humlorna. Humlor får avkomma på ett sätt som gör dem särskilt känsliga för inavel. Jag har prövat två metoder för att upptäcka inavel i två humlearter, mosshumla (Bombus muscorum) och haghumla (Bombus sylvarum),Bumblebees, a pollinator, are haplodiploid with single-locus complementary sex determination (sl-CSD) and as a consequence can give rise to diploid males. Diploid males have previously been found to be associated with high costs and multiple severe effects. Mostly studied on Bombus terrestris, a common species, the frequency of diploid males have been suggested as a measure of inbreeding and there

Human-mediated landscape alterations has led to habitat loss for many pollinator species, causing declines in both diversity and abundance. In addition to habitat loss, habitat fragmentation can reduce population connectivity and lead to declines in genetic diversity, the variation that enable adaptation to novel conditions. In spite of this, to which extent pollinator species have lost genetic di

The trade-off between current and future reproduction is universal and forms the basis of life-history theory. Brood size manipulations is one of the most common way to test this trade-off. Although the effect of brood size manipulation on immune response have been tested in many studies, little is known about baseline innate immune function. To fill this gap, I created three groups (enlarged, red

Organisms must aim to find suitable places to settle and reproduce, and this choice varies according to environmental and individual features. The choice of an adequate place can have crucial repercussions on the reproductive success and thus, animal fitness. In many species natal dispersal is a key process accounting for crucial implications for a species spatial distribution. Hence, natal disper

The sperm whale (Physeter macrocephalus) is a cosmopolitan species with a broad distribution that ranges from the tropics to the poles. Males are known to migrate between nutrient-rich high latitude waters and low latitude breeding grounds. In the North Atlantic, large males are found up to the southern limits of the ice edge. However, their seasonal distribution patterns remain poorly known in th

The creation of floral resources for pollinators, such as flower strips, is seen as a relevant and needed intervention but comes with both cost and an opportunity for farmers. It may be worth it if, for example, pollinators are attracted to pollinator-dependent crops and deliver crop pollination. Unfortunately, since pollinators are mobile organisms, the spatial distribution of crop pollination re

Bumblebees (Bombus terrestris) are central place foragers, that have been shown to use path integration based vectors to navigate their environment. They also have remarkable learning and memory abilities, and can readily learn different cues. Recently, a behavioural assay has been developed that allows for rigorous testing of these mechanisms in a laboratory setting. This thesis aimed to use this

Överdrivet synkroniserade urladdningar i mänskliga hjärnkulturer Under flera decennier har forskare försökt förklara vad det är som sker i hjärnan under ett epileptiskt anfall. Detta tillstånd kännetecknas av att små eller stora populationer av hjärnceller överaktiveras i synkroni under förloppet av sekunder eller flera timmar. En obalans mellan inhibitoriska hjärnceller, som stänger av celler ocHigh synchronicity within cortical circuits resulting from imbalance between excitatory and inhibitory activity is a key feature of epileptiform seizures and different neuronal development stages. The exact mechanism contributing to this activity is still debated but multiple receptors expressed by cortical cells such as Glutamatergic, GABAergic neurons and astrocytes could be involved. With the r

This thesis revisits one of the most prominent contributions to the literature on labour income shares by \citet{blanchard1997} and offers an alternative perspective on the developments in European and Anglo-Saxon countries between 1970 and 2019. Labour shares in both groups of countries declined resulting from changes in relative factor prices and quantities. I find that changes in relative facto

In this project, RAM, we wanted to question today’s consumption of furniture and create furniture with longevity in mind. Explore the possibilities of designing furniture that would grow with you through life to avoid having the need to buy new in different stages of life. The project resulted in a storage system that can adapt to different living situations which can accrue through life. O

Vid byggande, sanering av före detta avfallsdeponier eller liknande företag som påverkar marken krävs noggranna markundersökningar för att kunna utföra arbetet så tids- och kostnadseffektivt som möjligt samt för att minimera miljöpåverkan. Sådana markundersökningar sker inte sällan med hjälp av geofysiska mätmetoder, där seismik är en av dem. Det är vanligt att använda aktiva metoder med exempelvi

Bark beetle attacks have led to widespread tree disturbance and deaths in many parts of the world, and thereby also economic and biodiversity losses. Forest-rich Sweden has experienced periodic attacks, latest in 2018. There is a great interest in identifying the most important explanatory features behind bark beetle attacks and making spatial predictions on where attacks might happen. This could

Gensax löser gåta om cellandning Gensaxen CRISPR-Cas9 är ett användbart redskap för att studera proteiner och deras funktioner. Den tillåter modifikationer att göras på specifika positioner på DNA som kan resultera i olika varianter av proteiner. Dessa varianter kan studeras och slutsatser kan dras om deras funktioner. Här utvärderas en CRISPR-Cas9-baserad metod, samt används för att studera samm

Plastic production and disposal have excessively contributed to climate change and other environmental problems. Therefore, the green route for the production of recyclable polymers, which is industrially and economically practical, is indispensable. 2,5-furan dicarboxylic acid (FDCA) synthesised from 5-Hydroxymethylfurfural (HMF) is a new alternative biobased resource for polymers. FDCA has been

T-celler – kroppens eget försvar för att besegra barncancer I Sverige drabbas runt 350 barn av cancer varje år. En variant av barncancer där tumörerna ofta uppstår på binjurarna och påverkar nervsystemet är neuroblastom (NBL). I det här projektet har vi studerat hur immunförsvaret och då mer specifikt hur mördar-T-cellerna kan användas för att bekämpa cancern. Genom att hitta nya målproteiner somNeuroblastoma (NBL) is the most common pediatric extracranial solid tumor and often manifests in the adrenal gland affecting the sympathetic nervous system. Despite many treatment alternatives, the risk of relapse remains, and the overall five-year survival is around 50 %. By downregulating major histocompatibility complex I (MHC-I), the NBL cells can evade the immune system affecting the function

Detection of c-di-GMP level in Bacillus subtilis with Biosensors Cyclic dinucleotides are signaling molecules that control several critical processes in bacteria. The most studied example is cyclic dimeric guanosine 3',5'-monophosphate (c-di-GMP) which is a universal bacterial second messenger. C-di-GMP is known to affect several cellular processes such as biofilm formation and dispersion

Under de senaste 30 åren har all elektronik fått allt mindre storlek. Detta beror på att man har lyckats skala ned de komponenter som bygger upp dagens elektronik till nanoskalan. En av de allra viktigaste strukturerna som har bidragit till den här utvecklingen är nanotrådar, som är i storlek av en miljarddels meter. Nanotrådar är små avlånga strukturer som är kristallina och kan användas att byggIII-V semiconductor material based nanowires have been extensively studied and shown to be a very exciting building block for future electronics. Material systems such as GaSb show a lot of promise in optoelectric and thermoelectric generation applications because of its high electron mobility and small bandgap. Although there is a lot of research about III-V nanowires, a gap in understanding anti

Alexander’s Disease is a progressive neurological disorder caused by a wide array of dominant, gain of function mutations in the GFAP gene. The disorder is characterized by the accumulation of GFAP in astrocytes, leading to the formation of protein inclusion bodies known as Rosenthal fibers. This results in a disruption of astrocytic function and the subsequent degeneration of white matter. Howeve

Understanding the effect of Myc on lung cancer immune signalling in vitro and in vivo Immune checkpoint blockade therapy (ICBT) is a promising treatment option that is commonly used for advanced non-small cell lung cancer (NSCLC). Immune checkpoint inhibitors targeting the PD-1/PD-L1 interaction have demonstrated remarkable effects. Blocking the PD-1/PD-L1 axis restores tumor cell recognition and

Bifidobakterier för bättre hälsa Bifidobakterier ingår i en familj av bakterier som kallas för mjölksyrabakterier. Många av dessa bakterier har en Y-form, därav namnet ”bifid” som betyder ”tvådelad”. Bifidobakterierna återfinns ofta i mag-tarmkanalen hos framförallt spädbarn. Dessa bakterier är fördelaktiga för den generella hälsan och kan påverka utvecklingen av bland annat immunsystemet och hjä