9,432 research outputs found
Norsk rÄ kumelk, en kilde til zoonotiske patogener?
The worldwide emerging trend of eating ânaturalâ foods, that has not been
processed, also applies for beverages. According to Norwegian legislation, all
milk must be pasteurized before commercial sale but drinking milk that has
not been heat-treated, is gaining increasing popularity. Scientist are warning
against this trend and highlights the risk of contracting disease from milkborne
microorganisms. To examine potential risks associated with drinking
unpasteurized milk in Norway, milk- and environmental samples were
collected from dairy farms located in south-east of Norway. The samples
were analyzed for the presence of specific zoonotic pathogens; Listeria
monocytogenes, Campylobacter spp., and Shiga toxin-producing Escherichia
coli (STEC). Cattle are known to be healthy carriers of these pathogens, and
Campylobacter spp. and STEC have a low infectious dose, meaning that
infection can be established by ingesting a low number of bacterial cells. L.
monocytogenes causes one of the most severe foodborne zoonotic diseases,
listeriosis, that has a high fatality rate. All three pathogens have caused milk
borne disease outbreaks all over the world, also in Norway.
During this work, we observed that the prevalence of the three examined
bacteria were high in the environment at the examined farms. In addition, 7%
of the milk filters were contaminated by STEC, 13% by L. monocytogenes and
4% by Campylobacter spp. Four of the STEC isolates detected were eaepositive,
which is associated with the capability to cause severe human
disease. One of the eae-positive STEC isolates were collected from a milk
filter, which strongly indicate that Norwegian raw milk may contain potential
pathogenic STEC.
To further assess the possibilities of getting ill by STEC after consuming raw
milk, we examined the growth of the four eae-positive STEC isolates in raw milk at different temperatures. All four isolates seemed to have ability to multiply in raw milk at 8°C, and one isolate had significant growth after 72 hours. Incubation at 6°C seemed to reduce the number of bacteria during the
first 24 hours before cell death stopped. These findings highlight the
importance of stable refrigerator temperatures, preferable < 4°C, for storage
of raw milk.
The L. monocytogenes isolates collected during this study show genetic
similarities to isolates collected from urban and rural environmental
locations, but different clones were predominant in agricultural
environments compared to clinical and food environments. However, the
results indicate that the same clone can persist in a farm over time, and that
milk can be contaminated by L. monocytogenes clones present in farm
environment.
Despite testing small volumes (25 mL) of milk, we were able to isolate both
STEC and Campylobacter spp. directly from raw milk. A proportion of 3% of
the bulk tank milk and teat milk samples were contaminated by
Campylobacter spp. and one STEC was isolated from bulk tank milk. L
monocytogenes was not detected in bulk tank milk, nor in teat milk samples.
The agricultural evolvement during the past decades have led to larger
production units and new food safety challenges. Dairy cattle production in
Norway is in a current transition from tie-stall housing with conventional
pipeline milking systems, to modern loose housing systems with robotic
milking. The occurrence of the three pathogens in this project were higher in
samples collected from farms with loose housing compared to those with tiestall
housing.
Pasteurization of cowâs milk is a risk reducing procedure to protect
consumers from microbial pathogens and in most EU countries, commercial
distribution of unpasteurized milk is legally restricted. Together, the results
presented in this thesis show that the animal housing may influence the level
of pathogenic bacteria in the raw milk and that ingestion of Norwegian raw
cowâs milk may expose consumers to pathogenic bacteria which can cause
severe disease, especially in children, elderly and in persons with underlying
diseases. The results also highlight the importance of storing raw milk at low
temperatures between milking and consumption.Ă
spise mat som er mindre prosessert og mer «naturlig» er en pÄgÄende
trend i Norge og i andre deler av verden. Interessen for Ă„ drikke melk som
ikke er varmebehandlet, sÄkalt rÄ melk, er ogsÄ Þkende. I Norge er det pÄbudt
Ă„ pasteurisere melk fĂžr kommersielt salg for Ă„ beskytte forbrukeren mot
sykdomsfremkallende mikroorganismer. Fagfolk advarer mot Ä drikke rÄ
melk, og pÄpeker risikoen for Ä bli syk av patogene bakterier som kan finnes i
melken.
I denne avhandlingen undersĂžker vi den potensielle risikoen det medfĂžrer Ă„
drikke upasteurisert melk fra Norge. I tillegg til Ă„ samle inn tankmelk- og
speneprÞver fra melkegÄrder i sÞrÞst Norge, samlet vi ogsÄ miljÞprÞver fra
de samme gÄrdene for Ä kartlegge forekomst og for Ä identifisere potensielle
mattrygghetsrisikoer i melkeproduksjonen. Alle prĂžvene ble analysert for de
zoonotiske sykdomsfremkallende bakteriene Listeria monocytogenes,
Campylobacter spp., og Shiga toksin-produserende Escherichia coli (STEC).
Kyr kan vĂŠre friske smittebĂŠrere av disse bakteriene, som dermed kan
etablere et reservoar pÄ gÄrdene. Bakteriene kan overfÞres fra gÄrdsmiljÞet
til melkekjeden og dermed utfordre mattryggheten. Disse bakteriene har
forÄrsaket melkebÄrne sykdomsutbrudd over hele verden, ogsÄ i Norge.
Campylobacter spp. og STEC har lav infeksiĂžs dose, som vil si at man kan bli
syk selv om man bare inntar et lavt antall bakterieceller. L. monocytogenes
kan gi sykdommen listeriose, en av de mest alvorlige matbÄrne zoonotiske
sykdommene vi har i den vestlige verden.
Resultater fra denne oppgaven viser en hĂžy forekomst av de tre patogenene i
gÄrdsmiljÞet. I tillegg var 7% av melkefiltrene vi testet positive for STEC, 13%
positive for L. monocytogenes og 4% positive for Campylobacter spp.. Fire av
STEC isolatene bar genet for Intimin, eae, som er ansett som en viktig
virulensfaktor som Ăžker sjansen for alvorlig sykdom. Ett av de eae-positive
isolatene ble funnet i et melkefilter, noe som indikerer at norsk rÄ melk kan
inneholde patogene STEC. For Ă„ videre vurdere risikoen for Ă„ bli syk av STEC
fra rÄ melk undersÞkte vi hvordan de fire eae-positive isolatene vokste i rÄ
melk lagret ved forskjellige temperaturer. For alle isolatene Ăžkte antall
bakterier etter lagring ved 8°C, og for et isolat var veksten signifikant. Etter
lagring ved 6°C ble antallet bakterier redusert de fÞrste 24 timene, deretter
stoppet reduksjonen i antall bakterier. Disse resultatene viser hvor viktig det
er Ä ha stabil lav lagringstemperatur for rÄ melk, helst < 4°C.
L. monocytogenes isolatene som ble samlet inn fra melkegÄrdene viste
genetiske likheter med isolater samlet inn fra urbane og rurale miljĂžer rundt
omkring i Norge. Derimot var kloner som dominerte i landbruksmiljĂžet
forskjellige fra kliniske isolater og isolater fra matproduksjonslokaler. Videre
sÄ man at en klone kan persistere pÄ en gÄrd over tid og at melk kan
kontamineres av L. monocytogenes kloner som er til stede i gÄrdsmiljÞet.
Til tross for smÄ testvolum av tankmelken (25 mL) fant vi bÄde STEC og
Campylobacter spp. i melkeprĂžvene. 3% av tankmelkprĂžvene og
speneprĂžvene var positive for Campylobacter spp. og ett STEC isolat ble
funnet i tankmelk. L. monocytogenes ble ikke funnet direkte i melkeprĂžvene.
Landbruket i Norge er i stadig utvikling der besetningene blir stĂžrre, men
fĂŠrre. Melkebesetningene er midt i en overgang der tradisjonell oppstalling
med melking pÄ bÄs byttes ut med lÞsdriftssystemer og melkeroboter.
Forekomsten av de tre patogenene funnet i denne studien var hĂžyere i
besetningene med lĂžsdrift sammenliknet med besetningene som hadde
melkekyrne oppstallet pÄ bÄs.
Pasteurisering er et viktig forebyggende tiltak for Ă„ beskytte konsumenter fra
mikrobielle patogener, og i de fleste EU-land er kommersielt salg av rÄ melk
juridisk begrenset. Denne studien viser at oppstallingstype kan pÄvirke
nivÄene av patogene bakterier i gÄrdsmiljÞet og i rÄ melk. Inntak av rÄ melk
kan eksponere forbruker for patogene bakterier som kan gi alvorlig sykdom,
spesielt hos barn, eldre og personer med underliggende sykdommer.
Resultatene underbygger viktigheten av Ă„ pasteurisere melk for Ă„ sikre
mattryggheten, og at det er avgjÞrende Ä lagre rÄ melk ved kontinuerlig lave
temperaturer for Ă„ forebygge vekst av zoonotiske patogener
TOWARDS AN UNDERSTANDING OF EFFORTFUL FUNDRAISING EXPERIENCES: USING INTERPRETATIVE PHENOMENOLOGICAL ANALYSIS IN FUNDRAISING RESEARCH
Physical-activity oriented community fundraising has experienced an exponential growth in popularity over the past 15 years. The aim of this study was to explore the value of effortful fundraising experiences, from the point of view of participants, and explore the impact that these experiences have on peopleâs lives. This study used an IPA approach to interview 23 individuals, recognising the role of participants as proxy (nonprofessional) fundraisers for charitable organisations, and the unique organisation donor dynamic that this creates. It also bought together relevant psychological theory related to physical activity fundraising experiences (through a narrative literature review) and used primary interview data to substantiate these. Effortful fundraising experiences are examined in detail to understand their significance to participants, and how such experiences influence their connection with a charity or cause. This was done with an idiographic focus at first, before examining convergences and divergences across the sample. This study found that effortful fundraising experiences can have a profound positive impact upon community fundraisers in both the short and the long term. Additionally, it found that these experiences can be opportunities for charitable organisations to create lasting meaningful relationships with participants, and foster mutually beneficial lifetime relationships with them. Further research is needed to test specific psychological theory in this context, including self-esteem theory, self determination theory, and the martyrdom effect (among others)
The Adirondack Chronology
The Adirondack Chronology is intended to be a useful resource for researchers and others interested in the Adirondacks and Adirondack history.https://digitalworks.union.edu/arlpublications/1000/thumbnail.jp
The Impact of a Play Intervention on the Social-Emotional Development of Preschool Children in Riyadh, Saudi Arabia
Practitioners working with children have emphasized that play is vital to childrenâs development, Links between childrenâs social-emotional development and play have been widely documented. However, rigorous research evidence of these links remains limited. This studyâs objectives were to measure the impact of play on childrenâs social-emotional development in the kingdom of Saudi Arabia; identify teachersâ viewpoints around the use of play intervention; and understand the childrenâs experience of play intervention. Fifty-nine children aged between five and six years, with mean age of 5.5 (SD 3.376) and eight teachers participated in the study. The study used a mixed-method strategy including questionnaires, interviews, and focus group discussions. Childrenâs social-emotional development was measured by using the Strengths and Difficulties Questioner (SDQ). A pre-/post-test counterbalanced design was used to measure the impact of the play intervention on childrenâs development. Teachersâ perspectives on play were obtained by interviewing eight teachers. Childrenâs views were gathered through focus group discussions. Repeated measures ANOVA was conducted to determine the differences in the SDQ score over three time points. Results showed that using unstructured loose parts play had positively impacted childrenâs social-emotional development. After participation in the play intervention, scores from the SDQ indicated that children demonstrated significantly less problematic emotional, conduct and peer relationship issues. They also scored significantly higher in their positive prosocial behaviour. These positive effects were sustained after six weeks of stopping the intervention. The play intervention did not however impact childrenâs hyperactivity level. The interviews analysis illustrates four main themes: concept and characteristics of play, play functions, developmental benefits of play, and play and practice. Regarding childrenâs discussion, affordance emerged as a main theme; this includes emotional, social, and functional affordances. Unstructured loose parts play intervention was demonstrated to have positive impacts on childrenâs social-emotional development. The studyâs findings support the view that play is a way to increase childrenâs development
Socio-endocrinology revisited: New tools to tackle old questions
Animalsâ social environments impact their health and survival, but the proximate links between sociality and fitness are still not fully understood. In this thesis, I develop and apply new approaches to address an outstanding question within this sociality-fitness link: does grooming (a widely studied, positive social interaction) directly affect glucocorticoid concentrations (GCs; a group of steroid hormones indicating physiological stress) in a wild primate? To date, negative, long-term correlations between grooming and GCs have been found, but the logistical difficulties of studying proximate mechanisms in the wild leave knowledge gaps regarding the short-term, causal mechanisms that underpin this relationship. New technologies, such as collar-mounted tri-axial accelerometers, can provide the continuous behavioural data required to match grooming to non-invasive GC measures (Chapter 1). Using Chacma baboons (Papio ursinus) living on the Cape Peninsula, South Africa as a model system, I identify giving and receiving grooming using tri-axial accelerometers and supervised machine learning methods, with high overall accuracy (~80%) (Chapter 2). I then test what socio-ecological variables predict variation in faecal and urinary GCs (fGCs and uGCs) (Chapter 3). Shorter and rainy days are associated with higher fGCs and uGCs, respectively, suggesting that environmental conditions may impose stressors in the form of temporal bottlenecks. Indeed, I find that short days and days with more rain-hours are associated with reduced giving grooming (Chapter 4), and that this reduction is characterised by fewer and shorter grooming bouts. Finally, I test whether grooming predicts GCs, and find that while there is a long-term negative correlation between grooming and GCs, grooming in the short-term, in particular giving grooming, is associated with higher fGCs and uGCs (Chapter 5). I end with a discussion on how the new tools I applied have enabled me to advance our understanding of sociality and stress in primate social systems (Chapter 6)
Free Movement of Persons and Access to the Labour Market: Lessons from the European Economic Community for the Association of Southeast Asian Nations Economic Community.
PhD Theses.While a regional framework on the free movement of persons does not exist within
the current AEC, it envisions advancing the region to have a freer flow of skilled labour. It
has initiated the regional movement of selected high-skilled labour through the MRAs on the
movement of selected professionals and the MNP on the movement of businesspersons.
However, the AEC does not have any integration at the regional level on the movement of
low-skilled labour. Thailand, which is the most preferred destination for low-skilled AEC
labour, has entered into bilateral agreements with other four AEC member states, namely,
Myanmar, Laos, Cambodia and Vietnam, in order to supplement the regional rule regarding
low-skilled labour.
This thesis postulates that the EEC free movement of persons framework, which
involved the movement of persons to pursue economic activities, could provide useful
lessons for the emerging AEC labour migration framework. The main supporting reason for
this hypothesis is that the original EEC framework has eventually developed into the most
mature regional system on the free movement of persons within the EU.
This thesis perceives the development of a regional framework on labour migration as
a historical development, which challenges labour migration theory. The central question of
this research is âHow can participating states develop and accept a legal framework on labour
migration within regional economic associations?â This thesis aims to examine the feasibility
of regional integration on labour migration within the AEC, taking into account the
experiences of the EEC free movement of persons framework. It aims to explore approaches
and main features of the labour migration framework of the EEC and the AEC. The
examination mainly relies on obstacles to labour migration including access to the labour
market, permission to perform economic activities, permission to reside, family reunification,
working conditions, and protection from expulsion.
This thesis also aims to prove the hypothesis of the new regionalism theory, which
proposed that regionalism emerges from below and within the region. Through the lens of the
new regionalism theory, it explores the challenge that reliance only on existing international
law may be inadequate for regional cooperation to achieve deep regionalism in respect of
labour migration. Nevertheless, an effective regional framework could be initiated by new
rules agreed by the participating states or developed from reciprocal bilateral agreements
Optimizing transcriptomics to study the evolutionary effect of FOXP2
The field of genomics was established with the sequencing of the human genome, a pivotal achievement that has allowed us to address various questions in biology from a unique perspective. One question in particular, that of the evolution of human speech, has gripped philosophers, evolutionary biologists, and now genomicists. However, little is known of the genetic basis that allowed humans to evolve the ability to speak. Of the few genes implicated in human speech, one of the most studied is FOXP2, which encodes for the transcription factor Forkhead box protein P2 (FOXP2). FOXP2 is essential for proper speech development and two mutations in the human lineage are believed to have contributed to the evolution of human speech. To address the effect of FOXP2 and investigate its evolutionary contribution to human speech, one can utilize the power of genomics, more specifically gene expression analysis via ribonucleic acid sequencing (RNA-seq).
To this end, I first contributed in developing mcSCRB-seq, a highly sensitive, powerful, and efficient single cell RNA-seq (scRNA-seq) protocol. Previously having emerged as a central method for studying cellular heterogeneity and identifying cellular processes, scRNA-seq was a powerful genomic tool but lacked the sensitivity and cost-efficiency of more established protocols. By systematically evaluating each step of the process, I helped find that the addition of polyethylene glycol increased sensitivity by enhancing the cDNA synthesis reaction. This, along with other optimizations resulted in developing a sensitive and flexible protocol that is cost-efficient and ideal in many research settings.
A primary motivation driving the extensive optimizations surrounding single cell transcriptomics has been the generation of cellular atlases, which aim to identify and characterize all of the cells in an organism. As such efforts are carried out in a variety of research groups using a number of different RNA-seq protocols, I contributed in an effort to benchmark and standardize scRNA-seq methods. This not only identified methods which may be ideal for the purpose of cell atlas creation, but also highlighted optimizations that could be integrated into existing protocols.
Using mcSCRB-seq as a foundation as well as the findings from the scRNA-seq benchmarking, I helped develop prime-seq, a sensitive, robust, and most importantly, affordable bulk RNA-seq protocol. Bulk RNA-seq was frequently overlooked during the efforts to optimize and establish single-cell techniques, even though the method is still extensively used in analyzing gene expression. Introducing early barcoding and reducing library generation costs kept prime-seq cost-efficient, but basing it off of single-cell methods ensured that it would be a sensitive and powerful technique. I helped verify this by benchmarking it against TruSeq generated data and then helped test the robustness by generating prime-seq libraries from over seventeen species. These optimizations resulted in a final protocol that is well suited for investigating gene expression in comprehensive and high-throughput studies.
Finally, I utilized prime-seq in order to develop a comprehensive gene expression atlas to study the function of FOXP2 and its role in speech evolution. I used previously generated mouse models: a knockout model containing one non-functional Foxp2 allele and a humanized model, which has a variant Foxp2 allele with two human-specific mutations. To study the effect globally across the mouse, I helped harvest eighteen tissues which were previously identified to express FOXP2. By then comparing the mouse models to wild-type mice, I helped highlight the importance of FOXP2 within lung development and the importance of the human variant allele in the brain.
Both mcSCRB-seq and prime-seq have already been used and published in numerous studies to address a variety of biological and biomedical questions. Additionally, my work on FOXP2 not only provides a thorough expression atlas, but also provides a detailed and cost-efficient plan for undertaking a similar study on other genes of interest. Lastly, the studies on FOXP2 done within this work, lay the foundation for future studies investigating the role of FOXP2 in modulating learning behavior, and thereby affecting human speech
Unraveling the effect of sex on human genetic architecture
Sex is arguably the most important differentiating characteristic in most mammalian
species, separating populations into different groups, with varying behaviors, morphologies,
and physiologies based on their complement of sex chromosomes, amongst other factors. In
humans, despite males and females sharing nearly identical genomes, there are differences
between the sexes in complex traits and in the risk of a wide array of diseases. Sex provides
the genome with a distinct hormonal milieu, differential gene expression, and environmental
pressures arising from gender societal roles. This thus poses the possibility of observing
gene by sex (GxS) interactions between the sexes that may contribute to some of the
phenotypic differences observed. In recent years, there has been growing evidence of GxS,
with common genetic variation presenting different effects on males and females. These
studies have however been limited in regards to the number of traits studied and/or
statistical power. Understanding sex differences in genetic architecture is of great
importance as this could lead to improved understanding of potential differences in
underlying biological pathways and disease etiology between the sexes and in turn help
inform personalised treatments and precision medicine.
In this thesis we provide insights into both the scope and mechanism of GxS across the
genome of circa 450,000 individuals of European ancestry and 530 complex traits in the UK
Biobank. We found small yet widespread differences in genetic architecture across traits
through the calculation of sex-specific heritability, genetic correlations, and sex-stratified
genome-wide association studies (GWAS). We further investigated whether sex-agnostic
(non-stratified) efforts could potentially be missing information of interest, including sex-specific trait-relevant loci and increased phenotype prediction accuracies. Finally, we
studied the potential functional role of sex differences in genetic architecture through sex
biased expression quantitative trait loci (eQTL) and gene-level analyses.
Overall, this study marks a broad examination of the genetics of sex differences. Our findings
parallel previous reports, suggesting the presence of sexual genetic heterogeneity across
complex traits of generally modest magnitude. Furthermore, our results suggest the need to
consider sex-stratified analyses in future studies in order to shed light into possible sex-specific molecular mechanisms
- âŠ