The Influence of Carboxylic Acid in Packaging Materials

Tetra Pak delivers food packing services world-wide and uses multilayer packaging materials to protect the food product from being affected by the environment. Loss of adhesion between the polymer and the aluminium layer in Tetra Paks packaging materials has proven to be a serious problem casing the package to lose its integrity and the food product to spoil. The problem is relatively unstudied but has shown to be connected to fatty and acidic products indicating a connection to the presence of carboxylic acids. This master thesis was conducted to identify the core mechanism of the delamination phenomenon and to create a base from which further studies can be conducted. Two basic hypothesis were provided by Tetra Pak for further study and evaluation. One is connected to the surface chemistry of the interface and the other is connected to changes in the mechanical properties of the polymers at the interface. A literature study was conducted and the work was delimited to the most basic carboxylic acid; acetic acid as well as the most commonly used polymer; low density polyethylene. The study indicated a connection between the presence of water and the delamination phenomena in agreement with the aluminium-water system. Three experiments where performed using two similar packaging materials produced at different times. These were exposed to food simulants containing different amounts of water to study the impact this would have on the delamination. The different experiments were then analysed using various methods to determine the mode of failure and connect these to the hypothesis. Results from peel testing showed a greater, or at least faster, loss in adhesion for the packaging materials that were exposed to food stimulants with high concentration of water. The FTIR measurements revealed interesting results for the simulant with average concentration of water showing a thin layer of polymer on the al surface at the highest peel force. This correlates with the hypothesis that the mechanics of the polymer would have changed. The FTIR measurements at the lowest peel force for the simulant with highest concentration of water however showed lower amounts of LDPE, supporting the theory that the delamination is due to surface chemistry. The FTIR findings were further supported by microscopic surface studies which showed a clearer fracture surface with less LDPE for the delaminated samples. The conclusion of this thesis shows that the setup used behaves according to the mechanism of the Al-water system which was strongly indicated by the formation of hydrogen gas and the lacking amount of polymer on the aluminium surface. The Al-water system in turn correlates with the hypothesis provided by Tetra Pak that the delamination phenomenon is due to surface chemistry.Inte hur förpackningen påverkar din mat, utan hur din mat påverkar förpackningen. Resultatet av detta arbete kan komma att ligga till grund för miljövänligare förpackningar som ger maten längre hållbarhet och förbättrar möjligheterna för att transportera mat över hela världen. Tetra Pak har länge arbetat med att leverera ett smartare och miljövänligare sätt att förpacka mat med sina pappförpackningar. I själva verket är det inte en simpel pappförpackning som skyddar maten utan ett flertal lager av plaster, lim och aluminiumfolie som alla har sin skyddande egenskap. Plast består av långa kedjor av atomer - man kan föreställa sig dem som en massa kokta spagetti. I dagens samhälle blir vi allt noggrannare med vad vi får i oss och vad som kan lossna från förpackningar och köksredskap och hamna i vår mat. Men något som många inte tänker på är hur maten kan påverka förpackningen. Denna studie undersökte ett sådant problem där mat innehållande fettsyror såsom ättiksyra, smörsyra och mjölksyra, efter en längre tid visar sig påverka förpackningen så att dess skydd bryts ned och hållbarheten på maten försämras. Det finns två hypoteser för hur man tror att fettsyror i maten bryter sammanfogningen mellan plastlagret närmast maten och det aluminiumlager som ligger närmare förpackningens utsida. Den första hypotesen är att fettsyrorna från maten tränger in mellan kolkedjorna i plastlagret, och när de når limmet som håller fast plasten i aluminiumfolien lossnar detta och fettsyrorna hamnar mellan plastlagret och aluminiumfolien, lite som hur tomatsås lägger sig i botten av tallriken och skjuter undan spagettin som annars klibbar fast i porslinet. Den andra hypotesen är att man tänker sig att kolkedjorna i plasten ligger intrasslade med varandra likt nykokt spagetti. När fettsyror tränger sig mellan kedjorna blir där ett halt glidlager likt när man häller olja på spagettin för att denna inte skall klibba. På samma sätt som spagettin, glider då kedjorna mot varandra och håller inte längre ihop lika bra, och plastlagret förstörs men lämnar kvar en mycket tunn film på aluminiumfolien. Genom att lagra lågt koncentrerad ättiksyra i kuvert gjorda av ett av Tetra Paks material kunde ättiksyrans påverkan på materialet över tid undersökas med en rad olika tester som bland annat mätte den kraft det krävdes för att separera plastlagret från aluminiumfolien och även undersöka vad för ämnen som bildats på de båda ytorna. Slutsatsen var att det i detta fall var den första hypotesen som orsakade mest skada på förpackningen. Detta bevisades delvis av att då plastlagret lossnat kom aluminiumfolien i kontakt med vattnet i den utspädda ättiksyran och det började bildas vätgas, som i sin tur fick kuverten att börja svälla upp. Detta skulle inte kunna ha skett om där var kvar en plast film som i den andra hypotesen

Relationship between commuting and health outcomes in a cross-sectional population survey in southern Sweden

<p>Abstract</p> <p>Background</p> <p>The need for a mobile workforce inevitably means that the length of the total work day (working and traveling time) will increase, but the health effects of commuting have been surprisingly little studied apart from perceived stress and the benefits of physically active commuting.</p> <p>Methods</p> <p>We used data from two cross-sectional population-based public health surveys performed in 2004 and 2008 in Scania, Sweden (56% response rate). The final study population was 21, 088 persons aged 18-65, working > 30 h/week. Duration (one-way) and mode of commuting were reported. The outcomes studied were perceived poor sleep quality, everyday stress, low vitality, mental health, self-reported health, and absence from work due to sickness during the past 12 months. Covariates indicating socioeconomic status and family situation, overtime, job strain and urban/rural residency were included in multivariate analyses. Subjects walking or cycling to work < 30 min were used as a reference category.</p> <p>Results</p> <p>Monotonous relations were found between duration of public transport commuting and the health outcomes. For the category commuting > 60 min odds ratios (ORs) ranged from 1.2 - 1.6 for the different outcomes. For car commuting, the relationships were concave downward or flat, with increasing subjective health complaints up to 30-60 min (ORs ranging from 1.2 - 1.4), and lower ORs in the > 60 min category. A similar concave downward relationship was observed for sickness absence, regardless of mode of transport.</p> <p>Conclusions</p> <p>The results of this study are concordant with the few earlier studies in the field, in that associations were found between commutation and negative health outcomes. This further demonstrates the need to consider the negative side-effects of commuting when discussing policies aimed at increasing the mobility of the workforce. Studies identifying population groups with increased susceptibility are warranted.</p

Genetic diversity in gooseberry (Ribes uva-crispa), as estimated with SSR markers

European gooseberry (Ribes uva-crispa L.) is a popular berry crop in many European countries, including Sweden, Denmark and Ukraine. There is no active gooseberry breeding programme in either Sweden or Denmark, but a successful programme is operating in Ukraine. In Sweden and Denmark, research on gooseberries is primarily focused on collection and phenotypic evaluation of genetic resources. As part of these activities, a large number of inventory finds have been collected but have not yet been characterised morphologically or molecularly. The goal of this study was thus to characterise gooseberry germplasm with 15 simple sequence repeat (SSR) markers. From 242 accessions analysed, 153 unique genotypes were identified. Cultivars that have been in widespread cultivation in Sweden, such as the Finnish cultivars 'Hinnonma & BULL;en Keltainen' and 'Hinnonma & BULL;en Punainen', had relatively large numbers of synonymous samples. While many inventory finds were identifiable as synonyms of known cultivars, several were found to constitute unique genotypes within the germplasm studied. The studied genotypes clustered relatively well in three posterior groups, consisting of cultivars originating before and after the American gooseberry mildew (Sphaerotheca mors-uvae) outbreak around 1900 and cultivars originating from the territory of the former Soviet Union. A fourth genetic cluster consisting mainly of inventory finds from central and northern Sweden was also identified. In addition, it was possible to verify recorded and stipulated parentages for some of the cultivars studied and to identify three likely parent-parent-child trios. Thus, inventories of local gooseberry germplasm and a subsequent genotyping proved successful in finding unique local genotypes, with potential local adaptation. The data obtained provide a foundation for future studies of gooseberry genetic re-sources, while also illustrating the importance of a well-curated and phenotypically characterised set of reference cultivars for future studies

Potential for increased connectivity between differentiated wolverine populations

Information on genetic population structure provides important knowledge for species conservation. Yet, few studies combine extensive genetic data to evaluate the structure and population dynamics of transboundary populations. Here we used single nucleotide polymorphisms (SNPs), microsatellites and mitochondrial haplotypes to analyze the genetic population structure of wolverines (Gulo gulo) across Fennoscandia using a long-term monitoring dataset of 1708 individuals. Clear population subdivision was detected between the Scandinavian and the eastern Finnish population with a steep cline in the contact zone. While the Scandinavian population showed isolation by distance, large swaths of this population were characterized by high connectivity. Areas with high resistance to gene flow are likely explained by a combination of factors, such as historical isolation and founder effects. From a conservation perspective, promoting gene flow from the population in eastern Finland to the northwest of Scandinavia could augment the less variable Scandinavian population, and increase the demographic resilience of all subpopulations. Overall, the large areas of low resistance to gene flow suggest that transboundary cooperation with aligned actions of harvest and conflict mitigation could improve genetic connectivity across Finland, Sweden, and Norway

Diet and body constitution in relation to subgroups of breast cancer defined by tumour grade, proliferation and key cell cycle regulators

BACKGROUND: The general lack of clear associations between diet and breast cancer in epidemiological studies may partly be explained by the fact that breast cancer is a heterogeneous disease that may have disparate genetic associations and different aetiological bases. METHOD: A total of 346 incident breast cancers in a prospective cohort of 17,035 women enrolled in the Malmö Diet and Cancer study (Sweden) were subcategorized according to conventional pathology parameters, proliferation and expression of key cell cycle regulators. Subcategories were compared with prediagnostic diet and body measurements using analysis of variance. RESULTS: A large hip circumference and high body mass index were associated with high grade tumours (P = 0.03 and 0.009, respectively), whereas low energy and unadjusted fat intakes were associated with high proliferation (P = 0.03 and 0.004, respectively). Low intakes of saturated, monounsaturated and polyunsaturated fatty acids were also associated with high proliferation (P = 0.02, 0.004 and 0.003, respectively). Low energy and unadjusted fat intakes were associated with cyclin D(1 )overexpression (P = 0.02 and 0.007, respectively), whereas cyclin E overexpression was positively correlated with fat intake. Oestrogen receptor status and expression of the tumour suppressor gene p27 were not associated with either diet or body constitution. CONCLUSION: Low energy and low total fat (polyunsaturated fatty acids in particular) intakes, and high body mass index were associated with relatively more malignant breast tumours. Dietary behaviours and body constitution may be associated with specific types of breast cancer defined by conventional pathology parameters and cyclin D(1 )and cyclin E expression. Further studies including healthy control individuals are needed to confirm our results

Determinants of serum levels of vitamin D: a study of life-style, menopausal status, dietary intake, serum calcium, and PTH

Background: Low blood levels of vitamin D (25-hydroxy D3, 25OHD3) in women have been associated with an increased risk of several diseases. A large part of the population may have suboptimal 25OHD3 levels but high-risk groups are not well known. The aim of the present study was to identify determinants for serum levels of 25OHD3 in women, i.e. factors such as lifestyle, menopausal status, diet and selected biochemical variables. Methods: The study was based on women from the Malmo Diet and Cancer Study (MDCS), a prospective, population-based cohort study in Malmo, Sweden. In a previous case-control study on breast cancer, 25OHD3 concentrations had been measured in 727 women. In these, quartiles of serum 25OHD3 were compared with regard to age at baseline, BMI (Body Max Index), menopausal status, use of oral contraceptives or menopausal hormone therapy (MHT), life-style (e. g. smoking and alcohol consumption), socio-demographic factors, season, biochemical variables (i.e. calcium, PTH, albumin, creatinine, and phosphate), and dietary intake of vitamin D and calcium. In order to test differences in mean vitamin D concentrations between different categories of the studied factors, an ANOVA test was used followed by a t-test. The relation between different factors and 25OHD3 was further investigated using multiple linear regression analysis and a logistic regression analysis. Results: We found a positive association between serum levels of 25OHD3 and age, oral contraceptive use, moderate alcohol consumption, blood collection during summer/autumn, creatinine, phosphate, calcium, and a high intake of vitamin D. Low vitamin D levels were associated with obesity, being born outside Sweden and high PTH levels. Conclusions: The present population-based study found a positive association between serum levels of 25OHD3 and to several socio-demographic, life-style and biochemical factors. The study may have implications e. g. for dietary recommendations. However, the analysis is a cross-sectional and it is difficult to suggest Lifestyle changes as cause-effect relationships are difficult to assess

Evaluating expert-based habitat suitability information of terrestrial mammals with GPS-tracking data

Aim Macroecological studies that require habitat suitability data for many species often derive this information from expert opinion. However, expert-based information is inherently subjective and thus prone to errors. The increasing availability of GPS tracking data offers opportunities to evaluate and supplement expert-based information with detailed empirical evidence. Here, we compared expert-based habitat suitability information from the International Union for Conservation of Nature (IUCN) with habitat suitability information derived from GPS-tracking data of 1,498 individuals from 49 mammal species. Location Worldwide. Time period 1998-2021. Major taxa studied Forty-nine terrestrial mammal species. Methods Using GPS data, we estimated two measures of habitat suitability for each individual animal: proportional habitat use (proportion of GPS locations within a habitat type), and selection ratio (habitat use relative to its availability). For each individual we then evaluated whether the GPS-based habitat suitability measures were in agreement with the IUCN data. To that end, we calculated the probability that the ranking of empirical habitat suitability measures was in agreement with IUCN's classification into suitable, marginal and unsuitable habitat types. Results IUCN habitat suitability data were in accordance with the GPS data (> 95% probability of agreement) for 33 out of 49 species based on proportional habitat use estimates and for 25 out of 49 species based on selection ratios. In addition, 37 and 34 species had a > 50% probability of agreement based on proportional habitat use and selection ratios, respectively. Main conclusions We show how GPS-tracking data can be used to evaluate IUCN habitat suitability data. Our findings indicate that for the majority of species included in this study, it is appropriate to use IUCN habitat suitability data in macroecological studies. Furthermore, we show that GPS-tracking data can be used to identify and prioritize species and habitat types for re-evaluation of IUCN habitat suitability data

Immune cells lacking Y chromosome show dysregulation of autosomal gene expression

Funder: Kjell och Märta Beijers Stiftelse (SE)Funder: Hjärnfonden; doi: http://dx.doi.org/10.13039/501100003792Funder: Cancerfonden; doi: http://dx.doi.org/10.13039/501100002794Funder: Vetenskapsrådet; doi: http://dx.doi.org/10.13039/501100004359Funder: Alzheimerfonden; doi: http://dx.doi.org/10.13039/501100008599Funder: Konung Gustaf V:s och Drottning Victorias Frimurarestiftelse (SE)Funder: Science for Life Laboratory (SE)Funder: Fundacja na rzecz Nauki Polskiej (PL)Funder: Uppsala UniversityAbstract: Epidemiological investigations show that mosaic loss of chromosome Y (LOY) in leukocytes is associated with earlier mortality and morbidity from many diseases in men. LOY is the most common acquired mutation and is associated with aberrant clonal expansion of cells, yet it remains unclear whether this mosaicism exerts a direct physiological effect. We studied DNA and RNA from leukocytes in sorted- and single-cells in vivo and in vitro. DNA analyses of sorted cells showed that men diagnosed with Alzheimer’s disease was primarily affected with LOY in NK cells whereas prostate cancer patients more frequently displayed LOY in CD4 + T cells and granulocytes. Moreover, bulk and single-cell RNA sequencing in leukocytes allowed scoring of LOY from mRNA data and confirmed considerable variation in the rate of LOY across individuals and cell types. LOY-associated transcriptional effect (LATE) was observed in ~ 500 autosomal genes showing dysregulation in leukocytes with LOY. The fraction of LATE genes within specific cell types was substantially larger than the fraction of LATE genes shared between different subsets of leukocytes, suggesting that LOY might have pleiotropic effects. LATE genes are involved in immune functions but also encode proteins with roles in other diverse biological processes. Our findings highlight a surprisingly broad role for chromosome Y, challenging the view of it as a “genetic wasteland”, and support the hypothesis that altered immune function in leukocytes could be a mechanism linking LOY to increased risk for disease