An increase in demand for sawed wood products is the reason why Norra Timber has to expand their facility at Sävar Sawmill. During the expansion, a new log sorting will be implemented which can sort ...timber with different characteristics and qualities compared to the current log sorting. The placement of the new log sorting and the logistics after the construction has not been decided. Therefore, the purpose of this thesis is to suggest a design of the new timber yard which includes placement of the new log sorting, log piles and roads to minimize travel distance for tractors between the log sorting and the saw. The thesis project started with examining the opportunities and challenges that exist in timber logistics through a literature study. Afterwards, the current logistics at Sävar Sawmill were studied. Relevant data was collected to create different layout suggestions and to determine which optimization model that should be used. The placement of the log sorting was determined after the data collection, together with a steering group at Sävar Sawmill. Three layout suggestions were created after the placement of the new log sorting and were restricted to the current asphalted surface for timber handling. All layout suggestions should have a storage capacity with the volumes 15 000 m3f, 20 000 m3f and 35 000 m3f. The unit of volume m3f, describes the solid volume of timber without bark. The assignment problem with the Hungarian algorithm was used to optimize the placement of log classes on the timber yard. Thereafter transport distances and driving hours were calculated with three different production levels. The results show that all timber fits in the timber yard for the three layout suggestions when the storage levels are 15 000 m3f and 20 000 m3f, where an optimal solution is found. In the beginning it was not possible to find an optimal solution when the storage levels increased to 35 000 m3f. To find a solution, one constraint was relaxed that allowed the log piles to become overfilled. Norra Timber did not believe a solution at 35 000 m3f existed and therefore accepted the relaxation. Layout suggestion 1 had the least amount of overfilled log piles and layout suggestion 2 had the most. There was a significant difference for the travel distance per year between the layout suggestions when the storage level was low compared to high. Layout suggestion 1 had the longest travel distance per year and layout suggestion 3 had the shortest for all the production levels. The positions and the number of log piles will be the same regardless the production levels, but the travel distance will increase when the production level increases. The number of driving hours is calculated from the travel distances to point out the differences in working hours for the tractor drivers. Layout suggestion 3 will be proposed to use in the future based on the result from the optimization model. The layout suggestion 3 has significant shorter transport distance for the two lower storage levels compared to the other suggestions. The tractor drivers also appreciated that layout suggestion 3 had more available log piles and that the placement of the log piles will ease their daily work and save many working hours.
En ökad efterfrågan på sågade trävaror gör att Norra Timber är i behov av att expandera sin nuvarande anläggning på Sävar såg. Vid expansionen kommer en ny timmersortering installeras som kan sortera timret på flera egenskaper och kvaliteter jämfört med den befintliga. Varken placeringen av den nya timmersorteringen eller hur logistiken ska fungera efter expansionen är bestämt. Syftet med examensarbetet är att ta fram ett förslag på hur Norra Timber ska designa området med placering av den nya timmersorteringen, vältplatser och vägar för att minimera transportavstånd för traktorerna mellan timmersorteringen och sågen. Examensarbetet inleddes med att undersöka vilka möjligheter och utmaningar som finns inom timmerlogistik genom en litteraturstudie. Logistiken på Sävar såg studerades sedan och varje aktivitet förklarades i en nulägesbeskrivning. Relevant fakta samlades in för att kunna skapa olika designförslag och avgöra vilken optimeringsmodell som skulle användas. Efter datainsamling bestämdes placeringen av den nya timmersorteringen tillsammans med en projektgrupp på Sävar såg. Utifrån den nya timmersorteringens placering skapades tre olika designförslag som var begränsade till den asfalterade ytan vid den nuvarande timmerhanteringen. Alla designförslag skulle klara av en lagernivå på 15 000 m3f, 20 000 m3f och 35 000 m3f. Volymenheten m3f står för den fasta volymen timmer utan bark. För att optimera var timmerklasserna skulle placeras i vältor på timmerplanen användes tillordningsproblemet med Hungarian algoritm där indatat anpassades efter lager- och produktionsnivå. Transportavstånd och körtimmar räknas sedan ut för alla designförslag med tre olika produktionsnivåer. Resultatet visar att när lagernivåerna är 15 000 m3f och 20 000 m3f får allt timmer plats på timmerplanen i alla designförslag och modellen hittar en optimal lösning. När lagernivån ökade till 35 000 m3f kunde inte en optimal lösning hittas till en början. För att hitta en lösning relaxerades ett bivillkor vilket gjorde att överfulla vältor tilläts. Norra Timber trodde inte en lösning vid 35 000 m3f existerade och accepterade därför relaxationen. Minst antal överfulla vältor hade designförslag 1 och designförslag 2 hade högst antal. Designförslagens transportavstånd per år skiljer sig mycket mellan den lägsta lagernivån jämfört med den högsta. Designförslag 1 har längst avstånd och designförslag 3 har kortast avstånd för alla lagernivåer. Oavsett vilken produktionsnivå sågen har kommer vältplaceringarna att vara samma för ett designförslag där endast den totala körsträckan ökar. Antal körtimmar beräknas utifrån transportavstånd och presenteras för att visa på skillnaderna mellan traktorförarnas arbetstid. Utifrån optimeringsmodellens resultat rekommenderas Norra Timber att designa den nya timmerplanen på Sävar såg efter designförslag 3. Förslaget har signifikant kortare transportavstånd vid de två lägre lagernivåerna jämfört med de andra två designförslagen. Traktorförarna uppskattade också att förslaget hade fler vältplatser och vältornas placering som kommer underlätta deras vardagliga arbete och spara in många arbetstimmar.
Despite extensive research the etiologies of neuropsychiatric disorders such as schizophrenia remain obscure. It is currently believed that complex interactions between a number of genetic and ...environmental risk factors contribute to the development of these disorders. The studies in this thesis were undertaken to investigate the potential of a neurotropic influenza A virus infection during early life, to induce changes in the brain leading to functional deficits later in life. Differential expression of transcripts from human endogenous retrovirus (HERV )elements, including syncytin, has been observed in patients with schizophrenia, however, the function of such transcripts in the brain is not known. We therefore investigated if the suggested analogues in mouse were induced and regulated in the same way as human syncytin. Infection with influenza A/WSN/33 virus induced the expression of syncytin B but not syncytin A as well as the suggested regulator glial cells missing 1(GCM1) in mouse primary neuron and glial cell cultures. GCM1 seemed to regulate the expression of transcripts encoding syncytin B but not A. Thus, syncytin B appears to be an analogue to human syncytin and the function of such expression can be studied in vivo. To investigate the short- and long-term effects of a neonatal CNS infection with influenza A/WSN/33 virus in vivo, wild type and Tap1-/- mice, lacking CD8+ T cells, were infected at postnatal day 3 or 4. The spread of the infection in the brain and clearance of virus did not differ between the two genotypes of mice, which contrasts observations in adult infected mice. Elevated levels of transcripts encoding IFN-γ and TNF were observed in the brain of both genotypes, however, the Tap1-/- mice seemed to have a more pronounced innate immune response based on the elevated levels of iNOS and syncytin B only in these mice at P24. The kynurenine pathway metabolizes tryptophan into several immunomodulatory and neuroactive metabolites and is suggested to be part of the innate immune response. To investigate the effects of an influenza A/WSN/33 virus infection on the kynurenine pathway we infected mouse primary neuron and glial cell cultures. The infection induced several transcripts encoding enzymes in this pathway in both cell culture types. Next we investigated the effects of a neonatal infection with influenza A/WSN/33 on the kynurenine pathway in wild type and Tap1-/- mice. The pathway was induced in both genotypes of mice and a transient elevation of kynurenic acid was observed in the brains at P13. Infected Tap1-/- mice exhibited a prolonged induction of the kynurenine pathway compared to infected wild type mice. When investigating the long-term effects of the neonatal infection in adult mice we found infected Tap1-/- mice to exhibit increased rearing and anxiety-like behavior compared to uninfected Tap1-/- mice. In addition, the infected Tap1-/- mice were deficient in a working memory task and had disrupted sensorimotor gating as measured by prepulse inhibition. No differences in the behavior of infected wild type mice compared to uninfected wild type mice were observed. The infected Tap1-/- mice, with working memory deficits, had lower expression transcripts encoding type III neuregulin 1 in the prefrontal cortex. This is in line with a recent report illustrating a role for type III neuregulin 1 in both working memory and sensorimotor gating.
In this study, we tested the hypothesis that exposure to a maternal infection during fetal life can lead to the appearance of alterations in the brain later in life. C57BL/6 mice were infected ...intranasally with influenza A/WSN/33 virus on day 14 of gestation. The levels of transcripts encoding neuroleukin and fibroblast growth factor 5 were significantly elevated in the brains of the virus-exposed offspring at 90 and 280 days of age, but not at earlier time-points. For neuroleukin, this difference could also be observed at the protein level. Thus, a maternal influenza A virus infection can give rise to alterations in gene expression in the brain that become apparent only after a prepubertal latency period.
Schizophrenia and related disorders are devastating human neuropsychiatric disorders of complex etiology. Epidemiological and family studies indicate both genetic and environmental contributions to ...disease etiology.We propose that the altered expression of endogenous retroviruses such asHERV-Wcontribute to somecases of schizophrenia. We present both theoretical considerations and experimental evidence supporting this association. The further study of endogenous retroviral expression within the central nervous system might lead to new methods for the diagnosis and treatment of schizophrenia and related disorders.
Systemic low-grade inflammation may be a pathophysiological mechanism in a subtype of depression. In this study we investigate a novel candidate mechanism of inflammatory depression - Selective ...Glomerular Hypofiltration Syndromes (SGHS) - which are characterized by a reduced estimated glomerular filtration rate (eGFR) based on cystatin C (cysC) relative to eGFR based on creatinine (crea). SGHS have been associated with increased blood levels of pro-inflammatory markers, but have never been investigated in a sample of depressed individuals.
The prevalence of SGHS was compared between 313 patients with difficult-to-treat depression and 73 controls. Since there is no single established eGFRcysC/eGFRcrea-ratio cut-off to define SGHS, several cut-offs were investigated in relation to a depression diagnosis, inflammation, and symptom severity. Plasma inflammatory markers tumor necrosis factor alpha (TNF-α), interferon gamma (IFN-γ), interleukin (IL)-6, IL-8, and IL-10 were available from 276 depressed patients. We examined mediation effects of IL-6 on the relationship between SGHS and depression.
Depressed patients were more likely to have SGHS compared to controls defining SGHS as either eGFRcysC/eGFRcrea-ratio < 0.9 (33.2 % vs 20.5 %, p = 0.035) or < 0.8 (15.7 % vs 5.5 %, p = 0.023). Lower eGFRcysC/eGFRcrea-ratio was associated with higher levels of inflammatory markers in depressed patients. IL-6 partly mediated the relationship between SGHS and depression.
This is the first study to demonstrate a link between SGHS and inflammatory depression. If replicated in independent and longitudinal cohorts, this may prove to be a relevant pathophysiological mechanism in some cases of depression that could be targeted in future intervention and prevention studies.
•SGHS is a recently identified group of kidney disorders that has been linked to inflammation.•SGHS was more common in patients with difficult-to-treat depression compared to controls.•SGHS was associated with low-grade inflammation in depression.•Pro-inflammatory cytokine IL-6 mediated part of the relationship between SGHS and depression.
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