Crown development of Scots pine trees following thinning and nitrogen fertilization

The effects of thinning and nitrogen fertilization, singly and in combination, on the growth of 45-year-old Scots pine (Pinus sylvestris L.) trees in northern Sweden, were studied from 1983-1988 inclusive. Sixteen trees were examined each year for crown development. The number of branches, shoot axes and buds produced, branch elongation on main axes, and dry weight production of shoot axes, needles, buds, cones, and dead material on live branches, were determined destructively on four trees per treatment. Both thinning and fertilization influenced the number of crown components produced annually. Branch elongation was increased by fertilization, and decreased by thinning. The weights of the components studied were increased more by fertilization than by thinning. Thinning promoted the distribution of growth to the lower crown, while fertilization promoted growth in the upper crown. Combined thinning and fertilization increased the weight of shoot axes, needles and buds more rapidly than did thinning or fertilization applied individually

The future labour in Swedish forestry : the attraction of forest machine operation as a profession

The scarcity of qualified forest machine operators as well as the increased competition for competent machine operators among others from the mining industry in Norrland, were the reasons to investigate what attracts and what deters active and potential forest machine operators to the occupation. An interview study was conducted among four groups with four persons in each group. The groups were students in year 1 and 3 respectively at a forestry school at upper secondary school level as well as employees of a forest company and employees of contractors. The majority of all respondents were of the opinion that their interests in machines had been important for the choice of occupation. But for the active machine operators both the interest in the forest and their interest for machines have had importance for choosing this occupation. More students than active machine operators could consider a change of occupation. The salary level was the most important reason for those that could consider a change. An increased salary level was also the most mentioned recommendation among the respondents to increase the attraction of the occupation. The most important aspect however in work was comradeship and an interesting and varied work, something that is not offered in the present work organization according to respondents. The possibility to flexible working hours was highly appreciated by the active machine operators while at the same time the shift forms used at present were considered to be among the worst aspects of the work. Freedom in the meaning of being in charge of once own performance, working outdoors and/or flexible working hours is still an important aspect attracting machine operators to the occupation. Suggestions for improvements are to start stimulating young people's interest in the forest early. To limit the risk of losing qualified personnel, it is important to develop leadership, working conditions and salary.Bristen på kvalificerade skogsmaskinförare samt ökad konkurrens om arbetskraft från bland annat gruvnäringen, gav anledning till att undersöka vad som attraherade och avskräckte aktiva och potentiella skogsmaskinförare till yrket. En intervjustudie genomfördes på fyra grupper med fyra personer i varje. Grupperna var elever i årskurs ett och tre på ett skogsbruksinriktat naturbruksgymnasium samt anställda skogsmaskinförare hos ett skogsbolag och hos entreprenörer. Majoriteten av alla respondenter tyckte att deras maskinintresse hade haft betydelse vid yrkes/utbildningsval, men för de aktiva maskinförarna var både intresset för skogen och maskinintresset viktiga för yrkesvalet. Det var fler gymnasieelever än aktiva maskinförare som kunde tänka sig arbeta som något annat än skogsmaskinförare. Den främsta anledningen till att byta till ett annat yrke var lönen. Det förslag för att göra yrket mer attraktivt som angavs av flest respondenter var ”högre lön”. Viktigast i ett arbete ansågs dock vara kamratskap samt ett intressant och omväxlande arbete och här brister yrkets nuvarande upplägg enligt respondenterna. Möjligheten till flexibla arbetstider uppskattades högt av de aktiva maskinförare samtidigt som arbetstider i form av skiftarbete ansågs vara en av de sämsta faktorerna i arbetet. Frihet i betydelsen att göra arbetet efter eget huvud, arbeta utomhus och/eller möjlighet till flexibla arbetstider är fortfarande en viktig faktor som attraherar maskinförarna till yrket. Som åtgärder föreslås att näringen uppmuntrar ungdomars intresse för skog. För att minska risken för avhopp av kvalificerad arbetskraft bör ledarskap, arbetsmiljöfaktorer och lön utvecklas

Influence of Mycoplasma cynos infection on the expression of inflammatory response genes in canine macrophage cell line DH82

Mycoplasma cynos je edina mikoplazma, za katero so doslej dokazali povezavo z razvojem bolezni dihal pri psih. Bila je večkrat izolirana iz obolelih psov, predvsem tistih, živečih v psarnah. Domneva se, da je, tako kot druge mikoplazme, ki naseljujejo dihala, lahko povezana s številnimi bolezenskimi zapleti ter, da je v klinični obravnavi teh stanj pogosto spregledana. Vzrok je verjetno v tem, da je relativno slabo proučena, predvsem je slabo poznana povezava med bakterijo in celicami gostitelja. V okviru magistrske naloge smo z uporabo metode PCR v realnem času, preverili vpliv okužbe trajne pasje celične linije DH82 z M. cynos na izražanje genov za citokine IL-1beta, IL-6, IL-8 in za transkripcijski dejavnik NF-kapaB1. Ugotovili smo, da se okužba z M. cynos odraža v postopnem zviševanju relativnih sprememb v izražanju gena za IL-1beta do 12 h po okužbi, v postopnem zniževanju izražanja gena za IL-6 do 12 h po okužbi, v postopnem zviševanju izražanja gena za IL-8 do 24 h in nato padcu izražanja po 48 h ter v relativno majhnem spreminjanju izražanja gena za NF-kapaB1 do 6 h po okužbi. Okužba ima tudi vpliv na morfološke spremembe celic DH82. Po 24 h po okužbi se te kažejo v obliki vakuolizacije celic, po 48 h pa še v lizi posameznih celic DH82. Pri teh dveh časovnih točkah je opazen tudi padec viabilnosti celic, in sicer na približno 87 % po 24 h in na 70 % po 48 h. Opazili smo tudi padec števila M. cynos v supernatantih celic DH82 v prvih 3 h po okužbi. V supernatantih celic DH82 nismo zaznali spremenjenih koncentracij dušikovega oksida (NO).Mycoplasma cynos is the only species of mycoplasma that has been proven to be associated with the development of respiratory disease in dogs. It was isolated several times from the diseased dogs, mainly those living in kennels. Like other mycoplasmas that inhabit the respiratory system, it is believed that M. cynos is associated with many health complications and that it is often overlooked in clinical treatments. The reason may be in the lack of studies, especially in terms of the relationship between the bacterium and its host cells. Using quantitative PCR, we analysed the influence of M. cynos infection on the expression of genes for cytokines IL-1beta, IL-6, IL-8 and the transcription factor NF-kappaB1 in the immortalised dog cell line DH82. We came to a conclusion that the infection results in a gradual increase in IL-1beta gene expression until 12 h after the infection, in a gradual decrease in IL-6 gene expression until 12 h after the infection, in a gradual increase in IL-8 gene expression until 24 h and then a decrease in 48 h after the infection, and in relatively minor variation of NF-kappaB1 gene expression until 6 h after the infection. M. cynos infection also has an influence on the morphology of DH82 cells, which is manifested in increased vacuolisation 24 h following the infection and in the lysis of individual DH82 cells after 48 h. During this time, an apparent drop in cell viability can also be observed. The viability dropped to 87% after 24 h and to 70% after 48 h after the infection. We also observed a drop in M. cynos concentrations in DH82 cell supernatants in the first 3 h after the infection. We were unable to detect any changes in nitric oxide (NO) concentrations in DH82 cell supernatants, after the infection with M. cynos

Mathematical models for description of hydrodynamics, mass and heat transfer in microreactor systems

Over the last decades the increased use of microreactors in all types of industries is observed. This phenomenon is based on the advantages that the microreactor systems can achieve in term of better process control, more efficient heat transfer and handling of hazardous chemicals. During this time mathematical models that describe flow inside microchannels have emerged ranging from Navier-Stokes equations to simplified mathematical models for laminar and segmented flows. The aim of this review is to present current studies in term of mathematical models that are nowadays commonly used for the description of hydrodynamics, mass and heat transfer in microreactor systems

NEAR INFRARED SPECTROSCOPY (NIRS) AS FOOD QUALITY AND FOOD FRAUD DETECTOR – APPLIED ON FISH STICKS

The aim of this study was to present the professional application of near infrared spectroscopy (NIRs) in the detection of food quality on purchased fish sticks. The measured NIR spectra of samples prepared from fish or squid were related to nutritional labels such as the amount of certain macronutrient and the proportion of the starting material (fish/squid). In the standard procedure, NIRs coupled with chemometric tools such as principal component analysis (PCA) and partial least square regression (PLSR) was used to investigate the qualitative and/or quantitative capabilities in determining food quality. Excellent qualitative differentiation was achieved with PCA, with biplots showing how the explanation of variation increased from 80.12 % when only nutritional information was used in the observation to 96.89% when nutritional information was coupled with the corresponding NIR spectrum. Since higher levels of animal protein in food are associated with an increase in price, the detection probabilities of different protein sources (fish/meat) were tested using PLSR, with 100% of the samples successfully detected. PLSR was also used to detect the correlation of the NIR spectra to the macronutrient contents and the strongest correlation was determined for proteins (R2 = 0.99). The results confirmed the feasibility of using NIRs in the qualitative evaluation of samples where it is possible to determine the predominance of fish or squid, and also to estimate the expected protein content. The protein content is related to the price of the product, since all products containing animal proteins have higher prices that grow proportionally to their share. NIRs is not a qualitative method, but it can help in the selection of products, whose exact composition and possible adulteration can be confirmed by additional laboratory analysis

NEAR INFRARED SPECTROSCOPY (NIRS) AS FOOD QUALITY AND FOOD FRAUD DETECTOR – APPLIED ON FISH STICKS

The aim of this study was to present the professional application of near infrared spectroscopy (NIRs) in the detection of food quality on purchased fish sticks. The measured NIR spectra of samples prepared from fish or squid were related to nutritional labels such as the amount of certain macronutrient and the proportion of the starting material (fish/squid). In the standard procedure, NIRs coupled with chemometric tools such as principal component analysis (PCA) and partial least square regression (PLSR) was used to investigate the qualitative and/or quantitative capabilities in determining food quality. Excellent qualitative differentiation was achieved with PCA, with biplots showing how the explanation of variation increased from 80.12 % when only nutritional information was used in the observation to 96.89% when nutritional information was coupled with the corresponding NIR spectrum. Since higher levels of animal protein in food are associated with an increase in price, the detection probabilities of different protein sources (fish/meat) were tested using PLSR, with 100% of the samples successfully detected. PLSR was also used to detect the correlation of the NIR spectra to the macronutrient contents and the strongest correlation was determined for proteins (R2 = 0.99). The results confirmed the feasibility of using NIRs in the qualitative evaluation of samples where it is possible to determine the predominance of fish or squid, and also to estimate the expected protein content. The protein content is related to the price of the product, since all products containing animal proteins have higher prices that grow proportionally to their share. NIRs is not a qualitative method, but it can help in the selection of products, whose exact composition and possible adulteration can be confirmed by additional laboratory analysis

The Smaller, The Better - Microtechnology for a Macroresults

There is a well-known expression The Bigger, The Better, on which many would agree but when it comes to microreac- tors it is necessary to make the slight modification and say The Smaller, The Better. Reduction in reactor size emerged in many positive effects on many chemical and biochemical reactions. Faster reactions, smaller usage of reaction com- ponents, smaller amount of waste streams, safer reaction conditions, easier process manipulation etc. are just some of the advantages of microreactors. The aim of this review is to present microreactor technology in a simple way and to show its basic characteristics such as structure, advantages and disadvantages, types and general application