Kan fisk vokse på trær? Næringsverdi og funksjonelle egenskaper av gjær i fôret til Atlantisk laks (Salmo salar)

Yeasts are gaining attention as alternative ingredients in fish feeds. The nutritional and health potentials of non-saccharomyces yeasts in fish are scarce in literature. Three non-saccharomyces yeasts; Cyberlindnera jadinii (CJ), Blastobotrys adeninivorans (BA) and Wickerhamomyces anomalus (WA) are the focus of this thesis. The objective of the current thesis was to investigate the nutritional values and health effects of the three selected yeasts in the diets of Atlantic salmon (Salmo salar) with focus on growth performance, intestinal health, gut microbiota, and immune responses of fish. The three yeasts were produced in-house using a growth medium containing a blend of enzymatic hydrolysates of pre-treated spruce wood (Picea abies) and chicken by-products. After harvesting, the selected yeasts were processed by direct heat-inactivation with spray-drying (ICJ, IBA and IWA) or autolyzed at 50 ºC for 16 h, followed by spray-drying (ACJ, ABA and AWA). The present thesis comprises of seven papers. Paper I used a desk study approach to review the state-of-the art on the use of yeasts in fish feeds and identified gaps in literature regarding the use of yeasts as aquafeed ingredients. Yeasts are efficient converter of low-value non-food biomass into high-value resources. Yeasts showed comparatively similar amino acids with fishmeal (FM) and soybean meal (SBM), except for methionine, lysine, arginine, and phenylalanine which need to be supplemented when used in fish feeds. Genetic modification and/or nutrient digestibility through exogenous enzyme supplementation and the use of cost-effective down-stream processing (DSP) are possible strategies to increase the nutritive values of yeasts in fish. Additional investment in large-scale production at competitive price is needed for yeasts to be considered as feasible replacement for FM and SBM in fish feeds. Paper II investigated the impacts of yeast species and processing on performance, immune response and gut health of Atlantic salmon fry fed SBM-based diet in freshwater. In a 37-day feeding experiment, the fish were fed one of the nine experimental diets: a FM-based diet, a challenging diet with 40% SBM and six other diets containing 40% SBM and 5% each of ICJ, ACJ, IBA, ABA, IWA and AWA yeast products. An additional control containing 40% SBM and 5% of a reference inactivated C. jadinii (ICU), known for its ability to counteract SBM-induced enteritis (SBMIE) was used in this experiment. C. jadinii and W. anomalus yeasts showed the most promising effects on gut health based on widening of lamina propria and immune response parameters. The AWA was effective in ameliorating SBMIE in fish, while only limited effects were observed for other yeasts products. The ability of yeasts to counteract SBMIE is linked to the activation of immune responses in fish. The results also revealed that the amounts, length, adhesion, and accessibility of cell wall components could be important for the ameliorating effects of yeasts on SBMIE in fish. Paper III assessed the effects of yeasts species and processing on systemic immune response of Atlantic salmon fry fed SBM-based diet in freshwater and demonstrated whether spleen can be used as a target organ to characterize immunomodulatory effects of functional ingredients in fish. The production of yeasts, experiment diets and fish experimental protocol were fully described in Paper II. Four experimental diets (FM, SBM, ICJ, and ACJ) were used in Paper III. The immunomodulatory effects of the diets were analyzed in the spleen of fish after 37 days of feeding, using a transcriptomic evaluation by RNA sequencing and protein expression of specific immunological markers through indirect ELISA. The results showed that SBM induced a down-regulation of pathways associated with ion binding and transport, along with an increase at the protein levels of pro-inflammatory cytokines TNFα and IFNγ. The inclusion of ACJ in the diet was able to control the inflammatory profile caused by SBM through activation of biological pathways related to endocytosis, along with increased protein expression of IL-10 and decreased level of TNFα. The functionality of yeasts in improving gut health of fish is dependent on the yeast species and DSP used after harvesting the yeasts. The results also showed that spleen was a good target organ to characterize the immunomodulatory effects of functional ingredients in Atlantic salmon. Paper IV investigated the effects of yeast species and processing on nutrient digestibility of yeasts in Atlantic salmon. The production and processing of yeasts used in Paper IV were as described in Paper II. Seven experimental diets were used in paper. The control feeds consisted of 100% reference diet (REF) and six other diets comprising of 70% REF diet and 30% each of the yeast products (ICJ, ACJ, IBA, ABA, IWA and AWA). The protein and amino acids of the three yeast species were moderately digested in Atlantic salmon. Autolysis slightly increased protein digestibility of C. jadinii and W. anomalus in Atlantic salmon, but not B. adeninivorans. The results revealed that cell wall porosity as demonstrated by nitrogen solubility had larger impact on nutrient digestibility of yeasts than cell wall thickness. The nutrient digestibility of yeasts in Atlantic salmon is dependent on the yeast species and DSP used after harvesting the yeasts. Based on the results of Papers II, III and IV, a second batch of C. jadinii and W. anomalus yeast were produced to understand the response of Atlantic salmon reared in seawater to dietary yeasts. Therefore, Paper V evaluated the effects of yeasts species and processing on intestinal health and transcriptomic profile from DI and spleen tissue of Atlantic salmon fed SBM-based diet in seawater. The yeasts were produced and processed following the procedure described in Paper II. The ICJ, ACJ, IWA and AWA yeasts products were used in this paper. Six diets were formulated, one based on FM, a challenging diet containing 30% SBM and four other diets containing 30% SBM and 10% each of the yeast products (ICJ, ACJ, IWA and AWA). The inclusion of ICJ and ACJ yeasts reduced the loss of enterocyte supranuclear vacuolization and reduced the population of CD8α positive cells in the lamina propria of fish fed SBM diets. The ICJ and ACJ yeasts controlled the inflammatory profile through upregulation of pathways connected to wound healing and taurine metabolism. The IWA and AWA yeasts controlled the inflammatory profile in fish fed SBM through down-regulation of pathways associated with toll-like receptor signaling, C-lectin receptor and signal transduction. This paper strengthened our earlier observations (Papers II and III) that C. jadinii and W. anomalus are promising novel ingredients with health beneficial effects in terms of controlling distal intestine inflammation associated by feeding plant based diets to Atlantic salmon. Paper VI investigated the effects of yeast species and processing on gut microbiota of fish. The yeast production and processing, experimental diets and fish experimental protocol were as described in Paper V. After 42 days of feeding, six fish from each tank were randomly selected to collect digesta samples from the DI for 16S rRNA sequencing. Water samples (from the source and rearing tanks) and feed samples were also collected for the sequencing analysis. The microbiota of fish fed SBM diet differed from those fed FM diet. The microbiota composition, richness and diversity were similar in fish fed ICJ, IWA and SBM diets. Fish fed ACJ increased relative abundance of Pediococcus, and mucin O-glycan degradation pathway, while fish fed AWA diet increased relative abundance of Bacillaceae compared with fish fed the other diets. Despite the significant modulation of intestinal microbiota of fish fed the autolyzed yeasts (ACJ and AWA), the histological and transcriptomic results revealed that the autolyzed yeasts did not improve gut health of fish beyond the level observed for the inactivated yeasts (ICJ and IWA) (Paper V). These results suggest that the ameliorating effects of yeasts on SBMIE is connected to their ability to stimulate immune responses in Atlantic salmon (Papers II, III and V), rather than through modulation of intestinal microbiota (Paper VI).publishedVersio

E-band slotted microstip patch antenna array for 5G broadband applications

An antenna is one of solution for wireless devices which can be proposed for future 5G systems for high data rate broadband, communications. The antenna system can be design for multiple-input-multiple-output (MIMO) system at a waveband of millimeter (mm) range. The MIMO system consists of the mm-wave array of 2 by 1 slot antennas. The combination of the antenna array system covers the range of frequency from 83.581GHz to 86.483GHz of mm-wave band at 85 GHz. The antenna array dimension is 0.94 mm by 2.28 mm by 0.16 mm. Results obtained from simulation across the 5G band showed peak gain values of 5.82dBi, VSWR of 1.09 with -10dB return loss of -27.5dB

A meta-analysis to determine factors associated with the severity of enteritis in Atlantic salmon (Salmo salar) fed soybean meal-based diets

A meta-analytic approach was used to determine factors associated with the severity of enteritis in distal intestine of Atlantic salmon fed soybean meal (SBM)-based diets. Dataset from 26 fish studies were extracted and standardized for use in the meta-analysis. After standardization, the data were analyzed with ordinal logistic regression model by comparing the SBM treatment(s) in each study with the neutral-reference treatment. The log-odds ratio of the proportional odds model and its standard error were extracted and analyzed using the random effects model to estimate the effect size of dietary SBM on enteritis using four semi-quantitative histological variables: reduction in mucosal fold height; disappearance of supranuclear vacuolization; inflammatory cell infiltration of lamina propria, and of submucosa. Both univariate and multivariate meta-regression were used to identify study factors with significant association to the severity of enteritis in Atlantic salmon. The results showed that fish production phase, feed type, SBM inclusion level, year of study and water temperature are significantly associated with the severity of enteritis in Atlantic salmon. Further meta-analysis of sub datasets according to production phase, revealed that fish reared in seawater were more prone to develop enteritis compared with fish reared in freshwater. The absence of positive relationship between SBM inclusion level and the severity of enteritis was probably due to difference in source, batch, processing, and level of anti-nutritional factors in the SBM used in the different studies combined in the meta-analysis. Subgroup analysis based on year of study revealed that the severity of enteritis in fish fed SBM-based diets has decreased over the years. Additional results revealed that fish fed SBM-based diet at low water temperature showed increased severity of enteritis, compared with fish raised in high water temperature. Linear and quadratic regressions conducted to explore possible impact of enteritis on fish performance, showed that the specific growth rate and thermal growth coefficient of fish decreased with increased severity of enteritis. However, this relationship depends on the fish production phase and the histological variables used for the regression analysis. The current study concluded that the severity of enteritis in Atlantic salmon fed SBM-based diets are significantly associated with fish production phase, feed type, SBM inclusion level, year of study and water temperature, but not the exposure time. Also, the study showed that increased severity of enteritis reduced specific growth rate and thermal growth coefficient of fish fed SBM-based diets.A meta-analysis to determine factors associated with the severity of enteritis in Atlantic salmon (Salmo salar) fed soybean meal-based dietspublishedVersio

Effects of Yeast Species and Processing on Intestinal Health and Transcriptomic Profiles of Atlantic Salmon (Salmo salar) Fed Soybean Meal-Based Diets in Seawater

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Fish, roots, tubers and bananas: opportunities and constraints for agri-food system integration

Agri-food system integration has the potential to increase and add value to agricultural production, reduce cost of and dependency on external inputs, generate additional income to farmers, and encourage the diversification of outputs and diets. Agri-food system integrations such as livestock-fish, poultry-fish, crop-livestock and rice-fish farming have been well documented in academic literature. However, information on fish and root, tuber and banana (RTB) crops integration is scarcely available, despite their worldwide cultural, dietary, and economic importance. This article, which is informed by a narrative literature review and ground-truthing through key informant interviews, documents existing linkages between two agri-food systems – fish and RTB – and identifies opportunities and challenges for strengthening their integration. We found that recorded instances of fish-RTB integration are limited and predominantly discuss production-related activities. Nevertheless, initial evidence suggests that there are important livelihood-enhancing opportunities as well as environmental, nutrition and food-security related benefits, which need to be considered. These include the potential to improve the nutritional status of vulnerable populations and lower the cost of fish production and thus improve the livelihoods of small-scale fish farmers. Further field-based research is recommended to explore these outcomes in more detail

COMBUSTION CHARACTERISTICS OF BIO-DEGRADABLE BIOMASS BRIQUETTES

This paper reports on the combustion characteristics of biodegradable biomass briquettes prepared from charcoal, sawdust and sugarcane bagasse. The three materials were mixed in respective ratio of 20:20:60, 20:30:50, 20:40:40, 20:50:30 and 20:60:20. The briquettes were produced using Budenberg dial gauge hydraulic compression machine with the formation of briquettes under 64 MPa pressure with 120 seconds dwell time. Combustion characteristics such as proximate analysis, fuel-burning rate, fuel ignition time and afterglow time of the produced briquettes were determined. Results show that briquette with sample composition of 20:50:30 has better calorific value of 24613.69 kJ/kg and sample with ratio 20:30:50 has lowest calorific value of 22500.3 kJ/kg, while sampling with ratio 20:30:50 has better physical properties with shatter resistance of 99.61% and porosity index value of 47.40%

Assessing the viability of a grid-connected PV power plant in Mubi, Adamawa State, Nigeria

This paper is based on a techno-economic analysis and the environmental impact of a proposed 1 MW solar photovoltaic (PV) power plant at the main campus of the Federal Polytechnic Mubi (FPM) in north-eastern Nigeria. A photovoltaic power plant converts solar radiation into electricity that can be used as a source of electrical power to meet the daily energy requirements of homes, equipment, and all tertiary institutions. RETScreen Expert software was used to evaluate the techno-economic and environmental sustainability of installing a grid-connected PV power plant. The research results revealed that with an annual solar radiation of 5.74 kWh/m2/day, the maximum annual energy production was estimated to be 1,550.98 MWh. It was discovered that the maximum energy production in March was 146.89 MWh. The project’s profitability and economic sustainability were determined with a good internal rate of return (IRR) of 11.9% and a positive net present value (NPV) of $681,164. The proposed PV power plant has a simple payback period of 11.4 years. The maximum greenhouse gas (GHG) emission reduction is 670.9 tCO2, equivalent to 61.7 ha of forest-absorbing carbon emissions

Leverage and firm performance: New evidence on the role of firm size

In this paper, we draw on the Hansen (1999) threshold regression model to examine the empirical links between leverage and firm performance by means of a new threshold variable, firm size. We ask whether there exists an optimal firm size for which leverage is not negatively related to firm performance. Accordingly, with a panel data of 101 listed firms in Nigeria between 2003 and 2007, we explore whether the ultimate effect of leverage on firm performance is contingent on firm size; that is, whether the type of impact that leverage has on the performance of a firm is dependent on the size of the firm. Our results show that the negative effect of leverage on firm performance is most eminent and significant for small-sized firms and that the evidence of a negative effect diminishes as a firm grows, eventually vanishing when firm size exceeds its estimated threshold level. We find that this result continues to hold, irrespective of the debt ratios utilized. In line with earlier studies, our results show that the effect of leverage on Tobin’s Q is positive for Nigeria’s listed firms. However, our new finding is the evidence that the strength of the positive relationship depends on the size of the firm and is mostly higher for small-sized firms

Nijerya’da İslâm: Yoruba Toplumunda İslâm’ın yapılanması

ÖZETTezimizin konusu “Nijerya’da İslâm: Yoruba Toplumunda İslâm’ın Yapılanması” olmakla birlikte önce Yoruba toplumunun İslâm’dan önceki ve sonraki durumunu detaylı bir şekilde inceledik. İslâm’dan önce Yorubalar geleneksel inançlara sahiplerdi. Yoruba toplumunda 401 küçük tanrı (Orişa) bulunmaktadır ve her ailenin istediği Orişa’ya tapma özgürlüğü vardı. Yorubaların yaşam tarzları bu inanca bağlıydı. İslâm’ın gelmesiyle birlikte Yorubalar arasında bu geleneksel inançlar ortadan kaybolmaya başlamıştır. İslâm’ı benimseyen Yorubalar geleneksel inançlarına göre değil, artık İslâm’a göre yaşam tarzlarını belirlemeye başlamışlardır.İslâm, Yoruba toplumunda tarikatlar, İslâmî kurumlar ve cemaatler ve birçok etkili Müslüman liderlerin hareketleri ve gayretleri ile hayat bulmuştur. Başka bir deyişle, Yoruba toplumunda İslâm’ın gelişmesi, Yoruba toplumunda bulunan bu tarikat ve İslâmî cemaatlerin hareketlerine bağlıdır. Yoruba toplumunda Ticanî ve Kadirî olmak üzere iki farklı tarikat özellikle etkilidir. Bu iki tarikat dışında farklı büyüklüklerde onlarca İslâmî cemaat vardır. Biz araştırmamızda en etkili olan Ahmedî, Ansar-Deen, Nawair-Deen, Zümretü’l-Müminîn, Alasalatu Grubu, Nasfat Cemaati ve fundamentalist dinî grup olarak kabul ettiğimiz Tebliğ cemaatine yer verdik. Bu cemaatlerin hepsi inançta ortak bir paydayı paylaşmakta ve aynı amaç yönünde çalışmaktadırlar. Hepsi farklı zamanlarda farklı Müslümanların ihtiyaçlarını karşılamak için kurulmuşlardır. Aralarındaki farklılıklar büyük ölçüde isimlerinden ve kimliklerinden ibarettir.İslâm, Yoruba toplumunda büyük etkiler yapmıştır. Bu etkiler eğitim, siyaset, ekonomi ve aile gibi temel Yoruba toplumsal kurumlarda açıkça görülmektedir. Araştırmamızda hem İslâmiyet’in toplum üzerindeki etkileri incelenmiş, hem de geleneksel Yoruba kültürünün İslâm’ın algılanması ve yaşanması hususunda yapmış olduğu etkiler değerlendirilmiştir. ABSTRACTAs the topic of our thesis is “Islam in Nigeria: The Foundation of Islam in the Yoruba Society”, we tried to analyse the position of Yoruba Society before and after the existence of Islam. The Yorubas were practising traditional religion (paganism) before Islam. In Yoruba Society, there are 401 deities and every family has the right to choose their own god. The life style of the ancient Yorubas were always planned according to the traditional believes. But with the existence of Islam in Yoruba Society, all the traditional believes started disappearing. The Yorubas that accepted Islam now planned their life according to Islam and not paganism.We also found out that the growth of Islam in the Yoruba Society mostly depends on the actions of the tarikats, Islamic organisations, Islamic Societies and some active muslim leaders in Yoruba Society. There are two kind of tarikat in Yoruba Society namely Ticanîyyah and Kadiriyyah. Also there are many active Islamic Societies all with common believe and goals. The most differences among them is their names and identities as they are all founded at different times to solve muslims problems.We also found out that Islam has a very big effect on Yoruba Society. Islam does not only affect the Yorubas, but also the other basic Yoruba social institutions like education, politics, economics and family. As it is confirmed in our research that Islam has a very big effect on Yoruba Society, Yoruba Culture also has affect on Islam as well