Sialic acid is the terminal sugar found on most glycoproteins and is crucial in determining serum half-life and immunogenicity on glycoproteins. The scarce supply of sialic acid hinders its advancement in basic research, diagnostic development and therapeutic production. In this work, the recombinant E. coli BRL04 (pBRL89) producing sialic acid was studied by some batch and fed batch runs of high cell density cultivation using a 3-L fermentor. Some cultivation conditions including carbon source, induction time, dissolved oxygen were optimized and different feeding strategies were compared to enhance sialic acid production. The results may be helpful to the further scale-up of sialic acid production and the production of other recombinant proteins by high cell density cultivation of E. coli.

Sialic acid is the terminal sugar found on most glycoproteins and is crucial in determining serum half-life and immunogenicity on glycoproteins. The scarce supply of sialic acid hinders its advancement in basic research, diagnostic development and therapeutic production. In this work, the recombinant E. coli BRL04 (pBRL89) producing sialic acid was studied by some batch and fed batch runs of high cell density cultivation using a 3-L fermentor. Some cultivation conditions including carbon source, induction time, dissolved oxygen were optimized and different feeding strategies were compared to enhance sialic acid production. The results may be helpful to the further scale-up of sialic acid production and the production of other recombinant proteins by high cell density cultivation of E. coli.

The effects of feeding with two high energy diets ( high carbohydrate and high lipid) and the feeding regime of the two diets on growth, feeding conversion rate, and body composition of the cobia were studied. Based on the observation of lipid redistribution under dietary regime change in rats, this study was aimed to understand how regime change affects the tissue lipid content in the cobia. The study had three parts: preliminary experiment, experiment I, and experiment II. The preliminary experiment was designed to find the proper time to switch the high energy diets and to see the adaptation of cobia to the highe energy dietary treatments. The experiment I was conducted to monitor the growth and body composition of cobia fed for thirty-two days with different experimental diets, including control diets, high carbohydrate diets (HC), high lipid diets (HL), and different feeding regimes (HC¡÷HL: feeding the HC diet for the first sixteen days and the HL diet for the subsequent sixteen days; HL¡÷HC: feeding the HL diet for the first sixteen days and the HC diet for the subsequent sixteen days. The experiment II was studied serum concentration of glucose, triacylglycerol, and free fatty acids and tissues triacylglycerol concentration in liver and white muscle. The fish fed with the HC diet had higher body weight and lower feeding conversion rate than the HL group in first sixteen days; however, the growth of the two groups was not significantly different during the thirty-two day period. The lipid content of dorsal muscle was significantly higher in HC¡÷HL than that in HL¡÷HC; wherease, the lipid content of ventral muscle and viscera was not signficantly affected. The concentrations of serum triacylglycerol, free fatty acid, and relative mean ratio of triacylglycerol in muscle to triacylglycerol in liver were significantly affected. The results of relative mean ratio of serum TG to serum FFA and relative mean ratio of muscle TG to liver TG, suggest that high carbohydrate diet drives de nova lipid production in liver, which circulates to the peripheral tissues for storage as triacylglycerol. High lipid diet preferentially offers energy for lipolysis to produce energy. These results are consistant with the results in rats. Our results show that high energy diets provided a higher growth rate than the control diet, but there were no growth difference in cobia fed high carbohydrate diets, or high lipid diets, or between different feeding regimes. The cobia fed the high carbohydrate diet and the high lipid diet might use different ways for lipid accumulation. These fed the high carbohydrate diet had formed more triacylglycerol than that these fed high lipid diets. The feeding regime shift between the high carbohydrate diet and the high lipid diet significantly affect the the lipid content of the dorsal muscle in the cobia.

Magister Public Health - MPH / Background: Mother to child HIV transmission is a significant public health problem especially in Southern Africa. South Africa is the second highest burden country globally with 71 000 infants being HIV infected every year. The aim of this study was to identify and measure the influence of risk factors of late postnatal HIV transmission and/or mortality among infants born to HIV positive mothers. Study design: Historical cohort data collected during 2002 – 2004 from 3 purposively selected PMTCT sites in South Africa (namely: Rietvlei, Umlzai and Paarl) is used. These three sites are purposively selected to reflect different HIV prevalence, socioeconomic and geographical locations. A total sample size of 469 mother–infant pairs were followed for 36 weeks. Data Collection: Data were collected by trained field researchers and community health workers using semi-structured interviews including: infant feeding practices, infant and maternal mortality, disclosure of HIV status, basic knowledge of HIV/AIDS and MTCT and sociodemographic information. Dried blood spots were collected by heel prick in the baby at 3, 24 and 36 weeks, whilst in the mother finger prick was taken at 3 and 36 week visits. Data Analysis: Data from all questionnaires were coded, captured and cleaned. STATA version 10 is used to analyze and measure the independent influence of risk factors of HIV-free survival rate. Variables found having significant association in the bivariate analysis were analyzed using Cox-proportional hazard model. Result: Our study shows that early mixed feeding is a common practice in South Africa. Overall, 83% (as high as 90.26% in Rietvlei) of mothers were either mixed breast feeding or mixed formula feeding before the infant is at age 5 weeks. MBF at 7 weeks was associated with 3.5 fold increased risk of transmission and/or mortality as compared to EBF (p-value=0.22), while PBF had a 2 fold less hazard of transmission and mortality compared to MBF (p-value=0.1). In this study, failure to disclose, poor counselling and lack of close support by health facilities were major factors that contributed to inappropriate feeding choice and non-compliance to exclusive feeding. Poor counseling (below the average of expected level) had an associated 55% increased risk of transmission and/or mortality. A substantial proportion (70.61%) of women in our study didn’t disclose their status to anyone. Failure to disclose was associated with 44% of increased risk of transmission and mortality. The study also showed households who had shortage of food were at increased risk (adjusted hazard ratio 1.7) of HIV transmission and/or mortality of infants. Maternal and infant factors such as premature birth, maternal viral load, poor weight gain during pregnancy and low birth weight were significant influential factors of HIV-free survival rate. Conclusion: In general, this study has given us an idea that postnatal HIV-free survival is determined by the interrelated effect of multilevel co-factors. Therefore, comprehensive multi-sectorial approach is needed to address the MTCT and child mortality problem in South Africa. The health sector should take urgent action to improve the quality of counselling and health services given in health facilities. Government should give enough attention to reduce the bureaucratic hassles of receiving grant by HIV positive mothers.

No description available.

The family Megastigmidae (Hymenoptera: Chalcidoidea), one of the hymenopteran parasitoid families, is unique in containing many species with phytophagous larval feeding strategy. A number of species of different genera are seed-feeders and the genus Bortesia is even capable of inducing galls. The family Megastigmidae is found mainly in the Australian region but a few genera/species groups are widespread throughout different areas, mainly in the Oriental and the Holarctic region. The main goal of this study was to map phylogenetic relationships among genera and clarify the following: the overall number of transitions between a parasitoid and a phytophagous way of life, the ancestral feeding strategy of the family, the evolution of feeding strategies in the genus Megastigmus, and the geographical area of origin of the family. The questions were tested based on a phylogeny reconstructed by a state-of-the-art method - sequencing of "Ultra-Conserved Elements (UCEs)" - using 100 specimens of Megastigmidae from 11 out of 12 currently valid genera selected taking into consideration their feeding strategy and biogeographical origin. The final dataset contains 1210 loci (570,000 base pairs in length) and most nodes are supported by bootstrap value 100. The results show that the family can be divided into 3...

<p dir="ltr">Boars in the swine industry are one of the select animals subject to limit feeding. Limit feeding boars occurs once boars are selected to enter the boar stud. Before selection boars are <i>ad libitum</i> fed like a nursery or grow finishing pig. Research involving boar nutrition and the impact it has on growth, development, and semen characteristics are limited compared to the rest of the swine industry. The objective of these studies conducted at Purdue University were to determine how varying nutritional feeding strategies impact semen quality and quantity as well as growth and development of artificial insemination boars.</p><p dir="ltr">Feeding fiber is a commonly used strategy in gestating sow nutrition to mitigate some of the negative side effects of limit feeding animals. A variety of fiber sources are available to the swine industry, however most of the common sources used are wheat bran, alfalfa meal, sugar beet pulp, and soybean hulls. Soyhulls are one of the more easily accessible sources of fiber in Indiana and the Midwest U.S. due to large amounts of soybean production and processing which will continue to grow with bi-energy demands. Boars fed the fiber diet (14.3% soyhulls) had increased bodyweight and body condition changes over the twelve-week period. Additionally, fiber inclusion in the diet had no impact on semen characteristics but semen was impacted by the age and breed of the boar. Salivary cortisol levels were reduced in boars fed fiber as well as some changes in behavior were observed.</p><p dir="ltr">The addition of fiber had impacts on growth and development but no impacts on semen. Since boars are limit-fed for so long from selection after the grow-finish period until they are culled this drew up the question if feeding boars different levels after selection (1.8 kg/d or 2.7 kg/d) impacted trainability, first time semen collection characteristics, growth and development of young boars. No differences were observed for feeding level impacting trainability with 92% of all boars regardless of treatment being successfully trained. Semen volume was increased in boars fed 2.72 kg/d by approximately 50% but no other semen characteristics were impacted. Boars fed 2.72 kg/d also had increased bodyweight and body condition score measures.</p><p dir="ltr">The boars subject to the training study unknowingly arrived at the farm naturally infected with porcine circovirus three (PCV3). Research has been conducted on the ability of viruses (PRRSv, PEDv) to be detected and transmitted through semen. Porcine circovirus three is a relatively new variant of circovirus so the opportunity to evaluate the question of if this virus was able to be detected in seminal plasma and the impacts it has on semen characteristics was presented. Serum and semen samples were collected for polymerase chain reaction analysis of detection of PCV3 conducted at Purdue Animal Disease Diagnostic Laboratory. Porcine circovirus three was able to be detected in the serum of positive boars however no positive detection occurred for seminal plasma samples. Morphological abnormalities such as distal midpiece reflex, distal droplets, and head and tail differed between infected and non-infected boars. Young boars sero-positive for PCV3 had decreased total sperm, total normal sperm motility, and head and tail abnormalities but had decreased distal midpiece reflex abnormalities when compared to PCV3 negative young boars. Young boars were also able to maintain the virus for 98+ days, while some old boars were able to clear the virus withing 14 weeks of becoming positive.</p><p dir="ltr">The next chapter evaluated maintenance energy equation listed in the swine NRC 2012 and if it was still accurate for sexually active boars and if weight management through the use of this equation impacted boar performance. Boars were subject to three treatments (150%, 100%, 80%) of maintenance energy for the first nine-week period and 150% and 80% diets were switched for second nine-week period while 100% stayed the same the entire time in a cross-over design. Semen, bodyweight, and body condition parameters were analyzed throughout the two nine-week periods. Boars fed 80% of maintenance had the largest reduction in semen parameters compared to 150% and 100% maintenance fed boars. Additionally, switching 80% feed intake boars to 150% maintenance feed intake, boars were able to recover some of the negative impacts, however they were not able to fully recover in the second nine-week period. Boars fed 100% and 80% maintenance energy lost weight regardless of age. The loss of body weight of the 100% maintenance fed boars indicates the swine NRC 2012 equation is underestimating the modern AI boar maintenance needs. Old boars were able to handle changes in weight and body condition better than young boars as there was reduced variation in serum metabolites analyzed with old boars compared to young boars.</p><p dir="ltr">The last chapter of this thesis focused on a big data project from commercial sow farms. The objective of this study was to determine if breeding gilts at first signs of estrus or after has an impact on sow performance and economic value to parity three. A regression model was developed from on farm data to determine the difference in total born piglets to parity 3 between gilts bred on their first estrus or after. Gilts bred on their first estrus had six fewer total piglets to parity three compared to gilts who were bred after the first estrus. Also, gilts bred after their first estrus had a larger percentage of sows being profitable compared to gilts bred on first estrus. This model data was compared to actual data for comparison between the two. The model with the limited variables inputted and compared to the actual data was fairly accurate with economic profitability and with more refinement the accuracy can be increased.</p><p dir="ltr">Overall, nutrition of the boar needs to be an area of interest in the swine industry to continue improving efficiency of production. Feeding fiber to boars has minimal impact on semen characteristics but can be used to reduce stress in boars that are limit-fed for weight and body condition management. Limit feeding boars beginning at selection reduces growth and development and had negative impacts on first time semen collection volume. Porcine circovirus 3 was not found in the seminal plasma of naturally infected boars when serum analysis was positive. Boars fed below maintenance levels listed in the swine NRC 2012 have negative impacts on semen, bodyweight, and body condition parameters. Once diets were changed boars were able to recover from the feed restriction but not meet baseline measures prior to feed restriction. Young boars are more sensitive to feeding changes than old boars, this could be due to the young animal still growing while the older animal is closer to mature size. Big data projects can aid producers in making production changes decisions to estimate the economic impact it can have to an individual farm or the entire production system.</p>

Childhood cancer is a life-threatening disease with a profound impact on the family. Treatment side-effects and accompanied dietary difficulties are for example severe stressors, as appropriate nutrition is important for the treatment success and quality of life. In addition, (unhealthy) dietary patterns established in childhood tend to maintain in survivors. Parents are key players in feeding and establishing these pat-terns, though, systematic research on how parents experience these dietary difficulties is limited. This study aimed at exploring parental experiences of children’s dietary changes and difficulties during cancer treatment and after completion: what feelings do parents experience regarding their child’s dietary changes and difficulties, what feeding strategies to they apply to handle these difficulties, and how did they experience professional support and what are parental support needs. A systematic literature review was conducted and resulted in 21 suitable articles. The children were 0-21 years old, had various types of cancer, and received various types of therapy. Findings showed that parents reported many dietary changes (e.g. increase or decrease in food intake) and associated symptoms (e.g. nausea, changed tastes) during and after the cancer treatment course. Parents reported mainly negative feelings towards these dietary difficulties (e.g. distress and anxiety) and applied a wide range of behavioural feeding strategies, both negative (e.g. pressure to eat) and positive (e.g. provide healthy food) strategies. Parents also used complementary and alternative medicine. A high need for informational support regarding eating and feeding was expressed by parents during treatment, a need for emotional and practical support to a lower extent. These results showed how frequent and profound eating and feeding difficulties are in the childhood cancer and survivor population, and their (negative) impact on parents. Parents consequently need more support: they need oral and written information to set realistic expectations and install appropriate feeding strategies. This is important for the child’s nutritional status and general health both during and after cancer.

Die Etablierung eines gesunden Ernährungsverhaltens unserer Kinder ist die wichtigste Voraussetzung für ihre körperliche, kognitive und emotionale Entwicklung. Dabei sind neben einer genetischen Disposition und kulturellen Gegebenheiten vor allem die Einflüsse der jeweiligen Betreuungspersonen ausschlaggebend. Die Eltern steuern sowohl direkt (durch Aufforderungen, Verbote u.ä.) als auch indirekt (durch die Förderung eigenverantwortlicher Entscheidungen u.ä.) das Ernährungsverhalten ihres Kindes. Untersuchungen zum mütterlichen Steuerungsverhalten konzentrierten sich bisher vorwiegend auf die Betrachtung direkter Strategien sowie auf altershomogene und sozial besser gestellte Gruppen. Aufgrund möglicher Verzerrungen durch die Betrachtung einzelner Ausschnitte des Zusammenhangs zwischen Steuerung und Ernährung wurde in der vorliegenden Arbeit ein Gesamtmodell spezifiziert, welches den Zusammenhang zwischen elterlicher Steuerung und kindlicher Ernährung unter Berücksichtigung von Sozial- und Gewichtsfaktoren abbildet. Dazu wurden drei Erhebungen mit insgesamt über 900 Müttern 1 – 10-jähriger Kinder durchgeführt. Innerhalb dieser Untersuchungen ist es gelungen, erstmalig ein deutschsprachiges Instrument zur Messung elterlicher Steuerungsstrategien in der Essenssituation (ISS) zu entwickeln. Die Analysen zeigten, dass bisher nur selten untersuchte Strategien, wie das explizite Bemühen um Vorbildwirkung und das Erlauben von eigenverantwortlichen Entscheidungen des Kindes, von den Müttern häufig angewandt werden. Die Analyse des komplexen Wirkungsgefüge von Steuerung, kindlicher Ernährung sowie sozialer und gewichtsbezogener Faktoren zeigte weiterhin, dass neben stabilen Faktoren, wie dem mütterlichen Status und dem Alter des Kindes, ein entscheidender Anteil der mütterlichen Steuerungsstrategien für die kindliche Ernährung verantwortlich ist. Die berichteten Ergebnisse zeigen auf, wie relevant die gemeinsame Betrachtung von gesunden und problematischen Nahrungsmitteln sowie die den Zusammenhang zwischen Steuerung und Ernährung beeinflussenden Faktoren innerhalb eines Modells ist. Zusammengefasst scheint vor allem die Steuerung durch Belohnung von und mit bestimmten Nahrungsmitteln eine für das kindliche Ernährungsverhalten und das Übergewichtsrisiko besonders kritische Strategie zu sein. Dies ist umso bedeutender, als bisherige Untersuchungen dieses Verhalten häufig in restriktive Strategien integriert betrachteten. Die separate Analyse wies jedoch darauf hin, dass vor allem die belohnenden Verhaltensanteile relevant sind. Dies zeigt, dass es für die Entwicklung einer gesunden kindlichen Ernährung tatsächlich veränderbare Verhaltensweisen gibt, die Eltern in Präventionsprogrammen oder anderen mit Kursen zum kindlichen Wohl assoziierten Einrichtungen vermittelt werden können. / The establishment of healthy eating for our children is an important precondition for their physical, cognitive, and emotional development. Besides genetic and cultural effects that influence children’s food preferences and eating behavior, parents play a pivotal role. Both direct (e.g., demands and restrictions) and indirect strategies (e.g., modeling and monitoring) are used to influence the child’s eating. Previous research about maternal feeding strategies has concentrated mostly on either direct feeding strategies or age-homogenous samples with high social status. To avoid bias by ignoring interdependencies I have explored the association of maternal feeding strategies and the child’s food intake in a complex model, which includes socio-demographic and weight aspects. I undertook three investigations with a total of over 900 mothers of 1- to 10-year-old children. I achieved to develop a German instrument for measuring the parental feeding strategies (ISS). Further analyses showed that rarely examined strategies, such as an explicit modeling or allowing the child to control his food, were often used. We examined a multi-factorial model of the relationship between maternal feeding practices and child’s food intake, taking into account the influences of age, socioeconomic and weight factors. This underlines the relevance of some feeding strategies (namely rewarding and modeling) besides the influence of the child’s age and the mother’s social status. The described results demonstrate the need for considering a model including healthy and unhealthy foods as well as demographic, age and weight variables, to detect relevant strategies in the complex association between parental feeding and child’s food intake. Rewarding turned out to be a critical feeding strategy for the child’s unhealthy food intake and obesity risk, whereas modeling seems to have a protective effect. This is important given that previous research mostly considers this behavior as part of restrictive strategies. The separate analysis shows that the rewarding behavior is especially relevant for the child’s eating. In summary, the results point out the existence of modifiable behavior for the development of healthy eating in a child, which could be conveyed to parents during prevention programs and other facilities.

In this study, effects of different carbon sources and their feeding strategies on recombinant human growth hormone (rhGH) production by Pichia pastoris were investigated by means of cell growth, recombinant protein production and expression levels of hGH and alcohol oxidase (AOX) genes. In this content, firstly, the strain to be used for high level rhGH production was selected between the two phenotypes, i.e., P. pastoris hGH-Mut+ and P. pastoris hGH-MutS. In this selection both phenotypes were compared in two different media containing glycerol/methanol or sorbitol/methanol and P. pastoris-hGH-Mut+ strain grown on medium containing 30 g/L sorbitol with 1% (v/v) methanol was found to have the highest hGH expression level and rhGH production level, 9.84x109 copies/mg CDW and 120 mg/L, respectively. Thereafter, effects of sorbitol, mannitol, fructose, lactose, sucrose, citric acid, lactic acid and acetic acid were investigated by using P. pastoris hGH-Mut+ strain in laboratory scale bioreactors. Among them sorbitol and sucrose were selected to be compared for production in pilot scale bioreactors by adding them batch-wise at the beginning of induction phase with fed batch methanol feeding scheme at &amp / #956 / =0.03h-1. It was shown that sucrose does not support cell growth as sorbitol although it does not repress recombinant protein production. Then three different feeding strategies were applied to develop sorbitol/methanol mixed feeding i) single sorbitol addition at t=0, ii) besides at t=0, adding second batch-wise sorbitol at t=9 h, iii) giving pulse methanol at t=24 h to trigger AOX promoter. These three strategies were compared with a production without addition of co-substrate sorbitol. Substrate consumption, cell growth, recombinant protein production and expression levels of hGH and AOX were investigated for these different feeding strategies. The highest cell concentration was achieved in third strategy as 55 g/L where the highest extracellular rhGH production (301 mg/L) was achieved in the second strategy, with addition of two times of sorbitol. For this highest recombinant protein production case, overall cell and product yield on total substrate were found as 0.17 g/g and 1.71 mg/g, respectively. Moreover, the highest hGH and AOX expression levels were obtained in this strategy.