511 research outputs found
A Qualitative Study on a Process of Parents’ Acceptance of Children’s Severe Motor and Intellectual Disabilities (SMID)
No full text本論文は、重症心身障害児・者の親の会に加入している８人の心身に重度の障害をもつ子どもの親が、子どもの障害をどのように認識し、どのようにその障害を受容していくのか、というリサーチクエスチョンを基にインタビューを行い、MAXqdaの基本原理に沿った紙媒体を用いて分析を行った。その結果、心身に重度の障害をもつようになった子どもの親の障害受容について、次の６つの概念で捉えることができた。
「医療の対応への不満」、「母親の育児スキル学習」、「家族の支え」、「夫と妻の意思のズレ」、「拠り所となる集団成員」、「世代間の差違」である。
子どもが障害をもつようになった時、「拠り所となる集団成員」の存在が大きな意味を持ってくる。具体的には、３つの視点が見えてくる。１つ目に、子どもが障害をもつようになった場合、同じような障害の子どもをもつ親と悩みや喜びをシェアし、ポジティブな思考に繋がっていくこと、２つ目に、親同士の繋がりができると、次第にネットワークが強化され、それが自助グループ活動として展開する。そして、３つ目に、親はそのネットワークを使って、実態に合わない制度の変更に向けて運動を起こしていく、という視点である。The purpose of this paper was to generate viewpoints on how parents acknowledge and accept children with severe motor and intellectual disabilities (SMID) by interviewing eight parents with children who have SMID. The author used a basic principle of a paper-based MAXqda to examine the process and analyze the interview data. The result of the analysis indicated that six concepts were found concerning parents’ acceptance of children with SMID: complaint of medical care, learning of child-raising skills by mothers, support by families, differences in ways of thinking between husbands and wives, reference group members, and generation gaps.
When parents had children with SMID, it was meaningful to have groups to rely on. In particular, the author found three viewpoints. First, parents’ sharing their suffering or joy with other parents who had SMID led to a positive way of thinking. Second, once the parents became connected with other parents, they established a network.
Then, the network was reinforced and deployed as activities of a peer group. Third, the parents tried to change the system which contradicted the reality by using the network established.departmental bulletin pape
Tailor-made memory: natural differences in associative olfactory learning in two closely related wasp species
No full textLearning and memory formation are often seen as traits that are purely beneficial, but they are associated with metabolic costs as well. Since costs and gains of learning and memory are expected to vary between species, the ease and speed with which stable (consolidated) long-term memory (LTM) is formed, is expected to differ between species. For animals that occupy different ecological niches, ‘slow’ learning may be as adaptive as ‘fast’ learning. If an animal encounters a relatively predictable environment during its lifetime, fast learning is a good strategy. If the environment is relatively unpredictable, however, an animal may need more time and experiences to evaluate information before storing it as long-lasting memories. This concept is known as tailor-made memories: a species learns in the way that is most favourable, given the circumstances. In order to assess how such tailor-made memories evolve, I have used a multitrophic model system. This system consisted of (1) two closely related parasitic wasps (Cotesia glomerata and C. rubecula) that show a profound difference in learning, (2) the herbivorous cabbage white butterfly larvae Pieris brassicae and P. rapae, in which the parasitic wasps lay their eggs, and (3) the host plants Brussels sprouts (Brassica oleracea var. Gemmifera) and nasturtium (Tropaeolum majus). In my experiments, the wasps could learn to associate the odours of a plant with the presence of suitable hosts, by having one or more oviposition experiences (‘conditioning trials’) on that plant. Previous experiments showed that C. glomerata needs only one conditioning trial to form LTM, whereas C. rubecula needs three trials spaced in time to do so. In addition to LTM, another form of consolidated memory exists; anaesthesia-resistant memory (ARM). Both LTM and ARM are resistant to retrograde amnesia, which can be induced by cooling the wasps after conditioning. In contrast to LTM however, ARM is not protein synthesis-dependent. It can therefore be seen as a ‘cheap’ form of long lasting memory. Consolidated memory in C. glomerata is thought to consist exclusively of LTM, whereas in C. rubecula it appears to be a mixture of both ARM and LTM. LTM formation requires protein synthesis, a process in which the transcription factor cAMP response element-binding protein (CREB) plays a key role. As a result of alternative splicing of the CREB mRNA transcript, the CREB protein occurs in different forms called isoforms. In model organisms such as the fruit fly Drosophila melanogaster, the mollusc Aplysia californica, and also in mammals such as mice and men, CREB isoforms have been shown to activate or repress transcription. Therefore, it has been hypothesized that the ratio of activator and repressor isoforms acts as a molecular switch for LTM formation. Such a switch could be responsible for species-specific differences in learning and memory. In this study the CREB gene of C. glomerata and C. rubecula was cloned and sequenced, and nine isoforms were identified in the two Cotesia species. The abundance of two of the nine mRNA variants coding for these isoforms differs significantly between C. glomerata and C. rubecula; the other variants are expressed similarly in both species. A conditioning trial, however, seems to induce changes in the expression of some of the major isoforms, indicating that the learning process itself may establish a ratio between activators and repressors that determines whether LTM is consolidated or not. Although such molecular mechanisms can potentially act very quickly, it may sometimes take up to days or weeks before information is stored in long-lasting memories. To explain how and why such differences in memory dynamics occur, we need insight in what happens when selection acts on natural variation in learning rate. In order to investigate this, I applied a bidirectional selection regime and reared two lines of C. glomerata wasps that differed significantly in learning rate (the decreased-learning line (DLL) and the increased-learning line (ILL)). By applying the protein synthesis inhibitor anisomycin before conditioning and measuring memory retention after conditioning, I showed that the memory consolidation dynamics of the selection lines differed. The DLL did not consolidate LTM anymore, whereas the ILL still did. By combining this study with experiments in which I induced retrograde amnesia by cooling at certain time intervals after conditioning, I demonstrated that in C. glomerata, anaesthesia-sensitive short-term memory directly consolidates into LTM, without an intermediate ARM phase. ARM represents a low-cost form of long-lasting memory (since it is not protein synthesis-dependent) and its presence is assumed to be favourable in animals that need more time to evaluate information, before storing it in the form of consolidated memories (e.g., in C. rubecula). The inability of C. glomerata to form ARM is costly because it may lead to an expenditure of energy (i.e., protein synthesis) on the ‘premature’ storage of unreliable information. Comparison of my selection lines showed that a high learning rate has costs. Longevity appeared to be significantly higher in wasps from the DLL than in those from the ILL. Moreover, females of the ILL have significantly larger brains than females from the DLL, while retaining a similar body size. These exciting results show that trade-offs occur (i.e., brain size vs. longevity) as a result of the bidirectional selection pressure that we applied. Moreover, the costs associated with a high learning rate seem to be of a constitutive nature. This means that animals that are able to quickly form consolidated memory pay for it by maintaining a large, costly brain and having a decreased lifespan, even when they do not actually use their learning abilities. The results of my work show that comparative research involving a model system consisting of two closely related animals with a natural difference in learning rate yields unique information, and is preferred over the use of ‘traditional’ model organisms. It enables testing of various hypotheses with an ecologically relevant learning paradigm. Neuroscience (and biology in general) would benefit greatly from an increase in the use of model systems that consist of closely related species that show differences in the trait of interest. The work described in this thesis shows how fruitful such a comparative approach can be. <br/
Towards understanding breast cancer mechanisms to metastasize
No full textAccession Number: GSE47389 Platform: GPL570: [HG-U133_Plus_2] Affymetrix Human Genome U133 Plus 2.0 Array Organism: Homo sapiens Published on 2013-11-01 Summary: How organ-specific metastatic traits accumulate in primary tumors remains unknown. We identified a role of the primary tumor stroma in selecting breast cancer cells that are primed for metastasis in the bone. A fibroblast-rich stroma in breast tumors creates a microenvironment that is similar to that of bone metastases in its abundance of the cytokines CXCL12 and IGF1. Heterogeneous breast cancer cell populations growing in such mesenchymal environment evolve towards a preponderance of clones that thrive on CXCL12 and IGF1. Fibroblast-driven selection of bone metastatic clones in mammary tumors is suppressed by CXCL12 and IGF1 receptor inhibition. Thus, a fibroblast-rich stroma in breast tumors can pre-select bone metastatic seeds, promoting the evolution of metastatic traits and the interplay between a primary tumor and its distant metastases. Overall Design: Affymetrix U133 Plus2 arrays were hybridized according to the manufacturer's procedure using RNA extracted from 47 primary breast tumors. Specific gene sets were evaluated in this cohort. Contact: Name: Marcel Smid Organization: Erasmus MC Deparment: Medical Oncology Address: Dr. Molewaterplein 50 Rotterdam Netherlands Organization: Affymetrix, Inc. Address: Santa Clara CA 95051 USA Email: [email protected], [email protected] Phone: 888-362-2447 Web-Link: http://www.affymetrix.com/index.aff
Towards understanding breast cancer mechanisms to metastasize
No full textAccession Number: GSE47389 Platform: GPL570: [HG-U133_Plus_2] Affymetrix Human Genome U133 Plus 2.0 Array Organism: Homo sapiens Published on 2013-11-01 Summary: How organ-specific metastatic traits accumulate in primary tumors remains unknown. We identified a role of the primary tumor stroma in selecting breast cancer cells that are primed for metastasis in the bone. A fibroblast-rich stroma in breast tumors creates a microenvironment that is similar to that of bone metastases in its abundance of the cytokines CXCL12 and IGF1. Heterogeneous breast cancer cell populations growing in such mesenchymal environment evolve towards a preponderance of clones that thrive on CXCL12 and IGF1. Fibroblast-driven selection of bone metastatic clones in mammary tumors is suppressed by CXCL12 and IGF1 receptor inhibition. Thus, a fibroblast-rich stroma in breast tumors can pre-select bone metastatic seeds, promoting the evolution of metastatic traits and the interplay between a primary tumor and its distant metastases. Overall Design: Affymetrix U133 Plus2 arrays were hybridized according to the manufacturer's procedure using RNA extracted from 47 primary breast tumors. Specific gene sets were evaluated in this cohort. Contact: Name: Marcel Smid Organization: Erasmus MC Deparment: Medical Oncology Address: Dr. Molewaterplein 50 Rotterdam Netherlands Organization: Affymetrix, Inc. Address: Santa Clara CA 95051 USA Email: [email protected], [email protected] Phone: 888-362-2447 Web-Link: http://www.affymetrix.com/index.aff
Een Onbekookte Niewigheid? - Invoering, omvang, inhoud en betekenis van het wiskundeonderwijs op de Franse en Latijnse scholen 1815-1863
No full textElectrical Engineering, Mathematics and Computer Scienc
Het berekenen van evenwichten volgens de "Minimale vrije enthalpie" methode
No full textDocument(en) uit de collectie Chemische ProcestechnologieDelftChemTechApplied Science
Development of probiotic mutandabota, a locally sustainable functional food incorporating Lactobacillus rhamnosus
No full textDevelopment of probiotic mutandabota, a locally sustainable functional food incorporating Lactobacillus rhamnosus Mutandabota or umlondo is an indigenous food that is consumed in Southern Africa on a daily basis. The product is made by mixing raw cow’s or goat’s milk with 14 % (wt/vol) dry pulp of the baobab fruit (Adansonia digitata L.) and 7 % sugar. Mutandabota has a high protein content, and is rich in vitamin C and minerals. It also provides fibre to the diet, which evidently has potential health benefits in preventing diabetes, cardiovascular diseases, some cancers and constipation. Predominant microorganisms were isolated from mutandabota and identified. This indicated that different species of bacteria and yeast survive the acidity and low pH of 3.4±0.1 in mutandabota. While no pathogens were isolated, the identified microorganisms are capable of spoiling the product. Preparation of mutandabota is a gendered activity dominated by women. A probiotic dairy product was then developed at village level on the basis of mutandabota to enable resource-poor populations in Southern Africa to accrue health benefits from a functional food. Raw cow’s milk was pasteurised and dry baobab fruit pulp was added to the milk at a concentration of 4 % (wt/vol). This mixture was inoculated with the probiotic Lactobacillus rhamnosus yoba, an isolate of Lactobacillus rhamnosus GG, and left to ferment for 24 h. Baobab fruit pulp at 4% promoted growth of L. rhamnosus yoba. More pulp and sugar were then added to produce yoba mutandabota with 14 % (wt/vol) baobab fruit pulp and 7 % sugar. The final pH of yoba mutandabota was pH 3.5, which ensured the microbiological safety of the product. Viable plate count of L. rhamnosus yoba was 8.8 ± 0.4 log cfu/mL at the moment of consumption, thereby meeting the criterion to have a viable count of the probiotic bacterium in excess of 6 log cfu/mL in the product. There was no significant difference (p=0.31) in consumers’ preference between traditional and yoba mutandabota, despite a significant difference (pL. rhamnosus yoba on competing pathogens in mutandabota were done. In traditional mutandabota (pH 3.4±0.1) some food-borne pathogens survived and withstood the acids and low pH of the product. However, yoba mutandabota (pH 3.4±0.1) inactivated all tested food-borne bacterial pathogens during the 24 h potential consumption time. This demonstrated that yoba mutandabota can be safer stored than traditional mutandabota. The L. rhamnosus yoba showed robustness and grew from 5.5 log cfu/mL to 9.0 log cfu/mL within 24 h in the presence of pathogens in yoba mutandabota. The outcome of this work was a safe, healthy, optimum-quality product of relevant nutritional value. Although this work focused on growth of L. rhamnosus yoba in mutandabota, the potential exists to apply this approach to other traditional foods worldwide as a low-cost method to improve dietary quality and gastro-intestinal health of consumers. Yoba mutandabota processing and trading may ameliorate the well-being of rural households through improvements in health status and livelihoods.</p
Simultaneous growth and metabolite production by yoghurt starters and probiotics: a metabolomics approach
No full text The main objective of this research was to investigate the simultaneous growth and metabolite production by yoghurt starters and different probiotic strains, i.e. Lactobacillus rhamnosus GG, Bifidobacterium animalis subsp. lactis BB12 and Lactobacillus plantarum WCFS1, during set-yoghurt fermentation and refrigerated storage. In this context, the microbial activity was evaluated in terms of bacterial population dynamics, milk acidification and formation of volatile and non-volatile metabolites in set-yoghurt. A complementary metabolomics approach using headspace SPME-GC/MS and 1H-NMR was applied for characterization of biochemical changes associated with the microbial metabolism during fermentation and storage. The results revealed that incorporation of the three probiotic strains did not significantly influence the acidity and concentrations of key-aroma volatile compounds of set-yoghurt. Still, the presence of probiotics substantially contributed to the formation of a large number of volatile and non-volatile metabolites detected at low concentration. Because many probiotic strains are not able to survive well in fermented milk, a strategy to enhance their survival was additionally applied by preculturing the three probiotic strains under sublethal salt and low pH stress conditions prior to inoculation in milk. The results revealed an improved survival of L. rhamnosus GG and B. animalis subsp. lactis BB12, specifically by preculturing at relatively low pH conditions. Moreover, incorporation of sublethally precultured L. plantarum WCFS1 significantly impaired the survival of L. delbrueckii subsp. bulgaricus, which consequently reduced the post-acidification of yoghurt. Metabolomics analyses revealed that the presence of stress-adapted probiotics induced significant changes in the overall metabolite profile of yoghurt. This finding is important, since variations in the relative abundance of various organic acids, aroma volatiles and proteolytic-derived compounds may directly influence the organoleptic quality of product. Finally, multivariate analysis enabled to distinguish yoghurts fermented by different types of starter combinations and different durations of storage according to their metabolite profiles. This research provides new information regarding the impact of probiotics on the metabolome of yoghurt and potential application of stress-adapted probiotics in an actual food-carrier environment.</p
Natural variation in memory formation among Nasonia parasitic wasps : from genes to behaviour
No full text The ability to learn and form memory has been demonstrated in various animal species, ranging from relatively simple invertebrates, such as snails and insects, to more complex vertebrate species, including birds and mammals. The opportunity to acquire new skills or to adapt behaviour through learning is an obvious benefit. However, memory formation is also costly: it can be maladaptive when unreliable associations are formed and the process of memory formation can be energetically costly. The balance between costs and benefits determines if learning and memory formation are beneficial to an animal or not. Variation in learning abilities and memory formation between species is thought to reflect species-specific differences in ecology. This thesis focused on variation in the number of trials required to form long-term memory (LTM). LTM is considered the most stable and durable type of memory, but also the most costly, because it requires protein synthesis. Many animal species require multiple learning experiences, which are spaced in time, to form LTM. This allows re-evaluation of information before an animal invests in costly LTM. There is, however, variation in the number of trials that animal species require to induce LTM formation. A number of insect species, including a number of parasitic wasp species, form LTM after only a single learning experience. Parasitic wasps can learn odours that guide them towards suitable hosts for their offspring, so-called oviposition learning. Substantial differences in LTM formation are observed among closely related species of parasitic wasps, which provides excellent opportunities for comparative studies. Both ecological and genetic factors involved in variation in LTM formation have been studied in this project. A multidisciplinary approach is essential to understand the evolution of variation in LTM formation, because the interaction between genes and environment shapes learning and memory formation. LTM formation was studied in closely related species of the genus Nasonia. These small parasitic wasps (~2 mm in length) lay their eggs in various species of fly pupae and differences in the ecology of the four known species of this genus have been described. A high-throughput method for olfactory conditioning was developed in which the wasps associated an odour, either chocolate or vanilla, with the reward of a host. A T-maze olfactometer was designed for high-throughput testing of memory retention. Using these methods, variation in memory retention was observed between three Nasonia species. Both N. vitripennis and N. longicornis form a long-lasting memory after a single conditioning trial, which lasts at least 5 days. Nasonia giraulti, on the other hand, lost its memory after 1 to 2 days after a single conditioning trial. Further studies focused on the difference between N. vitripennis and N. giraulti, which was most pronounced. By inhibiting LTM with transcription and translation inhibitors, it was confirmed that N. vitripennis forms this type of memory after a single conditioning trial. LTM is visible 4 days after conditioning in N. vitripennis. Nasonia giraulti does not form LTM after a single conditioning trial. Long-lasting memory is only formed after two trials, with a 4-hour interval between them. This difference in LTM formation makes N. vitripennis and N. giraulti excellent model species to study both ecological and genetic factors involved in this difference. Ecological factors such as the value of the reward and the reliability of the learned association have been shown to affect memory formation in a number of animal species. A recent study on oviposition learning in two parasitic wasp species demonstrated that LTM formation depends on the host species, i.e. the reward offered during conditioning. LTM was formed when a host with a higher quality was offered, but not when a host of lower quality was offered. The effect of host quality on memory retention of N. vitripennis and N. giraulti was tested. Either a large host, Calliphora vomitoria, a medium-sized host, Lucilia sericata, or a small host, Musca domestica, was offered during conditioning. These hosts were observed to differ significantly in their quality, i.e. in the number of parasitoid offspring that emerged and the size of the offspring. There was, however, no effect of host species on memory retention in either Nasonia species. These results suggest that host quality is not important for LTM formation in N. vitripennis and N. giraulti. This observation shows that ecological factors that are important for memory formation in one species may not be important for another species. The genetic basis of memory formation is highly conserved among distant animal phyla. A large number of genes involved in LTM formation have been identified in genetic model organisms, including fruit flies, honeybees, the California sea hare, mice and rats, and the zebra finch.Genetic factors responsible for natural variation in LTM formation between species are currently unknown, however. Two approaches were used to study genetic factors responsible for the difference in LTM formation between N. vitripennis and N. giraulti. The first approach took advantage of the unique possibility to interbreed Nasonia species. Hybrid offspring of N. vitripennis and N. giraulti did not form LTM after a single conditioning trial, similar to N. giraulti. The dominant LTM phenotype of N. giraulti was then backcrossed into the genetic background of N. vitripennis for up to 5 generations. Using a genotyping microarray analysis and subsequent confirmation experiments, we detected two genomic regions (quantitative trait loci – QTLs) that both reduce long-lasting memory, but not completely remove this memory. These results indicate that multiple QTLs regulate the difference in LTM formation between the two Nasonia species. Concluding, our approach has provided insights in the genomic basis of a naturally occurring difference in LTM formation between two species. Excellent opportunities for fine-scale QTL mapping are available for the genus Nasonia. This will allow identification of decisive regulatory mechanisms involved in LTM formation that are located in the two genomic regions detected in this study. The second approach took advantage of next-generation sequencing techniques that allow transcriptome-wide studies of gene expression levels. RNA from heads of N. vitripennis and N. giraulti was collected before conditioning and immediately, 4 hours, or 24 hours after conditioning. This RNA was sequenced strand-specifically using HiSeq technology, which allows detection of sense and antisense transcripts. Various genes, from a number of different signalling pathways known to be involved in LTM formation, were uniquely differentially expressed after conditioning in N. vitripennis. These genes are likely involved in the ongoing process of LTM formation in this species. A number of other genes with a known role in LTM formation,including genes involved in dopamine synthesis and in the Ras-MAPK and PI3K signalling pathways, were uniquely differentially expressed in N. giraulti. These genes may have a role in a LTM inhibitory mechanism in this species. Antisense transcripts were detected for a number of known memory genes, which may indicate a role inregulation of transcription, alternative splicing, or translation. This study is the first to compare gene expression patterns after conditioning between two species that differ in LTM formation. The results provide promising candidate genes for future studies in which the regulation of these genes, the function of specific splice variants, and spatial expression patterns in the brain should be studied to understand how these genes are involved in the regulation of LTM formation. Learning and memory formation have an important role in animal and human behaviour.Novel and valuable insights on both ecological and genetic factors responsible for variation in LTM formation have been revealed by the research presented in this thesis. Integrating ecological factors and genetic factors is essential, as genes are the level on which ecological factors can drive the evolution of variation in learning and memory formation. The genus Nasonia has offered excellent opportunities for ecological research as well as unique opportunities for studies on genomic and genetic factors, which were addressed by comparing closely related species that differ in memory formation. This thesis provides the basis for the identification of genomic differences responsible for the difference in memory formation between Nasonia species, but it also characterized the consequences of these genomic differences on gene expression. The genetic basis of learning and memory formation are highly conserved among distant animal species and insights from this thesis are likely applicable to other animal species and humans, as well.Altogether, these small parasitic wasps allow us to understand and value differences in memory formation.</p
Daqu : a traditional fermentation starter in China: microbial ecology and functionality
No full textAbstract Fermented products have high nutritional value and constitute an important part of the Chinese dietary profile; they are also gaining popularity throughout the world. Daqu is a traditional natural fermentation starter culture that has a significant impact on the quality and flavour of Chinese liquor and vinegar. A review of the literature was conducted focusing on the classification, composition, and manufacture of Daqu. The review provided a preliminary understanding of the link between the fermentation process and the characteristics of the final Daqu product. Then the occurrence, levels, and diversity of microorganisms were studied in different types of Daqu produced by various fermentation processes. The results showed that Bacillus licheniformis and Saccharomycopsis fibuligera were present in all the tested samples of Daqu. Regional comparisons showed Staphylococcus gallinarum and Staphylococcus saprophyticus in southern Daqu. The fungi Sm. fibuligera and Lichtheimia ramosa were found in low/medium-temperature Daqu and Thermomyces lanuginosus occurred in high-temperature Daqu. In order to study the functionality of Daqu and the contribution of the predominant microorganisms to alcoholic fermentation, the mesophilic and thermophilic bacteria and spores, Enterobacteriaceae, lactic acid bacteria, yeasts, and moulds present in the core and outer portions of Fen-Daqu were isolated. The isolates were identified by culture-dependent sequencing of rRNA genes (16S rRNA for bacteria; 18S rRNA, 26S rRNA, and ITS rRNA for fungi). A succession of fungi, lactic acid, and Bacillus spp. was associated with prevailing acidity, moisture content, and temperature during Daqu fermentation. The predominant species in fermentation were B. licheniformis, Pediococcus pentosaceus, Lactobacillus plantarum, Pichia kudriavzevii, Wickerhamomyces anomalus, Sacchromyces cerevisiae, and Sm. fibuligera. One strain of the each of the above-mentioned predominant species, with the highest starch degrading ability and alcohol tolerance, was selected and used in different combinations to perform alcoholic fermentation. Metabolite composition differed significantly between various fermentation trials. S. cerevisiae provided superior ethanol production. Sm. fibuligera and B. licheniformis provided the amylolytic activity that converted starch and polysaccharides into fermentable sugars. Finally, W. anomalus was found to be an important contributor to formation of the liquor aroma. Understanding the microbial diversity and functional activity, as well as the production dynamics and safety of Daqu will enable commercial producers to improve and/or scale-up traditional processes and enhance product quality and safety, thus facilitating entry into international markets. </p
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