Thesis (PhD)--Stellenbosch University, 2005. / ENGLISH ABSTRACT: Since their inception, biology and biochemistry have been spectacularly successful in characterising the living cell and its components. As the volume of information about cellular components continues to increase, we need to ask how we should use this information to understand the functioning of the living cell? Computational systems biology uses an integrative approach that combines theoretical exploration, computer modelling and experimental research to answer this question. Central to this approach is the development of computational models, new modelling strategies and computational tools. Against this background, this study aims to: (i) develop a new modelling package: PySCeS, (ii) use PySCeS to study discontinuous behaviour in a metabolic pathway in a way that was very difficult, if not impossible, with existing software, (iii) develop an interactive, web-based repository (JWS Online) of cellular system models. Three principles that, in our opinion, should form the basis of any new modelling software were laid down: accessibility (there should be as few barriers as possible to PySCeS use and distribution), flexibility (pySCeS should be extendable by the user, not only the developers) and usability (PySCeS should provide the tools we needed for our research). After evaluating various alternatives we decided to base PySCeS on the freely available programming language, Python, which, in combination with the large collection of science and engineering algorithms in the SciPy libraries, would give us a powerful modern, interactive development environment. / AFRIKAANSE OPSOMMING: Sedert hul totstandkoming was biologie en, meer spesifiek, biochemie uiters suksesvol in die karakterisering van die lewende sel se komponente. Steeds groei die hoeveelheid informasie oor die molekulêre bestanddele van die sel daagliks; ons moet onself dus afvra hoe ons hierdie informasie kan integreer tot 'n verstaanbare beskrywing van die lewende sel se werking. Om dié vraag te beantwoord gebruik rekenaarmatige sisteembiologie 'n geïntegreerde benadering wat teorie, rekenaarmatige modellering en eksperimenteeIe navorsing kombineer. Sentraal tot die benadering is die ontwikkeling van nuwe modelle, strategieë vir modellering, en sagteware. Teen hierdie agtergrond is die hoofdoelstelling van hierdie projek: (i) die ontwikkeling van 'n nuwe modelleringspakket, PySCeS (ii) die benutting van PySCeS om diskontinue gedrag in n metaboliese sisteem te bestudeer (iets wat met die huidiglik beskikbare sagteware redelik moeilik is), (en iii) die ontwikkeling vann interaktiewe, internet-gebaseerde databasis van sellulêre sisteem modelle, JWS Online. Ons is van mening dat nuwe sagteware op drie belangrike beginsels gebaseer behoort te wees: toeganklikheid (die sagteware moet maklik bekombaar en bruikbaar wees), buigsaamheid (die gebruiker moet self PySCeS kan verander en ontwikkel) en bruikbaarheid (al die funksionalitiet wat ons vir ons navorsing nodig moet in PySCeS ingebou wees). Ons het verskeie opsies oorweeg en besluit om die vrylik verkrygbare programmeringstaal, Python, in samehang die groot kolleksie wetenskaplike algoritmes, SciPy, te gebruik. Hierdie kombinasie verskaf n kragtige, interaktiewe ontwikkelings- en gebruikersomgewing. PySCeS is ontwikkel om onder beide die Windows en Linux bedryfstelsels te werk en, meer spesifiek, om gebruik te maak van 'n 'command line interface'. Dit beteken dat PySCeS op enige interaktiewe rekenaar-terminaal Python ondersteun sal werk. Hierdie eienskap maak ook moontlik die gebruik van PySCeS as 'n modelleringskomponent in 'n groter sagteware pakket onder enige bedryfstelsel wat Python ondersteun. PySCeS is op 'n modulere ontwerp gebaseer, wat dit moontlik vir die eindgebruiker maak om die sagteware se bronkode verder te ontwikkel. As 'n toepassing is PySCeS gebruik om die oorsaak van histeretiese gedrag van 'n lineêre, eindproduk-geïnhibeerde metaboliese pad te ondersoek. Ons het hierdie interessante gedrag in 'n vorige studie ontdek, maar kon nie, met die sagteware wat op daardie tydstip tot ons beskikking was, hierdie studie voortsit nie. Met PySCeS se ingeboude vermoë om parameter kontinuering te doen, kon ons die oorsake van hierdie diskontinuë gedrag volledig karakteriseer. Verder het ons 'n nuwe metode ontwikkel om hierdie gedrag te visualiseer as 'n interaksie tussen die volledige sisteem se subkomponente. Tydens PySCeS se ontwikkeling het ons opgemerk dat dit baie moeilik was om metaboliese modelle wat in die literature gepubliseer is te herbou en te bestudeer. Hierdie situasie is grotendeels die gevolg van die feit dat nêrens 'n sentrale databasis vir metaboliese modelle bestaan nie (soos dit wel bestaan vir genomiese data of proteïen strukture). Die JWS Online databasis is spesifiek ontwikkel om hierdie leemte te vul. JWS Online maak dit vir die gebruiker moontlik om, via die internet en sonder die installasie van enige gespesialiseerde modellerings sagteware, gepubliseerde modelle te bestudeer en ook af te laai vir gebruik met ander modelleringspakkette soos bv. PySCeS. JWS Online het alreeds 'n onmisbare hulpbron vir sisteembiologiese navorsing en onderwys geword.

No description available.

Projektuojamas biologijos dalyko žinių bazės sistemos įrankis integruotas virtualioje mokymosi aplinkoje leis pasitikrinti biologijos žinias apie žuvis.Tokioje sistemoje vartotojui bus leidžiama pasiekti turinį ir parsisiųsti elektroninius išteklius. Sistema turėtų būti prieinama daugeliui vartotojų ir ją galėtų naudoti kaip mokymo priemonę. Biologijos žinių bazės įrankio paskirtis - pateikti vartotojui reikalingas žinias, padėti atrasti atsakymus į užduotus klausimus ir palengvinti mokymąsi. / Designing of Biology Subject Knowledge Base integrated virtual study environment enable coat check principles of biology about fish. At that system user was enable access contents and send paperless reservoir. System must be accessible many users and it must be used learning tools. Biology Subject Knowledge Base tools purpose – lay users required knowledge and help discover answers in put question and make easer training.

Thesis (MScAgric)--University of Stellenbosch, 1994 / 127 Leaves printed single pages, preliminary pages i-viii and numberd pages 1-118.Includes bibliography,tables and figures. / Date on t.p.: Dec. 1994. / ENGLISH ABSTRACT: Effects of pH,sucrose, boric acid and temperature on in vitro germination of pollen of Protea repens (L.) L. cv. 'Embers' were investigated in hanging-drop culture to establish optimum conditions for germination. Optimum values were found within ranges pH: 5 - 8, sucroseconcentration:0.4 - 0.7 M, boric acid concentration:50 - 500 mg.e-1 , and incubation temperature: 5 - 30°C. Storage temperature and humidity on pollen viability was studied in four Pro tea clones. Pollen was stored at a range of temperatures and relative humidities for up to one year and tested for ability to germinate in vitro. Pollen of P. repens cv. 'Sneyd', P. eximia cv. 'Fiery Duchess' andP. magnifica clone 'T 84 07 OS', stored in liquid nitrogen (-196°C) and in a freezer (-14° to -18°C), retained a germination percentage as high as that of fresh pollen regardless of humidity. The study showed that long-term storage of protea pollen is not feasible at temperatures above O°C. The correlations between the fluorochromatic reaction (FCR) and germinability were found to be low and nonsignificant. Fifteen month old cryopreserved 'Sneyd' pollen was shown to retain its ability to fertilize and set seed equal to that of fresh pollen. 'Sneyd', 'Fiery Duchess' and 'T 84 07 OS' pollen could be repeatedly thawed and frozen in liquid nitrogen before its germinability in vitro decreased. The morphology and size of Protea pollen was studied, using light and scanning electron microscopy. Polymorphic grains were observed in two interspecific hybrids. Very small differences in pollen grain size were recorded between clones/species. The male fertility of 25 interspecific Pro tea hybrids, based on in vitro pollen germinability, was investigated. The majority of hybrids were found to be sufficiently fertile to be used in a breeding programme. Pistil structure and pollen tube pathways were investigated in 'Sneyd' using light and scanning electron microscopy. The pistil had four distinct regions, consisting of the stigma, the vertebra-shaped upper style, the heart-shaped lower style, and the ovary. The pistil had a stylar canal along its entire length and this canal was also the route by which pollen tubes grew to the ovary. Very low numbers of pollen tubes reached the ovary. The breeding system of 'Sneyd' and 'Fiery Duchess' were determined from pollen tube and seed set data, after controlled hand-pollinations. Both clones were found to be fully selfcompatible. Very low percentages autogamous seed set were recorded. Interspecific crosses had a low success rate. An incompatibility reaction probably occurred on the stigma and/or in the upper style regions.The attainment of maximum stigma receptivity of two Protea cultivars was investigated by means of seed set experiments, pollen tube growth observations and measurement of the degree of opening and closing of the stigmatic groove. Both cultivars were found to be protandrous. The maximum stigmatic groove width of both cultivars never exceeded the pollen grain diameter. It was concluded that Protea spp. must be hand-pollinated two to six days after anthesis in order to obtain maximum seed set; while for the observations of pollen tubes in the ovary, inflorescences must not be harvested before seven days after pollination. / AFRIKAANSE OPSOMMING: Ten einde 'n optimale medium vir die in vitro-ontkieming van Protea-stuifmeel te ontwikkel, is die effek van pH, sukrose, boorsuur, en temperatuur op die in vitro-ontkieming van Protea repens (L.) L. cv. 'Embers'-stuifmeel deur middel van die hangdruppel-metode ondersoek. Die volgende reekse van veranderlikes wat getoets is, is as optimaal gevind; pH: 5 - 8, sukrosekonsentrasie: 0.4 - 0.7 M, boorsuurkonsentrasie: 50 - 500 mg.e-1 en inkubasietemperatuur: 5 - 30°C. Die invloed van bergingstemperatuur en humiditeit op stuifmeel-Iewenskragtigheid is in vier Protea-klone ondersoek. Stuifmeel is gestoor by 'n reeks temperature en relatiewe humiditeite vir tot eenjaar, en vir in vitro-ontkiemingsvermoe getoets.' Stuifmeel van P. repens <?v. 'Sneyd', P. eximia cv. 'Fiery Duchess', en P. magnifica kloon'T 84 07 OS', in vloeibare stikstof (-196°C) en in 'n vrieskas (-14° tot - 18°C) geberg, het 'n ontkiemingspersentasie gelykstaande aan die van vars stuifmeel gehandhaaf, ongeag van die humiditeit. Hierdie studie het verder aangetoon dat langtermynberging van Protea-stuifmeel bokant O°C me die moeite werd is me. Die korrelasie tussen die fluorochromatiese reaksie (FCR) en ontkieming was laag en me betekemsvol me. 'Sneyd' -stuifmeel wat vir 15 maande in vloeibare stikstof gestoor is, het die bevrugtings- en saadsetvermoe gelykstaande aan vars stuifmeel behou. 'Sneyd', 'Fiery Duchess' en 'T 84 07 OS'-stuifmeel kon herhaaldelik in vloeibare stikstof gevries en ontdooi word voordat hul ontkiemingsvermoe afgeneem het. Die morfologie en grootte van Proteastuifmeel is deur middel van lig- en skandeerelektronmikroskopie bestudeer. Polimorfiese stuifmeelkorrels is in twee interspesie-hibriede waargeneem. Baie klein verskille in stuifmeelkorrelgroottes het tussen klone/spesies voorgekom. Die manlike vrugbaarheid van 25 Protea-interspesiehibriede, gebaseer op die in vitro-ontkiembaarheid, is ondersoek. Dit is gevind dat die meerderheid hibriede 'n voldoende graad van vrugbaarheid het om in 'n teelprogram te gebruik. Die stamperstruktuur en stuifmeelbuiswee in P. repens is deur middel van lig- en skandeer-elektronmikroskopie ondersoek. Die stamper bestaan uit vier kenmerkende gebiede, naamlik die stempel, die werwelvormige bo-styl, die hartvormige onderstyl, en die vrugbeginsel. Die stamper het 'n stylkanaal regdeur die totale lengte van die stamper, en hierdie kanaal is ook die weg waarvolgens stuifmeelbuise na die vrugbeginsel gegroei het. Min stuifmeelbuise het die vrugbeginsel bereik. Die teelsisteem van 'Sneyd' en 'Fiery Duchess' is deur middel van stuifmeelbuis- en saadsetdata na gekontroleerde handbestuiwings ondersoek. Beide kIone was ten volle selfverenigbaar. Die persentasie outogame saadset was baie laag. Interspesiekruisings het 'n baie lae sukses gehad. Dit is voorgestel dat die onverenigbaarheidsreaksie in die stempel en/of in die bopunt van die styl plaasvind. Die bereiking van maksimum stempelontvanklikheid van twee Protea-cultivars is deur middel van saadseteksperimente, stuifmeelbuisdata en waarnemings van die oop- en toemaak van die stempelgroef ondersoek. Beide cultivars was protandries. Die maksimum stempelgroefwydte het nooit die stuifmeelkorreldeursnee oorskry nie. Dit is afgelei dat Protea-spesies twee tot ses dae na antese handbestuif moet word vir optimale saadset. Vir die waarneming van stuifmeelbuise in die vrugbeginsel, moet bloeiwyses nie voor sewe dae na bestuiwing geoes word nie.

Thesis (MScAgric)--University of Stellenbosch, 2000. / ENGLISH ABSTRACT: Ineffective pollination of the main cultivar with the pollinator cultivar is due to either an incompatibility problem between the main and pollinator cultivar, or because the flowering times of the main and pollinator cultivars do not overlap adequately. Three trials were conducted to try and find a more effective way to determine cultivar compatibility and to group cultivars together according to their budburst reaction to chilling. Most apple cultivars are self-incompatible and need cross-pollination for fruit set. Due to differences in the genetically defined fertilisation compatibility between the pollen from the male parent (pollinator) and the egg cell of the female parent, various apple pollinators differ in their ability to set fruit with viable seed. Fruit weight and size are positively correlated with seed set although it has been found that the pollinator can have a direct influence on fruit quality. 'African Red' apple trees on M7 rootstock in an evaluation block on a commercial farm in the Koue Bokkeveld region (32°55'N 19°27'E, Mediterranean climate, ;::::1060Utah chill units, and ;::::530mm rainfall annually; altitude 966 m) were used to assess the influence of 5 pollinators ('Granny Smith', 'Winter Banana', 'Cripps' Pink', 'Cripps' Red' and 'Simpson Crab') on fruit set, fruit weight and length and diameter. The degree to which 'African Red' is self-compatible was also assessed and the effect of flowering position ("king" vs. lateral) on fruit quality was determined. None of the pollinators showed a significantly higher fruit set. No differences in fruit set were found between the "king" and lateral flowering positions. No significant differences were found in the average number or weight of well developed seeds between pollinators. In both years fruit weight was significantly correlated to seed number for all five pollinator cultivars. In 1998 'Simpson crab' gave fruit that were significantly more elongated than those of 'Cripps' Pink'. 'African Red' is highly self incompatible. Compatibility assessments that are based on the number of fruit that develop after the flowers ofthe main cultivar had been hand pollinated in field trials are a time-consuming process. Allele-specific PCR amplification for some of the known S-alleles of the incompatibility S-gene (S2, S3, S5, S7 and S9) was carried out to successfully predict the compatibility of genotypes. The results compared well with that found in literature. For all the Malus domestica cultivars tested at least one, but in some instances both alleles of the S-gene were determined. 'Simpson crab' (Malus baccata) did, however, not possess any of the tested S-alleles. One-year-old, ca. 40 mm long shoots of various apple cultivars were selected from commercial orchards in both the Elgin [34°S, 305 m, ca. 750 chill units (CU) (Richardson et al., 1974)] and Koue Bokkeveld (33°S, 945 m, ca. 1300 CU) regions of the Western Cape, South Africa in two consecutive years (1998 and 1999). Shoots were forced at a constant 25°C with continuous illumination after receiving their allocated chill units. The effect of chilling period on the budburst of each cultivar in both regions was estimated by determining, 1) the total proportion of budburst (%Bb), 2) the proportion of shoots with terminal budburst (%TBb), and 3) the rate of budburst [lI(days to 25% budburst)]. It was found that these indices differed significantly between cultivars, and within cultivars between areas, as far as budburst patterns, in reaction to chilling, were concerned. The rate of budburst was the most consistent in describing the reaction of buds to different chilling periods and could be used to group cultivars together according to their budburst reaction to chilling. / AFRIKAANSE OPSOMMING: KRUISBESTUIWINGSBIOLOGIE VAN APPELS MET SPESIALE VERWYSING NA 'AFRICAN RED'. Oneffektiewe kruisbestuiwing III die boord kan toegeskryf word aan Of onverenigbaarheid tussen die hoof- en bestuiwingskultivar Of as gevolg van die blomtyd van die kruisbestuiwer wat nie genoegsaam oorvleuel met die van die hoofkultivar nie. Drie proewe is uitgevoer om 'n meer effektiewe proses daar te stel vir die toets van kultivarverenigbaarheid en om kultivars te probeer groepeer na gelang van hul reaksie op bepaalde hoeveelhede koue. Meeste appelkultivars is selfonverenigbaar en benodig kruisbestuiwing vir genoegsame vrugset. As gevolg van verskille III die geneties gedefinieerde bevrugtingsverenigbaarheid tussen die stuifmeel van die manlike ouer (bestuiwer) en die eiersel van die vroulike ouer (hoofkultivar), verskil bestuiwers in hul vermoë om vrugte met sade te set. Vruggrootte en -massa is positief gekorreleerd met saadset alhoewel dit al gevind is dat die bestuiwer op sig self ook 'n invloed op vrugkwaliteit kan hê. 'African Red' appelbome op M7 onderstamme, in 'n evaluasie blok op 'n kommersiële plaas in die Koue Bokkeveld (32°55'N 19°27'E, Meditereense klimaat, ::::1060 Utah koue eenhede, en ::::530mmjaarlikse reënval; ligging 966 m), is gebruik om die invloed van 5 bestuiwers ('Granny Smith', 'Winter Banana', 'Cripps' Pink', 'Cripps' Red' and 'Simpson Crab') op vrugset, vrugmassa, -lengte en -deursnee oor twee seisoene te bepaal. Die mate waartoe 'African Red' self onverenigbaar is en die effek van blomposisie ("king" vs laterale blom) op vrugkwaliteit is ook bepaal. Geen een van die bestuiwers het vrugset beduidend beïnvloed nie. Ook is daar geen verskille gevind tussen die "king" en laterale blomposisies t.o.v. vrugset nie. Geen beduidende verskille is tussen bestuiwers gevind in die gemiddelde aantal of gewig van volsade geset nie .. In albei jare was die vrugmassa beduidend gekorreleerd met saadset vir al vyf bestuiwerkultivars. In 1998 het 'Simpson Crab' vrugte geset wat beduidend langer was as vrugte wat geset het toe 'Cripps' Pink' as bestuiwer gebruik is. Daar is ook gevind dat 'African Red' hoogs selfonverenigbaar is. Verenigbaarheidstoetse wat gebaseer is op die aantal vruggles wat ontwikkel nadat blomme van die hoofkultivar met die hand bestuif is, is 'n tydsame proses. Allele spesifieke PCR amplifikasie vir bekende S-allele van die onverenigbaarheids S-geen (S2, S3, S5 S7en S9) is suksesvol uitgevoer om die verenigbaarheid van genotipes vooraf te bepaal. Die resultate het goed vergelyk met wat in literatuur gevind is. Vir al die Malus domestica spesies wat getoets is, is ten minste een, en in sommige gevalle twee, van die S-allele gevind. Die blomappel 'Simpson' (Malus baccata) het egter nie een van die vyf S-allele opgelewer nie Een-jaar-oue, 40 mm lang lote van verskeie appelkultivars, is in twee opeenvolgende jare (1998 en 1999) vanuit kommersiële boorde in beide die Elgin [34°S, 305 m, ca. 750 koue eenhede (CU) (Richardson et al., 1974)] and Koue Bokkeveld (33°S, 945 m, ca. 1300 CU) areas van die Wes Kaap gsny. Die lote is geforseer om te bot by 'n konstante temperatuur van 25°C met deurlopende beligting, nadat elke groep lote aan 'n bepaalde hoeveelheid koue blootgestel is. Die effek van koue op bot van elke kultivar in beide areas is bepaal deur, 1) die totale persentasie knoppe wat gebot het, 2) die persentasie terminale knoppe wat gebot het, en 3) die tempo van bot [l/(dae tot 25% bot)] te meet. Daar is gevind dat bo-genoemde parameters beduidend tussen kultivars, en binne kultivars tussen areas, verskil. As 'n beskrywing van die reaksie van knoppe op koue het die tempo van bot die mees konstante resultate oor die twee opeenvolgende seisoene gelewer en kon hierdie parameter gebruik word om kultivars in groepe, na gelang van hul reaksie op koue, in te deel.

Text in English, abstract in English, Shona and Xhosa / The purpose of this study was to explore the practice of quality control in the onscreen marking (OSM) environment of Biology (5008) examinations between 2013 and 2017. Examination marking is gradually being migrating from paper-based marking (PBM) to OSM in a bid to improve the efficiency and quality of marking. The Zimbabwe School Examinations Council (ZIMSEC) introduced OSM for some O Level subjects in June 2012, in a context characterised by a persistent economic crisis, patchy internet coverage, erratic power supplies and low digital literacy, among other challenges. The Council encountered some difficulties related to quality control, which triggered this qualitative instrumental single case study that was informed by the ontology, epistemology, methods and axiology of the constructivist philosophy. Data were collected through face-to-face and focus group interviews on the WhatsApp platform with 4 subject managers, 11 senior markers and 18 normal markers, and through document review. The findings of the study suggest that the quality of marking was influenced by the context in which the examinations were marked. The socio-political climate that prevailed in Zimbabwe impacted on the technological infrastructure for the OSM and the digital literacy of the examination personnel. The capacity of the examiners to work in the OSM environment was influenced by knowledge and skills transfer from training and standardisation to the live marking. The quality of marking was monitored by the seeds approach to script moderation, automatically generated reports and audit trails, and escalation of problem scripts. It was also influenced by the structure of the question papers, cognitive demands of the questions and mark schemes on the examiners, spaces provided for candidates’ responses and mark scheme features such as language and marks to marking points ratio. The assessment framework provided by the syllabus guided the design and marking of Biology examinations. From these findings, a framework that could guide the practice of quality control in the OSM environment was formulated. OSM technology could enhance the quality of marking Biology examinations, thereby eliminating challenges associated with PBM. Some of the opportunities were, however, reduced by the challenges encountered during the OSM of the examinations. It is recommended that ZIMSEC put in place policies and procedures that could guide specific quality control activities in the OSM environment and establish computer centres in the provincial capital towns. The Council could also consider benchmarking examiner recruitment, training and standardisation procedures with international examination authorities. / Tsvakurudzo ino yanga yakananga kuvandudza nharaunda yemakwenyero ebvunzo kubudikidza nemichina pachidzidzo cheBhayaroji, 5008 pakati pemakore a2013-2017. Vandudzo iyi iri kuuya zvishoma nezvishoma kubva pakukwenya pamapepa zvichienda mukukwenya nemichina (on screen marking :OSM ) nechinangwa chekuda kukwenenzvera mhando yebasa rezvekukwenya . Bazi rebvunzo reZimbabwe School Examinations Council (ZIMSEC) rakavarura kukwenya kubudikidza nemichina (OSM) kubvunzo dzedanho reOdhinari revhuru muna Chikumi 2012 , mumamiriro anozivikanwa ematambudziko ezveupfumi, masaisai eindaneti asingavimbiki anouya zvigamba zvigamba , magetsi asingawanikwe nguva dzose, nezivo yezvemichina muvakwenyi isina kupararira pakati pezvimwe zvimhingamupini. Kanzuru yezvebvunzo yakasangana nemamwe matambudziko ane chokuita nounaku hwezvemakwenyerwe ebvunzo hwakakonzera kuti paitwe tsvakurudzo ino yezveudzamu (qualitative) muchinzvimbo chiduku chakasarudzwa (case study) yaitungamirirwa nemaziviro evacho vanoona nezvekukwenya bvunzo (interpretivist epistemology) nemaziviro okuti chokwadi chinosiyana nekusiyana kwenharaunda nokuti chigadzirwa chevarimukati mekukwenya (constructivist ontology), nekuumba mufungo kubudikidza neumboo huchabuda mutsvakurudzo (inductive theory) nenzira nezvinokosheswa nenharaunda mukuumba ruzivo (constructivist philosophy). Umboo hwetsvakurudzo hwakawanikwa kubudikidza nebvunzurudzo ine udzamu padungamunhu nemumapoka nekupindurana padare reWatsiApu nevanotungamira zvidzidzo (Subject managers ) vana , zvidza mune zvokukwenywa bvunzo gumi neumwe, nevamwewo vakwenyi gumi nevasere uye kuongorora magwaro. Mamiriro ezvemagariro nematongerwo enyika mu / Ihloso yaleli rhubhululo bekukuphenya indlela ikhwalithi elawulwa ngayo ngehlelo lokutshwaya ngekhomphyutha kwe enhlahlubo zeBhayiloji (5008) phakathi komnyaka ka-2013 no-2017. Ukutshwaywa kwe enhlahlubo kancanikancani kuyasuka ehlelweni lokutshwaya iphepha ngesandla (PBM) kuya ehlelweni lokutshwaya ngekhomphyutha (OSM) ngomzamo wokuthuthukisa umsebenzi omuhle kanye nokuletha iqophelo eliphezulu lokutshwaya. Hlangana nezinye iintjhijilo, UMkhandlu wezokuTshwaywa kwe eNhlahlubo eZimbabwe (Zimbabwe School Examinations Council) (ZIMSEC) sewungenise ihlelo le-OSM kwezinye iimfundo zesigaba sika-O Level ngenyangaka Mgwengweni 2012, ngaphasi kobujamo obumbibe zomnotho, kobujamo obumaratha be-inthanedi, obuqokeme kobokuphakelwa ngegezi kanye na ngaphasi kwezinga eliphasi lefundo ye dijithali. UMkhandlu uhlangabezene nobunye ubudisi obumalunga nanokulawulwa kwekhwalithi, okubujamo obukhwezelele isizathu sokobana kube nerhubhululo linye elisebenzako elisebenzisa indlela yerhubhululo yekulumo, kanti lokhu kwabangelwayi-ontholoji, i-ephistemoloji, iindlela zerthubhululo kanye ne-akziyoloji yefilosofi i-constructivist philosophy. Idatha ibuthelelwe ngendlela yehlolombono yokubuza umuntu ngamunye ubuso nobuso kanye nokubuza iinqhema zabantu ezinqotjhiwe kokukundla yezokucocisana, i-WhatsApp platform kanye nabaphathi beemfundo aba-4 subject managers, abatshwayi abakhulu abali-11, kanye nabatshwayi abajayelekileko abali-18, kanti lokhu kwenziwa ngokubuyekeza umtlolo. Ilwazi elifumane keerhubhululweni liphakamisa kobana izinga lekhwalithi lokutshwaya laba nomthintela wobujamo/wendawo lapho iinhlahlubo zatshwaywa khona. Ubujamo bezehlalakuhle yabantu kezepolotik iebebusezweni leZimbabwe laba nomthelela phezu komthanga lasisekelo wethekinoloji, kanti kwathinta abasebenzi behlelo le-OSM kanye nezinga lefundo yedijithali. Amandla wekghono labatshwayi lokusebenza ebhodulukweni le-OSM lalilawulwa kudluliselwa kwelwazi kanye namakghonofundwa ukusukela ekubandulweni kanye nokwenza izinto ngendlela efanako ehlelweni elibonakala ngamehlo lokutshwaya. Izinga lokutshwaya lalitjhejwe yindlela yokulinganiswa kwamaphepha atshwayiwako, ihlelo le-seeds approach to script moderation, kanti ihlelwe lingokwalo lihlanganisa imibiko begodu lilandelela ukuhlolwa, kanti goduli yakwazi nokuveza amaphepha ane miraro. Leli hlelo begodula lilawulwa sisakhiwo sephepha lemibuzo, lilwazi elifunekako ephepheni lemibuzo kanye namaskimu wamaksi phezu kwabatshwayi bamaphepha, iinkhala ezenzelwako bana abafundi baphendulele kizo kanye namaskimu wokutshwaya okunje ngelimi kanye namamaksi asesilinganiswe nisamamaksi, phecelezi-marking points ratio. Isakhiwo sokuhlola sinikelwa yisilabhasi, okungiyo eyikombandlela yedizayini kanye nokutshwaywa kwe enhlahlubo zeBhayiloji. Ngalelilwazi elitholakeleko, kukghonakele ukuthi kutlanywe isakhiwo ebesingabayi kombandlela yendlela engalandelwa ukulawula ikhwalithi ebhodulukweni ye-OSM. Ithekinoloji ye-OSM beyinga siza izinga lokumakha iinhlahlubo zeBhayiloji, ngalokho lokhu bekungaphungula iintjhijilo ezihlobene nehlelo le-PBM. Nanyana kunjalo, amanye amathuba, aphungulwazi intjhijilo ekuhlangabezenwe nazo nakutshwaywa iinhlahlubo zehlelo le-OSM. Kuye kwa tjhukunyiswa ukobana i-ZIMSEC izene mithethomgomo kanye ne enkambiso ezingabayikombandlela elayela imisebenzi ethile koyokulawulwa kwekhwalithi ebhodulukweni le-OSM kanye nokuhloma iinkhungo zekhomphyutha kumadorobhahloko we emfunda. UMkhandlu begodu ungatjheja yokubeka izinga lokuqatjhwa kwabatshwayi, lokubandulwa kanye nehlelolokwenza izinto ngendlela efanako neyamaziko we entjhabatjhaba alawula iinhlahlubo. / Science and Technology Education / D. Phil. (Education)

Background A well-balanced nutritious diet is important for the pregnant woman and the growing fetus, as well as for their future health. Poor nutrition results from both over-consumption of energy-rich foods which can lead to a higher weight gain than is healthy and under-nutrition of essential nutrients. Food intake is regulated in complex biological systems by many factors, where steroid hormone is one factor involved. The overall aim of this thesis is to describe dietary intake, vitamin D levels, dietary information and dietary changes, and to study the relation between allopregnanolone and weight gain during pregnancy and postpartum. Methods Study I was a qualitative study with focus group interviews with 23 pregnant women. The text was analysed with content analysis. Study II was a quantitative cross-sectional study conducted in early pregnancy (n=209) with a reference group (n=206). Self-reported dietary data from a questionnaire was analysed using descriptive comparative statistics and a cluster analysis model (Partial Least Squares modelling). Study III had a quantitative longitudinal design. Vitamin D concentrations were analysed in 184 women, collected on five occasions during pregnancy and postpartum. Descriptive comparative statistics and a linear mixed model were used. Study IV was a quantitative longitudinal study with 60 women. Concentrations of allopregnanolone were analysed in gestational week 12 and 35. Descriptive and comparative statistics as well as Spearman’s correlation (rho) were used to describe the relationship between weight gain and allopregnanolone concentrations.   Results The focus group interviews showed that women wanted to know more about different foods to reduce any risk for their child but the information about foods was partly up to themselves to find out. They expressedfeelingsof insecurityand guiltif they accidentallyate something“forbidden”. The recommendationswere followedas best as possiblealong withcommon sense todeal with dietchanges. The main themes were “Finding out by oneself”, “Getting professional advice when health problems occur”, “Being uncertain” and “Being responsible with a pinch of salt”. Some differences in the dietary patterns were found among the pregnant women compared to references, with less, vegetables (47 g/day), potatoes/rice/pasta (31 g/day), meat/fish (24 g/day) and intake of alcohol and tobacco/snuff but a higher intake of supplements. Bothpregnant women and referenceshad intakes offolatethrough diet45% (pregnant) and 22% (references) lower than current recommendations(500vs400g/day). Vitamin Dintake was34% lower than the recommendationsof 10mg/day. At least a third of the participants had insufficient plasma levels below 50 nmol/L of vitamin D. Season was a strong factor influencing the longitudinal pattern. Gestational week, season, total energy intake, dietary intake of vitamin D, and multivitamin supplementation over the previous 14 days were factors related to vitamin D levels. A correlation betweenallopregnanoloneconcentrations ingestationalweek 35and weight gainin weeks12–35was seen (p = 0.016). Therewas alsoa correlation betweenthe increase inallopregnanolone(weeks12–35) andweight gain(see above) (p = 0.028).   Conclusions Dietary recommendations were described as contradictory and confusing and the dietary advice felt inadequate. The women faced their diet changes and sought information on their own but would have wished for more extensive advice from the midwife. The intake of vitamins essential for pregnancy was lower than recommended, which is also confirmed by low plasma levels of vitamin D in at least one third of the pregnant women. Vitamin D levels peaked in late pregnancy. Aside from gestational week and season which were related to plasma levels, intake from foods and supplements also affected the levels. Reasons for weight gain are complex and depend on many factors. Allopregnanolone is a factor that was seen to relate to the weight gain of the studied pregnant women. / Bakgrund En välbalanserad näringsrik kost är viktig för den gravida kvinnan och det växande fostret, så även för deras framtida hälsa. En bristfällig kost kan utgöras av både överförbrukning av energirika livsmedel vilket kan leda till högre viktuppgång än vad som är hälsosamt och bristande intag av viktiga näringsämnen. Kostintag regleras av komplexa biologiska system där flera faktorer är inblandade däribland steroidhormonet allopregnanolon. Det övergripande syftet med denna avhandling är att under och efter graviditet beskriva kostintag, vitamin D-nivåer, kostinformation och kostförändringar och att studera allopregnanolons relation till viktökning. Metod Studie I var en kvalitativ studie med fokusgruppsintervjuer med 23 gravida kvinnor. Texten analyserades med innehållsanalys. Studie II var en kvantitativ tvärsnittsstudie som genomfördes i tidig graviditet (n = 209) och med en grupp icke-gravida kvinnor (kontrollgrupp) (n=206). Självrapporterade kostdata från ett frågeformulär analyserades med beskrivande, jämförande statistik och en klusteranalysmodell (Partial Least Squares modellering). Studie III hade en kvantitativ longitudinell design. Vitamin D-koncentrationer analyserades hos 184 kvinnor, vid fem tillfällen under graviditeten och efter förlossningen. Beskrivande, jämförande statistik och en linjär mixad regressionsmodell användes. Studie IV var en kvantitativ longitudinell studie med 60 kvinnor. Koncentrationerna av allopregnanolon analyserades vid graviditetsvecka 12 och 35. Beskrivande och jämförande statistik samt Spearman’s korrelation användes för att beskriva samband mellan viktökning och koncentrationer av allopregnanolon. Resultat Intervjuerna i studie I visade att kvinnor ville veta mer om olika typer av mat för att minska en eventuell risk för sina barn men kostinformation var delvis upp till dem själva att ta reda på. De VIII uttryckte känslor av osäkerhet och skuld om de råkat äta något ”förbjudet”. Rekommendationerna följdes så väl som möjligt, tillsammans med sunt förnuft för att hantera kostförändringar. Huvudteman var ”Söka information på egen hand”, ”Få professionell rådgivning när problem uppstår”, ”Känna sig osäker” och ”Ta ansvar med en nypa salt”. I studie II kunde man se vissa skillnader i kostmönster bland de gravida kvinnorna jämfört med kontrollgruppen: mindre intag av grönsaker (47 g/dag), potatis/ris/pasta (31 g/dag), kött/fisk (24 g/dag) och alkohol och tobak/snus och ett högre intag av kosttillskott. Både gravida kvinnor och kontrollgruppen hade lägre intag av folsyra via kosten med 45 % (gravida) och 22 % (kontrollgruppen) än de gällande rekommendationer som är (500 resp 400 g/dag). I studie III såg man att inta et av vitamin D var 34 % lägre än rekommendationen på 10 µg/dag. Minst en tredjedel av deltagarna hade otillräckliga plasma nivåer av vitamin D, under 50 nmol/L. Årstid var en stark faktor som påverkar det longitudinella mönstret. Graviditetsvecka, säsong, totala energiintaget, intaget av vitamin D och multivitamintillskott under de senaste 14 dagarna var faktorer som relaterade till Dvitaminnivåer. I studie IV sågs ett samband mellan allopregnanolon-koncentrationer vid graviditetsvecka 35 och viktökning från vecka 12 till 35 (p = 0,016). Det sågs också ett samband mellan ökningen av allopregnanolon (vecka 12–35) och viktökningen (se ovan) (p = 0,028). Slutsatser Kostrekommendationer beskrevs som motsägelsefulla och förvirrande och kostråden de fick uppfattades som otillräckliga. Kvinnorna tog itu med sina kostförändringar och sökte information på egen hand men hade önskat mer omfattande råd från barnmorskan. Intaget av vitaminer viktiga för graviditeten var lägre än rekommendationerna, vilket också bekräftas av låga plasmanivåer av D-vitamin hos cirka en tredjedel av de gravida kvinnorna. D-vitaminnivåerna nådde en topp i slutet av graviditeten. Graviditetsvecka och säsong på året påverkade D vitaminnivåer, så även intag via mat och kosttillskott. Orsakertill viktökning är komplexa och beror på många faktorer. Allopregnanolon är en faktor som sågs relatera till viktökningen hos de undersökta gravida kvinnorna.

This master thesis studies the problem of parameter identification for system biology. Two methods have been studied. The method of interval analysis uses subpaving as a class of objects to manipulate and store inner and outer approximations of compact sets. This method works well with the model given as a system of differential equations, but has its limitations, since the analytical expression for the solution to the ODE is not always obtainable, which is needed for constructing the inclusion function. The other method, studied, is SDP-relaxation of a nonlinear and non-convex feasibility problem. This method, implemented in the toolbox bio.SDP, works with system of difference equations, obtained using the Euler discretization method. The discretization method is not exact, raising the need of bounding this discretization error. Several methods for bounding this error has been studied. The method of ∞-norm optimization, also called worst-case-∞-norm is applied on the one-step error estimation method. The methods have been illustrated solving two system biological problems and the resulting SCP have been compared. / Det här examensarbetet studerar problemet med parameteridentifiering för systembiologi. Två metoder har studerats. Metoden med intervallanalys använder union av intervallvektorer som klass av objekt för att manipulera och bilda inre och yttre approximationer av kompakta mängder. Denna metod fungerar väl för modeller givna som ett system av differentialekvationer, men har sina begränsningar, eftersom det analytiska uttrycket för lösningen till differentialekvationen som är nödvändigt att känna till för att kunna formulera inkluderande funktioner, inte alltid är tillgängliga. Den andra studerade metoden, använder SDP-relaxering, som ett sätt att komma runt problemet med olinjäritet och icke-konvexitet i systemet. Denna metod, implementerad i toolboxen bio.SDP, utgår från system av differensekvationer, framtagna via Eulers diskretiserings metod. Diskretiseringsmetoden innehåller fel och osäkerhet, vilket gör det nödvändigt att estimera en gräns för felets storlek. Några felestimeringsmetoder har studerats. Metoden med ∞-norm optimering, också kallat worst-case-∞-norm är tillämpat på ett-stegs felestimerings metoder. Metoderna har illustrerats genom att lösa två system biologiska problem och de accepterade parametermängderna, benämnt SCP, har jämförts och diskuterats.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2002. / Härtill 4 uppsatser.