The effect of natural genetic variation at Ppd-H1 on the regulation of pre-anthesis development in barley (Hordeum vulgare L.) in response to the photoperiod

The timing of reproductive development determines spike architecture and thus yield in temperate grasses such as barley (Hordeum vulgare L.). Reproductive development in barley is controlled by the photoperiod response gene Ppd-H1 which accelerates flowering time under long-day (LD) conditions. A natural mutation in Ppd-H1 prevalent in spring barley causes a reduced photoperiod response, and thus, late flowering under LD. However, it is not very well understood how LD and Ppd-H1 control pre-anthesis development, and thus spike architecture and yield in barley. This work reports about morphological and molecular changes in the leaf and at the shoot apex of barley in response to the photoperiod and genetic variation at Ppd-H1. Expression variation in the leaf and main shoot apices (MSA) were analyzed using RNA-sequencing and qRT-PCR in the three spring barley cultivars Scarlett, Bowman and Triumph and derived introgression lines. The spring barley lines were characterized by the natural mutation in Ppd-H1, whereas the derived introgression lines carry the photoperiod responsive, dominant wild type Ppd-H1 allele introduced from wild or winter barley. LD and the dominant Ppd-H1 allele accelerated all phases of shoot apex development, but had the strongest effect on inflorescence maturation. Photoperiod-shift experiments revealed that the duration of the vegetative and early reproductive phase determined the number of spikelet primordia and seeds per spike. Whereas in Arabidopsis a few long days are sufficient for floral commitment, in barley flowering only occurred under continuous LD exposure. Short-day (SD) did not prevent floral transition, but impaired inflorescence development and caused the abortion of the main shoot inflorescence. Consequently, long photoperiods and the dominant Ppd-H1 allele reduced the number of spikelet primordia, but promoted spikelet fertility and ensured main shoot survival. In the absence of a complete barley genome reference sequence, we generated a barley reference sequence for improved analysis of a shoot apex specific transcriptome from the vegetative and early reproductive phases. Genes differentially regulated during development or in response to day length and variation at Ppd-H1 were classified into 31 co-expression clusters, and characterized by enriched Gene Ontology terms, thus providing a valuable resource for future studies on shoot apex development in barley. LD and the dominant Ppd-H1 allele caused an up-regulation of the barley orthologs of Flowering Locus T, HvFT1 in the leaf and HvFT2 in the MSA. Both genes were co-regulated with genes involved in nutrient transport and flower fertility, suggesting that improved nutrient mobilization under LD was important to maintain inflorescence development. LD and the dominant Ppd-H1 allele up-regulated the expression of the three AP1/FUL-like MADS box transcription factors, HvVRN1, HvBM3 and HvBM8 and floral homeotic genes homologous to APETALA3, PISTILATA, SEPALLATA1 and 3 of Arabidopsis. Floral development was thus strongly LD dependent. Contrastingly, floral transition correlated with the day-length and Ppd-H1 independent down-regulation of the SHORT VEGETATIVE PHASE-like (SVP-like) genes HvBM1, HvBM10 and HvVRT2 and a Ppd-H1 independent up-regulation of HvSOC1-1 in the MSA. Thus, expression of SVP-like genes and HvSOC1-1 in the MSA seemed to be independent of HvFT1 and HvFT2 expression levels in barley. These results point to differences in the regulation of the floral transition in Arabidopsis, where SOC1 and SVP are regulated by FT. In summary, our results demonstrate that LD and Ppd-H1 control the number and maturation of floral primordia presumably by up-regulating FT-like genes and improving nutrient mobilization in the leaf and MSA. The study thus lays the foundation to understanding the genetic and molecular control of pre-anthesis development and yield structure in temperate cereals

The British motor cycle industry, 1935-1975

Between 1935 and 1975, the British motor cycle industry declined from world supremacy to bankruptcy. The industry blamed its troubles on government policy, specifically taxation and regulation. These, it was maintained, had weakened and manufacturers' ability to effectively meet foreign competition, particularly after 1960 from Japan. The existing historiography has identified boardroom mismanagement as the main culprit. However, what the literature lacks is a wider perspective, especially one which extends to the period before 1945. Those years are critical to understanding the nature of the industry. This dissertation provides such a perspective combined with an analysis based on extensive primary research, particularly amongst recently opened trade and company records, as well as government documents at the Public Records Office. Although no single factor was entirely responsible for the industry's downfall, this dissertation will offer several explanations of varying importance. The failure to develop a cheap, lightweight motor cycle is particularly significant. This, in turn, reflected a 'management culture' which prevailed within many company boardrooms. The 'culture' was closely related to and influenced by a deep seated dedication to motor cycle sport and resulted in a narrow view of the market and the 'typical' consumer, both in Britain and abroad

Factors affecting shrivelling and friction discolouration of pears (Pyrus communis L. )

Thesis (MScAgric)--University of Stellenbosch, 2005.ENGLISH ABSTRACT: Shrivelling and friction discolouration (FD), as postharvest disorders, negatively influence the marketability and potential shelf life of pears. By investigating the contributing factors in each of the disorders, the potential involvement of handling and storage variables were determined. This allowed for a better understanding of the responsible factors that create susceptible environments for these disorders to occur. From the moment that pears are harvested they lose weight by means of transpiration and, to a lesser extent, respiration. When excessive losses are experienced, the fruit will appear shrivelled and the marketability and shelf life are negatively influenced. By minimizing the rates of weight loss, the occurrence of shrivelling among pears during the postharvest handling can be lessened. The periods that proved to be most conducive to shrivelling (during a simulated postharvest handling duration) were where temperatures above 0 °C were experienced. These short periods proved more perilous for shrivelling than lengthy storage durations at low temperatures. This influenced the transpiration rate in such a way that the driving force accelerated the rate of weight loss in all the cultivars that were studied. Removing field heat from fresh produce and maintaining the cold chain reduces the driving force behind the transpiration of the pears. In all the cultivars studied, ‘Packham’s Triumph’, ‘Beurrè Bosc’ and ‘Forelle’, smaller and less mature fruit were more inclined to appear shrivelled. The surface area to volume ratio is fundamental in determining the rate of weight loss. This was most evident in ‘Beurrè Bosc’. Although no reproducible results could be obtained from the morphological studies, literature has attributed this phenomenon to the composition and quantity of the cuticle layer. Reduction of weight loss was obtained by sealing of the fruit stem. This obstructed water movement from the fruit through the xylem conducting tissue to the surrounding atmosphere. Not only did the stem appear greener and fresher, but less weight loss and subsequent shrivel was noticeable in the treated fruit. This effect was most evident in ‘Packham’s Triumph’ and ‘Beurrè Bosc’, but not in ‘Forelle’. ‘Forelle’ typically has a very short, thin stem in comparison to the other two cultivars.All the cultivars showed visual shrivel symptoms after 11 days at 18 °C. Rate of weight loss was the lowest in ‘Packham’s Triumph’, but due to its prominent dimensions, it appeared shrivelled before any of the other cultivars. ‘Beurrè Bosc’ lost weight at the highest rate (0.42%.day-1). As fruit injury, in the presence of oxygen, is inevitable, the oxidative enzymatic browning of pears will always be troublesome. This defensive mechanism partially prevents the infection of the fruit where epidermal cells are injured. To minimize FD, impact and frictional forces need to be lower during both harvesting and handling practices. A laboratory scale method was developed through which reproduceable treatments could be performed, thereby subjecting the fruit to industry related friction, rather than impact, injury. By assessing the discolouration in terms of both extent and intensity, the influence of variables could be determined on both ‘Packham’s Triumph’ and ‘Doyenne du Comice’ pears. As also found in practice, ‘Doyenne du Comice’ proved to be far more susceptible to FD than ‘Packham’s Triumph’, although the activity of the enzyme, polyphenol oxidase (PPO) was found to be higher in the latter. Although no significant difference was found between the FD encountered at fruit temperature of 3 °C and 15 °C, discolouration was greater at the higher temperature. This might be attributed to a greater degree of water loss, lower cell turgidity or higher enzyme activity. Thus, fruit taken from storage and sorted directly thereafter will exhibit less FD. The contribution of condensation forming on the fruit, acting as lubrication, cannot be ignored. Such fruit, with high turgor pressure, might again be more susceptible to bruising which will only be revealed well after the injury. Since enzymes, which include PPO, catalyse biochemical reactions, the availability of sufficient substrate most probably regulates the extent of this biochemical discolouration. Harvesting at optimum maturity and preventing any unnecessary friction will most definitely reduce the occurrence of FD. The ultimate challenge remains to optimize sorting and packing conditions without compromising on fruit quality.AFRIKAANSE OPSOMMING: Verrimpeling en friksie verbruining (FV), as na-oes defekte, het ’n negatiewe invloed op die bemarkbaarheid en potensiële raklewe van pere. Hierdie studie het die bydraende faktore vir elkeen van die defekte ondersoek. Daar is gepoog om die effek van verskillende hanteringsen opbergingsmetodes op bogenoemde defekte te bepaal. ‘n Beter begrip is verkry van die oorsaaklike faktore wat bydra tot die ontstaan van die betrokke defekte. Direk na die oes van pere, begin die vrug gewig verloor as gevolg van veral transpirasie. Oormatige verliese sal lei tot ’n vrug wat verrimpeld voorkom, met ‘n negatiewe invloed op die bemarkbaarheid en raklewe daarvan. Die voorkoms van die verrimpeling van pere tydens die na-oes hantering van die vrugte, kan verminder word deur vermindering van die tempo van gewigsverlies. Die periodes waartydens die verrimpeling veral voorgekom het, (soos gevind in ’n gesimuleerde na-oes hanteringsmodel) was wanneer temperature bo 0 °C ondervind is. Sulke kort periodes was meer geneig om aanleiding te gee tot verrimpeling as die verlengde periodes van opberging by lae temperature. Sulke periodes van hoër temperature het gelei tot versnelde transpirasie en ’n versnelde tempo van gewigsverlies in al die kultivars wat ondersoek is. Die transpirasietempo van pere kan verlaag word deur die verwydering van veld-hitte en deur die streng behoud van die koue-ketting. In al die kultivars wat ondersoek is, ‘Packham’s Triumph’, ‘Beurrè Bosc’ en ‘Forelle’, is gevind dat die kleiner en minder volwasse vrugte meer geneig was tot verrimpeling. Die oppervlak area tot volume verhouding is krities in die bepaling van die tempo van gewigsverlies. Hierdie bevinding was die prominentste in ‘Beurrè Bosc’. Alhoewel geen beduidende resultate verkry kon word van die morfologiese studies nie, is daar verskeie verwysings in die literatuur wat hierdie verskynsel toeskryf aan die samestelling en hoeveelheid van die kutikula laag. Vermindering van gewigsverlies is verkry deur verseëling van die vrugtestingel. Hierdie tegniek het gelei tot ’n blokkering van die watervloei van die vrug na die omgewing deur die xileem weefsel. Verseëling van die stingel het dit groener en varser laat voorkom, en het ook ’n merkbare vermindering in gewigsverlies en die daaropvolgende verrimpeling tot gevolg gehad. Die effek van stingel-verseëling was die prominentste in ‘Packham’s Triumph’ en‘Beurrè Bosc’. Dit was minder duidelik in ‘Forelle’ wat tipies gekenmerk word deur ‘n baie korter, dun stingel in vergelyking met die ander twee kultivars. Al die kultivars het makroskopiese verrimpeling getoon na ‘n opbergingperiode van 11 dae by 18 °C. Die tempo van gewigsverlies was die laagste in ‘Packham’s Triumph’ alhoewel dit eerste verrimpeld voorgekom het. Dit kan toegeskryf word aan die spesifieke afmetings van hierdie betrokke kultivar. ‘Beurrè Bosc’ het vinnigste gewig verloor (0.42%.dag-1). Aangesien die besering van vrugte, in die aanwesigheid van suurstof, onvermydelik is, sal oksidatiewe, ensiematiese verbruining van pere altyd problematies wees. Hierdie verdedigingsmeganisme voorkom tot ’n mate die infeksie van die vrug wanneer epidermale selle beskadig word. FV kan beperk word deur die vrugte tydens oes en hanteringsprosedures so min as moontlik bloot te stel aan impak en friksie kragte. ’n Laboratorium-model is ontwikkel ter nabootsing van die omstandighede in die industrie. Die vrugte is aan friksie, eerder as impak, onderwerp, soos ondervind in die industrie. Die omvang asook die intensiteit van die verbruining is gemeet in beide ‘Packham’s Triumph’ en ‘Doyenne du Comice’ pere. Op hierdie wyse kon die invloed van die onderskeie veranderlikes in elke kultivar bepaal word. Alhoewel die ensiematiese aktiwiteit van die polifenol oksidase ensiem (PFO) die hoogste in ‘Packham’s Triumph’ was, is gevind dat ‘Doyenne du Comice’ veel meer geneig was tot FV as ‘Packham’s Triumph’. Hierdie bevinding bevestig die verskynsel soos in die praktyk gevind. Alhoewel geen betekenisvolle verskil gevind is tussen FV by vrug temperatuur van 3 °C en 15 °C nie, was daar meer verbruining by die hoër temperatuur. Hierdie verskynsel kan toegeskryf word aan ’n groter mate van waterverlies, laer sel turgiditeit en hoër ensiem aktiwiteit. Dus sal vrugte wat direk na opberging gesorteer word, minder FV toon. Die bydrae van die kondensasie wat op die vrug vorm, en as ’n smeermiddel dien, kan nie geïgnoreer word nie. Sulke vrugte met hoër turgiditeit, mag egter meer vatbaar wees vir kneusing, wat egter eers ’n geruime tyd na die kneusing tevoorverskyn mag kom. Aangesien ensieme, wat PFO insluit, as katalis dien in biochemiese reaksies, sal die beskikbaarheid van voldoende substraat, na alle waarskynlikheid die omvang van die biochemiese verkleuring reguleer.Die oes van pere tydens optimum volwassenheid, en die voorkoming van onnodige friksie sal definitief die voorkoms van FV verminder. Die uitdaging is steeds om sortering- en verpakkingstegnieke verder te verfyn sonder om ’n negatiewe invloed op vrugtekwaliteit te hê

Bostonia Magazine: A Boston University Alumni House Publication. Volume 54

Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs

The narrow front versus the broad front: An analysis of the narrow front plan and the factors affecting its success

When the United States entered the Second World War General Bernard L. Montgomery of Great Britain believed the war in Europe could be concluded by the end of 1944. He maintained this view during the ensuing months and in August 1944 recognized an opportunity to end the war in accordance with his timetable. His plan, which called for a narrow front approach to Berlin, was refuted in favor of the previously planned broad front approach of General Dwight D. Eisenhower. The conduct of the campaign in northwestern Europe under the broad front approach versus the narrow front has remained a subject of controversy since that time

Canonical queries as a query answering device (Information Science)

Issued as Annual reports [nos. 1-2], and Final report, Project no. G-36-60

DEVELOPMENT OF THE FIRST-IN-CLASS ORAL FACTOR D INHIBITOR DANICOPAN FOR THE TREATMENT OF PAROXYSMAL NOCTURNAL HEMOGLOBINURIA

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare acquired hematological disorder of the hematopoietic stem cells, characterized by chronic complement-mediated intravascular hemolysis (IVH) due to absence of complement regulators CD55 and CD59 on affected erythrocytes, thromboembolic events affecting mostly venous vessels and bone marrow failure of different degrees. Danicopan is a, first-in-class proximal, complement alternative pathway (AP) factor D (FD) inhibitor, proximal AP inhibition may disable both terminal complement activation (inhibiting MAC–mediated IVH) and C3 fragment opsonization (preventing extravascular hemolysis (EVH)), with additional convenience of oral administration. Untreated hemolytic PNH patients received danicopan monotherapy (100-200 mg thrice daily). Endpoints included change in lactate dehydrogenase (LDH) and hemoglobin. Safety, pharmacokinetics/pharmacodynamics, and patient-reported outcomes were measured. Danicopan used in monotherapy resulted in inhibition of IVH, with significant LDH reduction at day 28 (primary endpoint), it also prevented C3 deposition on surviving GPI-deficient erythrocytes, preventing EVH (confirmed by reduction of bilirubin and reticulocytes). Concomitant inhibition of IVH and prevention of C3-mediated EVH resulted in improvement of anemia, with a mean hemoglobin gain of 1.7 g/dL after 12 weeks of treatment. Consistent with these findings, all patients exhibited significant increases in the percentage of GPI-deficient erythrocytes, confirming their extended half-life in vivo, and improvement in FACIT-Fatigue quality-of-life measurements

Limited Liability and the Known Unknown

Limited liability is a double-edged sword. On the one hand, limited lia-bility may help overcome investors’ risk aversion and facilitate capital formation and economic growth. On the other hand, limited liability is widely believed to contribute to excessive risk-taking and externaliza-tion of losses to the public. The externalization problem can be mitigated imperfectly through existing mechanisms such as regulation, mandatory insurance, and minimum capital requirements. These mechanisms would be more effective if information asymmetries between industry and poli-cymakers were reduced. Private businesses typically have better infor-mation about industry-specific risks than policymakers. A charge for limited liability entities—resembling a corporate income tax but calibrated to risk levels—could have two salutary effects. First, a well-calibrated limited liability tax could help compensate the public fisc for risks and reduce externalization. Second, a limited liability tax could force private industry actors to reveal information to policymakers and regulators, thereby dynamically improving the public response to externalization risk. Charging firms for limited liability at initially similar rates will lead relatively low-risk firms to forgo limited liability, while relatively high-risk firms will pay for limited liability. Policymakers will then be able to focus on the industries whose firms have self-identified as high risk, and thus develop more finely tailored regulatory responses. Because the ben-efits of making the proper election are fully internalized by individual firms, whereas the costs of future regulation or limited liability tax changes will be borne collectively by industries, firms will be unlikely to strategically mislead policymakers in electing limited or unlimited lia-bility. By helping to reveal private information and focus regulators’ at-tention, a limited liability tax could accelerate the pace at which poli-cymakers learn, and therefore, the pace at which regulations improve