Application Software, Domain-Specific Languages, and Language Design Assistants

While application software does the real work, domain-specific languages (DSLs) are tools to help produce it efficiently, and language design assistants in turn are meta-tools to help produce DSLs quickly. DSLs are already in wide use (HTML for web pages, Excel macros for spreadsheet applications, VHDL for hardware design, ...), but many more will be needed for both new as well as existing application domains. Language design assistants to help develop them currently exist only in the basic form of language development systems. After a quick look at domain-specific languages, and especially their relationship to application libraries, we survey existing language development systems and give an outline of future language design assistants.Comment: To be presented at SSGRR 2000, L'Aquila, Ital

Identification and characterization of M23 peptidase VcsP involved in cell separation in Vibrio parahaemolyticus

The peptidoglycan is an important structural element of the bacterial cell envelope and is involved in many cellular processes such as maintenance of cell shape, cell division as well as protection against extracellular stresses. Established model organisms like Escherichia coli or Bacillus subtilis have been studied extensively regarding peptidoglycan biosynthesis as well as degradation. The main goal of our research is to apply established knowledge and at the same time widen the understanding of peptidoglycan biogenesis in the human pathogen Vibrio parahaemolyticus. While the spatio-temporal organization of many synthetic and lytic enzymes is required during the bacterial cell cycle, this work focuses on the characterization of M23 peptidases, a class of enzymes responsible to reverse the trans-peptidation reaction that link the stem peptides of parallel glycan strands. Here we show that the V. parahaemolyticus genome encodes for seven M23 peptidases, some of which are homologues to identified factors important for cell division and shape in other organisms. However, we also find three previously uncharacterized, paralogous M23 peptidases. Through series of experiments, we identify one particular protein, VcsP, to be important for cell separation through its conserved M23 peptidase domain. Upon its deletion, cells exhibit a chaining phenotype that compromises the cell envelope, increasing its sensitivity to Polymyxin type antibiotics. We distinctly show that VcsP is the most important out of three paralogues. Interestingly, the dimorphic lifestyle of V. parahaemolyticus is unaffected in the absence of VcsP and cells are able to differentiate from swimmer to swarmer cell type. We utilized several approaches to find interaction partners and affectors of VcsP, and so far we show that vcsP is co-transcribed with vp0549, which encodes for a PilZ domain protein that binds the second messenger c-di-GMP. Together these findings have significantly increased our knowledge of M23 peptidases in V. parahaemolyticus and it will be interesting to find out more about VcsP and its effects in the future. We also raised additional questions in this study that we would like to address in future research

Üldistatud happelisuse skaala katseline teostus ja rakendused

Väitekirja elektrooniline versioon ei sisalda publikatsiooneHappelisus on keskkonna, toodete ja toidu puhul tähtis näitaja. Kõik teavad, et sidrun on hapum kui maasikas, kuid kõiki asju ei saa maitsta. Kuidas sellisel juhul happelisust hinnata? Happelisuse hindamiseks on kasutusel pH ning mida väiksem on mingi olluse pH näit, seda happelisem see on. Vees on pH skaala ulatus 0 kuni 14 ning skaala keskel, pH 7 juures on vesi neutraalne. Vees on pH mõõtmine lihtne, olles üks levinumaid mõõtmisi keemia laborites. Hoopis keerulisem on asi mittevesikeskkondades – bensiinis, taimeõlis, lihas jne. Sisuliselt võib öelda, et igal keskkonnal on oma pH skaala, kuid need ei ole omavahel võrreldavad. Temperatuuri mõõtmiseks kasutatakse näiteks Celsiuse ja Kelvini skaalat, kuid temperatuuri osatakse ühest skaalast teise teisendada. Sama ei saa öelda pH puhul, kuna skaalade nullpunktid eri keskkondades on teadmata. Seega kehtis kuni viimase ajani kahetsusväärne olukord, kus mõiste pH tähendab igas keskkonnas ise asja ja need pH väärtused ei ole omavahel võrreldavad. 2010. aastal töötati välja üldistatud happelisuse (pHabs) skaala kontseptsioon – üks skaala kõigi keskkondade jaoks. Selles skaalas esitatuna on võimalik kõikide keskkondade happelisusi omavahel võrrelda. Teoorias asendas üks skaala kõiki neid sadu ja tuhendeid pH skaalasid, kuid see kontseptsioon oli algselt olemas vaid teooria tasemel – mõõta pHabs väärtusi veel ei osatud. Doktoritöö eesmärk oli viia see teooria ellu ehk arendada välja meetod pHabs mõõtmiseks ning esimest korda ajaloos mõõta üldistatud happelisusi. Töö eesmärk täideti edukalt ning nüüd on olemas võimalus mõõta üldistatud happelisusi. Loodud meetodi esmaseks rakenduseks oli vesi-metanooli ja vesi-atsetonitriili segude üldistatud happelisuste mõõtmine. Neid segusid kasutatakse mobiilfaasidena vedelikkromatograafia-massispektromeetria meetodis, mis on praegusel ajal üks levinumaid ja võimekamaid analüüsimeetodeid. Valdavalt käib mobiilfaasi pH valimine katse-eksitusmeetodil. Tegeliku happelisuse teadmine võimaldab valida sobivaima mobiilfaasi, säästes keskkonda, aega ja raha. Selle töö suurim saavutus on mõõtevõimekuse tekitamine. Nüüdsest saab mõõta järgmiste huvipakkuvate objektide üldistatud happelisusi ning järjest avardada inimkonna arusaama happelisusest väljaspool teada-tuntud vesikeskkonda.Acidity is an important property of environment, products and food. Everybody knows that a lemon is more sour than a strawberry, but one cannot taste everything. In such a case, how can you evaluate the acidity? The typical measure of acidity is pH. The lower the pH value of a substance, the more acidic it is. The acidity scale in water ranges from 0 to 14 and in the middle, near pH 7, the water is neutral. It is easy to measure pH in water, being one of the most common measurements in chemical laboratories. It is a different story in nonaqueous medium – in gasoline, vegetable oil, meat etc. Basically one can say that every medium has its own pH scale but these scales are unfortunately incomparable. Temperature also has several scales, for example Celsius and Kelvin scale, but one can convert temperature value from one scale to another. The same is not true for pH, where the shifts of the zero points are unknown. So until now there was an unfortunate situation, where the term pH value had a different meaning in every medium and it was not possible to compare these values to each other. In 2010 the concept of unified acidity (pHabs) was put forward – one pH scale for all media! In this scale one can compare the acidities of every medium to one another. In theory this one scale substitutes all of those hundreds and thousands of pH scales, but only in theory – no one knew how to measure it. The aim of my work was to put the theory into practice, in other words develop a method to measure pHabs and for the first time in history measure unified acidities. This aim has been reached and now there is a possibility to measure unified acidities. The first experiments with the developed method were unified acidity measurements of water-methanol and water-acetonitrile mixtures. These mixtures are used as mobile phases in liquid chromatography mass spectrometry, currently one of the most used and capable method of analysis. Usually, choosing the pH of a mobile phase is done by trial and error. Knowing the pHabs helps to choose the most appropriate mobile phase, thus saving environment, time and money. The biggest achievement in this work is the measurement capability. From now on one can measure unified acidities of substances of interest and broaden the mankind’s knowledge about acidities beyond the well-known water

Cleopatra and Berenice: The Perception and Presentation of Two Queens

This paper focuses on two queens who lived and ruled on the periphery of the Roman world: Cleopatra and Berenice. Cleopatra, the last Ptolemaic queen, lived in the mid-first century BCE, while Berenice, the last Herodian queen, lived in the mid-first century CE. My project analyzes the ancient and modern texts about them in order to determine how they are perceived and presented in texts in terms of their power and agency. While there are similarities between the two queens, there are also important and telling differences in the ways ancient authors discuss them that continue to have implications for how they are perceived

Radiation Damage Studies of Silicon Photomultipliers

We report on the measurement of the radiation hardness of silicon photomultipliers (SiPMs) manufactured by Fondazione Bruno Kessler in Italy (1 mm$^2$ and 6.2 mm$^2$), Center of Perspective Technology and Apparatus in Russia (1 mm$^2$ and 4.4 mm$^2$), and Hamamatsu Corporation in Japan (1 mm$^2$). The SiPMs were irradiated using a beam of 212 MeV protons at Massachusetts General Hospital, receiving fluences of up to $3 \times 10^{10}$ protons per cm$^2$ with the SiPMs at operating voltage. Leakage currents were read continuously during the irradiation. The delivery of the protons was paused periodically to record scope traces in response to calibrated light pulses to monitor the gains, photon detection efficiencies, and dark counts of the SiPMs. The leakage current and dark noise are found to increase with fluence. Te leakage current is found to be proportional to the mean square deviation of the noise distribution, indicating the dark counts are due to increased random individual pixel activation, while SiPMs remain fully functional as photon detectors. The SiPMs are found to anneal at room temperature with a reduction in the leakage current by a factor of 2 in about 100 days.Comment: 35 pages, 25 figure

Quantification of structural information: on a question raised by Brooks

We introduce the notion of 'generative software complexity' to illustrate some of the problems one may run into when trying to tackle a special case of a question recently raised by Brooks

Eenheid en verscheidenheid der sociale uitkeringsregelingen

Social insurance, 'state pension' (financial aid by way of public service), social assistance and poor relief (public assistance) are only different types of social payment schemes. Although they are different, their aim in many respects is the same. In order to compare them it is necessary first to draw up the 'iron curtain' which is often separating one from the other. ... Zie: Summar