Theory Of Droplet Growth In Clouds. I. The Transient Stage Of The Boundary-coupled Simultaneous Heat And Mass Transport In Cloud Formation

Two solutions to the system of equations describing the simultaneous heat and mass transport involved in the condensational growth of a droplet in a supersaturated atmosphere are presented. The first, valid for very short times, describes the transient stage of such growth; the second, valid for longer times, presupposes the establishment of a steady-state condition. The two are shown to be complementary for the cases examined. The equations examined satisfy the usual boundary conditions imposed on a drop in a concentric sphere as required by the cellular model for cloud formation. Hence our results can be immediately extended to the treatment of the growth rate of drops in assemblage. © 1970

Aspekte van nasionale en kulturele identiteit van 'n verenigende Europa sedert 1958 : enkele gevallestudies

Thesis (MA)--University of Stellenbosch, 2003.ENGLISH ABSTRACT: In a globalizing world it follows that the identity of individuals will come under scrutiny as borders between states fade. It is exactly for this reason that so many people feel uncomfortable within themselves and become involved in a desperate search for new terms of reference and value systems. By virtue of this, history is utilized to explore the problem by tracing circumstances on a continent where the issue is currently very topical. Certain facets of Europe, which was the axis of the catastrophic Second World War but simultaneously the cradle of an Eurocentrism which has evolved gradually over centuries, is carefully scrutinized in order to determine what tendencies are becoming noticeable. This investigation cannot ignore the demise of the Soviet Empire and the burgeoning nation states of Eastern Europe since it represents an important divide in the European history of the twentieth century. A unifying Europe is embodied in various institutions which have sprung up since the Second World War, partially due to efforts of Europeans to organise themselves or alternatively, as a consequence of the Atlantic allies' attempts to present a united front to Soviet Russia. With the demise of the Soviet Republic in 1989, the concept underwent a further change when the Eastern European countries joined the institutional structures of a unifying nature such as the Council of Europe. It is exactly because of this that the identity issue came to the fore. The only realistic and pragmatic yardstick to measure national and cultural identity within the defined period is by employing the sovereignty of the nation state. Concurrently with this yardstick is the realisation that the protection or loss of sovereignty occurs within the upper constitutional or political levels where the public is seldom involved, but ultimately as a consequence affected. This reflects a democratic deficit. Seen from the angle of the early protagonists of Eurocentrism as well as the USA, there were conflicting views on the protection or loss of sovereignty, but an admission that greater unity could lead to the loss of some sovereignty. Britain, without publicly acknowledging it, had indeed surrendered some of its sovereignty during the 1970's when it became a member of the European Economic Community, by subjecting itself to the ruling that European Union legislation would be superior to that of Britain in the event of a conflict. Britain had thus, with regard to national and cultural identity, already proceeded to a new relationship. This new relationship was reinforced by Britain's under-writing of the principle of subsidiarity which ultimately promotes a dual identity of being British and European. The same tendency was noticeable in the institutional arrangements and programmes of the Council of Europe and the European Union. On investigating the viewpoints and role which Belgium, as one of the founder members of the European Economic Community, and simultaneously a small nation, this tendency also becomes very apparent, but possibly with greater emphasis of the regional role as a result of strong identity forming influences. In conclusion, it is thus apparent that being a European, and British or Flemish simultaneously, is currently becoming the vogue. However, being European is currently of a consumer-goods nature. It does not embrace a vibrant European identity particularly as a consequence of the language difference which limit the Europeanisation of national and cultural identities. Attempts to resolve the problem through adages such as "unity in diversity" has not produced the expected results.AFRIKAANSE OPSOMMING: In 'n globaliserende wêreld volg dit dat die identiteit van individue onder druk sal kom omdat die grense tussen state neig om te vervaag. Dit is juis as gevolg hiervan dat soveel mense ongemaklik voel met hulself en betrokke raak by 'n desperate soeke na nuwe punte van verwysing en nuwe waardestelsels. Gedagtig hieraan word die geskiedenis ingespan om die problematiek te verken deur ondersoek in te stel na die verloop van omstandighede op 'n kontinent waar die kwessie inderdaad tans uiters aktueel is. Sekere aspekte van Europa, wat die spilpunt van die katastrofale Tweede Wêreld Oorlog was, maar terselfdertyd ook die bakermat van 'n Eurosentrisme wat geleidelik oor eeue ontluik het, word onder die vergrootglas geplaas ten einde te bepaal watter neigings te bespeur is. Hierdie ondersoek kon ook nie die val van die Sowjet-ryk en die opkomende nasiestate in Oos-Europa ignoreer nie, omdat dit 'n belangrike breuklyn in die Europese geskiedenis van die twintigste eeu verteenwoord ig. 'n Verenigende Europa word vergestalt in verskeie organisasies wat sedert die Tweede Wêreld Oorlog ontstaan het enersyds vanweë pogings van Europeërs om hulself te orden, of andersyds, vanweë pogings van die Atlantiese bondgenote om 'n verenigende front jeens Sowjet-Rusland te vorm. Met die val van die Sowjet-Republiek in 1989, het die begrip 'n verdere verandering ondergaan toe Oos-Europese lande aangesluit het by institusionele strukture van 'n verenigende aard soos die Raad van Europa. Juis as gevolg hiervan het die identiteitskwessie sterker na vore getree. Die enigste realistiese en pragmatiese norm om dit te meet binne die gegewe tydsgewrig was aan die hand van die soewereiniteit van die nasiestate. Die meting gaan egter gepaard met die wete dat soewereiniteitsbeskerming of -verlies plaasvind op hoë politieke of konstitusionele vlakke waarby die algemene publiek selde betrek, maar inderdaad as uitvloeisel, geaffekteer word. Dit lei dus tot 'n gebrekkige demokratiseringsproses. Gesien vanuit die oogpunt van die vroeër denkers van Europeanisering asook die VSA, was daar botsende menings oor die verlies of beskerming van soewereiniteit, maar 'n erkenning dat groter eenheid tog tot "n mate van soewereiniteitsverlies kon lei. Brittanje het inderdaad, sonder om dit openlik te erken, reeds met sy aansluiting in die 1970's afstand gedoen van "n gedeelte van haar soewereiniteit deur die aanvaarding van die toetredingsvoorwaarde dat, waar Britse en Europese Ekonomiese Gemeenskap wetgewing bots, laasgenoemde sou oorheers. Gedagtig hieraan, is dit dus duidelik dat wat nasionale en kulturele identiteit betref, Brittanje reeds haarself begeef het in "n nuwe verhouding. Die nuwe verhouding versterk deur Brittanje se onderskrywing van die beginsel van subsidiariteit, kom eintlik daarop neer dat "n persoon terselfdertyd Brits en Europeër kan wees. Dieselfde tendens is te bespeur in die institusionele reëlings en programme van die Raad van Europa asook die Europese Unie. Wanneer die standpunte en rol van België as een van die stigterlande van die Europese Ekonomiese Gemeenskap, maar terselfdertyd "n kleinstaat, ondersoek word, kom die verskynselook sterk na vore, moontlik egter met nog meer beklemtoning van die streeksrolle van gebiede as gevolg van sterk identiteitsvormende invloede. Ten laaste word dit dus duidelik dat "n gelyktydige Europees-wees asook Brits-wees, of Vlaams-wees, nou aan die orde van die dag begin kom. Die Europees-wees is egter nog van "n verbruikersgoedere aard. Dit omvat nog nie "n lewenskragtige Europese identiteit nie veral as gevolg van die taalverskille wat belemmerend inwerk op die Europeanisering van nasionale en kulturele identiteite. Pogings om die probleem op te los deur slagspreuke soos "eenheid in diversiteit" werp nog nie die nodige vrugte af nie

Sampling locality is more detectable than taxonomy or ecology in the gut microbiota of the brood-parasitic Brown-headed Cowbird (Molothrus ater)

Brown-headed Cowbirds (Molothrus ater) are the most widespread avian brood parasite in North America, laying their eggs in the nests of approximately 250 host species that raise the cowbird nestlings as their own. It is currently unknown how these heterospecific hosts influence the cowbird gut microbiota relative to other factors, such as the local environment and genetics. We test a Nature Hypothesis (positing the importance of cowbird genetics) and a Nurture Hypothesis (where the host parents are most influential to cowbird gut microbiota) using the V6 region of 16S rRNA as a microbial fingerprint of the gut from 32 cowbird samples and 16 potential hosts from nine species. We test additional hypotheses regarding the influence of the local environment and age of the birds.We found no evidence for the Nature Hypothesis and little support for the Nurture Hypothesis. Cowbird gut microbiota did not forma clade, but neither did members of the host species. Rather, the physical location, diet and age of the bird, whether cowbird or host, were the most significant categorical variables. Thus, passerine gut microbiota may be most strongly influenced by environmental factors. To put this variation in a broader context, we compared the bird data to a fecal microbiota dataset of 38 mammal species and 22 insect species. Insects were always the most variable; on some axes, we found more variation within cowbirds than across all mammals. Taken together, passerine gut microbiota may be more variable and environmentally determined than other taxonomic groups examined to date. © 2014 Hird et al

CARbon DIoxide for the treatment of Febrile seizures: rationale, feasibility, and design of the CARDIF-study

Background: 2-8% of all children aged between 6 months and 5 years have febrile seizures. Often these seizures cease spontaneously, however depending on different national guidelines, 20-40% of the patients would need therapeutic intervention. For seizures longer than 3-5 minutes application of rectal diazepam, buccal midazolam or sublingual lorazepam is recommended. Benzodiazepines may be ineffective in some patients or cause prolonged sedation and fatigue. Preclinical investigations in a rat model provided evidence that febrile seizures may be triggered by respiratory alkalosis, which was subsequently confirmed by a retrospective clinical observation. Further, individual therapeutic interventions demonstrated that a pCO2-elevation via re-breathing or inhalation of 5% CO2 instantly stopped the febrile seizures. Here, we present the protocol for an interventional clinical trial to test the hypothesis that the application of 5% CO2 is effective and safe to suppress febrile seizures in children. Methods: The CARDIF (CARbon DIoxide against Febrile seizures) trial is a monocentric, prospective, double-blind, placebo-controlled, randomized study. A total of 288 patients with a life history of at least one febrile seizure will be randomized to receive either carbogen (5% CO2 plus 95% O2) or placebo (100% O2). As recurrences of febrile seizures mainly occur at home, the study medication will be administered by the parents through a low-pressure can fitted with a respiratory mask. The primary outcome measure is the efficacy of carbogen to interrupt febrile seizures. As secondary outcome parameters we assess safety, practicability to use the can, quality of life, contentedness, anxiousness and mobility of the parents. Prospect: The CARDIF trial has the potential to develop a new therapy for the suppression of febrile seizures by redressing the normal physiological state. This would offer an alternative to the currently suggested treatment with benzodiazepines. This study is an example of academic translational research from the study of animal physiology to a new therapy

Transmitters and Pathways Mediating Inhibition of Spinal Itch-Signaling Neurons by Scratching and Other Counterstimuli

Scratching relieves itch, but the underlying neural mechanisms are poorly understood. We presently investigated a role for the inhibitory neurotransmitters GABA and glycine in scratch-evoked inhibition of spinal itch-signaling neurons in a mouse model of chronic dry skin itch. Superficial dorsal horn neurons ipsilateral to hindpaw dry skin treatment exhibited a high level of spontaneous firing that was significantly attenuated by cutaneous scratching, pinch and noxious heat. Scratch-evoked inhibition was nearly abolished by spinal delivery of the glycine antagonist, strychnine, and was markedly attenuated by respective GABAA and GABAB antagonists bicuculline and saclofen. Scratch-evoked inhibition was also significantly attenuated (but not abolished) by interruption of the upper cervical spinal cord, indicating the involvement of both segmental and suprasegmental circuits that engage glycine- and GABA-mediated inhibition of spinal itch-signaling neurons by noxious counterstimuli

Surface-Oxygen Induced Electrochemical Self-Assembly of Mesoporous Conducting Polymers for Electrocatalysis

Porous polymers have immense potential in catalysis, energy conversion and storage, separation sciences and life sciences due to their high surface area and high diffusion flux. Developing porous polymers with micro and mesoscale porosity with long-range order is challenging and involves multistep templated approaches. Here we demonstrate a simple surface-oxygen induced electropolymerization route to directly obtain self-assembled porous polymers of polyparaphenylene (PPP) and PPP based copolymers in ionic liquids. By combining experimental and theoretical studies, we show that surface oxygen on Cu changes the orientation and assembly of benzene which then results in a change in electropolymerization mechanism leading to a self-assembled porous structure with porosity between 2 and 5 μm. Furthermore, with controlled experimental parameters, bicontinuous conducting polymers with porosity of >10 μm are obtained. The porous conducting polymers show absorption of light in the visible range which was also used as an efficient electrode for investigation of the photoelectrochemical oxygen evolution reaction.We acknowledge the use of Athena at HPC Midlands+ in this research, which was funded by the EPSRC (grant EP/P020232/1) via the EPSRC RAP call of spring 2018 and 2019. Supercomputer Wales is also thanked for the computing time. In this work ARCHER - the UK National Supercomputing Service (https://www.archer.ac.uk) was also used via the membership of the UK’s HEC Materials Chemistry Consortium, which is funded by EPSRC (EP/L000202)

THE EFFECT OF TONE ON THE SUCCESSIVE COMPARISON OF BRIGHTNESS

Last updated: 6/12/200

Smoking and drinking habits of women in subsequent pregnancies after specific advice about the dangers of these exposures during pregnancy

Background. Although women are informed about the dangers of drinking and smoking during pregnancy when they book for antenatal care, it is uncertain whether this advice is accepted, or whether attempts are made to apply it in subsequent pregnancies.Objectives. To assess how pregnant women respond to the advice to refrain from smoking and drinking during pregnancy in subsequent pregnancies.Methods. Research staff were trained to obtain accurate prospective information on smoking and drinking during pregnancy in a prospective study, using well-standardised methods. Care was taken to inform participants about the dangers of smoking and drinking during pregnancy. They were also given pamphlets on these dangers in their own language and a list of telephone numbers where they could find help to quit should they need it. This information was repeated at subsequent study visits (ranging from 1 to 3, depending on the gestational age at which they enrolled). Gestational age was determined by early ultrasound. Z-scores of birthweight for gestational age were determined according to the INTERGROWTH-21st study. Pregnancy outcomes of women who enrolled twice (n=888) or three times (n=77) in the Safe Passage Study were compared with those of women in the first enrolment (n=889).Results. The proportion of drinkers did not change significantly (p=0.058) from the first to the second and third enrolments (63.8%, 59.0% and 54.6%, respectively). A similar trend was found for smokers (73.3%, 72.2% and 68.4%, respectively). Cannabis use was reported by 15.1%, 9.7% and 12.0% (p<0.005) of women, respectively, and use of methamphetamine by 10.1%, 6.6% and 12.7% (p<0.005). There was an increase in the rate of preterm births from 15.5% to 17.5% and 24.7%, respectively, but the increase was not significant. Although mean birthweight was lower in the third enrolment compared with the second, the difference was not significant. The z-score of birthweight for gestational age was significantly lower in the second enrolment compared with the first.Conclusions. Detailed information on the adverse effects of smoking and drinking during pregnancy was not effective in the population studied. Other methods to reduce or stop these toxic exposures should therefore be investigated. A short inter-pregnancy interval, as demonstrated by three enrolments in 7.5 years, is associated with preterm labour and fetal growth restriction, and is probably indicative of the role played by confounders such as poor socioeconomic conditions and drug exposure during pregnancy

Increased resistance to biotrophic pathogens in the Arabidopsis constitutive induced resistance 1 mutant is EDS1 and PAD4-dependent and modulated by environmental temperature

The Arabidopsis constitutive induced resistance 1 ( cir1 ) mutant displays salicylic acid (SA)-dependent constitutive expression of defence genes and enhanced resistance to biotrophic pathogens. To further characterise the role of CIR1 in plant immunity we conducted epistasis analyses with two key components of the SA-signalling branch of the defence network, ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1) and PHYTOALEXIN DEFICIENT4 (PAD4). We demonstrate that the constitutive defence phenotypes of cir1 require both EDS1 and PAD4, indicating that CIR1 lies upstream of the EDS1-PAD4 regulatory node in the immune signalling network. In light of this finding we examined EDS1 expression in cir1 and observed increased protein, but not mRNA levels in this mutant, suggesting that CIR1 might act as a negative regulator of EDS1 via a post-transcriptional mechanism. Finally, as environmental temperature is known to influence the outcome of plant-pathogen interactions, we analysed cir1 plants grown at 18, 22 or 25°C. We found that susceptibility to Pseudomonas syringae pv. tomato ( Pst ) DC3000 is modulated by temperature in cir1 . Greatest resistance to this pathogen (relative to PR-1:LUC control plants) was observed at 18°C, while at 25°C no difference in susceptibility between cir1 and control plants was apparent. The increase in resistance to Pst DC3000 at 18°C correlated with a stunted growth phenotype, suggesting that activation of defence responses may be enhanced at lower temperatures in the cir1 mutant