Showing papers by "Cardiff University published in 1973"

A comparative study of the reproductive system of mature, immature and ‘unisexual’ female Schistosoma mansoni

Abstract: The ultrastructure of the reproductive system of mature (54-day-old), immature (32-day-old) and females from unisexual infections of Schistosoma mansoni is described in detail. The uterus is tegumentary in structure but the vitelline duct and oviduct are complex and possess cilia as well as lamellae on their luminal surfaces. The characteristics of the cells forming the walls of the ducts suggests that they may have a digestive function. The posterior portion of the oviduct of the adult worm contains sperm which become enveloped by lamellae. The vitelline cells of the adult contain vitelline droplets, much lipid and little glycogen. A second type of body derived from endoplasmic whorls is also present. Mehlis's gland contains only one type of gland cell and these cells pass through the ootype wall and open into its lumen. The female from unisexual infections has an incompletely developed Mehlis's gland, an ovary in which the Golgi complexes do not produce typical cortical granules and has vitelline cells which remain immature. The oviduct, ootype and uterus are well developed in contrast to the vitelline duct. A comparison with young, but not inseminated worms, suggests that the presence of sperm in the oviduct is not the major stimulus which induces maturation of the female worm.

Mothers, brothers and sisters of patients with spina bifida.

Abstract: UMMARY A comparison of the iq scores of a group of spina bifida children and their siblings and a group of matched control children and their siblings indicated that maldevelopment of or damage to the central nervous system is associated with lower iq, even when social class is taken into account. The frequency of maladjustment was found to be almost four times higher in the siblings of the children with spina bifida than in the siblings of the normal control children. No differences were observed in Bristol Social Adjustment Guide (bsag) scores of siblings according to whether the child with spina bifida was away at a residential school or was living at home. The birth rank of the child with spina bifida was not found to influence the siblings' adjustment, but spina bifida children with slight handicaps were found to have the highest bsag scores, and the siblings of the moderately handicapped spina bifida children had the lowest. The malaise scores of the mothers exceeded those in other studies of children with different forms of handicap. RESUME Meres, freres et soeurs de malades atteints de spina bifida Une comparaison des qi d'un groupe de spina bifida et de leurs freres et soeurs d'une part et d'un groupe controle apparie avec egalement les freres et soeurs indique que le mauvais developpement ou la lesion du systeme nerveux central est associea un qi bas meme lorsqu'on tient compte de la classe sociale. La frequence de l'inadaptation a ete trouvee pres de 4 fois plus importante chez les freres et soeurs des enfants atteints de spina bifida que dans l'entourage du groupe controle. Aucune difference n'a ete notee dans les resultats au Bristol Social Adjustement Guide (bsag) chez les freres et soeurs que l'enfant atteint de spina bifida soit dans un centre scolaire ou qu'il vive a la maison. Le rang de naissance de l'enfant atteint n'avait pas d'influence sur l'adaptation des freres et soeurs mais les spina bifida avec leger handicap avaient les scores les plus eleves au bsag et les freres et soeurs de spina bifida moderement handicapes les scores les plus bas. Les scores de mauvais equilibre affectif chez les meres ont ete trouves superieurs a ceux notes dans d'autres etudes. ZUSAMMENFASSUNG Mutter, Bruder und Schwestern von Spina-bifida Patienten Eine vergleichende Untersuchung der iq Ergebnisse einer Gruppe von Spina-bifida Fallen und ihren Geschwistern und einer Gruppe entsprechender Kontrollpatienten und deren Geschwistern zeigt, das eine Fehlentwicklung oder eine Schadigung des Zentralnervensystems mit einem neidrigen iq einhergeht, sogar wenn die soziale Gruppenzugehorigkeit mit in die Berechnung einbezogen wird. Es wurde gefunden, das die Frequenz schlechter Anpassung bei den Geschwistern der Spina-bifida Kinder nahezu viermal hoher war als bei den Geschwistern der normalen Kontrollen. Keine Unterschiede wurden gefunden in den Ergebnissen des Bristol Social Adjustment Guide (bsag) der Angehorigen hinsichtlich dessen, ob das Spina-bifida Kind zur Schule ging oder zu Hause lebte. Der Rang in der Geburtsreihenfolge des Spina-bifida Kindes war ohne Einflus auf die Anpassung der Geschwister, aber Spina-bifida Kinder mit geringfugigen Beeintrachtigungen hatten die hochsten Ergebnisse im bsag und die Geschwister der masig behinderten Spina-bifida Falle die niedrigsten Ergebnisse. Die Ergebnisse des Unbehagens der Mutter ubertrafen die in anderen Studien. RESUMEN Madres, hermanos y hermanas de pacientes con espina bifida Una comparacion de los puntajes del ci de un grupo de casos con espina bifida y sus hermanos y de un grupo de controles comparativos y sus hermanos indica que el mal desarrollo de la lesion del sistema nervioso central esta asociado con un bajo ci, incluso cuando la clase social no es tenida en cuenta. La frecuencia de desajuste se encontro que era cuatro veces mas alta en los hermanos de ninos con espina bifida que en los hermanos de los controles normales. No habia ninguna diferencia en el puntaje de la Guia de Ajuste Social de Bristol (b.s.a.g.) de los hermanos tanto si el nino con espina bifida iba a la escuela o vivia en su casa. El orden entre los hermanos del nino con espina bifida no se hallo que tuviera influencia en el ajuste de los hermanos, pero los ninos con espina bifida con ligeras minusvalias presentaron los puntajes mas altos en el b.s.a.g. y los hermanos de los ninos con espina bifida y minusvalencia moderada presentaban los puntajes mas bajos. Los puntajes de malestar de las madres se hallo que excedian los de otros estudios.

Language as a determinant of Welsh identity

Abstract: The study was designed, using the ‚matched-guise' technique, to determine how different groups of Welshmen perceive members of their own national group who use various linguistic codes Three matched groups of adult Welsh Ss were used: Bilinguals, those who were learning Welsh and those who could not speak Welsh and were not learning it either These Ss were asked to evaluate on 22 scales the personalities of various Welsh speakers they heard reading the same passage of prose on tape Essentially, the stimulus tape consisted of two male bilinguals reading the passage once each in Welsh, in English with a Welsh accent and in English with an RP accent It was found, despite the fact that the groups differed in their language skills and self-perceived Welshness, that Ss as a whole upgraded the bilingual speakers on most traits Indeed, the RP speakers were evaluated most favourably on only one trait - self-confidence It was suggested that language to a large extent serves as a symbol of Welsh identity, and the results were discussed in relation to how other ethnic groups appear to view their own linguistic codes

Circulation-time models of the uptake of inhaled anaesthetics and data for quantifying them.

Abstract: Conventional compartmental models of the uptake and distribution of inhaled anaesthetics assume that blood moves from lungs to tissues and from tissues back to lungs in zero time. Three new models which incorporate alternative representations of the finite time actually taken have been constructed in terms of Algol programs for a digital computer. It is shown that the conventional approach causes systematic errors in the computed uptake of low-solubility agents, in the arterial tension of high-solubility agents, and in the tissue tensions of all agents. The errors are important in the first minute or two of administration or recovery. The conventional distribution of blood volume between compartments is shown to be in error and to cause even greater systematic errors in computed results. Three different published distributions of tissue volume and cardiac output give different computed results and a "preferred" distribution is suggested.

Comparison of the effects of dexamphetamine and 1-benzylpiperazine in former addicts.

Abstract: The subjective, behavioural and autonomic effects of dexamphetamine 10 mg, 1-benzylpiperazine 100 mg and lactose dummy were compared in a group of 18 former amphetamine addicts. All subjects received the three preparations according to a balanced design under double blind conditions. 1-Benzylpiperazine and dexamphctamine produced indistinguishable subjective effects and both were liked. The effects of both compounds differed significantly from the effects following the dummy preparation. Increases in pulse rate and both systolic and diastolic blood pressure were similar following the two active compounds, but 1-benzylpiperazine produced pupillary dilation whereas no significant change in pupil size followed dummy or dexamphetamine. It was concluded that 1-benzylpiperazine is a compound liable to abuse by an addict population, and that this type of study might be of value in predicting abuse liability of other new drugs.

Cardiovascular and respiratory effects of cannabis in cat and rat.

Abstract: 1. In anaesthetized rats, intravenous administration of cannabis extract (10 mg/kg), Delta(1)-tetrahydrocannabinol (THC) (0.5 mg/kg) and Delta(6)-THC (0.5 mg/kg) caused a reduction in systemic blood pressure, pulse rate and respiratory rate.2. Neither cannabinol (1 mg/kg, i.v.) nor cannabidiol (1 mg/kg, i.v.) had any observed effects on the cardiovascular and respiratory systems of the rat.3. Pretreatment of rats with atropine (1 mg/kg, i.v.) reduced the hypotension and bradycardia caused by Delta(1)-THC or the extract.4. In anaesthetized cats with autoperfused hindquarters, cannabis extract (10 mg/kg, i.v.) and Delta(1)-THC (0.2 mg/kg, i.v.) caused hypotension, bradycardia, depression of respiratory rate and reduction of hindlimb perfusion pressure.5. Both cannabis extract and Delta(1)-THC potentiated reflex vasodilation and direct vasoconstriction in the hindlimb induced by intravenous noradrenaline in the cat; they reduced reflex hindlimb vasoconstriction elicited by histamine, acetylcholine or bilateral carotid occlusion.6. Tolerance to these cardiovascular and respiratory effects of cannabis extract developed in rats which had been treated i.p. with the extract at (50 mg/kg) per day for 14 days.

Communicative effectiveness as a function of accented speech

Abstract: Five groups of accented seventeen‐year‐olds from Britain were matched for sex, regional membership, and attitude toward capital punishment for murder. These groups were presented with the same persuasive message against capital punishment. Four of the groups heard the message on tape in a different accent produced by a speaker adopting the matched‐guise technique; the fifth group was given a typescript of the message. The results showed that the greater the accent prestige of the communicator's voice, the greater the perceived quality of the argument. Only the nonstandard regional accented messages, however, changed listeners’ attitudes significantly in the predicted direction.

Studies on the sulphation of 3,4-dihydroxyphenylethylamine (dopamine) and related compounds by rat tissues

Abstract: The formation of sulpho-conjugates of 3,4-dihydroxyphenylethylamine (dopamine) and related compounds was examined in preparations of rat tissues. Liver high-speed-supernatant preparations readily transferred sulphate from adenosine 3′-phosphate 5′-sulphato-phosphate to dopamine under standard conditions. The main product was identified as the 3-O-sulphate. The preparation also sulphated the 3- and 4-methoxy derivatives but to a lesser extent (44% and 95% respectively) relative to dopamine. Brain preparations possessed only half the activity of liver but formed both the 3- and 4-O-sulphates in the molar ratio of 1.7:1. l-3,4-Dihydroxyphenylalanine (l-dopa) in both tissue preparations did not yield any significant amount of sulpho-conjugate when the dopa decarboxylase present was inhibited. The sulphotransferase activity of preparations was doubled in the presence of dithiothreitol and it was concluded that l-tyrosine methyl ester sulphotransferase was the enzyme involved. A method for the preparation of authentic dopamine 3-O-sulphate and 4-O-sulphate was developed.

Changes in shape of the human hip joint during its development and their relation to its stability

Abstract: 1. Dissection of forty-four developing human hip joints has shown that while the embryonic acetabulum is a deeply set cavity which almost totally encloses the head it gradually becomes more shallow as birth approaches. During the same period the femoral head becomes less globular and at the end of foetal life is almost hemispherical. The cover afforded to the femoral head by the acetabulum also becomes decreased. 2. After birth these trends reverse: the acetabulum becomes deeper again and the femoral head more globular. This process continues throughout childhood. 3. The findings provide a possible explanation for the increased liability to dislocation of the infantile hip.

Histamine H1 and H2-Receptors at a Ganglionic Synapse

Abstract: MANY humoral agents are capable of modulating synaptic transmission in sympathetic ganglia and it has been proposed that a variety of receptors are present at the ganglionic synapse (see Haefely1). There are thus many possible modulatory mechanisms at this synapse, some of which have a dual nature, the same substance being able both to facilitate and to depress ganglionic transmission by an action on two different populations of receptors. We wish to present evidence that histamine, like the catecholamines2 and 5-hydroxytryptamine (serotonin)3, has a dual action at the ganglionic synapse.

Problems associated with the assay of arylsulphatases A and B of rat tissues.

Abstract: A method for the separation and purification of rat liver arylsulphatases A and B by gel filtration on Sephadex G-200 is described. The properties of the A enzyme and its molecular weight are similar to those of the corresponding ox liver enzyme. The B enzymes were found to be dissimilar. The method already developed for the assay of the corresponding enzymes from human tissues was shown to be unsuitable for the assay of the enzymes of rat tissues. A method of assay was developed which permits an approximate determination of the individual rat liver enzymes in a mixture of the two, but precise determination requires prior separation of the enzymes by gel-filtration chromatography.

The Ballantrae ophiolite

Abstract: The Ballantrae complex, variously interpreted in the light of plate tectonics, is reappraised on the basis of comparisons with ophiolites of the Newfoundland Appalachians and the southwestern Pacific. All the main components of a typical ophiolite sequence can be recognized although the sequence has been greatly disturbed by post-emplacement Caledonian deformation. The presence of a garnet granulite-amphibolite ‘aureole’ beneath the peridotite member of the complex is confirmed, thus establishing the affinity of the complex to other ophiolite-amphibolite associations of the Appalachian and Alpine systems. Rock units previously described as agglomerates are re-interpreted as olistostromes, and the important Pinbain Beach ‘shaly group’ containing fragments of ophiolitic debris, garnet-ariegite, and glaucophane schist, is considered to be a Wildflysch unit of Middle Arenig age. The olistostromes were deposited following obduction of oceanic lithosphere represented by the ultramafic and mafic rocks of the Ballantrae complex. Recognition of the complex as overthrust ophiolite removes certain constraints on the position of a Lower Paleozoic subduction zone within the Southern Uplands.

Biological method of estimating smoke and sulphur dioxide pollution.

Abstract: SMOKE and sulphur dioxide levels are measured by the Warren Spring Laboratory at many sites in Great Britain1, but little information is collected in rural areas. Here we describe a method for estimating atmospheric pollution which can be applied in most areas where trees are found.

Rate equations and transient phenomena in semiconductor lasers

Abstract: This contribution attempts to review certain resonance effects which occur in the dynamic behaviour of semiconductor lasers. To study these effects theoretically, a rate equation approach is used for single-mode operation in the region of lasing threshold. The two basic rate equations are given and their transient solutions discussed. The existence of two time constants in these equations, viz. the electron lifetimeτ e and the photon lifetimeτ e; gives rise to a characteristic resonance frequency in the GHz region. This resonance manifests itself in transient ‘spiking’ effects, in quantum noise phenomena, and in high-frequency modulation experiments. In a modified form the resonance frequency may also be studied in lasers with external cavities and in double-diode configurations (or, equivalently, conventional devices with non-uniform excitation along the cavity length). In the latter two examples mentioned above, the resonance is excited by optical feedback of the laser radiation into the active medium via a ‘lossy’ or insufficiently inverted region. In the ‘spiking’ oscillations commonly observed at the commencement of laser operation, the initial ‘population overshoot’ is the cause of the resonance. For the case of quantum noise it is the requirement that the photon and electron populations have integer values which supplies the driving force-a true quantum effect. High-frequency modulation experiments directly reveal the same resonance frequency where a strong maximum in modulation intensity occurs.

Flux distribution and power loss in the mitered overlap joint in power transformer cores

Abstract: The design of the joints in a power transformer core has a marked influence on the efficiency of the core as a whole. Two experimental cores have been built such that the lengths of their 45° mitered overlaps could be varied from 0 to 2.0 cm. The larger core, with 1.0 m limbs, was used for investigating flux and loss variations and the second, smaller core was used to study how the results might be affected by changes in dimensions. For the larger core, the power loss was measured in two ways for a range of overlaps: first, using the localized power loss technique, and then by measuring the total power loss with a precision wattmeter. In both cases, a minimum power loss was found when the core was built with an overlap of 0.5 cm. The overlap length was varied in the smaller core and again a minimum power loss was found, but with a 1.0 cm overlap. A change in loss of over 20% was found for the range of overlap lengths used, and the optimum overlap length was independent of flux density over the range from 1.0 T to 1.8 T. The special flux distribution was determined from an array of search coils. The variations in flux distribution enables a qualitative explanation of the occurrence of the minimum in power loss.

Atmospheric pollution and industrial melanism.

Abstract: The distribution of melanic forms in two moth and two ladybird species has been analysed in relation to fourteen environmental variables by multiple regression. Local smoke levels emerge as important factors in Phigalia pedaria and Adalia bipunctata whereas in Biston betularia sulphur dioxide appears to be the more important. The importance of crypsis is indicated in P. pedaria but not in the warningly coloured A. bipunctata; nor is it confirmed in B. betularia despite earlier experimental results. There is no evidence for industrial melanism in Adalia decempunctata.

Biosynthetic pathway of desmosines in elastin.

Abstract: 1. Elastins purified by various methods from the ligamentum nuchae and the lungs of cattle of various ages were analysed for amino acid compositions and lysine-derived cross-links. 2. In fully mature elastins from adults the main cross-links were desmosine, isodesmosine and lysinonorleucine and the so-called aldol-condensation product. Trace amounts of merodesmosine were also found. 3. During the normal maturation of elastins the amounts of desmosine, isodesmosine and lysinonorleucine increased, whereas the aldol-condensation product and intact lysine residues decreased and merodesmosine remained the same. 4. Elastins from young animals contained significant amounts of dehydromerodesmosine whereas elastins from adults contained virtually nil. Evidence is presented which suggests that the biosynthetic pathway of desmosine and isodesmosine proceeds via the aldol-condensation product and dehydromerodesmosine.

The spatial variation of localized power loss in two practical transformer T-joints

Abstract: The power loss and flux distribution in two commercial T-joints have been compared. The simple 45°-90° T-joint and the slightly more complex 45° offset T-joint were chosen for the investigation, as they are the most common joints currently used in power transformers. The localized and overall power loss of each joint was measured using now-established techniques. Each joint was built in turn into a three-limb, three-phase core, employing 15-cm wide, 0.03-cm-thick 3.2% grain-oriented silicon iron laminations. The cores were magnetized at the same overall flux densities. The localized flux distribution in individual laminations in the joints were related to the localized loss variation. Rotational flux was found to occur in both joints and it caused areas of high localized loss. A combination of normal flux between adjacent layers of laminations, rotating flux, and circulating 3rd-harmonic fluxes caused the localized loss to rise to double the average core loss in some regions of the T-joints. For the 15-cm-wide laminations used, the 45° offset joint was 10% more efficient than the 45°-90° T-joint at a flux density of 1.6 T; the mean loss of both joints was more than 25% higher than the loss in the yokes and limbs.

Effect of parathyroid extract on blood calcium and osteoclast count in mice.

Abstract: A sensitive method for identifying and counting osteoclasts has been developed, using the intense succinic dehydrogenase activity demonstrable in these cells. The method was used to compare the time relation of the changes in blood calcium and osteoclast numbers in the mouse femur after the administration of 1 U PTE/mouse. An age-related decrease in osteoclast count was found. The earliest significant rise in osteoclast numbers, after the administration of PTE, occurred much earlier than has been previously reported. While the results at present indicated that the hypercalcaemic response to an intravenous injection of PTE was complete before an appreciable rise occurred in the osteoclast count, they did not exclude the possibility that the osteoclasts exert a hypercalcaemic effect by an increase in activity rather than in numbers. Alternatively, the results may indicate that osteoclasts are not involved in the mediation of the hypercalcaemic response to PTE.