Efficiency of statistics of stereology

Imperial Users onl

Review of Patrick O\u27Brien, Derek Keene, eds. Urban Achievement in Early Modern Europe: Golden Ages in Antwerp, Amsterdam and London.

Patrick O\u27Brien, Derek Keene, eds. Urban Achievement in Early Modern Europe: Golden Ages in Antwerp, Amsterdam and London. Cambridge: Cambridge University Press, 2001. 361 pp. ISBN 0521594081

Review of Patrick O\u27Brien, Derek Keene, eds. Urban Achievement in Early Modern Europe: Golden Ages in Antwerp, Amsterdam and London.

Patrick O\u27Brien, Derek Keene, eds. Urban Achievement in Early Modern Europe: Golden Ages in Antwerp, Amsterdam and London. Cambridge: Cambridge University Press, 2001. 361 pp. ISBN 0521594081

Molecular studies on intraspecific diversity and phylogenetic position of Coniothyrium minitans

Simple sequence repeat (SSR)±PCR amplification using a microsatellite primer (GACA)% and ribosomal RNA gene sequencing were used to examine the intraspecific diversity in the mycoparasite Coniothyrium minitans based on 48 strains, representing eight colony types, from 17 countries world-wide. Coniothyrium cerealis, C. fuckelii and C. sporulosum were used for interspecific comparison. The SSR±PCR technique revealed a relatively low level of polymorphism within C. minitans but did allow some differentiation between strains. While there was no relationship between SSR±PCR profiles and colony type, there was some limited correlation between these profiles and country of origin. Sequences of the ITS 1 and ITS 2 regions and the 5±8S gene of rRNA genes were identical in all twenty-four strains of C. minitans examined irrespective of colony type and origin. These results indicate that C. minitans is genetically not very variable despite phenotypic differences. ITS and 5±8S rRNA gene sequence analyses showed that C. minitans had similarities of 94% with C. fuckelii and C. sporulosum (which were identical to each other) and only 64% with C. cerealis. Database searches failed to show any similarity with the ITS 1 sequence for C. minitans although the 5±8S rRNA gene and ITS 2 sequences revealed an 87% similarity with Aporospora terricola. The ITS sequence including the 5±8S rRNA gene sequence of Coniothyrium cerealis showed 91% similarity to Phaeosphaeria microscopica. Phylogenetic analyses using database information suggest that C. minitans, C. sporulosum, C. fuckelii and A. terricola cluster in one clade, grouping with Helminthosporium species and 'Leptosphaeria' bicolor. Coniothyrium cerealis grouped with Ampelomyces quisqualis and formed a major cluster with members of the Phaeosphaeriacae and Phaeosphaeria microscopica

Doctor of Philosophy

dissertationInjury from explosive blast is a growing public health threat worldwide with complex mechanisms and limited treatment and prevention pathways. Blast-related traumatic brain injury (bTBI) is a multimodal injury event in which cerebral blood vessels play a central role in both the mechanical and physiological response to blast loading. This dissertation seeks to define the nature of vessel injury from primary blast loading by measuring injury thresholds for vasculature in bTBI by assessing blood-brain barrier (BBB) integrity and disruption, examining which types of vessels are affected, and mapping the distribution of injury in the brain. To assess the consequences of vascular injury, we measured inflammatory changes in glial cell activity with immunohistological techniques, and evaluated changes in behavior in a rodent model of bTBI. The importance of overpressure duration and impulse are examined by performing matched assays with two distinct blast tube devices capable of producing a wide range of blast wave characteristics. Exploration in measuring changes in cerebral blood flow, blood oxygen levels, and cerebral hemorrhage is described. Our primary findings include the presence of focal deposits of IgG in the parenchymal brain tissue indicating an elevated permeability of the blood-brain barrier, a heterogeneous distribution of these lesions among various brain structures, changes in astrocyte glial fibrillary acidic protein (GFAP) expression at lesion locations, and decrease in nociception and pedal withdrawal reflex following primary blast exposure. Changes in macrophage and neural cell populations were observed using markers for IBA1, CD68, and NeuN. Injury levels between devices were broadly similar; however, some differences in both histology and behavior were seen following high-impulse blast testing. Blast injury research remains an important topic with many unanswered questions, and further effort will provide help to those afflicted and preventative protection for those at risk

Assessing sustainability of aquaculture development

Aquaculture, as an aquatic based economic activity, has risen from relative obscurity to a position of global recognition in just over two decades, and is forecast to become increasingly important in the next century. This growth, however, has been accompanied by increasing concerns over the environmental and social costs associated with the exploitation of the natural resource base on which it depends. This occurs in the broader context of increasing awareness of the finite capacity of the global system, and the need for development of more sustainable resource management regimes. The objective of the study is to examine if and how 'sustainability' can be brought into assessment for aquaculture development. The main concepts of sustainability are discussed, and key issues for assessment identified. The range of impacts associated with aquaculture development is reviewed, and broad categories of sectoral sustainability indicators proposed. Specific issues and assessment approaches are examined in three case studies, focusing on environment interactions, resource use assessment, and the rural development context, respectively. There follows a structured analysis of applicability of selected generic appraisal methods, concluding that while all may contribute, none is sufficiently broad to account for all sustainability perspectives. A more comprehensive framework for the assessment is therefore proposed, by which sustainability features of any system can be described, potential indicators and methods of assessment identified, and results communicated to the decision making process. This does not offer a definitive judgement on sustainability, but presents an holistic view, allowing explicit recognition of trade-offs involved between conflicting sustainability objectives. It is concluded that sufficient information is available for this approach to be developed and applied on a wider basis. Constraints to more sustainable development relate more to the social, political and economic environment than to problems of uncertainty in forecasting biological and physical systems

Peptic ulceration of the oesophagus in combination with partial thoracic stomach

The subject - "Peptic Ulceration of the Oesophagus in combination with Partial Thoracic Stomach" - is one which has been recognised only within the past few years. It has been my fortune, as radiologist to a large teaching hospital, to find over twenty cases during the past five years. The thesis reviews the pathogenesis and clinical features together with a description of diagnostic methods and treatment. The appendix contains full clinical notes of eighteen cases which have been under treatment and observation for more than a year. The clinical importance in recognising the condition lies in the fact that the alternative diagnosis is cancer of the lower end of the oesophagus. Peptic ulceration is not uncommon and if erroneously treated by radiotherapy the results might prove disastrous. The academic interest of the subject centres round the lower end of the oesophagus and the partial thoracic stomach. The congenital and acquired types of gastric herniation through the oesophageal hiatus are fully discussed and the accepted anatomical site of the cardia is called into question. As regurgitation into the oesophagus plays a large part in the production of peptic ulceration this point assumes considerable importance. The recognition of the position of the cardia in relation to neighbouring structures is most readily determined by radiology and stress is laid on the distinguishing features

The Photodegradation of Copolymers of 2,2-Chloroacrylonitrile With Styrene and With Methyl Methacrylate

Methyl methacrylate/2,2-chloroacrylonitrile and styrene/2,2-chloroacrylonitrile copolymers of various molar ratios have been prepared by free-radical, addition polymerisation and characterised by nuclear magnetic resonance spectroscopy and microanalysis. The photodegradation by 254nm radiation of thin copolymer films has been studied at ambient temperatures. Spectroscopic examination of the residual films, separation of degradation products by a recently developed, low-temperature, thermal volatilisation analysis technique, cumulative, quantitative product analysis and product identification by spectroscopic techniques have enabled the photodegradation processes to be studied in depth. The results indicate that, as the proportion of 2,2-chloroacrylonitrile in the copolymer with methyl methacrylate is increased, the well-established degradative behaviour of poly(methyl methacrylate)--- a rapid decrease in molecular weight and formation of products from ester decomposition--- is gradually replaced by crosslinking, unsaturation, insolubility, the production of hydrogen chloride from 2,2-chloroacrylonitrile units and methyl chloride from both monomers. Around the 1 : 1 molar ratio a highly absorbing surface layer begins to be formed. The effect of 2,2-chloroacrylonitrile units on polystyrene photodegradation is less marked. The major reaction is hydrogen chloride formation. For the same molar ratio, the rate of formation of hydrogen chloride from 2,2-chloroacrylonitrile copolymers with styrene is considerably greater than with methyl methacrylate. This is attributed to the different absorption coefficients of radiation of the two co-monomers. Solvent participation in photodegradation reactions is indicated by anomolous molecular weight measurements on the methyl methacrylate system and by post-irradiation absorption spectra of copolymer films of both systems. The effect of pre-irradiation on the thermal degradative behaviour of copolymer films has been studied. The nature of the degradation products remains unchanged but the effects of crosslinking and unsaturation on the methyl methacrylate system are reflected in thermogravimetric analyses and differential condensation thermal volatilisation analyses on the system. The initiation processes involved, the scissioning reactions, the development of unsaturation in the copolymers and the related discoloration of copolymer films are discussed in the course of the work. Comparisons are drawn with studies on similar polymer systems and various references are listed which have been found relevant to the present study

Master of Science

thesisHyporheic flow has been identified as a major component of stream flow in Red Butte Canyon. While most hyporheic flow systems tend to have transit times of hours to days, previously conducted stream tracer tests suggest that, in Red Butte, these transit times are much longer. A stream survey of radon concentrations was used to identify specific areas of hyporheic discharge, including spring discharge from a tufa mound that is recharged from the stream approximately 200 m upslope. The hydraulic connection between the stream and the tufa spring was verified by performing an active bromide injection into the stream and monitoring for bromide concentrations in the spring. Two passive techniques, namely, variations of H and O isotope ratios and of noble gas concentrations, were evaluated as means of measuring hyporheic transit times. Peak concentrations of bromide in the tufa spring were observed approximately 18 days after a 24-h injection into the stream, with center of mass transit times of 34-48. However, substantial dispersion resulted in measurable bromide existing 17 weeks after injection. The stable isotope method used storm events with unique H and O isotopic values to reveal an approximately 16-day lag between the stream and the spring that discharges the hyporheic system. Dispersion resulted in significant flattening and spreading of the O and H peaks. However, with better resolution, the stable isotopes are the most promising passive technique. The noble gas method relies on the temperature dependence of the equilibrium solubility of atmospheric noble gases (e.g., Kr and Xe) combined with diurnal and seasonal temperature fluctuation in the stream. However, a 27-h sampling event revealed that the spring had large variations in noble gas concentrations, even though its measured temperature was constant, which could be a result of some exposure to the air before the water is discharged. The noble gases in the spring showed apparent equilibration temperatures similar to the air temperature but lagged by about 13 h. With air temperature appearing to affect the solubility of the gases, and due to the size of the data population, conclusive results from the noble gases could not be determined