Increased concentrations of the oxidative DNA adduct 7, 8-dihydro-8-oxo-2-deoxyguanosine in the germ-line of men with type 1 diabetes

The effects of diabetes mellitus on male reproductive health have not been clearly defined. A previous publication from this group reported significantly higher levels of nuclear DNA fragmentation and mitochondrial DNA deletions in spermatozoa from men with type 1 diabetes. This study compared semen profiles, sperm DNA fragmentation and levels of oxidative DNA modification in spermatozoa of diabetic and non-diabetic men. Semen samples from 12 non-diabetic, fertile men and 11 type 1 diabetics were obtained and subjected to conventional light microscopic semen analysis. Nuclear DNA fragmentation was assessed using an alkaline Comet assay and concentrations of 7,8-dihydro-8-oxo-2-deoxyguanosine (8-OHdG), an oxidative adduct of the purine guanosine, were assessed by high-performance liquid chromatography. Conventional semen profiles were similar in both groups, whilst spermatozoa from type 1 diabetics showed significantly higher levels of DNA fragmentation (44% versus 27%; P < 0.05) and concentrations of 8-OHdG (3.6 versus 2.0 molecules of 8-OHdG per 105 molecules of deoxyguanosine; P < 0.05). Furthermore, a positive correlation was observed between DNA fragmentation and concentrations of 8-OHdG per 105 molecules of deoxyguanosine (rs = 0.7, P < 0.05). The genomic damage evident in spermatozoa of type 1 diabetics may have important implications for their fertility and the outcome of pregnancies fathered by these individuals.

Exploring figures of merit associated with the suboptimum operation of class-E power amplifiers

Closed-form design equations for the operation of a class-E amplifier for zero switch voltage slope and arbitrary duty cycle are derived. This approach allows an additional degree of freedom in the design of class-E amplifiers which are normally designed for 50 duty ratio. The analysis developed permits the selection of non-unique solutions where amplifier efficiency is theoretically 100 but power output capability is less than that the 50 duty ratio case would permit. To facilitate comparison between 50 (optimal) and non-50 (suboptimal) duty ratio cases, each important amplifier parameter is normalised to its corresponding optimum operation value. It is shown that by choosing a non-50 suboptimal solution, the operating frequency of a class-E amplifier can be extended. In addition, it is shown that by operating the amplifier in the suboptimal regime, other amplifier parameters, for example, transistor output capacitance or peak switch voltage, can be included along with the standard specification criteria of output power, DC supply voltage and operating frequency as additional input design specifications. Suboptimum class-E operation may have potential advantages for monolithic microwave integrated circuit realisation as lower inductance values (lower series resistance, higher self-resonance frequency, less area) may be required when compared with the results obtained for optimal class-E amplifier synthesis. The theoretical analysis conducted here was verified by harmonic balance simulation, with excellent agreement between both methods. © The Institution of Engineering and Technology 2007.

Development and validation of an HPLC method for the rapid and simultaneous determination of 6-mercaptopurine and four of its metabolites in plasma and red blood cells

An HPLC method has been developed and validated for the rapid determination of mercaptopurine and four of its metabolites; thioguanine, thiouric acid, thioxanthine and methylmercaptopurine in plasma and red blood cells. The method involves a simple treatment procedure based on deproteinisation by perchloric acid followed by acid hydrolysis and heating for 45 min at 100 degrees C. The developed method was linear over the concentration range studied with a correlation coefficient >0.994 for all compounds in both plasma and erythrocytes. The lower limits of quantification were 13, 14, 3, 2, 95 pmol/8 x 101 RBCs and 2, 5, 2, 3, 20 ng/ml plasma for thioguanine, thiouric acid, mercaptopurine, thioxanthine and methylmercaptopurine, respectively. The method described is selective and sensitive enough to analyse the different metabolites in a single run under isocratic conditions. Furthermore, it has been shown to be applicable for monitoring these metabolites in paediatric patients due to the low volume requirement (200 mu l of plasma or erythrocytes) and has been successfully applied for investigating population pharmacokinetics, pharmacogenetics and non-adherence to therapy in these patients. (C) 2008 Elsevier B.V. All rights reserved.

Influence of maternal diabetes mellitus on fetal iron status

OBJECTIVE: To determine the effects of maternal diabetes on fetal iron status using serum transferrin receptors (STfR) and their ratio to ferritin (TfR-F index) in cord blood. METHODS: Iron, ferritin, erythropoietin, STfR and haemoglobin concentration were measured and TfR-F index calculated in 97 maternal/cord blood pairs. Forty-nine women had type 1 diabetes (diagnosed before pregnancy) and these were compared with forty-eight non- diabetic controls. The women with type 1 diabetes were recruited consecutively from attendance at the joint antenatal endocrine clinic while the control group of women was recruited from consecutive attendance at the remaining antenatal clinics. RESULTS: The infants of the diabetic women had significantly lower levels of ferritin (47 vs 169 mug/l; p

Reflecting the Public Value of Sport: A game of two halves

This article draws on qualitative research that explores the concept of public value in the delivery of sport services by the organization Sport England. The research took place against a backdrop of shifting priorities following the award of the 2012 Olympic Games to London. It highlights the difficulties that exist in measuring the qualitative nature of the public value of sport and suggests there is a need to understand better the idea. Research with organizations involved alongside Sport England in the delivery of sport is described. This explores the potential to create a public value vision, how to measure it and how to focus public value on delivery beyond the aim of ‘sport for sports sake’ and more towards ‘sport for the greater good’. The article argues that this represents a game of ‘two halves’ in which the first half focuses on 2012 with the second half concerned with its legacy.

Mineralogy of selected geological deposits from the United Kingdom and the Republic of Ireland as possible capping materials for low-level radioactive waste disposal facilities

Solid low-level radioactive waste (LLW) is currently being disposed at a number of facilities in the United Kingdom (UK). The safety of these facilities relies to some extent on the use of engineered barriers, such as a cap, to isolate the waste and protect the environment. Generally, the material used as the barrier layer within such a cap should be of low permeability and it should retain this property over long timescales (beyond a few decades normally required for facilities containing non-radioactive wastes). The objective of this research is to determine the mineralogy of selected geological deposits from the UK and Ireland as part of a larger project to examine their suitability as a capping material, particularly on LLW sites. Mineral transformations, as a result of future climate change, may impact on the long-term performance of the cap and even the disposal facility. X-ray diffraction (XRD) was carried-out on the sand, silt and clay fractions of the London Clay, Belfast Upper Boulder Clay, Irish Glacial Till, Belfast Sleech, and Ampthill Clay geological deposits. Minerals were present that could pose both positive and negative effects on the long-term performance of the cap. Smectite, which has a high shrink swell potential, may produce cracks in London Clay, Belfast Upper Boulder Clay and Ampthill Clay capping material during dry, hotter periods as a possible consequence of future climate change; thus, resulting in higher permeability. Ampthill Clay and Belfast Sleech had elevated amounts of organic matter (OM) at 5.93% and 5.88%, respectively, which may also contribute to cracking. Over time, this OM may decompose and result in increased permeability. Gypsum (CaSO4) in the silt and sand fractions of Ampthill Clay may reduce the impact of erosion during wetter periods if it is incorporated into the upper portion of the cap. There are potential negative effects from the acidity created by the weathering of pyrite (FeS2) present in the silt and sand fractions of Belfast Sleech and Ampthill Clay that could impede the growth of grasses used to stabilize the surface of the capping material if this material is used as part of the vegetative soil layer. Additionally, acidic waters generated from pyrite weathering could negatively impact the lower lying capping layers and the disposal facility in general. However, the calcium carbonate (CaCO3) present in the silt and sand fractions of these deposits, and dolomite (CaMg(CO3)2) in Belfast Sleech, may counter act the acidity.

"Bobok" y "Pedro Páramo", dos narraciones sobre muertos

El presente estudio realiza un análisis comparativo entre la novela del mexicano Juan Rulfo, Pedro Páramo (1955), y un cuento del escritor ruso Dostoievski que trata también el tema del Más allá, titulado Bobok (1873). Paralelamente, se trabaja con la posibilidad de que el relato ruso hubiese podido ser una más de las fuentes literarias de la novela mexicana, y se trata de determinar las posibles conexiones -directas o indirectas- entre las dos obras. Ambas son puestas en común por su género literario, y a partir de ahí se estudian los elementos constitutivos que tienen en común, sus afinidades y divergencias más llamativas.

Vegetation and climate c. 12 300-9000 cal. yr BP at Andoya, NW Norway

Owing to proximity of the North Atlantic Stream and the shelf, the And circle divide ya biota are assumed to have responded rapidly to climatic changes taking place after the Weichselian glaciation. Palynological, macrofossil, loss-on-ignition, tephra and C-14 data from three sites at the northern part of the island of And circle divide ya were studied. The period 12 300-11 950 cal. yr BP was characterized by polar desert vegetation, and 11 950-11 050 cal. yr BP by a moisture-demanding predominantly low-arctic Oxyria vegetation. During the period 11 050-10 650 cal. yr BP, there was a climatic amelioration towards a sub-arctic climate and heaths dominated by Empetrum. After 10 650 cal. yr BP the Oxyria vegetation disappeared. As early as about 10 800 cal. yr BP the bryozoan Cristatella mucedo indicated a climate sufficient for Betula woodland. However, tree birch did not establish until 10 420-10 250 cal. yr BP, indicating a time-lag for the formation of Betula ecotypes adapted to the oceanic climate of And circle divide ya. From about 10 150 to 9400 cal. yr BP the summers were dry and warm. There was a change towards moister, though comparatively warm, climatic conditions about 9400 cal. yr BP. The present data are compared with evidence from marine sediments and the deglaciation history in the region. It is suggested that during most of the period 11 500-10 250 cal. yr BP a similar situation as in present southern Greenland existed, with birch woodland in the inner fjords near the ice sheet and low-arctic heath vegetation along the outer coast.

Towards Educational Inclusion in a Contested Society: From Critical Reflection to Cultural Action

This paper is written by democratic educators who stand for the idea that is it worth developing, through classrooms and schools, a socially just (egalitarian), anti-discriminatory society where interdependent relationships are valued. This paper significantly develops some of the ideas explored in the authors’ earlier contribution concerned with progress in Northern Ireland towards educational inclusion, and how this might more effectively advance in a post-conflict transforming society. In particular, the paper poses the ‘so what’ question, and it responds by exploring the practical implications of six key ideas thought essential for transforming learning environments supportive of cultural diversity, equity and excellence for all. In addition, it includes examples of how school staff, along with collaborating partners, might utilize these key principles in order to facilitate school improvement.

Mass transfer correlation in flotation of palm oil by colloidal gas aphrons

Colloidal gas aphrons (CGAs) are micron-sized bubbles, which are produced by stirring a dilute surfactant solution at a high speed. In this work, CGAs have been used to clarify oily wastewater by flotation technique. The CGAs sparging rate was a critical factor that governed the efficiency of the process. A model for the determination of the mass transfer coefficient is also developed for the purpose of process design.