Functional outcome following direct repair or intervertebral fusion for adolescent spondylolysis : a systematic review

A systematic review of the literature was performed to establish whether direct repair of the pars defect or intervertebral fusion achieves better Oswestry Disability Index scores in adolescent spondylolysis or low-grade spondylolisthesis. Nine studies fulfilled the inclusion criteria, reporting a minimum total of 80 direct repairs and 108 fusions because of presumed replication of data between studies. Little statistically or clinically significant difference could be established between the two interventions. The only comparative study showed improved long-term outcome with fusion. Further well-designed prospective comparative studies are required to establish the optimum treatment for this condition

Analysis of Interphase Chromatin Motion in HeLa Cells

Motion of particles under influencing forces may be observed under light microscopy techniques. Variations in mobility of particles may give relevant biophysical information. Automated high resolution single particle tracking techniques were used to characterize interphase chromatin mobility in the cell nucleus. Interphase chromatin undergo replication prior to cell division with the assistance of replication proteins (machinery) which modify chromatin mobility. Using dual color imaging of flourescently tagged chromatin and proliferating cell nuclear antigen (PCNA) were followed through interphase. Chromatin motion was modelled as a two dimensional random walk. Reduction in chromatin mobility was observed during S phase was dependent on proximity to the replication machinery. Mobility during G1 and G2 phase is independent of proximity to GFP-PCNA maxima and is higher than during S phase. These results suggest that replication selectively inhibits chromatin mobility. Local proximity to replication machinery however, cannot account for the entire mobility difference. By modelling the mean square displacement as a power law, sub-diffusive behavior was observed in S phase chromatin whereas non S phase exhibited normal diffusional characteristics

can integration of pv within uk electricity network be improved a gis based assessment of storage

This paper analyses the potential of distributed storage to mitigate impacts of embedded PV generation on the distribution grid by improving local balance between generation and demand, thereby enabling higher levels of PV penetration. In particular it looks at the potential of storage to: 1. reduce impacts on power flows due to local supply and demand imbalances driven by PV deployment within the UK domestic and non-domestic markets; 2. of improving PV capacity credit, i.e. the contribution of installed PV to meeting electricity demand within the UK electricity system. Results highlight how, under current levels of deployment, PV generation does not create major problems for the local distribution network, but that storage might play a relevant role for higher levels of PV deployment across the UK. The paper contribute to academic debate in the field by providing a novel locally disaggregated framework for the analysis of embedded PV generation integration into the distribution grid. It also provides a useful tool for network operators, regulators and policy makers

Correction to: the role of the complement system in traumatic brain injury: a review

Abstract After publication of the article [1], it was brought to our attention that Tables 1 and 2 were missing from the final manuscript, These tables can be seen below and have now been added to the revised version of the article

La confianza interpersonal en el Per?: estudio psicosocial de campesinos y obreros

Presenta un resumen de dos estudios separados realizados por el autor acerca de la confianza interpersonal en el Per?. Uno de ellos examina las relaciones entre la confianza y las caracter?sticas objetivas del campesinado peruano, as? como las actitudes de este en relaci?n con la confianza. El segundo se ocupa de la confianza entre el personal de empleados y obreros de la industria automotriz peruana. Se inicia con una presentaci?n de trabajos anteriormente realizados sobre el tema, luego se desarrollan y ponen a prueba varias hip?tesis. La confianza se midi? haciendo uso de una escala de siete puntos y se encontr? su relaci?n con las caracter?sticas socioecon?micas y de actitud de los entrevistados. Entre los hallazgos principales se pueden mencionar: una mayor estratificaci?n significa mayor desconfianza, que tiende a ser mayor para los miembros de la ubicaci?n m?s baja dentro de la jerarqu?a; el poder, seg?n lo denotan la masculinidad, el alfabetismo, la educaci?n y la posici?n dentro de la organizaci?n, va en paralelo con una mayor confianza; las relaciones entre la confianza y las actitudes fueron m?s fuertes que las relaciones entre la confianza y las caracter?sticas objetivas; en el estudio acerca del personal industrial, la mayor confianza est? vinculada con distintas variables organizacionales, tales como posici?n, supervisi?n autoritaria, preferencia por el trabajo con otras personas, satisfacci?n en el empleo, y sentimientos de seguridad econ?mica; adem?s, la confianza est? relacionada con las personalidades m?s desarrolladas, es decir con personas que se consideran m?s capaces de afrontar con ?xito las realidades organizacionales

Taphonomic Bias of Selective Silicification Revealed by Paired Petrographic and Insoluble Residue Analysis

Silicification is an important mode of fossil preservation but the extent to which silicified material represents an unbiased sampling of the total fossil assemblage within a given rock sample remains poorly quantified. Here, we use paired analyses of thin sections and acid-extracted silicified specimens from the same samples to examine the biases introduced during silicification of Lower Triassic Virgin Limestone carbonates preserved in the Muddy Mountains of southern Nevada. Bivalves dominate most thin sections in the point count data, but rarely silicify completely enough to be recognized in residue. Echinoderms and gastropods are less abundant in thin section but dominate the residues. The abundances of these groups in thin section and residue are only weakly correlated. These findings suggest that although silicification generally captures relative trends in proportional abundance of higher taxa among samples, the silicification process can be taxonomically biased. Given the biases that can occur during silicification, it should not be assumed that silicified collections present a pristine picture of taxonomic or paleoecologic composition. Petrographic analysis has the potential to illuminate the reliability of paleontological data based on silicified collections

Understanding the structure/property/processing inter-relationships in organic semiconducting blends

Over the last few years organic semiconductors have seen a dramatic rise in interest from both academia and industry alike. This has been largely due to their promise of low-cost, high-throughput manufacture, combined with many other positive attributes including their: flexibility; semi-transparency and light-weight nature. This combination of factors show that organic semiconductors hold strong potential to compete with inorganic technologies in a number of existing and emerging applications. More specifically, blends comprised of a number organic semiconductors offer significant promise for devices such as organic photovoltaics (OPVs) and organic light emitting diodes (OLEDs), as tuning the chemical nature of the constituting materials can influence the blend’s optoelectronic properties. However, during processing, such as blending, complex mixture of phases are formed which renders understanding these systems challenging. This thesis examines the relationships between the three critical aspects that affect organic semiconducting blends, namely: the processing route selected, the resulting microstructure and, as a consequence, the induced optoelectronic properties. A more comprehensive understanding is developed of how the processing route (solution casting from common solvent vs. bilayer fabrication via lamination) can affect the structural formation processes in organic semiconductor systems, such as crystallisation, vitrification etc. Additionally, this thesis elucidates how the structural formation processes influence the mixture of phases that evolve and discusses how the microstructure that is created affects the photo-physical processes such as exciton quenching and charge generation, within these systems. The results within this thesis highlight the sensitive interplay between the three areas of structure, property and processing. Clear insights into how to manipulate these aspects to positively impact the photo-physical processes are conferred. The findings discussed here give, thus, clear guidelines as to how to further enhance understanding and terminally improve the performance of devices such as organic solar cells.Open Acces

Neuroimmune regulation of adult hippocampal neurogenesis by Complement Component 3 and Complement C3a Receptor

New neurons are added to the dentate gyrus of the hippocampus throughout adult life, through the process known as adult hippocampal neurogenesis (AHN). This important form of structural plasticity supports learning and memory in mammalian species. AHN is tightly regulated by a myriad of factors, including the immune system. Previous evidence suggests that signalling via Complement Component 3 (C3) and Complement C3a Receptor (C3aR) may regulate AHN under physiological conditions, although the mechanism of this putative regulation is unclear. In addition, C3a/C3aR signalling may regulate neuronal morphology. Using C3-/- and C3aR-/- mice, I used a combined in vitro and in vivo approach to investigate the role of C3/C3aR signalling in AHN. In Chapter 2, I demonstrate that C3a/C3aR signalling is able to directly influence hippocampal precursor cells in primary cultures. Furthermore, in the adult mouse brain, there is an increase in the number of immature neurons in the absence of C3 and C3aR, suggesting that C3a/C3aR signalling exerts an anti-neurogenic effect in the healthy brain. In Chapter 3 I report that the dendritic arborisation of newborn neurons is altered in the absence of C3aR, but not C3, suggesting involvement of an alternative ligand. Therefore, C3aR signalling via an as yet-unidentified ligand is important for maintaining the normal neuronal morphology of adult born neurons. Both the net levels of AHN and immature neuronal morphology have important functional consequences for cognitive and affective processes involving the hippocampus, which I investigate in Chapter 4. I report superior performance of C3-/- and C3aR-/- mice in a hippocampus-dependent spatial discrimination task, consistent with their elevated levels of AHN. Furthermore, C3a/C3aR deficiency was associated with abnormal anxiety phenotypes. In conclusion,these results demonstrate a novel mechanism for neuroimmune regulation of AHN, which is of functional consequence to learning, memory and affective behaviour

Direct gas-in-place measurements prove much higher production potential than expected for shale formations

Shale gas exploitation has been the game-changer in energy development of the past decade. However, the existing methods of estimating gas in place in deep formations suffer from large uncertainties. Here, we demonstrate, by using novel high-pressure experimental techniques, that the gas in place within deep shale gas reservoirs can be up to five times higher than that estimated by implementing industry standard approaches. We show that the error between our laboratory approach and the standard desorption test is higher for gases with heavier compositions, which are of strongest commercial interests. The proposed instrumentation is reliable for deep formations and, provides quick assessment of the potential for the gas in place, which could be useful for assessing hydrocarbon reservoirs, and the potential for geological carbon sequestration of a given formation