Development and AFM study of porous scaffolds for wound healing applications

An engineering approach to the development of biomaterials for promotion of wound healing emphasises the importance of a well-controlled architecture and concentrates on optimisation of morphology and surface chemistry to stimulate guidance of the cells within the wound environment. A series of three-dimensional porous scaffolds with 80–90% bulk porosity and fully interconnected macropores were prepared from two biodegradable materials – cellulose acetate (CA) and poly (lacticco-glycolic acid) (PLGA) through the phase inversion mechanism of formation. Surface morphology of obtained scaffolds was determined using atomic force microscopy (AFM) in conjunction with optical microscopy. Scanning Electron Microscopy (SEM) was applied to characterise scaffolds bulk morphology. Biocompatibility and biofunctionality of the prepared materials were assessed through a systematic study of cell/material interactions using atomic force microscopy (AFM) methodologies together with in vitro cellular assays. Preliminary data with human fibroblasts demonstrated a positive influence of both scaffolds on cellular attachment and growth. The adhesion of cells on both biomaterials were quantified by AFM force measurements in conjunction with a cell probe technique since, for the first time, a fibroblast probe has been successfully developed and optimal conditions of immobilisation of the cells on the AFM cantilever have been experimentally determined

Southampton no.1 (Western Esplanade) geothermal well: geological well completion report

Southampton No 1 (Western Esplanade) was drilled as a geothermal development well, on behalf of the Department of Energy in association with Southampton City Council, following the successful testing of Marchwood No 1 Borehole and studies of the geothermal potential of the Wessex Basin area by the Institute of Geological Sciences. The site was selected near Southampton city centre, with the aim of providing space heating for the proposed Western Esplanade development area. The nearby Marchwood No 1 Borehole is situated 1.8 km to the south-west, and the south-east part of NERC 81-1 seismic line is adjacent to the site (Figure 1.2). Southampton No 1 is situated in an -area of negative gravity anomaly as indicated on the regional Bouguer anomaly map (Figure 1.4)

Distribution and rate of spread of scentless chamomile on the Black and Gray soils in Saskatchewan

Non-Peer ReviewedIn 1987 a questionnaire survey was conducted to determine the distribution of the noxious weed scentless chamomile on the Black and Gray soils of Saskatchewan. As well information was obtained on the year of first sighting, habitats affected, farmers' perception of the problem, the percentage of their land affected, and methods used to control or manage the weed. A total of 29,666 questionnaires were distributed, of which 2120 (7.1 %) usable responses were returned. Of these, 35.6 % indicated that scentless chamomile occurred on land they farmed or on adjacent roadsides. In the group which reported occurrence the most common habitat, reported by 69.5 %, was the roadside. Annual crops were reported as scentless chamomile habitats by 30.0 % and wet areas of fields, which can sometimes be cropped, by 39.0 %. The most common methods reported for control of the weed were tillage, hand-weeding and herbicide use. Of the 214 farmers who indicated herbicide use, 26.2 % used herbicides containing bromoxynil, 16.4 % used herbicides containing dicamba and 15.4 % used glyphosate. Spread of the weed has increased rapidly in the last 20 years. Of the responses to year of first sighting 19.0 % were between 1968 and 1977, and 69.0 % reported first sighting the weed within the last decade

An investigation of the relationship between BOLD and perfusion signal changes during epileptic generalised spike wave activity

In pathological conditions interpretation of functional magnetic resonance imaging (fMRI) results can be difficult. This is due to a reliance on the assumed coupling between neuronal activity and changes in cerebral blood flow (CBF) and oxygenation. We wanted to investigate the coupling between blood oxygen level dependant contrast (BOLD) and CBF time courses in epilepsy patients with generalised spike wave activity (GSW) to better understand the underlying mechanisms behind the EEG-fMRI signal changes observed, especially in regions of negative BOLD response (NBR). Four patients with frequent GSW were scanned with simultaneous electroencephalographic (EEG)-fMRI with BOLD and arterial spin labeling (ASL) sequences. We examined the relationship between simultaneous CBF and BOLD measurements by looking at the correlation of the two signals in terms of percentage signal change on a voxel-by-voxel basis. This method is not reliant on coincident activation. BOLD and CBF were positively correlated in patients with epilepsy during background EEG activity and GSW. The subject average value of the ΔCBF/ΔBOLD slope lay between +19 and +36 and also showed spatial variation which could indicate areas with altered vascular response. There was not a significant difference between ΔCBF/ΔBOLD during GSW, suggesting that neurovascular coupling to BOLD signal is generally maintained between states and, in particular, within areas of NBR

Researching ecosystems in innovation contexts

Purpose – The rapid adoption of the ecosystem concept in innovation contexts has led to a proliferation of differing uses. Scholars need to be crystal clear which concept of the ecosystem they are using to facilitate communication between scholars and allow for cumulativeness and creativity. This paper aims to introduce some clarity into the conceptual mist that surrounds the notion of “ecosystems” in innovation contexts. Design/methodology/approach – A review of the extant literature on ecosystems in innovation contexts to derive an integrated approach to understanding the variety of constructs in use. Findings – This paper introduces clarity into the conceptual mist that surrounds the term “innovation ecosystem”, showing there are three basic types of ecosystems, all of which have a common focus on the collective production of a coherent system-level output. Originality/value – Contributes through a comprehensive overview of the differing ecosystem types in innovation contexts and with a heuristic to disambiguate types of innovation ecosys tems

Geochemical-geophysical investigations, Fairbanks district

Trace element distribution in a subarctic valley in the Cleary Hill area of the Fairbanks gold district has been studied. Zinc and arsenic have been found excellent pathfinder elements for auriferous deposits. Methods of analysis for copper, lead, zinc, molybdenum, silver and arsenic as well as heavy metals are discussed. The University of Alaska method #2 has been improved, Terrain, slope, and frozen ground have little effect upon the distribution of trace elements associated with the Cleary H i l l vein. A new method for the determination of zinc using dilute acid is proposed. Analysis of geochemical data by trend surface procedures proved effective for localization of anomalies

Digital innovation: transforming research and practice

There is no doubt that digital technologies are spawning ongoing innovation across most if not all sectors of the economy and society. In this essay, we take stock of the characteristics of digital technologies that give rise to this new reality and introduce the papers in this special issue. In addition, we also highlight the unprecedent opportunities that digital innovation provides to study innovation processes more generally. Overall, we conclude that the speed, observability, and relative ease in investigating relationships between multiple analytical levels, mean that digital innovation is both a ‘model of’ that also provides a ‘model for’ the study of innovation processes more broadly in non-digital and hybrid contexts

A comparison of post-saccadic oscillations in European-Born and China-Born British University Undergraduates

Previous research has revealed that people from different genetic, racial, biological, and/or cultural backgrounds may display fundamental differences in eye-tracking behavior. These differences may have a cognitive origin or they may be at a lower level within the neurophysiology of the oculomotor network, or they may be related to environment factors. In this paper we investigated one of the physiological aspects of eye movements known as post-saccadic oscillations and we show that this type of eye movement is very different between two different populations. We compared the post-saccadic oscillations recorded by a video-based eye tracker between two groups of participants: European-born and Chinese-born British students. We recorded eye movements from a group of 42 Caucasians defined as White British or White Europeans and 52 Chinese-born participants all with ages ranging from 18 to 36 during a prosaccade task. The post-saccadic oscillations were extracted from the gaze data which was compared between the two groups in terms of their first overshoot and undershoot. The results revealed that the shape of the post-saccadic oscillations varied significantly between the two groups which may indicate a difference in a multitude of genetic, cultural, physiologic, anatomical or environmental factors. We further show that the differences in the post-saccadic oscillations could influence the oculomotor characteristics such as saccade duration. We conclude that genetic, racial, biological, and/or cultural differences can affect the morphology of the eye movement data recorded and should be considered when studying eye movements and oculomotor fixation and saccadic behaviors

Analytical study of non Gaussian fluctuations in a stochastic scheme of autocatalytic reactions

A stochastic model of autocatalytic chemical reactions is studied both numerically and analytically. The van Kampen perturbative scheme is implemented, beyond the second order approximation, so to capture the non Gaussianity traits as displayed by the simulations. The method is targeted to the characterization of the third moments of the distribution of fluctuations, originating from a system of four populations in mutual interaction. The theory predictions agree well with the simulations, pointing to the validity of the van Kampen expansion beyond the conventional Gaussian solution.Comment: 15 pages, 8 figures, submitted to Phys. Rev.