Optically-controlled platforms for transfection and single- and sub-cellular surgery

Improving the resolution of biological research to the single- or sub-cellular level is of critical importance in a wide variety of processes and disease conditions. Most obvious are those linked to aging and cancer, many of which are dependent upon stochastic processes where individual, unpredictable failures or mutations in individual cells can lead to serious downstream conditions across the whole organism. The traditional tools of biochemistry struggle to observe such processes: the vast majority are based upon ensemble approaches analysing the properties of bulk populations, which means that the detail about individual constituents is lost. What are required, then, are tools with the precision and resolution to probe and dissect cells at the single-micron scale: the scale of the individual organelles and structures that control their function. In this review, we highlight the use of highly-focused laser beams to create systems providing precise control and specificity at the single cell or even single micron level. The intense focal points generated can directly interact with cells and cell membranes, which in conjunction with related modalities such as optical trapping provide a broad platform for the development of single and sub-cellular surgery approaches. These highly tuneable tools have demonstrated delivery or removal of material from cells of interest, but can simultaneously excite fluorescent probes for imaging purposes or plasmonic structures for very local heating. We discuss both the history and recent applications of the field, highlighting the key findings and developments over the last 40 years of biophotonics researc

National and Regional Estimates of the Prevalence of Opiate and/or Crack Cocaine use 2008-09: A summary of key findings

<p>This report summarises the results of a follow-up study to a three year project to estimate the prevalence of ‘problem drug use’ (defined as use of opiates and/or crack cocaine) nationally (England only), regionally and locally. The follow-up was carried out two years after the final sweep of the original project, so could therefore be considered as ‘sweep 5’. An overview of the national and regional estimates are presented in this report, as are comparisons with the estimates produced by the third (2006-07) sweep of the study. Estimates for 2007-08 are not available as a study was not commissioned for that year.</p> <p>Information about the number of people who use illicit drugs such as heroin, other opiates or crack cocaine is key to formulating effective policies for tackling drug-related harm as these drugs are associated with the highest levels of harm. It also helps inform service provision at the local level and provides a context in which to understand the population impact of interventions to reduce drug-related harm.</p> <p>Direct enumeration of those engaged in a largely covert activity such as the use of class A drugs is difficult and standard household survey techniques tend to underestimate the extent of such activity. Indirect techniques making use of various data sources offer a more reliable way of calculating prevalence estimates for the use of opiates and/or crack cocaine. The estimates presented in this report are derived using two indirect measurement techniques: the capture-recapture method (CRC ); and the multiple indicator (MIM ) method. These methods are described in detail in Hay et al., 2006 and Hay et al., 2007a. Methodological developments throughout the course of the previous three sweeps are discussed elsewhere (Hay et al., 2007b, Hay et al., 2008). The individuals covered by this study were people aged 15 to 64 and resident in each DAT area, and known to be using heroin, methadone, other opiate drugs or crack cocaine.</p&gt

Current and Future Issues in the Development of Spinal Agents for the Management of Pain.

Targeting analgesic drugs for spinal delivery reflects the fact that while the conscious experience of pain is mediated supraspinally, input initiated by high intensity stimuli, tissue injury and/or nerve injury is encoded at the level of the spinal dorsal horn and this output informs the brain as to the peripheral environment. This encoding process is subject to strong upregulation resulting in hyperesthetic states and downregulation reducing the ongoing processing of nociceptive stimuli reversing the hyperesthesia and pain processing. The present review addresses the biology of spinal nociceptive processing as relevant to the effects of intrathecally-delivered drugs in altering pain processing following acute stimulation, tissue inflammation/injury and nerve injury. The review covers i) the major classes of spinal agents currently employed as intrathecal analgesics (opioid agonists, alpha 2 agonists; sodium channel blockers; calcium channel blockers; NMDA blockers; GABA A/B agonists; COX inhibitors; ii) ongoing developments in the pharmacology of spinal therapeutics focusing on less studied agents/targets (cholinesterase inhibition; Adenosine agonists; iii) novel intrathecal targeting methodologies including gene-based approaches (viral vectors, plasmids, interfering RNAs); antisense, and toxins (botulinum toxins; resniferatoxin, substance P Saporin); and iv) issues relevant to intrathecal drug delivery (neuraxial drug distribution), infusate delivery profile, drug dosing, formulation and principals involved in the preclinical evaluation of intrathecal drug safety

Airborne Hydrographic Surveying in the Canadian Arctic

In August 1985 Canadian Hydrographers broke new ground by being the first to use airborne laser scanning techniques to locate and survey shipping channels through parts of the Southern Route of the Northwest Passage. This survey was a landmark event in hydrographic surveying as it signaled the first time that an active airborne sensor was used for chartmaking purposes. Laser soundings were acquired in two of the highest priority areas and the processed results are being used in the compilation of a new nautical chart in the area. In 1986 the airborne team returned to this area to continue the sweep through the entire Southern Route

Academic performance & student engagement in level 1 physics undergraduates

At the beginning of academic year 2007-08, staff in the Department of Physics & Astronomy at the University of Glasgow started to implement a number of substantial changes to the administration of the level 1 physics undergraduate class. The main aims were to improve the academic performance and progression statistics. With this in mind, a comprehensive system of learning support was introduced, the main remit being the provision of an improved personal contact and academic monitoring and support strategy for all students at level 1. The effects of low engagement with compulsory continuous assessment components had already been observed to have a significant effect for students sitting in the middle of the grade curve. Analysis of data from the 2007-08 class showed that even some nominally high-achieving students achieved lowered grades due to the effects of low engagement. Nonetheless, academic and other support measures put in place during 2007-08 played a part in raising the passrate for the level 1 physics class by approximately 8% as well as raising the progression rate by approximately 10%.Comment: 12 pages, 3 figure

Contours and Contouring in Hydrography Part II - Interpolation

In Part I of this series, the authors discussed those issues which we feel are fundamentally important and which must be addressed by any method which aims to mechanize the drawing of depth contours for hydrographic charts. In this article we begin the discussion of the How of contouring. In particular, we concentrate on some of the most common methods used in the interpolation of the synthetic surface upon which computed contours will lie

Impacts of Forage Cropping Decisions on Feed-Flows in Cool- Temperate Grazing Systems

Intensive cool-temperate grasslands often rely on adding forage crops to help supply feed when pasture growth is limited by cool temperatures and low sunlight. We tested the impacts of using single- or multi-graze crops to alter feed supply in either summer/autumn or winter on productivity in red deer farming systems in a cool-temperate environment. The choice of single-graze or multi-graze crops to provide forage in deer grazing systems had an impact on the feed flows and the amount of pasture available, with multi-graze crops supplying more feed during the dry summer months while single-graze crops supplying more feed during the cool winter months. The limited growth rates of young red deer, and the late calving of hinds meant that pasture covers could be low during the late winter and early spring without compromising animal production. Overall, the use of a multi-graze crop, especially when used early in autumn to promote weaner liveweight gain, increased overall productivity by 5% and increased feed conversion efficiency by 2.5% in the venison production system