Ion exchange chromatography – basic principles and application

Ion-Exchange Chromatography (IEC) allows for the separation of ionizable molecules on the basis of differences in charge properties. Its large sample-handling capacity, broad applicability (particularly to proteins and enzymes), moderate cost, powerful resolving ability, and ease of scale-up and automation have led to it becoming one of the most versatile and widely used of all liquid chromatography (LC) techniques. In this chapter, we review the basic principles of IEC, as well as the broader criteria for selecting IEC conditions. By way of further illustration, we outline protocols necessary to partially purify a serine peptidase from bovine whole brain cytosolic fraction, covering crude tissue extract preparation through to partial purification of the target enzyme using anion-exchange chromatography. Protocols for assaying total protein and enzyme activity in both pre- and post-IEC fractions are also described. The target serine peptidase, prolyl oligopeptidase (POP, EC3.4.21.26), is an 80 kDa enzyme with endopeptidase activity towards peptide substrates of ≤30 amino acids. POP is a ubiquitous post-proline cleaving enzyme with particularly high expression levels in the mammalian brain, where it participates in the metabolism of neuroactive peptides and peptide-like hormones (e.g. thyroliberin, gonadotropin-releasing hormone)

Some Economic Implications of a Federal Ireland. ESRI Memorandum Series No. 97 1974

Economists are frequently accused of building elaborate structures out of the most unlikely set of hypotheses. One cannot help suspecting that this charge will be levelled against this paper which makes no attempt to assess the political probability of any agreement on a Federal relationship between Northern Ireland and the Republic. In defense it can be argued that the object of this paper is to examine some of the economic issues that would arise under a federal arrangement while recognising that economic factors are unlikely to be the sole, or dominant, influences in the future political position of Northern Ireland. It would not, of course, be possible to explore every aspect of the economic consequences of a Federal Ireland even under the assumption that the structure of the economy of Northern Ireland and the Republic remains as it is today. Rather we shall have to be content to examine some of the major problems that would face any proposed federation. Thus, to some extent, the bias of this paper will be pessimistic since it will not concentrate on any credit side of the balance sheet. However it must be stated that most of the benefits, if they exist, flow from the assumed dynamic effects of federation; which effects seem to owe more to wishful thinking than an analysis of the present structure of both economies

Seasonality and Unemployment in Ireland. Quarterly Economic Commentary, October 1975

It is widely known that many statistical series exhibit a distinct seasonal pattern. That is, they tend to rise or fall according to the time of the year even when the underlying levels of the series are constant. Such seasonal movements are often a reflection of variations in the climate-ice-cream sales peak in the summer and coal-sales peak in the winter-or of traditional holiday periods. Obviously we would wish to remove the seasonal variation in order to examine the underlying trend of any given economic' series. If we do not correct data for seasonality it becomes quite difficult to distinguish between movements which reflect the normal seasonal pattern and other underlying movements

Motivations and Implications of Corporate Tax Inversion

The phenomenon of tax inversion has returned to the public eye as American companies in every sector explore expatriation as a means to avoid the highest corporate tax rate in the developed world. In response to billions of dollars in tax revenue flowing overseas, legislators have proposed dozens of laws over the past four decades aimed at curbing this technique, but to no avail. In 2015 alone, tens of billions of dollars\u27 worth of tax inversion transactions were announced. This thesis analyzes the motivations behind corporate emigration using both legal and economic framework, and models this behavior using Probit analysis. We conclude that run rate tax differentials, rather than the distinction between worldwide and territorial systems, motivate corporate inversion. We suggest that a tax holiday would limit the short-term benefits of expatriation and provide time for a new administration to work with Congress to enact a competitive reduction in the corporate income tax rate

Contingent Fee Litigation in New York City

Since 1957, New York courts have required contingent fee lawyers to file closing statements that disclose settlement amounts, lawyers\u27 fees, an accounting of expenses, and other information. This Article provides a preliminary analysis of these data for the period 2004- 2013. Among this Article\u27s findings are that settlement rates in New York state courts are very high (84%) relative to previous studies; that very few cases are resolved by dispositive motions; that litigated cases and settled cases have almost exactly the same average recovery; that median litigation expenses, other than attorney\u27s fees, are 3% of gross recovery; that claims are disproportionately from poor neighborhoods; and that attorneys\u27 fees are almost always one-third of net recovery, which is the maximum allowed by law

Waterford Institute of Technology: Authorship and Data Retention Policy

This document outlines the policies relating to authorship of research papers and other scholarly artefacts and the retention of any data used in their creation

Endovascular Thrombectomy for Ischemic Stroke Increases Disability-Free Survival, Quality of Life, and Life Expectancy and Reduces Cost

Background: Endovascular thrombectomy improves functional outcome in large vessel occlusion ischemic stroke. We examined disability, quality of life, survival and acute care costs in the EXTEND-IA trial, which used CT-perfusion imaging selection. Methods: Large vessel ischemic stroke patients with favorable CT-perfusion were randomized to endovascular thrombectomy after alteplase versus alteplase-only. Clinical outcome was prospectively measured using 90-day modified Rankin scale (mRS). Individual patient expected survival and net difference in Disability/Quality-adjusted life years (DALY/QALY) up to 15 years from stroke were modeled using age, sex, 90-day mRS, and utility scores. Level of care within the first 90 days was prospectively measured and used to estimate procedure and inpatient care costs (US$reference year 2014). Results: There were 70 patients, 35 in each arm, mean age 69, median NIHSS 15 (IQR 12-19). The median (IQR) disability-weighted utility score at 90 days was 0.65 (0.00-0.91) in the alteplase-only versus 0.91 (0.65-1.00) in the endovascular group (p = 0.005). Modeled life expectancy was greater in the endovascular versus alteplaseonly group (median 15.6 versus 11.2 years, p = 0.02). The endovascular thrombectomy group had fewer simulated DALYs lost over 15 years [median (IQR) 5.5 (3.2-8.7) versus 8.9 (4.7-13.8), p = 0.02] and more QALY gained [median (IQR) 9.3 (4.2-13.1) versus 4.9 (0.3-8.5), p = 0.03]. Endovascular patients spent less time in hospital [median (IQR) 5 (3-11) days versus 8 (5-14) days, p = 0.04] and rehabilitation [median (IQR) 0 (0-28) versus 27 (0-65) days, p = 0.03]. The estimated inpatient costs in the first 90 days were less in the thrombectomy group (average US$15,689 versus US$30,569, p = 0.008) offsetting the costs of interhospital transport and the thrombectomy procedure (average US$10,515). The average saving per patient treated with thrombectomy was US$4,365. c Conclusion: Thrombectomy patients with large vessel occlusion and salvageable tissue on CT-perfusion had reduced length of stay and overall costs to 90 days. There was evidence of clinically relevant improvement in long-term survival and quality of life.Peer reviewe

Association between alcohol and cardiovascular disease: Mendelian randomisation analysis based on individual participant data.

OBJECTIVE: To use the rs1229984 variant in the alcohol dehydrogenase 1B gene (ADH1B) as an instrument to investigate the causal role of alcohol in cardiovascular disease. DESIGN: Mendelian randomisation meta-analysis of 56 epidemiological studies. PARTICIPANTS: 261 991 individuals of European descent, including 20 259 coronary heart disease cases and 10 164 stroke events. Data were available on ADH1B rs1229984 variant, alcohol phenotypes, and cardiovascular biomarkers. MAIN OUTCOME MEASURES: Odds ratio for coronary heart disease and stroke associated with the ADH1B variant in all individuals and by categories of alcohol consumption. RESULTS: Carriers of the A-allele of ADH1B rs1229984 consumed 17.2% fewer units of alcohol per week (95% confidence interval 15.6% to 18.9%), had a lower prevalence of binge drinking (odds ratio 0.78 (95% CI 0.73 to 0.84)), and had higher abstention (odds ratio 1.27 (1.21 to 1.34)) than non-carriers. Rs1229984 A-allele carriers had lower systolic blood pressure (-0.88 (-1.19 to -0.56) mm Hg), interleukin-6 levels (-5.2% (-7.8 to -2.4%)), waist circumference (-0.3 (-0.6 to -0.1) cm), and body mass index (-0.17 (-0.24 to -0.10) kg/m(2)). Rs1229984 A-allele carriers had lower odds of coronary heart disease (odds ratio 0.90 (0.84 to 0.96)). The protective association of the ADH1B rs1229984 A-allele variant remained the same across all categories of alcohol consumption (P=0.83 for heterogeneity). Although no association of rs1229984 was identified with the combined subtypes of stroke, carriers of the A-allele had lower odds of ischaemic stroke (odds ratio 0.83 (0.72 to 0.95)). CONCLUSIONS: Individuals with a genetic variant associated with non-drinking and lower alcohol consumption had a more favourable cardiovascular profile and a reduced risk of coronary heart disease than those without the genetic variant. This suggests that reduction of alcohol consumption, even for light to moderate drinkers, is beneficial for cardiovascular health

AI is a viable alternative to high throughput screening: a 318-target study

: High throughput screening (HTS) is routinely used to identify bioactive small molecules. This requires physical compounds, which limits coverage of accessible chemical space. Computational approaches combined with vast on-demand chemical libraries can access far greater chemical space, provided that the predictive accuracy is sufficient to identify useful molecules. Through the largest and most diverse virtual HTS campaign reported to date, comprising 318 individual projects, we demonstrate that our AtomNet® convolutional neural network successfully finds novel hits across every major therapeutic area and protein class. We address historical limitations of computational screening by demonstrating success for target proteins without known binders, high-quality X-ray crystal structures, or manual cherry-picking of compounds. We show that the molecules selected by the AtomNet® model are novel drug-like scaffolds rather than minor modifications to known bioactive compounds. Our empirical results suggest that computational methods can substantially replace HTS as the first step of small-molecule drug discovery