Biophysical, biochemical and structural characterization of Poly(ADP-ribose) Polymerase-1 (PARP-1) and its complexes with DNA-damage models and chromatin substrates, The

2013 Spring.Includes bibliographical references.Eukaryotic DNA is highly dynamic and must be compacted and organized with the help of cellular machines, proteins, into 'heterochromatin' state. At its basic level, chromatin is comprised of spool-like structures of protein complexes termed histones, which bind and organize DNA into larger fibrous structures. Cellular processes like transcription and DNA-damage repair require that chromatin be at least partially stripped of its protein components, which in turn allows for complete accessibility by DNA-repair or transcription machinery. A number of protein factors contribute to chromatin structure regulation. Poly(ADP-ribose) Polymerase-1 (PARP-1) is one of these proteins that exists in all eukaryotic organisms except for yeast. In its inactive form, it compacts chromatin, but performs its chromatin-opening function by covalently modifying itself and other nuclear proteins with long polymers of ADP-ribose in response to DNA damage. Thus, it also serves as a first responder to many types of DNA damage. The highly anionic polymers serve to disrupt protein-DNA interactions and thus allow for the creation of a temporary euchromatin structure. Contained herein are investigations aimed at addressing key questions regarding key differences between the interactions of PARP-1 and chromatin and its DNA-damage substrates. Our experiments show that human PARP-1 interacts with and is enzymatically activated to a similar level by a variety of different DNA substrates. In terms of chromatin, it appears that PARP-1 fails to interact with nucleosomes that do not have linker DNA. PARP-1 most effectively interacts with chromatin by simultaneously binding two DNA strands through contacts made by its two N-terminal Zn-finger domains. Small-Angle X-ray (SAXS) and Neutron Scattering (SANS) and molecular dynamics (MD) experiments were combined with biophysical and biochemical studies to better describe the structural effects of DNA binding on PARP-1. The average solution structure of PARP-1 indicates that the enzyme is a monomeric, non-spherical, elongated molecule with a radius of gyration (Rg) of ~55Å. The DNA-bound form of PARP-1 is also monomeric and binding DNA causes the molecule to become more elongated with an average Rg of ~80Å

Manufacturing Matters: A Case Study of Alabama

Over the last fifty years, the United States has been marked by two important secular trends. One is a continuous increase in income inequality. Second, the nation has transitioned through three periods of manufacturing: (a) “The Industrial Period” during 1945-1979, (b) the “Deindustrialization of America” during 1980-2000, and (c) the “Re-industrialization of America” during 2000-present, as it began to shift to an economy largely dominated by service and knowledge jobs, with a major reduction in labor-intensive manufacturing. This study examines the relationship between manufacturing employment and income inequality in the state of Alabama to test the hypothesis that manufacturing plays a key role in moderating inequality. In particular, we consider whether manufacturing or other economic and demographic factors are determinants of the rising income inequality in Alabama. We control for other factors that are also likely to be related to rising income inequality. We employ empirical techniques that are best suited to address potential econometric problems in the empirical work. In general, our results indicate that manufacturing does indeed play a key role in moderating inequality. Other key findings are that more educated communities have less inequality, that rural areas have especially high inequality, that counties with a high proportion of African Americans face disproportionately high inequality, and that the poorest counties have the highest level of inequality Keywords: Manufacturing, Deindustrialization, Reindustrialization, Income Inequality DOI: 10.7176/JESD/11-6-12 Publication date:March 31st 202

Effect of Functional Fatigue on Knee Force Sense in Amateur Adult Female Football Players

Background Intact proprioception (joint position sense, kinaesthesia, force sense (FS)) is critical for optimal neuromuscular control of knee functional joint stability. Fatigue impairs knee FS in adult male footballers. The effect of fatigue on knee FS and resulting implications for injury prevention practice have not been studied for adult female footballers. Aim Determine the effect of functional fatigue on knee flexion FS (KF-FS) in amateur adult female football players. Methods Twenty-one players participated (mean±SD: age 23.3±3.5yr; height 164.1±6.4cm; mass 62.6±6.4kg). Functional fatigue was defined/induced using the Functional Agility Short-Term Fatigue Protocol (FAST-FP). The FAST-FP incorporated acceleration-deceleration tasks typical of football training/match-play. Dominant leg (preferred stance leg) KF-FS was measured (Newtons (N)). Players sat on an isokinetic dynamometer in isometric mode, the knee flexed 45°. A knee flexion target trial-reproduction trial sequence was repeated three times, the difference between trials designated the absolute error (AE), the mean AE used for data analyses. Force sense measurements occurred before and immediately after the FAST-FP. Results Force sense AE did not significantly change following fatigue (pre-fatigue = 7.0±4.8N; post-fatigue = 10.1±6.8N; pre-/post-difference = 7.7±5.6N; P = 0.14; Cohen’s d = 0.34). Four players’ (19%) post-fatigue FS deteriorated by more than twice the group’s pre-/post-difference standard deviation. Conclusion Despite functional fatigue, group mean KF-FS did not significantly change. However, one-fifth of players’ KF-FS deteriorated substantially after functional fatigue was induced. Some players, therefore, may be more in need of fatigue-resistance training than others to maintain optimal KF-FS and neuromuscular control of knee functional joint stability

Effects of Zn additions to highly magnetoelastic FeGa alloys

Fe1−xMx (M = Ga, Ge, Si, Al, Mo and x ∼ 0.18) alloys offer an extraordinary combination ofmagnetoelasticity and mechanical properties. They are rare-earth-free, can be processed using conventional deformation techniques, have high magnetic permeability, low hysteresis, and low magnetic saturation fields, making them attractive for device applications such as actuators and energy harvesters. Starting with Fe-Ga as a reference and using a rigid-band-filling argument, Zhang et al. predicted that lowering the Fermi level by reducing the total number of electrons could enhance magnetoelasticity. To provide a direct experimental validation for Zhang\u27s hypothesis, elemental additions with lower-than-Ga valence are needed. Of the possible candidates, only Be and Zn have sufficient solubility. Single crystals of bcc Fe-Ga-Zn have beengrown with up to 4.6 at. % Zn in a Bridgman furnace under elevated pressure (15 bars) in order to overcome the high vapor pressure of Zn and obtain homogeneous crystals. Single-crystalmeasurements of magnetostriction and elastic constants allow for the direct comparison of themagnetoelastic coupling constants of Fe-Ga-Zn with those of other magnetoelastic alloys in its class. The partial substitution of Ga with Zn yields values for the magnetoelastic coupling factor, −b 1, comparable to those of the binary Fe-Ga alloy

An Expanded Stratigraphic Record of the Devonian-Carboniferous Boundary Hangenberg Biogeochemical Event from Southeast Iowa (U.S.A.)

The Devonian-Carboniferous boundary in the type area of the Mississippian subsystem (tri-state area of Iowa, Illinois, and Missouri) has been historically difficult to identify. Many of the localities contain similar lithologies and stratigraphic successions, but chronostratigraphic correlation of seemingly identical lithologies can vary greatly in this interval and frequently this has led to miscorrelation. In particular, the similar lithofacies that comprise the McCraney Formation and Louisiana Formation have been a source of stratigraphic confusion for over 100 years. To investigate the Devonian-Carboniferous boundary interval in the Mississippian type area we selected two localities in southeastern Iowa, the H-28 core from Lee County outside of Keokuk, Iowa, and the Starr’s Cave outcrop located near Burlington, Iowa. In total, 62 conodont samples and 299 carbonate carbon isotope samples were processed for this study and recorded the Hangenberg positive carbon isotope excursion and 25 conodont species, including a diverse assemblage of siphonodellids. The Hangenberg excursion is recorded in over 20 m of strata in southeast Iowa, making this one of the thickest stratigraphic records of this important biogeochemical event yet recovered, and helps to define more clearly the position of the base of the Carboniferous System in the region. These results show that the “McCraney” Fm. at the Starr’s Cave outcrop and the coeval carbonate unit in the H-28 core are both the Louisiana Formation, and calls into question the use of the name McCraney throughout the State of Iowa

Proposed treatment strategy for reactive hypoglycaemia

Background/aim: Managing reactive hypoglycaemia (RH) poses challenges due to limited and often ineffective treatment options. We report a case series and draw on this to propose a stepwise treatment approach consisting of lifestyle modifications, metformin, GLP-1 analogues, and the use of flash glucose monitoring technology. Method: A retrospective review was conducted to analyse the management of 11 cases presenting with recurrent RH symptoms. Result: Two patients experienced successful resolution of symptoms through lifestyle modifications. Metformin alone was effective in treating seven out of nine patients who received pharmacological treatment. Two patients with previous upper gastrointestinal surgery showed a partial response to metformin and benefited further from additional long-acting GLP-1 analogue. Pharmacological intervention led to significant reductions in insulin and C-peptide levels in repeat mixed meal tolerance tests (P-values 0.043 for insulin and 0.006 for C-peptide). Finally, flash glucose monitoring technology was useful in early detection and preventing episodes of hypoglycaemia in one of these patients with persistent symptoms. Conclusion: These findings highlight the potential efficacy of escalated treatment strategies for RH, including the use of metformin, GLP-1 analogues, and flash glucose monitoring technology

Automated pipeline for rapid production and screening of HIV-specific monoclonal antibodies using pichia pastoris

Monoclonal antibodies (mAbs) that bind and neutralize human pathogens have great therapeutic potential. Advances in automated screening and liquid handling have resulted in the ability to discover antigen-specific antibodies either directly from human blood or from various combinatorial libraries (phage, bacteria or yeast). There remain, however, bottlenecks in the cloning, expression and evaluation of such lead antibodies identified in primary screens that hinder high-throughput screening. As such, ‘hit-to-lead identification’ remains both expensive and time-consuming. By combining the advantages of overlap extension PCR (OE-PCR) and a genetically stable yet easily manipulatable microbial expression host Pichia pastoris, we have developed an automated pipeline for the rapid production and screening of full-length antigenspecific mAbs. Here, we demonstrate the speed, feasibility and cost-effectiveness of our approach by generating several broadly neutralizing antibodies against human immunodeficiency virus (HIV).Bill & Melinda Gates FoundationUnited States. Defense Advanced Research Projects AgencySpace and Naval Warfare Systems Center San Diego (U.S.) (Contract N66001-13-C-4025)W. M. Keck FoundationNational Institute of Allergy and Infectious Diseases (U.S.) (U19AI090970).National Cancer Institute (U.S.) (David H. Koch Institute for Integrative Cancer Research at MIT. Support (Core) Grant P30-CA14051

Determinants of Length of Stay Following Total Anterior Circulatory Stroke

Identification of factors that determine length of stay (LOS) in total anterior circulatory stroke (TACS) has potential for targeted intervention to reduce the associated health care burden. This study aimed to determine which factors predict LOS following either ischaemic or haemorrhagic TACS. The study sample population was drawn from the Norfolk and Norwich Stroke and Transient Ischemic Attack (TIA) Register (1996 – 2012), a prospective registry. 2965 patients admitted with TACS verified by a stroke specialist team were included. Primary analysis identified predictors of length of stay (LOS) in either haemorrhagic or ischaemic TACS. Secondary analyses identified predictors of LOS in patients who were discharged alive or who died during admission separately. Moderate (p=0.014) to severe disability (p=0.015) and history of congestive heart failure (p=0.027) in the primary analysis and pre-stroke residence in a care facility among patients who survived to discharge (p=0.013) were associated with a shorter length of stay. Factors associated with increased length of stay included presence of neurological lateralisation in the primary analysis (p=0.004) and amongst patients who died (p=0.003 and p=0.014 for ischaemic and haemorrhagic stroke, respectively). Patients with advanced age (≥85 years) with haemorrhagic stroke had longer LOS regardless of mortality outcome. Patients with low pre-morbid disability (modified Rankin score ≤2 who died following haemorrhagic TACS also had longer LOS. Our study found predictors of LOS following TACS include neurological lateralisation, pre-stroke disability status, congestive heart failure, pre-morbid residence and age. The identification of such factors would assist in resource allocation and discharge planning