Molecular Aspects of Dopaminergic Neurodegeneration: Gene-Environment Interaction in Parkin Dysfunction

Parkinson’s disease (PD) is a common neurodegenerative movement disorder that is characterized pathologically by a progressive loss of midbrain dopaminergic neurons and by protein inclusions, designated Lewy bodies and Lewy neurites. PD is one of the most common neurodegenerative diseases, affecting almost 1% of the population over 60 years old. Although the symptoms and neuropathology of PD have been well characterized, the underlying mechanisms and causes of the disease are still not clear. Genetic mutations can provide important clues to disease mechanism, but most PD cases are sporadic rather than familial; environmental factors have long been suspected to contribute to the disease. Although more than 90% of PD cases occur sporadically and are thought to be due, in part, to oxidative stress and mitochondrial dysfunction, the study of genetic mutations has provided great insight into the molecular mechanisms of PD. Furthermore, rotenone, a widely used pesticide, and paraquat and maneb cause a syndrome in rats and mice that mimics, both behaviorally and neurologically, the symptoms of PD. In the current review, we will discuss various aspects of gene-environment interaction that lead to progressive dopaminergic neurodegenration, mainly focusing on our current finding based on stress-mediated parkin dysfunction

Performance evaluation of Cu-Ni 90/10 alloyed structures exposed to various seawater compositions and their remaining service life estimation

The Cu-Ni 90/10 alloy is extensively used in seawater applications mainly because of its excellent heat transferability, resistance toward corrosion and marine fouling. The corrosion resistance of Cu-Ni 90/10 has been found to be far superior in open natural seawater, however, several premature failures have often been reported during their exposure in the pollutant-rich seawater typically found near harbours, jetties and coastlines. This paper investigates the corrosion behaviour of Cu-Ni 90/10 alloyed coupons exposed to natural seawater, and pollutant-rich harbour seawater in a submerged position. Moreover, this research also investigates the corrosion mechanism on marine heat exchanger tubes of material that failed prematurely while operating in similar seawater compositions. The field experimental results for short-term corrosion results from coupons, and the long-term corrosion results from heat exchanger tubes have been evaluated, to formulate a relationship and corrosion modelling

Simian Virus 40 Large T Antigen as a Model to Test the Efficacy of Flouroquinolones against Viral Helicases

Simian virus 40 large T-antigen (SV40 LT-Ag) is a 708 amino acid nuclear phosphoprotein. Among many functions of LT-Ag is its ability to perform as an ATPase-helicase, catalyzing the unwinding of viral genome during replication. The LT-Ag has been employed in the studies of helicase structure and function, and has served as a model helicase for the screening of antiviral drugs that target viral helicase. In this study, using in vitro enzyme assays and in silico computer modeling, we screened a batch of 18 fluoroquinolones to assess their potential as antivirals by virtue of their inhibition of the LT-Ag helicase. We found all fluoroquinolones to be inhibitory to the helicase activity of LT-Ag. In our docking analysis, most of these tested drugs showed similarity in their interactions with LT-Ag. Our study shows the potential of fluoroquinolones as antiviral drugs and of SV40 LT-Ag as a model protein for screening drugs against viral helicases

Stability Analysis of Charged Rotating Black Ring

We study the electromagnetic field equation along with the WKB approximation. The boson tunneling phenomenon from charged rotating black ring(CRBR) is analyzed. It is examined that reserve radiation consistent with CRBR can be computed in general by neglecting back reaction and self-gravitational of the radiated boson particle. The calculated temperature depends upon quantum gravity and CRBR geometry. We also examine the corrected tunneling rate/probability of boson particles by assuming charge as well as energy conservation laws and the quantum gravity. Furthermore, we study the graphical behavior of the temperature and check the stability and instability of CRBR.Comment: 7 pages, 2 figures, version accepted for publication in Symmetr

An Experimental Study of the Effect of Out-of-the-Window Cues on Training Novice Pilots on a Flight Simulator

The effects of out-of-the-window cues on learning a straight-in landing approach and a level 360deg turn by novice pilots on a flight simulator have been investigated. The treatments consisted of training with and without visual cues as well as density of visual cues. The performance of the participants was then evaluated through similar but more challenging tasks. It was observed that the participants in the landing study who trained with visual cues performed poorly than those who trained without the cues. However the performance of those who trained with a faded-cues sequence performed slightly better than those who trained without visual cues. In the level turn study it was observed that those who trained with the visual cues performed better than those who trained without visual cues. The study also showed that those participants who trained with a lower density of cues performed better than those who trained with a higher density of visual cues

Paradoxical Association of Smoking With In‐Hospital Mortality Among Patients Admitted With Acute Ischemic Stroke

Background: Compared to those who never smoked, a paradoxical effect of smoking on reducing mortality in patients admitted with myocardial ischemia has been reported. We sought to determine if this effect was present in patients hospitalized with ischemic stroke. Methods and Results: Using the local Get with the Guidelines‐Stroke registry, we analyzed 4305 consecutively admitted ischemic stroke patients (March 2002–December 2011). The sample was divided into smokers versus nonsmokers. The main outcome of interest was the overall inpatient mortality. Compared to nonsmokers, tobacco smokers were younger, more frequently male and presented with fewer stroke risk factors such as hypertension, hyperlipidemia, diabetes, coronary artery disease, and atrial fibrillation. Smokers also had a lower average NIH Stroke Scale (NIHSS) and fewer received tissue plasminogen activator (tPA). Patients in both groups had similar adherence to early antithrombotics, dysphagia screening prior to oral intake, and deep vein thrombosis (DVT) prophylaxis. Smoking was associated with lower all‐cause in‐hospital mortality (6.6% versus 12.4%; unadjusted OR 0.46; CI [0.34 to 0.63]; P<0.001). In multivariable analysis, adjusted for age, gender, ethnicity, hypertension, diabetes mellitus, hyperlipidemia, CAD, atrial fibrillation, NIHSS, and tPA, smoking remained independently associated with lower mortality (adjusted OR 0.64; CI [0.42 to 0.96]; P=0.03). Conclusions: Similar to myocardial ischemia, smoking was independently associated with lower inpatient mortality in acute ischemic stroke. This effect may be due to tobacco‐induced changes in cerebrovascular vasoreactivity, or may be due in part to residual confounding. Larger, multicenter studies are needed to confirm the finding and the effect on 30‐day and 1‐year mortality

Peak-to-average power ratio reduction in OFDM systems using smoothing technique

This paper presents a new peak-to-average power ratio (PAPR) reduction technique by smoothing the power components of OFDM signals. The smoothing technique only adds a simple process to the existing OFDM signal processing. Also, there is no need to send side information to the receiver for signal recovery. Smoothed OFDM system with 64 subcarrier and 16-QAM modulation achieved reduction in PAPR in the range of 0.5 to 2.5 dB, with out-of-band shoulder lying less than -15 dB compared to in-band level

Effect of sonication conditions: solvent, time, temperature and reactor type on the preparation of micron sized vermiculite particles

International audienceThe effects of temperature, time, solvent and sonication conditions under air and Argon are described for the preparation of micron and sub-micron sized vermiculite particles in a double-jacketed Rosett-type or cylindrical reactor. The resulting materials were characterized via X-ray powder diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), Fourier Transform Infrared (FTIR) Spectroscopy, BET surface area analysis, chemical analysis (elemental analysis), thermogravimetry analysis (TGA) and Laser Granulometry. The sonicated vermiculites displayed modified particle morphologies and reduced sizes (observed by scanning electron microscopy and laser granulometry). Under the conditions used in this work, sub-micron sized particles were obtained after 5 h of sonication, whereas longer times promoted aggregation again. Laser granulometry data revealed also that the smallest particles were obtained at high temperature while it is generally accepted that the mechanical effects of ultrasound are optimum at low temperatures according to physical/chemical properties of the used solvent. X-ray diffraction results indicated a reduction of the crystallite size along the basal direction [001]; but structural changes were not observed. Sonication at different conditions also led to surface modifications of the vermiculite particles brought out by BET surface measurements and Infrared Spectroscopy. The results indicated clearly that the efficiency of ultrasound irradiation was significantly affected by different parameters such as temperature, solvent, type of gas and reactor type