Post-activation depression of primary afferents reevaluated in humans

Amplitude variation of Hoffmann Reflex (H-reflex) was used as a tool to investigate many neuronal networks. However, H-reflex itself is a subject to intrinsic changes including post-activation depression (P-AD). We aimed to investigate P-AD and its implication on motor control in humans. Upon tibial nerve stimulation in 23 healthy participants, peak-to-peak amplitude change of H-reflex was investigated using surface electromyography (SEMG) of soleus muscle. Variety of stimulus intensities, interstimulus intervals (ISIs), voluntary contraction levels/types and force recording were used to investigate the nature of P-AD. We have shown that P-AD was significantly stronger in the shorter ISIs. The only exception was the ISI of 200 msecs which had a weaker P-AD than some of the longer ISIs. Sudden muscle relaxation, on the other hand, further increased the effectiveness of the ongoing P-AD. Moreover, P-AD displayed its full effect with the first stimulus when there was no muscle contraction and was efficient to reduce the muscle force output by about 30%. These findings provide insight about the variations and mechanism of P-AD and could lead to improvements in diagnostic tools in neurological diseases

Transcription-replication conflicts: How they occur and how they are resolved

The frequent occurrence of transcription and DNA replication in cells results in many encounters, and thus conflicts, between the transcription and replication machineries. These conflicts constitute a major intrinsic source of genome instability, which is a hallmark of cancer cells. How the replication machinery progresses along a DNA molecule occupied by an RNA polymerase is an old question. Here we review recent data on the biological relevance of transcription-replication conflicts, and the factors and mechanisms that are involved in either preventing or resolving them, mainly in eukaryotes. On the basis of these data, we provide our current view of how transcription can generate obstacles to replication, including torsional stress and non-B DNA structures, and of the different cellular processes that have evolved to solve them

XRN2 Links Transcription Termination to DNA Damage and Replication Stress

We thank the Proteomics Core Facility. We thank Dr. Robert J. Crouch for providing us with GFP- and GFP-RNase H expression plasmids. We also thank Dr. Stephen H. Leppla for providing us with antibodies directed against RNA:DNA hybrids (R loops) (S9.6). We thank Novus Biologicals for generously providing XRN2 and Rrp45 antibodies. We also thank the members of the Boothman lab for critical reading of this manuscript.Author Summary Genomic instability is one of the primary causes of disease states, in particular cancer. One major cause of genomic instability is the formation of DNA double strand breaks (DSBs), which are one of the most dangerous types of DNA lesions the cell can encounter. If not repaired in a timely manner, one DSB can lead not only to cell death. If misrepaired, one DSB can lead to a hazardous chromosomal aberration, such as a translocation, that can eventually lead to cancer. The cell encounters and repairs DSBs that arise from naturally occurring cellular processes on a daily basis. A number of studies have demonstrated that aberrant structures that form during transcription under certain circumstances, in particular RNA:DNA hybrids (R loops), can lead to DSB formation and genomic instability, especially during DNA synthesis. Thus, it is important to understand how the cell responds and repairs transcription-mediated DNA damage in general and R loop-related DNA damage in particular. This paper both demonstrates that the XRN transcription termination factor links transcription and DNA damage, but also provides a better understanding of how the cell prevents transcription-related DNA damage.Yeshttp://www.plosgenetics.org/static/editorial#pee

A New Short Signature Scheme with Random Oracle from Bilinear Pairings

In this paper, we propose a new and efficient short signature scheme from the bilinear pairings. Our scheme is constructed by bilinear inverse-square Diffie-Hellman problem (BISDHP) and does not require any special hash function. The exact security proofs are also explained in the random Oracle model. We give the implementation and comparison results of our proposed signature scheme with the signature scheme proposed by Boneh, Lynn, Shacham (BLS) and Zhang, Safavi, Susilo (ZSS). Furthermore, we use this signature scheme to construct a ring signature scheme

Effects of Latanoprost 0.005%/timolol maleate 0.5% and Dorzolamide 2%/timolol maleate 0.5% fixed combinations on 24-hour intraocular pressure in patients with primary open-angle glaucoma [Primer Açi{dotless}k Açi{dotless}li{dotless} Glokomlu Hastalarda %0,005 Latanoprost /%0,5 Timolol Maleat ile %2 Dorzolamid/%0,5 Timolol Maleat Sabit Bileşimlerinin 24 Saatlik Göz İçi Basi{dotless}nci{dotless}na Etkileri]

Purpose: To evaluate the effects of latanoprost/timolol maleate and dorzolamid/timolol maleate fixed combinations on-24 hours intraocular pressure in patients with open-angle glaucoma. Ma te ri als and Met hod: Forty-eight eyes of 24 patients with open-angle glaucoma were enrolled in the study. They were randomized to receive fixed combinations of either latanoprost/timolol maleate (Group 1 - 24 eyes of 12 patients) or dorzolamid/timolol maleate (Group 2 - 24 eyes of 12 patients). Patients who achieved intraocular pressure of ? 21 mmHg 3 weeks after combined therapy were hospitalized and intraocular pressure was monitored at hour 06:00, 10:00, 14:00, 18:00, 22:00 and 02:00 for 24 hours. Diurnal and nocturnal fluctuations were determined by measurements done between 06:00 and 18:00 hours and between 22:00 and 02:00, respectively. Mean intraocular pressure and fluctuations of intraocular pressure between the two groups were compared. Results: There was no difference between the groups in terms of age, sex, visual acuity and cup/disc ratio (p>0.05). Three weeks after combined therapy, all patients achieved target intraocular pressure of ? 21 mmHg. There was no statistically significant difference between the two groups with regard to mean intraocular pressure over 24 hours (17.1±2.3 mmHg and 17.27±2.3 mmHg for Group 1 and Group 2, respectively; p>0.05). Diurnal fluctuations were 3.6 mmHg for Group 1 and 4.7 mmHg for Group 2; nocturnal fluctuations were 4.3 mmHg for Group 1 and 2.3 mmHg for Group 2. Diurnal fluctuations in Group 1 were lower than in Group 2, while nocturnal fluctuations were lower in Group 2 than in Group 1 (p<0.05). Discussion: Both latanoprost/timolol maleate and dorzolamid/timolol maleate fixed combinations are effective for 24-hour intraocular pressure control. Latanoprost/timolol maleate fixed combination is superior to dorzolamid/timolol maleate in controlling diurnal fluctuations, while dorzolamid/timolol maleate is better in controlling nocturnal fluctuations

Outcome of pediatric uveitis at an university clinic [Bir üniversite klinigindeki pediatrik üveit olgulari{dotless}ni{dotless}n sonuçlari{dotless}]

Purpose: To determine the etiology, clinical course, complications, and outcome of uveitis in pediatric patients. Material and Method: We retrospectively reviewed the medical charts of 64 eyes of 43 patients, who had been followed up at a University clinic. Demographic and etiological features, clinical course, complications, and visual outcome were analyzed. Results: Male/female ratio was 22/21. Median age at the first visit was 14 (3-18) years. Unilateral involvement was observed in 22 (51.16%) patients. Anterior uveitis was the most common form (67.19%). Idiopathic uveitis was seen in 25 (58.14%) patients. The most commonly identified etiological entities were juvenile idiopathic arthritis (JIA) (5 patients) and Behcet's disease (4 patients). Both glaucoma and cataract were the most common complications (12.50%, 6.25%; respectively). Final VA was equal or better than 20/40 in 47 eyes (73.43%). Discussion: Uveitis in pediatric patients was mostly idiopathic. The most commonly identified etiologic entities were JIA and Behcet's disease. Final visual outcome was favorable with appropriate treatment

Inhibition effect of 2-amino-4-methylpyridine on mild steel corrosion: Experimental and theoretical investigation

The effect of 2-amino-4-methylpyridine (AMP) on the corrosion behavior of mild steel (MS) in 0.5. M HCl is investigated with electrochemical methods and theoretical calculations. The electrochemical tests show that the polarization resistance of MS increasing the presence of AMP in acid solution. Adsorption of AMP on MS surface is a physical and obeys the Langmuir isotherm. The quantum parameters signaled adsorption occurs on amine and methyl substituents of AMP. The inhibition efficiency is related to frontier orbital's energy band gap of AMP, which are 5.357 and 6.490. eV for neutral and protonated molecules in aqueous solution, respectively. © 2014 Elsevier Ltd

Electrochemical and quantum chemical studies of 2-amino-4-methyl-thiazole as corrosion inhibitor for mild steel in HCl solution

The application of 2-amino-4-methyl-thiazole (2A4MT) as a corrosion inhibitor for mild steel (MS) protection was investigated in 0.5M HCl solution. The electrochemical impedance spectroscopy and potentiodynamic measurements were used at various concentrations and temperatures. The surface of MS was analyzed with scanning electron microscope in absence and presence of 2A4MT. Results showed that the correlation between experimental (inhibition efficiency, surface charge, ?Gadso,Ea) and quantum calculation parameters (dipole moment, EHOMO, ELUMO). It was concluded that the high corrosion inhibition efficiency of 2A4MT was associated with its strong adsorption as a barrier film on the MS surface. © 2014 Elsevier Ltd.FEF2013BAP10The authors are greatly thankful to Cukurova University research fund (Project No. FEF2013BAP10 ) for financial support

Fast and efficient circuit topologies for finding the maximum of n k-bit numbers

Due to copyright restrictions, the access to the full text of this article is only available via subscription.Finding the value and/or index of the maximum (or minimum) element of a set of n numbers (each with k-bits) is a fundamental arithmetic operation and is needed in many applications. This paper proposes several maximum-finder (or minimum-finder) circuit topologies, which are parallel. We wrote circuit generators at hardware description language level for our topologies and previous works. Then we synthesized these circuits for 20 different (n, k) cases (with values up to 64) and compared their efficiency in timing (latency), area, and energy. The timing complexity of our fastest topology is O(log n + log k), whereas the fastest in the literature is O(log n log k). The synthesis results showed that our fastest topology is 1.2-2.2 times (1.6 times on the average) faster than the state-of-the-art. In this paper, we argue that a more fair metric of area efficiency is area-timing product. In terms of ATP, our proposed topologies are better than the state-of-the-art in 19 out of the 20 cases. In terms of energy (i.e., power-timing product, abbreviated as PTP), we are better in 11 cases out of 20