Modeling DNA Structure, Elasticity and Deformations at the Base-pair Level

We present a generic model for DNA at the base-pair level. We use a variant of the Gay-Berne potential to represent the stacking energy between neighboring base-pairs. The sugar-phosphate backbones are taken into account by semi-rigid harmonic springs with a non-zero spring length. The competition of these two interactions and the introduction of a simple geometrical constraint leads to a stacked right-handed B-DNA-like conformation. The mapping of the presented model to the Marko-Siggia and the Stack-of-Plates model enables us to optimize the free model parameters so as to reproduce the experimentally known observables such as persistence lengths, mean and mean squared base-pair step parameters. For the optimized model parameters we measured the critical force where the transition from B- to S-DNA occurs to be approximately $140{pN}$. We observe an overstretched S-DNA conformation with highly inclined bases that partially preserves the stacking of successive base-pairs.Comment: 15 pages, 25 figures. submitted to PR

PENGARUH PENAMBAHAN LENSA NOZZLE DAN JUMLAH BLADE AIRFOIL TIPE NACA 4415 TERHADAP HASIL DAYA LISTRIK TURBIN ANGIN SUMBU HORISONTAL

Danur Lambang Pristiandaru. PENGARUH PENAMBAHAN LENSA NOZZLE TURBIN ANGIN DAN JUMLAH BLADE AIRFOIL TIPE NACA 4415 TERHADAP HASIL DAYA LISTRIK. Skripsi, Fakultas Keguruan dan Ilmu Pendidikan Universitas Sebelas Maret Surakarta. Januari 2016 Tujuan penelitian ini adalah: (1) Menyelidiki pengaruh jumlah blade pada turbin angin non-twisted blade tipe airfoil NACA 4415 terhadap daya listrik yang dihasilkan. (2) Menyelidiki pengaruh penambahan lensa nozzle pada turbin angin non-twisted blade tipe airfoil NACA 4415 terhadap daya listrik yang dihasilkan turbin angin. (3) Menyelidiki pengaruh bersama (interaksi) antara penambahan lensa nozzle dan jumlah blade terhadap daya listrik yang dihasilkan turbin angin. Penelitian ini menggunakan metode deskriptif kuantitatif. Sampel dalam penelitian ini adalah Turbin Angin Sumbu Horisontal (TASH) dengan desain blade airfoil NACA 4415 non-twisted. 3 desain lensa nozzle digunakan untuk mengetahui pengaruhnya terhadap peningkatan daya listrik TASH. Terdapat 3 variasi jumlah blade yaitu jumlah blade 2, jumlah blade 3, dan jumlah blade 4. Variasi kecepatan angin yang digunakan dalam penelitian ini adalah 2,5 m/s, 3,5 m/s, dan 4,5 m/s. Data diperoleh dengan melakukan pengujian TASH menggunakan angin rekayasa, daya listrik yang dihasilkan dibaca dan direkam oleh data logger. Data yang diperoleh dari hasil penelitian dimasukkan ke dalam tabel dan ditampilkan dalam bentuk grafik, kemudian dianalisis. Berdasarkan hasil penelitian dapat disimpulkan bahwa: (1) Adanya pengaruh variasi jumlah blade terhadap daya listrik turbin angin. TASH 3 blade menghasilkan daya listrik yang paling besar yaitu 0,7222 W pada kecepatan angin 4,5 m/s. (2) Adanya pengaruh penambahan lensa nozzle terhadap turbin angin. Lensa nozzle mampu meningkatkan hasil daya listrik turbin angin semua jenis variasi jumlah blade dibandingkan turbin angin tanpa lensa nozzle. (3) Ada pengaruh bersama yang signifikan antara variasi jumlah blade dan variasi jenis lensa terhadap daya listrik turbin angin. TASH 3 blade dengan lensa C pada kecepatan angin 4,5 m/s memiliki daya listrik tertinggi yaitu sebesar 0,82041 W. Daya listrik tersebut meningkat 13,60% dibanding TASH 3 blade tanpa penambahan lensa, yaitu 0,7222 W. Kata kunci: Turbin Angin, Lensa Nozzle, Daya Listrik, Data Logge

Experimental study of the astrophysically important Na 23 (α,p) Mg 26 and Na 23 (α,n) Al 26 reactions

The Na23(α,p)Mg26 and Na23(α,n)Al26 reactions are important for our understanding of the Al26 abundance in massive stars. The aim of this work is to report on a direct and simultaneous measurement of these astrophysically important reactions using an active target system. The reactions were investigated in inverse kinematics using He4 as the active target gas in the detector. We measured the excitation functions in the energy range of about 2 to 6 MeV in the center of mass. We have found that the cross sections of the Na23(α,p)Mg26 and the Na23(α,n)Al26 reactions are in good agreement with previous experiments and with statistical-model calculations. The astrophysical reaction rate of the Na23(α,n)Al26 reaction has been reevaluated and it was found to be larger than the recommended rate

Reaction rate for carbon burning in massive stars

Carbon burning is a critical phase for nucleosynthesis in massive stars. The conditions for igniting this burning stage, and the subsequent isotope composition of the resulting ashes, depend strongly on the reaction rate for C12+C12 fusion at very low energies. Results for the cross sections for this reaction are influenced by various backgrounds encountered in measurements at such energies. In this paper, we report on a new measurement of C12+C12 fusion cross sections where these backgrounds have been minimized. It is found that the astrophysical S factor exhibits a maximum around Ecm=3.5-4.0 MeV, which leads to a reduction of the previously predicted astrophysical reaction rate

Study of the Alm 26 (d,p) Al 27 Reaction and the Influence of the Al 26 0+ Isomer on the Destruction of Al 26 in the Galaxy

The existence of Al26 (t1/2=7.17×105 yr) in the interstellar medium provides a direct confirmation of ongoing nucleosynthesis in the Galaxy. The presence of a low-lying 0+ isomer (Al26m), however, severely complicates the astrophysical calculations. We present for the first time a study of the Al26m(d,p)Al27 reaction using an isomeric Al26 beam. The selectivity of this reaction allowed the study of â.,"=0 transfers to T=1/2, and T=3/2 states in Al27. Mirror symmetry arguments were then used to constrain the Al26m(p,γ)Si27 reaction rate and provide an experimentally determined upper limit of the rate for the destruction of isomeric Al26 via radiative proton capture reactions, which is expected to dominate the destruction path of Al26m in asymptotic giant branch stars, classical novae, and core collapse supernovae

How well do we understand the reaction rate of C burning?

Carbon burning plays a crucial role in stellar evolution, where this reaction is an important route for the production of heavier elements. A particle-γ coincidence technique that minimizes the backgrounds to which this reaction is subject and provides reliable cross sections has been used at the Argonne National Laboratory to measure fusion cross-sections at deep sub-barrier energies in the 12C+12C system. The corresponding excitation function has been extracted down to a cross section of about 6 nb. This indicates the existence of a broad S-factor maximum for this system. Experimental results are presented and discussed

First direct observation of enhanced octupole collectivity in 146Ba

The octupole strength present in the neutron-rich, radiocative nucleus 146Ba has been experimentally determined for the first time using Coulomb excitation. To achieve this, A=146 fission fragments from CARIBU were post-accelerated by the Argonne Tandem Linac Accelerator System (ATLAS) and impinged on a thin 208Pb target. Using the GRETINA γ-ray spectrometer and the CHICO2 heavy-ion counter, the reduced transition probability B(E3; 3-→0+) was determined as 48(+21-29) W.u. The new result provides further experimental evidence for the presence of a region of octupole deformation surrounding the neutron-rich barium isotopes

Reaction rate for carbon burning in massive stars

Carbon burning is a critical phase for nucleosynthesis in massive stars. The conditions for igniting this burning stage, and the subsequent isotope composition of the resulting ashes, depend strongly on the reaction rate for C12+C12 fusion at very low energies. Results for the cross sections for this reaction are influenced by various backgrounds encountered in measurements at such energies. In this paper, we report on a new measurement of C12+C12 fusion cross sections where these backgrounds have been minimized. It is found that the astrophysical S factor exhibits a maximum around Ecm=3.5-4.0 MeV, which leads to a reduction of the previously predicted astrophysical reaction rate

Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

Optimisation of antihypertensive treatment by crossover rotation of four major classes

Original article can be found at: http://www.sciencedirect.com/science/journal/01406736 Copyright Elsevier Ltd. [Full text of this article is not available in the UHRA]Most comparisons of antihypertensive drugs aee undertaken in parallel groups. We undertook a crossover rotation of the four main classes of antihypertensive drugs, in untreated young hypertensive patients, to assess the response rate with monotherapy achieved by a systematic rotation.Peer reviewe