668 research outputs found
An Exactly Solvable Model of Interacting Bosons
We introduce a class of exactly solvable boson models. We give explicit
analytic expressions for energy eigenvalues and eigenvectors for an sd-boson
Hamiltonian, which is related to the SO(6) chain of the Interacting Boson Model
Hamiltonian.Comment: 8 pages of LATE
Exactly Solvable Pairing Model Using an Extension of Richardson-Gaudin Approach
We introduce a new class of exactly solvable boson pairing models using the
technique of Richardson and Gaudin. Analytical expressions for all energy
eigenvalues and first few energy eigenstates are given. In addition, another
solution to Gaudin's equation is also mentioned. A relation with the
Calogero-Sutherland model is suggested.Comment: 9 pages of Latex. In the proceedings of Blueprints for the Nucleus:
From First Principles to Collective Motion: A Festschrift in Honor of
Professor Bruce Barrett, Istanbul, Turkey, 17-23 May 200
Spectra and Symmetry in Nuclear Pairing
We apply the algebraic Bethe ansatz technique to the nuclear pairing problem
with orbit dependent coupling constants and degenerate single particle energy
levels. We find the exact energies and eigenstates. We show that for a given
shell, there are degeneracies between the states corresponding to less and more
than half full shell. We also provide a technique to solve the equations of
Bethe ansatz.Comment: 15 pages of REVTEX with 2 eps figure
Endothelial nitric oxide synthase gene polymorphisms associated with periodontal diseases in Turkish adults
Endothelial nitric oxide synthase (NOS3) is involved in key steps of immune response. Genetic factors predispose individuals to periodontal disease. This study's aim was to explore the association between NOS3 gene polymorphisms and clinical parameters in patients with periodontal disease. Genomic DNA was obtained from the peripheral blood of 23 subjects with aggressive periodontitis (AgP), 26 with chronic periodontitis (CP), 31 with gingivitis (G) and 50 healthy controls. Probing depth (PD), clinical attachment loss (CAL), plaque index (PI) and gingival index (GI) were recorded as clinical parameters. We genotyped NOS3 polymorphisms using the PCR and/or PCR-RFLP method. Genotype frequencies differed significantly among periodontal diseases and controls for these polymorphisms. A significant association was detected between NOS3 +894 polymorphism and PD and CAL in the CP and AgP patient groups; whereas NOS VNTR analysis detected no associations with clinical parameters in theCP and AgP groups. However, a significant association was detected between the AA genotype and both PI and GI in patients with gingivitis; and a significant association was shown between the BB genotype and PI. The present study shows that two common polymorphisms of the NOS3 gene cluster are significantly associated with the occurrence of periodontal diseases
Thalassemia mutations in Gaziantep, Turkey
Ninety-eight postnatal and six prenatal cases of thalassemia were studied by the reverse dot-blot hybridization technique in the city of Gaziantep, Turkey. We found the following mutations: IVS 1.110 (G>A) in 29.1%, IVS 2.1 (G>A) in 12.3%, IVS 1.1 (G>A) in 7.7%, Codon 8 (-AA) in 5.6%, -30 (T>A) in 4.6%, IVS 1.6 (T>C) in 4.6%, Codon 39 (C>T) in 3.6%, Codon 44 (-C) in 3.1%, IVS 2.745 (C>G) in 1.5%, Codon 8/9 (+G) in 2.1%, Codon 36/37 (-T) in 2.1%, IVS 1.5 (G>C) in 2.1%, Codon 22 (7pb del) in 0.5%, Codon 5 (-CT) in 0.5% while 20.9% were undetermined. 54 of the thalassemia patients were homozygotes, 12 were compound heterozygous and 31 were heterozygotes. In one allele of 5 thalassemia patients, - thalassemia mutation (3.7 single gene deletions in 1 patient, anti-3.7 gene triplication in 4 patients) wasdetermined at the same time. Finally, this is the first comprehensive study in this region and percentage of and - globin genes mutation is 2.6 and 79.4%, respectively
Neutrino Spectral Split in the Exact Many Body Formalism
We consider the many-body system of neutrinos interacting with each other
through neutral current weak force. Emerging many-body effects in such a system
could play important roles in some astrophysical sites such as the core
collapse supernovae. In the literature this many-body system is usually treated
within the mean field approximation which is an effective one-body description
based on omitting entangled neutrino states. In this paper, we consider the
original many-body system in an effective two flavor mixing scenario under the
single angle approximation and present a solution without using the mean field
approximation. Our solution is formulated around a special class of many-body
eigenstates which do not undergo any level crossings as the neutrino self
interaction rate decreases while the neutrinos radiate from the supernova. In
particular, an initial state which consists of electron neutrinos and
antineutrinos of an orthogonal flavor can be entirely decomposed in terms of
those eigenstates. Assuming that the conditions are perfectly adiabatic so that
the evolution of these eigenstates follow their variation with the interaction
rate, we show that this initial state develops a spectral split at exactly the
same energy predicted by the mean field formulation.Comment: Published version. 30 pages, 11 figure
Technology-assisted stroke rehabilitation in Mexico: a pilot randomized trial comparing traditional therapy to circuit training in a Robot/technology-assisted therapy gym
Background Stroke rehabilitation in low- and middle-income countries, such as Mexico, is often hampered by lack of clinical resources and funding. To provide a cost-effective solution for comprehensive post-stroke rehabilitation that can alleviate the need for one-on-one physical or occupational therapy, in lower and upper extremities, we proposed and implemented a technology-assisted rehabilitation gymnasium in Chihuahua, Mexico. The Gymnasium for Robotic Rehabilitation (Robot Gym) consisted of low- and high-tech systems for upper and lower limb rehabilitation. Our hypothesis is that the Robot Gym can provide a cost- and labor-efficient alternative for post-stroke rehabilitation, while being more or as effective as traditional physical and occupational therapy approaches. Methods A typical group of stroke patients was randomly allocated to an intervention (n = 10) or a control group (n = 10). The intervention group received rehabilitation using the devices in the Robot Gym, whereas the control group (n = 10) received time-matched standard care. All of the study subjects were subjected to 24 two-hour therapy sessions over a period of 6 to 8 weeks. Several clinical assessments tests for upper and lower extremities were used to evaluate motor function pre- and post-intervention. A cost analysis was done to compare the cost effectiveness for both therapies. Results No significant differences were observed when comparing the results of the pre-intervention Mini-mental, Brunnstrom Test, and Geriatric Depression Scale Test, showing that both groups were functionally similar prior to the intervention. Although, both training groups were functionally equivalent, they had a significant age difference. The results of all of the upper extremity tests showed an improvement in function in both groups with no statistically significant differences between the groups. The Fugl-Meyer and the 10 Meters Walk lower extremity tests showed greater improvement in the intervention group compared to the control group. On the Time Up and Go Test, no statistically significant differences were observed pre- and post-intervention when comparing the control and the intervention groups. For the 6 Minute Walk Test, both groups presented a statistically significant difference pre- and post-intervention, showing progress in their performance. The robot gym therapy was more cost-effective than the traditional one-to-one therapy used during this study in that it enabled therapist to train up to 1.5 to 6 times more patients for the approximately same cost in the long term. Conclusions The results of this study showed that the patients that received therapy using the Robot Gym had enhanced functionality in the upper extremity tests similar to patients in the control group. In the lower extremity tests, the intervention patients showed more improvement than those subjected to traditional therapy. These results support that the Robot Gym can be as effective as traditional therapy for stroke patients, presenting a more cost- and labor-efficient option for countries with scarce clinical resources and funding. Trial registration ISRCTN98578807
Combined mutation screening of NKX2-5, GATA4, and TBX5 in congenital heart disease: multiple heterozygosity and novel mutations
Background: Variants of several genes encoding transcription modulators, signal transduction, and structural proteins are known to cause Mendelian congenital heart disease (CHD). NKX2-5 and GATA4 were the first CHD-causing genes identified by linkage analysis in large affected families. Mutations of TBX5 cause Holt–Oram syndrome, which includes CHD as a clinical feature. All three genes have a well-established role in cardiac development.
Design: In order to investigate the possible role of multiple mutations in CHD, a combined mutation screening was performed in NKX2-5, GATA4, and TBX5 in the same patient cohort. Samples from a cohort of 331 CHD patients were analyzed by polymerase chain reaction, double high-performance liquid chromatography and sequencing in order to identify changes in the NKX2-5, GATA4, and TBX5 genes.
Results: Two cases of multiple heterozygosity of putative disease-causing mutations were identified. One patient was found with a novel L122P NKX2-5 mutation in combination with the private A1443D mutation of MYH6. A patient heterozygote for a D425N GATA4 mutation carries also a private mutation of the MYH6 gene (V700M).
Conclusions: In addition to reporting two novel mutations of NKX2-5 in CHD, we describe families where multiple individual mutations seem to have an additive effect over the pathogenesis of CHD. Our findings highlight the usefulness of multiple gene mutational analysis of large CHD cohorts
Tool flank wear prediction using high-frequency machine data from industrial edge device
Tool flank wear monitoring can minimize machining downtime costs while
increasing productivity and product quality. In some industrial applications,
only a limited level of tool wear is allowed to attain necessary tolerances. It
may become challenging to monitor a limited level of tool wear in the data
collected from the machine due to the other components, such as the flexible
vibrations of the machine, dominating the measurement signals. In this study, a
tool wear monitoring technique to predict limited levels of tool wear from the
spindle motor current and dynamometer measurements is presented. High-frequency
spindle motor current data is collected with an industrial edge device while
the cutting forces and torque are measured with a rotary dynamometer in
drilling tests for a selected number of holes. Feature engineering is conducted
to identify the statistical features of the measurement signals that are most
sensitive to small changes in tool wear. A neural network based on the long
short-term memory (LSTM) architecture is developed to predict tool flank wear
from the measured spindle motor current and dynamometer signals. It is
demonstrated that the proposed technique predicts tool flank wear with good
accuracy and high computational efficiency. The proposed technique can easily
be implemented in an industrial edge device as a real-time predictive
maintenance application to minimize the costs due to manufacturing downtime and
tool underuse or overuse.Comment: The first four authors have equal contributio
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