State Transitions and Decoherence in the Avian Compass

The radical pair model has been successful in explaining behavioral characteristics of the geomagnetic compass believed to underlie the navigation capability of certain avian species. In this study, the spin dynamics of the radical pair model and decoherence therein are interpreted from a microscopic state transition point of view. This helps to elucidate the interplay between the hyperfine and Zeeman interactions that enables the avian compass, and the distinctive effects of nuclear and environmental decoherence on it. Using a quantum information theoretic quantifier of coherence, we find that nuclear decoherence induces new structure in the spin dynamics without materially affecting the compass action; environmental decoherence, on the other hand, completely disrupts it.Comment: 6 pages, 6 figure

On the functional window of the avian compass

The functional window is an experimentally observed property of the avian compass that refers to its selectivity around the geomagnetic field strength. We show that the radical-pair model, using biologically feasible hyperfine parameters, can qualitatively explain the salient features of the avian compass as observed from behavioral experiments: its functional window, as well as disruption of the compass action by an RF field of specific frequencies. Further, we show that adjustment of the hyperfine parameters can tune the functional window, suggesting a possible mechanism for its observed adaptability to field variation. While these lend strong support to the radical-pair model, we find it impossible to explain quantitatively the observed width of the functional window within this model, or even with simple augmentations thereto. This suggests that a deeper generalization of this model may be called for; we conjecture that environmental coupling may be playing a subtle role here that has not been captured accurately. Lastly, we examine a possible biological purpose to the functional window; assuming evolutionary benefit from radical-pair magnetoreception, we conjecture that the functional window is simply a corollary thereof and brings no additional advantage.Comment: 7 pages, 4 figure

DDoS Mitigation by Blockchain With Approach of Cost Model

Computer networks and internet services are increasingly threatened by attacks like Distributed Denial-of-Service (DDoS). DDoS attack mitigation techniques now in use are ineffective due to a lack of resources and a lack of adaptability. Using blockchains like Ethereum, DDoS attacks can be thwarted in innovative ways. With smart contracts, it is possible to track down the IP addresses of attackers without additional hardware. This study examines blockchain-based solutions to combat DDoS attacks for feasibility, effectiveness, as well as cost and performance. The cost model delves into economic aspects like gas, gas price, and Ether value. In it, the evaluation of various smart contracts for the signalization of DDoS attacks is documented and compared to assess three system variants, analyzing gas costs, deployment, speed, and accuracy. It also details Ethereum's ecosystem and how that affects smart contract design and it also acknowledges scalability challenges and suggests outsourcing data for a more scalable solution, advocating for specialized blockchains for DDoS signaling applications. The analysis provides insights into the gas costs associated with different variants, considering various scenarios and highlighting the trade-offs and efficiencies of each approach

Sonographic and histopathological correlation and evaluation of causes of abnormal uterine bleeding in perimenopausal women

Background: Perimenopausal period in a woman’s lifetime marks a transition from reproductive phase to that of menopause. Abnormal uterine bleeding (AUB) is a common problem among women in the reproductive age.Methods: It was a prospective study on 100 perimenopausal women in age group 39-51 years with abnormal uterine bleeding who underwent Hysterectomy at SMS Hospital, Jaipur. At the end clinical diagnosis, ultrasonographic findings and histopathological reports were correlated.Results: 42.0% cases had HMB menstrual pattern followed by 24.0% cases had HPMB and 18.0% of the cases had PB. Intermenstrual bleeding was seen in 2% cases.  In clinical finding, 71.0% cases had fibroid followed by 15.0% cases had adenomyosis and 6.0% of the cases had fibroid+adenomyosis. The clinical diagnosis was confirmed by ultrasonography. Ultrasound detected fibroid in 95.8% of the cases who were suspected to have fibroid on clinical examination. Out of the 15 patients who were clinically suspected to have adenomyosis, 53.3% confirmed on ultrasound, ultimate diagnosis was made on the basis of histology, so every hysterectomy specimen was sent for histopathological examination. Out of the 68 patients who were diagnosed to have fibroid uterus on ultrsonography, 66 patients were confirmed to have fibroid. Out of the 8 patients who were labelled as adenomyosis after ultrasound, 4 patients were diagnosed to have adenomyosis on histopathology and in rest 4 patients, no gross pathology was detected.Conclusions: A transvaginal ultrasound should be offered as the first line of imaging. Clinical, radiological and pathological evaluation correlated well to diagnose fibroids, however clinically as well as USG proved to be of little help in diagnosing adenomyosis

2p3/2 –13x–1–3x–13d–1 X-ray satellites spectra in the Lα1 region of 4d transition elements

The X-ray satellite spectra arising due to 2p3/2–13x–1–3x–13d–1 (x = s, p, d) transition array, in elements with Z = 40 to 48, have been calculated, using available Hartree-Fock-Slater (HFS) data on 1s–1–2p–1 3x – and 2p3/2–1–3x–1,3x–1 Auger transition energies. The relative intensities of all the possible transitions have been estimated by considering cross – sections for the Auger transitions simultaneous to a hole creation and then distributing statistically the total cross sections for initial two hole states 2p3/2–1–3x–1 amongst various allowed transitions from these initial states to 3x–1 3d–1 final states by Coster-Kronig (CK) and shake off processes. In both these processes initial single hole creation is the prime phenomenon. Each transition has been assumed to give rise to a Gaussian line and the overall spectrum has been computed as the sum of these Gaussian curves. The calculated spectra have been compared with the measured satellite energies in La1 spectra. Their intense peaks have been identified as the observed satellite lines. The peaks in the theoretical satellite spectra were identified as the experimentally reported satellites a3, a4 and a5, which lie on the high-energy side of the La1 dipole line.Author Affiliation: Surendra Poonia and S N Sonib 1.Division of Natural Resources and Environment, Central Arid Zone Research Institute, Jodhpur-342 003, Rajasthan, India bX-ray Laboratory, Physics Department, Jai Narain Vyas University, Jodhpur-342 005, Rajasthan, India E-mail : [email protected] of Natural Resources and Environment, Central Arid Zone Research Institute, Jodhpur-342 003, Rajasthan, India bX-ray Laboratory, Physics Department, Jai Narain Vyas University, Jodhpur-342 005, Rajasthan, Indi