735 research outputs found
Stationary two-atom entanglement induced by nonclassical two-photon correlations
A system of two two-level atoms interacting with a squeezed vacuum field can
exhibit stationary entanglement associated with nonclassical two-photon
correlations characteristic of the squeezed vacuum field. The amount of
entanglement present in the system is quantified by the well known measure of
entanglement called concurrence. We find analytical formulas describing the
concurrence for two identical and nonidentical atoms and show that it is
possible to obtain a large degree of steady-state entanglement in the system.
Necessary conditions for the entanglement are nonclassical two-photon
correlations and nonzero collective decay. It is shown that nonidentical atoms
are a better source of stationary entanglement than identical atoms. We discuss
the optimal physical conditions for creating entanglement in the system, in
particular, it is shown that there is an optimal and rather small value of the
mean photon number required for creating entanglement.Comment: 17 pages, 5 figure
Pemberian Berbagai Jenis Pakan Organik terhadap Kandungan β-Karoten dalam Telur Puyuh Jepang (Coturnix Japonica)
Penelitian ini bertujuan untuk optimalisasi kualitas telur puyuh yang kaya β-karoten. Penelitian ini adalah penelitian eksperimental dengan Rancangan Acak Lengkap (RAL). Hewan yang digunakan untuk produksi telur adalah 60 puyuh Jepang (Coturnix japonica) betina dikelompokkan dalam 4 kelompok percobaan, yaitu P0: Kontrol (puyuh diberi pakan komersial), P1: Puyuh diberi perlakuan dengan pakan organik standar, P2: Puyuh yang diberi perlakuan pakan organik yang mengandung ikan kembung, daun singkong + serbuk kunyit P3: Puyuh yang diberi perlakuan pakan organic yang mengandung rumput laut, daun singkong + serbuk kunyit. Masing-masing perlakuan terdiri dari 15 kali ulangan percobaan. Data dianalisis dengan Anova, dilanjutkan dengan uji Duncan (α=0.05.) Hasil penelitian menunjukkan bahwa pemberian perlakuan pakan organik pada puyuh menyebabkan bobot telur puyuh menjadi lebih kecil dibandingkan yang tidak diberi perlakuan akan organik. Tidak terdapat perbedaan nyata terhadap konsumsi pakan dan bobot kuning telur, namun terdapat peningkatan rasio bobot kuning telur : bobot telur, peningkatan kadar β-karoten pada telur puyuh organik, baik pada P1, P2, dan P3.Hasil penelitian dapat disimpulkan bahwa pemberian pakan organik dapat meningkatkan kandungan β-karoten dalam telur puyuh
Quantum noise and mixedness of a pumped dissipative non-linear oscillator
Evolutions of quantum noise, characterized by quadrature squeezing parameter
and Fano factor, and of mixedness, quantified by quantum von Neumann and linear
entropies, of a pumped dissipative non-linear oscillator are studied. The model
can describe a signal mode interacting with a thermal reservoir in a
parametrically pumped cavity with a Kerr non-linearity. It is discussed that
the initial pure states, including coherent states, Fock states, and finite
superpositions of coherent states evolve into the same steady mixed state as
verified by the quantum relative entropy and the Bures metric. It is shown
analytically and verified numerically that the steady state can be well
approximated by a nonclassical Gaussian state exhibiting quadrature squeezing
and sub-Poissonian statistics for the cold thermal reservoir. A rapid increase
is found in the mixedness, especially for the initial Fock states and
superpositions of coherent states, during a very short time interval, and then
for longer evolution times a decrease in the mixedness to the same, for all the
initial states, and relatively low value of the nonclassical Gaussian state.Comment: 10 pages, 12 figure
Impact of migraine on fibromyalgia symptoms
Background: Fibromyalgia (FMS) and high frequency episodic/chronic migraine (M) very frequently co-occur, suggesting common pathophysiological mechanisms; both conditions display generalized somatic hyperalgesia. In FMS-M comorbidity we assessed if: a different level of hyperalgesia is present compared to one condition only; hyperalgesia is a function of migraine frequency; migraine attacks trigger FMS symptoms. Methods: Female patients with fibromyalgia (FMS)(n.40), high frequency episodic migraine (M1)(n.41), chronic migraine (M2)(n.40), FMS + M1 (n.42) and FMS + M2 (n.40) underwent recording of: −electrical pain thresholds in skin, subcutis and muscle and pressure pain thresholds in control sites, −pressure pain thresholds in tender points (TePs), −number of monthly migraine attacks and fibromyalgia flares (3-month diary). Migraine and FMS parameters were evaluated before and after migraine prophylaxis, or no prophylaxis, for 3 months with calcium-channel blockers, in two further FMS + H1 groups (n.49, n.39). 1-way ANOVA was applied to test trends among groups, Student’s t-test for paired samples was used to compare pre and post-treatment values. Results: The lowest electrical and pressure thresholds at all sites and tissues were found in FMS + M2, followed by FMS + H1, FMS, M2 and M1 (trend: p < 0.0001). FMS monthly flares were progressively higher in FMS, FMS + M1 and FMS + M2 (p < 0.0001); most flares (86–87 %) occurred within 12 h from a migraine attack in co-morbid patients (p < 0.0001). Effective migraine prophylaxis vs no prophylaxis also produced a significant improvement of FMS symptoms (decreased monthly flares, increased pain thresholds)(0.0001 < p < 0.003). Conclusions: Co-morbidity between fibromyalgia and migraine involves heightened somatic hyperalgesia compared to one condition only. Increased migraine frequency – with shift towards chronicity – enhances both hyperalgesia and spontaneous FMS pain, which is reversed by effective migraine prophylaxis. These results suggest different levels of central sensitization in patients with migraine, fibromyalgia or both conditions and a role for migraine as a triggering factor for FMS
Master equations for effective Hamiltonians
We reelaborate on a general method for obtaining effective Hamiltonians that
describe different nonlinear optical processes. The method exploits the
existence of a nonlinear deformation of the su(2) algebra that arises as the
dynamical symmetry of the original model. When some physical parameter (usually
related to the dispersive limit) becomes small, we immediately get a diagonal
effective Hamiltonian that represents correctly the dynamics for arbitrary
states and long times. We apply the same technique to obtain how the noise
terms in the original model transform under this scheme, providing a systematic
way of including damping effects in processes described in terms of effective
Hamiltonians.Comment: 10 pages, no figure
Surgical site infection after caesarean section. Space for post-discharge surveillance improvements and reliable comparisons
Surgical site infections (SSI) after caesarean section (CS) represent a substantial health system concern. Surveying SSI has been associated with a reduction in SSI incidence. We report the findings of three (2008, 2011 and 2013) regional active SSI surveillances after CS in community hospital of the Latium region determining the incidence of SSI. Each CS was surveyed for SSI occurrence by trained staff up to 30 post-operative days, and association of SSI with relevant characteristics was assessed using binomial logistic regression. A total of 3,685 CS were included in the study. A complete 30 day post-operation follow-up was achieved in over 94% of procedures. Overall 145 SSI were observed (3.9% cumulative incidence) of which 131 (90.3%) were superficial and 14 (9.7%) complex (deep or organ/space) SSI; overall 129 SSI (of which 89.9% superficial) were diagnosed post-discharge. Only higher NNIS score was significantly associated with SSI occurrence in the regression analysis. Our work provides the first regional data on CS-associated SSI incidence, highlighting the need for a post-discharge surveillance which should assure 30 days post-operation to not miss data on complex SSI, as well as being less labour intensive
Etude de l'invasion de la Nouvelle-Calédonie par la fourmi pionnière Wasmannia auropunctata (Roger) : modalités, impact sur la diversité et le fonctionnement des écosystèmes, moyens d'une maîtrise de la nuisance : programme INWASCAL : rapport final
Say NO to ROS: Their roles in embryonic heart development and pathogenesis of congenital heart defects in maternal diabetes
Congenital heart defects (CHDs) are the most prevalent and serious birth defect, occurring in 1% of all live births. Pregestational maternal diabetes is a known risk factor for the development of CHDs, elevating the risk in the child by more than four-fold. As the prevalence of diabetes rapidly rises among women of childbearing age, there is a need to investigate the mechanisms and potential preventative strategies for these defects. In experimental animal models of pregestational diabetes induced-CHDs, upwards of 50% of offspring display congenital malformations of the heart, including septal, valvular, and outflow tract defects. Specifically, the imbalance of nitric oxide (NO) and reactive oxygen species (ROS) signaling is a major driver of the development of CHDs in offspring of mice with pregestational diabetes. NO from endothelial nitric oxide synthase (eNOS) is crucial to cardiogenesis, regulating various cellular and molecular processes. In fact, deficiency in eNOS results in CHDs and coronary artery malformation. Embryonic hearts from diabetic dams exhibit eNOS uncoupling and oxidative stress. Maternal treatment with sapropterin, a cofactor of eNOS, and antioxidants such as N-acetylcysteine, vitamin E, and glutathione as well as maternal exercise have been shown to improve eNOS function, reduce oxidative stress, and lower the incidence CHDs in the offspring of mice with pregestational diabetes. This review summarizes recent data on pregestational diabetes-induced CHDs, and offers insights into the important roles of NO and ROS in embryonic heart development and pathogenesis of CHDs in maternal diabetes
Lymph-vascular Space Involvement and Outer One-third Myometrial Invasion Are Strong Predictors of Distant Haematogeneous Failures in Patients with Stage I-II Endometrioid-type Endometrial Cancer
The aim of this retrospective study was to assess the predictive value of different clinicopathological variables (patient age, tumour size, FIGO grade, myometrial invasion, lymph-vascular space involvement [LVSI], invasion margins, peri-tumour phlogistic infiltrate and mitotic activity) for the risk of distant haematogenous recurrences in patients with endometrioid-type stage Ib-II endometrial cancer. Between August 1990 and April 2005, 259 patients had undergone laparotomy, peritoneal washing, total abdominal hysterectomy and bilateral salpingo-oophorectomy, with or without pelvic +/- para-aortic lymphadenectomy for endometrioid-type endometrial cancer. Thirty-six (13.9%) patients had developed recurrent disease after a median time of 17 months (range, 2-128 months). The relapse had been locoregional in 9, distant in 21 and both locoregional plus distant in 6 cases. This study assessed 12 patients with FIGO stage Ib-II disease who had developed distant haematogenous recurrences and 20 randomly chosen control patients with FIGO stage Ib-II disease who had remained recurrence-free after a median follow-up of 52 months (range, 37-66 months). Adjuvant therapy had been: no further treatment in 15 patients, external pelvic irradiation in 14 patients, adjuvant external pelvic irradiation plus brachytherapy in 2 patients and platinum-based chemotherapy followed by external pelvic irradiation in I patient. The site of distant failure had been the lung in 9 patients, liver in 2 patients and lung plus liver in I patient. A concomitant locoregional relapse (vagina or lymph nodes) had occurred in 3 patients. The median interval between surgery and the development of distant failure had been 16.5 months (range, 5-113 months). On univariate analysis, a higher incidence of FIGO grade 3 (50% versus 10%, p=0.0114), outer one-third myometrial invasion (91.7% versus 35.0%, p=0.0051) and LVSI (75.0.% versus 20.0%, p=0.0022) was found in the patients who had developed distant haematogeneous metastases compared to the recurrence-free women. Multivariate analysis showed that LVSI (p=0.0264) and deep myometrial invasion (p=0.0345) were independent predictive variables for the risk of distant haematogeneous failure. Patients with these pathological findings should be enrolled in randomised trials designed to assess the role of adjuvant chemotherapy alone or combined with sequential and /or concomitant external pelvic irradiation
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