100 research outputs found
Universal resonant ultracold molecular scattering
The elastic scattering amplitudes of indistinguishable, bosonic,
strongly-polar molecules possess universal properties at the coldest
temperatures due to wave propagation in the long-range dipole-dipole field.
Universal scattering cross sections and anisotropic threshold angular
distributions, independent of molecular species, result from careful tuning of
the dipole moment with an applied electric field. Three distinct families of
threshold resonances also occur for specific field strengths, and can be both
qualitatively and quantitatively predicted using elementary adiabatic and
semi-classical techniques. The temperatures and densities of heteronuclear
molecular gases required to observe these univeral characteristics are
predicted. PACS numbers: 34.50.Cx, 31.15.ap, 33.15.-e, 34.20.-bComment: 4 pages, 5 figure
The variable phase method used to calculate and correct scattering lengths
It is shown that the scattering length can be obtained by solving a Riccati
equation derived from variable phase theory. Two methods of solving it are
presented. The equation is used to predict how long-range interactions
influence the scattering length, and upper and lower bounds on the scattering
length are determined. The predictions are compared with others and it is shown
how they may be obtained from secular perturbation theory.Comment: 7 pages including 3 figure
Resonance phenomena in ultracold dipole-dipole scattering
Elastic scattering resonances occurring in ultracold collisions of either
bosonic or fermionic polar molecules are investigated. The Born-Oppenheimer
adiabatic representation of the two-bodydynamics provides both a qualitative
classification scheme and a quantitative WKB quantization condition that
predicts several sequences of resonant states. It is found that the
near-threshold energy dependence of ultracold collision cross sections varies
significantly with the particle exchange symmetry, with bosonic systems showing
much smoother energy variations than their fermionic counterparts. Resonant
variations of the angular distributions in ultracold collisions are also
described.Comment: 19 pages, 6 figures, revtex4, submitted to J. Phys.
The weight of water
Leonardo da Vinci’s pioneering work on hydrostatics combined traditional knowledge and innovative empiricism in an attempt to understand an object fraught with paradox: the water-filled container
Optimization of Supercritical Carbon Dioxide Extraction of Rice Bran Oil and γ-Oryzanol Using Multi-Factorial Design of Experiment
After rice harvesting, the milling processes generate many by-products including husk, bran, germs, and broken rice representing around 40% of the total grain. Bran, one of the external cereal layers, contains proteins, dietary fibers, minerals, and lipids. One of the most common rice bran utilization is the extraction of rice bran oil (RBO). Among all vegetable oils, RBO presents a unique chemical composition rich in antioxidant compounds such as γ-oryzanol that provide several beneficial properties. RBO is generally extracted by exploiting hexane, a solvent toxic to the environment and human health. The growing demand for this oil has led researchers to look for more sustainable extraction techniques. Supercritical carbon dioxide (SC-CO2) has been successfully applied to extract oil and functional compounds from several matrices. In this work, the SC-CO2 extraction of RBO was optimized using a Design of Experiment (DoE) on a pilot scale. "The DoE approach involving multilinear regression allowed modelling the yield in RBO and gamma oryzanol as a function of temperature and pressure, keeping the extraction time constant, as decided by the company. This approach made it possible to optimize the extraction yield and to identify the best temperature (40 °C), while also highlighting that pressure did not play any influential role in the process, at least concerning the analyzed experimental domain on this industrial plant. A model for computing the extraction yield as a function of temperature and pressure was obtained. This study shows that it is possible to obtain good quality RBO, rich in γ-oryzanol and essential fatty acids, using low temperatures and pressures, starting from a rice milling by-product. Graphical Abstract: [Figure not available: see fulltext.
Low energy atomic collision with dipole interactions
We apply quantum defect theory to study low energy ground state atomic
collisions including aligned dipole interactions such as those induced by an
electric field. Our results show that coupled even () relative orbital
angular momentum partial wave channels exhibit shape resonance structures while
odd () channels do not. We analyze and interpret these resonances within the
framework of multichannel quantum defect theory (MQDT).Comment: 27 pages, 17 figures, an inadvertent typo correcte
Quantum Simulations of Extended Hubbard Models with Dipolar Crystals
In this paper we study the realization of lattice models in mixtures of
atomic and dipolar molecular quantum gases. We consider a situation where polar
molecules form a self-assembled dipolar lattice, in which atoms or molecules of
a second species can move and scatter. We describe the system dynamics in a
master equation approach in the Brownian motion limit of slow particles and
fast phonons, which we find appropriate for our system. In a wide regime of
parameters, the reduced dynamics of the particles leads to physical
realizations of extended Hubbard models with tuneable long-range interactions
mediated by crystal phonons. This extends the notion of quantum simulation of
strongly correlated systems with cold atoms and molecules to include
phonon-dynamics, where all coupling parameters can be controlled by external
fields.Comment: 44 pages, 14 figure
CD56, HLA-DR, and CD45 recognize a subtype of childhood AML harboring CBFA2T3-GLIS2 fusion transcript
The presence of CBFA2T3‐GLIS2 fusion gene has been identified in childhood Acute Myeloid Leukemia (AML). In view of the genomic studies indicating a distinct gene expression profile, we evaluated the role of immunophenotyping in characterizing a rare subtype of AML‐CBFA2T3‐GLIS2 rearranged. Immunophenotypic data were obtained by studying a cohort of 20 pediatric CBFA2T3‐GLIS2‐AML and 77 AML patients not carrying the fusion transcript. Enrolled cases were included in the Associazione Italiana di Ematologia Oncologia Pediatrica (AIEOP) AML trials and immunophenotypes were compared using different statistical approaches. By multiple computational procedures, we identified two main core antigens responsible for the identification of the CBFA2T3‐GLIS2‐AML. CD56 showed the highest performance in single marker evaluation (AUC = 0.89) and granted the most accurate prediction when used in combination with HLA‐DR (AUC = 0.97) displaying a 93% sensitivity and 99% specificity. We also observed a weak‐to‐negative CD45 expression, being exceptional in AML. We here provide evidence that the combination of HLA‐DR negativity and intense bright CD56 expression detects a rare and aggressive pediatric AML genetic lesion improving the diagnosis performance
Addressing Women's Non-Maternal Healthcare Financing in Developing Countries: What Can We Learn from the Experiences of Rural Indian Women?
Background and Objectives: This paper focuses on the inadequate attention on women’s non-maternal healthcare in lowand middle-income countries. The study assessed the purchase of and financial access to non-maternal healthcare. It also scoped for mainstreaming household financial resources in this regard to suggest for alternatives. Methods: A household survey through multi-stage stratified sampling in the state of Orissa interviewed rural women above 15 years who were neither pregnant nor had any pregnancy-related outcome six weeks preceding the survey. The questions explored on the processes, determinants and outcomes of health seeking for non-maternal ailments. The outcome measures were healthcare access, cost of care and financial access. The independent variables for bivariate and multivariate analyses were contextual factors, health seeking and financing pattern. Results: The survey obtained a response rate of 98.64 % and among 800 women, 43.8 % had no schooling and 51 % were above 60 years. Each woman reported at least one episode of non-maternal ailment; financial constraints prevented 68% from receiving timely and complete care. Distress coping measures (e.g. borrowings) dominated the financing source (67.9%) followed by community–based measures (32.1%). Only 6 % had financial risk-protection; financial risk of not obtaining care doubled for women aged over 60 years (OR 2.00, 95 % CI 0.84–4.80), seeking outpatient consultation (OR 2.01, 95 % CI 0.89–4.81), facing unfavourable household response (OR 2.04, 95 % CI 1.09–3.83), and lacking other financia
Survival of neonates in rural Southern Tanzania: does place of delivery or continuum of care matter?
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The concept of continuum of care has recently been highlighted as a core principle of maternal, newborn and child health initiatives, and as a means to save lives. However, evidence has consistently revealed that access to care during and post delivery (intra and postpartum) remains a challenge in the continuum of care framework. In places where skilled delivery assistance is exclusively available in health facilities, access to health facilities is critical to the survival of the mother and her newborn. However, little is known about the association of place of delivery and survival of neonates. This paper uses longitudinal data generated in a Health and Demographic Surveillance System in rural Southern Tanzania to assess associations of neonatal mortality and place of delivery. Three cohorts of singleton births (born 2005, 2006 and 2007) were each followed up from birth to 28 days. Place of birth was classified as either "health facility" or "community". Neonatal mortality rates were produced for each year and by place of birth. Poisson regression was used to estimate crude relative risks of neonatal death by place of birth. Adjusted ratios were derived by controlling for maternal age, birth order, maternal schooling, sex of the child and wealth status of the maternal household. Neonatal mortality for health facility singleton deliveries in 2005 was 32.3 per 1000 live births while for those born in the community it was 29.7 per 1000 live births. In 2006, neonatal mortality rates were 28.9 and 26.9 per 1,000 live births for deliveries in health facilities and in the community respectively. In 2007 neonatal mortality rates were 33.2 and 27.0 per 1,000 live births for those born in health facilities and in the community respectively. Neonates born in a health facility had similar chances of dying as those born in the community in all the three years of study. Adjusted relative risks (ARR) for neonatal death born in a health facility in 2005, 2006 and 2007 were 0.99 (95% CI: 0.58 - 1.70), 0.98 (95% CI: 0.62 - 1.54) and 1.18 (95% CI: 0.76 - 1.85) respectively. We found no evidence to suggest that delivery in health facilities was associated with better survival chances of the neonates.\u
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