Probing polaron clouds by Rydberg atom spectroscopy

In recent years, Rydberg excitations in atomic quantum gases have become a successful platform to explore quantum impurity problems. A single impurity immersed in a Fermi gas leads to the formation of a polaron, a quasiparticle consisting of the impurity being dressed by the surrounding medium. With a radius of about the Fermi wavelength, the density profile of a polaron cannot be explored using in-situ optical imaging techniques. In this work, we propose a new experimental measurement technique that enables the in-situ imaging of the polaron cloud in ultracold quantum gases. The impurity atom is first excited to an interacting state which induces the formation of a polaron cloud. This is followed by the excitation of the impurity atom to a Rydberg state. Due to the mesoscopic interaction range of Rydberg excitations, which can be tuned by the principal numbers of the Rydberg state, atoms extracted from the polaron cloud form dimers with the impurity. By performing first principle calculations of the absorption spectrum based on a functional determinant approach, we show how the occupation of the dimer state can be directly observed in spectroscopy experiments and can be mapped onto the density profile of the gas particles, hence providing a direct, real-time, and in-situ measure of the polaron cloud.Comment: 15 pages, 12 figure

High-temperature scaling limit for directed polymers on a hierarchical lattice with bond disorder

Diamond "lattices" are sequences of recursively-defined graphs that provide a network of directed pathways between two fixed root nodes, $A$ and $B$. The construction recipe for diamond graphs depends on a branching number $b\in \mathbb{N}$ and a segmenting number $s\in \mathbb{N}$, for which a larger value of the ratio $s/b$ intuitively corresponds to more opportunities for intersections between two randomly chosen paths. By attaching i.i.d. random variables to the bonds of the graphs, I construct a random Gibbs measure on the set of directed paths by assigning each path an "energy" given by summing the random variables along the path. For the case $b=s$, I propose a scaling regime in which the temperature grows along with the number of hierarchical layers of the graphs, and the partition function (the normalization factor of the Gibbs measure) appears to converge in law. I prove that all of the positive integer moments of the partition function converge in this limiting regime. The motivation of this work is to prove a functional limit theorem that is analogous to a previous result obtained in the $b<s$ case.Comment: 28 pages, 1 figur

Not all respondents use a multiplicative utility function in choice experiments for health state valuations, which should be reflected in the elicitation format (or statistical analysis)

Discrete choice experiments (DCEs) that include health states and duration are becoming a common method for estimating quality‐adjusted life year (QALY) tariffs. These DCEs need to be analyzed under the assumption that respondents treat health and duration multiplicatively. However, in the most commonly used DCE duration format there is no guarantee that respondents actually do so; in fact, respondents can easily simplify the choice tasks by considering health and duration separately. This would result in valid DCE responses but preclude subsequent QALY tariff calculations. Using a Bayesian latent class model and data from two existing valuation studies, our analyses confirm that in both datasets the majority of respondents do not appear to have used a multiplicative utility function. Moreover, a statistical correction for respondents who used an incorrect function changes the range of the QALY weights. Hence our results imply that one can neither assume that respondents use the theoretically required multiplicative utility function nor assume that the type of utility function that respondents use does not affect the estimated QALY weights. As a solution, we advise researchers to use an alternative, more constrained DCE elicitation format that avoids these behavioral problems

Neural correlates of intentional and stimulus-driven inhibition: a comparison

People can inhibit an action because of an instruction by an external stimulus, or because of their own internal decision. The similarities and differences between these two forms of inhibition are not well understood. Therefore, in the present study the neural correlates of intentional and stimulus-driven inhibition were tested in the same subjects. Participants performed two inhibition tasks while lying in the scanner: the marble task in which they had to choose for themselves between intentionally acting on, or inhibiting a prepotent response to measure intentional inhibition, and the classical stop signal task in which an external signal triggered the inhibition process. Results showed that intentional inhibition decision processes rely on a neural network that has been documented extensively for stimulus-driven inhibition, including bilateral parietal and lateral prefrontal cortex and pre-supplementary motor area. We also found activation in dorsal frontomedian cortex and left inferior frontal gyrus during intentional inhibition that depended on the history of previous choices. Together, these results indicate that intentional inhibition and stimulus-driven inhibition engage a common inhibition network, but intentional inhibition is also characterized by additional context-dependent neural activation in medial prefrontal cortex

State reform, emergence of decentralization and environmental policies

No contexto da reforma do Estado brasileiro, a descentralização das competências políticas e administrativas na arena ambiental tem se mostrado um processo dinâmico. Muitas instâncias locais já respondem pela questão ambiental. No entanto, isso não significa mais competência administrativa, sustentabilidade institucional, tampouco participação democrática. Dois casos de política ambiental são retratados no texto: o licenciamento industrial pelos municípios brasileiros e o a gestão florestal pelo Estado do Mato Grosso. A descentralização do licenciamento ambiental para o âmbito municipal ainda parece frágil em municípios menores, em um processo que parece ser induzido pelo Estado e não pelo controle social local. Em relação à política florestal, o caso do Mato Grosso é emblemático. Ele mostra que a cooperação com o poder público federal e, em determinados momentos, sua coordenação são de suma importância para que as políticas públicas ambientais não fiquem à mercê de governos estaduais, que podem enviesá-las em favor do “desenvolvimentismo”, nem percam a legitimidade adiante da fragilidade financeira e institucional dos órgãos ambientais locais. _______________________________________________________________________________________ RESUMENAnte la reforma del Estado brasileño, la decentralización de las competencias políticas y administrativas en el ámbito ambiental se han mostrado un proceso dinámico. Muchas de las instancias locales ya responden por la cuestión ambiental. Sin embargo, eso no significa competencia administrativa, sustentabilidad institucional, tampoco participación democratica. En este estudio se presentan dos casos de política ambiental: el licenciamiento industrial por parte de los municipios brasileños y la gestión forestal por parte del Estado de Mato Grosso. La descentralización del licenciamiento ambiental para el nivel municipal todavia se muestra frágil en los municipios más pequeños, debido a que el proceso aun está controlado por el estado por encuanto que la sociedades locales tienen menos participación. En relación a la política forestal, el caso del Estado de Mato Grosso demuestra que la cooperación y, en ciertos momentos, la coordinación del poder público federal determinan la vulnerabilidad de las políticas ambientales. Esto es debido a que los intereses “desarrollistas” de gobiernos estaduales pueden influenciar dichas políticas. Por otra parte, la fragilidad financiera y institucional de los órganos ambientales locales pueden también influenciarlas. _______________________________________________________________________________________ ABSTRACTMirroring the reform of the Brazilian State, the decentralization of administrative and political competences in the environmental arena has been a dynamic process. Many local governments and agencies already hold responsibility for environmental issues. However, it does not mean stronger administrative competency, institutional sustainability or wider democratic participation. Two cases of environmental policy are described here: the industrial licensing carried out by Brazilian municipalities and the State of Mato Grosso´s forest management. The decentralization of environmental licensing to the municipal level still seems to be fragile process in small municipalities, since it is likely to be induced by the State rather than by the local community. Regarding the forest policy, the case of Mato Grosso is emblematic: it shows that cooperation and, at times, coordination of the federal government is of great importance in order to assure the independence of environmental public policies from state governments that are biased in favor of agro-industries, as well to guarantee their legitimacy, weakened by the institutional and financial fragility of the local environmental institution

Nitrogen Transport in a Shallow Outwash Aquifer at Olean, Cattaraugus County, New York

Groundwater beneath an industrial park at Olean, New York, contained nitrogen compounds in concentrations that in 1983 ranged from 10 to 1,280 mg/L as nitrogen, mainly in the form of ammonium. Continuous pumping from an industrial well field creates a cone of depression that prevents the nitrogen compounds from migrating to municipal-supply wells, 7,000 ft away. A two-dimensional solute transport model was used to simulate changes in nitrogen concentrations that would result from a permanent shutdown of the well field. The model assumed the nitrogen source decayed at an exponential rate with a decay constant of 0.3/year to account for nitrogen removed from the aquifer by pumping during 1978-84. The source of contamination was found to be sensitive to the volume of pumpage at the industrial well field, which altered the rate of groundwater flow through the contaminated area. Simulations of a permanent shutdown of the well field, assuming nitrogen migrates as a conservative solute, indicated that nitrogen-bearing groundwater would reach the municipal well field within 5 years and the peak concentrations at the municipal well field would range from 2 to 5 mg/L. Simulations of Langmuir adsorption of the dissolved ammonium with a one-dimensional model indicated that the arrival of the solute front at the municipal well field would be retarded by a factor of three. (USGS

CP-violating top quark couplings at future linear e+e−e^+e^- colliders

We study the potential of future lepton colliders to probe violation of the CP symmetry in the top quark sector. In certain extensions of the Standard Model, such as the two-Higgs-doublet model (2HDM), sizeable anomalous top quark dipole moments can arise, that may be revealed by a precise measurement of top quark pair production. We present results from detailed Monte Carlo studies for the ILC at 500~\GeV{} and CLIC at 380~\gev{} and use parton-level simulations to explore the potential of high-energy operation. We find that precise measurements in $e^+e^- \rightarrow t\bar{t}$ production with subsequent decay to lepton plus jets final states can provide sufficient sensitivity to detect Higgs-boson-induced CP violation in a viable two-Higgs-doublet model. The potential of a linear $e^+e^-$ collider to detect CP-violating electric and weak dipole form factors of the top quark exceeds the prospects of the HL-LHC by over an order of magnitude

HIV and hepatitis virus infections among injecting drug users in a medically controlled heroin prescription programme

Background: In Switzerland, 1,035 patients were accepted for admission to the medically controlled prescription of narcotics programme (PROVE) from 1 January 1994 until 31 December 1996. Heroin, methadone, and morphine were prescribed. This paper presents the prevalence and incidence of HIV and hepatitis B/C infections in the sociomedical context of the participants. Methods: Admission criteria were a minimum age of 20 years, at least a two-year duration of daily heroin consumption, a negative outcome of at least two previous treatments, and documented social and health deficits as a consequence of their heroin dependence. The patients were examined at admission and every six months. A serological test was carried out at the same time for HIV and hepatitis B/C. Results: Serological testing on admission could be performed in more than 80% of the entrants and documented a very high seroprevalence of antibodies against HBcore (73%) and HCV (82%). The prevalence of HIV and hepatitis B/C increased with duration of drug intake. In the follow-up analysis of seronegative individuals, a halving of the risk of viral hepatitis infection was shown when comparing the first six months with the period greater then six months after PROVE entry. Conclusion: The tests conducted showed high prevalence and incidence rates of HIV and hepatitis B/C among patients who had consumed intravenous drugs for years. The descriptive analysis in heroin-assisted treatment showed a reduction in infection risk for viral hepatitis corresponding to the lower risk behaviour of patient