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The effect of inner-shell photodetachment channels on outer-shell photodetachment is investigated using the R-matrix method. The simplest multishell closed-shell negative ion, Li−, is examined near the 1s detachment threshold and the results show that the interchannel coupling significantly alters the shapes and magnitudes of the valence photodetachment cross sections in this energy region. [ABSTRACT FROM AUTHOR]

The relativistic-random-phase approximation (RRPA) methodology, developed by Walter Johnson and his collaborators, has been used extensively over the past three decades to calculate various aspects of the atomic photoionization process, cross sections, and branching ratios along with dipole and nondipole contributions to the photoelectron angular distribution. In this paper, some of the progress made in our understanding of the photoionization process as a result of RRPA calculations is reviewed.PACS No.: 32.80.Fb [ABSTRACT FROM AUTHOR]

Motor control demands coordinated excitation and inhibition across distributed brain neuronal networks. Recent work has suggested that multiple sclerosis (MS) may be associated with impairments of neuronal inhibition as part of more general progressive impairments of connectivity. Here, we report results from a prospective, multi-centre fMRI study designed to characterise the changes in patients relative to healthy controls during a simple cued hand movement task. This study was conducted at eight European sites using 1.5 Tesla scanners. Brain deactivation during right hand movement was assessed in 56 right-handed patients with relapsing-remitting or secondary progressive MS without clinically evident hand impairment and in 60 age-matched, healthy subjects. The MS patients showed reduced task-associated deactivation relative to healthy controls in the pre- and postcentral gyri of the ipsilateral hemisphere in the region functionally specialised for hand movement control. We hypothesise that this impairment of deactivation is related to deficits of transcallosal connectivity and GABAergic neurotransmission occurring with the progression of pathology in the MS patients. This study has substantially extended previous observations with a well-powered, multicentre study. The clinical significance of these deactivation changes is still uncertain, but the functional anatomy of the affected region suggests that they could contribute to impairments of motor control. [ABSTRACT FROM AUTHOR]

This paper examines the use of evolutionary programming in agent‐based modelling to implement the theory of bounded rationality. Evolutionary programming, which draws on Darwinian analogues of computing to create software programs, is a readily accepted means for solving complex computational problems. Evolutionary programming is also increasingly used to develop problem‐solving strategies in accordance with bounded rationality, which addresses features of human decision‐making such as cognitive limits, learning, and innovation. There remain many unanswered methodological and conceptual questions about the linkages between bounded rationality and evolutionary programming. This paper reports on how changing parameters in one variant of evolutionary programming, genetic programming, affects the representation of bounded rationality in software agents. Of particular interest are: the ability of agents to solve problems; limits to the complexity of agent strategies; the computational resources with which agents create, maintain, or expand strategies; and the extent to which agents balance exploration of new strategies and exploitation of old strategies. [ABSTRACT FROM AUTHOR]

This special review summarizes and illustrates the state of our knowledge regarding the mental health needs of American Indians and Alaska Natives. These needs are considerable and pervasive. The discussion begins by reflecting on the limits of psychiatric nomenclature and conceptual frameworks for revealing Native constructions of mental health and mental illness. The experience and manifestation of psychopathology can be both different and the same across cultures, hinging upon the extent to which such basic assumptions as the relationship of mind to body--and spirit in the case of Native people--or the primacy of the individual or social collective are shared. Having set the stage, this paper moves to recent empirical evidence regarding the mental health needs of American Indians and Alaska Natives: we review that evidence and consider it within the broader context of available services. The report closes with a brief overview of the most pressing issues and forces for change afoot in Indian country in the US. Most have to do with the structure and financing of care as tribes and other Native community-based organizations seek to balance self-determination and resource management to arrive at effective, fiscally responsible, culturally informed prevention, treatment, and aftercare options for their members. These changes may herald similar trends among First Nations people to the immediate north. [ABSTRACT FROM AUTHOR]

A semiempirical model of single differential cross sections (SDCS) for ionization of water vapor by fast electrons and bare ions is presented. At low secondary-electron energy, the model is based on an asymptotic expansion of the first Born approximation with coefficients, that are independent of projectile properties, evaluated from experimental photoabsorption and proton-impact ionization data. As the secondary-electron energy increases, the model converges to a binary-encounter approximation. Comparisons with measured differential, total, and dissociative cross sections for ionization of water by fast electrons are used to test the model. For primary electrons with energy greater than about 500 eV, agreement with these data is generally within experimental uncertainty; however, some discrepancies of uncertain origin exist. [ABSTRACT FROM AUTHOR]

Youth suicide is increasing in the United States, with deaths among younger people of color driving this upward trend. For more than four decades, American Indian and Alaska Native (AIAN) communities have suffered disproportionate rates of youth suicide and years of productive life lost compared to other U.S. Races. The National Institute of Mental Health (NIMH) recently funded three regional Collaborative Hubs to carry out suicide prevention research, practice, and policy development with AIAN communities in Alaska and rural and urban areas of the Southwestern United States. The Hub partnerships are supporting a diverse array of tribally-driven studies, approaches, and policies with immediate value for increasing empirically driven public health strategies to address youth suicide. We discuss unique features of the cross-Hub work, including: (a) long-standing Community-Based Participatory Research processes that led to the Hubs' innovative designs and novel approaches to suicide prevention and evaluation, (b) comprehensive ecological theoretical approaches that contextualize individual risk and protective factors in multilevel social contexts; (c) unique task-shifting and systems of care approaches to increase reach and impact on youth suicide in low-resource settings; and (d) prioritization of strengths-based approaches. The work of the Collaborative Hubs for AIAN youth suicide prevention is generating specific and substantive implications for practice, policy, and research presented in this article at a time when youth suicide prevention is a dire national priority. Approaches also have relevance for historically marginalized communities worldwide. [ABSTRACT FROM AUTHOR]

Rotational grazing (RG) is a livestock management practice that moves grazing cattle among small temporary pastures called paddocks. In dairy farming, RG has potential to improve soil and water conservation by situating well-managed perennial vegetation on erosion-prone parts of farm landscapes. Recently, geospatial technologies have enabled precise identification of "critical source areas" (CSAs). CSAs are sites where slope, soil, and water flow factors coincide to create the largest potential impacts on surface water quality from erosion within the landscape of a farm. Examination of land-use and land-cover (LULC) practices on CSAs allows nuanced comparisons of effects on water resources among agricultural production systems, enabling us to test the hypothesis that RG dairy farms manage CSAs so as to have lesser effects on water resources than comparable-sized nongrazing dairy farms. We assessed LULC on CSAs in 53 small dairy farms in New York, Pennsylvania, and Wisconsin, United States, using satellite imagery and other spatial data. Among these farms, 22 used some form of RG, while the remainder did not use grazing. We also did on-farm observations of most CSAs to assess the frequency of features that may particularly affect water resources, such as unvegetated areas within pastures. RG dairy farms differed significantly from nongrazing dairy farms in the total allocation of CSA area to hayfields and rotational pastures--two LULC types that are likely to reduce runoff and emissions of sediment and nutrients into waterways--but this difference varied across the states and was pronounced only in the Pennsylvania farms, where high-intensity grazing farms allocated these perennial LULC types to over 60% of CSA lands, while nongrazing farms allocated these LULC types to about 20% of CSAs. In New York and Pennsylvania, RG farms allocated significantly less erosion-prone annual cropland to CSA sites than nongrazing farms, and allocated less of the total farm area to LULC practices that are relatively vulnerable to soil erosion. However, these differences between farm types were pronounced only in Pennsylvania farms. Our results do not support the hypothesis that RG dairy farms are generally superior to comparably sized nongrazing dairy farms in their management of CSAs. It is likely that targeted technical and cost-share support could improve management of CSAs in RG farms, allowing them to more fully realize the potential of RG systems to improve soil and water conservation. [ABSTRACT FROM AUTHOR]

The combined effects of interchannel coupling, relativistic interactions and endohedral confinement on the photoionization of atomic Kr are studied. The confinement of the Kr atom placed at the centre of the C60 cage is modelled by placing the atom inside an annular spherical potential. Cross sections for the photoionization and angular distribution of photoelectrons from the 4p, 4s, 3d and 3p subshells are reported within the framework of the relativistic-random-phase approximation. [ABSTRACT FROM AUTHOR]

The photoabsorption by an electron bound by a two-centre potential has been investigated within the framework of the zero-range potential model. Expressions for total photoabsorption cross sections and for the photoelectron angular distributions have been derived for fixed-in-space and randomly oriented targets. The analytical formulae for gerade and ungerade molecular states have been used to analyse separately the molecular effects due to the two-centre ground state of quasi-molecule and diffraction effects that are connected with the spherical waves in the molecular continuum. It is shown that the interference of these waves significantly influences the magnitude of the cross sections near threshold but does not significantly distort the shape of the photoelectron angular distribution and it depends rather weakly on the character of the forces acting between the electron and molecular residue: Coulomb forces for neutral molecular photoionization or the short-range forces in the case of photodetachment of molecular negative ions. It is shown that despite the fact that the photoionization of diatomic molecules is reminiscent of Young's double-slit experiment, the similarity between these processes has been grossly exaggerated. This is confirmed by comparing the results of the classical interference of an electron scattered by two spatially separated centres with molecular photoelectron angular distributions [ABSTRACT FROM AUTHOR]

Recent development of ultrafast measurement techniques on the sub-femtosecond time scale has enabled us to see the atom–laser interaction in real time. One of the important observables to study the temporally resolved dynamics is the various time delay in the process. Time delays is an experimentally measurable quantity, where the time is not. Time delays in quantum collisions and in photoionization/photodetachment of atomic and molecular systems is reviewed. The formalisms of time delay in the context of quantum collisions by Eisenbud and Wigner that by Smith and their equivalence is discussed. The time-reversal symmetry between solutions with outgoing and ingoing wave boundary conditions allow us to interpret photoionization/photodetachment as half-scattering. Subsequently, the formalism of Eisenbud–Wigner–Smith time delay is extended in photoionization/photodetachment from collisions. We discuss that the time delay can be written as a self-adjoint quantum operator which depicts its measurability. On the experimental side, the measurement protocols are reviewed for attosecond streaking and RABBITT. Along with the EWS time delay, the measurement introduces an additional (which is negative) time delay. From the measurement of total delay and an analytical/numerical estimate of the measurement induced part, one gets the EWS time delay in the process. A few illustrative examples of studies on time delay are given to get a flavour of the outstanding advances made in this field in the last two decades. [ABSTRACT FROM AUTHOR]

A new theory for near-threshold photoionization of inner electrons of atoms confined in multicentered atomic formations, e.g. molecules or clusters, is developed. The formulas for fixed-in-space molecules have been derived. The interaction of the photoelectron in the continuum with atoms that surround the atom being ionized, is replaced by the suitable boundary conditions imposed on the photoelectron wave function at the location of nuclei of these atoms in the molecule. The general formulas derived are used to calculate photoelectron angular distributions of diatomic molecules. The calculated data are in qualitative agreement with experimental data and results of other calculations. [ABSTRACT FROM AUTHOR]

Photoionization of the free and confined Mg (Mg@C60) have been calculated in the vicinity of the inner-shell 2p thresholds using R -matrix at the Breitâ€"Pauli R -matrix level with a particular emphasis on the various resonance series leading up to the two lowest inner-shell thresholds and the changes resulting from the confinement. For free Mg, the calculated resonance positions agree well with NIST values, and a number of new resonances are identified. For confined Mg, the calculation was done for various depths of the confining potential well in order to follow the trajectories of the resonances as a function of well depth. The results for the well depth corresponding to Mg@C60 showed that most of the resonances moved to higher photon energy, as a result of the confinement, but a few moved to lower energies. This phenomenology was found to result from the fact that the 3p, 3d and 4s excitations are trapped by the confining potential well, while the higher excitations were not. [ABSTRACT FROM AUTHOR]

Confined atomic systems are of great importance owing a multitude of possible applications in various areas of science and technology. Of particular interest are atoms encaged in the C 60 molecule, A @ C 60 , since the near-spherical symmetry of C 60 simplifies theoretical studies, and the stability of C 60 renders it amenable to experimental examination. A review of investigations of the electronic structure and dynamics of A @ C 60 is presented in this manuscript focusing on developments in the last decade. Addressed mainly are how the confinement affects electronic structure properties such as ionization potentials, localization of atomic electrons, Shannon entropy, correlation effects, relativistic interactions, and others. In the area of dynamics, photoionization and e- A @ C 60 scattering are reviewed and summarized, and the major effects of confinement on the dynamical properties, e.g., confinement resonances, hybridization, Wigner time delay, are delineated. [ABSTRACT FROM AUTHOR]

Calculations of the photoionization cross sections of the ground states of the superheavy atoms No (Z = 102), Cn (Z = 112) and Og (Z = 118) have been performed using fully relativistic methodologies. The photoionization cross sections are dominated by interchannel coupling, in all cases, over a broad energy range including both outer and inner shells. [ABSTRACT FROM AUTHOR]

We report studies of photoelectron angular distribution and cross-section for photoionization of xenon 5s electrons using the relativistic multiconfiguration Tamm–Dancoff (MCTD) approximation. We find that MCTD provides a significantly improved agreement with experiment, compared to some of the other relativistic many body approximations such as the relativistic random phase approximation and the relativistic random phase approximation with relaxation, over the entire photon energy region bracketing the near-threshold 5s Cooper minimum, from the 5s threshold up to about 70 eV. The MCTD results in the length form are in much better agreement with the experiment than those in the velocity form, suggesting residual correlations that must be of importance. [ABSTRACT FROM AUTHOR]

The 3d core level photoemission of metallic Ag and In was measured over a wide energy range including the 2p ionization thresholds. The intensities (photoionization cross sections) of the 3d5/2 and 3d3/2 lines were observed to modulate significantly with photon energy, both absolute and relative, and this is most pronounced in the vicinity of the 2p thresholds, i.e., at photon energies about an order of magnitude above the 3d thresholds. Calculations based on the relativistic-random-phase approximation show that this effect is due to interchannel coupling of the 3d photoionization channels with the 2p channels affecting the cross section over a wide range of energies. It is argued that this is a general phenomenon in high-energy photoionization throughout the periodic table. [ABSTRACT FROM AUTHOR]

An analytical formula is developed to accurately represent the photoabsorption cross section of O I for all energies of interest in X-ray spectral modeling. In the vicinity of the K edge, a Rydberg series expression is used to fit R-matrix results, including important orbital relaxation effects, that accurately predict the absorption oscillator strengths below threshold and merge consistently and continuously to the above-threshold cross section. Further, minor adjustments are made to the threshold energies in order to reliably align the atomic Rydberg resonances after consideration of both experimental and observed line positions. At energies far below or above the K-edge region, the formulation is based on both outer- and inner-shell direct photoionization, including significant shake-up and shake-off processes that result in photoionization-excitation and double-photoionization contributions to the total cross section. The ultimate purpose for developing a definitive model for oxygen absorption is to resolve standing discrepancies between the astronomically observed and laboratory-measured line positions, and between the inferred atomic and molecular oxygen abundances in the interstellar medium from XSTAR and SPEX spectral models. [ABSTRACT FROM AUTHOR]

The photoionization of Ba 5s in the high-energy Cooper minimum region has been investigated using the relativistic-random-phase approximation and the relativistic-randomphase approximation with relaxation. Comparison with recent experiment shows good agreement for the total cross section, but only qualitative agreement for the photoelectron angular distribution asymmetry parameter, ß. The disagreement was traced to the omission of photoionization-plus-excitation channels arising from the 4d subshell. [ABSTRACT FROM AUTHOR]

Magnetic dichroism in the angular distribution has been demonstrated for single-electron photoemission from inner ns² subshells of gaseous atomic targets using the example of K-shell photoionization of polarized Li atoms laser prepared in the 1s²2p ²P3/2 excited state. The effect is pronounced for the conjugate shakeup and conjugate shakedown photoelectron lines, and less important, though observable, for the main and direct shakeup lines. The phenomenon is caused by configuration interaction in the final continuum state and is quantitatively described by the close-coupling R-matrix calculations. [ABSTRACT FROM AUTHOR]

The photodetachment cross sections and angular distribution asymmetry parameters are calculated for intermediate p shells of chlorine and bromine negative ions in the relativistic random phase approximation (RRPA) to account for relativistic effects and many electron correlations, and, additionally, in the modified RRPA (RRPA-R) to account for the relaxation of the atomic core in the photodetachment process. The results of the calculations with and without the relaxation effects are compared, and it is found that the results for cross sections with and without relaxation effects in RRPA-R and RRPA are very different close to the corresponding thresholds. An attempt is made to explain the difference between the results of RRPA and RRPA-R close to the corresponding channel thresholds.PACS Nos.: 32.80.Gc, 32.80.Fb [ABSTRACT FROM AUTHOR]

Background. Empirical findings suggest that psychiatric illness is associated with cardiovascular disease (CVD). The purpose of this study was to compare the strength of the association of lifetime post-traumatic stress disorder (PTSD) and lifetime major depression on CVD among Northern Plains American Indians.Method. A total of 1414 participants aged 18-57 years completed a structured interview that assessed psychiatric diagnoses, alcohol abuse/dependence, self-reported CVD, and traditional CVD risk factors including age, sex, education, diabetes, high blood pressure, and smoking. Logistic regression analyses compared the odds ratios of CVD in participants with and without diagnosed PTSD or major depression.Results. The rates of lifetime PTSD and major depression were 15% and 8% respectively. CVD was more commonly reported by participants with PTSD than by those without PTSD (12% v. 5%, p[less-than-or-eq, slant]0.01). Likewise, more participants with major depression reported CVD than did their non-depressed counterparts (14% v. 6%, p[less-than-or-eq, slant]0·05). PTSD was significantly associated with CVD even after controlling for traditional CVD risk factors and major depression (odds ratio 2.0, confidence interval 1.1-3.8). In contrast, the association of major depression with CVD was not significant after accounting for both traditional risk factors and PTSD.Conclusions. Rates of PTSD are high in American Indian communities. Rising CVD rates in this population may be better understood if PTSD is considered along with other traditional risk factors. Future research should examine the association and mechanisms of PTSD and CVD prospectively. Such data could lead to more effective CVD prevention efforts for American Indians. [ABSTRACT FROM AUTHOR]

The changes in energy and photoionization spectra of atoms upon confinement by a spherical environment are explored theoretically. Two kinds of confinement are considered: an endohedral confinement, such as inside the bucky-ball C[sub 60], and an impenetrable spherical confinement of adjustable radius. We demonstrate modifications in the energy spectrum and electron correlation effects in confined atoms, the appearance, nature and origin of "confinement" resonances in photoionization spectra of such atoms, as well as new regularities in the periodic table for "compressed" atoms. These findings are of importance for basic and applied physics and chemistry of atoms, molecules, surfaces, etc. [ABSTRACT FROM AUTHOR]

Twenty five patients with AML who had neither a history of toxic exposure or myelodysplasia were treated with a remission induction regimen consisting of two pulses of chemotherapy separated by 96 hrs. Each pulse consisted of cytarabine 2gm/m[sup2] (at t = 0 and t = 12 hrs) with mitoxantrone [30mg/m[sup2]] administered immediately after the second cytarabine administration. Amifostine was administered three times a week [on Monday, Wednesday, and Friday] until the outcome of therapy was known. This regimen induced complete remissions in 15 of 17 patients less than 70 years of age and in 5 of 8 patients older than 70 years. [ABSTRACT FROM AUTHOR]

Little is known about prevention among elderly or urban American Indian/Alaska Native (AI/AN) populations. We reviewed the medical records of 550 older urban AI/AN primary care patients to evaluate how frequently preventive measures were received. Adherence to guidelines was examined by a culturally appropriate (> or =50 years) and standard age threshold (> or =65 years), and by performance of preventive measures at any time ("ever") and in the past year. Lifetime performance was inadequate for the many measures, including mammograms (56%), fecal occult blood testing (37%), audiometry (33%), visual acuity testing (50%), smoking cessation counseling (50%), and pneumococcal (22%) and influenza (49%) vaccinations. Performance of the measures was less frequent in the prior year, but did not differ by age threshold. Predictors of adherence included female gender, having insurance, and having more health problems and medications. Nonadherence infrequently resulted from patients' failure to comply with recommendations. We conclude that use of most preventive services among elderly urban AI/ANs is suboptimal and should be improved. [ABSTRACT FROM AUTHOR]

Prior classroom achievement and verbal IQ are identified as predictors of school performance for both Native and non-Native youngsters. Children's assessments of their competence, which appear to be, in part, a product of interactions with teachers, were found to be independent predictors of classroom performance. Results suggest that verbal IQ and compromised self-assessments contribute to the difficulties many Native children experience in majority-culture schools. [ABSTRACT FROM AUTHOR]

A model to treat multiphoton ionization through Rydberg states, taking into account blackbody radiation and other processes which lead to ionization with transfer of excitation among the closely-spaced highly excited Rydberg states is presented. The basic idea is to make the rate equations tractable by compacting all of the Rydberg states that experience physically similar processes into a single 'bath' in the equations. The model is applied to sodium Rydberg atoms and the predictions show excellent agreement with experiments. [ABSTRACT FROM AUTHOR]

To ascertain the extent of, and risk factors for, physical abuse among older urban American Indian/Alaska Natives (AI/ANs), we conducted a chart review of 550 urban AI/AN primary care patients >/=50 years old seen during 1 year. Mistreatment was documented in 10%. A logistic regression found younger age (P <.001), female gender (P <.001), current depression (P <.001), and dependence on others for food (P <.05) to be significant correlates of physical abuse. In only 31% of instances of definite abuse were the authorities notified. We conclude that providers should be alert to the possibility of physical mistreatment among older urban AI/ANs. Improvements in detection and management are sorely needed. [ABSTRACT FROM AUTHOR]