4,931 research outputs found
Liver transplantation of American veterans under FK 506 immunosuppression: A preliminary report
Magnetic ordering of Mn sublattice, dense Kondo lattice behavior of Ce in (RPd3)8Mn (R = La, Ce)
We have synthesized two new interstitial compounds (RPd3)8Mn (R = La and Ce).
The Mn ions present in "dilute" concentration of just 3 molar percent form a
sublattice with an unusually large Mn-Mn near neighbor distance of ~ 85 nm.
While the existence of (RPd3)8M (where M is a p-block element) is already
documented in the literature, the present work reports for the first time the
formation of this phase with M being a 3d element. In (LaPd3)8Mn, the Mn
sub-lattice orders antiferromagnetically as inferred from the peaks in
low-field magnetization at 48 K and 23 K. The latter peak progressively shifts
towards lower temperatures in increasing magnetic field and disappears below
1.8 K in a field of ~ 8 kOe. On the other hand in (CePd3)8Mn the Mn sublattice
undergoes a ferromagnetic transition around 35 K. The Ce ions form a dense
Kondo-lattice and are in a paramagnetic state at least down to 1.5 K. A
strongly correlated electronic ground state arising from Kondo effect is
inferred from the large extrapolated value of C/T = 275 mJ/Ce-mol K^2 at T = 0
K. In contrast, the interstitial alloys RPd3Mnx (x = 0.03 and 0.06), also
synthesized for the first time, have a spin glass ground state due to the
random distribution of the Mn ions over the available "1b" sites in the parent
RPd3 crystal lattice.Comment: 18 figures and 20 pages of text documen
Work-Related Mental Health and Job Performance: Can Mindfulness Help?
Work-related mental health issues such as work-related stress and addiction to work impose a significant health and economic burden to the employee, the employing organization, and the country of work more generally. Interventions that can be empirically shown to improve levels of work-related mental health – especially those with the potential to concurrently improve employee levels of work performance – are of particular interest to occupational stakeholders. One such broad-application interventional approach currently of interest to occupational stakeholders in this respect is mindfulness-based interventions (MBIs). Following a brief explication of the mindfulness construct, this paper critically discusses current research directions in the utilization of mindfulness in workplace settings and assesses its suitability for operationalization as an organization-level work-related mental health intervention. By effecting a perceptual-shift in the mode of responding and relating to sensory and cognitive-affective stimuli, employees that undergo mindfulness training may be able to transfer the locus of control for stress from external work conditions to internal metacognitive and attentional resources. Therefore, MBIs may constitute cost-effective organization-level interventions due to not actually requiring any modifications to human resource management systems and practises. Based on preliminary empirical findings and on the outcomes of MBI studies with clinical populations, it is concluded that MBIs appear to be viable interventional options for organizations wishing to improve the mental health of their employees
Three-party qutrit-state sharing
A three-party scheme for securely sharing an arbitrary unknown single-qutrit
state is presented. Using a general Greenberger-Horne-Zeilinger (GHZ) state as
the quantum channel among the three parties, the quantum information (i.e., the
qutrit state) from the sender can be split in such a way that the information
can be recovered if and only if both receivers collaborate. Moreover, the
generation of the scheme to multi-party case is also sketched.Comment: 7 page
Adoption of agricultural conservation practices in the United States: Evidence from 35 years of quantitative literature
This is a comprehensive review of all published, quantitative studies focused on adoption of agricultural conservation practices in the United States between 1982 and 2017. This review finds that, taken as a whole, few independent variables have a consistent statistically significant relationship with adoption. Analyses showed that variables positively associated with adoption include the farmer self-identifying primarily as stewardship motivated or otherwise nonfinancially motivated, environmental attitudes, a positive attitude toward the particular program or practice, previous adoption of other conservation practices, seeking and using information, awareness of programs or practices, vulnerable land, greater farm size, higher levels of income and formal education, engaging in marketing arrangements, and positive yield impact expected. Some variables often thought to be important, such as land tenure, did not emerge as consistently important in this cross-study review. Other variables, such as farmers\u27 sense of place, training, presence of institutional conditions supporting adoption, and the role of collective decision making are not measured in enough studies to draw conclusions but potentially have a relationship with adoption decisions. Implications for how to promote conservation adoption and directions for future research are discussed. Because positive attitudes and awareness of conservation programs or practices are positive predictors of adoption, practitioners should share benefits of specific practices and programs and leverage existing practice adoption. Further work to explore relationships between conservation adoption and the role of farmer identity, nuances of land tenure, and the influence of structural factors is needed. Moreover, we suggest that future research should focus on the impact of different messages and avenues of reaching farmers in order to continue to inform conservation practices. Future research should consider both individual and institutional factors that facilitate and constrain adoption
High temperatures in the terrestrial mid-latitudes during the early Palaeogene
The early Paleogene (56–48 Myr) provides valuable information about the Earth’s climate system in an equilibrium high pCO2 world. High ocean temperatures have been reconstructed for this greenhouse period, but land temperature estimates have been cooler than expected. This mismatch between marine and terrestrial temperatures has been difficult to reconcile. Here we present terrestrial temperature estimates from a newly calibrated branched glycerol dialkyl glycerol tetraether-based palaeothermometer in ancient lignites (fossilized peat). Our results suggest early Palaeogene mid-latitude mean annual air temperatures of 23–29 °C (with an uncertainty of ± 4.7 °C), 5–10 °C higher than most previous estimates. The identification of archaeal biomarkers in these same lignites, previously observed only in thermophiles and hyperthermophilic settings, support these high temperature estimates. These mid-latitude terrestrial temperature estimates are consistent with reconstructed ocean temperatures and indicate that the terrestrial realm was much warmer during the early Palaeogene than previously thought
Clay minerals as the key to the sequestration of carbon in soils
Results from earlier laboratory and field experiments were interrogated for the possibilities of sequestration, or longterm accumulation, of carbon from excess greenhouse gases in the atmosphere. In the laboratory study, samples of three (top) soils dominated by kaolinite and illite (together), smectite, and allophane were examined for the adsorption and desorption of dissolved organic carbon (DOC). Adsorption and desorption of DOC were carried out on clay fractions extracted physically and after first native organic matter and then iron oxides were removed chemically. Labeled organic material was added to the soils to assess the priming effect of organic carbon (OC). In the field, changes in OC were measured in sandy soils that had been amended by additions of clay for between 3 and 17 years, both through incorporation of exogenous clay and delving of in situ clay. The laboratory experiments demonstrated that a portion of DOC was held strongly in all soils. The amount of DOC adsorbed depended on clay mineral types, including Fe oxides. Much adsorbed DOC was lost by desorption in water and a substantial amount of native OC was lost on priming with new OC. Addition of clay to soils led to increased OC. Therefore, addition of clay to soil may enhance net sequestration of C. Organic carbon close to mineral surfaces or within microaggregates is held most strongly. Carbon sequestration may occur in subsoils with unsaturated mineral surfaces. However, incorporation of carbon into macroaggregates from enhanced plant growth might be most effective in removing excess carbon from the atmosphere, albeit over the short-term
Bone marrow-derived epithelial cells and hair follicle stem cells contribute to development of chronic cutaneous neoplasms
We used allogeneic bone marrow transplantation (BMT) and a mouse multistage cutaneous carcinogenesis model to probe recruitment of bone marrow-derived epithelial cells (BMDECs) in skin tumors initiated with the carcinogen, dimethylbenz[a]anthracene (DMBA), and promoted with 12-O-tetradecanolyphorbol-13-acetate (TPA). BMDECs clustered in the lesional epithelium, expressed cytokeratins, proliferated, and stratified. We detected cytokeratin induction in plastic-adherent bone marrow cells (BMCs) cultured in the presence of filter-separated keratinocytes (KCs) and bone morphogenetic protein 5 (BMP5). Lineage-depleted BMCs migrated towards High Mobility Group Box 1 (HMGB1) protein and epidermal KCs in ex vivo invasion assays. Naive female mice receiving BMTs from DMBA-treated donors developed benign and malignant lesions after TPA promotion alone. We conclude that BMDECs contribute to the development of papillomas and dysplasia, demonstrating a systemic contribution to these lesions. Furthermore, carcinogen-exposed BMCs can initiate benign and malignant lesions upon tumor promotion. Ultimately, these findings may suggest targets for treatment of non-melanoma skin cancers
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Volumetric laser endomicroscopy and its application to Barrett's esophagus: results from a 1,000 patient registry.
Volumetric laser endomicroscopy (VLE) uses optical coherence tomography (OCT) for real-time, microscopic cross-sectional imaging. A US-based multi-center registry was constructed to prospectively collect data on patients undergoing upper endoscopy during which a VLE scan was performed. The objective of this registry was to determine usage patterns of VLE in clinical practice and to estimate quantitative and qualitative performance metrics as they are applied to Barrett's esophagus (BE) management. All procedures utilized the NvisionVLE Imaging System (NinePoint Medical, Bedford, MA) which was used by investigators to identify the tissue types present, along with focal areas of concern. Following the VLE procedure, investigators were asked to answer six key questions regarding how VLE impacted each case. Statistical analyses including neoplasia diagnostic yield improvement using VLE was performed. One thousand patients were enrolled across 18 US trial sites from August 2014 through April 2016. In patients with previously diagnosed or suspected BE (894/1000), investigators used VLE and identified areas of concern not seen on white light endoscopy (WLE) in 59% of the procedures. VLE imaging also guided tissue acquisition and treatment in 71% and 54% of procedures, respectively. VLE as an adjunct modality improved the neoplasia diagnostic yield by 55% beyond the standard of care practice. In patients with no prior history of therapy, and without visual findings from other technologies, VLE-guided tissue acquisition increased neoplasia detection over random biopsies by 700%. Registry investigators reported that VLE improved the BE management process when used as an adjunct tissue acquisition and treatment guidance tool. The ability of VLE to image large segments of the esophagus with microscopic cross-sectional detail may provide additional benefits including higher yield biopsies and more efficient tissue acquisition. Clinicaltrials.gov NCT02215291
Relativistic separable dual-space Gaussian Pseudopotentials from H to Rn
We generalize the concept of separable dual-space Gaussian pseudopotentials
to the relativistic case. This allows us to construct this type of
pseudopotential for the whole periodic table and we present a complete table of
pseudopotential parameters for all the elements from H to Rn. The relativistic
version of this pseudopotential retains all the advantages of its
nonrelativistic version. It is separable by construction, it is optimal for
integration on a real space grid, it is highly accurate and due to its analytic
form it can be specified by a very small number of parameters. The accuracy of
the pseudopotential is illustrated by an extensive series of molecular
calculations
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