343 research outputs found
Spontaneous Emission in ultra-cold spin-polarised anisotropic Fermi Seas
We examine and explain the spatial emission patterns of ultracold excited
fermions in anisotropic trapping potentials in the presence of a spin polarised
Fermi sea of ground state atoms. Due to the Pauli principle, the Fermi sea
modifies the available phase space for the recoiling atom and thereby modifies
its decay rate and the probability of the emitted photon's direction. We show
that the spatial anisotropies are due to an intricate interplay between Fermi
energies and degeneracy values of specific energy levels and identify a regime
in which the emission will become completely directional. Our results are
relevant for recent advances in trapping and manipulating cold fermionic
samples experimentally and give an example of a conceptually new idea for a
directional photon source.Comment: 7 pages, 7 figure
Coherent adiabatic transport of atoms in radio-frequency traps
Coherent transport by adiabatic passage has recently been suggested as a high-fidelity technique to engineer the center-of-mass state of single atoms in inhomogeneous environments. While the basic theory behind this process is well understood, several conceptual challenges for its experimental observation have still to be addressed. One of these is the difficulty that currently available optical or magnetic micro-trap systems have in adjusting the tunneling rate time dependently while keeping resonance between the asymptotic trapping states at all times. Here we suggest that both requirements can be fulfilled to a very high degree in an experimentally realistic setup based on radio-frequency traps on atom chips. We show that operations with close to 100% fidelity can be achieved and that these systems also allow significant improvements for performing adiabatic passage with interacting atomic clouds
Coherent transport by adiabatic passage on atom chips
Adiabatic techniques offer some of the most promising tools for achieving high-fidelity control of the center-of-mass degree of freedom of single atoms. Because the main requirement of these techniques is to follow an eigenstate of the system, constraints on timing and field strength stability are usually low, especially for trapped systems. In this paper we present a detailed example of a technique to adiabatically transport a single atom between different waveguides on an atom chip. To ensure that all conditions are fulfilled, we carry out fully three-dimensional simulations of the system, using experimentally realistic parameters. We also detail our method for simulating the system in very reasonable time scales on a consumer desktop machine by leveraging the power of graphics-processing-unit computing
Preparing Social Workers for Practice with LGBT Populations Affected by Substance Use: Perceptions from Students, Alumni and Service Providers
Trends in the field of service among those with alcohol and other drug addictions highlight the urgent need for schools of social work to effectively train students to serve clients with substance use disorders, and have cultural humility to effectively serve disproportionately affected LGBT consumers. Online surveys and interviews examined perceptions of graduate social work students and alumni in a certified alcohol and drug counselor program, along with several service providers within an urban setting in the US. Results indicated that students and alumni did not feel adequately prepared through coursework to practice with LGBT populations affected by substance use, while feeling more clinically competent to practice with LGB individuals, than with transgender consumers. Similar findings related to unique differences associated with perceptions of faculty support, along with field preparedness to practice with LGB individuals when compared to transgender individuals. Service providers noted an overall commitment and to serve LGBT consumers as well as positive perceptions of students and alumni to do the same. Implications examine the role of faculty in addressing challenges related to preparation of social work students to practice with LGBT consumers affected by substance use disorders, along with suggestions for curricular changes, and ongoing field trainings
Self identified research needs of New York organic farmers
A survey of organic farmers in New York State identified problems in need of university research. Weed management was the most frequently mentioned problem by far, identified as significant by two-thirds of the organic farmers. Only a few other problems were listed as significant, including insufficient time for farm work, lack of markets, low prices, and lack of appropriate tools. These were cited by more than a third of the farmers. Drought, insect management, and a lack of a dependable supply of labor were cited by about one-third of the respondents. The survey also examined organic farmers' information sources. They do not use conventional sources of agricultural information, such as the extension service and conventional agricultural media, as much as books, magazines, and newsletters on organic f arming, other organic f armers, and on-farm experiments. Many respondents noted that local extension agents did not know very much about non-chemical solutions to organic production problems. They considered University Extension to be accessible, but not very useful in solving problems specific to organic farming, and had many suggestions to improve Land Grant research in organic agriculture
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Adipose Concentrations of Organochlorine Compounds and Breast Cancer Recurrence in Long Island, New York
Several studies have measured the association between blood or adipose concentrations of organochlorinated compounds (OCs), such as pesticides and polychlorinated biphenyls (PCBs), and breast cancer. The estrogenic effects of OCs might adversely affect breast cancer recurrence. The participants were 224 women with nonmetastatic breast cancer enrolled in a New York-based case-control study. Supercritical fluid extraction followed by gas chromatography was conducted on adipose surgical specimens to determine OC concentrations. The mean follow-up time from surgery was 3.6 years. Thirty women (13.4%) were diagnosed with a recurrence. The concentration of pesticides and PCBs was correlated with baseline age and body mass index, but not with cancer stage. The highest tertile of total PCB concentration was associated with an increased risk of recurrence [relative risk (RR), 2.9; 95% confidence interval (CI), 1.02-8.2 versus the lowest tertile]. The risk for the highest tertile of the PCB congener Ballschmiter and Zell 118 was 4.0 (95% CI, 1.3-4.9). There was an increased risk for the middle level of the most abundant pesticide, 1,1-dichloro-2,2-di(4-chlorophenyl)ethylene (RR, 2.3; 95% CI, 0.9-5.7), and for beta-hexachlorocyclohexane, but not for their highest levels. Self-reported home termiticide exposure, alcohol consumption (> or = 1 drink/day), and race were not associated with prognosis. The RR for current cigarette smoking at diagnosis was 2.1 (95% CI, 0.9-5.1). In contrast to previous data showing no relationship between OC exposure and risk of breast cancer in these women, adipose PCB concentrations were associated with tumor recurrence. Pesticide levels were not related to recurrence
Π£ΡΠ»ΠΎΠ²ΠΈΡ ΡΠΎΡΠΌΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΈ ΠΏΡΠΎΠ±Π»Π΅ΠΌΡ ΡΡΠ½ΠΊΡΠΈΠΎΠ½ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΊΡΡΠΏΠ½ΡΡ Π΄ΠΈΠ²Π΅ΡΡΠΈΡΠΈΡΠΈΡΠΎΠ²Π°Π½Π½ΡΡ ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄ΡΡΠ²Π΅Π½Π½ΠΎ-ΠΊΠΎΡΠΏΠΎΡΠ°ΡΠΈΠ²Π½ΡΡ ΡΡΡΡΠΊΡΡΡ Π² Π£ΠΊΡΠ°ΠΈΠ½Π΅
Π£ ΡΡΠ°ΡΡΡ ΡΠΎΠ·Π³Π»ΡΠ½ΡΡΠΎ ΡΠΌΠΎΠ²ΠΈ ΡΠΎΡΠΌΡΠ²Π°Π½Π½Ρ ΡΠ° ΡΡΠ½ΠΊΡΡΠΎΠ½ΡΠ²Π°Π½Π½Ρ, Π° ΡΠ°ΠΊΠΎΠΆ ΡΡΡΠΎΡΡΡ ΡΠΎΠ·Π²ΠΈΡΠΊΡ Π²Π΅Π»ΠΈΠΊΠΈΡ
Π΄ΠΈΠ²Π΅ΡΡΠΈΡΡΠΊΠΎΠ²Π°Π½ΠΈΡ
Π²ΠΈΡΠΎΠ±Π½ΠΈΡΠΎ-ΠΊΠΎΡΠΏΠΎΡΠ°ΡΠΈΠ²Π½ΠΈΡ
ΡΡΡΡΠΊΡΡΡ Π² Π£ΠΊΡΠ°ΡΠ½Ρ. ΠΡΠΎΠΏΠΎΠ½ΡΡΡΡΡΡ ΠΏΡΠ΄Ρ
ΠΎΠ΄ΠΈ ΠΎΡΡΠ½ΠΊΠΈ ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠΈΠ²Π½ΠΎΡΡΡ ΠΏΡΠΎΡΠ΅ΡΡ Π΄ΠΈΠ²Π΅ΡΡΠΈΡΡΠΊΠ°ΡΡΡ Π· Π²ΠΈΠΊΠΎΡΠΈΡΡΠ°Π½Π½ΡΠΌ ΡΡΠ·Π½ΠΈΡ
ΠΌΠ΅ΡΠΎΠ΄ΠΈΠΊ. ΠΠΈΠ·Π½Π°ΡΠ΅Π½ΠΎ, ΡΠΎ Π² Π΄Π°Π½ΠΈΠΉ ΡΠ°Ρ ΠΎΡΡΠ½ΠΊΠ° ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠΈΠ²Π½ΠΎΡΡΡ ΠΏΡΠΎΡΠ΅ΡΡ Π΄ΠΈΠ²Π΅ΡΡΠΈΡΡΠΊΠ°ΡΡΡ ΠΌΠΎΠΆΠ»ΠΈΠ²Π° Π»ΠΈΡΠ΅ Π½Π΅ΠΏΡΡΠΌΠΈΠΌΠΈ ΠΌΠ°ΡΠ΅ΠΌΠ°ΡΠΈΡΠ½ΠΈΠΌΠΈ ΠΌΠ΅ΡΠΎΠ΄Π°ΠΌΠΈ.Π ΡΡΠ°ΡΡΠ΅ ΡΠ°ΡΡΠΌΠΎΡΡΠ΅Π½Ρ ΡΡΠ»ΠΎΠ²ΠΈΡ ΡΠΎΡΠΌΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΈ ΡΡΠ½ΠΊΡΠΈΠΎΠ½ΠΈΡΠΎΠ²Π°Π½ΠΈΡ, Π° ΡΠ°ΠΊΠΆΠ΅ ΠΈΡΡΠΎΡΠΈΡ ΡΠ°Π·Π²ΠΈΡΠΈΡ ΠΊΡΡΠΏΠ½ΡΡ
Π΄ΠΈΠ²Π΅ΡΡΠΈΡΠΈΡΠΈΡΠΎΠ²Π°Π½Π½ΡΡ
ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄ΡΡΠ²Π΅Π½Π½ΠΎ-ΠΊΠΎΡΠΏΠΎΡΠ°ΡΠΈΠ²Π½ΡΡ
ΡΡΡΡΠΊΡΡΡ Π² Π£ΠΊΡΠ°ΠΈΠ½Π΅. ΠΡΠ΅Π΄Π»Π°Π³Π°ΡΡΡΡ ΠΏΠΎΠ΄Ρ
ΠΎΠ΄Ρ ΠΎΡΠ΅Π½ΠΊΠΈ ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠΈΠ²Π½ΠΎΡΡΠΈ ΠΏΡΠΎΡΠ΅ΡΡΠ° Π΄ΠΈΠ²Π΅ΡΡΠΈΡΠΈΠΊΠ°ΡΠΈΠΈ Ρ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΠ΅ΠΌ ΡΠ°Π·Π½ΡΡ
ΠΌΠ΅ΡΠΎΠ΄ΠΈΠΊ. ΠΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΎ, ΡΡΠΎ Π² Π½Π°ΡΡΠΎΡΡΠ΅Π΅ Π²ΡΠ΅ΠΌΡ ΠΎΡΠ΅Π½ΠΊΠ° ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠΈΠ²Π½ΠΎΡΡΠΈ ΠΏΡΠΎΡΠ΅ΡΡΠ° Π΄ΠΈΠ²Π΅ΡΡΠΈΡΠΈΠΊΠ°ΡΠΈΠΈ Π²ΠΎΠ·ΠΌΠΎΠΆΠ½Π° Π»ΠΈΡΡ ΠΊΠΎΡΠ²Π΅Π½Π½ΡΠΌΠΈ ΠΌΠ°ΡΠ΅ΠΌΠ°ΡΠΈΡΠ΅ΡΠΊΠΈΠΌΠΈ ΠΌΠ΅ΡΠΎΠ΄Π°ΠΌΠΈ.In the article address the formation and functioning of the conditions, as well as story development of large industrial and corporate structures, becoming diversification in Ukraine. Proposes approaches assessing impact of the process of diversification, using of different methods. Proved that the current performance assessment process of diversification can only be indirect mathematical methods
Erratum to βCancer Incidence and Mortality in a Cohort of US Blood Donors: A 20-Year Studyβ
Cancer Incidence and Mortality in a Cohort of US Blood Donors: A 20-Year Study
Blood donors are considered one of the healthiest populations. This study describes the epidemiology of cancer in a cohort of blood donors up to 20 years after blood donation. Records from donors who participated in the Retroviral Epidemiology Donor Study (REDS, 1991β2002) at Blood Centers of the Pacific (BCP), San Francisco, were linked to the California Cancer Registry (CCR, 1991β2010). Standardized incidence ratios (SIR) were estimated using standard US 2000 population, and survival analysis used to compare all-cause mortality among donors and a random sample of nondonors with cancer from CCR. Of 55,158 eligible allogeneic blood donors followed-up for 863,902 person-years, 4,236 (7.7%) primary malignant cancers were diagnosed. SIR in donors was 1.59 (95% CI = 1.54,1.64). Donors had significantly lower mortality (adjusted HR = 0.70, 95% CI = 0.66β0.74) compared with nondonor cancer patients, except for respiratory system cancers (adjusted HR = 0.93, 95% CI = 0.82β1.05). Elevated cancer incidence among blood donors may reflect higher diagnosis rates due to health seeking behavior and cancer screening in donors. A βhealthy donor effectβ on mortality following cancer diagnosis was demonstrated. This population-based database and sample repository of blood donors with long-term monitoring of cancer incidence provides the opportunity for future analyses of genetic and other biomarkers of cancer
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