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1.
Rev Sci Instrum ; 88(9): 094701, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28964202

ABSTRACT

An electro-optomechanical device capable of microwave-to-optics conversion has recently been demonstrated, with the vision of enabling optical networks of superconducting qubits. Here we present an improved converter design that uses a three-dimensional microwave cavity for coupling between the microwave transmission line and an integrated LC resonator on the converter chip. The new design simplifies the optical assembly and decouples it from the microwave part of the setup. Experimental demonstrations show that the modular device assembly allows us to flexibly tune the microwave coupling to the converter chip while maintaining small loss. We also find that electromechanical experiments are not impacted by the additional microwave cavity. Our design is compatible with a high-finesse optical cavity and will improve optical performance.

2.
Phys Rev Lett ; 116(6): 063601, 2016 Feb 12.
Article in English | MEDLINE | ID: mdl-26918990

ABSTRACT

The radiation pressure of light can act to damp and cool the vibrational motion of a mechanical resonator, but even if the light field has no thermal component, shot noise still sets a limit on the minimum phonon occupation. In optomechanical sideband cooling in a cavity, the finite off-resonant Stokes scattering defined by the cavity linewidth combined with shot noise fluctuations dictates a quantum backaction limit, analogous to the Doppler limit of atomic laser cooling. In our work, we sideband cool a micromechanical membrane resonator to the quantum backaction limit. Monitoring the optical sidebands allows us to directly observe the mechanical object come to thermal equilibrium with the optical bath. This level of optomechanical coupling that overwhelms the intrinsic thermal decoherence was not reached in previous ground-state cooling demonstrations.

3.
Science ; 339(6121): 801-4, 2013 Feb 15.
Article in English | MEDLINE | ID: mdl-23413350

ABSTRACT

The quantum mechanics of position measurement of a macroscopic object is typically inaccessible because of strong coupling to the environment and classical noise. In this work, we monitor a mechanical resonator subject to an increasingly strong continuous position measurement and observe a quantum mechanical back-action force that rises in accordance with the Heisenberg uncertainty limit. For our optically based position measurements, the back-action takes the form of a fluctuating radiation pressure from the Poisson-distributed photons in the coherent measurement field, termed radiation pressure shot noise. We demonstrate a back-action force that is comparable in magnitude to the thermal forces in our system. Additionally, we observe a temporal correlation between fluctuations in the radiation force and in the position of the resonator.

4.
J Mol Biol ; 286(5): 1609-19, 1999 Mar 12.
Article in English | MEDLINE | ID: mdl-10064718

ABSTRACT

In an effort to quantify the importance of hydrogen bonding and alpha-helix formation to protein stability, a capping box motif was introduced into the small phosphocarrier protein HPr. Previous studies had confirmed that Ser46, at the N-cap position of the short helix-B in HPr, serves as an N-cap in solution. Thus, only a single-site mutation was required to produce a canonical S-X-X-E capping box: Lys49 at the N3 position was substituted with a glutamic acid residue. Thermal and chemical denaturation studies on the resulting K49E HPr show that the designed variant is approximately 2 kcal mol-1 more stable than the wild-type protein. However, NMR studies indicate that the side-chain of Glu49 does not participate in the expected capping H-bond interaction, but instead forms a new tertiary H-bond that links helix-B to the four-stranded beta-sheet of HPr. Here, we demonstrate that a strategy in which new non-native H-bonds are introduced can generate proteins with increased stability. We discuss why the original capping box design failed, and compare the energetic consequences of the new tertiary side-chain to main-chain H-bond with a local (helix-capping) side-chain to main-chain H-bond on the protein's global stability.


Subject(s)
Escherichia coli/chemistry , Mutation , Phosphoenolpyruvate Sugar Phosphotransferase System/chemistry , Protein Engineering , Amino Acid Substitution , Bacterial Proteins/chemistry , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Hydrogen Bonding , Kinetics , Models, Molecular , Nuclear Magnetic Resonance, Biomolecular , Phosphoenolpyruvate Sugar Phosphotransferase System/genetics , Phosphoenolpyruvate Sugar Phosphotransferase System/metabolism , Protein Conformation , Protein Denaturation , Protein Folding , Protein Structure, Secondary , Protons , Serine/genetics , Serine/metabolism , Solvents , Temperature , Thermodynamics , Urea
5.
Appl Opt ; 36(28): 7162-71, 1997 Oct 01.
Article in English | MEDLINE | ID: mdl-18264223

ABSTRACT

Two dual-beam differential direct-phase-detecting optical interferometers for scanning moving surfaces are described. Two beams from these interferometers are focused ~42 mum apart on moving surfaces, and the difference in their reflected path lengths is measured to provide the surface roughness measurement. These interferometers are exceptionally insensitive to environmental vibrations and to surface physical and chemical factors. Applications discussed include the measurement of the surface roughness of a rotating cylinder and a moving web.

7.
Am J Orthopsychiatry ; 62(1): 142-6, 1992 Jan.
Article in English | MEDLINE | ID: mdl-1546753

ABSTRACT

Factors associated with family reunification following a short-term stay in a shelter for runaway and troubled youth were examined. Children who were not reunified with their caretakers following their stay reported more family problems, appeared to be at higher risk of suicide, and stayed longer in the shelter. Implications for delivery of shelter service programs are discussed.


Subject(s)
Child Behavior Disorders/psychology , Crisis Intervention , Family/psychology , Foster Home Care/psychology , Residential Treatment , Social Work, Psychiatric , Adolescent , Affective Symptoms/psychology , Affective Symptoms/rehabilitation , Child , Child Behavior Disorders/rehabilitation , Female , Humans , Life Change Events , Male , Personality Assessment , Personality Development
9.
Health Care Financ Rev ; 6(2): 43-51, 1984.
Article in English | MEDLINE | ID: mdl-10310951

ABSTRACT

In Wisconsin, level-of-care assessments are used to set Medicaid reimbursement and determine nursing home eligibility. This study examined three methods of assessing level of care: 1) the Wisconsin quality assurance project (QAP) method, based on observations of patients, patient records, and staff interviews; 2) the Wisconsin standard (STD) method, based primarily on a clinical record review; and, 3) an adaptation of New York's "DMS-I," a checklist with numerical weights used to set level of care. Results address interrater reliability, the agreement between assessments by research teams and actual levels of care set by the State, and the implications that agreement has for reimbursement.


Subject(s)
Costs and Cost Analysis , Diagnosis-Related Groups , Insurance, Health, Reimbursement , Nursing Homes/economics , Patient Care Planning/methods , Statistics as Topic , Wisconsin
11.
Inquiry ; 21(4): 380-93, 1984.
Article in English | MEDLINE | ID: mdl-6240469

ABSTRACT

This exploratory study examined differences in the direct costs of acute inpatient psychiatric services in seven public county-operated specialty hospital units and six private community general hospital units in Wisconsin. There were no significant or substantial differences in measures of severity of patients between the public and private systems. Direct costs per stay and per day were significantly lower in the private units, although charges may have been higher in the private units. These differences in costs appear to be the result of private units having a significantly higher average daily census, more goal emphasis for cost containment, and more psychiatrist influence on how the unit was run. Our findings suggest that mental health system managers examine opportunities for achieving economies of scale and that they set and manage goals for efficiency.


Subject(s)
Economics, Hospital , Hospitals, Psychiatric/economics , Hospitals, Public/economics , Hospitals, Voluntary/economics , Cost Control , Costs and Cost Analysis , Humans , Mental Disorders/economics , Quality of Health Care/economics , Socioeconomic Factors , Wisconsin
12.
Med Care ; 21(9): 911-28, 1983 Sep.
Article in English | MEDLINE | ID: mdl-6413790

ABSTRACT

A common objective of health services is to provide high quality care at the least cost, yet some services achieve these objectives better than others. Moreover, there are questions about relationships between cost and quality: do higher expenditures usually result in higher quality, or, conversely, is it possible to provide higher quality of care at expenditure levels that may be lower than other institutions? This paper reports on a study of 13 acute inpatient psychiatric units in which a range of quality and direct cost outcomes was found. Some units had higher quality and lower direct costs than the others. Some had higher quality and higher direct cost, some had lower direct costs and lower quality as well, while another group had lower quality and higher direct costs. Differences in costs and quality were found to be related more to management than to patient, staff, environmental, or institutional characteristics of these units. The findings of this study suggest that proactive management that focuses on organizational outcomes, that makes consequences of operation visible, and that promotes mutual coordination will achieve higher quality and efficient performance.


Subject(s)
Psychiatric Department, Hospital/organization & administration , Quality of Health Care/economics , Costs and Cost Analysis , Diagnosis-Related Groups , Hospital Administrators , Humans , Management Audit , Personnel, Hospital , Psychiatric Department, Hospital/economics , Psychiatric Department, Hospital/standards , United States
17.
Appl Opt ; 16(11): 2968-71, 1977 Nov 01.
Article in English | MEDLINE | ID: mdl-20174277

ABSTRACT

An experimental arrangement to study the temperature dependence of the response of instrumentation used for the measurement of cw or chopped laser radiation is described. Preliminary measurements of the temperature dependent responses for five instruments are presented. The results indicate that the temperature dependent response for certain instruments is significant.

18.
Science ; 193(4249): 193, 1976 Jul 16.
Article in English | MEDLINE | ID: mdl-17796135
19.
Conf Board Rec ; 12(7): 38-40, 1975 Jul.
Article in English | MEDLINE | ID: mdl-12258508

ABSTRACT

PIP: The problem of famine, malnourishment, deforestation and accompanying floods, overgrazing, and unemployment that have been caused by the population pressures of today can no longer be dealt with by emigrating to new areas. In developing countries particularly population growth has accelerated since mortality rates have been reduced. In contrast population growth rates have been steadily decreasing in developing countries due to the lowering of the birthrate. This means that the proportion of the world's population living in developing countries has been steadily increasing. The world population problem is a definite threat to world stability and the cause of an increasing amount of human suffering in many countries. It has now been demonstrated in a number of developing countries that population growth can be significantly reduced by a combination of programs including the provision of family planning services. The 3 mechanisms available for providing family planning services to developing nations requesting such services are the U.N. Fund for Population Activities (UNFPA), private nonprofit organizations, and bilateral arrangements between donor nations and recipients. A critical ingredient for success is widespread availability of reliable contraceptives which interested persons find acceptable and economical to use. The future for many other developing countries that are now requesting assistance depends greatly on whether the following countries that are now requesting assistance depends greatly on whether the following actions are taken: 1) the U.S. government providing strong leadership in helping to resolve this problem, 2) all nations capable of assisting increasing their support of the UNFPA, and 3) increasing funding for federal research programs on the control of human reproduction as soon as practicable.^ieng


Subject(s)
Financial Management , Government Agencies , Population Growth , United Nations , Demography , Economics , International Agencies , Organizations , Population , Population Dynamics
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