2,395 research outputs found
Multi-fingered robotic hand
A robotic hand is presented having a plurality of fingers, each having a plurality of joints pivotally connected one to the other. Actuators are connected at one end to an actuating and control mechanism mounted remotely from the hand and at the other end to the joints of the fingers for manipulating the fingers and passing externally of the robot manipulating arm in between the hand and the actuating and control mechanism. The fingers include pulleys to route the actuators within the fingers. Cable tension sensing structure mounted on a portion of the hand are disclosed, as is covering of the tip of each finger with a resilient and pliable friction enhancing surface
Studies on maximum yield of wheat for the controlled environments of space
The economic feasibility of using food-producing crop plants in a closed ecological Life-Support System (CELSS) will ultimately depend on the energy and area (or volume) required to provide the nutritional requirements for each person. Energy and area requirements are, to some extent, inversely related; that is, an increased energy input results in a decreased area requirement and vice versa. A major goal of the research effort was to determine the controlled-environment good-production efficiency of wheat per unit area, per unit time, and per unit energy input
Constraints and Reality Conditions in the Ashtekar Formulation of General Relativity
We show how to treat the constraints and reality conditions in the
-ADM (Ashtekar) formulation of general relativity, for the case of a
vacuum spacetime with a cosmological constant. We clarify the difference
between the reality conditions on the metric and on the triad. Assuming the
triad reality condition, we find a new variable, allowing us to solve the gauge
constraint equations and the reality conditions simultaneously.Comment: LaTeX file, 12 pages, no figures; to appear in Classical and Quantum
Gravit
The risk of cancer in primary care patients with hypercalcaemia: a cohort study using electronic records.
PublishedJournal ArticleBACKGROUND: The risk of cancer with hypercalcaemia in primary care is unknown. METHODS: This was a cohort study using calcium results in patients aged ⩾40 years in a primary care electronic data set. Diagnoses of cancer in the following year were identified. RESULTS: Participants (54 267) had calcium results: 1674 (3%) were ⩾2.6 mmol l(-1). Hypercalcaemia was strongly associated with cancer, especially in males: OR 2.92, 95% CI 2.17-3.93, P=<0.001; positive predictive value (PPV) 11.5%; females: OR 1.86, 95% CI 1.39-2.50, P<0.001: PPV 4.1%. CONCLUSIONS: Hypercalcaemia is strongly associated with cancer in primary care, with men at most risk, despite hypercalcaemia being more common in women
The impact of co-located NHS walk-in centres on emergency departments
Objectives:
To determine the impact of establishing walk-in centres alongside emergency departments
on attendance rates, visit duration, process, costs and outcome of care.
Methods:
Eight hospitals with co-located emergency departments and walk-in centres were compared
with eight matched emergency departments without walk-in centres. Site visits were
conducted. Routine data about attendance numbers and use of resources were analysed. A
random sample of records of patients attending before and after walk-in centres opened
were also assessed. Patients who had not been admitted to hospital were sent a postal
questionnaire.
Results:
In most sites, the walk-in centres did not have a distinct identity and there were few
differences in the way services were provided compared with control sites. Overall, there
was no evidence of an increase in attendance at sites with walk-in centres, but considerable
variability across sites. The proportion of patients managed within the four-hour NHS target
improved at sites both with and without walk-in centres. There was no evidence of any
difference in re-consultation rates, costs of care or patient outcomes at sites with or without
walk-in centres.
Conclusions:
Most hospitals in this study implemented the walk-in centre concept to a very limited extent.
Consequently there was no evidence of any impact on attendance rates, process, costs or
outcome of care
Optical-fiber Preamplifiers for Ladar Detection and Associated Measurements for Improving the Signal-to-noise Ratio
In an effort to increase achievable postdetection signal-tonoise ratios (SNRs) of continuous-wave, 1-gm all-solid-state ladar systems, a prototype rare-earth-doped optical-fiber amplifier has been included in the optical return signal path of both a heterodyne and a directdetection ladar system. We provide numerical predictions for SNR increases according to our previously developed theory. We also detail our experimental efforts and provide the results of SNR measurements for four distinct cases: direct ladar detection with and without a fiber amplifier, and heterodyne ladar detection with and without a fiber amplifier. Experimentally measured increases in SNRs for ladar systems incorporating an optical-fiber amplifier are then compared with our earlier predictions. Specifically, we have found that for direct detection with a fiber amplifier in place, the predicted SNR increase is 42.0 dB, and we have measured an increase of 36.5 dB. Similarly, for heterodyne ladar detection with a fiber amplifier, the predicted SNR increase is 3.8 dB, and we have measured an increase of 8.0 dB
Sensitivity Improvement of a 1-μm Ladar System Incorporating an Active Optical Fiber Preamplifier
In an effort to increase the SNR of a continuous wave, 1-μm all solid state ladar system, a rare-earth-doped optical fiber amplifier is investigated as a preamplifier for ladar return signals. The experimental system is detailed and a theoretical analysis of the fiber amplifier\u27s effect on both heterodyne and direct detection schemes is provided. Beginning with the optical powers incident on the detector, the signal and noises are analyzed, through the detector electronics, to predict the SNR. The SNR is then plotted as a function of the return signal power, and a SNR threshold is defined to determine a minimum detectable signal power. The return signals required to attain the SNR threshold are then compared for four cases: direct detection with and without the fiber amplifier and heterodyne detection with and without the fiber amplifier. For the direct detection scheme considered, our results predict a sensitivity increase of 20.6 dB with the addition of the fiber amplifier, yet for heterodyne detection the predicted sensitivity increase is only 3.1 dB
Comparing care at walk-in centres and at accident and emergency departments: an exploration of patient choice, preference and satisfaction
Objectives:
To explore the impact of establishing walk-in centres alongside emergency departments on
patient choice, preference and satisfaction.
Methods:
A controlled, mixed-method study comparing eight emergency departments with co-located
walk-in centres with the same number of ‘traditional’ emergency departments. This paper
focuses on the results of a cross-sectional questionnaire survey of users.
Results:
Survey data demonstrated that patients were frequently unable to distinguish between being
treated at a walk-in centre or an A&E department, and even where this was the case,
opportunities to exercise choice about their preferred care provider were often limited. Few
made an active choice to attend a co-located walk-in centre. Patients attending walk-in
centres were just as likely to be satisfied overall with the care they received as their
counterparts who were treated in the co-located A&E facility, although a small proportion of
walk-in centre users did report greater satisfaction with some specific aspects of their care
and consultation.
Conclusions:
Whilst one of the key policy goals underpinning the co-location of walk-in centres next to an
A&E department was to provide patients with more options for accessing healthcare and
greater choice, leading in turn to increased satisfaction, this evaluation was able to provide
little evidence to support this. The high percentage of patients expressing a preference for
care in an established emergency department compared to a new walk-in centre facility
raises questions for future policy development. Further consideration should therefore be
given to the role that A&E focused walk-in centres play in the Department of Health’s
current policy agenda, as far as patient choice is concerned
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