A table-top PXI based low-field spectrometer for solution dynamic nuclear polarization.

We present the development of a portable dynamic nuclear polarization (DNP) instrument based on the PCI eXtensions for Instrumentation platform. The main purpose of the instrument is for study of 1 H polarization enhancements in solution through the Overhauser mechanism at low magnetic fields. A DNP probe set was constructed for use at 6.7 mT, using a modified Alderman-Grant resonator at 241 MHz for saturation of the electron transition. The solenoid for detection of the enhanced 1 H signal at 288 kHz was constructed with Litz wire. The largest observed 1 H enhancements (ε) at 6.7 mT for 14 N-CTPO radical in air saturated aqueous solution was ε~65. A concentration dependence of the enhancement is observed, with maximum ε at 5.5 mM. A low resonator efficiency for saturation of the electron paramagnetic resonance transition results in a decrease in ε for the 10.3 mM sample. At high incident powers (42 W) and long pump times, capacitor heating effects can also decrease the enhancement. The core unit and program described here could be easily adopted for multi-frequency DNP work, depending on available main magnets and selection of the "plug and play" arbitrary waveform generator, digitizer, and radiofrequency synthesizer PCI eXtensions for Instrumentatione cards.

Lambda exonuclease digestion of CGG trinucleotide repeats.

Fragile X syndrome and other trinucleotide diseases are characterized by an elongation of a repeating DNA triplet. The ensemble-averaged lambda exonuclease digestion rate of different substrates, including one with an elongated FMR1 gene containing 120 CGG repeats, was measured using absorption and fluorescence spectroscopy. By use of magnetic tweezers sequence-dependent digestion rates and pausing was measured for individual lambda exonucleases. Within the triplet repeats a lower average and narrower distribution of rates and a higher frequency of pausing was observed.

The Macular Assessment Profile test - a new VDU-based technique for measuring the spatial distribution of the macular pigment, lens density and rapid flicker sensitivity.

The measurement of macular pigment optical density (MPOD) in the eye is often carried out using optical techniques based on heterochromatic flicker photometry (HFP). These require the use of two spectrally-narrow beams, one at the wavelength of maximum absorption of the macular pigment (MP) and the other in the long wavelength region of the visible spectrum where MP absorption is negligible. A new technique for the measurement of MPOD spatial profiles has been developed by overcoming the current shortcomings associated with the use of visual displays. The new Macular Assessment Profile (MAP) test makes use of a 'notch' filter and a photometric model to measure and compute the peak MPOD value. Two other useful parameters are also computed from the same measurements. These describe the subject's sensitivity to rapid flicker and the absorption of blue light by the lens. MPOD profiles, lens density, rapid flicker sensitivity, and red/green (RG) and yellow/blue (YB) colour thresholds were measured in 54 normal subjects aged 18-61 years. The results confirm previous findings on ageing effects and demonstrate the complete absence of correlation between MPOD and the subject's YB chromatic thresholds. In contrast, RG chromatic sensitivity improves with higher levels of MPOD.

The fabrication of uniform cylindrical nanoshells and their use as spectrally tunable MRI contrast agents.

A new form of tunable magnetic resonance imaging agent based on precisely dimensioned cylindrical magnetic nanoshells is introduced. Using top-down prepatterned substrates, the nanoshells are fabricated by exploiting what is usually regarded as a detrimental processing side-effect, namely the redeposition of material back-sputtered during ion-milling. The well-resolved nuclear magnetic resonance peaks of the resulting nanostructures attest to the nanoscale fabrication control and the general feasibility of such sputter redeposition for fabrication of a variety of self-supporting, highly monodisperse nanoscale structures.

A chip-scale atomic clock based on 87Rb with improved frequency stability.

We demonstrate a microfabricated atomic clock physics package based on coherent population trapping (CPT) on the D1 line of 87Rb atoms. The package occupies a volume of 12 mm3 and requires 195 mW of power to operate at an ambient temperature of 200 degrees C. Compared to a previous microfabricated clock exciting the D2 transition in Cs [1], this 87Rb clock shows significantly improved short- and long-term stability. The instability at short times is 4 x?10-11 / tau?/2 and the improvement over the Cs device is due mainly to an increase in resonance amplitude. At longer times (tau?> 50 s), the improvement results from the reduction of a slow drift to ?5 x 10-9 / day. The drift is most likely caused by a chemical reaction of nitrogen and barium inside the cell. When probing the atoms on the D1 line, spin-exchange collisions between Rb atoms and optical pumping appear to have increased importance compared to the D2 line.

Spontaneous rupture of splenic artery aneurysm: sixth instance of both maternal and fetal survival.

Spontaneous rupture of a splenic artery aneurysm in the third trimester of pregnancy is a catastrophic event associated with a very high fetal and maternal mortality rate. There are only five reported instances of both maternal and fetal survival after spontaneous rupture of a splenic artery aneurysm. This report not only documents the sixth such case, but also recommends a different therapeutic approach for the management of such cases.

A comparative evaluation of a fibromyalgia rehabilitation program.

OBJECTIVE: To compare an evidence-based clinical fibromyalgia program, referred to as Fibro-Fit, with results of controlled clinical trials. METHODS: An interdisciplinary group education and exercise program with 36 sessions over 12 weeks was used. Demographic, clinical, and outcome variables were collected on 149 participants, of whom 71% completed the program. Outcomes included measures of self-efficacy, pain, physical fitness, function, and coping skills. RESULTS: Results of the prospective before-after evaluation showed statistically significant (P < 0.005) improvements in all outcomes except for grip strength. These results were comparable with controlled clinical trials found in the literature. Data suggest that smoking, fibromyalgia support groups, and medications may be important modifiable factors. CONCLUSIONS: Results suggest that Fibro-Fit was effective in improving physical impairments and function. Further investigation is required to refine the effective components of these programs and determine how modifiable factors can be used to improve outcomes.

Interference filter calibration for vision research.

The radiant flux (F) transmitted by bandpass interference filters of similar type is approximately proportional to the product of peak transmittance (tp) and half-height bandwidth (Wh). A study of 297 filters of varied design (1-, 2-, 3-cavity), the collections of six vision laboratories, showed that this relation was not accurate across all filters. However, a simple function, incorporating Wh and another bandwidth Wi at a lower transmittance t, predicts F with a precision that is ample (+/- 5%) for most psychophysical research. This function provides a rapid means of calibration. Bandwidth errors caused by 2- and 3-cavity filters are discussed as well as their luminous 'blocking' efficacy.

Macular pigment and the colour-specificity of visual evoked potentials.

A modified Moreland anomaloscope was used to examine two subjects, one with dense macular pigment, the other with relatively light pigmentation. Chromatic visual evoked potentials (VEPs) were elicited from these two subjects using coarse, isoluminant gratings of different sizes. Colour-specificity was verified by comparing chromatic onset VEPs (reflecting sustained activity) with chromatic reversal VEPs (reflecting mainly transient activity) and also by Fourier analysis (colour-specific responses are dominated by the fundamental, transient activity by the second harmonic). Achromatic (transient-type) intrusions, produced by large blue-green gratings could be related to the extent of subject-specific macular pigmentation.

Effect of diabetes associated increases in lens optical density on colour discrimination in insulin dependent diabetes.

Optical density (OD) of the crystalline lens has been shown in non-diabetics to increase linearly with age over the first five decades and at an increased rate thereafter; in insulin dependent diabetic (IDDM) patients, lens OD increases with age and with duration of diabetes at a rate similar to that in non-diabetics over the age of 60 years. Recently, it has been established that colour discrimination is abnormal in a majority of young patients with uncomplicated IDDM and angiographically normal retinas. Colour discrimination loss was attributed to functional abnormalities in the retina or neural pathways; yet the possibility exists that increases in lens OD may account for part or all of the colour discrimination loss in IDDM. In the present study, colour discrimination was compared in aretinopathic IDDM patients and age-matched controls, and then in a group of aretinopathic IDDM patients individually matched to controls with respect to lens OD. Colour discrimination was significantly worse in diabetic patients than in age-matched controls, and was significantly worse when diabetic patients were compared with controls matched for OD. The magnitude of the difference in 100 hue error score between diabetic patients and OD matched controls was, however, considerably less than the difference between diabetic patients and age-matched controls. These data suggest that colour discrimination loss in aretinopathic IDDM patients cannot be explained solely on the basis of diabetes induced increases in lens OD, but must involve abnormalities of the retina or its neural connections.

Design and implementation of a collaborative molecular graphics environment.

During the determination of macromolecular structures, scientists routinely use complex graphics software to display various representations of the molecule of interest. Once the structure determination is complete, coordinates are deposited in the Protein Data Bank (PDB), from where anyone with an Internet connection may download and view them or request them on CD-ROM. However, the currently available visualization software is such that causal users, whose expertise may not be in structure determination, often cannot obtain useful images of interesting molecules without expending considerable time and effort. Existing visualization software is generally very complex, requiring a high degree of familiarity to obtain the best results, or else it is too simplistic to provide users with the level of customizability needed to get the most out of the atomic coordinates. Few of the existing software packages have the capability for collaborative visualization via the Internet. These and other issuses are being addressed by the Molecular Interactive Collaborative Environment (MICE) project (http://mice.sdsc.edu/). The core of the MICE project is the MICE application, an interactive molecular structure viewer with built-in collaborative capabilities. MICE not only addresses the issues of usability and flexibility but also extends the role of traditional visualization tools by allowing multiple users to view, manipulate, and interact with a single representation of a macromolecular structure. MICE is written entirely in Java, using the Java3D extensions for rendering and manipulation of the three-dimensional scene, and the Common Object Request Broker Architecture (CORBA) communications suite to enable collaborative manipulation of that scene.

Radiographic analysis of the axial alignment of the lower extremity.

The axial alignment of the lower extremities of twenty-five normal male volunteers whose mean age was thirty years was studied using a standardized radiograph of the entire lower extremity. The extremities were found to be in a mean of 1.5 degrees (right) and 1.1 degrees (left) of varus angulation at the knee between the tibial and femoral mechanical axes. The transverse axis of the knee lacked a mean of 3.0 degrees (right) and 2.6 degrees (left) of being perpendicular to the mechanical axis of the tibia. The anatomical axis of the femur did not pass through the center of the knee.

Efficacy of electromyographic biofeedback compared with conventional physical therapy for upper-extremity function in patients following stroke: a research overview and meta-analysis.

BACKGROUND AND PURPOSE: The purpose of this study was to examine the efficacy of electromyographic biofeedback compared with conventional physical therapy for improving upper-extremity function in patients following a stroke. SUBJECTS AND METHODS: A literature search was done for the years 1976 to 1992. The selection criteria included single-blinded randomized control trials. Study quality was assessed for nine criteria. For functional (disability index or stage of recovery) and impairment outcomes, meta-analyses were performed on odds ratios for improvement versus no improvement. Mann-Whitney U-Test probability values were combined across studies. RESULTS: Six studies were selected, and outcome data were obtained for five studies. The common odds ratio was 2.2 for function and 1.1 for impairments in favor of biofeedback. The estimate of the number needed to treat to prevent a nonresponder was 11 for function and 22 for impairments. None of the meta-analyses were statistically significant. CONCLUSIONS AND DISCUSSION: The results do not conclusively indicate superiority of either form of therapy. Although there is a chance of Type II error, the estimated size of the effect is small. Given this estimate of little or no difference, therapists need to consider cost, ease of application, and patient preference when selecting these therapies.

Reliability of the Fugl-Meyer assessment for testing motor performance in patients following stroke.

BACKGROUND AND PURPOSE: The purpose of this study was to establish the interrater reliability of assessments made with the Fugl-Meyer evaluation of physical performance in a rehabilitation setting. SUBJECTS: Twelve patients (7 male, 5 female), aged 49 to 86 years (mean = 66), who had sustained a cerebrovascular accident participated in the study. All patients were admitted consecutively to a rehabilitation center and were between 6 days and 6 months poststroke. METHODS: Three physical therapists, each with more than 10 years of experience, assessed the patients in a randomized and balanced order using this assessment. The therapists standardized the assessment approach prior to the study but did not discuss the procedure once the study began. RESULTS: The overall reliability was high (overall intraclass correlation coefficient = .96), and the intraclass correlation coefficients for the subsections of the assessment varied from .61 for pain to .97 for the upper extremity. CONCLUSION AND DISCUSSION: The relative merits of using the Fugl-Meyer assessment as a research tool versus a clinical assessment for stroke are discussed.

Defining the minimum level of detectable change for the Roland-Morris questionnaire.

BACKGROUND AND PURPOSE: The Roland-Morris Questionnaire (RMQ) is a self-administered disability measure in which greater levels of disability are reflected by higher numbers on a 24-point scale. The RMQ has been shown to yield reliable measurements, which are valid for inferring the level of disability, and to be sensitive to change over time for groups of patients with low back pain. Little is known about the usefulness of this instrument in aiding decision making regarding individual patients. The purpose of this study was to determine the minimum level of detectable change when the RMQ is applied to individual patients. SUBJECTS: The study sample consisted of 60 outpatients with low back pain. METHODS: The RMQ was administered at the subjects' initial visit and again 4 to 6 weeks later. Conditional standard errors of measurement (CSEMs) were computed for initial and follow-up RMQ scores, and these values were used to estimate the minimum level of detectable change. Results. Minimum levels of detectable change at the 90% confidence level varied from 4 to 5 RMQ points. CONCLUSION AND DISCUSSION: The magnitude of CSEMs is sufficiently small to detect change in patients with initial scores in the central portion of the scale (4-20 RMQ points); however, the magnitude is too large to detect improvement in patients with scores of less than 4 and deterioration in patients who have scores greater than 20.

The program for rheumatic independent self-management: a pilot evaluation.

The 'Program for Rheumatic Independent Self-Management' (PRISM) is an interdisciplinary programme that integrates group education and individualised treatment using the principles of self-management, adult learning, case management and self-efficacy enhancement. This study is a before-after evaluation of 57 individuals who attended PRISM. Outcome measures were selected to measure self-efficacy, disability, pain and ability to cope. The mean self-efficacy score increased immediately following the programme and this improvement was maintained at 6-month follow-up. Disability decreased from baseline to 6-month follow-up. There was a decrease in the mean level of pain from post-class to 6-month follow-up. All of these changes were statistically significant. These preliminary findings suggest that PRISM may be effective in enhancing self-efficacy, and reducing disability and pain.

Effects of estrogen on the stress response in CuSO4-exposed PLHC-1 cells.

As part of an effort to validate the use of heat shock proteins (hsp) as a biomarker of adverse effect, we investigated the impact of estrogen (E2), the hormone responsible for vitellogenisis in fish, on the induction of hsp 60 and 70. PLHC-1 (Pociliopsis lucida hepatoma cell line) cells were cultured under standard conditions and treated with either 16 ppm copper; a known inducer of hsp 60 and 70, 1 microM estradiol, a combination of copper and estradiol, or media alone. Copper induced both hsp 60 and 70 two fold, while E2 alone had no effect. The combination of the copper and E2 inhibited the hsp 70 response, indicated by a 51% decrease in cellular hsp 70 compared to the copper treatment alone. In contrast, the expression of hsp 60 in the cells exposed to the copper-estradiol mixture was not significantly different than that in the copper-exposed cells. The results suggest that the use of hsp 70 induction in fish liver as a biomarker of effect may be limited by the gender and sexual maturity of the fish.

A new teaching model to prolong breastfeeding among Latinos.

Latino women in Salt Lake City, Utah, have some of the lowest breastfeeding rates in the state. In an attempt to prolong breastfeeding duration in this population, the authors designed a new class to be taught by certified WIC (Special Supplemental Nutrition Program for Women, Infants, and Children) personnel to pregnant Spanish-speaking participants. The class was designed after a literature review and onsite ethnographic research. The term la cuarentena del bebé was introduced to signify the recommended 40 days when mothers should exclusively breastfeed, avoiding bottles, pacifiers, and supplementation. As part of the teaching model, class participants prepare an infant-feeding plan. Preliminary interviews show that WIC participants and staff view the new approach as an improvement. A randomized controlled trial is under way to evaluate the effectiveness of the class.

Interrater reliability of six tests of trunk muscle function and endurance.

Some studies have shown a relationship between trunk muscle strength and low back pain. Measures of trunk muscle strength and endurance, which are feasible in the clinical setting, are needed. The purpose of this study was to determine interrater reliability of six tests of abdominal and trunk extensor muscle strength and endurance. The tests included abdominal and extensor dynamic endurance, hand-held dynamometry of isometric flexion and extension, and abdominal and extensor static endurance. Thirty-nine healthy workers were recruited as subjects. Each was tested by three raters on 3 days within 1 week. Intraclass correlation coefficients (ICC) and the standard error of measurement (SEM) were calculated: abdominal dynamic endurance ICC = .89, SEM = 8 repetitions; extensor dynamic endurance ICC = .78, SEM = 9 repetitions; abdominal isometric force ICC = .25, SEM = 60 N; extensor isometric force ICC = .24, SEM = 68 N; abdominal static endurance ICC = .51, SEM = 35 seconds; extensor static endurance ICC = .59, SEM = 20 seconds. The dynamic endurance tests had acceptable interrater reliability. For the others, reliability was poor and the SEMs were large.

Integrated systems to reduce length of stay for knee and hip joint replacement surgeries.

To reduce length of stay while maintaining quality of care, St. Joseph's Hospital, Hamilton, ON implemented a care path with three discharge options. Two of these discharge options were early discharge to integrated community services. Patients meeting early discharge criteria are discharged home five days post-operatively with follow-up by home care nursing and physiotherapy. Otherwise, patients are discharged on day four to a multi-disciplinary rehabilitation unit at a separate facility. Patients requiring acute medical services for complications or co-morbidity stay in the acute care hospital. A prospective cohort evaluation showed no difference in complications and similar functional outcomes for the three discharge options.