Computer program to determine roots of polynomials by ratio of successive derivatives

High speed computing finds roots of polynomials with real number coefficients. Ratios of successive polynomial derivatives approach provides accurate roots-of-polynomial computer programs with very high reliability. With derivative ratio method, root analysis can still be done even though the polynomial and its lower order derivatives cannot be evaluated with sufficient accuracy

Fish Assemblages and Benthic Biota Associated with Natural Hard-Bottom Areas in the Northwestern Gulf of Mexico

We report new observations of fish and benthic invertebrate assemblages at shallow-water (\u3c35 m depth), hard-bottom sites in the northwestern Gulf of Mexico. The biota of these previously unstudied areas and of three high-relief features in deeper water was observed during May 1980 using a combination of diver reconnaissance, videotape surveys, still-camera photography, and collection of invertebrates for identification. The six hard-bottom sites in shallow water typically comprised, small, often patchy, rock outcrops, and the associated sessile invertebrates included hydroids, bryozoans, sponges, octocorals, and ahermatypic stony corals. Sea urchins and arrow crabs were the most common motile epifauna. Fish assemblages were typified by red snapper, Atlantic spadefish, blue runner gray triggerfish, sheepshead, and tomtate. Three deeper stations had many of the same fish and invertebrate species, but also possessed a more tropical assemblage including fire corals, antipatharians, spiny lobsters, and a variety of tropical fish species. Hermatypic corals characteristic of some large, offshore banks were not abundant at any of the sites. Differences in the composition of fish assemblages between nearshore and deeper stations parallel those previously observed at petroleum platforms in the area. Shallow-water stations presumably experience a greater seasonal temperature range and lower absolute temperatures in winter and may be exposed to stresses such a lowered salinity and depleted oxygen levels due to their relative proximity to Mississippi River discharge. The fauna of these shallow hard-bottom sites has predominantly warm-temperate rather than tropical affinities

Genetic heterogeneity and trans regulators of gene expression

Heterogeneity poses a challenge to linkage mapping. Here, we apply a latent class extension of Haseman-Elston regression to expression phenotypes with significant evidence of linkage to trans regulators in 14 large pedigrees. We test for linkage, accounting for heterogeneity, and classify individual families as "linked" and "unlinked" on the basis of their contribution to the overall evidence of linkage

Assessment of Surfactant Use in Preterm Infants as a Marker of Neonatal Intensive Care Unit Quality

Background Proposed neonatal quality measures have included structural measures such as average daily census, and outcome measures such as mortality and rates of complications of prematurity. However, process measures have remained largely unexamined. The objective of this research was to examine variation in surfactant use as a possible process measure of neonatal quality. Methods We obtained data on infants 30 to 34 weeks gestation admitted with respiratory distress syndrome (RDS) within 48 hours of birth to 16 hospitals participating in the Pediatric Health Information Systems database from 2001-2006. Models were developed to describe hospital variation in surfactant use and identify patient and hospital predictors of use. Another cohort of all infants admitted within 24 hours of birth was used to obtain adjusted neonatal intensive care unit (NICU) mortality rates. To assess the construct validity of surfactant use as a quality metric, adjusted hospital rates of mortality and surfactant use were compared using Kendall\u27s tau. Results Of 3,633 infants, 46% received surfactant. For individual hospitals, the adjusted odds of surfactant use varied from 2.2 times greater to 5.9 times less than the hospital with the median adjusted odds of surfactant use. Increased annual admissions of extremely low birth weight infants to the NICU were associated with greater surfactant use (OR 1.80, 95% CI 1.02-3.19). The correlation between adjusted hospital rates of surfactant use and in-hospital mortality was 0.37 (Kendall\u27s tau p = 0.051). Conclusions Though results were encouraging, efforts to examine surfactant use in infants with RDS as a process measure reflecting quality of care revealed significant challenges. Difficulties related to adequate measurement including defining RDS using administrative data, accounting for care received prior to transfer, and adjusting for severity of illness will need to be addressed to improve the utility of this measure

Dually noted: the effects of a pressure headcollar on compliance, discomfort and stress in horses during handling

Horse handlers often encounter problem behaviour resulting from a lack of stimulus control. Handlers are often only 15% of the weight of horses, which evolved strong flight responses. Therefore, many riders and handlers resort to the use of "aids" to maintain control of their animals. However, there are increasing concerns about the efficacy and welfare implication of such devices, particularly when applied to sensitive facial structures. One such device is a Dually® headcollar which aims to increase compliance. Despite its popularity, little is known about the effects of this aid on behaviour or stress. The aim of the current study was to determine whether the use of a Dually headcollar improves compliance during handling and, if so, whether this might be achieved with concomitant increases in stress or discomfort. Subjects completed two novel handling tests, one wearing a Dually with a line attached to the pressure mechanism and one attached to the standard ring as a Control. Crossing time and proactive behaviour were recorded as indicators of compliance. Core temperature and the discrepancy between eye temperatures were measured using IRT before and after testing as an indicator of stress. The Horse Grimace Scale (HGS) was used to measure discomfort caused by each configuration of the device. The Dually did not result in more compliant behaviour, compared to the Control (p=0.935; p=0.538). However, the Dually configuration did result in a significantly higher HGS scores (p=0.034). This may indicate that there is an impact on animal welfare by using this device that is not justified by improved behaviour. However, IRT readings of core temperature (p=0.186) and discrepancy between the eyes (p=0.972) did not indicate the Dually increased stress in subjects. Taken together, this suggests the Dually is ineffective in naïve horses but causes increased discomfort

Recruitment for a Hospital-Based Pragmatic Clinical Trial using Volunteer Nurses and Students

BACKGROUND/AIMS: Recruitment of subjects is critical to the success of any clinical trial, but achieving this goal can be a challenging endeavor. Volunteer nurse and student enrollers are potentially an important source of recruiters for hospital-based trials; however, little is known of either the efficacy or cost of these types of enrollers. We assessed volunteer clinical nurses and health science students in their rates of enrolling family members in a hospital-based, pragmatic clinical trial of cardiopulmonary resuscitation education, and their ability to achieve target recruitment goals. We hypothesized that students would have a higher enrollment rate and are more cost-effective compared to nurses. METHODS: Volunteer nurses and student enrollers were recruited from eight institutions. Participating nurses were primarily bedside nurses or nurse educators while students were pre-medical, pre-nursing, and pre-health students at local universities. We recorded the frequency of enrollees recruited into the clinical trial by each enroller. Enrollers\u27 impressions of recruitment were assessed using mixed-methods surveys. Cost was estimated based on enrollment data. Overall enrollment data were analyzed using descriptive statistics and generalized estimating equations. RESULTS: From February 2012 to November 2014, 260 hospital personnel (167 nurses and 93 students) enrolled 1493 cardiac patients\u27 family members, achieving target recruitment goals. Of those recruited, 822 (55%) were by nurses, while 671 (45%) were by students. Overall, students enrolled 5.44 (95% confidence interval (CI): 2.88, 10.27) more subjects per month than nurses (p \u3c 0.01). After consenting to participate in recruitment, students had a 2.85 (95% CI: 1.09, 7.43) increased chance of enrolling at least one family member (p = 0.03). Among those who enrolled at least one subject, nurses enrolled a mean of 0.51(95% CI: 0.42, 0.59) subjects monthly, while students enrolled 1.63 (95% CI: 1.37, 1.90) per month (p \u3c 0.01). Of 198 surveyed hospital personnel (127 nurses, 71 students), 168/198 (85%) felt confident conducting enrollment. The variable cost per enrollee recruited was $25.38 per subject for nurses and$23.30 per subject for students. CONCLUSIONS: Overall, volunteer students enrolled more subjects per month at a lower cost than nurses. This work suggests that recruitment goals for a pragmatic clinical trial can be successfully obtained using both nurses and students

Validation of Diffuse Correlation Spectroscopic Measurement of Cerebral Blood Flow Using Phase-Encoded Velocity Mapping Magnetic Resonance Imaging

Diffuse correlation spectroscopy (DCS) is a novel optical technique that appears to be an excellent tool for assessing cerebral blood flow in a continuous and non-invasive manner at the bedside. We present new clinical validation of the DCS methodology by demonstrating strong agreement between DCS indices of relative cerebral blood flow and indices based on phase-encoded velocity mapping magnetic resonance imaging (VENC MRI) of relative blood flow in the jugular veins and superior vena cava. Data were acquired from 46 children with single ventricle cardiac lesions during a hypercapnia intervention. Significant increases in cerebral blood flow, measured both by DCS and by VENC MRI, as well as significant increases in oxyhemoglobin concentration, and total hemoglobin concentration, were observed during hypercapnia. Comparison of blood flow changes measured by VENC MRI in the jugular veins and by DCS revealed a strong linear relationship, R = 0.88, p \u3c 0.001, slope = 0.91 ± 0.07. Similar correlations were observed between DCS and VENC MRI in the superior vena cava, R = 0.77, slope = 0.99 ± 0.12, p \u3c 0.001. The relationship between VENC MRI in the aorta and DCS, a negative control, was weakly correlated, R = 0.46, slope = 1.77 ± 0.45, p \u3c 0.001

Video-Only Cardiopulmonary Resuscitation Education for High-Risk Families Before Hospital Discharge: A Multicenter Pragmatic Trial

BACKGROUND: Cardiopulmonary resuscitation (CPR) training rates in the United States are low, highlighting the need to develop CPR educational approaches that are simpler, with broader dissemination potential. The minimum training required to ensure long-term skill retention remains poorly characterized. We compared CPR skill retention among laypersons randomized to training with video-only (VO; no manikin) with those trained with a video self-instruction kit (VSI; with manikin). We hypothesized that VO training would be noninferior to the VSI approach with respect to chest compression (CC) rate. METHODS AND RESULTS: We performed a prospective, cluster randomized trial of CPR education for family members of patients with high-risk cardiac conditions on hospital cardiac units, using a multicenter pragmatic design. Eight hospitals were randomized to offer either VO or VSI training before discharge using volunteer trainers. CPR skills were assessed 6 months post training. Mean CC rate among those trained with VO compared with those trained with VSI was assessed with a noninferiority margin set at 8 CC per min; as a secondary outcome, mean differences in CC depth were assessed. From February 2012 to May 2015, 1464 subjects were enrolled and 522 subjects completed a skills assessment. The mean CC rates were 87.7 (VO) CC per min and 89.3 (VSI) CC per min; we concluded noninferiority for VO based on a mean difference of -1.6 (90% confidence interval, -5.2 to 2.1). The mean CC depth was 40.2 mm (VO) and 45.8 mm (VSI) with a mean difference of -5.6 (95% confidence interval, -7.6 to -3.7). Results were similar after multivariate regression adjustment. CONCLUSIONS: In this large, prospective trial of CPR skill retention, VO training yielded a noninferior difference in CC rate compared with VSI training. CC depth was greater in the VSI group. These findings suggest a potential trade-off in efforts for broad dissemination of basic CPR skills; VO training might allow for greater scalability and dissemination, but with a potential reduction in CC depth. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01514656