Search PubMed⌕ Search

Biomedical subjects

D Blackman

Publications and source records attributed to D Blackman.

At least 19 recordsLinked to original sources
PubMed2005

Towards a vulnerability assessment of the UK and northern European coasts: the role of regional climate variability.

Within the framework of a Tyndall Centre research project, sea level and wave changes around the UK and in the North Sea have been analysed. This paper integrates the results of this project. Many aspects of the contribution of the North Atlantic Oscillation (NAO) to sea level and wave height have been resolved. The NAO is a major forcing parameter for sea-level variability. Strong positive response to increasing NAO was observed in the shallow parts of the North Sea, while slightly negative response was found in the southwest part of the UK. The cause of the strong positive response is mainly the increased westerly winds. The NAO increase during the last decades has affected both the mean sea level and the extreme sea levels in the North Sea. The derived spatial distribution of the NAO-related variability of sea level allows the development of scenarios for future sea level and wave height in the region. Because the response of sea level to the NAO is found to be variable in time across all frequency bands, there is some inherent uncertainty in the use of the empirical relationships to develop scenarios of future sea level. Nevertheless, as it remains uncertain whether the multi-decadal NAO variability is related to climate change, the use of the empirical relationships in developing scenarios is justified. The resulting scenarios demonstrate: (i) that the use of regional estimates of sea level increase the projected range of sea-level change by 50% and (ii) that the contribution of the NAO to winter sea-level variability increases the range of uncertainty by a further 10-20cm. On the assumption that the general circulation models have some skill in simulating the future NAO change, then the NAO contribution to sea-level change around the UK is expected to be very small (<4cm) by 2080. Wave heights are also sensitive to the NAO changes, especially in the western coasts of the UK. Under the same scenarios for future NAO changes, the projected significant wave-height changes in the northeast Atlantic will exceed 0.4m. In addition, wave-direction changes of around 20 degrees per unit NAO index have been documented for one location. Such changes raise the possibility of consequential alteration of coastal erosion.

Climate↗
PubMed2001

Reforming the core clerkship in internal medicine: the SGIM/CDIM Project. Society of General Internal Medicine/Clerkship Directors in Internal Medicine.

Dramatic changes in health care have stimulated reform of undergraduate medical education. In an effort to improve the teaching of generalist competencies and encourage learning in the outpatient setting, the Society of General Internal Medicine joined with the Clerkship Directors in Internal Medicine in a federally sponsored initiative to develop a new curriculum for the internal medicine core clerkship. Using a broad-based advisory committee and working closely with key stakeholders (especially clerkship directors), the project collaborators helped forge a new national consensus on the learning agenda for the clerkship (a prioritized set of basic generalist competencies) and on the proportion of time that should be devoted to outpatient care (at least one third of the clerkship). From this consensus emerged a new curricular model that served as the basis for production of a curriculum guide and faculty resource package. The guide features the prioritized set of basic generalist competencies and specifies the requisite knowledge, skills, and attitudes/values needed to master them, as well as a list of suggested training problems. It also includes recommended training experiences, schedules, and approaches to faculty development, precepting, and student evaluation. Demand for the guide has been strong and led to production of a second edition, which includes additional materials, an electronic version, and a pocket guide for students and faculty. A follow-up survey of clerkship directors administered soon after completion of the first edition revealed widespread use of the curricular guide but also important barriers to full implementation of the new curriculum. Although this collaborative effort appears to have initiated clerkship reform, long-term success will require an enhanced educational infrastructure to support teaching in the outpatient setting.

Clinical Clerkship↗
PubMed2001

Self-reported Papanicolaou smears and hysterectomies among women in the United States.

OBJECTIVE: To evaluate the potential overuse of Papanicolaou smears among women who have had a hysterectomy. METHODS: We analyzed two surveys of US women aged 18 years or older, the Behavioral Risk Factor Surveillance System (1992-1997) and the National Health Interview Survey (1993-1994), and one survey of US hospitals (National Hospital Discharge Survey, 1980-1997). We examined the number of women who have had a hysterectomy who had a recent (within 3 years) Papanicolaou smear. We also examined trends in the proportions and rates of hysterectomies by diagnoses and type of procedure that potentially could require a Papanicolaou smear. RESULTS: From the Behavioral Risk Factor Surveillance System, an estimated 21.2% of US women have had a hysterectomy. Among women who have had a hysterectomy, 78.3% had a recent Papanicolaou smear. Among those reporting no hysterectomy, 82.1% had a recent Papanicolaou smear. Estimates from the National Health Interview Survey were similar. From the National Hospital Discharge Survey, an estimated 6.7% to 15.4% of women with a history of hysterectomy would require a subsequent Papanicolaou smear because they had a diagnosis related to cervical neoplasia or because they had undergone a supracervical hysterectomy. For an estimated 10.6-11.6 million of the 12.5 million women who had a hysterectomy and a recent Papanicolaou smear, that test could be considered unnecessary. CONCLUSION: Continued Papanicolaou screening of women without an intact uteri may result in excessive use of resources in time and money with minimal impact on decreasing cervical cancer.

Adolescent↗
PubMed2001

A statewide analysis of level I and II trauma centers for patients with major injuries.

BACKGROUND: This study examines statewide outcomes and resource use in Level I and II trauma centers for patients with major injuries. METHODS: This study analyzed trauma registry data on patients admitted to North Carolina Level I and II trauma centers from January 1995 to December 1996 with one of four major injuries: thoracic aortic disruption, liver injury, pelvic fracture, or pulmonary contusion. RESULTS: There were 59 thoracic aortic disruptions, 109 liver injuries, 153 pelvic fractures, and 962 pulmonary contusions identified among 26,030 admissions. Case fatality was not significantly different (Level I, 16.8%; Level II, 14.9%). Hospital charges were significantly higher in Level I centers (Level I, $47,366; Level II, $35,490), but this difference was confined to transferred patients. Controlling for Revised Trauma Score, Injury Severity Score, age, gender, and race, multivariable regression confirmed findings regarding hospital charges, and multiple logistic regression confirmed findings regarding case fatality. CONCLUSION: Case fatality was similar in Level I and Level II trauma centers in North Carolina, and hospital charges were comparable in patients with comparable injuries not requiring transfer. This suggests that patients with major injuries may be optimally cared for in both Level I and Level II trauma centers.

Adolescent↗
PubMed2000

Equivalence classes in individuals with minimal verbal repertoires.

Studies from two different laboratories tested for equivalence classes in individuals with severe mental retardation and minimal verbal repertoires. In the first study, 3 individuals learned several matching-to-sample performances: matching picture comparison stimuli to dictated-word sample stimuli (AB), matching those same pictures to printed letter samples (CB), and also matching the pictures to nonrepresentative forms (DB). On subsequent tests, all individuals immediately displayed Emergent Relations AC, AD, BC, BD, CD, and DC, together constituting a positive demonstration of equivalence (as defined by Sidman). The second study obtained a positive equivalence test outcome in 1 of 2 individuals with similarly minimal verbal repertoires. Taken together, these studies call into question previous assertions that equivalence classes are demonstrable only in individuals with well-developed language repertoires.

Adolescent↗
PubMed1999

In vivo degradation of bleaching gel used in whitening teeth.

BACKGROUND: The purpose of the study described here was to determine the in vivo degradation rate of 10 percent carbamide peroxide, or CP, gel in bleaching trays. The degradation rate indicates the remaining concentration of the active agent on the facial surfaces at various intervals. METHODS: The researchers fabricated bleaching trays with 0.5-millimeter reservoirs and loaded them with a 10 percent CP whitening gel. The tray was seated in place in 15 patients for six different intervals that ranged from 15 seconds to 10 hours. When the tray was removed, three samples were collected from each patient: the gel remaining in the tray; the adherent gel scraped from the teeth; and a "grab" sample from the reservoir of tooth no. 8. The researchers analyzed these samples for CP according to the method specified by the U.S. Pharmacopeial Convention. RESULTS: The percentage of CP recovered decreased as the intervals increased: 87 percent at 15 seconds, 10 percent at 10 hours. Log of tray, teeth and grab samples, respectively, at 15 seconds were 0.94, 0.98 and 0.96 and at 10 hours were -0.13, -0.38 and 0.11. The first-hour degradation rate for tray, teeth and grab samples, respectively, was 2.0 times, 3.6 times and one time the rate during the next nine hours. The within-subject repeatability of the samples was excellent. CONCLUSIONS: The degradation rate of CP during the bleaching process is biexponential. In the tray and teeth samples, the degradation rate was accelerated during the first hour. Further research is needed to determine the cause of this acceleration. CLINICAL IMPLICATIONS: The active agent in CP bleaching gel is available in bleaching trays for more than 10 hours. After two hours, more than 50 percent of the active agent is available, and 10 percent is available after 10 hours.

Adult↗
PubMed1999

Coding mammograms using the classification "probably benign finding--short interval follow-up suggested".

OBJECTIVE: Many benign breast lesions revealed by mammography show features indicating that the lesions have a high, but not complete, likelihood of being benign. The Breast Imaging Reporting and Data System (BI-RADS) allows radiologists to classify these mammograms as "probably benign finding-short interval follow-up suggested" (category 3). We explored whether certain factors are associated with the use of category 3 in a national cancer detection program. MATERIALS AND METHODS: We analyzed data from the National Breast and Cervical Cancer Early Detection Program, a comprehensive nationwide program that provides cancer screening for low-income and medically underserved women. The study population included all women at least 40 years old who had undergone mammography on or before September 30, 1996 (n = 372,760). RESULTS: Of the 372,760 mammograms, 7.7% were classified as category 3. The probability of receiving a category 3 classification decreased as patients' ages increased. Women who were symptomatic were nearly twice as likely as women who were asymptomatic to receive a category 3 classification, and women whose clinical breast examinations had abnormal findings were more than twice as likely as women with examinations having normal findings to receive a category 3 classification. The percentage of mammograms classified as category 3 by state or tribal organization ranged from 1.4% to 14.0%. CONCLUSION: Several patient variables, including patient symptomatology, were associated with the probability of having a mammogram classified as category 3. One of the most important determinants was where the patient underwent mammography, which suggests that variability exists among radiologists themselves in using this BI-RADS code for "probably benign" mammographic lesions.

Adult↗
PubMed1996

Challenging behaviour: the effectiveness of specialist support teams.

Two specialist community services for people with learning disabilities and challenging behaviour were evaluated over approximately 3 years. Intervention effectiveness was assessed with respect to changes in subjects' skills, challenging behaviours, mental health and quality of life, and to changes in staff morale. Subjects assessed as having challenging behaviour but not referred for specialist input were also studied. Comparison of changes in referred and non-referred samples over time showed minor differences only, indicating little intervention effect and demonstrating stability in the comparison sample. Analysis of the two services separately yielded different results. Positive client change was evident with respect to one service, whilst little change was noted with respect to the other. There was little evidence to suggest that either service had any effect on staff morale. Differences between the two services in terms of structure, staffing characteristics and operational policies are discussed as possible factors in the differential results obtained. A major issue raised by the study concerns the quality of settings from which the subjects were referred for specialist support. This is discussed as a factor which may limit the effectiveness of specialist input.

Adolescent↗
PubMed1995

People with learning disabilities and challenging behaviour: the characteristics of those referred and not referred to specialist teams.

The characteristics of two samples of people with learning disabilities and severely challenging behaviour were examined. The experimental sample comprised subjects who had been referred to two specialist challenging behaviour services in separate counties. The comparison sample comprised subjects from the same counties who were not referred or accepted for specialist intervention. No significant differences were found between the samples in terms of age, gender, social impairment, dependency characteristics, ability levels and mental health. Significant differences between them were found in the nature and severity of aberrant behaviour presented, as assessed by their carers. The implications of these findings are discussed with regard to how the term 'severely challenging behaviour' is defined in practice.

Activities of Daily Living↗
PubMed1993

Common phosphatidylinositol 4,5-bisphosphate pools are involved in carbachol and serotonin activation of tracheal smooth muscle.

We examined the rate and extent of labeling of total cellular phosphatidylinositol 4,5-bisphosphate (PIP2) and phosphatidylinositol (PI) in canine tracheal smooth muscle in response to maximum levels of two different contractile agonists, carbachol (5.5 microM) and serotonin (5-hydroxytryptamine, 5-HT) (47 microM) and when a second agonist was given during a maximal contraction evoked by the first agonist. Unstimulated tracheal smooth muscle strips were incubated with [3H]-myo-inositol (MI) to label tissue MI without much labeling of inositol phospholipids. With carbachol, there was a 20-fold increase in the [3H]-MI incorporation rate into inositol phospholipids, decreases in PI and PIP2 contents, and increases in phosphatidic acid and diacylglycerol contents. PI and PIP2 specific radioactivities reached plateaus, 0.90 +/- 0.03 and 0.80 +/- 0.04, respectively, compared with [3H]-MI specific radioactivity. 5-HT at 47 microM evoked smaller changes including force development, [3H]-MI incorporation rate and lipid mass changes. However, the plateau of PI and PIP2 labeling reached levels similar to that determined during carbachol-evoked force, 0.90 +/- 0.06 and 0.82 +/- 0.04, respectively. Carbachol (55 microM) addition after incubation with 5-HT did not significantly alter the plateau levels of the specific radioactivities of PI or PIP2, although force and lipid mass changes were significantly changed. We conclude that 5-HT and muscarinic receptor coupling mechanisms utilize the same pool of PIP2 as a substrate for phospholipase C activation and the same PI pool for conversion to PIP and PIP2.

Animals↗
PubMed1992

Efficacy of nursing home preadmission screening.

This study evaluates the efficacy of four state nursing home preadmission screening instruments. Using data from three community-based services demonstration experiments, the screens were compared on measures of sensitivity, specificity, and proportions of false negatives and false positives. Results indicate that the more restrictive screens tended to have lower sensitivity but higher specificity, and to generate a higher proportion of false negative decisions than the more liberal screens. Overall rates of correct prediction were higher for the more restrictive screens. Results highlight differences in eligibility restrictiveness across states as well as possible tradeoffs of cost containment and access in designing a preadmission screen.

Aged↗