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F McDermott

Publications and source records attributed to F McDermott.

At least 19 recordsLinked to original sources
PubMed2001

Centennial-scale Holocene climate variability revealed by a high-resolution speleothem delta 18O record from SW Ireland.

Evaluating the significance of Holocene submillennial delta18O variability in the Greenland ice cores is crucial for understanding how natural climate oscillations may modulate future anthropogenic warming. A high-resolution oxygen isotope record from a speleothem in southwestern Ireland provides evidence for centennial-scale delta18O variations that correlate with subtle delta18O changes in the Greenland ice cores, indicating regionally coherent variability in the early Holocene. Evidence for previously undetected early Holocene cooling events is presented, but mid- to late-Holocene ice rafting in the North Atlantic appears to have had little impact on delta18O at this ocean margin site.

Journal Article↗
PubMed1998

ESR and U-series analyses of teeth from the palaeoanthropological site of Hexian, Anhui Province, China.

ESR and U-series analyses of teeth from the palaeoanthropological site of Hexian which contained Homo erectus remains, illustrate the limited effectiveness of stand-alone ESR and U-series age estimates on faunal materials. The problem lies in the unknown U-uptake history causing very large uncertainties in the age results of both techniques. This study demonstrates the particular strength that lies in the integration of ESR and U-series dating analyses allowing the estimation of the U-uptake history. We obtained a combined ESR/U-series age estimate of 412 +/- 25 ka (average of six analyses on two teeth). This pinpoints the deposition of the faunal remains to the time of the transition between oxygen isotope stages 12 and 11. This is in agreement with the faunal composition which show a mixture of cold adapted northern mammals and more subtropical-tropical southern elements. The age also implies that the advanced Hexian Homo erectus occurred at a similar time as the less advanced Homo erectus specimens at Locality 1 at Zhoukoudian (LI-LIII).

Animals↗
PubMed1997

U-Th Isotopes in Arc Magmas: Implications for Element Transfer from the Subducted Crust

Uranium-thorium isotope results from island arc volcanic rocks were used to investigate the rates of transfer of fluids and sediments from the downgoing slab. Uranium, but not thorium, is readily mobilized in the fluid. A negative array between thorium/cerium and neodymium-143/neodymium-144 indicates that significant amounts of the thorium in arc rocks are derived from subducted sediments, although perhaps only about 30 percent of the thorium in subducted sediments is returned to the crust in this way. The transfer times for fluid through the mantle wedge are about 30,000 to 120,000 years, whereas those for sediment melts may be several million years. The low average uranium/thorium ratios of bulk crust primarily reflect different crustal generation processes in the Archaean.

Journal Article↗
PubMed1993

Mass-spectrometric U-series dates for Israeli Neanderthal/early modern hominid sites.

The nature of the relationship between Neanderthals and early modern Homo sapiens is controversial, yet it is fundamental to our understanding of early human evolution. The Middle Palaeolithic sites of Israel are critical to this debate, because unlike those of western Europe and Africa they contain both Neanderthal (at Tabun and Kebara for example) and anatomically modern hominids (as at Skhul and Qafzeh). Here we present new mass spectrometric 230Th/234U dates for dental fragments from the Middle Palaeolithic burial sites of Tabun, Qafzeh and Skhul. These data, combined with published ages from electron spin resonance (ESR), provide compelling evidence that the Tabun Neanderthals and Qafzeh early modern Homo sapiens were approximately coeval in the southern Levant some 100 +/- 5 kyr ago, but indicate that some of the Skhul material is younger. The study also shows that combined mass-spectrometric 230Th/234U and ESR dating is an invaluable technique for dating archaeological sites beyond the range of radiocarbon dating.

Animals↗
PubMed1991

Risk factors in breast cancer.

Risk factors are identified in less than 25 per cent of women who develop invasive breast cancer. The risk factors include a family history of breast cancer in a first degree family relative, late menopause, nulliparity, a first full term pregnancy after the age of 35 years, increasing age, P2 and DY mammographic parenchymal patterns, increasing dosage of non contraceptive oestrogens, mammary dysplasia associated with epithelial proliferation, a previous invasive breast carcinoma and carcinoma in situ.

Breast Neoplasms↗
PubMed1990

Structure of the T-cell antigen receptor: evidence for two CD3 epsilon subunits in the T-cell receptor-CD3 complex.

The T-cell antigen receptor (TCR) consists of heterodimeric glycoproteins (TCR alpha beta or gamma delta) that demonstrate homology with immunoglobulins. Noncovalently associated with the alpha beta (or gamma delta) heterodimer are at least five nonvariant proteins (CD3-gamma, -delta, -epsilon, -zeta, and -eta), which together comprise the TCR-CD3 complex. The stoichiometry of the antigen receptor has been assumed to be either alpha beta gamma delta epsilon zeta zeta or alpha beta gamma delta epsilon zeta eta. In this paper we provide several lines of evidence that support the notion that the mature TCR-CD3 complex on the cell surface contains two CD3-epsilon polypeptide chains. Transfection of two murine T cell-T cell hybridomas with the human DNA encoding CD3-epsilon protein demonstrated that both murine and human CD3-epsilon chains were present within the same TCR-CD3 complex. Analysis of thymocytes isolated from transgenic mice that expressed high copy numbers of the human CD3-epsilon gene showed that the heterologous human CD3-epsilon subunits were coexpressed with murine CD3-epsilon in the same TCR-CD3 complex. Since CD3-epsilon was shown to form disulfide-linked homodimers both in human and murine T cells, the two CD3-epsilon subunits present in the TCR-CD3 complex were in direct contact with one another. The presence of two CD3-epsilon polypeptide chains in close proximity to one another in the TCR-CD3 complex may have important implications for its assembly and its signal transduction mechanisms.

Animals↗
PubMed1990

Effect of experimental blunt head injury on acute regional cerebral blood flow and edema.

Acute edema occurs in cerebral hemispheres with contusion after a cranial impact-acceleration injury in the cat. In the present study, we asked whether changes in rCBF could contribute to this early pathophysiology. Cortical and white matter blood flow were measured with RMS before and at 10, 30, and 60 min after cranial impact. Specific gravity was tested peripheral to sample sites for rCBF. Head-injured animals with severe unilateral (grade 2) contusions had bilateral postinjury decreases in rCBF despite adequate cerebral perfusion pressure and carefully regulated PCO2 and PO2. Injured cats without cerebral contusion (grade 0) had substantial individual variation in rCBF after injury, with no group changes from preinjury values. Edema was measurable in the left cortex of grade 2 animals. Because of differences in sample sites, specific gravity data could not be reliably correlated with rCBF. Our findings suggest that acute oligemia can occur in the traumatized brain without systemic dysfunction.

Animals↗
PubMed1985

Prognostic significance of the absolute lymphocyte count in acute pancreatitis.

The absolute lymphocyte count was calculated with 48 hours of admission in 154 patients with acute pancreatitis. Twenty-three patients had severe pancreatitis and 131 patients had mild pancreatitis. The mean absolute lymphocyte count for the severe group was 880 +/- 102 cells/mm3 and for the mild group, 1,115 +/- 116 cells/mm3. The absolute lymphocyte count accurately predicted 78 percent of the severe attacks and 86 percent of the mild attacks.

Acute Disease↗
PubMed1982

Symptom duration, tumor staging and survival in patients with carcinoma of the breast.

Between 1950 and 1980, 435 patients were operated upon for carcinoma of the breast. Symptom duration data were available for 402 patients. Fifty-three of the patients had preoperative symptoms for less than one one week; 113, for one week to one month; 144, for one to six months and 92, for six months or more. Tumor staging was available on 353 of the 402 patients. With increasing peroperative symptom duration, there was an increase in the incidence of Stage IV tumors, p=0.003, and a reduction in Stage I tumors, p=0.006. Cancer specific survival time was better for the total patient series and for those treated by potentially curative operation when symptoms had been present for one week or less as compared with those who had symptom duration of six months or more, p=0.007. Survival prospects were also better in those patients who had symptoms from one week to one month as compared with those who had six months or more symptom duration, p=0.005. These results indicate that patients in whom diagnosis is made and operation performed early in the symptomatic phase of carcinoma of the breast have less advanced tumors and better survival prospects.

Adult↗
PubMed1982

Long term results of restorative resection and total excision for carcinoma of the middle third of the rectum.

Restorative resection for carcinoma of the middle third of the rectum has been facilitated by the recent introduction of the staplers. Before restorative resection with end-to-end anastomosis can become the treatment of choice, it must be proved that survival prospects after restorative resection are similar to those obtained after total abdominoperineal excision. The results of curative restorative resection and total excision in 417 patients with a single carcinoma of the middle third of the rectum managed by one of us are examined. Between 1950 and 1980, the proportion of patients treated by restorative resection for carcinoma of the middle third of the rectum increased from 26 to 93 per cent. Distribution by sex, age, tumor stage and tumor differentiation did not differ significantly between the two groups of patients operated upon. Cancer specific survival did not differ significantly between patients treated by restorative resection or total excision. Ten year survival rates were 60 and 59 per cent, respectively. Survival related to tumor stage and differentiation was not influenced by the type of operation. Tumor size, greater--p less than 0.04--in patients managed by total excision, had no significant influence on survival prospects. The results justify sphincter preservation and suggest that increased usage of restorative resection by stapling technique is not likely to lessen survival prospects in patients with carcinoma of the middle third of the rectum.

Adenocarcinoma↗
PubMed1981

Ovarian involvement in adenocarcinoma of the colon and rectum.

Thirty-six of 998 female patients with carcinoma of the colon and rectum had ovarian involvement at the time of the initial operation. Resection of tumor of the colon and rectum was performed upon 882 patients. The ovarian tumors were removed in 30 of the 36 patients with ovarian involvement. Ovarian involvement was associated with a significantly worsened, p = 0.009, cancer specific five year survival rate; five year survival prospects for patients with, and without, ovarian involvement were 38 and 60 per cent, respectively. Ovarian involvement also significantly, p = 0.014, worsened the survival rate of the 25 patients treated by curative resection of the tumor of the colon and rectum and associated ovarian spread. The five year cancer specific survival rate for female patients without ovarian involvement was 72 per cent, whereas ovarian involvement reduced the survival rate to 50 per cent.

Adenocarcinoma↗
PubMed1981

Symptom duration and survival prospects in carcinoma of the rectum.

Between 1950 and 1978, 1,228 patients were operated upon by one of us for carcinoma of the rectum. Symptom duration data were available for 1,081 patients. Forty-five per cent of the patients had symptoms preoperatively for less than three months, 22 per cent for three to six months, 15 per cent for six to 12 months and 18 per cent for 12 months or longer. The frequency of major symptoms did not differ significantly with increasing symptom duration. Symptom duration was not related to sex, age, tumor site within the rectum or tumor stage distribution. The proportion of curative to palliative operative procedures performed was unrelated to the duration of symptoms. The cancer specific survival rate was better for the total patient series and for those treated by curative resection if symptoms had been present for 12 months or longer compared with those of less than three months' duration, p = 0.001 and p = 0.01, respectively. Survival prospects were also better for patients with symptoms of less than six months' duration compared with those of six months or longer, p = 0.01 and p = 0.04, respectively. These results indicate that earlier diagnosis during the symptomatic period of carcinoma of the rectum cannot be expected to improve cancer specific survival rates. They direct attention to the importance of preclinical diagnosis.

Adult↗
PubMed1980

Mortality and morbidity of Crohn's disease and ulcerative colitis in Australia.

In Australia, between 1968 and 1977, the number of fatalities attributed to Crohn's disease increased significantly from 0.07/10(5) mean population (1968 to 1972) to 0.12/10(5) mean population (1873 to 1977). Over the same period, the mortality rate for ulcerative colitis was 0.23/10(5), with no increase. The ratio of the mortality rate for ulcerative colitis to that for Crohn's disease was similar in Australia to that in England and Wales, but the mortality rates for both diseases in Australia were approximately one-third of the corresponding rates in northern Europe and North America. Between 1959 and 1978 the relative frequency of public hospital admissions for Crohn's disease increased markedly in comparison with that for ulcerative colitis. A registry for inflammatory bowel disease should be established for monitoring epidemiological changes in Australia.

Adolescent↗
PubMed1979

Vechile-occupant fatalities after legislation for compulsory wearing of seat belts in Australia: different trends between the sexes.

The protective value of legislation for compulsory wearing of seat belts has been supported by Australian and overseas experience. An evaluation of changes during the period from 1957 to 1977 in the incidence of road crash fatalities for male and female vehicle occupants in Victoria and the rest of Australia (that is, in Australia minus Victoria) is presented. Reduction in the number of fatalities and the fatality rate in the number of fatalities per 10,000 vehicles) for vehicle occupants has resulted largely from statistically significant decreases for male drivers and adult passengers, especially females. However, the fatality rates have remained within the 95% confidence limits of expected post-legislation values for female drivers in Victoria and the rest of Australia, and for male adult passengers in the rest of Australia. There has been virtually no reduction in road crash fatalities for passengers less than 17 years of age. Hypotheses are advanced to explain these findings and further countermeasures are suggested.

Accidents, Traffic↗
PubMed1978

Compulsory blood alcohol testing of road crash casualties in Victoria: the first three years.

The history, rationale and implementation of legislation for compulsory blood alcohol tests on adult road crash casualties presenting at Victorian hospitals are reviewed. Drinking drivers admitted to casualty departments can now be identified and prosecuted; doctors can obtain blood alcohol test results on road crash casualties without threat of litigation; drinking drivers with alcohol problems may be directed to appropriate re-education or rehabilitation programmes; the opportunity also exists for treatment of non-driver casualties with alcohol problems. In the first three years of testing, 27.1% of 21,863 male driver casualties had blood alcohol concentrations in excess of the legal limit of 0.05 g/100 mL (11 mmol/L), and 13.7% had blood alcohol levels in excess of 0.15 g/100 mL (33 mmol/L); the blood alcohol levels in 8.7% of 9187 female driver casualties exceeded 0.05 g/100 mL, and in 3.7% exceeded 0.15 g/100 mL. Non-drivers had a slightly lower incidence of elevated alcohol concentrations. The implementation of further drink-driving countermeasures, expansion of services for the management of alcohol problems, and development of a national policy directed at prevention of alcohol abuse are recommended.

Accidents, Traffic↗
PubMed1978

Epithelial cell population kinetics of isolated ileal loops (thirty-vella fistulae) after 40% small in testinal resection. Autoradiographic studies in the rat.

The influence of 40% small intestinal resection on epithelial cell population kinetics of isolated ileal loops (Thirty-Vella fistulae) was investigated by autoradiography with H3-thymidine in the rat. Sixty days after resection increases were found in the size of the proliferative (0.05 less than P less than 0.1) and villous (P less than 0.01) zones. In isolated ileal loops of animals not subjected to 40% small bowel resection proliferative and villous zones were reduced in size in comparison to those of ileum in continuity in a group subjected to jejunal transection and anastomosis (P less than 0.002). The findings support the hypothesis that villous size is increased after resection by the action of a systemic factor. However, they provide only limited evidence for the influence of a systemic factor on crypt cell proliferation.

Animals↗