Interpopulation differences and temporal synchrony in rates of adult survival between two seabird colonies that differ in population size and distance to foraging grounds

Understanding the processes that drive interpopulation differences in demography and population dynamics is central to metapopulation ecology. In colonial species, populations are limited by local resource availability. However, individuals from larger colonies will travel greater distances to overcome density-dependent competition. Consequently, these individuals may also experience greater carry-over effects and interpopulation differences in demography. To test this prediction, we use mark-recapture data collected over four decades from two breeding colonies of a seabird, the Manx shearwater (Puffinus puffinus), that exhibit strong spatial overlap throughout the annual cycle but differ in population size and maximum foraging distances. We quantify interpopulation differences and synchrony in rates of survival and assess whether local mean wind speeds act to strengthen or disrupt synchrony. In addition, we examine whether the imputed interpopulation differences in survival can generate population-level consequences. The colony where individuals travel further during the breeding season had slightly lower and more variable rates of survival, indicative of individuals experiencing greater carry-over effects. Fluctuations in survival were highly synchronous between the colonies, but neither synchronous, nor asynchronous, variation could be strongly attributed to fluctuations in local mean wind speeds. Finally, we demonstrate that the imputed interpopulation differences in rates of survival could lead to considerable differences in population growth. We hypothesise that the observed interpopulation differences in rates of adult survival reflect carry-over effects associated with foraging distances during the breeding season. More broadly, our results highlight that breeding season processes can be important for understanding interpopulation differences in the demographic rates and population dynamics of long-lived species, such as seabirds.

Breeding phenology and winter activity predict subsequent breeding success in a trans-global migratory seabird

Inter-seasonal events are believed to connect and affect reproductive performance (RP) in animals. However, much remains unknown about such carry-over effects (COEs), in particular how behaviour patterns during highly mobile life-history stages, such as migration, affect RP. To address this question, we measured at-sea behaviour in a long-lived migratory seabird, the Manx shearwater (Puffinus puffinus) and obtained data for individual migration cycles over 5 years, by tracking with geolocator/immersion loggers, along with 6 years of RP data. We found that individual breeding and non-breeding phenology correlated with subsequent RP, with birds hyperactive during winter more likely to fail to reproduce. Furthermore, parental investment during one year influenced breeding success during the next, a COE reflecting the trade-off between current and future RP. Our results suggest that different life-history stages interact to influence RP in the next breeding season, so that behaviour patterns during winter may be important determinants of variation in subsequent fitness among individuals.

Stranger danger awareness in Williams syndrome

BACKGROUND

The developmental disorder Williams syndrome (WS) is characterised by a distinctive cognitive profile and an intriguing social phenotype. Individuals with the disorder are often highly social engaging with familiar and unfamiliar people and once in an interaction they often show subtle abnormalities of social behaviour. Atypically increased approach to unfamiliar people is widely reported in the existing literature for both children and adults. Parents frequently report interactions with unfamiliar people as a major concern.

METHODS

In this study we aimed to evaluate 'stranger danger' awareness using a video vignette task with individuals who had WS. When linked to other components of the WS phenotype (e.g. reduced intellectual ability, increased social approach) an awareness of stranger danger is particularly important.

RESULTS

Qualitative and quantitative data showed that young people with WS have difficulties making judgements about whether or not to trust and engage in conversation with unfamiliar people. Qualitative data showed that individuals with WS often suggested that they would engage in an interaction with an unfamiliar person.

CONCLUSIONS

The findings have substantial implications for the safety of young people with the disorder and emphasise the need for intervention regarding this behaviour.

The role of advanced nursing practice in occupational health

BACKGROUND

There is a concern that current specialist occupational health (OH) training programmes in the UK are not delivering nurses equipped to deal with the challenges of emerging practice. The development of new training programmes and advanced nurse practitioner (ANP) roles provide a potential solution. Although a model of advanced nursing practice has been developing, its relevance to OH has not been assessed.

AIMS

To collate information about OH nurses in the UK, their levels of training, and to collect their views on the relevance of ANP competencies to the specialty.

METHODS

An online questionnaire survey was carried out using a database of nurses working in OH. Each nurse received a direct invitation to participate with a link to the survey and one reminder.

RESULTS

Nine hundred and ninety-eight responses were included in the analysis. Eighty nine per cent had a specialist qualification in OH. A large majority of respondents believed that almost all the generic ANP competencies were important in current and future OH nursing practice. Only a few competencies (examination, diagnosis, referral, treatment) were felt to be more important in the future than currently. Over half (57%) agreed that in the future where OH nurses were working as specialists they should be trained as advanced nurse practitioners. Seventy one per cent of OH nurses agreed that a new multi-disciplinary qualification would be beneficial.

CONCLUSIONS

OH nurses recognize that ANP competencies are important to their current and future practice. There is enthusiasm in OH nursing for the introduction of advanced nursing practice and a new training programme.

Semi-inclusive lambda and K(S) production in p-Au collisions at 17.5 GeV/c

The first detailed measurements of the centrality dependence of strangeness production in p-A collisions are presented. Lambda and K(S) dn/dy distributions from 17.5 GeV/ c p-Au collisions are shown as a function of "grey" track multiplicity and the estimated number of collisions, nu, made by the proton. The nu dependence of the Lambda yield deviates from a scaling of p-p data by the number of participants, increasing faster than this scaling for nu</=5 and saturating for larger nu. A slower growth in K(S) multiplicity with nu is observed, consistent with a weaker nu dependence of K&Kmacr; production than YK production.

G2A is an oncogenic G protein-coupled receptor

G2A is a heptahelical cell surface protein that has recently been described as a potential tumor suppressor, based on its ability to counteract transformation of pre-B cells and fibroblasts by Bcr-Abl, an oncogenic tyrosine kinase. We have isolated cDNAs encoding G2A in the course of screening libraries for clones that cause oncogenic transformation of NIH3T3 fibroblasts. When expressed at high levels in NIH3T3 cells by retroviral transduction, G2A induced a full range of phenotypes characteristic of oncogenic transformation, including loss of contact inhibition, anchorage-independent survival and proliferation, reduced dependence on serum, and tumorigenicity in mice. When expressed by transfection, G2A greatly enhanced the ability of a weakly oncogenic form of Raf-1 to transform NIH3T3 cells. These results demonstrate that G2A is potently oncogenic both on its own and in cooperation with another oncogene. Expression of G2A in fibroblasts and endothelial cells resulted in changes in cell morphology and cytoskeleton structure that were equivalent to those induced by the G protein subunit Galpha13. Transformation of NIH3T3 cells via G2A expression was completely suppressed by co-expression of LscRGS, a GTPase activating protein that suppresses signaling by Galpha12 and Galpha13. Hyperactivity of Galpha12 or Galpha13 has previously been shown to result in activation of Rho GTPases. G2A expression resulted in activation of Rho, and transformation via G2A was suppressed by a dominant negative form of RhoA. These results indicate that G2A may be directly coupled to Galpha13, and that it is the activation of this Rho-activating Galpha protein which is responsible for the ability of G2A to transform fibroblasts.

Complementation of growth factor receptor-dependent mitogenic signaling by a truncated type I phosphatidylinositol 4-phosphate 5-kinase

Substitution of phenylalanine for tyrosine at codon 809 (Y809F) of the human colony-stimulating factor 1 (CSF-1) receptor (CSF-1R) impairs ligand-stimulated tyrosine kinase activity, prevents induction of c-MYC and cyclin D1 genes, and blocks CSF-1-dependent progression through the G1 phase of the cell cycle. We devised an unbiased genetic screen to isolate genes that restore the ability of CSF-1 to stimulate growth in cells that express mutant CSF-1R (Y809F). This screen led us to identify a truncated form of the murine type Ibeta phosphatidylinositol 4-phosphate 5-kinase (mPIP5K-Ibeta). This truncated protein lacks residues 1 to 238 of mPIP5K-Ibeta and is catalytically inactive. When we transfected cells expressing CSF-1R (Y809F) with mPIP5K-Ibeta (delta1-238), CSF-1-dependent induction of c-MYC and cyclin D1 was restored and ligand-dependent cell proliferation was sustained. CSF-1 normally triggers the rapid disappearance of CSF-1R (Y809F) from the cell surface; however, transfection of cells with mPIP5K-Ibeta (delta1-238) stabilized CSF-1R (Y809F) expression on the cell surface, resulting in elevated levels of ligand-activated CSF-1R (Y809F). These results suggest a role for PIP5K-Ibeta in receptor endocytosis and that the truncated enzyme compensated for a mitogenically defective CSF-1R by interfering with this process.

Expression cloning of lsc, a novel oncogene with structural similarities to the Dbl family of guanine nucleotide exchange factors

In a screen for genes with oncogenic potential expressed by the murine B6SUtA1 myeloid progenitor cell line, we isolated a 2. 5-kilobase pair cDNA whose expression causes strong morphological transformation and deregulated proliferation of NIH 3T3 cells. The transforming cDNA encodes a truncated protein (designated Lsc) with a region of sequence similarity to the product of the lbc oncogene. This region includes the tandem Dbl homology and pleckstrin homology domains that are hallmarks of the Dbl-like proteins, a family of presumptive or demonstrated guanine nucleotide exchange factors that act on Rho family GTPases. Lsc requires intact Dbl homology and pleckstrin homology domains for its oncogenic activity. The transforming activity of Lsc in NIH 3T3 cells is reduced by cotransfection with p190 (a GTPase activating protein for Rho family GTPases) and the Rho family dominant-negative mutants RhoA(19N), CDC42(17N), and Rac1(17N). These results indicate a role for the Rho family of GTPases in mediating the transforming activity of Lsc and are consistent with the exchange specificities that have been attributed to Dbl family members. The lsc gene is expressed in a variety of tissues and is particularly abundant in hemopoietic tissues (thymus, spleen, and bone marrow). Lsc is a member of a growing family of proteins that may function as activators of Rho family GTPases in a developmental or tissue-specific manner.

Expression cloning of lfc, a novel oncogene with structural similarities to guanine nucleotide exchange factors and to the regulatory region of protein kinase C

In order to identify cDNAs that can induce oncogenic transformation, a retroviral vector was used to transfer a library of cDNAs from the murine 32D hemopoietic cell line into NIH 3T3 fibroblasts. We have identified and recovered a provirus containing a 1.8-kilobase pair cDNA whose expression causes morphological transformation in NIH 3T3 cells. The transforming cDNA contains a complete open reading frame that encodes a protein (designated Lfc) with a region of sequence similarity to the product of the lbc oncogene. This region includes a domain that is characteristic of the CDC24 family of guanine nucleotide exchange factors in tandem with a pleckstrin homology (PH) domain. The Lfc protein is distinguished from Lbc by a 150-amino acid NH2-terminal extension that contains a cysteine- and histidine-rich domain similar to the diacylglycerol-binding site (zinc butterfly) found in protein kinase C. NH2- and COOH-terminal deletion analysis revealed that both the PH and putative guanine nucleotide exchange factor domains are required, but the zinc butterfly is dispensable, for transformation. Although the removal of the PH domain of the Lfc protein completely eliminated its ability to transform NIH 3T3 cells, replacement of this domain with an isoprenylation site restored all of its transforming activity. This suggests that a PH domain-dependent recruitment of the Lfc protein to the cellular membrane is a necessary step for cellular transformation. The lfc gene is expressed in a broad range of tissues as well as in a variety of hemopoietic and non-hemopoietic cell lines. Lfc appears to be a new member of a growing family of proteins that are likely to act as activators of Ras-like proteins in a developmental or cell-lineage specific manner.

Retroviral transduction and oncogenic selection of a cDNA encoding Dbs, a homolog of the Dbl guanine nucleotide exchange factor

A retroviral vector was used to transfer a large library of cDNAs from the 32D murine hemopoietic cell line to NIH3T3 fibroblasts, for the purpose of selecting cDNAs that induce oncogenic transformation. One highly transformed colony arising in the infected NIH3T3 cell culture contained a provirus with a 1900 bp cDNA insert. After recovery and reincorporation into a retroviral vector, this cDNA induced rapid morphological transformation and proliferation when expressed in NIH3T3 or C3H10T1/2 fibroblast cell lines. The transforming cDNA encoded a protein, designated Dbs, which had a region of high sequence similarity to the Dbl proto-oncogene. This region included motifs characteristic of the CDC24 family of guanine nucleotide exchange factors, and an adjacent pleckstrin homology domain. Dbs was distinguished from Dbl by an N-terminal extension and the presence of an SH3 domain at its C terminus. Deletions of the Dbs-encoding cDNA demonstrated that transformation of NIH3T3 cells required intact exchange factor and pleckstrin homology domains, but did not require the SH3 domain. In contrast to Dbl, the N-terminal sequences of Dbs did not suppress its transforming activity. The Dbs gene was expressed at low levels in several murine hemopoietic cell lines and in thymus and spleen, and at higher levels in other tissues, particularly in brain. Dbs may be one of a large family of exchange factors which provide cell-type specific pathways for regulating proliferating via the activation of Ras-like proteins.

Expression cloning of oncogenes by retroviral transfer of cDNA libraries

a cDNA library transfer system based on retroviral vectors has been developed for expression cloning in mammalian cells. The use of retroviral vectors results in stable cDNA transfer efficiencies which are at least 100-fold higher than those achieved by transfection and therefore enables the transfer and functional screening of very large libraries. In our initial application of retroviral transfer of cDNA libraries, we have selected for cDNAs which induce oncogenic transformation of NIH 3T3 fibroblasts, as measured by loss of contact inhibition of proliferation. Nineteen different transforming cDNAs were isolated from a total of 300,000 transferred cDNA clones. Three of these cDNAs were derived from known oncogenes (raf-1, lck, and ect2), while nine others were derived from genes which had been cloned previously but were not known to have the ability to transform fibroblasts (beta-catenin, thrombin receptor, phospholipase C-gamma 2 and Spi-2 protease inhibitor genes). The Spi-2 cDNA was expressed in antisense orientation and therefore is likely to act as an inhibitor of an endogenous transformation suppressor. Seven novel cDNAs with transforming activities, including those for three new members of the CDC24 family of guanine nucleotide exchange factors, were also cloned from the retroviral cDNA libraries. Retroviral transfer of libraries should be generally useful for cloning cDNAs which confer selectable phenotypes on many different types of mammalian cells.

Images of aging--over the last 100 years

Discussions on care of the elderly today often lack definitions of various issues and concepts relating to the elderly in question and their needs. One problem is the tendency to categorise the elderly in general as one homogeneous group of frail individuals. Another is an increasing tendency to paint a posy picture of the third age, overlooking the problems of "the fourth age". The categorisation of "the elderly" dates back 100 years in history, when the first political initiatives on pension policy were taken. Denmark was the first country to introduce such legislation, with old age (over 60) as the basic criterion. However, the basis for drawing a vertical line at the age of 60 was a series of findings by German and French scholars of medicine and statistics on age-related decline in various functions. The development of geriatric medicine occurred rather late in Denmark, probably because of a relatively high level of quality and capacity of social institutions and other services for the elderly. Thus, longterm care for old people was not a major issue in the health care system until recent decades. Today, the new images of aging are not limited to visualisation of old people in "the third age". Nursing homes are changed to individual flats and provision of 24-hour home care services is available. This development requires coordinated education, training, and management of staff. A better knowledge of the changing images of aging in history is an important element of staff development.

An in vitro study of the effect of picolinic acid on metal translocation across lipid bilayers

The effect of picolinic acid (pyridine-2-carboxylic acid) on the efflux of divalent metal ions from multilamellar liposomes was examined to determine the possible specificity and mechanism for its reported beneficial effects on the intestinal absorption and systemic metabolism of zinc. Extraliposomal picolinic acid increased the efflux of Zn, Cu, Co, Mn, Ni, Cd, Pb, Fe(II) and Ca from the vesicles. However, when picolinic acid was trapped with Co, Cu and Zn within the liposomes, the loss of metals was reduced. In a partition study, picolinic acid increased the aqueous solubility of Zn, Cu, Co and Cd at alkaline pH, but did not transfer the metal to an organic bulk phase of chloroform. It is proposed that picolinic acid does not act as an ionophore and that any effect it may have on zinc metabolism is dependent upon its unselective chelating properties, which may also lead to altered dietary and systemic compartmentation of other divalent cations.

Apolipoprotein B gene variants are involved in the determination of serum cholesterol levels: a study in normo- and hyperlipidaemic individuals

We have investigated the frequencies of 3 restriction fragment length polymorphisms (RFLPs) of the apolipoprotein B (apo B) gene in normo- and hyperlipidaemic individuals. In individuals with type III hyperlipidaemia, the allele frequency for the RFLP detected with XbaI was significantly different from the allele frequency in normolipidaemic individuals and in those with other types of hyperlipidaemia. No significant difference in allele frequency was found among these groups for the RFLPs detected with MspI or EcoRI. Within a sample of 62 normolipidaemic individuals, homozygotes for the X2 allele (cutting site) of the XbaI RFLP had a significantly higher serum cholesterol level than homozygotes for the XI allele, with individuals of the genotype X1X2 having an intermediate value (X2X2 mean 5.71 mmol/l, X1X1 mean 4.81 mmol/l, X1X2 mean 5.30 mmol/l). There were also significant differences in serum triglyceride levels in individuals with different XbaI genotypes. In these normolipidaemic individuals there was no correlation between the EcoRI and MspI RFLP genotypes and levels of any serum lipid variable. Information from the XbaI and EcoRI RFLPs was used in conjunction to define apo B haplotypes. These haplotypes are a more precise measure of the genotypic variation, and they explain a greater fraction of the serum cholesterol and triglyceride levels than the single-site polymorphisms considered separately. This study suggests that variations in the gene for apo B are associated with the determination of serum cholesterol and triglyceride levels both in patients with type III hyperlipidaemia and in the normal population.

DNA polymorphisms in and around the Apo-A1-CIII genes and genetic hyperlipidemias

We have studied the frequency of DNA polymorphisms in and around the apolipoprotein A-1 (Apo-A1) and apolipoprotein CIII (Apo-CIII) gene loci in 53 persons of Caucasian descent with genetic hyperlipidemias. Three restriction-fragment-length polymorphisms (RFLPs) have previously been located 5' and 3' to the Apo-A1 gene and in the Apo-CIII gene and were detected after digestion with XmnI, PstI, and SstI, respectively, and hybridization with a 2.2-kb fragment of the Apo-A1 gene. These RFLPs are in linkage equilibrium. The rare variant sites for XmnI (X2) and SstI (S2) were more frequent in familial combined hyperlipidemia (FCH) than in controls and persons with other genetic hyperlipidemias. When considered as a haplotype, this difference was significant (P less than .03). The findings in this study suggest that the previously reported association between S2 and hypertriglyceridemia may be accounted for, in part, by inclusion of numerous patients with FCH. Our data provide further evidence that these RFLPs around and within the Apo-A1/Apo-CIII genes do not participate in unmasking clinical expression in persons with familial dysbetalipoproteinemia.

The effect of amphotericin B on the permeability of lipid bilayers to divalent trace metals

In this study amphotericin B released the divalent trace metals Zn2+, Co2+, Cu2+, Ni2+, Mn2+, Fe2+, Cd2+ and Pb2+ from multilamellar liposomes containing cholesterol. This observation is consistent with amphotericin B channels being permeable to these metals, and it is proposed, therefore, that the antibiotic may be useful in investigating the metabolism of these elements.

Drug absorption and hepatic drug metabolism in patients with different types of intestinal shunt operation for obesity. A study with phenazone

Seventeen patients with intestinal shunt for obesity and 11 control patients were given 15 mg phenazone per kg perorally to estimate the rate of absorption and hepatic metabolism of phenazone. The rate of absorption and the plasma clearance of phenazone as well as the 4-hydroxyphenazone excretion in the urine did not differ in the patients with intestinal shunt after the weight had stabilized. Thus, drug absorption and hepatic drug metabolizing capacity appear to be unaffected 12--57 months after intestinal shunting.

Long-time observations on the Blalock-Taussig operation VIII. 20 to 28 year follow-up on patients with a tetralogy of Fallot

This study extends our previous observation on patients with a tetralogy of Fallot, operated on by the late Dr; Alfred Blalock and his associates between 1945 and 1951, from a 15 year follow-up to 20 years and assesses the final status of these patients 20 to 28 years after their first operation. This study is mainly concerned with the 432 patients known to be alive at the beginning of the 15th postoperative year. At the beginning of the 20th year, 376 patients were alive, 24 had died, 32 had been lost to follow-up. Review of the final status of those 432 patients showed that 169 had no further cardiac surgery after their initial operation, 36 had further palliative surgery, and 227 had total correction. Thirty-seven percent of the first group, and 79.3% of those with total correction were doing well. These two groups, however, are not comparable. Approximately 250 patients have married; 161 have one or more children. Thirty-five percent have graduated from college and 68.7% are earning substantial incomes. The high scholastic achievement of many of these patients is strong evidence that low oxygen saturation of arterial blood is not a prime cause of mental retardation. The occupations of the patients indicate that the quality of their lives is extremely good and that a cardiac handicap in childhood does not preclude success in adult life. Approximately 69% of these patients have repaid in taxes the cost to society of their rehabilitation.