- Australia
- Research interests in medicine, anthropology, language, and anything related to the island of Sumba.edit
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Hairless SKH-1 mice were exposed once to UVB light (180 mJ/cm2), and mechanistically important early adaptive responses in the epidermis were evaluated by immunohistochemical and morphological methods. Interrelationships in the time... more
Hairless SKH-1 mice were exposed once to UVB light (180 mJ/cm2), and mechanistically important early adaptive responses in the epidermis were evaluated by immunohistochemical and morphological methods. Interrelationships in the time course for these UVB-induced responses were examined. The number of epidermal cells with DNA strand breaks (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling-positive cells) or with thymine dimers increased to maximal levels within 30 min after UVB. The number of cells with DNA strand breaks located specifically in the basal layer of the epidermis was increased substantially by 3-30 min after UVB and gradually increased further over the next 5.5 hours. DNA strand breaks specifically in the basal layer of the epidermis were increased maximally at 6 h after UVB. The number of epidermal cells with DNA strand breaks or thymine dimers decreased markedly between 12 and 36 h. Pyrimidine (6-4) pyrimidone photodimers (6-4 photoproducts) in iso...
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In this paper we demonstrate that the mutants CHO7PV and CHO4PV isolated by us from the CHO-K1 prol- cell line represent two new complementation groups of UV-sensitive excision repair-defective rodent mutants. We have classified the... more
In this paper we demonstrate that the mutants CHO7PV and CHO4PV isolated by us from the CHO-K1 prol- cell line represent two new complementation groups of UV-sensitive excision repair-defective rodent mutants. We have classified the mutant CHO7PV as representative of Group 9 and CHO4PV as representative of Group 10. Cellular and biochemical characterization of these mutants indicates that they are moderately sensitive to a broad spectrum of mutagens (UV and mono- and bifunctional alkylating agents), partially unable to perform UV-induced DNA repair synthesis, and partially defective in the incision step of the DNA excision repair pathway and in the removal of the two main lesions caused by UV [cyclobutane pyrimidine dimers and (6-4) photo-products]. In terms of UV survival and incision, CHO4PV is apparently more defective than CHO7PV (40% and 50% of wild-type survival, respectively, and 55% and 75% of wild-type incision), whereas when repair DNA synthesis and lesion removal are comp...
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The genus Xiphophorus is an important model for investigating the etiology and genetics of sunlight-induced melanoma as well as other cancers. We investigated the role DNA damage plays in tumorigenesis in Xiphophorus using a variety of... more
The genus Xiphophorus is an important model for investigating the etiology and genetics of sunlight-induced melanoma as well as other cancers. We investigated the role DNA damage plays in tumorigenesis in Xiphophorus using a variety of immunological techniques to examine the induction, distribution, and repair of the major photoproducts in DNA after exposure to solar (ultraviolet-B) radiation. We found that cyclobutane pyrimidine dimers (CPDs) were induced at 5- to 10-fold greater frequency than the (6-4) photoproduct ((6-4)PD) in Xiphophorus signum, and the efficiency of photoproduct formation was tissue-dependent, with the scales providing considerable photoprotection against both types of damage. Both of these lesions are efficiently repaired in the presence of visible light by photoenzymatic repair with CPDs repaired at about twice the rate of (6-4)PDs. Photoenzymatic repair of cyclobutane dimers is inducible by prior exposure to low levels of visible light and can be extremely ...
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Chronic exposure to sunlight causes skin cancer in humans, yet little is known about how habitual exposure to low doses of ultraviolet B radiation (UVB) affects DNA damage in the skin. We treated Skh-1 hairless mice with daily doses of... more
Chronic exposure to sunlight causes skin cancer in humans, yet little is known about how habitual exposure to low doses of ultraviolet B radiation (UVB) affects DNA damage in the skin. We treated Skh-1 hairless mice with daily doses of suberythemal UVB for 40 days and analyzed the amount and distribution of DNA photodamage using RIAs and immunofluorescence micrography. We found that DNA damage accumulated in mouse skin as a result of chronic irradiation and that this damage persisted in the dermis and epidermis for several weeks after the chronic treatment was terminated. Although the persistent damage was evenly distributed throughout the dermis, it remained in the epidermis as a small number of heavily damaged cells at the dermal-epidermal boundary. Rates of DNA damage induction and repair were determined at different times over the course of chronic treatment in response to a higher challenge dose of UVB light. The amount of damage induced by the challenge dose increased in respo...
Research Interests: Cancer, DNA damage, DNA repair, DNA, Low Dose, and 9 moreSkin Cancer, Mice, Ultraviolet, Female, Animals, Skin, Sunlight, ultraviolet-B radiation, and Ultraviolet Rays
We evaluated the potential role of photoradiation therapy with a benzoporphyrin derivative, monoacid ring A (BPD-MA), and dihematoporphyrin ether (DHE), for the ex vivo purging of residual tumor cells from autologous bone marrow (BM)... more
We evaluated the potential role of photoradiation therapy with a benzoporphyrin derivative, monoacid ring A (BPD-MA), and dihematoporphyrin ether (DHE), for the ex vivo purging of residual tumor cells from autologous bone marrow (BM) grafts. BPD-MA and DHE photosensitizing activity was tested against two human large-cell lymphoma cell lines and colony-forming unit-leukemia (CFU-L) derived from patients with acute myelogenous leukemia (AML). In mixing experiments, 4-log elimination of tumor cell lines was observed after 1 hour of incubation with 75 ng/mL of BPD-MA or 30 minutes of treatment with 12.5 micrograms/mL of DHE followed by white light exposure. By comparison, using the same concentration of BPD-MA, the mean recovery of normal BM progenitors was 4% +/- 0.8% (mean +/- SD) for granulocyte-macrophage colony-forming unit (CFU-GM) and 5% +/- 0.8% for burst-forming unit-erythroid (BFU-E). Similarly, DHE treatment resulted in the recovery of 5.2% +/- 2% and 9.8% +/- 3% of CFU-GM an...
Research Interests: Kinetics, Stem Cell, Porphyrins, Cancer treatment, Cell line, and 15 moreAcute Myeloid Leukemia, Humans, Blood, Drug Resistance, Bone marrow, Clinical Sciences, White Light, Singlet Oxygen, Diffuse Large B-Cell Lymphoma, Photolysis, Growth Inhibition, Cell Survival, Acute Promyelocytic Leukemia, Cardiovascular medicine and haematology, and Paediatrics and reproductive medicine
ABSTRACT The treatment of end stage renal failure is renal replacement therapy. This may be by dialysis (blood or peritoneal) or by kidney transplantation. The outlook for those who have a successful renal transplant has improved... more
ABSTRACT The treatment of end stage renal failure is renal replacement therapy. This may be by dialysis (blood or peritoneal) or by kidney transplantation. The outlook for those who have a successful renal transplant has improved significantly over the past 20 years: graft survival from non-heart-beating donation is now a mean of 14 years, and 18 years for live donor transplants.Unfortunately the number of renal transplants fails to meet the demand from patients on the transplant waiting list. The shortfall has to be managed by dialysis. Life expectancy of a patient on haemodialysis is one-fifth to one-quarter of that of the age-matched healthy population, but doubles following successful transplantation.The predominant type of dialysis is blood dialysis. To provide this, patients require a portal of access to the circulation. This patient group requires timely and well-planned renal access surgery. Circulatory access is their lifeline. Failure of access, coupled with the need for emergency admission, is a major cause of morbidity and mortality.
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In an attempt to decrease the relapse rate after bone marrow transplantation (BMT) for advanced acute leukemia, we initiated studies using 131I-labeled anti-CD45 antibody (BC8) to deliver radiation specifically to hematopoietic tissues,... more
In an attempt to decrease the relapse rate after bone marrow transplantation (BMT) for advanced acute leukemia, we initiated studies using 131I-labeled anti-CD45 antibody (BC8) to deliver radiation specifically to hematopoietic tissues, followed by a standard transplant preparative regimen. Biodistribution studies were performed in 23 patients using 0.5 mg/kg trace 131I-labeled BC8 antibody. The BC8 antibody was cleared rapidly from plasma with an initial disappearance half-time of 1.5 +/- 0.2 hours, presumably reflecting rapid antigen-specific binding. The mean radiation absorbed doses (cGy/mCi131I administered) were as follows: marrow, 7.1 +/- 0.8; spleen, 10.8 +/- 1.4; liver, 2.7 +/- 0.2; lungs, 2.1 +/- 0.1; kidneys, 0.7 +/- 0.1; and total body, 0.4 +/- 0.03. Patients with acute myelogenous leukemia (AML) in relapse had a higher marrow dose (11.4 cGy/mCi) than those in remission (5.2 cGy/mCi; P = .001) because of higher uptake and longer retention of radionuclide in marrow. Twent...
Research Interests: Adolescent, Hematopoiesis, Humans, Kidney, Liver, and 15 moreFemale, Blood, Male, Immunosuppression, Bone marrow, Lung, Clinical Sciences, Middle Aged, Bone Marrow Transplantation, Adult, Cyclophosphamide, immunoglobulin G, Combined Modality Therapy, Myelodysplastic syndromes, and Cardiovascular medicine and haematology
Melanin is thought to serve in photoprotection. To investigate this, we have compared the responses of cultured human melanocytes derived from different pigmentary phenotypes (skin types I-VI) to a single irradiation with different doses... more
Melanin is thought to serve in photoprotection. To investigate this, we have compared the responses of cultured human melanocytes derived from different pigmentary phenotypes (skin types I-VI) to a single irradiation with different doses of UVB light, ranging between 11.7 and 70.1 mJ/cm2. After UVB irradiation, heavily pigmented melanocytes had the same percent survival but a greater capacity to resume proliferation than their lightly pigmented counterparts. A significant increase in melanin content was observed in heavily pigmented but not in lightly pigmented melanocytes. Irradiation with UVB light blocked melanocytes, regardless of their melanin content, in G1, and induced the expression of the tumor suppressor p53 protein within 4 h. This induction steadily increased up to 48 h in lightly pigmented melanocytes; however, in heavily pigmented melanocytes, p53 level peaked at 24 h after UVB treatment and declined thereafter. Additionally, DNA from lightly pigmented melanocytes cont...
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UV exposure has been linked to skin cancer in humans by epidemiology and the rare genetic disease xeroderma pigmentosum. However, UV produces multiple photoproducts in DNA, and their relative contribution is uncertain. An enzyme which... more
UV exposure has been linked to skin cancer in humans by epidemiology and the rare genetic disease xeroderma pigmentosum. However, UV produces multiple photoproducts in DNA, and their relative contribution is uncertain. An enzyme which specifically repairs cyclobutane pyrimidine dimers in DNA, T4 endonuclease V, was encapsulated in liposomes for topical delivery into mouse and human skin. In both species, liposomes applied after UV exposure localized in the epidermis and stimulated the removal of cyclobutane pyrimidine dimers. UV-irradiated mice treated with these liposomes had a dose-dependent decrease in the incidence of squamous cell carcinoma compared to controls. The results demonstrate that unrepaired cyclobutane pyrimidine dimers in DNA are a direct cause of cancer in mammalian skin.
Research Interests: Cancer, DNA damage, DNA repair, Dosage Form, DNA, and 15 moreIn Vitro, Humans, Skin Cancer, Mice, Female, Animals, Squamous Cell Carcinoma, Liposomes, Skin, Liposome, Enzyme, In Vivo, Drug Carriers, Skin Neoplasms, and Human skin
A partial revertant (RH1-26) of the UV-sensitive Chinese hamster V79 cell mutant V-H1 (complementation group 2) was isolated and characterized. It was used to analyze the mutagenic potency of the 2 major UV-induced lesions, cyclobutane... more
A partial revertant (RH1-26) of the UV-sensitive Chinese hamster V79 cell mutant V-H1 (complementation group 2) was isolated and characterized. It was used to analyze the mutagenic potency of the 2 major UV-induced lesions, cyclobutane pyrimidine dimers and (6-4) photoproducts. Both V-H1 and RH1-26 did not repair pyrimidine dimers measured in the genome overall as well as in the active hprt gene. Repair of (6-4) photoproducts from the genome overall was slower in V-H1 than in wild-type V79 cells, but was restored to normal in RH1-26. Although V-H1 cells have a 7-fold enhanced mutagenicity, RH1-26 cells, despite the absence of pyrimidine dimer repair, have a slightly lower level of UV-induced mutagenesis than observed in wild-type V79 cells. The molecular nature of hprt mutations and the DNA-strand specificity were similar in V79 and RH1-26 cells but different from that of V-H1 cells. Since in RH1-26 as well as in V79 cells most hprt mutations were induced by lesions in the non-trans...
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Current models that describe the extension of fungal hyphae and development of a mycelium either do not describe the role of vesicles in hyphal extension or do not correctly describe the experimentally observed profile for distribution of... more
Current models that describe the extension of fungal hyphae and development of a mycelium either do not describe the role of vesicles in hyphal extension or do not correctly describe the experimentally observed profile for distribution of vesicles along the hypha. The present work uses the n-tanks-in-series approach to develop a model for hyphal extension that describes the intracellular transport of nutrient to a sub-apical zone where vesicles are formed and then transported to the tip, where tip extension occurs. The model was calibrated using experimental data from the literature for the extension of reproductive aerial hyphae of three different fungi, and was able to describe different profiles involving acceleration and deceleration of the extension rate. A sensitivity analysis showed that the supply of nutrient to the sub-apical vesicle-producing zone is a key factor influencing the rate of extension of the hypha. Although this model was used to describe the extension of a sin...
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Phytophthora nicotianae and P. palmivora infect and cause rot of fibrous roots of susceptible and tolerant citrus rootstocks in Florida orchards. The infection and colonization by the two Phytophthora spp. of a susceptible citrus host,... more
Phytophthora nicotianae and P. palmivora infect and cause rot of fibrous roots of susceptible and tolerant citrus rootstocks in Florida orchards. The infection and colonization by the two Phytophthora spp. of a susceptible citrus host, sour orange (Citrus aurantium), and a tolerant host, trifoliate orange (Poncirus trifoliata), were compared using light and electron microscopy. Penetration by both Phytophthora spp. occurred within 1 h after inoculation, regardless of the host species. No differences were observed in mode of penetration of the hypodermis or the hosts' response to infection. After 24 h, P. palmivora had a significantly higher colonization of cortical cells in susceptible sour orange than in tolerant trifoliate orange. Intracellular hyphae of both Phytophthora spp. were observed in the cortex of sour orange, and cortical cells adjacent to intercellular hyphae of P. palmivora were disrupted. In contrast, the cortical cells of sour orange and trifoliate orange adjace...
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Management of Australian wetlands is confounded by an absence of adequate environmental monitoring data. To a large extent we are still not sure of the exact location and extent of many wetlands. Inventory and monitoring information are... more
Management of Australian wetlands is confounded by an absence of adequate environmental monitoring data. To a large extent we are still not sure of the exact location and extent of many wetlands. Inventory and monitoring information are intricately linked and at the heart of successful wetland management. Monitoring addresses the extent of change in the environment, yet, for wetlands, it
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We present a model for the kinetics of microbial growth that incorporates the influence of the temperature variations that typically occur during solid-state culture in large-scale bioreactors. The model proposes that the specific growth... more
We present a model for the kinetics of microbial growth that incorporates the influence of the temperature variations that typically occur during solid-state culture in large-scale bioreactors. The model proposes that the specific growth rate constant depends on the level of an essential component within the biomass, with the rate of the synthesis and denaturation reactions of this component depending
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Research Interests: Protein Folding, Macromolecular X-Ray Crystallography, Aspergillus, Crystal structure, Software, and 11 moreComputer Simulation, Animals, Structural equation models, Phytase, Protein Secondary Structure Prediction, Rats, Cysteine, Amino Acid Sequence, Static Electricity, Molecular Sequence Data, and Acid Phosphatase
Superconductor containing filaments having embedments of superconducting material surrounded by a rayon matrix are formed by preparing a liquid suspension which contains at least 10 weight percent superconducting material; forming a... more
Superconductor containing filaments having embedments of superconducting material surrounded by a rayon matrix are formed by preparing a liquid suspension which contains at least 10 weight percent superconducting material; forming a multicomponent filament having a core of the suspension and a viscose sheath which contains cellulose xanthate; and thereafter, regenerating cellulose from the cellulose xanthate to form a rayon matrix.
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Accurate adjustment of surgical outcome data for risk is vital in an era of surgeon-level reporting. Current risk prediction models for abdominal aortic aneurysm (AAA) repair are suboptimal. We aimed to develop a reliable risk model for... more
Accurate adjustment of surgical outcome data for risk is vital in an era of surgeon-level reporting. Current risk prediction models for abdominal aortic aneurysm (AAA) repair are suboptimal. We aimed to develop a reliable risk model for in-hospital mortality after intervention for AAA, using rigorous contemporary statistical techniques to handle missing data. Using data collected during a 15-month period in the United Kingdom National Vascular Database, we applied multiple imputation methodology together with stepwise model selection to generate preoperative and perioperative models of in-hospital mortality after AAA repair, using two thirds of the available data. Model performance was then assessed on the remaining third of the data by receiver operating characteristic curve analysis and compared with existing risk prediction models. Model calibration was assessed by Hosmer-Lemeshow analysis. A total of 8088 AAA repair operations were recorded in the National Vascular Database duri...
Research Interests: Treatment Outcome, Risk assessment, Vascular Surgery, Discriminant Analysis, Humans, and 13 moreUnited States, Risk factors, ROC Curve, Reproducibility of Results, Risk Factors, Risk Assessment, Hospital Mortality, Area Under Curve, Predictive value of tests, Endovascular Procedures, Decision Support Techniques, Patient selection, and Medical and Health Sciences
Recently, it has been suggested that pectinases could be used to hydrolyze pectin in biorefineries based on pectin-rich agro-industrial wastes. However, for this to be viable, the cost of their production would need to be lowered... more
Recently, it has been suggested that pectinases could be used to hydrolyze pectin in biorefineries based on pectin-rich agro-industrial wastes. However, for this to be viable, the cost of their production would need to be lowered significantly. In fact, over the last few decades, there have been many attempts to improve pectinase production by existing strains or to screen for new strains from environmental isolates. In these studies, it is necessary to measure pectinase activities. Many researchers use single-time-point assays that involve incubation of pectinolytic extracts with pectic substrates for a fixed time, followed by determination of the liberated reducing sugars. However, different researchers use quite different conditions for this assay. Furthermore, no attention has been given to the reaction profile during the assay. In the current work, we show, for the first time, that a significant deceleration of the rate of liberation of reducing sugars occurs over the first ten...
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Solid-state fermentation has centuries of history, but it is only in the last two decades that there has been a concerted effort to understand the bioprocessing issues involved and to apply them to a wide range of new products. This... more
Solid-state fermentation has centuries of history, but it is only in the last two decades that there has been a concerted effort to understand the bioprocessing issues involved and to apply them to a wide range of new products. This article provides an overview of the knowledge of solid-state bioprocessing that has been gained over this time. It shows that, although significant advances have been achieved in understanding of what controls process performance, much research is still required.
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We investigate algorithmic questions that arise in the statistical problem of computing lines or hyperplanes of maximum regression depth among a set of n points. We work primarily with a dual representation and find points of maximum... more
We investigate algorithmic questions that arise in the statistical problem of computing lines or hyperplanes of maximum regression depth among a set of n points. We work primarily with a dual representation and find points of maximum undirected depth in an arrangement of lines or hyperplanes. An O(nd) time and space algorithm computes directed depth of all points in d
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The p21-activated kinases Ste20p and Cla4p carry out undefined functions that are essential for viability during budding in Saccharomyces cerevisiae. To gain insight into the roles of Ste20p, we have used a synthetic lethal mutant screen... more
The p21-activated kinases Ste20p and Cla4p carry out undefined functions that are essential for viability during budding in Saccharomyces cerevisiae. To gain insight into the roles of Ste20p, we have used a synthetic lethal mutant screen to identify additional genes that are required in the absence of Cla4p. Altogether, we identified 65 genes, including genes with roles in cell polarity, mitosis, and cell wall maintenance. Herein, we focus on a set that defines a function carried out by Bni1p and several of its interacting proteins. We found that Bni1p and a group of proteins that complex with Bni1p (Bud6p, Spa2p, and Pea2p) are essential in a cla4delta mutant background. Bni1p, Bud6p, Spa2, and Pea2p are members of a group of polarity determining proteins referred to as the polarisome. Loss of polarisome proteins from a cla4delta strain causes cells to form elongated buds that have mislocalized septin rings. In contrast, other proteins that interact with or functionally associate w...
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We propose a new model for the formation of spokes in Saturn's rings. The model involves the electrostatic charging of sub-micron dust grains in the rings by magnetic field-aligned electron beams. Such beams have recently been... more
We propose a new model for the formation of spokes in Saturn's rings. The model involves the electrostatic charging of sub-micron dust grains in the rings by magnetic field-aligned electron beams. Such beams have recently been observed by the MIMI instrument aboard Cassini at 3.1 Saturn radii, outside the main ring system. It is reasonable to expect the beams to
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Under certain conditions small amounts of DNA can survive for long periods of time and can be used as polymerase chain reaction (PCR) substrates for the study of phylogenetic relationships and population genetics of extinct plants and... more
Under certain conditions small amounts of DNA can survive for long periods of time and can be used as polymerase chain reaction (PCR) substrates for the study of phylogenetic relationships and population genetics of extinct plants and animals, including hominids. Because of extensive DNA degradation, these studies are limited to species that lived within the past 10(4)-10(5) years (Late Pleistocene), although DNA sequences from 10(6) years have been reported. Ancient DNA (aDNA) has been used to study phylogenetic relationships of protists, fungi, algae, plants, and higher eukaryotes such as extinct horses, cave bears, the marsupial wolf, the moa, and Neanderthal. In the past few years, this technology has been extended to the study of infectious disease in ancient Egyptian and South American mummies, the dietary habits of ancient animals, and agricultural practices and population dynamics of early native Americans. Hence, ancient DNA contains information pertinent to numerous fields...
Research Interests: Population Genetics, Oxidative Stress, Native American, DNA damage, DNA repair, and 15 moreDNA, PCR, SAP, mtDNA, Mutation, Late Pleistocene, Infectious Disease, Ancient DNA, Polymerase Chain Reaction, Oxidative Damage, Freezing, Population dynamic, DNA fragmentation, DNA sequence, and Dietary Habits
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Solid-state cultivation involves the growth of microorganisms in beds of moist solid particles that have a minimum of free water between the particles. The chapter describes environmentally-related solid-state cultivation processes. For... more
Solid-state cultivation involves the growth of microorganisms in beds of moist solid particles that have a minimum of free water between the particles. The chapter describes environmentally-related solid-state cultivation processes. For example, some processes ...
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Spiritual and cultural issues at the end of life are common and a natural part of the process of life and death. They often present as distress or agitation in the patient and should be considered when pain control is difficult to manage.... more
Spiritual and cultural issues at the end of life are common and a natural part of the process of life and death. They often present as distress or agitation in the patient and should be considered when pain control is difficult to manage. Spirituality can be defined as our sense of meaning in life. It is often influenced by, and regularly confused with, religion and culture. While it can be suggested that society is becoming more secular and less religious, it can also be argued that it is the structure and practice of religion rather than the faith itself that is being rejected, with people picking and choosing the elements from different religions and cultures on which to base their sense of meaning. Identifying and assessing spiritual and cultural issues require healthcare professionals to engage on a human level with patients and their families/carers. Each patient is unique and individual, and while manuals and guidelines on spiritual, religious and cultural care are a guide, the only true approach is to ‘ask the patient’. As with all end-of-life issues, spiritual and cultural issues can be complex, and healthcare chaplains should be consulted for advice or the patient referred for intervention.
Research Interests: Medicine and End of life
Step changes in the gas environment and temperature during membrane culture of Rhizopus oligosporus were made to mimic those changes which arise during solid-state fermentation due to mass and heat transfer limitations. A decrease of O2... more
Step changes in the gas environment and temperature during membrane culture of Rhizopus oligosporus were made to mimic those changes which arise during solid-state fermentation due to mass and heat transfer limitations. A decrease of O2 concentration from 21% to 0.5% did not alter protease production by R. oligosporus but retarded amyloglucosidase production. An upshift from 37°C to 50°C decreased
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Titan's nitrogen-rich atmosphere is directly bombarded by energetic ions, due to its lack of a significant intrinsic magnetic field. Singly-charged energetic ions from Saturn's magnetosphere undergo charge exchange collisions with... more
Titan's nitrogen-rich atmosphere is directly bombarded by energetic ions, due to its lack of a significant intrinsic magnetic field. Singly-charged energetic ions from Saturn's magnetosphere undergo charge exchange collisions with neutral atoms in Titan's exosphere, being transformed into energetic neutral atoms (ENAs). The Ion and Neutral Camera (INCA), one of the three sensors that comprise the Magnetosphere Imaging Instrument (MIMI)
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The recent results of the INMS instrument, onboard Cassini, have shown evidence for a hot Titan corona, with non thermal profiles for N2 and CH4 in the lower exosphere (below 2000 km altitude). We propose here to use these observations... more
The recent results of the INMS instrument, onboard Cassini, have shown evidence for a hot Titan corona, with non thermal profiles for N2 and CH4 in the lower exosphere (below 2000 km altitude). We propose here to use these observations for modelling the extended non thermal exosphere of Titan, through the use of non thermal distributions at the exobase. Non
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A rapid and convenient method of protein purification involves creating a fusion protein with glutathione S-transferase (GST) (Smith and Johnson, Gene 67, 31-40, 1988). In this report, we describe two vectors for the conditional... more
A rapid and convenient method of protein purification involves creating a fusion protein with glutathione S-transferase (GST) (Smith and Johnson, Gene 67, 31-40, 1988). In this report, we describe two vectors for the conditional expression of GST fusions in Saccharomyces cerevisiae. The parent plasmid is based on a high-copy, galactose-inducible shuttle vector previously described (Baldari et al., EMBO J. 6, 229-243, 1987). We have demonstrated the use of this system by creating fusions between GST and the yeast RAS2 gene. GST-Ras2 fusion proteins undergo the post-translational modifications required for Ras2p to become membrane localized. These vectors provide a useful system for the expression and purification of eukaryotic proteins requiring post-translational modification.
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Titan's nitrogen-rich atmosphere is directly bombarded by energetic ions, due to its lack of a significant intrinsic magnetic field. Singly-charged energetic ions from Saturn's magnetosphere undergo charge exchange collisions with... more
Titan's nitrogen-rich atmosphere is directly bombarded by energetic ions, due to its lack of a significant intrinsic magnetic field. Singly-charged energetic ions from Saturn's magnetosphere undergo charge exchange collisions with neutral atoms in Titan's exosphere, being transformed into energetic neutral atoms (ENAs). The Ion and Neutral Camera (INCA), one of the three sensors that comprise the Magnetosphere Imaging Instrument (MIMI)
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Protein enrichment of sago starch of three different diameters was investigated both in flask culture and under forced aeration in a packed-bed fermenter using two strains of Rhizopus. Protein production by R. oligosporus UQM 145F was... more
Protein enrichment of sago starch of three different diameters was investigated both in flask culture and under forced aeration in a packed-bed fermenter using two strains of Rhizopus. Protein production by R. oligosporus UQM 145F was superior to Rhizopus sp. UQM 186F in the flask culture without aeration, with both preferring larger diameter (3 to 4 mm) spherical sago-beads. In the packed-bed fermenter with forced aeration, Rhizopus sp. UQM 186F led to more rapid protein production compared to R. ollgosporus UQM 145F and produced equivalent final yields (about 10% protein on a dry wt basis).
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Titan's nitrogen-rich atmosphere is directly bombarded by energetic ions, due to its lack of a significant intrinsic magnetic field. Singly-charged energetic ions from Saturn's magnetosphere undergo charge exchange collisions with... more
Titan's nitrogen-rich atmosphere is directly bombarded by energetic ions, due to its lack of a significant intrinsic magnetic field. Singly-charged energetic ions from Saturn's magnetosphere undergo charge exchange collisions with neutral atoms in Titan's exosphere, being transformed into energetic neutral atoms (ENAs). The Ion and Neutral Camera (INCA), one of the three sensors that comprise the Magnetosphere Imaging Instrument (MIMI)