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1.
Ecol Lett ; 20(8): 1054-1063, 2017 08.
Article in English | MEDLINE | ID: mdl-28677298

ABSTRACT

Both top-down (grazing) and bottom-up (resource availability) forces can determine the strength of priority effects, or the effects of species arrival history on the structure and function of ecological communities, but their combined influences remain unresolved. To test for such influences, we assembled experimental communities of wood-decomposing fungi using a factorial manipulation of fungivore (Folsomia candida) presence, nitrogen availability, and fungal assembly history. We found interactive effects of all three factors on fungal species composition and wood decomposition 1 year after the fungi were introduced. The strength of priority effects on community structure was affected primarily by nitrogen availability, whereas the strength of priority effects on decomposition rate was interactively regulated by nitrogen and fungivores. These results demonstrate that top-down and bottom-up forces jointly determine how strongly assembly history affects community structure and function.


Subject(s)
Arthropods , Wood , Animals , Biota , Fungi
2.
Ecol Lett ; 15(2): 133-41, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22188588

ABSTRACT

Assembly history, or the order of species arrival, can have wide-ranging effects on species, communities and ecosystems. However, it remains unclear whether assembly history primarily affects individual species, with effects attenuating at the level of communities and ecosystems or, alternatively, has consistent effect sizes across increasing levels of ecological organisation. We address this question using a field-based manipulation of assembly history of wood-inhabiting fungi. The largest effect sizes were observed for the frequency of some individual species, and mean effect sizes were lower for community metrics of fungi immigrating from the regional species pool. There was little evidence, however, of attenuation in effect sizes at the ecosystem level (carbon, nitrogen, decomposition) in comparison to the species or community level. These results indicate that assembly history can have strong effects on ecosystem properties even under natural levels of environmental variability.


Subject(s)
Ecosystem , Fagaceae/microbiology , Fungi/physiology , Trees/microbiology , Wood/microbiology , Biodiversity , Models, Biological , New Zealand , Species Specificity
3.
Pregnancy Hypertens ; 2(3): 237, 2012 Jul.
Article in English | MEDLINE | ID: mdl-26105321

ABSTRACT

INTRODUCTION: Preeclampsia (PEC) is a well-established risk factor for the development of future premature cardiovascular disease (CVD). However, women with PEC are not routinely counselled about these longterm risks, nor are their risk factors regularly assessed or treated for prevention of CVD. An interdisciplinary PPPEC clinic was recently established at the University of Alberta in order to address patient education and CVD risk factor management. OBJECTIVES: (1) To describe the implementation of a novel interdisciplinary clinic for postpartum women with PEC designed to both educate women of their CVD risk and manage their risk factors. (2) To describe our one-year experience with this clinic, identifying attendance issues common to postpartum clinics. METHODS: We performed a retrospective chart review using data obtained from standardized clinic booking lists. From these records, we extracted the following information: number of referrals, attendance dates (including adherence to visit) and patient demographics. Descriptive statistics were used to summarize patient demographics and percentages of missed visits were calculated. RESULTS: PPPEC Clinic Implemenation: All patients who attend this PPPEC clinic received education on PEC, its implications for future vascular health, and evidence-based strategies for CVD risk reduction through both a slide presentation, educational handouts as well as individualized CVD risk assessment by the interdisciplinary team (Obstetric Internist, nurse practitioner, pharmacist and dietician). Next, specific patient-directed lifestyle modification goals were developed in the form of an "Action Plan" for each CVD risk factor: blood pressure, cholesterol, glucose intolerance, physical activity level, weight, and smoking. These goals were reviewed at each follow-up visit. PPPEC Clinic Experience: From Sept 2010 to Feb 2012, there were 123 appointments in this bi-weekly clinic (63 new consults and 60 follow ups). The women's mean age was 29.4 years (range 17-43). Seventy-four percent of scheduled apointments were attended. Of those that were missed, half were initial consultations and halfwere follow-up appointments. CONCLUSION: This interdisciplinary PPPEC addresses an important gap in clinical care for CVD prevention for these high-risk women. This study identified suboptimal attendance of scheduled postpartum visits. Future plans include: (1) identifying barriers to postpartum clinic attendance and strategies to overcome them, (2) examining the effectiveness of the educational and clinical intervention model in reducing cardiovascular risk factors in these women.

4.
Ecol Lett ; 13(6): 675-84, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20412280

ABSTRACT

Community assembly history is increasingly recognized as a fundamental determinant of community structure. However, little is known as to how assembly history may affect ecosystem functioning via its effect on community structure. Using wood-decaying fungi as a model system, we provide experimental evidence that large differences in ecosystem functioning can be caused by small differences in species immigration history during community assembly. Direct manipulation of early immigration history resulted in three-fold differences in fungal species richness and composition and, as a consequence, differences of the same magnitude in the rate of decomposition and carbon release from wood. These effects - which were attributable to the history-dependent outcome of competitive and facilitative interactions - were significant across a range of nitrogen availabilities observed in natural forests. Our results highlight the importance of considering assembly history in explaining ecosystem functioning.


Subject(s)
Carbon/metabolism , Ecosystem , Fungi/metabolism , Models, Biological , Trees/microbiology , Wood/microbiology , Biodiversity , New Zealand , Trees/metabolism , Wood/metabolism
6.
Eur J Neurol ; 14(6): 644-9, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17539942

ABSTRACT

In response to concern about the reported frequency of ergot-associated valvulopathy in patients with Parkinson's disease (PD), Eli Lilly and Company updated the Risk Minimization Program for pergolide, changing the Summary of Product Characteristics (SmPC) and distributing a Dear Doctor Letter (DDL) highlighting the new label changes. A survey was conducted subsequently to assess neurologists' awareness of the revised SmPC and their resulting changes in practice. A random sample of 20.3% of neurologists (n = 4056) from 12 eligible EU countries were invited to participate. Of the target population of 247 neurologists who treated patients with PD, used pergolide in 2005, and were willing to participate, 244 (99%) responded. Overall awareness of the DDL and the SmPC changes was 94.2%. Over half (58.3%) of neurologists indicated that they prescribe pergolide exclusively as second-line treatment, although some (21.9%) used pergolide exclusively as first-line treatment. In response to the DDL, most neurologists perform echocardiograms before treatment (67.5%) and during treatment (76.7%), and over half (55%) avoid prescribing doses >5 mg/day. Overall, use of a DDL to communicate an SmPC change was effective in increasing the awareness of pergolide-associated valvulopathy and in modifying neurologists' clinical practice to minimize this risk.


Subject(s)
Antiparkinson Agents/adverse effects , Awareness , Heart Valve Diseases/chemically induced , Neurology , Pergolide/adverse effects , Practice Patterns, Physicians' , Data Collection , Europe , Female , Humans , International Cooperation , Male
7.
Nucleosides Nucleotides Nucleic Acids ; 20(8): 1485-95, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11554541

ABSTRACT

A possible pH-dependent conformational switch was investigated for cyclic ADP-ribose. NMR signals for the exchangeable protons were observed in H2O at low temperature, but there was no direct evidence for the protonation of N-3 at neutral pH that has previously been postulated. MNDO calculations indicated that pH dependent 31P chemical shift changes are attributable to protonation of the phosphate adjacent to the N-1 of adenine, and not due to trans-annular hydrogen bonding with a protonated N-3.


Subject(s)
Adenosine Diphosphate Ribose/analogs & derivatives , Adenosine Diphosphate Ribose/chemistry , Magnetic Resonance Spectroscopy , Cyclic ADP-Ribose , Hydrogen Bonding , Hydrogen-Ion Concentration , Models, Molecular , Molecular Conformation , Protons , Thermodynamics
8.
Aust Vet J ; 79(3): 187-9, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11301746

ABSTRACT

A 9-month-old speyed Burmese cat was presented with a cutaneous lesion in the dorsal thoracolumbar region. The lesion was characterised by alopecia and whitish deposits within the subcutis and had occurred at the site of a previous progestogen injection (Covinan; Intervet). Excisional biopsy confirmed the diagnosis of calcinosis circumscripta. Recovery of the cat following surgical excision was excellent, with no recurrence of the lesion detected 12 months later. The classification of tissue calcification and the proposed aetiology of calcinosis circumscripta is reviewed. It is concluded that further work is required to determine any link between subcutaneous injections, especially of progestogens, and calcinosis circumscripta.


Subject(s)
Calcinosis/veterinary , Cat Diseases/chemically induced , Cat Diseases/diagnosis , Estrus , Progesterone Congeners/adverse effects , Progesterone/analogs & derivatives , Progesterone/adverse effects , Skin Neoplasms/veterinary , Animals , Calcinosis/chemically induced , Calcinosis/diagnosis , Cat Diseases/pathology , Cat Diseases/surgery , Cats , Diagnosis, Differential , Male , Skin Neoplasms/chemically induced , Skin Neoplasms/diagnosis
9.
Aust Vet J ; 78(9): 605-7, 2000 Sep.
Article in English | MEDLINE | ID: mdl-11022285

ABSTRACT

A captive adult male Eastern barred bandicoot (Perameles gunnii) presented with three palpable subcutaneous masses in November 1998. A diagnosis of haemangiosarcoma was made based on histological examination of one excised mass. Euthanasia of the animal was performed 11 days postsurgery and a proliferative lesion in the paralumbar musculature and similar, smaller proliferative lesions surrounding the right popliteal lymph node and in the ventricular wall of the heart were found. Metastatic lesions were found in the liver and lung. The histological features of the neoplastic tissues supported the diagnosis of a poorly differentiated, disseminated haemangiosarcoma. This is the first reported case of haemangiosarcoma in the Eastern barred bandicoot.


Subject(s)
Hemangiosarcoma/veterinary , Marsupialia , Soft Tissue Neoplasms/veterinary , Animals , Animals, Wild , Animals, Zoo , Diagnosis, Differential , Hemangiosarcoma/secondary , Lumbosacral Region , Male , Soft Tissue Neoplasms/pathology
10.
Obstet Gynecol ; 95(1): 95-103, 2000 Jan.
Article in English | MEDLINE | ID: mdl-10636510

ABSTRACT

OBJECTIVE: To determine the effects of a selective estrogen receptor modulator, raloxifene, on postmenopausal endometrium. METHODS: Healthy postmenopausal women (n = 415) were randomly assigned to one of the following four groups: 60 or 150 mg/day raloxifene hydrochloride, 0.625 mg/day conjugated equine estrogens, or placebo, and treated for 1 year. Endometrial biopsies were obtained in a blinded fashion at baseline and every 6 months after the ultrasound studies. Transvaginal ultrasound, with uterine size measurements, was done at baseline and at 3-month intervals. Saline-infusion sonohysterography was done at baseline and every 6 months. RESULTS: There were no statistically significant differences in baseline characteristics. Mean endometrial thickness, measured by transvaginal ultrasound, was unchanged from baseline to end point in the placebo and raloxifene groups, whereas in the estrogen group it was significantly thicker by 5.5 mm (P < .001). Mean uterine volume, calculated from transvaginal ultrasound measurements, was higher in the estrogen group only (22 cm3, P < .001). Of the 358 women with paired biopsies, endometrial hyperplasia was present in 2.1%, 0%, and 26.1% of the end-point biopsies in the placebo, raloxifene, and estrogen groups, respectively (P < .001). Proliferative endometrium was present in 2.1% of the end-point biopsies in the placebo group, 1.7% in the combined raloxifene groups, and 39.8% in the estrogen group (P < .001). CONCLUSION: Raloxifene, at 60 or 150 mg/day for 1 year, did not stimulate the postmenopausal endometrium. End-point endometrial thickness, morphology, and uterine volume in the raloxifene groups were similar to those observed at baseline and in the placebo group.


Subject(s)
Endometrium/drug effects , Estradiol Congeners/pharmacology , Raloxifene Hydrochloride/pharmacology , Selective Estrogen Receptor Modulators/pharmacology , Adult , Double-Blind Method , Female , Humans , Middle Aged
11.
Article in English | MEDLINE | ID: mdl-11138188

ABSTRACT

A general class of integrodifferential non-Markovian master equations is developed which is representative of the dynamics of small subsystems interacting with open reservoirs with memory. Conditions which guarantee positivity of the subsystem reduced density are established.

12.
Chembiochem ; 1(4): 262-71, 2000 Nov 17.
Article in English | MEDLINE | ID: mdl-11828418

ABSTRACT

Inositol monophosphatase plays a pivotal role in the biosynthesis of secondary messengers and is believed to be a target for lithium therapy. It is established how a lithium ion works in inhibiting the enzyme but details of the mechanism for the direct magnesium ion activated hydrolysis of the substrate have been elusive. It is known that substrates require a minimal 1,2-diol phosphate structural motif, which in D-myo-inositol 1-phosphate relates to the fragment comprising the 1-phosphate ester and the 6-hydroxy group. Here it is shown that inhibitors that are D-myo-inositol 1-phosphate substrate analogues possessing 6-substituents larger than the 6-hydroxy group of the substrate, for example, the 6-O-methyl analogue, are able to bind to the enzyme in a congruous manner to the substrate. It is demonstrated, however, that such compounds show no substrate activity whatsoever. It is also shown that a 6-amino group is able to fulfil the role of the 6-hydroxy group of the substrate in conferring substrate activity and that a 6-methylamino group is similarly able to support catalysis. The results indicate that a 6-substituent capable of serving as a hydrogen-bond donor is required in the catalytic mechanism for hydrolysis. It has recently been shown that inositol is displaced from phosphorus with inversion of stereochemistry and we expect that the nucleophilic species is associated with Mg(2+)-1. It is proposed here that the role of the 6-hydroxy group of the substrate is to H-bond with a water molecule or hydroxide ion located on Mg(2+)-2. From this analysis, it appears that the water molecule bound to Mg(2+)-2 serves as a proton donor for the inositolate leaving group in a process that stabilises the alkoxide product and retards the back-reaction.


Subject(s)
Inositol Phosphates/chemistry , Magnesium/chemistry , Phosphoric Monoester Hydrolases/chemistry , Animals , Binding Sites , Binding, Competitive , Catalytic Domain , Cattle , Hydrogen Bonding , Hydrolysis , Inositol Phosphates/metabolism , Inositol Phosphates/pharmacology , Models, Chemical , Models, Molecular , Protein Conformation , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Stereoisomerism , Substrate Specificity , Water/chemistry
15.
Birth ; 24(2): 90-7, 1997 Jun.
Article in English | MEDLINE | ID: mdl-9271974

ABSTRACT

BACKGROUND: A study of breastfeeding mothers was conducted from October 1993 through July 1994 in the western United States to determine the influence of components of hospital discharge packs on the duration of breastfeeding. METHOD: On discharge from the hospital, over 1600 breastfeeding mothers were given one of four free discharge packs, identical in all ways except that one contained a can of powdered formula, one a manual breast pump, one both formula and pump, and one neither. During the following 6 months, mothers were interviewed by telephone three times by an independent research firm to determine how and what they were feeding their infants. Analysis of the independent and interactive effects of both formula and pump was performed, and the moderating effects of age, ethnicity, marital and insurance status, prebirth feeding plan, and the effect of returning to outside employment or school were examined. RESULTS: Across the entire sample, the contents of the discharge packs had a negligible effect on feeding method and breastfeeding duration. Examination of select subgroups revealed modest discharge pack effects, wherein the presence of discharge pack formula increased the likelihoof2p4 introducing supplementation during the first 6 weeks whereas receipt of pumps prolonged full breastfeeding. Even in these select groups, however, no effect was observed on the overall duration of breastfeeding. CONCLUSION: Relative to other known influences on the choice of feeding method and on breastfeeding duration, discharge pack contents do not merit great concern.


Subject(s)
Bottle Feeding/instrumentation , Breast Feeding/psychology , Choice Behavior , Infant Food , Mothers/psychology , Patient Discharge , Suction/instrumentation , Adult , Female , Humans , Infant, Newborn , Surveys and Questionnaires
16.
Phys Rev Lett ; 77(14): 3056, 1996 Sep 30.
Article in English | MEDLINE | ID: mdl-10062120
17.
Eur J Surg Oncol ; 21(5): 548-50, 1995 Oct.
Article in English | MEDLINE | ID: mdl-7589604

ABSTRACT

This prospective randomized trial evaluated the effect of DTIC and interferon as adjuvant therapy for high risk stage 1 malignant melanoma in 26 patients. Both groups were well matched for depth of disease, site of melanoma and other prognostic criteria. Like other studies the findings of 2.6 times increased relative risk of mortality in the treatment arm do not support a rationale for adjuvant immuno-chemotherapy even in patients at high risk of recurrence.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Melanoma/drug therapy , Skin Neoplasms/drug therapy , Adult , Aged , Dacarbazine/administration & dosage , Female , Humans , Interferons/administration & dosage , Male , Melanoma/pathology , Middle Aged , Neoplasm Staging , Prospective Studies , Skin Neoplasms/pathology , Treatment Outcome
20.
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