Instream vegetation survey of Marsh Creek

Agriculture can have a vast impact on stream ecosystems through increasing erosion and nutrient inputs. Vegetation influences an array of ecosystem characteristics in streams, including concentrations of dissolved oxygen and nutrients. Physical characteristics can be influenced as well, including flow velocity, turbidity, light penetration, and turbulence. Using the Braun-Blanquet cover scale we measured instream vegetation cover at six sites along Marsh Creek, a stream in southeastern Idaho that has seen strong anthropomorphic influences through the development of agriculture, both croplands and pastures. We found that in stream vegetation cover was high overall, but varied across sites. Mean vegetation cover across all sites was 25-50%. The highest cover observed was 75-100% and the lowest was 5-25%. From this data we can see variations from site to site as you move downstream but no discernible patterns are evident. Surveys will be continued through the summer to assess temporal trends across sites, and vegetation cover will be compared with dissolved oxygen and turbidity data to assess relationships between vegetation and water quality. This study will yield important information about stream ecosystem responses to agriculture and the role of instream vegetation

Effets de l’ovariectomie et de l’activité physique sur l’homéostasie du glucose chez les rates ZDF

Introduction: La ménopause est associée à l’insulino-résistance et augmente le risque de diabète de type 2 (DT2) chez les sujets sains. Cependant, peu d’informations existent à savoir comment la ménopause et l’activité physique peuvent influencer l’homéostasie du glucose chez des sujets insulino-résistants. Objectifs: Déterminer 1) l’effet du retrait des œstrogènes ovariens par ovariectomie sur l’homéostasie du glucose des rates ZDF (Zucker Diabetic Fatty; prédisposées au diabète de type 2) et 2) évaluer l’influence de l’activité physique volontaire sur ces réponses. Méthodologie: Vingt-quatre rates furent d’abord nourries et hébergées dans des cages conventionnelles les 28 premiers jours pour ensuite subir une ovariectomie (OVX, n=16) ou une opération simulée (SHAM-Inactive, n=8). Les rates ovariectomisées furent ensuite assignées au groupe entraîné volontairement dans une cage à roue (OVX-Active, n=8) ou demeurèrent sédentaires (OVX-Inactive, n=8) pendant les 44 jours suivants. Résultats: Au jour 56, la glycémie à l’état nourri fut significativement augmentée par l’ovariectomie (p<0,01) et ramenée au niveau initial chez les rates OVX-Active (p<0,01). L’ovariectomie diminua la captation de glucose induite par l’insuline dans le muscle de façon significative (0,63 ± 0,08 vs 1,13 ± 0,27 μmol•g-1•h-1). L’entraînement améliora la tolérance au glucose (p<0,01) ainsi que la prise de glucose induite par l’insuline dans le muscle (p<0,05). Conclusion: Le retrait des estrogènes ovariens par ovariectomie perturbe l’homéostasie du glucose chez les rates ZDF femelles, sans pour autant provoquer le diabète de type 2. L’activité physique a un effet bénéfique sur l’homéostasie du glucose malgré la perte d’estrogènes ovariens.Introduction: Menopause is associated with insulin resistance and increased risks of type 2 diabetes in healthy human subjects. However, little is known about its effects on glucose homeostasis in insulin-resistant subjects. Aims: Our aim was to study 1) the effects of ovariectomy and 2) voluntary physical activity on glucose homeostasis in ZDF (Zucker diabetic fatty) female rats, a well-known animal model of insulin resistance and diabetes. Methodology: Twenty-four rats were fed and housed in standard cages during 28 days after which they either underwent an ovariectomy (Ovx) or a sham operation (SHAM-Inactive, n=8). The ovariectomized rats either engaged in voluntary wheel cage running (OVX-Active, n=8) or remained inactive (OVX-Inactive, n=8) for the following 44 days. Results: Fed glycaemia at day 56 was significantly increased by Ovx (p<0.01) and lowered back to control level in OVX-Active rats (p<0.01). Ovx significantly decreased insulin-stimulated muscle glucose uptake (0.63 ± 0.08 vs 1.13 ± 0.27 μmol•g-1•h-1). OVX-Inactive rats also showed increased triglyceride (p<0.001) and lower glycogen (p<0.001) contents in their liver whereas pancreatic insulin content was increased (p<0.05) as compared to SHAM-Inactive rats. Training markedly improved glucose tolerance (p<0.01) and insulin-stimulated muscle glucose uptake (p<0.05) as compared to SHAM-Inactive rats. Ovx-induced alterations in pancreatic insulin content (p<0.01) and liver glycogen (p<0.05) were improved by physical activity. Conclusion: Our data suggest that ovariectomy-induced loss of ovarian estrogens impairs glucose homeostasis in female ZDF rats without triggering overt type 2 diabetes. Physical activity improves glucose homeostasis despite the estrogen loss

Phytoestrogens

Collectively, plants contain several different families of natural products among which are compounds with weak estrogenic or antiestrogenic activity toward mammals. These compounds, termed phytoestrogens, include certain isoflavonoids, flavonoids, stilbenes, and lignans. The best-studied dietary phytoestrogens are the soy isoflavones and the flaxseed lignans. Their perceived health beneficial properties extend beyond hormone-dependent breast and prostate cancers and osteoporosis to include cognitive function, cardiovascular disease, immunity and inflammation, and reproduction and fertility. In the future, metabolic engineering of plants could generate novel and exquisitely controlled dietary sources with which to better assess the potential health beneficial effects of phytoestrogens

The first cyborg and First World War bodies as anti-war propaganda

This article discusses a play published in The Strand Magazine during the First World War which features a cyborg presenting anti-war and pacifist messages, used by The Strand to create anti-German propaganda. The article draws on theories of disability, cyborgs and the posthuman, and from new research on wartime fiction magazines. The importance of the cyborg character, Soldier 241, for the literary history of science fiction is explored by focusing on the relations between the mechanical and the impaired body, and on the First World War as a nexus for technological, surgical and military development. As a cyborg, this character reflects politicized desires that the wartime authorities did not acknowledge: a longing for the end of war, and refusal to countenance a society that rejected the impaired body

Performativity and primary teacher relations

A performativity discourse currently pervades teachers' work. It is a discourse that relies on teachers and schools instituting self-disciplinary measures to satisfy newly transparent public accountability and it operates alongside a market discourse. The introduction of the performativity discourse has affected teacher relations at three levels of professional work: with students, colleagues and local advisor/inspectors. Ethnographic research with primary teachers - which focused on their experience of Ofsted inspections in six schools over periods of up to four years - is the source of this paper. The paper argues that a humanist discourse prevalent in teacher relations with students, colleagues and advisor/inspectors has been challenged by a performativity discourse that: distances teachers from students and creates a dependency culture in opposition to previous mutual and intimate relations; creates self disciplining teams that marginalize individuality and stratifies collegial relations in opposition to previous relations where primary teachers sought consensus; and creates subjugatory, contrived and de-personalized relations between local advisors/inspectors in preference to previous partnership relations. The paper concludes that the change in relations is an indicator of fundamental change to social relations but that primary teachers are in a good position to influence the performativity discourse, albeit it a struggle, by reconstituting it through the maintenance of humanist relations

Dietary cooked navy beans and their fractions attenuate colon carcinogenesis in azoxymethane-induced ob/ob mice

Based on the protective effects of cooked dry bean consumption in a human intervention study, we evaluated which fraction of cooked dry beans is responsible for its cancer-preventive effects. Cooked navy beans (whole beans), the insoluble fraction (bean residue) or soluble fraction of the 60% (vol:vol) ethanol extract of cooked navy beans (bean extract), or a modified AIN-93G diet (16.6% fat including 12.9% lard) as control diet were fed to 160 male obese ob/ob mice after 2 azoxymethane injections. In comparison to control-fed mice, dysplasia, adenomas, or adenocarcinomas were detected in fewer mice on either bean fraction diet (percent reduction from control: whole beans 54%, P = 0.10; bean residue 81%, P = 0.003 ; bean extract 91%, P = 0.007) , and any type of colon lesions, including focal hyperplasia, were found in fewer mice on each of the 3 bean diets percent reduction from control: whole bean 56%, P= 0.04; bean residue 67%, P = 0.01; bean extract 87%, 373 374 G. BOBE ET AL. P = 0.0003. These results suggest that both the soluble and the insoluble fraction of the extract contribute to the cancer-protective effect of cooked navy beans. INTRODUCTION Colorectal cancer (CRC) is the third most commonly diagnosed type of cancer and the fourth most common cause of cancer-related death worldwide (1). In the United States, CRC is the fourth leading cancer in incidence rates and the second leading cause of cancer-related mortality with a 5-yr survival rate of 64% (2). Despite the effectiveness of screening (3,4), there is limited impact for CRC prevention because of low screening rates (5). Nutrition remains critical for CRC prevention. It is estimated that nutrition could prevent 70-80% of all CRC cases (6). This is important, as the annual CRC treatment costs in the United States are estimated to be $6.5 billion (7). Two of the main risk factors for CRC, which are both diet related, are obesity and inflammation (8). Thus, ob/ob mice might provide a suitable animal model to study the link between diet and CRC because they have a mutation in the leptin gene, which results in hyperphagia, obesity, hyperinsulinemia, hyperglycemia, and increased inflammatory response to liposaccharides (9). Dry beans (Phaseolus vulgaris L.), which belong to the Leguminosae family, are a dietary staple in many Latin American, Eastern, and South African countries that potentially could prevent CRC (10,11). Ecological analysis indicates a decreased risk of death associated with colon cancer in countries with higher consumption of beans (12). In studies that have examined the association between colon cancer and individual intakes of legumes, the results indicate a protective effect in populations with higher legume consumption (13-18). In the only study that examined the effect of dry bean consumption separately, male participants, who consumed at least 31 g of cooked dry beans daily, had reduced risk of advanced adenomatous polyp recurrence in a 4-yr nutrition intervention study (Polyp Prevention Trial (19); unpublished data). In animal models, dry beans commonly consumed in the United States, such as pinto, black, and navy beans, reduced azoxymethane(AOM)-induced colon adenocarcinomas in F344 rat

BRCA1 and BRCA2 as molecular targets for phytochemicals indole-3-carbinol and genistein in breast and prostate cancer cells

Indole-3-carbinol (I3C) and genistein are naturally occurring chemicals derived from cruciferous vegetables and soy, respectively, with potential cancer prevention activity for hormone-responsive tumours (e.g., breast and prostate cancers). Previously, we showed that I3C induces BRCA1 expression and that both I3C and BRCA1 inhibit oestrogen (E2)-stimulated oestrogen receptor (ER-α) activity in human breast cancer cells. We now report that both I3C and genistein induce the expression of both breast cancer susceptibility genes (BRCA1 and BRCA2) in breast (MCF-7 and T47D) and prostate (DU-145 and LNCaP) cancer cell types, in a time- and dose-dependent fashion. Induction of the BRCA genes occurred at low doses of I3C (20 μM) and genistein (0.5–1.0 μM), suggesting potential relevance to cancer prevention. A combination of I3C and genistein gave greater than expected induction of BRCA expression. Studies using small interfering RNAs (siRNAs) and BRCA expression vectors suggest that the phytochemical induction of BRCA2 is due, in part, to BRCA1. Functional studies suggest that I3C-mediated cytoxicity is, in part, dependent upon BRCA1 and BRCA2. Inhibition of E2-stimulated ER-α activity by I3C and genistein was dependent upon BRCA1; and inhibition of ligand-inducible androgen receptor (AR) activity by I3C and genistein was partially reversed by BRCA1-siRNA. Finally, we provide evidence suggesting that the phytochemical induction of BRCA1 expression is due, in part, to endoplasmic reticulum stress response signalling. These findings suggest that the BRCA genes are molecular targets for some of the activities of I3C and genistein

Identification of Estrogen Receptor Dimer Selective Ligands Reveals Growth-Inhibitory Effects on Cells That Co-Express ERα and ERβ

Estrogens play essential roles in the progression of mammary and prostatic diseases. The transcriptional effects of estrogens are transduced by two estrogen receptors, ERα and ERβ, which elicit opposing roles in regulating proliferation: ERα is proliferative while ERβ is anti-proliferative. Exogenous expression of ERβ in ERα-positive cancer cell lines inhibits cell proliferation in response to estrogen and reduces xenografted tumor growth in vivo, suggesting that ERβ might oppose ERα's proliferative effects via formation of ERα/β heterodimers. Despite biochemical and cellular evidence of ERα/β heterodimer formation in cells co-expressing both receptors, the biological roles of the ERα/β heterodimer remain to be elucidated. Here we report the identification of two phytoestrogens that selectively activate ERα/β heterodimers at specific concentrations using a cell-based, two-step high throughput small molecule screen for ER transcriptional activity and ER dimer selectivity. Using ERα/β heterodimer-selective ligands at defined concentrations, we demonstrate that ERα/β heterodimers are growth inhibitory in breast and prostate cells which co-express the two ER isoforms. Furthermore, using Automated Quantitative Analysis (AQUA) to examine nuclear expression of ERα and ERβ in human breast tissue microarrays, we demonstrate that ERα and ERβ are co-expressed in the same cells in breast tumors. The co-expression of ERα and ERβ in the same cells supports the possibility of ERα/β heterodimer formation at physio- and pathological conditions, further suggesting that targeting ERα/β heterodimers might be a novel therapeutic approach to the treatment of cancers which co-express ERα and ERβ

Mast Cells in Stress, Pain, Blood-Brain Barrier, Neuroinflammation and Alzheimer’s Disease

Mast cell activation plays an important role in stress-mediated disease pathogenesis. Chronic stress cause or exacerbate aging and age-dependent neurodegenerative diseases. The severity of inflammatory diseases is worsened by the stress. Mast cell activation-dependent inflammatory mediators augment stress associated pain and neuroinflammation. Stress is the second most common trigger of headache due to mast cell activation. Alzheimer’s disease (AD) is a progressive irreversible neurodegenerative disease that affects more women than men and woman’s increased susceptibility to chronic stress could increase the risk for AD. Modern life-related stress, social stress, isolation stress, restraint stress, early life stress are associated with an increased level of neurotoxic beta amyloid (Aβ) peptide. Stress increases cognitive dysfunction, generates amyloid precursor protein (APP), hyperphosphorylated tau, neurofibrillary tangles (NFTs), and amyloid plaques (APs) in the brain. Stress-induced Aβ persists for years and generates APs even several years after the stress exposure. Stress activates hypothalamic-pituitary adrenal (HPA) axis and releases corticotropin-releasing hormone (CRH) from hypothalamus and in peripheral system, which increases the formation of Aβ, tau hyperphosphorylation, and blood-brain barrier (BBB) disruption in the brain. Mast cells are implicated in nociception and pain. Mast cells are the source and target of CRH and other neuropeptides that mediate neuroinflammation. Microglia express receptor for CRH that mediate neurodegeneration in AD. However, the exact mechanisms of how stress-mediated mast cell activation contribute to the pathogenesis of AD remains elusive. This mini-review highlights the possible role of stress and mast cell activation in neuroinflammation, BBB, and tight junction disruption and AD pathogenesis