2,146 research outputs found
Letter from George P. Ahern to John Muir, 1905 Mar 22.
[letterhead]March 22/05My dear Mr MuirYour letter & books were waiting for me in Manila. I returned early in this month & was so disappointed not to have seen you when I was in California. My stay there was very short. Many thanks for the books I shall enjoy reading them very much. I wish to send03552 for a copy of the Century in which is found the Stikine dog story. Please give me the date. It is the best dog story I have ever read.The same old grind has been resumed - the Lamas forest reserve is a veritable mine of botanical material. I hope you can give us another visit.Thanking you for your kindness in sending the booksbelieve me respectfullyGeorge P. Aher
An Analysis of the Tradeoffs between Policy Instruments to Induce Dairy Producers in California to Participate in a Centralized Digester
Tradeoff between different utility rates and policy intervention to induce dairy producer to join a regional digester are studied. Results demonstrate that a regional digester for the dairy industry in California is feasible given the digester receives 0.0925 per kWh with no intervention.Agricultural and Food Policy, Livestock Production/Industries,
A Cation-π Interaction Discriminates among Sodium Channels That Are Either Sensitive or Resistant to Tetrodotoxin Block
Voltage-gated sodium channels control the upstroke of the action potential in excitable cells of nerve and muscle tissue, making them ideal targets for exogenous toxins that aim to squelch electrical excitability. One such toxin, tetrodotoxin (TTX), blocks sodium channels with nanomolar affinity only when an aromatic Phe or Tyr residue is present at a specific location in the external vestibule of the ion-conducting pore. To test whether TTX is attracted to Tyr401 of NaV1.4 through a cation-{pi} interaction, this aromatic residue was replaced with fluorinated derivatives of Phe using in vivo nonsense suppression. Consistent with a cation-{pi} interaction, increased fluorination of Phe401, which reduces the negative electrostatic potential on the aromatic face, caused a monotonic increase in the inhibitory constant for block. Trifluorination of the aromatic ring decreased TTX affinity by ~50-fold, a reduction similar to that caused by replacement with the comparably hydrophobic residue Leu. Furthermore, we show that an energetically equivalent cation-{pi} interaction underlies both use-dependent and tonic block by TTX. Our results are supported by high level ab initio quantum mechanical calculations applied to a model of TTX binding to benzene. Our analysis suggests that the aromatic side chain faces the permeation pathway where it orients TTX optimally and interacts with permeant ions. These results are the first of their kind to show the incorporation of unnatural amino acids into a voltage-gated sodium channel and demonstrate that a cation-{pi} interaction is responsible for the obligate nature of an aromatic at this position in TTX-sensitive sodium channels
TRPV1-null mice are protected from diet-induced obesity
AbstractWe explored a role for the capsaicin receptor, transient receptor potential channel vanilloid type 1 (TRPV1), in the regulation of feeding and body mass. On a 4.5% fat diet, wild-type and TRPV1-null mice gained equivalent body mass. On an 11% fat diet, however, TRPV1-null mice gained significantly less mass and adiposity; at 44 weeks the mean body weights of wild-type and TRPV1-null mice were ∼51 and 34g, respectively. Both groups of mice consumed equivalent energy and absorbed similar amounts of lipids. TRPV1-null mice, however, exhibited a significantly greater thermogenic capacity. Interestingly, we found that 3T3-L1 preadipocytes expressed functional calcitonin gene-related peptide receptors. Thus, these data support a potential neurogenic mechanism by which TRPV1-sensitive sensory nerves may regulate energy and fat metabolism
Analyse de la démarche du médecin alors qu'il évalue l'aptitude à consentir aux soins : étude qualitative de protocoles de penser à voix haute a posteriori
L'évaluation de l'aptitude à consentir aux soins se situe au coeur de la pratique clinique des médecins, voire des autres professionnels de la santé. Elle est une partie intégrante du consentement aux soins, pivot tant éthique que juridique de la promotion de l'autonomie du patient. L'appréciation de l'aptitude demeure encore imprécise et il n'existe pas d'outil fiable pour l'évaluer. Le jugement clinique du médecin est l'un des étalons de mesure de celle-ci, et ce jugement n'a pas été étudié. Il est implicite à la pratique clinique et il est important de l'explorer pour poursuivre les travaux dans le domaine. Notre objectif est ainsi de mieux décrire l'expérience du clinicien alors qu'il évalue l'aptitude à consentir aux soins d'un patient. Pour ce faire, nous avons développé un outil de recherche dont l'utilisation en clinique est novatrice: le protocole de penser à voix haute a posteriori. Ancré dans la théorie de la gestion de l'information en psychologie cognitive, cet outil a surtout été utilisé en laboratoire pour des tâches courtes. Nous nous le sommes appropriés pour tenter de l'utiliser dans un contexte d'une entrevue longue avec l'aide d'un soutien audiovisuel. Il a aussi fallu le resituer dans un paradigme de recherche différent afin d'en faciliter l'analyse: une approche qualitative mixte issue de la théorie ancrée et de la casuistique. Nous avons réussi à former un échantillon critique de médecins constitué de 8 individus ayant complété 14 entrevues. Les médecins étaient des neurologues, des gériatres, des psychiatres et des médecins de famille. Les patients étaient atteints de pathologies médicales multiples, parfois avec des répercussions psychiatriques. Une grille de codes a été développée au sein du groupe de recherche à partir d'une recension des écrits. Elle emploie des codes issus de l'anamnèse clinique et des critères d'évaluation de l'aptitude à consentir aux soins et de la compétence éthique. Nos entrevues nous ont ouvert un vaste univers expérientiel. Elles ont permis de mettre au jour la démarche que les médecins emploient. Les médecins qui évaluent l'aptitude à consentir n'emploient pas de façon formelle des outils d'évaluation des habiletés décisionnelles. C'est dans l'histoire qu'il collige du patient, dans la qualité de sa narration et dans la description de son projet de vie que le médecin validera l'évaluation cognitive du patient et son aptitude à consentir. Les médecins ne font pas un arrêt particulier pour évaluer l'aptitude; ils tentent de comprendre le patient, l'histoire de sa maladie, son histoire de vie. Les médecins apprécient l'aptitude à consentir aux soins proposés tout en poursuivant leur démarche diagnostique des pathologies qui affligent le patient. La démarche s'intègre dans un dialogue et met l'emphase sur le caractère raisonnable et crédible de la narration du patient. Notre recherche, après analyse des critères de scientificité de la recherche qualitative, s'avère fiable et crédible. Elle permet de mettre au jour certains des éléments du jugement du médecin, ce qui est nouveau dans la littérature. Ces données ouvrent la voie à d'autres recherches complémentaires qui se situent à de multiples niveaux. Sur le plan de la recherche, les travaux doivent se poursuivre afin de mieux utiliser le protocole de penser à voix haute en recherche. Sur le plan de l'éducation, notre étude souligne l'importance d'associer une formation en éthique à la démarche clinique. Le développement de nouveaux outils de formation s'impose aussi. Notre recherche ouvre un espace nouveau visant à mieux comprendre comment les outils de mesures des habiletés décisionnelles peuvent compléter ou éclairer l'évaluation clinique
Exploring the effectiveness of a rapid participatory method in mapping the role of agricultural biodiversity in local food systems to identify potential entry points to improve peoples' capabilities to be nutrition secure
Vietnam has improved its food security situation at the price of losing traditional varieties adapted to local tastes and conditions due to increased production and use of high-yield crop varieties (mainly large scale mono-cropping). Decreased diversity of foods is a growing issue, and the existence of malnutrition in regions where staple crop production and food availability are sufficient highlights the necessity for a multidisciplinary approach to design interventions that target the four dimensions of food security - availability, access, stability and utilisation, of a diverse group of locally available nutritious foods.
This paper demonstrates the use of the Four Cell Approach to participatory research to rapidly identify trends in a) species and food usage in a landscape and b) the dynamics of the food system which may contribute to, or be leveraged to improve, peoples' capabilities to be nutrition secure. In the case of Son La Province, Vietnam, explored in this paper, it is possible to conclude a positive relationship between increased production diversity and dietary diversity, and highlight the importance of markets for diffusion of diverse foods. Diversification of species production and consumption has a positive effect on resilience during the off-season, and diversification of coping mechanisms utilised by communities can build resilience for future shocks. Food-based approaches that promote diversified production and consumption of locally available nutritious foods that local people value, while ensuring access to markets, have the potential to improve capabilities of local people to provide nutritious foods for themselves and their communities while improving resilience to be food and nutrition secure at all time
Microbiology and atmospheric processes: Biological, physical and chemical characterization of aerosol particles
The interest in bioaerosols has traditionally been linked to health hazards for humans, animals and plants. However, several components of bioaerosols exhibit physical properties of great significance for cloud processes, such as ice nucleation and cloud condensation. To gain a better understanding of their influence on climate, it is therefore important to determine the composition, concentration, seasonal fluctuation, regional diversity and evolution of bioaerosols. In this paper, we will review briefly the existing techniques for detection, quantification, physical and chemical analysis of biological particles, attempting to bridge physical, chemical and biological methods for analysis of biological particles and integrate them with aerosol sampling techniques. We will also explore some emerging spectroscopy techniques for bulk and single-particle analysis that have potential for in-situ physical and chemical analysis. Lastly, we will outline open questions and further desired capabilities (e. g., in-situ, sensitive, both broad and selective, on-line, time-resolved, rapid, versatile, cost-effective techniques) required prior to comprehensive understanding of chemical and physical characterization of bioaerosols
Digoxin treatment is associated with an increased incidence of breast cancer: a population-based case-control study
INTRODUCTION. Laboratory and epidemiologic studies have suggested a modifying effect of cardiac glycosides (for example, digoxin and digitoxin) on cancer risk. We explored the association between digoxin treatment and invasive breast cancer incidence among postmenopausal Danish women. METHODS. We used Danish registries to identify 5,565 postmenopausal women diagnosed with incident invasive breast carcinoma between 1 January 1991 and 31 December 2007, and 55,650 matched population controls. Cardiac glycoside prescriptions were ascertained from county prescription registries. All subjects had at least 2 years of recorded prescription drug and medical history data. We estimated the odds ratio associating digoxin use with breast cancer in conditional logistic regression models adjusted for age, county of residence, and use of anticoagulants, non-steroidal anti-inflammatory drugs (NSAIDs), aspirin, and hormone replacement therapy. We also explored the impact of confounding by indication and detection bias. RESULTS. Digoxin was the sole cardiac glycoside prescribed to subjects during the study period. There were 324 breast cancer cases (5.8%) and 2,546 controls (4.6%) with a history of digoxin use at least 1 year before their index date (adjusted odds ratio (OR): 1.30; 95% confidence interval: 1.14 to 1.48). The breast cancer OR increased modestly with increasing duration of digoxin exposure (adjusted OR for 7 to 18 years of digoxin use: 1.39; 95% confidence interval: 1.10 to 1.74). The association was robust to adjustment for age, receipt of hormone replacement therapy, coprescribed drugs, and confounding by indication. A comparison of screening mammography rates between cases and controls showed no evidence of detection bias. CONCLUSIONS. Our results suggest that digoxin treatment increases the risk of invasive breast cancer among postmenopausal women.Congressionaly Directed Medical Research Programs (BC073012); Karen Elise Jensen Foundation; Western Danish Research Forum for Health Science
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