WorldWideScience

Sample records for hyperinsulinism apport limite

  1. Apport maternel chez la balane tropicale : Plasticite de l'allocation de la ressource trophique pour la production larvaire en conditions de limitation nutritionnelle et de stress environnemental

    Science.gov (United States)

    Freuchet, Florian

    Dans le milieu marin, l'abondance du recrutement depend des processus qui vont affecter les adultes et le stock de larves. Sous l'influence de signaux fiables de la qualite de l'habitat, la mere peut augmenter (effet maternel anticipatoire, 'anticipatory mother effects', AME) ou reduire (effet maternel egoiste, 'selfish maternai effects', SME) la condition physiologique de la progeniture. Dans les zones tropicales, generalement plus oligotrophes, la ressource nutritive et la temperature sont deux composantes importantes pouvant limiter le recrutement. Les effets de l'apport nutritionnel et du stress thermique sur la production de larves et sur la stategie maternelle adoptee ont ete testes dans cette etude. Nous avons cible la balane Chthamalus bisinuatus (Pilsbry) comme modele biologique car el1e domine les zones intertidales superieures le long des cotes rocheuses du Sud-Est du Bresil (region tropicale). Les hypotheses de depart stipulaient que l'apport nutritionnel permet aux adultes de produire des larves de qualite elevee et que le stress thermique genere une ponte precoce, produisant des larves de faible qualite. Afin de tester ces hypotheses, des populations de C. bisinuatus ont ete elevees selon quatre groupes experimentaux differents, en combinant des niveaux d'apport nutritionnel (eleve et faible) et de stress thermique (stresse et non stresse). Des mesures de survie et de conditions physiologiques des adultes et des larves ont permis d'identifier les reponses parentales pouvant etre avantageuses dans un environnement tropical hostile. L'analyse des profils en acides gras a ete la methode utilisee pour evaluer la qualite physiologique des adultes et de larves. Les resultats du traitement alimentaire (fort ou faible apport nutritif), ne montrent aucune difference dans l'accumulation de lipides neutres, la taille des nauplii, l'effort de reproduction ou le temps de survie des nauplii en condition de jeune. Il semble que la faible ressource nutritive est

  2. Apports et limites du marquage individuel dans la connaissance de l'écobiologie du chevaine (Leuciscus cephalus

    Directory of Open Access Journals (Sweden)

    LE LOUARN H.

    1997-04-01

    Full Text Available Depuis 1991, des marquages individuels ont été effectués sur des chevaines (Leuciscus cephalus de la rivière Boutonne, affluent de la Charente, afin d'améliorer les connaissances écobiologiques de l'espèce qui restent très fragmentaires pour les populations atlantiques françaises. 718 individus, de taille supérieure à 120 mm, ont été capturés par pêche électrique sur un secteur de 2,7 km, lors de la période de reproduction (mi-juin, et marqués essentiellement par marque nouille (5 années mais également par implant visible (une année durant cinq ans. Au total, 162 poissons ont été recapturés et certains individus plusieurs fois au cours de la période d'étude. L'analyse des résultats fait ressortir que : - Seuls deux poissons marqués par implant visible ont été recapturés (0,9 % ; le taux moyen de recapture des individus marqués par marque nouille a été de 22,3 % mais a varié selon l'année et l'état de maturité du poisson (de 6,6 à 37,7 % ; il apparaît plus faible pour les immatures (6,4 % que pour les géniteurs (25,2 % et reste identique chez les deux sexes. - La méthode de capture-recapture a permis de valider l'estimation de l'âge et de la croissance par scalimétrie : définition de la marque hivernale ; existence d'une chronologie de l'apparition de l'anneau hivernal et donc de la reprise de croissance ; validation de la régression reliant la longueur du poisson à celle de son écaille pour la population étudiée. - Les déplacements à l'intérieur du secteur étudié sont faibles et les femelles montrent une grande fidélité à leur site de reproduction. - Le marquage par marque nouille entraîne un déficit de croissance, principalement chez les poissons de plus de cinq ans ; ce déficit semble se réduire dès la deuxième année suivant le marquage. La discussion des résultats montre qu'en dépit de certains facteurs limitants, l'utilisation de cette technique de marquage individuel appara

  3. Genotype-phenotype associations in children with congenital hyperinsulinism

    DEFF Research Database (Denmark)

    Melikyan, Maria; Brusgaard, Klaus; Petraykina, Elena

    Congenital hyperinsulinism (CHI) is a heterogeneous disease in terms of clinical presentation, genetics and histology. Mutations in eight genes are known to be a cause of CHI, of which ABCC8, KCNJ11 and GCK are among the most common. We investigated genotype-phenotype associations in a cohort of ...

  4. Genotype-phenotype associations in children with congenital hyperinsulinism

    DEFF Research Database (Denmark)

    Melikyan, Maria; Brusgaard, Klaus; Petraykina, Elena

    Congenital hyperinsulinism (CHI) is a heterogeneous disease in terms of clinical presentation, genetics and histology. Mutations in eight genes are known to be a cause of CHI, of which ABCC8, KCNJ11 and GCK are among the most common. We investigated genotype-phenotype associations in a cohort of ...

  5. [Electrophysiologic study of neonatal hypoglycemia prolonged by hyperinsulinism].

    Science.gov (United States)

    Parain, D; Samson-Dollfus, D

    1983-11-01

    A case of neonatal hyperinsulinism with hypoglycemia is reported. The EEGs were abnormal because of a lack of sleep modulation. The CT scan showed pathological occipital hypodensities. The flashes VER were abnormal at 1, 2 and 6 months of age, chiefly on the right occipital lead and showing a possible lesion of the right retrochiasmatic pathways.

  6. Nouvelles formes de gouvernance dans le domaine de l’eau. Apports et limites de la coopération décentralisée dans les pays en développement

    Directory of Open Access Journals (Sweden)

    Raoudha Makkaoui

    2010-09-01

    Full Text Available La problématique de cet article porte sur le rôle de la coopération décentralisée dans le domaine de l’eau, dans la mesure où celle-ci semble pouvoir apporter des réponses concrètes au problème de l’accès universel à l’eau et constituer une nouvelle option pour la communauté internationale. Dans une première partie, on présentera les problèmes rencontrés par les différents modes de gestion de l’eau dans les pays en développement et la façon dont ils ont successivement tenté de satisfaire à certains objectifs bien précis (accès universel à l’eau, réduction des coûts, prise en compte des besoins prioritaires. Dans une deuxième partie, sur la base d’une initiative de coopération décentralisée entre le Conseil régional de Seine-Saint-Denis et la ville marocaine de Figuig, on s’interrogera sur les apports et limites de cette nouvelle forme de partenariat participatif afin d’en évaluer la pérennité ainsi que la « soutenabilité sociale », montrant, de ce fait, sa proximité avec l’économie solidaire.Our paper builds on this issue of decentralized cooperation in the field of water management. Cooperation between decentralized entities in order to ensure the access to safe drinking water for all now constitutes in many places a preferred water governance option. Therefore, in the first part, we will provide an overview of the current difficulties encountered by the various forms of water management in developing countries, showing the solutions that they successively brought to specific issues (access for all, cost reduction, priority needs. In the second part, we will address the particular case of decentralized cooperation between the General Council of Seine-Saint-Denis in the suburbs of Paris, France, in partnership with the city of Figuig in Morocco. We review the insights and limits of such processes that refer to the people’s capabilities, at both individual and collective levels, in

  7. Hyperinsulinism and hyperammonemia syndrome: report of twelve unrelated patients.

    Science.gov (United States)

    De Lonlay, P; Benelli, C; Fouque, F; Ganguly, A; Aral, B; Dionisi-Vici, C; Touati, G; Heinrichs, C; Rabier, D; Kamoun, P; Robert, J J; Stanley, C; Saudubray, J M

    2001-09-01

    Hyperinsulinism and hyperammonemia syndrome has been reported as a cause of moderately severe hyperinsulinism with diffuse involvement of the pancreas. The disorder is caused by gain of function mutations in the GLUD1 gene, resulting in a decreased inhibitory effect of guanosine triphosphate on the glutamate dehydrogenase (GDH) enzyme. Twelve unrelated patients (six males, six females) with hyperinsulinism and hyperammonemia syndrome have been investigated. The phenotypes were clinically heterogeneous, with neonatal and infancy-onset hypoglycemia and variable responsiveness to medical (diazoxide) and dietary (leucine-restricted diet) treatment. Hyperammonemia (90-200 micromol/L, normal carbamylglutamate administration. The patients had mean basal GDH activity (18.3 +/- 0.9 nmol/min/mg protein) not different from controls (17.9 +/- 1.8 nmol/min/mg protein) in cultured lymphoblasts. The sensitivity of GDH activity to inhibition by guanosine triphosphate was reduced in all patient lymphoblast cultures (IC(50), or concentrations required for 50% inhibition of GDH activity, ranging from 140 to 580 nM, compared with control IC(50) value of 83 +/- 1.0 nmol/L). The allosteric effect of ADP was within the normal range. The activating effect of leucine on GDH activity varied among the patients, with a significant decrease of sensitivity that was correlated with the negative clinical response to a leucine-restricted diet in plasma glucose levels in four patients. Molecular studies were performed in 11 patients. Heterozygous mutations were localized in the antenna region (four patients in exon 11, two patients in exon 12) as well as in the guanosine triphosphate binding site (two patients in exon 6, two patients in exon 7) of the GLUD1 gene. No mutation has been found in one patient after sequencing the exons 5-13 of the gene.

  8. Hyperinsulinism induced by targeted suppression of beta cell KATP channels.

    Science.gov (United States)

    Koster, J C; Remedi, M S; Flagg, T P; Johnson, J D; Markova, K P; Marshall, B A; Nichols, C G

    2002-12-24

    ATP-sensitive K+ (K(ATP)) channels couple cell metabolism to electrical activity. To probe the role of K(ATP) in glucose-induced insulin secretion, we have generated transgenic mice expressing a dominant-negative, GFP-tagged K(ATP) channel subunit in which residues 132-134 (Gly-Tyr-Gly) in the selectivity filter were replaced by Ala-Ala-Ala, under control of the insulin promoter. Transgene expression was confirmed by both beta cell-specific green fluorescence and complete suppression of channel activity in those cells ( approximately 70%) that did fluoresce. Transgenic mice developed normally with no increased mortality and displayed normal body weight, blood glucose levels, and islet architecture. However, hyperinsulinism was evident in adult mice as (i) a disproportionately high level of circulating serum insulin for a given glucose concentration ( approximately 2-fold increase in blood insulin), (ii) enhanced glucose-induced insulin release from isolated islets, and (iii) mild yet significant enhancement in glucose tolerance. Enhanced glucose-induced insulin secretion results from both increased glucose sensitivity and increased release at saturating glucose concentration. The results suggest that incomplete suppression of K(ATP) channel activity can give rise to a maintained hyperinsulinism.

  9. beta-cell hyperexcitability: from hyperinsulinism to diabetes.

    Science.gov (United States)

    Nichols, C G; Koster, J C; Remedi, M S

    2007-11-01

    Nutrient oxidation in beta cells generates a rise in [ATP]:[ADP] ratio. This reduces K(ATP) channel activity, leading to depolarization, activation of voltage-dependent Ca(2+) channels, Ca(2+) entry and insulin secretion. Consistent with this paradigm, loss-of-function mutations in the genes (KCNJ11 and ABCC8) that encode the two subunits (Kir6.2 and SUR1, respectively) of the ATP-sensitive K(+) (K(ATP)) channel underlie hyperinsulinism in humans, a genetic disorder characterized by dysregulated insulin secretion. In mice with genetic suppression of K(ATP) channel subunit expression, partial loss of K(ATP) channel conductance also causes hypersecretion, but unexpectedly, complete loss results in an undersecreting, mildly glucose-intolerant phenotype. When challenged by a high-fat diet, normal mice and mice with reduced K(ATP) channel density respond with hypersecretion, but mice with more significant or complete loss of K(ATP) channels cross over, or progress further, to an undersecreting, diabetic phenotype. It is our contention that in mice, and perhaps in humans, there is an inverse U-shaped response to hyperexcitabilty, leading first to hypersecretion but with further exacerbation to undersecretion and diabetes. The causes of the overcompensation and diabetic susceptibility are poorly understood but may have broader implications for the progression of hyperinsulinism and type 2 diabetes in humans.

  10. Définition des limites de flexibilité des apports en acides oléique, linoléique et alphalinolénique sur la lipidémie et les paramètres d’athérothrombose chez l’homme : intérêt des huiles végétales combinées

    Directory of Open Access Journals (Sweden)

    Delplanque Bernadette

    2002-07-01

    Full Text Available Les maladies cardiovasculaires représentent le premier problème de santé publique des pays occidentaux. Des études récentes de prévention secondaire ont montré que des régimes maintenant un apport en acide oléique de 10 à 13% de l’apport énergétique total (AET pouvaient protéger de l’apparition d’accidents cardio-vasculaires [8], mais augmenter cet apport d’acide oléique à plus de 20% de l’AET pourrait limiter cet effet bénéfique en induisant une augmentation du LDL-C [12, 34]. Grundy, dans le but de clarifier le ratio nécessaire entre acides gras saturés et insaturés (mono and poly, concluait en 1997 à d’« insufficient data for recommended Oleic intake », et proposait pour le moment 15-16% d’acide oléique à titre de « reasonable compromise ». L’objectif de notre étude était de définir des rapports entre acides oléique, linoléique et alphalinolénique (OL/LA/ALA ratio et de valider l’apport oléique après avoir stabilisé le rapport linoléique/alphalinolénique du régime d’hommes normolipidémiques (n = 40. Pour atteindre 11, 13 et 16% de l’AET sous forme d’acide oléique, nous avons utilisé des huiles de tournesol, de tournesol oléique (HOSO et de colza pour obtenir des mélanges spécifiques ajustés à l’apport en acides gras proposés au protocole. Chacun de ces trois régimes (comportant 11, 13 et 16% d’acide oléique a été suivi pendant 16 semaines et l’épuration postprandiale d’un repas gras (1 000 Kcal, 62,5% lipides a été suivie pendant 8 heures à la fin de chaque période de régime. Les résultats indiquent que la stabilité des paramètres d’athérogenèse évalués à jeun et en postprandial est maintenue à un niveau favorable après ces régimes à 11, 13 et 16% d’apport en acide oléique : il n’y a pas de différences statistiques significatives sur les concentrations à jeun de LDL-C, non-HDL-C, HDL-C, TG, ApoB, ApoAI ou sur l’amplitude de la r

  11. Protein causes hyperinsulinemia: a Chinese patient with hyperinsulinism/hyperammonaemia syndrome due to a glutamate dehydrogenase gene mutation

    Institute of Scientific and Technical Information of China (English)

    CHEN Shi; XIAO Xin-hua; DIAO Cheng-ming; TONG An-li; WANG Ou; QIU Zheng-qing; YU Kang; WANG Tong

    2010-01-01

    @@ Glucose is derived from three sources: intestinal absorption, glycogenolysis, and gluconeogenesis. Hypoglycemia in child is often attributed to depletion of glycogen stores. However, recently, congenital hyperinsulinism becomes an important cause of hypoglycaemia in early infancy. Mutations in the genes encoding SUR1 and KIR6.2 are the most frequent genetic causes of hyperinsulinism followed by mutations in the glutamate dehydrogenase (GDH) gene which encodes hyperinsulinism/hyperammonaemia (HI/HA) syndrome.

  12. Managing congenital hyperinsulinism: improving outcomes with a multidisciplinary approach

    Directory of Open Access Journals (Sweden)

    Ackermann AM

    2015-07-01

    Full Text Available Amanda M Ackermann, Andrew A Palladino Division of Endocrinology and Diabetes, The Children’s Hospital of Philadelphia, Philadelphia, PA, USA Abstract: Congenital hyperinsulinism (CHI is the most common cause of persistent hypoglycemia in pediatric patients and is associated with significant risk of hypoglycemic seizures and developmental delays. CHI results from mutations in at least nine genes that play a role in regulating beta-cell insulin secretion. Thus, patients with CHI have dysregulated insulin secretion that is unresponsive to blood glucose level. Each different genetic etiology of CHI is associated with particular clinical characteristics that affect management decisions. Given the broad phenotypic spectrum and relatively rare prevalence of CHI, it is important that patients with CHI be evaluated by clinicians experienced with CHI and the multiple subspecialty services that are necessary for the management of the disorder. In this review, we summarize the pathophysiology and genetic causes of CHI and then focus primarily on the most common genetic cause (mutations in the ATP-gated potassium [KATP] channel for further discussion of diagnosis, medical and surgical management, and potential acute and chronic complications. We provide insight from relevant published studies and reports, in addition to anecdotal information from our center’s clinical experience in caring for over 400 patients with CHI. Careful assessment of each patient’s individual pathophysiology is necessary to determine the appropriate treatment regimen, and continued close follow-up and monitoring of disease- and treatment-related complications are essential. Although significant improvements have been made in the past several years with regard to diagnosis and management, given the continued high morbidity rate in patients with CHI, improved diagnostic techniques and new therapeutic options would be welcomed. Keywords: hypoglycemia, hyperinsulinism, beta

  13. Surgical versus non-surgical treatment of congenital hyperinsulinism.

    Science.gov (United States)

    Mazor-Aronovitch, Kineret; Landau, Heddy; Gillis, David

    2009-03-01

    Congenital hyperinsulinism is a functional disorder of insulin secretion. In its diffuse severe form, it is traditionally treated with over 95% pancreatectomy. However, even after this procedure normoglycemia is not always achieved. Non-surgical therapy with frequent or continuous feeding, medication and close monitoring is another alternative. In this review we compare the two approaches to this condition focusing on early complications, diabetes, neurological outcome and home management issues. Early complications of pancreatectomy include mechanical, metabolic and infectious complications. Non-surgical interventions can be complicated by unwarranted effects of medications and of invasive procedures. Diabetes occurs with both approaches but much less frequently and years later with non-surgical treatment. Regarding neurodevelopmental outcome, most data come from heterogeneous groups. Nevertheless, it appears that outcome is not adversely affected by avoiding surgery. Home management is far more difficult for the non-surgical form. When the non-surgical approach is successful in achieving normoglycemia and parents are highly motivated, this mode of therapy should be considered.

  14. Treatment of congenital hyperinsulinism with lanreotide acetate (Somatuline Autogel).

    Science.gov (United States)

    Modan-Moses, Dalit; Koren, Ilana; Mazor-Aronovitch, Kineret; Pinhas-Hamiel, Orit; Landau, Heddy

    2011-08-01

    Congenital hyperinsulinism (CH) may be treated conservatively in many children with octreotide given by multiple sc injections or via an insulin pump. We describe two children treated with a once-monthly injection of a long-acting somatostatin analog. Both patients presented with hypoglycemia 30 min after birth and were subsequently diagnosed with CH. Patients were initially treated with diazoxide, hydrochlorothiazide, frequent feedings, and octreotide via an insulin pump. With this therapy, they were normoglycemic with a good growth rate, normal weight gain, and excellent neurodevelopment. Treatment with the long-acting somatostatin analog lanreotide acetate (Somatuline Autogel), administered by deep sc injection of 30 mg once a month, was started at the ages of 4½ and 4 yr, respectively. Octreotide infusion was gradually weaned over 1 month. Continuous glucose monitoring after discontinuation of pump therapy showed normoglycemia. The first patient has now been treated with the lanreotide acetate for over 5 yr, and the second for 3 yr. Treatment is well-tolerated, and both the patients and their parents are satisfied with the transition from pump therapy to once-a-month injection and prefer it to pump therapy. Lanreotide acetate may be a safe and effective alternative to octreotide pump therapy in patients with CH, offering an improved quality of life. Longer follow-up of a larger patient group is needed.

  15. Paraneoplastic hyperinsulinism and secondary hypoglycaemia in a patient with advanced colon cancer: A rare association

    Institute of Scientific and Technical Information of China (English)

    Roberto Díaz; Jorge Aparicio; Andrea Mendizóbal; Marisa Faus; Tania Fleitas; Francisco Aparisi; Maria Martín

    2008-01-01

    We review the case of a 74-year-old patient with advanced colon cancer who suffered recurrent bouts of hypoglycemia. A state of inappropriate, non-suppressed hyperinsulinism in the presence of severe hypoglycemia was diagnosed. We finally discuss the known mechanisms behind fasting hypoglycemia in patients with advanced cancer, the diagnosis, and possible treatments of this rare paraneoplastic endocrine complication.

  16. Both Low Blood Glucose and Insufficient Treatment Confer Risk of Neurodevelopmental Impairment in Congenital Hyperinsulinism

    DEFF Research Database (Denmark)

    Rasmussen, Annett Helleskov; Melikyan, Maria; Globa, Evgenia

    2017-01-01

    BACKGROUND/AIMS: Congenital hyperinsulinism (CHI) is a heterogeneous disease most frequently caused by KATP-channel (ABCC8 and KCNJ11) mutations, with neonatal or later onset, variable severity, and with focal or diffuse pancreatic involvement as the two major histological types. CHI confers a hi...

  17. Long-term non-surgical therapy of severe persistent congenital hyperinsulinism with glucagon

    NARCIS (Netherlands)

    Mohnike, K.; Blankenstein, O.; Pfuetzner, A.; Poetzsch, S.; Schober, E.; Steiner, S.; Hardy, O. T.; Grimberg, A.; van Waarde, W. M.

    2008-01-01

    Background: Congenital hyperinsulinism (CHI) is characterized by severe hypoglycemia caused by dysregulated insulin secretion. The long-term outcome is dependent on prevention of hypoglycemic episodes to avoid the high risk of permanent brain damage. Severe cases are usually resistant to diazoxide o

  18. [Congenital hyperinsulinism in the north-east Netherlands. Clinical features and DNA diagnostics in 22 children

    NARCIS (Netherlands)

    Verheul, J.C.; Ris-Stalpers, C.; Bikker, H.; Bakker-van Waarde, W.M.; Noordam, C.

    2011-01-01

    OBJECTIVE: To describe the clinical features and relevant genetic mutations in 22 children with congenital hyperinsulinism in the north-east Netherlands. DESIGN: Retrospective, descriptive study. METHOD: Children born between June 1988 and June 2009, who were presented at the academic medical centre

  19. Anorexia nervosa versus hyperinsulinism: therapeutic effects of neuropharmacological manipulation

    Directory of Open Access Journals (Sweden)

    Fuad Lechin

    2011-02-01

    :adrenaline ratio and disappearance of abnormal plasma glucose elevation were registered throughout the three-month duration of the trial. Significant and sustained increases in body weight were documented in all cases. No relapses were observed.Conclusion: We have confirmed our previously published findings showing that the anorexia nervosa syndrome depends on the hypomotility of the gastrointestinal tract plus hyperglycemia, both of which are triggered by adrenal sympathetic hyperactivity. The above neuroendocrine plus neuroautonomic and clinical disorders which underpinned anorexia nervosa were abruptly suppressed since the first oral dose of amantadine, a drug able to revert the C1(Ad over A5(NA pontomedullary predominance responsible for adrenal and neural sympathetic activity, respectively. Keywords: amantadine, anorexia nervosa, adrenal sympathetic activity, hyperglycemia, hyperinsulinism, neural sympathetic activity

  20. Congenital hyperinsulinism: current trends in diagnosis and therapy

    Directory of Open Access Journals (Sweden)

    Bellanné-Chantelot Christine

    2011-10-01

    Full Text Available Abstract Congenital hyperinsulinism (HI is an inappropriate insulin secretion by the pancreatic β-cells secondary to various genetic disorders. The incidence is estimated at 1/50, 000 live births, but it may be as high as 1/2, 500 in countries with substantial consanguinity. Recurrent episodes of hyperinsulinemic hypoglycemia may expose to high risk of brain damage. Hypoglycemias are diagnosed because of seizures, a faint, or any other neurological symptom, in the neonatal period or later, usually within the first two years of life. After the neonatal period, the patient can present the typical clinical features of a hypoglycemia: pallor, sweat and tachycardia. HI is a heterogeneous disorder with two main clinically indistinguishable histopathological lesions: diffuse and focal. Atypical lesions are under characterization. Recessive ABCC8 mutations (encoding SUR1, subunit of a potassium channel and, more rarely, recessive KCNJ11 (encoding Kir6.2, subunit of the same potassium channel mutations, are responsible for most severe diazoxide-unresponsive HI. Focal HI, also diazoxide-unresponsive, is due to the combination of a paternally-inherited ABCC8 or KCNJ11 mutation and a paternal isodisomy of the 11p15 region, which is specific to the islets cells within the focal lesion. Genetics and 18F-fluoro-L-DOPA positron emission tomography (PET help to diagnose diffuse or focal forms of HI. Hypoglycemias must be rapidly and intensively treated to prevent severe and irreversible brain damage. This includes a glucose load and/or a glucagon injection, at the time of hypoglycemia, to correct it. Then a treatment to prevent the recurrence of hypoglycemia must be set, which may include frequent and glucose-enriched feeding, diazoxide and octreotide. When medical and dietary therapies are ineffective, or when a focal HI is suspected, surgical treatment is required. Focal HI may be definitively cured when the partial pancreatectomy removes the whole lesion. By

  1. Vineland Adaptive Behavior Scales to identify neurodevelopmental problems in children with Congenital Hyperinsulinism (CHI)

    OpenAIRE

    Salomon Estebanez, Maria; Mohamed, Zainab; Michaelidou, Maria; Collins, Hannah; Rigby, Lindsey; Skae, Mars; Padidela, Raja; Rust, Stewart; Dunne, Mark; Cosgrove, Karen; Banerjee, Indraneel; Nicholson, Jacqueline

    2017-01-01

    Background Congenital Hyperinsulinism (CHI) is a disease of severe hypoglycaemia caused by excess insulin secretion and associated with adverse neurodevelopment in a third of children. The Vineland Adaptive Behavior Scales Second Edition (VABS-II) is a parent report measure of adaptive functioning that could be used as a developmental screening tool in patients with CHI. We have investigated the performance of VABS-II as a screening tool to identify developmental delay in a relatively large c...

  2. Stem cells. Asymmetric apportioning of aged mitochondria between daughter cells is required for stemness.

    Science.gov (United States)

    Katajisto, Pekka; Döhla, Julia; Chaffer, Christine L; Pentinmikko, Nalle; Marjanovic, Nemanja; Iqbal, Sharif; Zoncu, Roberto; Chen, Walter; Weinberg, Robert A; Sabatini, David M

    2015-04-17

    By dividing asymmetrically, stem cells can generate two daughter cells with distinct fates. However, evidence is limited in mammalian systems for the selective apportioning of subcellular contents between daughters. We followed the fates of old and young organelles during the division of human mammary stemlike cells and found that such cells apportion aged mitochondria asymmetrically between daughter cells. Daughter cells that received fewer old mitochondria maintained stem cell traits. Inhibition of mitochondrial fission disrupted both the age-dependent subcellular localization and segregation of mitochondria and caused loss of stem cell properties in the progeny cells. Hence, mechanisms exist for mammalian stemlike cells to asymmetrically sort aged and young mitochondria, and these are important for maintaining stemness properties. Copyright © 2015, American Association for the Advancement of Science.

  3. Le débat interprétatif : un genre disciplinaire. Apports et limites d’un « outil » d’analyse de l’évolution d’une discipline scolaire

    Directory of Open Access Journals (Sweden)

    Ana Dias-Chiaruttini

    2014-01-01

    Full Text Available Based on the elements of a recent research, which focused on the emergence and actual practices of interpretative debate in the teaching of literature, in Cycle 3 primary in school in France, this article is a reflection on the contributions and limitations of the concept of disciplinary genre in school as analysis, both theoretical and methodological, from the evolution of disciplinary contents and teaching practices. It discusses various approaches to this proposed notion within different research teams concepts and outlines the choices that were made and the results build which describe the interpretative debate as a kind of metatextual discourse revealing some discursive learnings, allowing to understand the renewal of the teaching of literature in primary school in France and resistance to renewal.

  4. Hyperinsulinism and diabetes: genetic dissection of beta cell metabolism-excitation coupling in mice.

    Science.gov (United States)

    Remedi, Maria Sara; Nichols, Colin G

    2009-12-01

    The role of metabolism-excitation coupling in insulin secretion has long been apparent, but in recent years, in parallel with studies of human hyperinsulinism and diabetes, genetic manipulation of proteins involved in glucose transport, metabolism, and excitability in mice has brought the central importance of this pathway into sharp relief. We focus on these animal studies and how they provide important insights into not only metabolic and electrical regulation of insulin secretion, but also downstream consequences of alterations in this pathway and the etiology and treatment of insulin-secretion diseases in humans.

  5. Hyperinsulinism and Diabetes: Genetic dissection of β-cell metabolism-excitation coupling in mice

    Science.gov (United States)

    Remedi, Maria Sara; Nichols, Colin G.

    2011-01-01

    The role of metabolism-excitation coupling in insulin secretion has long been apparent but, in parallel with studies of human hyperinsulinism and diabetes, genetic manipulation of proteins involved in glucose transport, metabolism and excitability in mice has brought the central importance of this pathway into sharp relief in recent years. We focus on these animal studies, and how they not only provide important insights to metabolic and electrical regulation of insulin secretion, but also to downstream consequences of alterations in this pathway, and to the etiology and treatment of insulin-secretion diseases in humans. PMID:19945402

  6. The spectrum of ABCC8 mutations in Norwegian patients with congenital hyperinsulinism of infancy

    DEFF Research Database (Denmark)

    Sandal, T; Laborie, L B; Brusgaard, K

    2009-01-01

    Potassium channels in the plasma membrane of the pancreatic beta cells are critical in maintaining glucose homeostasis by responding to ATP and coupling metabolic changes to insulin secretion. These channels consist of subunits denoted the sulfonylurea receptor SUR1 and the inwardly rectifying ion...... channel KIR6.2, which are encoded by the genes ABCC8 and KCNJ11, respectively. Activating mutations in the subunit genes can result in monogenic diabetes, whereas inactivating mutations are the most common cause of congenital hyperinsulinism of infancy (CHI). Twenty-six Norwegian probands with CHI were...

  7. Mechanisms of amino acid-stimulated insulin secretion in congenital hyperinsulinism

    OpenAIRE

    Zhang, Tingting; Li, Changhong

    2012-01-01

    The role of amino acids in the regulation of insulin secretion in pancreatic beta-cells is highlighted in three forms of congenital hyperinsulinism (HI), namely gain-of-function mutations of glutamate dehydrogenase (GDH), loss-of-function mutations of ATP-dependent potassium channels, and a deficiency of short-chain 3-hydroxyacyl-CoA dehydrogenase. Studies on disease mouse models of HI suggest that amino acid oxidation and signaling effects are the major mechanisms of amino acid-stimulated in...

  8. Cognitive and developmental outcome of conservatively treated children with congenital hyperinsulinism.

    Science.gov (United States)

    Levy-Shraga, Yael; Pinhas-Hamiel, Orit; Kraus-Houminer, Efrat; Landau, Heddy; Mazor-Aronovitch, Kineret; Modan-Moses, Dalit; Gillis, David; Koren, Ilana; Dollberg, Daphna; Gabis, Lidia V

    2013-01-01

    Congenital hyperinsulinism (CHI) is the most common cause of persistent hypoglycemia in infants. Its management can be extremely complicated, and may involve medical therapy and surgery. The mainstay of the treatment is to maintain normoglycemia, since hypoglycemia during infancy can have severe neurological consequences. To assess the cognitive and developmental levels and the adaptive skills achieved by children with CHI who were treated medically over the past decade. Fourteen children with CHI, under the age of 10 years, who received medical treatment only, underwent a physical and neurological examination and standardized assessments that included the Bayley Scale of Infant and Toddler Development, 3rd Edition, or Kaufman Assessment Battery for Children, the Vineland Adaptive Behavior Scales and the Achenbach Child Behavior Checklist (CBCL) parent questionnaire form. Twelve children (86%) achieved normal range scores in the cognitive and development assessments (Bayley Scale of Infant and Toddler Development or Kaufman Assessment Battery for Children). Only two showed cognitive achievements below the normal range. The Vineland questionnaire, which was based on parental report, showed below normal adaptive skills in eight patients (57%). In contrast to previous studies showing a high prevalence of neurodevelopmental difficulties in children with congenital hyperinsulinism, our study showed normal cognitive achievements in most children. This may be attributed to the earlier recognition and better management of the disease in the past decade.

  9. Hyperinsulinism/hyperammonemia syndrome: insights into the regulatory role of glutamate dehydrogenase in ammonia metabolism.

    Science.gov (United States)

    Stanley, Charles A

    2004-04-01

    The second most common form of congenital hyperinsulinism, the hyperinsulinism/hyperammonemia syndrome (HI/HA), is associated with dominantly expressed missense mutations of the mitochondrial matrix enzyme, glutamate dehydrogenase (GDH). GDH catalyzes the oxidative deamination of glutamate to alpha-ketoglutarate plus ammonia, using NAD or NADP as co-factor. HI/HA mutations impair GDH sensitivity to its allosteric inhibitor, GTP, resulting in a gain of enzyme function and increased sensitivity to its allosteric activator, leucine. The phenotype is dominated by hypoglycemia with post-prandial hypoglycemia following protein meals, as well as fasting hypoglycemia. Plasma ammonia levels are increased 3-5 times normal due to expression of mutant GDH in liver, probably reflecting increased ammonia release from glutamate as well as impaired synthesis of NAG, due to reduction of hepatic glutamate pools. Ammonia levels are unaffected by feeding or fasting and appear to cause no symptoms, perhaps due to a protective effect of increased GDH activity in brain. The clinical consequences of the HI/HA mutations imply that GDH plays a central role in overall control of amino acid catabolism and ammonia metabolism integrating responses to changes in intracellular energy potential and amino acid levels.

  10. Mechanisms of amino acid-stimulated insulin secretion in congenital hyperinsulinism

    Institute of Scientific and Technical Information of China (English)

    Tingting Zhang; Changhong Li

    2013-01-01

    The role of amino acids in the regulation of insulin secretion in pancreatic beta-cells is highlighted in three forms of congenital hyperinsulinism (HI),namely gain-of-function mutations of glutamate dehydrogenase (GDH),loss-of-function mutations of ATP-dependent potassium channels,and a deficiency of short-chain 3-hydroxyacyl-CoA dehydrogenase.Studies on disease mouse models of HI suggest that amino acid oxidation and signaling effects are the major mechanisms of amino acid-stimulated insulin secretion.Amino acid oxidation via GDH produces ATP and triggers insulin secretion.The signaling effect of amino acids amplifies insulin release after beta-cell depolarization and elevation of cytosolic calcium.

  11. L'apport d'un glossaire juridique

    OpenAIRE

    2014-01-01

    Le présent travail vise à obtenir une réponse à la problématique suivante : Quel est l'apport d'un glossaire juridique élaboré à partir de textes traduits au cours d'une formation de traduction juridique? Peut-il être utile à des étudiants débutant ladite formation ainsi qu'éventuellement à des jeunes diplômés?

  12. Persistent congenital hyperinsulinism in two patients with Beckwith-Wiedemann syndrome due to mosaic uniparental disomy 11p.

    Science.gov (United States)

    Zarate, Yuri A; Shur, Natasha; Robin, Andrew; Garnica, Adolfo D; Quintos, Jose Bernardo; Schaefer, G Bradley

    2014-09-01

    Congenital hyperinsulinism (CHI) is a rare metabolic disease characterized by inappropriate insulin secretion in the presence of hypoglycemia. We describe the clinical presentation and management of congenital hyperinsulinism and persistent hypoglycemia in two infants. Both patients had an initial clinical diagnosis of Beckwith-Wiedemann syndrome (BWS) but normal methylation analysis for LIT1 and H19 status. Both patients were eventually found to have mosaic uniparental disomy 11p diagnosed by single nucleotide polymorphism (SNP) array in DNA isolated from lymphoblasts and fibroblasts, respectively. We report that patients with mosaic BWS are at increased risk for both transient and refractory hypoglycemia that may need aggressive management with diazoxide, octreotide, high glucose infusion rates, and a frequent feeding regime. Our patient experience supports the case for pursuing further testing in patients with features of BWS with normal methylation studies, karyotype, and SNP arrays on blood. The next logical step is SNP array on skin biopsy to rule out mosaicism.

  13. Anorexia nervosa depends on adrenal sympathetic hyperactivity: opposite neuroautonomic profile of hyperinsulinism syndrome

    Directory of Open Access Journals (Sweden)

    Lechin F

    2010-09-01

    Full Text Available Fuad Lechin1,2, Bertha van der Dijs1,2, Betty Pardey-Maldonado1, Jairo E Rivera1, Scarlet Baez1, Marcel E Lechin31Department of Pathophysiology, Sections of Neuroendocrinology, Neuropharmacology, and Neurochemistry, Instituto de Medicina Experimental, Faculty of Medicine, Universidad Central de Venezuela, Caracas; 2Instituto de Vias Digestivas Caracas, Centro Clínico Profesional, Caracas, Venezuela; 3Department of Internal Medicine, Texas A and M Health Science Center, College of Medicine, Texas, USAObjective: The aim of our study was to determine the central and peripheral autonomic nervous system profiles underlying anorexia nervosa (AN syndrome, given that affected patients present with the opposite clinical profile to that seen in the hyperinsulinism syndrome.Design: We measured blood pressure and heart rate, as well as circulating neurotransmitters (noradrenaline, adrenaline, dopamine, plasma serotonin, and platelet serotonin, using high-performance liquid chromatography with electrochemical detection, during supine resting, one minute of orthostasis, and after five minutes of exercise. In total, 22 AN patients (12 binge-eating/purging type and 10 restricting type and age-, gender-, and race-matched controls (70 ± 10.1% versus 98 ± 3.0% of ideal body weight were recruited.Results: We found that patients with AN had adrenal sympathetic overactivity and neural sympathetic underactivity, demonstrated by a predominance of circulating adrenaline over noradrenaline levels, not only during the supine resting state (52 ± 2 versus 29 ± 1 pg/mL but also during orthostasis (67 ± 3 versus 32 ± 2 pg/mL, P < 0.05 and after exercise challenge (84 ± 4 versus 30 ± 3 pg/mL, P < 0.01.Conclusion: Considering that this peripheral autonomic nervous system disorder depends on the absolute predominance of adrenomedullary C1 adrenergic nuclei over A5 noradrenergic pontine nucleus, let us ratify the abovementioned findings. The AN syndrome depends on the

  14. Focal congenital hyperinsulinism in a patient with septo-optic dysplasia.

    Science.gov (United States)

    Padidela, Raja; Kapoor, Ritika R; Moyo, Yuva; Gilbert, Clare; Flanagan, Sarah E; Ellard, Sian; Hussain, Khalid

    2010-11-01

    An infant diagnosed as having hypopituitarism and on adequate hydrocortisone replacement therapy was referred to a tertiary endocrine unit at 5 weeks of age with persistent hypoglycemia that required a high rate of intravenous glucose infusion (up to 18 mg/kg•min⁻¹) to maintain euglycemia. A controlled hypoglycemia screen was performed to measure levels of plasma glucose, insulin, C-peptide and 3-β-hydroxybutyrate concentrations. The pancreas was analyzed by fluorine-18-L-3,4-dihydroxyphenylalanine ((18)F-DOPA) PET scan. Genetic analyses were performed on the peripheral blood leukocytes, and loss of heterozygosity within the resected focal lesion of the pancreas was investigated by microsatellite analysis. A glucagon stimulation test helped determine pituitary function, and an MRI of the brain and pituitary gland was performed to define the anatomy of the intracranial structures and the pituitary gland. Focal form of congenital hyperinsulinism localized to the head of the pancreas, septo-optic dysplasia and pituitary hormone deficiencies. Resection of the focal lesion from the head of the pancreas and hormonal replacement therapy for hypopituitarism.

  15. Dipeptidyl peptidase-4 expression in pancreatic tissue from patients with congenital hyperinsulinism.

    Science.gov (United States)

    Rahman, Sofia A; Senniappan, Senthil; Sherif, Maha; Tahir, Sophia; Hussain, Khalid

    2015-01-01

    Congenital hyperinsulinism (CHI) is caused by unregulated insulin release and leads to hyperinsulinaemic-hypoglycaemia (HH). Glucagon like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), peptide YY (PYY) and the enzyme; dipeptidyl peptidase-4 (DPP-4) all regulate appetite and glucose homeostasis. These proteins have been identified as possible contributors to HH but the mechanism remains poorly understood. We aimed to look at the expression pattern of pancreatic DPP-4 in children with focal and diffuse CHI (FCHI and DCHI, respectively). Using immunohistochemistry; we determined DPP-4 expression patterns in the pancreas of CHI patients. DPP-4 was found to be expressed in the pancreatic β, α and δ-cells in and around the focal area. However, it was predominantly co-localised with β-cells in the paediatric tissue samples. Additionally, proliferating β-cells expressed DPP-4 in DCHI, which was absent in the FCHI pancreas. Insulin was found to be present in the exocrine acini and duct cells of the DCHI pancreas suggestive of exocrine to endocrine transdifferentiation. Furthermore, 6 medically-unresponsive DCHI pancreatic samples showed an up-regulation of total pancreatic DPP-4 expression. In conclusion; the expression studies have shown DPP-4 to be altered in HH, however, further work is required to understand the underlying role for this enzyme.

  16. Long-term lanreotide treatment in six patients with congenital hyperinsulinism.

    Science.gov (United States)

    Kühnen, Peter; Marquard, Jan; Ernert, Andrea; Meissner, Thomas; Raile, Klemens; Wannenmacher, Gertrud; Blankenstein, Oliver

    2012-01-01

    Medical treatment is a substantial therapeutic measure to achieve glycemic control and prevent hypoglycemic brain damage without surgery in patients with congenital hyperinsulinism (CHI). However, only few drugs are available and even fewer are approved as a medical therapy to maintain normal blood glucose levels. The established therapies are demanding for caregivers and complicated by different side effects such as gastrointestinal symptoms, hypertrichosis, and obesity. Therefore, it is important to develop new strategies to improve blood glucose control. We report the use of the very-long-acting somatostatin analogue lanreotide autogel in 6 patients with CHI over a mean duration of 40.8 months. Blood glucose levels before and after the start and dosage titration of lanreotide in these patients are compared. In 3 of 6 patients, switching to lanreotide raised mean blood glucose levels and reduced individually as well as overall the risk for hypoglycemic episodes (odds ratio 0.38) significantly. Lanreotide autogel can be used as an alternative pharmacological treatment and may be beneficial in conservatively treated patients with CHI. Copyright © 2012 S. Karger AG, Basel.

  17. Fluoxetine-Induced Hypoglycaemia in a Patient with Congenital Hyperinsulinism on Lanreotide Therapy.

    Science.gov (United States)

    Giri, Dinesh; Price, Victoria; Yung, Zoe; Didi, Mohammed; Senniappan, Senthil

    2016-09-01

    Antidepressant drugs are reported to cause alterations in blood glucose homeostasis in adults with diabetes mellitus. We report a patient with persistent congenital hyperinsulinism (CHI) who developed recurrent hypoglycaemia following fluoxetine therapy. This 15-year-old girl was initially managed with diazoxide therapy. She developed troublesome hypertrichosis, which affected her quality of life adversely. Diazoxide was then slowly weaned and stopped with the introduction of octreotide, to which she responded well. Subcutaneous lanreotide (long-acting somatostatin analogue) was subsequently commenced (30 mg, once monthly) as injecting octreotide multiple times a day was proving to be difficult for the patient. The continuous blood glucose monitoring on monthly lanreotide injections revealed good glycaemic control. Six months later, she developed depression due to psychosocial problems at school. She was started on fluoxetine by the psychiatry team. She subsequently developed recurrent symptomatic hypoglycaemic episodes (blood glucose <3.5 mmol/L) and fluoxetine was discontinued, following which the hypoglycaemic episodes resolved within a week. Fluoxetine has been associated with hypoglycaemia in patients with diabetes mellitus. We report, for the first time, hypoglycaemia secondary to fluoxetine in a patient with CHI.

  18. Apports et limites des tâches web 2.0 dans un projet de télécollaboration asymétrique / Benefits and limitations of web 2.0 tasks in an asymmetrical tele-collaboration project

    Directory of Open Access Journals (Sweden)

    Charlotte Dejean-Thircuir

    2014-05-01

    Full Text Available Cet article se penche sur un échange en ligne lors duquel des étudiants de Master FLE (futurs enseignants de français ont fait réaliser une soixantaine de tâches d’apprentissage à distance à des apprenants chypriotes et lettons. Pour un tiers de ces tâches, qui constituent l’objet d’analyse, les étudiants de FLE ont fait appel à des applications du Web 2.0. L’article en propose d’abord une délimitation et une catégorisation. Puis il cherche à comprendre les raisons pour lesquelles ces tâches n’ont pas débouché sur des échanges avec le monde extérieur, ni même, dans certains cas, à une diffusion des productions finales ; il s’oriente pour cela vers la question du ou des destinataire(s des productions réalisées par les apprenants. This article focuses on an online exchange in which students in a Master FLE (French as a Foreign Language class (future French language teachers asked Cypriot and Latvian French-language learners to complete sixty distance-learning tasks. One third of these tasks, which are the focus of this article, used Web 2.0 applications. The article first describes and categorizes the tasks. Then it tries to understand why these tasks have not led to the expected interactions with a wider online audience nor to the anticipated dissemination of the content developed by the learners. It (continues concludes by exploring the question of who are the intended recipient(s of the content produced by these learners.

  19. Abnormal neurodevelopmental outcomes are common in children with transient congenital hyperinsulinism

    Directory of Open Access Journals (Sweden)

    Bindu Hima Avatapalle

    2013-05-01

    Full Text Available Introduction: Neuroglycopaenia is recognised to be associated with abnormal neurodevelopmental outcomes in 26-44% of children with persistent congenital hyperinsulinism (P-CHI. The prevalence of abnormal neurodevelopment in transient CHI (T-CHI is not known. We have aimed to investigate abnormal neurodevelopment and associated factors in T-CHI and P-CHI. Materials and Methods: A cohort of children with CHI (n=67, age 2.5-5 years was assessed at follow up review and noted to have normal or abnormal (mild or severe neurodevelopmental outcomes for the domains of speech and language, motor and vision. Children were classified as P-CHI (n=33, if they had undergone surgery or remained on medical therapy, or T-CHI (n=34, if medical treatment for hypoglycaemia was stopped. Results: Overall, abnormal neurodevelopment was present in 26 (39% children with CHI, of whom 18 (69% were severe. Importantly, the incidence of abnormal neurodevelopment in T-CHI was similar to that in P-CHI (30% v 47% respectively, p=0.16. The prevalence of severe abnormal neurodevelopment in speech, motor and vision domains was similar in both T-CHI and P-CHI children. For this cohort, we found that the severity of disease (based upon maximal diazoxide dose, [odds ratio (95% confidence intervals 1.3 (1.1;1.5, p=0.03] and early presentation of CHI <7 days following birth [5.9 (1.3;27.8, p=0.02] were significantly associated with abnormal neurodevelopment. There was no significant association with gender, genotype or the histopathological basis of CHI. Conclusions: Abnormal neurodevelopment was evident in one third of children with both T-CHI and P-CHI, early presentation and severe CHI being risk factors. Early recognition and rapid correction of hypoglycaemia are advocated to avoid abnormal neurodevelopment in children with CHI.

  20. Focal congenital hyperinsulinism managed by medical treatment: a diagnostic algorithm based on molecular genetic screening.

    Science.gov (United States)

    Maiorana, Arianna; Barbetti, Fabrizio; Boiani, Arianna; Rufini, Vittoria; Pizzoferro, Milena; Francalanci, Paola; Faletra, Flavio; Nichols, Colin G; Grimaldi, Chiara; de Ville de Goyet, Jean; Rahier, Jacques; Henquin, Jean-Claude; Dionisi-Vici, Carlo

    2014-11-01

    Congenital hyperinsulinism (CHI) requires rapid diagnosis and treatment to avoid irreversible neurological sequelae due to hypoglycaemia. Aetiological diagnosis is instrumental in directing the appropriate therapy. Current diagnostic algorithms provide a complete set of diagnostic tools including (i) biochemical assays, (ii) genetic facility and (iii) state-of-the-art imaging. They consider the response to a therapeutic diazoxide trial an early, crucial step before proceeding (or not) to specific genetic testing and eventually imaging, aimed at distinguishing diffuse vs focal CHI. However, interpretation of the diazoxide test is not trivial and can vary between research groups, which may lead to inappropriate decisions. Objective of this report is proposing a new algorithm in which early genetic screening, rather than diazoxide trial, dictates subsequent clinical decisions. Two CHI patients weaned from parenteral glucose infusion and glucagon after starting diazoxide. No hypoglycaemia was registered during a 72-h continuous glucose monitoring (CGMS), or hypoglycaemic episodes were present for no longer than 3% of 72-h. Normoglycaemia was obtained by low-medium dose diazoxide combined with frequent carbohydrate feeds for several years. We identified monoallelic, paternally inherited mutations in KATP channel genes, and (18) F-DOPA PET-CT revealed a focal lesion that was surgically resected, resulting in complete remission of hypoglycaemia. Although rare, some patients with focal lesions may be responsive to diazoxide. As a consequence, we propose an algorithm that is not based on a 'formal' diazoxide response but on genetic testing, in which patients carrying paternally inherited ABCC8 or KCNJ11 mutations should always be subjected to (18) F-DOPA PET-CT. © 2014 John Wiley & Sons Ltd.

  1. Vineland adaptive behavior scales to identify neurodevelopmental problems in children with Congenital Hyperinsulinism (CHI).

    Science.gov (United States)

    Salomon-Estebanez, Maria; Mohamed, Zainab; Michaelidou, Maria; Collins, Hannah; Rigby, Lindsey; Skae, Mars; Padidela, Raja; Rust, Stewart; Dunne, Mark; Cosgrove, Karen; Banerjee, Indraneel; Nicholson, Jacqueline

    2017-05-22

    Congenital Hyperinsulinism (CHI) is a disease of severe hypoglycaemia caused by excess insulin secretion and associated with adverse neurodevelopment in a third of children. The Vineland Adaptive Behavior Scales Second Edition (VABS-II) is a parent report measure of adaptive functioning that could be used as a developmental screening tool in patients with CHI. We have investigated the performance of VABS-II as a screening tool to identify developmental delay in a relatively large cohort of children with CHI. VABS-II questionnaires testing communication, daily living skills, social skills, motor skills and behaviour domains were completed by parents of 64 children with CHI, presenting both in the early neonatal period (Early-CHI, n = 48) and later in infancy (Late-CHI, n = 16). Individual and adaptive composite (Total) domain scores were converted to standard deviation scores (SDS). VABS-II scores were tested for correlation with objective developmental assessment reported separately by developmental paediatricians, clinical and educational psychologists. VABS-II scores were also investigated for correlation with the timing of hypoglycaemia, gender and phenotype of CHI. Median (range) total VABS-II SDS was low in CHI [-0.48 (-3.60, 4.00)] with scores VABS-II Total scores correctly identified developmental delay diagnosed by objective assessment in the majority [odds ratio (OR) (95% confidence intervals, CI) 0.52 (0.38, 0.73), p VABS-II Total scores were inversely correlated (adjusted R(2) = 0.19, p = 0.001) with age at presentation (p = 0.024) and male gender (p = 0.036), males having lower scores than females in those with Late-CHI [-1.40 (-3.60, 0.87) v 0.20 (-1.07, 1.27), p = 0.014]. The presence of a genetic mutation representing severe CHI also predicted lower scores (R(2) = 0.19, p = 0.039). The parent report VABS-II is a reliable and specific tool to identify developmental delay in CHI patients. Male gender, later age

  2. Treatment with long-acting lanreotide autogel in early infancy in patients with severe neonatal hyperinsulinism.

    Science.gov (United States)

    Corda, Heike; Kummer, Sebastian; Welters, Alena; Teig, Norbert; Klee, Dirk; Mayatepek, Ertan; Meissner, Thomas

    2017-06-02

    Treatment of severe diffuse congenital hyperinsulinism (CHI) without sufficient response to diazoxide is complicated by the lack of approved drugs. Therefore, patients are often hospitalized long-term or have to undergo pancreatic surgery if episodes of severe hypoglycaemia cannot be prevented. A long-acting somatostatin analogue, octreotide, has been reported to be an effective treatment option that prevents severe hypoglycaemia in children with CHI, and its off-label use is common in CHI. However, octreotide requires continuous i.v. or s.c. infusion or multiple daily injections. Here, we report our experiences with the use of a monthly application of a long-acting somatostatin analogue, lanreotide autogel® (LAN-ATG), in early infancy. The mean blood glucose concentration within 7 days before the first LAN-ATG administration were compared to 7 days after the first LAN-ATG administration and increased by 0.75 mmol/L (range 0.39-1.19 mmol/L). In the following weeks intravenous glucose infusions, octreotide, and glucagon treatment could be successfully stopped in all patients 3-20 days after the first LAN-ATG injection without substantial worsening of the hypoglycaemia rate. Increased carbohydrate requirements could be normalized with an average reduction in the carbohydrate-intake of 7 g/kg body weight/d (range 1.75-12.8 g/kg body weight/d). Over a total of 52 treatment months, no serious adverse effects occurred. Long-term LAN-ATG treatment improved blood glucose concentrations, lowered the frequency of hypoglycaemia or allowed for normalization of oral carbohydrate intake in infants with CHI younger than 6 months of age. No severe side effects were observed. LAN-ATG might be an alternative treatment option in infants with severe CHI who lack risk factors for necrotizing enterocolitis and are not responding to current treatment regimens as an alternative to surgery after careful individual evaluation.

  3. Mechanism of Hyperinsulinism in Short-chain 3-Hydroxyacyl-CoA Dehydrogenase Deficiency Involves Activation of Glutamate Dehydrogenase*

    Science.gov (United States)

    Li, Changhong; Chen, Pan; Palladino, Andrew; Narayan, Srinivas; Russell, Laurie K.; Sayed, Samir; Xiong, Guoxiang; Chen, Jie; Stokes, David; Butt, Yasmeen M.; Jones, Patricia M.; Collins, Heather W.; Cohen, Noam A.; Cohen, Akiva S.; Nissim, Itzhak; Smith, Thomas J.; Strauss, Arnold W.; Matschinsky, Franz M.; Bennett, Michael J.; Stanley, Charles A.

    2010-01-01

    The mechanism of insulin dysregulation in children with hyperinsulinism associated with inactivating mutations of short-chain 3-hydroxyacyl-CoA dehydrogenase (SCHAD) was examined in mice with a knock-out of the hadh gene (hadh−/−). The hadh−/− mice had reduced levels of plasma glucose and elevated plasma insulin levels, similar to children with SCHAD deficiency. hadh−/− mice were hypersensitive to oral amino acid with decrease of glucose level and elevation of insulin. Hypersensitivity to oral amino acid in hadh−/− mice can be explained by abnormal insulin responses to a physiological mixture of amino acids and increased sensitivity to leucine stimulation in isolated perifused islets. Measurement of cytosolic calcium showed normal basal levels and abnormal responses to amino acids in hadh−/− islets. Leucine, glutamine, and alanine are responsible for amino acid hypersensitivity in islets. hadh−/− islets have lower intracellular glutamate and aspartate levels, and this decrease can be prevented by high glucose. hadh−/− islets also have increased [U-14C]glutamine oxidation. In contrast, hadh−/− mice have similar glucose tolerance and insulin sensitivity compared with controls. Perifused hadh−/− islets showed no differences from controls in response to glucose-stimulated insulin secretion, even with addition of either a medium-chain fatty acid (octanoate) or a long-chain fatty acid (palmitate). Pull-down experiments with SCHAD, anti-SCHAD, or anti-GDH antibodies showed protein-protein interactions between SCHAD and GDH. GDH enzyme kinetics of hadh−/− islets showed an increase in GDH affinity for its substrate, α-ketoglutarate. These studies indicate that SCHAD deficiency causes hyperinsulinism by activation of GDH via loss of inhibitory regulation of GDH by SCHAD. PMID:20670938

  4. Mechanism of hyperinsulinism in short-chain 3-hydroxyacyl-CoA dehydrogenase deficiency involves activation of glutamate dehydrogenase.

    Science.gov (United States)

    Li, Changhong; Chen, Pan; Palladino, Andrew; Narayan, Srinivas; Russell, Laurie K; Sayed, Samir; Xiong, Guoxiang; Chen, Jie; Stokes, David; Butt, Yasmeen M; Jones, Patricia M; Collins, Heather W; Cohen, Noam A; Cohen, Akiva S; Nissim, Itzhak; Smith, Thomas J; Strauss, Arnold W; Matschinsky, Franz M; Bennett, Michael J; Stanley, Charles A

    2010-10-01

    The mechanism of insulin dysregulation in children with hyperinsulinism associated with inactivating mutations of short-chain 3-hydroxyacyl-CoA dehydrogenase (SCHAD) was examined in mice with a knock-out of the hadh gene (hadh(-/-)). The hadh(-/-) mice had reduced levels of plasma glucose and elevated plasma insulin levels, similar to children with SCHAD deficiency. hadh(-/-) mice were hypersensitive to oral amino acid with decrease of glucose level and elevation of insulin. Hypersensitivity to oral amino acid in hadh(-/-) mice can be explained by abnormal insulin responses to a physiological mixture of amino acids and increased sensitivity to leucine stimulation in isolated perifused islets. Measurement of cytosolic calcium showed normal basal levels and abnormal responses to amino acids in hadh(-/-) islets. Leucine, glutamine, and alanine are responsible for amino acid hypersensitivity in islets. hadh(-/-) islets have lower intracellular glutamate and aspartate levels, and this decrease can be prevented by high glucose. hadh(-/-) islets also have increased [U-(14)C]glutamine oxidation. In contrast, hadh(-/-) mice have similar glucose tolerance and insulin sensitivity compared with controls. Perifused hadh(-/-) islets showed no differences from controls in response to glucose-stimulated insulin secretion, even with addition of either a medium-chain fatty acid (octanoate) or a long-chain fatty acid (palmitate). Pull-down experiments with SCHAD, anti-SCHAD, or anti-GDH antibodies showed protein-protein interactions between SCHAD and GDH. GDH enzyme kinetics of hadh(-/-) islets showed an increase in GDH affinity for its substrate, α-ketoglutarate. These studies indicate that SCHAD deficiency causes hyperinsulinism by activation of GDH via loss of inhibitory regulation of GDH by SCHAD.

  5. Les apports nutritionnels conseillés (ANC en protéines

    Directory of Open Access Journals (Sweden)

    Patureau mirand Philippe

    2003-01-01

    Full Text Available La définition d’apports conseillés en protéines repose sur l’analyse des besoins protéiques. Un ANC avec comme objectif mesuré le maintien de la masse des protéines corporelles, a été fixé à 0,8 g de protéines de bonne qualité par kg de poids et par jour. Toutefois le besoin protéique est beaucoup plus complexe en raison de la diversité de la nature des nutriments requis pour le satisfaire (azote, acides aminés, peptides, protéines et de la multiplicité de leurs fonctions. L’ANC en protéines intègre en grande partie cette diversité et constitue un repère simple qui permet de s’assurer globalement de la couverture des besoins protéiques d’une large population. Sa simplicité en limite cependant la pertinence pour des sous-populations ayant des besoins plus spécifiques.

  6. Limiter

    Science.gov (United States)

    Cohen, S.A.; Hosea, J.C.; Timberlake, J.R.

    1984-10-19

    A limiter with a specially contoured front face is provided. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution. This limiter shape accommodates the various power scrape-off distances lambda p, which depend on the parallel velocity, V/sub parallel/, of the impacting particles.

  7. Apport de l’ethnicité à la culture en sciences de gestion

    OpenAIRE

    Vassili Joannides

    2011-01-01

    (VF)Cet article part des critiques de Bhimani (1999), Baskerville (2003) et Hofstede (2003) adressées à l’utilisation du modèle développé par Hofstede (1980, 2001) pour appréhender la culture. Ces critiques soulignent qu’étudier l’ethnicité dans un cadre plus souple permettrait une compréhension plus fine des outils et pratiques de gestion. Ainsi, cet article vise à évaluer les apports de l’ethnicité aux sciences de gestion via l’analyse de vingt publications en contrôle. Ses apports sont : u...

  8. Apports de la simulation multi-agents à l’étude des processus de diffusion

    Directory of Open Access Journals (Sweden)

    Eric Daudé

    2004-02-01

    Full Text Available Cet article présente les principaux apports d’une approche individu-centrée pour modéliser et simuler les processus de diffusion dans l’espace géographique. L’intérêt d’une telle approche est discuté au regard des limites d’une modélisation d'échelle macro-géographique traditionnellement employée pour décrire de tels phénomènes. L’équation logistique est présentée comme un exemple représentatif de cette catégorie de modèle. Les modèles de simulation à base d’agents représentent une alternative possible à une approche macro-géographique des phénomènes de diffusion. Associés aux théories de l’auto-organisation, on postule que les phénomènes observés à un certain niveau sont le résultat des nombreuses interactions qui se produisent à un ou plusieurs niveaux inférieurs. En tant qu’outil de simulation prédisposé à l’analyse de telles dynamiques, les systèmes multi-agents sont brièvement présentés. Cet article se termine par une application, la modélisation et la simulation de la diffusion d’une innovation agricole (le modèle d'Hägerstrand revisité.

  9. Sar1-GTPase-dependent ER exit of KATP channels revealed by a mutation causing congenital hyperinsulinism

    DEFF Research Database (Denmark)

    Taneja, Tarvinder K; Mankouri, Jamel; Karnik, Rucha

    2009-01-01

    The ATP-sensitive potassium (K(ATP)) channel controls insulin secretion by coupling glucose metabolism to excitability of the pancreatic beta-cell membrane. The channel comprises four subunits each of Kir6.2 and the sulphonylurea receptor (SUR1), encoded by KCNJ11 and ABCC8, respectively. Mutations...... in these genes that result in reduced activity or expression of K(ATP) channels lead to enhanced beta-cell excitability, insulin hypersecretion and hypoglycaemia, and in humans lead to the clinical condition congenital hyperinsulinism (CHI). Here we have investigated the molecular basis of the focal form of CHI...... caused by one such mutation in Kir6.2, E282K. The study led to the discovery that Kir6.2 contains a di-acidic ER exit signal, (280)DLE(282), which promotes concentration of the channel into COPII-enriched ER exit sites prior to ER export via a process that requires Sar1-GTPase. The E282K mutation...

  10. Next-Generation Sequencing Reveals Deep Intronic Cryptic ABCC8 and HADH Splicing Founder Mutations Causing Hyperinsulinism by Pseudoexon Activation

    Science.gov (United States)

    Flanagan, Sarah E.; Xie, Weijia; Caswell, Richard; Damhuis, Annet; Vianey-Saban, Christine; Akcay, Teoman; Darendeliler, Feyza; Bas, Firdevs; Guven, Ayla; Siklar, Zeynep; Ocal, Gonul; Berberoglu, Merih; Murphy, Nuala; O’Sullivan, Maureen; Green, Andrew; Clayton, Peter E.; Banerjee, Indraneel; Clayton, Peter T.; Hussain, Khalid; Weedon, Michael N.; Ellard, Sian

    2013-01-01

    Next-generation sequencing (NGS) enables analysis of the human genome on a scale previously unachievable by Sanger sequencing. Exome sequencing of the coding regions and conserved splice sites has been very successful in the identification of disease-causing mutations, and targeting of these regions has extended clinical diagnostic testing from analysis of fewer than ten genes per phenotype to more than 100. Noncoding mutations have been less extensively studied despite evidence from mRNA analysis for the existence of deep intronic mutations in >20 genes. We investigated individuals with hyperinsulinaemic hypoglycaemia and biochemical or genetic evidence to suggest noncoding mutations by using NGS to analyze the entire genomic regions of ABCC8 (117 kb) and HADH (94 kb) from overlapping ∼10 kb PCR amplicons. Two deep intronic mutations, c.1333-1013A>G in ABCC8 and c.636+471G>T HADH, were identified. Both are predicted to create a cryptic splice donor site and an out-of-frame pseudoexon. Sequence analysis of mRNA from affected individuals’ fibroblasts or lymphoblastoid cells confirmed mutant transcripts with pseudoexon inclusion and premature termination codons. Testing of additional individuals showed that these are founder mutations in the Irish and Turkish populations, accounting for 14% of focal hyperinsulinism cases and 32% of subjects with HADH mutations in our cohort. The identification of deep intronic mutations has previously focused on the detection of aberrant mRNA transcripts in a subset of disorders for which RNA is readily obtained from the target tissue or ectopically expressed at sufficient levels. Our approach of using NGS to analyze the entire genomic DNA sequence is applicable to any disease. PMID:23273570

  11. Données récentes sur les apports en acides gras des Français

    Directory of Open Access Journals (Sweden)

    Tressou Jessica

    2016-05-01

    Full Text Available L’Anses a mis à disposition en accès libre en septembre 2014 l’ensemble des données brutes obtenues dans l’étude individuelle nationale sur les consommations alimentaires 2006–2007 (INCA 2. Terres Univia, a fait réaliser une étude statistique détaillée des apports en acides gras de la population française et de la place des matières grasses végétales dans ces apports. Ces apports ont pu être comparés aux apports nutritionnels conseillés (ANC pour les acides gras définis par l’Anses en mars 2010. L’étude révèle que, pour la population adulte, l’apport total moyen quotidien en lipides est de 38,0 % de l’apport énergétique total sans alcool (AESA, ce qui est conforme aux ANC (35–40 % de l’AESA. Pour autant, l’analyse détaillée montre que l’apport de certains acides gras est parfois éloigné des valeurs recommandées par l’Anses. Il est donc important de savoir choisir ses matières grasses. En septembre 2015, l’Anses a publié son propre rapport sur les apports en acides gras de la population vivant en France et leur comparaison aux ANC 2010. Les résultats de l’Anses sont semblables à ceux de Terres Univia.

  12. Evaluation d'un ecosysteme pastoral sahelien: Apport de la geomatique (Oursi, Burkina Faso)

    Science.gov (United States)

    Kabore, Seraphine Sawadogo

    L'objectif principal de cette recherche est la mise au point d'une architecture d'integration de donnees socio-bio-geographiques et de donnees satellitales dans un Systeme d'Information Geographique (SIG) en vue d'une aide a la prise de decisions dans un environnement semi-aride au nord du Burkina Faso. Elle repond a la question fondamentale de l'interpretation des effets des facteurs climatiques et socioeconomiques sur le milieu pastoral. La recherche s'est appuyee sur plusieurs hypotheses de travail: possibilite d'utilisation de modele de simulation, d'approche multicritere et de donnees de teledetection dans un cadre de systeme d'information geographique. L'evolution spatiotemporelle des parametres de productivite du milieu a ete evaluee par approche dynamique selon le modele de Wu et al. (1996) qui modelise les interactions entre le climat, le milieu physique, le vegetal et l'animal pour mieux quantifier la biomasse primaire. A ce modele, quatre parametres ont ete integres par approche floue et multicritere afin de prendre en compte la dimension socioeconomique de la productivite pastorale (apport majeur de la recherche): la sante, l'education, l'agriculture et l'eau. La teledetection (imagerie SPOT) a permis de definir la production primaire a partir de laquelle les simulations ont ete realisees sur 10 annees. Les resultats obtenus montrent une bonne correlation entre biomasse primaire in situ et celle calculee pour les deux modeles, avec toutefois une meilleure efficacite du modele modifie (4 fois plus) dans les zones de forte productivite ou l'on note un taux de surexploitation agricole eleve. A cause de la variabilite spatiale de la production primaire in situ, les erreurs des resultats de simulation (8 a 11%) sont acceptables et montrent la pertinence de l'approche grace a l'utilisation des SIG pour la spatialisation et l'integration des differents parametres des modeles. Les types de production secondaire preconises (production de lait pendant 7 mois ou

  13. Les agendas 21 locaux : quels apports sous quelles latitudes ?

    Directory of Open Access Journals (Sweden)

    Cyria Emelianoff

    2005-05-01

    Full Text Available Since the Rio conference, several thousands local agendas 21 have assisted the penetration of the concept of sustainable development at the local level. This article presents a synthesis of the approaches employed by local authorities in 9 European countries, with an emphasis on the benefits and limitations presented by the local agendas 21 in place. We characterised the specificities of French local authorities and determined the geographical dimensions of the mobilisation in favour of local agendas 21.

  14. Value of {sup 18}F-fluoro-L-dopa PET in the Preoperative Localization of Focal Lesions in Congenital Hyperinsulinism

    Energy Technology Data Exchange (ETDEWEB)

    Capito, C.; Khen-Dunlop, N.; Brunelle, F.; Aigrain, Y.; Cretolle, C.; Jaubert, F.; De Lonlay, P.; Nihoul-Fekete, C. [Necker-Enfants Malades Hospital, AP-HP, 149 rue de Sevres 75015 Paris (France); Ribeiro, M.J. [Biomedical Imaging Institute, Life Sciences Division CEA, Frederic Joliot Hospital, Orsay (France)

    2009-07-01

    Purpose: To retrospectively compare fluorine 18 ({sup 18}F) fluoro-L-dopa positron emission tomography (PET) and pancreatic venous sampling (PVS) in the preoperative differentiation of diffuse from focal congenital hyperinsulinism (CHI) and localization of focal lesions. Materials and Methods: This study was approved by the institutional ethical committee, and informed consent for the research study was obtained from the parents of all subjects. Fifty-one patients evaluated for focal CHI between January 1, 1995, and January 31, 2008, were included. Thirty five underwent PVS evaluation alone, and 16 underwent a PET evaluation alone. The sensitivity values of each technique for the diagnosis and localization of focal lesions were compared in regard to results of surgery and pathologic analyses. In each patient, perioperative treatment was reviewed, and the presence of postoperative hypoglycemia was assessed as evidence of incomplete resection. Comparisons of the sensitivity values and recurrence rates were performed by using the Fisher exact test in regard to the number of patients. Comparisons of median age, weight, or number of biopsies were performed with a two-tailed unpaired Mann-Whitney U test. A difference with P {<=}.05 was considered significant. Results: For PVS and PET groups, there was no error in differentiating focal from diffuse forms. PVS was not completed in four of 35 patients. In 27 (87%) of 31 patients in whom PVS was completed and 13 (81%) of 16 patients in whom PET was completed, preoperative localization of the focal lesion was in accordance with the surgical findings (P =.7). Although not significant, the number of biopsies performed before discovering the focal lesion was higher in the PET group compared with the PVS group (P .06). Inadequate localization occurred in two (6%) patients in the PVS group and five (31%) patients in the PET group at initial preoperative imaging study; these patients underwent repeat surgery for residual CHI (P

  15. Comment augmenter l’apport nutritionnel en acides gras n-3 ?

    Directory of Open Access Journals (Sweden)

    Legrand Philippe

    2004-01-01

    Full Text Available Le statut nutritionnel des français en acide gras n-3 indique une insuffisance par rapport aux apports nutritionnels conseillés (ANC. Pour orienter les stratégies nutritionnelles et industrielles, il faut connaître la biosynthèse et la disponibilité métabolique des acides gras n-3. La biosynthèse des acides gras polyinsaturés n-3 à très longue chaîne (EPA, DHA se fait par une succession de désaturations et d’élongations, à partir de l’acide α-linolénique. Les étapes de désaturation sont considérées comme limitantes et portent le poids des régulations. Le précurseur indispensable l’acide α-linolénique est apporté en quantité insuffisante et il est un excellent substrat de la β-oxydation, donc peu disponible pour la voie de synthèse des dérivés n-3, elle-même variablement mais très faiblement active. De plus, les désaturases étant communes pour les voies n-3 et n-6, la présence surabondante des acides gras n-6 constitue une inhibition compétitive pour la synthèse des dérivés n-3. Afin d’augmenter l’apport nutritionnel en acides gras n-3, il faut considérer tous les acides gras n-3 et pas seulement le précurseur ou seulement les dérivés, car tous ont des rôles spécifiques. L’alimentation doit être variée, mais doit inclure les huiles riches en acide α-linolénique (colza, soja, noix pour l’apport de précurseur et le poisson gras pour les très longues chaînes. Devant le constat net d’insuffisance des apports en acides gras n-3, l’usage du vecteur animal est à étudier, à optimiser, à valoriser avec finesse, et à encadrer depuis les pratiques d’élevage jusqu’aux allégations et recommandations. À titre d’exemple, l’apport du lin en alimentation animale constitue ensuite une source d’acides gras n-3 pour l’homme, en incluant le précurseur et les dérivés.

  16. The added value of [{sup 18}F]fluoro-L-DOPA PET in the diagnosis of hyperinsulinism of infancy: a retrospective study involving 49 children

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Maria-Joao; Bourgeois, Sandrine; Delzescaux, Thierry [Frederic Joliot Hospital, Biomedical Imaging Institute, Life Sciences Division, CEA, Orsay (France); Boddaert, Nathalie; Brunelle, Francis [Necker-Enfants Malades Hospital, AP-HP, Department of Radiology, Paris (France); Bellanne-Chantelot, Christine [Saint-Antoine Hospital, AP-HP, Department of Cytogenetics, Paris (France); Valayannopoulos, Vassili; Lonlay, Pascale de [Necker-Enfants Malades Hospital, AP-HP, Department of Pediatrics, Paris (France); Jaubert, Francis [Necker-Enfants Malades Hospital, AP-HP, Department of Pathology, Paris (France); Nihoul-Fekete, Claire [Necker-Enfants Malades Hospital, AP-HP, Department of Surgery, Paris (France)

    2007-12-15

    Neuroendocrine diseases are a heterogeneous group of entities with the ability to take up amine precursors, such as L-DOPA, and convert them into biogenic amines, such as dopamine. Congenital hyperinsulinism of infancy (HI) is a neuroendocrine disease secondary to either focal adenomatous hyperplasia or a diffuse abnormal pancreatic insulin secretion. While focal hyperinsulinism may be reversed by selective surgical resection, diffuse forms require near-total pancreatectomy when resistant to medical treatment. Here, we report the diagnostic value of PET with [{sup 18}F]fluoro-L-DOPA in distinguishing focal from diffuse HI. Forty-nine children were studied with [{sup 18}F]fluoro-L-DOPA. A thoraco-abdominal scan was acquired 45-65 min after the injection of 4.2 {+-} 1.0 MBq/kg of [{sup 18}F]fluoro-L-DOPA. Additionally, 12 of the 49 children were submitted to pancreatic venous catheterisation for blood samples (PVS) and 31 were also investigated using MRI. We identified abnormal focal pancreatic uptake of [{sup 18}F]fluoro-L-DOPA in 15 children, whereas diffuse radiotracer uptake was observed in the pancreatic area in the other 34 patients. In children studied with both PET and PVS, the results were concordant in 11/12 cases. All patients with focal radiotracer uptake and nine of the patients with diffuse pancreatic radiotracer accumulation, unresponsive to medical treatment, were submitted to surgery. In 21 of these 24 patients, the histopathological results confirmed the PET findings. In focal forms, selective surgery was followed by clinical remission without carbohydrate intolerance. These data demonstrate that PET with [{sup 18}F]fluoro-L-DOPA is an accurate non-invasive technique allowing differential diagnosis between focal and diffuse forms of HI. (orig.)

  17. A propos des apports nutritionnels conseillés (ANC en lipides

    Directory of Open Access Journals (Sweden)

    Legrand Philippe

    2001-01-01

    Full Text Available Les apports nutritionnels conseillés (ANC qui viennent d’être publiés sont le fruit d’un long travail collectif ayant impliqué près de cent auteurs [1]. En ce qui concerne les lipides, la commission était composée de cinq personnes : J.-M. Bourre, B. Descomps, G. Durand, S. Renaud et P. Legrand. Par rapport à l’édition antérieure (1992, il a été demandé de traiter non seulement les acides gras essentiels mais également les acides gras saturés, mono-insaturés, le cholestérol, etc., et la part des lipides dans l’apport calorique. En complément, une approche par groupe d’âge et/ou statut physiologique est également présentée (nouveau-né, femme enceinte ou allaitante, personne âgée. Sans être révolutionnaires, ces nouveaux ANC proposent plusieurs grandes orientations dictées par l’état des connaissances scientifiques.

  18. Comment augmenter l’apport nutritionnel en acides gras n-3 ?

    OpenAIRE

    Legrand Philippe

    2004-01-01

    Le statut nutritionnel des français en acide gras n-3 indique une insuffisance par rapport aux apports nutritionnels conseillés (ANC). Pour orienter les stratégies nutritionnelles et industrielles, il faut connaître la biosynthèse et la disponibilité métabolique des acides gras n-3. La biosynthèse des acides gras polyinsaturés n-3 à très longue chaîne (EPA, DHA) se fait par une succession de désaturations et d’élongations, à partir de l’acide α-linolénique. Les étapes de désaturation sont con...

  19. Congenital hyperinsulinism in an infant with paternal uniparental disomy on chromosome 11p15: few clinical features suggestive of Beckwith-Wiedemann syndrome.

    Science.gov (United States)

    Adachi, Hiroyuki; Takahashi, Ikuko; Higashimoto, Ken; Tsuchida, Satoko; Noguchi, Atsuko; Tamura, Hiroaki; Arai, Hirokazu; Ito, Tomoo; Masue, Michiya; Nishibori, Hironori; Takahashi, Tsutomu; Soejima, Hidenobu

    2013-01-01

    Beckwith-Wiedemann syndrome (BWS) is the most common congenital overgrowth syndrome involving tumor predisposition. BWS is caused by various epigenetic or genetic alterations that disrupt the imprinted genes on chromosome 11p15.5 and the clinical findings of BWS are highly variable. Hyperinsulinemic hypoglycemia is reported in about half of all babies with BWS. We identified an infant with diazoxide-unresponsive congenital hyperinsulinism (HI) without any apparent clinical features suggestive of BWS, but diagnosed BWS by molecular testing. The patient developed severe hyperinsulinemic hypoglycemia within a few hours after birth, with macrosomia and mild hydronephrosis. We excluded mutations in the K(ATP) channel genes on chromosome 11p15.1, but found a rare homozygous single nucleotide polymorphism (SNP) of ABCC8. Parental SNP pattern suggested paternal uniparetal disomy in this region. By microsatellite marker analysis on chromosome 11p15, we could diagnose BWS due to the mosaic of paternal uniparental disomy. Our case suggests that some HI of unknown genetic etiology could involve undiagnosed BWS with no apparent clinical features, which might be diagnosed only by molecular testing.

  20. Diagnostic performance of fluorine-18-dihydroxyphenylalanine positron emission tomography in diagnosing and localizing the focal form of congenital hyperinsulinism: a meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Treglia, Giorgio; Giordano, Alessandro; Rufini, Vittoria [Catholic University of the Sacred Heart, Institute of Nuclear Medicine, Rome (Italy); Mirk, Paoletta [Catholic University of the Sacred Heart, Institute of Radiology, Rome (Italy)

    2012-11-15

    We performed a meta-analysis on published data on the diagnostic performance of fluorine-18 dihydroxyphenylalanine ({sup 18}F-DOPA) positron emission tomography (PET) in diagnosing and localizing focal congenital hyperinsulinism (CHI). A comprehensive computer literature search of studies published up to 31 January 2012 regarding {sup 18}F-DOPA PET or PET/CT in patients with CHI was performed. Pooled sensitivity and specificity, area under the ROC curve and diagnostic odds ratio (DOR) of {sup 18}F-DOPA PET or PET/CT in diagnosing focal CHI were calculated. The localization accuracy of focal CHI was also estimated. Seven studies comprising 195 CHI patients were included. The pooled sensitivity and specificity of {sup 18}F-DOPA PET or PET/CT in differentiating between focal and diffuse CHI were 89% (95% confidence interval [CI]:81-95%) and 98% (95% CI:89-100%), respectively. The DOR was 74.5 (95% CI:18-307). The area under the ROC curve was 0.95. The pooled accuracy of these functional imaging methods in localizing focal CHI was 80% (95% CI:71-88%). In CHI patients, {sup 18}F-DOPA PET or PET/CT demonstrated high sensitivity and specificity in differentiating between focal and diffuse CHI. {sup 18}F-DOPA PET or PET/CT are accurate methods of localizing focal CHI. Nevertheless, possible sources of false-negative results for focal CHI should be kept in mind. (orig.)

  1. Use of Long-Acting Somatostatin Analogue (Lanreotide) in an Adolescent with Diazoxide-Responsive Congenital Hyperinsulinism and Its Psychological Impact.

    Science.gov (United States)

    Shah, Pratik; Rahman, Sofia A; McElroy, Sharon; Gilbert, Clare; Morgan, Kate; Hinchey, Louise; Senniappan, Senthil; Levy, Hannah; Amin, Rakesh; Hussain, Khalid

    2015-01-01

    Congenital hyperinsulinism (CHI) is a common cause of hypoglycaemia due to unregulated insulin secretion from pancreatic β cells. Medical management includes use of oral diazoxide (a KATP channel agonist) and daily injectable octreotide (somatostatin analogue) therapy. However, diazoxide is associated with severe sideeffects such as coarse facies, hypertrichosis and psychosocial/compliance issues in adolescents. Lanreotide (a long-acting somatostatin analogue) is used in adults with neuroendocrine tumours; however, its role in patients with CHI has not been well described. A 15-year-old girl with diazoxide-responsive CHI had severe hypertrichosis secondary to diazoxide and subsequent compliance/psychosocial issues. She was commenced on 30 mg of lanreotide every 4 weeks as a deep subcutaneous injection, in an attempt to address these issues. She was able to come off diazoxide treatment 2 months after starting lanreotide. Presently, after 2.5 years of lanreotide treatment, her blood glucose control is stable with complete resolution of hypertrichosis. Clinically significant improvements in the self-reported Paediatric Quality of Life (PedsQL) questionnaire and Strengths and Difficulties Questionnaire (SDQ) were reported after 1 year on lanreotide. No side effects were found, and her liver/thyroid function and abdominal ultrasound have been normal. We report the first case on the use of lanreotide in an adolescent girl with diazoxide-responsive CHI with significant improvement of quality of life. © 2015 S. Karger AG, Basel.

  2. Activating glucokinase (GCK) mutations as a cause of medically responsive congenital hyperinsulinism: prevalence in children and characterisation of a novel GCK mutation

    DEFF Research Database (Denmark)

    Christesen, Henrik B T; Tribble, Nicholas D; Molven, Anders;

    2008-01-01

    OBJECTIVE: Activating glucokinase (GCK) mutations are a rarely reported cause of congenital hyperinsulinism (CHI), but the prevalence of GCK mutations is not known. METHODS: From a pooled cohort of 201 non-syndromic children with CHI from three European referral centres (Denmark, n=141; Norway, n......=26; UK, n=34), 108 children had no K(ATP)-channel (ABCC8/KCNJ11) gene abnormalities and were screened for GCK mutations. Novel GCK mutations were kinetically characterised. RESULTS: In five patients, four heterozygous GCK mutations (S64Y, T65I, W99R and A456V) were identified, out of which S64Y...... was novel. Two of the mutations arose de novo, three were dominantly inherited. All the five patients were medically responsive. In the combined Danish and Norwegian cohort, the prevalence of GCK-CHI was estimated to be 1.2% (2/167, 95% confidence interval (CI) 0-2.8%) of all the CHI patients. In the three...

  3. Hiperinsulinismo na infância: quando apenas uma dosagem de insulina não é suficiente Hyperinsulinism in infancy and childhood: when an insulin level is not always enough

    Directory of Open Access Journals (Sweden)

    Andrew A. Palladino

    2008-12-01

    átricos, radiologistas, cirurgiões e patologistas, os quais são treinados para diagnosticar, identificar e tratar o hiperinsulinismo.BACKGROUND: Hypoglycemia in infants and children can lead to seizures, developmental delay, and permanent brain damage. Hyperinsulinism (HI is the most common cause of both transient and permanent disorders of hypoglycemia. HI is characterized by dysregulated insulin secretion, which results in persistent mild to severe hypoglycemia. The various forms of HI represent a group of clinically, genetically, and morphologically heterogeneous disorders. CONTENT: Congenital hyperinsulinism is associated with mutations of SUR-1 and Kir6.2, glucokinase, glutamate dehydrogenase, short-chain 3-hydroxyacyl-CoA dehydrogenase, and ectopic expression of SLC16A1 on β-cell plasma membrane. Hyperinsulinism may be associated with perinatal stress such as birth asphyxia, maternal toxemia, prematurity or intrauterine growth retardation, resulting in prolonged neonatal hypoglycemia. Mimickers of hyperinsulinism include neonatal panhypopituitarism, drug-induced hypoglycemia, insulinoma, antiinsulin and insulin-receptor stimulating antibodies, Beckwith-Wiedemann Syndrome, and congenital glycosylation disorders. Laboratory testing for hyperinsulinism may include quantification of blood glucose, plasma insulin, plasma β-hydroxybutyrate, plasma fatty acids, plasma ammonia, plasma acylcarnitine profile and urine organic acids. Genetic testing is available at commercial laboratories for genes known to be associated with hyperinsulinism. Acute insulin response (AIR tests are useful in phenotypic characterization. Imaging and histological tools are also available to diagnose and classify hyperinsulinism. The goal of treatment in infants with hyperinsulinism is to prevent brain damage from hypoglycemia by maintaining plasma glucose levels above 700 mg/l (70 mg/dl through pharmacologic or surgical therapy. SUMMARY: The treatment of hyperinsulinism requires a multidisciplinary approach

  4. apport alimentaire chez des patients attients la sclérose en plaque dans la region de Tlemcen

    OpenAIRE

    haddaoui, hadjer

    2015-01-01

    La sclérose en plaques (SEP) est une maladie inflammatoire et démyélinisant du système nerveux central (SNC). L'apparition de plaques démyélinisées dans le SNC est associée à un infiltrat inflammatoire principalement composé de macrophages et de lymphocytes T (LT). L'objectif de notre étude est d'évaluer l'apport alimentaire chez une population atteinte de Sclérose en plaque dans la wilaya de Tlemcen, et d'essayer de déterminer la relation entre l'apport alimentaire de fer, vit...

  5. Three electron beams from a laser-plasma wakefield accelerator and the energy apportioning question.

    Science.gov (United States)

    Yang, X; Brunetti, E; Gil, D Reboredo; Welsh, G H; Li, F Y; Cipiccia, S; Ersfeld, B; Grant, D W; Grant, P A; Islam, M R; Tooley, M P; Vieux, G; Wiggins, S M; Sheng, Z M; Jaroszynski, D A

    2017-03-10

    Laser-wakefield accelerators are compact devices capable of delivering ultra-short electron bunches with pC-level charge and MeV-GeV energy by exploiting the ultra-high electric fields arising from the interaction of intense laser pulses with plasma. We show experimentally and through numerical simulations that a high-energy electron beam is produced simultaneously with two stable lower-energy beams that are ejected in oblique and counter-propagating directions, typically carrying off 5-10% of the initial laser energy. A MeV, 10s nC oblique beam is ejected in a 30°-60° hollow cone, which is filled with more energetic electrons determined by the injection dynamics. A nC-level, 100s keV backward-directed beam is mainly produced at the leading edge of the plasma column. We discuss the apportioning of absorbed laser energy amongst the three beams. Knowledge of the distribution of laser energy and electron beam charge, which determine the overall efficiency, is important for various applications of laser-wakefield accelerators, including the development of staged high-energy accelerators.

  6. Three electron beams from a laser-plasma wakefield accelerator and the energy apportioning question

    Science.gov (United States)

    Yang, X.; Brunetti, E.; Gil, D. Reboredo; Welsh, G. H.; Li, F. Y.; Cipiccia, S.; Ersfeld, B.; Grant, D. W.; Grant, P. A.; Islam, M. R.; Tooley, M. P.; Vieux, G.; Wiggins, S. M.; Sheng, Z. M.; Jaroszynski, D. A.

    2017-01-01

    Laser-wakefield accelerators are compact devices capable of delivering ultra-short electron bunches with pC-level charge and MeV-GeV energy by exploiting the ultra-high electric fields arising from the interaction of intense laser pulses with plasma. We show experimentally and through numerical simulations that a high-energy electron beam is produced simultaneously with two stable lower-energy beams that are ejected in oblique and counter-propagating directions, typically carrying off 5–10% of the initial laser energy. A MeV, 10s nC oblique beam is ejected in a 30°–60° hollow cone, which is filled with more energetic electrons determined by the injection dynamics. A nC-level, 100s keV backward-directed beam is mainly produced at the leading edge of the plasma column. We discuss the apportioning of absorbed laser energy amongst the three beams. Knowledge of the distribution of laser energy and electron beam charge, which determine the overall efficiency, is important for various applications of laser-wakefield accelerators, including the development of staged high-energy accelerators. PMID:28281679

  7. Apport du rayonnement synchrotron à l'étude de cheveux archéologiques

    Science.gov (United States)

    Bertrand, L.; Chevallier, P.; Doucet, J.; Simionovici, A.; Tsoucaris, G.; Walter, P.

    2002-07-01

    La préservation dans certains contextes archéologiques des cheveux humains et des fibres animales est favorisée par leur transformation chimique au contact d'objets métalliques. Afin de mieux comprendre les phénomènes complexes mis en jeu, nous avons étudié expérimentalement la fixation de cations métalliques (Cu et Pb) dans des cheveux modèles à partir de différentes méthodes de caractérisation utilisant le rayonnement X synchrotron. Nous avons ainsi pu mettre en évidence la fixation spécifique d'une partie de ces cations au sein des lipides structurés du cheveu. La comparaison entre échantillons modèles et archéologiques apporte de nouvelles données concernant les premières étapes d'altération des cheveux archéologiques.

  8. Three electron beams from a laser-plasma wakefield accelerator and the energy apportioning question

    CERN Document Server

    Yang, X; Reboredo Gil, David; Welsh, Gregor H; Li, Y.F; Cipiccia, Silvia; Ersfeld, Bernhard; Grant, D. W; Grant, P. A; Islam, Muhammad; Tooley, M.B; Vieux, Gregory; Wiggins, Sally; Sheng, Zheng-Ming; Jaroszynski, Dino

    2017-01-01

    Laser-wakefield accelerators are compact devices capable of delivering ultra-short electron bunches with pC-level charge and MeV-GeV energy by exploiting the ultra-high electric fields arising from the interaction of intense laser pulses with plasma. We show experimentally and through numerical simulations that a high-energy electron beam is produced simultaneously with two stable lowerenergy beams that are ejected in oblique and counter-propagating directions, typically carrying off 5–10% of the initial laser energy. A MeV, 10s nC oblique beam is ejected in a 30°–60° hollow cone, which is filled with more energetic electrons determined by the injection dynamics. A nC-level, 100s keV backward-directed beam is mainly produced at the leading edge of the plasma column. We discuss the apportioning of absorbed laser energy amongst the three beams. Knowledge of the distribution of laser energy and electron beam charge, which determine the overall efficiency, is important for various applications of laser-wake...

  9. Analyzing Source Apportioned Methane in Northern California During DISCOVER-AQ-CA Using Airborne Measurements and Model Simulations

    Science.gov (United States)

    Johnson, Matthew S.

    2014-01-01

    This study analyzes source apportioned methane (CH4) emissions and atmospheric concentrations in northern California during the Discover-AQ-CA field campaign using airborne measurement data and model simulations. Source apportioned CH4 emissions from the Emissions Database for Global Atmospheric Research (EDGAR) version 4.2 were applied in the 3-D chemical transport model GEOS-Chem and analyzed using airborne measurements taken as part of the Alpha Jet Atmospheric eXperiment over the San Francisco Bay Area (SFBA) and northern San Joaquin Valley (SJV). During the time period of the Discover-AQ-CA field campaign EDGAR inventory CH4 emissions were 5.30 Gg/day (Gg 1.0 109 grams) (equating to 1.9 103 Gg/yr) for all of California. According to EDGAR, the SFBA and northern SJV region contributes 30 of total emissions from California. Source apportionment analysis during this study shows that CH4 concentrations over this area of northern California are largely influenced by global emissions from wetlands and local/global emissions from gas and oil production and distribution, waste treatment processes, and livestock management. Model simulations, using EDGAR emissions, suggest that the model under-estimates CH4 concentrations in northern California (average normalized mean bias (NMB) -5 and linear regression slope 0.25). The largest negative biases in the model were calculated on days when hot spots of local emission sources were measured and atmospheric CH4 concentrations reached values 3.0 parts per million (model NMB -10). Sensitivity emission studies conducted during this research suggest that local emissions of CH4 from livestock management processes are likely the primary source of the negative model bias. These results indicate that a variety, and larger quantity, of measurement data needs to be obtained and additional research is necessary to better quantify source apportioned CH4 emissions in California and further the understanding of the physical processes

  10. Apports spontanés en acides gras oméga 3 chez des diabétiques de type 2 tunisiens

    Directory of Open Access Journals (Sweden)

    Jamoussi Henda

    2014-09-01

    Full Text Available Il est admis à l’unanimité que les acides gras oméga 3 ont de multiples bénéfices pour la santé et plus précisément des effets protecteurs contre les maladies cardiovasculaires et neurodégénératives. L’objectif de ce travail était d’estimer les apports spontanés en acides alphalinolénique (ALA, docosahexaénoïque (DHA, éicosapentaénoïque (EPA et linoléique (LA. Cette étude d’observation a été réalisée auprès de 42 diabétiques de type 2 (21 hommes et 21 femmes âgés de 30 à 75 ans. L’estimation des apports en acides gras a été réalisée en utilisant la méthode d’enregistrement sur sept jours. Les résultats ont montré que l’apport moyen en ALA était de 0,99 ± 0,40 g/j soit 0,42 ± 0,13 % de l’apport énergétique total (AET. Aucun de nos patients n’avait un apport suffisant en ALA. Les apports quotidiens moyens en DHA et en EPA étaient respectivement de 90,0 ± 85 mg/j et de 83,5 ± 80 mg/j. Quant à la contribution des aliments aux apports en EPA et en DHA, les poissons et les fruits de mer représentaient la part la plus importante (57 % de ces deux acides gras. Nos résultats appellent à renforcer l’éducation nutritionnelle des diabétiques afin d’augmenter les apports en acides gras oméga 3 et d’assurer un rapport LA/ALA optimal qui contribuerait à la prévention des maladies cardiovasculaires.

  11. GENOMIQUE ET NUTRITION HUMAINE Biodisponibilité des acides gras et apports nutritionnels conseillés

    Directory of Open Access Journals (Sweden)

    Combe Nicole

    2002-03-01

    Full Text Available Les recommandations en terme d’apports en lipides évoluent en même temps que la connaissance de leurs effets sur la santé. La troisième édition des apports nutritionnels conseillés (ANC, pour la population française, a été publiée en 2001. L’examen de l’état des lieux, au travers de diverses données récentes d’enquêtes alimentaires, permet de souligner les écarts importants par rapport aux ANC. Il y a lieu de diminuer la consommation d’acides gras saturés [de 18 à 8% de l’apport énergétique total quotidien (AETQ] et d’augmenter celle des acides gras monoinsaturés (de 15 à 20%. Il ressort également que l’apport en 18:3 n-3 est insuffisant (0,3% au lieu de 0,8% AETQ recommandé. Les stratégies à envisager pour optimiser l’apport en acides gras polyinsaturés doivent prendre en compte un certain nombre de critères, dont celui de leur biodisponibilité. Il est rappelé que la biodisponibilité d’un acide gras ne dépend pas uniquement de sa teneur au sein des triglycérides ingérés mais également de sa répartition entre les positions interne (sn2 et externes (sn1 + sn3 du squelette glycérol. À partir de corps gras « structurés » ou « inter-estérifiés », des études ont montré que l’athérogénicité de l’acide palmitique est plus importante lorsqu’il est situé en position sn2 des triglycérides alimentaires. C’est en effet cette position qui, d’une part, lui assure le coefficient d’absorption intestinale maximum et, d’autre part lui permet de se maintenir à cette même position dans les lipides plasmatiques, ce qui contribuerait à augmenter son pouvoir athérogène. S’agissant des acides gras insaturés, la biodisponibilité de l’acide linoléique comme précurseur d’acides gras essentiels serait corrélée à ses proportions en sn2 dans les triglycérides; celle des acides gras polyinsaturés à longue chaîne est fonction de leur digestibilité qui est m

  12. Using ensemble models to identify and apportion heavy metal pollution sources in agricultural soils on a local scale.

    Science.gov (United States)

    Wang, Qi; Xie, Zhiyi; Li, Fangbai

    2015-11-01

    This study aims to identify and apportion multi-source and multi-phase heavy metal pollution from natural and anthropogenic inputs using ensemble models that include stochastic gradient boosting (SGB) and random forest (RF) in agricultural soils on the local scale. The heavy metal pollution sources were quantitatively assessed, and the results illustrated the suitability of the ensemble models for the assessment of multi-source and multi-phase heavy metal pollution in agricultural soils on the local scale. The results of SGB and RF consistently demonstrated that anthropogenic sources contributed the most to the concentrations of Pb and Cd in agricultural soils in the study region and that SGB performed better than RF.

  13. Genetics Home Reference: congenital hyperinsulinism

    Science.gov (United States)

    ... Med Genet. 2009 May;46(5):289-99. doi: 10.1136/jmg.2008.064337. Epub 2009 Mar 1. Review. Citation on PubMed Kapoor RR, James C, Hussain K. ... Metab. 2009 Feb;5(2):101-12. doi: 10.1038/ncpendmet1046. Review. Erratum in: Nat Clin ...

  14. Apportioning sources of organic matter in streambed sediments: An integrated molecular and compound-specific stable isotope approach

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, Richard J., E-mail: Richard.J.Cooper@uea.ac.uk [School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ (United Kingdom); Pedentchouk, Nikolai; Hiscock, Kevin M.; Disdle, Paul [School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ (United Kingdom); Krueger, Tobias [IRI THESys, Humboldt University, 10099 Berlin (Germany); Rawlins, Barry G. [British Geological Survey, Keyworth, Nottingham NG12 5GG (United Kingdom)

    2015-07-01

    We present a novel application for quantitatively apportioning sources of organic matter in streambed sediments via a coupled molecular and compound-specific isotope analysis (CSIA) of long-chain leaf wax n-alkane biomarkers using a Bayesian mixing model. Leaf wax extracts of 13 plant species were collected from across two environments (aquatic and terrestrial) and four plant functional types (trees, herbaceous perennials, and C{sub 3} and C{sub 4} graminoids) from the agricultural River Wensum catchment, UK. Seven isotopic (δ{sup 13}C{sub 27}, δ{sup 13}C{sub 29}, δ{sup 13}C{sub 31}, δ{sup 13}C{sub 27–31}, δ{sup 2}H{sub 27}, δ{sup 2}H{sub 29}, and δ{sup 2}H{sub 27–29}) and two n-alkane ratio (average chain length (ACL), carbon preference index (CPI)) fingerprints were derived, which successfully differentiated 93% of individual plant specimens by plant functional type. The δ{sup 2}H values were the strongest discriminators of plants originating from different functional groups, with trees (δ{sup 2}H{sub 27–29} = − 208‰ to − 164‰) and C{sub 3} graminoids (δ{sup 2}H{sub 27–29} = − 259‰ to − 221‰) providing the largest contrasts. The δ{sup 13}C values provided strong discrimination between C{sub 3} (δ{sup 13}C{sub 27–31} = − 37.5‰ to − 33.8‰) and C{sub 4} (δ{sup 13}C{sub 27–31} = − 23.5‰ to − 23.1‰) plants, but neither δ{sup 13}C nor δ{sup 2}H values could uniquely differentiate aquatic and terrestrial species, emphasizing a stronger plant physiological/biochemical rather than environmental control over isotopic differences. ACL and CPI complemented isotopic discrimination, with significantly longer chain lengths recorded for trees and terrestrial plants compared with herbaceous perennials and aquatic species, respectively. Application of a comprehensive Bayesian mixing model for 18 streambed sediments collected between September 2013 and March 2014 revealed considerable temporal variability in the

  15. Apports alimentaires en acides linoléique et alpha-linolénique d’une population d’Aquitaine

    Directory of Open Access Journals (Sweden)

    Combe Nicole

    2001-03-01

    Full Text Available Les apports alimentaires quotidiens en acides linoléique (18:2 n-6 et alpha-linolénique (18:3 n-3 ont fait récemment l’objet de recommandations pour la population française (ANC 2001. Cependant, peu d’informations sont actuellement disponibles sur la situation réelle, en particulier vis-à-vis du 18:3 n-3. Cette étude montre que la consommation de 18:2 n-6, en Aquitaine (n = 140 femmes, représente en moyenne 4,4 % (± 1,8 de l’apport énergétique total (AET, valeur acceptable par rapport aux ANC (4 %. En revanche, l’apport en 18:3 n-3 est insuffisant (0,34 ± 0,1 % au lieu de 0,8 % recommandé. Dans cette population, le 18:3 n-3 est à 75 % d’origine animale. La contribution des huiles est faible (9 %. La teneur moyenne en 18:2 n-6 et 18:3 n-3 du tissu adipeux des sujets est respectivement égale à 14 % et 0,5 % des acides gras totaux. Dans le plasma, ce sont les esters de cholestérol (EC qui en véhiculent le plus (53 % de 18:2 n-6 et 0,42 % de 18:3 n-3. Cette étude met en évidence une corrélation positive entre les pourcentages de 18:2 n-6 dans les EC plasmatiques et ceux du tissu adipeux (r = 0,606 et p < 0,001, confirmant que cette fraction plasmatique est un « marqueur » non invasif des apports en acide linoléique.

  16. L'impact de l'autoroute Tunis-Bizerte sur le paysage : apport de la géomatique

    Directory of Open Access Journals (Sweden)

    H. SAMAALI,

    2010-09-01

    Full Text Available L’IMPACT DE L’AUTOROUTE TUNIS-BIZERTE SUR LE PAYSAG E : APPORT DE LA GÉOMATIQUE H. SAMAALI 1 , M. C. RABIA 1 , A. CHERIF 2 En signant le traité de libre-échange avec l’Union Européenne, la Tunisie s’est engagée à développer son économie et à s’ouvrir à la concurre nce au moyen du Schéma Directeur d’Aménagement du Territoire National de 1996 (SDATN . Le renforcement du réseau routier est un des axes structurants du SDATN. L’autoroute Tuni s-Bizerte a été l’un des projets qui assure la liaison entre les deux pôles du Nord-Est, le Grand Tunis et Bizerte. Le but du présent travail est l’étude de l’impact d e l’autoroute Tunis-Bizerte sur le paysage, naturel et l’occupation du sol (le milieu humain. Cette étude suppose le recours à des outils de gestion et de suivi bien adaptés. Elle vi se la mise en place d’une base de données sous SIG, afin d’indiquer et de prévoir l’influence de l ’autoroute à travers certaines zones clés : la forê t d’Errimel, Garaât El Mabtouha, la région d’El Alia, etc. Pour ce faire, nous avons suivi une approche intégr ant des données multi sources et multi dates (cartes, photographies aériennes et images sa tellitaires etc. qui a permis de bien apprécier les changements d’occupation des sols par suite de la réalisation de l’autoroute. L’impact de l’autoroute Tunis-Bizerte sur le paysag e naturel consiste à l’enlaidissement de plusieurs sites comme la forêt d’Errimel. L’impact se traduit, en effet, par la disparition du couvert végétal. La conséquence en est alors une ac célération de l’érosion éolienne et une apparition de dunes de sable. Au niveau de garaât E l Mabtouha, l’autoroute en vraie digue, découpe la garâa en deux sous-écosystèmes avec une perturbation des apports fluviatiles et par conséquent une influence sur la pédogenèse de la ré gion. Par ailleurs, certaines modifications en relation a vec l’homme et l

  17. Pulmonary embolism: spiral CT evaluation; Embolie pulmonaire: apport de la tomodensitometrie helicoidale

    Energy Technology Data Exchange (ETDEWEB)

    Senac, J.P.; Vernhet, H.; Bousquet, C.; Giron, J.; Pieuchot, P.; Durand, G.; Benezet, O.; Aubas, P. [Centre Hospitalier Universitaire, 34 - Montpellier (France)

    1995-06-01

    Purpose: Spiral computed tomography was compared retrospectively with digital substraction pulmonary angiography (PA) in 45 patients suspected of having acute or chronic pulmonary embolism. Materials and method : 45 patients in whom the presence of acute or chronic pulmonary embolism was suspected underwent examination by spiral CT and PA. Diagnosis of pulmonary embolism was based on the direct visualization of intraluminal clots. The study of the agreement between the two methods was based on the Kappa test. In 35 cases, pulmonary emboli were proved. Acute pulmonary emboli were present in 28 cases and chronic in 7 cases. Results: Spiral computed tomography represents an excellent way to detect acute pulmonary embolism. In the chronic form, spiral CT is better than PA to detect intraluminal clots. However, Spiral CT can fail to detect small emboli in the peripheral arterial bed. In the 10 patients without pulmonary embolism, the spiral CT proved diagnosis pulmonary oedema (n=3), lymphangi-carcinoma (n=4), pleural effusion (n=3). Conclusion: This study suggest that the spiral CT examination is accurate for diagnosis of pulmonary embolism specifically in case of suspected important embolism. The advantages of spiral CT are multiple (non invasive, wide diagnosis spectrum). However, may be a limitation to is use is insufficient distal thrombi detection. This eventuality (5 to 10% in the Pioped study) justify the practice of pulmonary angiography. Spiral CT improvements should reduce this insufficiency in the next future. (Authors). 16 refs., 4 figs., 3 tabs.

  18. 改革以来农民的分化与平摊税费的方式%Stratification among Peasants and the System of Equally Apportioned Rural Taxes and Fees in the Reform Process

    Institute of Scientific and Technical Information of China (English)

    周批改

    2003-01-01

    The unreasonable shares of tax and fee among different stratifications of peasants have become main problems of tax and fee system in contemporary China''s countryside. These problems stem from the contradiction between the peasants'' stratification and the equally apportioned system of rural tax and fee. The equally apportioned system of rural tax and fee which has taxed every peasant with equal amount regardless of peasants'' income and wealth situation,especially results in the facts that the agricultural laborers in the central and western countrysides are taxed more than they can bear.

  19. Végétation fixée et phosphore en petit cours d'eau. Conséquences d'une réduction des apports de phosphore

    Directory of Open Access Journals (Sweden)

    PELTRE M. C.

    1993-10-01

    Des actions permettant des réductions supplémentaires de ces apports et la restauration du lit sont engagées pour prolonger cette démarche qui restait encore insuffisante pour avoir un impact sur les proliférations végétales observées.

  20. Etude pour quantifier la part des apports internes dans bâtiment tertiaire BBC. Application au bâtiment de PREDIS

    OpenAIRE

    Chenailler, Hervé; Wurtz, Frédéric; Ploix, Stéphane; Joussellin, Florence; Bontemps, André

    2010-01-01

    National audience; La conception de bâtiments a longtemps été réduite à la conception de leurs enveloppes, reléguant ainsi la représentation des usages à des courbes d'apports internes gratuits. Or, la recherche de meilleures performances en termes d'efficacité énergétique, qui se traduit par le rapport entre les besoins en énergie non gratuite sur le confort pour les occupants, pose le problème de conception en des termes nouveaux. Il s'agit dès lors de vérifier que l'énergie consommée corre...

  1. Rapid Genetic Analysis in Congenital Hyperinsulinism

    DEFF Research Database (Denmark)

    Christesen, Henrik Thybo; Brusgaard, Klaus; Alm, Jan

    2007-01-01

    . METHODS: In 4 patients, a rapid genetic analysis of the ABBC8 and KCNJ11 genes was performed within 2 weeks on request prior to the decision of pancreatic surgery. RESULTS: Two patients had no mutations, rendering the genetic analysis non-informative. Peroperative multiple biopsies showed diffuse disease....... One patient had a paternal KCNJ11 mutation and focal disease confirmed by positron emission tomography scan and biopsies. One patient had a de novo heterozygous ABBC8 mutation and unexplained diffuse disease confirmed by positron emission tomography scan and biopsies. CONCLUSION: A rapid analysis...

  2. Le rapprochement Chercheur-Consultant en aménagement du territoire : un apport à haute valeur ajoutée ?

    Directory of Open Access Journals (Sweden)

    Christine Chemin

    2010-02-01

    Full Text Available En aménagement du territoire, de nouvelles pratiques partenariales semblent émerger lors de la réalisation d'expertises (études, ingénierie de projets, audits, etc.. Si le recours aux cabinets-conseils – au Consultant – et aux laboratoires scientifiques – au Chercheur – par les services de l'Etat ou les collectivités territoriales existe depuis de nombreuses années, le rapprochement et le partenariat entre les consultants et les chercheurs est récent. Certes, cette pratique n’est pas encore systématique en aménagement du territoire mais elle constitue, selon les commanditaires publics, un apport à haute valeur ajoutée dans les prestations de services.In urban planning new partnership practices seem to appear through the realization of expertises (studies, projects engineering, audits…. Although the appeal to consulting firms – to consultants – and in the scientific laboratories – to researchers – by the State services or local government, exists for a long time now, the partnership between consultants and researchers is recent. Even though this partnership is not systematic in urban planning, it brings a contribution with a high added value in the services, according to the public partners.

  3. Clinical analysis of 12 cases with congenital hyperinsulinism with spontaneous remission%自行缓解的先天性高胰岛素血症12例临床分析

    Institute of Scientific and Technical Information of China (English)

    徐子迪; 吴玉筠; 桑艳梅; 闫洁; 刘敏; 梁学军; 张亚南; 张微

    2015-01-01

    目的对12例自行缓解的先天性高胰岛素血症(CHI)患儿的临床特征及随访资料进行回顾性分析,以期为CHI患儿治疗提供理论依据。方法选取2008年12月至2014年1月间首都医科大学附属北京儿童医院收治且自行缓解的12例CHI患儿为研究对象,对患儿的临床资料及后期随访数据进行分析。结果12例患儿的血糖不需要药物治疗,或者是停用药物后即可维持正常血糖至少3个月,提示该组为自行缓解的CHI患儿。其中4例患儿未服用任何药物仅需加强喂养即可自行缓解,另8例患儿均接受了二氮嗪治疗后逐渐减停药物后获得缓解,其中5例有效,3例无效;8例患儿中有1例患儿同时接受了二氮嗪及奥曲肽治疗,且均有效。12例患儿起病年龄均在1岁以内,且多于6个月以内起病(10/12),多为足月适于胎龄儿(7/12),另有巨大儿4例,足月小于胎龄儿1例。12例患儿中,有7例(7/12)于1岁以内低血糖症状缓解,最晚缓解年龄为6岁,其中有4例患儿检测出携带ABCC8基因突变。结论部分CHI患儿有自行缓解的趋势,应延长患儿的随访年龄,对二氮嗪治疗无效的CHI患儿应谨慎选择手术治疗,从而最大限度地避免术后并发症的发生。%Objective To provide a more reasonable therapeutic schedule for congenital hyperinsulinism (CHI) children and to analyze the clinical characteristics and follow-up data of the 12 cases with CHI whose symptoms alleviated spontaneously. Methods We choosed 12 patients with CHI whose symptoms alleviated spontaneously, hospitalized in Beijing Children′s Hospital from December 2008 to January 2014,as research subjects. The clinical data and post follow-up data were analyzed retrospectively. Results The 12 patients can maintain normal blood glucose for at least three months without drug treatment or after stopping the drug, which suggest that the group of children with

  4. Le rôle des institutions dans le processus de l’innovation ; l’apport de Thorstein Veblen

    Directory of Open Access Journals (Sweden)

    Diane-Gabrielle Tremblay

    2007-10-01

    Full Text Available Nous nous intéressons ici au rôle des institutions dans le processus de l’innovation, puisque Veblen le met en valeur. Cet apport de Veblen nous paraît déterminant pour mieux comprendre l’innovation, surtout que l’on parle de plus en plus d’une diversité de formes d’innovation (technologique, mais aussi organisationnelle, sociale et de produit, et que celles-ci sont mieux comprises lorsque l’on tient compte du rôle des institutions dans la diffusion ou le blocage de l’innovation. Veblen met aussi en évidence le caractère parfois retardataire des institutions, ainsi que la réciprocité des effets entre technologie et institutions, autant d’éléments fort pertinents pour l’analyse, encore aujourd’hui.This paper addresses the role of institutions in the process of innovation, since Veblen highlights this role. This contribution of Veblen appears determinant to better understand the process of innovation, especially in a context where we are more and more interested in various forms of innovation (technological, but also organisational, social and product innovations; these various forms of innovation are better understood and analysed when the role of institutions in their diffusion or lack of diffusion is taken into account. Veblen also highlights the fact that institutions sometimes block or slow down the process of diffusion of innovations, as well as the reciprocity of effects between technology and institutions, contributions which are all the more important for the analysis of innovation today.

  5. Current limiters

    Energy Technology Data Exchange (ETDEWEB)

    Loescher, D.H. [Sandia National Labs., Albuquerque, NM (United States). Systems Surety Assessment Dept.; Noren, K. [Univ. of Idaho, Moscow, ID (United States). Dept. of Electrical Engineering

    1996-09-01

    The current that flows between the electrical test equipment and the nuclear explosive must be limited to safe levels during electrical tests conducted on nuclear explosives at the DOE Pantex facility. The safest way to limit the current is to use batteries that can provide only acceptably low current into a short circuit; unfortunately this is not always possible. When it is not possible, current limiters, along with other design features, are used to limit the current. Three types of current limiters, the fuse blower, the resistor limiter, and the MOSFET-pass-transistor limiters, are used extensively in Pantex test equipment. Detailed failure mode and effects analyses were conducted on these limiters. Two other types of limiters were also analyzed. It was found that there is no best type of limiter that should be used in all applications. The fuse blower has advantages when many circuits must be monitored, a low insertion voltage drop is important, and size and weight must be kept low. However, this limiter has many failure modes that can lead to the loss of over current protection. The resistor limiter is simple and inexpensive, but is normally usable only on circuits for which the nominal current is less than a few tens of milliamperes. The MOSFET limiter can be used on high current circuits, but it has a number of single point failure modes that can lead to a loss of protective action. Because bad component placement or poor wire routing can defeat any limiter, placement and routing must be designed carefully and documented thoroughly.

  6. Apports des hautes résolutions spatiales pour l'étude et la cartographie des algues vertes. Application à la grève de St-Michel(22)

    OpenAIRE

    Ruiz, Olivier

    1994-01-01

    Les apports croissants d'effluents agricoles associés avec des situations hydrodynamiques particulières sont à l'origine de fortes proliférations d'algues vertes du type ulva lactuca (ulves). Lorsque la mer se retire les algues se déposent sur les plages et créent des nuisances pour le tourisme et les professionnels de la mer. Les estimations de biomasse sont alors nécessaires à la fois pour comprendre le phénomène et pour mesurer son ampleur. Pendant la période de forts coefficients de marée...

  7. Limited Neutrality

    DEFF Research Database (Denmark)

    Nielsen, Morten Ebbe Juul

    2006-01-01

    Article Concerning the prospect of a kind of limited neutrality in place of the standard liberal egalitarian "neutrality of justification."......Article Concerning the prospect of a kind of limited neutrality in place of the standard liberal egalitarian "neutrality of justification."...

  8. Limiting Skepticism

    DEFF Research Database (Denmark)

    Hendricks, Vincent Fella; Symons, John

    2011-01-01

    Skeptics argue that the acquisition of knowledge is impossible given the standing possibility of error. We present the limiting convergence strategy for responding to skepticism and discuss the relationship between conceivable error and an agent’s knowledge in the limit. We argue that the skeptic...

  9. Limited Neutrality

    DEFF Research Database (Denmark)

    Nielsen, Morten Ebbe Juul

    2006-01-01

    Article Concerning the prospect of a kind of limited neutrality in place of the standard liberal egalitarian "neutrality of justification."......Article Concerning the prospect of a kind of limited neutrality in place of the standard liberal egalitarian "neutrality of justification."...

  10. Inverse Limits

    CERN Document Server

    Ingram, WT

    2012-01-01

    Inverse limits provide a powerful tool for constructing complicated spaces from simple ones. They also turn the study of a dynamical system consisting of a space and a self-map into a study of a (likely more complicated) space and a self-homeomorphism. In four chapters along with an appendix containing background material the authors develop the theory of inverse limits. The book begins with an introduction through inverse limits on [0,1] before moving to a general treatment of the subject. Special topics in continuum theory complete the book. Although it is not a book on dynamics, the influen

  11. Modélisation des installations de chauffage à eau chaude. Les économies d’énergie apportées par la mise en place des pompes à vitesse variable

    Directory of Open Access Journals (Sweden)

    Mirela Slavu

    2007-01-01

    Full Text Available L’objectif visé dans cette étude est la définition et la validation des modèles de simulation hydraulique et thermique des installations de chauffage à eau, bitube, à circulation forcée, avec des radiateurs équipés de robinets thermostatiques. Dans l’environnement du logiciel de simulation TRNSYS, le modèle de simulation de l’installation de chauffage, couplé à un modèle représentatif d’un bâtiment multizone, est ensuite utilisé pour évaluer les économies d’énergie apportées par la mise en place des pompes à vitesse variable. L’étude simulée du fonctionnement et des performances est réalisée pour une installation de chauffage d’un petit bâtiment tertiaire qui aboitte des bureaux. Les simulations sont effectuées dans l’ensemble de la saison de chauffage à l’aide de fichiers météorologiques au pas horaire. L’analyse porte principalement sur les économies d’énergie apportées par la mise en place d’une pompe à vitesse variable avec les deux types de réglage (H=const. et H -- proportionnelle.

  12. Apport de la tomodensitométrie dans le diagnostic de la tuberculose vertébrale à propos de 496 cas à Abidjan

    Science.gov (United States)

    Gbané-Koné, Mariam; Ouattara, Baly; Diomandé, Mohamed; Sessou, Viva; Kaboré, Fulgence; Djoko, Kouadio Flore; Traoré, Moriba; Eti, Edmond; Kouakou, N'zué Marcel

    2015-01-01

    Introduction Le mal de Pott est la forme la plus fréquente des tuberculoses ostéo articulaires, le diagnostic de certitude reste difficile. L'imagerie tient une place indéniable dans le diagnostic. L'objectif de cette étude était de déterminer la prévalence de la tuberculose vertébrale et l'apport de la TDM dans le diagnostic. Méthodes Nous avons mené une étude rétrospective sur dossiers de tuberculose vertébrale dans le service de Rhumatologie du CHU de Cocody de Janvier 2006 à Décembre 2013. N'ont pas été inclus dans l’étude, tous les dossiers ne comportant pas d'imagerie. Resultats La prévalence hospitalière de la tuberculose vertébrale était de 10,95%, elle représentait 90,2% de la tuberculose ostéoarticulaire. Elle concernait les 2 sexes, l’âge moyen était de 43,27 ans (4-88ans). L'atteinte dorsolombaire était la localisation la plus fréquente (95,13%). L'atteinte du rachis cervical était rare. La spondylodiscite était fréquente (92,14%). La spondylite (6%) et l'atteinte de l'arc postérieur (0,86%) étaient rares. La spondylodiscite était unique le plus souvent (70,05%), les formes multiétagées ont été notées dans 28,65% des cas, les atteintes mutifocales ont été notées dans14, 63% des cas. Les localisations inhabituelles étaient: atteinte sous occipitale (n=3), atteinte concomitante des 3 segments rachidiens (n=3), atteinte du sacrum (n=1), abcès isolés du psoas (n=4). La prévalence des abcès était de 85,91%, celle des épidurites était de 80,17%. La ponction scannoguidée des abcès a été réalisée dans 20 cas, la recherche de BAAR était positive dans 15 cas. Il existait une tuberculose viscérale évolutive dans 20% des cas. Conclusion La TDM est indéniable dans le diagnostic positif et lésionnel de la tuberculose vertébrale. Le retard au diagnostic explique l’étendue des lésions. PMID:26113932

  13. Limits on $\

    CERN Document Server

    Perego, D L

    2002-01-01

    A limit on the tau neutrino mass is obtained using all the $Z^{0} \\to \\tau^{+} \\tau^{-}$ data collected at LEP by the DELPHI detector between 1992 and 1995. In this analysis events in which one of the taus decays into one charged particle, while the second $\\tau$ decays into f{}ive charged pions (1-5 topology) have been used. The neutrino mass is determined from a bidimensional \\fit ~on the invariant mass $m^{*}_{5 \\pi}$ and on the energy $E_{5 \\pi}$ of the f{}ive $\\pi^{\\pm}$ system. The result found is $m_{\

  14. L’apport de la méthode DEA au pilotage de la performance des centres de coût : l’exemple de la logistique amont

    OpenAIRE

    Cavaignac, Laurent F.; Villesèque-Dubus, Fabienne

    2014-01-01

    Cet article a pour objectif de s’intéresser au pilotage de la performance des centres de coût en prenant le cas particulier de la logistique amont. Il s’agit plus précisément de s’interroger sur l’apport de la méthode DEA (méthode d’analyse d’enveloppement des données) comme outil d’analyse multidimensionnel de la performance pour gérer globalement les différentes composantes de cette performance multidimensionnelle, à savoir les coûts, la qualité et les délais. A partir de la réalisation d’u...

  15. Age Limits.

    Science.gov (United States)

    Antfolk, Jan

    2017-03-01

    Whereas women of all ages prefer slightly older sexual partners, men-regardless of their age-have a preference for women in their 20s. Earlier research has suggested that this difference between the sexes' age preferences is resolved according to women's preferences. This research has not, however, sufficiently considered that the age range of considered partners might change over the life span. Here we investigated the age limits (youngest and oldest) of considered and actual sex partners in a population-based sample of 2,655 adults (aged 18-50 years). Over the investigated age span, women reported a narrower age range than men and women tended to prefer slightly older men. We also show that men's age range widens as they get older: While they continue to consider sex with young women, men also consider sex with women their own age or older. Contrary to earlier suggestions, men's sexual activity thus reflects also their own age range, although their potential interest in younger women is not likely converted into sexual activity. Compared to homosexual men, bisexual and heterosexual men were more unlikely to convert young preferences into actual behavior, supporting female-choice theory.

  16. Apport de diverses sources de données à la réalisation d’une intervention ergonomique Contribution of various data sources to an ergonomics intervention Contribución de diversas fuentes de datos en la realización de una intervención ergonómica

    Directory of Open Access Journals (Sweden)

    Denys Denis

    2007-05-01

    principales caractéristiques, avantages et limites des différentes sources de données dans le contexte étudié. Dans cette perspective, l’étude peut apporter beaucoup aux ergonomes, praticiens et chercheurs.The study presented is a methodological reflection on the ergonomic intervention process. The study’s objectives were to specify the contribution of nine sources of data to an ergonomic intervention. A posteriori follow-up was done on an intervention field study aiming to reduce MSDs in a warehouse superstore in the retail sales sector. Nine sources of data classically used in ergonomics were analyzed: questionnaires, interview data, observation data. Interview data were found to provide more information and cover more topics than observation data. However, the latter are more precise. Individual interview data and autoconfrontations are more meaningful because they provide more links between the different topics covered. Interview data contribute to the social construction of the intervention and to the evolution of the participants’ representations. Observation data, because they are quantified, have the power to convince the employer of the severity of the different problems. The majority of the information collected by the different sources was found to be new information (54.7%, while less was clarifications (34.6%, and only 11% was confirmations. As a result, learning continues throughout the analysis of the various sources of data. The ergonomic diagnosis must therefore be considered as progressively becoming more precise through the different data sources by a gradual construction of the information throughout the intervention. The conclusion assesses the study’s contribution. The authors believe that the study initiates profound reflection, used as a basis in specifying the main characteristics, advantages and limitations of the different sources of data in the context studied. From this perspective, ergonomists, practitioners and researchers can

  17. Apport de la pression sur les performances d'une cellule d'électrolyse de la vapeur d'eau à haute température

    OpenAIRE

    Cacciuttolo, Quentin

    2014-01-01

    In order to improve the industrial attractiveness of high temperature steam electrolysis (HTSE), the increase in the operating pressure is one of the most promising solutions. In this context, this study is dedicated to the analysis of the pressure influence on the electrochemical reactions occurring in HTSE. A Model and experimental results dealing with the effect of pressure increase have been carried out. Concerning the cathodic side model, the limiting current density due to the lack of s...

  18. Progrès apportés par l'utilisation des zéolithes en cracking catalytique Advances Resulting from Using Zeolites in Catalytic Cracking

    Directory of Open Access Journals (Sweden)

    Marcilly Ch.

    2006-11-01

    Full Text Available Cet article a pour but d'exposer les progrès intervenus dans le cracking catalytique depuis l'utilisation des tamis moléculaires. II présente les nouveaux catalyseurs, compare leurs propriétés et leurs performances à celles des catalyseurs traditionnels et décrit les modifications et les progrès technologiques qu'ont entraînés l'utilisation des zéolithes. II se limite au cracking catalytique en lit fluide (FCC qui est le type de mise en oeuvre de loin le plus exploité. The aim of this article is to describe advances made in catalytic cracking since molecular sieves began being used. New catalyts are described, their properties and performances are compared with those of traditional catalysts, and the changes and technological advances resulting from the use of zeolites are explained. The article is limited to fluid catalytic cracking IFCCI which is by far the most widely used procedure.

  19. Pharyngolaryngeal tumors: spiral CT with 3D reconstruction; Tumeurs du pharyngo-larynx: apport de la tomodensitometrie en acquisition volumique avec reconstructions tridimensionnelles

    Energy Technology Data Exchange (ETDEWEB)

    Arnould, V.; Troufleau, P.; Stines, J. [Centre de Lutte Contre le Cancer, 54 - Nancy (France); Regent, D. [Centre Hospitalier Universitaire, 54 - Nancy (France)

    1995-04-01

    Spiral CT allows the exploration of the whole larynx and hypopharynx in 30 seconds. This is a good adjustment between the technique and the organ. Performed on 15 patients during a 30 seconds Valsalva maneuver, the exploration yields results from good to excellent. In two cases, conventional and helical CT are compared. The limitation of mA is not a drawback in such a thin region and there is no shift of organ or lesion between two scans, because the whole range is scanned in a single breathhold. 3D display of larynx and pharynx can performed with some advantage, especially easiness of presentation for surgeon. They help topographic analysis and make correlation between endoscopic views and axial scans. They could be useful for surgical simulation and 3D photon treatment plannings. (authors). 17 refs., 17 figs.

  20. Heterogeneity in Phenotype of Usher-Congenital Hyperinsulinism Syndrome

    DEFF Research Database (Denmark)

    Al Mutair, Angham N; Brusgaard, Klaus; Bin-Abbas, Bassam;

    2013-01-01

    and nonautoimmune diabetes at age 11 years, no additional mutations were found in HNF1A, HNF4A, GCK, INS, and INSR. Retinitis pigmentosa was found in two patients aged 9 and 13 years. No patients had enteropathy or renal tubular defects. Neuromotor development ranged from normal to severe delay with epilepsy...

  1. Contribution of brain imaging techniques: CT-scan and magnetic resonance imaging (MRI); Apports de l`imagerie cerebrale (tomodensitometrie et imagerie par resonance magnetique)

    Energy Technology Data Exchange (ETDEWEB)

    Pasco-Papon, A.; Gourdier, A.L.; Papon, X.; Caron-Poitreau, C. [Centre Hospitalier Universitaire, 49 - Angers (France)

    1996-06-01

    In light of the current lack of consensus on the benefit of carotid artery surgery to treat asymptomatic carotid artery stenosis, the decision to operate on a patient depends on individual evaluation and characterization of risk factors on carotid artery stenosis greater than 70 %. The assessment of such risk factors is based especially on non-invasive brain imaging techniques.Computed tomography scanning (CT-scan) and magnetic resonance imaging (MRI) enable two types of stenosis to be differentiated, i.e. stenoses which are symptomatic and those that are radiologically proven versus those which are clinically and radiologically silent. CT-scan investigation (with and without injection of iodinated contrast media) still continues to be a common routine test in 1996 whenever a surgical revascularization procedure is planned. The presence of deep lacunar infarcts ipsilateral to the carotid artery stenosis generally evidence the reality of stenosis and thus are useful to the surgeon in establishing whether surgery is indicated. In the absence a consensus on indications for surgical management, the surgeon could use the CT-scan and MRI as medicolegal records which could be compared to a subsequent postoperative CT-scan in case of ischemic complications associated with the surgical procedure. Furthermore, recent cerebral ischemia as evidenced by filling with contrast material, will call for postponing treatment by a few weeks. Although conventional MRI is more contributive than brain CT-scan in terms of sensibility and specificity, its indications are narrower because of its limited availability and cost constraints. But, development of angio-MRI and functional imaging promise that its future is assured and even perhaps as the sole diagnostic method if its indications are expanded to include preoperative angiographic evaluation of atheromatous lesions of supra-aortic trunks. (authors). 37 refs.

  2. Risques et bénéfices pour la santé des acides gras trans apportés par les aliments. Recommandations

    Directory of Open Access Journals (Sweden)

    Léger Claude-Louis

    2005-01-01

    peroxydations. The main AFSSA’s recommendations (non exhaustive list are as follows : people should decrease their consumption of bakery products by 30 %, TFA contents of bakery products should not exceed 1 g per 100 g of the commercialized product, TFA contents of every types of margarines bought by the consumer should be lower than 1% of total fatty acids. Because of the prevalence of calcium deficiency particularly in children, declining consumption of dairy products is not recommended, but consumption of (half-skimmed milk or products elaborated with (half-skimmed milk should be preferred. Considering the lack of information on the relationship between animal traditional feeding and TFA contents of animal products that people consume, no content upper-limit is proposed for animal (or more specifically dairy products. AFSSA points out that administration of the synthetic CLA supplement is not justified in humans and animals as well. Information on trans fatty acid in nutrition labeling should be mandatory for contents higher than 0.1 g/100 g in bakery and dairy products, and 0.1% for vegetable oils, margarines and butter. Given the very low levels of CLA in foods usually consumed, the CLA labeling is assumed to be purposeless.

  3. Capitalisme raisonnable et développement durable : quels apports possibles à partir de l’institutionnalisme de John  ‎‏R. Commons ? Reasonable Capitalism and Sustainable Development: Potential Contributions from John R. Commons’ Institutionalism

    Directory of Open Access Journals (Sweden)

    Muriel Maillefert

    2010-12-01

    Full Text Available La problématique du développement durable interpelle directement le fonctionnement du capitalisme depuis une bonne dizaine d’années, en appelant à des changements dont l’ampleur varie en fonction des acceptions de la durabilité retenues. L’article tente de préciser les apports possibles de l’institutionnalisme de J.R. Commons à l’analyse d’une « action collective environnementale » représentative d’une volonté de structurer les conflits au sein d’un capitalisme durable. Après avoir rappelé les principales questions qui se posent au sujet de la compatibilité du capitalisme à la problématique du développement durable, nous analysons la pertinence des concepts avancés par J.R. Commons pour l’émergence d’un capitalisme durable. Pour cela, nous soulignons plus particulièrement la fécondité des principes du capitalisme raisonnable tels que définis par cet auteur, et leur proximité potentielle avec le développement durable. En se démarquant sensiblement de la posture de l’économie politique classique, l’institutionnalisme de Commons introduit en effet une opportunité intéressante pour la compréhension des enjeux de la durabilité. Puis nous nous interrogeons sur les difficultés d’une transposition de ces principes aux enjeux actuels de la définition d’un capitalisme durable, en insistant sur les limites d’une application des concepts de « valeur raisonnable » et de « transactions » aux démarches d’intégration des contraintes environnementales dans les comportements économiques du capitalisme contemporain.For over a decade, the concept of sustainable development questions the very functioning of capitalism by calling for changes of various magnitude depending on the underlying meaning given to this concept. This paper aims at specifying the potential contributions of John R. Commons’ institutionalism to the analysis of « environmental collective action ». The latter

  4. HOME Income Limits

    Data.gov (United States)

    Department of Housing and Urban Development — HOME Income Limits are calculated using the same methodology that HUD uses for calculating the income limits for the Section 8 program. These limits are based on HUD...

  5. Passive immitance limiters

    OpenAIRE

    Filinyuk N. A.; Lischinskaya L. B.; Chekhmestruk R. Yu.

    2015-01-01

    The paper presents quadripole R, L, C immittance limiters, in which output immittance to the certain value depends on the input immittance. A classification of immittance limiters is given. Basic parameters are considered: low and high levels of output immittance limiters; low and high values of input immittance, corresponding to low and high levels of limitation, accordingly; range of possible values of output immittance; steepness of immittance limiters; time of wearing-out (or delay); high...

  6. VT Limited Access Highways

    Data.gov (United States)

    Vermont Center for Geographic Information — A limited-access road, known by various terms worldwide, including limited-access highway, dual carriageway, expressway, and partial controlled access highway, is a...

  7. Robust test limits

    NARCIS (Netherlands)

    Albers, Willem/Wim; Kallenberg, W.C.M.; Otten, G.D.

    1997-01-01

    Because of inaccuracies of the measurement process inspection of manufactured parts requires test limits which are more strict than the given specification limits. Test limits derived under the assumption of normality for product characteristics turn out to violate the prescribed bound on the

  8. Apport de l'analyse des réseaux sociaux à l'étude des communautés d'apprentissage en ligne Using social network analysis for the study of online learning communities

    Directory of Open Access Journals (Sweden)

    Cédric Sarré

    2012-09-01

    Full Text Available S'il est vrai que de nombreuses recherches ont porté, ces vingt dernières années, sur l'apport de la communication médiatisée par ordinateur (CMO à l'acquisition des langues secondes (L2, peu de travaux se sont intéressés à ce jour à la CMO à base orale (audioconférence et visioconférence et à ses différences et similitudes avec la CMO à base écrite. Cet article se propose d'examiner et de comparer les interactions entre apprenants générées lors de la réalisation de tâches collaboratives en anglais L2 selon trois modes de CMO : le clavardage, la visioconférence et le forum électronique. Les tâches collaboratives ont été proposées aux apprenants dans le cadre du dispositif hybride English for biologists dont l'objectif principal était de favoriser le développement de leur compétence interactionnelle en L2. L'analyse sociométrique des échanges nous permet de mettre en évidence l'influence du mode de CMO utilisé sur la charge interactionnelle (degré de prise en compte de l'autre et sur la configuration des interactions, ainsi que sur l'efficacité de la télécollaboration. Nous en tirons également des conclusions relatives à l'impact du mode de CMO sur l'entrée des apprenants dans la communauté d'apprentissage qui émerge de chacun des groupes de travail auquel ils appartiennent.In spite of the amount of published research on the use of computer-mediated communication (CMC in second language acquisition (SLA in the past twenty years, few of these studies deal with voice-based CMC (audioconferencing and videoconferencing and with how it compares with text-based CMC. This article aims at bridging this gap by examining and comparing learner-to-learner interactions in L2 English that were generated during the completion of collaborative tasks using three different CMC modes: text chat, desktop videoconferencing and discussion board. The collaborative tasks to be completed were part of a blended learning system

  9. Passive immitance limiters

    Directory of Open Access Journals (Sweden)

    Filinyuk N. A.

    2015-06-01

    Full Text Available The paper presents quadripole R, L, C immittance limiters, in which output immittance to the certain value depends on the input immittance. A classification of immittance limiters is given. Basic parameters are considered: low and high levels of output immittance limiters; low and high values of input immittance, corresponding to low and high levels of limitation, accordingly; range of possible values of output immittance; steepness of immittance limiters; time of wearing-out (or delay; high and low cutoff frequencies; central working frequency; frequency band; relative range of working frequencies; non-linearity coefficient. The authors have designed passive R-, L-, C-limiters with possibility of limitation from above and from below. The influence of the input parasitic immittances on the immittance transfer characteristic is evaluated. In most cases parasite immittance does not influence the considered devices, including R-limiters «from above» with the input quality factor of QR(Linp=0,1…0,2 and L-limiters «from above» with high-quality input circuits with QL(Rinp>2. The analysis also shows that high-qualitiy circuits with QN(RinpN>3 should be used in C-limiters with input parasitic immittances, while at parasitic immittance of the limiting element low-quality circuits with QN(RiN>0,2 should be selected.

  10. Limitations to sharing entanglement

    CERN Document Server

    Kim, Jeong San; Sanders, Barry C

    2011-01-01

    We discuss limitations to sharing entanglement known as monogamy of entanglement. Our pedagogical approach commences with simple examples of limited entanglement sharing for pure three-qubit states and progresses to the more general case of mixed-state monogamy relations with multiple qudits.

  11. Limits to Inclusion

    Science.gov (United States)

    Hansen, Janne Hedegaard

    2012-01-01

    In this article, I will argue that a theoretical identification of the limit to inclusion is needed in the conceptual identification of inclusion. On the one hand, inclusion is formulated as a vision that is, in principle, limitless. On the other hand, there seems to be an agreement that inclusion has a limit in the pedagogical practice. However,…

  12. Limits to Inclusion

    Science.gov (United States)

    Hansen, Janne Hedegaard

    2012-01-01

    In this article, I will argue that a theoretical identification of the limit to inclusion is needed in the conceptual identification of inclusion. On the one hand, inclusion is formulated as a vision that is, in principle, limitless. On the other hand, there seems to be an agreement that inclusion has a limit in the pedagogical practice. However,…

  13. Numerical Limit Analysis:

    DEFF Research Database (Denmark)

    Damkilde, Lars

    2007-01-01

    Limit State analysis has a long history and many prominent researchers have contributed. The theoretical foundation is based on the upper- and lower-bound theorems which give a very comprehensive and elegant formulation on complicated physical problems. In the pre-computer age Limit State analysis...

  14. Numerical Limit Analysis:

    DEFF Research Database (Denmark)

    Damkilde, Lars

    2007-01-01

    Limit State analysis has a long history and many prominent researchers have contributed. The theoretical foundation is based on the upper- and lower-bound theorems which give a very comprehensive and elegant formulation on complicated physical problems. In the pre-computer age Limit State analysis...... also enabled engineers to solve practical problems within reinforced concrete, steel structures and geotechnics....

  15. Modeling Complex Time Limits

    Directory of Open Access Journals (Sweden)

    Oleg Svatos

    2013-01-01

    Full Text Available In this paper we analyze complexity of time limits we can find especially in regulated processes of public administration. First we review the most popular process modeling languages. There is defined an example scenario based on the current Czech legislature which is then captured in discussed process modeling languages. Analysis shows that the contemporary process modeling languages support capturing of the time limit only partially. This causes troubles to analysts and unnecessary complexity of the models. Upon unsatisfying results of the contemporary process modeling languages we analyze the complexity of the time limits in greater detail and outline lifecycles of a time limit using the multiple dynamic generalizations pattern. As an alternative to the popular process modeling languages there is presented PSD process modeling language, which supports the defined lifecycles of a time limit natively and therefore allows keeping the models simple and easy to understand.

  16. The Hugoniot Elastic Limit Decay Limit

    Science.gov (United States)

    Billingsley, J. P.

    1997-07-01

    The Hugoniot Elastic Limit(HEL) precursor decay in shock loaded solids has been the subject of considerable experimental and theoretical investigation. Comparative evidence is presented to show that the elastic precursor wave particle velocity, UPHEL, for certain materials decays asymptotically with propagation distance to the DeBroglie velocity, V1, level. This is demonstrated for the following materials: iron, aluminum alloy 6061-T6, plexiglas(PMMA), nickel alloy(MAR-M200), and lithium flouride(LiF). The DeBroglie velocity, V1, equals h/2md, where h is Planck's Constant, m is the mass of one atom, and d is the closest distance between atoms. Thus a relationship has been established between a microscopically derived velocity, V1, and a macroscopically observed velocity, UPHEL.

  17. ACA Federal Upper Limits

    Data.gov (United States)

    U.S. Department of Health & Human Services — Affordable Care Act Federal Upper Limits (FUL) based on the weighted average of the most recently reported monthly average manufacturer price (AMP) for...

  18. HUD Program Income Limits

    Data.gov (United States)

    Department of Housing and Urban Development — Income limits used to determine the income eligibility of applicants for assistance under three programs authorized by the National Housing Act. These programs are...

  19. Limit experiments of GARCH

    CERN Document Server

    Buchmann, Boris; 10.3150/10-BEJ328

    2012-01-01

    GARCH is one of the most prominent nonlinear time series models, both widely applied and thoroughly studied. Recently, it has been shown that the COGARCH model (which was introduced a few years ago by Kl\\"{u}ppelberg, Lindner and Maller) and Nelson's diffusion limit are the only functional continuous-time limits of GARCH in distribution. In contrast to Nelson's diffusion limit, COGARCH reproduces most of the stylized facts of financial time series. Since it has been proven that Nelson's diffusion is not asymptotically equivalent to GARCH in deficiency, in the present paper, we investigate the relation between GARCH and COGARCH in Le Cam's framework of statistical equivalence. We show that GARCH converges generically to COGARCH, even in deficiency, provided that the volatility processes are observed. Hence, from a theoretical point of view, COGARCH can indeed be considered as a continuous-time equivalent to GARCH. Otherwise, when the observations are incomplete, GARCH still has a limiting experiment, which we ...

  20. Limited Denial of Participation

    Data.gov (United States)

    Department of Housing and Urban Development — A Limited Denial of Participation (LDP) is an action taken by a HUD Field Office or the Deputy Assistant Secretary for Single Family (DASSF) or Multifamily (DASMF)...

  1. HOME Rent Limits

    Data.gov (United States)

    Department of Housing and Urban Development — In accordance with 24 CFR Part 92.252, HUD provides maximum HOME rent limits. The maximum HOME rents are the lesser of: The fair market rent for existing housing for...

  2. PLT rotating pumped limiter

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, S.A.; Budny, R.V.; Corso, V.; Boychuck, J.; Grisham, L.; Heifetz, D.; Hosea, J.; Luyber, S.; Loprest, P.; Manos, D.

    1984-07-01

    A limiter with a specially contoured front face and the ability to rotate during tokamak discharges has been installed in a PLT pump duct. These features have been selected to handle the unique particle removal and heat load requirements of ICRF heating and lower-hybrid current-drive experiments. The limiter has been conditioned and commissioned in an ion-beam test stand by irradiation with 1 MW power, 200 ms duration beams of 40 keV hydrogen ions. Operation in PLT during ohmic discharges has proven the ability of the limiter to reduce localized heating caused by energetic electron bombardment and to remove about 2% of the ions lost to the PLT walls and limiters.

  3. Limited Income and Resources

    Data.gov (United States)

    U.S. Department of Health & Human Services — Information for those with limited income and resources (those who may qualify for or already have the Low Income Subsidy to lower their prescription drug coverage...

  4. Limited Angle Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ho Kyung; Cho, Min Kook; Kim, Seong Sik [Pusan National University, Busan (Korea, Republic of)

    2007-07-01

    In computed tomography (CT), many situations are restricted to obtain enough number of projections or views to avoid artifacts such as streaking and geometrical distortion in the reconstructed images. Speed of motion of an object to be imaged can limit the number of views. Cardiovascular imaging is a representative example. Size of an object can also limit the complete traverse motion or geometrical complexity can obscure to be imaged at certain range of angles. These situations are frequently met in industrial nondestructive testing and evaluation. Dental CT also suffers from similar situation because cervical spine causes less x-ray penetration from some directions such that the available information is not sufficient for standard reconstruction algorithms. The limited angle tomography is now greatly paid attention as a new genre in medical and industrial imaging, popularly known as digital tomosynthesis. In this study, we introduce a modified filtered backprojection method in limited angle tomography and demonstrate its application for the dental imaging.

  5. SIS - Annual Catch Limit

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Annual Catch Limit (ACL) dataset within the Species Information System (SIS) contains information and data related to management reference points and catch data.

  6. Skeletal muscle power and fatigue at the tolerable limit of ramp-incremental exercise in COPD.

    Science.gov (United States)

    Cannon, Daniel T; Coelho, Ana Claudia; Cao, Robert; Cheng, Andrew; Porszasz, Janos; Casaburi, Richard; Rossiter, Harry B

    2016-12-01

    Muscle fatigue (a reduced power for a given activation) is common following exercise in chronic obstructive pulmonary disease (COPD). Whether muscle fatigue, and reduced maximal voluntary locomotor power, are sufficient to limit whole body exercise in COPD is unknown. We hypothesized in COPD: 1) exercise is terminated with a locomotor muscle power reserve; 2) reduction in maximal locomotor power is related to ventilatory limitation; and 3) muscle fatigue at intolerance is less than age-matched controls. We used a rapid switch from hyperbolic to isokinetic cycling to measure the decline in peak isokinetic power at the limit of incremental exercise ("performance fatigue") in 13 COPD patients (FEV1 49 ± 17%pred) and 12 controls. By establishing the baseline relationship between muscle activity and isokinetic power, we apportioned performance fatigue into the reduction in muscle activation and muscle fatigue. Peak isokinetic power at intolerance was ~130% of peak incremental power in controls (274 ± 73 vs. 212 ± 84 W, P Muscle fatigue as a fraction of baseline peak isokinetic power was not different in COPD patients vs. controls (0.11 ± 0.20 vs. 0.19 ± 0.11). Baseline to intolerance, the median frequency of maximal isokinetic muscle activity, was unchanged in COPD patients but reduced in controls (+4.3 ± 11.6 vs. -5.5 ± 7.6%, P power was greater in COPD vs. controls and related to resting (FEV1/FVC) and peak exercise (V̇E/maximal voluntary ventilation) pulmonary function (r(2) = 0.47 and 0.55, P power and define exercise intolerance. Copyright © 2016 the American Physiological Society.

  7. Altruism and Reproductive Limitations

    Directory of Open Access Journals (Sweden)

    Carey J. Fitzgerald

    2009-04-01

    Full Text Available We examined how different types of reproductive limitations — functional (schizoid personality disorder and schizophrenia, physical (malnutrition, and sexual (bisexuality and homosexuality — influenced altruistic intentions toward hypothetical target individuals of differing degrees of relatedness (r = 0, .25, and .50. Participants were 312 undergraduate students who completed a questionnaire on altruism toward hypothetical friends, half-siblings, and siblings with these different types of reproductive limitations. Genetic relatedness and reproductive limitations did not influence altruistic decision-making when the cost of altruism was low but did as the cost of altruism increased, with participants being more likely to help a sibling over a half-sibling and a half-sibling over a friend. Participants also indicated they were more likely to help a healthy (control person over people with a reproductive limitation. Of the three types of reproductive limitations, functional limitations had the strongest effect on altruistic decision-making, indicating that people were less likely to help those who exhibit abnormal social behavior.

  8. Fundamental Limits of Cooperation

    CERN Document Server

    Lozano, Angel; Andrews, Jeffrey G

    2012-01-01

    Cooperation is viewed as a key ingredient for interference management in wireless systems. This paper shows that cooperation has fundamental limitations. The main result is that even full cooperation between transmitters cannot in general change an interference-limited network to a noise-limited network. The key idea is that there exists a spectral efficiency upper bound that is independent of the transmit power. First, a spectral efficiency upper bound is established for systems that rely on pilot-assisted channel estimation; in this framework, cooperation is shown to be possible only within clusters of limited size, which are subject to out-of-cluster interference whose power scales with that of the in-cluster signals. Second, an upper bound is also shown to exist when cooperation is through noncoherent communication; thus, the spectral efficiency limitation is not a by-product of the reliance on pilot-assisted channel estimation. Consequently, existing literature that routinely assumes the high-power spect...

  9. The quantum geometric limit

    CERN Document Server

    Lloyd, Seth

    2012-01-01

    This letter analyzes the limits that quantum mechanics imposes on the accuracy to which spacetime geometry can be measured. By applying the fundamental physical bounds to measurement accuracy to ensembles of clocks and signals moving in curved spacetime -- e.g., the global positioning system -- I derive a covariant version of the quantum geometric limit: the total number of ticks of clocks and clicks of detectors that can be contained in a four volume of spacetime of radius r and temporal extent t is less than or equal to rt/\\pi x_P t_P, where x_P, t_P are the Planck length and time. The quantum geometric limit bounds the number of events or `ops' that can take place in a four-volume of spacetime: each event is associated with a Planck-scale area. Conversely, I show that if each quantum event is associated with such an area, then Einstein's equations must hold. The quantum geometric limit is consistent with and complementary to the holographic bound which limits the number of bits that can exist within a spat...

  10. FANCM limits meiotic crossovers.

    Science.gov (United States)

    Crismani, Wayne; Girard, Chloé; Froger, Nicole; Pradillo, Mónica; Santos, Juan Luis; Chelysheva, Liudmila; Copenhaver, Gregory P; Horlow, Christine; Mercier, Raphaël

    2012-06-22

    The number of meiotic crossovers (COs) is tightly regulated within a narrow range, despite a large excess of molecular precursors. The factors that limit COs remain largely unknown. Here, using a genetic screen in Arabidopsis thaliana, we identified the highly conserved FANCM helicase, which is required for genome stability in humans and yeasts, as a major factor limiting meiotic CO formation. The fancm mutant has a threefold-increased CO frequency as compared to the wild type. These extra COs arise not from the pathway that accounts for most of the COs in wild type, but from an alternate, normally minor pathway. Thus, FANCM is a key factor imposing an upper limit on the number of meiotic COs, and its manipulation holds much promise for plant breeding.

  11. Quantum-Limited Spectroscopy

    CERN Document Server

    Truong, Gar-Wing; May, Eric F; Stace, Thomas M; Luiten, Andre N

    2015-01-01

    Spectroscopy has an illustrious history delivering serendipitous discoveries and providing a stringent testbed for new physical predictions, including applications from trace materials detection, to understanding the atmospheres of stars and planets, and even constraining cosmological models. Reaching fundamental-noise limits permits optimal extraction of spectroscopic information from an absorption measurement. Here we demonstrate a quantum-limited spectrometer that delivers high-precision measurements of the absorption lineshape. These measurements yield a ten-fold improvement in the accuracy of the excited-state (6P$_{1/2}$) hyperfine splitting in Cs, and reveals a breakdown in the well-known Voigt spectral profile. We develop a theoretical model that accounts for this breakdown, explaining the observations to within the shot-noise limit. Our model enables us to infer the thermal velocity-dispersion of the Cs vapour with an uncertainty of 35ppm within an hour. This allows us to determine a value for Boltzm...

  12. Quantum-limit spectroscopy

    CERN Document Server

    Ficek, Zbigniew

    2017-01-01

    This book covers the main ideas, methods, and recent developments of quantum-limit optical spectroscopy and applications to quantum information, resolution spectroscopy, measurements beyond quantum limits, measurement of decoherence, and entanglement. Quantum-limit spectroscopy lies at the frontier of current experimental and theoretical techniques, and is one of the areas of atomic spectroscopy where the quantization of the field is essential to predict and interpret the existing experimental results. Currently, there is an increasing interest in quantum and precision spectroscopy both theoretically and experimentally, due to significant progress in trapping and cooling of single atoms and ions. This progress allows one to explore in the most intimate detail the ways in which light interacts with atoms and to measure spectral properties and quantum effects with high precision. Moreover, it allows one to perform subtle tests of quantum mechanics on the single atom and single photon scale which were hardly eve...

  13. Limits of Lubrication in

    DEFF Research Database (Denmark)

    Olsson, David Dam

    by strategic surfaces in comparison to normal stainless steel surfaces implying a larger extent of bi-axial stretching. Numerical simulations have been applied in order to evaluate limits of lubrication in the simulative strip reduction based on predictions of critical parameters appearing in terms...... of temperature and contact pressure. The numerical models have been calibrated regarding friction and thermal contact resistance based on experimental results from actual testing conditions. It has been found that predictions of limits of lubrication are possible by numerical means and that the FE...

  14. Limits to responsible innovation

    NARCIS (Netherlands)

    de Hoop, E.; Pols, Auke; Romijn, Henny

    2016-01-01

    Responsible Innovation (RI) is a young field of research that has nevertheless had remarkable successes in dissemination within academic and political circles. However, there is relatively little awareness of its limits, blind spots and situations in which it cannot be used for actual innovation tra

  15. The Limits of Laughter.

    Science.gov (United States)

    Mindess, Harvey

    1983-01-01

    Three incidents which elucidate the limits of laughter are described. Most persons enjoy humor as comic relief, but when humor strikes a blow at something they hold dear, they find it very hard to laugh. People are upset by an irreverent attitude toward things they hold in esteem. (RM)

  16. Pushing the Photon Limit

    NARCIS (Netherlands)

    Wientjes, Emilie; Renger, Jan; Cogdell, Richard; Hulst, van Niek F.

    2016-01-01

    Nanoantennas are well-known for their effective role in fluorescence enhancement, both in excitation and emission. Enhancements of 3-4 orders of magnitude have been reported. Yet in practice, the photon emission is limited by saturation due to the time that a molecule spends in singlet and especi

  17. Tightening Home Purchase Limits

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    More Chinese cities will limit home purchase to cool the red-hot real estate market In June 2011,the average house price in 100 Chinese cities was 8,856 yuan ($1,373)per square meter.Of these cities,house prices in 75 of them increased

  18. Limitation of Auditors' Liability

    DEFF Research Database (Denmark)

    Werlauff, Erik; Foged-Ladefoged, Lise Kolding

    2014-01-01

    The article examines the question of whether rules on the limitation of auditors’ liability within the perspective of EU law are needed, and if so, which rules can provide an appropriate balance between the potential injured party’s interests and those of the auditing sector, including with respect...

  19. Limits of Software Reuse

    NARCIS (Netherlands)

    Holenderski, L.

    2006-01-01

    Software reuse is considered one of the main techniques to increasesoftware productivity. We present two simple mathematical argumentsthat show some theoretical limits of reuse. It turns out that the increase of productivity due to internal reuse is at most linear, farfrom the needed exponential gr

  20. Age Limit of Pediatrics.

    Science.gov (United States)

    Hardin, Amy Peykoff; Hackell, Jesse M

    2017-09-01

    Pediatrics is a multifaceted specialty that encompasses children's physical, psychosocial, developmental, and mental health. Pediatric care may begin periconceptionally and continues through gestation, infancy, childhood, adolescence, and young adulthood. Although adolescence and young adulthood are recognizable phases of life, an upper age limit is not easily demarcated and varies depending on the individual patient. The establishment of arbitrary age limits on pediatric care by health care providers should be discouraged. The decision to continue care with a pediatrician or pediatric medical or surgical subspecialist should be made solely by the patient (and family, when appropriate) and the physician and must take into account the physical and psychosocial needs of the patient and the abilities of the pediatric provider to meet these needs. Copyright © 2017 by the American Academy of Pediatrics.

  1. Limitations Of Infrared Thermography

    Science.gov (United States)

    Schott, John R.

    1983-03-01

    The state of the art of quantitative infrared thermography is addressed. We are asking more and more of thermography in the field of energy conservation. An energy and dollar conscious public wants to know how much heat is being lost and how much money can be saved by retrofit. Many mission oriented approaches have been developed to address these questions. However, many fundamental questions about how thermography works and how far its capabilities can be pushed have not been addressed. In addition, the theoretical and practical limits of doing benefit cost studies with thermography have not been seriously addressed. This paper discusses the limitations of the current technology and describes many unanswered but important questions facing the future use of thermography for quantitative heat loss analysis.

  2. Telescopic limiting magnitudes

    Science.gov (United States)

    Schaefer, Bradley E.

    1990-01-01

    The prediction of the magnitude of the faintest star visible through a telescope by a visual observer is a difficult problem in physiology. Many prediction formulas have been advanced over the years, but most do not even consider the magnification used. Here, the prediction algorithm problem is attacked with two complimentary approaches: (1) First, a theoretical algorithm was developed based on physiological data for the sensitivity of the eye. This algorithm also accounts for the transmission of the atmosphere and the telescope, the brightness of the sky, the color of the star, the age of the observer, the aperture, and the magnification. (2) Second, 314 observed values for the limiting magnitude were collected as a test of the formula. It is found that the formula does accurately predict the average observed limiting magnitudes under all conditions.

  3. Current limiter circuit system

    Energy Technology Data Exchange (ETDEWEB)

    Witcher, Joseph Brandon; Bredemann, Michael V.

    2017-09-05

    An apparatus comprising a steady state sensing circuit, a switching circuit, and a detection circuit. The steady state sensing circuit is connected to a first, a second and a third node. The first node is connected to a first device, the second node is connected to a second device, and the steady state sensing circuit causes a scaled current to flow at the third node. The scaled current is proportional to a voltage difference between the first and second node. The switching circuit limits an amount of current that flows between the first and second device. The detection circuit is connected to the third node and the switching circuit. The detection circuit monitors the scaled current at the third node and controls the switching circuit to limit the amount of the current that flows between the first and second device when the scaled current is greater than a desired level.

  4. Limiting Temperatures in Multifragmentation

    CERN Document Server

    Trautmann, W

    2008-01-01

    The systematic data set on isotopic effects in spectator fragmentation collected recently at the GSI laboratory permits the investigation of the N/Z dependence of the nuclear caloric curve which is of interest in several respects. In particular, new light is shed on the proposed interpretation of chemical breakup temperatures as a manifestation of the limiting temperatures predicted by the Hartree-Fock model. The obtained results are discussed within the general context of temperature measurements in multifragmentation reactions.

  5. Limits of Nuclear Stability

    CERN Document Server

    Nerlo-Pomorska, B; Kleban, M

    2003-01-01

    The modern version of the liquid-drop model (LSD) is compared with the macroscopic part of the binding energy evaluated within the Hartree-Fock- Bogoliubov procedure with the Gogny force and the relativistic mean field theory. The parameters of a liquid-drop like mass formula which approximate on the average the self-consistent results are compared with other models. The limits of nuclear stability predicted by these models are discussed.

  6. Limits of proton conductivity.

    Science.gov (United States)

    Kreuer, Klaus-Dieter; Wohlfarth, Andreas

    2012-10-15

    Parasitic current seems to be the cause for the "highest proton conductivity" of a material reported to date. Kreuer and Wohlfarth verify this hypothesis by measuring the conductivity of the same materials after preparing them in a different way. They further explain the limits of proton conductivity and comment on the problems of determining the conductivity of small objects (e.g., whiskers, see picture).

  7. Elastic limit of silicane.

    Science.gov (United States)

    Peng, Qing; De, Suvranu

    2014-10-21

    Silicane is a fully hydrogenated silicene-a counterpart of graphene-having promising applications in hydrogen storage with capacities larger than 6 wt%. Knowledge of its elastic limit is critical in its applications as well as tailoring its electronic properties by strain. Here we investigate the mechanical response of silicane to various strains using first-principles calculations based on density functional theory. We illustrate that non-linear elastic behavior is prominent in two-dimensional nanomaterials as opposed to bulk materials. The elastic limits defined by ultimate tensile strains are 0.22, 0.28, and 0.25 along armchair, zigzag, and biaxial directions, respectively, an increase of 29%, 33%, and 24% respectively in reference to silicene. The in-plane stiffness and Poisson ratio are reduced by a factor of 16% and 26%, respectively. However, hydrogenation/dehydrogenation has little effect on its ultimate tensile strengths. We obtained high order elastic constants for a rigorous continuum description of the nonlinear elastic response. The limitation of second, third, fourth, and fifth order elastic constants are in the strain range of 0.02, 0.08, and 0.13, and 0.21, respectively. The pressure effect on the second order elastic constants and Poisson's ratio were predicted from the third order elastic constants. Our results could provide a safe guide for promising applications and strain-engineering the functions and properties of silicane monolayers.

  8. Limits to growth reconsidered.

    Science.gov (United States)

    Hagen, E E

    1972-01-01

    In their book, ''The Limits of Growth,'' the authors conclude that through pollution, exhaustion of natural resources, and limits to the food supply, the world faces a catastrophic fall in population and in living standards by the middle of the 21st century. The authors fail to state, however, 1 centrally important assumption underlying their results, but which is present through their omission of the contrary assumption. In their model the continuing technical progress that has been a primary feature of the material world for the past 200 years suddenly ceases. The assumptions of the model presented in ''Limits of Growth'' are not the assumptions other analysts make - these are strangely unrealistic. These assumptions require closer examination. The assumption concerning population assumes that the sole determinants of birthrates are the level of industrialization and the food supply. This is not good demography, for demographers have long recognized that it may have been the decrease in death rates, not industrialization or the rise in income, that caused the decrease in birthrates. Furthermore, their theory that many of the natural resources are irreplacable is like the belief that the sun revolves around the earth. It is obvious and false. It neglects that part of technical process which includes invention of new natural resources. Technical advance is needed and the following are some of the problems that technical advance must overcome: 1) a need to discover how to increase food production progressively while preventing the runoff of chemical fertilizers from the soil into waterways, 2) the ''natural'' minerals on which until recently all have depended are ''biodegradable,'' 3) there is a similar problem with radioactive nuclear wastes; 4) energy must dissipate into heat; and 5) there is a need to hasten the decline in birthrates throughout the world. In conclusion, indefinitely continuing growth is not regarded as desirable only as possible.

  9. Orind Refractories Limited

    Institute of Scientific and Technical Information of China (English)

    Mr R. Mishra; Group Manging Director

    2005-01-01

    @@ "Sight can be acquired, Vision cannot". Orind Refractories Limited (ORIND), China was formed with this rare vision. At a time when the world was testing the tepid waters of China; Mr. Ravin Jhunjhunwala, Chairman of ORIND and the management of ORIND India had looked over the Great Wall to begin a journey of success. Incorported on 18th August 1994 with an initial investment of USD 5 million, ORL caters to the ever-demanding needs of the steel industry and beyond. Incidentally ORIND was the first wholly owned India company to set up base in China. Pesently, ORIND China has a 616 strong work force including 23 expatriates.

  10. Drinking to the Limit

    DEFF Research Database (Denmark)

    Järvinen, Margaretha; Ellersgaard, Christoph Houman; Larsen, Anton Grau

    2014-01-01

    The aim of this article is to analyse social status differences in alcohol norms and practices seen from the perspective of ‘health governance’. Survey data on 1442 employees in a middle-sized, Danish firm are used to construct a Bourdieu-inspired social space, tied to four forms of capital: econ...... by the Danish National Health Board. Rather, this article identifies a relatively large group of high-positioned respondents balancing at the limits of risky drinking – or transgressing them, if measured by international standards....

  11. Limitations in forensic odontology

    Directory of Open Access Journals (Sweden)

    B Kavitha

    2009-01-01

    Full Text Available The concept of using dental evidence in forensic investigation has kindled so much interest in the recent past that forensic odontology is even suggested as the single positive identification method to solve certain forensic cases. In this process, the shortcomings in forensic odontology though few are overlooked. These discrepancies associated with various methods are to be weighed cautiously to make forensic odontology a more accurate, reliable, and reproducible investigatory science. In this paper, we present our understanding of the limitations in various methods employed in forensic odontology.

  12. Marketing with limited budget

    OpenAIRE

    Smirnova, Daria

    2017-01-01

    The purpose of this research-based thesis was to get an idea how managers of two small resembling hotels of a specific region deal with marketing process with a limited budget. In addition, the aim of the thesis was to examine if hotel managers who were interviewed perceive marketing only in the way of ‘promotion’ rather than marketing research, marketing mix and marketing environment theories. It was also found out if hotel managers of those hotels consider marketing as a key to successful h...

  13. Limits to biofuels

    Directory of Open Access Journals (Sweden)

    Johansson S.

    2013-06-01

    Full Text Available Biofuel production is dependent upon agriculture and forestry systems, and the expectations of future biofuel potential are high. A study of the global food production and biofuel production from edible crops implies that biofuel produced from edible parts of crops lead to a global deficit of food. This is rather well known, which is why there is a strong urge to develop biofuel systems that make use of residues or products from forest to eliminate competition with food production. However, biofuel from agro-residues still depend upon the crop production system, and there are many parameters to deal with in order to investigate the sustainability of biofuel production. There is a theoretical limit to how much biofuel can be achieved globally from agro-residues and this amounts to approximately one third of todays’ use of fossil fuels in the transport sector. In reality this theoretical potential may be eliminated by the energy use in the biomass-conversion technologies and production systems, depending on what type of assessment method is used. By surveying existing studies on biofuel conversion the theoretical limit of biofuels from 2010 years’ agricultural production was found to be either non-existent due to energy consumption in the conversion process, or up to 2–6000TWh (biogas from residues and waste and ethanol from woody biomass in the more optimistic cases.

  14. Smoothness of limit functors

    Indian Academy of Sciences (India)

    Benedictus Margaux

    2015-05-01

    Let be a scheme. Assume that we are given an action of the one dimensional split torus $\\mathbb{G}_{m,S}$ on a smooth affine -scheme $\\mathfrak{X}$. We consider the limit (also called attractor) subfunctor $\\mathfrak{X}_{}$ consisting of points whose orbit under the given action `admits a limit at 0’. We show that $\\mathfrak{X}_{}$ is representable by a smooth closed subscheme of $\\mathfrak{X}$. This result generalizes a theorem of Conrad et al. (Pseudo-reductive groups (2010) Cambridge Univ. Press) where the case when $\\mathfrak{X}$ is an affine smooth group and $\\mathbb{G}_{m,S}$ acts as a group automorphisms of $\\mathfrak{X}$ is considered. It also occurs as a special case of a recent result by Drinfeld on the action of $\\mathbb{G}_{m,S}$ on algebraic spaces (Proposition 1.4.20 of Drinfeld V, On algebraic spaces with an action of $\\mathfrak{G}_{m}$, preprint 2013) in case is of finite type over a field.

  15. Limitations of inclusive fitness.

    Science.gov (United States)

    Allen, Benjamin; Nowak, Martin A; Wilson, Edward O

    2013-12-10

    Until recently, inclusive fitness has been widely accepted as a general method to explain the evolution of social behavior. Affirming and expanding earlier criticism, we demonstrate that inclusive fitness is instead a limited concept, which exists only for a small subset of evolutionary processes. Inclusive fitness assumes that personal fitness is the sum of additive components caused by individual actions. This assumption does not hold for the majority of evolutionary processes or scenarios. To sidestep this limitation, inclusive fitness theorists have proposed a method using linear regression. On the basis of this method, it is claimed that inclusive fitness theory (i) predicts the direction of allele frequency changes, (ii) reveals the reasons for these changes, (iii) is as general as natural selection, and (iv) provides a universal design principle for evolution. In this paper we evaluate these claims, and show that all of them are unfounded. If the objective is to analyze whether mutations that modify social behavior are favored or opposed by natural selection, then no aspect of inclusive fitness theory is needed.

  16. (Limiting the greenhouse effect)

    Energy Technology Data Exchange (ETDEWEB)

    Rayner, S.

    1991-01-07

    Traveler attended the Dahlem Research Conference organized by the Freien Universitat, Berlin. The subject of the conference was Limiting the Greenhouse Effect: Options for Controlling Atmospheric CO{sub 2} Accumulation. Like all Dahlem workshops, this was a meeting of scientific experts, although the disciplines represented were broader than usual, ranging across anthropology, economics, international relations, forestry, engineering, and atmospheric chemistry. Participation by scientists from developing countries was limited. The conference was divided into four multidisciplinary working groups. Traveler acted as moderator for Group 3 which examined the question What knowledge is required to tackle the principal social and institutional barriers to reducing CO{sub 2} emissions'' The working rapporteur was Jesse Ausubel of Rockefeller University. Other working groups examined the economic costs, benefits, and technical feasibility of options to reduce emissions per unit of energy service; the options for reducing energy use per unit of GNP; and the significant of linkage between strategies to reduce CO{sub 2} emissions and other goals. Draft reports of the working groups are appended. Overall, the conference identified a number of important research needs in all four areas. It may prove particularly important in bringing the social and institutional research needs relevant to climate change closer to the forefront of the scientific and policy communities than hitherto.

  17. Array Antenna Limitations

    CERN Document Server

    Jonsson, B L G; Hussain, N

    2013-01-01

    This letter defines a physical bound based array figure of merit that provides a tool to compare the performance of both single and multi-band array antennas with respect to return-loss, thickness of the array over the ground-plane, and scan-range. The result is based on a sum-rule result of Rozanov-type for linear polarization. For single-band antennas it extends an existing limit for a given fixed scan-angle to include the whole scan-range of the array, as well as the unit-cell structure in the bound. The letter ends with an investigation of the array figure of merit for some wideband and/or wide-scan antennas with linear polarization. We find arrays with a figure of merit >0.6 that empirically defines high-performance antennas with respect to this measure.

  18. Personal Freedom beyond Limits

    Directory of Open Access Journals (Sweden)

    Juan Fernando Sellés

    2013-07-01

    Full Text Available In this work we distinguish between freedom in the human manifestations (intelligence, will,actions and personal freedom in the personal intimacy. This second is beyond the freedom reached bythe classic and modern thought, since it takes root in the personnel act of being. Because of it, it is not possible to characterize this freedom like the classic description as ‘domain over the own acts’, becauseit is a description of ‘categorial’ order; neither like present day ‘autonomy’ or ‘independence’, becausethe existence of one person alone is impossible, since ‘person’ means relation, personal free openingto other persons, description of the ‘transcendental’ order and, therefore, to the margin of limits.

  19. Universal Limit on Communication

    CERN Document Server

    Bousso, Raphael

    2016-01-01

    I derive a universal upper bound on the capacity of any communication channel between two distant systems. The Holevo quantity, and hence the mutual information, is at most of order $E \\Delta t / \\hbar$, where $E$ the average energy of the signal, and $\\Delta t$ is the amount of time for which detectors operate. The bound does not depend on the size or mass of the emitting and receiving systems, nor on the nature of the signal. No restrictions on preparing and processing the signal are imposed. As an example, I consider the encoding of information in the transverse or angular position of a signal emitted and received by systems of arbitrarily large cross-section. In the limit of a large message space, quantum effects become important even if individual signals are classical, and the bound is upheld.

  20. Clinical limitations of Invisalign.

    Science.gov (United States)

    Phan, Xiem; Ling, Paul H

    2007-04-01

    Adult patients seeking orthodontic treatment are increasingly motivated by esthetic considerations. The majority of these patients reject wearing labial fixed appliances and are looking instead to more esthetic treatment options, including lingual orthodontics and Invisalign appliances. Since Align Technology introduced the Invisalign appliance in 1999 in an extensive public campaign, the appliance has gained tremendous attention from adult patients and dental professionals. The transparency of the Invisalign appliance enhances its esthetic appeal for those adult patients who are averse to wearing conventional labial fixed orthodontic appliances. Although guidelines about the types of malocclusions that this technique can treat exist, few clinical studies have assessed the effectiveness of the appliance. A few recent studies have outlined some of the limitations associated with this technique that clinicians should recognize early before choosing treatment options.

  1. The Limits to Relevance

    Science.gov (United States)

    Averill, M.; Briggle, A.

    2006-12-01

    Science policy and knowledge production lately have taken a pragmatic turn. Funding agencies increasingly are requiring scientists to explain the relevance of their work to society. This stems in part from mounting critiques of the "linear model" of knowledge production in which scientists operating according to their own interests or disciplinary standards are presumed to automatically produce knowledge that is of relevance outside of their narrow communities. Many contend that funded scientific research should be linked more directly to societal goals, which implies a shift in the kind of research that will be funded. While both authors support the concept of useful science, we question the exact meaning of "relevance" and the wisdom of allowing it to control research agendas. We hope to contribute to the conversation by thinking more critically about the meaning and limits of the term "relevance" and the trade-offs implicit in a narrow utilitarian approach. The paper will consider which interests tend to be privileged by an emphasis on relevance and address issues such as whose goals ought to be pursued and why, and who gets to decide. We will consider how relevance, narrowly construed, may actually limit the ultimate utility of scientific research. The paper also will reflect on the worthiness of research goals themselves and their relationship to a broader view of what it means to be human and to live in society. Just as there is more to being human than the pragmatic demands of daily life, there is more at issue with knowledge production than finding the most efficient ways to satisfy consumer preferences or fix near-term policy problems. We will conclude by calling for a balanced approach to funding research that addresses society's most pressing needs but also supports innovative research with less immediately apparent application.

  2. Limited Engagements? Women's and Men's Work/Volunteer Time in the Encore Life Course Stage.

    Science.gov (United States)

    Moen, Phyllis; Flood, Sarah

    2013-05-01

    Americans are living healthier and longer lives, but the shifting age distribution is straining existing and projected social welfare protections for older adults (e.g., Social Security, Medicare). One solution is to delay retirement. Another is an alternative to "total leisure" retirement -- an "encore" stage of paid or unpaid engagement coming after career jobs but before infirmities associated with old age. We draw on gendered life-course themes together with data from the American Time Use Survey (2003-2009) to examine the real time American men and women ages 50-75 apportion to paid work and unpaid volunteer work on an average day, as well as factors predicting their time allocations. We find that while full-time employment declines after the 50s, many Americans allot time to more limited engagements - working part time, being self-employed, volunteering, helping out - through and even beyond their 60s. Caring for a child or infirm adult reduces the odds of paid work but not volunteering. While time working for pay declines with age (though more slowly for men than women), time volunteering does not. Older men and women in poor health, without a college degree, with a disability or SSI income are the least likely to be publicly engaged. This social patterning illustrates that while the ideal of an encore of paid or unpaid voluntary, flexible, and meaningful engagement is an emerging reality for some, it appears less attainable for others. This suggests the importance of organizational and public policy innovations offering all Americans a range of encore opportunities.

  3. Protéines alimentaires et prévention des dysrégulations glycémiques: effets du glutathion et de l'apport en cystéine

    OpenAIRE

    Blouet, Clémence

    2006-01-01

    ABSTRACT: Although it has been repeatedly demonstrated that amino acids alter several mechanisms involved in glycemic control, the impact of dietary protein quantity and quality on glucose homeostasis is still a matter of debate. Oxidative stress is acknowledged as an initiating factor in the pathogenesis of insulin resistance, but the effects of cysteine intake, the rate-limiting substrate for glutathione synthesis, on glycemic control has been overlooked. Following a review of the literatur...

  4. Mobilités actives et santé : apports et limites d’un protocole de mesure de la marche et du vélo combinant des capteurs de mouvements (GPS et accéléromètres)

    OpenAIRE

    Misslin, Renaud; Charreire, Hélène; Weber, Christiane; Enaux, Christophe; Bastian, Thomas; Simon, Chantal; Oppert, Jean-Michel

    2015-01-01

    Les mobilités urbaines représentent un ensemble de comportements complexes à appréhender et difficiles à mesurer. Indépendamment des choix et des motivations individuelles, ces comportements peuvent être influencés par les caractéristiques de l’environnement urbain. Les mobilités actives, représentées par la marche et le vélo, sont peu étudiées en tant que comportements de santé alors que l’activité physique est l’un des déterminants des principales pathologies chroniques (maladies cardio-vas...

  5. Le dumping de coton-fibre : quelle réponse y apporter ? Le Sud contre le Nord, ou l'émergence d'un modèle agricole viable aux quatre coins du globe ?

    Directory of Open Access Journals (Sweden)

    Parmentier S.

    2006-01-01

    Full Text Available How to deal with cotton dumping ? The South versus the North or the emergence of a global and viable form ofagriculture ? If there is today a broad consensus on the legitimacy and the need to put an end to the dumping of the exportationof cotton fi ber, there is currently no general agreement on the way to end this practice. The strategy most often recommendedis based on the belief that this dumping originates entirely from the provision of subsidies and consists simply and only inproposing to eliminate subsidies. This strategy raises a number of issues, however. First, it relies on an erroneous diagnosis ofthe origin of dumping, and consequently prevents any real solution to the source of the problem. In addition, such strategy doesnot offer any guarantee of fair and stable prices on the international markets. Finally, this strategy conditions an amelioration ofconditions for the cotton lines of West and Central Africa (WCA to the downfall of a signifi cant part of the cotton productionin the developed countries. Starting from the examination of the limitations and problems inherent to this strategy, the presentarticle attempts to outline the contours of an alternative strategy able that is not subject to the same limitations. This alternativestrategy aims to regulate adequately the setting of agricultural prices and to manage subsidize agriculture advisedly. Ultimately,examining these two strategies partly boils down to examining the fundamental objectives of agricultural policies in the contextof the North-South relations and the current globalization. In conclusion, is the pivotal goal to « defend the South against theNorth », or rather to promote a sustainable agricultural model for farmers and other agricultural stakeholders across the world ?A corollary question is that of the means necessary to optimize the outcome of agricultureʼs aims and objectives.

  6. CFO of CNOOC Limited Changed

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ CNOOC Limited announced on December 24 that Yang Hua, Senior Vice President of CNOOC Limited and President of CNOOC International Limied will succeed Dr.Mark Qiu as Chief Financial Officer effective on January 1,2005.

  7. Charter Halibut Limited Access Program

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This limited access system limits the number of charter vessels that may participate in the guided sport fishery for halibut in area 2C and 3A. NMFS issues a charter...

  8. Guidelines for setting speed limits

    CSIR Research Space (South Africa)

    Wium, DJW

    1986-02-01

    Full Text Available A method is described for setting the speed limit for a particular road section. Several speed limits based on different criteria are described for each of nine traffic and road factors. The most appropriate speed limit for each relevant factor...

  9. The Limits of Exercise Physiology

    DEFF Research Database (Denmark)

    Gabriel, Brendan M; Zierath, Juleen R

    2017-01-01

    Many of the established positive health benefits of exercise have been documented by historical discoveries in the field of exercise physiology. These investigations often assess limits: the limits of performance, or the limits of exercise-induced health benefits. Indeed, several key findings have...

  10. Interference and memory capacity limitations.

    Science.gov (United States)

    Endress, Ansgar D; Szabó, Szilárd

    2017-10-01

    Working memory (WM) is thought to have a fixed and limited capacity. However, the origins of these capacity limitations are debated, and generally attributed to active, attentional processes. Here, we show that the existence of interference among items in memory mathematically guarantees fixed and limited capacity limits under very general conditions, irrespective of any processing assumptions. Assuming that interference (a) increases with the number of interfering items and (b) brings memory performance to chance levels for large numbers of interfering items, capacity limits are a simple function of the relative influence of memorization and interference. In contrast, we show that time-based memory limitations do not lead to fixed memory capacity limitations that are independent of the timing properties of an experiment. We show that interference can mimic both slot-like and continuous resource-like memory limitations, suggesting that these types of memory performance might not be as different as commonly believed. We speculate that slot-like WM limitations might arise from crowding-like phenomena in memory when participants have to retrieve items. Further, based on earlier research on parallel attention and enumeration, we suggest that crowding-like phenomena might be a common reason for the 3 major cognitive capacity limitations. As suggested by Miller (1956) and Cowan (2001), these capacity limitations might arise because of a common reason, even though they likely rely on distinct processes. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  11. Contributions of vitreous natural analogs to the investigation of long-term nuclear glass behavior; Apports des analogues naturels vitreux a la validation des codes de prediction du comportement a long terme des verres nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Techer, I

    1999-07-01

    This study assesses the extend of the analogy between the alteration behavior in water and in a moist clay environment of aluminosilicate volcanic glass and alumino-borosilicate nuclear containment glass. Basaltic glass alteration in water initially occurs by hydrolysis processes with an activation energy on the order of 73 kJ.mol{sup -1}. As the reaction progresses, the alteration rate drops by over four orders of magnitude from the initial rate r{sub 0}, The alteration kinetics are not governed by the alteration solution chemistry alone, the glass alteration film appears to have a major role as a diffusion barrier limiting the transfer of reaction species and products. All these aspects highlight the behavioral analogy between basaltic glass and nuclear borosilicate glass in aqueous media. Conversely, the alteration reaction of obsidian-type volcanic glass involves other mechanisms than those governing the dissolution of borosilicate glass. Basaltic glass alteration is also examined in the presence of a clay environmental material, in a study of the natural basaltic glass and argillaceous pelites system of the Salagou basin in southern France, in an approach combining mineralogical, chemical and isotopic data to assess the interactions between a basaltic glass and the argillaceous pelites. Laboratory leach test results with basaltic glass and measured data for the Salagou glass in its natural environment are modeled using a code implementing a kinetic law coupling diffusive transfer of dissolved silica with a reaction affinity law. (author)

  12. Material limitations on the detection limit in refractometry.

    Science.gov (United States)

    Skafte-Pedersen, Peder; Nunes, Pedro S; Xiao, Sanshui; Mortensen, Niels Asger

    2009-01-01

    We discuss the detection limit for refractometric sensors relying on high-Q optical cavities and show that the ultimate classical detection limit is given by min {Δn} ≳ η, with n + iη being the complex refractive index of the material under refractometric investigation. Taking finite Q factors and filling fractions into account, the detection limit declines. As an example we discuss the fundamental limits of silicon-based high-Q resonators, such as photonic crystal resonators, for sensing in a bio-liquid environment, such as a water buffer. In the transparency window (λ ≳ 1100 nm) of silicon the detection limit becomes almost independent on the filling fraction, while in the visible, the detection limit depends strongly on the filling fraction because the silicon absorbs strongly.

  13. Material Limitations on the Detection Limit in Refractometry

    CERN Document Server

    Skafte-Pedersen, Peder; Xiao, Sanshui; Mortensen, Niels Asger; 10.3390/s91108382

    2009-01-01

    We discuss the detection limit for refractometric sensors relying on high-Q optical cavities and show that the ultimate classical detection limit is given by min{Dn} > eta with n+i*eta being the complex refractive index of the material under refractometric investigation. Taking finite Q factors and filling fractions into account, the detection limit declines. As an example we discuss the fundamental limits of silicon-based high-Q resonators, such as photonic crystal resonators, for sensing in a bio-liquid environment, such as a water buffer. In the transparency window of silicon the detection limit becomes almost independent on the filling fraction, while in the visible, the detection limit depends strongly on the filling fraction because silicon absorbs strongly.

  14. Material Limitations on the Detection Limit in Refractometry

    Directory of Open Access Journals (Sweden)

    Niels Asger Mortensen

    2009-10-01

    Full Text Available We discuss the detection limit for refractometric sensors relying on high-Q optical cavities and show that the ultimate classical detection limit is given by min {Δn} ≳ η with n + iη being the complex refractive index of the material under refractometric investigation. Taking finite Q factors and filling fractions into account, the detection limit declines. As an example we discuss the fundamental limits of silicon-based high-Q resonators, such as photonic crystal resonators, for sensing in a bio-liquid environment, such as a water buffer. In the transparency window (λ ≳ 1100 nm of silicon the detection limit becomes almost independent on the filling fraction, while in the visible, the detection limit depends strongly on the filling fraction because the silicon absorbs strongly.

  15. Material limitations on the detection limit in refractometry

    DEFF Research Database (Denmark)

    Skafte-Pedersen, Peder; Nunes, Pedro; Xiao, Sanshui

    2009-01-01

    We discuss the detection limit for refractometric sensors relying on high-Q optical cavities and show that the ultimate classical detection limit is given by min {Δn} ≳ η with n + iη being the complex refractive index of the material under refractometric investigation. Taking finite Q factors...... and filling fractions into account, the detection limit declines. As an example we discuss the fundamental limits of silicon-based high-Q resonators, such as photonic crystal resonators, for sensing in a bio-liquid environment, such as a water buffer. In the transparency window (λ ≳ 1100 nm) of silicon...... the detection limit becomes almost independent on the filling fraction, while in the visible, the detection limit depends strongly on the filling fraction because the silicon absorbs strongly....

  16. Material Limitations on the Detection Limit in Refractometry

    OpenAIRE

    Niels Asger Mortensen; Sanshui Xiao; Peder Skafte-Pedersen; Nunes, Pedro S.

    2009-01-01

    We discuss the detection limit for refractometric sensors relying on high-Q optical cavities and show that the ultimate classical detection limit is given by min {Δn} ≳ η, with n + iη being the complex refractive index of the material under refractometric investigation. Taking finite Q factors and filling fractions into account, the detection limit declines. As an example we discuss the fundamental limits of silicon-based high-Q resonators, such as photonic crystal resonators, for sensing in ...

  17. Contribution of the modulation of intensity and the optimization to deliver a dose adapted to the biological heterogeneities; Apport de la modulation d'intensite et de l'optimisation pour delivrer une dose adaptee aux heterogeneites biologiques

    Energy Technology Data Exchange (ETDEWEB)

    Kubs, F

    2007-10-15

    The recent progress in functional imaging by Positron Emission Tomography (TEP) opens new perspectives in the delineation of target volumes in radiotherapy. The functional data is major; we can intend to adapt the irradiation doses on the tumor activity (TA) and to perform a dose escalation. Our objectives were (i) to characterize the TEP threshold, by quantifying the uncertainties of the target volume contour according to the lesion size and the threshold contour level, (ii) to set up the geometry suited to perform a high-precision irradiation based on the TA, (iii) to estimate the dosimetric impact of this new protocol and (iv) to verify that dosimetry is perfectly distributed. Three original phantoms were specially created to satisfy the constraints met, as well as two virtual phantoms containing 3 dose levels (dose level 3 = TA). Our results showed the importance of the effect threshold-volume on the planning in radiotherapy. To use this irradiation method, the diameter of 1 cm for the third level was able to be reached. A dose escalation of 20 Gy was possible between the second (70 Gy) and the third level (90 Gy). The dosimetric impact estimated on two real cases was suitable - increase of COIN (conformal index) from 0.6 to 0.8 and decrease of NTCP (normal tissue complication probability) of a factor 5 -. In absolute and relative dosimetry, the clinical tolerances were respected. So all the treatment process, going from the diagnosis with the TEP to reveal the TA, to the patient treatment made beforehand on phantom, and going through the ballistic and the dose calculation, was estimated and validated according to our objective to adapt the irradiation to the biological heterogeneities. However such high doses should be carefully estimated before being prescribed clinically and progress is also expected in imaging, because the minimal size which we can irradiate is on the limit of the resolution TEP. (author)

  18. Compte-rendu et apport de la conférence-débat : "Nature, conditionnalité et verdissement de la PAC : un tournant wallon ?", 9 novembre 2011, Espace Senghor, Gembloux, Belgique

    Directory of Open Access Journals (Sweden)

    Piqueray, J.

    2013-01-01

    Full Text Available Proceedings of the conference: "Nature, conditionnalité et verdissement de la PAC : un tournant wallon ?". 9th November 2011. Espace Senghor, Gembloux, Belgium. Recently, the European Union (EU proposed a reform project for the Common Agricultural Policy (CAP. One of the proposed reforms consists of imposing a set aside proportion of 7% of arable land for biodiversity support purposes. A conference on this proposal was held in Gembloux, Belgium, on 9th November 2011. Such a set aside system already exists in neighboring countries. The French and Swiss systems were presented at the conference in order to highlight their advantages and limitations. Scientific arguments underlying such policies were also presented. It was shown that the creation of semi-natural elements within the agricultural matrix is an efficient way to promote biodiversity. Both the quantity and the quality of these elements need to be considered. In addition, biodiversity is likely to provide services to agriculture, notably crop pollination and pest control. Currently, uncertainties remain regarding areas that are eligible to be designated as reaching the 7% threshold. However, based on the most probable scenarios, the current likely eligible areas cover only 4.3% of arable land in Wallonia. Less than 20% of Walloon farms already reach the 7% threshold proposed by the EU. If the European project is approved, it will therefore be of great importance to have some form of societal recognition afforded to farmers for their efforts. In order to optimize the positive effects of the policy on biodiversity, it is also imperative to ensure that a high level of biological quality is reached in the areas dedicated to biodiversity and to monitor this quality using clearly defined objectives. Economical, societal and environmental issues all need to be considered when applying this policy in order to improve agricultural sustainability and to stop the decline in biodiversity in

  19. Evaluation des apports solaires a l'echelle d'un quartier urbain en periode de chauffe selon sa typologie, son orientation et sa latitude dans un contexte de densification de la ville

    Science.gov (United States)

    Chenard, Laurent

    Mass urbanization is a major issue for town administrators. Population increase will have an impact on the quality of the environment for citizens. Government will have to take decisions to limit those effects. Green energies are part of the solution to reach fixed goals by the public administration for sustainable development. Passive solar energy is studied in this work in an urban canopy located in five different towns: San Francisco, Montreal, Bordeaux, Lyon and Stockholm. Passive solar energy is calculated in the heating season. Direct and diffuse solar radiation is considered by using the Perez model. Radiosity is not taken into account. Heating demand is calculated by the heating degree day method. Seven urban forms have been created to determine the amount of solar energy entering in every window of the urban canopy while taking into account urban context and forms. Optimal orientation of the canopy shows an increase of 5% of the passive solar radiation from original orientation, 180 degrees rotation from first orientation straight south. This value goes lower when stories are added to the urban context. A rotation of 90 degrees from the first orientation shows a decrease of 6 to 15% in solar passive gain. Densification of the urban canopy by adding stories to the buildings results in a loss up to 65% of the solar gain for the first story. It is showed that solar passive energy has a low ratio of 5% for space heating for old buildings, 1960 constructions. Today's buildings have a difference between passive solar energy and heating demand of 10 to 75% depending on the model and location.

  20. Determination of the Limiting Magnitude

    Science.gov (United States)

    Kingery, Aaron; Blaauw, Rhiannon

    2017-01-01

    The limiting magnitude of an optical camera system is an important property to understand since it is used to find the completeness limit of observations. Limiting magnitude depends on the hardware and software of the system, current weather conditions, and the angular speed of the objects observed. If an object exhibits a substantial angular rate during the exposure, its light spreads out over more pixels than the stationary stars. This spreading causes the limiting magnitude to be brighter when compared to the stellar limiting magnitude. The effect, which begins to become important when the object moves a full width at half max during a single exposure or video frame. For targets with high angular speeds or camera systems with narrow field of view or long exposures, this correction can be significant, up to several magnitudes. The stars in an image are often used to measure the limiting magnitude since they are stationary, have known brightness, and are present in large numbers, making the determination of the limiting magnitude fairly simple. In order to transform stellar limiting magnitude to object limiting magnitude, a correction must be applied accounting for the angular velocity. This technique is adopted in meteor and other fast-moving object observations, as the lack of a statistically significant sample of targets makes it virtually impossible to determine the limiting magnitude before the weather conditions change. While the weather is the dominant factor in observing satellites, the limiting magnitude for meteors also changes throughout the night due to the motion of a meteor shower or sporadic source radiant across the sky. This paper presents methods for determining the limiting stellar magnitude and the conversion to the target limiting magnitude.

  1. Developpement de competences de resolution reflexive de problemes environnementaux aupres d'enseignants en formation du Botswana: Apport d'un modele pedagogique base sur une recherche-action participative

    Science.gov (United States)

    Gauthier, Benoit

    2000-10-01

    'adaptation dans l'action par les participants presente ainsi un certain potentiel pour le developpement de plusieurs competences associees a la resolution de problemes environnementaux, et ce, dans un contexte transculturel. Cependant l'aspect reflexif associe a cette demarche demeure limite et demanderait a etre approfondi lors d'autres mises a l'essai.

  2. DISCUSSION ON DECISION LIMIT AND DETECTION LIMIT IN SPECTROSCOPY

    Institute of Scientific and Technical Information of China (English)

    郑仁圻; 余君岳; 等

    1995-01-01

    Based on fundamental arguments,the expressions for the decision limit and the detection limit both in the count domain and in the cout rate domain are derive4d.These expressions are found to be different from those shown in the existing literature.

  3. Welfare Dynamics under Time Limits

    OpenAIRE

    Jeff Grogger; Charles Michalopoulos

    2003-01-01

    Among the most important changes brought about by the Personal Responsibility and Work Opportunity Reconciliation Act of 1996 (PRWORA) is the imposition of time limits. In this paper, we analyze a simple model in which a potential welfare recipient chooses how to allocate her time-limited endowment of benefits so as to maximize her expected lifetime utility. Not surprisingly, the model reveals that time limits provide an incentive for the consumer to conserve, or bank, her benefits. More inte...

  4. Optimum shapes for pump limiters

    Energy Technology Data Exchange (ETDEWEB)

    Ulrickson, M.

    1982-05-01

    The design of a pump limiter depends strongly on the details of the plasma scrapeoff zone. A model has been developed which allows the transport coefficients in the scrapeoff to be functions of n and t. This model has been used to predict scrapeoff profiles for FED/INTOR. The profiles are used to find and analyze limiter profiles. The results suggest the use of limiter shapes which curve toward the plasma.

  5. Limit cycles in quantum systems

    Energy Technology Data Exchange (ETDEWEB)

    Niemann, Patrick

    2015-04-27

    In this thesis we investigate Limit Cycles in Quantum Systems. Limit cycles are a renormalization group (RG) topology. When degrees of freedom are integrated out, the coupling constants flow periodically in a closed curve. The presence of limit cycles is restricted by the necessary condition of discrete scale invariance. A signature of discrete scale invariance and limit cycles is log-periodic behavior. The first part of this thesis is concerned with the study of limit cycles with the similarity renormalization group (SRG). Limit cycles are mainly investigated within conventional renormalization group frameworks, where degrees of freedom, which are larger than a given cutoff, are integrated out. In contrast, in the SRG potentials are unitarily transformed and thereby obtain a band-diagonal structure. The width of the band structure can be regarded as an effective cutoff. We investigate the appearance of limit cycles in the SRG evolution. Our aim is to extract signatures as well as the scaling factor of the limit cycle. We consider the 1/R{sup 2}-potential in a two-body system and a three-body system with large scattering lengths. Both systems display a limit cycle. Besides the frequently used kinetic energy generator we apply the exponential and the inverse generator. In the second part of this thesis, Limit Cycles at Finite Density, we examine the pole structure of the scattering amplitude for distinguishable fermions at zero temperature in the medium. Unequal masses and a filled Fermi sphere for each fermion species are considered. We focus on negative scattering lengths and the unitary limit. The properties of the three-body spectrum in the medium and implications for the phase structure of ultracold Fermi gases are discussed.

  6. Chunk Limits and Length Limits in Immediate Recall: A Reconciliation

    Science.gov (United States)

    Chen, Zhijian; Cowan, Nelson

    2008-01-01

    Whereas some research on immediate recall of verbal lists has suggested that it is limited by the number of chunks that can be recalled (e.g., Tulving & Patkau, 1962; Cowan, Chen, & Rouder, 2004), other research has suggested that it is limited by the length of the material to be recalled (e.g., Baddeley, Thomson, & Buchanan, 1975). We investigated this question by teaching new paired associations between words to create two-word chunks. The results suggest that both chunk capacity limits and length limits come into play. For the free recall of 12-word lists, 6 pre-learned pairs could be recalled about as well as 6 pre-exposed singletons, suggesting a chunk limit. However, for the serially-ordered recall of 8-word lists, 4 pre-learned pairs could be recalled about as well as 8 pre-exposed singletons, suggesting a length limit. Other conditions yielded intermediate results suggesting that sometimes both limits may operate together. PMID:16393043

  7. LimitS - A system for limit state analysis and optimal material layout

    DEFF Research Database (Denmark)

    Damkilde, Lars; Krenk, Steen

    1997-01-01

    A system LimitS for limit state analysis and material optimization has been developed and implemented in a PC environment. The program is formulated in a general finite element format with stress-based elements. The solution method is based on the lower-bound theorem, where an optimal stress...... the statics and kinematics of the collapse mode are determined via the dual variables of the LP-problem. In LimitS the following element types are implemented: two- and three-dimensional beam elements; truss elements; triangular slab elements; and shear and stringer elements for plates with in-plane loading....... Examples of all three problem types are given including both limit state analysis and material optimization....

  8. LimitS - A system for limit state analysis and optimal material layout

    DEFF Research Database (Denmark)

    Damkilde, Lars; Krenk, Steen

    1997-01-01

    A system LimitS for limit state analysis and material optimization has been developed and implemented in a PC environment. The program is formulated in a general finite element format with stress-based elements. The solution method is based on the lower-bound theorem, where an optimal stress...... the statics and kinematics of the collapse mode are determined via the dual variables of the LP-problem. In LimitS the following element types are implemented: two- and three-dimensional beam elements; truss elements; triangular slab elements; and shear and stringer elements for plates with in-plane loading....... Examples of all three problem types are given including both limit state analysis and material optimization....

  9. Solubility limits on radionuclide dissolution

    Energy Technology Data Exchange (ETDEWEB)

    Kerrisk, J.F.

    1984-12-31

    This paper examines the effects of solubility in limiting dissolution rates of a number of important radionuclides from spent fuel and high-level waste. Two simple dissolution models were used for calculations that would be characteristics of a Yucca Mountain repository. A saturation-limited dissolution model, in which the water flowing through the repository is assumed to be saturated with each waste element, is very conservative in that it overestimates dissolution rates. A diffusion-limited dissolution model, in which element-dissolution rates are limited by diffusion of waste elements into water flowing past the waste, is more realistic, but it is subject to some uncertainty at this time. Dissolution rates of some elements (Pu, Am, Sn, Th, Zr, Sm) are always limited by solubility. Dissolution rates of other elements (Cs, Tc, Np, Sr, C, I) are never solubility limited; their release would be limited by dissolution of the bulk waste form. Still other elements (U, Cm, Ni, Ra) show solubility-limited dissolution under some conditions. 9 references, 3 tables.

  10. Delving into Limits of Sequences

    Science.gov (United States)

    Cory, Beth; Smith, Ken W.

    2011-01-01

    Limits are foundational to the central concepts of calculus. However, the authors' experiences with students and educational research abound with examples of students' misconceptions about limits and infinity. The authors wanted calculus students to understand, appreciate, and enjoy their first introduction to advanced mathematical thought. Thus,…

  11. Delving into Limits of Sequences

    Science.gov (United States)

    Cory, Beth; Smith, Ken W.

    2011-01-01

    Limits are foundational to the central concepts of calculus. However, the authors' experiences with students and educational research abound with examples of students' misconceptions about limits and infinity. The authors wanted calculus students to understand, appreciate, and enjoy their first introduction to advanced mathematical thought. Thus,…

  12. Beam-limiting and radiation-limiting interlocks

    Energy Technology Data Exchange (ETDEWEB)

    Macek, R.J.

    1996-04-01

    This paper reviews several aspects of beam-limiting and radiation- limiting interlocks used for personnel protection at high-intensity accelerators. It is based heavily on the experience at the Los Alamos Neutron Science Center (LANSCE) where instrumentation-based protection is used extensively. Topics include the need for ``active`` protection systems, system requirements, design criteria, and means of achieving and assessing acceptable reliability. The experience with several specific devices (ion chamber-based beam loss interlock, beam current limiter interlock, and neutron radiation interlock) designed and/or deployed to these requirements and criteria is evaluated.

  13. Force Limited Vibration Testing Monograph

    Science.gov (United States)

    Scharton, Terry D.

    1997-01-01

    The practice of limiting the shaker force in vibration tests was investigated at the NASA Jet Propulsion Laboratory (JPL) in 1990 after the mechanical failure of an aerospace component during a vibration test. Now force limiting is used in almost every major vibration test at JPL and in many vibration tests at NASA Goddard Space Flight Center (GSFC) and at many aerospace contractors. The basic ideas behind force limiting have been in the literature for several decades, but the piezo-electric force transducers necessary to conveniently implement force limiting have been available only in the last decade. In 1993, funding was obtained from the NASA headquarters Office of Chief Engineer to develop and document the technology needed to establish force limited vibration testing as a standard approach available to all NASA centers and aerospace contractors. This monograph is the final report on that effort and discusses the history, theory, and applications of the method in some detail.

  14. Chunk Limits and Length Limits in Immediate Recall: A Reconciliation

    Science.gov (United States)

    Chen, Zhijian; Cowan, Nelson

    2005-01-01

    Whereas some research on immediate recall of verbal lists has suggested that it is limited by the number of chunks that can be recalled (e.g., N. Cowan, Z. Chen, & J. N. Rouder, 2004; E. Tulving & J. E. Patkau, 1962), other research has suggested that it is limited by the length of the material to be recalled (e.g., A. D. Baddeley, N. Thomson, &…

  15. Physical limits in semiconductor electronics.

    Science.gov (United States)

    Keyes, R W

    1977-03-18

    Although the limitations of the methods of lithography in use at a particular time are easily recognized and attract substantial attention, experience shows that technological ingenuity keeps pushing them to ever-smaller dimensions. There seems to be no fundamental reason to expect that lithographic limits will not continue to recede. The limits to the advance of miniaturization are to be found in the ability of materials to withstand high electric fields and in the ability of packaging technology to remove heat from active components and provide for power distribution, signal interconnection, and flexible mechanical assembly.

  16. Fundamental Limits of Ultrathin Metasurfaces

    CERN Document Server

    Arbabi, Amir

    2014-01-01

    We present universal theoretical limits on the operation and performance of non-magnetic passive ultrathin metasurfaces. In particular, we prove that their local transmission, reflection, and polarization conversion coefficients are confined to limited regions of the complex plane. As a result, full control over the phase of the light transmitted through such metasurfaces cannot be achieved if the polarization of the light is not to be affected at the same time. We also establish fundamental limits on the maximum polarization conversion efficiency of these metasurfaces, and show that they cannot achieve more than 25% polarization conversion efficiency in transmission.

  17. The Limits to Giving Back

    Directory of Open Access Journals (Sweden)

    Jade S. Sasser

    2014-07-01

    Full Text Available In this thematic section, authors consider the limitations on giving back that they faced in field research, or saw others face. For some authors, their attempts at giving back were severely limited by the scope of their projects, or their understandings of local cultures or histories. For others, very specific circumstances and historical interventions of foreigners in certain places can limit how and to what extent a researcher is able to have a reciprocal relationship with the participating community. Some authors, by virtue of their lesser positions of power relative to those that they were studying, simply decided not to give back to those communities. In each article it becomes apparent that how and in what ways people give back is unique (and limited both to their personal values and the contexts in which they do research.

  18. OECD Maximum Residue Limit Calculator

    Science.gov (United States)

    With the goal of harmonizing the calculation of maximum residue limits (MRLs) across the Organisation for Economic Cooperation and Development, the OECD has developed an MRL Calculator. View the calculator.

  19. Multifamily Tax Subsidy Income Limits

    Data.gov (United States)

    Department of Housing and Urban Development — Multifamily Tax Subsidy Projects (MTSP) Income Limits were developed to meet the requirements established by the Housing and Economic Recovery Act of 2008 (Public...

  20. Limits of Kansei - Kansei unlimited

    OpenAIRE

    BONGARD-BLANCHY, Kerstin; Bouchard, Carole; AOUSSAT, Améziane

    2013-01-01

    International audience; This article discusses momentary limitations of the Kansei Engineering methods. There are for example the focus on the evaluation of colour and form factors, as well as the highly time consuming creation of the questionnaires. To overcome these limits we firstly suggest the integration of word lists from related research fields, like sociology and cognitive psychology on product emotions in the Kansei questionnaires. Thereafter we present a study on the wide range of K...

  1. Limit cycle vibrations in turbomachinery

    Science.gov (United States)

    Ryan, S. G.

    1991-01-01

    The focus is on an examination of rotordynamic systems which are simultaneously susceptible to limit cycle instability and subharmonic response. Characteristics of each phenomenon are determined as well as their interrelationship. A normalized, single mass rotor model is examined as well as a complex model of the high pressure fuel turbopump and the Space Shuttle Main Engine. Entrainment of limit cycle instability by subharmonic response is demonstrated for both models. The nonuniqueness of the solution is also demonstrated.

  2. Time-limited optimal dynamics beyond the Quantum Speed Limit

    DEFF Research Database (Denmark)

    Gajdacz, Miroslav; Das, Kunal K.; Arlt, Jan

    2015-01-01

    -off expressed in terms of the direct Hilbert velocity provides a robust prediction of the quantum speed limit and allows to adapt the control optimization such that it yields a predefined fidelity. The results are verified numerically in a multilevel system with a constrained Hamiltonian, and a classification......The quantum speed limit sets the minimum time required to transfer a quantum system completely into a given target state. At shorter times the higher operation speed has to be paid with a loss of fidelity. Here we quantify the trade-off between the fidelity and the duration in a system driven...

  3. Stable isotopes as a tool to apportion atmospheric iron.

    Science.gov (United States)

    Majestic, Brian J; Anbar, Ariel D; Herckes, Pierre

    2009-06-15

    Identification of atmospheric iron is a key parameter to understanding the source of iron in urban and remote areas. Atmospheric deposition of desert dust, which also can include an anthropogenic component, is a primary nutrient source for most of the open ocean. To better assess particulate matter (PM) sources specific to iron, we measured the iron isotopic composition of aerosols in two size fractions: PM with aerodynamic diameters less than 2.5 microm and less than 10 microm (PM2.5 and PM10, respectively). Using colocated samplers, atmospheric aerosol samples were collected in the U.S. desert Southwest at a mixed suburban/agricultural site near Phoenix, AZ. The measurements are presented as delta56Fe relative to the IRMM-014 (Institute for Reference Materials and Measurements) standard. Using multiple collector inductively coupled plasma mass spectrometry, we found differences in iron isotopic composition within the PM10 aerosol. Half of the PM10 samples had an iron isotopic signature similar to crustal material (+0.03 per thousand), which implicates wind-blown soil-dust as the primary source. The other PM10 samples showed a lighter iron isotopic composition, centered at -0.18 per thousand. Further analysis showed thatthe lighter iron was associated with winds originating from the southwest. This strongly suggests that there is a different PM10 source in this direction, with a distinct iron isotopic composition. The iron in the PM2.5 samples was usually substantially lighter than the corresponding PM10 samples, which is consistent with coarse and fine particles having different sources, again with distinctively different isotopic compositions. The magnitude of the iron isotopic difference between the PM10 and the PM2.5 size fractions (delta56Fe(PM10) - delta56Fe(PM2.5)) correlated with the PM2.5 concentrations of elements known to be emitted from industrial sources (Pb, Cd, As, V, and Cr). This observation implies that the isotopically light iron is created or emitted alongside industrial processes. Our data demonstrate that iron isotope composition can be a valuable tool in the source-apportionment of iron in atmospheric particles.

  4. Apports lipidiques et prise de poids : aspects qualitatifs

    Directory of Open Access Journals (Sweden)

    Ailhaud Gérard

    2008-01-01

    Full Text Available The importance of dietary fat in human obesity remains a controversial issue as the prevalence of overweight and obesity has increased despite no dramatic change in the amount of ingested fats over the last decades. However qualitative changes, i.e. the fatty acid composition of fats, have been largely disregarded. In this review, we summarize experimental evidence which supports polyunsaturated fatty acids of the x6 series as potent stimulators of both adipogenesis in vitro and adipose tissue development in vivo. Changes observed over the last decades in the fatty acid composition of dietary fats observed in breast milk and formula milk, i.e. increase in LA with lower or no change in LNA content, may be responsible at least in part of the dramatic rise in the prevalence of childhood overweight and obesity. Similar changes, which are observed in most consumed foods, can be traced to changes in human food habits and in the feeding pattern of breeding stock. These qualitative changes, acting in concert with a positive energy balance, should promote excessive adipose tissue development. Whether prevention of obesity appears critical to avoid difficult if not insurmountable health problems to solve in the future, the status of dietary lipids should be reconsidered from the very beginning of the food chain.

  5. Apports nutritionnels, dépense et bilan énergétiques chez l’homme et les primates non-humains : aspects méthodologiques Nutritional intakes, energy expenditure and energy balance in human and non-human primates: methodological aspects

    Directory of Open Access Journals (Sweden)

    Laurent Tarnaud

    2011-02-01

    Full Text Available Cet article est une revue des méthodes de terrain et des techniques de laboratoire, traditionnelles et récentes, qui permettent d’évaluer les apports alimentaires et nutritionnels, les profils d’activité, la dépense énergétique et les réserves énergétiques corporelles des primates humains et non-humains. Cette revue a pour objectif de faire le point sur l’avancement des techniques utilisées pour estimer les paramètres énergétiques en anthropobiologie. Les primates non-humains et l’homme partagent un certain nombre de traits psycho-physiologiques issus des processus d’adaptation biologique à l’environnement et/ou liés à l’inertie phylogénétique. Identifier les mécanismes qui président à la dynamique énergétique chez les primates non-humains permet ainsi de situer certaines des bases biologiques partagées avec l’homme dans le contexte de l’évolution. Cette revue s'attache donc à présenter les méthodes en dégageant, lorsqu’ils existent, les points de recoupement des différentes approches méthodologiques appliquées à l’homme et aux primates non-humains. Par ailleurs, des comparaisons inter-populationnelles au sein de l’espèce humaine ou chez des primates non-humains permettent de préciser les relations entre les variables écologiques et les adaptations énergétiques. Dans cet article le lecteur trouvera différentes méthodes, présentées dans différents chapitres, selon qu'il s'intéresse à décrire et quantifier les apports alimentaires, nutritionnels et énergétiques des individus dans des conditions environnementales spécifiques, mesurer les dépenses énergétiques associées aux activités ou déterminer le statut nutritionnel et la composition corporelle des individus ou encore préciser le rôle des composés secondaires sur la sélection des items alimentaires et les propriétés pharmacologiques des plantes consommées. À l’origine descriptives, les méthodes actuelles

  6. Generalized Geometric Quantum Speed Limits

    Science.gov (United States)

    Pires, Diego Paiva; Cianciaruso, Marco; Céleri, Lucas C.; Adesso, Gerardo; Soares-Pinto, Diogo O.

    2016-04-01

    The attempt to gain a theoretical understanding of the concept of time in quantum mechanics has triggered significant progress towards the search for faster and more efficient quantum technologies. One of such advances consists in the interpretation of the time-energy uncertainty relations as lower bounds for the minimal evolution time between two distinguishable states of a quantum system, also known as quantum speed limits. We investigate how the nonuniqueness of a bona fide measure of distinguishability defined on the quantum-state space affects the quantum speed limits and can be exploited in order to derive improved bounds. Specifically, we establish an infinite family of quantum speed limits valid for unitary and nonunitary evolutions, based on an elegant information geometric formalism. Our work unifies and generalizes existing results on quantum speed limits and provides instances of novel bounds that are tighter than any established one based on the conventional quantum Fisher information. We illustrate our findings with relevant examples, demonstrating the importance of choosing different information metrics for open system dynamics, as well as clarifying the roles of classical populations versus quantum coherences, in the determination and saturation of the speed limits. Our results can find applications in the optimization and control of quantum technologies such as quantum computation and metrology, and might provide new insights in fundamental investigations of quantum thermodynamics.

  7. Generalized Geometric Quantum Speed Limits

    Directory of Open Access Journals (Sweden)

    Diego Paiva Pires

    2016-06-01

    Full Text Available The attempt to gain a theoretical understanding of the concept of time in quantum mechanics has triggered significant progress towards the search for faster and more efficient quantum technologies. One of such advances consists in the interpretation of the time-energy uncertainty relations as lower bounds for the minimal evolution time between two distinguishable states of a quantum system, also known as quantum speed limits. We investigate how the nonuniqueness of a bona fide measure of distinguishability defined on the quantum-state space affects the quantum speed limits and can be exploited in order to derive improved bounds. Specifically, we establish an infinite family of quantum speed limits valid for unitary and nonunitary evolutions, based on an elegant information geometric formalism. Our work unifies and generalizes existing results on quantum speed limits and provides instances of novel bounds that are tighter than any established one based on the conventional quantum Fisher information. We illustrate our findings with relevant examples, demonstrating the importance of choosing different information metrics for open system dynamics, as well as clarifying the roles of classical populations versus quantum coherences, in the determination and saturation of the speed limits. Our results can find applications in the optimization and control of quantum technologies such as quantum computation and metrology, and might provide new insights in fundamental investigations of quantum thermodynamics.

  8. Why Property Tax Limitations Won't Limit Everyone's Taxes.

    Science.gov (United States)

    Picus, Larry

    Property tax limitation measures passed in 1978 by voters in California and Idaho contain provisions that apparently will reduce the equity of the property tax system in both states. Changes in assessment practices mandated by the new laws will shift the property tax burden away from business and commercial property and toward residential property…

  9. Ultimate physical limits to computation

    CERN Document Server

    Lloyd, S

    1999-01-01

    Computers are physical systems: what they can and cannot do is dictated by the laws of physics. In particular, the speed with which a physical device can process information is limited by its energy, and the amount of information that it can process is limited by the number of degrees of freedom it possesses. The way in which it processes information is determined by the forces of nature that the computer has at its disposal. This paper explores the fundamental physical limits of computation as determined by the speed of light c, the quantum scale as given by Planck's constant h, and the gravitational constant G. As an example, quantitative bounds are put to the computational power of an `ultimate laptop' with a mass of one kilogram confined to a volume of one liter.

  10. Derived limits for surface contamination

    CERN Document Server

    Wrixon, A D; Linsley, G S; White, D F

    1979-01-01

    Derived limits (DLs) for surface contamination were first established for use in the nuclear energy industry where a wide variety of radionuclides is encountered. They were later used in factories, hospitals, and universities, where the radionuclides used are normally fewer in number, either known or readily identifiable, and often of low toxicity. In these situations the current limits are frequently over-restrictive. This report describes a reassessment of the values in the light of more recent information on the possible pathways of exposure and the dose equivalent limits given in ICRP Publication 26. The reassessment is prompted also by the introduction of SI units. The results of the reassessment are used to produce a classification of DLs for all radionuclides for active and inactive area surfaces and for skin.

  11. Limitations on quantum key repeaters.

    Science.gov (United States)

    Bäuml, Stefan; Christandl, Matthias; Horodecki, Karol; Winter, Andreas

    2015-04-23

    A major application of quantum communication is the distribution of entangled particles for use in quantum key distribution. Owing to noise in the communication line, quantum key distribution is, in practice, limited to a distance of a few hundred kilometres, and can only be extended to longer distances by use of a quantum repeater, a device that performs entanglement distillation and quantum teleportation. The existence of noisy entangled states that are undistillable but nevertheless useful for quantum key distribution raises the question of the feasibility of a quantum key repeater, which would work beyond the limits of entanglement distillation, hence possibly tolerating higher noise levels than existing protocols. Here we exhibit fundamental limits on such a device in the form of bounds on the rate at which it may extract secure key. As a consequence, we give examples of states suitable for quantum key distribution but unsuitable for the most general quantum key repeater protocol.

  12. On Setting Limits for Supersymmetry

    Science.gov (United States)

    Simeon, Paul; Toback, David

    2004-10-01

    When searching for new particles two separate production mechanisms from the same theory may produce the same final state. For example, in gauge mediated supersymmetry breaking with \\chi^0_1arrow γ tildeG at least two production mechanisms, \\chi^0_1\\chi^±1 and \\chi^0_2\\chi^±_1, can cascade to produce events with two photons and missing transverse energy. If there is no discovery one wants to set the best possible limits. While it seems obvious that the goal is to find the lowest possible cross section limit, one should be careful and focus on excluding the largest amount of parameter space for a theory. We show that the combined cross section limit from both (or all) production mechanisms that produce the same final state is the most sensitive way to attempt to exclude a theory.

  13. The Newtonian Limit of Geometrostatics

    CERN Document Server

    Cederbaum, Carla

    2012-01-01

    This thesis discusses the Newtonian limit of General Relativity for static isolated systems with compactly supported matter. We call these systems "geometrostatic" to underline their geometric nature. We introduce new quasi-local notions of mass and center of mass that can be read off locally in the vicinity of the matter/black holes. We prove that these notions asymptotically coincide with ADM-mass and the Huisken-Yau CMC-center of mass. Moreover, we prove that they converge to Newtonian mass and center of mass in the Newtonian limit. The Newtonian limit is discussed in the language of Ehlers' frame theory. Furthermore, we prove several uniqueness claims in geometrostatics as well as other geometric and physical properties of these systems. We analyze equipotential sets, provide a pseudo-Newtonian reformulation of geometrostatics, and prove uniqueness of static photon spheres.

  14. Complex ABCC8 DNA variations in congenital hyperinsulinism: lessons from functional studies

    DEFF Research Database (Denmark)

    Muzyamba, Morris; Farzaneh, Tabasum; Behe, Phillip

    2007-01-01

    nonfunctional. Combining the two mutations (SUR1D1193V/R1436Q) led to intracellular retention of the channel complex. In a second family, the patient had histologically focal disease and was heterozygous for two mutations from his father (G228D and D1471N) and one from his mother (V1572I). SUR1 G228D and D1471N...

  15. The spectrum of ABCC8 mutations in Norwegian patients with congenital hyperinsulinism of infancy

    DEFF Research Database (Denmark)

    Sandal, T; Laborie, L B; Brusgaard, K;

    2009-01-01

    Potassium channels in the plasma membrane of the pancreatic beta cells are critical in maintaining glucose homeostasis by responding to ATP and coupling metabolic changes to insulin secretion. These channels consist of subunits denoted the sulfonylurea receptor SUR1 and the inwardly rectifying ion...

  16. Long-term lanreotide treatment in six patients with congenital hyperinsulinism

    National Research Council Canada - National Science Library

    Kühnen, Peter; Marquard, Jan; Ernert, Andrea; Meissner, Thomas; Raile, Klemens; Wannenmacher, Gertrud; Blankenstein, Oliver

    2012-01-01

    .... Therefore, it is important to develop new strategies to improve blood glucose control. We report the use of the very-long-acting somatostatin analogue lanreotide autogel in 6 patients with CHI over a mean duration of 40.8 months...

  17. Reconnectable Network with Limited Resources

    Institute of Scientific and Technical Information of China (English)

    史维更

    1991-01-01

    The reachability of a strongly connected network may be destroyed after link damage.Since many networks are directed or equivalent directed,connected by directed links with the potential for reversal.Therefore the reachability can be restored by reversing the direction of links.[1] has studied this matter under unlimited resources (transmitter and receiver) condition.In this paper the reconnectability of a network with limited number of receivers and transmitters is discussed.Also a linear time algorithm is given to find a reconnected reversal for limited receivers and transmitters.

  18. Paradox of simple limiter control.

    Science.gov (United States)

    Hilker, Frank M; Westerhoff, Frank H

    2006-05-01

    Chaos control by simple limiters is an easy-to-implement and effective method of stabilizing irregular fluctuations. Here we show that applying limiter control to a state variable can significantly shift its mean value. In many situations, this is a countereffective as well as unexpected result, when the aim of control is also to restrict the dynamics. We discuss this effect on the basis of a model of population dynamics and conclude that it can have severe implications for the management of pest species and epidemic spread.

  19. 77 FR 76841 - Lending Limits

    Science.gov (United States)

    2012-12-31

    ... surplus if the loan is fully secured. Section 5(u)(1) of the Home Owners' Loan Act (HOLA), 12 U.S.C. 1464...) of HOLA, 12 U.S.C. 1464(u)(2), includes exceptions to the lending limits for certain loans made by savings associations. These HOLA provisions apply to both Federal and state-chartered savings...

  20. Aluminum honeycomb impact limiter study

    Energy Technology Data Exchange (ETDEWEB)

    Yaksh, M.C.; Thompson, T.C. (Nuclear Assurance Corp., Norcross, GA (United States)); Nickell, R.E. (Applied Science and Technology, Inc., Poway, CA (United States))

    1991-07-01

    Design requirements for a cask transporting radioactive materials must include the condition of the 30-foot free fall of the cask onto an unyielding surface. To reduce the deceleration loads to a tolerable level for all the components of the cask, a component (impact limiter) is designed to absorb the kinetic energy. The material, shape, and method of attachment of the impact limiter to the cask body comprises the design of the impact limiter. The impact limiter material of interest is honeycomb aluminum, and the particular design examined was for the NAC Legal Weight Truck cask (NAC-LWT) for spent fuel from light water reactors. The NAC-LWT has a design weight of 52,000 pounds, and it has a nominal length of 200 inches. The report describes the numerical calculations embodied in the FADE program to determine the accelerations and crush strain resulting from an arbitrary height and angle of orientation. Since the program serves as a design tool, static tests are performed to assess the effect of the shell containing the honeycomb aluminum. The static tests and their results are contained in the study. The static tests are used to demonstrate for licensing purposes the level of accelerations imposed on the cask during a 30-foot drop. 3 refs., 41 figs., 15 tabs.

  1. Corporate Architecture and Limited Liability

    NARCIS (Netherlands)

    Couwenberg, Oscar

    2007-01-01

    Abstract This paper studies the effect of limited liability on corporate architecture. Corporate architecture refers to the use of governance instruments within the firm to control the behavior of employees. Four general instruments are defined that form the basis of the firm as a governance arrange

  2. Historical Drawbacks of Limited Liability

    Directory of Open Access Journals (Sweden)

    Denis Boyle

    2016-07-01

    Full Text Available Limited liability is a human invention which has facilitated enormous economic growth around the world, particularly since the time of its general application in advanced countries during the nineteenth century. The individual legal identity of companies, coupled with the limited liability of their owners, has provided protection for investors from the risks associated with their investments. It has thus contributed to increase the sources of capital available to finance projects which might otherwise have been considered unviable. However, the legal protection offered to investors has negative consequences for other participants in economies. Speculation in stock markets often damages society. It is very important to study the drawbacks of limited liability and to suggest modifications to achieve a more stable, less volatile, economic growth in the world. Although this article goes to some lengths to recognise the work of authors who emphasise the positive historical economic contribution of limited lability, its main objective is to provoke a reflection around texts which point out the drawbacks and propose solutions.

  3. Certifying Equality With Limited Interaction

    DEFF Research Database (Denmark)

    Brody, Joshua Eric; Chakrabarti, Amit; McGregor, Andrew

    2012-01-01

    by focusing on two subtle aspects. The first is to consider the {\\em expected} communication cost (at a worst-case input) for a protocol that uses limited interaction---i.e., a bounded number of rounds of communication---and whose error probability is zero or close to it. The second is to consider the {\\em...

  4. Limits to Scale and Scope

    DEFF Research Database (Denmark)

    Pedersen, Kurt; Sørensen, Peter

    2007-01-01

    slaughterhouse merger in 1890/91 between the established private slaughterhouses and the rising co-operative ones. The article deals with the question of the relevance of Chandler's concepts to the negotiation process and with that of the limits to the explanatory power of the framework. In order to answer...

  5. Explosion limits for combustible gases

    Institute of Scientific and Technical Information of China (English)

    TONG Min-ming; WU Guo-qing; HAO Ji-fei; DAI Xin-lian

    2009-01-01

    Combustible gases in coal mines are composed of methane, hydrogen, some multi-carbon alkane gases and other gases. Based on a numerical calculation, the explosion limits of combustible gases were studied, showing that these limits are related to the concentrations of different components in the mixture. With an increase of C4H10 and C6H14, the Lower ExplosionLimit (LEL) and Upper Explosion-Limit (UEL) of a combustible gas mixture will decrease clearly. For every 0.1% increase in C4H10 and C6H14, the LEL decreases by about 0.19% and the UEL by about 0.3%. The results also prove that, by increasing the amount of H2, the UEL of a combustible gas mixture will increase considerably. If the level of H2 increases by 0.1%, the UEL will increase by about 0.3%. However, H2 has only a small effect on the LEL of the combustible gas mixture. Our study provides a theoretical foundation for judging the explosion risk of an explosive gas mixture in mines.

  6. Landscape genetics and limiting factors

    Science.gov (United States)

    Samuel A. Cushman; Andrew J. Shirk; Erin L. Landguth

    2013-01-01

    Population connectivity is mediated by the movement of organisms or propagules through landscapes. However, little is known about how variation in the pattern of landscape mosaics affects the detectability of landscape genetic relationships. The goal of this paper is to explore the impacts of limiting factors on landscape genetic processes using simulation...

  7. Environmental risk limits for zinc

    NARCIS (Netherlands)

    Bodar CWM; SEC

    2007-01-01

    Environmental Riks Limits (ERLs) were derived for zinc. ERLs serve as advisory values to set environmental quality standards in the Netherlands. The ERLs for zinc closely follow the outcomes of earlier discussions on zinc within the Water Framework Directive and EC Regulation 793/93. The ERLs refer

  8. Environmental risk limits for zinc

    NARCIS (Netherlands)

    Bodar CWM; SEC

    2007-01-01

    Environmental Riks Limits (ERLs) were derived for zinc. ERLs serve as advisory values to set environmental quality standards in the Netherlands. The ERLs for zinc closely follow the outcomes of earlier discussions on zinc within the Water Framework Directive and EC Regulation 793/93. The ERLs ref

  9. The Limits of Collaborative Evaluation.

    Science.gov (United States)

    Lewkowicz, Jo A.; Nunan, David

    1999-01-01

    Describes the development of a collaborative evaluation model and its application to a curricular innovation project within a secondary school system in Hong Kong. Focuses on the limits of collaboration in long-term evaluation projects with multiple stakeholders. (Author/VWL)

  10. The Limits of Collaborative Evaluation.

    Science.gov (United States)

    Lewkowicz, Jo A.; Nunan, David

    1999-01-01

    Describes the development of a collaborative evaluation model and its application to a curricular innovation project within a secondary school system in Hong Kong. Focuses on the limits of collaboration in long-term evaluation projects with multiple stakeholders. (Author/VWL)

  11. Active inrush-current limiter

    Science.gov (United States)

    Kichak, R. A.

    1977-01-01

    By stretching turn-on time from approximately 1 to 200 ms, effects of inrush current (and of associated large current spikes) and current rate of rise (dl/dt) are made potentially less severe. Limiter arrangement consists of time-variable impedance connected in series between input dc power source return and power circuit of converter.

  12. Setting time limits on tests

    NARCIS (Netherlands)

    Linden, van der Wim J.

    2011-01-01

    It is shown how the time limit on a test can be set to control the probability of a test taker running out of time before completing it. The probability is derived from the item parameters in the lognormal model for response times. Examples of curves representing the probability of running out of ti

  13. LIMITS OF THE EARTH BIOSPHERE

    Directory of Open Access Journals (Sweden)

    Karel KUDRNA

    2011-01-01

    Full Text Available Evaluation of the state of CO2 accumulation in the atmosphere demands knowledge on possibilities of the biosphere – its photosynthetizing apparatus, conditions and limits of absorption. A decisive precondition is to determine relation of CO2 accumulation by photosynthesis in dependence on the water balance, especially on its control quantity – transpiration, which is stabilized by supporting of underground waters.

  14. Limits of time in cosmology

    CERN Document Server

    Rugh, Svend E

    2016-01-01

    We provide a discussion of some main ideas in our project about the physical foundation of the time concept in cosmology. It is standard to point to the Planck scale (located at $\\sim 10^{-43}$ seconds after a fictitious "Big Bang" point) as a limit for how far back we may extrapolate the standard cosmological model. In our work we have suggested that there are several other (physically motivated) interesting limits -- located at least thirty orders of magnitude before the Planck time -- where the physical basis of the cosmological model and its time concept is progressively weakened. Some of these limits are connected to phase transitions in the early universe which gradually undermine the notion of 'standard clocks' widely employed in cosmology. Such considerations lead to a 'scale problem' for time which becomes particularly acute above the electroweak phase transition (before $\\sim 10^{-11}$ seconds). Other limits are due to problems of building up a cosmological reference frame, or even contemplating a s...

  15. Time-limited optimal dynamics beyond the Quantum Speed Limit

    DEFF Research Database (Denmark)

    Gajdacz, Miroslav; Das, Kunal K.; Arlt, Jan

    2015-01-01

    The quantum speed limit sets the minimum time required to transfer a quantum system completely into a given target state. At shorter times the higher operation speed has to be paid with a loss of fidelity. Here we quantify the trade-off between the fidelity and the duration in a system driven...... by a time-varying control. The problem is addressed in the framework of Hilbert space geometry offering an intuitive interpretation of optimal control algorithms. This approach leads to a necessary criterion for control optimality applicable as a measure of algorithm convergence. The time fidelity trade......-off expressed in terms of the direct Hilbert velocity provides a robust prediction of the quantum speed limit and allows to adapt the control optimization such that it yields a predefined fidelity. The results are verified numerically in a multilevel system with a constrained Hamiltonian, and a classification...

  16. 40 CFR 161.175 - Certified limits.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Certified limits. 161.175 Section 161... Certified limits. The applicant must propose certified limits for the ingredients in the product. Certified limits become legally binding limits upon approval of the application. Certified limits will apply to...

  17. Limitation and life in space

    Science.gov (United States)

    Israel, Marvin; Smith, T. Scott

    1986-08-01

    ``The Earth is the very quintescence of the human condition...,'' says Hannah Arendt. Georg Simmel writes: ``The stranger is by nature no `owner of soil'—soil not only in the physical, but also in the figurative sense of a life-substance which is fixed, if not in a point in space, at least in an ideal point of social environment.'' How will no longer being Earthbound affect persons' experience of themselves and of others? Space colonization offers an opportunity for new self-definition by the alteration of existing limits. Thus ``limitation'' is a useful concept for exploring the physical, social and psychological significance of the colonization of space. Will people seek the security of routine, of convention, of hierarchy as in the military model governing our present-day astronauts? or will they seek to maximize the freedom inherent in extraordinary living conditions—as bohemians, deviants, travelers?

  18. Swimming as a limit cycle

    CERN Document Server

    Jacobs, Henry O

    2012-01-01

    Steady swimming can be characterized as both periodic and stable. These characteristics are the very definition of limit cycles, and so we ask "Can we view swimming as a limit cycle?" In this paper we will find that the answer is "yes". We will define a class of dissipative systems which correspond to the passive dynamics of a body immersed in a Navier-Stokes fluid (i.e. the dynamics of a dead fish). Upon performing reduction by symmetry we will find a hyperbolically stable fixed point which corresponds to the stability of a dead fish in stagnant water. Given a periodic force on the shape of the body we will invoke the persistence theorem to assert the existence of a loop which approximately satisfies the exact equations of motion. If we lift this loop with a phase reconstruction formula we will find that the lifted loops are not loops, but stable trajectories which represent regular periodic motion reminiscent of swimming.

  19. Surfactants at the Design Limit.

    Science.gov (United States)

    Czajka, Adam; Hazell, Gavin; Eastoe, Julian

    2015-08-04

    This article analyzes how the individual structural elements of surfactant molecules affect surface properties, in particular, the point of reference defined by the limiting surface tension at the aqueous cmc, γcmc. Particular emphasis is given to how the chemical nature and structure of the hydrophobic tails influence γcmc. By comparing the three different classes of surfactants, fluorocarbon, silicone, and hydrocarbon, a generalized surface packing index is introduced which is independent of the chemical nature of the surfactants. This parameter ϕcmc represents the volume fraction of surfactant chain fragments in a surface film at the aqueous cmc. It is shown that ϕcmc is a useful index for understanding the limiting surface tension of surfactants and can be useful for designing new superefficient surfactants.

  20. Load limiting parachute inflation control

    Energy Technology Data Exchange (ETDEWEB)

    Redmond, J.; Hinnerichs, T.; Parker, G.

    1994-01-01

    Excessive deceleration forces experienced during high speed deployment of parachute systems can cause damage to the payload and the canopy fabric. Conventional reefing lines offer limited relief by temporarily restricting canopy inflation and limiting the peak deceleration load. However, the open-loop control provided by existing reefing devices restrict their use to a specific set of deployment conditions. In this paper, the sensing, processing, and actuation that are characteristic of adaptive structures form the basis of three concepts for active control of parachute inflation. These active control concepts are incorporated into a computer simulation of parachute inflation. Initial investigations indicate that these concepts promise enhanced performance as compared to conventional techniques for a nominal release. Furthermore, the ability of each controller to adapt to off-nominal release conditions is examined.

  1. Nuclear Structure at the Limits

    Energy Technology Data Exchange (ETDEWEB)

    Nazarewicz, W.

    1998-01-12

    One of the frontiers of today�s nuclear science is the �journey to the limits� of atomic charge and nuclear mass, of neutron-to-proton ratio, and of angular momentum. The tour to the limits is not only a quest for new, exciting phenomena, but the new data are expected, as well, to bring qualitatively new information about the fundamental properties of the nucleonic many-body system, the nature of the nuclear interaction, and nucleonic correlations at various energy-distance scales. In this series of lectures, current developments in nuclear structure at the limits are discussed from a theoretical perspective, mainly concentrating on medium-mass and heavy nuclei.

  2. Penrose Limits and Spacetime Singularities

    CERN Document Server

    Blau, Matthias; O'Loughlin, M; Papadopoulos, G; Blau, Matthias; Borunda, Monica; Loughlin, Martin O'; Papadopoulos, George

    2003-01-01

    We give a covariant characterisation of the Penrose plane wave limit: the plane wave profile matrix $A(u)$ is the restriction of the null geodesic deviation matrix (curvature tensor) of the original spacetime metric to the null geodesic, evaluated in a comoving frame. We also consider the Penrose limits of spacetime singularities and show that for a large class of black hole, cosmological and null singularities (of Szekeres-Iyers ``power-law type''), including those of the FRW and Schwarzschild metrics, the result is a singular homogeneous plane wave with profile $A(u)\\sim u^{-2}$, the scale invariance of the latter reflecting the power-law behaviour of the singularities.

  3. China Rare Earth Holdings Limited

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    China Rare Earth Holdings Limited is a large trans-area corporation and a public company listed in Hong Kong Stock Exchange (Name: China Rare Earth, Code: 0769), with headquarter in Hong Kong. Located on the bank of beautiful Taihu Lake, the subsidiary in Yinxing covers area of 200,000 m2. It has nearly 1,000 employees, 30% of whom are technical staffs. After self-administration and effort, the company passed ISO 9001: 2000 and ISO 14000 Certificaitons.

  4. Fundamental Limits to Cellular Sensing

    Science.gov (United States)

    ten Wolde, Pieter Rein; Becker, Nils B.; Ouldridge, Thomas E.; Mugler, Andrew

    2016-03-01

    In recent years experiments have demonstrated that living cells can measure low chemical concentrations with high precision, and much progress has been made in understanding what sets the fundamental limit to the precision of chemical sensing. Chemical concentration measurements start with the binding of ligand molecules to receptor proteins, which is an inherently noisy process, especially at low concentrations. The signaling networks that transmit the information on the ligand concentration from the receptors into the cell have to filter this receptor input noise as much as possible. These networks, however, are also intrinsically stochastic in nature, which means that they will also add noise to the transmitted signal. In this review, we will first discuss how the diffusive transport and binding of ligand to the receptor sets the receptor correlation time, which is the timescale over which fluctuations in the state of the receptor, arising from the stochastic receptor-ligand binding, decay. We then describe how downstream signaling pathways integrate these receptor-state fluctuations, and how the number of receptors, the receptor correlation time, and the effective integration time set by the downstream network, together impose a fundamental limit on the precision of sensing. We then discuss how cells can remove the receptor input noise while simultaneously suppressing the intrinsic noise in the signaling network. We describe why this mechanism of time integration requires three classes (groups) of resources—receptors and their integration time, readout molecules, energy—and how each resource class sets a fundamental sensing limit. We also briefly discuss the scheme of maximum-likelihood estimation, the role of receptor cooperativity, and how cellular copy protocols differ from canonical copy protocols typically considered in the computational literature, explaining why cellular sensing systems can never reach the Landauer limit on the optimal trade

  5. Summary of Dissolved Concentration Limits

    Energy Technology Data Exchange (ETDEWEB)

    Yueting Chen

    2001-06-11

    According to the Technical Work Plan titled Technical Work Plan for Waste Form Degradation Process Model Report for SR (CRWMS M&O 2000a), the purpose of this study is to perform abstractions on solubility limits of radioactive elements based on the process-level information and thermodynamic databases provided by Natural Environment Program Operations (NEPO) and Waste Package Operations (WPO). The scope of this analysis is to produce solubility limits as functions, distributions, or constants for all transported radioactive elements identified by the Performance Assessment Operations (PAO) radioisotope screening. Results from an expert elicitation for solubility limits of most radioactive elements were used in the previous Total System Performance Assessments (TSPAs). However, the elicitation conducted in 1993 does not meet the criteria set forth by the U.S. Nuclear Regulatory Commission (NRC) due to lack of documentation and traceability (Kotra et al. 1996, Section 3). Therefore, at the Waste Form Abstraction Workshop held on February 2-4, 1999, at Albuquerque, New Mexico, the Yucca Mountain Site Characterization Project (YMP) decided to develop geochemical models to study solubility for the proposed Monitored Geologic Repository. WPO/NEPO is to develop process-level solubility models, including review and compilation of relevant thermodynamic data. PAO's responsibility is to perform abstractions based on the process models and chemical conditions and to produce solubility distributions or response surfaces applicable to the proposed repository. The results of this analysis and conceptual model will feed the performance assessment for Total System Performance Assessment--Site Recommendation (TSPA-SR) and Total System Performance Assessment--License Application (TSPA-LA), and to the Waste Form Degradation Process Model Report section on concentration limits.

  6. Limit laws for exponential families

    OpenAIRE

    Balkema, August A.; Klüppelberg, Claudia; Resnick, Sidney I.

    1999-01-01

    For a real random variable [math] with distribution function [math] , define ¶ [math] ¶ The distribution [math] generates a natural exponential family of distribution functions [math] , where ¶ [math] ¶ We study the asymptotic behaviour of the distribution functions [math] as [math] increases to [math] . If [math] then [math] pointwise on [math] . It may still be possible to obtain a non-degenerate weak limit law [math] by choosing suitable scaling and centring constants [math] an...

  7. Problems of anthropogenic tritium limitation

    Directory of Open Access Journals (Sweden)

    Kochetkov О.A.

    2013-12-01

    Full Text Available This article contains the current situation in respect to the environmental concentrations of anthropogenic and natural tritium. There are presented and analyzed domestic standards for НТО of all Radiation Safety Standards (NRB, as well as the regulations analyzed for tritium in drinking water taken in other countries today. This article deals with the experience of limitation of tritium and focuses on the main problem of rationing of tritium — rationing of organically bound tritium.

  8. Limits to global groundwater consumption

    Science.gov (United States)

    de Graaf, I.; Van Beek, L. P.; Sutanudjaja, E.; Wada, Y.; Bierkens, M. F.

    2016-12-01

    Groundwater is the largest accessible freshwater resource worldwide and is of critical importance for irrigation, and so for global food security. For many regions of the world where groundwater abstraction exceeds groundwater recharge, persistent groundwater depletion occurs. A direct consequence of depletion is falling groundwater levels, reducing baseflows to rivers, harming ecosystems. Also, pumping costs increase, wells dry up and land subsidence can occur. Water demands are expected to increase further due to growing population, economic development and climate change, posing the urgent question how sustainable current water abstractions are worldwide and where and when these abstractions approach conceivable limits with all the associated problems. Here, we estimated past and future trends (1960-2050) in groundwater levels resulting from changes in abstractions and climate and predicted when limits of groundwater consumption are reached. We explored these limits by predicting where and when groundwater levels drop that low that groundwater becomes unattainable for abstractions and how river flows are affected. Water availabilities, abstractions, and lateral groundwater flows are simulated (5 arcmin. resolution) using a coupled version of the global hydrological model PCR-GLOBWB and a groundwater model based on MODFLOW. The groundwater model includes a parameterization of the worlds confined and unconfined aquifer systems, needed for a realistic simulation of groundwater head dynamics. Results show that, next to the existing regions experiencing groundwater depletion (like India, Pakistan, Central Valley) new regions will develop, e.g. Southern Europe, the Middle East, and Africa. Using a limit that reflects present-day feasibility of groundwater abstraction, we estimate that in 2050 groundwater becomes unattainable for 20% of the global population, mainly in the developing countries and pumping cost will increase significantly. Largest impacts are found

  9. Limit laws for exponential families

    OpenAIRE

    Balkema, August A.; Klüppelberg, Claudia; Resnick, Sidney I.

    1999-01-01

    For a real random variable [math] with distribution function [math] , define ¶ [math] ¶ The distribution [math] generates a natural exponential family of distribution functions [math] , where ¶ [math] ¶ We study the asymptotic behaviour of the distribution functions [math] as [math] increases to [math] . If [math] then [math] pointwise on [math] . It may still be possible to obtain a non-degenerate weak limit law [math] by choosing suitable scaling and centring constants [math] an...

  10. Protection limits on free speech

    Institute of Scientific and Technical Information of China (English)

    李敏

    2014-01-01

    Freedom of speech is one of the basic rights of citizens should receive broad protection, but in the real context of China under what kind of speech can be protected and be restricted, how to grasp between state power and free speech limit is a question worth considering. People tend to ignore the freedom of speech and its function, so that some of the rhetoric cannot be demonstrated in the open debates.

  11. Application of fault current limiters

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, A.

    2007-11-30

    This report presents the results of a study commissioned by the Department for Business, Enterprise and Industry (BERR; formerly the Department of Trade and Industry) into the application of fault current limiters in the UK. The study reviewed the current state of fault current limiter (FCL) technology and regulatory position in relation to all types of current limiters. It identified significant research and development work with respect to medium voltage FCLs and a move to high voltage. Appropriate FCL technologies being developed include: solid state breakers; superconducting FCLs (including superconducting transformers); magnetic FCLs; and active network controllers. Commercialisation of these products depends on successful field tests and experience, plus material development in the case of high temperature superconducting FCL technologies. The report describes FCL techniques, the current state of FCL technologies, practical applications and future outlook for FCL technologies, distribution fault level analysis and an outline methodology for assessing the materiality of the fault level problem. A roadmap is presented that provides an 'action agenda' to advance the fault level issues associated with low carbon networks.

  12. Scaling Limits of Graphene Nanoelectrodes.

    Science.gov (United States)

    Sarwat, Syed Ghazi; Gehring, Pascal; Rodriguez Hernandez, Gerardo; Warner, Jamie H; Briggs, G Andrew D; Mol, Jan A; Bhaskaran, Harish

    2017-06-14

    Graphene nanogap electrodes have been of recent interest in a variety of fields, ranging from molecular electronics to phase change memories. Several recent reports have highlighted that scaling graphene nanogaps to even smaller sizes is a promising route to more efficient and robust molecular and memory devices. Despite the significant interest, the operating and scaling limits of these electrodes are completely unknown. In this paper, we report on our observations of consistent voltage driven resistance switching in sub-5 nm graphene nanogaps. We find that such electrical switching from an insulating state to a conductive state occurs at very low currents and voltages (0.06 μA and 140 mV), independent of the conditions (room ambient, low temperatures, as well as in vacuum), thus portending potential limits to scaling of functional devices with carbon electrodes. We then associate this phenomenon to the formation and rupture of carbon chains. Using a phase change material in the nanogap as a demonstrator device, fabricated using a self-alignment technique, we show that for gap sizes approaching 1 nm the switching is dominated by such carbon chain formation, creating a fundamental scaling limit for potential devices. These findings have important implications, not only for fundamental science, but also in terms of potential applications.

  13. Limit cycle behaviour in FELIX

    Science.gov (United States)

    Jaroszynski, D. A.; Bakker, R. J.; Oepts, D.; van der Meer, A. F. G.; van Amersfoort, P. W.

    1993-07-01

    The free electron laser for infrared experiments (FELIX) operates at wavelengths up to λ = 110 μm. A radio-frequency linear accelerator is used to produce electron micropulses with a duration of about 3 ps. With N = 38 undulator periods, this puts FELIX well into the regime where the slippage length, Nλ, exceeds the electron micropulse length, and prominent short pulse effects are expected. One of these effects, stable limit cycle oscillations of the pulse energy, has not been detected experimentally before. Such oscillations occur when the saturated optical pulses move away from the electron pulses, due to the changing balance between lethargy and desynchronism, while new subpulses grow periodically. In FELIX, limit cycle behaviour is clearly demonstrated. The observations are in agreement with numerical simulations of the pulse propagation, and the oscillation period is given by a simple formula containing the slippage length and the desynchronism between optical and electron pulses. We also show how lethargic behaviour can be used to reduce the optical bandwidth of the FEL and to store optical energy in the optical cavity without saturation limiting the energy stored.

  14. Pure Phase Solubility Limits: LANL

    Energy Technology Data Exchange (ETDEWEB)

    C. Stockman

    2001-01-26

    The natural and engineered system at Yucca Mountain (YM) defines the site-specific conditions under which one must determine to what extent the engineered and the natural geochemical barriers will prevent the release of radioactive material from the repository. Most important mechanisms for retention or enhancement of radionuclide transport include precipitation or co-precipitation of radionuclide-bearing solid phases (solubility limits), complexation in solution, sorption onto surfaces, colloid formation, and diffusion. There may be many scenarios that could affect the near-field environment, creating chemical conditions more aggressive than the conditions presented by the unperturbed system (such as pH changes beyond the range of 6 to 9 or significant changes in the ionic strength of infiltrated waters). For an extended period of time, the near-field water composition may be quite different and more extreme in pH, ionic strength, and CO{sub 2} partial pressure (or carbonate concentration) than waters at some distance from the repository. Reducing conditions, high pH (up to 11), and low carbonate concentration may be present in the near-field after reaction of infiltrating groundwater with engineered barrier systems, such as cementitious materials. In the far-field, conditions are controlled by the rock-mass buffer providing a near-neutral, oxidizing, low-ionic-strength environment that controls radionuclide solubility limits and sorption capacities. There is the need for characterization of variable chemical conditions that affect solubility, speciation, and sorption reactions. Modeling of the groundwater chemistry is required and leads to an understanding of solubility and speciation of the important radionuclides. Because experimental studies cannot be performed under the numerous potential chemical conditions, solubility limitations must rely on geochemical modeling of the radionuclide's chemistry. Fundamental thermodynamic properties, such as solubility

  15. Limits to Global Groundwater Consumption

    Science.gov (United States)

    Graaf, I. D.; Van Beek, R.; Sutanudjaja, E.; Wada, Y.; Bierkens, M. F.

    2015-12-01

    In regions with frequent water stress and large aquifer systems, groundwater is often used as an additional fresh water source. For many regions of the world groundwater abstraction exceeds groundwater recharge and persistent groundwater depletion occurs. The most direct effect of groundwater depletion is declining of water tables, leading to reduced groundwater discharge needed to sustain base-flow to e.g. rivers. Next to that, pumping costs increase, wells dry up and land subsidence occurs. These problems are expected to increase in the near future due to growing population and climate changes. This poses the urgent question of what the limits are of groundwater consumption worldwide. We simulate global water availability (5 arc-minute resolution, for 1960-2050) using the hydrological model PCR-GLOBWB (van Beek et al. 2011), coupled to a groundwater model based on MODFLOW (de Graaf et al. 2015), allowing for groundwater - surface water interactions. The groundwater model includes a parameterization of world's confined and unconfined aquifer systems needed for a realistic simulation of groundwater head dynamics. Water demands are included (from Wada et al. 2014). We study the limits to water consumption, focusing on locally attainable groundwater and groundwater levels critical to rivers to sustain low flows. We show an increasing trend (1960-2050) in groundwater head declines, due to increase in groundwater demand. Also, stream flow will decrease and low flow conditions will occur more frequent and will be longer in duration in the near future, especially for irrigated areas. Next to that, we provide a global overview of the years it takes until groundwater gets unattainable for e.g. a local farmer (100 m below land-surface used as a proxy), and estimate the increase in pumping cost for the near future. The results show where and when limits of groundwater consumption are reached globally.

  16. Limits to the growth debate

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, L.

    The first two major studies sponsored by the club of Rome were the report of the Meadows team at MIT, The Limits to Growth, published in 1972, and the Mesarovic and Pestel report, Mankind at the Turning Point, published in 1974. When the Club of Rome met in Philadelphia in April of 1976, its pronouncements reflected a frame of mind quite different from that of 1972. Recently, Herman Kahn and his colleagues at the Hudson Institute have published The Next 200 Years, a book evidently inspired as much by antagonism to the limits-to-growth school of thought as by affirmative faith in its own vision of technological optimism. The author discusses the content of the studies and summarizes his own position in four areas. (1) While no trend of growth of anything can continue indefinitely in the real world, there are not global physical limits to economic growth within a time frame susceptible to plausible foresight or relevant to policy making. (2) In some world regions, notably South Asia and tropical Africa, population growth rates do indeed threaten to create a kind of Malthusian trap, and the rapid reduction of fertility is critically important to their development prospects and urgent in time. (3) For other parts of the world, both rates and directions of growth will be more influenced by changes in preferences for consumption and in attitudes toward production than by physical constraints, although higher energy costs and environmental pressures will also be important influences in generating such changes in growth patterns. (4) Probable changes in directions of growth will generate new and important issues in international economic and political relations, with both dangers and opportunities for the evolving world order. (MCW)

  17. Combination trading with limit orders

    Directory of Open Access Journals (Sweden)

    Henry Schellhorn

    1997-01-01

    Full Text Available We model the exchange of commodities that are contingent upon each other, when traders place mostly limit orders. Examples include: 1 a market of financial futures where future spreads are also traded, 2 a market of mutual funds and stocks, 3 a market of options and stocks, under the viewpoint that they are both combinations of Arrow-Debreu securities. We prove that consistent prices are optimal. We develop a fixed-point algorithm to compute an optimal price and allocation. The algorithm combines ideas from contraction mapping theory and from homotopy theory. It is much faster than a traditional linear programming approach.

  18. LIMITED RESTAURANT SERVICE: EASTER WEEKEND

    CERN Multimedia

    2003-01-01

    As Friday, April 18 and Monday, April 21, 2003 are CERN holidays, restaurants no. 1 (COOP : Bldg. 501- Meyrin) and no. 3 (AVENANCE : Bldg. 866 - Prévessin) will be closed and will remain so on Saturday and Sunday, April 19 - 20. They will reopen on Tuesday, April 22 at 7h00. During these four days, a limited service will be provided by restaurant no. 2 (DSR : Bldg. 504 - Meyrin) from 8h00 to 21h00 with hot meals served from 11h30 to 14h00 and from 18h00 to 19h30.

  19. Limited Attention and Discourse Structure

    CERN Document Server

    Walker, M A

    1995-01-01

    This squib examines the role of limited attention in a theory of discourse structure and proposes a model of attentional state that relates current hierarchical theories of discourse structure to empirical evidence about human discourse processing capabilities. First, I present examples that are not predicted by Grosz and Sidner's stack model of attentional state. Then I consider an alternative model of attentional state, the cache model, which accounts for the examples, and which makes particular processing predictions. Finally I suggest a number of ways that future research could distinguish the predictions of the cache model and the stack model.

  20. Heisenberg limit superradiant superresolving metrology.

    Science.gov (United States)

    Wang, Da-Wei; Scully, Marlan O

    2014-08-22

    We propose a superradiant metrology technique to achieve the Heisenberg limit superresolving displacement measurement by encoding multiple light momenta into a three-level atomic ensemble. We use 2N coherent pulses to prepare a single excitation superradiant state in a superposition of two timed Dicke states that are 4N light momenta apart in momentum space. The phase difference between these two states induced by a uniform displacement of the atomic ensemble has 1/4N sensitivity. Experiments are proposed in crystals and in ultracold atoms.

  1. CSS3 pushing the limits

    CERN Document Server

    Greig, Stephen

    2013-01-01

    Push CSS3 and your design skills to the limit-and beyond! Representing an evolutionary leap forward for CSS, CSS3 is chock-full of new capabilities that dramatically expand the boundaries of what a styling language can do. But many of those new features remain undocumented, making it difficult to learn what they are and how to use them to create the sophisticated sites and web apps clients demand and users have grown to expect. Until now. This book introduces you to all of CSS3's new and advanced features, and, with the help of dozens of real-world examples and live

  2. Modern Cosmology: Assumptions and Limits

    Science.gov (United States)

    Hwang, Jai-Chan

    2012-06-01

    Physical cosmology tries to understand the Universe at large with its origin and evolution. Observational and experimental situations in cosmology do not allow us to proceed purely based on the empirical means. We examine in which sense our cosmological assumptions in fact have shaped our current cosmological worldview with consequent inevitable limits. Cosmology, as other branches of science and knowledge, is a construct of human imagination reflecting the popular belief system of the era. The question at issue deserves further philosophic discussions. In Whitehead's words, ``philosophy, in one of its functions, is the critic of cosmologies.'' (Whitehead 1925).

  3. Limited Regulation of Lake Erie.

    Science.gov (United States)

    1983-11-01

    Ontario,, Cedar Point in Ohio, Presque Isle in Pennsylvania and Hamlin in New York. Recreational boating is a significant activity on Lake Erie . Along...RD-Al47 936 LIMITED REGULATION OF LAKE ERIE (U) INTERNATIONAL LAKE i/i ERIE REGULATION STUDY BOARD NOV 83 UNCLASSIFIED F/G 13/2 N lhhhhh..hEmhhI...o lake Erie ’Governmen of 4,- % * L CTE " 84100400 .- Canad Unite Stte INTRNAIONL OIN COMISIO 4WD’ This document hais been ow for public rleoe and so

  4. On noise limited cellular networks

    CERN Document Server

    Decreusefond, Laurent; Vu, Thanh-Tung

    2010-01-01

    This paper introduces a general theoretical framework to analyze noise limited networks. More precisely, we consider two homogenous Poisson point processes of base stations and users. General model of radio signal propagation and effect of fading are also considered. The main difference of our model with respect to other existing models is that a user connects to his best servers but not necessarily the closest one. We provide general formula for the outage probability. We study functionals related to the SNR as well as the sum of these functionals over all users per cell. For the latter, the expectation and bounds on the variance are obtained.

  5. The Limit of Large Vessels

    Institute of Scientific and Technical Information of China (English)

    Yang Peiju

    2011-01-01

    On Feb 21(st),the industry was shocked by the news that AP Moller-Maersk placed an order of 10 container ships of 18,000 TEU with the South Korean ship yards.The order brings the development of large vessels to a new climax and at the same time puts forward a series of research subjects to the industry,such as what is the limit for the development of large vessels,whether ship safety can be guaranteed,and etc.

  6. Inverting the central limit theorem

    CERN Document Server

    Navascues, Miguel; Villanueva, Ignacio

    2011-01-01

    The central limit theorem states that the sum of N independently distributed n-tuples of real variables (subject to appropriate normalization) tends to a multivariate gaussian distribution for large N. Here we propose to invert this argument: given a set of n correlated gaussian variables, we try to infer information about the structure of the discrete microscopic probability distributions whose convolution generated such a macroscopic behavior. The techniques developed along the article are applied to prove that the classical description of certain macroscopic optical experiments is infinitely more complex than the quantum one.

  7. Modern Cosmology: Assumptions and Limits

    CERN Document Server

    Hwang, Jai-chan

    2012-01-01

    Physical cosmology tries to understand the Universe at large with its origin and evolution. Observational and experimental situations in cosmology do not allow us to proceed purely based on the empirical means. We examine in which sense our cosmological assumptions in fact have shaped our current cosmological worldview with consequent inevitable limits. Cosmology, as other branches of science and knowledge, is a construct of human imagination reflecting the popular belief system of the era. The question at issue deserves further philosophic discussions. In Whitehead's words, "philosophy, in one of its functions, is the critic of cosmologies". (Whitehead 1925)

  8. Nanofabrication principles, capabilities and limits

    CERN Document Server

    Cui, Zheng

    2017-01-01

    This second edition of Nanofabrication is one of the most comprehensive introductions on nanofabrication technologies and processes. A practical guide and reference, this book introduces readers to all of the developed technologies that are capable of making structures below 100nm. The principle of each technology is introduced and illustrated with minimum mathematics involved. Also analyzed are the capabilities of each technology in making sub-100nm structures, and the limits of preventing a technology from going further down the dimensional scale. This book provides readers with a toolkit that will help with any of their nanofabrication challenges.

  9. The Limits of CD Metrology

    Science.gov (United States)

    Rice, Bryan J.; Cao, Heidi; Grumski, Michael; Roberts, Jeanette

    2005-09-01

    One of the many technology decisions facing the semiconductor industry for the 32 nm node (and beyond) is the selection of the best critical dimension (CD) metrology equipment to meet the needs of process equipment suppliers and semiconductor manufacturers. Over the past three years Intel ® has fabricated a variety of test structures and performed a number of technology evaluations aimed at determining the limits of today's CD metrology. In this paper we discuss the capability of those technologies to measure structures having dimensions representative of the 45 nm, 32 nm, and 22 nm nodes.

  10. Controlling chaos with simple limiters

    Science.gov (United States)

    Corron; Pethel; Hopper

    2000-04-24

    New experimental results demonstrate that chaos control can be accomplished using controllers that are very simple relative to the system being controlled. Chaotic dynamics in a driven pendulum and a double scroll circuit are controlled using an adjustable, passive limiter-a weight for the pendulum and a diode for the circuit. For both experiments, multiple unstable periodic orbits are selectively controlled using minimal perturbations. These physical examples suggest that chaos control can be practically applied to a much wider array of important problems than initially thought possible.

  11. The limits of human performance.

    Science.gov (United States)

    Beneke, Ralph; Böning, Dieter

    2008-01-01

    Human performance, defined by mechanical resistance and distance per time, includes human, task and environmental factors, all interrelated. It requires metabolic energy provided by anaerobic and aerobic metabolic energy sources. These sources have specific limitations in the capacity and rate to provide re-phosphorylation energy, which determines individual ratios of aerobic and anaerobic metabolic power and their sustainability. In healthy athletes, limits to provide and utilize metabolic energy are multifactorial, carefully matched and include a safety margin imposed in order to protect the integrity of the human organism under maximal effort. Perception of afferent input associated with effort leads to conscious or unconscious decisions to modulate or terminate performance; however, the underlying mechanisms of cerebral control are not fully understood. The idea to move borders of performance with the help of biochemicals is two millennia old. Biochemical findings resulted in highly effective substances widely used to increase performance in daily life, during preparation for sport events and during competition, but many of them must be considered as doping and therefore illegal. Supplements and food have ergogenic potential; however, numerous concepts are controversially discussed with respect to legality and particularly evidence in terms of usefulness and risks. The effect of evidence-based nutritional strategies on adaptations in terms of gene and protein expression that occur in skeletal muscle during and after exercise training sessions is widely unknown. Biochemical research is essential for better understanding of the basic mechanisms causing fatigue and the regulation of the dynamic adaptation to physical and mental training.

  12. Limiting factors of starch hydrolysis.

    Science.gov (United States)

    Colonna, P; Leloup, V; Buléon, A

    1992-10-01

    Foods appear as complex structures, in which starch may be present in different forms. These, including the molecular characteristics and the crystalline organization, depend on processing conditions and compositions of ingredients. The main changes in starch macro- and microstructures are the increase of surface area to volume ratio in the solid phase, the modification of the crystallinity as affected by gelatinization and gelation, and the depolymerization of amylose and amylopectin. Starch modification may be estimated by different methodologies, which should be selected according to the level of structure considered. When amylose and amylopectin are in solution, rapid and total hydrolysis leads to the formation of a mixture of linear oligosaccharides and branched alpha-limit dextrins. However, starch usually occurs in foods as solid structures. Structural factors of starchy materials influence their enzymic hydrolysis. A better understanding of the enzymatic process enables the identification of the structural factors limiting hydrolysis: diffusion of enzyme molecules, porosity of solid substrates, adsorption of enzymes onto solid substrates, and the catalytic event. A mechanistic modelling should be possible in the future.

  13. DC superconducting fault current limiter

    Science.gov (United States)

    Tixador, P.; Villard, C.; Cointe, Y.

    2006-03-01

    There is a lack of satisfying solutions for fault currents using conventional technologies, especially in DC networks, where a superconducting fault current limiter could play a very important part. DC networks bring a lot of advantages when compared to traditional AC ones, in particular within the context of the liberalization of the electric market. Under normal operation in a DC network, the losses in the superconducting element are nearly zero and only a small, i.e. a low cost, refrigeration system is then required. The absence of zero crossing of a DC fault current favourably accelerates the normal zone propagation. The very high current slope at the time of the short circuit in a DC grid is another favourable parameter. The material used for the experiments is YBCO deposited on Al2O3 as well as YBCO coated conductors. The DC limitation experiments are compared to AC ones at different frequencies (50-2000 Hz). Careful attention is paid to the quench homogenization, which is one of the key issues for an SC FCL. The University of Geneva has proposed constrictions. We have investigated an operating temperature higher than 77 K. As for YBCO bulk, an operation closer to the critical temperature brings a highly improved homogeneity in the electric field development. The material can then absorb large energies without degradation. We present tests at various temperatures. These promising results are to be confirmed over long lengths.

  14. Performance limits of heliostat fields

    Energy Technology Data Exchange (ETDEWEB)

    Kribus, A.; Krupkin, V.; Yogev, A. [Weizmann Inst. of Science, Rehovot (Israel). Environmental Sciences and Energy Research Dept.; Spirkl, W. [Ludwig-Maximilians-Univ. Muenchen (Germany). Sektion Physik

    1998-11-01

    Geometric and thermodynamic arguments are used to derive upper limits on the performance of a solar energy collection system, consisting of an axisymmetric heliostat field, a solar tower, secondary optics and a black receiver. Performance limits on collected power, concentration, and work output are presented. Performance of tower systems with several secondary optics options is compared: tower-top Compound Parabolic Concentrator (CPC), Tailored Edge-Ray Concentrator (TERC) approximated by a cone, and Cassegrainian with ground-level CPC or Compound Elliptic Concentrator (CEC). Optimized ray tracing is used to generate the design parameters of the secondary concentrators that yield the highest optical efficiency. The results show that the tower-top Cone provides the best performance regarding both concentration and efficiency, except for very large fields. The Cassegrainian designs come in second, but become equal and even better than the Cone for large fields. The results for the Cassegrainian are sensitive to the value of the reflectivity, due to the additional reflections incurred. The choice of a CEC is better than a CPC for the terminal concentration in a Cassegrainian system, but the difference is small. The suitability of the different design options for high-temperature solar applications is discussed. The recommendations regarding optical configuration depend on field size, as well as on application-specific constraints.

  15. Measurement limits in flash thermography

    Science.gov (United States)

    Shepard, Steven M.; Lhota, James R.; Ahmed, Tasdiq

    2009-05-01

    Although active thermography has traditionally been regarded as a qualitative NDT method, its potential for quantitative measurement of thermophysical properties including wall thickness, flaw size and depth, thermal diffusivity or effusivity has been the subject of numerous investigations. Enabled by improvements in IR camera technology and fast, abundant and inexpensive computing power for advanced signal processing, measurement results have been reported using a variety of excitation and signal processing schemes. Results are often presented as a correlation between thermography data and nominal properties or independent measurements by another "validated" method. However, given the diffusion mechanism that underlies thermography, and the quantization and sampling conditions implicit in using an IR camera as a temperature sensor, there are definite limits to what can be achieved in a thermography measurement. While many benefits can be achieved with improved instrumentation, efficient energy insertion or optimized signal processing, ultimately, the limits imposed by diffusion and instrumentation take precedence, and cannot be circumvented. In this paper, the effects of camera frame rate and sensitivity on measurement of the thickness of a slab are examined, using basic 1-dimensional diffusion approximations.

  16. Energy-limited escape revised

    CERN Document Server

    Salz, M; Czesla, S; Schmitt, J H M M

    2016-01-01

    Gas planets in close proximity to their host stars experience photoevaporative mass loss. The energy-limited escape concept is generally used to derive estimates for the planetary mass-loss rates. Our photoionization hydrodynamics simulations of the thermospheres of hot gas planets show that the energy-limited escape concept is valid only for planets with a gravitational potential lower than $\\log_\\mathrm{10}\\left( -\\Phi_{\\mathrm{G}}\\right) < 13.11~$erg$\\,$g$^{-1}$ because in these planets the radiative energy input is efficiently used to drive the planetary wind. Massive and compact planets with $\\log_\\mathrm{10}\\left( -\\Phi_{\\mathrm{G}}\\right) \\gtrsim 13.6~$erg$\\,$g$^{-1}$ exhibit more tightly bound atmospheres in which the complete radiative energy input is re-emitted through hydrogen Ly$\\alpha$ and free-free emission. These planets therefore host hydrodynamically stable thermospheres. Between these two extremes the strength of the planetary winds rapidly declines as a result of a decreasing heating eff...

  17. 40 CFR 158.350 - Certified limits.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Certified limits. 158.350 Section 158... REQUIREMENTS FOR PESTICIDES Product Chemistry § 158.350 Certified limits. The applicant must propose certified limits for the ingredients in the product. Certified limits become legally binding limits upon...

  18. 36 CFR 4.21 - Speed limits.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Speed limits. 4.21 Section 4... TRAFFIC SAFETY § 4.21 Speed limits. (a) Park area speed limits are as follows: (1) 15 miles per hour... superintendent may designate a different speed limit upon any park road when a speed limit set forth in...

  19. 50 CFR 622.37 - Size limits.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Size limits. 622.37 Section 622.37... limits. All size limits in this section are minimum size limits unless specified otherwise. Except for... compliance with its size limit, as specified in this section, in or from the Caribbean, Gulf, South...

  20. Homogeneity and plane-wave limits

    CERN Document Server

    Figueroa-O'Farrill, J M; Philip, S; Farrill, Jos\\'e Figueroa-O'; Meessen, Patrick; Philip, Simon

    2005-01-01

    We explore the plane-wave limit of homogeneous spacetimes. For plane-wave limits along homogeneous geodesics the limit is known to be homogeneous and we exhibit the limiting metric in terms of Lie algebraic data. This simplifies many calculations and we illustrate this with several examples. We also investigate the behaviour of (reductive) homogeneous structures under the plane-wave limit.

  1. Quantum parallelism may be limited

    CERN Document Server

    Ozhigov, Yu I

    2016-01-01

    We consider quantum formalism limited by the classical simulating computer with the fixed memory. The memory is redistributed in the course of modeling by the variation of the set of classical states and the accuracy of the representation of amplitudes. This computational description completely preserves the conventional formalism and does not contradicts to experiments, but it makes impossible fast quantum algorithms. This description involves the slow down of quantum evolutions with the growth of the dimension of the minimal subspace containing entangled states, which arise in the evolution. This slow down is the single difference of the proposed formalism from the standard one; it is negligible for the systems from the usual experiments, including those in which many entangled particle participate, but grows rapidly in the attempt to realize the scalable quantum computations, which require the unlimited parallelism. The experimental verification of this version of quantum formalism is reduced to the fixati...

  2. THE LIMITS OF ESP TESTS

    Directory of Open Access Journals (Sweden)

    Norica-Felicia BUCUR

    2015-07-01

    Full Text Available Global market forces have determined not only higher education institutions all over the world to include ESP courses in their curriculum to enhance their students’ future employability, but also public and private organisations to offer their employees the opportunity to attend ESP courses in order to meet the continuously growing ESP needs. From this perspective, ESP compentence could become a subcomponent of one of the key competences for lifelong learning, communication in foreign languages. Therefore assessing ESP competence seems to acquire paramount importance since stakeholders need accurate information about the ESP learners’ abilities to cope with specific language tasks. This article offers a concise overview of the principles and practices of ESP assessment, a detailed description of the features of ESP tests, while focusing particularly on the limits of ESP tests in order to identify possible solutions to overcome them.

  3. Mathematical methods for hydrodynamic limits

    CERN Document Server

    Masi, Anna

    1991-01-01

    Entropy inequalities, correlation functions, couplings between stochastic processes are powerful techniques which have been extensively used to give arigorous foundation to the theory of complex, many component systems and to its many applications in a variety of fields as physics, biology, population dynamics, economics, ... The purpose of the book is to make theseand other mathematical methods accessible to readers with a limited background in probability and physics by examining in detail a few models where the techniques emerge clearly, while extra difficulties arekept to a minimum. Lanford's method and its extension to the hierarchy of equations for the truncated correlation functions, the v-functions, are presented and applied to prove the validity of macroscopic equations forstochastic particle systems which are perturbations of the independent and of the symmetric simple exclusion processes. Entropy inequalities are discussed in the frame of the Guo-Papanicolaou-Varadhan technique and of theKipnis-Oll...

  4. The Limits of Custodial Symmetry

    CERN Document Server

    Chivukula, R Sekhar; Foadi, Roshan; Simmons, Elizabeth H

    2010-01-01

    We introduce a toy model implementing the proposal of using a custodial symmetry to protect the Z b_L bbar_L coupling from large corrections. This "doublet-extended standard model" adds a weak doublet of fermions (including a heavy partner of the top quark) to the particle content of the standard model in order to implement an O(4) x U(1)_X = SU(2)_L x SU(2)_R x P_LR x U(1)_X symmetry in the top-quark mass generating sector. This symmetry is softly broken to the gauged SU(2)_L x U(1)_Y electroweak symmetry by a Dirac mass M for the new doublet; adjusting the value of M allows us to explore the range of possibilities between the O(4)-symmetric (M to 0) and standard-model-like (M to infinity) limits.

  5. The Limits of Custodial Symmetry

    CERN Document Server

    Chivukula, R Sekhar; Foadi, Roshan; Simmons, Elizabeth H

    2010-01-01

    We introduce a toy model implementing the proposal of using a custodial symmetry to protect the Zbb coupling from large corrections. This "doublet-extended standard model" adds a weak doublet of fermions (including a heavy partner of the top quark) to the particle content of the standard model in order to implement an O(4) x U(1)_X = SU(2)_L x SU(2)_R x P_{LR} x U(1)_X symmetry that protects the Zbb coupling. This symmetry is softly broken to the gauged SU(2)_L x U(1)_Y electroweak symmetry by a Dirac mass M for the new doublet; adjusting the value of M allows us to explore the range of possibilities between the O(4)-symmetric (M to 0) and standard-model-like (M to infinity) limits.

  6. LIMITED RESTAURANT SERVICE 'JEUNE GENEVOIS'

    CERN Multimedia

    2000-01-01

    On Thursday, September 7, 2000, all restaurants, cafétérias and kiosques will be closed except for restaurant no. 1 and its cafétéria (COOP - building 501 - Meyrin) which will provide a limited service from 8h00 to 21h00. Hot meals will be served from 11h30 to 14h00 and from 18h00 to 19h30. For technical reasons, restaurant no. 2 and its cafétéria (DSR - building 504 - Meyrin) will remain closed on Friday, September 8. They will resume their normal activities on Monday, September 11, 2000. The other restaurants, cafétérias and kiosques will offer their normal service as from Friday, September 8.

  7. LIMITED RESTAURANT SERVICE : EASTER WEEKEND

    CERN Multimedia

    Restaurant Supervisory Committee

    2002-01-01

    As Friday, March 29 and Monday, April 1st, 2002 are CERN holidays, restaurants no. 1 (COOP : Bldg. 501- Meyrin) and no. 3 (Avenance : Bldg. 866 - Prévessin) will be closed and will remain so on Saturday and Sunday, March 30 - 31. They will reopen on Tuesday, April 2 at 7h00. During these four days, a limited service will be provided by restaurant no. 2 (DSR : Bldg. 504 - Meyrin) from 8h00 to 21h00 with hot meals served from 11h30 to 14h00 and from 18h00 to 19h30. On Thursday, March 28, all three restaurants will operate according to the usual times except for restaurant no. 1 which will close at 21h00 instead of 1 o'clock in the morning.   Restaurant Supervisory Committee, tel. 77551

  8. LIMITED RESTAURANT SERVICE : EASTER WEEKEND

    CERN Multimedia

    Restaurant Supervisory Committee

    2002-01-01

    As Friday 29 March and Monday 1st April 2002 are CERN holidays, restaurants no. 1 (COOP, bldg. 501- Meyrin) and no. 3 (Avenance, bldg. 866 - Prévessin) will be closed and will remain so on Saturday and Sunday 30-31 March. They will reopen on Tuesday 2 April at 7h00. During these four days, a limited service will be provided by restaurant no. 2 (DSR, bldg. 504 - Meyrin) from 8h00 to 21h00 with hot meals served from 11h30 to 14h00 and from 18h00 to 19h30. On Thursday 28 March, all three restaurants will operate according to the usual times except for restaurant no. 1 which will close at 21h00 instead of 1 o'clock in the morning. Restaurant Supervisory Committee Tel. 77551

  9. LIMITED RESTAURANT SERVICE : EASTER WEEKEND

    CERN Multimedia

    2003-01-01

    As Friday, April 18 and Monday, April 21, 2003 are CERN holidays, restaurants no. 1 (COOP : Bldg. 501- Meyrin) and no. 3 (AVENANCE : Bldg. 866 - Prévessin) will be closed and will remain so on Saturday and Sunday, April 19 - 20. They will reopen on Tuesday, April 22 at 7h00. During these four days, a limited service will be provided by restaurant no. 2 (DSR : Bldg. 504 - Meyrin) from 8h00 to 21h00 with hot meals served from 11h30 to 14h00 and from 18h00 to 19h30. On Thursday, April 17, all three restaurants will operate according to the usual times except for restaurant no. 1 which will close at 21h00 instead of 1 o'clock in the morning.

  10. The limits of Muscovite autocracy

    OpenAIRE

    Soldat, Cornelia

    2005-01-01

    Les limites de l’autocratie moscovite. Les relations entre le grand-prince et les bojare vues à travers l’œuvre de Josif Volockij, Prosvetitel´.– Depuis que Sigismund Herberstein a affirmé que le tsar moscovite régnait en « maître », donc en « tyran », sur ses sujets, qui se désignaient eux-mêmes comme ses « esclaves » (holopy), l’historiographie occidentale ne manque pas de décrire la relation entre le tsar et ses bojare comme patriarcale et empreinte de cruauté. L’auteur de l’article soutie...

  11. Certifying Equality With Limited Interaction

    DEFF Research Database (Denmark)

    Brody, Joshua Eric; Chakrabarti, Amit; McGregor, Andrew;

    2012-01-01

    The \\textsc{equality} problem is usually one's first encounter with communication complexity and is one of the most fundamental problems in the field. Although its deterministic and randomized communication complexity were settled decades ago, we find several new things to say about the problem...... by focusing on two subtle aspects. The first is to consider the {\\em expected} communication cost (at a worst-case input) for a protocol that uses limited interaction---i.e., a bounded number of rounds of communication---and whose error probability is zero or close to it. The second is to consider the {\\em...... cost bounds, we obtain new bounded-round randomized lower bounds for the \\textsc{or-equality} problem that have a direct-sum flavor. Such lower bounds were previously known only for deterministic protocols or one-round randomized protocols. The \\textsc{or-equality} problem is in turn closely related...

  12. Pericytes limit tumor cell metastasis

    DEFF Research Database (Denmark)

    Xian, Xiaojie; Håkansson, Joakim; Ståhlberg, Anders

    2006-01-01

    Previously we observed that neural cell adhesion molecule (NCAM) deficiency in beta tumor cells facilitates metastasis into distant organs and local lymph nodes. Here, we show that NCAM-deficient beta cell tumors grew leaky blood vessels with perturbed pericyte-endothelial cell-cell interactions...... and deficient perivascular deposition of ECM components. Conversely, tumor cell expression of NCAM in a fibrosarcoma model (T241) improved pericyte recruitment and increased perivascular deposition of ECM molecules. Together, these findings suggest that NCAM may limit tumor cell metastasis by stabilizing...... the microvessel wall. To directly address whether pericyte dysfunction increases the metastatic potential of solid tumors, we studied beta cell tumorigenesis in primary pericyte-deficient Pdgfb(ret/ret) mice. This resulted in beta tumor cell metastases in distant organs and local lymph nodes, demonstrating a role...

  13. The limits of filopodium stability

    CERN Document Server

    Pronk, Sander; Fletcher, Daniel A

    2008-01-01

    Filopodia are long, finger-like membrane tubes supported by cytoskeletal filaments. Their shape is determined by the stiffness of the actin filament bundles found inside them and by the interplay between the surface tension and bending rigidity of the membrane. Although one might expect the Euler buckling instability to limit the length of filopodia, we show through simple energetic considerations that this is in general not the case. By further analyzing the statics of filaments inside membrane tubes, and through computer simulations that capture membrane and filament fluctuations, we show under which conditions filopodia of arbitrary lengths are stable. We discuss several in vitro experiments where this kind of stability has already been observed. Furthermore, we predict that the filaments in long, stable filopodia adopt a helical shape.

  14. Solving Limited Memory Influence Diagrams

    CERN Document Server

    Mauá, Denis Deratani; Zaffalon, Marco

    2011-01-01

    We present a new algorithm for exactly solving decision making problems represented as influence diagrams. We do not require the usual assumptions of no forgetting and regularity; this allows us to solve problems with simultaneous decisions and limited information. The algorithm is empirically shown to outperform a state-of-the-art algorithm on randomly generated problems of up to 150 variables and $10^{64}$ solutions. We show that the problem is NP-hard even if the underlying graph structure of the problem has small treewidth and the variables take on a bounded number of states, but that a fully polynomial time approximation scheme exists for these cases. Moreover, we show that the bound on the number of states is a necessary condition for any efficient approximation scheme.

  15. Prostatic carcinoma: limited field irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Rounsaville, M.C.; Green, J.P.; Vaeth, J.M.; Purdon, R.P.; Heltzel, M.M.

    1987-07-01

    This is a retrospective study of 251 patients with histologically proven adenocarcinoma treated primarily with limited field radiotherapy techniques, under the principle direction of authors JMV and JPG, between 1968 and 1981 in San Francisco, California. All patients are followed for a minimum of 3 years; mean follow-up is 7.3 years. Routine clinical staging procedures included: HandP, digital prostate exam, cystoscopy, biopsy, blood studies including serum acid phosphatase, and imaging studies including chest X ray, IVP, bone survey or radionucleotide bone scan, and in recent years, pelvic CT scans. Twelve patients are Stage A1, 37-Stage A2, 50-Stage B, 140-Stage C1 and 12-Stage C2. Ninety percent of all cases and 85% of Stage C patients were treated with limited fields to the prostate and periprostatic volume only. Total doses were prescribed at midplane or isocenter and were generally 6500-7000 cGy, daily doses of 180-200 cGy, 5 days per week. Actuarial 5- and 10-year survival rates are: entire population-69% and 47%; Stage A1-74% and 50%; Stage A2-81% and 67%; Stage B-84% and 53%; Stage C1-63% and 42%; Stage C2-32% and 11%. The 5- and 10-year disease-free actuarial survivals are: entire population-71% and 50%; Stage A1-89% and 74%; Stage A2-82% and 69%; Stage B-71% and 52%; Stage C1-67% and 44%; Stage C2-0%. Sites of recurrence, alone or as a component of the failure pattern are: 37 (15%) local, 11 (4%) symptomatic regional recurrence (lower extremity edema, pelvic pain/sciatica, hydroureteronephrosis), and 87 (35%) distant metastasis. Seven (3%) had unknown sites of failure. Local-regional failure occurred in 42% of Stage C2 patients.

  16. Prospective Optimization with Limited Resources.

    Science.gov (United States)

    Snider, Joseph; Lee, Dongpyo; Poizner, Howard; Gepshtein, Sergei

    2015-09-01

    The future is uncertain because some forthcoming events are unpredictable and also because our ability to foresee the myriad consequences of our own actions is limited. Here we studied how humans select actions under such extrinsic and intrinsic uncertainty, in view of an exponentially expanding number of prospects on a branching multivalued visual stimulus. A triangular grid of disks of different sizes scrolled down a touchscreen at a variable speed. The larger disks represented larger rewards. The task was to maximize the cumulative reward by touching one disk at a time in a rapid sequence, forming an upward path across the grid, while every step along the path constrained the part of the grid accessible in the future. This task captured some of the complexity of natural behavior in the risky and dynamic world, where ongoing decisions alter the landscape of future rewards. By comparing human behavior with behavior of ideal actors, we identified the strategies used by humans in terms of how far into the future they looked (their "depth of computation") and how often they attempted to incorporate new information about the future rewards (their "recalculation period"). We found that, for a given task difficulty, humans traded off their depth of computation for the recalculation period. The form of this tradeoff was consistent with a complete, brute-force exploration of all possible paths up to a resource-limited finite depth. A step-by-step analysis of the human behavior revealed that participants took into account very fine distinctions between the future rewards and that they abstained from some simple heuristics in assessment of the alternative paths, such as seeking only the largest disks or avoiding the smaller disks. The participants preferred to reduce their depth of computation or increase the recalculation period rather than sacrifice the precision of computation.

  17. Prospective Optimization with Limited Resources.

    Directory of Open Access Journals (Sweden)

    Joseph Snider

    2015-09-01

    Full Text Available The future is uncertain because some forthcoming events are unpredictable and also because our ability to foresee the myriad consequences of our own actions is limited. Here we studied how humans select actions under such extrinsic and intrinsic uncertainty, in view of an exponentially expanding number of prospects on a branching multivalued visual stimulus. A triangular grid of disks of different sizes scrolled down a touchscreen at a variable speed. The larger disks represented larger rewards. The task was to maximize the cumulative reward by touching one disk at a time in a rapid sequence, forming an upward path across the grid, while every step along the path constrained the part of the grid accessible in the future. This task captured some of the complexity of natural behavior in the risky and dynamic world, where ongoing decisions alter the landscape of future rewards. By comparing human behavior with behavior of ideal actors, we identified the strategies used by humans in terms of how far into the future they looked (their "depth of computation" and how often they attempted to incorporate new information about the future rewards (their "recalculation period". We found that, for a given task difficulty, humans traded off their depth of computation for the recalculation period. The form of this tradeoff was consistent with a complete, brute-force exploration of all possible paths up to a resource-limited finite depth. A step-by-step analysis of the human behavior revealed that participants took into account very fine distinctions between the future rewards and that they abstained from some simple heuristics in assessment of the alternative paths, such as seeking only the largest disks or avoiding the smaller disks. The participants preferred to reduce their depth of computation or increase the recalculation period rather than sacrifice the precision of computation.

  18. Pure Phase Solubility Limits: LANL

    Energy Technology Data Exchange (ETDEWEB)

    C. Stockman

    2001-01-26

    The natural and engineered system at Yucca Mountain (YM) defines the site-specific conditions under which one must determine to what extent the engineered and the natural geochemical barriers will prevent the release of radioactive material from the repository. Most important mechanisms for retention or enhancement of radionuclide transport include precipitation or co-precipitation of radionuclide-bearing solid phases (solubility limits), complexation in solution, sorption onto surfaces, colloid formation, and diffusion. There may be many scenarios that could affect the near-field environment, creating chemical conditions more aggressive than the conditions presented by the unperturbed system (such as pH changes beyond the range of 6 to 9 or significant changes in the ionic strength of infiltrated waters). For an extended period of time, the near-field water composition may be quite different and more extreme in pH, ionic strength, and CO{sub 2} partial pressure (or carbonate concentration) than waters at some distance from the repository. Reducing conditions, high pH (up to 11), and low carbonate concentration may be present in the near-field after reaction of infiltrating groundwater with engineered barrier systems, such as cementitious materials. In the far-field, conditions are controlled by the rock-mass buffer providing a near-neutral, oxidizing, low-ionic-strength environment that controls radionuclide solubility limits and sorption capacities. There is the need for characterization of variable chemical conditions that affect solubility, speciation, and sorption reactions. Modeling of the groundwater chemistry is required and leads to an understanding of solubility and speciation of the important radionuclides. Because experimental studies cannot be performed under the numerous potential chemical conditions, solubility limitations must rely on geochemical modeling of the radionuclide's chemistry. Fundamental thermodynamic properties, such as solubility

  19. 24 CFR 585.302 - Award limits.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 3 2010-04-01 2010-04-01 false Award limits. 585.302 Section 585... DEVELOPMENT COMMUNITY FACILITIES YOUTHBUILD PROGRAM Youthbuild Implementation Grants § 585.302 Award limits... than the specified limit....

  20. 50 CFR 660.232 - Limited entry daily trip limit (DTL) fishery for sablefish.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Limited entry daily trip limit (DTL... limit (DTL) fishery for sablefish. (a) Limited entry DTL fisheries both north and south of 36° N. lat... restrictions and limits of the limited entry daily and/or weekly trip limit (DTL) fishery for...

  1. IDENTIDADES MASCULINAS: LIMITES E POSSIBILIDADES

    Directory of Open Access Journals (Sweden)

    May-Lin Wang

    2006-06-01

    Full Text Available O presente trabalho toma por base uma abordagem psicossocial para discorrer sobre os limites impostos pelos estereótipos de gênero à construção de uma identidade masculina, em contraposição às possibilidades de subjetivação, num cenário cultural de pluralidade identitária. Ênfase é dada à socialização estereotipada dos meninos, num processo no qual se verifica uma espécie de superposição do contexto socio-histórico em que cresceram os pais àquele no qual o menino é socializado, acentuando determinadas crenças sobre gênero. O modelo tradicional de virilidade, que imperava inquestionável até bem pouco tempo, ignorando as necessidades afetivas e valorizando características como a competitividade, a preocupação com o desempenho, o autoritarismo, a dominação e a opressão, vem sendo questionado como pilar maior da identidade masculina tradicional.

  2. Exploring life's limits: Deep geobiochemistry

    Science.gov (United States)

    Cox, A. D.

    2014-12-01

    N-dimensional chemical space on Earth and beyond produces diverse habitats for microbial activity. Hydrothermal environments cover a wide range of habitable space up to and including life's known limits and provide a window into deep geological, geochemical, and biological processes. Hydrothermal water compositions, as sampled from and measured in terrestrial hot springs on Earth's surface, vary in chemical constituent speciation and concentrations over orders of magnitude in a plethora of geochemical parameters with biological significance, including hydronium ion, sulfide, iron, zinc, magnesium, manganese, and molybdenum. Proteins provide a link between geochemistry and microbial activity by catalyzing chemical reactions. Proteins extracted and identified by tandem mass spectrometry from 13 hot spring sediments and biofilms - covering pH values from 2-9 and diverse geochemical compositions - function as efflux transporters, permeases, electron transporters, and others, suggesting that these processes were present in the environment and occurring at the time of sampling. Metalloenzymes have been identified, including the iron protein rubrerythrin, thought to be involved in oxidative stress protection in anaerobic bacteria and archaea, as well as proteins involved in macronutrient processing (carbon, phosphorus, nitrogen, and sulfur). The melding of biochemistry with geochemistry shows potential for quantifying microbial activity in deep environments by demonstrating the presence - and as techniques improve, relative abundances - of reaction-catalyzing enzymes. Moreover, using hot spring sources and their outflow channels as chemical and biological models of geologic time helps decipher the origin and co-evolution of life and geochemistry.

  3. Limits to Drift Chamber Resolution

    CERN Document Server

    Riegler, Werner

    1998-01-01

    ATLAS (A Large Toroidal LHC Apparatus) will be a general-purpose experiment at the Large Hadron Collider that will be operational at CERN in the year 2004. The ATLAS muon spectrometer aims for a momentum resolution of 10% for a transverse momentum of pT=1TeV. The precision tracking devices in the muon system will be high pressure drift tubes (MDTs) with a single wire resolution of 1100 chambers covering an area of ≈ 2500m2. The high counting rates in the spectrometer as well as the aim for excellent spatial resolution and high efficiency put severe constraints on the MDT operating parameters. This work describes a detailed study of all the resolution limiting factors in the ATLAS environment. A ’full chain’ simulation of the MDT response to photons and charged particles as well as quantitative comparisons with measurements was performed. The good agreement between simulation and measurements resulted in a profound understanding of the drift chamber processes and the individual contributions to the spat...

  4. Shear wall ultimate drift limits

    Energy Technology Data Exchange (ETDEWEB)

    Duffey, T.A. [Duffy, (T.A.) Tijeras, NM (United States); Goldman, A. [Goldman, (A.), Sandia, Los Alamos, NM (United States); Farrar, C.R. [Los Alamos National Lab., NM (United States)

    1994-04-01

    Drift limits for reinforced-concrete shear walls are investigated by reviewing the open literature for appropriate experimental data. Drift values at ultimate are determined for walls with aspect ratios ranging up to a maximum of 3.53 and undergoing different types of lateral loading (cyclic static, monotonic static, and dynamic). Based on the geometry of actual nuclear power plant structures exclusive of containments and concerns regarding their response during seismic (i.e.,cyclic) loading, data are obtained from pertinent references for which the wall aspect ratio is less than or equal to approximately 1, and for which testing is cyclic in nature (typically displacement controlled). In particular, lateral deflections at ultimate load, and at points in the softening region beyond ultimate for which the load has dropped to 90, 80, 70, 60, and 50 percent of its ultimate value, are obtained and converted to drift information. The statistical nature of the data is also investigated. These data are shown to be lognormally distributed, and an analysis of variance is performed. The use of statistics to estimate Probability of Failure for a shear wall structure is illustrated.

  5. Agriculture: access to technology limited.

    Science.gov (United States)

    1997-01-01

    From country to country and even regionally, the roles of women in agriculture vary, but most of their labor is in unpaid subsistence production and their contributions tend to be underestimated, according to the results of the [UN] Secretary-General's report. Depending on circumstances, they have complementary roles with men, sharing or dividing tasks in the production of crops, care of animals, and forestry management. In sub-Saharan Africa, for example, women contribute 60-80% of labor in food production for both household consumption and sale, while in Malaysia the women account for only 35% of the agricultural labor force, and in Ireland the participation rate is only 10.4%. Although women make this important amount of labor contributions to agricultural production, "development policies tend to favor export crops to earn foreign exchange and the agricultural research tends to address the improvement of production and technologies for commercial production". This results in limited access for women to technical knowledge and innovations, including irrigation, machinery, farming techniques and extension services. This is strengthened by the fact that most of the extension services target farmers who own land and can obtain credit to invest in input and technology. full text

  6. Photon and graviton mass limits

    Energy Technology Data Exchange (ETDEWEB)

    Nieto, Michael [Los Alamos National Laboratory; Goldhaber Scharff, Alfred [SUNY

    2008-01-01

    We review past and current studies of possible long-distance, low-frequency deviations from Maxwell electrodynamics and Einstein gravity. Both have passed through three phases: (1) Testing the inverse-square laws of Newton and Coulomb, (2) Seeking a nonzero value for the rest mass of photon or graviton, and (3) Considering more degrees of freedom, allowing mass while preserving gauge or general-coordinate invariance. For electrodynamics there continues to be no sign of any deviation. Since our previous review the lower limit on the photon Compton wavelength (associated with weakening of electromagnetic fields in vacuum over large distance scale) has improved by four orders of magnitude, to about one astronomical unit. Rapid current progress in astronomical observations makes it likely that there will be further advances. These ultimately could yield a bound exceeding galactic dimensions, as has long been contemplated. Meanwhile, for gravity there have been strong arguments about even the concept of a graviton rest mass. At the same time there are striking observations, commonly labeled 'dark matter' and 'dark energy' that some argue imply modified gravity. This makes the questions for gravity much more interesting. For dark matter, which involves increased attraction at large distances, any explanation by modified gravity would be qualitatively different from graviton mass. Because dark energy is associated with reduced attraction at large distances, it might be explained by a graviton-mass-like effect.

  7. Fault current limiters using superconductors

    Science.gov (United States)

    Norris, W. T.; Power, A.

    Fault current limiters on power systems are to reduce damage by heating and electromechanical forces, to alleviate duty on switchgear used to clear the fault, and to mitigate disturbance to unfaulted parts of the system. A basic scheme involves a super-resistor which is a superconductor being driven to high resistance when fault current flows either when current is high during a cycle of a.c. or, if the temperature of the superconductive material rises, for the full cycle. Current may be commuted from superconductor to an impedance in parallel, thus reducing the energy dispersed at low temperature and saving refrigeration. In a super-shorted transformer the ambient temperature primary carries the power system current; the superconductive secondary goes to a resistive condition when excessive currents flow in the primary. A super-transformer has the advantage of not needing current leads from high temperature to low temperature; it behaves as a parallel super-resistor and inductor. The supertransductor with a superconductive d.c. bias winding is large and has small effect on the rate of fall of current at current zero; it does little to alleviate duty on switchgear but does reduce heating and electromechanical forces. It is fully active after a fault has been cleared. Other schemes depend on rapid recooling of the superconductor to achieve this.

  8. Glacial effects limiting mountain height.

    Science.gov (United States)

    Egholm, D L; Nielsen, S B; Pedersen, V K; Lesemann, J-E

    2009-08-13

    The height of mountain ranges reflects the balance between tectonic rock uplift, crustal strength and surface denudation. Tectonic deformation and surface denudation are interdependent, however, and feedback mechanisms-in particular, the potential link to climate-are subjects of intense debate. Spatial variations in fluvial denudation rate caused by precipitation gradients are known to provide first-order controls on mountain range width, crustal deformation rates and rock uplift. Moreover, limits to crustal strength are thought to constrain the maximum elevation of large continental plateaus, such as those in Tibet and the central Andes. There are indications that the general height of mountain ranges is also directly influenced by the extent of glaciation through an efficient denudation mechanism known as the glacial buzzsaw. Here we use a global analysis of topography and show that variations in maximum mountain height correlate closely with climate-controlled gradients in snowline altitude for many high mountain ranges across orogenic ages and tectonic styles. With the aid of a numerical model, we further demonstrate how a combination of erosional destruction of topography above the snowline by glacier-sliding and commensurate isostatic landscape uplift caused by erosional unloading can explain observations of maximum mountain height by driving elevations towards an altitude window just below the snowline. The model thereby self-consistently produces the hypsometric signature of the glacial buzzsaw, and suggests that differences in the height of mountain ranges mainly reflect variations in local climate rather than tectonic forces.

  9. Apport des expériences en canal à l'interprétation sédimentologique des dépôts de cônes détritiques sous-marins . . . Contribution of Channel Experiments to the Sedimentological Interpretation of Marine Detrital Cone Deposits

    Directory of Open Access Journals (Sweden)

    Ravenne C.

    2006-11-01

    Full Text Available Nous présentons les résultats des expériences réalisées en canal au laboratoire de Mécanique des Fluides de Grenoble visant à l'étude des courants turbides et leur apport à la compréhension de l'arrangement et de la constitution des différents éléments observés dans les dépôts d'origine gravitaire généralement rencontrés dans les bassins sédimentaires profonds. La première partie concerne les expériences et montre: 1 la distinction entre courant de densité et bouffée turbide ; 2 les différentes phases d'un écoulement turbide et leur mécanisme : - mise en mouvement de la masse initiale ; - formation d'un mass-flow; - formation d'un débris-flowou d'un grain-flow; - l'importance du ressaut hydraulique ; - la formation d'une bouffée de densité ; - la décélération de la bouffée. La deuxième partie concerne l'interprétation des éléments constitutifs d'une séquence liée à des écoulements turbides telle qu'elle a été observée dans la Série des Grès d'Annotet comprenant notamment les termes suivants : - bancs de grès homogènes ; - barre massive et ses différentes composantes : niveau de grès homogène ; niveau à galets mous - érosion ; niveau à granules ; niveau grano classé ; niveau à figures d'échappement d'eau ; niveau à figures de progradation ; - intercalations argilo-silteuses. Chacun de ces éléments est relié à une phase ou une partie de phase décrite dans la première partie. Nous proposons en même temps que cette interprétation un processus de mise en place des différents éléments et de leur arrangement séquentiel: série strato-croissante très rapide, barre massive et série strato-décroissante progressive. Ce processus est centré sur un épisode catastrophique majeur (séisme ou déstabilisation de pente responsable de la création de la barre massive. La série strato-croissante est liée aux prémices de cette phase majeure et la série stratotlécroissante à ses r

  10. 45 CFR 5.35 - Time limits.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Time limits. 5.35 Section 5.35 Public Welfare... Denial of Records § 5.35 Time limits. (a) General. FOIA sets certain time limits for us to decide whether... time limits, but if it appears that processing your request may take longer than we would wish, we...

  11. 5 CFR 2604.305 - Time limits.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Time limits. 2604.305 Section 2604.305... Disclosure of Records Under FOIA § 2604.305 Time limits. (a)(1) Initial request. Following receipt of a... appeal. (c) Extension of time limits. The time limits specified in either paragraph (a) or (b) of...

  12. 49 CFR 218.35 - Yard limits.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Yard limits. 218.35 Section 218.35 Transportation... TRANSPORTATION RAILROAD OPERATING PRACTICES Protection of Trains and Locomotives § 218.35 Yard limits. (a) After August 1, 1977, yard limits must be designated by— (1) Yard limit signs, and (2) Timetable, train...

  13. Tracial Limit of C*-algebras

    Institute of Scientific and Technical Information of China (English)

    Shan Wen HU; Hua Xin LIN; Yi Feng XUE

    2003-01-01

    A new limit of C*-algebras, the tracial limit, is introduced in this paper. We show thata separable simple C*-algebra 4 is a tracial limit of C*-algebras in Z(k) if and only if A has tracialtopological rank no more than k. We present several known results using the notion of tracial limits.

  14. 7 CFR 52.3185 - Moisture limits.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Moisture limits. 52.3185 Section 52.3185 Agriculture... Moisture limits. Dried prunes shall not exceed the moisture limits for the applicable grades and kind and size of packaging as designated in Table IV of this subpart except there is no moisture limit when...

  15. 78 FR 57790 - Extension of Time Limits

    Science.gov (United States)

    2013-09-20

    ... International Trade Administration 19 CFR Part 351 RIN 0625-AA94 Extension of Time Limits AGENCY: Import... Department of Commerce (the Department) is modifying its regulation concerning the extension of time limits... clarifies that parties may request an extension of time limits before any time limit established under...

  16. 36 CFR 1004.21 - Speed limits.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Speed limits. 1004.21 Section... limits. (a) Speed limits in the area administered by the Presidio Trust are as follows: (1) 15 miles per... Presidio Trust roads. (b) The Board may designate a different speed limit upon any Presidio Trust road...

  17. 45 CFR 1160.13 - Indemnification limits.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Indemnification limits. 1160.13 Section 1160.13... ACT § 1160.13 Indemnification limits. The dollar amounts of the limits described below are found in the guidelines referred to in § 1160.1 and are based upon the statutory limits in the Arts...

  18. 45 CFR 3.26 - Speed limit.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Speed limit. 3.26 Section 3.26 Public Welfare... INSTITUTES OF HEALTH FEDERAL ENCLAVE Traffic Regulations § 3.26 Speed limit. The speed limit is 25 miles per hour, unless otherwise posted. A driver of a vehicle may not exceed the speed limit....

  19. 50 CFR 20.24 - Daily limit.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Daily limit. 20.24 Section 20.24 Wildlife... (CONTINUED) MIGRATORY BIRD HUNTING Taking § 20.24 Daily limit. No person shall take in any 1 calendar day, more than the daily bag limit or aggregate daily bag limit, whichever applies....

  20. The role of limiter in Egyptor Tokamak

    CERN Document Server

    Ei-Sisi, A B

    2002-01-01

    In Egyptor Tokamak, the limiter is used for separation of the plasma from the vessel. In this work an overview of limiter types, and construction of limiter in Egyptor Tokamak is discussed. Also simulation results of the radial electron density distribution in case of limiter are presented. The results of the simulation are in agreement with the experimental and analytical results.

  1. Power limits for microbial life

    Directory of Open Access Journals (Sweden)

    Doug eLaRowe

    2015-07-01

    Full Text Available To better understand the origin, evolution and extent of life, we seek to determine the minimum flux of energy needed for organisms to remain viable. Despite the difficulties associated with direct measurement of the power limits for life, it is possible to use existing data and models to constrain the minimum flux of energy required to sustain microorganisms. Here, a we apply a bioenergetic model to a well characterized marine sedimentary environment in order to quantify the amount of power organisms use in an ultralow-energy setting. In particular, we show a direct link between power consumption in this environment and the amount of biomass (cells cm-3 found in it. The power supply resulting from the aerobic degradation of particular organic carbon (POC at IODP Site U1370 in the South Pacific Gyre is between ~ 10-12 and 10-16 W cm-3. The rates of POC degradation are calculated using a continuum model while Gibbs energies have been computed using geochemical data describing the sediment as a function of depth. Although laboratory-determined values of maintenance power do a poor job of representing the amount of biomass in U1370 sediments, the number of cells per cm-3 can be well-captured using a maintenance power, 190 zW cell-1, two orders of magnitude lower than the lowest value reported in the literature. In addition, we have combined cell counts and calculated power supplies to determine that, on average, the microorganisms at Site U1370 require 50 – 3500 zW cell-1, with most values under ~300 zW cell-1. Furthermore, we carried out an analysis of the absolute minimum power requirement for a single cell to remain viable to be on the order of 1 zW cell-1.

  2. A geographic model to assess and limit cumulative ecological degradation from Marcellus Shale exploitation in New York, USA

    Science.gov (United States)

    Davis, John B.; Robinson, George R.

    2012-01-01

    When natural resources are exploited, environmental costs and economic benefits are often asymmetric. An example is apparent in the environmental impacts from fossil fuel extraction by hydraulic fracturing. So far, most scrutiny has been focused on water quality in affected aquifers, with less attention paid to broader ecological impacts beyond individual drilling operations. Marcellus Shale methane exploitation in New York State, USA, has been delayed because of a regulatory moratorium, pending evaluation that has been directed primarily at localized impacts. We developed a GIS-based model, built on a hexagonal grid underlay nested within the U.S. Environmental Protection Agency’s EMAP system, to examine potential cumulative ecological impacts. In a two-step process, we characterized > 19,000 hexagons, each sized to approximate the footprint of one drilling site (2.57 km²), using ecological attributes; we then developed a method for apportioning resource access that includes assessments of cumulative ecological costs. Over one-quarter of the hexagons were excluded as off-limits on the basis of six criteria: slope suitability, regulated wetland cover, protected-land cover, length of high-quality streams, mapped road density, and open water cover. Three additional criteria were applied to assess the estimated conservation vulnerability of the remaining sites: density of grassland birds (North American Breeding Bird Survey), percent core forest (Coastal Change Analysis Program), and total density of all state-mapped streams; these were determined and used in combination to rank the 14,000 potentially accessible sites. In a second step, an iterative process was used to distribute potential site access among all towns (sub-county governments) within the Marcellus Shale Formation. At each iteration, one site was selected per town, either randomly or in rank order of increasing vulnerability. Results were computed as percent cumulative impact versus the number of

  3. A Geographic Model to Assess and Limit Cumulative Ecological Degradation from Marcellus Shale Exploitation in New York, USA

    Directory of Open Access Journals (Sweden)

    George R. Robinson

    2012-06-01

    Full Text Available When natural resources are exploited, environmental costs and economic benefits are often asymmetric. An example is apparent in the environmental impacts from fossil fuel extraction by hydraulic fracturing. So far, most scrutiny has been focused on water quality in affected aquifers, with less attention paid to broader ecological impacts beyond individual drilling operations. Marcellus Shale methane exploitation in New York State, USA, has been delayed because of a regulatory moratorium, pending evaluation that has been directed primarily at localized impacts. We developed a GIS-based model, built on a hexagonal grid underlay nested within the U.S. Environmental Protection Agency’s EMAP system, to examine potential cumulative ecological impacts. In a two-step process, we characterized > 19,000 hexagons, each sized to approximate the footprint of one drilling site (2.57 km², using ecological attributes; we then developed a method for apportioning resource access that includes assessments of cumulative ecological costs. Over one-quarter of the hexagons were excluded as off-limits on the basis of six criteria: slope suitability, regulated wetland cover, protected-land cover, length of high-quality streams, mapped road density, and open water cover. Three additional criteria were applied to assess the estimated conservation vulnerability of the remaining sites: density of grassland birds (North American Breeding Bird Survey, percent core forest (Coastal Change Analysis Program, and total density of all state-mapped streams; these were determined and used in combination to rank the 14,000 potentially accessible sites. In a second step, an iterative process was used to distribute potential site access among all towns (sub-county governments within the Marcellus Shale Formation. At each iteration, one site was selected per town, either randomly or in rank order of increasing vulnerability. Results were computed as percent cumulative impact versus

  4. Internal polarization limits coronagraph contrast

    Science.gov (United States)

    Breckinridge, James Bernard; Lam, Wai Sze T.; Chipman, Russell A.

    2015-08-01

    The performance of exoplanet imaging coronagraphs is limited by internal polarization. The point spread function (PSF) of these systems is determined by the details of the opto-mechanical layout selected to package the system and by the highly reflective metal thin films needed to maintain high optical system transmittance. To obtain the high contrast levels needed for terrestrial exoplanet science requires a comprehensive understanding of the vector electromagnetic wave from the source through the system. The literature contains many studies of polarization transmissivity of telescopes and instruments for the purpose of photo-polarimetry. Here we report for the first time the effects of polarization on high-performance image quality.We modeled a typical 2.4-meter Cassegrain telescope system with one 90-degree fold mirror and analyzed the system for polarization aberrations.We find: 1. The image plane irradiance distribution is the linear superposition of four PSF images: One for each of the two orthogonal polarizations and one for each of two cross-product polarization terms. 2. The PSF image is brighter by 9% for one polarization component compared to its orthogonal state. 3. The image of the PSF for orthogonal components are shifted across the focal plane with respect to each other, causing the PSF image for astronomical sources (polarized or unpolarized) to become slightly elongated (elliptical) with a centroid separation of about 0.6 masec. 4. The orthogonally polarized components of unpolarized sources contain different wavefront aberrations, which are separated by approximately 32 milliwaves. This implies that a wavefront correction system cannot optimally correct the aberrations for all polarizations simultaneously. 5. The polarization aberrations couple small parts (~1E-5) of each polarization component of the light into the orthogonal polarization to create highly distorted secondary, or “ghost” PSF image.. The radius of the spatial extent of the 90

  5. On thermodynamic limits of entropy densities

    NARCIS (Netherlands)

    Moriya, H; Van Enter, A

    1998-01-01

    We give some sufficient conditions which guarantee that the entropy density in the thermodynamic limit is equal to the thermodynamic limit of the entropy densities of finite-volume (local) Gibbs states.

  6. Infrared limit in external field scattering

    CERN Document Server

    Herdegen, Andrzej

    2012-01-01

    Scattering of electrons/positrons by external classical electromagnetic wave packet is considered in infrared limit. In this limit the scattering operator exists and produces physical effects, although the scattering cross-section is trivial.

  7. FDA Suggests Limits on Lead in Cosmetics

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_162726.html FDA Suggests Limits on Lead in Cosmetics Agency notes ... the authority to enforce such a limit, the FDA recommended in a draft guidance issued Thursday that ...

  8. High temperature superconducting fault current limiter

    Energy Technology Data Exchange (ETDEWEB)

    Hull, John R. (Hinsdale, IL)

    1997-01-01

    A fault current limiter (10) for an electrical circuit (14). The fault current limiter (10) includes a high temperature superconductor (12) in the electrical circuit (14). The high temperature superconductor (12) is cooled below its critical temperature to maintain the superconducting electrical properties during operation as the fault current limiter (10).

  9. The density limit in JET diverted plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, D.J.; Clement, S.; Gottardi, N.; Gowers, C.; Harbour, P.; Loarte, A.; Horton, L.; Lingertat, J.; Lowry, C.G.; Saibene, G.; Stamp, M.; Stork, D. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Monk, R. [Royal Holloway Coll., London (United Kingdom). Dept. of Physics

    1994-07-01

    In JET limiter plasmas the density limit is associated with radiated power fractions of 100% and, in plasmas with carbon limiters, it is invariably disruptive. However, in discharges with solid beryllium limiters the limit is identified with the formation of a MARFE and disruptions are less frequent. In addition, the improved conditioning of the vessel arising from the use of beryllium has significantly improved the density limit scaling, so that the maximum density rises with the square root of the input power. In diverted plasmas several confinement regimes exist, making the characterization of the density limit more complex. While the density limit in L-mode plasmas is generally disruptive, the limit in ELMy and ELM-free H-modes generally prompts a return to the L-mode and a disruption is not inevitable. The density limit does rise with the increasing power, but the L-to-H transition complicates the analysis. Nevertheless, at low plasma currents (<2 MA), densities significantly above the Greenwald limit can be achieved, while at higher currents power handling limitations have constrained the range of density which can be achieved. (authors). 7 refs., 4 figs.

  10. 50 CFR 38.13 - Speed limits.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Speed limits. 38.13 Section 38.13 Wildlife... NATIONAL WILDLIFE REFUGE SYSTEM MIDWAY ATOLL NATIONAL WILDLIFE REFUGE Prohibitions § 38.13 Speed limits. No person on Midway Atoll National Wildlife Refuge will exceed the speed limit for automobiles,...

  11. 50 CFR 20.33 - Possession limit.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Possession limit. 20.33 Section 20.33... PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Possession § 20.33 Possession limit. No person shall possess more migratory game birds taken in the United States than the possession limit or the...

  12. 47 CFR 18.307 - Conduction limits.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Conduction limits. 18.307 Section 18.307... Standards § 18.307 Conduction limits. For the following equipment, when designed to be connected to the... on any frequency or frequencies shall not exceed the limits in the following tables. Compliance...

  13. 40 CFR 63.802 - Emission limits.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Emission limits. 63.802 Section 63.802... Standards for Wood Furniture Manufacturing Operations § 63.802 Emission limits. (a) Each owner or operator of an existing affected source subject to this subpart shall: (1) Limit VHAP emissions from...

  14. 38 CFR 21.1033 - Time limits.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Time limits. 21.1033... Time limits. The provisions of this section are applicable to informal claims and formal claims. (a) Failure to furnish form, information, or notice of time limit. VA's failure to give a claimant...

  15. 38 CFR 3.109 - Time limit.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Time limit. 3.109 Section..., Compensation, and Dependency and Indemnity Compensation Administrative § 3.109 Time limit. (a) Notice of time limit for filing evidence. (1) If a claimant's application is incomplete, the claimant will be...

  16. 34 CFR 685.203 - Loan limits.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false Loan limits. 685.203 Section 685.203 Education..., DEPARTMENT OF EDUCATION WILLIAM D. FORD FEDERAL DIRECT LOAN PROGRAM Borrower Provisions § 685.203 Loan limits... Direct Stafford/Ford Loan Program and Federal Stafford Loan Program aggregate limits. The...

  17. 40 CFR 1501.8 - Time limits.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Time limits. 1501.8 Section 1501.8 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY NEPA AND AGENCY PLANNING § 1501.8 Time limits. Although the Council has decided that prescribed universal time limits for the entire NEPA process are...

  18. 14 CFR 36.103 - Noise limits.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Noise limits. 36.103 Section 36.103... Noise limits. (a) For subsonic transport category large airplanes and subsonic jet airplanes compliance... greater than the Stage 3 noise limit prescribed in section B36.5(c) of appendix B of this part. (c)...

  19. 50 CFR 648.145 - Possession limit.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Possession limit. 648.145 Section 648.145... Fishery § 648.145 Possession limit. (a) No person shall possess more than 25 black sea bass, in, or... that is not eligible for a black sea bass moratorium permit are subject to this possession limit....

  20. 7 CFR 1400.106 - Payment limits.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Payment limits. 1400.106 Section 1400.106 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT OF... SUBSEQUENT CROP, PROGRAM, OR FISCAL YEARS Payment Limitation § 1400.106 Payment limits. (a) Payments made...

  1. 50 CFR 635.20 - Size limits.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Size limits. 635.20 Section 635.20..., DEPARTMENT OF COMMERCE ATLANTIC HIGHLY MIGRATORY SPECIES Management Measures § 635.20 Size limits. Link to an... (160 cm), LJFL. (4) The Atlantic blue and white marlin minimum size limits, specified in paragraphs...

  2. 7 CFR 3560.63 - Loan limits.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Loan limits. 3560.63 Section 3560.63 Agriculture... DIRECT MULTI-FAMILY HOUSING LOANS AND GRANTS Direct Loan and Grant Origination § 3560.63 Loan limits. (a... housing tax credits, limits will be those specified in § 3560.53(l). (2) Developer's fee. While,...

  3. 14 CFR 36.501 - Noise limits.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Noise limits. 36.501 Section 36.501..., Commuter Category Airplanes § 36.501 Noise limits. (a) Compliance with this subpart must be shown for— (1... applicable limit set in Part D of appendix F. (c) For aircraft covered by this subpart for...

  4. 17 CFR 150.2 - Position limits.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 1 2010-04-01 2010-04-01 false Position limits. 150.2 Section 150.2 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION LIMITS ON POSITIONS § 150.2 Position limits. No person may hold or control positions, separately or in combination, net...

  5. 7 CFR 4274.331 - Loan limits.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Loan limits. 4274.331 Section 4274.331 Agriculture... (IRP) § 4274.331 Loan limits. (a) Intermediary. (1) No loan to an intermediary will exceed the maximum... be used for loans to ultimate recipients that exceed $150,000. This limit does not apply to...

  6. 47 CFR 15.207 - Conducted limits.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Conducted limits. 15.207 Section 15.207... Conducted limits. (a) Except as shown in paragraphs (b) and (c) of this section, for an intentional radiator... to 30 MHz, shall not exceed the limits in the following table, as measured using a 50 μH/50 ohms...

  7. 18 CFR 807.2 - Time limits.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Time limits. 807.2... WITHDRAWAL REGISTRATION § 807.2 Time limits. (a) Except for agricultural water use projects, all registration... limit the responsibility of a project sponsor to apply for and obtain an approval as may be...

  8. 47 CFR 15.315 - Conducted limits.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Conducted limits. 15.315 Section 15.315... Communications Service Devices § 15.315 Conducted limits. An unlicensed PCS device that is designed to be connected to the public utility (AC) power line must meet the limits specified in § 15.207....

  9. 14 CFR 36.805 - Noise limits.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Noise limits. 36.805 Section 36.805...: AIRCRAFT TYPE AND AIRWORTHINESS CERTIFICATION Helicopters § 36.805 Noise limits. (a) Compliance with the... levels of the helicopter are no greater than the applicable limits prescribed under section H36.305...

  10. 32 CFR 935.132 - Speed limits.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Speed limits. 935.132 Section 935.132 National... WAKE ISLAND CODE Motor Vehicle Code § 935.132 Speed limits. Each person operating a motor vehicle on..., or both; and (b) That does not exceed 40 miles an hour or such lesser speed limit as may be posted....

  11. 32 CFR 806.22 - Time limits.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Time limits. 806.22 Section 806.22 National... INFORMATION ACT PROGRAM § 806.22 Time limits. Any FOIA appeals received after the 60-day time limit are not processed, unless the requester provides adequate justification for failing to comply with the time...

  12. 47 CFR 90.1215 - Power limits.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Power limits. 90.1215 Section 90.1215... § 90.1215 Power limits. The transmitting power of stations operating in the 4940-4990 MHz band must not exceed the maximum limits in this section. (a)(1) The maximum conducted output power should not...

  13. 5 CFR 847.304 - Time limit.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Time limit. 847.304 Section 847.304... Procedures for Elections Under the Retroactive Provisions § 847.304 Time limit. (a) Except as provided in paragraph (b) of this section, the time limit for making an election under subpart D of this part is...

  14. 50 CFR 648.125 - Possession limit.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Possession limit. 648.125 Section 648.125... § 648.125 Possession limit. (a) No person shall possess more than 10 scup in, or harvested from, the EEZ... moratorium permit are subject to this possession limit. The owner, operator, and crew of a charter or...

  15. 10 CFR 1017.21 - Limited access.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Limited access. 1017.21 Section 1017.21 Energy DEPARTMENT... INFORMATION Access to Unclassified Controlled Nuclear Information § 1017.21 Limited access. (a) A person who is not eligible for routine access to specific UCNI under § 1017.20 may request limited access...

  16. SEMICLASSICAL LIMIT OF NONLINEAR SCHRODINGER EQUATION (Ⅱ)

    Institute of Scientific and Technical Information of China (English)

    张平

    2002-01-01

    In this paper, we use the Wigner measure approach to study the semiclassical limit of nonlinear Schrodinger equation in small time. We prove that: the limits of the quantum density: pε =: |ψε|2, and the quantum momentum: Jε =: εIm(ψεψε) satisfy the compressible Euler equations before the formation of singularities in the limit system.

  17. 12 CFR 616.6600 - Leasing limit.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Leasing limit. 616.6600 Section 616.6600 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM LEASING § 616.6600 Leasing limit. All leases made by Farm Credit System institutions shall be subject to the lending and leasing limit in subpart...

  18. 47 CFR 73.1725 - Limited time.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Limited time. 73.1725 Section 73.1725... Rules Applicable to All Broadcast Stations § 73.1725 Limited time. (a) Operation is applicable only to... stations on the channel. (b) No authorization will be granted for: (1) A new limited time station; (2)...

  19. Multiple Limit Cycles in an Immune System

    Institute of Scientific and Technical Information of China (English)

    Xun-cheng Huang; Le-min Zhu; Minaya Villasana

    2008-01-01

    The nonlinear oscillatory phenomenon has been observed in the system of immune response, which corresponds to the limit cycles in the mathematical models. We prove that the system simulating an immune response studied by Huang has at least three limit cycles in the system. The conditions for the multiple limit cycles are useful in analyzing the nonlinear oscillation in immune response.

  20. Optimizing discrete control systems with phase limitations

    Energy Technology Data Exchange (ETDEWEB)

    Shakhverdian, S.B.; Abramian, A.K.

    1981-01-01

    A new method is proposed for solving discrete problems of optimizing control systems with limitations on the phase coordinates. Results are given from experimental research which demonstrate the need to introduce tangential limitations independent of the method of accounting for the phase limitations.

  1. 40 CFR 264.94 - Concentration limits.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Concentration limits. 264.94 Section... From Solid Waste Management Units § 264.94 Concentration limits. (a) The Regional Administrator will specify in the facility permit concentration limits in the ground water for hazardous constituents...

  2. 12 CFR 24.4 - Investment limits.

    Science.gov (United States)

    2010-01-01

    ... ENTITIES, COMMUNITY DEVELOPMENT PROJECTS, AND OTHER PUBLIC WELFARE INVESTMENTS § 24.4 Investment limits. (a) Limits on aggregate outstanding investments. A national bank's aggregate outstanding investments under... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Investment limits. 24.4 Section 24.4 Banks and...

  3. Determination of the meteor limiting magnitude

    Science.gov (United States)

    Kingery, A.; Blaauw, R. C.

    2017-09-01

    We present our method to calculate the meteor limiting magnitude. The limiting meteor magnitude defines the faintest magnitude at which all meteors are still detected by a given system. An accurate measurement of the limiting magnitude is important in order to calculate the meteoroid flux from a meteor shower or sporadic source. Since meteor brightness is linked to meteor mass, the limiting magnitude is needed to calculate the limiting mass of the meteor flux measurement. The mass distribution of meteoroids is thought to follow a power law, thus being slightly off in the limiting magnitude can have a significant effect on the measured flux. Sky conditions can change on fairly short timescales; therefore one must monitor the meteor limiting magnitude at regular intervals throughout the night, rather than just measuring it once. We use the stellar limiting magnitude as a proxy of the meteor limiting magnitude. Our method for determining the stellar limiting magnitude and how we transform it into the meteor limiting magnitude is presented. These methods are currently applied to NASA's wide-field meteor camera network to determine nightly fluxes, but are applicable to other camera networks.

  4. The Translation of Numerals and its Limits

    Institute of Scientific and Technical Information of China (English)

    吴贤雯

    2013-01-01

    Through probing into the diversity of numerals’functions in language use which gives prominence to the importance of numeral translation, this paper aims to analyze the limits of numeral translation and explain the cause for these limits. The analy-sis of the limits in numeral translation is guided by the principle of functional equivalence. It is discussed that in numeral transla-tion, the limits on different levels of culture, image, sound and form arise when the full functional equivalence can not be achieved. Furthermore, this paper finds that the differences in culture and formal structure as well as the semantic fuzziness are three reasons for the presence of limits in numeral translation. However, the author suggests that these limits in numeral transla-tion can be adjusted with the further development of research on translation methodology and the deep infiltration of different cultures.

  5. Existence of Multiagent Equilibria with Limited Agents

    CERN Document Server

    Bowling, M; 10.1613/jair.1332

    2011-01-01

    Multiagent learning is a necessary yet challenging problem as multiagent systems become more prevalent and environments become more dynamic. Much of the groundbreaking work in this area draws on notable results from game theory, in particular, the concept of Nash equilibria. Learners that directly learn an equilibrium obviously rely on their existence. Learners that instead seek to play optimally with respect to the other players also depend upon equilibria since equilibria are fixed points for learning. From another perspective, agents with limitations are real and common. These may be undesired physical limitations as well as self-imposed rational limitations, such as abstraction and approximation techniques, used to make learning tractable. This article explores the interactions of these two important concepts: equilibria and limitations in learning. We introduce the question of whether equilibria continue to exist when agents have limitations. We look at the general effects limitations can have on agent b...

  6. The Limitations and Application Methods of Suggestopedia

    Institute of Scientific and Technical Information of China (English)

    李苗苗; 宋宝梅

    2015-01-01

    For a long time,college English teaching was mainly teacher-centered.Teachers played a dominant role in the classroom whereas students played a passive role.The"Suggestopedia"theory is such an effective way.However,there exist some limitations when apply the Suggestopedia theory.Teachers must pay attention to these limitations when apply the Suggestopedia theory.This thesis not only presents the limitations but also give some advises to the proper application of Suggestopedia Theory in teaching.

  7. 19 CFR 145.23 - Time limits.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Time limits. 145.23 Section 145.23 Customs Duties... (CONTINUED) MAIL IMPORTATIONS Administrative Review of Mail Entries § 145.23 Time limits. A mail entry may be... requests such amendment within the time limits prescribed therein (see §§ 173.4 and 173.5 of this...

  8. Investigation of pulsed voltage limiters characteristics

    Directory of Open Access Journals (Sweden)

    Karimov A. V.

    2012-06-01

    Full Text Available A new method for measuring the voltage limit is offered. It has been designed to measure high-power pulsed current of voltage limiters. The error of this method is half as much as the error of the known method of direct measurement. The investigation of dependence of power capability of single-crystal and double-crystal voltage limiters and of the pulsed operation time on pulse duration.

  9. The Limitations and Application Methods of Suggestopedia

    Institute of Scientific and Technical Information of China (English)

    李苗苗; 宋宝梅

    2015-01-01

    For a long time,college English teaching was mainly teacher-centered.Teachers played a dominant role in the classroom whereas students played a passive role.The"Suggestopedia" theory is such an effective way.However,there exist some limitations when apply the Suggestopedia theory.Teachers must pay attention to these limitations when apply the Suggestopedia theory.This thesis not only presents the limitations but also give some advises to the proper application of Suggestopedia Theory in teaching.

  10. Inproved grade length limitation of freeways

    Institute of Scientific and Technical Information of China (English)

    XING En-hui; PEI Yu-long

    2006-01-01

    A method of ascertaining grade length limitation of freeways in mountain terrain is presented. The relationship models between 15th percentile speeds and grades were built through the surveys and analyses of operation speeds on 7 typical sections of 3 freeways in mountain terrain. Using 15th percentile and 85th percentile as speed limitations, the methods of determining admitted velocities were put forward according to the grades. Deceleration distances of longitudinal slopeways were analyzed utilizing the theories of vehicle. According to the results of analysis, grade length limitation was loosed. Finally the values of grade length limitation for freeways were put forward. The results could be used as references for freeway design.

  11. Fundamental gravitational limitations to quantum computing

    CERN Document Server

    Gambini, R; Pullin, J; Gambini, Rodolfo; Porto, Rafael A.; Pullin, Jorge

    2005-01-01

    Lloyd has considered the ultimate limitations physics places on quantum computers. He concludes in particular that for an ``ultimate laptop'' (a computer of one liter of volume and one kilogram of mass) the maximum number of operations per second is bounded by $10^{51}$. The limit is derived considering ordinary quantum mechanics. Here we consider additional limits that are placed by quantum gravity ideas, namely the use of a relational notion of time and fundamental gravitational limits that exist on time measurements. We then particularize for the case of an ultimate laptop and show that the maximum number of operations is further constrained to $10^{47}$ per second.

  12. 47 CFR 80.511 - Assignment limitations.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Assignment limitations. 80.511 Section 80.511 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES STATIONS IN THE MARITIME SERVICES Private Coast Stations and Marine Utility Stations § 80.511 Assignment limitations. (a...

  13. Central Limit Theorem for Coloured Hard Dimers

    Directory of Open Access Journals (Sweden)

    Maria Simonetta Bernabei

    2010-01-01

    Full Text Available We study the central limit theorem for a class of coloured graphs. This means that we investigate the limit behavior of certain random variables whose values are combinatorial parameters associated to these graphs. The techniques used at arriving this result comprise combinatorics, generating functions, and conditional expectations.

  14. Optical limiting in semiconductor-doped glasses

    Science.gov (United States)

    Bindra, K. S.; Oak, S. M.; Rustagi, K. C.

    1996-02-01

    We report optical limiting at 527 nm in two Schott semiconductor-doped glasses OG530 and OG515. These two glasses show quite contrasting nonlinear optical behaviour. The glass OG515 shows strong clamping while OG530 shows no clamping in optical limiting inspite of having much larger nonlinear refractive index. Similarly OG530 exhibits saturation of absorption while OG515 does not.

  15. Limited dependent variable models for panel data

    NARCIS (Netherlands)

    Charlier, E.

    1997-01-01

    Many economic phenomena require limited variable models for an appropriate treatment. In addition, panel data models allow the inclusion of unobserved individual-specific effects. These models are combined in this thesis. Distributional assumptions in the limited dependent variable models are

  16. 14 CFR 43.16 - Airworthiness limitations.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Airworthiness limitations. 43.16 Section 43.16 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT MAINTENANCE, PREVENTIVE MAINTENANCE, REBUILDING, AND ALTERATION § 43.16 Airworthiness limitations. Each...

  17. 33 CFR 401.28 - Speed limits.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Speed limits. 401.28 Section 401... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Seaway Navigation § 401.28 Speed limits. (a) The maximum speed over the bottom for a vessel of more than 12 m in overall length shall be regulated so as not...

  18. 47 CFR 78.115 - Modulation limits.

    Science.gov (United States)

    2010-10-01

    ... SERVICE Technical Regulations § 78.115 Modulation limits. (a) If amplitude modulation is employed..., frequencies 78.36 Cross reference to other rules 78.3 D Definitions 78.5 E Eligibility for license 78.13 Emission designator 78.104 Emissions; emission limitations 78.103 Equal employment opportunities...

  19. 40 CFR 1502.7 - Page limits.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Page limits. 1502.7 Section 1502.7 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY ENVIRONMENTAL IMPACT STATEMENT § 1502.7 Page limits. The text of final environmental impact statements (e.g., paragraphs (d) through (g) of §...

  20. 40 CFR 503.43 - Pollutant limits.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Pollutant limits. 503.43 Section 503... THE USE OR DISPOSAL OF SEWAGE SLUDGE Incineration § 503.43 Pollutant limits. (a) Firing of sewage... 40 CFR part 61. (c) Pollutant limit—lead. (1) The average daily concentration for lead in...

  1. 46 CFR 298.21 - Limits.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Limits. 298.21 Section 298.21 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION VESSEL FINANCING ASSISTANCE OBLIGATION GUARANTEES Guarantees § 298.21 Limits. (a) Actual Cost basis. We will issue a guarantee on an amount of the...

  2. 47 CFR 73.855 - Ownership limits.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Ownership limits. 73.855 Section 73.855 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO BROADCAST SERVICES Low Power FM Broadcast Stations (LPFM) § 73.855 Ownership limits. (a) No authorization for an...

  3. 5 CFR 1205.23 - Time limits.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Time limits. 1205.23 Section 1205.23 Administrative Personnel MERIT SYSTEMS PROTECTION BOARD ORGANIZATION AND PROCEDURES PRIVACY ACT REGULATIONS Amendment of Records § 1205.23 Time limits. The Clerk of the Board, Regional Director, or...

  4. 10 CFR 52.9 - Jurisdictional limits.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Jurisdictional limits. 52.9 Section 52.9 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS General Provisions § 52.9 Jurisdictional limits. No permit, license, standard design approval, or standard...

  5. 19 CFR 357.106 - Time limits.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Time limits. 357.106 Section 357.106 Customs Duties INTERNATIONAL TRADE ADMINISTRATION, DEPARTMENT OF COMMERCE SHORT SUPPLY PROCEDURES § 357.106 Time limits. (a) The Secretary will determine, no later than the day specified in paragraph (b) of...

  6. 24 CFR 585.202 - Award limits.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 3 2010-04-01 2010-04-01 false Award limits. 585.202 Section 585.202 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued... DEVELOPMENT COMMUNITY FACILITIES YOUTHBUILD PROGRAM Youthbuild Planning Grants § 585.202 Award limits....

  7. 32 CFR 169a.19 - Study limits.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 1 2010-07-01 2010-07-01 false Study limits. 169a.19 Section 169a.19 National Defense Department of Defense OFFICE OF THE SECRETARY OF DEFENSE DEFENSE CONTRACTING COMMERCIAL ACTIVITIES PROGRAM PROCEDURES Procedures § 169a.19 Study limits. No DoD funds shall be available to perform any...

  8. 38 CFR 36.4214 - Geographical limits.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Geographical limits. 36.4214 Section 36.4214 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED... Preparation General Provisions § 36.4214 Geographical limits. The site for any manufactured home...

  9. 27 CFR 11.4 - Jurisdictional limits.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Jurisdictional limits. 11.4 Section 11.4 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS CONSIGNMENT SALES Scope of Regulations § 11.4 Jurisdictional limits....

  10. 14 CFR 25.25 - Weight limits.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Weight limits. 25.25 Section 25.25 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Flight General § 25.25 Weight limits. (a) Maximum weights....

  11. 49 CFR 236.753 - Limits, interlocking.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Limits, interlocking. 236.753 Section 236.753 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Limits, interlocking. The tracks between the opposing home signals of an interlocking....

  12. 27 CFR 10.4 - Jurisdictional limits.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Jurisdictional limits. 10.4 Section 10.4 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS COMMERCIAL BRIBERY Scope of Regulations § 10.4 Jurisdictional limits....

  13. 14 CFR 27.25 - Weight limits.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Weight limits. 27.25 Section 27.25 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight General § 27.25 Weight limits. (a) Maximum weight. The...

  14. 7 CFR 3560.612 - Loan limits.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Loan limits. 3560.612 Section 3560.612 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, DEPARTMENT OF AGRICULTURE DIRECT MULTI-FAMILY HOUSING LOANS AND GRANTS On-Farm Labor Housing § 3560.612 Loan limits. The...

  15. 27 CFR 8.4 - Jurisdictional limits.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Jurisdictional limits. 8.4 Section 8.4 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS EXCLUSIVE OUTLETS Scope of Regulations § 8.4 Jurisdictional limits. (a)...

  16. 38 CFR 36.4411 - Geographical limits.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Geographical limits. 36.4411 Section 36.4411 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED... Geographical limits. Any real property purchased, constructed, altered, improved, repaired, or...

  17. 49 CFR 10.43 - Time limits.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Time limits. 10.43 Section 10.43 Transportation Office of the Secretary of Transportation MAINTENANCE OF AND ACCESS TO RECORDS PERTAINING TO INDIVIDUALS Correction of Records § 10.43 Time limits. Within ten days (excluding Saturday, Sunday, and legal...

  18. 40 CFR 66.93 - Time limits.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Time limits. 66.93 Section 66.93 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ASSESSMENT AND... limits. The Presiding Officer upon designation shall notify the parties and shall, if...

  19. 10 CFR 14.27 - Time limit.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Time limit. 14.27 Section 14.27 Energy NUCLEAR REGULATORY COMMISSION ADMINISTRATIVE CLAIMS UNDER FEDERAL TORT CLAIMS ACT Filing Procedures and Requirements § 14.27 Time limit. The claimant shall furnish evidence and information of the types described in 10 CFR...

  20. 40 CFR 61.162 - Emission limits.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Emission limits. 61.162 Section 61.162 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL... From Glass Manufacturing Plants § 61.162 Emission limits. (a) The owner or operator of an...

  1. 38 CFR 36.4523 - Geographical limits.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Geographical limits. 36.4523 Section 36.4523 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) LOAN GUARANTY Direct Loans § 36.4523 Geographical limits. Any real property purchased, constructed,...

  2. 40 CFR 503.13 - Pollutant limits.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Pollutant limits. 503.13 Section 503.13 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SEWAGE SLUDGE STANDARDS FOR THE USE OR DISPOSAL OF SEWAGE SLUDGE Land Application § 503.13 Pollutant limits. (a) Sewage sludge....

  3. 14 CFR 29.25 - Weight limits.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Weight limits. 29.25 Section 29.25 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight General § 29.25 Weight limits. (a) Maximum weight....

  4. 47 CFR 90.1323 - Emission limits.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Emission limits. 90.1323 Section 90.1323 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Wireless Broadband Services in the 3650-3700 MHz Band § 90.1323 Emission limits....

  5. 25 CFR 87.3 - Time limits.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Time limits. 87.3 Section 87.3 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR TRIBAL GOVERNMENT USE OR DISTRIBUTION OF INDIAN JUDGMENT FUNDS § 87.3 Time limits. (a) The Secretary shall cause to begin as early as possible the necessary research...

  6. 47 CFR 24.133 - Emission limits.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Emission limits. 24.133 Section 24.133 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES PERSONAL COMMUNICATIONS SERVICES Narrowband PCS § 24.133 Emission limits. (a) The power of any emission shall be attenuated...

  7. 12 CFR 1805.402 - Assistance limits.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Assistance limits. 1805.402 Section 1805.402 Banks and Banking COMMUNITY DEVELOPMENT FINANCIAL INSTITUTIONS FUND, DEPARTMENT OF THE TREASURY COMMUNITY DEVELOPMENT FINANCIAL INSTITUTIONS PROGRAM Investment Instruments § 1805.402 Assistance limits....

  8. 47 CFR 15.107 - Conducted limits.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Conducted limits. 15.107 Section 15.107... Conducted limits. (a) Except for Class A digital devices, for equipment that is designed to be connected to... power line on any frequency or frequencies within the band 150 kHz to 30 MHz shall not exceed the...

  9. 47 CFR 10.430 - Character limit.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Character limit. 10.430 Section 10.430 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL COMMERCIAL MOBILE ALERT SYSTEM Alert Message Requirements § 10.430 Character limit. A CMAS Alert Message processed by a Participating CMS Provider must...

  10. 14 CFR 31.14 - Weight limits.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Weight limits. 31.14 Section 31.14 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: MANNED FREE BALLOONS Flight Requirements § 31.14 Weight limits. (a) The range of weights...

  11. 27 CFR 6.4 - Jurisdictional limits.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Jurisdictional limits. 6.4 Section 6.4 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS âTIED-HOUSEâ Scope of Regulations § 6.4 Jurisdictional limits. (a) General....

  12. 38 CFR 36.4332 - Geographical limits.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Geographical limits. 36.4332 Section 36.4332 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED... Geographical limits. Any real property purchased, constructed, altered, improved, or repaired with the...

  13. 12 CFR 308.546 - Limitations.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Limitations. 308.546 Section 308.546 Banks and Banking FEDERAL DEPOSIT INSURANCE CORPORATION PROCEDURE AND RULES OF PRACTICE RULES OF PRACTICE AND PROCEDURE Program Fraud Civil Remedies and Procedures § 308.546 Limitations. (a) The notice of hearing with...

  14. Common Cause Abduction : Its Scope and Limits

    NARCIS (Netherlands)

    Dziurosz-Serafinowicz, Patryk

    2012-01-01

    Patryk Dziurosz-Serafmowicz, Common Cause Abduction: Its Scope and Limits This article aims to analyze the scope and limits of common cause abduction which is a version of explanatory abduction based on Hans Reichenbach's Principle of the Common Cause. First, it is argued that common cause abduction

  15. 42 CFR 403.508 - Limitations.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Limitations. 403.508 Section 403.508 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PROVISIONS SPECIAL PROGRAMS AND PROJECTS Beneficiary Counseling and Assistance Grants § 403.508 Limitations. (a)...

  16. 30 CFR 18.47 - Voltage limitation.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Voltage limitation. 18.47 Section 18.47 Mineral... § 18.47 Voltage limitation. (a) A tool or switch held in the operator's hand or supported against his... particular voltage(s) are provided in the design and construction of the equipment, its wiring,...

  17. 14 CFR 142.31 - Advertising limitations.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Advertising limitations. 142.31 Section 142...) SCHOOLS AND OTHER CERTIFICATED AGENCIES TRAINING CENTERS General § 142.31 Advertising limitations. (a) A certificate holder may not conduct, and may not advertise to conduct, any training, testing, and checking...

  18. 14 CFR 141.23 - Advertising limitations.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Advertising limitations. 141.23 Section 141...) SCHOOLS AND OTHER CERTIFICATED AGENCIES PILOT SCHOOLS General § 141.23 Advertising limitations. (a) The... certificate may not advertise that the school is certificated unless it clearly differentiates between...

  19. Back to Classics: Teaching Limits through Infinitesimals.

    Science.gov (United States)

    Todorov, Todor D.

    2001-01-01

    Criticizes the method of using calculators for the purpose of selecting candidates for L, for the limit value of a function. Suggests an alternative: a working formula for calculating the limit value L of a real function in terms of infinitesimals. (Author/ASK)

  20. A singular limit for compressible rotating fluids

    CERN Document Server

    Feireisl, Eduard; Novotny, Antonin

    2010-01-01

    We consider a singular limit problem for the Navier-Stokes system of a rotating compressible fluid, where the Rossby and Mach numbers tend simultaneously to zero. The limit problem is identified as the 2-D Navier-Stokes system in the ``horizontal'' variables containing an extra term that accounts for compressibility in the original system.

  1. Back to Classics: Teaching Limits Through Infinitesimals

    CERN Document Server

    Todorov, Todor D

    2011-01-01

    The usual $\\epsilon,\\delta$-definition of the limit of a function (whether presented at a rigorous or an intuitive level) requires a "candidate $L$" for the limit value. Thus, we have to start our first calculus course with "guessing" instead of "calculating". In this paper we criticize the method of using calculators for the purpose of selecting candidates for $L$. We suggest an alternative: a working formula for calculating the limit value L of a real function in terms of infinitesimals. Our formula, if considered as a definition of limit, is equivalent to the usual $\\epsilon,\\delta$-definition but does not involve a candidate $L$ for the limit value. As a result, the Calculus becomes to "calculate" again as it was originally designed to do.

  2. Reflective Optical Limiter Based on Resonant Transmission

    CERN Document Server

    Makri, Eleana; Vitebskiy, Ilya

    2014-01-01

    Optical limiters transmit low-level radiation while blocking electromagnetic pulses with excessively high energy (energy limiters) or with excessively high peak intensity (power limiters). A typical optical limiter absorbs most of the high-level radiation which can cause its destruction via overheating. Here we introduce the novel concept of a reflective energy limiter which blocks electromagnetic pulses with excessively high total energy by reflecting them back to space, rather than absorbing them. The idea is to use a defect layer with temperature dependent loss tangent embedded in a low-loss photonic structure. The low energy pulses with central frequency close to that of the localized defect mode will pass through. But if the cumulative energy carried by the pulse exceeds certain level, the entire photonic structure reflects the incident light (and does not absorb it!) for a broad frequency window. The underlying physical mechanism is based on self-regulated impedance mismatch which increases dramatically...

  3. Well limit behaviors of term rewriting systems

    Institute of Scientific and Technical Information of China (English)

    MA Shilong; SUI Yuefei; XU Ke

    2007-01-01

    The limit behaviors of computations have not been fully explored.It is necessary to consider such limit behaviors when we consider the properties of infinite objects in computer science,such as infinite logic programs,the symbolic solutions of infinite polynomial equations.Usually,we can use finite objects to approximate infinite objects,and we should know what kinds of infinite objects are approximable and how to approximate them effectively.A sequence {Rκ:κω}of term rewriting systems has the well limit behavior if under the condition that the sequence has the Set-theoretic limit or the distance-based limit,the sequence {Th(Rκ):κ∈ω} of corresponding theoretic closures of Rκ has the set-theoretic or distance-based limit,and limκ→∞ Th(Rκ) is equal to the theoretic closure of the limit of {Rκ:κ∈ω).Two kinds of limits of term rewriting systems are considered:one is based on the set-theoretic limit,the other is on the distance-based limit.It is proved thatgiven a sequence {Rκ:κ∈ω) of term rewriting systems Rκ,if there is a well-founded ordering (-<) on terms such that every Rκ is (-<)-well-founded,and the set-theoretic limit of {Rκ:κ∈ω).exists,then {Rκ:κ∈ω).has the well limit behavior;and if (1) there is a well-founded ordering(-<)on terms such that every Rκ is(-<-well-founded,(2) there is a distance d on terms which is closed under substitutions and contexts and (3) {Rκ:κ∈ω).is Cauchy under d then {Rκ:κ∈ω).has the well limit behavior.The results are used to approximate the least Herbrand models of infinite Horn logic programs and real Horn logic programs,and the solutions and Cr(o)bner bases of (infinite) sets of real polynomials by sequences of (finite) sets of rational polynomials.

  4. The limits on trypanosomatid morphological diversity.

    Directory of Open Access Journals (Sweden)

    Richard John Wheeler

    Full Text Available Cell shape is one, often overlooked, way in which protozoan parasites have adapted to a variety of host and vector environments and directional transmissions between these environments. Consequently, different parasite life cycle stages have characteristic morphologies. Trypanosomatid parasites are an excellent example of this in which large morphological variations between species and life cycle stage occur, despite sharing well-conserved cytoskeletal and membranous structures. Here, using previously published reports in the literature of the morphology of 248 isolates of trypanosomatid species from different hosts, we perform a meta-analysis of the occurrence and limits on morphological diversity of different classes of trypanosomatid morphology (trypomastigote, promastigote, etc. in the vertebrate bloodstream and invertebrate gut environments. We identified several limits on cell body length, cell body width and flagellum length diversity which can be interpreted as biomechanical limits on the capacity of the cell to attain particular dimensions. These limits differed for morphologies with and without a laterally attached flagellum which we suggest represent two morphological superclasses, the 'juxtaform' and 'liberform' superclasses. Further limits were identified consistent with a selective pressure from the mechanical properties of the vertebrate bloodstream environment; trypanosomatid size showed limits relative to host erythrocyte dimensions. This is the first comprehensive analysis of the limits of morphological diversity in any protozoan parasite, revealing the morphogenetic constraints and extrinsic selection pressures associated with the full diversity of trypanosomatid morphology.

  5. Optimal Disturbance Accommodation with Limited Model Information

    CERN Document Server

    Farokhi, F; Johansson, K H

    2011-01-01

    The design of optimal dynamic disturbance-accommodation controller with limited model information is considered. We adapt the family of limited model information control design strategies, defined earlier by the authors, to handle dynamic-controllers. This family of limited model information design strategies construct subcontrollers distributively by accessing only local plant model information. The closed-loop performance of the dynamic-controllers that they can produce are studied using a performance metric called the competitive ratio which is the worst case ratio of the cost a control design strategy to the cost of the optimal control design with full model information.

  6. A History of the Central Limit Theorem

    CERN Document Server

    Fischer, Hans

    2011-01-01

    This study discusses the history of the central limit theorem and related probabilistic limit theorems from about 1810 through 1950. In this context the book also describes the historical development of analytical probability theory and its tools, such as characteristic functions or moments. The central limit theorem was originally deduced by Laplace as a statement about approximations for the distributions of sums of independent random variables within the framework of classical probability, which focused upon specific problems and applications. Making this theorem an autonomous mathematical

  7. Fractional Diffusion Limit for Collisional Kinetic Equations

    KAUST Repository

    Mellet, Antoine

    2010-08-20

    This paper is devoted to diffusion limits of linear Boltzmann equations. When the equilibrium distribution function is a Maxwellian distribution, it is well known that for an appropriate time scale, the small mean free path limit gives rise to a diffusion equation. In this paper, we consider situations in which the equilibrium distribution function is a heavy-tailed distribution with infinite variance. We then show that for an appropriate time scale, the small mean free path limit gives rise to a fractional diffusion equation. © 2010 Springer-Verlag.

  8. Absolute Stability Limit for Relativistic Charged Spheres

    CERN Document Server

    Giuliani, Alessandro

    2007-01-01

    We find an exact solution for the stability limit of relativistic charged spheres for the case of constant gravitational mass density and constant charge density. We argue that this provides an absolute stability limit for any relativistic charged sphere in which the gravitational mass density decreases with radius and the charge density increases with radius. We then provide a cruder absolute stability limit that applies to any charged sphere with a spherically symmetric mass and charge distribution. We give numerical results for all cases. In addition, we discuss the example of a neutral sphere surrounded by a thin, charged shell.

  9. Work of Breathing Limits for Heliox Breathing

    Science.gov (United States)

    2010-11-01

    UBA; and Category 5. Semiclosed Circuit, Ejector or Pump-Driven UBA. Table 2. Limits for WOB/VT presented by two European standards. standard...it must be borne in mind that the statistical analysis will verify whether a ―measured average is below a given limit, rather than whether such a...1.76 + 0.2 · 2.776‡ / 5 = 1.76 + 0.25 = 2.01 kPa. With typical statistical analysis , the sample mean must be below a limit. Thus, the maximum sample

  10. Cosmological Background torsion limits from Lorentz violation

    CERN Document Server

    Garcia de Andrade, L C

    2001-01-01

    Cosmological limits on Lorentz invariance breaking in Chern-Simons $(3+1)-dimensional$ electrodynamics are used to place limits on torsion. Birefrigence phenomena is discussed by using extending the propagation equation to Riemann-Cartan spacetimes instead of treating it in purely Riemannian spaces. The parameter of Lorentz violation is shown to be proportional to the axial torsion vector which allows us to place a limit on cosmological background torsion from the Lorentz violation constraint which is given by $ 10^{-33} eV <|S^{\\mu}| < 10^{-32} eV$ where $|S^{\\mu}|$ is the axial torsion vector.

  11. Extreme Physics and Informational/Computational Limits

    Energy Technology Data Exchange (ETDEWEB)

    Di Sia, Paolo, E-mail: paolo.disia@univr.it, E-mail: 10alla33@virgilio.it [Department of Computer Science, Faculty of Science, Verona University, Strada Le Grazie 15, I-37134 Verona (Italy) and Faculty of Computer Science, Free University of Bozen, Piazza Domenicani 3, I-39100 Bozen-Bolzano (Italy)

    2011-07-08

    A sector of the current theoretical physics, even called 'extreme physics', deals with topics concerning superstring theories, multiverse, quantum teleportation, negative energy, and more, that only few years ago were considered scientific imaginations or purely speculative physics. Present experimental lines of evidence and implications of cosmological observations seem on the contrary support such theories. These new physical developments lead to informational limits, as the quantity of information, that a physical system can record, and computational limits, resulting from considerations regarding black holes and space-time fluctuations. In this paper I consider important limits for information and computation resulting in particular from string theories and its foundations.

  12. Scallop License Limitation Program (SLLP) Permit Program

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A federal Scallop License Limitation Program (SLLP) license is required onboard any vessel deployed in scallop fisheries in Federal waters off Alaska (except for...

  13. Author: IM Rautenbach PROPORTIONALITY AND THE LIMITATION ...

    African Journals Online (AJOL)

    10332324

    , ... basis of all different constitutional languages and cultures".3 Cohen-Eliya ... European Court of Human Rights and in Canada, Germany and Israel, their work ..... constitutional protection" within the framework of applying limitation clauses.

  14. Limit Interchange and L'Hopital's Rule

    Science.gov (United States)

    Ecker, Michael W.

    2011-01-01

    Conventional application of these two calculus staples is stretched here, somewhat recreationally, but also to raise solid questions about the role of limit interchange in analysis--without, however, delving any deeper than first-year Calculus.

  15. The computation of Buehler confidence limits

    Institute of Scientific and Technical Information of China (English)

    FANG; Xiangzhong; CHEN; Jiading

    2005-01-01

    In medicine and industry, small sample size often arises owing to the high test cost. Then exact confidence inference is important. Buehler confidence limit is a kind of exact confidence limit for the function of parameters in a model. It can be always defined if the order in sample space is given. But the computing problem is often difficult, especially for the cases with high dimension parameter or with incomplete data. This paper presents an algorithm to compute the Buehler confidence limits by EM algorithm. This is the firsttime usage of EM algorithm on Buehler confidence limits, but the algorithm is often used for maximum likelihood estimate in literatures. Three computation examples are given to illustrate the method.

  16. Cities, Towns and Villages - City Limit (polygon)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Data available online through GeoStor at http://www.geostor.arkansas.gov. Arkansas Cities: This data set contains all of the city limit boundaries within the state...

  17. Physical Limitations in Lithography for Microelectronics.

    Science.gov (United States)

    Flavin, P. G.

    1981-01-01

    Describes techniques being used in the production of microelectronics kits which have replaced traditional optical lithography, including contact and optical projection printing, and X-ray and electron beam lithography. Also includes limitations of each technique described. (SK)

  18. Sensitivity Limitations for Multivariable Linear Filtering

    Directory of Open Access Journals (Sweden)

    Steven R. Weller

    2007-01-01

    Full Text Available This paper examines fundamental limitations in performance which apply to linear filtering problems associated with multivariable systems having as many inputs as outputs. The results of this paper quantify unavoidable limitations in the sensitivity of state estimates to process and measurement disturbances, as represented by the maximum singular values of the relevant transfer matrices. These limitations result from interpolation constraints imposed by open right half-plane poles and zeros in the transfer matrices linking process noise and output noise with state estimates. Using the Poisson integral inequality, this paper shows how sensitivity limitations and tradeoffs in multivariable filtering problems are intimately related to the directionality properties of the open right half-plane poles and zeros in these transfer matrices.

  19. Zero noise limits using local times

    OpenAIRE

    2013-01-01

    We consider a well-known family of SDEs with irregular drifts and the correspondent zero noise limits. Using (mollified) local times, we show which trajectories are selected. The approach is completely probabilistic and relies on elementary stochastic calculus only.

  20. Limitations of science and adaptive management

    Energy Technology Data Exchange (ETDEWEB)

    Narasimhan, T.N.

    2001-12-20

    Adaptive management consists in patterning human sustenancewithin the constraints of Earth and biological systems whose behavior isinherently uncertain and difficult to control. For successful adaptivemanagement, a mind-set recognizing the limitations of science isneeded.

  1. Does decoherence in the thermodynamic limit exist?

    CERN Document Server

    Frasca, M

    2002-01-01

    We consider the Jaynes-Cummings model for N particles in the thermodynamic limit showing how it can produce decoherence on a Schr\\"odinger cat state. This mechanism can be observed in current experiments with cavities.

  2. Southern Hemisphere Ice Limits, 1973-1978

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Weekly Southern Ocean ice limits, have been digitized from U.S. Navy Fleet Weather Facility ice charts, at the Max-Planck Institut fur Meteorologie, Hamburg....

  3. Some Limit Theorems in Geometric Processes

    Institute of Scientific and Technical Information of China (English)

    Yeh Lam; Yao-hui Zheng; Yuan-lin Zhang

    2003-01-01

    Geometric process (GP) was introduced by Lam[4,5], it is defined as a stochastic process {Xn, n =1, 2,...} for which there exists a real number a > 0, such that {an-1Xn, n = 1, 2,...} forms a renewal process (RP). In this paper, we study some limit theorems in GP. We first derive the Wald equation for GP and then obtain the limit theorems of the age, residual life and the total life at t for a GP. A general limit theorem for Sn with a > 1 is also studied. Furthermore, we make a comparison between GP and RP, including the comparison of their limit distributions of the age, residual life and the total life at t.

  4. 48 CFR 1417.402 - Limitations.

    Science.gov (United States)

    2010-10-01

    ... CONTRACT TYPES SPECIAL CONTRACTING METHODS Leader Company Contracting 1417.402 Limitations. Use of leader... discussion with the Director, PAM, prior to approval by the HCA. This authority may not be redelegated...

  5. Health Outcomes Survey - Limited Data Set

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Medicare Health Outcomes Survey (HOS) limited data sets (LDS) are comprised of the entire national sample for a given 2-year cohort (including both respondents...

  6. Matrix model calculations beyond the spherical limit

    Energy Technology Data Exchange (ETDEWEB)

    Ambjoern, J. (Niels Bohr Institute, Copenhagen (Denmark)); Chekhov, L. (L.P.T.H.E., Universite Pierre et Marie Curie, 75 - Paris (France)); Kristjansen, C.F. (Niels Bohr Institute, Copenhagen (Denmark)); Makeenko, Yu. (Institute of Theoretical and Experimental Physics, Moscow (Russian Federation))

    1993-08-30

    We propose an improved iterative scheme for calculating higher genus contributions to the multi-loop (or multi-point) correlators and the partition function of the hermitian one matrix model. We present explicit results up to genus two. We develop a version which gives directly the result in the double scaling limit and present explicit results up to genus four. Using the latter version we prove that the hermitian and the complex matrix model are equivalent in the double scaling limit and that in this limit they are both equivalent to the Kontsevich model. We discuss how our results away from the double scaling limit are related to the structure of moduli space. (orig.)

  7. Limiting Spectral Distribution of Sample Autocovariance Matrices

    CERN Document Server

    Basak, Anirban; Sen, Sanchayan

    2011-01-01

    The empirical spectral distribution (ESD) of the sample variance covariance matrix of i.i.d. observations under suitable moment conditions converges almost surely as the dimension tends to infinity. The limiting spectral distribution (LSD) is universal and is known in closed form with support [0, 4]. In this article we show that the ESD of the sample autocovariance matrix converges as the dimension increases, when the time series is a linear process with reasonable restriction on the coefficients. This limit does not depend on the distribution of the underlying driving i.i.d. sequence but in contrast to the sample variance covariance matrix, its support is unbounded. The limit moments are certain functions of the autocovariances. This limit is inconsistent in the sense that it does not coincide with the spectral distribution of the theoretical autocovariance matrix. However, if we consider a suitably tapered version of the autocovariance matrix, then its LSD also exists and is consistent. We also discuss the ...

  8. Optimized chaos control with simple limiters.

    Science.gov (United States)

    Wagner, C; Stoop, R

    2001-01-01

    We present an elementary derivation of chaos control with simple limiters using the logistic map and the Henon map as examples. This derivation provides conditions for optimal stabilization of unstable periodic orbits of a chaotic attractor.

  9. Semiclassical limit of the FZZT Liouville theory

    CERN Document Server

    Hadasz, L; Hadasz, Leszek; Jaskolski, Zbigniew

    2006-01-01

    The semiclassical limit of the FZZT Liouville theory on the upper half plane with bulk operators of arbitrary type and with elliptic boundary operators is analyzed. We prove the Polyakov conjecture for an appropriate classical Liouville action. This action is calculated in a number of cases: one bulk operator of arbitrary type, one bulk and one boundary, and two boundary elliptic operators. The results are in agreement with the classical limits of the corresponding quantum correlators.

  10. Semiclassical limit of the FZZT Liouville theory

    Energy Technology Data Exchange (ETDEWEB)

    Hadasz, Leszek [Physikalisches Institut, Rheinische Friedrich-Wilhelms-Universitaet, Nussallee 12, 53115 Bonn (Germany); M. Smoluchowski Institute of Physics, Jagiellonian University, W. Reymonta 4, 30-059 Cracow (Poland)]. E-mail: hadasz@th.if.uj.edu.pl; Jaskolski, Zbigniew [Institute of Theoretical Physics, University of Wroclaw, pl. M. Borna 9, 50-204 Wroclaw (Poland)]. E-mail: jask@ift.uni.wroc.pl

    2006-11-27

    The semiclassical limit of the FZZT Liouville theory on the upper half plane with bulk operators of arbitrary type and with elliptic boundary operators is analyzed. We prove the Polyakov conjecture for an appropriate classical Liouville action. This action is calculated in a number of cases: One bulk operator of arbitrary type, one bulk and one boundary, and two boundary elliptic operators. The results are in agreement with the classical limits of the corresponding quantum correlators.

  11. Compression limits in cascaded quadratic soliton compression

    DEFF Research Database (Denmark)

    Bache, Morten; Bang, Ole; Krolikowski, Wieslaw;

    2008-01-01

    Cascaded quadratic soliton compressors generate under optimal conditions few-cycle pulses. Using theory and numerical simulations in a nonlinear crystal suitable for high-energy pulse compression, we address the limits to the compression quality and efficiency.......Cascaded quadratic soliton compressors generate under optimal conditions few-cycle pulses. Using theory and numerical simulations in a nonlinear crystal suitable for high-energy pulse compression, we address the limits to the compression quality and efficiency....

  12. Gulf of Mexico mud toxicity limitations

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, H.E.; Beardmore, D.H. (Phillips Petroleum Co., Bartlesville, OK (USA)); Stewart, W.S. (Drilling Specialties Co. (US))

    1989-10-01

    Because of the Environmental Protection Agency's recent toxicity limits on drilling mud discharges for offshore Gulf of Mexico, Phillips Petroleum conducted a mud toxicity study based on both field and lab tests. The study, discussed in this article, found the polyanionic cellulose-sulfomethylated quebracho-chrome lignosulfonate mud Phillips had been using would comfortably pass the toxicity limitations. The study also found barite and thinners were of low toxicity, and hydrocarbons and surfactants were highly toxic.

  13. Quantum-limited amplification via reservoir engineering.

    Science.gov (United States)

    Metelmann, A; Clerk, A A

    2014-04-04

    We describe a new kind of phase-preserving quantum amplifier which utilizes dissipative interactions in a parametrically coupled three-mode bosonic system. The use of dissipative interactions provides a fundamental advantage over standard cavity-based parametric amplifiers: large photon number gains are possible with quantum-limited added noise, with no limitation on the gain-bandwidth product. We show that the scheme is simple enough to be implemented both in optomechanical systems and in superconducting microwave circuits.

  14. Quantum-Limited Amplification via Reservoir Engineering

    OpenAIRE

    Metelmann, A.; Clerk, A. A.

    2013-01-01

    We describe a new kind of phase-preserving quantum amplifier which utilizes dissipative interactions in a parametrically-coupled three-mode bosonic system. The use of dissipative interactions provides a fundamental advantage over standard cavity-based parametric amplifiers: large photon number gains are possible with quantum-limited added noise, with no limitation on the gain-bandwidth product. We show that the scheme is simple enough to be implemented both in optomechanical systems and in su...

  15. Revisiting Uraltsev's BPS limit for Heavy Quarks

    CERN Document Server

    Heinonen, Johannes

    2016-01-01

    Motivated by the recent experimental data of the values of the Heavy Quark Expansion parameters, in particular the spin-orbit and Darwin terms, we argue that nature actually may be close to a limit of QCD which has been suggested by Uraltsev more than ten years ago. Assuming that this limit is not accidental, we derive the relations among the Heavy Quark Expansion parameters that occur up to the order 1/mb^5.

  16. Photon-limited Sensing and Surveillance

    Science.gov (United States)

    2015-01-29

    including night vision, space weather, imaging through fog , and spectral imaging. The photon-limited video reconstruction problem is particularly challenging...photon-limited video, it is possible to compute more accurate reconstructions by exploiting not only spatial structured, as describe above, but also...function that will facilitate using off-the-shelf convex optimization tools to compute an image estimate. In contrast, our approach is far more flexible in

  17. Very Massive Stars and the Eddington Limit

    CERN Document Server

    Crowther, Paul A; Walborn, Nolan R; Yusof, N

    2012-01-01

    We use contemporary evolutionary models for Very Massive Stars (VMS) to assess whether the Eddington limit constrains the upper stellar mass limit. We also consider the interplay between mass and age for the wind properties and spectral morphology of VMS, with reference to the recently modified classification scheme for O2-3.5If*/WN stars. Finally, the death of VMS in the local universe is considered in the context of pair instability supernovae.

  18. A Central Limit Theorem for Repeating Patterns

    CERN Document Server

    Abrams, Aaron; Landau, Henry; Landau, Zeph; Pommersheim, James

    2012-01-01

    This note gives a central limit theorem for the length of the longest subsequence of a random permutation which follows some repeating pattern. This includes the case of any fixed pattern of ups and downs which has at least one of each, such as the alternating case considered by Stanley in [2] and Widom in [3]. In every case considered the convergence in the limit of long permutations is to normal with mean and variance linear in the length of the permutations.

  19. Limits and Signatures of Relativistic Spaceflight

    CERN Document Server

    Yurtsever, Ulvi

    2015-01-01

    While special relativity imposes an absolute speed limit at the speed of light, our Universe is not empty Minkowski spacetime. The constituents that fill the interstellar/intergalactic vacuum, including the cosmic microwave background photons, impose a lower speed limit on any object travelling at relativistic velocities. Scattering of cosmic microwave phtotons from an ultra-relativistic object may create radiation with a characteristic signature allowing the detection of such objects at large distances.

  20. Governing economies in areas of limited statehood

    DEFF Research Database (Denmark)

    Rasmussen, Jacob; Varming, Kirstine Strøh

    This DIIS–GOVSEA working paper reviews key debates within economic anthropology and related academic disciplines explaining how economic life is governed in areas of limited statehood. The paper briefly introduces some of the origins of economic anthropology before going into deeper discussions....../non-state, rational/moral, in order to provide insights for the study of economic behaviour and economic governance in areas of limited statehood....

  1. Fundamental energetic limits of radio communication systems

    Science.gov (United States)

    Baudais, Jean-Yves

    2017-02-01

    The evaluation of the energy consumption of a radiocommunication requires to analyse the life cycle of the elements used. However, this analysis does not specify the energetic limits. Theoretical approaches allow one to draw these limits, which are known in multiple cases of information transmission. However, the answers are not always satisfactory, in particular in the case of time-varying channels. After a brief presentation of the notion of energetic limits of a radiocommunication, and beginning with a global approach, we show that, contrary to the published results, the energetic limits always differ from zero if the physical constraints are correctly expressed. xml:lang="fr" Cependant, les réponses ne sont pas toujours satisfaisantes, particulièrement dans le cas de canaux variants dans le temps. Après une rapide présentation des notions d'énergie limite d'une radiocommunication, et en commençant par une approche globale du problème, nous montrons que, contrairement aux résultats publiés, les limites énergétiques sont toujours différentes de zéro si les contraintes physiques sont correctement exprimées.

  2. UV driven evaporation of close-in planets: energy-limited; recombination-limited and photon-limited flows

    CERN Document Server

    Owen, James E

    2016-01-01

    We have investigated the evaporation of close-in exoplanets irradiated by ionizing photons. We find that the properties of the flow are controlled by the ratio of the recombination time to the flow time-scale. When the recombination time-scale is short compared to the flow time-scale the the flow is in approximate local ionization equilibrium with a thin ionization front, where the photon mean free path is short compared to flow scale. In this "recombination limited" flow the mass-loss scales roughly with the square root of the incident flux. When the recombination time is long compared to the flow time-scale the ionization front becomes thick and encompasses the entire flow, with the mass-loss rate scaling linearly with flux. If the planet's potential is deep the flow is approximately "energy-limited"; however, if the planet's potential is shallow we identify a new limiting mass-loss regime, which we term "photon-limited". In this scenario the mass-loss rate is purely limited by the incoming flux of ionizing...

  3. Communicative action as a way of annihilating the human limits. Human limits in transhumanism

    OpenAIRE

    TEREC-VLAD LOREDANA

    2015-01-01

    In this paper we aim to analyse the biological limits of the human individual and the limits of knowledge, as well as the way they can be overcome Transhumanism can be defined as: the idea that humans can use reason in order to transcend the limit of the human condition within transhumanism

  4. A brightness exceeding simulated Langmuir limit

    Energy Technology Data Exchange (ETDEWEB)

    Nakasuji, Mamoru [2-15-11, Serigaya-chou, Kounan-ku, Yokohama-shi, Kanagawa-ken (Japan)

    2013-08-15

    When an excitation of the first lens determines a beam is parallel beam, a brightness that is 100 times higher than Langmuir limit is measured experimentally, where Langmuir limits are estimated using a simulated axial cathode current density which is simulated based on a measured emission current. The measured brightness is comparable to Langmuir limit, when the lens excitation is such that an image position is slightly shorter than a lens position. Previously measured values of brightness for cathode apical radii of curvature 20, 60, 120, 240, and 480 μm were 8.7, 5.3, 3.3, 2.4, and 3.9 times higher than their corresponding Langmuir limits, respectively, in this experiment, the lens excitation was such that the lens and the image positions were 180 mm and 400 mm, respectively. From these measured brightness for three different lens excitation conditions, it is concluded that the brightness depends on the first lens excitation. For the electron gun operated in a space charge limited condition, some of the electrons emitted from the cathode are returned to the cathode without having crossed a virtual cathode. Therefore, method that assumes a Langmuir limit defining method using a Maxwellian distribution of electron velocities may need to be revised. For the condition in which the values of the exceeding the Langmuir limit are measured, the simulated trajectories of electrons that are emitted from the cathode do not cross the optical axis at the crossover, thus the law of sines may not be valid for high brightness electron beam systems.

  5. Histological features of the pancreas in a patient with congenital hyperinsulinism due to Beckwith-Wiedemann syndrome

    DEFF Research Database (Denmark)

    Christensen, Lene; Christesen, Henrik Boye Thybo; Brusgaard, Klaus

    Introduction: Beckwith-Wiedemann syndrome (BWS) is a genetic disorder with typical features such as macroglossia, abdominal wall defects, macrosomia, visceromegaly and embryonal tumors. Hypoglycemia is reported in about half of all newborns with BWS, usually resolving spontaneously within the first...

  6. Chronic Hyperinsulinism Induced Down-regulation of Insulin Post-Recentor Signaling Transduction in Hep G2 Cells

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Summary: To study the regulatory effect of acute and chronic insulin treatment on insulin post-re-ceptor signaling transduction pathway in a human hepatoma cell line (Hep G2), Hep G2 cells wereincubated in the presence or absence of insulin with different concentrations in serum free mediafor 16 h and then stimulated with 100 nmol/L insulin for 1 min. Protein levels of insulin receptorβ-subunit (IRβ), insulin receptor substrate-1 (IRS-1) and p85 subunit of phosphatidylinositol 3-kinase (PI 3-kinase) were determined in total cell lysates by Western-immunoblot. Phosphorylat-ed proteins IRβ, IRS-1 and interaction of PI 3-kinase with IRS-1 were determined by immunopre-cipitation. Results showed that 1-min insulin stimulation rapidly induced tyrosine phosphorylationof IRβ and IRS-l, which in turn, resulting in association of PI 3-kinase with IRS-1. 1-100 nmol/L chronic insulin treatment induced a dose-dependent decrease in the protein level of IRβ and aslight decrease in the protein level of IRS-1. There wass more marked reduction in the phospho-rylation of IRβ, IRS-1, reaching a nadir of 22 % (P<0. 01) and 15 % (P<0. 01) of control lev-els, respectively, after 16 h treatment with 100 nmol/L insulin. The association between IRS-1and PI 3-kinase was decreased by 66 % (P<0. 01). There was no significant change in PI 3-ki-nase protein levels. These data suggest that chronic insulin treatment can induce alterations ofIRβ, IRS-1 and PI 3-kinase three early steps in insulin action, which contributes significantly toinsulin resistance, and may account for desensitization of insulin action.

  7. Functional hyperactivity of hepatic glutamate dehydrogenase as a cause of the hyperinsulinism/hyperammonemia syndrome: effect of treatment

    NARCIS (Netherlands)

    J.G.M. Huijmans (Jan); M. Duran; J.B.C. de Klerk (Johannes); M.J. Rovers; H.R. Scholte (Hans)

    2000-01-01

    textabstractOBJECTIVE: The combination of persistent hyperammonemia and hypoketotic hypoglycemia in infancy presents a diagnostic challenge. Investigation of the possible causes and regulators of the ammonia and glucose disposal may result in a true diagnosis and predic

  8. Limiting factors in caribou population ecology

    Directory of Open Access Journals (Sweden)

    David R. Klein

    1991-10-01

    Full Text Available Caribou and wild reindeer populations fluctuate over time. On this fact there is general agreement. Factors responsible for population limitation and subsequent declines have been examined within the framework of animal population theory. There is, however, little agreement when factors limiting specific populations are generalized to Rangifer populations over broad geographic regions. Comparative examinations of wild Rangifer populations worldwide discloses that factors that have regulated those populations are highly variable between populations, apparently as a reflection of the differences in environmental variables unique to each population. Examples exist of populations where major regulating factors have been climatic extremes, predation, hunting mortality, food limitation, insects, parasites, disease, interspecific competition, and human developmental impacts or combinations of these factors. This diversity of limiting factors affecting caribou and wild reindeer populations is a reflection of the ecologial complexity of the species, a concept that has often been ignored in past efforts to reach management decisions by extrapolation from the limited localized knowledge available on the species.

  9. Multiple Soft Limits of Cosmological Correlation Functions

    CERN Document Server

    Joyce, Austin; Simonović, Marko

    2015-01-01

    We derive novel identities satisfied by inflationary correlation functions in the limit where two external momenta are taken to be small. We derive these statements in two ways: using background-wave arguments and as Ward identities following from the fixed-time path integral. Interestingly, these identities allow us to constrain some of the O(q^2) components of the soft limit, in contrast to their single-soft analogues. We provide several nontrivial checks of our identities both in the context of resonant non-Gaussianities and in small sound speed models. Additionally, we extend the relation at lowest order in external momenta to arbitrarily many soft legs, and comment on the many-soft extension at higher orders in the soft momentum. Finally, we consider how higher soft limits lead to identities satisfied by correlation functions in large-scale structure.

  10. Multiple soft limits of cosmological correlation functions

    Energy Technology Data Exchange (ETDEWEB)

    Joyce, Austin [Enrico Fermi Institute and Kavli Institute for Cosmological Physics, University of Chicago, Chicago, IL 60637 (United States); Khoury, Justin [Center for Particle Cosmology, Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104 (United States); Simonović, Marko, E-mail: ajoy@uchicago.edu, E-mail: jkhoury@sas.upenn.edu, E-mail: msimonov@sissa.it [SISSA, via Bonomea 265, 34136, Trieste (Italy)

    2015-01-01

    We derive novel identities satisfied by inflationary correlation functions in the limit where two external momenta are taken to be small. We derive these statements in two ways: using background-wave arguments and as Ward identities following from the fixed-time path integral. Interestingly, these identities allow us to constrain some of the O(q{sup 2}) components of the soft limit, in contrast to their single-soft analogues. We provide several nontrivial checks of our identities both in the context of resonant non-Gaussianities and in small sound speed models. Additionally, we extend the relation at lowest order in external momenta to arbitrarily many soft legs, and comment on the many-soft extension at higher orders in the soft momentum. Finally, we consider how higher soft limits lead to identities satisfied by correlation functions in large-scale structure.

  11. Limitation of computational resource as physical principle

    CERN Document Server

    Ozhigov, Y I

    2003-01-01

    Limitation of computational resources is considered as a universal principle that for simulation is as fundamental as physical laws are. It claims that all experimentally verifiable implications of physical laws can be simulated by the effective classical algorithms. It is demonstrated through a completely deterministic approach proposed for the simulation of biopolymers assembly. A state of molecule during its assembly is described in terms of the reduced density matrix permitting only limited tunneling. An assembly is treated as a sequence of elementary scatterings of simple molecules from the environment on the point of assembly. A decoherence is treated as a forced measurement of quantum state resulted from the shortage of computational resource. All results of measurements are determined by a choice from the limited number of special options of the nonphysical nature which stay unchanged till the completion of assembly; we do not use the random numbers generators. Observations of equal states during the ...

  12. Constructing Amplitudes from Their Soft Limits

    Energy Technology Data Exchange (ETDEWEB)

    Boucher-Veronneau, Camille; Larkoski, Andrew J.; /SLAC

    2011-12-09

    The existence of universal soft limits for gauge-theory and gravity amplitudes has been known for a long time. The properties of the soft limits have been exploited in numerous ways; in particular for relating an n-point amplitude to an (n-1)-point amplitude by removing a soft particle. Recently, a procedure called inverse soft was developed by which 'soft' particles can be systematically added to an amplitude to construct a higher-point amplitude for generic kinematics. We review this procedure and relate it to Britto-Cachazo-Feng-Witten recursion. We show that all tree-level amplitudes in gauge theory and gravity up through seven points can be constructed in this way, as well as certain classes of NMHV gauge-theory amplitudes with any number of external legs. This provides us with a systematic procedure for constructing amplitudes solely from their soft limits.

  13. Constructing amplitudes from their soft limits

    Science.gov (United States)

    Boucher-Veronneau, Camille; Larkoski, Andrew J.

    2011-09-01

    The existence of universal soft limits for gauge-theory and gravity amplitudes has been known for a long time. The properties of the soft limits have been exploited in numerous ways; in particular for relating an n-point amplitude to an ( n - 1)-point amplitude by removing a soft particle. Recently, a procedure called inverse soft was developed by which "soft" particles can be systematically added to an amplitude to construct a higher-point amplitude for generic kinematics. We review this procedure and relate it to Britto-Cachazo-Feng-Witten recursion. We show that all tree-level amplitudes in gauge theory and gravity up through seven points can be constructed in this way, as well as certain classes of NMHV gauge-theory amplitudes with any number of external legs. This provides us with a systematic procedure for constructing amplitudes solely from their soft limits.

  14. Family caregivers and limitations in social activities.

    Science.gov (United States)

    Miller, B; Montgomery, A

    1990-03-01

    Constriction of social and personal activities is one of the most frequently noted consequences of caring for a frail elder. This study analyzed the correlates of perceived limitations in social activities using data from a national sample of the frail elderly and their caregivers. Two research issues were addressed: 1) What differences in demographic, family, and caregiving attributes are associated with variation in perceived restricted social activities? and, 2) How does the process influencing restriction of social activities vary by family relationship of the caregiver? Higher levels of elder dependency and task demands were characteristic of those who reported social limitations, and daughters and wives were more likely to report such limitations than sons and husbands. Subjective assessment of time and task demands, however, were more important influences than objective caregiving activities for all family caregivers.

  15. AdS orbifolds and Penrose limits

    Energy Technology Data Exchange (ETDEWEB)

    Alishahiha, Mohsen; Sheikh-Jabbari, Mohammad M.; Tatar, Radu

    2002-12-09

    In this paper we study the Penrose limit of AdS{sub 5} orbifolds. The orbifold can be either in the pure spatial directions or space and time directions. For the AdS{sub 5}/{Lambda} x S{sup 5} spatial orbifold we observe that after the Penrose limit we obtain the same result as the Penrose limit of AdS{sub 5} x S{sup 5}/{Lambda}. We identify the corresponding BMN operators in terms of operators of the gauge theory on R x S{sup 3}/{Lambda}. The semi-classical description of rotating strings in these backgrounds have also been studied. For the spatial AdS orbifold we show that in the quadratic order the obtained action for the fluctuations is the same as that in S{sup 5} orbifold, however, the higher loop correction can distinguish between two cases.

  16. Photon Feedback: Screening and the Eddington Limit

    CERN Document Server

    Socrates, Aristotle

    2013-01-01

    Bright star-forming galaxies radiate well below their Eddington Limit. The value of the flux-mean opacity that mediates the radiation force onto matter is orders of magnitude smaller than the UV or optical dust opacity. On empirical grounds, it is shown that high-redshift ULIRGs radiate at two orders of magnitude below their Eddington Limit, while the local starbursters M82 and Arp 220 radiate at a few percent of their Eddington Limit. A simple model for the radiative transfer of UV and optical light in dust-rich environments is considered. Radiation pressure on dust does not greatly affect the large-scale gas dynamics of star-forming galaxies.

  17. Altitudinal distribution limits of aquatic macroinvertebrates

    DEFF Research Database (Denmark)

    Madsen, Philip B.; Morabowen, Andrés; Andino, Patricio

    2015-01-01

    altitudinal patterns in population densities, (ii) transplants of the five taxa upstream of their natural altitudinal limit to test the short-term (14days) effect on survival, and (iii) in situ experiments of locomotory activity as a proxy for animal response to relatively small differences in temperature (5...... relatively small differences in temperature and oxygen may produce effects explaining ecological patterns, and depending on the taxon, either water temperature or oxygen saturation, without clear interacting effects, are important drivers of altitudinal limits.......1. Temperature and oxygen are recognised as the main drivers of altitudinal limits of species distributions. However, the two factors are linked, and both decrease with altitude, why their effects are difficult to disentangle. 2. This was experimentally addressed using aquatic macroinvertebrates...

  18. PHOTON FEEDBACK: SCREENING AND THE EDDINGTON LIMIT

    Energy Technology Data Exchange (ETDEWEB)

    Socrates, Aristotle [Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540 (United States); Sironi, Lorenzo, E-mail: socrates@ias.edu, E-mail: lsironi@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States)

    2013-08-01

    Bright star-forming galaxies radiate well below their Eddington limits. The value of the flux-mean opacity that mediates the radiation force onto matter is orders of magnitude smaller than the UV or optical dust opacity. On empirical grounds, it is shown that high-redshift ULIRGs radiate at two orders of magnitude below their Eddington limits, while the local starbursters M82 and Arp 220 radiate at a few percent of their Eddington limits. A model for the radiative transfer of UV and optical light in dust-rich environments is considered. Radiation pressure on dust does not greatly affect the large-scale gas dynamics of star-forming galaxies.

  19. Resistive Ferroresonance Limiter for Potential Transformers

    Directory of Open Access Journals (Sweden)

    Hamid Radmanesh

    2012-01-01

    Full Text Available The ferroresonance or nonlinear resonance is a complex phenomenon, which may cause overvoltage in the electrical power system and endangers the system reliability and operation. The ability to predict the ferroresonance in the transformer depends on the accuracy of the transformer model used. In this paper, the effect of the new suggested ferroresonance limiter on the control of the chaotic ferroresonance and duration of chaotic transients in a potential transformer including nonlinear core losses is studied. To study the proposed ferroresonance limiter, a single phase 100 VA, 275 kV potential transformer is simulated. The magnetization characteristic of the potential transformer is modeled by a single-value two-term polynomial. The core losses are modeled by third order power series in terms of voltage and include core nonlinearities. The simulation results show that the ferroresonance limiter has a considerable effect on the ferroresonance overvoltage.

  20. Occupational Exposures and Chronic Airflow Limitation

    Directory of Open Access Journals (Sweden)

    Helen Dimich-Ward

    1996-01-01

    Full Text Available The recent literature was reviewed to evaluate whether chronic airflow limitation is associated with occupational exposures to dusts. Only those studies that controlled for the effects of smoking were included. There is compelling evidence that exposure to inorganic dusts, such as from coal and hardrock mining or asbestos, are associated with the development of chronic airflow limitation, independently of pneumoconiosis. Nonsmoking gold miners are particularly at high risk of airflow obstruction and emphysema. Findings from studies of organic dusts, such as exposures to wood, cotton, grain or other agricultural dusts, or to mixed dust exposures, were less consistent but tended to show positive dose-response associations. In the majority of studies, no statistical interaction was shown between dust exposures and smoking; however, the effects of the dust exposures were often more pronounced. An occupational history should be considered, in addition to a smoking history, as an integral part of an investigation of chronic airflow limitation in a patient.

  1. The limits of human athletic performance.

    Science.gov (United States)

    Maughan, R J

    2005-01-01

    For each individual, there is a limit to the capacity to perform exercise. The limitation, however, depends on the nature of the task and is also influenced by a number of other factors. Muscle strength is determined largely by muscle mass, specifically muscle cross-sectional area, but is also influenced by neural drive and biomechanical factors. Endurance performance depends on both cardiovascular capacity and the metabolic characteristics of the skeletal muscles. These factors are determined in part by genetic endowment: the elite sprinter has a high proportion of Type 2 muscle fibres while the leg muscles of the successful marathon runner are composes mainly of Type 1 fibres. Whatever the genetic potential, expression of this depends on the intensity, duration and frequency of the applied training stimulus, diet and other factors. The limitation may also depend on environmental factors, such as altitude and temperature.

  2. Propagation Limits of High Pressure Cool Flames

    Science.gov (United States)

    Ju, Yiguang

    2016-11-01

    The flame speeds and propagation limits of premixed cool flames at elevated pressures with radiative heat loss are numerically modelled using dimethyl ether mixtures. The primary focus is paid on the effects of pressure, mixture dilution, flame size, and heat loss on cool flame propagation. The results showed that cool flames exist on both fuel lean and fuel rich sides and thus dramatically extend the lean and rich flammability limits. There exist three different flame regimes, hot flame, cool flame, and double flame. A new flame flammability diagram including both cool flames and hot flames is obtained at elevated pressure. The results show that pressure significantly changes cool flame propagation. It is found that the increases of pressure affects the propagation speeds of lean and rich cool flames differently due to the negative temperature coefficient effect. On the lean side, the increase of pressure accelerates the cool flame chemistry and shifts the transition limit of cool flame to hot flame to lower equivalence ratio. At lower pressure, there is an extinction transition from hot flame to cool flame. However, there exists a critical pressure above which the cool flame to hot flame transition limit merges with the lean flammability limit of the hot flame, resulting in a direct transition from hot flame to cool flame. On the other hand, the increase of dilution reduces the heat release of hot flame and promotes cool flame formation. Moreover, it is shown that a smaller flame size and a higher heat loss also extend the cool flame transition limit and promote cool flame formation.

  3. The Twist Limit for Bipolar Active Regions

    Science.gov (United States)

    Moore, Ron; Falconer, David; Gary, Allen

    2008-01-01

    We present new evidence that further supports the standard idea that active regions are emerged magnetic-flux-rope omega loops. When the axial magnetic twist of a cylindrical flux rope exceeds a critical amount, the flux rope becomes unstable to kinking, and the excess axial twist is converted into writhe twist by the kinking. This suggests that, if active regions are emerged omega loops, then (1) no active region should have magnetic twist much above the limit set by kinking, (2) active regions having twist near the limit should often arise from kinked omega loops, and (3) since active regions having large delta sunspots are outstandingly twisted, these arise from kinked omega loops and should have twist near the limit for kinking. From each of 36 vector magnetograms of bipolar active regions, we have measured (1) the total flux of the vertical field above 100 G, (2) the area covered by this flux, and (3) the net electric current that arches over the polarity inversion line. These three quantities yield an estimate of the axial magnetic twist in a simple model cylindrical flux rope that corresponds to the top of the active region s hypothetical omega loop prior to emergence. In all 36 cases, the estimated twist is below the critical limit for kinking. The 11 most twisted active regions (1) have estimated twist within a factor of approx.3 of the limit, and (2) include all of our 6 active regions having large delta sunspots. Thus, our observed twist limit for bipolar active regions is in good accord with active regions being emerged omega loops.

  4. Central Limit Theorem for Nonlinear Hawkes Processes

    CERN Document Server

    Zhu, Lingjiong

    2012-01-01

    Hawkes process is a self-exciting point process with clustering effect whose jump rate depends on its entire past history. It has wide applications in neuroscience, finance and many other fields. Linear Hawkes process has an immigration-birth representation and can be computed more or less explicitly. It has been extensively studied in the past and the limit theorems are well understood. On the contrary, nonlinear Hawkes process lacks the immigration-birth representation and is much harder to analyze. In this paper, we obtain a functional central limit theorem for nonlinear Hawkes process.

  5. Limit theorems for fragmentation processes with immigration

    CERN Document Server

    Knobloch, Robert

    2012-01-01

    In this paper we extend two limit theorems which were recently obtained for fragmentation processes to such processes with immigration. More precisely, in the setting with immigration we consider a limit theorem for the process counted with a random characteristic as well as the asymptotic behaviour of an empirical measure associated with the stopping line corresponding to the first blocks, in their respective line of descent, that are smaller than a given size. In addition, we determine the asymptotic decay rate of the size of the largest block in a homogeneous fragmentation process with immigration. The techniques used to proves these results are based on submartingale arguments.

  6. Limited feedback achieves the empirical capacity

    CERN Document Server

    Eswaran, Krishnan; Sahai, Anant; Gastpar, Michael

    2007-01-01

    The utility of limited feedback for coding over an individual sequence of DMCs is investigated. This study complements recent results showing how limited or noisy feedback can boost the reliability of communication. A strategy with fixed input distribution $P$ is given that asymptotically achieves rates arbitrarily close to the mutual information induced by $P$ and the state-averaged channel. When the capacity achieving input distribution is the same over all channel states, this achieves rates at least as large as the capacity of the state averaged channel, sometimes called the empirical capacity.

  7. Limited resources in a driven diffusion process.

    Science.gov (United States)

    Brackley, Chris A; Romano, M Carmen; Grebogi, Celso; Thiel, Marco

    2010-08-13

    The advance of particles in many driven diffusion systems depends on the availability of resources in the surrounding environment. In the balance between supply and demand of such resources we are confronted with a regime in which, under limited resource availability, the flow is markedly reduced. In the context of mRNA translation this represents the finite availability of amino acid-tRNA molecules. In this limited resources regime a severe depletion of amino acid tRNAs is also observed. These dramatic effects are vital to our understanding of translation, and are likely to also be important for the many other applications of driven diffusion models.

  8. Limits of zeros of polynomial sequences

    OpenAIRE

    Zhu, Xinyun; Grossman, George

    2007-01-01

    In the present paper we consider $F_k(x)=x^{k}-\\sum_{t=0}^{k-1}x^t,$ the characteristic polynomial of the $k$-th order Fibonacci sequence, the latter denoted $G(k,l).$ We determine the limits of the real roots of certain odd and even degree polynomials related to the derivatives and integrals of $F_k(x),$ that form infinite sequences of polynomials, of increasing degree. In particular, as $k \\to \\infty,$ the limiting values of the zeros are determined, for both odd and even cases. It is also ...

  9. Flux limiters. [for shock tube flow computation

    Science.gov (United States)

    Sweby, P. K.

    1985-01-01

    It is well known that first order accurate difference schemes for the numerical solution of conservation laws produce results which suffer from excessive numerical diffusion, classical second order schemes, although giving better resolution, suffer from spurious oscillations. Recently much effect has been put into achieving high resolution without these oscillations, using a variety of techniques. Here one class of such methods, that of flux limiting, is outlined together with the TVD constraint used to ensure oscillation free solutions. Brief numerical comparisons of different limiting functions are also presented.

  10. Superconducting fault current limiter for railway transport

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, L. M., E-mail: LMFisher@niitfa.ru; Alferov, D. F.; Akhmetgareev, M. R.; Budovskii, A. I.; Evsin, D. V.; Voloshin, I. F.; Kalinov, A. V. [National Technical Physics and Automation Research Institute (Russian Federation)

    2015-12-15

    A resistive switching superconducting fault current limiter (SFCL) for DC networks with voltage of 3.5 kV and nominal current of 2 kA is developed. The SFCL consists of two series-connected units: block of superconducting modules and high-speed vacuum breaker with total disconnection time not more than 8 ms. The results of laboratory tests of superconducting SFCL modules in current limiting mode are presented. The recovery time of superconductivity is experimentally determined. The possibility of application of SFCL on traction substations of Russian Railways is considered.

  11. Astronomical Limiting Magnitude at Langkawi Observatory

    Science.gov (United States)

    Zainuddin, Mohd. Zambri; Loon, Chin Wei; Harun, Saedah

    2010-07-01

    Astronomical limiting magnitude is an indicator for astronomer to conduct astronomical measurement at a particular site. It gives an idea to astronomer of that site what magnitude of celestial object can be measured. Langkawi National Observatory (LNO) is situated at Bukit Malut with latitude 6°18' 25'' North and longitude 99°46' 52'' East in Langkawi Island. Sky brightness measurement has been performed at this site using the standard astronomical technique. The value of the limiting magnitude measured is V = 18.6+/-1.0 magnitude. This will indicate that astronomical measurement at Langkawi observatory can only be done for celestial objects having magnitude less than V = 18.6 magnitudes.

  12. Focusing of light beyond the diffraction limit

    CERN Document Server

    Chen, K R

    2009-01-01

    Diffraction limits the behaviour of light in optical systems and sets the smallest achievable line width at half the wavelength. With a novel subwavelength plasmonic lens to reduce the diffraction via an asymmetry and to generate and squeeze the wave functions, an incident light is focused by the aperture to a single-line with its width beyond the limit outside the near zone. The fields focused are radiative and capable of propagating to the far zone. The light focusing process, besides being of academic interest, is expected to open up a wide range of application possibilities.

  13. Limits on Non-Linear Electrodynamics

    CERN Document Server

    Fouché, M; Rizzo, C

    2016-01-01

    In this paper we set a framework in which experiments whose goal is to test QED predictions can be used in a more general way to test non-linear electrodynamics (NLED) which contains low-energy QED as a special case. We review some of these experiments and we establish limits on the different free parameters by generalizing QED predictions in the framework of NLED. We finally discuss the implications of these limits on bound systems and isolated charged particles for which QED has been widely and successfully tested.

  14. Limit cycle walking on a regularized ground

    CERN Document Server

    Jacobs, Henry O

    2012-01-01

    The singular nature of contact problems, such as walking, makes them difficult to analyze mathematically. In this paper we will "regularize" the contact problem of walking by approximating the ground with a smooth repulsive potential energy and a smooth dissipative friction force. Using this model we are able to prove the existence of a limit cycle for a periodically perturbed system which consists of three masses connected by springs. In particular, this limit cycle exists in a symmetry reduced phase. In the unreduced phase space, the motion of the masses resembles walking.

  15. Metamaterial polarization converter analysis: limits of performance

    DEFF Research Database (Denmark)

    Markovich, Dmitry L.; Andryieuski, Andrei; Zalkovskij, Maksim;

    2013-01-01

    In this paper, we analyze the theoretical limits of a metamaterial-based converter with orthogonal linear eigenpolarizations that allow linear-to-elliptical polarization transformation with any desired ellipticity and ellipse orientation. We employ the transmission line approach providing a needed...... and a single layer with a ground plane can have 100 % polarization conversion efficiency. We tested our conclusions numerically reaching the designated limits of efficiency using a simple metamaterial design. Our general analysis provides useful guidelines for the metamaterial polarization converter design...

  16. Controlled Limiter in the Synchronous Detection Circuit

    Directory of Open Access Journals (Sweden)

    Yauheni Bialetski

    2017-07-01

    Full Text Available This variant of construction of the electrical circuit is aimed at reducing the effects of impulse noise. The measuring channels of the primary transducers are subject to interference of various types. In the case of a small ratio between a useful signal and noise level, synchronous detection is used. Impulse noise leaves a big mark even after using synchronous detection. To improve the performance of such measuring devices, it is proposed to use a controlled amplitude limiter at the input. Comparative analysis of solutions with controlled limiters is carried out in the article and conditions for its optimal operation are determined.

  17. Extremely Correlated Limit of the Hubbard Model

    OpenAIRE

    Perepelitsky, Edward

    2014-01-01

    In this work, we describe the simplifications to the Extremely Correlated Fermi Liquid Theory (ECFL) \\cite{ECFL, Monster} which occur in the limit of infinite spatial dimensions. In particular, we show that the single-particle electron Green's function G(k) can be written in terms of two momentum-independent self-energies. Moreover, we elucidate the nature of the ECFL \\lambda expansion in the limit of infinite dimensions and carry out this expansion explicitly to O(\\lambda^2). Additionally, w...

  18. Produire plus de bois tout en préservant mieux la biodiversité, apports de l’étude « Biomasse et biodiversité forestières » Produce more wood while better preserving biodiversity Contribution of the Forest biomass and biodiversity study

    Directory of Open Access Journals (Sweden)

    Guy Landmann, Frédéric Gosselin et Marion Gosselin

    2010-10-01

    Full Text Available Peut-on produire plus de bois en préservant mieux la biodiversité des forêts? C'est une question à forts enjeux face aux problématiques liées à l'énergie. L'étude présentée ici laisse apparaître les limites de cette politique issue du Grenelle de l'Environnement et les points d'amélioration à envisager.

  19. Simple a posteriori slope limiter (Post Limiter) for high resolution and efficient flow computations

    Science.gov (United States)

    Kitamura, Keiichi; Hashimoto, Atsushi

    2017-07-01

    A simple and efficient a posteriori slope limiter (;Post Limiter;) is proposed for compressible Navier-Stokes and Euler equations, and examined in 1D and 2D. The Post Limiter tries to employ un-limited solutions where and when possible (even at shocks), and blend the un-limited and (1st-order) limited solutions smoothly, leading to equivalently four times resolution in 1D. This idea was inspired by a posteriori limiting approaches originally developed by Clain et al. (2011) [18] for higher-order flow computations, but proposed here is an alternative suitable and simplified for 2nd-order spatial accuracy with improved both solution and convergence. In fact, any iteration processes are no longer required to determine optimal orders of accuracy, since the limited and un-limited values are available at one time at 2nd-order. In 2D, several numerical examples have been dealt with, and both the κ = 1 / 3 MUSCL (in a structured solver) and Green-Gauss (in an unstructured solver) reconstructions demonstrated resolution improvement (nearly 4 × 4 times), convergence acceleration, and removal of numerical noises. Even on triangular meshes (on which least-squares reconstruction is used), the unstructured solver showed the improved solutions if cell geometries (cell-orientation angles) are properly taken into account. Therefore, the Post Limiter is readily incorporated into existing codes.

  20. 47 CFR 78.101 - Power limitations.

    Science.gov (United States)

    2010-10-01

    ... that use Automatic Transmitter Power Control (ATPC) shall not exceed the EIRP specified on the station... power delivered to an antenna shall be the minimum amount of power necessary to carry out the... +35 18,800 to 19,700 +55 1 The power delivered to the antenna is limited to −3 dBW. 2...