Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 435
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
Phys Rev Lett ; 124(16): 163604, 2020 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-32383959

RESUMEN

We demonstrate a new mechanical transduction platform for individual spin qubits. In our approach, single micromagnets are trapped using a type-II superconductor in proximity of spin qubits, enabling direct magnetic coupling between the two systems. Controlling the distance between the magnet and the superconductor during cooldown, we demonstrate three-dimensional trapping with quality factors around 1×10^{6} and kHz trapping frequencies. We further exploit the large magnetic moment to mass ratio of this mechanical oscillator to couple its motion to the spin degrees of freedom of an individual nitrogen vacancy center in diamond. Our approach provides a new path towards interfacing individual spin qubits with mechanical motion for testing quantum mechanics with mesoscopic objects, realization of quantum networks, and ultrasensitive metrology.

2.
J Fish Biol ; 92(4): 1090-1109, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29479689

RESUMEN

Headwater-resident fishes may be prone to a high rate of isolation and a pronounced hierarchical genetic structure due to a combination of niche preference and dendritic effects of river networks. Genetic isolation patterns were compared using microsatellites in six headwater fishes, Fundulus olivaceus, Semotilus atromaculatus, Erimyzon claviformis, Etheostoma artesiae, Etheostoma whipplei and Etheostoma parvipinne, in three geographic regions that included drainages of small, medium and large sizes in the southern United States. All species showed hierarchical nesting of genetic populations and there were clear and mostly consistent differences between species and regions that were identified through summary statistics derived from two independent analyses. For species comparisons, a high isolation grouping (increased number of isolated genetic clusters or sites within regions) and a low-isolation grouping (decreased number of clusters or sites) were identified. Species group placement was related to niche breadth along the river continuum and presumed abundance and variability of preferred microhabitats, with increased headwater specialization among species being associated with placement in the high-isolation grouping. There was a weakly significant positive effect of drainage size on the number of isolated clusters or sites across all species. Regional patterns were shared in two species, with the region containing the smallest drainages having lower rates of isolation in both datasets. This study shows the effects of regional and species characteristics on genetic isolation for headwater species, which are especially prone to isolation due to spatial, dendritic effects of river networks.


Asunto(s)
Fundulidae/genética , Genética de Población , Percas/genética , Aislamiento Reproductivo , Animales , Ecosistema , Geografía , Repeticiones de Microsatélite , Ríos , Estados Unidos
3.
J Immunoassay Immunochem ; 38(6): 579-594, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28699839

RESUMEN

INTRODUCTION: The pharmacotherapy of pediatric patients suffering from heart failure is extrapolated from adults due to missing data in children. OBJECTIVES: Development and validation of a low-volume immunoassay for the reliable determination of renin. EXPERIMENTAL: The immunoassay was validated according to international guidelines. RESULTS: The assay allows the reliable determination of renin in 40 µL plasma within a calibration range of 4-128 pg/mL. Between-run accuracy varied from -3.3 to +3.0% (relative error), while between-run precision ranged from 4.9 to 11.3% (coefficient of variation). CONCLUSION: The low-volume immunoassay facilitates the reliable collection of pharmacodynamic data in children.


Asunto(s)
Inmunoensayo/normas , Pediatría/métodos , Renina/sangre , Adulto , Niño , Femenino , Voluntarios Sanos , Humanos
4.
Reprod Domest Anim ; 52(3): 397-402, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28066955

RESUMEN

To achieve a standardized number of spermatozoa in the final AI dose, varying amounts of extender fluid with a fixed concentration of antimicrobial substances are currently added to boar ejaculates. This practice ignores the different degrees of dilution of the antimicrobials in the end product. In calculating the final concentration of gentamicin in AI doses from 27,538 processed boar ejaculates, we demonstrated varying gentamicin concentrations in the resultant extended boar semen samples. The median concentration was 220.37 mg/L. In 25 of the samples (0.09%), the gentamicin concentration fell below 5 mg/L, which is close to or below the epidemiological cut-off value for many bacteria. We calculated the minimum inhibitory concentration of gentamicin for bacteria isolated from raw and extended ejaculates. Five of the isolates from extended ejaculates exceeded the maximum test concentration of 512 mg/L. As a result, we are presenting an alternative method of boar semen preservation whereby a particular combination of gentamicin concentrate and antibiotic-free extender is incorporated that standardizes the antibiotic concentration in the diluted semen. The addition of standardized antibiotic concentrations did not negatively affect sperm quality when compared to the use of ready-to-use extenders. In conclusion, an end volume-based and standardized addition of gentamicin to boar ejaculates can be a helpful alternative to prevent insufficient dosage of antibiotics in liquid preserved boar semen without affecting semen quality.


Asunto(s)
Antibacterianos/farmacología , Gentamicinas/farmacología , Preservación de Semen/veterinaria , Porcinos , Animales , Antibacterianos/administración & dosificación , Relación Dosis-Respuesta a Droga , Gentamicinas/administración & dosificación , Masculino , Semen/microbiología , Preservación de Semen/métodos
5.
Genes Immun ; 17(2): 79-84, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26673963

RESUMEN

Roquin-1 (Rc3h1) is an E3 ubiquitin ligase originally discovered in a mutational screen for genetic factors contributory to systemic lupus erythematosus-like symptoms in mice. A single base-pair mutation in the Rc3h1 gene resulted in the manifestation of autoantibody production and sustained immunological inflammation characterized by excessive T follicular helper cell activation and formation of germinal centers. Subsequent studies have uncovered a multifactorial process by which Roquin-1 contributes to the maintenance of immune homeostasis. Through its interactions with partner proteins, Roquin-1 targets mRNAs for decay with inducible costimulator being a primary target. In this review, we discuss newly discovered functions of Roquin-1 in the immune system and inflammation, and in disease manifestation, and discuss avenues of further research. A model is presented for the role of Roquin in health and disease.


Asunto(s)
Autoanticuerpos/biosíntesis , Homeostasis/inmunología , Proteína Coestimuladora de Linfocitos T Inducibles/genética , Lupus Eritematoso Sistémico/genética , Proteínas de Unión al ARN/genética , Ubiquitina-Proteína Ligasas/genética , Animales , Modelos Animales de Enfermedad , Regulación de la Expresión Génica , Centro Germinal/inmunología , Centro Germinal/patología , Homeostasis/genética , Humanos , Inmunidad Innata , Proteína Coestimuladora de Linfocitos T Inducibles/inmunología , Lupus Eritematoso Sistémico/inmunología , Lupus Eritematoso Sistémico/patología , Activación de Linfocitos , Ratones , Mutación , Proteínas de Unión al ARN/inmunología , Receptores del Factor de Necrosis Tumoral/genética , Receptores del Factor de Necrosis Tumoral/inmunología , Transducción de Señal , Linfocitos T Colaboradores-Inductores/inmunología , Linfocitos T Colaboradores-Inductores/patología , Ubiquitina-Proteína Ligasas/inmunología
6.
Phys Rev Lett ; 116(10): 106802, 2016 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-27015502

RESUMEN

Using inelastic electron scattering in combination with dielectric theory simulations on differently prepared graphene layers on silicon carbide, we demonstrate that the coupling between the 2D plasmon of graphene and the surface optical phonon of the substrate cannot be quenched by modification of the interface via intercalation. The intercalation rather provides additional modes like, e.g., the silicon-hydrogen stretch mode in the case of hydrogen intercalation or the silicon-oxygen vibrations for water intercalation that couple to the 2D plasmons of graphene. Furthermore, in the case of bilayer graphene with broken inversion symmetry due to charge imbalance between the layers, we observe a similar coupling of the 2D plasmon to an internal infrared-active mode, the LO phonon mode. The coupling of graphene plasmons to vibrational modes of the substrate surface and internal infrared active modes is envisioned to provide an excellent tool for tailoring the plasmon band structure of monolayer and bilayer graphene for plasmonic devices such as plasmon filters or plasmonic waveguides. The rigidity of the effect furthermore suggests that it may be of importance for other 2D materials as well.

7.
Chemistry ; 21(39): 13696-702, 2015 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-26264355

RESUMEN

Ion-like ethylzinc(II) compounds with weakly coordinating aluminates [Al(OR(F))4](-) and [(R(F)O)3Al-F-Al(OR(F))3](-) (R(F)=C(CF3)3) were synthesized in a one-pot reaction and fully characterized by single-crystal X-ray diffraction, NMR and vibrational spectroscopy, and by quantum chemical calculations. The catalytic activity of ion-like Et-Zn[Al(OR(F))4] in intermolecular hydroamination and in the unusual double hydroamination of anilines and alkynes was investigated. Favorable performance was also found in comparison to the Et2Zn/[PhNMe2H](+)[B(C6F5)4](-) system generated in situ at lower catalyst loadings of 2.5 mol %.

8.
Eur J Neurol ; 22(11): 1429-35, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26204918

RESUMEN

Myofibrillar myopathies are a genetically diverse group of skeletal muscle disorders, with distinctive muscle histopathology. Causative mutations have been identified in the genes MYOT, LDB3, DES, CRYAB, FLNC, BAG3, DNAJB6, FHL1, PLEC and TTN, which encode proteins which either reside in the Z-disc or associate with the Z-disc. Mitochondrial abnormalities have been described in muscle from patients with a myofibrillar myopathy. We reviewed the literature to determine the extent of mitochondrial dysfunction in each of the myofibrillar myopathy subtypes. Abnormal mitochondrial distribution is a frequent finding in each of the subtypes, but a high frequency of COX-negative or ragged red fibres, a characteristic finding in some of the conventional mitochondrial myopathies, is a rare finding. Few in vitro studies of mitochondrial function have been performed in affected patients.


Asunto(s)
Mitocondrias/patología , Humanos , Miopatías Estructurales Congénitas/clasificación , Miopatías Estructurales Congénitas/genética , Miopatías Estructurales Congénitas/patología
9.
Prev Sci ; 15(4): 557-69, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23609793

RESUMEN

Representative surveys indicate that eating disorders are an increasing problem, especially among (pre)adolescents. We assessed the effects of a German school-based primary prevention program ("Torera") for seventh graders. Torera especially relates to pathological eating behavior in the realm of bulimia nervosa or binge eating disorder. The program is built upon two previously evaluated modules for sixth graders with a gender-specific adaption. The coeducational intervention involves nine manual-guided lessons touching a wide range of eating-related problems. Twenty-two Thuringian secondary schools (n = 256 boys and 277 girls, aged 11-13 years at baseline) participated in a trial with 2 control groups (untreated and pretreated) with pre-post assessment. Primary outcomes were conspicuous eating behavior and body self-esteem, measured by standardized questionnaires (SCOFF, EAT-26D, and FBeK). Girls and students at risk showed significant improvement with small (d = 0.35) to medium (d = 0.66) effect sizes on eating behavior, significantly mediated by body self-esteem. Boys only improved with respect to eating attitudes, revealing a small effect size (d = 0.35). With relatively low implementation costs (about 2.50 per student), Torera provides an efficient model for reducing risky eating behavior and strengthening body self-esteem without negative side effects. To improve the effectiveness of the intervention, further research efforts focusing on at-risk groups (secondary prevention) and structural actions for prevention (e.g., offering healthy school catering) are needed.


Asunto(s)
Trastornos de Alimentación y de la Ingestión de Alimentos/prevención & control , Conducta de Reducción del Riesgo , Adolescente , Actitud Frente a la Salud , Niño , Trastornos de Alimentación y de la Ingestión de Alimentos/psicología , Femenino , Alemania , Humanos , Masculino
10.
J Fish Biol ; 85(5): 1726-32, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25123486

RESUMEN

A total of 17 polymorphic microsatellite loci were isolated from the blackstripe topminnow Fundulus notatus. In a sample of 29 individuals, these loci were found to possess two to 19 alleles with expected heterozygosity values ranging from 0.212 to 0.919 and all but one of the loci conformed to Hardy-Weinberg equilibrium expectations. Many of these loci were polymorphic in the closely related species Fundulus olivaceus and Fundulus euryzonus providing a set of markers that should prove useful in future ecological and evolutionary studies of members of this species complex.


Asunto(s)
Cyprinidae/genética , Repeticiones de Microsatélite , Alelos , Animales , Sitios Genéticos , Análisis de Secuencia de ADN
11.
Internist (Berl) ; 55(5): 601-6, 2014 May.
Artículo en Alemán | MEDLINE | ID: mdl-24770979

RESUMEN

Guidelines for the reduction of cholesterol to prevent atherosclerotic vascular events were recently released by the American Heart Association and the American College of Cardiology. The authors claim to refer entirely to evidence from randomized controlled trials, thereby confining their guidelines to statins as the primary therapeutic option. The guidelines derived from these trials do not specify treatment goals, but refer to the percentage of cholesterol reduction by statin medication with low, moderate, and high intensity. However, these targets are just as little tested in randomized trials as are the cholesterol goals derived from clinical experience. The same applies to the guidelines of the four patient groups which are defined by vascular risk. No major statin trial has included patients on the basis of their global risk; thus the allocation criteria are also arbitrarily chosen. These would actually lead to a significant increase in the number of patients to be treated with high or maximum dosages of statins. Also, adhering to dosage regulations instead of cholesterol goals contradicts the principles of individualized patient care. The option of the new risk score to calculate lifetime risk up to the age of 80 years in addition to the 10-year risk can be appreciated. Unfortunately it is not considered in the therapeutic recommendations provided, despite evidence from population and genetic studies showing that even a moderate lifetime reduction of low-density lipoprotein (LDL) cholesterol or non-HDL cholesterol has a much stronger effect than an aggressive treatment at an advanced age. In respect to secondary prevention, the new American guidelines broadly match the European guidelines. Thus, the involved societies from Germany, Austria and Switzerland recommend continuing according to established standards, such as the EAS/ESC guidelines.


Asunto(s)
Anticolesterolemiantes/administración & dosificación , Aterosclerosis/sangre , Aterosclerosis/prevención & control , Dietoterapia/normas , Hipercolesterolemia/sangre , Hipercolesterolemia/prevención & control , Guías de Práctica Clínica como Asunto , Austria , Cardiología/normas , Humanos , Factores de Riesgo , Suiza
12.
Eur J Neurol ; 20(7): 997-1005, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23627674

RESUMEN

BACKGROUND: Myalgia, defined as any pain perceived in muscle, is very common in the general population and a frequent cause for referral to neurologists, rheumatologists and internists in general. It is however only rarely due to primary muscle disease and often referred from ligaments, joints, bones, the peripheral and central nervous system. A muscle biopsy should only be performed if this is likely to be diagnostically useful. At present no 'guidelines' exist. METHODS: An EFNS panel of muscle specialists was set to review relevant studies from PubMed dating as far back as 1/1/1990. Only Class IV studies were available and therefore the recommendations arrived at are 'best practice recommendations' based on information harvested from the literature search and expert opinion. RESULTS: Muscle cramps should be recognized while drugs, infections, metabolic/ endocrinological and rheumatological causes of myalgia should be identified from the history and examination and pertinent laboratory tests. A muscle biopsy is more likely to be diagnostically useful if myalgia is exertional and if one or more of the following apply: i) there is myoglobinuria, (ii) there is a second wind phenomenon, (iii) there is muscle weakness, (iv) there is muscle hypertrophy /atrophy, (v) there is hyperCKemia (>2-3× normal), and (vi) there is a myopathic EMG. CONCLUSIONS: Patients presenting with myalgia can be recommended to have a biopsy based on careful history and examination and on simple laboratory screening.


Asunto(s)
Biopsia/normas , Mialgia/diagnóstico , Ejercicio Físico/fisiología , Humanos , Mialgia/etiología , Mialgia/fisiopatología , Valor Predictivo de las Pruebas
13.
Neuropediatrics ; 43(6): 339-45, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23129438

RESUMEN

INTRODUCTION: A total of 83% of children report headache during a 6-month period. The estimated 1-year prevalence of chronic daily headache (CDH) in children is at least 1 to 2%. Muscle pain is associated with headache severity and chronicity. Muscle pain can be associated with active muscular trigger points, a functional concept still remaining a controversy. An integrated approach including bio-behavioral management is accepted as standard treatment but does not provide sufficient pain relief in all patients. OBJECTIVE: We report the individual clinical course of five adolescents with treatment-refractory CDH associated with focal muscle pain. We describe a concept of short-term integrative intervention including botulinum toxin (StiBo) in a personalized "follow the referred pain pattern" injection regimen with the focus on long-term follow-up. RESULTS: StiBo showed short-term efficacy on headache frequency and severity. In the long-term follow-up, CDH was not existent in any of the patients. CONCLUSION: The treatment may have enabled the patients to draw attention away from a repeated circle of muscle-triggered pain and withdrawal of daily activities toward self-driven activities, thereby potentially preventing the development of further chronification. To prove this hypothesis, a prospective, placebo-controlled study in young adolescents with CDH should be initiated including objective outcome parameters on muscular level.


Asunto(s)
Toxinas Botulínicas/uso terapéutico , Trastornos de Cefalalgia/tratamiento farmacológico , Dolor Musculoesquelético/tratamiento farmacológico , Adolescente , Niño , Estudios de Seguimiento , Trastornos de Cefalalgia/complicaciones , Humanos , Dolor Musculoesquelético/complicaciones , Dimensión del Dolor , Índice de Severidad de la Enfermedad , Resultado del Tratamiento
14.
Herz ; 37(1): 51-5, 2012 Feb.
Artículo en Alemán | MEDLINE | ID: mdl-22258137

RESUMEN

The risk for myocardial infarction can be reduced by almost 50% solely by lowering LDL cholesterol. Despite success reducing LDL and cholesterol, atherosclerosis and myocardial infarction remain significant challenges. However, mechanisms of the reverse cholesterol transport system might be used more effectively in the foreseeable future. Although the benefit of high HDL cholesterol appears to be obvious, most clinical trials aimed at increasing HDL cholesterol failed to generate convincing results. Therefore, the question arises as to whether indeed only HDL level or perhaps rather more HDL function is of considerable therapeutic relevance. If function is the crucial issue drugs such as CETP (cholesteryl ester transfer protein) activators or SR-B1 (scavenger receptor type B-1) upregulators could be beneficial. These types of drugs could improve HDL metabolism and might have beneficial effects despite the fact that they lower HDL levels. Ongoing studies on next generation CETP inhibitors and nicotinic acid will clarify this question and might help in our struggle against atherosclerosis.


Asunto(s)
Aterosclerosis/prevención & control , HDL-Colesterol/sangre , Infarto del Miocardio/prevención & control , Anticolesterolemiantes/efectos adversos , Anticolesterolemiantes/uso terapéutico , Aterosclerosis/sangre , Atorvastatina , Proteínas de Transferencia de Ésteres de Colesterol/agonistas , Proteínas de Transferencia de Ésteres de Colesterol/antagonistas & inhibidores , Proteínas de Transferencia de Ésteres de Colesterol/fisiología , LDL-Colesterol/sangre , Ensayos Clínicos como Asunto , Quimioterapia Combinada , Terminación Anticipada de los Ensayos Clínicos , Femenino , Fluorobencenos/efectos adversos , Fluorobencenos/uso terapéutico , Ácidos Heptanoicos/efectos adversos , Ácidos Heptanoicos/uso terapéutico , Humanos , Masculino , Proteínas de Transporte de Membrana/fisiología , Infarto del Miocardio/sangre , Infarto del Miocardio/mortalidad , Niacina/efectos adversos , Niacina/uso terapéutico , Pirimidinas/efectos adversos , Pirimidinas/uso terapéutico , Pirroles/efectos adversos , Pirroles/uso terapéutico , Quinolinas/efectos adversos , Quinolinas/uso terapéutico , Ensayos Clínicos Controlados Aleatorios como Asunto , Valores de Referencia , Rosuvastatina Cálcica , Receptores Depuradores de Clase B/fisiología , Sulfonamidas/efectos adversos , Sulfonamidas/uso terapéutico , Tasa de Supervivencia , Regulación hacia Arriba/fisiología
15.
Eur J Neurol ; 17(6): 767-73, 2010 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-20402744

RESUMEN

OBJECTIVE: To provide evidence-based guidelines to general neurologists for the assessment of patients with pauci- or asymptomatic hyperCKemia. BACKGROUND: Recent epidemiologic studies show that up to 20% of 'normal' individuals have an elevated creatine kinase activity in the serum (sCK). The possibility of a subclinical myopathy is often raised, and patients may be unnecessarily denied treatment with statins. SEARCH STRATEGY: Electronic databases including Medline, the Cochrane Library and the American Academy of Neurology were searched for existing guidelines. Articles dealing with series of patients investigated for asymptomatic/pauci-symptomatic hyperCKemia and articles dealing with myopathies that can present with asymptomatic hyperCKemia were identified and reviewed. RESULTS: The only guidelines found were those approved by the Italian Association of Myology Committee, and the only relevant articles identified describe class IV studies. RECOMMENDATIONS: HyperCKemia needs to be redefined as values beyond 1.5 times the upper limit of normal (which itself needs to be appropriately defined). Pauci- or asymptomatic hyperCKemia with no apparent medical explanation may be investigated with a muscle biopsy if one or more of the following are present; the sCK is >or=3x normal, the electromyogram is myopathic or the patient is <25 years of age. In addition, women with sCK<3 times normal may be offered DNA testing because of the possibility of carrying a dystrophin mutation.


Asunto(s)
Creatina Quinasa/sangre , Enfermedades Musculares/sangre , Enfermedades Musculares/diagnóstico , Femenino , Humanos , Enfermedades Musculares/enzimología , Valores de Referencia
16.
Nature ; 425(6958): 602-5, 2003 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-14534582

RESUMEN

If the rich functionality of organic molecules is to be exploited in devices such as light-emitting diodes or field-effect transistors, interface properties of organic materials with various (metallic and insulating) substrates must be tailored carefully. In many cases, this calls for well-ordered interfaces. Organic epitaxy-that is, the growth of molecular films with a commensurate structural relationship to their crystalline substrates--relies on successful recognition of preferred epitaxial sites. For some large pi-conjugated molecules ('molecular platelets') this works surprisingly well, even if the substrate exhibits no template structure into which the molecules can lock. Here we present an explanation for site recognition in non-templated organic epitaxy, and thus resolve a long-standing puzzle. We propose that this form of site recognition relies on the existence of a local molecular reaction centre in the extended pi-electron system of the molecule. Its activity can be controlled by appropriate side groups and--in a certain regime--may also be probed by molecularly sensitized scanning tunnelling microscopy. Our results open the possibility of engineering epitaxial interfaces, as well as other interfacial nanostructures for which specific site recognition is essential.

17.
J Fish Biol ; 76(6): 1498-507, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20537028

RESUMEN

A new species of Profundulus, Profundulus portillorum, from the Honduran central highlands is described. Profundulus portillorum belongs to the Profundulus labialis species group and is distinct from the Profundulus punctatus species group in that it lacks a humeral spot and less than half of the caudal fin is scaled. Within the P. labialis species group, P. portillorum has a more slender body, smaller eye, fewer anal rays, caudal rays and lateral-line scales than other species. Forty-one specimens were collected around emergent vegetation in the margins of two small (2-5 m in width, 20-40 cm in depth), high-elevation (1300 m) tributaries of the Río Calam within the Río Ulúa drainage. These specimens represent the easternmost collection of any Profundulus and the first collection of any member of the P. labialis species group from Honduras.


Asunto(s)
Ciprinodontiformes/clasificación , Animales , Ciprinodontiformes/anatomía & histología , Agua Dulce , Honduras , Análisis Multivariante , Análisis de Componente Principal
18.
Sci Adv ; 6(38)2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32938673

RESUMEN

Glacial lake outburst floods (GLOFs) are a substantial hazard for downstream communities in vulnerable regions, yet unpredictable triggers and remote source locations make GLOF dynamics difficult to measure and quantify. Here, we revisit a destructive GLOF that occurred in Bhutan in 1994 and apply cross-correlation-based seismic analyses to track the evolution of the GLOF remotely (~100 kilometers from the source region). We use the seismic observations along with eyewitness reports and a downstream gauge station to constrain a numerical flood model and then assess geomorphic change and current state of the unstable lakes via satellite imagery. Coherent seismic energy is evident from 1 to 5 hertz beginning approximately 5 hours before the flood impacted Punakha village, which originated at the source lake and advanced down the valley during the GLOF duration. Our analysis highlights potential benefits of using real-time seismic monitoring to improve early warning systems.

19.
Genes Immun ; 10(1): 18-26, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18754015

RESUMEN

Although cells of the immune system can produce thyroid-stimulating hormone (TSH), the significance of that remains unclear. Using 5' rapid amplification of cDNA ends (RACE), we show that mouse bone marrow (BM) cells produce a novel in-frame TSHbeta splice variant generated from a portion of intron 4 with all of the coding region of exon 5, but none of exon 4. The TSHbeta splice variant gene was expressed at low levels in the pituitary, but at high levels in the BM and the thyroid, and the protein was secreted from transfected Chinese hamster ovary (CHO) cells. Immunoprecipitation identified an 8 kDa product in lysates of CHO cells transfected with the novel TSHbeta construct, and a 17 kDa product in lysates of CHO cells transfected with the native TSHbeta construct. The splice variant TSHbeta protein elicited a cAMP response from FRTL-5 thyroid follicular cells and a mouse alveolar macrophage (AM) cell line. Expression of the TSHbeta splice variant, but not the native form of TSHbeta, was significantly upregulated in the thyroid during systemic virus infection. These studies characterize the first functional splice variant of TSHbeta, which may contribute to the metabolic regulation during immunological stress, and may offer a new perspective for understanding autoimmune thyroiditis.


Asunto(s)
Empalme Alternativo , Células de la Médula Ósea/metabolismo , Glándula Tiroides/metabolismo , Tirotropina de Subunidad beta/genética , Regulación hacia Arriba , Secuencia de Aminoácidos , Animales , Células CHO , Cricetinae , Cricetulus , Medios de Cultivo/química , Exones , Femenino , Intrones , Ratones , Ratones Endogámicos C57BL , Datos de Secuencia Molecular , Hipófisis/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Estructura Secundaria de Proteína , ARN Mensajero/genética , ARN Mensajero/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Infecciones por Reoviridae/genética , Infecciones por Reoviridae/metabolismo , Tirotropina de Subunidad beta/biosíntesis , Tirotropina de Subunidad beta/química , Transfección
20.
Science ; 235(4793): 1200-4, 1987 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-3823880

RESUMEN

Cross-polarization magic-angle-spinning nuclear magnetic resonance spectroscopy has been used to determine insect cuticle composition and cross-link structure during sclerotization or tanning. Unsclerotized cuticle from newly ecdysed pupae of the tobacco hornworm, Manduca sexta L., had a high protein content with lesser amounts of lipid and chitin. Concentrations of chitin, protein, and catechol increased substantially as dehydration and sclerotization progressed. Analysis of intact cuticle specifically labeled with carbon-13 and nitrogen-15 revealed direct covalent linkages between ring nitrogens of protein histidyl residues and ring carbons derived from the catecholamine dopamine. This carbon-nitrogen adduct was present in chitin isolated from cuticle by alkaline extraction and is probably bound covalently to chitin. These data support the hypothesis that the stiffening of insect cuticle during sclerotization results primarily from the deposition of protein and chitin polymers and their crosslinking by quinonoid derivatives of catecholamines.


Asunto(s)
Reactivos de Enlaces Cruzados/metabolismo , Insectos/metabolismo , Piel/metabolismo , Animales , Isótopos de Carbono , Fenómenos Químicos , Química , Espectroscopía de Resonancia Magnética , Isótopos de Nitrógeno
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA