1,565 research outputs found

    Zeros and the functional equation of the quadrilateral zeta function

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    In this paper, we show that all real zeros of the bilateral Hurwitz zeta function Z(s,a):=ζ(s,a)+ζ(s,1a)Z(s,a):=\zeta (s,a) + \zeta (s,1-a) with 1/4a1/21/4 \le a \le 1/2 are on only the non-positive even integers exactly same as in the case of (2s1)ζ(s)(2^s-1) \zeta (s). We also prove that all real zeros of the bilateral periodic zeta function P(s,a):=Lis(e2πia)+Lis(e2πi(1a))P(s,a):={\rm{Li}}_s (e^{2\pi ia}) + {\rm{Li}}_s (e^{2\pi i(1-a)}) with 1/4a1/21/4 \le a \le 1/2 are on only the negative even integers just like ζ(s)\zeta (s). Moreover, we show that all real zeros of the quadrilateral zeta function Q(s,a):=Z(s,a)+P(s,a)Q(s,a):=Z(s,a) + P(s,a) with 1/4a1/21/4 \le a \le 1/2 are on only the negative even integers. On the other hand, we prove that Z(s,a)Z(s,a), P(s,a)P(s,a) and Q(s,a)Q(s,a) have at least one real zero in (0,1)(0,1) when 0<a<1/20<a<1/2 is sufficiently small. The complex zeros of these zeta functions are also discussed when 1/4a1/21/4 \le a \le 1/2 is rational or transcendental. As a corollary, we show that Q(s,a)Q(s,a) with rational 1/4<a<1/31/4 < a < 1/3 or 1/3<a<1/21/3 < a < 1/2 does not satisfy the analogue of the Riemann hypothesis even though Q(s,a)Q(s,a) satisfies the functional equation that appeared in Hamburger's or Hecke's theorem and all real zeros of Q(s,a)Q(s,a) are located at only the negative even integers again as in the case of ζ(s)\zeta (s).Comment: 12 pages. We changed the title. Some typos are correcte

    Meta-analysis of genome-wide association studies of asthma in ethnically diverse North American populations.

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    Asthma is a common disease with a complex risk architecture including both genetic and environmental factors. We performed a meta-analysis of North American genome-wide association studies of asthma in 5,416 individuals with asthma (cases) including individuals of European American, African American or African Caribbean, and Latino ancestry, with replication in an additional 12,649 individuals from the same ethnic groups. We identified five susceptibility loci. Four were at previously reported loci on 17q21, near IL1RL1, TSLP and IL33, but we report for the first time, to our knowledge, that these loci are associated with asthma risk in three ethnic groups. In addition, we identified a new asthma susceptibility locus at PYHIN1, with the association being specific to individuals of African descent (P = 3.9 × 10(-9)). These results suggest that some asthma susceptibility loci are robust to differences in ancestry when sufficiently large samples sizes are investigated, and that ancestry-specific associations also contribute to the complex genetic architecture of asthma

    Combination antiretroviral therapy and the risk of myocardial infarction

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    The macroeconomics of a financial Dutch disease

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    We describe the medium-run macroeconomic effects and long-run development consequences of a financial Dutch disease that may take place in a small developing country with abundant natural resources. The first move is in financial markets. An initial surge in foreign direct investment targeting natural resources sets in motion a perverse cycle between exchange rate appreciation and mounting short- and medium-term capital flows. Such a spiral easily leads to exchange rate volatility, capital reversals, and sharp macroeconomic instability. In the long run, macroeconomic instability and overdependence on natural resource exports dampen the development of nontraditional tradable goods sectors and curtail labor productivity dynamics. We advise the introduction of constraints to short- and medium-term capital flows to tame exchange rate/capital flows boom-and-bust cycles. We support the implementation of a developmentalist monetary policy targeting competitive nominal and real exchange rates in order to encourage product and export diversification

    Chemical interaction, interfacial effect and the microstructural characterization of the induced zinc–aluminum–Solanum tuberosum in chloride solution on mild steel

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    In this study, we report the effect of Solanum tuberosum (ST) as a strong additive on the morphological interaction, wear, and hardness properties of electroplated zinc coating in chloride bath solutions. The structural and the mechanical behavior of the Zn–Al–ST coating were studied and compared with the properties of Zn coatings. Characterization of the electrodeposited coatings were carried out using scanning electron microscopy, energy dispersive spectrometer, AFM, and X-ray diffraction techniques. The adhesion between the coatings and substrate was examined mechanically using hardness and wear techniques. From the results, amorphous Zn–Al–ST coatings were effectively obtained by electrodeposition using direct current. The coating morphology was revealed to be reliant on the bath composition containing strong leveling additives. From all indications, ST content contribute to a strong interfacial surface effect leading to crack-free and better morphology, good hardness properties, and improved wear resistance due to the precipitation of Zn2Si and Zn7Al2Si3. Hence, addition of ST is beneficial for the structural strengthening, hardness, and wear resistance properties of such coatings

    Diagnostische Bedeutung der Proteinbindung von Plasmacortisol, bestimmt durch Dextrangelfiltration

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    1. Mittels Dextrangelfiltration wurde nach Inkubation von markiertem Cortisol und Plasma der proteingebundene und der sog. freie Anteil (%) des endogenen Plasmacortisols ermittelt und bei gleichzeitiger fluorimetrischer Bestimmung der 11-OHCS auch die Menge proteingebundenen, bzw. sog. freien Cortisols (µg-%) berechnet. 2. Die diagnostische Brauchbarkeit der Methode wurde bei Patienten mit Nebennierenrindeninsuffizienz, mit Hypophysentumoren, nach Hypophysektomie, mit Cushing-Syndrom mit der fluorimetrischen Bestimmung der 11-OHCS verglichen. Die einfache Bestimmung der Cortisolbindung war bei hypophysektomierten Patienten der Bestimmung der 11-OHCS überlegen und entsprach der aufwendigeren ACTH-Belastung. 3. Falsch hohe fluorimetrische 11-OHCS-Spiegel im Plasma unter Spirolacton- oder Oestrogenbehandlung und in der Gravidität lassen sich durch Bestimmung der Cortisolbindung klären. Bei Schilddrüsenüberfunktion war das sog. freie Cortisol im Plasma relativ und absolut vermehrt, bei Schilddrüsenunterfunktion fand sich eine Zunahme des plasmaproteingebundenen Cortisols.1. Following incubation of labeled cortisol and plasma the percentages of protein bound and socalled free endogenous cortisol were determined by means of dextran gel filtration. 2. The diagnostic value of this method was compared with fluorimetric determinations of 11-OHCS for patients with adrenal insufficiency, Cushing-Syndrome, pituitary tumors and after hypophysectomy. In hypophysectomized patients the simple determination of protein bound cortisol was found to correlate well with diagnostic ACTH-infusion tests and to be more sensitive than fluorimetric determinations of 11-OHCS in 9 a.m. plasma. 3. Falsely elevated fluorimetric values of plasma 11-OHCS in patients treated with spirolactone or estrogens, resp. during pregnancy may be recognized through determination of cortisol binding. — In thyrotoxicosis socalled free cortisol was elevated, both relatively and absolutely; in hypothyroidism an increase of protein bound cortisol was found

    Identifying extra pulmonary vein targets for persistent atrial fibrillation ablation: bridging advanced and conventional mapping techniques

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    Aims: Advanced technologies such as charge density mapping (CDM) show promise in guiding adjuvant ablation in patients with persistent atrial fibrillation (AF); however, their limited availability restricts widespread adoption. We sought to determine whether regions of the left atrium containing CDM-identified pivoting and rotational propagation patterns during AF could also be reliably identified using more conventional contact mapping techniques. Methods and results: Twenty-two patients undergoing de novo ablation of persistent AF underwent both CDM and electroanatomic voltage mapping during AF and sinus rhythm with multiple pacing protocols. Through the use of a left atrium statistical shape model, the location of distinctive propagation patterns identified by CDM was compared with low-voltage areas (LVAs) and regions of slow conduction velocity (CV). Neither LVA nor CV mapping during paced rhythms reliably identified regions containing CDM propagation patterns. Conduction velocity mapping during AF did correlate with these regions (ρ = −0.63, P < 0.0001 for pivoting patterns; ρ = −0.54, P < 0.0001 for rotational patterns). These propagation patterns consistently occurred in two specific anatomical regions across patients: the anteroseptal and inferoposterior walls of the left atrium. Conclusion: Mapping techniques during paced rhythms do not reliably correspond with regions of CDM-identified propagation patterns in persistent AF. However, these propagation patterns are consistently observed in two specific anatomical regions, suggesting a predisposition to abnormal electrophysiological properties. While further research is needed, these regions may serve as promising targets for empirical ablation, potentially reducing the reliance on complex mapping techniques

    Predicting glycated hemoglobin levels in the non-diabetic general population:Development and validation of the DIRECT-DETECT prediction model - a DIRECT study

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    AIMS/HYPOTHESIS: To develop a prediction model that can predict HbA1c levels after six years in the non-diabetic general population, including previously used readily available predictors. METHODS: Data from 5,762 initially non-diabetic subjects from three population-based cohorts (Hoorn Study, Inter99, KORA S4/F4) were combined to predict HbA1c levels at six year follow-up. Using backward selection, age, BMI, waist circumference, use of anti-hypertensive medication, current smoking and parental history of diabetes remained in sex-specific linear regression models. To minimize overfitting of coefficients, we performed internal validation using bootstrapping techniques. Explained variance, discrimination and calibration were assessed using R2, classification tables (comparing highest/lowest 50% HbA1c levels) and calibration graphs. The model was externally validated in 2,765 non-diabetic subjects of the population-based cohort METSIM. RESULTS: At baseline, mean HbA1c level was 5.6% (38 mmol/mol). After a mean follow-up of six years, mean HbA1c level was 5.7% (39 mmol/mol). Calibration graphs showed that predicted HbA1c levels were somewhat underestimated in the Inter99 cohort and overestimated in the Hoorn and KORA cohorts, indicating that the model's intercept should be adjusted for each cohort to improve predictions. Sensitivity and specificity (95% CI) were 55.7% (53.9, 57.5) and 56.9% (55.1, 58.7) respectively, for women, and 54.6% (52.7, 56.5) and 54.3% (52.4, 56.2) for men. External validation showed similar performance in the METSIM cohort. CONCLUSIONS/INTERPRETATION: In the non-diabetic population, our DIRECT-DETECT prediction model, including readily available predictors, has a relatively low explained variance and moderate discriminative performance, but can help to distinguish between future highest and lowest HbA1c levels. Absolute HbA1c values are cohort-dependent

    Фармаконагляд у процесі фармацевтичної розробки лікарських засобів для педіатрії

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    Вступ. Фармацевтична розробка та впровадження у виробництво оригінальних лікарських засобів (ЛЗ) є довготривалим та дороговартістним процесом, що потребує значних фінансових витрат та інтелектуальних внесків на кожному з етапів життєвого циклу лікарського препарату: синтез хімічних сполук, вибір оптимальної композиції екстрактів та інших активних фармацевтичних інгредієнтів (АФІ), вирощування та стандартизація лікарської рослинної сировини (ЛРС), мікробіологічне культивування продуктів біотехнології, а також подальші фармакологічні, фармако-технологічні, аналітичні та інші види досліджень. Метою дослідження було проаналізувати особливості фармаконагляду в ході фармацевтичної розробки лікарських засобів для педіатрії. Матеріали та методи. Під час проведення дослідження нами було застосовано загальнотеоретичні наукові методи, такі як бібліографічний метод, метод системного аналізу, інформаційного синтезу та узагальнення. Результати. Основою для управління ризиками, яка була скерована на забезпечення якості та безпеки ЛЗ, можуть слугувати дані, одержані при дослідженнях в ході фармацевтичної розробки. Варто зазначити, що норми якості, яким має відповідати лікарський препарат, не можуть бути перевірені в готовому ЛЗ; оскільки вони мають бути дотримані на етапі розробки. Варіації в складі та в ході виробничих процесів, які можуть виникати під час розробки і протягом життєвого циклу, мають розглядатися як можливості поглиблення знань для подальшого визначення простору проєктних параметрів. Крім того, може стати в нагоді залучення відповідних відомостей, одержаних в ході експериментів, результат яких був неочікуваним. Висновки. Процес фармаконагляду має здійснюватися протягом всього життєвого циклу лікарського засобу для педіатрії – від стадії in silico до кінця періоду маркетингу для виявлених побічних реакцій на різних стадіях доклінічних і клінічних досліджень, аналізу, профілактики і подальшого формування його профілю безпеки і ефективності.  Безпека та якість мають закладатися як підґрунтя  на первинному етапі фармацевтичної розробки як оригінальних, так і генеричних ліків
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