1,312 research outputs found

    Prevalence of Exocrine Pancreatic Insufficiency in Women with Obesity Syndrome: Assessment by Pancreatic Fecal Elastase 1

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    Background. Previous research on the combined association of 25-hydroxyvitamin D [25(OH)D] and exocrine pancreas insufficiency may have been limited by restricted age variability and a lack of representation of both body weight and body mass index. There are still too few conclusive reports about conspicuous vitamin D metabolism according to pancreatic fecal elastase 1 (FE1) in obese patients. Methods. Between May 2004 and July 2008, we investigated in 125 female patients with obesity syndrome at an average age of approximately 52.9 years as well as in age-matched 80 healthy female controls the prevalence of pancreas insufficiency. Serum levels of PTH, total calcium, and D3 vitamins calcitriol and calcifediol, as well as the concentration of fecal elastase 1 (FE1) were determined in patients and controls. Results. In 75 female nondiabetic patients with obesity syndrome (BMI 35 ≤ 40 kg/m2), calcifediol was markedly decreased (25.0 ± 4.9 ng/mL) compared to controls (50.2 ± 14.7 nmol/L; P < 0.01). FE1 level was significantly decreased in obese subjects compared to controls ( P < 0.01). Calcifediol was significantly lower in patients with morbid obesity (for calcifediol,  P < 0.05). Conclusion. In obese females, pancreatic FE1 in feces confirms the extent of vitamin D supply, and thus shows a vitamin D3 deficiency, depending on the loss of stool content. There seems to be a connection between the loss of exocrine function and the increasing body mass index. Pancreas insufficiency, as detected by low FE1 concentrations, is frequent in obese patients. However, the BMI is an additional factor for lowered fecal excretion of FE1

    Traveling Poles Elimination Scheme And Calculations Of External Quality Factors Of HOMS In SC Cavities

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    The main scope of this work is the automation of the extraction procedure of the external quality factors Qext of Higher Order Modes HOMs in Superconducting SC radio frequency RF cavities. The HOMs are generated by charged particle beams traveling through a SC cavity at the speed of light amp; 8776; 1 . The HOMs decay very slowly, depending on localization inside the structure and cell to cell coupling, and may influence succeeding charged particle bunches. Thus it is important, at the SC cavity design optimization stage, to calculate the Qext of HOMs. Traveling Poles Elimination TPE scheme was used to automatically extract Qext from the transmission spectra and careful eigenmode analysis of the SC cavity was performed to confirm TPE results. The eigenmode analysis also delivers important information about band structure, cell to cell coupling and allows rapid identification of modes that could interact with the charged particle bunches

    Supersymmetric version of a hydrodynamic system in Riemann invariants and its solutions

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    In this paper, a supersymmetric extension of a system of hydrodynamic type equations involving Riemann invariants is formulated in terms of a superspace and superfield formalism. The symmetry properties of both the classical and supersymmetric versions of this hydrodynamical model are analyzed through the use of group-theoretical methods applied to partial differential equations involving both bosonic and fermionic variables. More specifically, we compute the Lie superalgebras of both models and perform classifications of their respective subalgebras. A systematic use of the subalgebra structures allow us to construct several classes of invariant solutions, including travelling waves, centered waves and solutions involving monomials, exponentials and radicals.Comment: 30 page

    Final design for the bERLinPro main LINAC cavity

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    The Berlin Energy Recovery Linac Project bERLinPro is designed to develop and demonstrateCWLINAC technology for 100 mA class ERLs. High current operation requires an effective damping of higher order modes HOMs of the 1.3 GHz main linac cavities. We have studied elliptical 7 cell cavities based on a modified Cornell ERL design combined with JLab s waveguide HOM damping approach. This paper will summarize the final optimization of the end cell tuning for minimum external Q of the HOMs, coupler kick calculations of the single TTF fundamental power coupler FPC as well as multipole expansion analysis of the given modes and a discussion on operational aspects

    Results and Performance Simulations of the Main Linac Design for BERLinPro

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    The Berlin Energy Recovery Linac Project BERLinPro is designed to develop and demonstrate CW LINAC technology for 100 mA class ERLs. High current operation requires an effective damping of higher ordermodes HOMs of the 1.3 GHz main linac cavities. We have studied elliptical seven cell cavities damped by five waveguides at the adjacent beam tubes. Eigenmode calculations for geometrical figures of merit show that the present design should allow successful cw linac operation at the maximum beam current of 100 mA 77pC bunch charge. In this paper the progress in HOM calculations to avoid beam breakup instabilities for the favored cavity structure is presente

    Planktonic Aggregates as Hotspots for Heterotrophic Diazotrophy: The Plot Thickens

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    Biological dinitrogen (N-2) fixation is performed solely by specialized bacteria and archaea termed diazotrophs, introducing new reactive nitrogen into aquatic environments. Conventionally, phototrophic cyanobacteria are considered the major diazotrophs in aquatic environments. However, accumulating evidence indicates that diverse non-cyanobacterial diazotrophs (NCDs) inhabit a wide range of aquatic ecosystems, including temperate and polar latitudes, coastal environments and the deep ocean. NCDs are thus suspected to impact global nitrogen cycling decisively, yet their ecological and quantitative importance remain unknown. Here we review recent molecular and biogeochemical evidence demonstrating that pelagic NCDs inhabit and thrive especially on aggregates in diverse aquatic ecosystems. Aggregates are characterized by reduced-oxygen microzones, high C:N ratio (above Redfield) and high availability of labile carbon as compared to the ambient water. We argue that planktonic aggregates are important loci for energetically-expensive N-2 fixation by NCDs and propose a conceptual framework for aggregate-associated N-2 fixation. Future studies on aggregate-associated diazotrophy, using novel methodological approaches, are encouraged to address the ecological relevance of NCDs for nitrogen cycling in aquatic environments

    A fully relativistic radial fall

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    Radial fall has historically played a momentous role. It is one of the most classical problems, the solutions of which represent the level of understanding of gravitation in a given epoch. A {\it gedankenexperiment} in a modern frame is given by a small body, like a compact star or a solar mass black hole, captured by a supermassive black hole. The mass of the small body itself and the emission of gravitational radiation cause the departure from the geodesic path due to the back-action, that is the self-force. For radial fall, as any other non-adiabatic motion, the instantaneous identity of the radiated energy and the loss of orbital energy cannot be imposed and provide the perturbed trajectory. In the first part of this letter, we present the effects due to the self-force computed on the geodesic trajectory in the background field. Compared to the latter trajectory, in the Regge-Wheeler, harmonic and all others smoothly related gauges, a far observer concludes that the self-force pushes inward (not outward) the falling body, with a strength proportional to the mass of the small body for a given large mass; further, the same observer notes an higher value of the maximal coordinate velocity, this value being reached earlier on during infall. In the second part of this letter, we implement a self-consistent approach for which the trajectory is iteratively corrected by the self-force, this time computed on osculating geodesics. Finally, we compare the motion driven by the self-force without and with self-consistent orbital evolution. Subtle differences are noticeable, even if self-force effects have hardly the time to accumulate in such a short orbit.Comment: To appear in Int. J. Geom. Meth. Mod. Phy
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