An immunohistochemical study of the pancreatic endocrine cells of the Korean golden frog, Rana plancyi chosenica

The regional distribution and quantitative frequency of pancreatic endocrine cells were demonstrated in the Korean golden frog (Rana plancyi chosenica Okada), which is known as a Korean endemic species, for the first time by immunohistochemical methods using specific mammalian antisera to insulin, glucagon, somatostatin and human pancreatic polypeptide (PP). In the pancreas of the Korean golden frog, all four endocrine cell types were demonstrated. Insulin- and glucagon-positive cells were located in the pancreas as single cells or islet-like clusters, respectively. Somatostatin-containing cells were also dispersed in the pancreas as single cells or clusters but in the case of clusters, they are exclusively situated in the marginal regions of insulin- or glucagon-positive cell clusters. PP-containing cells were also distributed as single cells or clusters. Clusters consisted of PP-positive cells are distributed as a core type and a marginally distributed type. Overall, there were 40.84±3.81% insulin-, 26.02±1.71% glucagon-, 7.63±2.09% somatostatin- and 25.51±3.26% PP-IR cells

A batch-service queueing model with a discrete batch Markovian arrival process

Queueing systems with batch service have been investigated extensively during the past decades. However, nearly all the studied models share the common feature that an uncorrelated arrival process is considered, which is unrealistic in several real-life situations. In this paper, we study a discrete-time queueing model, with a server that only initiates service when the amount of customers in system (system content) reaches or exceeds a threshold. Correlation is taken into account by assuming a discrete batch Markovian arrival process (D-BMAP), i.e. the distribution of the number of customer arrivals per slot depends on a background state which is determined by a first-order Markov chain. We deduce the probability generating function of the system content at random slot marks and we examine the influence of correlation in the arrival process on the behavior of the system. We show that correlation merely has a small impact on the threshold that minimizes the mean system content. In addition, we demonstrate that correlation might have a significant influence on the system content and therefore has to be included in the model

CP violation in 5D Split Fermions Scenario

We give a new configuration of split fermion positions in one extra dimension with two different Yukawa coupling strengths for up-type, $h_u$, and down-type, $h_d$, quarks at $\frac{h_u}{h_d}=36.0$. The new configurations can give enough CP violating (CPV) phase for accommodating all currently observed CPV processes. Therefore, a 5D standard model with split fermions is viable. In addition to the standard CKM phase, new CPV sources involving Kaluza-Klein(KK) gauge bosons coupling which arise from the fact that unitary rotation which transforms weak eigenstates into their mass eigenstates only holds for the zero modes which are the SM fields and not for the KK excitations. We have examined the physics of kaon, neutron, and $B/D$ mesons and found the most stringent bound on the size $R$ of the extra dimension comes from $|\epsilon_K|$. Moreover, it depends sensitively on the width, $\sigma$, of the Gaussian wavefunction in the extra dimension used to describe of the fermions. When $\sigma/R \ll 1$, the constraint will be lifted due to GIM suppression on the flavor changing neutral current(FCNC) and CPV couplings.Comment: 24 pages, 8 figure

Dynamical properties of the unitary Fermi gas: collective modes and shock waves

We discuss the unitary Fermi gas made of dilute and ultracold atoms with an infinite s-wave inter-atomic scattering length. First we introduce an efficient Thomas-Fermi-von Weizsacker density functional which describes accurately various static properties of the unitary Fermi gas trapped by an external potential. Then, the sound velocity and the collective frequencies of oscillations in a harmonic trap are derived from extended superfluid hydrodynamic equations which are the Euler-Lagrange equations of a Thomas-Fermi-von Weizsacker action functional. Finally, we show that this amazing Fermi gas supports supersonic and subsonic shock waves.Comment: 9 pages, 3 figures, invited talk at the International Workshop "Critical Stability 2011" (Erice, October 2011), to be published in the journal Few Body System

Prognostic significance of nm23-H1 expression in oral squamous cell carcinoma

Recent studies indicated nm23-H1 played a role in cancer progression. Therefore, we investigated clinical significance of nm23-H1 expression in oral squamous cell carcinoma (OSCC). In total, 86 OSCC specimens were immunohistochemically stained with nm23-H1-specific monoclonal antibodies. Immunohistochemical staining of nm23-H1 was confirmed by immunoblotting. The relations between nm23-H1 expression and clinicopathologic variables were evaluated by chi(2) analysis. As increased size of primary tumour could escalate metastatic potential and the data of patients at the late T stage might confound statistical analyses, we thus paid special attention to 54 patients at the early T stage of OSCC. Statistical difference of survival was compared by a log-rank test. Immunohistochemically, nm23-H1 expression was detected in 48.8% (42 out of 86) of tumorous specimens. It positively correlated with larger primary tumour size (P = 0.03) and inversely with cigarette-smoking habit (P = 0.042). In patients at the early T stage, decreased nm23 expression was associated with increased incidence of lymph node metastasis (P = 0.004) and indicated poor survival (P = 0.014). Tumour nm23-H1 expression is a prognostic factor for predicting better survival in OSCC patients at the early T stage, which may reflect antimetastatic potential of nm23. Therefore, modulation of nm23-H1 expression in cancer cells can provide a novel possibility of improving therapeutic strategy at this stage. In addition, our results further indicated cigarette smoking could aggravate the extent of nm23-H1 expression and possibly disease progression of OSCC patients. (C) 2004 Cancer Research UK

Fragmentation Function and Hadronic Production of the Heavy Supersymmetric Hadrons

The light top-squark \sto may be the lightest squark and its lifetime may be `long enough' in a kind of SUSY models which have not been ruled out yet experimentally, so colorless `supersymmetric hadrons (superhadrons)' (\sto \bar{q}) ($q$ is a quark except $t$-quark) may be formed as long as the light top-squark \sto can be produced. Fragmentation function of \sto to heavy `supersymmetric hadrons (superhadrons)' (\sto \bar{Q}) ($\bar{Q}=\bar{c}$ or $\bar{b}$) and the hadronic production of the superhadrons are investigated quantitatively. The fragmentation function is calculated precisely. Due to the difference in spin of the SUSY component, the asymptotic behavior of the fragmentation function is different from those of the existent ones. The fragmentation function is also applied to compute the production of heavy superhadrons at hadronic colliders Tevatron and LHC under the so-called fragmentation approach. The resultant cross-section for the heavy superhadrons is too small to observe at Tevatron, but great enough at LHC, even when all the relevant parameters in the SUSY models are taken within the favored region for the heavy superhadrons. The production of `light superhadrons' (\sto \bar{q}) ($q=u, d, s$) is also roughly estimated. It is pointed out that the production cross-sections of the light superhadrons (\sto \bar{q}) may be much greater than those of the heavy superhadrons, so that even at Tevatron the light superhadrons may be produced in great quantities.Comment: 20 pages, 9 figure

A simple and efficient numerical scheme to integrate non-local potentials

As nuclear wave functions have to obey the Pauli principle, potentials issued from reaction theory or Hartree-Fock formalism using finite-range interactions contain a non-local part. Written in coordinate space representation, the Schrodinger equation becomes integro-differential, which is difficult to solve, contrary to the case of local potentials, where it is an ordinary differential equation. A simple and powerful method has been proposed several years ago, with the trivially equivalent potential method, where non-local potential is replaced by an equivalent local potential, which is state-dependent and has to be determined iteratively. Its main disadvantage, however, is the appearance of divergences in potentials if the wave functions have nodes, which is generally the case. We will show that divergences can be removed by a slight modification of the trivially equivalent potential method, leading to a very simple, stable and precise numerical technique to deal with non-local potentials. Examples will be provided with the calculation of the Hartree-Fock potential and associated wave functions of 16O using the finite-range N3LO realistic interaction.Comment: 8 pages, 2 figures, submitted to Eur. Phys. J.

Brachial artery reconstruction for occlusive disease: A 12-year experience

AbstractObjective: Symptomatic arterial disease of the upper extremity is an uncommon problem. In this study, we evaluate our results with brachial artery reconstruction in patients who present with symptomatic atherosclerotic occlusive disease and compare this cohort's demographics with a similar group with lower extremity ischemia. Methods: From 1986 to 1998, all patients presenting for upper extremity revascularization with chronic ischemia were prospectively entered into a vascular registry. Demographics, indications, outcomes, and patency were recorded. Patients presenting with embolus, pseudoaneurysm, or trauma were excluded. The Fisher exact and Student t tests were used to assess significance. Results: Fifty-one (83%) bypass grafts were performed with autogenous conduit and the remainder with polytetrafluoroethylene. Indications included 18 (30%) patients with exertional arm pain, 35 (57%) with rest pain, and 8 (13%) with tissue loss. Twenty-five (45%) patients were male, 8 (14%) had diabetes, and 30 (54%) were smokers. The mean age was 58 years (range, 33-93). The operative mortality rate was 1.8%, and follow-up ranged from 1 to 140 months. Eight occlusions were identified, with six occurring early. Five of these were in women with a smoking history. Only one of the 26 reconstructions that did not cross a joint occluded, whereas bypass grafts that did cross a joint occluded more frequently. No other major complications were recognized. Conclusion: Arm revascularization for ischemia can be performed with reasonable mortality and morbidity rates. These patients may represent a different subgroup of atherosclerotic disease than those with lower extremity involvement: they are more commonly women and smokers and less likely to be diabetic. (J Vasc Surg 2001;33:802-5.

CPW fed compact UWB 4-element MIMO antenna with high isolation

In the paper, an extremely compact multiple-input-multiple-output (MIMO) antenna is proposed for portable wireless ultrawideband (UWB) applications. The proposed prototype consists of four monopole antenna elements, which are placed perpendicularly to achieve polarization diversity. In addition, the mutual coupling between antenna elements is suppressed by designing the gap between the radiation element and the ground plane. Moreover, a matching stub has been connected to the feedline to ensure impedance matching in high frequency. Both simulated and measured results indicate that the proposed antenna has a bandwidth of 3–20 GHz, with a high isolation better than 17 dB. In addition, the designed MIMO antenna offers excellent radiation characteristics and stable gain over the whole working band. The envelope correlation coefficient (ECC) is less than 0.1, which shows that the antenna can meet the polarization diversity characteristics well