The Spo13/Meikin pathway confines the onset of gamete differentiation to meiosis II in yeast

Sexual reproduction requires genome haploidization by the two divisions of meiosis and a differentiation program to generate gametes. Here, we have investigated how sporulation, the yeast equivalent of gamete differentiation, is coordinated with progression through meiosis. Spore differentiation is initiated at metaphase II when a membrane-nucleating structure, called the meiotic plaque, is assembled at the centrosome. While all components of this structure accumulate already at entry into meiosis I, they cannot assemble because centrosomes are occupied by Spc72, the receptor of the gamma-tubulin complex. Spc72 is removed from centrosomes by a pathway that depends on the polo-like kinase Cdc5 and the meiosis-specific kinase Ime2, which is unleashed by the degradation of Spo13/Meikin upon activation of the anaphase-promoting complex at anaphase I. Meiotic plaques are finally assembled upon reactivation of Cdk1 at entry into metaphase II. This unblocking-activation mechanism ensures that only single-copy genomes are packaged into spores and might serve as a paradigm for the regulation of other meiosis II-specific processes

Gauge Equivalence in Two--Dimensional Gravity

Two-dimensional quantum gravity is identified as a second-class system which we convert into a first-class system via the Batalin-Fradkin (BF) procedure. Using the extended phase space method, we then formulate the theory in most general class of gauges. The conformal gauge action suggested by David, Distler and Kawai is derived from a first principle. We find a local, light-cone gauge action whose Becchi-Rouet-Stora-Tyutin invariance implies Polyakov's curvature equation $\partial_{-}R=\partial_{-}^{3}g_{++}=0$, revealing the origin of the $SL(2,R)$ Kac-Moody symmetry. The BF degree of freedom turns out be dynamically active as the Liouville mode in the conformal gauge, while in the light-cone gauge the conformal degree of freedom plays that r{\^o}le. The inclusion of the cosmological constant term in both gauges and the harmonic gauge-fixing are also considered.Comment: 30 pages, KANAZAWA 93-

On Type II Strings in Two Dimensions

We consider type IIA/B strings in two-dimensions and their projection with respect to the nilpotent space-time supercharge. Based on the ground ring structure, we propose a duality between perturbed type II strings and the topological B-model on deformed Calabi-Yau singularities. Depending on the type II spectra, one has either the conifold or the suspended pinch point geometry. Using the corresponding quiver gauge theory, obtained by D-branes wrapping in the resolved suspended pinch point geometry, we propose the all orders perturbative partition function.Comment: 1+23 page

A tüdőrák molekuláris diagnosztikája

Development of the target therapies of lung cancer was a rapid process which fundamentally changed the pathological diagnosis as well. Furthermore, molecular pathology became essential part of the routine diagnostics of lung cancer. These changes generated several practical problems and in underdeveloped countries or in those with reimbursement problems have been combined with further challenges. The central and eastern region of Europe are characterized by similar problems in this respect which promoted the foundation of NSCLC Working Group to provide up to date protocols or guidelines. This present paper is a summary of the molecular pathology and target therapy guidelines written with the notion that it has to be upgraded continuously according to the development of the field

Beta Functions of Orbifold Theories and the Hierarchy Problem

We examine a class of gauge theories obtained by projecting out certain fields from an N=4 supersymmetric SU(N) gauge theory. These theories are non-supersymmetric and in the large N limit are known to be conformal. Recently it was proposed that the hierarchy problem could be solved by embedding the standard model in a theory of this kind with finite N. In order to check this claim one must find the conformal points of the theory. To do this we calculate the one-loop beta functions for the Yukawa and quartic scalar couplings. We find that with the beta functions set to zero the one-loop quadratic divergences are not canceled at sub-leading order in N; thus the hierarchy between the weak scale and the Planck scale is not stabilized unless N is of the order 10^28 or larger. We also find that at sub-leading orders in N renormalization induces new interactions, which were not present in the original Lagrangian.Comment: 21 pages, LaTeX, 6 figures. Minor clarifications, references adde

Multidisciplinary consensus statement on the clinical management of patients with pancreatic cancer

Pancreatic cancer (PC) remains one of the most aggressive tumors with an increasing incidence rate and reduced survival. Although surgical resection is the only potentially curative treatment for PC, only 15-20% of patients are resectable at diagnosis. To select the most appropriate treatment and thus improve outcomes, the diagnostic and therapeutic strategy for each patient with PC should be discussed within a multidisciplinary expert team. Clinical decision-making should be evidence-based, considering the staging of the tumor, the performance status and preferences of the patient. The aim of this guideline is to provide practical and evidence-based recommendations for the management of PC

Effects of Endogenous Cannabinoid Anandamide on Voltage-Dependent Sodium and Calcium Channels in Rat Ventricular Myocytes

BACKGROUND AND PURPOSE: The endocannabinoid anandamide (N-arachidonoyl ethanolamide; AEA) exerts negative inotropic and antiarrhythmic effects in ventricular myocytes. EXPERIMENTAL APPROACH: Whole-cell patch-clamp technique and radioligand-binding methods were used to analyse the effects of anandamide in rat ventricular myocytes. KEY RESULTS: In the presence of 1-10 μM AEA, suppression of both Na(+) and L-type Ca(2+) channels was observed. Inhibition of Na(+) channels was voltage and Pertussis toxin (PTX) - independent. Radioligand-binding studies indicated that specific binding of [(3) H] batrachotoxin (BTX) to ventricular muscle membranes was also inhibited significantly by 10 μM metAEA, a non-metabolized AEA analogue, with a marked decrease in Bmax values but no change in Kd . Further studies on L-type Ca(2+) channels indicated that AEA potently inhibited these channels (IC50 0.1 μM) in a voltage- and PTX-independent manner. AEA inhibited maximal amplitudes without affecting the kinetics of Ba(2+) currents. MetAEA also inhibited Na(+) and L-type Ca(2+) currents. Radioligand studies indicated that specific binding of [(3) H]isradipine, was inhibited significantly by metAEA. (10 μM), changing Bmax but not Kd . CONCLUSION AND IMPLICATIONS: Results indicate that AEA inhibited the function of voltage-dependent Na(+) and L-type Ca(2+) channels in rat ventricular myocytes, independent of CB1 and CB2 receptor activation

Semiclassical String Solutions on deformed NS5-brane Backgrounds and New Plane wave

We study different Penrose limits of supergravity solution of NS5-brane in the presence of RR field. Although in the case of NS5-brane we get a 4-dimensional plane wave, in the case with RR field we will get two different plane waves; a 4-dimensional and a 3-dimensional one. These plane wave solutions are the backgrounds that a particular string solution feels at one loop approximation. Using the one loop correction one can identify a particular subsector of LST/deformed LST which is dual to type II string theories on these plane waves.Comment: 18 pages, latex, v2: Minor changes, typos correcte

Ct angiography evaluation of the renal vascular pathologies: a pictorial review

The emergence of CT angiography (CTA) has a groundbreaking impact on the evaluation of renal vessels and is gradually replacing the conventional catheter angiography as the standard imaging procedure. In this review, we aimed to describe the renal CTA technique and imaging findings of several renal arterial (i.e. atherosclerosis, fibromuscular dysplasia, aneurysms of the renal arteries, dissection, vasculitidis, follow-up of patients with renal arterial stent) and venous (i.e. nut-cracker syndrome, pelvic congestion syndrome) pathologies