Cytoplasmic RNA and nuclear changes detected cytochemically during the degeneration of salivary glands of the tick Rhipicephalus sanguineus (Latreille, 1806) (Acari, Ixodidae)

The present study reports cytochemistry data about salivary glands of females (unfed, engorged, and at day three post-engorgement) and males (unfed, at day seven post-attachment, and at days three and seven post-detachment from the host) of the tick Rhipicephalus sanguineus. The results revealed nuclear changes in engorged females and at day three post-engorgement, and in males in all stages (except unfed). These changes were more prominent in females. Cytoplasmic changes were also observed in cells of all acini of males and females. In types II and III acini of engorged females, nuclear changes were observed in the shape (irregular, with blebs, fragmenting or fragmented), size (enlarged or reduced), and arrangement and condensation level of chromatin (marginal or as blebs). Changes were also detected in nucleoli, regarding their shape (fragmenting or fragmented), size (enlarged), and location (central, marginal or as blebs). Some nucleoli were also compacted or disorganized. In females at day three pos-engorgement, all acini exhibited similar changes to those observed in engorged females. RNA staining was stronger in cells of engorged females than those at day three post-engorgement. In males at day seven post-attachment, cells of types II, III, IV acini presented changes in the size of the nucleus and condensation level of chromatin similar to those of females. The shape of the nucleus was round, irregular or undergoing fragmentation, and the chromatin was located at the margin or throughout the nucleus. The changes in the nucleolus were similar to those of females, regarding size and organization, although round-shaped and in the central location. In males at day three post-detachment, cells of all acini exhibited nuclear changes similar to those of males at day seven post-attachment, in addition to the fragmentation of the nucleolus. At day seven post-detachment, changes were detected in all acini similar to the observed in males at day seven post-attachment. Regarding cytoplasmic RNA, staining was prominent in males at day seven post-attachment and weak in those at day seven post-detachment from the host. In females as well as males, different RNA staining patterns in the cytoplasm and nuclear changes characterized apoptotic cell death.     

Variety of available coordination sites for extra-framework iron in LTA and MFI zeolites

Variations in coordination states of extra-framework iron are studied in low iron content ferrisilicates (Si/⁵⁷Fe ≈ 200) during various in situ treatments. In Fe-LTA complete Fe³⁺ ? Fe^2?+? reversibility is observed. In Fe-MFI extra-framework iron can be stabilized in Fe^2?+? state in spite of ambient oxidizing conditions (N₂O, 620 K). Further, in Fe-MFI simultaneous stabilization of Fe^2?+? and Fe^3?+? may take place providing centres for redox catalytic processes.     

Using permutations to detect dependence between time series

In this paper, we propose an independence test between two time series which is based on permutations. The proposed test can be carried out by means of different common statistics such as Pearson’s chi-square or the likelihood ratio. We also point out why an exact test is necessary. Simulated and real data (return exchange rates between several currencies) reveal the capacity of this test to detect linear and nonlinear dependences.     

Cylindrical magnetization model for glass-coated microwires with circular anisotropy: Statics

The static magnetization profile of glass-coated microwires with effective circular anisotropy is investigated using micromagnetics. In this family of microwires, the ferromagnetic nucleus with an amorphous character presents a magnetic structure composed of an inner region with axial domains and an outer region with circular domains, due to magnetoelastic anisotropy. A one-dimensional micromagnetic model is developed, taking into account both the exchange and magnetoelastic anisotropy energies, and solved quasi analytically. The total energy, magnetization profiles and magnetization curves are investigated as a function of radius and anisotropy constant of the nucleus. This work represents a fundamental study of the magnetization process in these amorphous microwires and provides guidelines for the production of microwires with tailored magnetic properties. En passant, the nucleation problem in an infinite cylinder, introduced by W.F. Brown, is revisited.     

On some consequences of an external magnetic field applied to HTS coils

A computational model which enables to evaluate the distribution of the critical currents, electric fields and the voltage in the winding of a solenoidal high temperature superconducting (HTS) magnets subjected to an external magnetic field parallel with the magnet axis, was developed. The model comes out from the well-known power law between the electric field and the transport current of the HTS tape short sample. It allows to predict the voltage–current V(I) characteristics of both the pancake coils and the complete magnet. The model was applied to the magnet system consisting of 22 pancake coils made of multifilamentary Bi(2223)/Ag tape at 20 K, which is subjected to an external uniform magnetic field parallel with the coil axis. A rather unexpected behavior of the magnet at different operating conditions (operating current and external magnetic field strength) is predicted, analyzed and reported together with a theoretical explanation. On one hand, the external uniform magnetic field parallel with the coil axis increases the resulting magnetic field strength, however, on the other hand it simultaneously decreases the angle between the resulting magnetic field and the tape surface. Thus, the effect of higher magnetic loading caused by the presence of an external magnetic field strength which is acting on individual turns located close to the coil’s flanges is compensated by more favorable orientation of the tape with respect to the resulting magnetic field. As a result, increase in the critical currents of these turns is expected. Further, the results indicate, that in case of the high field HTS insert coils the anisotropy in the I_c(B) characteristic does not play a substantial role. As a consequence, the technology of the production of the tapes for high field insert HTS coils should concentrate rather on the tapes having the current carrying capacity as high as possible, than on the attempt how to decrease the anisotropy in the I_c(B) by changing the architecture of the filaments in the tape.     

Search for a very light CP-odd Higgs boson in top quark decays from pp collisions at sqrt(s)]=1.96 TeV

We present the results of a search for a very light CP-odd Higgs boson a(1)(0) originating from top quark decays t → H(±)b → W(±(*)) a(1)(0)b, and subsequently decaying into τ+ τ-. Using a data sample corresponding to an integrated luminosity of 2.7 fb(-1) collected by the CDF II detector in pp collisions at 1.96 TeV, we perform a search for events containing a lepton, three or more jets, and an additional isolated track with transverse momentum in the range 3 to 20 GeV/c. Observed events are consistent with background sources, and 95% C.L. limits are set on the branching ratio of t → H(±)b for various masses of H(±) and a(1)(0).     

Towards a superstatistical SU(2) Yang-Mills EoS

We study an SU(2) lattice gauge field system on a 10⁴ symmetric and on a 10³ × 2 asymmetric lattice in order to learn about the equation of state.     

Intracavity system design for IR multiphoton dissociation

An intracavity system for the infrared multiple photon dissociation (IRMPD) of molecules with high dissociation energy threshold has been designed and implemented. The system design based on a TEA CO₂ laser with a cavity folded in V-shape included the analysis of its stability varying the cavity dimensions as well as the analysis of the positions of the beam waists and of the beam size at them. The intracavity energy as a function of the total sample pressure has been measured and the laser-operation threshold has been determined. Intracavity IRMPD has been compared to traditional IRMPD performed in an irradiation geometry in which the radiation is focused into a photoreactor placed outside the laser cavity. Dissociation volumes in intracavity irradiation have resulted an order of magnitude larger than those obtained in experiments performed with the photoreactor outside the laser cavity.     

Asymptotics of Self-similar Solutions to Coagulation Equations with Product Kernel

We consider mass-conserving self-similar solutions for Smoluchowski’s coagulation equation with kernel K(ξ,η)=(ξη) ^λ with λ∈(0,1/2). It is known that such self-similar solutions g(x) satisfy that x ^?1+2λ g(x) is bounded above and below as x→0. In this paper we describe in detail via formal asymptotics the qualitative behavior of a suitably rescaled function h(x)=h _λ x ^?1+2λ g(x) in the limit λ→0. It turns out that \(h \sim 1+ C x^{\lambda/2} \cos(\sqrt{\lambda} \log x)\) as x→0. As x becomes larger h develops peaks of height 1/λ that are separated by large regions where h is small. Finally, h converges to zero exponentially fast as x→∞. Our analysis is based on different approximations of a nonlocal operator, that reduces the original equation in certain regimes to a system of ODE.