A blowup criterion for the 3D generalized MHD system with zero magnetic diffusivity

This paper proves a new regularity criterion ω: = rotu∈L1(0,T;B·0∞,∞) for the 3D generalized MHD system with fractional diffusion terms(-Δ)αu with α >9/8 and zero magnetic diffusivity. Here u is the fluid velocity,ω is the vorticity and B·0∞,∞is the homogeneous Besov space.

Sexual Dimorphism in Pelvic Bone Shape of the North Pacific Common Minke Whales (Balaenoptera acutorostrata)

Little is known about the morphology of the pelvic girdle of modern cetaceans, although many species have a vestigial pelvis (pelvic bone) and part of the hind limb bones inside the body. Previous studies have focused almost exclusively on hard tissues as well, despite the fact that the bones are comprised of cartilaginous tissue, especially in the case of femur. In the present study, we characterized the pelvic bones and searched for vestigial femurs among 43 North Pacific common minke whales (Balaenoptera acutorostrata), all of which were sexually mature individuals. The shape of the pelvic bones clearly differs depending on sex. Specifically, the pelvic bones of females were flat, but those of adult males consist of two types: one with a twisted caudal portion (Twisted type) and the other with a thickened caudal portion (Hypertrophied type). Those pelvic bone features in male are found only among North Pacific common minke whales. 98% of the individuals in this study had vestigial femur. The presence rate of vestigial femur may differ by subspecies. The shape of the pelvic and hind limb bones of modern cetaceans may vary between species and probably by region, at least at the Ocean basin scale.

White Patch on the Fore-Flipper of Common Minke Whale, as a Potential Morphological Index to Identify Stocks

Past studies have indicated that there are two different stocks (J and O stocks) in the North Pacific common minke whale Balaenoptera acutorostrata population. These two stocks differ from each other in certain characteristics, such as body size, conception dates, and genetics. However, till date, few studies have investigated differences in the external body appearance between the two stocks. Therefore, in the present study, we focused on the unique white patch on the flipper of this whale species to elucidate inter-stock differences. We used the animals collected from JARPNII research during 2012 and 2013;stock information was determined by microsatellite DNA analysis (n = 220). We focused on the morphological differences in the size and pattern of the white patch on the flipper of each whale. The length of the white patch along the anterior (ventral) margin of the flipper tends to be proportionally larger in O stock. The pattern of the boundary area of the white patch named as the “Grayish Accessary Layer (GAL)” was remarkably different between stocks. Within animals with “no GAL” type, 94% were J stock. Conversely, of animals with GAL expanding over the half the flipper width, 96% were O stock. We concluded from our study that there were clear morphological differences in the flipper color pattern between J and O stocks, which enable to apply widely to other individuals.

THE LOCAL WELL-POSEDNESS OF A CHEMOTAXIS-SHALLOW WATER SYSTEM WITH VACUUM

In this paper we prove the local well-posedness of strong solutions to a chemotaxisshallow water system with initial vacuum in a bounded domainΩ■R^(2)without the standard compatibility condition for the initial data.This improves some results obtained in[J.Differential Equations 261(2016),6758-6789].

Growth and Reproductive Activity of a Captive Female Harbour Porpoise (Phocoena phocoena) from Japanese Water

This report describes growth and annual reproductive cycle of female harbour porpoise (Phocoena phocoena) rescued from Japanese water in 2007. The maximum body length was 179 cm and body weight was 69.8 kg. The average daily food consumption was 7.0 kg (ranging 3.7 - 9.9 kg), 11.8% of the body weight. In this report, the porpoise was kept in 17 °C water annually and the blubber thicknesses showed almost constant throughout the year (average 18 mm, range 13 - 22 mm). Therefore, we added new evidence to this hypothesis by showing that body weight and the blubber thickness do not fluctuate seasonally in fixed water temperature. Serum progesterone level of the female showed five peaks from September to November, and each cycle lasted the average of 20.5 days. Such result indicates that harbour porpoise exhibits seasonal polyestrous activity.

Developmental Changes in the Morphology of Western North Pacific Bryde’s Whales (<i>Balaenoptera edeni</i>)

Developmental changes in the body proportions of western North Pacific Bryde’s whales (Balaenoptera edeni) were investigated by examining the proportion of each body part to the total body length. The head and chest region increased to a certain body length;subsequently, the length of head region stabilized, and that of the chest region decreased. The length of the abdominal region remained constant to a certain body length and subsequently showed a marked increase, and that of the tail region decreased consistently. The length of dorsal fin and flukes decreased consistently, whereas that of the flippers remained constant to a certain body length and subsequently decreased. The relative growth pattern determined by an allometric analysis was positive for the head region but negative for the lower body part, flippers, flukes, and dorsal fin. Both sexes demonstrated the same growth pattern, but the coefficients differed. This is the first study to investigate developmental changes in the body proportions of Bryde’s whales using more than 700 specimens covering a wide body length range. We believe that the results of this study will contribute to various research fields, including taxonomy, phylogeny, and feeding ecology of this species.

Matching of the Gray Whales of off Sakhalin and the Pacific Coast of Japan, with a Note on the Stranding at Wadaura, Japan in March, 2016

The coast of Japan is a migratory corridor for the western stock of the gray whales (Eschrichtius robustus), which was once considered as extinct and remains endangered. According to the historical records, from 1955 to 2014, only 21 gray whales occurrence has been recorded in 59 years. However, from 2015 to 2016, intensive occurrence including the seven sightings and the two strandings were noted. In this paper, we found that those sightings were re-sightings of the same individual, which was initially sighted off Sakhalin during August, 2014. On 4 March, 2016, a young female gray whale (8.9 m in body length) was stranded at Wadaura beach, Chiba prefecture. We also conducted research on this animal including taking pictures and external measurements. In addition, we flensed this animal to observe the internal organs and collect a skeletal specimen. The reason for the death of this animal remains unclear;however, from its external characteristics, we identified that this animal was not an identical one, sighted off Sakhalin and the coast of Japan from 2014 to 2016. On 5 April, 2016, another young female gray whale (7 m in body length) was stranded at Arai beach, Shizuoka prefecture. We concluded that from 2015 to 2016, at least three distinct gray whales have migrated along the coast of Japan.

Window Effect in the Power Spectrum Analysis of a Galaxy Redshift Survey

We investigate the effect of the window function on the multipole power spectrum in two different ways. First, we consider the convolved power spectrum including the window effect, which is obtained by following the familiar (FKP) method developed by Feldman, Kaiser and Peacock. We show how the convolved multipole power spectrum is related to the original power spectrum, using the multipole moments of the window function. Second, we investigate the deconvolved power spectrum, which is obtained by using the Fourier deconvolution theorem. In the second approach, we measure the multipole power spectrum deconvolved from the window effect. We demonstrate how to deal with the window effect in these two approaches, applying them to the Sloan Digital Sky Survey (SDSS) luminous red galaxy (LRG) sample.

NUMERICAL IMPLEMENTATION FOR A 2-D THERMAL INHOMOGENEITY THROUGH THE DYNAMICAL PROBE METHOD

In this paper, we present the theory and numerical implementation for a 2-D thermal inhomogeneity through the dynamical probe method. The main idea of the dynamical probe method is to construct an indicator function associated with some probe such that when the probe touch the boundary of the inclusion the indicator function will blow up. From this property, we can get the shape of the inclusion. We will give the numerical reconstruction algorithm to identify the inclusion from the simulated Neumann-to-Dirichlet map.

A NEW APPROACH AND ERROR ANALYSIS FOR RECONSTRUCTING THE SCATTERED WAVE BY THE POINT SOURCE METHOD

Consider an inverse scattering problem by an obstacle D belong to R^2 with impedance boundary. We investigate the reconstruction of the scattered field u^s from its far field pattern u^∞ using the point source method. First, by applying the boundary integral equation method, we provide a new approach to the point-source method of Potthast by classical potential theory. This extends the range of the point source method from plane waves to scattering of arbitrary waves. Second, by analyzing the behavior of the Hankel function, we obtain an improved strategy for the choice of the regularizing parameter from which an improved convergence rate （compared to the result of [15]） is achieved for the reconstruc- tion of the scattered wave. Third, numerical implementations are given to test the validity and stability of the inversion method for the impedance obstacle.

On fluorescence imaging:The diffusion equation model and recovery of the absorption coefficient of fluorophores

To quantify fluorescence imaging of biological tissues,we need to solve an inverse problem for the coupled radiative transfer equations which describe the excitation and emission fields in biological tissues.We begin by giving a concise mathematical argument to derive coupled diffusion equations with the Robin boundary condition as an approximation of the radiative transfer system.Then by using this coupled system of equations as a model for the fluorescence imaging,we have a nonlinear inverse problem to identify the absorption coefficient in this system.The associated linearized inverse problem is to ignore the absorbing effect on the excitation field.We firstly establish the estimates of errors on the excitation field and the solution to the inverse problem,which ensures the reasonability of the model approximation quantitatively.Some numerical verification is presented to show the validity of such a linearizing process quantitatively.Then,based on the analytic expressions of excitation and emission fields,the identifiability of the absorption coefficient from the linearized inverse problem is rigorously analyzed for the absorption coefficient in the special form,revealing the physical difficulty of the3-dimensional imaging model by the back scattering diffusive system.

Local Well-Posedness for the Compressible Nematic Liquid Crystals Flow with Vacuum

In this paper we prove the local well-posedness of strong solutions to the compressible nematic liquid crystals flow with vacuum in a bounded domainΩ■R3.

Uniform Regularity for the Isentropic Compressible Magnetohydrodynamic System

In this paper we first establish the uniform regularity of smooth solutions with respect to the viscosity coefficients to the isentropic compressible magnetohydrodynamic system in a periodic domain T;.We then apply our result to obtain the isentropic compressible magnetohydrodynamic system with zero viscosity.

Two regularity criteria for 3D Navier-Stokes equations in a bounded domain

We prove two new regularity criteria for the 3D incompressible Navier-Stokes equations in a bounded domain. Our results also hold for the 3D Boussinesq system with zero heat conductivity.