Superfluid Fermi atomic gas as a quantum simulator for the study of neutron-star equation of state

We theoretically propose an idea to use an ultracold Fermi gas as a quantum simulator for the study of the neutron-star equation of state (EoS) in the low-density region. Our idea is different from the standard quantum simulator that heads for {\it perfect} replication of another system, such as a Hubbard model discussed in high-$T_{\rm c}$ cuprates. Instead, we use the {\it similarity} between two systems, and theoretically make up for the difference between them. That is, (1) we first show that the strong-coupling theory developed by Nozi\`eres-Schmitt Rink (NSR) can quantitatively explain the recent EoS experiment on a $^6$Li superfluid Fermi gas in the BCS (Bardeen-Cooper-Schrieffer)-unitary limit far below the superfluid phase transition temperature $T_{\rm c}$. This region is considered to be very similar to the low density region (crust regime) of a neutron star (where a nearly unitary $s$-wave neutron superfluid is expected). (2) We then theoretically compensate the difference that, while the effective range $r_{\rm eff}$ is negligibly small in a superfluid $^6$Li Fermi gas, it cannot be ignored ($r_{\rm eff}=2.7$ fm) in a neutron star, by extending the NSR theory to include effects of $r_{\rm eff}$. The calculated EoS when $r_{\rm eff}=2.7$ fm is shown to agree well with the previous neutron-star EoS in the low density region predicted in nuclear physics. Our idea indicates that an ultracold atomic gas may more flexibly be used as a quantum simulator for the study of other complicated quantum many-body systems, when we use, not only the experimental high tunability, but also the recent theoretical development in this field. Since it is difficult to directly observe a neutron-star interior, our idea would provide a useful approach to the exploration for this mysterious astronomical object.Comment: 29 pages, 7 figure

Discovery of Enhanced Radiative Recombination Continua of He-like Iron and Calcium from IC 443 and Its Implications

We present deep observations of the Galactic supernova remnant IC 443 with the {\it Suzaku X-ray satellite}. We find prominent K-shell lines from iron and nickel, together with a triangle residual at 8--10~keV, which corresponds to the energy of the radiative recombination continuum (RRC) of He-like iron. In addition, the wavy residuals have been seen at $\sim$5.1 and $\sim$5.5~keV. We confirm that the residuals show the first enhanced RRCs of He- and H-like calcium found in supernova remnants. These facts provide robust evidence for the recombining plasma. We reproduce the plasma in the 3.7--10~keV band using a recombining plasma model at the electron temperature 0.65~keV. The recombination parameter $n_{\rm e}t$ ($n_{\rm e}$ is electron density and $t$ is elapsed time after formation of a recombining plasma) and abundances of iron and nickel are strongly correlated, and hence the errors are large. On the other hand, the ratio of nickel to iron relative to the solar abundances is well constrained to 11$^{+4}_{-3}$ (1$\sigma$). A possibility is that the large abundance ratio is a result of an asymmetric explosion of the progenitor star.Comment: 4 pages, 5 figures, published in Ap

SUCCESSFUL PAIN RELIEF BY MOTOR CORTEX STIMULATION FOR EXTENSIVE THALAMIC PAIN : CASE REPORT

Thalamic pain is known as the most difficult pain syndrome to treat. This paper describes our case treated successfully by motor cortex stimulation for extensive thalamic pain. A 59-year-old man with left thalamic pain was readmitted two years after an episode of right thalamic hemorrhage. He complained of tearing pain in the left eye, burning pain in the left upper and lower extremities, and chest pain. After one week of test stimulation, permanent implantation using two electrode arrays to include the area of the lower extremity was done. Excellent pain relief has been sustained for 10 months

Recombining Plasma and Hard X-ray Filament in the Mixed-Morphology Supernova Remnant W44

We report new features of the typical mixed-morphology (MM) supernova remnant (SNR) W44. In the X-ray spectra obtained with Suzaku, radiative recombination continua (RRCs) of highly ionized atoms are detected for the first time. The spectra are well reproduced by a thermal plasma in a recombining phase. The best-fit parameters suggest that the electron temperature of the shock-heated matters cooled down rapidly from $\sim1$,keV to $\sim 0.5$,keV, possibly due to adiabatic expansion (rarefaction) occurred $\sim20,000$ years ago. We also discover hard X-ray emission which shows an arc-like structure spatially-correlated with a radio continuum filament. The surface brightness distribution shows a clear anti-correlation with $^{12}$CO (J=2-1) emission from a molecular cloud observed with NANTEN2. While the hard X-ray is most likely due to a synchrotron enhancement in the vicinity of the cloud, no current model can quantitatively predict the observed flux.Comment: 10 pages, 5 figures, accepted for publication in PAS

Exome sequencing reveals a novel TTC19 mutation in an autosomal recessive spinocerebellar ataxia patient

BACKGROUND: Spinocerebellar ataxias (SCAs) are heterogeneous diseases characterized by progressive cerebellar ataxia associated with dysarthria, oculomotor abnormalities, and mental impairment. To identify the causative gene, we performed exome sequencing on a Japanese patient clinically diagnosed with recessive SCA. METHOD: The patient is a 37-year-old Japanese woman with consanguineous parents. The head magnetic resonance imaging (MRI) showed cerebellar atrophy and T1 low/T2 high intensity at the bilateral inferior olives. Single-nucleotide polymorphism (SNP) genotyping and next-generation sequencing were performed, and the variants obtained were filtered and prioritized. RESULTS: After these manipulations, we identified a homozygous nonsense mutation of the TTC19 gene (p.Q277*). TTC19 has been reported to be a causative gene of a neurodegenerative disease in Italian and Portuguese families and to be involved in the pathogenesis of mitochondrial respiratory chain complex III (cIII) deficiency. This report is the first description of a TTC19 mutation in an Asian population. Clinical symptoms and neuroimaging are consistent with previous reports. The head MRI already showed abnormal features four years before her blood lactate and pyruvate levels were elevated. CONCLUSIONS: We should consider the genetic analysis of TTC19 when we observe such characteristic MRI abnormalities. Genes associated with mitochondrial function cause many types of SCAs; the mutation we identified should help to elucidate the pathology of these disorders

CLINICOPATHOLOGICAL STUDY OF CEREBRAL SUBCORTICAL CAVERNOUS ANGIOMA AS EPILEPTOGENIC FOCUS

The authors conducted a comparative histological study of two groups of patients with cerebral subcortical cavernous angioma. One group was composed of 5 asymptomatic cases detected accidentally. The other group was composed of 4 patients presenting as epilepsy. The results obtained may be summarized as follows ; 1) Hemosiderin deposit and gliosis were seen in all cases examined ; 2) Granulomatous change was a histological finding associated with epileptogenesis ; 3) The histological changes, starting with proliferation of collagen fibers and leading to hyaline degeneration, calcification, and then hemangioma calcificans, seem to represent a course of spontaneous healing, when viewed from epileptogenesis

POSTOPERATIVE VASOSPASM IN PITUITARY ADENOMA WITH PITUITARY APOPLEXY

A patient who developed complications relating to intracranial arterial vasospasm following transcranial removal of a pituitary adenoma with pituitary apoplexy is reported. A 23-year-old female was admitted because of headache. Computed tomography (CT) and magnetic resonance (MR) imaging revealed a pituitary adenoma with suprasellar extension and pituitary apoplexy and sinusitis in the right maxillary and ethmoid sinuses. A transcranial approach was selected because of active sinusitis. A large, pink intra- and suprasellar neoplasm and intratumoral clot were removed smoothly. Postoperatively, the patient remained stuporous and showed right hemiplegia. Angiography demonstrated stenosis of the left internal carotid artery and severe spasm of perforating arteries from the left middle cerebral artery. Large pituitary adenoma with pituitary apoplexy requires careful perioperative management, with particular attention paid to the surgical approach and procedures

Improvement of Left Ventricular Function by Permanent Direct His-Bundle Pacing in a Case with Dilated Cardiomyopathy

The patient was a 67-year-old female diagnosed with dilated cardiomyopathy. She had chronic atrial fibrillation (AF) with bradycardia and low left ventricular function (left ventricular ejection fraction (LVEF) 40%). She was admitted for congestive heart failure. She remained New York Heart Association (NYHA) functional class III due to AF bradycardia. Pacemaker implantation was necessary for treatment of heart failure and administration of dose intensive β-blockers. As she had normal His-Purkinje activation, we examined the optimal pacing sites. Hemodynamics of His-bundle pacing and biventricular pacing were compared. Pulmonary capillary wedge pressure (PCWP) was significantly lower on Hisbundle pacing than right ventricular (RV) apical pacing and biventricular pacing (13mmHg, 19mmHg, and 19mmHg, respectively) with an almost equal cardiac index. Based on the examination we implanted a permanent pacemaker for Direct His-bundle pacing (DHBP). After the DHBP implantation, the LVEF immediately improved from 40% to 55%, and BNP level decreased from 422 pg/ml to 42 pg/ml. The number of premature ventricular complex (PVC) was decreased, and non sustained ventricular tachycardia (NSVT) disappeared. Pacing threshold for His-bundle pacing has remained at the same level. His-bundle pacing has been maintained during 27 months and her long-term DHBP can improve cardiac function and the NYHA functional class

First records of non-native species Callitriche deflexa (Plantaginaceae), which was previously misidentified as C. terrestris in Japan

The cosmopolitan genus Callitriche (Plantaginaceae) is a clade of small herbaceous plants that encompasses terrestrial and aquatic species. In Japan, six Callitriche species have been identified: four native and two naturalised species. Callitriche terrestris, a naturalised terrestrial species, was first reported in 1984 in Kanagawa Prefecture and it is thriving today.We report the presence of a new naturalised terrestrial species, Callitriche deflexa, which has been previously misidentified as C. terrestris because of its similar morphology. Callitriche deflexa can be distinguished from C. terrestris through genetic differences and distinct morphological traits, such as longer pedicels. Re-examination of herbarium specimens in the Kanagawa Prefectural Museum of Natural History confirmed that most of the specimens labelled as C. terrestris, including voucher specimens from the original report, were indeed C. terrestris, but a few were C. deflexa. We also noted that the plants referred to as “C. terrestris” in our previous developmental studies should be corrected to C. deflexa