79 research outputs found

    Can chemotactic effects lead to blow-up or not in two-species chemotaxis-competition models?

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    This paper deals with the two-species chemotaxis-competition models \begin{align*} \begin{cases} u_t = d_1 \Delta u - \chi_1 \nabla \cdot (u \nabla w) + \mu_1 u (1- u^{\kappa_1-1} - a_1 v^{\lambda_1-1}), &\quad x \in \Omega,\ t>0,\\ % v_t = d_2 \Delta v - \chi_2 \nabla \cdot (v \nabla w) + \mu_2 v (1- a_2 u^{\lambda_2-1} - v^{\kappa_2-1}), &\quad x \in \Omega,\ t>0,\\ % 0 = d_3 \Delta w + \alpha u + \beta v - h(u,v,w), &\quad x \in \Omega,\ t>0, \end{cases} \end{align*} where ΩRn\Omega \subset \mathbb{R}^n (n2)(n\ge2) is a bounded domain with smooth boundary, and h=γwh=\gamma w or h=1ΩΩ(αu+βv)dxh=\frac{1}{|\Omega|}\int_\Omega(\alpha u+ \beta v)\,dx. In the case that κ1=λ1=κ2=λ2=2\kappa_1=\lambda_1=\kappa_2=\lambda_2=2 and h=γwh=\gamma w, it is known that smallness conditions for the chemotacic effects lead to boundedness of solutions (Math.\ Methods Appl.\ Sci.; 2018; 41; 234--249). However, the case that the chemotactic effects are large seems not to have been studied yet; therefore it remains to consider the question whether the solution is bounded also in the case that the chemotactic effects are large. The purpose of this paper is to give a negative answer to this question

    Wood Property Variation in Acacia Auriculiformis Growing in Bangladesh

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    This study examined the radial variations of wood properties in 11-yr-old Acacia auriculiformis grown in Bangladesh having diameters of 222 ± 38 mm. The basic density, fiber length, and fiber length increment increased up to about 80 mm radial distance from the pith and then were almost constant toward the bark. The compressive strength (CS) increased from the pith to 50 mm and then became nearly constant to the bark. Conversely, the specific compressive strength, the ratio of CS to air-dried density, was almost constant from pith to bark, indicating positive relationships. However, the air-dried density explained only 50% variation of the CS. On the basis of radial variation of basic density, the core wood and outer wood boundary can be delineated at 70 - 90 mm from the pith. Similarly, the fiber length and fiber length increment curves showed that this boundary could be marked at 60 - 90 mm from the pith. The selected wood properties except CS varied significantly among the trees, which indicated the potential of tree selection for wood quality improvement through tree breeding

    Disseminated Mycobacterium genavense infection mimicking TAFRO syndrome

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    TAFRO syndrome is a rare variant of idiopathic multicentric Castleman's disease, for which disseminated non-tuberculous mycobacteria (NTM) infection must be excluded. However, due to the slow and fastidious growth of the organisms, identification of the pathogen is often challenging. We herein describe a case of disseminated Mycobacterium genavence infection, in which manifestations of the patient were confusingly similar to those of TAFRO syndrome. A 69-year-old Japanese man presented with prolonged fever accompanying pain in his back and ribs on the right side. Systemic investigations revealed thrombocytopenia, marked elevation of alkaline phosphatase, anasarca (pleural effusion and ascites), megakaryocytosis in the bone marrow, and hepatomegaly. Magnetic resonance imaging (MRI) showed diffuse, T1-and T2-low-intensity spotted lesions on his vertebral bodies, but biopsy showed inconclusive results. The patient met the diagnostic criteria of TAFRO syndrome and was started on prednisolone, which improved his general condition shortly thereafter. Blood culture after 42 days of incubation revealed the presence of Mycobacterium; however, we considered it a contamination at that time because no organisms grew on conventional agars, and the patient was discharged. Ten weeks after the isolation of Mycobacterium, he developed persistent fever and was readmitted. This time, vertebral bone mallow biopsy demonstrated a large amount of mycobacterium, which was later successfully identified as M. genavense by sequencing analysis. Under a final diagnosis of disseminated M. genavense infection, we treated the patient with clarithromycin, rifampicin, and ethambutol. This case highlighted that disseminated NTM infection may follow a similar clinical course as that of TAFRO syndrome

    Clinical Application of the Ratio of Serum Bone Isoform to Total Alkaline Phosphatase in General Practice

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    Alkaline phosphatase (ALP) is an enzyme that is expressed in a variety of tissues. Among the isoforms of ALP, bone-specific alkaline phosphatase (BAP) is used as a marker for evaluating bone metabolism. We investigated the clinical usefulness of the ratio of serum BAP to total ALP for the diagnosis of various disorders in general practice. We retrospectively analyzed the cases of 107 Japanese patients whose serum BAP levels were exam-ined, focusing on clinical characteristics. We observed that the BAP/ALP ratios of the patients with fever and those with inflammatory diseases were significantly lower than the ratios of other patient groups. The BAP/ALP ratios of the patients with osteoporosis and those with metabolic bone diseases were higher than those of the patients with other conditions. The BAP/ALP ratio was found to be negatively correlated with age, a cor-relation that has not been found in other ethnicities. The serum BAP/ALP ratio was inversely correlated with serum CRP levels but was positively correlated with serum albumin levels and hemoglobin concentrations. Collectively, our results suggest that the BAP/ALP ratio could be a useful predictor for important geriatric con-ditions seen in general practice

    Invasive non-typeable Haemophilus influenzae infection due to endometritis associated with adenomyosis

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    Background The widespread administration of the Haemophilus influenzae type b vaccine has led to the predominance of non-typable H. influenzae (NTHi). However, the occurrence of invasive NTHi infection based on gynecologic diseases is still rare. Case presentation A 51-year-old Japanese woman with a history of adenomyoma presented with fever. Blood cultures and a vaginal discharge culture were positive with NTHi. With the high uptake in the uterus with 67Ga scintigraphy, she was diagnosed with invasive NTHi infection. In addition to antibiotic administrations, a total hysterectomy was performed. The pathological analysis found microabscess formations in adenomyosis. Conclusions Although NTHi bacteremia consequent to a microabscess in adenomyosis is rare, this case emphasizes the need to consider the uterus as a potential source of infection in patients with underlying gynecological diseases, including an invasive NTHi infection with no known primary focus.

    On the origin and evolution of the asteroid Ryugu: A comprehensive geochemical perspective

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    Presented here are the observations and interpretations from a comprehensive analysis of 16 representative particles returned from the C-type asteroid Ryugu by the Hayabusa2 mission. On average Ryugu particles consist of 50% phyllosilicate matrix, 41% porosity and 9% minor phases, including organic matter. The abundances of 70 elements from the particles are in close agreement with those of CI chondrites. Bulk Ryugu particles show higher δ18O, Δ17O, and ε54Cr values than CI chondrites. As such, Ryugu sampled the most primitive and least-thermally processed protosolar nebula reservoirs. Such a finding is consistent with multi-scale H-C-N isotopic compositions that are compatible with an origin for Ryugu organic matter within both the protosolar nebula and the interstellar medium. The analytical data obtained here, suggests that complex soluble organic matter formed during aqueous alteration on the Ryugu progenitor planetesimal (several 10’s of km), <2.6 Myr after CAI formation. Subsequently, the Ryugu progenitor planetesimal was fragmented and evolved into the current asteroid Ryugu through sublimation
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