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Topological swirling spin textures, such as skyrmions and merons, have recently attracted much attention as potential building blocks for high-density magnetic information devices. Controlling the transformation between different types of these quasiparticles is an important challenge. To date, these transitions have mostly been limited to a few non-centrosymmetric systems, where they are driven by the Dzyaloshinskii–Moriya interaction. Here we demonstrate multistep topological transitions among a variety of meron and skyrmion crystal states in a centrosymmetric magnet GdRu 2 Ge 2 . These are governed by the competition between Ruderman–Kittel–Kasuya–Yosida interactions at inequivalent wave vectors. These findings demonstrate that even a simple centrosymmetric magnet with competing interactions can be a promising material platform to realize a richer variety of magnetic quasiparticles with distinctive symmetry and topology, whose stability can be tuned by various external stimuli. Topological magnetic spin structures such as skyrmions and merons have the potential to be used in magnetic information devices. Now multistep transformations between such structures are demonstrated in a centrosymmetric material.

Magnetic skyrmion is a topologically protected particle-like object in magnetic materials, appearing as a nanometric swirling spin texture. The size and shape of skyrmion particles can be flexibly controlled by external stimuli, which suggests unique features of their crystallization and lattice transformation process. Here, we investigated the detailed mechanism of structural transition of skyrmion lattice (SkL) in a prototype chiral cubic magnet Cu 2 OSeO 3 , by combining resonant soft X-ray scattering (RSXS) experiment and micromagnetic simulation. This compound is found to undergo a triangular-to-square lattice transformation of metastable skyrmions by sweeping magnetic field ( B ). Our simulation suggests that the symmetry change of metastable SkL is mainly triggered by the B- induced modification of skyrmion core diameter and associated energy cost at the skyrmion-skyrmion interface region. Such internal deformation of skyrmion particle has further been confirmed by probing the higher harmonics in the RSXS pattern. These results demonstrate that the size/shape degree of freedom of skyrmion particle is an important factor to determine their stable lattice form, revealing the exotic manner of phase transition process for topological soliton ensembles in the non-equilibrium condition. Skyrmions are topological spin textures and are of great interest due to their impressive stability. Here, by sweeping an applied magnetic field, the authors observe a change in the skyrmion lattice structure, shedding light on the relation between skyrmion size and stability.

Phase separation between the CE-type charge-orbital ordered (CE) phase and the A-type antiferromagnetic ordered (A-AF) phase has been investigated in the bilayer manganite, La 2-2 x Sr 1+2 x Mn 2 O 7 ( x = 0.51), by resonant soft X-ray scattering (RSXS) at the Mn L 2,3 edge. The order parameters of CE and A-AF phases were measured at 1/4 1/4 0 and 0 0 1 reflections, respectively, and the phase separation was observed at the intermediate temperature region. Using a scanning-type RSXS with an X-ray focused by a Fresnel zone plate, the real-space images of domains for both the competing CE-phase and A-AF-phase were successfully observed. In the phase-separated state, we revealed that the domain of the CE phase forms a stripe pattern, and it seems to originate from the inhomogeneity of the chemical composition on sample.

Jolt accentuation or exacerbation of a baseline headache with horizontal rotation of the neck is a physical finding believed to assess for meningeal irritation. We conducted a prospective observational study of neurologically intact emergency department (ED) patients undergoing lumbar puncture in 2 inner city academic EDs to validate the sensitivity and specificity of jolt accentuation and to assess the sensitivity and specificity of Kernig sign, Brudzinski sign, and nuchal rigidity, in predicting cerebrospinal fluid (CSF) pleocytosis in individuals being assessed for meningitis. Adult patients 18 years and older undergoing lumbar puncture between 2006 and 2009 were approached for consent. Exclusions included inability to consent and altered mental status. Physicians were asked to answer a questionnaire of physical examination findings before receiving CSF results. The primary outcome was the presence or absence of pleocytosis, defined as greater than or equal to 5 cells/high-power field in the fourth CSF tube. We calculated descriptive statistics and tests of diagnostic accuracy. A total of 230 patients consented for participation and had CSF white blood cell counts recorded. Forty-seven individuals (20%) had pleocytosis. A total of 197 patients had headache and were, hence, eligible for jolt accentuation assessment. For pleocytosis, the sensitivity of jolt accentuation was 21%, Kernig sign was 2%, Brudzinski sign was 2%, and nuchal rigidity was 13%. The specificity of jolt accentuation was 82%, Kernig sign was 97%, Brudzinski sign was 98%, and nuchal rigidity was 80%. Jolt accentuation in our cohort was poorly predictive of pleocytosis and insensitive. The presence of Kernig sign, Brudzinski sign, or nuchal rigidity has moderate positive but no negative predictive value for pleocytosis.

Topological magnetic structure possesses topological stability characteristics that make it robust against disturbances which are a big advantage for data processing or storage devices of spintronics; nonetheless, such characteristics have been rarely clarified. This paper focused on the formation of chiral soliton lattice (CSL), a one-dimensional topological magnetic structure, and provides a discussion of its topological stability and influence of thermal fluctuation. Herein, CSL responses against change of temperature and applied magnetic field were investigated via small-angle resonant soft X-ray scattering in chromium niobium sulfide ( CrNb 3 S 6 ). CSL transformation relative to the applied magnetic field demonstrated a clear agreement with the theoretical prediction of the sine-Gordon model. Further, there were apparent differences in the process of chiral soliton creation and annihilation, discussed from the viewpoint of competing between thermal fluctuation and the topological metastability.

Topological magnetic structure possesses topological stability characteristics that make it robust against disturbances which are a big advantage for data processing or storage devices of spintronics; nonetheless, such characteristics have been rarely clarified. This paper focused on the formation of chiral soliton lattice (CSL), a one-dimensional topological magnetic structure, and provides a discussion of its topological stability and influence of thermal fluctuation. Herein, CSL responses against change of temperature and applied magnetic field were investigated via small-angle resonant soft X-ray scattering in chromium niobium sulfide ($$\\hbox {CrNb}_3\\hbox {S}_6$$CrNb 3 S 6 ). CSL transformation relative to the applied magnetic field demonstrated a clear agreement with the theoretical prediction of the sine-Gordon model. Further, there were apparent differences in the process of chiral soliton creation and annihilation, discussed from the viewpoint of competing between thermal fluctuation and the topological metastability.

To prevent falls in Japan, both gait and resistance training of the lower extremities are recommended. However, resistance training for the elderly induces muscle damage. Recently, aquatic exercise using water buoyancy and resistance have commonly been performed by the elderly. We have now produced new water-resistance equipment. The purpose of the present study was to evaluate the efficacy of aquatic exercise training using the new equipment for the elderly. Subjects were divided into two groups: a resistance group of 12 subjects (using water-resistance equipment) and a non-resistance group of eight subjects (without the equipment). The aquatic exercise training was 90 min, three times per week for 8 weeks, and mostly consisted of walking. All subjects underwent anthropometric measurements, physical performance testing, and profile of mood states (POMS). Significant improvements were observed in muscle strength in plantar flexion, and the timed up and go test (TUG) in both groups. Additionally, 10-m obstacle walking and 5-m maximum walking speed and length with eye-open were significantly improved in the resistance group. Also, a low negative correlation was found between the degree of change in TUG and POMS (tension and anxiety) scores in the resistance group. As it became easier to maintain posture, stand, and move, tension and anxiety in everyday life were alleviated with improvement of strength of the lower extremities and balance function. The present aquatic exercise training using water-resistance equipment may be used by the elderly to improve balance and walking ability, which are associated with the prevention of falls.

Background. Giardia intestinalis is the most commonly reported human intestinal parasite in the United States. Increased incidence of chronic gastrointestinal complaints has been reported after some giardiasis outbreaks. We examined the relationship between giardiasis diagnosis and irritable bowel syndrome (IBS) diagnosis. Methods. We used the 2006–2010 MarketScan commercial insurance database. Persons with at least 1 giardiasis diagnosis were individually matched on age group, sex, and enrollment length in months to 5 persons without a giardiasis diagnosis. Persons diagnosed with IBS before the date of study entry were excluded. We calculated crude incidence rates (IRs) and developed Cox proportional hazards models. Results. The matched cohort included 3935 persons with giardiasis and 19 663 persons without giardiasis. One-year incidence of IBS was higher in persons with giardiasis (IR = 37.7/1000 person-years vs 4.4/1000 person-years). The unadjusted hazard ratio was 4.8 (95% confidence interval [CI] = 3.6–6.4), attenuated slightly to 3.9 (95% CI = 2.9–5.4) after adjusting for anxiety, depression, and healthcare utilization. Conclusions. In a large insurance database, individuals diagnosed with giardiasis were more likely to have a subsequent IBS diagnosis, despite accounting for confounders. Future research on risk factors for IBS among giardiasis patients and the pathophysiology of postinfectious IBS is needed.

Aims: (1) To examine whether prevalence of burnout is higher among community psychiatric nurses working under recently introduced job specific work systems than among public health nurses (PHNs) engaged in other public health services. (2) To identify work environment factors potentially contributing to burnout. Methods: Two groups were examined. The psychiatric group comprised 525 PHNs primarily engaged in public mental health services at public health centres (PHCs) that had adopted the job specific work system. The control group comprised 525 PHNs primarily engaged in other health services. Pines’ Burnout Scale was used to measure burnout. Respondents were classified by burnout score into three groups: A (mentally stable, no burnout); B (positive signs, risk of burnout); and C (burnout present, action required). Groups B and C were considered representative of “burnout”. A questionnaire was also prepared to investigate systems for supporting PHNs working at PHCs and to define emergency mental health service factors contributing to burnout. Results: Final respondents comprised 785 PHNs. Prevalence of burnout was significantly higher in the psychiatric group (59.2%) than in the control group (51.5%). Responses indicating lack of job control and increased annual frequency of emergency overtime services were significantly correlated with prevalence of burnout in the psychiatric group, but not in the control group. Conclusions: Prevalence of burnout is significantly higher for community psychiatric nurses than for PHNs engaged in other services. Overwork in emergency services and lack of job control appear to represent work environment factors contributing to burnout.

Turing instability in activator–inhibitor systems provides a paradigm of non-equilibrium self-organization; it has been extensively investigated for biological and chemical processes. Turing instability should also be possible in networks, and general mathematical methods for its treatment have been formulated previously. However, only examples of regular lattices and small networks were explicitly considered. Here we study Turing patterns in large random networks, which reveal striking differences from the classical behaviour. The initial linear instability leads to spontaneous differentiation of the network nodes into activator-rich and activator-poor groups. The emerging Turing patterns become furthermore strongly reshaped at the subsequent nonlinear stage. Multiple coexisting stationary states and hysteresis effects are observed. This peculiar behaviour can be understood in the framework of a mean-field theory. Our results offer a new perspective on self-organization phenomena in systems organized as complex networks. Potential applications include ecological metapopulations, synthetic ecosystems, cellular networks of early biological morphogenesis, and networks of coupled chemical nanoreactors. Differences in diffusion constants of activator and inhibitor species can destabilize biological and chemical processes, leading to the spontaneous emergence of periodic spatial patterns. A general framework now provides the tools for studying such so-called Turing patterns in systems organized in complex networks.