A detached double X-ray tail in the merging galaxy cluster Z8338 with a large double tail

When subhalos infall into galaxy clusters, their gas content is ram pressure stripped by the intracluster medium (ICM) and may turn into cometary tails. We report the discovery of two spectacular X-ray double tails in a single galaxy cluster, Z8338, revealed by 70 ks Chandra observations. The brighter one, with an X-ray bolometric luminosity of $3.9 \times 10^{42}{\rm\ erg\ s}^{-1}$, is a detached tail stripped from the host halo and extended at least 250 kpc in projection. The head of the detached tail is a cool core with the front tip of the cold front $\sim$ 30 kpc away from the nucleus of its former host galaxy. The cooling time of the detached cool core is $\sim 0.3$ Gyr. For the detached gas, the gravity of the once-associated dark matter halo further enhances the Rayleigh-Taylor (RT) instability. From its survival, we find that a magnetic field of a few $\mu$G is required to suppress the hydrodynamic instability. The X-ray temperature in the tail increases from 0.9 keV at the front tip to 1.6 keV in the wake region, which suggests the turbulent mixing with the hotter ICM. The fainter double X-ray tail, with a total X-ray luminosity of $2.7 \times 10^{42}{\rm\ erg\ s}^{-1}$, appears to stem from the cool core of a subcluster in Z8338, and likely was formed during the ongoing merger. This example suggests that X-ray cool cores can be displaced and eventually destroyed by mergers, while the displaced cool cores can survive for some extended period of time.Comment: 11 pages, 8 figures, MNRAS accepte

Irisin treatment improves healing of dystrophic skeletal muscle

Background: Irisin is an exercise induced myokine that is shown to promote browning of adipose tissue and hence, increase energy expenditure. Furthermore, our unpublished results indicate that Irisin improves myogenic differentiation and induces skeletal muscle hypertrophy. Since exercise induced skeletal muscle hypertrophy improves muscle strength, we wanted to investigate if ectopic injection of Irisin peptide improves skeletal muscle function in a mouse model of muscular dystrophy. This utility of Irisin peptide is yet to be studied in animal models. Methods: In order to test this hypothesis, we expressed and purified recombinant murine Irisin peptide from E. coli. Three- to six-week-old male mdx mice were injected IP with either vehicle (dialysis buffer) or Irisin recombinant peptide for two or four weeks, three times-a-week. Results: Irisin injection increased muscle weights and enhanced grip strength in mdx mice. Improved muscle strength can be attributed to the significant hypertrophy observed in the Irisin injected mdx mice. Moreover, Irisin treatment resulted in reduced accumulation of fibrotic tissue and myofiber necrosis in mdx mice. In addition, Irisin improved sarcolemmal stability, which is severely compromised in mdx mice. Conclusion: Irisin injection induced skeletal muscle hypertrophy, improved muscle strength and reduced necrosis and fibrotic tissue in a murine dystrophy model. These results demonstrate the potential therapeutic value of Irisin in muscular dystrophy

Irisin is a pro-myogenic factor that induces skeletal muscle hypertrophy and rescues denervation-induced atrophy

Exercise induces expression of the myokine irisin, which is known to promote browning of white adipose tissue and has been shown to mediate beneficial effects following exercise. Here we show that irisin induces expression of a number of pro-myogenic and exercise response genes in myotubes. Irisin increases myogenic differentiation and myoblast fusion via activation of IL6 signaling. Injection of irisin in mice induces significant hypertrophy and enhances grip strength of uninjured muscle. Following skeletal muscle injury, irisin injection improves regeneration and induces hypertrophy. The effects of irisin on hypertrophy are due to activation of satellite cells and enhanced protein synthesis. In addition, irisin injection rescues loss of skeletal muscle mass following denervation by enhancing satellite cell activation and reducing protein degradation. These data suggest that irisin functions as a pro-myogenic factor in mice

From oil wealth to green growth - An empirical agent-based model of recession, migration and sustainable urban transition

This paper develops an empirical, multi-layered and spatially-explicit agent-based model that explores sustainable pathways for Aberdeen city and surrounding area to transition from an oil-based economy to green growth. The model takes an integrated, complex systems approach to urban systems and incorporates the interconnectedness between people, households, businesses, industries and neighbourhoods. We find that the oil price collapse could potentially lead to enduring regional decline and recession. With green growth, however, the crisis could be used as an opportunity to restructure the regional economy, reshape its neighbourhoods, and redefine its identity in the global economy. We find that the type of the green growth and the location of the new businesses will have profound ramifications for development outcomes, not only by directly creating businesses and employment opportunities in strategic areas, but also by redirecting households and service businesses to these areas. New residential and business centres emerge as a result of this process. Finally, we argue that industries, businesses and the labour market are essential components of a deeply integrated urban system. To understand urban transition, models should consider both household and industrial aspects

Paraneoplastic secretion of multiple phosphatonins from a deep fibrous histiocytoma causing oncogenic osteomalacia

Context: Literature suggests that oncogenic osteomalacia is usually caused by a benign mesenchymal tumor secreting fibroblast growth factor subtype-23 (FGF-23), but the involvement of other phosphatonins has only been scarcely reported. We have previously published a seemingly typical case of oncogenic osteomalacia. Following curative neoplasm resection, we now report unique molecular characteristics and biology of this tumor. Case Description: A 25-year-old man had been diagnosed with severe oncogenic osteomalacia that gradually crippled him over 6 years. 68Ga-DOTA-TATE positron emission tomography/computed tomography scan localized the culprit tumor to his left sole, which on resection revealed a deep fibrous histiocytoma displaying a proliferation of spindle cells with storiform pattern associated with multinucleated giant cells resembling osteoclasts. Circulating FGF-23, which was elevated more than 2-fold, declined to undetectable levels 24 h after surgery. Microarray analysis revealed increased tumor gene expression of the phosphatonins FGF-23, matrix extracellular phosphoglycoprotein (MEPE) and secreted frizzled-related protein subtype 4, with elevated levels of all 3 proteins confirmed through immunoblot analysis. Differential expression of genes involved in bone formation and bone mineralization were further identified. The patient made an astonishing recovery from being wheelchair bound to fully self-ambulant 2 months postoperatively. Conclusion: This report describes oncogenic osteomalacia due to a deep fibrous histiocytoma, which coincidentally has been found to induce profound muscle weakness via the overexpression of 3 phosphatonins, which resolved fully upon radical resection of the tumor. Additionally, genes involved in bone formation and bone remodeling contribute to the molecular signature of oncogenic osteomalacia

Ancient Polyploidy and Genome Evolution in Palms

Mechanisms of genome evolution are fundamental to our understanding of adaptation and the generation and maintenance of biodiversity, yet genome dynamics are still poorly characterized in many clades. Strong correlations between variation in genomic attributes and species diversity across the plant tree of life suggest that polyploidy or other mechanisms of genome size change confer selective advantages due to the introduction of genomic novelty. Palms (order Arecales, family Arecaceae) are diverse, widespread, and dominant in tropical ecosystems, yet little is known about genome evolution in this ecologically and economically important clade. Here, we take a phylogenetic comparative approach to investigate palm genome dynamics using genomic and transcriptomic data in combination with a recent, densely sampled, phylogenetic tree. We find conclusive evidence of a paleopolyploid event shared by the ancestor of palms but not with the sister clade, Dasypogonales. We find evidence of incremental chromosome number change in the palms as opposed to one of recurrent polyploidy. We find strong phylogenetic signal in chromosome number, but no signal in genome size, and further no correlation between the two when correcting for phylogenetic relationships. Palms thus add to a growing number of diverse, ecologically successful clades with evidence of whole-genome duplication, sister to a species-poor clade with no evidence of such an event. Disentangling the causes of genome size variation in palms moves us closer to understanding the genomic conditions facilitating adaptive radiation and ecological dominance in an evolutionarily successful, emblematic tropical clade

AGN feedback in the FR II galaxy 3C 220.1

We present results from a deep (174 ks) Chandra observation of the FR-II radio galaxy 3C 220.1, the central brightest cluster galaxy (BCG) of a $kT \sim$ 4 keV cluster at $z=0.61$. The temperature of the hot cluster medium drops from $\sim5.9$ keV to $\sim3.9$ keV at $\sim$ 35 kpc radius, while the temperature at smaller radii may be substantially lower. The central active galactic nucleus (AGN) outshines the whole cluster in X-rays, with a bolometric luminosity of $2.0\times10^{46}$ erg s$^{-1}$ ($\sim10$% of the Eddington rate). The system shows a pair of potential X-ray cavities $\sim35$ kpc east and west of the nucleus. The cavity power is estimated within the range of $1.0\times10^{44}$ erg s$^{-1}$ and $1.7\times10^{45}$ erg s$^{-1}$, from different methods. The X-ray enhancements in the radio lobes could be due to inverse Compton emission, with a total 2-10 keV luminosity of $\sim8.0\times10^{42}$ erg s$^{-1}$. We compare 3C 220.1 with other cluster BCGs, including Cygnus A, as there are few BCGs in rich clusters hosting an FR-II galaxy. We also summarize the jet power of FR-II galaxies from different methods. The comparison suggests that the cavity power of FR-II galaxies likely under-estimates the jet power. The properties of 3C 220.1 suggest that it is at the transition stage from quasar-mode feedback to radio-mode feedback.Comment: 14 pages, 13 figures, MNRAS accepte

Development of a high throughput and low cost model for the study of semi-dry biofilms

The persistence of microorganisms as biofilms on dry surfaces resistant to the usual terminal cleaning methods may pose an additional risk of transmission of infections. In this study, the Centre for Disease Control (CDC) dry biofilm model (DBM) was adapted into a microtiter plate format (Model 1) and replicated to create a novel in vitro model that replicates conditions commonly encountered in the healthcare environment (Model 2). Biofilms of Staphylococcus aureus grown in the two models were comparable to the biofilms of the CDC DBM in terms of recovered log10 CFU well−1. Assessment of the antimicrobial tolerance of biofilms grown in the two models showed Model 2 a better model for biofilm formation. Confirmation of the biofilms’ phenotype with an extracellular matrix deficient S. aureus suggested stress tolerance through a non-matrix defined mechanism in microorganisms. This study highlights the importance of conditions maintained in bacterial growth as they affect biofilm phenotype and behaviour

Impedance adaptation for optimal robot–environment interaction

In this paper, impedance adaptation is investigated for robots interacting with unknown environments. Impedance control is employed for the physical interaction between robots and environments, subject to unknown and uncertain environments dynamics. The unknown environments are described as linear systems with unknown dynamics, based on which the desired impedance model is obtained. A cost function that measures the tracking error and interaction force is defined, and the critical impedance parameters are found to minimize it. Without requiring the information of the environments dynamics, the proposed impedance adaptation is feasible in a large number of applications where robots physically interact with unknown environments. The validity of the proposed method is verified through simulation studies