33 research outputs found
Eosinophilic esophagitis
Eosinophilic esophagitis (EoE) is an atopic condition of the esophagus that has become increasingly recognized over the last decade. Diagnosis of the disorder is dependent on the patient’s clinical manifestations and histologic findings on esophageal mucosal biopsies. Patients with eosinophilic esophagitis should be referred to both an allergist and gastroenterologist for optimal management, which may include dietary modifications, pharmacologic agents such as corticosteroids, leukotriene modifiers and biologics as well as mechanical dilatation of the esophagus. The epidemiology, pathophysiology, diagnosis, treatment, and prognosis of EoE are discussed in this review
Electrical Stimulation Influences Satellite Cell Proliferation and Apoptosis in Unloading-Induced Muscle Atrophy in Mice
Muscle atrophy caused by disuse is accompanied by adverse physiological and functional consequences. Satellite cells are the primary source of skeletal muscle regeneration. Satellite cell dysfunction, as a result of impaired proliferative potential and/or increased apoptosis, is thought to be one of the causes contributing to the decreased muscle regeneration capacity in atrophy. We have previously shown that electrical stimulation improved satellite cell dysfunction. Here we test whether electrical stimulation can also enhance satellite cell proliferative potential as well as suppress apoptotic cell death in disuse-induced muscle atrophy. Eight-week-old male BALB/c mice were subjected to a 14-day hindlimb unloading procedure. During that period, one limb (HU-ES) received electrical stimulation (frequency: 20 Hz; duration: 3 h, twice daily) while the contralateral limb served as control (HU). Immunohistochemistry and western blotting techniques were used to characterize specific proteins in cell proliferation and apoptosis. The HU-ES soleus muscles showed significant improvement in muscle mass, cross-sectional area, and peak tetanic force relative to the HU limb (p<0.05). The satellite cell proliferative activity as detected within the BrdU+/Pax7+ population was significantly higher (p<0.05). The apoptotic myonuclei (detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling) and the apoptotic satellite cells (detected by cleaved Poly [ADP-ribose] polymerase co-labeled with Pax7) were reduced (p<0.05) in the HU-ES limb. Furthermore the apoptosis-inducing factor and cleaved caspase-3 were down-regulated while the anti-apoptotic Bcl-2 protein was up-regulated (p<0.05), in the HU-ES limb. These findings suggest that the electrical stimulation paradigm provides an effective stimulus to rescue the loss of myonuclei and satellite cells in disuse muscle atrophy, thus maintaining a viable satellite cell pool for subsequent muscle regeneration. Optimization of stimulation parameters may enhance the outcome of the intervention
A model for the metallicity evolution of damped Lyman-alpha systems
We apply a physically motivated stellar feedback model to analyse the
statistical properties of damped Lyman-alpha systems (DLAs) expected in the
concordance cold dark matter (CDM) model. Our feedback model produces extended
low-metallicity cold gaseous discs around small galaxies. Since the space
density of galaxies with low circular speeds is high, these discs dominate the
cross-section for the identification of DLAs at all redshifts. The combined
effects of star formation, outflows and infall in our models result in mild
evolution of the N_{HI}-weighted metallicity content in DLAs with redshift,
consistent with observations. According to our model, DLAs contribute only a
small fraction of the volume averaged star formation rate at redshifts z \simlt
5. Our model predicts weak evolution in Omega_{HI} over the redshift range
z=0-5. Furthermore, we show that the cosmological evolution of Omega_{HI} and
the cosmic star formation rate are largely disconnected and conclude that the
evolution of Omega_{HI} as a function of redshift is more likely to tell us
about feedback processes and the evolution of the outer gaseous components of
small galaxies than about the cosmic history of star formation.Comment: 18 pages, 12 figures, accepted for publication in MNRAS (minor
changes
Landscape relatedness: detecting contemporary fine-scale spatial structure in wild populations
The community of Hymenoptera parasitizing necrophagous Diptera in an urban biotope
Most reports published in the field of forensic entomology are focused on Diptera and neglect the Hymenoptera community. However, Hymenoptera are part of the entomofaunal colonisation of a dead body. The use of Hymenoptera parasitoids in forensic entomology can be relevant to evaluate the time of death. Hymenoptera parasitoids of the larvae and pupae of flies may play an important role in the estimation of the post-mortem period, because their time of attack is often restricted to a small, well-defined windows of time in the development of the host insect. However, these parasitoids can interfere with the developmental times of colonising Diptera, and therefore a better understanding of their ecology is needed. The work reported here monitored the presence of adult Hymenoptera parasitoids on decaying pig carcasses in an urban biotope during the summer season (from May to September). Six families and six species were recorded in the field: Aspilota fuscicornis Haliday, Alysia manducator Panzer, Nasonia vitripennis Walker, Tachinaephagus zealandicus Ashmead, Trichopria sp., and Figites sp. In the laboratory, five species emerged from pupae collected in the field: Trichopria sp., Figites sp., A. manducator, N. vitripennis, and T. zealandicus. These five species colonise a broad spectrum of Diptera hosts, including those species associated with decomposing carcasses: Calliphoridae, Muscidae, Fanniidae, and Sarcophagida
Cultural Influences on Innovation and Competitiveness
Innovation is not just a result of R&D activities, the use of advanced technology, and science-based industries. Above all, it is a vehicle for the creation of future entrepreneurship advantage. A key way to realize an environment conducive to continuous innovation is by creating a cultural environment in which innovation can continuously flourish. Creating an innovation culture offers an important source of competitive advantage, both for individual enterprises and for the economy as a whole. This chapter shows that the cultural background of societies can boost economic innovation and thus accelerate competitiveness. © 2016, Springer New York
Artifact Categorization. Trends and Problems
The general question (G) How do we categorize artifacts? can be subject to
three different readings: an ontological, an epistemic and a semantic one. According to
the ontological reading, asking (G) is equivalent to asking in virtue of what properties, if
any, a certain artifact is an instance of some artifact kind: (O) What is it for an artifact a to
belong to kind K? According to the epistemic reading, when we ask (G) we are
investigating what properties of the object we exploit in order to decide whether a
certain artifact belongs to a certain kind. (G) thus becomes: (E) How can we know that
artifact a belongs to kind K? Finally, (G) can also be read as a question concerning the
semantics of artifact kind terms. The semantic reading of (G) is: (S) What kind of
reference do artifact kind terms have, if any? In this editorial we expand on the different
answers to (O), (E) and (S) that are given in the selected literature on the topic. The result
should give us an overall picture of the possible answers to (G)