2,589 research outputs found
Protein tyrosine phosphatase receptor type O (Ptpro) regulates cerebellar formation during zebrafish development through modulating Fgf signaling
Protein activities controlled by receptor protein tyrosine phosphatases (RPTPs) play comparably important roles in transducing cell surface signals into the cytoplasm by protein tyrosine kinases. Previous studies showed that several RPTPs are involved in neuronal generation, migration, and axon guidance in Drosophila, and the vertebrate hippocampus, retina, and developing limbs. However, whether the protein tyrosine phosphatase type O (ptpro), one kind of RPTP, participates in regulating vertebrate brain development is largely unknown. We isolated the zebrafish ptpro gene and found that its transcripts are primarily expressed in the embryonic and adult central nervous system. Depletion of zebrafish embryonic Ptpro by antisense morpholino oligonucleotide knockdown resulted in prominent defects in the forebrain and cerebellum, and the injected larvae died on the 4th day post-fertilization (dpf). We further investigated the function of ptpro in cerebellar development and found that the expression of ephrin-A5b (efnA5b), a Fgf signaling induced cerebellum patterning factor, was decreased while the expression of dusp6, a negative-feedback gene of Fgf signaling in the midbrain-hindbrain boundary region, was notably induced in ptpro morphants. Further analyses demonstrated that cerebellar defects of ptpro morphants were partially rescued by inhibiting Fgf signaling. Moreover, Ptpro physically interacted with the Fgf receptor 1a (Fgfr1a) and dephosphorylated Fgfr1a in a dose-dependant manner. Therefore, our findings demonstrate that Ptpro activity is required for patterning the zebrafish embryonic brain. Specifically, Ptpro regulates cerebellar formation during zebrafish development through modulating Fgf signaling. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00018-013-1259-7) contains supplementary material, which is available to authorized users
Increased stress in Asiatic black bears relates to food limitation, crop raiding, and foraging beyond nature reserve boundaries in China
AbstractAsiatic black bears (Ursus thibetanus) are declining throughout much of their range. In China they are partially protected by a nature reserve system and rely heavily on hard mast as a food source prior to winter denning. Bears may compensate for mast shortages by raiding agricultural crops and killing livestock, mainly outside reserves where they are exposed to increased threats of poaching. We hypothesized that stress would vary with availability of high-quality refugia and fluctuations in mast abundance. We collected fecal samples from free-ranging bears in and around nature reserves in southwestern China, recorded habitat characteristics at each fecal sample location, and quantified abundance of hard mast. We used feces for genetic and endocrine analysis and identified 106 individuals. Feces collected outside reserves, or in agricultural fields within reserves, contained elevated concentrations of glucocorticoid metabolites compared to samples collected in intact, mast-producing forests within reserves. Relationships with habitat variables indicated that the hypothalamic–pituitary–adrenal (HPA) axis of the Asiatic black bear is responsive to human activity, abundance of hard mast, extent of forest cover, and quality of diet. Our findings demonstrate biological reactions of a large mammal to variable forest quality, human threats, and foraging relative to boundaries of protected areas
Extreme Active Molecular Jets in L1448C
The protostellar jet driven by L1448C was observed in the SiO J=8-7 and CO
J=3-2 lines and 350 GHz dust continuum at ~1" resolution with the Submillimeter
Array (SMA). A narrow jet from the northern source L1448C(N) was observed in
the SiO and the high-velocity CO. The jet consists of a chain of emission knots
with an inter-knot spacing of ~2" (500 AU) and a semi-periodic velocity
variation. The innermost pair of knots, which are significant in the SiO map
but barely seen in the CO, are located at ~1" (250 AU) from the central source,
L1448C(N). Since the dynamical time scale for the innermost pair is only ~10
yr, SiO may have been formed in the protostellar wind through the gas-phase
reaction, or been formed on the dust grain and directly released into the gas
phase by means of shocks. It is found that the jet is extremely active with a
mechanical luminosity of ~7 L_sun, which is comparable to the bolometric
luminosity of the central source (7.5 L_sun). The mass accretion rate onto the
protostar derived from the mass-loss rate is ~10^{-5} M_sun/yr. Such a high
mass accretion rate suggests that the mass and the age of the central star are
0.03-0.09 M_sun and (4-12)x10^3 yr, respectively, implying that the central
star is in the very early stage of protostellar evolution. The low-velocity CO
emission delineates two V-shaped shells with a common apex at L1448C(N). The
kinematics of these shells are reproduced by the model of a wide opening angle
wind. The co-existence of the highly-collimated jets and the wide-opening angle
shells can be explained by the unified X-wind model" in which highly-collimated
jet components correspond to the on-axis density enhancement of the
wide-opening angle wind. The CO =3--2 map also revealed the second outflow
driven by the southern source L1448C(S) located at ~8.3" (2000 AU) from
L1448C(N).Comment: 45 pages, 13 figures, Accepted for the publication in the
Astrophysical Journa
Autonomous indoor wayfinding for individuals with cognitive impairments
<p>Abstract</p> <p>Background</p> <p>A challenge to individuals with cognitive impairments in wayfinding is how to remain oriented, recall routines, and travel in unfamiliar areas in a way relying on limited cognitive capacity. While people without disabilities often use maps or written directions as navigation tools or for remaining oriented, this cognitively-impaired population is very sensitive to issues of abstraction (e.g. icons on maps or signage) and presents the designer with a challenge to tailor navigation information specific to each user and context.</p> <p>Methods</p> <p>This paper describes an approach to providing distributed cognition support of travel guidance for persons with cognitive disabilities. A solution is proposed based on passive near-field RFID tags and scanning PDAs. A prototype is built and tested in field experiments with real subjects. The unique strength of the system is the ability to provide unique-to-the-user prompts that are triggered by context. The key to the approach is to spread the context awareness across the system, with the context being flagged by the RFID tags and the appropriate response being evoked by displaying the appropriate path guidance images indexed by the intersection of specific end-user and context ID embedded in RFID tags.</p> <p>Results</p> <p>We found that passive RFIDs generally served as good context for triggering navigation prompts, although individual differences in effectiveness varied. The results of controlled experiments provided more evidence with regard to applicabilities of the proposed autonomous indoor wayfinding method.</p> <p>Conclusions</p> <p>Our findings suggest that the ability to adapt indoor wayfinding devices for appropriate timing of directions and standing orientation will be particularly important.</p
IL-6-174 G/C and -572 C/G Polymorphisms and Risk of Alzheimer’s Disease
Associations between interleukin 6 (IL-6) polymorphisms and Alzheimer’s disease (AD) remain controversial and ambiguous. The aim of this meta-analysis is to explore more precise estimations for the relationship between IL-6-174 G/C and -572 C/G polymorphisms and risk for AD. Electronic searches for all publications in databases PubMed and EMBASE were conducted on the associations between IL-6 polymorphisms and risk for AD until January 2012. Odds ratio (OR) and 95% confidence intervals (CIs) were calculated using fixed and random effects models. Twenty-seven studies were included with a total of 19,135 individuals, involving 6,632 AD patients and 12,503 controls. For IL-6-174 G/C polymorphism, the combined results showed significant differences in recessive model (CC vs. CG+GG: OR = 0.65, 95%CI = 0.52–0.82). As regards IL-6-572 C/G polymorphism, significant associations were shown in dominant model (CG+GG vs. CC: OR = 0.73, 95% CI = 0.62–0.86) and in additive model (GG vs. CC, OR = 0.66, 95% CI = 0.46–0.96). In conclusion, genotype CC of IL-6-174 G/C and genotype GG plus GC of IL-6-572 C/G could decrease the risk of AD
PLK1 Interacts and Phosphorylates Axin That Is Essential for Proper Centrosome Formation
10.1371/journal.pone.0049184PLoS ONE711
The state of the Martian climate
60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes
Integration of fluorescence collection optics with a microfabricated surface electrode ion trap
We have successfully demonstrated an integrated optical system for collecting
the fluorescence from a trapped ion. The system, consisting of an array of
transmissive, dielectric micro-optics and an optical fiber array, has been
intimately incorporated into the ion-trapping chip without negatively impacting
trapping performance. Epoxies, vacuum feedthrough, and optical component
materials were carefully chosen so that they did not degrade the vacuum
environment, and we have demonstrated light detection as well as ion trapping
and shuttling behavior comparable to trapping chips without integrated optics,
with no modification to the control voltages of the trapping chip.Comment: 14 pages, 12 figure
Status of Muon Collider Research and Development and Future Plans
The status of the research on muon colliders is discussed and plans are
outlined for future theoretical and experimental studies. Besides continued
work on the parameters of a 3-4 and 0.5 TeV center-of-mass (CoM) energy
collider, many studies are now concentrating on a machine near 0.1 TeV (CoM)
that could be a factory for the s-channel production of Higgs particles. We
discuss the research on the various components in such muon colliders, starting
from the proton accelerator needed to generate pions from a heavy-Z target and
proceeding through the phase rotation and decay ()
channel, muon cooling, acceleration, storage in a collider ring and the
collider detector. We also present theoretical and experimental R & D plans for
the next several years that should lead to a better understanding of the design
and feasibility issues for all of the components. This report is an update of
the progress on the R & D since the Feasibility Study of Muon Colliders
presented at the Snowmass'96 Workshop [R. B. Palmer, A. Sessler and A.
Tollestrup, Proceedings of the 1996 DPF/DPB Summer Study on High-Energy Physics
(Stanford Linear Accelerator Center, Menlo Park, CA, 1997)].Comment: 95 pages, 75 figures. Submitted to Physical Review Special Topics,
Accelerators and Beam
A De Facto Asian-Currency Unit Bloc in East Asia: It has Been There but We did not Look for It
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