Model-Independent Distance Measurements from Gamma-Ray Bursts and Constraints on Dark Energy

Gamma-Ray Bursts (GRB) are the most energetic events in the Universe, and provide a complementary probe of dark energy by allowing the measurement of cosmic expansion history that extends to redshifts greater than 6. Unlike Type Ia supernovae (SNe Ia), GRBs must be calibrated for each cosmological model considered, because of the lack of a nearby sample of GRBs for model-independent calibration. For a flat Universe with a cosmological constant, we find Omega_m=0.25^{+0.12}_{-0.11} from 69 GRBs alone. We show that the current GRB data can be summarized by a set of model-independent distance measurements, with negligible loss of information. We constrain a dark energy equation of state linear in the cosmic scale factor using these distance measurements from GRBs, together with the "Union" compilation of SNe Ia, WMAP five year observations, and the SDSS baryon acoustic oscillation scale measurement. We find that a cosmological constant is consistent with current data at 68% confidence level for a flat Universe. Our results provide a simple and robust method to incorporate GRB data in a joint analysis of cosmological data to constrain dark energy.Comment: 8 pages, 5 color figures. Version expanded and revised for clarification, and typo in Eqs.(3)(4)(12) corrected. PRD, in pres

Ring Formation in Magnetically Subcritical Clouds and Multiple Star Formation

We study numerically the ambipolar diffusion-driven evolution of non-rotating, magnetically subcritical, disk-like molecular clouds, assuming axisymmetry. Previous similar studies have concentrated on the formation of single magnetically supercritical cores at the cloud center, which collapse to form isolated stars. We show that, for a cloud with many Jeans masses and a relatively flat mass distribution near the center, a magnetically supercritical ring is produced instead. The supercritical ring contains a mass well above the Jeans limit. It is expected to break up, through both gravitational and possibly magnetic interchange instabilities, into a number of supercritical dense cores, whose dynamic collapse may give rise to a burst of star formation. Non-axisymmetric calculations are needed to follow in detail the expected ring fragmentation into multiple cores and the subsequent core evolution. Implications of our results on multiple star formation in general and the northwestern cluster of protostars in the Serpens molecular cloud core in particular are discussed.Comment: 25 pages, 4 figures, to appear in Ap

Exploiting Features and Logits in Heterogeneous Federated Learning

Due to the rapid growth of IoT and artificial intelligence, deploying neural networks on IoT devices is becoming increasingly crucial for edge intelligence. Federated learning (FL) facilitates the management of edge devices to collaboratively train a shared model while maintaining training data local and private. However, a general assumption in FL is that all edge devices are trained on the same machine learning model, which may be impractical considering diverse device capabilities. For instance, less capable devices may slow down the updating process because they struggle to handle large models appropriate for ordinary devices. In this paper, we propose a novel data-free FL method that supports heterogeneous client models by managing features and logits, called Felo; and its extension with a conditional VAE deployed in the server, called Velo. Felo averages the mid-level features and logits from the clients at the server based on their class labels to provide the average features and logits, which are utilized for further training the client models. Unlike Felo, the server has a conditional VAE in Velo, which is used for training mid-level features and generating synthetic features according to the labels. The clients optimize their models based on the synthetic features and the average logits. We conduct experiments on two datasets and show satisfactory performances of our methods compared with the state-of-the-art methods

Wavelength-swept Tm-doped fiber laser operating in the two-micron wavelength band

A wavelength-swept thulium-doped silica fiber laser using an intracavity rotating slotted-disk wavelength scanning filter in combination with an intracavity solid etalon for passive control of temporal and spectral profiles is reported. The laser yielded a wavelength swept output in a step-wise fashion with each laser pulse separated from the previous pulse by a frequency interval equal to the free-spectral-range of the etalon and with an instantaneous linewidth of <0.05 nm. Scanning ranges from 1905 nm to 2049 nm for a cladding-pumping laser configuration, and from 1768 nm to 1956 nm for a core-pumping laser configuration were achieved at average output powers up to ~1 W

High-order volterra model predictive control and its application to a nonlinear polymerisation process

Model Predictive Control (MPC) has recently found wide acceptance in the process industry, but the existing design and implementation methods are restricted to linear process models. A chemical process involves, however, severe nonlinearity which cannot be ignored in practice. This paper aims to solve this nonlinear control problem by extending MPC to nonlinear models. It develops an analytical framework for nonlinear model predictive control (NMPC), and also offers a third-order Volterra series based nonparametric nonlinear modelling technique for NMPC design which relieves practising engineers from the need for first deriving a physical-principles based model. An on-line realisation technique for implementing the NMPC is also developed. The NMPC is then applied to a Mitsubishi Chemicals polymerisation reaction process. The results show that this nonlinear MPC technique is feasible and very effective. It considerably outperforms linear and low-order Volterra model based methods. The advantages of the approach developed lie not only in control performance superior to existing NMPC methods, but also in relieving practising engineers from the need for deriving an analytical model and then converting it to a Volterra model through which the model can only be obtained up to the second order

Brane Inflation from Rotation of D4 Brane

In this paper, a inflationary model from the rotation of D4-brane is constructed. We show that for a very wide rage of parameter, this model satisfies the observation and find that regarded as inflaton, the rotation of branes may be more nature than the distance between branes. Our model offers a new avenue for brane inflation.Comment: 6 pages, no figure

Constructing a new nigrostriatal pathway in the Parkinsonian model with bridged neural transplantation in substantia nigra

The physical repair and restoration of a completely damaged pathway in the brain has not been achieved previously. In a previous study, using excitatory amino acid bridging and fetal neural transplantation, we demonstrated that a bridged mesencephalic transplant in the substantia nigra generated an artificial nerve pathway that reinnervated the striatum of 6-hydroxydopamine (6-OHDA)-lesioned rats. In the current study, we report that a bridged mesencephalic transplant can anatomically, neurochemically, and functionally reinstate the 6-OHDA-eradicated nigro-striatal pathway. An excitatory amino acid, kainic acid, laid down in a track during the transplant generated a trophic environment that effectively guided the robust growth of transplanted neuronal fibers in a bundle to innervate the distal striatum. Growth occurred at the remarkable speed of approximately 200 microm/d. Two separate and distinct types of dopamine (DA) innervation from the transplant have been achieved for the first time: (1) DA innervation of the striatum, and (2) DA innervation of the pars reticularis of the substantia nigra. In addition, neuronal tracing revealed that reciprocal connections were achieved. The grafted DA neurons in the SNr innervated the host's striatum, whereas the host's striatal neurons, in turn, innervated the graft within 3-8 weeks. Electrochemical volt- ammetry recording revealed the restoration of DA release and clearance in a broad striatal area associated with the DA reinnervation. Furthermore, the amphetamine-induced rotation was attenuated, which indicates that the artificial pathways were motor functional. This study provides additional evidences that our bridged transplantation technique is a potential means for the repair of a completely damaged neuronal pathway

Outcomes of a remote, decentralized health center-based HIV/AIDS antiretroviral program in Zambia, 2003 to 2007

A cross-sectional study of patients living with HIV/ AIDS treated during 2003 to 2007 in decentralized, rural health centers in Zambia was performed to measure virological outcomes after 12 months of antiretroviral therapy and identify factors associated with virological failure. Data from 228 patients who started antiretroviral therapy >12 months prior were analyzed. In all, 93% received stavudine + lamivudine + nevirapine regimens, and median antiretroviral therapy duration was 23.5 months (interquartile range 20-28). Of the 205 patients tested for viral load, 177 (86%) had viral load <1000 copies/mL. Probability of developing virological failure (viral load >1000 copies/mL) was 8.9% at 24 months and 19.6% at 32 months. Predictors for virological failure were <100% adherence, body mass index <18.5 kg/m(2), and women <40 years old. Of those with virological failure who underwent 3 to 6 months of intensive adherence counseling, 45% obtained virological success. In a remote, resource-limited setting in decentralized health centers, virological and immunological assessments of patients on antiretroviral therapy >12 months showed that positive health outcomes are achievable

Discovery of Molecular Gas in the Outflow and Tidal Arms around M82

We present the first fully sampled map of 12CO (1-0) emission from M82 covering the entire galaxy. Our map contains a 12 x 15 kpc^2 area. We find that extraplanar CO emission, previously reported at short distances above the galactic plane, extends to heights of up to 6 kpc above the disk. Some of this emission is associated with tidal arms seen in HI, implying either that M82 contained substantial amounts of molecular gas in the outer disk, or that molecular gas formed after the tidal features. CO emission along the direction of the outflow extends to distances of 3 kpc above and below the disk. At this distance, the line is shifted in velocity about 100 km/s, and has the same sense as the galactic outflow from the central starburst. This implies that molecular gas may be entrained into the outflow.Comment: 4 pages, 6 figures. Uses emulateapj5. Accepted by ApJ Letter