The Sunyaev-Zel'dovich Infrared Experiment: A Millimeter-wave Receiver for Cluster Cosmology

Measurements of the Sunyaev-Zel'dovich (S-Z) effect towards distant clusters of galaxies can be used to determine the Hubble constant and the radial component of cluster peculiar velocities. Determination of the cluster peculiar velocity requires the separation of the two components of the S-Z effect, which are due to the thermal and bulk velocities of the intracluster plasma. The two components can be separated practically only at millimeter (mm) wavelengths. Measurements of the S-Z effect at mm wavelengths are subject to minimal astrophysical confusion and, therefore, provide an important test of results obtained at longer wavelengths. We describe the instrument used to make the first significant detections of the S-Z effect at millimeter wavelengths. This instrument employs new filter, detector, and readout technologies to produce sensitive measurements of differential sky brightness stable on long time scales. These advances allow drift scan observations which achieve high sensitivity while minimizing common sources of systematic error.Comment: 19 pages, 15 postscript figures, LaTeX(aaspptwo.sty), ApJ(in press

Using SuZIE arcminute-scale CMB anisotropy data to probe open and flat-\Lambda CDM cosmogonies

We use arcminute-scale data from the Sunyaev-Zel'dovich Infrared Experiment to set limits on anisotropies in the cosmic microwave background radiation in open and spatially-flat-Lambda cold dark matter cosmogonies. There are no 2-sigma detections for the models tested. The upper limits obtained are consistent with the amplitude of anisotropy detected by the COBE/DMR experiment.Comment: 17 pages including 4 postscript figures. Latex. Uses aaspp4. ApJ, in pres

Genes Involved in the Balance between Neuronal Survival and Death during Inflammation

Glucocorticoids are potent regulators of the innate immune response, and alteration in this inhibitory feedback has detrimental consequences for the neural tissue. This study profiled and investigated functionally candidate genes mediating this switch between cell survival and death during an acute inflammatory reaction subsequent to the absence of glucocorticoid signaling. Oligonucleotide microarray analysis revealed that following lipopolysaccharide (LPS) intracerebral administration at striatum level, more modulated genes presented transcription impairment than exacerbation upon glucocorticoid receptor blockage. Among impaired genes we identified ceruloplasmin (Cp), which plays a key role in iron metabolism and is implicated in a neurodegenative disease. Microglial and endothelial induction of Cp is a natural neuroprotective mechanism during inflammation, because Cp-deficient mice exhibited increased iron accumulation and demyelination when exposed to LPS and neurovascular reactivity to pneumococcal meningitis. This study has identified genes that can play a critical role in programming the innate immune response, helping to clarify the mechanisms leading to protection or damage during inflammatory conditions in the CNS

Measurement of the Hubble Constant from X-ray and 2.1 mm Observations of Abell 2163

We report 2.1 mm observations of the Sunyaev-Zel'dovich (S-Z) effect; these observations confirm our previous detection of a decrement in the Cosmic Microwave Background intensity towards the cluster Abell 2163. The S-Z data are analyzed using the relativistically correct expression for the Comptonization. We begin by assuming the intracluster (IC) gas to be isothermal at the emission weighted average temperature determined by a combined analysis of the ASCA and GINGA X-ray satellite observations. Combining the X-ray and S-Z measurements, we determine the Hubble constant to be H_0(q_0=0.5)= 60 +40/-23 km/s/Mpc, where the uncertainty is dominated by the systematic difference in the ASCA and GINGA determined IC gas temperatures. ASCA observations suggest the presence of a significant thermal gradient in the IC gas. We determine $H_0$ as a function of the assumed IC gas thermal structure. Using the ASCA determined thermal structure and keeping the emission weighted average temperature the same as in the isothermal case, we find H_0(q_0=0.5)= 78 +54/-28 km/s/Mpc. Including additional uncertainties due to cluster asphericity, peculiar velocity, IC gas clumping, and astrophysical confusion, we find H_0(q_0=0.5)= 78 +60/-40 km/s/Mpc.Comment: 24 pages, 10 postscript figures, LaTeX(aaspptwo.sty), ApJ(in press

The Invariance Hypothesis Implies Domain-Specific Regions in Visual Cortex

Is visual cortex made up of general-purpose information processing machinery, or does it consist of a collection of specialized modules? If prior knowledge, acquired from learning a set of objects is only transferable to new objects that share properties with the old, then the recognition system’s optimal organization must be one containing specialized modules for different object classes. Our analysis starts from a premise we call the invariance hypothesis: that the computational goal of the ventral stream is to compute an invariant-to-transformations and discriminative signature for recognition. The key condition enabling approximate transfer of invariance without sacrificing discriminability turns out to be that the learned and novel objects transform similarly. This implies that the optimal recognition system must contain subsystems trained only with data from similarly-transforming objects and suggests a novel interpretation of domain-specific regions like the fusiform face area (FFA). Furthermore, we can define an index of transformation-compatibility, computable from videos, that can be combined with information about the statistics of natural vision to yield predictions for which object categories ought to have domain-specific regions in agreement with the available data. The result is a unifying account linking the large literature on view-based recognition with the wealth of experimental evidence concerning domain-specific regions.National Science Foundation (U.S.). Science and Technology Center (Award CCF-1231216)National Science Foundation (U.S.) (Grant NSF-0640097)National Science Foundation (U.S.) (Grant NSF-0827427)United States. Air Force Office of Scientific Research (Grant FA8650-05-C-7262)Eugene McDermott Foundatio

Pan-Eurasian Experiment (PEEX): Towards a holistic understanding of the feedbacks and interactions in the land-Atmosphere-ocean-society continuum in the northern Eurasian region

The northern Eurasian regions and Arctic Ocean will very likely undergo substantial changes during the next decades. The Arctic-boreal natural environments play a crucial role in the global climate via albedo change, carbon sources and sinks as well as atmospheric aerosol production from biogenic volatile organic compounds. Furthermore, it is expected that global trade activities, demographic movement, and use of natural resources will be increasing in the Arctic regions. There is a need for a novel research approach, which not only identifies and tackles the relevant multi-disciplinary research questions, but also is able to make a holistic system analysis of the expected feedbacks. In this paper, we introduce the research agenda of the Pan-Eurasian Experiment (PEEX), a multi-scale, multi-disciplinary and international program started in 2012 (https://www.atm.helsinki.fi/peex/). PEEX sets a research approach by which large-scale research topics are investigated from a system perspective and which aims to fill the key gaps in our understanding of the feedbacks and interactions between the land-Atmosphere-Aquatic-society continuum in the northern Eurasian region. We introduce here the state of the art for the key topics in the PEEX research agenda and present the future prospects of the research, which we see relevant in this context

Role of IKK/NF-κB Signaling in Extinction of Conditioned Place Aversion Memory in Rats

The inhibitor κB protein kinase/nuclear factor κB (IKK/NF-κB) signaling pathway is critical for synaptic plasticity. However, the role of IKK/NF-κB in drug withdrawal-associated conditioned place aversion (CPA) memory is unknown. Here, we showed that inhibition of IKK/NF-κB by sulphasalazine (SSZ; 10 mM, i.c.v.) selectively blocked the extinction but not acquisition or expression of morphine-induced CPA in rats. The blockade of CPA extinction induced by SSZ was abolished by sodium butyrate, an inhibitor of histone deacetylase. Thus, the IKK/NF-κB signaling pathway might play a critical role in the extinction of morphine-induced CPA in rats and might be a potential pharmacotherapy target for opiate addiction