B3 0003+387: AGN Marked Large-Scale Structure at z=1.47?

We present evidence for a significant overdensity of red galaxies, as much as a factor of 14 over comparable field samples, in the field of the z=1.47 radio galaxy B3 0003+387. The colors and luminosities of the brightest red galaxies are consistent with their being at z>0.8. The radio galaxy and one of the red galaxies are separated by 5" and show some evidence of a possible interaction. However, the red galaxies do not show any strong clustering around the radio galaxy nor around any of the brighter red galaxies. The data suggest that we are looking at a wall or sheet of galaxies, possibly associated with the radio galaxy at z=1.47. Spectroscopic redshifts of these red galaxies will be necessary to confirm this large-scale structure.Comment: 19 pages, 7 figures, LaTeX2e/AASTeX v5.0.2. The full photometric catalog is included as a separate deluxetable file. To appear in the Astronomical Journal (~Nov 00

Shortcuts in a Nonlinear Dynamical Braneworld in Six Dimensions

We consider a dynamical brane world in a six-dimensional spacetime containing a singularity. Using the Israel conditions we study the motion of a 4-brane embedded in this setup. We analyse the brane behaviour when its position is perturbed about a fixed point and solve the full nonlinear dynamics in the several possible scenarios. We also investigate the possible gravitational shortcuts and calculate the delay between graviton and photon signals and the ratio of the corresponding subtended horizons.Comment: 26 pages, 9 figures. References and discussion added. Title changed to match the version accepted in Class. and Quant. Gra

Conserved Mechanisms of Tumorigenesis in the Drosophila Adult Midgut

<div><p>Whereas the series of genetic events leading to colorectal cancer (CRC) have been well established, the precise functions that these alterations play in tumor progression and how they disrupt intestinal homeostasis remain poorly characterized. Activation of the Wnt/Wg signaling pathway by a mutation in the gene APC is the most common trigger for CRC, inducing benign lesions that progress to carcinomas due to the accumulation of other genetic alterations. Among those, Ras mutations drive tumour progression in CRC, as well as in most epithelial cancers. As mammalian and <i>Drosophila</i>'s intestines share many similarities, we decided to explore the alterations induced in the <i>Drosophila</i> midgut by the combined activation of the Wnt signaling pathway with gain of function of Ras signaling in the intestinal stem cells. Here we show that compound Apc-Ras clones, but not clones bearing the individual mutations, expand as aggressive intestinal tumor-like outgrowths. These lesions reproduce many of the human CRC hallmarks such as increased proliferation, blockade of cell differentiation and cell polarity and disrupted organ architecture. This process is followed by expression of tumoral markers present in human lesions. Finally, a metabolic behavioral assay shows that these flies suffer a progressive deterioration in intestinal homeostasis, providing a simple readout that could be used in screens for tumor modifiers or therapeutic compounds. Taken together, our results illustrate the conservation of the mechanisms of CRC tumorigenesis in <i>Drosophila</i>, providing an excellent model system to unravel the events that, upon mutation in Apc and Ras, lead to CRC initiation and progression.</p></div

Optical Spectroscopy of Embedded Young Stars in the Taurus-Auriga Molecular Cloud

This paper describes the first optical spectroscopic survey of class I sources (also known as embedded sources and protostars) in the Taurus-Auriga dark cloud. We detect 10 of the 24 known class I sources in the cloud at 5500-9000 A. All detected class I sources have strong H-alpha emission; most also have strong [O I] and [S II] emission. These data - together with high quality optical spectra of T Tauri stars in the Taurus-Auriga cloud - demonstrate that forbidden emission lines are stronger and more common in class I sources than in T Tauri stars. Our results also provide a clear discriminant in the frequency of forbidden line emission between weak-emission and classical T Tauri stars. In addition to strong emission lines, three class I sources have prominent TiO absorption bands. The M-type central stars of these sources mingle with optically visible T Tauri stars in the HR diagram and lie somewhat below both the birthline for spherical accretion and the deuterium burning sequence for disc accretion.Comment: 19 pages of text, 4 pages of tables, and 10 pages of figure

Smart Focal Plane Technologies for VLT Instruments

As we move towards the era of ELTs, it is timely to think about the future role of the 8-m class telescopes. Under the OPTICON programme, novel technologies have been developed that are intended for use in multi-object and integral-field spectrographs. To date, these have been targeted at instrument concepts for the European ELT, but there are also significant possibilities for their inclusion in new VLT instruments, ensuring the continued success and productivity of these unique telescopes.Comment: 5 pages, to appear in the proceedings of the ESO Workshop "Science with the VLT in the ELT era

The Magnetic Fields of Classical T Tauri Stars

We report new magnetic field measurements for 14 classical T Tauri stars (CTTSs). We combine these data with one previous field determination in order to compare our observed field strengths with the field strengths predicted by magnetospheric accretion models. We use literature data on the stellar mass, radius, rotation period, and disk accretion rate to predict the field strength that should be present on each of our stars according to these magnetospheric accretion models. We show that our measured field values do not correlate with the field strengths predicted by simple magnetospheric accretion theory. We also use our field strength measurements and literature X-ray luminosity data to test a recent relationship expressing X-ray luminosity as a function of surface magnetic flux derived from various solar feature and main sequence star measurements. We find that the T Tauri stars we have observed have weaker than expected X-ray emission by over an order of magnitude on average using this relationship. We suggest the cause for this is actually a result of the very strong fields on these stars which decreases the efficiency with which gas motions in the photosphere can tangle magnetic flux tubes in the corona.Comment: 25 pages, 5 figure

Development of a Li2MoO4 scintillating bolometer for low background physics

We present the performance of a 33 g Li2MoO4 crystal working as a scintillating bolometer. The crystal was tested for more than 400 h in a dilution refrigerator installed in the underground laboratory of Laboratori Nazionali del Gran Sasso (Italy). This compound shows promising features in the frame of neutron detection, dark matter search (solar axions) and neutrinoless double-beta decay physics. Low temperature scintillating properties were investigated by means of different alpha, beta/gamma and neutron sources, and for the first time the Light Yield for different types of interacting particle is estimated. The detector shows great ability of tagging fast neutron interactions and high intrinsic radiopurity levels (< 90 \muBq/kg for 238-U and < 110 \muBq/kg for 232-Th).Comment: revised versio

Reducing the impact of radioactivity on quantum circuits in a deep-underground facility

As quantum coherence times of superconducting circuits have increased from nanoseconds to hundreds of microseconds, they are currently one of the leading platforms for quantum information processing. However, coherence needs to further improve by orders of magnitude to reduce the prohibitive hardware overhead of current error correction schemes. Reaching this goal hinges on reducing the density of broken Cooper pairs, so-called quasiparticles. Here, we show that environmental radioactivity is a significant source of nonequilibrium quasiparticles. Moreover, ionizing radiation introduces time-correlated quasiparticle bursts in resonators on the same chip, further complicating quantum error correction. Operating in a deep-underground lead-shielded cryostat decreases the quasiparticle burst rate by a factor fifty and reduces dissipation up to a factor four, showcasing the importance of radiation abatement in future solid-state quantum hardware

Efficacy of epidermal growth factor receptor targeting in advanced chordoma: case report and literature review

<p>Abstract</p> <p>Background</p> <p>Chordomas are very rare low-grade malignant bone tumors that arise from the embryonic rests of the notochord. They are characterized by slow growth and long history with frequent local relapses, and sometimes metastases. While chemotherapy is not efficient, imatinib has shown antitumor activity.</p> <p>Case presentation</p> <p>We report on a 76-year-old patient with EGFR-overexpressing advanced chordoma that progressed on imatinib and subsequently responded to erlotinib during 12 months.</p> <p>Conclusions</p> <p>We report the fourth case of advanced chordoma treated with an EGFR inhibitor. We also review the literature concerning the rationale and potential of EGFR targeting in chordoma.</p

Stratification of unresponsive patients by an independently validated index of brain complexity.

OBJECTIVE: Validating objective, brain-based indices of consciousness in behaviorally unresponsive patients represents a challenge due to the impossibility of obtaining independent evidence through subjective reports. Here we address this problem by first validating a promising metric of consciousness-the Perturbational Complexity Index (PCI)-in a benchmark population who could confirm the presence or absence of consciousness through subjective reports, and then applying the same index to patients with disorders of consciousness (DOCs). METHODS: The benchmark population encompassed 150 healthy controls and communicative brain-injured subjects in various states of conscious wakefulness, disconnected consciousness, and unconsciousness. Receiver operating characteristic curve analysis was performed to define an optimal cutoff for discriminating between the conscious and unconscious conditions. This cutoff was then applied to a cohort of noncommunicative DOC patients (38 in a minimally conscious state [MCS] and 43 in a vegetative state [VS]). RESULTS: We found an empirical cutoff that discriminated with 100% sensitivity and specificity between the conscious and the unconscious conditions in the benchmark population. This cutoff resulted in a sensitivity of 94.7% in detecting MCS and allowed the identification of a number of unresponsive VS patients (9 of 43) with high values of PCI, overlapping with the distribution of the benchmark conscious condition. INTERPRETATION: Given its high sensitivity and specificity in the benchmark and MCS population, PCI offers a reliable, independently validated stratification of unresponsive patients that has important physiopathological and therapeutic implications. In particular, the high-PCI subgroup of VS patients may retain a capacity for consciousness that is not expressed in behavior