Precision Measurements Using Squeezed Spin States via Two-axis Counter-twisting Interactions

We show that the two-axis counter twisting interaction squeezes a coherent spin state into three states of interest in quantum information, namely, the twin-Fock state, the equally-weighted superposition state, and the state that achieves the Heisenberg limit of optimal sensitivity defined by the Cramer-Rao inequality in addition to the well-known Heisenberg-limited state of spin fluctuations.Comment: 5 pages, 3 figure

Transverse momentum and centrality dependence of dihadron correlations in Au+Au collisions at sqrt(s_NN)=200 GeV: Jet-quenching and the response of partonic matter

Azimuthal angle \Delta\phi correlations are presented for charged hadrons from dijets for 0.4 < p_T < 10 GeV/c in Au+Au collisions at sqrt(s_NN) = 200 GeV. With increasing p_T, the away-side distribution evolves from a broad to a concave shape, then to a convex shape. Comparisons to p+p data suggest that the away-side can be divided into a partially suppressed "head" region centered at Delta\phi ~ \pi, and an enhanced "shoulder" region centered at Delta\phi ~ \pi +/- 1.1. The p_T spectrum for the "head" region softens toward central collisions, consistent with the onset of jet quenching. The spectral slope for the "shoulder" region is independent of centrality and trigger p_T, which offers constraints on energy transport mechanisms and suggests that the "shoulder" region contains the medium response to energetic jets.Comment: 420 authors from 58 institutions, 6 pages, 4 figures. Submitted to Physical Review Letters. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

Particle-species dependent modification of jet-induced correlations in Au+Au collisions at sqrt(s_NN) = 200 GeV

We report PHENIX measurements of the correlation of a trigger hadron at intermediate transverse momentum (2.5<p_{T,trig}<4 GeV/c), with associated mesons or baryons at lower p_{T,assoc}, in Au+Au collisions at sqrt(s_NN) = 200 GeV. The jet correlations for both baryons and mesons show similar shape alterations as a function of centrality, characteristic of strong modification of the away-side jet. The ratio of jet-associated baryons to mesons for this jet increases with centrality and p_{T,assoc} and, in the most central collisions, reaches a value similar to that for inclusive measurements. This trend is incompatible with in-vacuum fragmentation, but could be due to jet-like contributions from correlated soft partons which recombine upon hadronization.Comment: 344 authors, 4 pages text, RevTeX, 4 figures. Submitted to Physical Review Letters. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

Suppression pattern of neutral pions at high transverse momentum in Au+Au collisions at sqrt(s_NN) = 200 GeV and constraints on medium transport coefficients

For Au + Au collisions at 200 GeV we measure neutral pion production with good statistics for transverse momentum, p_T, up to 20 GeV/c. A fivefold suppression is found, which is essentially constant for 5 < p_T < 20 GeV/c. Experimental uncertainties are small enough to constrain any model-dependent parameterization for the transport coefficient of the medium, e.g. \mean(q^hat) in the parton quenching model. The spectral shape is similar for all collision classes, and the suppression does not saturate in Au+Au collisions; instead, it increases proportional to the number of participating nucleons, as N_part^2/3.Comment: 422 authors, 6 pages text, RevTeX-4, 4 figures, 1 Table. Submitted to Physical Review Letters. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Cognitive and Adaptive Outcome in Low-Grade Pediatric Cerebellar Astrocytomas: Evidence of Diminished Cognitive and Adaptive Functioning in National Collaborative Research Studies (CCG 9891/POG 9130)

Purpose Clinicians often assume that children with posterior fossa tumors are at minimal risk for cognitive or adaptive deficits if they do not undergo cranial irradiation. However, small case series have called that assumption into question, and have also suggested that nonirradiated cerebellar tumors can cause location-specific cognitive and adaptive impairment. This study (1) assessed whether resected but not irradiated pediatric cerebellar tumors are associated with cognitive and adaptive functioning deficits, and (2) examined the effect of tumor location and medical complications on cognitive and adaptive functioning. Patients and Methods The sample was composed of 103 children aged 3 to 18 years with low-grade cerebellar astrocytomas, who underwent only surgical treatment as part of Children's Cancer Group protocol 9891 or Pediatric Oncology Group protocol 9130. The sample was divided into three groups based on primary tumor location: vermis, left hemisphere, or right hemisphere. Data were collected prospectively on intelligence, academic achievement, adaptive skills, behavioral functioning, and pre-, peri-, and postsurgical medical complications. Results The sample as a whole displayed an elevated risk for cognitive and adaptive impairment that was not associated consistently with medical complications. Within this group of children with cerebellar tumors, tumor location had little effect on cognitive, adaptive, or medical outcome. Conclusion We did not replicate previous findings of location-specific effects on cognitive or adaptive outcome. However, the elevated risk of deficits in this population runs contrary to clinical lore, and suggests that clinicians should attend to the functional outcomes of children who undergo only surgical treatment for cerebellar tumors

Cognitive and Adaptive Outcome in Extracerebellar Low-Grade Brain Tumors in Children: A Report From the Children's Oncology Group

Purpose To determine whether pediatric patients treated with surgery only for low-grade tumors in the cerebral hemispheres, supratentorial midline, and exophytic brainstem evidence neurocognitive, academic, adaptive, or emotional/behavioral sequelae. Patients and Methods Ninety-three patients from a natural history study of low-grade astrocytomas were tested an average of 111 days after surgery. Rates of below average (≤ 25th percentile) scores in this sample were compared with test norms, and performances were compared across anatomic sites. Finally, the relationships of pre-, peri-, and postsurgical complications to outcome were investigated. Results For the entire sample, there was a significantly elevated rate of below average scores across intelligence quotient, achievement, and adaptive behavior, but not behavioral/emotional adjustment measures. Patients with hemispheric, midline, and brainstem tumors did not differ significantly. Patients with left hemisphere tumors generally performed worse than those with right hemisphere tumors. Finally, neurobehavioral outcome was unrelated to pre-, peri-, or postsurgery complications. Conclusion After surgery for low-grade brain tumors, a significant number of patients was found to function below average, by as much as 55% compared with 25% in the normative population. Moreover, these results suggest greater risk for patients with lesions situated in the left cerebral hemisphere. Routine neuropsychological follow-up of children after treatment for low-grade tumors is recommended