Manifestations of Broken Symmetry: The Surfaces Phases of Ca\u3csub\u3e2−x\u3c/sub\u3eSr\u3csub\u3ex\u3c/sub\u3eRuO\u3csub\u3e4\u3c/sub\u3e

The discovery of superconductivity in Sr2RuO4 has renewed vigor in the study of correlated electron systems. The evolution of a p-wave superconducting state from a para- magnetic 2-dimensional Fermi liquid shows the ruthenate superconductivity is anything but conventional. Sr2RuO4 is isostructural with La2CuO4, the parent compound for the high temperature superconducting family La2−xSrxRuO4. The substitution of Ca2+ for Sr2+ generates a different structure involving a static rotation and tilt of the RuO6 octahedral, however, the antiferromagnetic insulating ground state of Ca2RuO4 is more akin to the cuprate parent. The generation of Ca2−xSrxRuO4 has offered a new family of com- pounds where the evolution from an antiferromagnetic insulator to a superconductor can be studied. Bulk studies have demonstrated how the intricate couplings between structural, orbital, electronic, and magnetic degrees of freedom are responsible for the exotic phases of the system. The layered perovskite structure which plays a key role in the properties observed also makes the crystals amenable to cleaving. Breaking symmetry by the creation of a surface on a quasi 2-dimensional system offers an opportunity to gain insight into the role of structure and symmetry on the properties of the system and offers a new avenue to discover new physics. Inelastic neutron scattering has been utilized to reveal the structural instability against the RuO6 tilt. While the Σ4 phonon mode involving the octahedral tilt shows classic soft phonon mode behavior across a tetragonal to orthorhombic phase transition, a new anomalous mode is discovered and its origin is explored. Surface phonon dynamics have been investigated across a Mott metal-to-insulator transition utilizing High Resolution Electron Energy Loss Spectroscopy where it is revealed the surface electronic transition temperature is significantly lower than the bulk. Low Energy Electron Diffraction has been employed to investigate the surface structure and structural transitions on the surface. Results show surface relaxations inhibit the RuO6 tilt dramatically altering the ensuing orthorhombic phase transition near a quantum critical point at xc = 0.5. It is also revealed that structural distortions accompanying the bulk metal-to-insulator transition are simply nonexistent on the surface. Physical manifestations from breaking symmetry in a correlated electron system are revealed

1974

History of Golf (1) The Nine Toughest Holes in the World (2) Stockie Madness (3) Bartender, One More Round for Pythium (3) Panel: 1973 Turf Problems in Review - 1974 Possible Remedies (A1-A12) Movement of Water to a Holding Pond (A13) Maintenance of Low Budget, Short Season Golf Courses (A16) Turfgrass Fertilization (A18) Determining Turfgrass Fertilizer Needs (A25) Shortage of Plant Food and How to Adjust to Supply and Cost (A29) Panel: Tricalcium Arsenate - Use and Abuse (A33-A46) Operating and Maintaining Municipal Golf Courses (A48) Maintenance of a High Budget Golf Course (A51) Trends in Agricultural Education and Where Are the Emphases (A58) Maintenance of Municipal Parks and Recreation Areas (A60) Maintenance of Grass Tennis Courts (A63) Transition from Natural to Artificial Turf (A67) Plant materials for Outlying Areas (A71) Care of University Grounds (A76) Maintenance of Industrial Sites (A79) Turfgrass Diseases and Systemic Fungicides (A81) A Look at the Future (A 84) Watering of Golf Course Turf (A92

Pooled analysis of WHO Surgical Safety Checklist use and mortality after emergency laparotomy

Background The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89.6 per cent) compared with that in countries with a middle (753 of 1242, 60.6 per cent; odds ratio (OR) 0.17, 95 per cent c.i. 0.14 to 0.21, P <0001) or low (363 of 860, 422 per cent; OR 008, 007 to 010, P <0.001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference -94 (95 per cent c.i. -11.9 to -6.9) per cent; P <0001), but the relationship was reversed in low-HDI countries (+121 (+7.0 to +173) per cent; P <0001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0.60, 0.50 to 073; P <0.001). The greatest absolute benefit was seen for emergency surgery in low- and middle-HDI countries. Conclusion Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries.Peer reviewe

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

Chromosomal Alterations in Ulcerative Colitis-Related and Sporadic Colorectal Cancers by Comparative Genomic Hybridization

Both ulcerative colitis (UC)-related and sporadic colorectal cancers are thought to evolve through a multistep process of genomic instability, accumulation of genomic alterations and clonal expansion. This process may involve different genomic changes in UC-related cancers than in sporadic cancers due to the origin of UC-related cancers in an inflammatory field. This study was designed to define the specific genomic events in UC-related cancers. Comparative genomic hybridization (CGH) was performed on 32 UC-related and 42 stage-matched sporadic colorectal cancers. The mean number of chromosomal alterations per case was similar in the UC-related and sporadic tumor groups (8.6 in UC, 8.1 in sporadic). Frequently lost regions in both cancer groups were 18q (78% UC, 69% sporadic), 8p (53% UC, 50% sporadic), and 17p (44% UC, 57% sporadic). The three most frequent gains involved chromosomes 8q (63% UC, 45% sporadic), 20q (44% UC, 67% sporadic), and 13q (44% UC, 38% sporadic). Chromosome 5q was lost in 56% of UC-related but in only 26% of sporadic cancers. Losses of 17q and gains of 5p were also more frequent in UC-related cancers, whereas losses of 14q and gains of Xp were significantly less common in UC-related cancers than in sporadic tumors. There was a stage-related increase in chromosome 8 alterations in UC-related but not in sporadic cancers, while only sporadic tumors showed a stage progression for 5p loss, 17q gain, and 18q loss. Thus, differences in the frequency and timing of individual chromosomal alterations suggest that the genetic pathways in these two tumor groups are distinct from each other.