Optimal unravellings for feedback control in linear quantum systems.

For quantum systems with linear dynamics in phase space much of classical feedback control theory applies. However, there are some questions that are sensible only for the quantum case: Given a fixed interaction between the system and the environment what is the optimal measurement on the environment for a particular control problem? We show that for a broad class of optimal (state-based) control problems (the stationary linear-quadratic-Gaussian class), this question is a semidefinite program. Moreover, the answer also applies to Markovian (current-based) feedback.

Changes in metal levels and chromosome aberrations in the peripheral blood of patients after metal-on-metal hip arthroplasty.

A prospective study was performed to investigate changes in metal levels and chromosome aberrations in patients within 2 years of receiving metal-on-metal hip arthroplasties. There was a statistically significant increase of cobalt and chromium concentrations, with a small increase in molybdenum, in whole blood at 6, 12, and 24 months after surgery. There was also a statistically significant increase of both chromosome translocations and aneuploidy in peripheral blood lymphocytes at 6, 12, and 24 months after surgery.

A pathway of double-strand break rejoining dependent upon ATM, Artemis, and proteins locating to gamma-H2AX foci.

The hereditary disorder ataxia telangiectasia (A-T) is associated with striking cellular radiosensitivity that cannot be attributed to the characterized cell cycle checkpoint defects. By epistasis analysis, we show that ataxia telangiectasia mutated protein (ATM) and Artemis, the protein defective in patients with RS-SCID, function in a common double-strand break (DSB) repair pathway that also requires H2AX, 53BP1, Nbs1, Mre11, and DNA-PK. We show that radiation-induced Artemis hyperphosphorylation is ATM dependent.

Mycobacterial Ku and ligase proteins constitute a two-component NHEJ repair machine.

In mammalian cells, repair of DNA double-strand breaks (DSBs) by nonhomologous end-joining (NHEJ) is critical for genome stability. Although the end-bridging and ligation steps of NHEJ have been reconstituted in vitro, little is known about the end-processing reactions that occur before ligation. Recently, functionally homologous end-bridging and ligation activities have been identified in prokarya.

Human PTIP facilitates ATM-mediated activation of p53 and promotes cellular resistance to ionizing radiation.

Mus musculus Pax2 transactivation domain-interacting protein (Ptip) is an essential gene required for the maintenance of genome stability, although its precise molecular role is unclear. Human PTIP (hPTIP) was recently isolated in a screen for proteins, translated from cDNA pools, capable of interacting with peptides phosphorylated by the ATM (ataxia telangiectasia-mutated)/ATR (ataxia telangiectasia-related) protein kinases. hPTIP was described as a 757-amino acid protein bearing four BRCT domains.

Analysis of DNA ligase IV mutations found in LIG4 syndrome patients: the impact of two linked polymorphisms.

LIG4 syndrome patients have hypomorphic mutations in DNA ligase IV. Although four of the five identified patients display immunodeficiency and developmental delay, one patient was developmentally normal. The developmentally normal patient had the same homozygous mutation (R278H) in DNA ligase IV as one of the more severely affected patients, who additionally had two linked polymorphisms.

Selective loss of imprinting in the placenta following preimplantation development in culture.

Preimplantation development is a period of dynamic epigenetic change that begins with remodeling of egg and sperm genomes, and ends with implantation. During this time, parental-specific imprinting marks are maintained to direct appropriate imprinted gene expression. We previously demonstrated that H19 imprinting could be lost during preimplantation development under certain culture conditions.

Epigenetic repression of transcription by the Vitamin D3 receptor in prostate cancer cells.

Normal prostate epithelial cells are acutely sensitive to the antiproliferative action of 1alpha,25-dihydroxyvitamin D(3) (1alpha,25(OH)(2)D(3)), whilst prostate cancer cell lines and primary cultures display a range of sensitivities. We hypothesised that key antiproliferative target genes of the Vitamin D receptor (VDR) were repressed by an epigenetic mechanism in 1alpha,25(OH)(2)D(3)-insensitive cells. Supportively, we found elevated nuclear receptor co-repressor and reduced VDR expression correlated with reduced sensitivity to the antiproliferative action of 1alpha,25(OH)(2)D(3).

Wear debris from hip or knee replacements causes chromosomal damage in human cells in tissue culture.

Wear debris was extracted from 21 worn hip and knee replacements. Its mutagenic effects were tested on human cells in tissue culture using the micronucleus assay and fluorescent in situ hybridisation. The extracted wear debris increased the level of micronuclei in a linear dose-dependent manner but with a tenfold difference between samples.

Women's perceptions of support from partners, family members and close friends for smoking cessation during pregnancy--combining quantitative and qualitative findings.

This article reports on data collected as part of a four-phase study initiated to strengthen practice in the field of smoking cessation during pregnancy. It focuses on the perceived support pregnant smokers would receive for quitting smoking and how this support could be effectively used by incorporating the education of partners/family in smoking cessation intervention strategies. Both quantitative and qualitative methods were employed, and data were collected from pregnant smokers through semistructured interviews and self-completed questionnaires.

Quantum Kalman filtering and the Heisenberg limit in atomic magnetometry.

The shot-noise detection limit in current high-precision magnetometry [Nature (London) 422, 596 (2003)] is a manifestation of quantum fluctuations that scale as 1/sqrt[N] in an ensemble of N atoms. Here, we develop a procedure that combines continuous measurement and quantum Kalman filtering [Rep. Math.

EMSY links the BRCA2 pathway to sporadic breast and ovarian cancer.

The BRCA2 gene is mutated in familial breast and ovarian cancer, and its product is implicated in DNA repair and transcriptional regulation. Here we identify a protein, EMSY, which binds BRCA2 within a region (exon 3) deleted in cancer. EMSY is capable of silencing the activation potential of BRCA2 exon 3, associates with chromatin regulators HP1beta and BS69, and localizes to sites of repair following DNA damage.

The efficacy of BMP-2 to induce bone ingrowth in a total hip replacement model.

The purpose of this canine total hip arthroplasty (THA) study was fourfold: (1) to quantify the efficacy of rhBMP-2 in a carrier (alphaBSM) versus alphaBSM alone, and versus untreated controls to induce bone formation across a defect between a porous acetabular component and host bone; (2) to quantify whether rhBMP-2/alphaBSM improves bone growth into the porous surface beneath that defect; (3) to quantify the efficacy of rhBMP-2/alphaBSM in inducing bone ingrowth into the porous layer at points of intimate bone-implant contact; and (4) to determine whether rhBMP-2/alphaBSM placed in the lateral uncovered aspect of the porous acetabular component promotes de novo bone formation. Fifteen dogs were sacrificed 12 weeks after uncemented THA. Five dogs received rhBMP-2/alphaBSM, five dogs received alphaBSM, and five dogs were controls.

Cardiac effects of endothelin-1 (ET-1) and related C terminal peptide fragment: increased inotropy or contribution to heart failure?

The contrasting pattern of cardiac inotropy induced by human peptide endothelin-1 (ET-1) has not been satisfactorily explained. It is not clear whether ET-1 is primarily responsible for increased myocardial ET-1 expression and release with resultant inotropic effects, or for the induction of myocardial hypertrophy and heart failure. There are at least two subtypes of endothelin receptors (ET(A) and ET(B)) and the inotropic effects of ET-1 differ depending on the receptor involved.

Microcell-mediated chromosome transfer (MMCT): small cells with huge potential.

Microcell-mediated chromosome transfer (MMCT) is a technique that has been in use since the 1970s for the fusion of microcells, containing single or a small number of chromosomes, with whole cells, and the subsequent selection of the hybrids. MMCT can be carried out with somatic cells, embryonic carcinoma (EC) or embryonic stem (ES) cell recipients, to study in vitro or in vivo effects of the transferred genetic material. These effects may be unpredictable--do the transferred genes function normally while in the regulatory milieu of the host cell? Will epigenetic effects become apparent, and how will these alter gene expression? What happens to the host cell phenotype? Here, we present a review of MMCT in which we argue that, although this is an old technique, its adaptability and efficiency make it an excellent method for the dissection of gene function and dysfunction in a very wide range of current systems.

Role of nerve growth factor in the trinitrobenzene sulfonic acid-induced colonic hypersensitivity.

The majority of patients with digestive disorders display visceral pain. In these troubles, visceral pain threshold is decreased, demonstrating visceral hypersensitivity. There is growing evidence that nerve growth factor (NGF) may function as a mediator of persistent pain states.

Accuracy of self-reported height and weight in women: an integrative review of the literature.

Height and weight are two of the most commonly used anthropometric measurements in clinical practice and research. Self-reported height and weight measurement is a simple, efficient, inexpensive, and non-invasive method of collecting data from large numbers of people. This integrative review of the published research examined the accuracy of self-reported height and weight measurements in women.

The effects of treating bovine hide with steam at subatmospheric pressure on bacterial numbers and leather quality.

Aims: To examine the effect of subatmospheric steam treatment on total viable counts (TVCs) on bovine hide and on the quality of derived leather.

Methods And Results: Pieces of bovine hide were heated to 75 degrees C (+/-2 degrees C) (n = 3) or 80 degrees C (+/-2 degrees C) (n = 3) for periods of 1, 10 or 20 s by the application of steam at subatmospheric pressure in a laboratory scale apparatus. Treated hide pieces and untreated controls were tanned and the quality of leather was assessed.

The prevalence and spread of Escherichia coli O157:H7 at a commercial beef abattoir.

Aims: To investigate the prevalence and virulence characteristics of Escherichia coli O157:H7 after a number of beef process operations at a commercial Irish abattoir.

Methods And Results: Two 12-month studies were carried out. The first study (study 1) examined the prevalence of E.

Potential role for 53BP1 in DNA end-joining repair through direct interaction with DNA.

Upon DNA damage, p53-binding protein 1 (53BP1) relocalizes to sites of DNA double-strand breaks and forms discrete nuclear foci, suggesting its role in DNA damage responses. We show that 53BP1 changed its localization from the detergent soluble to insoluble fraction after treatment of cells with x-ray, but not with ultraviolet or hydroxyurea. Either DNase or phosphatase treatment of the insoluble fraction released 53BP1 into the soluble fraction, showing that 53BP1 binds to chromatin in a phosphorylation-dependent manner after X-irradiation of cells.

Characterisation of the expression of a novel constitutive maize promoter in transgenic wheat and maize.

A novel constitutive promoter from the maize histone H2Bgene was recently identified. In this study, we characterised H2B promoter activity in both wheat and maize tissues using the gusA reporter gene and two synthetic versions of the pat (phosphinothricin acetyl transferase) selectable marker gene, namely mopat and popat. Analyses of transgenic plants showed that the H2B promoter is able to drive the expression of gusA to strong, constitutive levels in wheat and maize tissues.