Positivity in the presence of initial system-environment correlation

The constraints imposed by the initial system-environment correlation can lead to nonpositive Dynamical maps. We find the conditions for positivity and complete positivity of such dynamical maps by using the concept of an assignment map. Any initial system-environment correlations make the assignment map nonpositive, while the positivity of the dynamical map depends on the interplay between the assignment map and the system-environment coupling. We show how this interplay can reveal or hide the nonpositivity of the assignment map. We discuss the role of this interplay in Markovian models.Comment: close to the published version. 5 pages, 1 figur

Stroke and HIV - casual or coincidental co-occurrence?

No Abstract. South African Medical Journal Vol. 96 (12) 2006: pp.1247-124

Preterm nutritional intake and MRI phenotype at term age: a prospective observational study

Objective: To describe (1) the relationship between nutrition and the preterm-at-term infant phenotype, (2) phenotypic differences between preterm-at-term infants and healthy term born infants and (3) relationships between somatic and brain MRI outcomes. Design: Prospective observational study. Setting: UK tertiary neonatal unit. Participants: Preterm infants (<32 weeks gestation) (n=22) and healthy term infants (n=39) Main outcome measures: Preterm nutrient intake; total and regional adipose tissue (AT) depot volumes; brain volume and proximal cerebral arterial vessel tortuosity (CAVT) in preterm infants and in term infants. Results: Preterm nutrition was deficient in protein and high in carbohydrate and fat. Preterm nutrition was not related to AT volumes, brain volume or proximal CAVT score; a positive association was noted between human milk intake and proximal CAVT score (r=0.44, p=0.05). In comparison to term infants, preterm infants had increased total adiposity, comparable brain volumes and reduced proximal CAVT scores. There was a significant negative correlation between deep subcutaneous abdominal AT volume and brain volume in preterm infants (r=−0.58, p=0.01). Conclusions: Though there are significant phenotypic differences between preterm infants at term and term infants, preterm macronutrient intake does not appear to be a determinant. Our preliminary data suggest that (1) human milk may exert a beneficial effect on cerebral arterial vessel tortuosity and (2) there is a negative correlation between adiposity and brain volume in preterm infants at term. Further work is warranted to see if our findings can be replicated and to understand the causal mechanisms

Foundations of Quantum Discord

This paper summarizes the basics of the notion of quantum discord and how it relates to other types of correlations in quantum physics. We take the fundamental information theoretic approach and illustrate our exposition with a number of simple examples.Comment: 3 pages, special issue edited by Diogo de Oliveira Soares Pinto et a

HER2 breast cancer therapies: a review

Amplification of the HER2 gene and/or overexpression of its protein product have been found in up to 25% to 30% of human breast cancers and have been shown to be associated with poorer outcomes compared to ‘HER2 normal’ breast cancer. Research has focused on developing therapies directed to the HER2 receptor and its pathway. These include the monoclonal antibody trastuzumab, which has improved outcomes when used in patients with both advanced and early breast cancer. Lapatinib is a small-molecule tyrosine kinase inhibitor which has demonstrated activity in advanced breast cancer and is currently being evaluated in early stage disease. We discuss the therapeutic rationale and clinical trial experience with these agents. Other novel and emerging strategies targeting the HER2 receptor and its pathway are also discussed. These strategies include novel HER2 antibodies and small-molecule inhibitors, antibody–drug conjugates, agents targeting downstream components of the HER2 signaling pathway, and heat shock protein 90 (HSP90) inhibitors

Characterizing quantum dynamics with initial system-environment correlations

We fully characterize the reduced dynamics of an open quantum system initially correlated with its environment. Using a photonic qubit coupled to a simulated environment we tomographically reconstruct a superchannel---a generalised channel that treats preparation procedures as inputs---from measurement of the system alone, despite its coupling to the environment. We introduce novel quantitative measures for determining the strength of initial correlations, and to allow an experiment to be optimised in regards to its environment.Comment: 10 pages, 15 figure

Anaesthetic Management of Ischemic Heart Disease patient for Total Abdominal Hysterectomy under Epidural Anaesthesia and Analgesia

Anaesthetic management of cardiac patient’s coming for non cardiac surgery has always been challenging. Goal of anaesthesia management is to keep myocardial oxygen supply greater than demand to avoid ischemia. Choice of anaesthesia has been general anaesthesia (GA) by achieving the goals, in order to prevent ischemia intra and post operatively in cardiac patient coming for non cardiac surgery. In this case report anaesthetic implications included assessment of cardio vascular status of the patient pre operatively with selection of epidural anaesthesia and analgesia technique. Incremental doses of local anaesthetic (LA) were given keeping in mind, myocardial oxygen supply to be greater than demand to avoid ischemia. To the best of our knowledge, there have been only few case reports on epidural anaesthesia for ischemic heart disease (IHD) patient coming for non cardiac surgery. Hence we report a successful anaesthetic management of a patient with ischemic heart disease for total abdominal hysterectomy under epidural anaesthesia and analgesia

How state preparation can affect a quantum experiment: Quantum process tomography for open systems

We study the effects of preparation of input states in a quantum tomography experiment. We show that maps arising from a quantum process tomography experiment (called process maps) differ from the well know dynamical maps. The difference between the two is due to the preparation procedure that is necessary for any quantum experiment. We study two preparation procedures, stochastic preparation and preparation by measurements. The stochastic preparation procedure yields process maps that are linear, while the preparations using von Neumann measurements lead to non-linear processes, and can only be consistently described by a bi-linear process map. A new process tomography recipe is derived for preparation by measurement for qubits. The difference between the two methods is analyzed in terms of a quantum process tomography experiment. A verification protocol is proposed to differentiate between linear processes and bi-linear processes. We also emphasize the preparation procedure will have a non-trivial effect for any quantum experiment in which the system of interest interacts with its environment.Comment: 13 pages, no figures, submitted to Phys. Rev.

Palladium(II) saccharinate complexes trans-[Pd(sac)(2)(LH)(2)] with amino- and acetylamino-pyridine co-ligands: molecular structures of trans-[PdCl2(2-ampyH)(2)].2dmf (2-ampyH=2-amino-3-methylpyridine) and trans-[Pd(kappa(2)-2-acmpy)(2)] (2-acmpyH=2-acetylamino-3-methylpyridine)

Reaction of Na2[PdCl4] with two equivalents of amino- or acetylamino-pyridines (LH) affords trans-[PdCl2-(LH)2] {LH = 2-amino-3-methylpyridine (2-ampyH), 3-aminopyridine (3-apyH), 2-acetylamino-3-methylpyridine (2-acmpyH), 3-acetylamino-pyridine (3-acpyH)}. An X-ray crystal structure of trans-[PdCl2(2-ampyH)2] shows that the 2-ampy-H ligands are coordinated in a monodentate fashion via the nitrogen atoms of the pyridine rings. Treatment of trans-[PdCl2(2-acmpyH)2] with NEt3 affords the cyclometalated complex, trans-[Pd(κ2-2-acmpy)2], the X-ray structure of which shows that the 2-acmpy ligand is coordinated to palladium in a bidentate fashion via the nitrogen atom of the pyridine ring and oxygen. Reaction of trans-[PdCl2(LH)2] with two equivalents of sodium saccharinate affords the bis(saccharinate) complexes, trans-[Pd(sac)2(LH)2], in which the saccharinate anions are coordinated via the amide nitrogen atom