Entanglement and Superdense Coding with Linear Optics

We discuss a scheme for a full superdense coding of entangled photon states employing only linear-optics elements. By using the mixed basis consisting of four states that are unambiguously distinguishable by a standard and polarizing beam splitters we can deterministically transfer four messages by manipulating just one of the two entangled photons. The sender achieves the determinism of the transfer either by giving up the control over 50% of sent messages (although known to her) or by discarding 33% of incoming photons.Comment: 8 pages, 1 figur

Mortality after surgery for benign prostate hyperplasia : a nationwide cohort study

Purpose To investigate postoperative mortality rates and risk factors for mortality after surgical treatment of benign prostate hyperplasia (BPH). Methods All patients who underwent partial prostate excision/resection from 2004 to 2014 in Finland were retrospectively assessed for eligibility using a nationwide registry. Procedures were classified as transurethral resection of the prostate (TURP), laser vaporization of the prostate (laser), and open prostatectomy. Univariable and multivariable regression were used to analyze the association of age, Charlson comorbidity index (CCI), operation type, annual center operation volume, study era, atrial fibrillation, and prostate cancer diagnosis with 90 days postoperative mortality. Results Among the 39,320 patients, TURP was the most common operation type for lower urinary tract symptoms in all age groups. The overall 90 days postoperative mortality was 1.10%. Excess mortality in the 90 days postoperative period was less than 0.5% in all age groups. Postoperative mortality after laser operations was 0.59% and 1.16% after TURP (p = 0.035). Older age, CCI score, and atrial fibrillation were identified as risk factors for postoperative mortality. Prostate cancer diagnosis and the center's annual operation volume were not significantly associated with mortality. The most common underlying causes of death were malignancy (35.5%) and cardiac disease (30.9%). Conclusion Elective urologic procedures for BPH are generally considered safe, but mortality increases with age. Laser operations may be associated with lower mortality rates than the gold standard TURP. Thus, operative risks and benefits must be carefully considered on a case-by-case basis. Further studies comparing operation types are needed.Peer reviewe

Vascular endothelium plays a key role in directing pulmonary epithelial cell differentiation.

The vascular endothelium is critical for induction of appropriate lineage differentiation in organogenesis. In this study, we report that dysfunctional pulmonary endothelium, resulting from the loss of matrix Gla protein (MGP), causes ectopic hepatic differentiation in the pulmonary epithelium. We demonstrate uncontrolled induction of the hepatic growth factor (HGF) caused by dysregulated cross talk between pulmonary endothelium and epithelium in Mgp-null lungs. Elevated HGF induced hepatocyte nuclear factor 4 α (Hnf4a), which competed with NK2 homeobox 1 (Nkx2.1) for binding to forkhead box A2 (Foxa2) to drive hepatic differentiation in Mgp-null airway progenitor cells. Limiting endothelial HGF reduced Hnf4a, abolished interference of Hnf4a with Foxa2, and reduced hepatic differentiation in Mgp-null lungs. Together, our results suggest that endothelial-epithelial interactions, maintained by MGP, are essential in pulmonary cell differentiation

On the diffeomorphism commutators of lattice quantum gravity

We show that the algebra of discretized spatial diffeomorphism constraints in Hamiltonian lattice quantum gravity closes without anomalies in the limit of small lattice spacing. The result holds for arbitrary factor-ordering and for a variety of different discretizations of the continuum constraints, and thus generalizes an earlier calculation by Renteln.Comment: 16 pages, Te

Angiopoietin-2 predicts morbidity in adults with Fontan physiology.

Morbidity in patients with single-ventricle Fontan circulation is common and includes arrhythmias, edema, and pulmonary arteriovenous malformations (PAVM) among others. We sought to identify biomarkers that may predict such complications. Twenty-five patients with Fontan physiology and 12 control patients with atrial septal defects (ASD) that underwent cardiac catheterization were included. Plasma was collected from the hepatic vein and superior vena cava and underwent protein profiling for a panel of 20 analytes involved in angiogenesis and endothelial dysfunction. Ten (40%) of Fontan patients had evidence of PAVM, eighteen (72%) had a history of arrhythmia, and five (20%) were actively in arrhythmia or had a recent arrhythmia. Angiopoietin-2 (Ang-2) was higher in Fontan patients (8,875.4 ± 3,336.9 pg/mL) versus the ASD group (1,663.6 ± 587.3 pg/mL, p < 0.0001). Ang-2 was higher in Fontan patients with active or recent arrhythmia (11,396.0 ± 3,457.7 vs 8,118.2 ± 2,795.1 pg/mL, p < 0.05). A threshold of 8,500 pg/mL gives Ang-2 a negative predictive value of 100% and positive predictive value of 42% in diagnosing recent arrhythmia. Ang-2 is elevated among adults with Fontan physiology. Ang-2 level is associated with active or recent arrhythmia, but was not found to be associated with PAVM

Simultaneous Bedside Assessment of Global Cerebral Blood Flow and Effective Cerebral Perfusion Pressure in Patients with Intracranial Hypertension

Background: We examined a bedside technique transcerebral double-indicator dilution (TCID) for global cerebral blood flow (CBF) as well as the concept of effective cerebral perfusion pressure (CPPeff) during different treatment options for intracranial hypertension, and compared global CBF and CPPeff with simultaneously obtained conventional parameters. Methods: Twenty-six patients developing intracranial hypertension in the course of traumatic brain injury or subarachnoid hemorrhage were prospectively analyzed using a combined assessment during elevated ventilation (n=15) or osmotherapy (hypertonic saline or mannitol). For calculation of global CBF, injections of ice-cold indocyanine green boluses were performed and temperature and dye concentration changes were monitored in the thoracic aorta and the jugular bulb. CBF was then calculated according to the mean transit time principle. Estimation of CCP, the arterial pressure at which cerebral blood flow becomes zero, was performed by synchronized registration of corresponding values of blood flow velocity in the middle cerebral artery and arterial pressure and extrapolation to zero-flow velocity. CPPeff was calculated as mean arterial pressure minus critical closing pressure (CPPeff=MAPc−CCP). Results: Elevated ventilation causes a decrease in both ICP (P<0.001) and CBF (P<0.001). While CPPconv increased (P<0.001), CPPeff decreased during this observation (P=0.002). Administration of osmotherapeutic agents resulted in a decrease of ICP (P<0.001) and a temporary increase of CBF (P=0.052). CPPconv and CPPeff showed no striking difference under osmotherapy. Conclusion: TCID allows repeated measurements of global CBF at the bedside. Elevated ventilation lowered and osmotherapy temporarily raised global CBF. In situations of increased vasotonus, CPPeff is a better indicator of blood flow changes than conventional CP

Tournament Leave-pair-out Cross-validation for Receiver Operating Characteristic (ROC) Analysis

Receiver operating characteristic (ROC) analysis is widely used for evaluating diagnostic systems. Recent studies have shown that estimating an area under ROC curve (AUC) with standard cross-validation methods suffers from a large bias. The leave-pair-out (LPO) cross-validation has been shown to correct this bias. However, while LPO produces an almost unbiased estimate of AUC, it does not provide a ranking of the data needed for plotting and analyzing the ROC curve. In this study, we propose a new method called tournament leave-pair-out (TLPO) cross-validation. This method extends LPO by creating a tournament from pair comparisons to produce a ranking for the data. TLPO preserves the advantage of LPO for estimating AUC, while it also allows performing ROC analysis. We have shown using both synthetic and real world data that TLPO is as reliable as LPO for AUC estimation and confirmed the bias in leave-one-out cross-validation on low-dimensional data.Comment: 13 pages, 8 figure