Characterization of the Positivity of the Density Matrix in Terms of the Coherence Vector Representation

A parameterization of the density operator, a coherence vector representation, which uses a basis of orthogonal, traceless, Hermitian matrices is discussed. Using this parameterization we find the region of permissible vectors which represent a density operator. The inequalities which specify the region are shown to involve the Casimir invariants of the group. In particular cases, this allows the determination of degeneracies in the spectrum of the operator. The identification of the Casimir invariants also provides a method of constructing quantities which are invariant under {\it local} unitary operations. Several examples are given which illustrate the constraints provided by the positivity requirements and the utility of the coherence vector parameterization.Comment: significantly rewritten and submitted for publicatio

Association of Infectious Disease Physician Approval of Peripherally Inserted Central Catheter With Appropriateness and Complications

Importance: Peripherally inserted central catheters (PICCs) are frequently used to deliver intravenous antimicrobial therapy. However, inappropriate PICC use may lead to patient harm. Objective: To evaluate whether infectious disease physician approval prior to PICC placement for intravenous antimicrobials is associated with more appropriate device use and fewer complications. Design, Setting, and Participants: This cohort study of 21 653 PICCs placed for a primary indication of intravenous antimicrobial therapy between January 1, 2015, and July 26, 2019, was conducted in 42 hospitals participating in a quality collaborative across Michigan among hospitalized medical patients. Main Outcomes and Measures: Appropriateness of PICCs was defined according to the Michigan Appropriateness Guide for Intravenous Catheters as a composite measure of (1) single-lumen catheter use, (2) avoiding use of PICCs for 5 days or less, and (3) avoiding use of PICCs for patients with chronic kidney disease (defined as an estimated glomerular filtration rate/min/1.73 m2). Complications related to PICCs included catheter occlusion, deep vein thrombosis, and central line-associated bloodstream infection. The association between infectious disease physician approval, device appropriateness, and catheter complications was assessed using multivariable models, adjusted for patient comorbidities and hospital clustering. Results were expressed as odds ratios with 95% CIs. Results: A total of 21 653 PICCs were placed for intravenous antimicrobials (11 960 PICCs were placed in men [55.2%]; median age, 64.5 years [interquartile range, 53.4-75.4 years]); 10 238 PICCs (47.3%) were approved by an infectious disease physician prior to placement. Compared with PICCs with no documented approval, PICCs with approval by an infectious disease physician were more likely to be appropriately used (72.7% [7446 of 10 238] appropriate with approval vs 45.4% [5180 of 11 415] appropriate without approval; odds ratio, 3.53; 95% CI, 3.29-3.79; P \u3c .001). Furthermore, approval was associated with lower odds of a PICC-related complication (6.5% [665 of 10 238] with approval vs 11.3% [1292 of 11 415] without approval; odds ratio, 0.55; 95% CI, 0.50-0.61). Conclusions and Relevance: This cohort study suggests that, when PICCs were placed for intravenous antimicrobial therapy, infectious disease physician approval of PICC insertion was associated with more appropriate device use and fewer complications. Policies aimed at ensuring infectious disease physician approval prior to PICC placement for antimicrobials may improve patient safety

Antibiotic stewardship teams and Clostridioides difficile practices in United States hospitals: A national survey in The Joint Commission antibiotic stewardship standard era

OBJECTIVE: Clostridioides difficile infection (CDI) can be prevented through infection prevention practices and antibiotic stewardship. Diagnostic stewardship (ie, strategies to improve use of microbiological testing) can also improve antibiotic use. However, little is known about the use of such practices in US hospitals, especially after multidisciplinary stewardship programs became a requirement for US hospital accreditation in 2017. Thus, we surveyed US hospitals to assess antibiotic stewardship program composition, practices related to CDI, and diagnostic stewardship. METHODS: Surveys were mailed to infection preventionists at 900 randomly sampled US hospitals between May and October 2017. Hospitals were surveyed on antibiotic stewardship programs; CDI prevention, treatment, and testing practices; and diagnostic stewardship strategies. Responses were compared by hospital bed size using weighted logistic regression. RESULTS: Overall, 528 surveys were completed (59% response rate). Almost all (95%) responding hospitals had an antibiotic stewardship program. Smaller hospitals were less likely to have stewardship team members with infectious diseases (ID) training, and only 41% of hospitals met The Joint Commission accreditation standards for multidisciplinary teams. Guideline-recommended CDI prevention practices were common. Smaller hospitals were less likely to use high-tech disinfection devices, fecal microbiota transplantation, or diagnostic stewardship strategies. CONCLUSIONS: Following changes in accreditation standards, nearly all US hospitals now have an antibiotic stewardship program. However, many hospitals, especially smaller hospitals, appear to struggle with access to ID expertise and with deploying diagnostic stewardship strategies. CDI prevention could be enhanced through diagnostic stewardship and by emphasizing the role of non-ID-trained pharmacists and clinicians in antibiotic stewardship

Expanding Access to Parasite-based Malaria Diagnosis through Retail Drug shops in Tanzania: Evidence from a Randomized Trial and Implications for Treatment.

Tanzania has seen a reduction in the fraction of fevers caused by malaria, likely due in part to scale-up of control measures. While national guidelines require parasite-based diagnosis prior to treatment, it is estimated that more than half of suspected malaria treatment-seeking in Tanzania initiates in the private retail sector, where diagnosis by malaria rapid diagnostic test (RDT) or microscopy is illegal. This pilot study investigated whether the introduction of RDTs into Accredited Drug Dispensing Outlets (ADDOs) under realistic market conditions would improve case management practices.\ud Dispensers from ADDOs in two intervention districts in Tanzania were trained to stock and perform RDTs and monitored quarterly. Each district was assigned a different recommended retail price to evaluate the need for a subsidy. Malaria RDT and artemisinin-based combination therapy (ACT) uptake and availability were measured pre-intervention and 1 year post-intervention through structured surveys of ADDO owners and exiting customers in both intervention districts and one contiguous control district. Descriptive analysis and logistic regression were used to compare the three districts and identify predictive variables for testing. A total of 310 dispensers from 262 ADDOs were trained to stock and perform RDTs. RDT availability in intervention ADDOs increased from 1% (n = 172) to 73% (n = 163) during the study; ACT medicines were available in 75% of 260 pre-intervention and 68% of 254 post-intervention ADDOs. Pre-treatment testing performed within the ADDO increased from 0 to 65% of suspected malaria patients who visited a shop (95% CI 60.8-69.6%) with no difference between intervention districts. Overall parasite-based diagnosis increased from 19 to 74% in intervention districts and from 3 to 18% in the control district. Prior knowledge of RDT availability (aOR = 1.9, p = 0.03) and RDT experience (aOR = 1.9, p = 0.01) were predictors for testing. Adherence data indicated that 75% of malaria positives received ACT, while 3% of negatives received ACT. Trained and supervised ADDO dispensers in rural Tanzania performed and sold RDTs under real market conditions to two-thirds of suspected malaria patients during this one-year pilot. These results support the hypothesis that introducing RDTs into regulated private retail sector settings can improve malaria testing and treatment practices without an RDT subsidy. Trial registration ISRCTN ISRCTN14115509

Evaluation of the Theoretical Uncertainties in the Z to ll Cross Sections at the LHC

We study the sources of systematic errors in the measurement of the Z to ll cross-sections at the LHC. We consider the systematic errors in both the total cross-section and acceptance for anticipated experimental cuts. We include the best available analysis of QCD effects at NNLO in assessing the effect of higher order corrections and PDF and scale uncertainties on the theoretical acceptance. In addition, we evaluate the error due to missing NLO electroweak corrections and propose which MC generators and computational schemes should be implemented to best simulate the events.Comment: 23 pages, 52 eps figures, LaTeX with JHEP3.cls, epsfig. Added a reference, acknowledgment, and a few clarifying comments. 4/29: Changes in references, minor rewordings and misprint corrections, and one new table (Table 4) comparing CTEQ and MRST PDFs in the NNLO calculation. Version 6 adds email addresses and corrects one referenc

Effects of Veliparib on Microglial Activation and Functional Outcomes after Traumatic Brain Injury in the Rat and Pig.

The inflammation response induced by brain trauma can impair recovery. This response requires several hours to develop fully and thus provides a clinically relevant therapeutic window of opportunity. Poly(ADP-ribose) polymerase inhibitors suppress inflammatory responses, including brain microglial activation. We evaluated delayed treatment with veliparib, a poly(ADP-ribose) polymerase inhibitor, currently in clinical trials as a cancer therapeutic, in rats and pigs subjected to controlled cortical impact (CCI). In rats, CCI induced a robust inflammatory response at the lesion margins, scattered cell death in the dentate gyrus, and a delayed, progressive loss of corpus callosum axons. Pre-determined measures of cognitive and motor function showed evidence of attentional deficits that resolved after three weeks and motor deficits that recovered only partially over eight weeks. Veliparib was administered beginning 2 or 24 h after CCI and continued for up to 12 days. Veliparib suppressed CCI-induced microglial activation at doses of 3 mg/kg or higher and reduced reactive astrocytosis and cell death in the dentate gyrus, but had no significant effect on delayed axonal loss or functional recovery. In pigs, CCI similarly induced a perilesional microglial activation that was attenuated by veliparib. CCI in the pig did not, however, induce detectable persisting cognitive or motor impairment. Our results showed veliparib suppression of CCI-induced microglial activation with a delay-to-treatment interval of at least 24 h in both rats and pigs, but with no associated functional improvement. The lack of improvement in long-term recovery underscores the complexities in translating anti-inflammatory effects to clinically relevant outcomes

Chronic myeloid leukemia stem cells are not dependent on Bcr-Abl kinase activity for their survival

Recent evidence suggests CML stem cells are insensitive to kinase inhibitors and responsible for minimal residual disease in treated patients. We investigated whether CML stem cells, in a transgenic mouse model of CML-like disease or derived from patients, are dependent on Bcr-Abl. In the transgenic model, following re-transplantation, donor-derived CML stem cells in which Bcr-Abl expression had been induced and subsequently shut off, were able to persist in vivo and re-initiate leukemia in secondary recipients upon Bcr-Abl re-expression. Bcr-Abl knockdown in human CD34+ CML cells cultured for 12 days in physiological growth factors achieved partial inhibition of Bcr-Abl and downstream targets p-CrkL and p-STAT5, inhibition of proliferation and colony forming cells, but no reduction of input cells. The addition of dasatinib further inhibited p-CrkL and p-STAT5, yet only reduced input cells by 50%. Complete growth factor withdrawal plus dasatinib further reduced input cells to 10%, however the surviving fraction was enriched for primitive leukemic cells capable of growth in long-term culture initiating cell assay and expansion upon removal of dasatinib and addition of growth factors. Together these data suggest that CML stem cell survival is Bcr-Abl kinase independent and suggest curative approaches in CML must focus on kinase-independent mechanisms of resistance

Uropathogenic Escherichia coli infection-induced epithelial trained immunity impacts urinary tract disease outcome

Previous urinary tract infections (UTIs) can predispose one to future infections; however, the underlying mechanisms affecting recurrence are poorly understood. We previously found that UTIs in mice cause differential bladder epithelial (urothelial) remodelling, depending on disease outcome, that impacts susceptibility to recurrent UTI. Here we compared urothelial stem cell (USC) lines isolated from mice with a history of either resolved or chronic uropathogenic Escherichia coli (UPEC) infection, elucidating evidence of molecular imprinting that involved epigenetic changes, including differences in chromatin accessibility, DNA methylation and histone modification. Epigenetic marks in USCs from chronically infected mice enhanced caspase-1-mediated cell death upon UPEC infection, promoting bacterial clearance. Increased Ptgs2os2 expression also occurred, potentially contributing to sustained cyclooxygenase-2 expression, bladder inflammation and mucosal wounding-responses associated with severe recurrent cystitis. Thus, UPEC infection acts as an epi-mutagen reprogramming the urothelial epigenome, leading to urothelial-intrinsic remodelling and training of the innate response to subsequent infection

Hippocampal and cortical mechanisms at retrieval explain variability in episodic remembering in older adults

Age-related episodic memory decline is characterized by striking heterogeneity across individuals. Hippocampal pattern completion is a fundamental process supporting episodic memory. Yet, the degree to which this mechanism is impaired with age, and contributes to variability in episodic memory, remains unclear. We combine univariate and multivariate analyses of fMRI data from a large cohort of cognitively normal older adults (N=100) to measure hippocampal activity and cortical reinstatement during retrieval of trial-unique associations. Trial-wise analyses revealed that (a) hippocampal activity scaled with reinstatement strength, (b) cortical reinstatement partially mediated the relationship between hippocampal activity and associative retrieval, (c) older age weakened cortical reinstatement and its relationship to memory behaviour. Moreover, individual differences in the strength of hippocampal activity and cortical reinstatement explained unique variance in performance across multiple assays of episodic memory. These results indicate that fMRI indices of hippocampal pattern completion explain within-and across-individual memory variability in older adults