Correlated Spectral and Recurrence Variations of Cygnus X-1

We present results of recurrence analysis of the black hole X-ray binary Cygnus X-1 using combined observations from the Rossi X-ray Timing Explorer All-sky Monitor and the Japanese Monitor of All-sky X-ray Image aboard the ISS. From the time-dependent windowed recurrence plot (RP), we compute ten recurrence quantities that describe the dynamical behavior of the source and compare them to the spectral state at each point in time. We identify epochs of state changes corresponding to transitions into highly deterministic or highly stochastic dynamical regimes and their correlation to specific spectral states. We compare k-Nearest Neighbors and Random Forest models for various sizes of the time-dependent RP. The spectral state in Cygnus X-1 can be predicted with greater than 95 per cent accuracy for both types of models explored across a range of RP sizes based solely on the recurrence properties. The primary features from the RP that distinguish between spectral states are the determinism, Shannon entropy, and average line length, all of which are systematically higher in the hard state compared to the soft state. Our results suggest that the hard and soft states of Cygnus X-1 exhibit distinct dynamical variability and the time domain alone can be used for spectral state classification.Comment: 17 pages, 10 figures, 7 tables; Accepted for publication in Monthly Notices of the Royal Astronomical Societ

The Air-temperature Response to Green/blue-infrastructure Evaluation Tool (TARGET v1.0) : an efficient and user-friendly model of city cooling

The adverse impacts of urban heat and global climate change are leading policymakers to consider green and blue infrastructure (GBI) for heat mitigation benefits. Though many models exist to evaluate the cooling impacts of GBI, their complexity and computational demand leaves most of them largely inaccessible to those without specialist expertise and computing facilities. Here a new model called The Air-temperature Response to Green/blue-infrastructure Evaluation Tool (TARGET) is presented. TARGET is designed to be efficient and easy to use, with fewer user-defined parameters and less model input data required than other urban climate models. TARGET can be used to model average street-level air temperature at canyon-to-block scales (e.g. 100 m resolution), meaning it can be used to assess temperature impacts of suburb-to-city-scale GBI proposals. The model aims to balance realistic representation of physical processes and computation efficiency. An evaluation against two different datasets shows that TARGET can reproduce the magnitude and patterns of both air temperature and surface temperature within suburban environments. To demonstrate the utility of the model for planners and policymakers, the results from two precinct-scale heat mitigation scenarios are presented. TARGET is available to the public, and ongoing development, including a graphical user interface, is planned for future work

Remote Sensing of Aboveground Biomass in Tropical Secondary Forests: A Review

Tropical landscapes are, in general, a mosaic of pasture, agriculture, and forest undergoing various stages of succession. Forest succession is comprised of continuous structural changes over time and results in increases in aboveground biomass (AGB). New remote sensing methods, including sensors, image processing, statistical methods, and uncertainty evaluations, are constantly being developed to estimate biophysical forest changes. We review 318 peer-reviewed studies related to the use of remotely sensed AGB estimations in tropical forest succession studies and summarize their geographic distribution, sensors and methods used, and their most frequent ecological inferences. Remotely sensed AGB is broadly used in forest management studies, conservation status evaluations, carbon source and sink investigations, and for studies of the relationships between environmental conditions and forest structure. Uncertainties in AGB estimations were found to be heterogeneous with biases related to sensor type, processing methodology, ground truthing availability, and forest characteristics. Remotely sensed AGB of successional forests is more reliable for the study of spatial patterns of forest succession and over large time scales than that of individual stands. Remote sensing of temporal patterns in biomass requires further study, in particular, as it is critical for understanding forest regrowth at scales useful for regional or global analyses

Anonymous quantum communication

We present the first protocol for the anonymous transmission of a quantum state that is information-theoretically secure against an active adversary, without any assumption on the number of corrupt participants. The anonymity of the sender and receiver is perfectly preserved, and the privacy of the quantum state is protected except with exponentially small probability. Even though a single corrupt participant can cause the protocol to abort, the quantum state can only be destroyed with exponentially small probability: if the protocol succeeds, the state is transferred to the receiver and otherwise it remains in the hands of the sender (provided the receiver is honest).Comment: 11 pages, to appear in Proceedings of ASIACRYPT, 200

Phase variation controls expression of Salmonella lipopolysaccharide modification genes by a DNA methylation-dependent mechanism

The O-antigen of Salmonella lipopolysaccharide is a major antigenic determinant and its chemical composition forms the basis for Salmonella serotyping. Modifications of the O-antigen that can affect the serotype include those carried out by the products of glycosyltransferase operons (gtr), which are present on specific Salmonella and phage genomes. Here we show that expression of the gtr genes encoded by phage P22 that confers the O1 serotype is under the control of phase variation. This phase variation occurs by a novel epigenetic mechanism requiring OxyR in conjunction with the DNA methyltransferase Dam. OxyR is an activator or a repressor of the system depending on which of its two binding sites in the gtr regulatory region is occupied. Binding is decreased by methylation at Dam target sequences in either site, and this confers heritability of the expression state to the system. Most Salmonella gtr operons share the key regulatory elements that are identified here as essential for this epigenetic phase variation

Influence of adjunct use andcheese microenvironment on nonstarter lactic acid bacteria populations in Cheddar-type cheese

This study investigated population dynamics of starter, adjunct, and nonstarter lactic acid bacteria (NSLAB) in reduced-fat Cheddar and Colby cheese made with or without a Lactobacillus casei adjunct. Duplicate vats of cheese were manufactured and ripened at 7°C. Bacterial populations were monitored periodically by plate counts and by DNA fingerprinting of cheese isolates with the random amplified polymorphic DNA technique. Isolates that displayed a unique DNA fingerprint were identified to the species level by partial nucleotide sequence analysis of the 16S rRNA gene. Nonstarter biota in both cheese types changed over time, but populations in the Colby cheese showed a greater degree of species heterogeneity. The addition of the L. casei adjunct to cheese milk at 104 cfu/ml did not completely suppress “wild” NSLAB populations, but it did appear to reduce nonstarter species and strain diversity in Colby and young Cheddar cheese. Nonetheless, nonstarter populations in all 6-mo-old cheeses were dominated by wild L. casei. Interestingly, the dominant strains of L. casei in each 6-mo-old cheese appeared to be affected more by adjunct treatment and not cheese variety

Enhanced Nutty Flavor Formation in Cheddar Cheese Made with Malty Lactococcus Lactis Adjunct Culture

Nutty flavor in Cheddar cheese is desirable, and recent research demonstrated that 2- and 3-methyl butanal and 2-methyl propanal were primary sources of nutty flavors in Cheddar. Because malty strains of Lac-tococcus lactis (formerly Streptococcus lactis var. malti-genes) are characterized by the efficient production of these and other Strecker aldehydes during growth, this study investigated the influence of a malty L. lactis adjunct culture on nutty flavor development in Cheddar cheese. Cheeses made with different adjunct levels (0, 10(4) cfu/mL, and 10(5) cfu/mL) were ripened at 5 or 13 degrees C and analyzed after 1 wk, 4 mo, and 8 mo by a combination of instrumental and sensory methods to characterize nutty flavor development. Cheeses ripened at 13 degrees C developed aged flavors (brothy, sulfur, and nutty flavors) more rapidly than cheeses held at 5 degrees C. Additionally, cheeses made with the adjunct culture showed more rapid and more intense nutty flavor development than control cheeses. Cheeses that had higher intensities of nutty flavors also had a higher concentration of 2/3-methyl butanal and 2-methyl propanal compared with control cheeses, which again confirmed that these compounds are a source of nutty flavor in Cheddar cheese. Results from this study provide a simple methodology for cheese manufacturers to obtain consistent nutty flavor in Cheddar cheese

Psychosocial predictors of exclusive breastfeeding duration to six moths postpartum

The World Health Organization recommend that for optimal growth and development all infants worldwide should be exclusively breastfed for the first six months of life. Previous studies have identified that psychosocial factors are important for the maintenance of exclusive breastfeeding. This study aimed to examine the psychosocial factors associated with exclusive breastfeeding duration to six months postpartum. Method: 125 women completed questionnaires at three time points; 32 weeks gestation, two and six months postpartum. Self-efficacy, body attitude, psychological adjustment, attitude, intention, confidence, motivation and importance of exclusive breastfeeding and breastfeeding status were measured. Findings: At 32 weeks gestation a woman’s confidence to achieve exclusive breastfeeding was a predictor of exclusive breastfeeding to six months postpartum. At two months postpartum, psychological adjustment and self-efficacy were predictive of exclusive breastfeeding duration. At six months postpartum, psychological adjustment, self-efficacy, confidence to maintain and feeling fat were predictive of exclusive breastfeeding duration. Conclusion: Self-efficacy, psychological adjustment, body image, motivation and confidence are important for the maintenance of exclusive breastfeeding to six months. This has clinical application for health psychology as antenatal breastfeeding education and postpartum support may be strengthened by strategies that build a woman’s confidence to exclusively breastfeed

Optimal growth ofLactobacillus casei in a Cheddar cheese ripening model system requires exogenous fatty acids

Flavor development in ripening Cheddar cheese depends on complex microbial and biochemical processes that are difficult to study in natural cheese. Thus, our group has developed Cheddar cheese extract (CCE) as a model system to study these processes. In previous work, we found that CCE supported growth of Lactobacillus casei, one of the most prominent nonstarter lactic acid bacteria (NSLAB) species found in ripening Cheddar cheese, to a final cell density of 108 cfu/mL at 37°C. However, when similar growth experiments were performed at 8°C in CCE derived from 4-mo-old cheese (4mCCE), the final cell densities obtained were only about 106 cfu/mL, which is at the lower end of the range of the NSLAB population expected in ripening Cheddar cheese. Here, we report that addition of Tween 80 to CCE resulted in a significant increase in the final cell density of L. casei during growth at 8°C and produced concomitant changes in cytoplasmic membrane fatty acid (CMFA) composition. Although the effect was not as dramatic, addition of milk fat or a monoacylglycerol (MAG) mixture based on the MAG profile of milk fat to 4mCCE also led to an increased final cell density of L. casei in CCE at 8°C and changes in CMFA composition. These observations suggest that optimal growth of L. casei in CCE at low temperature requires supplementation with a source of fatty acids (FA). We hypothesize that L. casei incorporates environmental FA into its CMFA, thereby reducing its energy requirement for growth. The exogenous FA may then be modified or supplemented with FA from de novo synthesis to arrive at a CMFA composition that yields the functionality (i.e., viscosity) required for growth in specific conditions. Additional studies utilizing the CCE model to investigate microbial contributions to cheese ripening should be conducted in CCE supplemented with 1% milk fat

Psychosocial predictors of exclusive breastfeeding duration to six moths postpartum

The World Health Organization recommend that for optimal growth and development all infants worldwide should be exclusively breastfed for the first six months of life. Previous studies have identified that psychosocial factors are important for the maintenance of exclusive breastfeeding. This study aimed to examine the psychosocial factors associated with exclusive breastfeeding duration to six months postpartum. Method: 125 women completed questionnaires at three time points; 32 weeks gestation, two and six months postpartum. Self-efficacy, body attitude, psychological adjustment, attitude, intention, confidence, motivation and importance of exclusive breastfeeding and breastfeeding status were measured. Findings: At 32 weeks gestation a woman’s confidence to achieve exclusive breastfeeding was a predictor of exclusive breastfeeding to six months postpartum. At two months postpartum, psychological adjustment and self-efficacy were predictive of exclusive breastfeeding duration. At six months postpartum, psychological adjustment, self-efficacy, confidence to maintain and feeling fat were predictive of exclusive breastfeeding duration. Conclusion: Self-efficacy, psychological adjustment, body image, motivation and confidence are important for the maintenance of exclusive breastfeeding to six months. This has clinical application for health psychology as antenatal breastfeeding education and postpartum support may be strengthened by strategies that build a woman’s confidence to exclusively breastfeed