Is the subtropical jet shifting poleward?

The tropics are expanding poleward at about 0.5∘ per decade in observations. This poleward expansion of the circulation is consistently reported using Hadley cell edge metrics and lower-atmospheric tropical edge metrics. However, some upper-atmospheric tropical metrics report smaller trends that are often not significant. One such upper-atmospheric metric is the subtropical jet latitude, which has smaller trends compared to the Hadley cell edge. In this study we investigate the robustness of the weak trends in the subtropical jet position by introducing a new method for locating the subtropical jet, and examining the trends and variability of the subtropical jet latitude. We introduce the tropopause gradient method based on the peak gradient in potential temperature along the dynamic tropopause. Using this method we find the trends in the subtropical jet latitude are indeed much smaller than 0.5∘ per decade, consistent with previous studies. We also find that natural variability within the subtropical jet latitude would not prevent trends from being detected if they were similar to the Hadley cell edge, as trends greater than 0.24∘ per decade could reliably be detected using monthly data or 0.09∘ per decade using daily data. Despite the poleward expansion of the tropics, there is no robust evidence to suggest the subtropical jet is shifting poleward in either hemisphere. Neither the current diagnostic methods nor natural variability can account for the small subtropical jet trends. The most likely explanation, which requires further investigation, is that the subtropical jet position is not tied dynamically to the Hadley cell edge

Paying for water services: effects of household characteristics

Maximising cost recovery is currently a top priority for managers of urban water utilities in low-income countries. This research was carried out in 11 major towns of Uganda to establish which household characteristics influence payment for water services. A questionnaire was used to collect data on customer satisfaction, customer loyalty and several socio-economic variables. Using regression techniques, it was established that the following attributes of the household head moderated the satisfaction and loyalty relationship: gender, occupation and level of education. Other significant factors were household income and property tenure status. These results could be used to make water utilities customer-focused

An early chondrichthyan and the evolutionary assembly of a shark body plan

Although relationships among the major groups of living gnathostomes are well established, the relatedness of early jawed vertebrates to modern clades is intensely debated. Here, we provide a new description of Gladbachus , a Middle Devonian (Givetian approx. 385-million-year-old) stem chondrichthyan from Germany, and one of the very few early chondrichthyans in which substantial portions of the endoskeleton are preserved. Tomographic and histological techniques reveal new details of the gill skeleton, hyoid arch and jaws, neurocranium, cartilage, scales and teeth. Despite many features resembling placoderm or osteichthyan conditions, phylogenetic analysis confirms Gladbachus as a stem chondrichthyan and corroborates hypotheses that all acanthodians are stem chondrichthyans. The unfamiliar character combination displayed by Gladbachus , alongside conditions observed in acanthodians, implies that pre-Devonian stem chondrichthyans are severely under-sampled and strongly supports indications from isolated scales that the gnathostome crown group originated at the latest by the early Silurian (approx. 440 Ma). Moreover, phylogenetic results highlight the likely convergent evolution of conventional chondrichthyan conditions among earliest members of this primary gnathostome division, while skeletal morphology points towards the likely suspension feeding habits of Gladbachus , suggesting a functional origin of the gill slit condition characteristic of the vast majority of living and fossil chondrichthyans. </jats:p

Urban corruption policy analysis

Corruption has been an issue in municipal government since the inception of government. The purpose of this research and paper is to explore the topic of urban corruption in the United States a sit pertains to city development. A review of the literature on this topic shows that this has been a neglected area of research in public administration. The literature review contained in this paper will look at both the research that has been done in the area of urban corruption and the way in which this type of research has been conducted over the years

Cost-Effectiveness of HIV Screening in STD Clinics, Emergency Departments, and Inpatient Units: A Model-Based Analysis

Identifying and treating persons with human immunodeficiency virus (HIV) infection early in their disease stage is considered an effective means of reducing the impact of the disease. We compared the cost-effectiveness of HIV screening in three settings, sexually transmitted disease (STD) clinics serving men who have sex with men, hospital emergency departments (EDs), settings where patients are likely to be diagnosed early, and inpatient diagnosis based on clinical manifestations.We developed the Progression and Transmission of HIV/AIDS model, a health state transition model that tracks index patients and their infected partners from HIV infection to death. We used program characteristics for each setting to compare the incremental cost per quality-adjusted life year gained from early versus late diagnosis and treatment. We ran the model for 10,000 index patients for each setting, examining alternative scenarios, excluding and including transmission to partners, and assuming HAART was initiated at a CD4 count of either 350 or 500 cells/µL. Screening in STD clinics and EDs was cost-effective compared with diagnosing inpatients, even when including only the benefits to the index patients. Screening patients in STD clinics, who have less-advanced disease, was cost-effective compared with ED screening when treatment with HAART was initiated at a CD4 count of 500 cells/µL. When the benefits of reduced transmission to partners from early diagnosis were included, screening in settings with less-advanced disease stages was cost-saving compared with screening later in the course of infection. The study was limited by a small number of observations on CD4 count at diagnosis and by including transmission only to first generation partners of the index patients.HIV prevention efforts can be advanced by screening in settings where patients present with less-advanced stages of HIV infection and by initiating treatment with HAART earlier in the course of infection

DNA and lipid bilayers: self-assembly and insertion

DNA–lipid complexes are of biomedical importance as delivery vectors for gene therapy. To gain insight into the interactions of DNA with zwitterionic and cationic (dimyristoyltrimethylammonium propane (DMTAP)) lipids, we have used coarse-grained molecular dynamics simulations to study the self-assembly of DPPC and DPPC/DMTAP lipid bilayers in the presence of a DNA dodecamer. We observed the spontaneous formation of lipid bilayers from initial systems containing randomly placed lipids, water–counterions and DNA. In both the DPPC and DPPC/DMTAP simulations, the DNA molecule is located at the water–lipid headgroup interface, lying approximately parallel to the plane of the bilayer. We have also calculated the potential of mean force for transferring a DNA dodecamer through a DPPC/DMTAP bilayer. A high energetic barrier to DNA insertion into the hydrophobic core of the bilayer is observed. The DNA adopts a transmembrane orientation only in this region. Local bilayer deformation in the vicinity of the DNA molecule is observed, largely as a result of the DNA–DMTAP headgroup attraction

Calixpyrroles, calixpyridinopyrroles and calixpyridines

The present invention provides calixpyrrole, calixpyridinopyrrole, and calixpyridine macrocycles, having 4, 5, 6, 7, or 8 heterocyclic rings, as well as syntheses, derivatives, conjugates, multimers, and solid supports thereof. Such macrocycles have proved to be effective and selective ion- and neutral molecule-binding agents forming supramolecular ensembles, and ion- and neutral molecule-separation agents. The macrocycles are fully meso-non-hydrogen-substituted porphyrinogens, a few molecules of which were previously known but not recognized as possessing anion- or molecule-binding properties. The binding mode is noncovalent, primarily that of hydrogen-bonding, thereby providing a new mode for liquid chromatography, that of Hydrogen Bonding Liquid Chromatography. Further useful applications of the macrocycles provided herein include environmental remediation by removal of undesired ions or neutral molecules, and removal of phosphate for kidney dialysis.Board of Regents, University of Texas Syste

In Vivo Assessment of Arsenic Bioavailability in Rice and Its Significance for Human Health Risk Assessment

BACKGROUND: Millions of people worldwide consume arsenic-contaminated rice; however, little is known about the uptake and bioavailability of arsenic species after arsenic-contaminated rice ingestion. OBJECTIVES: In this study, we assessed arsenic speciation in greenhouse-grown and supermarket-bought rice, and determined arsenic bioavailability in cooked rice using an in vivo swine model. RESULTS: In supermarket-bought rice, arsenic was present entirely in the inorganic form compared to greenhouse-grown rice (using irrigation water contaminated with sodium arsenate), where most (~ 86%) arsenic was present as dimethylarsinic acid (organic arsenic). Because of the low absolute bioavailability of dimethylarsinic acid and the high proportion of dimethylarsinic acid in greenhouse-grown rice, only 33 ± 3% (mean ± SD) of the total rice-bound arsenic was bioavailable. Conversely, in supermarket-bought rice cooked in water contaminated with sodium arsenate, arsenic was present entirely in the inorganic form, and bioavailability was high (89 ± 9%). CONCLUSIONS: These results indicate that arsenic bioavailability in rice is highly dependent on arsenic speciation, which in turn can vary depending on rice cultivar, arsenic in irrigation water, and the presence and nature of arsenic speciation in cooking water. Arsenic speciation and bioavailability are therefore critical parameters for reducing uncertainties when estimating exposure from the consumption of rice grown and cooked using arsenic-contaminated water

Knowledge capture to inform sustainable maritime operations

Knowledge capture to inform sustainable maritime operations Purpose - The purpose of this paper is to report an explicit taxonomy of maritime operations (MO) to guide Harbour Masters (HM)s of smaller ports in planning more sustainable operations. Design/methodology/approach - This research presents strategies for building theory to promote more sustainable port management in a two-stage research design. Starting from a base taxonomy in research stage one, ethnographic content analysis (ECA) of a sparse prior literature on MO generated a tentative taxonomy into a credible practitioner-informed final taxonomy. Findings - ECA offers researchers a powerful tool to analyse complex operational problems. In this paper MOs are represented in an explicit taxonomy. Practical implications - A final taxonomy of MOs guides sustainability strategy formulation by HMs and assists them to protect vital commercial revenues which serve supply chains and local communities. Originality/Value - An explicit final taxonomy of MO is derived using a novel methodology. The taxonomy guides sustainability strategy formulation and underpins subsequent planning of sustainable development policies