Mathematical model of Zika virus with vertical transmission

Zika is a flavivirus transmitted to humans through either the bites of infected Aedes mosquitoes or sexual transmission. Zika has been linked to congenital anomalies such as microcephaly. In this paper, we analyze a new system of ordinary differential equations which incorporates human vertical transmission of Zika virus, the birth of babies with microcephaly and asymptomatically infected individuals. The Zika model is locally and globally asymptotically stable when the basic reproduction number is less than unity. Our model shows that asymptomatic individuals amplify the disease burden in the community, and the most important parameters for ZIKV spread are the death rate of mosquitoes, the mosquito biting rate, the mosquito recruitment rate, and the transmission per contact to mosquitoes and to adult humans. Scenario exploration indicates that personal-protection is a more effective control strategy than mosquito-reduction strategy. It also shows that delaying conception reduces the number of microcephaly cases, although this does little to prevent Zika transmission in the broader community. However, by coupling aggressive vector control and personal protection use, it is possible to reduce both microcephaly and Zika transmission. 2000 Mathematics Subject Classifications: 92B05, 93A30, 93C15

Electrochemically controlled growth and positioning of suspended collagen membranes

Two independently recognized in vitro polymer aggregation variables, electric field and pH, can be used in concert to produce suspended membranes from solutions of type I collagen monomers, without need of a supporting substrate. A collagen network film can form at the alkalineacidic pH interface created during the normal course of water electrolysis with parallel plate electrodes, and the anchoring location can be controlled by adjusting the bulk electrolyte pH. Electrosynthesized films remain intact upon drying and rehydration and function as ion separation membranes even in submillimeter channels. This approach could benefit lab-on-a-chip technologies for rational placement of membranes in microfluidic devices

What’s Sex (Composition) Got to Do with It? The Importance of Sex Composition of Gangs for Female and Male Members’ Offending and Victimization

Sex composition of groups has been theorized in organizational sociology and found in prior work to structure female and male members’ behaviors and experiences. Peer group and gang literature similarly finds that the sex gap in offending varies across groups of differing sex ratios. Drawing on this and other research linking gang membership, offending, and victimization, we examine whether sex composition of gangs is linked to sex differences in offending in this sample, further assess whether sex composition similarly structures females’ and males’ victimization experiences, and if so, why. Self-report data from gang members in a multi-site, longitudinal study of 3,820 youths are employed. Results support previous findings about variations in member delinquency by both sex and sex composition of the gang and also indicate parallel variations in members’ victimization. These results are further considered within the context of facilitating effects such as gender dynamics, gang characteristics, and normative orientation

Upregulation of nitric oxide synthase in mice with severe hypoxia-induced pulmonary hypertension

BACKGROUND: The importance of nitric oxide (NO) in hypoxic pulmonary hypertension has been demonstrated using nitric oxide synthase (NOS) knockout mice. In that model NO from endothelial NOS (eNOS) plays a central role in modulating pulmonary vascular tone and attenuating hypoxic pulmonary hypertension. However, the normal regulation of NOS expression in mice following hypoxia is uncertain. Because genetically engineered mice are often utilized in studies of NO, we conducted the present study to determine how hypoxia alters NOS expression in wild-type mice. METHOD: Mice were exposed to sea level, ambient conditions (5280 feet) or severe altitude (17,000 feet) for 6 weeks from birth, and hemodynamics and lung NOS expression were assessed. RESULTS: Hypoxic mice developed severe pulmonary hypertension (right ventricular systolic pressure [RVsP] 60 mmHg) as compared with normoxic mice (27 mmHg). Using quantitative reverse-transcription PCR, it was found that expressions of eNOS and inducible NOS (iNOS) increased 1.5-fold and 3.5-fold, respectively, in the lung. In addition, the level of lung eNOS protein was increased, neuronal NOS (nNOS) protein was unchanged, and iNOS was below the limit of detection. Immunohistochemistry demonstrated no change in lung iNOS or nNOS staining in either central or peripheral areas, but suggested increased eNOS in the periphery following hypoxia. CONCLUSION: In mice, hypoxia is associated with increases in lung eNOS, possibly in iNOS, but not in nNOS; this suggests that the pattern of lung NOS expression following hypoxia must be considered in studies using genetically engineered mice

Organometallic iridium(III) anticancer complexes with new mechanisms of action: NCI-60 screening, mitochondrial targeting, and apoptosis

Platinum complexes related to cisplatin, cis-[PtCl2(NH3)2], are successful anticancer drugs; however, other transition metal complexes offer potential for combating cisplatin resistance, decreasing side effects, and widening the spectrum of activity. Organometallic half-sandwich iridium (IrIII) complexes [Ir(Cpx)(XY)Cl]+/0 (Cpx = biphenyltetramethylcyclopentadienyl and XY = phenanthroline (1), bipyridine (2), or phenylpyridine (3)) all hydrolyze rapidly, forming monofunctional G adducts on DNA with additional intercalation of the phenyl substituents on the Cpx ring. In comparison, highly potent complex 4 (Cpx = phenyltetramethylcyclopentadienyl and XY = N,N-dimethylphenylazopyridine) does not hydrolyze. All show higher potency toward A2780 human ovarian cancer cells compared to cisplatin, with 1, 3, and 4 also demonstrating higher potency in the National Cancer Institute (NCI) NCI-60 cell-line screen. Use of the NCI COMPARE algorithm (which predicts mechanisms of action (MoAs) for emerging anticancer compounds by correlating NCI-60 patterns of sensitivity) shows that the MoA of these IrIII complexes has no correlation to cisplatin (or oxaliplatin), with 3 and 4 emerging as particularly novel compounds. Those findings by COMPARE were experimentally probed by transmission electron microscopy (TEM) of A2780 cells exposed to 1, showing mitochondrial swelling and activation of apoptosis after 24 h. Significant changes in mitochondrial membrane polarization were detected by flow cytometry, and the potency of the complexes was enhanced ca. 5× by co-administration with a low concentration (5 μM) of the γ-glutamyl cysteine synthetase inhibitor L-buthionine sulfoximine (L-BSO). These studies reveal potential polypharmacology of organometallic IrIII complexes, with MoA and cell selectivity governed by structural changes in the chelating ligands

Design, development and validity testing of the Gang Affiliation Risk Measure (GARM)

This study aimed to create a measure of risk for gang affiliation, for use in the UK. A pilot stage invited gang affiliated and non-gang affiliated participants between the ages of 16–25 years to retrospectively self-report on 58 items of risk exposure at the age of 11 years. Based on performance of these items, a 26-item measure was developed and administered to a main study sample (n=185) of gang affiliated and non-gang affiliated participants. Categorical Principal Component Analysis was applied to data, yielding a single-factor solution (historic lack of safety and current perception of threat). A 15-item gang affiliation risk measure (GARM) was subsequently created. The GARM demonstrated good internal consistency, construct validity and discriminative ability. Items from the GARM were then transformed to read prospectively, resulting in a test measure for predictive purposes (T-GARM). The T-GARM requires further validation regarding its predictive utility and generalisability. However, this study has resulted in the first measure of gang affiliation, with promising results

Population policies and education: exploring the contradictions of neo-liberal globalisation

The world is increasingly characterised by profound income, health and social inequalities (Appadurai, 2000). In recent decades development initiatives aimed at reducing these inequalities have been situated in a context of increasing globalisation with a dominant neo-liberal economic orthodoxy. This paper argues that neo-liberal globalisation contains inherent contradictions regarding choice and uniformity. This is illustrated in this paper through an exploration of the impact of neo-liberal globalisation on population policies and programmes. The dominant neo-liberal economic ideology that has influenced development over the last few decades has often led to alternative global visions being overlooked. Many current population and development debates are characterised by polarised arguments with strongly opposing aims and views. This raises the challenge of finding alternatives situated in more middle ground that both identify and promote the socially positive elements of neo-liberalism and state intervention, but also to limit their worst excesses within the population field and more broadly. This paper concludes with a discussion outling the positive nature of middle ground and other possible alternatives

Argonne National Laboratory Reports

This report presents two detailed computerized operating procedures developed to assist and control the shearing and dissolution of irradiated fuel rods. The procedures were employed in the destructive analysis of end-of-life fuel rods from the Light Water Breeder Reactor (LWBR) that was designed by the Westinghouse Electric Corporation Bettis Atomic Power Laboratory. Seventeen entire fuel rods from the end-of-life core of the LWBR were sheared into 169 precisely characterized segments, and more than 150 of these segments were dissolved during execution of the LWBR Proof-of-Breeding (LWBR-POB) Analytical Support Project at Argonne National Laboratory. The procedures illustrate our approaches to process monitoring, data reduction, and quality assurance during the LWBR-POB work

Effects of branching spatial structure and life history on the asymptotic growth rate of a population

Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Theoretical Ecology 3 (2010): 137-152, doi:10.1007/s12080-009-0058-0.The dendritic structure of a river network creates directional dispersal and a hierarchical arrangement of habitats. These two features have important consequences for the ecological dynamics of species living within the network.We apply matrix population models to a stage-structured population in a network of habitat patches connected in a dendritic arrangement. By considering a range of life histories and dispersal patterns, both constant in time and seasonal, we illustrate how spatial structure, directional dispersal, survival, and reproduction interact to determine population growth rate and distribution. We investigate the sensitivity of the asymptotic growth rate to the demographic parameters of the model, the system size, and the connections between the patches. Although some general patterns emerge, we find that a species’ mode of reproduction and dispersal are quite important in its response to changes in its life history parameters or in the spatial structure. The framework we use here can be customized to incorporate a wide range of demographic and dispersal scenarios.Funding for this work came from the James S. McDonnell Foundation (EEG, HJL, WFF). MGN was supported by grants from the National Science Foundation (CMG-0530830, OCE-0326734, ATM-0428122)