Ground magnetic data are consistent with the interpretation that Lower Jurassic volcanic rocks of the Twin Buttes mine area (Ox Frame Volcanics) are confined to a distinct block by the northwest trending Sawmill Canyon Fault Zone which was initially active during the Lower Jurassic. Possible reactivation of the Sawmill Canyon Fault zone in the Middle Jurassic as a left-lateral wrench fault is recorded by the deposition of syntectonic red-beds (Rodolfo Formation). Lower Cretaceous rocks (Whitcomb Quartzite, Glance Conglomerate, and Angelica Akrose) were deposited in alluvial environments resulting from additional reactivation of the Sawmill Canyon Fault Zone. Upper Cretaceous (Laramide) deformation involved the formation of northwest trending folds and northwest and northeast trending reverse, tear, and later block faults during the uplift of Precambrian basement. Ore deposits of the Pima mining district are localized along a northeast trending fault zone with evidence for initial activity in the Middle Jurassic and later reactivation during the Laramide.

Bröstmjölk är en komplett näringskälla för det nyfödda barnet. Förutom att tillföra barnet alla näringsämnen hen behöver så ger bröstmjölken energi, bygger upp kroppen samt skyddar det nyfödda barnet mot sjukdomar. Amning är ett samspel mellan mamma och barn som påverkas av många faktorer. För en tvillingmamma är initiering av amning en större utmaning än för en mamma som fött ett barn, då omvårdnaden kring barnen blir dubbel. Syftet med studien var att beskriva tvillingmammors erfarenhet av amningsstöd, dels från vårdpersonal, dels från sociala medier, för att initiera och upprätthålla en fungerande amning. Studien är en intervjustudie med kvalitativ metod. Datamaterial samlades in genom intervjuer av sex utvalda tvillingmammor. Mammorna söktes och valdes ut via en Facebookgrupp. I resultatet framkom två kategorier: Mammans initiativ och Vårdpersonalens engagemang. Resultatet tyder på att de intervjuade mammornas erfarenhet är att vårdpersonal idag saknar den specifika kunskapen om/och förståelse för hur mycket arbete det innebär för en tvillingmamma att få amningen att fungera. Många mammor söker idag den information de inte erhållit via vårdpersonal på annat sätt, oftast via sociala medier. Utifrån den här studien kan vårdpersonal få en ökad förståelse för tvillingmammors behov av extra amningsstöd och information. / Breast milk is a complete food source for the newborn. In addition to supplying the baby all the nutrients it needs breast milk also provides energy, builds up the body and protects the newborn against disease. Breastfeeding is an interaction between mother and child that is affected by many factors. For a twin mother is initiation of breastfeeding more of a challenge than for a mother who gave birth to a child, then care about the children becomes twice.The purpose of this study was to describe the mother of twin´s experience of breastfeeding support, both from health professionals as well as from social media, to initiate and maintain a functional breastfeeding. The study is an interview study of qualitative method. Data material was collected through interviews with six selected twin mothers. The informants were sought and selected through a Facebook group. The results revealed two categories: The mother's initiative and The involvement of health professionals. The result indicates that the interviewed mothers experience is that health professionals today lack the specific knowledge and understanding of how much work it means for a twin mother to get a functional breastfeeding. Many mothers today are using other sources in seeking the information they did not receive by health professionals, mostly through social media. Based on this study, health professionals might gain a greater understanding of the need twin mothers have for more support and information regarding breast feeding twins.

In order to improve the flight performance of the Martin Jetpack research was undertaken to investigate the aerodynamic issues that were limiting the P-11A Jetpack's flight envelope. Through research of existing ducted-fan aircraft, a flight model describing the unique aerodynamics of the Martin Jetpack was developed using Matlab®/Simulink® software. The dynamic flight model, which can be ran in real time, includes the reactions from: ducted-fans, aircraft body aerodynamics, control surfaces, gyration and landing gear interactions. Abstract Numerous experiments were designed to quantify and validate assumptions used in the development of the model equations. The experiments took advantage of the small size of the Jetpack by designing and building test apparatuses that measured reactions directly on the actual aircraft. This avoided scaling issues that are traditionally encountered when employing wind tunnels for aerodynamic measurements. Abstract Implementing the experimental results into the model led to the modifications of the existing Jetpack airframe to produce the P-11C Jetpack prototype, which significantly improved the performance of the aircraft. The collected flight data was used to validate the model and good agreement was achieved. Abstract Based on this research a new Jetpack prototype (P-12) was developed that combined the flight performance of the P-11C Jetpack with the ability to carry a man or manned sized payload. The model was used to design the layout and to size the control vanes for the P-12 Jetpack. Further research was performed to design larger rotor and stator blades required for the P-12 Jetpack prototype. Abstract The developed model allows the user to efficiently evaluate various control methodologies and changes to key aerodynamic features of the aircraft to aid in the design and flying of the Martin Jetpack. Abstract The outcome of this research is a better understanding of the ducted-fan technology, and via the development of the Jetpack flight model, correctly applying this understanding to improve the Jetpack's flight performance.

The Standard Model (SM) of particle physics is widely taken as an elegant effective theory of nature at the electroweak scale, with new physics expected at higher energy. Collider searches and other experimental inputs play a vital role in our hunt for the unknown physics, offering great insights along the way and eventually establishing the extension to the SM. Here we present our studies on prospects of direct and indirect searches for three types of models beyond the SM. The Inert Doublet Model (IDM) extends the SM electroweak sector by an extra Higgs doublet with a Z₂-symmetry. We first examine the IDM dilepton signal at the LHC with a center-of-mass energy of 14 TeV and find it exceeding SM backgrounds at 3σ–12σ significance level, with 100 fb⁻¹ integrated luminosity. We further show that it is possible to obtain the IDM trilepton signal at the 5σ significance level, with an integrated luminosity of 300 fb⁻¹. The Left-Right Twin Higgs (LRTH) model solves the little Hierarchy problem by taking the SM Higgs as a pseudo-Goldstone boson from the spontaneous breaking of a global symmetry. We focus on the discovery potential of the heavy top quark partner in the LRTH model at the LHC. With a luminosity of 30 fb⁻¹ at the early stage of the LHC operation, we conclude that the heavy top partner could be observed at a significance level above 5σ. Supersymmetric extensions of the SM enable cancellations among loop corrections to the Higgs mass from bosonic and fermionic degrees of freedom, leading to a solution to the well-known Hierarchy problem. However, the supersymmetry has to be broken by certain mechanism. We present an exploration of the B-physics observables and electroweak precision data in three distinct soft supersymmetry-breaking scenarios. Projection for future sensitivities of the precision data is also explored.

Pressurized metered-dose inhalers (pMDIs) are the most widely-prescribed inhaler devices for therapeutic aerosol delivery in the treatment of lung diseases. In spite of its undoubted therapeutic and commercial success, the propellant flow mechanics and aerosol formation by the pMDIs is poorly understood. The process involves a complex transient cavitating turbulent fluid that flashes into rapidly evaporating droplets, but details remain elusive, partly due to the difficulty of performing experiments at the small length scales and short time scales. The objective of the current work is the development of a numerical model to predict the internal flow conditions (pressure, temperature, velocity, void fraction, quality, etc.) and provide deeper insight into the atomization process and fluid mechanics involved in the twin-orifice of pMDIs. The main focus is propellant metastability, which has been identified by several past authors as a key element that is missing in accounts of pMDI performance. First the flashing propellant flow through single orifice systems (both long and short capillary tubes) was investigated using three different models : homogeneous equilibrium model (HEM), delayed equilibrium model (DEM) and improved delayed equilibrium model (IDEM). Both, the pure propellants and the propellant mixtures were used as working fluid. The numerical results were compared with the experimental data. For long capillary tubes the three models gave reasonable predictions, but the present results showed that DEM predicts the mass flow rate well for pure propellants and IDEM predicts the mass flow rate well for propellant mixtures. For short capillary tubes, the present results showed that DEM predicts the mass flow rate and pressure distribution along the short tube better compared to HEM and IDEM. The geometry of the twin-orifice system of a pMDI is complex and involves several singularities (sudden enlargements and sudden contractions). Various assumptions were made to evaluate their effect on the vaporisation process and to evaluate the flow variables after the shock at the exit of the spray orifice when the flow is choked. Also, three different propellant flow regimes were explored at the inlet of the valve orifice. A specific combination of assumptions, which offers good agreement with the experimental data was selected for further computations. Numerical investigations were carried out using delayed equilibrium model (DEM) with these new assumptions to validate the two-phase metastable flow through twin-orifice systems with continuous flows of various propellants studied previously by Fletcher (1975) and Clark (1991). A new correlation was developed for the coefficient in the relaxation equation. Along with this correlation a constant coefficient was used in the relaxation equation to model the metastability. Both the coefficients showed good agreement against the Fletcher's experimental data. The comparison with the Clark s experimental data showed that the new correlation coefficient predicted the mass flow rate well in compare to that of the constant coefficient, but over predicted the expansion chamber pressure. The DEM with both the coefficients for continuous discharge flows were applied to investigate the quasi-steady flashing flow inside the metered discharge flows at various time instants. The DEM results were compared with the Clark s metered discharge experimental data and the well established homogeneous equilibrium model (HEM). The comparison between the HEM and DEM with Clark s (1991) experimental data showed that the DEM predicted the mass flow well in compare to that of HEM. Moreover, both the models underpredicted the expansion chamber pressure and temperature. The findings of the present thesis have given a better understanding of the role played by the propellant metastability inside the twin-orifice system of pMDIs. Also, these have provided detailed knowledge of thermodynamic state, void fraction and critical velocity of the propellant at the spray orifice exit, which are essential step towards the development of improved atomisation models. Improved understanding of the fluid mechanics of pMDIs will contribute to the development of next-generation pMDI devices with higher treatment efficacy, capable of delivering a wider range of therapeutic agents including novel therapies based around.

The purpose of this study was to examine the genetic and environmental influences on lifetime quit attempt in three US adolescent and young adult twin samples (N total = 6,322). The study utilized a common-contingent-causal (CCC) model to estimate these factors for lifetime quit attempts, after accounting for the factors for lifetime cigarette use and cigarettes per day. The study also examined age and sex differences, as well as the degree of relationship between these smoking phenotypes. The results demonstrated significant genetic influences for lifetime quit attempts in adolescents and young adults. No sex differences were observed for the contributions of genetic and environmental factors for lifetime quit attempts. Furthermore, separate liabilities for lifetime quit attempts and lifetime cigarette use were found for most age groups. Study findings have important implications for promoting quit attempts in adolescents and young adults.

This paper investigates the relationship between countries' fiscal balances and current accounts with an emphasis on the role of fiscal rules. The direct effect of fiscal policy on the current account via aggregate (import) demand is potentially amplified by indirect effects, materializing through interest rate effects and inter-generational transfers that reduce savings. On the other hand, the implied positive relation between fiscal and external balances is potentially attenuated by offsetting changes in savings through Ricardian equivalence considerations. We expect this attenuation effect to be stronger in countries with more stringent fiscal rules and test this hypothesis using a panel of 73 countries over the period 1985-2012. As previous studies we find a positive effect of fiscal balances on the current account, supporting the twin deficit hypothesis. However, the effect of fiscal balances on the current account depends on the stringency of fiscal (budget balance or debt) rules in place; it is reduced by one third on average and virtually eliminated for countries with the most stringent fiscal rules. (authors' abstract) / Series: Department of Economics Working Paper Series

This thesis investigated the etiology of individual differences in Chinese language and literacy skills with a two-wave longitudinal design using a sample of 312 Chinese twin pairs aged 3 to 11 in Hong Kong. Children were individually given tasks of Chinese word reading, receptive vocabulary, phonological memory, tone awareness, syllable and rhyme awareness, rapid automatized naming, morphological awareness, and orthographic skills, as well as nonverbal reasoning and audiometric screening tests. They were tested again on the same tasks, except nonverbal reasoning, one year after the initial testing. Children’s saliva was collected to perform SNP testing for zygosity determination. Also, their demographic information, home literacy environment profile, and motivation for learning text, were obtained from parent-rated questionnaires. Overall, there were four major findings on Chinese language and literacy abilities with the effects of age and nonverbal reasoning controlled for. First, genes and environments had differential influences on various skills, and there was a possibility of different etiology in language and reading development. Second, socioeconomic status and home literacy environment were plausible mediators but not moderators of general language and reading abilities. Third, the stability of various skills across a one-year time period was mainly mediated by genetic influences, but shared environmental factors also influenced syllable and rhyme awareness. Also, new genetic and environmental factors came into play at Time 2 for word reading, and results suggested new genetic influences and new shared environmental influences emerged at Time 2 for tone awareness and morphological awareness respectively. Fourth, both genes and environments contributed to parent-rated communicative ability and motivation for learning text. Furthermore, the link between word reading and parent-rated motivation was mediated by genetic processes. The universality of the genetic and environmental origins across languages and their specificity to Chinese, as well as the implications of these findings, were discussed.

This thesis investigated reading and related skills in Chinese children learning English as a second language (ESL) in 279 Chinese twin pairs aged from 3 to 11 years. Children were tested twice, a year apart, with measures of visual word recognition, receptive vocabulary, phonological awareness, phonological memory and speech perception in both Chinese and English and Chinese tone awareness. The thesis was divided into two sections with the first section exploring the phenotypic relationships and the second section estimating the genetic and environmental influences. In the first section, the causal relationships among the five ESL skills were modelled (chapter 4) and the relationships between Chinese and ESL skills were sought (chapter 4). In section two, the univariate heritability (chapter 6), the cross-linguistic genetic overlap (chapter 7) and the stability and instability of heritability estimates (chapter 8) for all skills were examined. Findings have shown that ESL speech perception is important to the development of ESL phonological awareness, phonological memory and receptive vocabulary, in turn, has an impact on ESL reading development. Genes play an important role in ESL and Chinese reading development. The differential environmental effects may be due to the differences in the ESL and Chinese acquisition ecologies.

Although previous research has shown a significant association between bulimia nervosa (BN) and drug use disorders (DUD), our knowledge of the underlying causes for this comorbidity remains limited. The purpose of the present study was to investigate possible influences on the comorbidity between BN and DUD. Subjects included 490 monozygotic and 354 dizygotic female twin pairs from the Virginia Adult Twin Study of Psychiatric and Substance Use Disorders. Multiple logistic regression analyses were used to test where putative shared correlates mediated the comorbidity between BN and DUD. Bivariate twin analyses were used to investigate the contribution of genes and environment to the correlation between BN and DUD. Regression analyses indicated a lifetime history of major depression, the personality trait of neuroticism, and childhood sexual abuse significantly mediated the associated between BN and DUD (using BN as the independent variable), while major depression, conduct disorder diagnosis, and childhood sexual abuse most significantly impacted the association when DUD was used as the independent variable. Bivariate twin analyses indicated there is additive genetic and nonshared environmental overlap between BN and DUD with genetic and unique environmental correlations of 0.39 and 0.10, respectively. Results show the reason for the association between BN and DUD is due mostly to overlapping genes with a smaller contribution from nonshared environmental influences. Major depression, the personality trait of neuroticism, and childhood sexual abuse are likely important shared correlates between BN and DUD.