Magister Artium (Development Studies) - MA(DVS) / Remittances inflows have gradually become one of the major sources of external financial inflows to developing countries. As a result, research abounds on the developmental effects of remittances in the home countries of migrants. At the micro level, recipients of remittances are more likely to have better access to quality health care, education as well as start-up fund for their own businesses. On the other hand at the macro level, remittances inflows can help increase the credit worthiness of countries by enabling them to use future remittances inflows as collateral for loans. Additionally, remittances inflows as a source of foreign exchange can be used by countries to fund import bills. Although there has been a surge of scholarship on remittances, this scholarship seems to be concentrated on the economic study of migration instead of the macroeconomic aspects of remittances. Furthermore, comparative studies on these macroeconomic aspects of remittances especially on African countries are underresearched and remains at the backwaters of academic study. Using quantitative time series data, this research seeks to do a comparative study on the countercyclical nature of remittances in four selected West African countries (Cameroon, Cape Verde, Nigeria and Senegal). The research used descriptive trend analysis, autocorrelation and an ARMAX model analyse the research problem. After critical analysis on whether remittances are countercyclical or not using the 2009 global financial crisis as a reference year in these four countries, it was found that, remittance inflows to Cameroon, Cape Verde, Nigeria and Senegal were pro-cyclical in nature. Moreover, in analysing the relationship between remittances inflows and gross domestic product (economic growth) the research revealed that there was a positive relationship between remittances inflows and economic growth for the four countries (Cameroon, Cape Verde, Nigeria and Senegal) observed. One recommendation given from this study is that, there is the need for remittances inflows to be invested in productive activities. This is because even if remittances continue to increase, without its investment in productive sectors, it cannot have any meaningful impact on economic growth in these countries.

We present proper motion measurements of 37 jets and HH objects in the Carina Nebula measured in two epochs of H alpha images obtained similar to 10 yr apart with Hubble Space Telescope/Advanced Camera for Surveys (ACS). Transverse velocities in all but one jet are faster than greater than or similar to 25 km s(-1), confirming that the jet-like H alpha features identified in the first epoch images trace outflowing gas. Proper motions constrain the location of the jet-driving source and provide kinematic confirmation of the intermediate-mass protostars that we identify for 20/37 jets. Jet velocities do not correlate with the estimated protostar mass and embedded driving sources do not have slower jets. Instead, transverse velocities (median similar to 75 km s(-1)) are similar to those in jets from low-mass stars. Assuming a constant velocity since launch, we compute jet dynamical ages (median similar to 10(4) yr). If continuous emission from inner jets traces the duration of the most recent accretion bursts, then these episodes are sustained longer (median similar to 700 yr) than the typical decay time of an FU Orionis outburst. These jets can carry appreciable momentum that may be injected into the surrounding environment. The resulting outflow force, dp/dt, lies between that measured in low- and high-mass sources, despite the very different observational tracers used. Smooth scaling of the outflow force argues for a common physical process underlying outflows from protostars of all masses. This latest kinematic result adds to a growing body of evidence that intermediate-mass star formation proceeds like a scaled-up version of the formation of low-mass stars.

We present CI(2-1) and multi-transition (CO)-C-12 observations of a dusty star-forming galaxy, ACT J2029+0120, which we spectroscopically confirm to lie at z = 2.64. We detect CO(3-2), CO(5-4), CO(7-6), CO(8-7), and CI (2-1) at high significance, tentatively detect HCO+(4-3), and place strong upper limits on the integrated strength of dense gas tracers (HCN(4-3) and CS(7-6)). Multi-transition CO observations and dense gas tracers can provide valuable constraints on the molecular gas content and excitation conditions in high-redshift galaxies. We therefore use this unique data set to construct a CO spectral line energy distribution (SLED) of the source, which is most consistent with that of a ULIRG/Seyfert or QSO host object in the taxonomy of the Herschel Comprehensive ULIRG Emission Survey. We employ RADEX models to fit the peak of the CO SLED, inferring a temperature of T similar to 117 K and n(H2) similar to 10(5) cm(-3), most consistent with a ULIRG/QSO object and the presence of high-density tracers. We also find that the velocity width of the C I line is potentially larger than seen in all CO transitions for this object, and that the L'(Ci(2-1))/L'(CO(3-2)) ratio is also larger than seen in other lensed and unlensed submillimeter galaxies and QSO hosts; if confirmed, this anomaly could be an effect of differential lensing of a shocked molecular outflow.

Der Projektabschlussbericht befasst sich mit der Bestimmung von Hochwasserscheitelabflüssen mit zugeordneter Jährlichkeit HQT an unbeobachteten Gewässerquerschnitten in Sachsen. Grundlage sind beobachtete Hochwasserscheitel an 113 Pegeln und hydrologische Überlegungen zur räumlichen Variabilität von Hochwassern. Zur Anwendung kommen Index-Flood-Verfahren, Top-Kriging und Georegression. Die Bewertung der Ergebnisse erfolgt mit einem Jack-Knife-Vergleich für die durch Pegel beobachteten Einzugsgebiete. Zur Bestimmung von Hochwasserspenden wird für Sachsen eine Kombination aller drei Verfahren empfohlen. Die Ergebnisse sollen Planern und Wasserbehörden für die Bemessung wasserbaulicher Anlagen zur Verfügung stehen.

Recombination line profile shapes are derived for ionized spherical stellar winds at radio wavelengths. It is assumed that the wind is optically thick owing to free-free opacity. Emission lines of arbitrary optical depth are obtained assuming that the free-free photosphere forms in the outer, constant expansion portion of the wind. Previous works have derived analytic results for isothermal winds when the line and continuum source functions are equal. Here, semi-analytic results are derived for unequal source functions to reveal that line shapes can be asymmetric about line center. A parameter study is presented and applications discussed.

We present new, contemporaneous Hubble Space Telescope STIS and XMM-Newton observations of the O7 III(n)((f)) star ξ Per. We supplement the new data with archival IUE spectra, to analyze the variability of the wind lines and X-ray flux of ξ Per. The variable wind of this star is known to have a 2.086-day periodicity. We use a simple, heuristic spot model that fits the low-velocity (near-surface) IUE wind line variability very well, to demonstrate that the low-velocity absorption in the new STIS spectra of N iv λ1718 and Si iv λ1402 vary with the same 2.086-day period. It is remarkable that the period and amplitude of the STIS data agree with those of the IUE spectra obtained 22 yr earlier. We also show that the time variability of the new XMM-Newton fluxes is also consistent with the 2.086-day period. Thus, our new, multiwavelength coordinated observations demonstrate that the mechanism that causes the UV wind line variability is also responsible for a significant fraction of the X-rays in single O stars. The sequence of events for the multiwavelength light-curve minima is Si iv λ1402, N iv λ1718, and X-ray flux, each separated by a phase of about 0.06 relative to the 2.086-day period. Analysis of the X-ray fluxes shows that they become softer as they weaken. This is contrary to expectations if the variability is caused by periodic excess absorption. Furthermore, the high-resolution X-ray spectra suggest that the individual emission lines at maximum are more strongly blueshifted. If we interpret the low-velocity wind line light curves in terms of our model, it implies that there are two bright regions, i.e., regions with less absorption, separated by 180°, on the surface of the star. We note that the presence and persistence of two spots separated by 180° suggest that a weak dipole magnetic field is responsible for the variability of the UV wind line absorption and X-ray flux in ξ Per.

The stellar winds of hot stars have an important impact on both stellar and galactic evolution, yet their structure and internal processes are not fully understood in detail. One of the best nearby laboratories for studying such massive stellar winds is the O4I(n)fp star ζ Pup. After briefly discussing existing X-ray observations from Chandra and XMM, we present a simulation of X-ray emission line profile measurements for the upcoming 840 kilosecond Chandra HETGS observation. This simulation indicates that the increased S/N of this new observation will allow several major steps forward in the understanding of massive stellar winds. By measuring X-ray emission line strengths and profiles, we should be able to differentiate between various stellar wind models and map the entire wind structure in temperature and density. This legacy X-ray spectrum of ζ Pup will be a useful benchmark for future X-ray missions.

This thesis focuses on the dynamics of benefit receipt in the Ontario Disability Support Program (ODSP) using individual-level administrative data from 2003 to 2013. This thesis is comprised of three self-contained essays. The first essay examines the dynamics of disability benefit receipt in Ontario. A five-year cohort analysis is carried out for those who first received disability benefits in any year between 2004 and 2009 to estimate the proportion exiting from such benefits within five years of first benefit receipt. This analysis is extended to type of exit (e.g., died, moved, or disqualified) and nature of exit (e.g., sustained or temporary). We find that only about 18 percent of benefit recipients exit, most within one and a half years of initial benefit receipt, and that more than one-third of those who exit return within five years. Recipients are both less likely to exit and more likely to return if single, divorced, or widowed rather than married or living common law, if they have children, or if they have mental rather than physical disabilities. The second essay identifies factors that influence ODSP benefits duration. We employ a flexible parametric technique to investigate the duration of disability benefit receipt. We also employ cure models to account for the proportion of recipients that never exit ODSP over the ten-year sample period. Of the whole sample, 20 percent of recipients completed a first spell and the remaining 80 percent were right censored. We find that time spent receiving ODSP benefits is negatively associated with education and positively associated with both age and severity of disability. Individuals who are single, divorced, separated, widowed, or immigrants have longer benefit spells as compared to those who are married, common law, and Canadian born. Individuals with children also spend longer time on ODSP than those relative without children. We provide evidence that recipient characteristics are associated with different probabilities of exiting or re-entering ODSP; that suggests that differentiated, and not ‘one size fit all’, policies are required to facilitate transitions from program dependence to economic independence. The third essay analyzes differences in the benefit receipt rates by immigration status and age. A flexible parametric duration analysis is employed to investigate how age at entry into benefits interacted with immigration status and, for immigrants, how age at arrival in Canada affects the exit rate from disability support. We find strong evidence of differences in age-dependence of benefit receipt and exit rates across immigration status categories. At younger (18-34) and middle (35-54) ages the Canadian-born have much higher benefit receipt rates than immigrants but lower rates at older (55 and over) ages. We speculate that the difference at younger and middle ages can be explained largely by the “healthy immigrant effect” (i.e., a selection effect of relatively healthier immigrants) and at older ages by differential eligibility for, and expected income from, alternative benefit programs such as the Canada Pension Plan, Old Age Security, and the Guaranteed Income Supplement. / Thesis / Doctor of Philosophy (PhD)

Quasars can affect their surrounding environment through a process known as active galactic nucleus (AGN) feedback, through which the quasar can curtail the formation of stars, regulate the evolution of its host galaxy, and affect its surrounding environment in other ways. One possible mechanism for this process is a quasar's outflow, which can be observed as blueshifted absorption troughs in the quasar's spectrum. With enough kinetic power, an outflow can contribute to AGN feedback, regulating star formation and host galaxy evolution. By analyzing spectra from the Very Large Telescope (VLT) Ultraviolet Echelle Spectrograph (UVES) and the Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS), we determined the physical parameters of the absorption outflows of five different quasars: including electron number density, Hydrogen column density, ionization parameter, distance from the source, and kinetic luminosity. We have found that an outflow's chemical abundance can be a determining factor of its ability to contribute to feedback effects. Particularly notable outflows include a mini broad absorption line (BAL) outflow system of SDSS J0242+0049, which we estimated to be ∼ 67 kpc away from the quasar, which is the farthest distance a mini-BAL has been found from its source. We also found a high velocity C IV BAL from the same quasar which showed noticeable signs of time variability, which suggests that the ionization of the outflow has changed over time. Another was SDSS J1321-0041 which displayed BAL troughs of C II and Si II, an unusual feature for an outflow of its type. In our analysis of the EUV500 BAL of QSO B0254-3327B, we compared it with other EUV500 outflows that have been previously studied, with a total sample of 24 outflows. In that comparison, we have found that the outflow of QSO B0254-3327B was one of the most ionized outflows in the sample. We have also found a weak negative correlation between logR and log |v|, where R is the distance of the outflow from its source, and v is the velocity of the outflow, with a Spearman rank of -0.43 and p value of 0.05, suggesting that the farther the outflow is from its source, the slower its velocity. / Doctor of Philosophy / From the prediction of their existence by general relativity, to the first direct image from the Event Horizon Telescope, black holes have been a fascinating subject for both physicists and the public alike. Most massive galaxies, including our own, are said to have a supermassive black hole (SMBH) at their center. In some galaxies, an accretion disk of orbiting matter forms around the black hole, in which gravitational energy is converted into light. This can sometimes cause the galactic nucleus to shine as bright as a star in the night sky, despite it being tens of thousands of times farther away from us than any star in our own galaxy. Such galactic nuclei are called "quasars", or "quasi-stellar objects". Some quasars show signs of outflowing gases which can absorb some of their emitted light. These are observed as blueshifted absorption troughs in quasar spectra from telescopes such as the Very Large Telescope (VLT) or the Hubble Space Telescope (HST). It is predicted that, with enough power, these outflows can contribute to a process called active galactic nucleus (AGN) feedback, through which the quasar can curtail the formation of stars, regulate the evolution of its host galaxy, and affect its surrounding environment in other ways. This dissertation discusses the study of five different quasars and their outflows observed with VLT and HST. We determined the physical parameters of the outflows such as electron number density, Hydrogen column density, ionization parameter, and distance of the outflow from its source, to ultimately find each outflow's kinetic luminosity, or kinetic power. While we found that some outflows are likely to be able to contribute to AGN feedback, there are a number of unknowns that still remain. Some interesting outflows we have found include the mini-BAL outflow of SDSS J0242+0049, which we found to be at a distance of ∼ 67 kpc (or ∼ 220, 000 lightyears) away from its source, the farthest distance observed to date. We also analyzed the extreme UV outflow of QSO B0254-3327B, which we compared to other outflows observed in a similar wavelength range. In that comparison, we found a weak negative correlation between velocity and outflow distance from the central source, suggesting that the farther away an outflow is from the quasar, the slower it becomes.

This thesis primarily uses submillimetre molecular line data from HARP, a heterodyne array on the James Clerk Maxwell Telescope (JCMT), to further investigate star formation in the Ophiuchus L1688 cloud. HARP was used to observe CO J = 3-2 isotopologues: 12CO, 13CO and C18O; and the dense gas tracer HCO+ J = 4-3. A method for calculating molecular line contamination in the SCUBA-2 450 and 850 μm dust continuum data was developed, which can be used to convert 12CO J =6-5and J =3-2 maps of integrated intensity (K km s−1) to molecular line flux (mJy beam−1) contaminating the continuum emission. Using HARP maps of 12CO J = 3-2, I quantified the amount of molecular line contamination found in the SCUBA-2 850 μm maps of three different regions, including NGC 1333 of Perseus and NGC 2071 and NGC 2024 of Orion B. Regions with ‘significant’ (i.e. > 20%) molecular line contamination correspond to molecular outflows. This method is now being used to remove molecular line contamination from regions with both SCUBA-2 dust continuum and HARP 12CO map coverage in the Gould Belt Legacy Survey (GBS). The Ophiuchus L1688 cloud was observed in all three CO J = 3-2 isotopologues. I carried out a molecular outflow analysis in the region on a list of 30 sources from the Spitzer ‘c2d’ survey [Evans et al., 2009]. Out of the 30 sources, 8 had confirmed bipolar outflows, 20 sources had ‘confused’ outflow detections and 2 sources did not have outflow detections. The Ophiuchus cloud was found to be gravitationally bound with the turbulent kinetic energy a factor of 7 lower than the gravitational binding energy. The high-velocity outflowing gas was found to be only 21% of the turbulence in the cloud, suggesting outflows are significant but not the dominant source of turbulence in the region. Other factors were found to influence the global high-velocity outflowing gas in addition to molecular outflows, including hot dust from nearby B-type stars, outflow remnants from less embedded sources and stellar winds from the Upper Scorpius OB association. To trace high density gas in the Ophiuchus L1688 cloud, HCO+ J = 4-3 was observed to further investigate the relationship between high column density and high density in the molecular cloud. Non-LTE codes RADEX and TORUS were used to develop density models corresponding to the HCO+ emission. The models involved both constant density and peaked density profiles. RADEX [van der Tak et al., 2007] models used a constant density model along the line-of-sight and indicated the HCO+ traced densities that were predominantly subthermally excited with den- sities ranging from 10^3–10^5 cm^−3. Line-of-sight estimates ranged from several parsecs to 90 pc, which was unrealistic for the Ophiuchus cloud. This lead to the implementation of peaked density profiles using the TORUS non-LTE radiative transfer code. Initial models used a ‘triangle’ density profile and a more complicated log-normal density probability density function (PDF) profile was subsequently implemented. Peaked density models were relatively successful at fitting the HCO+ data. Triangle models had density fits ranging from 0.2–2.0×10^6 cm^−3 and 0.1–0.3×10^6 cm^−3 for the 0.2 and 0.3 pc cloud length models re- spectively. Log-normal density models with constant-σ had peak density ranges from 0.2–1.0 ×10^5 cm^−3 and 0.6–2.0×10^5 cm^−3 for 0.2 and 0.3 pc models respectively. Similarly, log-normal models with varying-σ had lower and upper density limits corresponding to the range of FWHM velocities. Densities (lower and upper limits) ranged from 0.1–1.0 ×10^6 and 0.5–3.0 ×10^5 cm^-3 for the 0.2 and 0.3 pc models respectively. The result of the HCO+ density modelling indicated the distributions of starless, prestellar and protostellar cores do not have a preference for higher densities with respect to the rest of the cloud. This is contrary to past research suggesting the probability of finding a submillimetre core steeply rises as a function of column density (i.e. density; Belloche et al. 2011; Hatchell et al. 2005). Since the majority of sources are less embedded (i.e Class II/III), it is possible the evolutionary state of Ophiuchus is the main reason the small sample of Class 0/I protostars do not appear to have a preference for higher densities in the cloud.