Are Currency Crises Low-State Equilibria? An Empirical, Three-Interest-Rate Model

Suppose that the dynamics of the macroeconomy were given by (partly) random fluctuations between two equilibria: "good" and "bad." One would interpret currency crises (or recessions) as a shift from the good equilibrium to the bad. In this paper, the authors specify a dynamic investment-savings-aggregate-supply (IS-AS) model, determine its closed-form solution, and examine numerically its comparative statics. The authors estimate the model via maximum likelihood, using data for Argentina, Canada, and Turkey. Since the data show no support for the multiple-equilibrium explanation of fluctuations, the authors cast doubt on the third-generation models of currency crisis.Uncertainty and monetary policy

Bayesian methods to infer direct transmission using data from outbreaks in households

The study of how transmissible an infectious pathogen is and what its main routes of transmission are is key towards management and control of its spread. Some infections which begin with zoonotic or common-source transmission may additionally exhibit potential for direct person-to-person transmission. Methods to discern multiple transmission routes from observed outbreak datasets are thus essential. Features such as partial observation of the outbreak can make such inferences more challenging. This thesis presents a stochastic modelling framework to infer person-to-person transmission using data observed from a completed outbreak in a population of households. The model is specified hierarchically for the processes of transmission and observation. The transmission model specifies the process of acquiring infection from either the environment or infectious household members. This model is governed by two parameters, one for each source of transmission. While in continuous time they are characterised by transmission hazards, in discrete time they are characterised by escape probabilities. The observation model specifies the process of observation of outbreak based on symptom times and serological test results. The observation design is extended to address an ongoing outbreak with censored observation as well as to case-ascertained sampling where households are sampled based on index cases. The model and observation settings are motivated by the typical data from Hepatitis A virus (HAV) outbreaks. Partial observation of the infectious process is due to unobserved infection times, presence of asymptomatic infections and not-fully- sensitive serological test results. Individual-level latent variables are introduced in order to account for partial observation of the process. A data augmented Markov chain Monte Carlo (DA-MCMC) algorithm to estimate the transmission parameters by simultaneously sampling the latent variables is developed. A model comparison using deviance-information criteria (DIC) is formulated to test the presence of direct transmission, which is the primary aim in this thesis. In calculating DIC, the required computations utilise the DA-MCMC algorithm developed for the estimation procedures. \\ The inference methods are tested using simulated outbreak data based on a set of scenarios defined by varying the following: presence of direct transmission, sensitivity and specificity for observation of symptoms, values of the transmission parameters and household size distribution. Simulations are also used for understanding patterns in the distribution of household final sizes by varying the values of the transmission parameters. From the results using simulated outbreaks, DIC6 consistently indicates towards the correct model in almost all simulation scenarios and is robust across all the presented simulation scenarios. Also, the posterior estimates of the transmission parameters using DA- MCMC are fairly consistent with the values used in the simulation. The procedures presented in this thesis are for SEIR epidemic models wherein the latent period is shorter than the incubation period along with presence of asymptomatic infections. These procedures can be directly adapted to infections with similar or simpler natural history. The modelling framework is flexible and can be further extended to include components for vaccination and pathogen genetic sequence data

Comparing Evolutionary Operators, Search Spaces, and Evolutionary Algorithms in the Construction of Facial Composites

Facial composite construction is one of the most successful applications of interactive evolutionary computation. In spite of this, previous work in the area of composite construction has not investigated the algorithm design options in detail. We address this issue with four experiments. In the first experiment a sorting task is used to identify the 12 most salient dimensions of a 30-dimensional search space. In the second experiment the performances of two mutation and two recombination operators for interactive genetic algorithms are compared. In the third experiment three search spaces are compared: a 30-dimensional search space, a mathematically reduced 12-dimensional search space, and a 12-dimensional search space formed from the 12 most salient dimensions. Finally, we compare the performances of an interactive genetic algorithm to interactive differential evolution. Our results show that the facial composite construction process is remarkably robust to the choice of evolutionary operator(s), the dimensionality of the search space, and the choice of interactive evolutionary algorithm. We attribute this to the imprecise nature of human face perception and differences between the participants in how they interact with the algorithms. Povzetek: Kompozitna gradnja obrazov je ena izmed najbolj uspešnih aplikacij interaktivnega evolucijskega ra?cunanja. Kljub temu pa do zdaj na podro?cju kompozitne gradnje niso bile podrobno raziskane možnosti snovanja algoritma. To vprašanje smo obravnavali s štirimi poskusi. V prvem je uporabljeno sortiranje za identifikacijo 12 najbolj izstopajo?cih dimenzij 30-dimenzionalnega preiskovalnega prostora. V drugem primerjamo u?cinkovitost dveh mutacij in dveh rekombinacijskih operaterjev za interaktivni genetski algoritem. V tretjem primerjamo tri preiskovalne prostore: 30-dimenzionalni, matemati?cno reducirani 12-dimenzionalni in 12-dimenzionalni prostor sestavljen iz 12 najpomembnejših dimenzij. Na koncu smo primerjali uspešnost interaktivnega genetskega algoritma z interaktivno diferencialno evolucijo. Rezultati kažejo, da je proces kompozitne gradnje obrazov izredno robusten glede na izbiro evolucijskega operatorja(-ev), dimenzionalnost preiskovalnega prostora in izbiro interaktivnega evolucijskega algoritma. To pripisujemo nenatan?cni naravi percepcije in razlikam med interakcijami uporabnikov z algoritmom

Informed baseline subtraction of proteomic mass spectrometry data aided by a novel sliding window algorithm

Proteomic matrix-assisted laser desorption/ionisation (MALDI) linear time-of-flight (TOF) mass spectrometry (MS) may be used to produce protein profiles from biological samples with the aim of discovering biomarkers for disease. However, the raw protein profiles suffer from several sources of bias or systematic variation which need to be removed via pre-processing before meaningful downstream analysis of the data can be undertaken. Baseline subtraction, an early pre-processing step that removes the non-peptide signal from the spectra, is complicated by the following: (i) each spectrum has, on average, wider peaks for peptides with higher mass-to-charge ratios (m/z), and (ii) the time-consuming and error-prone trial-and-error process for optimising the baseline subtraction input arguments. With reference to the aforementioned complications, we present an automated pipeline that includes (i) a novel `continuous' line segment algorithm that efficiently operates over data with a transformed m/z-axis to remove the relationship between peptide mass and peak width, and (ii) an input-free algorithm to estimate peak widths on the transformed m/z scale. The automated baseline subtraction method was deployed on six publicly available proteomic MS datasets using six different m/z-axis transformations. Optimality of the automated baseline subtraction pipeline was assessed quantitatively using the mean absolute scaled error (MASE) when compared to a gold-standard baseline subtracted signal. Near-optimal baseline subtraction was achieved using the automated pipeline. The advantages of the proposed pipeline include informed and data specific input arguments for baseline subtraction methods, the avoidance of time-intensive and subjective piecewise baseline subtraction, and the ability to automate baseline subtraction completely. Moreover, individual steps can be adopted as stand-alone routines.Comment: 50 pages, 19 figure

Pediatric thyroid disease: when is surgery necessary, and who should be operating on our children?

Surgical diseases of the thyroid in the pediatric population represent a diverse set of both benign and malignant conditions. Overall, incidence is rare. Benign conditions include Graves' disease, toxic adenomas, congenital hyperthyroidism, and goiter. Differentiated thyroid cancer (DTC) and medullary thyroid carcinoma (MTC), with its related familial cancer syndromes, are the most common malignancies. Near-total or total thyroidectomy is the appropriate surgery for thyroid cancer, with/out central lymph node dissection. Emerging practice guidelines from professional societies are helpful, although they generally have not addressed surgical management of the pediatric patient. Thyroidectomy in children is associated with a higher rate of complications, such as recurrent laryngeal nerve injury and hypoparathyroidism, as compared to the surgery in adults. Therefore, it is essential that pediatric thyroidectomy be performed by high-volume thyroid surgeons, regardless of specialty. Case volume to support surgical expertise usually must be borrowed from the adult experience, given the relative paucity of pediatric thyroidectomies at an institutional level. These surgeons should work as part of a multidisciplinary team that includes pediatric endocrinologists and anesthesiologists, pediatricians, nuclear medicine physicians, and pathologists to afford children the best clinical outcomes

STOCHASTIC WEALTH DYNAMICS AND RISK MANAGEMENT AMONG A POOR POPULATION

The literature on economic growth and development has focused considerable attention on questions of risk management and the possibility of multiple equilibria associated with poverty traps. We use herd history data collected among pastoralists in southern Ethiopia to study stochastic wealth dynamics among a very poor population. These data yield several novel findings. Although covariate rainfall shocks plainly matter, household-specific factors, including own herd size, account for most observed variability in wealth dynamics. Despite longstanding conventional wisdom about common property grazing lands, we find no statistical support for the tragedy of the commons hypothesis. It appears that past studies may have conflated costly self-insurance with stocking rate externalities. Such self-insurance is important in this setting because weak livestock markets and meager social insurance cause wealth to fluctuate largely in response to biophysical shocks. These shocks move households between multiple dynamic wealth equilibria toward which households converge following nonconvex path dynamics. The lowest equilibrium is consistent with the notion of a poverty trap. These findings have broad implications for the design of development and relief strategies among a poor population extraordinarily vulnerable to climatic shocks.common property, covariate risk, Ethiopia, idiosyncratic risk, poverty traps, social insurance, Risk and Uncertainty, O1, Q12,

EVALUATIVE STUDY OF DIGITAL RECORD MANAGEMENT SYSTEM IN THE HOSPITALS IN MINNA METROPOLIS. (A CASE STUDY OF GENERAL HOSPITAL MINNA, NIGER STATE. NIGERIA).

ABSTRACT The study was conducted to evaluate digital record management system in the hospitals in Minna metropolis (a case study of General Hospital Minna, Niger State). Four research questions guided the study. Survey research design was adopted. The population of the study was one hundred and twenty four (124) medical staff (Doctors, Nurses, Laboratory Technologists and Pharmacists). There was no sampling as the entire population was used for the study. A 19 items structured questionnaire was developed from the literature and used for data collection. Three experts validated the instrument. Data collected was analysed using frequency and simple percentage. The findings revealed that the degree of application of digital record management system is high in general hospital Minna having a response indication of 62(50%) agreed and 52(41.9%) strongly agreed to the degree of application of digital record management system in the hospital. This implies that e-health record has the ability to improve the quality of health care services rendered by the hospital. Based on the findings, it was recommended that Policies, strategies and decisions to positively support and guide the proper implementation and usage of digital record management system should be upheld and considered very important in the hospital system

EXTERNALISM AS THE BASIS OF JUSTIFICATION IN AFRICAN EPISTEMOLOGY

Contemporary African epistemologists share a common commitment to promotea conception of knowledge that reflects the African cultural background and collective experience. However, they differ over the basic nature of justification in African epistemology. The challenge which centres on the Internalist-Externalist debateis that of deciding whether the factors by virtue of which beliefs acquire the status of being epistemically justified in African epistemology are internal or external to the African. With no possible resolution in sight, the intense intellectual scuffles generatedby the debatetend to heighten the division between sympathizers of eachperspective among contemporary African epistemologists. In view of resolving this seeming impasse, this paper advances reasonsto enhance the appreciation of the centrality of externalismin African epistemology. It rejects internalism as incompatible with justification in African epistemology, given the context-dependent and social nature of knowledge in African epistemology, where the role of the community is central in epistemic practices.The analytic, expository and critical methods of research are adopted in the paper

Knowledge Organisation and its Role in Multimedia Information Retrieval

Various kinds of knowledge organisation (such as thesauri) are routinely used to label or tag multimedia content such as images and music, to support information retrieval i.e. user search for such content. In this paper we outline why this is the case, in particular focusing on the semantic gap between content and concept based multimedia retrieval. We survey some indexing vocabularies used for multimedia retrieval, and argue that techniques such as thesauri will be needed for the foreseeable future in order to support users in their need for multimedia content. In particular we argue that Artificial Intelligence (A.I.) techniques are not mature enough to solve the problem of indexing multimedia conceptually, and will not be able to replace human indexers for the foreseeable future