Mozambique and natural disasters: human capital under threat

This paper assesses the effect of a sequence of natural disasters on children’s health that hit Mozambique at the start of the 21st Century. The disasters in question were the floods of 2000 and the droughts of the years 2002 and 2003. Height-for-age z-scores of children between 1 and 3 years old is used to capture the cumulative effects of this sequence of natural disasters. It was found that the effect of the disasters on these children’s height was, on average, -0.4236 standard deviations, which corresponds to the affected children being more than 1.5 cm shorter by the time of the survey. The findings in this paper are important because of the long term economic cost associated with the disasters, and urge the need for further public intervention to mitigate the damage caused by the shocks. This paper also contributes to the existing literature on the subject of the impact of shocks on child health in the developing world by focusing on measurement errors, differences in physical stature among ethnic groups and migratory movements.Mozambique; Health; Natural Disaster; Human Capital; Developing Country

A Data Model for Exploration of Temporal Virtual Reality Geographic Information Systems

Geographic information systems deal with the exploration, analysis, and presentation of geo-referenced data. Virtual reality is a type of human-computer interface that comes close to the way people perceive information in the real world. Thus, virtual reality environments become the natural paradigm for extending and enhancing the presentational and exploratory capability of GIs applications in both the spatial and temporal domains. The main motivation of this thesis is the lack of a framework that properly supports the exploration of geographic information in a multi-dimensional and multi-sensorial environment (i.e., temporal virtual reality geographic information systems). This thesis introduces a model for virtual exploration of animations. Virtual exploration of animations is a framework composed of abstract data types and a user interface that allow non-expert users to control, manipulate, analyze, and present objects\u27 behaviors in a virtual-reality environment. In the model for virtual exploration of animations, the manipulation of the dynamic environment is accomplished through a set of operations performed over abstractions that represent temporal characteristics of actions. An important feature of the model is that the temporal information is treated as first-class entities and not as a mere attribute of action\u27s representations. Therefore, entities of the temporal model have their own built-in functionality and are able to represent complex temporal structures. In an environment designed for the manipulation of the temporal characteristics of actions, the knowledge of relationships among objects\u27 behaviors plays a significant role in the model. This information comes from the knowledge base of the application domain and is represented in the model through constraints among entities of the temporal model. Such constraints vary from simply relating the end points of two intervals to a complex mechanism that takes into account all relations between sequences of intervals of cyclic behaviors. The fact that the exploration of the information takes place in a virtual reality environment imposes new requirements on the animation model. This thesis introduces a new classification of objects in a VR environment and describes the associated semantics of each element in the taxonomy. These semantics are used to direct the way an object interacts with an observer and with other objects in the environment

Stability in quadratic torsion theories

We revisit the definition and some of the characteristics of quadratic theories of gravity with torsion. We start from the most general Lagrangian density quadratic in the curvature and torsion tensors. By assuming that General Relativity should be recovered when torsion vanishes and investigating the behaviour of the vector and pseudovector torsion fields in the weak-gravity regime, we present a set of necessary conditions for the stability of these theories. Moreover, we explicitly obtain the gravitational field equations using the Palatini variational principle with the metricity condition implemented via a Lagrange multiplier

Considerations on the Identity and Delimitation of Celtis chichape (Wedd.) Miq. (Celtidaceae)

En la presente contribución se analizan los criterios usados por varios autores para interpretar la identidad de Celtis chichape (Wedd.) Miq. (Celtidaceae). Se considera que el propuesto por Dottori & Hunziker (1994) es el más adecuado y ajustado a las características naturales de estos arbustosIn the present contribution the criteria used by some authors for the interpretation of the identity of Celtis chichape (Wedd.) Miq. (Celtidaceae) are analyzed. It is considered that the proposal from Dottori & Hunziker (1994) is the more adequate and adjusted to the natural features of these shrubsFil: Oakley, Luis Jorge. Universidad Nacional de Rosario. Facultad de Cs.agrarias. Departamento de Biología. Cátedra de Botanica Morfológica y Sistematica Agronomica; ArgentinaFil: Prado, Darien Eros. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Departamento de Ciencias Biológicas. Cátedra de Botánica; Argentin

The private health care sector and the provision of prenatal care services in Latin America

Private providers have become an important source of health care in Latin America, yet there is still little documentation on them, especially regarding their role as providers of preventive and public health interventions. This paper uses Demographic and Health Surveys from various Latin American countries to compare the effectiveness of the private and public sectors in providing prenatal care. Although the number of prenatal visits is higher in the private sector, this is not accompanied by better delivery outcomes. We discuss different strategies to improve the role of private providers

Relativistic velocity addition from the geometry of momentum space

With the goal of developing didactic tools, we consider the geometrization of the addition of velocities in special relativity by using Minkowski diagrams in momentum space. For the case of collinear velocities, we describe three ruler-and-compass constructions that provide simple graphical solutions working with the mass-shell hyperbola in a 1 + 1-dimensional energy–momentum plane. In the spirit of dimensional scaffolding, we use those results to build a generalization in 1 + 2 dimensions for the case of non-collinear velocities, providing in particular a graphical illustration of how the velocity transverse to a boost changes while the momentum remains fixed. We supplement the discussion with a number of interactive applets that implement the diagrammatic constructions and constitute a visual tool that should be useful for students to improve their understanding of the subtleties of special relativityAgencia Estatal de Investigación | Ref. PID2020-118613GB-I00Agencia Estatal de Investigación | Ref. FIS2017-83762-PXunta de Galicia | Ref. ED431B 2018/57Xunta de Galicia | Ref. ED431B 2021/2