Polarization and Color Filtering Applied to Enhance Photogrammetric Measurements of Reflective Surfaces

Techniques for enhancing photogrammetric measurement of reflective surfaces by reducing noise were developed utilizing principles of light polarization. Signal selectivity with polarized light was also compared to signal selectivity using chromatic filters. Combining principles of linear cross polarization and color selectivity enhanced signal-to-noise ratios by as much as 800 fold. More typical improvements with combining polarization and color selectivity were about 100 fold. We review polarization-based techniques and present experimental results comparing the performance of traditional retroreflective targeting materials, cornercube targets returning depolarized light, and color selectivity

Diving into the vertical dimension of elasmobranch movement ecology

Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements

Ab initio calculations of optical properties of silver clusters: cross-over from molecular to nanoscale behavior

Electronic and optical properties of silver clusters were calculated using two different \textit{ab initio} approaches: 1) based on all-electron full-potential linearized-augmented plane-wave method and 2) local basis function pseudopotential approach. Agreement is found between the two methods for small and intermediate sized clusters for which the former method is limited due to its all-electron formulation. The latter, due to non-periodic boundary conditions, is the more natural approach to simulate small clusters. The effect of cluster size is then explored using the local basis function approach. We find that as the cluster size increases, the electronic structure undergoes a transition from molecular behavior to nanoparticle behavior at a cluster size of 140 atoms (diameter $\sim 1.7$\,nm). Above this cluster size the step-like electronic structure, evident as several features in the imaginary part of the polarizability of all clusters smaller than Ag$_\mathrm{147}$, gives way to a dominant plasmon peak localized at wavelengths 350\,nm$\le\lambda\le$ 600\,nm. It is, thus, at this length-scale that the conduction electrons' collective oscillations that are responsible for plasmonic resonances begin to dominate the opto-electronic properties of silver nanoclusters

E-government in Tanzania: Current status and future challenges

The public sector plays an important role in the economic growth and development of developing countries. The application of modern Information and Communication Technologies (ICT) may help improve the public sector by contributing to new services and processes that address citizens as well as government-to-government services, involve citizens more directly in decisions being made, and contribute to streamlining work processes and standardizations needed to develop a well-functioning public sector. Research focusing on E-government in developing countries is still dominated by case studies and conceptual pieces of work. Thus, more empirical-oriented work is needed to expand our knowledge on current status, challenges and future plans. The reported study has been initiated to address such needs. The objective is to investigate, from a broad perspective, on-going E-government initiatives in the public sector in Tanzania. The contribution of this work is twofold. First, the descriptive findings are important to gain insight into the current status of E-government projects in Tanzania. Second, the study reported here could guide the way forward for practice as well as research. We firmly believe that both practice and research should be based on the current situation and identified challenges and aim to describe such issues to guide future work

Perfil nutricional de recém-nascidos de mães adolescentes suplementadas com ferro, em diferentes concentrações, zinco e ácido fólico Nutritional profile of newborns of adolescent mothers supplemented with iron, in different concentrations, zinc and pholic acid

O objetivo deste estudo foi avaliar o estado nutricional de recém-nascidos de mães adolescentes com até 18 anos de idade, de baixa renda, suplementadas durante a gravidez com ferro, em diferentes concentrações, zinco e ácido fólico. Estas mães fizeram pré-natal no Instituto de Perinatologia Social do Piauí, Maternidade Dona Evangelina Rosa, no município de Teresina, Piauí, Nordeste do Brasil. As adolescentes foram aleatoriamente distribuídas em cinco grupos: grupos I e II receberam quantidades constantes de ácido fólico (250 µg) e diferentes concentrações de ferro, na forma de sulfato ferroso (120 e 80 mg, respectivamente); grupos III e IV receberam quantidades constantes de ácido fólico (250 µg) associado ao sulfato de zinco (5 mg) e ferro nas concentrações de 120 e 80 mg, respectivamente; e grupo V, considerado controle, recebeu apenas ferro (120 mg) (rotina da Instituição). A avaliação do estado nutricional de 74 recém-nascidos foi feita através de dados referentes à idade, peso, comprimento e perímetro cefálico, por ocasião do nascimento. De acordo com os resultados, as médias de peso (3000 ± 418 g), comprimento (48,07 ± 2,15 cm) e perímetro cefálico (33,53 ± 1,50 cm) encontradas para os filhos de mães do grupo V (rotina local) não diferem dos grupos de intervenção. Conclui-se que os recém-nascidos de adolescentes suplementadas com ferro em diferentes concentrações (120 e 80 mg), zinco e ácido fólico apresentaram um bom perfil nutricional. No entanto, não se observou, entre os grupos de intervenção e o controle, diferenças significativas na duração da gravidez ou no estado nutricional dos bebês.<br>The objective of this study was to evaluate the nutritional status of newborn infants of low income adolescent mothers, aged up to 18 years old, supplemented during pregnancy with iron, in different concentrations, zinc and folic acid. These mothers received prenatal care supervision in the Institute of Social Perinatology of Piauí, Dona Evangelina Rosa Maternity, located in the city of Teresina, Piauí, Northeast of Brazil. The adolescents were distributed at random into five groups: groups I and II received constant quantities of folicc acid (250 µg) and different iron concentrations, in the form of iron sulfate (120 and 80 mg, respectively); groups III and IV received constant quantities of folic acid (250 µg) associated to zinc sulfate (5 µg) and iron in the concentrations of 120 and 80 mg, respectively; and group V, considered control, received only 120 mg of iron (Institution routine). The evaluation of the nutritional status of 74 newborn infants was done through data referring to their age, weight, height and cephalic perimeter, on the occasion of their birth. According to the results, the averages of weight (3000 ± 418g), height ( 48.07 ± 2,15 cm) and cephalic perimeter (33.53 ± 1,50 cm) found in children of group V mothers (local routine) did not present significant differences in relation to the intervention groups. The newborn infants of adolescents supplemented with iron in different concentrations (120 and 80 mg), zinc and folic acid, presented a good nutritional profile. However, it was not observed, between the intervention groups and the control, significant differences in the pregnancy duration or in the nutritional status of the babies