Archaeometric Study of the White Marbles from “Madonna Della Febbre” Altar in San Domenico Church (Cosenza, Southern Italy)

San Domenico Church was built between 1441 and 1468 and represents one of the most important historical buildings of the Cosenza area (Calabria, Southern Italy) thanks to its architectonic style and the works inside, such as the “Madonna della Febbre”, a notable marble altar dated back to the XVI century. The church, as well as the sculptural group, underwent various interventions over time, unfortunately scarcely documented; thus, in this paper, the characterization of six white marble samples coming from the altar, was carried out to determine their provenance. The samples were analyzed by means of complementary methodologies well known in the archaeometric field: polarized optical microscopy (POM); an electron probe micro analyzer coupled with an energy dispersive spectrometer (EPMA-EDS); inductively coupled plasma–mass spectrometry (ICP-MS); and isotope ratio mass spectrometry (IRMS). The results provided important information about the “Madonna della Febbre” altar, suggesting the presence of different typologies of marbles and hypothesizing their possible provenance, including Carrara and Docimium. It was not clear if these marbles were re-used materials but, regardless, the reported information adds precious elements to the history of the entire architectonic complex, providing new issues to be deepened

Assessment of landscape change and occurrence at watershed level in city of Nairobi

To ecologically manage urban spaces, it is necessary to understand changes in spatial configuration of land uses within definitive ecosystem level processes. Change in landscape cover types and pattern within Nairobi city and its environs were investigated using landsat satellite data spanning three decades. Image data were georeferenced, classified and analyzed along watershed zones delineated from a digital elevation model (DEM) of Nairobi city and peripheral region on a geographical information system (GIS) platform. Land cover categories of riverine vegetation and forest land showed the most marked decrease in areal coverage by about 67 and 60%, respectively, while barren surfaces and urban areas increased by more than 100 and 98%, respectively, between 1976 and year 2000. At the watershed scale, land cover diversity was high in the upper and middle basins than on the lower basin of the watershed zones. Expansion of urban areas was confined mainly in the middle elevation watershed zones. Forest area declined notably in the central watersheds while savannah areas increased towards the southern watershed zones. Monitoring land cover change at the watershed scale is more indicative of impact level and where efforts for managing and conserving the urban landscape should be prioritized.Key words: Urban expansion, land cover type, remote sensing, watershed units, urban landscape conservation

EFFECT OF COMMUNITY DEVELOPMENT PROGRAMMES ON HOUSEHOLDS’ EMPOWERMENT: THE CASE OF GASABO DISTRICT, RWANDA

This paper aims to assess the effect of Community Development Programmes on households’ empowerment in Gasabo District of Kigali City, Rwanda. The level and the speed of economic growth in Rwanda are determined largely by community development programmes. Although, to achieve the goals of economic development in long run postulated in the vision 2020, several programmes have been implemented to improve families’ livelihoods mainly Rwandans’ in rural areas. The study sample size of households of 322 were employed. This research was employed both quantitative and qualitative techniques in data collection process, analysis presentation and discussion of findings. Basis on descriptive method employed, the findings show that the mean household size is 4.371 approximated to 4 persons per household with a standard deviation of 1.791 approximated to 2. The smallest family had 1 member and the largest had 11 members. This implies that households with big family size were more likely to participate in community development programmes to increase their income. Based on household revenues from agriculture production, handcraft and income from salaried employees among others, the results show also that total annual expenditure is less than total annual income. The study argues that households who had participated in any community development programme had increased their livelihoods. Based on the empirical results, the study is recommending the local government, have to give consideration to community development programmes, as well as encourage family planning both urban and rural areas so as to serve as rooter of social economic development and must also enhance their management ability and bring effort to reach the poor people in order to eradicate poverty and promote the welfare of the society

Unique Arrangement of α- and β-Cells in Human Islets of Langerhans

OBJECTIVE: It is generally admitted that the endocrine cell organization in human islets is different from that of rodent islets. However, a clear description of human islet architecture has not yet been reported. The aim of this work was to describe our observations on the arrangement of human islet cells. RESEARCH DESIGN AND METHODS: Human pancreas specimens and isolated islets were processed for histology. Sections were analyzed by fluorescence microscopy after immunostaining for islet hormones and endothelial cells. RESULTS: In small human islets (40-60 mum in diameter), beta-cells had a core position, alpha-cells had a mantle position, and vessels laid at their periphery. In bigger islets, alpha-cells had a similar mantle position but were found also along vessels that penetrate and branch inside the islets. As a consequence of this organization, the ratio of beta-cells to alpha-cells was constantly higher in the core than in the mantle part of the islets, and decreased with increasing islet diameter. This core-mantle segregation of islet cells was also observed in type 2 diabetic donors but not in cultured isolated islets. Three-dimensional analysis revealed that islet cells were in fact organized into trilaminar epithelial plates, folded with different degrees of complexity and bordered by vessels on both sides. In epithelial plates, most beta-cells were located in a central position but frequently showed cytoplasmic extensions between outlying non-beta-cells. CONCLUSIONS: Human islets have a unique architecture allowing all endocrine cells to be adjacent to blood vessels and favoring heterologous contacts between beta- and alpha-cells, while permitting homologous contacts between beta-cells

Importancia de la limpieza y la metodología en el análisis de lubricante

El análisis de lubricante es una herramienta de mantenimiento muy importante cuando es aplicada correctamente, en ciertos casos, hasta puede llegar a salvar al equipo de una falla catastrófica. Para ello deben tenerse en cuenta todas las recomendaciones y cuidados, desde la extracción de la muestra del equipo, la manipulación de la misma y su posterior análisis. En todos los casos, el no respetar cuidadosamente los pasos a seguir en forma ordenada, pueden llevar a pérdidas funcionales y económicas considerables, ya sea en insumos, mano de obra y, sobre todo, en el lucro cesante. El presente trabajo muestra un conjunto de metodologías y procedimientos a utilizar para la extracción de muestras, considerando los cuidados a tener en cuenta y la correcta elección del método, según el tipo de equipo elegido.Eje: Lubricación y tribología.Facultad de Ingenierí

Importancia de la limpieza y la metodología en el análisis de lubricante

El análisis de lubricante es una herramienta de mantenimiento muy importante cuando es aplicada correctamente, en ciertos casos, hasta puede llegar a salvar al equipo de una falla catastrófica. Para ello deben tenerse en cuenta todas las recomendaciones y cuidados, desde la extracción de la muestra del equipo, la manipulación de la misma y su posterior análisis. En todos los casos, el no respetar cuidadosamente los pasos a seguir en forma ordenada, pueden llevar a pérdidas funcionales y económicas considerables, ya sea en insumos, mano de obra y, sobre todo, en el lucro cesante. El presente trabajo muestra un conjunto de metodologías y procedimientos a utilizar para la extracción de muestras, considerando los cuidados a tener en cuenta y la correcta elección del método, según el tipo de equipo elegido.Eje: Lubricación y tribología.Facultad de Ingenierí

Experimental Demonstration of a Frequency-Domain Volterra Series Nonlinear Equalizer in Polarization-Multiplexed Transmission

Experimental demonstration of a dual-polarization Volterra series nonlinear equalizer applied in frequency-domain is carried out for 100G polarization-multiplexed QPSK test signals. We were able to reduce the BER by a factor of ~2.5x relatively to the single-polarization approach, with a 1 dB increase in the optimum power

Adaptive Stokes-Based Polarization Demultiplexing for Long-Haul Multi-Subcarrier Systems

We experimentally evaluate the performance of the adaptive Stokes polarization demultiplexing (PolDemux) algorithm over a long-haul optical link considering the propagation of 31 × 192 Gb/s channels modulated as PM-16QAM multisubcarrier (MSC) signals. Initially, we consider 1 × 24 Gbaud channel under test, and subsequently, we assess the performance of the algorithm on an increasing number of subcarriers (up to 12 × 2 Gbaud) while keeping the same aggregate symbol rate. Taking advantage of the higher robustness of MSC signals toward chromatic dispersion (CD), we demonstrate that the memoryless Stokes-based PolDemux algorithm, originally designed for short reach links, can also be used for low-complexity and modulation transparent polarization demultiplexing in long-haul systems. In addition, we demonstrate that the PolDemux rotation matrix for the MSC signals can be estimated over a restricted group of Nref subcarriers and seamlessly applied to all Nsc subcarriers, thereby significantly reducing the overall complexity by a factor of ∼Nsc/Nref