Assessing the queuing process using data envelopment analysis:an application in health centres

Queuing is one of the very important criteria for assessing the performance and efficiency of any service industry, including healthcare. Data Envelopment Analysis (DEA) is one of the most widely-used techniques for performance measurement in healthcare. However, no queue management application has been reported in the health-related DEA literature. Most of the studies regarding patient flow systems had the objective of improving an already existing Appointment System. The current study presents a novel application of DEA for assessing the queuing process at an Outpatients’ department of a large public hospital in a developing country where appointment systems do not exist. The main aim of the current study is to demonstrate the usefulness of DEA modelling in the evaluation of a queue system. The patient flow pathway considered for this study consists of two stages; consultation with a doctor and pharmacy. The DEA results indicated that waiting times and other related queuing variables included need considerable minimisation at both stages

Hearing in Cavefishes

Caves and associated subterranean habitats represent some of the harshest environments on Earth, yet many organisms, including fishes, have colonized and thrive in these habitats despite the complete absence of light, and other abiotic and biotic constraints. Over 170 species of fishes are considered obligate subterranean inhabitants (stygobionts) that exhibit some degree of troglomorphy, including degeneration of eyes and reduction in pigmentation. To compensate for lack of vision, many species have evolved constructive changes to non-visual sensory modalities. In this chapter we review hearing in cavefishes, with particular emphasize on our own studies on amblyopsid cavefishes. Hearing in cavefishes has not been well studied to date, as hearing ability has only been examined in four species. Two species show no differences in hearing ability relative to their surface relatives, while the other two species (family Amblyopsidae) exhibit regression in the form of reduced hearing range and reduction in hair cell densities on sensory epithelia. In addition to reviewing our current knowledge on cavefish hearing, we offer suggestions for future avenues of research on cavefish hearing and discuss the influence of Popper and Fay on the field of cavefish bioacoustics

Regressive evolution in Astyanax cavefish

A diverse group of animals, including members of most major phyla, have adapted to life in the perpetual darkness of caves. These animals are united by the convergence of two regressive phenotypes, loss of eyes and pigmentation. The mechanisms of regressive evolution are poorly understood. The teleost Astyanax mexicanus is of special significance in studies of regressive evolution in cave animals. This species includes an ancestral surface dwelling form and many con-specific cave-dwelling forms, some of which have evolved their recessive phenotypes independently. Recent advances in Astyanax development and genetics have provided new information about how eyes and pigment are lost during cavefish evolution; namely, they have revealed some of the molecular and cellular mechanisms involved in trait modification, the number and identity of the underlying genes and mutations, the molecular basis of parallel evolution, and the evolutionary forces driving adaptation to the cave environment

Subterranean Biodiversity Patterns from Global to Regional Scales

In the last two decades, there has been a substantial progress in the availability of records for several subterranean taxa, as well as in mapping and statistical modeling of biodiversity patterns. Currently, there is still a large bias toward analyses of aquatic compared to terrestrial subterranean taxa. We provide the first global map of species richness for groundwater crustaceans, indicating that tropics are not hotspots of species richness. Detailed analyses of subterranean biodiversity patterns in Europe show that species richness peaks in regions of mid-latitude, where the beneficial effects of a high productive energy and high habitat heterogeneity have not been counteracted by cold or arid historical events. The range size of European groundwater crustacean species increases northward, a pattern which is best explained by long-term climatic changes. Subterranean species have narrow distribution ranges, which results in a high spatial turnover in species composition across regions and a disproportionally high contribution of regional diversity to total species richness. Within regions, biodiversity patterns are diverse, and their explanations vary across regions, but hotspots contribute only a small proportion of the regional species pool. Molecular approaches to biodiversity studies offer promising research avenues for further documenting and understanding subterranean biodiversity patterns

Molecular phylogeny of the blind cavefish Phreatichthys andruzzii and Garra barreimiae within the family Cyprinidae

The phylogenetic relationships of two cavefish, Phreatichthys andruzzii and Garra barreimiae, belonging to the family Cyprinidae, were investigated by sequencing the mitochondrial cytochrome b gene. These cavefish species are native to Somalia (eastern Africa) and Oman (southeastern Arabian peninsula), respectively, and so far no molecular support to their taxonomy and phylogenetic position was ever provided. The analysis of cytochrome b sequences showed that the species are monophyletic taxa, closely related to each other and to other species of the genus Garra. Molecular clock calculations allowed to date the origin of these hypogaean species back to the Plio-Pleistocene and support the hypothesis that African cyprinids originated from Miocenic immigrations of Asian ancestors

The invertebrate ecology of the Chalk aquifer in England (UK)

The Chalk is an important water supply aquifer, yet ecosystems within it remain poorly understood. Boreholes (198) in seven areas of England (UK) were sampled to determine the importance of the Chalk aquifer as a habitat, and to improve understanding of how species are distributed. Stygobitic macro-invertebrates were remarkably common, and were recorded in 67 % of boreholes in unconcealed Chalk, although they were not recorded in Chalk that is concealed by low-permeability strata and thus likely to be confined. Most species were found in shallow boreholes (50 m) water tables, indicating that the habitat is vertically extensive. Stygobites were present in more boreholes in southern England than northern England (77 % compared to 38 %). Only two species were found in northern England compared to six in southern England, but overall seven of the eight stygobitic macro-invertebrate species found in England were detected in the Chalk. Two species are common in southern England, but absent from northern England despite the presence of a continuous habitat prior to the Devensian glaciation. This suggests that either they did not survive glaciations in the north where glaciers were more extensive, or dispersal rates are slow and they have never colonised northern England. Subsurface ecosystems comprising aquatic macro-invertebrates and meiofauna, as well as the microbial organisms they interact with, are likely to be widespread in the Chalk aquifer. They represent an important contribution to biodiversity, and may influence biogeochemical cycles and provide other ecosystem services